Easy-to-open laminate

Abstract

To provide a laminate which is excellent in gas barrier property, adhesion, and easy openability.SOLUTION: An easy-to-open laminate includes at least a base material layer, and a layer (C), a layer (B) and a layer (A) that are adjacent to each other from the base material layer side, wherein the layer (A) is composed of polyethylene (a), the layer (B) is a saponification product (b) of an ethylene-vinyl ester copolymer satisfying (i) to (ii), and the layer (C) is composed of an ethylene-vinyl alcohol copolymer (c) satisfying (iii) and satisfies (iv) to (v). (i) A melt mass flow rate (MFRADD) at 230°C measured by JIS 7210 (1999) is 2.0 g / 10 min or more and 20.0 g / 10 min or less, (ii) an acid content is 0.02 wt.% or more and 1.0 wt.% or less, (iii) an ethylene content C2 is 50 mol% or less, (iv) a thickness of the layer (A) is 1 μm or more and 15 μm or less, and (vi) the adhesive strength of the layer (A) and the layer (B) is 0.1 N / 15 mm or more and 3.0 N / 15 mm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an easy-open laminate. [Background technology]

[0002] Ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) is used in a variety of applications as a packaging material made from thermoplastic resins for foods, beverages, pharmaceuticals, etc., to prevent deterioration of the contents, as it has excellent gas barrier properties, aroma retention, and solvent resistance. Co-extruded films and laminates of polyethylene resins, acid-modified polyolefins, and EVOH (see, for example, Patent Document 1) are produced.

[0003] However, such films and laminates do not have the easy-to-open property (easy-peel property) required for container lids, etc. Therefore, it is necessary to use a so-called easy-peel resin for the sealing layer of the lid, which is inferior in cost.

[0004] In light of this background, there has been a demand for laminates that are excellent in gas barrier properties, adhesive properties, and ease of opening. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 1992-234645 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide a laminate that exhibits excellent gas barrier properties, adhesive properties, and easy-open properties. [Means for solving the problem]

[0007] As a result of extensive research aimed at solving the above problems, the present inventors have found that a specific laminate exhibits excellent gas barrier properties, adhesive properties, and easy-open properties, and have thus completed the present invention.

[0008] The embodiments of the present invention are [1] to [8] shown below. [1] An easy-open laminate comprising at least a base layer and a (C) layer / (B) layer / (A) layer adjacent to the base layer side, wherein the (A) layer is composed of polyethylene (a), the (B) layer is composed of acid-modified polypropylene (b) that satisfies (i) to (ii), and the (C) layer is composed of an ethylene-vinyl alcohol copolymer (c) that satisfies (iii), and the laminate satisfies (iv) to (v).

[0009] (i) Melt mass flow rate (MFR) at 230°C measured according to JIS 7210 (1999) ADD ) is 2.0g / 10min or more and 20.0g / 10min or less (ii) an acid content of 0.02% by weight or more and 1.0% by weight or less; (iii) Ethylene content C2 is 50 mol% or less (iv) The thickness of the (A) layer is 1 μm or more and 15 μm or less. (v) The adhesive strength between layer (A) and layer (B) is 0.1 N / 15 mm or more and 3.0 N / 15 mm or less. [2] The easy-open laminate according to [1] above, wherein the acid content of the acid-modified polypropylene (b) is 0.05% by weight or more and 0.40% by weight or less. [3] The easy-open laminate according to any one of the above [1] or [2], wherein the acid-modified polypropylene (b) is maleic anhydride-grafted modified polypropylene. [4] The easy-open laminate according to any one of the above [1] to [3], wherein the polyethylene (a) satisfies (vi) to (viii).

[0010] (vi) Melt mass flow rate (MFR) measured according to JIS K6922-1 (1997) PE ) is 1.0g / 10min or more and 10.0g / 10min or less (vii) Melt tension (MS) measured at a temperature of 190°C and a take-up speed of 10 m / min PE) is 3mN or more and 50mN or less (viii) MFR PE (g / 10 min) and MS PE (mN) product MFR PE ×MS PE is between 70 and 250 [5] The easy-open laminate according to any one of [1] to [4] above, wherein the polyethylene (a) comprises an ethylene-α-olefin copolymer and / or a high-pressure low-density polyethylene. [6] C2 (mol%) of ethylene-vinyl alcohol copolymer (c) and density D at 20℃ measured according to ISO1183-3 EVOH (kg / m 3 ) satisfies the following formula (1):

[0023]

[0024] The easy-open laminate according to any one of [1] to [5] above.

[0011] D EVOH <-4.265×C2+1325 (1) [7] The easy-open laminate according to any one of [1] to [6] above, further comprising an (E) layer / a (D) layer between the base material layer and the (C) layer, the (E) layer being adjacent to the base material layer, the (D) layer being adjacent to the (C) layer, the (E) layer being polyethylene (e), and the (D) layer being acid-modified polypropylene (d). [8] A method for producing an easy-open laminate according to any one of [1] to [7] above, wherein Layer C / Layer B / Layer A or Layer E / Layer D / Layer C / Layer B / Layer A are simultaneously formed by co-extrusion lamination molding. [Effects of the Invention]

[0012] According to the present invention, a laminate having excellent gas barrier properties, adhesive properties, and easy-open properties can be provided. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing formulas (1) and (2). DETAILED DESCRIPTION OF THE INVENTION

[0014] Each aspect of the present invention will be described in detail below.

[0015] An easy-open laminate according to one embodiment of the present invention is a laminate including at least a base layer and a (C) layer / (B) layer / (A) layer adjacent to the base layer, wherein the (A) layer is composed of polyethylene (a), the (B) layer is composed of acid-modified polypropylene (b) that satisfies (i) to (ii), and the (C) layer is composed of an ethylene-vinyl alcohol copolymer (c) that satisfies (iii), and satisfies (iv) to (v).

[0016] (i) Melt mass flow rate (MFR) at 230°C measured according to JIS 7210 (1999) ADD ) is 2.0g / 10min or more and 20.0g / 10min or less (ii) an acid content of 0.02% by weight or more and 1.0% by weight or less; (iii) Ethylene content C2 is 50 mol% or less (iv) The thickness of the (A) layer is 1 μm or more and 15 μm or less. (v) The adhesive strength between layer (A) and layer (B) is 0.1 N / 15 mm or more and 3.0 N / 15 mm or less. The layer (A) is composed of polyethylene (a).

