Films and laminates

Abstract

To provide a film having sufficient performance in preventing delamination between polyolefin resin layers and inorganic layers, and a laminate containing said film. [Solution] A film having an inorganic layer, a skin layer, and a base layer, wherein the inorganic layer, the skin layer, and the base layer are laminated in that order, the skin layer contains an ethylene copolymer (A) and a propylene copolymer (B), the ethylene copolymer (A) is one or more selected from the group consisting of unmodified ethylene-α-olefin copolymer (A1) and acid-modified ethylene-α-olefin copolymer (A2), and the ethylene copolymer (A) has a melt flow rate (MFR) measured at 230°C and a 2.16 kg load in accordance with ASTM D1238. 2.16 The amount is in the range of 15 to 50 g / 10 min, and the substrate layer is a film containing the propylene polymer (B).

Description

[Technical Field]

[0001] This invention relates to films and laminates. [Background technology]

[0002] Conventionally, flexible plastic packaging bags in various forms have been developed and put into practical use for filling and packaging various foods and beverages, cosmetics, pharmaceuticals, general merchandise, and other items. As the laminated material (laminated body) that constitutes the above-mentioned flexible packaging bag, various gas barrier materials that have the property of blocking the permeation of oxygen gas, water vapor, etc. have been used from the viewpoint of protecting the quality of the contents and extending the shelf life.

[0003] Furthermore, there is a problem in that sunlight or fluorescence from sources such as the sun or fluorescent lights can pass through, affecting the contents and causing photodegradation such as decomposition, alteration, or discoloration. For this reason, various light-shielding materials have been studied and proposed. As the most common materials used to impart the above-mentioned gas barrier or light-shielding functions, laminated films of aluminum foil and resin, or aluminum-deposited PET films, have been used.

[0004] On the other hand, from the perspective of reducing environmental impact, there is a demand for packaging materials with high recyclability. For recycling purposes, it is preferable that the plastic material is a so-called monomaterial, composed of a single type of polymer. Therefore, base films, sealant film layers, and laminates mainly composed of ethylene-based polymers or propylene-based polymers are preferred. Therefore, as a material that provides the above-mentioned gas barrier or light-shielding function while possessing high recyclability, aluminum-deposited unstretched or stretched films have been used instead of aluminum-deposited PET films.

[0005] Polyolefin resins, including polypropylene, are inexpensive, have excellent moldability, and possess superior oil resistance and sealant properties, making them suitable for use as packaging materials as described above. However, polyolefin resins generally have poor adhesion to dissimilar materials. For example, when a laminate is formed with an inorganic layer such as vapor-deposited aluminum, the vapor deposition strength between the polyolefin resin layer and the inorganic layer is inferior, which can lead to delamination depending on the usage environment or application.

[0006] Various methods have been proposed to prevent such delamination, and some of them have been put into practical use. For example, methods have been proposed to improve adhesion to metals, such as grafting maleic anhydride onto polypropylene in a specific way, or to add soft rubber to polypropylene to impart flexibility to its inherent rigidity (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2010 / 120295 [Patent Document 2] International Publication No. 2013 / 119316 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the deposition strength in the methods described in Patent Documents 1 and 2 was insufficient, and further improvements were needed.

[0009] The object of the present invention is to solve the above-mentioned problems, and the object of the present invention is to provide a film having sufficient performance in preventing delamination between polyolefin resin layers and inorganic layers, and a laminate containing said film. [Means for solving the problem]

[0010] As a result of intensive studies to solve the above problems, the inventors have found that the above problems can be solved by providing the following film and a laminate composed of the film, and have completed the present invention. That is, the present invention relates to the following [1] to [7].

[0011] [1] A film having an inorganic layer, a skin layer, and a base material layer, which is laminated in the order of the inorganic layer, the skin layer, and the base material layer, where the skin layer contains an ethylene-based copolymer (A) and a propylene-based polymer (B), the ethylene-based copolymer (A) is one or more selected from the group consisting of an unmodified ethylene·α-olefin copolymer (A1) and an acid-modified ethylene·α-olefin copolymer (A2), the ethylene-based copolymer (A) has a melt flow rate (MFR 2.16 ) measured under the conditions of 230 °C and a load of 2.16 kg in accordance with ASTM D1238 in the range of 15 to 50 g / 10 minutes, and the base material layer is a film containing the propylene-based polymer (B).

