Laminate and packaging bag

Abstract

To provide a laminate favorable as a packaging material capable of appropriately packaging an article to be used in a clean environment, and capable of preventing an interlayer lift from occurring.SOLUTION: A laminate at least includes a body part and a separation part in a lamination direction. The body part includes a first face and a second face opposing the first face. The separation part includes a first face and a second face opposing the first face. The separation part is disposed on the first face of the body part while allowing separation from the body part. The body part includes, as a layer forming the first face of the body part, a resin layer containing at least one kind of resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a laminate and a packaging bag.

Background Art

[0002] Semiconductor products are manufactured or used in a clean environment such as a high-cleanliness clean room because the quality may deteriorate if foreign substances such as dust and dirt adhere to the products. When bringing an article into such an environment, a package in which the article is housed in a plastic film bag is often brought into the clean environment. Therefore, high cleanliness is also required for packaging bags that house articles that require a high degree of cleanliness such as semiconductor products.

[0003] Conventionally, a package has been manufactured as follows using a double bag including at least an inner bag and an outer bag (see, for example, Patent Document 1). First, an article is placed inside the inner bag, degassed under vacuum, and the opening of the inner bag is sealed. Next, the inner bag is placed inside the outer bag, degassed under vacuum, and the opening of the outer bag is sealed. The article is packaged by such double packaging or triple packaging as required. When using the article, the outer bag is opened in the anteroom of the clean environment to take out the inner bag, and the clean inner bag is opened in the clean environment to take out the article.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When packaging an article using a double degassing package or a triple degassing package, the degassing packaging is performed multiple times. For this reason, the working efficiency of article packaging may not be high. Also, when opening the packaging bag, opening the bag multiple times may be troublesome. Therefore, the inventors considered producing a packaging bag using a laminate including a main body portion and a peelable peel portion. By peeling the peel portion of the packaging bag from the main body portion in the prechamber of a clean environment, a clean bag can be brought into the clean environment. However, the inventors found a new problem in that such a laminate has delamination between the layers and the appearance deteriorates.

[0006] An object of the present disclosure is to provide a laminate suitable as a packaging material that can suitably package an article used in a clean environment and suppress the occurrence of delamination between the layers.

Means for Solving the Problems

[0007] The laminate of one aspect of the present disclosure includes at least a main body portion and a peel portion in the lamination direction. The main body portion has a first surface and a second surface facing the first surface. The peel portion has a first surface and a second surface facing the first surface. The peel portion is provided on the first surface of the main body portion so as to be peelable from the main body portion. The main body portion includes a resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin as a layer constituting the first surface of the main body portion.

Effects of the Invention

[0008] According to the present disclosure, it is possible to provide a laminate suitable as a packaging material that can package an article used in a clean environment and suppress the occurrence of delamination between the layers.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 4

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Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail. The aspects of the present disclosure can be implemented in many different forms and should not be construed as limited to the description of the embodiments exemplified below. For the purpose of clearer explanation, the drawings may schematically represent the width, thickness, shape, etc. of each layer as compared with the embodiments, but this is merely an example and does not limit the interpretation of the present disclosure. In this specification and each figure, elements that are the same as those already described with respect to the previously shown figures may be denoted by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0011] In the present disclosure, when a plurality of upper limit candidates and a plurality of lower limit candidates for a certain parameter are given, the numerical range of the parameter may be constituted by combining any one of the upper limit candidates and any one of the lower limit candidates. Examples of the above parameters include physical property values, component content ratios, and layer thicknesses. As an example, the description "Parameter B is preferably A1 or more, more preferably A2 or more, still more preferably A3 or more. Parameter B is preferably A4 or less, more preferably A5 or less, still more preferably A6 or less." will be described. In this example, the numerical range of Parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

[0012] In the following description of this specification, each component that appears (for example, polyolefins such as polyethylene and polypropylene, α-olefins, resin materials such as heteroatom-containing resins, and additives) may be used singly or in combination of two or more.

[0013] In this specification, polyethylene refers to a polymer in which the content ratio of ethylene-derived constitutional units exceeds 50 mol% in the total amount of constitutional units derived from polymerizable monomers. In this polymer, the content ratio of ethylene-derived constitutional units is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The above content ratio is measured by nuclear magnetic resonance spectroscopy (NMR method).

[0014] In this specification, polyethylene may be a homopolymer of ethylene or a copolymer of ethylene and an ethylenically unsaturated monomer other than ethylene. Examples of the ethylenically unsaturated monomer other than ethylene include α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, and 6-methyl-1-heptene; vinyl monomers such as vinyl acetate and vinyl propionate; and (meth)acrylic acid esters such as methyl (meth)acrylate and ethyl (meth)acrylate. In this specification, the term “(meth)acrylic acid” is used to mean acrylic acid, methacrylic acid, or both acrylic acid and methacrylic acid. The same applies to terms such as (meth)acrylic acid ester.

[0015] In this specification, examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylic acid ester copolymer.

[0016] In this specification, the density of polyethylene is as follows. The density of high-density polyethylene is preferably more than 0.945 g / cm 3 and preferably not more than 0.965 g / cm 3 For example, it is more than 0.945 g / cm 3 and not more than 0.965 g / cm 3 The density of medium-density polyethylene is preferably more than 0.932 g / cm 3 and not more than 0.945 g / cm 3 The density of low-density polyethylene is preferably not less than 0.860 g / cm 3 and not more than 0.932 g / cm 3 More preferably, it is not less than 0.900 g / cm 3 and not more than 0.932 g / cm 3The following is the case. The density of linear low-density polyethylene is preferably 0.860 g / cm 3 or more and 0.932 g / cm 3 or less, more preferably 0.900 g / cm 3 or more and 0.932 g / cm 3 or less. The density of polyethylene is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0017] Low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene by a high-pressure polymerization method (high-pressure method low-density polyethylene). Linear low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene and a small amount of α-olefin by a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst.

[0018] Polyethylenes with different densities or degrees of branching can be obtained by appropriately selecting the polymerization method. For example, as the polymerization catalyst, a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst is used, and polymerization is preferably carried out in one or two or more stages by any of the methods of gas-phase polymerization, slurry polymerization, solution polymerization, and high-pressure ionic polymerization.

[0019] The melt flow rate (MFR) of polyolefins such as polyethylene and polypropylene, and acid-modified polyolefins such as acid-modified polyethylene and acid-modified polypropylene in this specification is described below. From the viewpoints of film-forming property and processability, the above MFR is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, still more preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, still more preferably 10 g / 10 min or less, and particularly preferably 5 g / 10 min or less. The above MFR is, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of polyolefins and acid-modified polyolefins is measured by Method A under the condition of a load of 2.16 kg in accordance with JIS K7210-1:2014. The measurement temperature of the MFR is set according to the melting point etc. of polyolefins and acid-modified polyolefins, and is 190°C in the case of polyethylene and acid-modified polyethylene, and 230°C in the case of polypropylene and acid-modified polypropylene.

[0020] In this specification, as resin materials such as polyolefins, acid-modified polyolefins, heteroatom-containing resins, and heat-sealable resins, biomass-derived resin materials (hereinafter also referred to as "biomass materials") may be used. The biomass material is, for example, a resin material obtained by using a biomass-derived raw material (specifically, a plant-derived raw material) as at least a part of the raw material. Since the biomass material is a carbon-neutral material, the environmental load caused by the laminate or the packaging bag can be reduced.

[0021] In this specification, as the above resin material, a mechanically recycled or chemically recycled resin material may be used. Thereby, the environmental load caused by the laminate or the packaging bag can be reduced.

[0022] In this specification, the "main component" in a certain layer refers to a component having a content ratio in the layer exceeding 50% by mass. The above content ratio of the main component is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more.

[0023] In this specification, terms such as "film" and "sheet" are not distinguished from each other based only on the difference in name.

[0024] [Laminated body] The laminated body of the present disclosure includes at least a main body part and a peeling part in the lamination direction. The main body part has a first surface and a second surface facing the first surface. The peeling part is provided on the first surface of the main body part so as to be peelable from the main body part. The peeling part has a first surface and a second surface facing the first surface. In the above laminated body, the peeling part is in contact with the main body part. Specifically, the first surface of the main body part and the second surface of the peeling part are in contact. The first surface of the main body part is usually the peeling surface when peeling the peeling part from the main body part. When a packaging bag is produced using the laminated body of the present disclosure, the main body part faces the accommodation space of the packaging bag.

[0025] The main body part includes, as a layer constituting the first surface of the main body part, a resin layer (hereinafter also referred to as "adhesive resin layer") containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin. Such an adhesive resin layer can have appropriate adhesion to the peeling part. Therefore, the laminated body provided with the above adhesive resin layer can suppress the lifting of the peeling part from the main body part, has excellent appearance, and can suppress the peeling of the peeling part from the main body part in an unintended situation.