[0017] The polyethylene (a) is not particularly limited, and examples thereof include ethylene homopolymers, copolymers of ethylene with α-olefins having 2 to 12 carbon atoms, such as propylene or 1-butene, and copolymers of ethylene with vinyl esters and / or acrylic esters. More specific examples include ethylene homopolymers such as high-pressure low-density polyethylene and high-density polyethylene; ethylene-α-olefin copolymers such as ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, and ethylene-4-methyl-1-pentene copolymers; and ethylene polymers such as ethylene-vinyl acetate copolymers, ethylene-acrylic ester copolymers, and ethylene-methacrylic ester copolymers. Polyethylene (a) may be used alone or in combination of two or more types. Among these, high-pressure low-density polyethylene and ethylene-α-olefin copolymers are preferred due to their excellent moldability. Furthermore, from the viewpoint of moldability, the ethylene-α-olefin copolymer preferably contains high-pressure low-density polyethylene.

[0018] An example of a method for producing high-pressure low-density polyethylene is high-pressure radical polymerization, and such a resin can be conveniently selected from commercially available products, such as those sold by Tosoh Corporation under the trade name Petrothene.

[0019] Ethylene-α-olefin copolymers can be obtained by copolymerizing ethylene and α-olefins using high, medium, or low pressure ionic polymerization methods with Ziegler-Natta, Phillips, or metallocene catalysts.

[0020] Examples of α-olefins constituting the ethylene-α-olefin copolymer include propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene, and one or more of these may be used. Among these α-olefins, α-olefins having 5 or less carbon atoms are preferred because of their excellent ease of opening.

[0021] Such ethylene-α-olefin copolymers can be conveniently selected from commercially available products, such as those available from Tosoh Corporation under the trade names Nipolon-L, Nipolon-Z, and Lumitack.

[0022] The melt mass flow rate (hereinafter referred to as "MFR") of polyethylene (a) measured according to JIS K6922-1 (1997) PE ") is preferably in the range of 1.0 g / 10 min or more and 10.0 g / 10 min or less, more preferably 1.0 g / 10 min or more and 6.0 g / 10 min or less, and most preferably 3.0 g / 10 min or more and 5.0 g / 10 min or less, because it has excellent co-extrusion lamination processability (migration) with acid-modified polypropylene and ethylene-vinyl alcohol copolymer.

[0023] The melt tension (hereinafter referred to as "MS") of polyethylene (a) measured at a temperature of 190°C and a take-up speed of 10 m / min PE ") is preferably in the range of 3 mN or more and 50 mN or less, more preferably 10 mN or more and 45 mN or less, and most preferably 15 mN or more and 40 mN or less, in order to achieve excellent productivity.

[0024] MS in the present invention PE is a value measured at an extrusion speed of 10 m / min, a take-up speed of 10 m / min, and a set temperature of 190°C using a capillary viscometer with a barrel diameter of 9.55 mm, equipped with a die having a length of 8 mm, a diameter of 2.095 mm, and an inlet angle of 90°, and equipped with a heat-retaining chamber.

[0025] MFR of polyethylene (a) PE (g / 10 min) and MS PE (mN) product MFR PE ×MS PE In view of excellent productivity, the MFR is preferably in the range of 70 to 250, more preferably in the range of 70 to 200, and most preferably in the range of 90 to 160. PE ×MS PEis a value that correlates with the ratio of melt elasticity to melt viscosity of polyethylene, that is, the nonlinearity of polyethylene during melt deformation.

[0026] The density of polyethylene (a) measured according to JIS K6922-1 (1997) (hereinafter simply referred to as density) is not particularly limited, and since it has excellent moldability and easy opening properties, it is preferably 880 to 970 kg / m 3 is preferably in the range of 900 to 950 kg / m 3 range, most preferably 905 to 940 kg / m 3 The range is.

[0027] The polyethylene (a) in the present invention may be blended with other thermoplastic resins as long as the object is achieved.

[0028] When mixing the thermoplastic resin with polyethylene (a), a pellet mixture obtained by mixing polyethylene pellets and thermoplastic resin pellets in a solid state may be used, but a mixture melt-kneaded using a single-screw extruder, twin-screw extruder, kneader, Banbury extruder, etc. is preferred because it provides a product of stable quality. When using a melt-kneading device, the melting temperature is preferably from the melting point of polyethylene to about 300°C.

[0029] Furthermore, additives generally used in polyolefin resins, such as antioxidants, light stabilizers, antistatic agents, lubricants, and antiblocking agents, may be added to the polyethylene (a) as needed, provided that the object of the present invention is not impaired.

[0030] The layer (B) is composed of an acid-modified polypropylene (b).

[0031] The polypropylene constituting the acid-modified polypropylene (b) of the present invention is not particularly limited as long as it achieves the object, and examples thereof include a propylene homopolymer and a copolymer of propylene and 50 mol% or less of an α-olefin such as ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, or 1-octene.

[0032] Examples of the acid-modified polypropylene (b) include copolymers of the above polypropylene with unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and acrylic acid ionomers, or ionomers thereof, copolymers of the above polypropylene with unsaturated dicarboxylic acids such as maleic acid and maleic anhydride, or anhydrides thereof, polypropylenes graft-modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and maleic anhydride, or anhydrides thereof, ionomers, boronic acids, etc., and copolymers of the above polypropylene with glycidyl methacrylate. These acid-modified polypropylenes (b) may be used singly or in combination of two or more.

[0033] Among these, from the viewpoints of adhesiveness and cost, it is preferable to use at least maleic anhydride grafted polypropylene (hereinafter sometimes abbreviated as "MAH-PP") or a copolymer of polypropylene and maleic anhydride, and more preferably MAH-PP.

[0034] Such maleic anhydride-modified polypropylene can be conveniently selected from commercially available products, and examples of such maleic anhydride-grafted modified polypropylene include those commercially available under the trade names Admer from Mitsui Chemicals, Inc., Modic from Mitsubishi Chemical Corporation, Fusabond from Dow Chemical Japan, OREVAC G from SK Geo Centric Japan, Polybond from Addivant Japan LLC, Rike-Aid from Riken Vitamin Co., Ltd., and Umex from Sanyo Chemical Industry Co., Ltd. Copolymers of polypropylene and maleic anhydride are commercially available under the trade name Honeywell AC Polyolefin Wax from Honeywell Japan Inc.