[0012] [2] The film according to [1], on which the inorganic layer is deposited.

[0013] [3] The film according to [1] or [2], wherein at least one of the skin layer and the base material layer is an unstretched layer.

[0014] [4] The film according to any one of [1] to [3], wherein the skin layer contains 1 to 40 parts by mass of the ethylene-based copolymer (A) and 60 to 99 parts by mass of the propylene-based polymer (B) (however, the total of the ethylene-based copolymer (A) and the propylene-based polymer (B) is 100 parts by mass).)

[0015] [5] The density of the ethylene copolymer (A) measured at 25°C in accordance with ASTM D1505 was 870-905 kg / m³. 3 A film described in any of [1] to [4] within the range of [1].

[0016] [6] A laminate comprising a stretched film and a film described in any of [1] to [5].

[0017] [7] A laminate comprising a stretched film, a film described in any of [1] to [5], and a sealant film layer, laminated in this order. [Effects of the Invention]

[0018] The present invention improves the vapor deposition strength of the skin layer and inorganic layer (e.g., metal vapor deposition surface) of a laminate using the film by using a composition containing a specific ethylene-α-olefin and propylene copolymer in a predetermined proportion in the skin layer constituting the film. [Modes for carrying out the invention]

[0019] [film] The film of the present invention (hereinafter also referred to as "this film") has an inorganic layer, a skin layer, and a substrate layer. The inorganic layer, skin layer, and substrate layer are laminated in the order of inorganic layer, skin layer, and substrate layer. The inorganic layer, skin layer, and substrate layer may each consist of one layer or multiple layers. The following describes in detail each layer that makes up this film.

[0020] ≪Base material layer≫ The base layer is preferably polypropylene or a resin composition containing polypropylene. Examples of polypropylene include propylene homopolymers and copolymers with propylene as the main monomer (propylene-based copolymers). The polypropylene may be used alone or in combination of two or more types.

[0021] When the polypropylene is a propylene copolymer, it may be a random copolymer or a block copolymer. Examples of comonomers copolymerized with propylene include α-olefins having 2 or 4 to 20 carbon atoms, and diene compounds.

[0022] The polypropylene contains 85 to 100 mol%, more preferably 90 to 99.5 mol%, of structural units derived from propylene, and preferably 0 to 15 mol%, more preferably 0.5 to 10 mol%, of structural units derived from comonomers (provided that the total of structural units derived from propylene and structural units derived from comonomers is 100 mol%). The combination of the lower and upper limits for structural units derived from propylene and structural units derived from comonomers is arbitrary.

[0023] Examples of α-olefins having 2 or 4 to 20 carbon atoms include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and 1-tetradecene. The α-olefins may be used individually or in combination of two or more types.

[0024] The aforementioned polypropylene melt flow rate (MFR 2.16 The melt flow rate (MFR) (according to ASTM D1238, 230°C, 2.16 kg load) is preferably 0.1 to 15 g / 10 min, more preferably 0.3 to 12 g / 10 min, and even more preferably 0.5 to 9 g / 10 min. The combination of the lower and upper limits of the structural units of the melt flow rate of the polypropylene is arbitrary. 2.16It is preferable that the range is within the above range, as this allows for molding at a high molding speed using existing molding machines and improves molding stability.

[0025] The polypropylene has a melting point (Tm) measured by differential scanning calorimetry (DSC) that is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, particularly preferably 125°C or higher, preferably 170°C or lower, and more preferably 168°C or lower.

[0026] Tm is the melting point (the temperature at the peak of the melting peak) observed when a DSC measuring device is used to hold the sample at 200°C for 10 minutes, then cool it to -20°C at a rate of 10°C / min, hold it at -20°C for 1 minute, and then heat it again to 200°C at a rate of 10°C / min.

[0027] Examples of the aforementioned polypropylene include propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer, propylene-1-butene-ethylene random copolymer, propylene-1-hexene random copolymer, propylene-3-methyl-1-butene random copolymer, and propylene-4-methyl-1-pentene random copolymer.