[0026] [Peeling part] The peeling part is provided on the main body part so as to be peelable from the main body part. In this specification, the film composed of the peeling part obtained by peeling the peeling part from the main body part of the laminated body or the packaging bag of the present disclosure is also referred to as "peeling film". The film composed of the main body part after the peeling is also referred to as "sealing film" or "packaging film".

[0027] The peel strength between the peeling part and the main body part is preferably 1.0 N / 15 mm width or less, more preferably 0.9 N / 15 mm width or less, still more preferably 0.8 N / 15 mm width or less, even more preferably 0.7 N / 15 mm width or less, and particularly preferably 0.6 N / 15 mm width or less. In the case of a laminate and a packaging bag having such a peel strength, the peeling part can be easily peeled from the main body part with an appropriate force without damaging the main body part. The above peel strength is, for example, 0.01 N / 15 mm width or more, preferably 0.05 N / 15 mm width or more, more preferably 0.10 N / 15 mm width or more, and still more preferably 0.15 N / 15 mm width or more. In the case of a laminate and a packaging bag having such a peel strength, the lifting of the peeling part from the main body part can be suppressed, the appearance of the laminate and the packaging bag is excellent, and the peeling of the peeling part from the main body part at an unintended time can be suppressed. The above peel strength is, for example, 0.01 N / 15 mm width or more and 1.0 N / 15 mm width or less.

[0028] The above peel strength is measured under the conditions of a peel angle of 180 degrees and a test speed of 50 mm / min. Specifically, the laminate or the packaging bag is cut to cut out a test piece having a size of a width of 15 mm and a length of 100 mm. The peeling part at one end in the length direction of the test piece is peeled and folded back, and the end of the partially peeled peeling part (peeling film) is attached to one gripper of a tensile tester, and the end of the main body part (sealing film, packaging film) after the partial peeling is attached to the other gripper of the tensile tester. The initial chuck distance is 100 mm. Then, the gripper to which the end of the peeling part is attached is pulled at a speed of 50 mm / min in a direction of 180 degrees with respect to the surface of the test piece while maintaining the posture of the test piece so that the angle is maintained, and the maximum strength (N) is measured. The maximum strength (N) measured for a 15-mm-wide test piece is taken as the peel strength (N / 15 mm width).

[0029] The release portion may include a heteroatom-containing resin layer containing a heteroatom-containing resin as a main component. The heteroatom-containing resin layer may form the second surface of the release portion. The heteroatom-containing resin layer may be in contact with the main body portion. A laminate in such a form is excellent in the releasability of the release portion from the main body portion. The release portion may be a heteroatom-containing resin layer. The heteroatom-containing resin layer may also form the first surface of the release portion.

[0030] The release portion may include a heteroatom-containing resin layer and a polyolefin layer containing a polyolefin as a main component. The polyolefin layer may form the first surface of the release portion. Such a laminate has excellent appearance, can have a thinner heteroatom-containing resin layer, and can reduce the manufacturing cost.

[0031] The heteroatom-containing resin layer in the release portion may be in contact with a resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin in the main body portion. A laminate in such a form is excellent in the balance between the releasability of the release portion from the main body portion and the adhesion between the release portion and the main body portion.

[0032] From the viewpoints of releasability, strength, and heat resistance, the thickness of the release portion is preferably 3 μm or more, more preferably 5 μm or more, still more preferably 10 μm or more, and particularly preferably 15 μm or more. From the viewpoint of processability, the thickness of the release portion is preferably 150 μm or less, more preferably 130 μm or less, still more preferably 100 μm or less, even more preferably 80 μm or less, particularly preferably 60 μm or less, 50 μm or less, or 40 μm or less. The thickness of the release portion is, for example, 3 μm or more and 150 μm or less. In this specification, the thicknesses of the laminate, each part, and each layer are the average values of the thicknesses at 10 locations measured in a SEM image obtained by observing a cross-section perpendicular to the surface of the laminate with a scanning electron microscope (SEM).

[0033] Hereinafter, each layer that the release portion can include will be described.

[0034] (Heteroatom-containing resin layer) The heteroatom-containing resin layer contains a heteroatom-containing resin as a main component. The peeling part provided with the heteroatom-containing resin layer is excellent in peelability from the main body part. The laminate provided with the heteroatom-containing resin layer is excellent in puncture resistance. Therefore, the packaging bag provided with such a laminate is excellent in the packaging property of hard articles. The laminate provided with the heteroatom-containing resin layer is excellent in gas barrier properties such as oxygen barrier property and water vapor barrier property, heat resistance, and rigidity.

[0035] Examples of the heteroatom in the heteroatom-containing resin include an oxygen atom, a sulfur atom, a nitrogen atom, and a chlorine atom. The heteroatom-containing resin has a heteroatom-containing group such as a hydroxy group, an amide bond, an ester bond, and an ether bond. Examples of the heteroatom-containing resin include polyamide, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyvinylidene chloride, polyester, polyether polyol, and polyester polyol. Among these, from the viewpoints of heat resistance, rigidity, and puncture resistance, polyamide, ethylene-vinyl alcohol copolymer, polyester, and polyvinyl alcohol are preferable, polyamide and ethylene-vinyl alcohol copolymer are more preferable, and polyamide is still more preferable.

[0036] Examples of the polyamide include aliphatic polyamide and aromatic polyamide. As the polyamide, aliphatic polyamide is preferable, and crystalline aliphatic polyamide is more preferable. Examples of the aliphatic polyamide include aliphatic homopolyamide and aliphatic copolyamide. In the following examples, polyamide is also referred to as "PA".

[0037] Examples of aliphatic homopolyamides specifically include polycaprolactam or poly(6-aminocaproic acid) (PA6), polyenanthlactam or poly(7-aminoenanthic acid) (PA7), polyundecane lactam or poly(11-aminoundecanoic acid) (PA11), polylauryl lactam or poly(12-aminolauric acid) (PA12), polypentamethylene adipamide (PA56), polyhexamethylene adipamide (PA66), polytetramethylene sebacamide (PA410), polytetramethylene dodecamide (PA412), polypentamethylene azelamide (PA59), polypentamethylene sebacamide (PA510), polypentamethylene dodecamide (PA512), polyhexamethylene azelamide (PA69), polyhexamethylene sebacamide (PA610), polyoctamethylene sebacamide (PA810), polyhexamethylene dodecamide (PA612), polynonamethylene adipamide (PA96), polynonamethylene azelamide (PA99), polynonamethylene sebacamide (PA910), polynonamethylene dodecamide (PA912), polydecamethylene adipamide (PA106), polydecamethylene azelamide (PA109), polydecamethylene decamide (PA1010), polydecamethylene dodecamide (PA1012), polydodecamethylene adipamide (PA126), polydodecamethylene azelamide (PA129), polydodecamethylene sebacamide (PA1210), and polydodecamethylene dodecamide (PA1212).

[0038] Examples of the aliphatic copolyamide include caprolactam / hexamethylenediamino adipic acid copolymer (PA6 / 66), caprolactam / hexamethylenediamino azelaic acid copolymer (PA6 / 69), caprolactam / hexamethylenediamino sebacic acid copolymer (PA6 / 610), caprolactam / hexamethylenediamino undecanoic acid copolymer (PA6 / 611), caprolactam / hexamethylenediamino dodecanoic acid copolymer (PA6 / 612), caprolactam / aminoundecanoic acid copolymer (PA6 / 11), caprolactam / lauryllactam copolymer (PA6 / 12), caprolactam / hexamethylenediamino adipic acid / lauryllactam copolymer (PA6 / 66 / 12), caprolactam / hexamethylenediamino adipic acid / hexamethylenediamino sebacic acid copolymer (PA6 / 66 / 610), and caprolactam / hexamethylenediamino adipic acid / hexamethylenediamino dodecanedicarboxylic acid copolymer (PA6 / 66 / 612).

[0039] The relative viscosity of the aliphatic polyamide is preferably 1.5 or more, more preferably 2.0 or more, still more preferably 2.5 or more, preferably 5.0 or less, more preferably 4.5 or less, for example, 1.5 or more and 5.0 or less. The relative viscosity of the aliphatic polyamide is measured at 25°C after dissolving 1 g of the polyamide in 100 mL of 96% concentrated sulfuric acid in accordance with JIS K6920-2:2009.

[0040] As the polyamide, a crystalline aliphatic polyamide is preferred. Examples of the crystalline aliphatic polyamide include PA6, PA11, PA12, PA66, PA610, PA612, PA1010, PA6 / 66, and PA6 / 66 / 12. The melting point (Tm) of the crystalline aliphatic polyamide is preferably 170°C or more, more preferably 180°C or more, preferably 300°C or less, more preferably 250°C or less, still more preferably 230°C or less, for example, 170°C or more and 300°C or less. The Tm of the crystalline aliphatic polyamide is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121:2012.