[0035] The melt mass flow rate (hereinafter referred to as "MFR") of acid-modified polypropylene (b) at 230°C measured according to JIS 7210 (1999) ADDThe MFR (abbreviated as "MFR") is in the range of 2.0 g / 10 min or more and 20.0 g / 10 min or less, more preferably 2.0 g / 10 min or more and 12.0 g / 10 min or less, and most preferably 4.0 g / 10 min or more and 10.0 g / 10 min or less, because it provides excellent co-extrusion lamination processability (migration) and moldability with polyethylene ethylene and ethylene-vinyl alcohol copolymers. ADD If the (g / 10 min) is less than 2.0 g / 10 min or exceeds 20.0 g / 10 min, the coextrusion lamination processability and moldability will be poor, which is not preferable.

[0036] The acid content of such acid-modified polypropylene (b) is in the range of 0.02 to 1.0% by weight, more preferably 0.05 to 0.40% by weight, and most preferably 0.10 to 0.25% by weight, since this provides excellent appearance after opening and film appearance. An acid content of less than 0.02% by weight is undesirable because the appearance after opening is poor, and an acid content of more than 1.0% by weight is undesirable because the film appearance is poor.

[0037] From the viewpoints of moldability and film appearance, the acid-modified polypropylene (b) is preferably a polypropylene composition containing at least an unmodified polyolefin and MAH-PP.

[0038] From the viewpoints of adhesiveness and film appearance, the polypropylene composition preferably contains 50 to 90 parts by weight of polyolefin and 10 to 50 parts by weight of MAH-PP (total of polyolefin and MAH-PP is 100 parts by weight), and more preferably contains 65 to 85 parts by weight of polyolefin and 15 to 35 parts by weight of MAH-PP (total of polyolefin and MAH-PP is 100 parts by weight).

[0039] Such polyolefins are not particularly limited, and examples thereof include homopolymers of α-olefins having 2 to 12 carbon atoms such as ethylene, propylene, and 1-butene, copolymers thereof, and copolymers of ethylene with vinyl esters and / or acrylic esters.

[0040] Examples of suitable polyolefins include ethylene homopolymers such as high-pressure low-density polyethylene and high-density polyethylene, ethylene-based polymers such as ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, ethylene-4-methyl-1-pentene copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylate copolymers, and ethylene-methacrylate copolymers, propylene homopolymers, propylene-ethylene copolymers, propylene-1-butene copolymers, poly-1-butene, poly-1-hexene, and poly-4-methyl-1-pentene. Polyolefins may be used singly or in combination of two or more. Among these, at least one selected from the group consisting of high-pressure low-density polyethylene, ethylene-vinyl acetate copolymers, high-density polyethylene, ethylene-1-butene copolymers, ethylene-1-hexene copolymers, and polypropylene is preferred from the standpoint of moldability, and these compositions are most preferred due to their excellent moldability.

[0041] Other thermoplastic resins may be blended with the acid-modified polypropylene (b) as long as the intended purpose is achieved. When mixing the thermoplastic resin with the acid-modified polypropylene (b), a pellet mixture in which pellets of saponified ethylene-vinyl ester copolymer and pellets of the thermoplastic resin are mixed in a solid state may be used. However, a mixture melt-kneaded using a single-screw extruder, twin-screw extruder, kneader, Banbury mixer, etc. is preferred because it produces a product of consistent quality. When using a melt-kneading device, the melting temperature is preferably from the melting point of the polyolefin composition to about 300°C.

[0042] Furthermore, if necessary, additives commonly used in polyolefin resins, such as antioxidants, light stabilizers, antistatic agents, lubricants, and antiblocking agents, may be added to the acid-modified polypropylene (b) within the range that does not impair the object of the present invention.

[0043] The ethylene content of the ethylene-vinyl alcohol copolymer (c) (hereinafter sometimes abbreviated as C2) is 50 mol% or less, preferably 20 to 35 mol%, because it has excellent gas barrier properties. This further improves the gas barrier properties. Here, C2 (mol%) refers to the content of ethylene components in the monomer units contained in the ethylene-vinyl alcohol copolymer (c).

[0044] There are no particular limitations on the method for producing the ethylene-vinyl alcohol copolymer (c). For example, a copolymer of ethylene and a fatty acid vinyl ester can be produced according to a known method, and then EVOH can be produced by hydrolyzing (saponifying) this copolymer.

[0045] The degree of saponification of such an ethylene-vinyl alcohol copolymer (c) is preferably in the range of 80% by weight or more, since this provides excellent gas barrier properties.

[0046] In addition to ethylene units and vinyl alcohol units, EVOH may contain small amounts of other structural units.

[0047] Such resins can be conveniently selected from commercially available products, and are commercially available, for example, under the trade names EVAL from Kuraray Co., Ltd., and Soarnol and G-Soarnol from Mitsubishi Chemical Corporation.

[0048] The melt mass flow rate (MFR) of the ethylene-vinyl alcohol copolymer (c) at 190°C measured in accordance with ISO 1133 (temperature: 190°C, load: 2.16 kg, hereinafter referred to as "MFR") EVOHFrom the viewpoints of formability and film appearance, the melt mass flow rate of the ethylene-vinyl alcohol copolymer (c) at 210°C (temperature 210°C, load 2.16 kg) measured in accordance with ISO 1133 is preferably in the range of 2.5 to 20.0 g / 10 min, more preferably 2.5 to 15.0 g / 10 min, and most preferably 2.5 to 7.5 g / 10 min.