[0028] The aforementioned polypropylene can be produced by polymerizing monomers using known polymerization methods such as gas-phase, bulk, or slurry methods in the presence of known catalysts such as Ziegler-Natta catalysts and metallocene catalysts.

[0029] The polypropylene contained in the base layer is preferably the propylene polymer (B) contained in the skin layer, as described later. When the polypropylene is the propylene polymer (B), the type of the propylene polymer (B) may be the same as or different from the propylene polymer (B) contained in the skin layer.

[0030] The raw materials for the polypropylene, such as propylene and α-olefins having 2 or 4 to 20 carbon atoms, may be, for example, monomers derived from fossil fuels, monomers derived from biomass, and / or monomers derived from chemical recycling. These monomers may be used individually or in combination of two or more.

[0031] The base layer may contain any additives, such as antioxidants, heat stabilizers, weather stabilizers, anti-fogging agents, anti-blocking agents, slip agents, lubricants, crystal nucleating agents, antistatic agents, flame retardants, pigments, dyes, fillers, etc., as long as they do not impair the effects of the present invention.

[0032] ≪Skin Layer≫ The skin layer is a resin composition containing an ethylene copolymer (A) and a propylene polymer (B). The ethylene copolymer (A) and the propylene polymer (B) may be used individually or in combination of two or more.

[0033] <Ethylene copolymer (A)> The ethylene copolymer (A) is a copolymer containing more than 50 mol% and up to 99 mol% of ethylene-derived structural units, and is preferably one or more selected from the group consisting of unmodified ethylene-α-olefin copolymer (A1) and acid-modified ethylene-α-olefin copolymer (A2).

[0034] Examples of unmodified ethylene-α-olefin copolymers (A1) include ethylene-α-olefin random copolymers. Unmodified ethylene-α-olefin copolymers (A1) may be used alone or in combination of two or more types.

[0035] The α-olefin has 3 to 20 carbon atoms, and examples include propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-hexadecene, 1-octadecene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, and 4,4-dimethyl-1-hexene, preferably propylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene, more preferably propylene, 1-butene, 1-octene, and even more preferably 1-butene. These α-olefins may be used individually or in combination of two or more. Furthermore, the unmodified ethylene-α-olefin copolymer (A1) may be further polymerized with small amounts of comonomers other than ethylene and α-olefin, as needed.

[0036] The raw materials for the unmodified ethylene-α-olefin copolymer (A1), namely ethylene and α-olefins having 3 to 20 carbon atoms, may be, for example, monomers derived from fossil fuels, monomers derived from biomass, and / or monomers derived from chemical recycling. These monomers may be used individually or in combination of two or more.

[0037] In the unmodified ethylene-α-olefin copolymer (A1), when the total amount of ethylene and α-olefins having 3 to 20 carbon atoms is set to 100 mol%, the lower limit of ethylene-derived constituent units is preferably 70 mol%, more preferably 75 mol%, and even more preferably 80 mol%, and the upper limit is preferably 99 mol%, more preferably 96 mol%, even more preferably 94 mol%, and particularly preferably 93 mol%. Note that the combination of the lower and upper limits of ethylene-derived constituent units is arbitrary. It is preferable that the ethylene-derived structural units of the unmodified ethylene-α-olefin copolymer (A1) fall within the aforementioned range, as this allows for the creation of a film with excellent blocking resistance, slip resistance, and metal deposition strength.

[0038] Furthermore, the lower limit of the constituent units derived from α-olefins having 3 to 20 carbon atoms is preferably 1 mol%, more preferably 4 mol%, even more preferably 6 mol%, and particularly preferably 7 mol%, while the upper limit is preferably 30 mol%, more preferably 25 mol%, and even more preferably 20 mol%.

[0039] Acid-modified ethylene-α-olefin copolymer (A2) is a copolymer obtained by graft-modifying unmodified ethylene-α-olefin copolymer (A1) with an unsaturated carboxylic acid and its derivatives.