[0041] Examples of the aromatic polyamide include, for example, semi-aromatic polyamide and wholly aromatic polyamide, and semi-aromatic polyamide is preferred. The semi-aromatic polyamide is a polyamide having a structural unit derived from an aromatic diamine and a structural unit derived from an aliphatic dicarboxylic acid, or a polyamide having a structural unit derived from an aliphatic diamine and a structural unit derived from an aromatic dicarboxylic acid. Examples of the semi-aromatic polyamide include, for example, a polyamide composed of an aromatic diamine and an aliphatic dicarboxylic acid, and a polyamide composed of an aliphatic diamine and an aromatic dicarboxylic acid.

[0042] Examples of the semi-aromatic polyamide include, for example, polyhexamethylene terephthalamide (PA6T), polyhexamethylene isophthalamide (PA6I), polynonamethylene terephthalamide (PA9T), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (PA66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (PA66 / 6I), polyhexamethylene terephthalamide / polycaproamide copolymer (PA6T / 6), polyhexamethylene isophthalamide / polycaproamide copolymer (PA6I / 6), polyhexamethylene terephthalamide / polydodecamide copolymer (PA6T / 12), polyhexamethylene isophthalamide / polyhexamethylene terephthalamide copolymer (PA6I / 6T), polyhexamethylene terephthalamide / poly(2-methylpentamethylene terephthalamide) copolymer (PA6T / M5T), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (PA66 / 6T / 6I), polyhexamethylene adipamide / polycaproamide / polyhexamethylene isophthalamide copolymer (PA66 / 6 / 6I), and polymetaxylylene adipamide (PAMXD6).

[0043] The melt volume rate (MVR) of the semi-aromatic polyamide is preferably 5 cm 3 / 10 min or more, more preferably 10 cm 3 / above 10 minutes, preferably 200 cm 3 / below 10 minutes, more preferably 100 cm 3 / below 10 minutes, for example 5 cm 3 / above 10 minutes and 200 cm 3 / is below 10 minutes. MVR is measured in accordance with JIS K7210-1:2014 at a temperature of 275 °C and a load of 5.00 kg.

[0044] The melt flow rate (MFR) of the polyamide is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, still more preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, still more preferably 10 g / 10 min or less, particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less, from the viewpoints of film-forming properties and processability. The MFR of the polyamide is measured by Method A under the conditions of a temperature of 235 °C and a load of 2.16 kg in accordance with JIS K7210-1:2014. The measurement temperature can be changed according to the melting point of the polyamide.

[0045] The content ratio of the heteroatom-containing resin in the heteroatom-containing resin layer is preferably more than 50% by mass, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more. Thereby, for example, the above-described physical properties such as the heat resistance of the packaging bag can be improved.

[0046] The heteroatom-containing resin layer may contain an additive. Examples of the additive include an antiblocking agent, a slip agent, an ultraviolet absorber, an antioxidant, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a compatibilizer, a crosslinking agent, a pigment, and a dye.

[0047] From the perspective of the heat resistance of the laminate, the thickness of the heteroatom-containing resin layer is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, and particularly preferably 5 μm or more. From the perspective of the recyclability of the peeling portion, the thickness of the heteroatom-containing resin layer is preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, and particularly preferably 20 μm or less. The thickness of the heteroatom-containing resin layer is, for example, 0.5 μm or more and 50 μm or less.

[0048] (Polyolefin layer) The polyolefin layer in the peeling portion contains polyolefin as a main component. Examples of the polyolefin include polyethylene and polypropylene. As the polyolefin layer, a polyethylene layer containing polyethylene as a main component and a polypropylene layer containing polypropylene as a main component are preferable, and a polyethylene layer is more preferable.

[0049] Examples of the polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. From the perspective of the heat resistance of the laminate during heat sealing, a polyethylene layer containing high-density polyethylene as a main component is preferable. From the perspective of the appearance and puncture resistance of the laminate, a polyethylene layer containing linear low-density polyethylene as a main component is preferable.

[0050] In this specification, examples of the linear low-density polyethylene include an ethylene-1-butene copolymer (C4-LLDPE) in which the comonomer is at least 1-butene, an ethylene-1-hexene copolymer (C6-LLDPE) in which the comonomer is at least 1-hexene, and an ethylene-1-octene copolymer (C8-LLDPE) in which the comonomer is at least 1-octene. In these copolymers, they are not limited to only the above comonomers, and additional comonomers may be used.

[0051] The density of polyethylene in the polyethylene layer is preferably 0.945 g / cm 3 or more and 0.965 g / cm 3 or less from the viewpoint of the heat resistance of the laminate. The density of polyethylene in the polyethylene layer is preferably 0.925 g / cm 3 or more and 0.932 g / cm 3 or less from the viewpoints of the appearance and puncture resistance of the laminate.

[0052] The melting point (Tm) of polyethylene in the polyethylene layer, from the viewpoint of heat resistance, is preferably 100°C or higher, more preferably 105°C or higher, still more preferably 110°C or higher, and particularly preferably 120°C or higher, and is preferably 140°C or lower, for example, 100°C or higher and 140°C or lower. Tm is the melting peak temperature obtained by DSC in accordance with JIS K7121:2012.

[0053] The content ratio of polyolefin in the polyolefin layer, particularly polyethylene in the polyethylene layer, is preferably more than 50% by mass, more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass or more. With such a configuration, for example, the recyclability of the peeling portion can be improved.

[0054] The polyolefin layer in contact with the heteroatom-containing resin layer may further contain an acid-modified polyolefin from the viewpoint of adhesion to the heteroatom-containing resin layer. Examples of the acid-modified polyolefin include modified products of polyolefins with modifying compounds, particularly graft-modified products of polyolefins with modifying compounds. Examples of the modifying compound include unsaturated carboxylic acids such as maleic acid and fumaric acid, or their esters or metal salts. The unsaturated carboxylic acid may be in the form of an acid anhydride. When the polyolefin is polyethylene, acid-modified polyethylene is preferred as the acid-modified polyolefin, and when the polyolefin is polypropylene, acid-modified polypropylene is preferred. Examples of the acid-modified polyethylene include acid-modified high-density polyethylene, acid-modified medium-density polyethylene, acid-modified low-density polyethylene, and acid-modified linear low-density polyethylene. The acid-modified polyethylene may be acid-modified high-density polyethylene or maleic anhydride graft-modified high-density polyethylene.

[0055] From the viewpoint of heat resistance, the melting point (Tm) of the acid-modified polyethylene is preferably 100 °C or higher, more preferably 105 °C or higher, still more preferably 110 °C or higher, particularly preferably 120 °C or higher, and preferably 140 °C or lower, for example, 100 °C or higher and 140 °C or lower. Tm is the melting peak temperature obtained by DSC in accordance with JIS K7121:2012.

[0056] The content ratio of the acid-modified polyolefin in the polyolefin layer in contact with the heteroatom-containing resin layer, particularly the acid-modified polyethylene in the polyethylene layer, is preferably less than 50% by mass, more preferably 40% by mass or less, still more preferably 30% by mass or less, particularly preferably 20% by mass or less, and preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, for example, 1% by mass or more and less than 50% by mass.

[0057] The polyolefin layer may contain resin materials other than polyolefins and acid-modified polyolefins. Examples of such resin materials include (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

[0058] The polyolefin layer may contain the above additives.

[0059] From the viewpoints of the strength, heat resistance, and recyclability of the peeling portion of the laminate, the thickness of the polyolefin layer is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 10 μm or more. From the viewpoint of the processability of the laminate, the thickness of the polyolefin layer is preferably 100 μm or less, more preferably 80 μm or less, still more preferably 70 μm or less, even more preferably 60 μm or less, particularly preferably 50 μm or less, 40 μm or less, or 30 μm or less. The thickness of the polyolefin layer is, for example, 1 μm or more and 100 μm or less.

[0060] <Main body portion> The main body portion includes, as a layer constituting the first surface of the main body portion, a resin layer (adhesive resin layer) containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin.

[0061] The main body portion may further include a heat-sealable resin layer as a layer constituting the second surface of the main body portion. The heat-sealable resin layer functions as a seal layer when producing a packaging bag using the laminate of the present disclosure. When a packaging bag is produced using the laminate of the present disclosure, the heat-sealable resin layer faces the accommodation space of the packaging bag. In the present specification, there is no hindrance to the fact that a layer other than the layer described as the "heat-sealable resin layer" has heat-sealability.

[0062] The main body portion may include an adhesive resin layer constituting the first surface of the main body portion and a heat-sealable resin layer constituting the second surface of the main body portion. The main body portion may further include an intermediate layer between the adhesive resin layer and the heat-sealable resin layer.