[0049] The density of ethylene-vinyl alcohol copolymer (c) at 20°C measured in accordance with ISO1183-3 (hereinafter referred to as "D EVOH ") is 1190 kg / m from the viewpoint of film appearance and adhesiveness. 3 Less than 1100-1180 kg / m is preferable. 3 More preferably, it is 1140 to 1180 kg / m 3 It is most preferable that:

[0050] In addition, the film appearance and adhesiveness were excellent, and the C2 (mol%) and D EVOH (kg / m 3 ) preferably satisfies the following formula (1), and more preferably satisfies the following formula (2):

[0051] D EVOH <-4.265×C2+1325 (1) D EVOH <-4.265×C2+1315 (2) The substrate layer is not particularly limited and can be selected appropriately depending on the application. Examples of suitable materials include films, woven fabrics, and nonwoven fabrics formed from synthetic polymers, as well as metal foils, paper, and cellophane. Examples of suitable synthetic polymers include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 66, polyethylene resins such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, and ionomers, polypropylene resins, polybutene, acrylic resins, polyvinyl alcohol, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polycarbonate, polyurethane, and cellulose resins. The synthetic polymer constituting the substrate layer may be the same as or different from the polyethylene (a). Furthermore, these polymer films and sheets may be further treated with aluminum vapor deposition, alumina vapor deposition, silicon dioxide vapor deposition, or acrylic. These polymer films and sheets may also be printed with urethane ink, etc. Examples of metal foils include aluminum foil and copper foil, and examples of paper include kraft paper, fine paper, stretched paper, glassine paper, and paperboard such as cup base paper and photographic paper base paper. These substrates may be used alone or in combination of two or more.

[0052] The laminate according to one embodiment of the present invention is characterized by comprising at least a substrate layer and, from the substrate layer side, a (C) layer, a (B) layer, and a (A) layer. It may be composed solely of these four components or may also contain other components, such as a (D), an (E), or an (F) layer. Specific examples include substrate layer / (C) layer / (B) layer / (A) layer, (D) layer / substrate layer / (C) layer / (B) layer / (A) layer, substrate layer / (D) layer / (C) layer / (B) layer / (A) layer, (E) layer / substrate layer / (D) layer / (C) layer / (B) layer / (A) layer, substrate layer / (E) layer / (D) layer / (C) layer / (B) layer / (A) layer, and (F) layer / substrate layer / (E) layer / (D) layer / (C) layer / (B) layer / (A) layer. The symbol / between layers indicates that the layers are adjacent.

[0053] Examples of layers (D), (E), and (F) include layers formed from synthetic polymers, woven fabrics, nonwoven fabrics, metal foils, paper, cellophane, etc. Examples of layers include layers formed from synthetic polymers, such as polyester resins (e.g., polyethylene terephthalate, polybutylene terephthalate), polyamide resins (e.g., nylon 6, nylon 66), polyethylene resins (e.g., high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ionomer), polypropylene resins, polybutene, acrylic resins, polyvinyl alcohol, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polycarbonate, polyurethane, and cellulose resins. Furthermore, these polymer films and sheets may be further treated with aluminum vapor deposition, alumina vapor deposition, silicon dioxide vapor deposition, or acrylic. Furthermore, these polymer films and sheets may be further printed with urethane ink, etc. Examples of metal foils include aluminum foil and copper foil, and examples of papers include kraft paper, fine paper, stretch paper, glassine paper, and paperboard such as cup base paper and photographic paper base paper.

[0054] Among these laminates, a laminate comprising at least adjacent layers of a substrate layer / (E) layer / (D) layer / (C) layer / (B) layer / (A) is preferred because of its excellent productivity and gas barrier properties. That is, a laminate further comprising a layer (E) / (D) layer between the substrate layer and the layer (C), the layer (E) being adjacent to the substrate layer, the layer (D) being adjacent to the layer (C), the layer (E) being polyethylene (e), and the layer (D) being acid-modified polypropylene (d). Here, the polyethylene (a) constituting the layer (A) and the polyethylene (e) constituting the layer (E) may be the same or different, but from the viewpoint of productivity, it is more preferable that they be the same component. Furthermore, the acid-modified polypropylene (b) constituting the layer (B) and the acid-modified polypropylene (e) constituting the layer (D) may be the same or different, but from the viewpoint of productivity, it is more preferable that they be the same component. The extrusion lamination method for obtaining a laminate is not particularly limited, and examples include various extrusion lamination methods such as tandem lamination, in which each layer is laminated in order, and coextrusion lamination, in which several layers are laminated simultaneously. Among these, from the viewpoint of cost, it is preferable to simultaneously form (C) layer / (B) layer / (A) layer or (E) layer / (D) layer / (C) layer / (B) layer / (A) layer by coextrusion lamination. Furthermore, the most preferred method is a three-kind five-layer extrusion lamination method in which (A) layer and (E) layer are made of the same component, and (B) layer and (D) layer are made of the same component. In such extrusion lamination methods, the resin temperature is preferably in the range of 180 to 280°C, and the surface temperature of the cooling roll is preferably in the range of 10 to 50°C.

[0055] In addition, in extrusion lamination, it is preferable to use a method in which, immediately after forming the thermoplastic resin constituting the layer adjacent to the substrate layer into an extruded layer in a molten state, the substrate adhesive surface of the layer is exposed to an oxygen-containing gas or an ozone-containing gas and then laminated to the substrate, since this method provides excellent adhesion to the substrate layer. When improving the adhesion between the thermoplastic resin and the substrate by using an ozone-containing gas, the amount of ozone gas to be treated is 1 / m of the film made of the thermoplastic resin extruded from the die. 2 It is preferable to spray 0.5 mg or more of ozone per 1000 particles.

[0056] In the extrusion lamination method for obtaining a laminate, in order to further improve the adhesion between the thermoplastic resin layer and the base layer, heat treatment can be performed for 10 hours or more at a temperature at which the resin of each layer does not foam, for example, a temperature of 30°C to 60°C. If necessary, the adhesive surface of the base layer may be subjected to a known surface treatment such as corona treatment, flame treatment, or plasma treatment. If necessary, an anchor coating agent may be applied to the base layer.

[0057] The thickness of Layer A is in the range of 1 μm to 15 μm, more preferably 3 μm to 10 μm, and most preferably 3 μm to 6 μm, in order to provide excellent ease of opening, appearance after opening, and sealing properties. A thickness of Layer A of less than 1 μm is undesirable because of poor sealing properties, and a thickness of more than 15 μm is undesirable because of poor ease of opening and appearance after opening.