[0040] Examples of the unsaturated carboxylic acid and its derivatives include unsaturated carboxylic acids having 3 to 10 carbon atoms, preferably 3 to 8 carbon atoms, and derivatives of the unsaturated carboxylic acid.

[0041] Examples of the aforementioned unsaturated carboxylic acids include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, and nadic acid. TM (Endosys-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid) is one example.

[0042] Examples of derivatives of the unsaturated carboxylic acid include acid halide compounds, ester compounds, imide compounds, acid anhydrides, and ester compounds of the unsaturated carboxylic acid. Specifically, examples include malenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate.

[0043] As the aforementioned unsaturated carboxylic acid and its derivatives, unsaturated dicarboxylic acids or their acid anhydrides are preferred, particularly maleic acid and nadic acid. TM Alternatively, these acid anhydrides are preferred.

[0044] The unsaturated carboxylic acid and its derivatives, which are one of the raw materials of the acid-modified ethylene·α-olefin copolymer (A2), may be, for example, monomers derived from fossil fuels, monomers derived from biomass, and / or monomers derived from chemical recycling. These monomers may be used alone or in combination of two or more kinds.

[0045] The graft modification amount (graft amount) of the acid-modified ethylene·α-olefin copolymer (A2) is preferably in the range of 0.1 to 2.0% by mass, more preferably 0.3 to 1.7% by mass, still more preferably 0.3 to 1.5% by mass, and particularly preferably 0.4 to 1.2% by mass, based on 100% by mass of the acid-modified ethylene·α-olefin copolymer (A2). The combination of the lower limit value and the upper limit value of the graft modification amount is arbitrary. When the graft modification amount is within the above range, a film excellent in metal deposition strength can be obtained.

[0046] The melt flow rate (MFR 2.16 ) of the ethylene-based copolymer (A) measured under the conditions of 230°C and a load of 2.16 kg in accordance with ASTM D1238 is 15 to 50 g / 10 min, preferably 17 to 45 g / 10 min, and more preferably 20 to 40 g / 10 min. The combination of the lower limit value and the upper limit value of the melt flow rate is arbitrary. When the MFR 2.16 of the ethylene-based copolymer (A) is within the above range, a film excellent in metal deposition strength can be obtained.

[0047] [[ID=十六]]The density of the ethylene-based copolymer (A) measured under the condition of 25°C in accordance with ASTM D15<>05 is preferably 870 to 905 kg / m 3 , more preferably 872 to 903 kg / m 3 , still more preferably 875 to 900 kg / m 3 . The combination of the lower limit value and the upper limit value of the density is arbitrary. When the density of the ethylene-based copolymer (A) is within the above range, it is preferable because a film excellent in blocking resistance, slipperiness, and metal deposition strength can be obtained.

[0048] The ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the ethylene copolymer (A), determined by gel permeation chromatography (GPC), is preferably 4.0 or less, more preferably 3.5 or less, even more preferably 3.0 or less, and particularly preferably 2.5 or less. The lower limit of Mw / Mn is not particularly limited, but is preferably 1.5.

[0049] There are no particular restrictions on the method of producing the ethylene copolymer (A), however, for example, the unmodified ethylene-α-olefin copolymer (A1) can be suitably produced using a metallocene catalyst.

[0050] <Propylene-based polymer (B)> Propylene-based polymers (B) are polymers containing more than 50 mol% and up to 100 mol% of propylene-derived structural units. Examples include propylene homopolymers; and copolymers (propylene-α-olefin copolymers) in which propylene is the main monomer and propylene is coupled with at least one α-olefin having 2 or 4 or more carbon atoms, preferably 2 or 4 to 20 carbon atoms.

[0051] Examples of α-olefins having 2 or 4 to 20 carbon atoms that copolymerize with propylene include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. These α-olefins may be used individually or in combination of two or more.

[0052] Examples of the propylene-α-olefin copolymer include propylene-ethylene copolymer, propylene-1-butene copolymer, and propylene-ethylene-1-butene copolymer.

[0053] The raw materials for the propylene polymer (B) are propylene and α-olefins having 2 or 4 to 20 carbon atoms. These may be monomers derived from fossil fuels, biomass, and / or chemical recycling. These monomers may be used individually or in combination of two or more.