[0063] In one embodiment, the main body part may further contain a resin material other than at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin as the resin constituting the main body part. Examples of the resin material include polyolefin, (meth)acrylic resin, vinyl resin, cellulose resin, polyamide, and polyester. Examples of the polyolefin include polyethylene such as linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylate copolymer, polypropylene, ethylene-propylene copolymer, and polybutene.

[0064] The content ratio of polyolefin in the resin material excluding the ethylene-unsaturated carboxylic acid copolymer and the ionomer resin in the main body part is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more. In one embodiment, the above "content ratio of polyolefin" can be read as "content ratio of polyethylene" or "content ratio of polypropylene".

[0065] In one embodiment, the main body part contains polyethylene. As the polyethylene, for example, at least one selected from high density polyethylene, medium density polyethylene, low density polyethylene, and linear low density polyethylene is preferable, and from the viewpoint of heat sealability, at least one selected from low density polyethylene and linear low density polyethylene is more preferable.

[0066] From the viewpoint of the balance between heat resistance and heat sealability, the melting point (Tm) of the polyethylene in the main body part is preferably 80°C or higher, more preferably 85°C or higher, preferably 140°C or lower, more preferably 130°C or lower, for example, 80°C or higher and 140°C or lower. Tm is the melting peak temperature obtained by DSC in accordance with JIS K7121:2012.

[0067] The main body part may contain the above-mentioned additive.

[0068] From the viewpoints of strength and heat sealability, the thickness of the main body part is preferably 10 μm or more, more preferably 15 μm or more, still more preferably 20 μm or more, and particularly preferably 30 μm or more. From the viewpoint of processability, the thickness of the main body part is preferably 250 μm or less, more preferably 200 μm or less, still more preferably 150 μm or less, and particularly preferably 100 μm or less. The thickness of the main body part is, for example, 10 μm or more and 250 μm or less.

[0069] Hereinafter, each layer that the main body part can include will be described.

[0070] (Adhesive resin layer) The adhesive resin layer is a layer that constitutes the first surface of the main body part, that is, the layer in contact with the peeling part. The adhesive resin layer contains at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin. Such an adhesive resin layer can have appropriate adhesion to the peeling part (particularly the heteroatom-containing resin layer). Therefore, the laminate provided with the above-mentioned adhesive resin layer can suppress the lifting of the peeling part from the main body part, has excellent appearance, and can suppress the peeling of the peeling part from the main body part in an unintended situation.

[0071] The ethylene-unsaturated carboxylic acid copolymer is a copolymer of a polymerizable monomer containing ethylene and an unsaturated carboxylic acid. The ethylene-unsaturated carboxylic acid copolymer has a structural unit derived from ethylene and a structural unit derived from an unsaturated carboxylic acid.

[0072] Examples of the unsaturated carboxylic acid include unsaturated carboxylic acids having 3 to 10 carbon atoms. Examples of the unsaturated carboxylic acid include monobasic acids and dibasic acids. Examples of the monobasic acid include (meth)acrylic acid, crotonic acid, and isocrotonic acid. Examples of the dibasic acid include maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, allyl succinic acid, nadic acid, methyl nadic acid, tetrahydrophthalic acid, and methylhexahydrophthalic acid. The dibasic acid may be in the form of an acid anhydride. As the unsaturated carboxylic acid having 3 to 10 carbon atoms, a monobasic acid is preferred, (meth)acrylic acid is more preferred, and methacrylic acid is even more preferred.

[0073] The content ratio of the structural unit derived from ethylene in the ethylene-unsaturated carboxylic acid copolymer is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 93% by mass or less, and is, for example, 60% by mass or more and 98% by mass or less. The content ratio of the structural unit derived from the unsaturated carboxylic acid (preferably (meth)acrylic acid) in the ethylene-unsaturated carboxylic acid copolymer is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 7% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. The content ratio of each structural unit such as the structural unit derived from the above unsaturated carboxylic acid is measured by Fourier transform infrared absorption spectroscopy (FT-IR method). When there is insufficient information in the measurement or it is difficult to specify the content ratio by the measurement, nuclear magnetic resonance spectroscopy (NMR method) shall be further used.

[0074] The ethylene-unsaturated carboxylic acid copolymer may further have a structural unit derived from a polymerizable monomer other than ethylene and the unsaturated carboxylic acid. Examples of the other polymerizable monomers include unsaturated carboxylic acid esters, vinyl esters, and α-olefins having 3 or more carbon atoms. Examples of the unsaturated carboxylic acid esters include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, and isooctyl (meth)acrylate. The number of carbon atoms in the alkyl moiety is preferably 1 or more and 10 or less, more preferably 1 or more and 4 or less. Examples of the vinyl esters include vinyl acetate and vinyl propionate. Examples of the α-olefins having 3 or more carbon atoms include α-olefins having 3 or more and 10 or less carbon atoms such as propylene, 1-butene, 1-pentene, and 1-hexene.

[0075] The content ratio of the structural unit derived from the other polymerizable monomer in the ethylene-unsaturated carboxylic acid copolymer is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less.

[0076] As the ethylene-unsaturated carboxylic acid copolymer, for example, an ethylene-unsaturated carboxylic acid binary copolymer and an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester terpolymer are preferable. Specific examples of the ethylene-unsaturated carboxylic acid copolymer include ethylene-(meth)acrylic acid copolymer, ethylene-maleic acid copolymer, and ethylene-fumaric acid copolymer. Among these, the ethylene-(meth)acrylic acid copolymer is preferable, and the ethylene-methacrylic acid copolymer is more preferable.

[0077] The ethylene-unsaturated carboxylic acid copolymer may be, for example, either a random copolymer or a block copolymer of a polymerizable monomer containing ethylene and an unsaturated carboxylic acid. However, in this specification, the ethylene-unsaturated carboxylic acid copolymer is not a graft-modified product of polyethylene with an unsaturated carboxylic acid.

[0078] Examples of the ionomer resin include ethylene-based ionomer resins, styrene-based ionomer resins, perfluorocarbon-based ionomer resins, and polyurethane-based ionomer resins. Among these, ethylene-based ionomer resins are preferred, and metal ion cross-linked products of the above-described ethylene-unsaturated carboxylic acid copolymers are more preferred. The metal ion cross-linked product is a resin in which the molecular chains of the ethylene-unsaturated carboxylic acid copolymer are ionically cross-linked by salt formation between the acid portion of the copolymer and metal ions. Specific examples and preferred examples of the ethylene-unsaturated carboxylic acid copolymer are as described above.

[0079] Examples of the metal ions contained in the ionomer resin include monovalent metal ions and divalent metal ions. Examples of the monovalent metal ions include sodium ions, lithium ions, and potassium ions, and sodium ions are preferred. Examples of the divalent metals include magnesium ions, zinc ions, calcium ions, copper ions, iron ions, and barium ions, and zinc ions are preferred. Sodium ions are particularly preferred as the metal ions contained in the ionomer resin.

[0080] As the ionomer resin, a metal ion cross-linked product of an ethylene-(meth)acrylic acid copolymer is more preferred, and a sodium ion cross-linked product of an ethylene-(meth)acrylic acid copolymer is particularly preferred.

[0081] The melting point (Tm) of the ethylene-unsaturated carboxylic acid copolymer and the ionomer resin is preferably 80°C or higher, more preferably 85°C or higher, still more preferably 90°C or higher, and preferably 130°C or lower, more preferably 120°C or lower, still more preferably 110°C or lower, for example, 80°C or higher and 130°C or lower. Tm is the melting peak temperature obtained by DSC in accordance with JIS K7121:2012.

[0082] The density of the ethylene-unsaturated carboxylic acid copolymer and the ionomer resin is preferably 0.910 g / cm 3 or more, more preferably 0.915 g / cm 3 or more, still more preferably 0.920 g / cm 3 or more, even more preferably 0.925 g / cm 3 or more, particularly preferably 0.930 g / cm 3 or more, and preferably 1.000 g / cm 3 or less, more preferably 0.980 g / cm 3 or less, still more preferably 0.960 g / cm 3 or less, for example, 0.910 g / cm 3 or more and 1.000 g / cm 3 or less. The above density is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0083] The adhesive resin layer containing the resin with the above lower limit value of density has appropriate adhesion to the peeling portion and is also excellent in strength such as puncture resistance. Therefore, such an adhesive resin layer can, for example, achieve both adhesion to the peeling portion and strength of the laminate.