[0058] The adhesive strength between Layer (A) and Layer (B) is in the range of 0.1 N / 15 mm or more and 3.0 N / 15 mm or less, more preferably 0.5 N / 15 mm or more and 2.0 N / 15 mm or less, in order to provide excellent ease of opening, appearance after opening, and sealing. An adhesive strength between Layer (A) and Layer (B) of less than 0.1 N / 15 mm is undesirable because sealing ability is poor, and an adhesive strength exceeding 3.0 N / 15 mm is undesirable because ease of opening and appearance after opening are poor.

[0059] The adhesive strength was measured by peeling the interface between Layer A and Layer B and then cutting the laminate into a 15 mm width, using a tensile tester Tensilon RTE-1210 (manufactured by Orientec Co., Ltd.) at a tensile speed of 300 mm / min and a peel angle of 180°.

[0060] The easy-open laminate of the present invention has excellent film appearance, adhesiveness, and gas barrier properties against oxygen and the like, and also has excellent ease of opening, so it can be suitably used for packaging materials and containers made of thermoplastic resins for foods, beverages, pharmaceuticals, and the like that require these properties. [Example]

[0061] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these. (1) Melt mass flow rate (MFR) The MFR was measured in accordance with JIS K6922-1 (1997), JIS K7210 (1999), or ISO1133. (2) Density The density was measured in accordance with JIS K6922-1 (1997), JIS K7210 (1999), or ISO1183-3. (3) Melt tension (MS) In a thermostatic chamber set to 23°C, the temperature was set to 190°C, and 18 g of polyolefin was filled into a capillary viscometer (Toyo Seiki Seisakusho, trade name: Capilograph) with a barrel diameter of 9.55 mm, equipped with a die having a length of 8 mm, a diameter of 2.095 mm, and an inlet angle of 90°, and a heat-retaining chamber. The piston descending speed was set to 10 mm / min, and the take-up speed was set to 10 m / min, and the load (mN) required for take-up was measured as the melt tension (MS). (6) Migration The rotation speed of each extruder was set to achieve the thickness described in the examples at a processing speed of 50 m / min, and the molten film extruded from the T-die was visually measured for migration. The molten film immediately below the die was observed, and the width of the EVOH layer that had not wrapped around at both ends of the molten film was measured, and the sum of the widths at both ends of the molten film was taken as migration (mm). The smaller the migration, the better the productivity. (7) Maximum processing speed / stretchability The maximum processing speed was determined by increasing the rotation speed of each extruder and the processing speed in conjunction with each other so that the thickness of the easy-open laminate would be the thickness described in the Examples, and the processing speed at which film breakage occurred was defined as the maximum processing speed (m / min). The higher the maximum processing speed, the better the stretchability and productivity. (8) Creation of sealant film MFR 8g / 10min, density 919kg / m 3High-pressure low-density polyethylene (manufactured by Tosoh Corporation, trade name Petrothene 203, hereafter abbreviated as LDPE) was fed into a single-screw extruder (manufactured by Sumitomo Heavy Industries Modern Co., Ltd.) with a 40 mm diameter screw set at 330°C, extruded through a T-die at a temperature of 330°C, and single-layer extrusion lamination molding was carried out on a PET / PE substrate (manufactured by Howa Sangyo Co., Ltd.) consisting of 25 μm of PET, an anchor coating agent, and 15 μm of polyethylene laminated in that order, at a processing speed of 50 m / min, with an air gap length of 110 mm, so that the LDPE thickness was 15 μm, and a sealant film consisting of PET, anchor coating agent, polyethylene, and LDPE laminated in that order was obtained. (9) Adhesive strength The easy-open laminate and sealant film obtained in the examples were cut into a width of 100 mm and a length of 100 mm. Layer A of the easy-open laminate was overlapped with the LDPE surface of the sealant film, and heat-sealed using a heat seal tester TP-701B (manufactured by Tester Sangyo Co., Ltd.) with a setting temperature of 160°C, single-sided heating (sealant film side), air pressure of 0.3 MPa, and a sealing time of 2 seconds using a 10 mm wide, 300 mm long seal bar. The test specimen was manually peeled to separate the interface between layers A and B, and then cut into a 15 mm wide piece. A peel test was performed using a tensile tester Tensilon RTE-1210 (manufactured by Orientec Co., Ltd.) at a tensile speed of 300 mm / min and a peel angle of 180° to measure the adhesive strength (N / 15 mm). (10) Opening strength / opening appearance Layer (A) of the easy-open laminate was placed on the LDPE side of the sealant film, and heat-sealing was performed using a heat seal tester TP-701B (Tester Sangyo Co., Ltd.) with a set temperature of 160°C, single-sided heating (sealant film side), air pressure of 0.3 MPa, and a sealing time of 2 seconds, using a 10 mm wide, 300 mm long seal bar. This test piece was cut into a 15 mm wide piece and subjected to a peel test using a tensile tester Tensilon RTE-1210 (Orientec Co., Ltd.) at a tensile speed of 300 mm / min and a peel angle of 180° to measure the opening strength (N / 15 mm).

[0062] Regarding ease of opening, an opening strength (N / 15mm) of 20 or more was rated as ×, 15 or more but less than 20 was △, 10 or more but less than 15 was 〇, and less than 10 was ◎. An opening strength (N / 15mm) of less than 20 was rated as good.

[0063] Next, regarding the appearance after opening, after measuring the opening strength, the seal part on the easy-open laminate side was visually observed, and if the edge tear where layer A breaks at both the peel start point and the peel end point was good, it was marked with a ◎, if the edge tear at either the peel start point or the peel end point was good, it was marked with a ○, if the edge tear at both the peel start point and the peel end point was poor, it was marked with a △, and if no edge tear occurred but triangular peeling occurred, where interlayer peeling between layers A and B and interfacial peeling between layer A and the LDPE of the sealant film occurred simultaneously, it was marked with an ×. The appearance after opening was considered good if triangular peeling did not occur.