[0054] In the propylene polymer (B), when the total amount of propylene and α-olefins having 2 or 4 to 20 carbon atoms is set to 100 mol%, the lower limit of the constituent units derived from propylene is preferably 51 mol%, more preferably 65 mol%, and the upper limit is preferably 90 mol%, more preferably 80 mol%. The combination of the lower and upper limits of the constituent units derived from propylene is arbitrary. It is preferable that the propylene-derived structural units of the propylene polymer (B) fall within the aforementioned range, as this allows for the creation of a film with excellent blocking resistance, slip resistance, and metal deposition strength. In the propylene polymer (B), the proportion of propylene-derived constituent units exceeds 50 mol%, which distinguishes it from the ethylene polymer (A).

[0055] Furthermore, the lower limit of the α-olefin-derived constituent units of α-olefins having 2 or 4 to 20 carbon atoms is preferably 10 mol%, more preferably 20 mol%, and the upper limit is preferably 49 mol%, more preferably 35 mol%.

[0056] Melt flow rate (MFR) of propylene polymer (B) 2.16 The melt flow rate (MFR) (ASTM D1238, 230°C, 2.16 kg load) is preferably 0.1 to 15 g / 10 min, more preferably 0.3 to 12 g / 10 min, and even more preferably 0.5 to 9 g / 10 min. The combination of the lower and upper limits of the melt flow rate is arbitrary. 2.16 It is preferable that the range is within the above range, as this allows for molding at a high molding speed using existing molding machines and improves molding stability.

[0057] The melting point (Tm) observed by differential scanning calorimetry (DSC) of the propylene polymer (B) is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, particularly preferably 125°C or higher, preferably 170°C or lower, and more preferably 168°C or lower. The combination of the lower and upper limits of the melting point is arbitrary. The method for measuring Tm is the same as the method for measuring DSC of the polypropylene substrate layer.

[0058] Propylene polymers (B) can be produced by polymerizing monomers using known polymerization methods such as gas-phase, bulk, or slurry methods in the presence of known catalysts such as Ziegler-Natta catalysts and metallocene catalysts.

[0059] <Resin composition constituting the skin layer> The resin composition constituting the skin layer preferably comprises 1 to 40 parts by mass of an ethylene copolymer (A) and 60 to 99 parts by mass of a propylene polymer (B), and more preferably comprises 2 to 30% by mass of an ethylene copolymer (A) and 70 to 98% by mass of a propylene polymer (B) (provided that the total of the ethylene copolymer (A) and the propylene polymer (B) is 100 parts by mass). When the content of ethylene copolymer (A) and propylene polymer (B) is within the aforementioned range, a film with excellent vapor deposition strength, blocking resistance, and slip resistance can be obtained.

[0060] The skin layer may contain any additives, such as antioxidants, heat stabilizers, weather stabilizers, anti-fogging agents, anti-blocking agents, slip agents, lubricants, nucleating agents, antistatic agents, flame retardants, pigments, dyes, fillers, etc., as long as they do not impair the effects of the present invention.

[0061] ≪Inorganic layer≫ Examples of inorganic materials constituting the inorganic layer include metals, metal oxides, metal nitrides, metal fluorides, and metal oxynitrides that can form a thin film with barrier properties. The inorganic material may be used alone or in combination of two or more types.

[0062] Specifically, examples include one inorganic substance selected from elements, oxides, nitrides, fluorides, or oxynitrides of Group 2A elements of the periodic table such as beryllium, magnesium, calcium, strontium, and barium; transition elements of the periodic table such as titanium, zirconium, ruthenium, hafnium, and tantalum; Group 2B elements of the periodic table such as zinc; Group 3A elements of the periodic table such as aluminum, gallium, indium, and thallium; Group 4A elements of the periodic table such as silicon, germanium, and tin; and Group 6A elements of the periodic table such as selenium and tellurium. In this embodiment, the group names of the inorganic layer in the periodic table are shown using the old CAS formula.

[0063] Furthermore, among the inorganic materials mentioned above, one or more inorganic materials selected from the group consisting of silicon dioxide, silicon monoxide, silicon dioxide, silicon dioxide, aluminum oxide, and aluminum are preferred because they offer an excellent balance of barrier properties, cost, and other factors.