[0084] Depending on the type or size of the article accommodated in the packaging bag, the packaging bag may be required to have high strength. For example, when the resin layer in contact with the peeling portion in the main body is a linear low-density polyethylene layer, it is conceivable to increase the strength of the packaging bag by increasing the density of the linear low-density polyethylene. However, in this case, the adhesion between the main body and the peeling portion tends to decrease, and the peeling portion may be peeled off from the main body in an unintended situation. The ethylene-unsaturated carboxylic acid copolymer and ionomer resin having a density equal to or higher than the above lower limit value can increase the strength of the packaging bag. Further, the ethylene-unsaturated carboxylic acid copolymer and ionomer resin can exhibit appropriate adhesion to the peeling portion even when the density is high, so that the peeling portion can be prevented from being peeled off from the main body in an unintended situation. That is, by using a laminate provided with an adhesive resin layer containing such a resin as the layer constituting the first surface of the main body, a packaging bag excellent in strength can be produced together with the balance between the adhesion and peelability of the peeling portion and the main body.

[0085] The MFR of the ethylene-unsaturated carboxylic acid copolymer and ionomer resin is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, still more preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, still more preferably 10 g / 10 min or less, particularly preferably 5 g / 10 min or less, from the viewpoints of film formability and processability. The above MFR is, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of the ethylene-unsaturated carboxylic acid copolymer and ionomer resin is measured by the A method under the conditions of a temperature of 190° C. and a load of 2.16 kg in accordance with JIS K7210-1:2014.

[0086] When the ionomer resin is a metal ion cross-linked product of an ethylene-unsaturated carboxylic acid copolymer, the neutralization degree of the ionomer resin may be, for example, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, and may also be 95% or less, 90% or less, 85% or less, 80% or less. The neutralization degree of the ionomer resin may be, for example, 5% or more and 95% or less. The neutralization degree of the ionomer resin refers to the ratio (mol%) of the carboxy groups neutralized by metal ions among all the carboxy groups contained in the ethylene-unsaturated carboxylic acid copolymer. The above neutralization degree is measured by the FT-IR method. In the FT-IR method, the neutralization degree is calculated from the signal heights of the carboxy groups and the metal salts of the carboxy groups.

[0087] The total content ratio of the ethylene-unsaturated carboxylic acid copolymer and the ionomer resin in the adhesive resin layer is preferably more than 50% by mass, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0088] The adhesive resin layer may contain resin materials other than the ethylene-unsaturated carboxylic acid copolymer and the ionomer resin. Examples of the resin materials include polyolefins, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, and polyesters. Examples of the polyolefins include polyethylenes such as linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylate copolymer, polypropylene, ethylene-propylene copolymer, and polybutene. The adhesive resin layer may contain the above additives.

[0089] From the viewpoint of peel strength, the thickness of the adhesive resin layer is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, and particularly preferably 5 μm or more. From the viewpoint of processability of film formation, the thickness of the adhesive resin layer is preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, and particularly preferably 20 μm or less. The thickness of the adhesive resin layer is, for example, 0.5 μm or more and 50 μm or less.

[0090] (Heat-sealable resin layer) The heat-sealable resin layer contains a heat-sealable resin as a main component. Examples of the heat-sealable resin include polyolefin resins and ionomer resins. Examples of the polyolefin resin include polyolefin and acid-modified polyolefin. Examples of the polyolefin include polyethylene such as linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylate copolymer, polypropylene, ethylene-propylene copolymer, and polybutene. Examples of the acid-modified polyolefin include acid-modified polyethylene and acid-modified polypropylene. As the heat-sealable resin, polyolefins such as polyethylene and polypropylene are preferable, and polyethylene is more preferable.

[0091] From the viewpoint of heat sealability, the heat-sealable resin layer preferably contains polyethylene as a main component. From the viewpoint of heat sealability, the heat-sealable resin layer preferably contains at least one selected from linear low-density polyethylene and low-density polyethylene as the above polyethylene. Examples of the linear low-density polyethylene include C4-LLDPE, C6-LLDPE, and C8-LLDPE.

[0092] In the heat-sealable resin layer, the total content ratio of linear low-density polyethylene and low-density polyethylene is preferably more than 50% by mass, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0093] In one embodiment, the heat-sealable resin layer contains linear low-density polyethylene and low-density polyethylene. Such a heat-sealable resin layer is excellent in the balance between heat-sealability and low contamination (suppression of outgas generation) with respect to the articles contained in the packaging bag.

[0094] The content ratio (LLDPE:LDPE) of linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) in the heat-sealable resin layer is preferably 5:95 to 95:5, more preferably 10:90 to 90:10, and still more preferably 20:80 to 80:20 on a mass basis.

[0095] From the viewpoint of the balance between heat resistance and heat-sealability, the melting point (Tm) of polyethylene in the heat-sealable resin layer is preferably 140°C or lower, more preferably 130°C or lower, still more preferably 125°C or lower, preferably 80°C or higher, more preferably 85°C or higher, still more preferably 90°C or higher, even more preferably 95°C or higher, and particularly preferably 100°C or higher, for example, 80°C or higher and 140°C or lower. Tm is the melting peak temperature obtained by DSC in accordance with JIS K7121:2012.

[0096] The heat-sealable resin layer may contain the above additives.

[0097] The thickness of the heat-sealable resin layer is preferably 5 μm or more, more preferably 10 μm or more, still more preferably 15 μm or more, particularly preferably 20 μm or more, preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less, even more preferably 80 μm or less, and particularly preferably 60 μm or less, for example, 5 μm or more and 200 μm or less.

[0098] (Intermediate layer) The intermediate layer preferably contains polyolefins such as polyethylene and polypropylene as the main component, and more preferably contains polyethylene as the main component. Examples of the polyethylene include linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, and high-density polyethylene. From the viewpoint of heat sealability, at least one selected from linear low-density polyethylene and low-density polyethylene is preferable as the polyethylene, and linear low-density polyethylene is more preferable from the viewpoint of the puncture resistance of the laminate. Examples of the linear low-density polyethylene include C4-LLDPE, C6-LLDPE, and C8-LLDPE.

[0099] The density of the polyethylene in the intermediate layer is preferably 0.925 g / cm 3 or more, more preferably 0.928 g / cm 3 or more, still more preferably 0.930 g / cm 3 or more. The laminate provided with such an intermediate layer is excellent in puncture resistance. The density of the polyethylene in the intermediate layer is preferably 0.932 g / cm 3 or less, for example, 0.925 g / cm 3 or more and 0.932 g / cm 3 or less.

[0100] From the viewpoint of heat resistance, the melting point (Tm) of the polyethylene in the intermediate layer is preferably 100 °C or higher, more preferably 105 °C or higher, still more preferably 110 °C or higher, particularly preferably 120 °C or higher, and preferably 140 °C or lower, for example, 100 °C or higher and 140 °C or lower. Tm is the melting peak temperature obtained by DSC in accordance with JIS K7121:2012.

[0101] From the viewpoint of the puncture resistance of the laminate, the content ratio of polyolefin such as polyethylene in the intermediate layer is preferably more than 50% by mass, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0102] The intermediate layer may contain the above resin material. The intermediate layer may contain the above additive.

[0103] The thickness of the intermediate layer is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, particularly preferably 10 μm or more, preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, particularly preferably 25 μm or less, and is, for example, 1 μm or more and 50 μm or less.

[0104] <Design layer> The laminate or packaging bag of the present disclosure may further include a design layer such as a printing layer. The design layer has an image. Examples of the image include characters, figures, patterns, symbols, and combinations thereof. The image may include character information such as a product name, the name of an article in the packaging bag, a manufacturer, and a raw material name. The image may be a single-color solid color (so-called solid image).

[0105] The design layer may be provided, for example, on the first surface of the peeling portion. In one embodiment, the design layer contains a colorant. The design layer may contain a resin material and may also contain the above additive. The design layer can be formed, for example, using an ink composition. Examples of the method for forming the design layer include a gravure printing method, an offset printing method, a flexographic printing method, a screen printing method, a letterpress printing method, and a transfer printing method. In one embodiment, from the viewpoint of reducing environmental impact, a flexographic printing method may be used.

[0106] The thickness of the design layer is preferably 0.1 μm or more, more preferably 0.2 μm or more, still more preferably 0.3 μm or more, preferably 10 μm or less, more preferably 5 μm or less, still more preferably 3 μm or less, and is, for example, 0.1 μm or more and 10 μm or less.

[0107] <Configuration and manufacturing method of the laminate> Figs. 1 to 5 show schematic cross-sectional views of an embodiment of the laminate of the present disclosure. These laminates are, in one embodiment, a laminate as a tubular film or a laminate as a front sheet and a back sheet constituting a packaging bag.