[0064] Example 1 The polyethylene constituting the (A) layer and the (E) layer has an MFR of 3.7 g / 10 min and a density of 923 kg / m 3 30 parts by weight of high-pressure low-density polyethylene (manufactured by Tosoh Corporation, trade name Petrothene 225), MFR 2.4 g / 10 min, density 920 kg / m 3 The mixture was blended with 70 parts by weight of an ethylene-1-butene copolymer (manufactured by Tosoh Corporation, trade name Nipolon-L08C52C), and melt-kneaded in a single-screw extruder (manufactured by Placo Corporation, caliber 40 mm) at a resin temperature of 160°C to obtain a low-density polyethylene composition (MFR PO 2.7g / 10min, density 921kg / m 3 , M.S. PE 32 mN) (A1) is an acid-modified polypropylene constituting layers (B) and (D), and has an MFR of 15.0 g / 10 min at 230°C and a density of 900 kg / m 3 60 parts by weight of polypropylene (trade name Novatec PP MG2T, manufactured by Japan Polypropylene Corporation) (B6), having a MFR of 7.0 g / 10 min at 230 °C and a density of 900 kg / m 3A polypropylene composition (MFR) was prepared by blending 40 parts by weight of a maleic anhydride graft-modified polypropylene (manufactured by SK Geo Centric Japan Co., Ltd., trade name Orevac G 18722) (B4) having an MAH content of 0.30% by weight, and melt-kneading the mixture in a single-screw extruder (manufactured by Placo Co., Ltd., 40 mm diameter) at a resin temperature of 200°C. ADD 11.0g / 10min, density 900kg / m 3 , MAH content 0.12 wt%) (B1) was used as the ethylene-vinyl alcohol copolymer constituting the (C) layer. EVOH is 2.0g / 10min, C2 is 32mol%, D EVOH is 1160kg / m 3 an ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., product name EVAL SP482B) (C1) having a MFR of 4.1 g / 10 min at 210 °C; 2 The paperboard (Nippon Paper Industries Co., Ltd., uncoated cup base paper) was used.

[0065] First, (A1) was fed into a single-screw extruder (manufactured by Sumitomo Heavy Industries Modern Co., Ltd.) with a 40 mm diameter screw set at 260°C, (B1) was fed into a single-screw extruder (manufactured by Sumitomo Heavy Industries Modern Co., Ltd.) with a 40 mm diameter screw set at 260°C, and (C1) was fed into a single-screw extruder (manufactured by Sumitomo Heavy Industries Modern Co., Ltd.) with a 40 mm diameter screw set at 260°C. They were extruded through a T-die at a temperature of 260°C, and the extrusion speed was set to 50 m / min, and the extrusion rotation speed was set so that (A1), (B1), (C1), (B1), and (A1) had thicknesses of 5 μm, 5 μm, 5 μm, 5 μm, and 5 μm, respectively, and migration was evaluated from the resulting molten film. Next, a three-type, five-layer extrusion lamination process was initiated on a 25 μm-thick PET film (manufactured by Toyobo Co., Ltd., product name Toyobo Polyester Film E5100) at a processing speed of 20 m / min and an air gap length of 110 mm, so that (A1), (B1), (C1), (B1), and (A1) had thicknesses of 5 μm, 5 μm, 5 μm, 5 μm, and 5 μm, respectively. The extrusion rotation speed and processing speed were increased in tandem to evaluate the maximum processing speed. Then, just before the three-type, five-layer extrusion lamination process, a current of 31 W·min / m was applied to the adhesive surface with (A1).2 On a paperboard that had been corona-treated at a treatment strength of 1000, (A1), (B1), (C1), (B1), and (A1) were extruded at a processing speed of 50 m / min with an air gap length of 110 mm to form three-type, five-layer extrusion laminates of 5 μm, 5 μm, 5 μm, 5 μm, and 5 μm, respectively. The three-type, five-layer film was then extruded at a rate of 78 mg / m on the surface of the (A1) layer, which was then bonded to the paperboard of the three-type, five-layer film in a molten state immediately after being extruded from the T-die. 2 By subjecting the board to ozone treatment at a treatment intensity of 1000 ppm, a laminate was obtained consisting of paperboard, polyethylene (A1) (layer (E)), acid-modified polypropylene (B1) (layer (D)), ethylene-vinyl alcohol copolymer (C1) (layer (C)), acid-modified polypropylene (B1) (layer (B)), and polyethylene (A1) (layer (A)). The resulting laminate was evaluated for adhesive strength, opening strength, and appearance after opening. The results are shown in Table 1.

[0066] Example 2 As the acid-modified polypropylene constituting the (B) layer and the (D) layer, 80 parts by weight of polypropylene (B6) and 20 parts by weight of maleic anhydride graft-modified polypropylene (B4) were blended and melt-kneaded at a resin temperature of 200°C in a single-screw extruder (manufactured by Placo Co., Ltd., diameter 40 mm) to obtain a polypropylene composition (MFR ADD 13.0g / 10min, density 900kg / m 3 Except for using a cellulose acetate copolymer (B2) containing 0.06% by weight of MAH, migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The resulting laminate was evaluated for adhesive strength, opening strength, and appearance upon opening. The results are shown in Table 1.

[0067] Example 3 As the acid-modified polypropylene constituting the (B) layer and the (D) layer, 20 parts by weight of polypropylene (B6) and 80 parts by weight of maleic anhydride graft-modified polypropylene (B4) were blended and melt-kneaded in a single-screw extruder (manufactured by Placo Co., Ltd., diameter 40 mm) at a resin temperature of 200°C to obtain a polypropylene composition (MFR ADD 8.0g / 10min, density 900kg / m 3Except for using a cellulose acetate copolymer having an MAH content of 0.24% by weight (B3), migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was used to evaluate adhesive strength, opening strength, and appearance after opening. The results are shown in Table 1.

[0068] Example 4 Except for using maleic anhydride-grafted modified polypropylene (B4) as the acid-modified polypropylene constituting layers (B) and (D), migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was used to evaluate adhesive strength, opening strength, and opening appearance. The results are shown in Table 1.

[0069] Example 5 The polyethylene constituting the (A) layer and the (E) layer has an MFR of 3.7 g / 10 min and a density of 923 kg / m 3 30 parts by weight of high-pressure low-density polyethylene (manufactured by Tosoh Corporation, trade name Petrothene 225), MFR 4.0 g / 10 min, density 922 kg / m 3 A low-density polyethylene composition (MFR) was prepared by melt-kneading the mixture at a resin temperature of 160°C in a single-screw extruder (manufactured by Placo Corporation, diameter 40 mm) with 70 parts by weight of high-pressure low-density polyethylene (Petrothene 190, product name, manufactured by Tosoh Corporation). PO 3.9g / 10min, density 922kg / m 3 , M.S. PO Except for using a pressure of 33 mN (A2), migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was used to evaluate adhesive strength, opening strength, and appearance after opening. The results are shown in Table 1.