[0064] The inorganic layer may consist of a single inorganic layer or multiple inorganic layers. Furthermore, if the inorganic layer consists of multiple inorganic layers, they may be composed of inorganic layers of the same type or different types.

[0065] ≪How this film was made≫ The present film is preferably an unoriented film, and more specifically, it is preferable that at least one of the skin layer and the base layer is an unoriented layer (a layer that has not undergone stretching treatment). The present film is obtained by laminating an inorganic layer, a skin layer, and a base layer. For example, it can be produced by using two extruders connected to T-dies, supplying the resin composition forming the skin layer and the resin composition forming the base layer to each extruder, co-extruding them, and forming an inorganic layer on the surface of the skin layer of the resulting film.

[0066] The thickness of the skin layer is typically 3 to 30 μm, preferably 5 to 25 μm, and the thickness of the substrate layer is typically 10 to 100 μm, preferably 20 to 75 μm. The combination of the lower and upper limits for the thickness of the skin layer and substrate layer is arbitrary. If there are multiple skin layers and substrate layers, it is preferable that the thickness of each skin layer falls within the above range.

[0067] The thickness of the inorganic layer is preferably 1 nm or more, more preferably 4 nm or more, preferably 1000 nm or less, more preferably 500 nm or less, even more preferably 300 nm or less, and particularly preferably 100 nm or less, from the viewpoint of balancing improved barrier properties and improved handling. The combination of the lower and upper limits for the thickness of the inorganic layer is arbitrary. Here, the thickness of the inorganic layer can be determined, for example, by observation images obtained using a transmission electron microscope or a scanning electron microscope.

[0068] The method for forming the inorganic layer is not particularly limited and known methods can be used. For example, the inorganic layer can be formed on the skin layer by vacuum deposition, ion plating, sputtering, chemical vapor deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma CVD, sol-gel method, etc. Among these, film formation under reduced pressure, such as by sputtering, ion plating, chemical vapor deposition, physical vapor deposition, and plasma CVD, is desirable.

[0069] This is expected to improve the surface smoothness of the inorganic layer and reduce pores by allowing chemically active molecular species containing silicon, such as silicon nitride and silicon oxidized nitride, to react rapidly. For these bonding reactions to occur rapidly, it is desirable that the inorganic atoms or compounds involved are chemically active molecular or atomic species. Furthermore, from the viewpoint of improving the balance between the barrier properties and productivity of the gas barrier laminate, the inorganic layer is preferably a vapor-deposited film. The overall thickness of this film is preferably 13 to 130 μm, more preferably 25 to 100 μm. The combination of the lower and upper limits for the overall film thickness is arbitrary.

[0070] ≪Laminated structure≫ The laminate of the present invention comprises the present film and a stretched film. The present film and the stretched film may be used individually or in combination of two or more types. The laminate can be configured such as a laminate of the present film and a stretched film, for example, a structure such as present film / stretched film or present film / stretched film / stretched film, but is not limited to these. For example, when multiple present films are used, they may be used individually or in combination of two or more types. An adhesive layer may also be optionally provided between the present film and the stretched film. In the laminate of the present invention, it is preferable that the substrate layer contained in the film is adjacent to the stretched film or in contact with it via an adhesive layer.

[0071] <Stretched film> The film constituting the stretched film can be any conventionally known film depending on the application. Specific examples include films made of polyester such as polyethylene terephthalate and polyethylene naphthalate, polyethylene carbonate films, polyamide films made of nylon 6, nylon 66, etc., ethylene-vinyl alcohol copolymer films, polyvinylidene chloride films, and films made of polyolefins such as polypropylene. Furthermore, the above films may be films coated with inorganic substances such as aluminum, zinc, or silica, or their oxides.

[0072] Among these, preferred is at least one selected from the group consisting of stretched PET film obtained by stretching a film formed from polyethylene terephthalate (PET), and stretched PP film obtained by stretching a film formed from polypropylene (PP).