[0108] The laminate 1 in Fig. 1 includes a release portion 10 and a main body portion 20 in this order in the lamination direction. The main body portion 20 may be, for example, an adhesive resin layer 22. The laminate 1 in Fig. 2 is the same as the laminate 1 in Fig. 1 except that the main body portion 20 includes an adhesive resin layer 22 and a heat-sealable resin layer 24. The adhesive resin layer 22 is in contact with the release portion 10. The laminate 1 in Fig. 3 is the same as the laminate 1 in Fig. 2 except that the release portion 10 includes a polyolefin layer 12 and a heteroatom-containing resin layer 14. The heteroatom-containing resin layer 14 is in contact with the adhesive resin layer 22. The laminate 1 in Fig. 4 is the same as the laminate 1 in Fig. 2 except that the main body portion 20 further includes an intermediate layer 23 between the adhesive resin layer 22 and the heat-sealable resin layer 24. The laminate 1 in Fig. 5 is the same as the laminate 1 in Fig. 4 except that the release portion 10 includes a polyolefin layer 12 and a heteroatom-containing resin layer 14.

[0109] From the viewpoints of the strength and heat resistance of the laminate, the total thickness of the laminate of the present disclosure is preferably 15 μm or more, more preferably 20 μm or more, still more preferably 30 μm or more, even more preferably 40 μm or more, and particularly preferably 50 μm or more. From the viewpoint of the processability of the laminate, the total thickness of the laminate of the present disclosure is preferably 300 μm or less, more preferably 250 μm or less, still more preferably 200 μm or less, even more preferably 150 μm or less, and particularly preferably 100 μm or less. The total thickness of the laminate of the present disclosure is, for example, 15 μm or more and 300 μm or less.

[0110] From the viewpoint of heat sealability, the laminate of the present disclosure is preferably an unstretched film. An unstretched film is a film that has not been subjected to stretching treatment, for example, an extruded film that has not been subjected to stretching treatment. The "unstretched film" is a concept that includes not only a film that has not been stretched at all but also a film that has been slightly stretched due to the tension applied during film formation by the inflation method or the like.

[0111] The laminate of the present disclosure can be manufactured by a conventionally known method. The laminate is preferably a coextruded multilayer film, and can be manufactured, for example, by a coextrusion film-forming method, and more preferably by a T-die method or an inflation method. The laminate of the present disclosure can be formed, for example, by extruding the resin or resin composition forming each layer from an extruder in a molten state.

[0112] According to the above method, neither the first surface in the main body portion that is in contact with the peeling portion comes into direct contact with the outside air during or after the manufacture of the laminate. Therefore, it is possible to suppress the adhesion of foreign matters such as dust and dirt to the first surface of the main body portion from the time of manufacture of the laminate until the peeling portion is peeled off and removed. When using the packaging bag, by peeling off and removing the peeling portion from the main body portion of the laminate, the first surface of the main body portion is exposed. This first surface is a clean surface with suppressed adhesion of foreign matters.

[0113] [Use] The laminate of the present disclosure can be suitably used as a packaging material constituting a packaging bag. The packaging bag of the present disclosure includes the laminate of the present disclosure.

[0114] In one embodiment, the packaging bag of the present disclosure includes a front sheet constituting the front surface and a back sheet constituting the back surface. The front sheet may be constituted by one laminate of the present disclosure. The back sheet may be constituted by another laminate of the present disclosure. The front sheet and the back sheet may be integrated, or may be constituted by one laminate of the present disclosure. The front sheet and the back sheet may be constituted by one tubular laminate of the present disclosure. The front sheet and the back sheet may be sheets derived from one tubular laminate of the present disclosure.

[0115] The packaging bag has a seal portion formed by joining (for example, heat-sealing) a part of the main body portions in the above laminate. The packaging bag has, for example, a seal portion formed by heat-sealing a part of the heat-sealable resin layers in the above laminate. The packaging bag has, for example, a seal portion formed by joining (for example, heat-sealing) a part of the main body portion in the front sheet and a part of the main body portion in the back sheet. The packaging bag has, for example, a seal portion formed by heat-sealing a part of the heat-sealable resin layer in the front sheet and a part of the heat-sealable resin layer in the back sheet. The seal portion can be formed by, for example, heat sealing. Examples of the heat-sealing method include bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing.

[0116] Examples of the packaging bag include various forms of packaging bags such as a standing pouch type, a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, an envelope sticker seal type, a clamshell sticker seal type (pillow seal type), a gusset seal type, a flat bottom seal type, a corner bottom seal type, and a gusset type. The planar shape of the packaging bag may be, for example, rectangular, or may be a shape other than rectangular such as circular.

[0117] The packaging bag may be provided with an easy-open portion. Examples of the easy-open portion include a notch portion that serves as a starting point for tearing the packaging bag and an easy-open line that serves as a path for tearing the packaging bag. The easy-open line can be formed, for example, using a laser or a cutter. The easy-open line is, for example, a half-cut line. A half-cut line refers to a cut line that reaches from the surface of the peeling portion constituting the laminate to the interface between the peeling portion and the main body portion but does not penetrate the laminate. Starting from the half-cut line, the peeling portion in the laminate can be easily peeled off by hand from the main body portion.

[0118] The position where the half-cut line is formed is not particularly limited. For example, in the case of a packaging bag having a rectangular planar shape, it is preferable to provide a half-cut line at at least one corner of the packaging bag. The half-cut line is preferably formed on both the front sheet and the back sheet of the packaging bag. In one embodiment, the half-cut line extends from the side outer edge to the lower outer edge at the corner of the front sheet and the back sheet.

[0119] Examples of the articles contained in the packaging bag include semiconductor products such as ICs and LSIs, semiconductor-related components such as valves for semiconductor devices and filters for semiconductor manufacturing, precision machinery, magnetic disks, silicon wafers, O-rings, bellows, pharmaceutical products, products for regenerative medicine, and chemical liquid products such as diluents for blood cell inspection devices and artificial dialysis solutions. Examples of the articles also include dust-proof clothes, dust-proof gloves, and instruments used in a clean environment.

[0120] Hereinafter, an example of the usage form of the packaging bag of the present disclosure will be described. Articles used in a clean environment such as a clean room require a high degree of cleanliness. The packaging bag containing the above articles is opened after being brought into the clean environment. Therefore, the packaging bag also requires a high degree of cleanliness. That is, when the packaging bag containing the above articles is brought into the clean environment, it is necessary to suppress the adhesion of foreign matters such as dust and dirt to the outer surface of the packaging bag and the intrusion of foreign matters into the clean environment together with the packaging bag. By using the packaging bag provided with the laminate of the present disclosure, for example, the intrusion of such foreign matters can be suppressed as follows.

[0121] First, the article is placed in the packaging bag of the present disclosure in a clean environment, degassed by vacuum degassing or the like as necessary, the opening of the packaging bag is sealed, and a package in which the article is contained in the packaging bag is obtained. Degassing is not limited to vacuum degassing as long as the gas in the packaging bag can be removed. For example, degassing may be performed by pressing the packaging bag from the outside using a pressing member. Bring the package into the anteroom of the clean environment. Here, the peeling portion in the laminate constituting the packaging bag is peeled off and removed from the main body portion. As a result, the first surface of the main body portion in the laminate constituting the packaging bag is exposed. The first surface of the main body portion is a clean surface with the adhesion of foreign matters suppressed as described above. In the bag obtained by peeling and removing the peeling portion from the main body portion, the amount of foreign matter adhering to the outer surface thereof is small. Bring such a bag into the clean environment. In the clean environment, open the bag, take out the article, and use it. In this way, the intrusion of foreign matters into the clean environment together with the packaging bag is suppressed.

[0122] According to the above configuration, it is not necessary to configure the packaging bag of the present disclosure as a double bag including at least an inner bag and an outer bag, or a bag of three or more layers. However, using the packaging bag of the present disclosure as an outer bag or the like in a double bag or a bag of three or more layers is not restricted in any way.

[0123] Several examples of the method for manufacturing the packaging bag are described below. The packaging bag may be manufactured by the following method. Prepare two laminates of the present disclosure. Stack the laminates with the main body portions of the two laminates facing each other. Next, form seal portions on the left and right and the lower part (three sides), which are the outer peripheral edge portions of the laminate. In this way, a packaging bag having an opening on one side is obtained.

[0124] The packaging bag may be manufactured by the following method. Prepare one laminate of the present disclosure. Fold and stack the laminate so that the second surfaces of the main body portion of the laminate face each other. Next, form seal portions on the left and right outer peripheral edge portions (two sides) of the laminate. In this way, a packaging bag having an opening on one side is obtained. In this case, a seal portion may also be formed on the lower part where the laminate is folded back, and the lower side portion of the lower seal portion may be cut off. Thereby, in each of the front sheet and the back sheet of the packaging bag, the peeling portion can be peeled off and removed from the main body portion.