[0070] Example 6 The polyethylene constituting the (A) layer and the (E) layer has an MFR of 3.7 g / 10 min and a density of 923 kg / m 3 30 parts by weight of high-pressure low-density polyethylene (manufactured by Tosoh Corporation, trade name Petrothene 225), MFR 2.4 g / 10 min, density 920 kg / m 340 parts by weight of ethylene-1-butene copolymer (manufactured by Tosoh Corporation, trade name Nipolon-L08L52C), MFR 3.5 g / 10 min, density 885 kg / m 3 The mixture was blended with 30 parts by weight of an ethylene-1-butene copolymer (manufactured by Tosoh Corporation, trade name Nipolon-L08L55B), and melt-kneaded in a single-screw extruder (manufactured by Placo Corporation, caliber 40 mm) at a resin temperature of 160°C to give a low-density polyethylene composition (MFR PE 3.0g / 10min, density 910kg / m 3 , M.S. PE Except for using a pressure of 31 mN (A3), migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was used to evaluate adhesive strength, opening strength, and opening appearance. The results are shown in Table 1.

[0071] Example 7 Except for the thickness of each of the (A) layer and the (E) layer being 3 μm, migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was used to evaluate adhesive strength, opening strength, and opening appearance. The results are shown in Table 1.

[0072] Example 8 Except for the thickness of each of the (A) layer and the (E) layer being 8 μm, migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was used to evaluate adhesive strength, opening strength, and opening appearance. The results are shown in Table 1.

[0073] Example 9 Except for the thickness of each of the (A) layer and the (E) layer being 15 μm, migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was used to evaluate adhesive strength, opening strength, and opening appearance. The results are shown in Table 1.

[0074] [Table 1]

[0075] Example 10 The polyethylene constituting the (A) layer and the (E) layer is MFR PE is 3.7g / 10min and density is 923kg / m 3 , M.S. PE A laminate was obtained after evaluating migration and maximum processing speed in the same manner as in Example 1, except that a high-pressure low-density polyethylene (Petrothene 225, product name, manufactured by Tosoh Corporation) (A4) with a compressive strength of 105 mN was used. The obtained laminate was used to evaluate adhesive strength, opening strength, appearance after opening, and resealability. The results are shown in Table 2.

[0076] Example 11 The polyethylene constituting the (A) layer and the (E) layer is MFR PE is 13.0g / 10min and density is 919kg / m 3 , M.S. PE A laminate was obtained after evaluating migration and maximum processing speed in the same manner as in Example 1, except that a high-pressure low-density polyethylene (Petrothene 212, product name, manufactured by Tosoh Corporation) (A5) with a compressive strength of 13 mN was used. The obtained laminate was evaluated for adhesive strength, opening strength, and appearance after opening. The results are shown in Table 2.

[0077] Example 12 (C) Layer is made up of ethylene-vinyl alcohol copolymer, MFR EVOH is 1.9g / 10min, C2 is 33mol%, D EVOH is 1180kg / m 3 The migration and maximum processing speed were evaluated in the same manner as in Example 1, except that an ethylene-vinyl alcohol copolymer (manufactured by Mitsubishi Chemical Corporation, trade name G-Soarnol GC3304B) (C2) with a MFR of 4.0 g / 10 min at 210°C was used, and then a laminate was obtained. The resulting laminate was evaluated for adhesive strength, opening strength, and appearance after opening. The results are shown in Table 2.

[0078] Example 13 (C) Layer is made up of ethylene-vinyl alcohol copolymer, MFR EVOHis 1.7g / 10min, C2 is 32mol%, D EVOH is 1190kg / m 3 The migration and maximum processing speed were evaluated in the same manner as in Example 1, except that an ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., product name EVAL F171B) (C3) with a MFR of 4.1 g / 10 min at 210°C was used, and then a laminate was obtained. The obtained laminate was evaluated for adhesive strength, opening strength, and appearance after opening. The results are shown in Table 2.

[0079] Example 14 As the acid-modified polypropylene constituting the (B) layer and the (D) layer, 60 parts by weight of polypropylene (B6) and 40 parts by weight of maleic anhydride graft-modified polypropylene (B4) were blended, and the MFR was 3.7 g / 10 min and the density was 923 kg / m for a total of 100 parts by weight of polypropylene (B6) and maleic anhydride graft-modified polypropylene (B4). 3 A polypropylene composition (MFR) was prepared by blending 30 parts by weight of a high-pressure low-density polyethylene (trade name: Petrothene 225, manufactured by Tosoh Corporation) and melt-kneading it at a resin temperature of 200°C in a single-screw extruder (manufactured by Placo Corporation, diameter: 40 mm). ADD 10.0g / 10min, density 900kg / m 3 Except for using a 0.09% by weight MAH copolymer (B5), migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The resulting laminate was evaluated for adhesive strength, opening strength, and appearance upon opening. The results are shown in Table 2.

[0080] Comparative Example 1 Except for using polypropylene (B6) as the acid-modified polypropylene constituting layers (B) and (D), migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was evaluated for adhesive strength, unsealing strength, and unsealed appearance. The results are shown in Table 2. The unsealed appearance was poor.

[0081] Comparative Example 2 The acid-modified polypropylene constituting the (B) layer and the (D) layer has an MFR of 21 g / 10 min at 230 °C and a density of 900 kg / m 3 60 parts by weight of polypropylene (trade name Novatec PP MA1B, manufactured by Japan Polypropylene Corporation) having a MFR of 35.0 g / 10 min at 230 °C and a density of 900 kg / m 3 A polypropylene composition (MFR) was prepared by blending 40 parts by weight of a maleic anhydride graft-modified polypropylene (manufactured by SK Geo Centric Japan Co., Ltd., trade name Orevac G 18751) having an MAH content of 0.30% by weight, and melt-kneading the mixture in a single-screw extruder (manufactured by Placo Co., Ltd., 40 mm diameter) at a resin temperature of 200°C. ADD 26.0g / 10min, density 900kg / m 3 Except for using a cellulose acetate copolymer (B7) containing 0.12% by weight of MAH, migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The resulting laminate was evaluated for adhesive strength, opening strength, and appearance upon opening. The results are shown in Table 2. The film formation was unstable, and a sample could not be prepared.