[0073] As for the stretching method, known methods for manufacturing stretched films can be used. Specifically, these include roll stretching, tenter stretching, and tubular stretching. The stretching ratio is usually 1.5 to 20 times, preferably 2 to 15 times.

[0074] The thickness of the stretched film is typically 10 to 50 μm, preferably 15 to 45 μm. If there are multiple stretched films, it is preferable that the thickness of each stretched film be within the above range. The combination of the lower and upper limits for the thickness of the stretched film is arbitrary. Furthermore, the overall thickness of the laminate according to the present invention is typically 30 to 150 μm, preferably 40 to 115 μm. The combination of the lower and upper limits for the overall thickness of the laminate is arbitrary.

[0075] The laminate of the present invention may further have a sealant film layer on the main film side. That is, the laminate of the above embodiment is laminated in the order of stretched film, main film, and sealant film layer. The sealant film layer may be stretched or unstretched.

[0076] <Sealant film layer> The film constituting the sealant film layer can be one of conventionally known types, depending on the application. Specifically, this includes a film made of a resin composition containing a 1-butene copolymer (C) and a propylene polymer (B).

[0077] Examples of the 1-butene copolymer (C) include a copolymer of 1-butene and an α-olefin having 2 to 3 or 5 to 20 carbon atoms (1-butene·α-olefin copolymer). The 1-butene copolymer (C) may be a single copolymer or a copolymer of two or more types.

[0078] Examples of α-olefins having 2 to 3 or 5 to 20 carbon atoms include ethylene, propylene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc. Among these α-olefins, ethylene, propylene, and 1-pentene are preferred, ethylene and propylene are more preferred, and propylene is even more preferred. The α-olefin may be used alone or in combination of two or more.

[0079] The 1-butene copolymer (C) contains 50 to 99 mol%, preferably 60 to 97 mol%, and more preferably 70 to 95 mol%, of 1-butene-derived structural units, and 1 to 50 mol%, preferably 3 to 40 mol%, and more preferably 5 to 30 mol%, of α-olefin-derived structural units having 2 to 3 or 5 to 20 carbon atoms (provided that the total of 1-butene-derived structural units and α-olefin-derived structural units is 100 mol%). By setting the content of 1-butene-derived structural units and α-olefin-derived structural units within the aforementioned range, the material exhibits excellent handling properties and facilitates heat sealing even at relatively low temperatures.

[0080] Furthermore, the 1-butene copolymer (C) has a melting point of less than 120°C as measured by DSC, or no melting point is observed by DSC, preferably with a melting point of 50°C to 115°C, more preferably 60°C to 110°C, and even more preferably 65°C to 110°C. By using a 1-butene copolymer (C) with a melting point within the above range, heat sealing is easy and good surface properties are obtained even at relatively low temperatures, and it tends to have excellent blocking resistance.

[0081] The melting point (Tm) of the 1-butene copolymer (C) is determined using a differential scanning calorimeter (e.g., Seiko Instruments DSC). Approximately 10 mg of the sample is placed in an aluminum pan for measurement, heated to 200°C at 100°C / min for 5 minutes, then cooled to -100°C at 10°C / min, and then heated to 200°C at 10°C / min. The temperature at the peak of the crystal melting peak is defined as the melting point (Tm) of the polymer. If multiple peaks are detected, the peak detected at the highest temperature is used.

[0082] Furthermore, the melt flow rate (MFR) of 1-butene copolymer (C) is measured in accordance with ASTM D1238 under conditions of 230°C and a 2.16 kg load. 2.16 The MFR is preferably 1 to 15 g / 10 min, more preferably 2 to 13 g / 10 min, and even more preferably 3 to 11 g / 10 min. 2.16 By using a 1-butene copolymer (C) within the aforementioned range, the fluidity of the resin composition constituting the sealant film layer is improved, making it easier to mold even relatively large sheets.

[0083] 1-butene copolymer (C) can be produced by polymerizing monomers using known polymerization methods such as gas-phase, bulk, or slurry methods in the presence of known catalysts such as Ziegler-Natta catalysts and metallocene catalysts.