[0125] The packaging bag may be manufactured by the following method. A tubular film (the laminate of the present disclosure) is obtained by film forming by the coextrusion inflation method, which includes at least a peeling portion constituting the outer surface of the tube and a main body portion constituting the inner surface of the tube. By performing a bag-making process including a cutting process and a heat-sealing process on the tubular film, a plurality of packaging bags having an opening on one side are obtained. In one embodiment in this case, the front sheet and the back sheet of the packaging bag are each a sheet derived from the same tubular film produced by the coextrusion inflation method.

[0126] In the above method, by deforming the tubular film into a flat shape and bringing the inner surfaces of the film into contact with each other, the second surface of the main body portion, which is the inner surface of the film, is kept clean without coming into contact with the outside air. By performing the bag-making process while the inner surfaces of the tubular film deformed into a flat shape are in contact with each other, a packaging bag can be manufactured while keeping the inner surface clean without coming into contact with the outside air. That is, the second surface of the main body portion is a clean surface with adhesion of foreign substances suppressed. In this case, the bag-making process does not necessarily have to be performed in a clean environment. When a higher degree of cleanliness is required, the bag-making process may be performed in a clean environment.

[0127] For example, in a clean environment, an article is loaded into the opening of the unsealed portion of the packaging bag manufactured above. Next, the opening of the packaging bag is heat-sealed to form a sealed portion. In this way, a package in which an article is accommodated in the packaging bag can be obtained.

[0128] FIG. 6a is a cross-sectional view showing an embodiment of the packaging bag of the present disclosure. The packaging bag 50 is manufactured using a laminate 1 including a release portion 10 and a main body portion 20. The sealed portion of the packaging bag 50 is formed by overlapping two laminates 1 and heat-sealing them. FIG. 6b is a cross-sectional view showing an embodiment of the usage form of the packaging bag of the present disclosure. For example, the release portions 10, 10 are peeled off from the main body portions 20, 20, respectively, before the packaging bag 50 containing the article 40 is brought into the clean room.

[0129] FIG. 7 is a front view showing an embodiment of the packaging bag of the present disclosure. Hereinafter, an example of the packaging bag will be described with reference to FIG. 7. The packaging bag 50 in FIG. 7 includes a storage portion (storage space) 50a for storing an article. The second surface of the main body portion included in the laminate of the present disclosure constitutes the inner surface facing the storage portion (storage space) of the packaging bag, that is, the surface with which the article in the packaging bag comes into contact.

[0130] The packaging bag 50 includes an upper portion 51, a lower portion 52, and side portions 53, 53, and has a substantially rectangular outline in a front view. Note that names such as "upper portion", "lower portion", and "side portion", as well as terms such as "above" and "below", merely represent the positions and directions of the packaging bag 50 and its components relatively. The posture of the packaging bag 50 during transportation or use is not limited by the names and terms in this specification.

[0131] As shown in FIG. 7, the packaging bag 50 includes a front sheet 54 that constitutes the front surface and a back sheet 55 that constitutes the back surface. The front sheet 54 and the back sheet 55 are joined at a seal portion. In the front view of the packaging bag 50 shown in FIG. 7, the seal portion is hatched. The seal portion is a portion where a part of the main body of the front sheet 54 and a part of the main body of the back sheet 55 are joined. The packaging bag 50 has half-cut lines 60 at its corners.

[0132] As shown in FIG. 7, the packaging bag 50 has seal portions extending along the four sides of the packaging bag 50. The seal portions include an upper seal portion 51a extending along the upper portion 51, a pair of side seal portions 53a, 53a extending along the pair of side portions 53, 53, and a lower seal portion 52a extending along the lower portion 52. In the packaging bag 50 in a state before an article is accommodated (a state where no article is accommodated), an opening (not shown) exists in the upper portion 51 of the packaging bag 50. After an article is accommodated in the packaging bag 50, a part of the main body of the front sheet 54 and a part of the main body of the back sheet 55 are joined at the upper portion 51. In this way, the upper seal portion 51a is formed, and the packaging bag 50 is sealed.

[0133] [An example of an aspect of the present disclosure] The present disclosure relates to, for example, the following [1] to

[14] . [1]A laminate, wherein the laminate comprises at least a main body part and a release part in a stacking direction, the main body part has a first surface and a second surface facing the first surface, the release part has a first surface and a second surface facing the first surface, the release part is provided on the first surface of the main body part so as to be peelable from the main body part, and the main body part comprises a resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin as a layer constituting the first surface of the main body part. [2]The laminate according to [1], wherein the ionomer resin is an ethylene-based ionomer resin. [3]The laminate according to [1] or [2], wherein the ethylene-unsaturated carboxylic acid copolymer and the ionomer resin each independently have a density of 0.910 g / cm 3 or more. [4]The laminate according to any one of [1] to [3], wherein the release part comprises at least a heteroatom-containing resin layer containing a heteroatom-containing resin as a main component, and the heteroatom-containing resin layer is in contact with the resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin in the main body part. [5]The laminate according to [4], wherein the heteroatom-containing resin contains at least one selected from polyamide, ethylene-vinyl alcohol copolymer, polyester, and polyvinyl alcohol. [6]The laminate according to [4] or [5], wherein the release part further comprises a polyolefin layer containing a polyolefin as a main component. [7]The laminate according to [6], wherein the polyolefin layer further contains an acid-modified polyolefin in addition to the polyolefin. [8]The laminate according to any one of [1] to [7], wherein the main body part further comprises a heat-sealable resin layer as a layer constituting the second surface of the main body part. [9] The laminate according to [8] above, wherein an intermediate layer is further provided between the resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin and the heat-sealable resin layer, and the main body portion contains the same.

[10] The laminate according to [9] above, wherein the intermediate layer contains linear low-density polyethylene as a main component.

[11] The laminate according to any one of [1] to

[10] above, wherein the peel strength between the peeled portion and the main body portion, measured under the conditions of a peel angle of 180 degrees and a test speed of 50 mm / min, is 1.0 N / 15 mm width or less.

[12] The laminate according to any one of [1] to

[11] above, which is a coextruded multilayer film.

[13] A packaging bag comprising the laminate according to any one of [1] to

[12] above.

[14] The packaging bag according to

[13] above, which has a seal portion formed by fusing a part of the main body portion in the laminate.

Examples

[0134] The laminate and the packaging bag of the present disclosure will be described more specifically based on examples, but the laminate and the packaging bag of the present disclosure are not limited by the examples at all.

[0135] [Production of laminate] The components used in the following examples and comparative examples are shown. [Raw material components] · Polyamide (PA) Manufactured by UBE, 5033X80, polyamide 6 / 66 copolymer, Melting point: 196 °C, density: 1.14 g / cm 3 , MFR: 4.0 g / 10 min (temperature 235 °C, load 2.16 kg) · High-density polyethylene (HDPE) Manufactured by Prime Polymer, HZ5000SF, Melting point: 132 °C, density: 0.954 g / cm 3 , MFR: 0.66 g / 10 min · Maleic anhydride graft-modified high-density polyethylene (mHDPE) Manufactured by Dow Chemical, BYNEL 40E 1053, Melting point: 130 °C, density: 0.960 g / cm 3 , MFR: 2.0 g / 10 min · Linear low density polyethylene (LLDPE) Manufactured by Prime Polymer, UZ2021L, C6-LLDPE, Melting point: 120 °C, density: 0.919 g / cm 3 , MFR: 2.0 g / 10 min · Linear low density polyethylene (LLDPE) Manufactured by Japan Polyethylene, Harmolex NF444N, Melting point: 121 °C, density: 0.912 g / cm 3 , MFR: 2.0 g / 10 min · Linear low density polyethylene (LLDPE) Manufactured by Prime Polymer, UZ3520L, C6-LLDPE, Melting point: 124 °C, density: 0.931 g / cm 3 , MFR: 2.1 g / 10 min · Linear low density polyethylene (LLDPE) Manufactured by Ube Maruzen Polyethylene, UMERIT125FN, Melting point: 120 °C, density: 0.924 g / cm 3 , MFR: 2.2 g / 10 min · Low density polyethylene (LDPE) Manufactured by Ube Maruzen Polyethylene, B128, Melting point: 114 °C, density: 0.928 g / cm 3 , MFR: 1.0 g / 10 min · Ionomer resin Manufactured by Mitsui Dow Polychemical, Himilan 1601, [[ID=�1]]Ethylene-based ionomer resin, Metal ion neutralization product of ethylene-methacrylic acid copolymer, Ion type: Na + , Degree of neutralization: 71%, Melting point: 97 °C, density: 0.940 g / cm 3 , MFR: 1.3 g / 10 min · Ethylene-(meth)acrylic acid copolymer Manufactured by Mitsui Dow Polychemicals, Nuclel N0903HC, Ethylene-methacrylic acid copolymer, Content ratio of structural units derived from ethylene: 91% by mass, Content ratio of structural units derived from methacrylic acid: 9% by mass, Melting point: 99°C, density: 0.930 g / cm 3 , MFR: 3.0 g / 10 min · Acid-modified polyethylene Manufactured by Mitsui Chemicals, Admer HE810, Maleic anhydride graft-modified polyethylene, Density: 0.960 g / cm 3 , MFR: 1.7 g / 10 min · Linear low-density polyethylene (LLDPE) Manufactured by Prime Polymer, SP2020, Density: 0.916 g / cm 3 , MFR: 2.3 g / 10 min · High-density polyethylene (HDPE) Manufactured by Prime Polymer, HZ3300F, Density: 0.950 g / cm 3 , MFR: 1.1 g / 10 min

[0136] [Example 1] A mixture of 80% by mass of HDPE (HZ5000SF) and 20% by mass of mHDPE (BYNEL 40E 1053), PA (5033X80), an ethylene-based ionomer resin (Hymilan 1601), LLDPE (UZ3520L), and a mixture of 80% by mass of LLDPE (UZ2021L) and 20% by mass of LDPE (B128) were extruded in a tube shape through a multilayer annular die from an extruder using a 5-layer coextrusion inflation apparatus, and this was inflated with air pressure while being drawn vertically to form a tubular film. The notation of mass% in the mixture indicates the content ratio of each component in the mixture.