[0082] Comparative Example 3 The polyethylene constituting the (A) layer and the (E) layer has an MFR of 3.7 g / 10 min and a density of 923 kg / m 3 30 parts by weight of high-pressure low-density polyethylene (manufactured by Tosoh Corporation, trade name Petrothene 225), MFR 3.5 g / 10 min, density 885 kg / m 3 The mixture was blended with 70 parts by weight of an ethylene-1-butene copolymer (manufactured by Tosoh Corporation, trade name Nipolon-L08L55B), and melt-kneaded in a single-screw extruder (manufactured by Placo Corporation, caliber 40 mm) at a resin temperature of 160°C to give a low-density polyethylene composition (MFR PE 3.6g / 10min, density 896kg / m 3 , M.S. PE Except for using a pressure of 30 mN (A6), migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was evaluated for adhesive strength, opening strength, and appearance after opening. The adhesive strength was high, but the ease of opening and appearance after opening were poor.

[0083] Comparative Example 4 Except for the thickness of Layer (A) and Layer (E) being 20 μm, migration and maximum processing speed were evaluated in the same manner as in Example 1, and then a laminate was obtained. The obtained laminate was evaluated for adhesive strength, opening strength, and opening appearance. The results are shown in Table 2. The opening appearance was poor.

[0084] [Table 2]

[0085] The ethylene content C2 (mol%) and density D of the ethylene-vinyl alcohol copolymer (c) described in the examples EVOH (kg / m 3 ) is shown in Figure 1. As shown in this figure, Example 12, which satisfies formula (1) described in the specification, is superior in appearance upon opening and sealability to Example 13, which does not satisfy formula (1). Furthermore, Example 1, which satisfies formula (2), is superior in sealability.

[0086] The slopes of formulas (1) and (2) are for standard and semi-standard grades C2 and D of Kuraray's ethylene-vinyl alcohol copolymer. EVOH Specifically, C2 was 27 mol%, D EVOH is 1210 kg / m 3 Ethylene-vinyl alcohol copolymer (Kuraray Co., Ltd., product name EVAL L171B), C2 is 32 mol%, D EVOH is 1190kg / m 3 Ethylene-vinyl alcohol copolymer (C3), C2 is 35 mol%, D EVOH is 1180kg / m 3 Ethylene-vinyl alcohol copolymer (Kuraray Co., Ltd., product name EVAL C109B), C2 is 38 mol%, D EVOH is 1170kg / m 3 Ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., trade name EVAL H171B), C2 is 44 mol%, D EVOH is 1140kg / m 3Ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., trade name EVAL E105B), C2 is 48 mol%, D EVOH is 1120kg / m 3 C2 and D of ethylene-vinyl alcohol copolymer (product name EVAL G156B, manufactured by Kuraray Co., Ltd.) EVOH was calculated from the correlation. [Industrial Applicability]

[0087] The easy-open property of the present invention can be used for laminates that require adhesive properties, gas barrier properties, and easy-open properties, and can be particularly suitably used for laminates used as packaging materials for foods, beverages, pharmaceuticals, etc.

Claims

1. An easily openable laminate comprising at least a base layer and a (C) layer / (B) layer / (A) layer adjacent to each other from the base layer side, wherein the (A) layer is composed of polyethylene (a), the (B) layer is composed of acid-modified polypropylene (b) that satisfies (i) to (ii), and the (C) layer is composed of an ethylene-vinyl alcohol copolymer (c) that satisfies (iii), and the laminate satisfies (iv) to (v). (i) Melt mass flow rate (MFR) at 230°C measured according to JIS 7210 (1999) ＡＤＤ ) is 2.0 g / 10 min or more and 20.0 g / 10 min or less (ii) an acid content of 0.02% by weight or more and 1.0% by weight or less; (iii) Ethylene content C ２ is 50 mol% or less (iv) The thickness of the (A) layer is 1 μm or more and 15 μm or less. (v) The adhesive strength between the (A) layer and the (B) layer is 0.1 N / 15 mm or more and 3.0 N / 15 mm or less.

2. The easy-open laminate according to claim 1, wherein the acid content of the acid-modified polypropylene (b) is 0.05% by weight or more and 0.40% by weight or less.

3. The easy-open laminate according to claim 1 or 2, wherein the acid-modified polypropylene (b) is a maleic anhydride-grafted modified polypropylene.

4. The easy-open laminate according to any one of claims 1 to 3, wherein the polyethylene (a) satisfies (vi) to (viii). (vi) Melt mass flow rate (MFR) measured according to JIS K6922-1 (1997) ＰＥ ) is 1.0 g / 10 min or more and 10.0 g / 10 min or less (vii) Melt tension (MS) measured at a temperature of 190°C and a take-up speed of 10 m / min ＰＥ ) is 3mN or more and 50mN or less (viii) MFR ＰＥ (g / 10 min) and MS ＰＥ (mN) product MFR ＰＥ ×MS ＰＥ is between 70 and 250

5. 5. The easy-open laminate according to claim 1, wherein the polyethylene (a) comprises an ethylene-α-olefin copolymer and / or a high-pressure low-density polyethylene.

6. C of ethylene vinyl alcohol copolymer (c) ２ (mol%) and density D at 20 ° C. measured according to ISO 1183-3 ＥＶＯＨ (kg / m ３ 6. The easy-open laminate according to claim 1, wherein the following formula (1) is satisfied: D ＥＶＯＨ <-4.265×C ２ +1325 (1)

7. 7. The easy-open laminate according to claim 1, further comprising an (E) layer / a (D) layer between the base material layer and the (C) layer, the (E) layer being adjacent to the base material layer, the (D) layer being adjacent to the (C) layer, the (E) layer being polyethylene (e), and the (D) layer being acid-modified polypropylene (d).

8. 8. The method for producing an easy-open laminate according to claim 1, wherein the (C) layer / (B) layer / (A) layer or the (E) layer / (D) layer / (C) layer / (B) layer / (A) layer are simultaneously formed by co-extrusion lamination molding.

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