[0137] The tubular film comprises an HDPE layer with a thickness of 30 μm that constitutes the outer surface of the tube, a PA layer with a thickness of 5 μm, an ionomer resin layer with a thickness of 20 μm, an LLDPE layer with a thickness of 20 μm, and a polyethylene blend layer with a thickness of 20 μm that constitutes the inner surface of the tube. The total thickness of the tubular film is 95 μm.

[0138] The inner surfaces of the tubular film were brought into contact with each other by pinch rolls and flattened. For the flattened film, using a high-speed three-side seal automatic bag-making machine (BH-60D manufactured by Totani Giken Kogyo Co., Ltd.), heat seal treatment was performed under the conditions of a temperature of 140 °C, a pressure-bonding time of 0.8 seconds, and a pressure of 3 kgf / cm 2 and a predetermined cutting process was performed to produce a three-side seal bag. The peeling portion consists of an HDPE layer (polyethylene layer) with a thickness of 30 μm and a PA layer (heteroatom-containing resin layer) with a thickness of 5 μm. The main body portion consists of an ionomer resin layer (adhesive resin layer) with a thickness of 20 μm, an LLDPE layer (polyethylene layer) with a thickness of 20 μm, and a polyethylene blend layer (heat-sealable resin layer) with a thickness of 20 μm.

[0139] [Examples 2 to 4 and Comparative Examples 1 to 6] Tubular films and three-side seal bags were obtained in the same manner as in Example 1, except that the composition ratios of the components of each layer were changed as described in Tables 1 and 2. In Tables 1 and 2, "←" means that the composition of the layer is the same as the composition in the left column.

[0140] [Physical Property Evaluation] The method for evaluating the physical properties of the three-side seal bag is described below. Unless otherwise specified, the environment during the measurement of each physical property is a temperature of 23 °C and a humidity of 50% RH. For each physical property, measurements were made on three test pieces, and the arithmetic mean value of the three obtained values was described as each physical property value.

[0141] [Peeling Strength] The three-sided sealed bag was cut to cut out test pieces having a size of width: 15 mm and length: 100 mm. Using a desktop tensile compression testing machine MCT-1150 (manufactured by AND) as the measuring instrument, under the conditions of an initial chuck distance: 100 mm, a peeling angle: 180 degrees, and a test speed: 50 mm / min, the peeling strength (N / 15 mm width) between the main body part and the peeling part in the above test piece was measured. When the peeling part could not be peeled from the main body part under the above conditions, it was described as "the peeling part cannot be peeled off".

[0142] <Appearance (lifting of the peeling part)> In each process during the manufacture of the three-sided sealed bag, the lifting between the main body part and the peeling part (the area where air bubbles entered and turned white, 1 cm 2 or more) was visually confirmed. The three-sided sealed bags with lifting of the peeling part were evaluated as "B", and the three-sided sealed bags without lifting of the peeling part were evaluated as "A".

[0143] <Puncturing strength> In accordance with JIS Z1707:2019, the puncturing strength of the three-sided sealed bag was measured as follows. The three-sided sealed bag was cut to obtain test pieces having a size of width: 5 cm and length: 5 cm. Using a desktop tensile compression testing machine MCT-1150 (manufactured by AND) as the measuring instrument, a semi-circular needle with a diameter of 1.0 mm and a tip shape radius of 0.5 mm was pierced into the test piece at a test speed of 50 mm / min, and the maximum strength (N) until the needle penetrated the test piece was measured and taken as the puncturing strength (N). The surface of the test piece where the above needle was pierced was taken as the first surface of the peeling part and the second surface of the main body part.

[0144] <Sealing strength> The three-sided sealed bag was cut to cut out test pieces having a size of width: 15 mm and length: 100 mm. Two test pieces were overlapped so that their heat-sealing resin layers (the second surfaces of the main body parts) were in contact with each other, at a temperature of 140 °C (one-sided heating), a crimping time of 1 second, and a pressure of 1 kgf / cm 2Under the following conditions, a 15 mm × 15 mm portion at one end of the test piece was heat-sealed to form a seal portion, and a test specimen was obtained. Except for changing the test conditions as described below, in accordance with JIS Z1707:2019, using a desktop tensile-compression testing machine MCT-1150 (manufactured by AND Corporation) as the measuring instrument, the seal strength (N / 15 mm width) was measured under the conditions of a chuck distance of 100 mm, a peeling mode of T-peeling, and a test speed of 300 mm / min. Specifically, the test specimen was opened 180 degrees so that the seal portion of the test specimen was at the center of the two grips of the testing machine, and both ends of the test specimen were attached to the two grips of the testing machine respectively. Then, it was pulled at a speed of 300 mm / min until the seal portion was broken, and the maximum strength (N) was obtained. The maximum strength (N) measured for the 15 mm-wide test specimen was taken as the seal strength (N / 15 mm width).

[0145]

Table 1

[0146]

Table 2

Explanation of Symbols

[0147] 1 … Laminate 10… Peeling portion 12… Polyolefin layer 14… Heteroatom-containing resin layer 20… Main body portion 22… Adhesive resin layer 23… Intermediate layer 24… Heat-sealable resin layer 40… Article 50… Packaging bag 50a… Accommodating portion (accommodating space) 51… Upper part 51a… Upper seal portion 52… Lower part 52a… Lower seal portion 53… Side part 53a… Side seal portion 54… Surface sheet 55... back sheet 60... half cut line

Claims

1. A laminate comprising: at least: a main body portion; a release portion; in a stacking direction; the main body portion has a first surface and a second surface facing the first surface, the release portion has a first surface and a second surface facing the first surface, and the release portion is provided on the first surface of the main body portion so as to be peelable from the main body portion; the main body portion includes a resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin as a layer constituting the first surface of the main body portion; A laminate.

2. The laminate according to claim 1, wherein the ionomer resin is an ethylene-based ionomer resin.

3. The ethylene-unsaturated carboxylic acid copolymer and the ionomer resin each independently have a density of 0.910 g / cm 3 or more, and the laminate according to claim 1.

4. The release portion includes at least a heteroatom-containing resin layer containing a heteroatom-containing resin as a main component; the heteroatom-containing resin layer is in contact with the resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin in the main body portion; The laminate according to claim 1.

5. The laminate according to claim 4, wherein the heteroatom-containing resin includes at least one selected from polyamide, ethylene-vinyl alcohol copolymer, polyester, and polyvinyl alcohol.

6. The laminate according to claim 4, wherein the release portion further includes a polyolefin layer containing a polyolefin as a main component.

7. The laminate according to claim 6, wherein the polyolefin layer further contains an acid-modified polyolefin in addition to the polyolefin.

8. The laminate according to claim 1, wherein the main body portion further includes a heat-sealable resin layer as a layer constituting the second surface of the main body portion.

9. The laminate according to claim 8, wherein the main body portion further includes an intermediate layer between the resin layer containing at least one resin selected from an ethylene-unsaturated carboxylic acid copolymer and an ionomer resin and the heat-sealable resin layer.

10. The laminate according to claim 9, wherein the intermediate layer contains linear low-density polyethylene as a main component.

11. The laminate according to any one of claims 1 to 10, wherein the peel strength between the release portion and the main body portion, measured under the conditions of a peel angle of 180 degrees and a test speed of 50 mm / min, is 1.0 N / 15 mm width or less.

12. The laminate according to any one of claims 1 to 10, which is a co-extruded multilayer film.

13. A packaging bag comprising the laminate according to any one of claims 1 to 10.

14. The packaging bag according to claim 13, having a seal portion formed by fusing a part of the main body portions in the laminate.

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