[0084] The resin composition constituting the sealant film layer preferably contains 10 to 70 parts by mass of a 1-butene copolymer (C) and 30 to 90 parts by mass of a propylene polymer (B), and more preferably contains 10 to 60% by mass of a 1-butene copolymer (C) and 40 to 90% by mass of a propylene polymer (B) (provided that the total of 1-butene copolymer (C) and propylene polymer (B) is 100 parts by mass). When the content of 1-butene copolymer (C) and propylene polymer (B) is within the above range, a film can be obtained that exhibits excellent low-temperature sealing properties of the laminate and has sufficient heat seal strength.

[0085] The resin composition constituting the sealant film layer may contain any additives, such as antioxidants, heat stabilizers, weather stabilizers, antifogging agents, antiblocking agents, slip agents, lubricants, nucleating agents, antistatic agents, flame retardants, pigments, dyes, fillers, etc., to the extent that they do not impair the effects of the present invention. The thickness of the sealant film layer is typically 10 to 50 μm, preferably 15 to 45 μm, and if there are multiple sealant film layers, it is preferable that the thickness of each sealant film layer be within the above range.

[0086] The 1-butene copolymer (C) and propylene polymer (B) used in the resin composition constituting the sealant film layer may each contain at least one biomass-derived monomer (biomass-derived propylene, biomass-derived ethylene, or biomass-derived α-olefin with 4 to 20 carbon atoms). The monomers of the same type constituting the polymer may consist only of biomass-derived monomers, only of fossil fuel-derived monomers, or may contain both biomass-derived monomers and fossil fuel-derived monomers.

[0087] The laminate of the present invention may be manufactured by laminating the present film and a stretched film by dry lamination, non-solvent lamination, sand lamination, etc., or by laminating the present film and a stretched film by melt extrusion lamination. Among these, the method of lamination by dry lamination or melt extrusion lamination is preferred.

[0088] Furthermore, the laminate of the present invention may further have at least one functional layer selected from a printing layer, a barrier layer, and an embossing layer in order to impart specific functions to each layer in the film and to the stretched film. From the viewpoint of imparting functions to each layer in the film and to the stretched film, it is preferable that the functional layer is adjacent to or in contact with at least one layer or film selected from each layer in the film and to the stretched film via an adhesive layer.

[0089] The functional layer can be a resin film coated with inorganic compounds or inorganic oxides, a metal foil, a resin coating with special functions, or a resin film printed with a pattern. The resin film used can be the same as the resin film used for the base film, and similar plastic compounding agents and additives can be added in any amount as needed, as long as they do not adversely affect other properties.

[0090] The resin film can be manufactured, for example, by using one or more resins selected from the same group of resins as those used for the base film, and by conventional film-forming methods such as extrusion, casting, T-die, cutting, or inflation, or by using two or more resins and a multilayer co-extrusion film-forming method. Furthermore, from the viewpoint of the film's strength, dimensional stability, and heat resistance, it can be stretched in one or two axes using methods such as the tenter method or the tubular method.

[0091] For example, a laminate further including a barrier layer can be manufactured by a method similar to the method for manufacturing a laminate, which includes the steps of forming the barrier layer as a layer in the sealant layer, substrate layer, or stretched film by metal deposition, coating, or co-extrusion, and laminating the unstretched film and the stretched film described above. [Examples]

[0092] Next, the laminate of the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. The materials used in the examples and comparative examples are shown below.

[0093] <Ethylene copolymer (A)> "Copolymer (A1-1)": Ethylene-1-butene copolymer (EBR) (MFR 2.16 (230℃, 2.16kg load, compliant with ASTM D1238): 33g / 10min, Density (compliant with ASTM D1505): 885kg / m³ 3Ethylene content: 88 mol% "Copolymer (A1-2)": Ethylene-1-butene copolymer (EBR) (MFR 2.16 (230℃, 2.16kg load, compliant with ASTM D1238): 33g / 10min, Density (compliant with ASTM D1505): 893kg / m³ 3 Ethylene content: 91 mol% "Copolymer (a1-1)": Ethylene-1-butene copolymer (EBR) (MFR 2.16 (230℃, 2.16kg load, compliant with ASTM D1238): 6.7g / 10min, Density (compliant with ASTM D1505): 885kg / m³ 3 Ethylene content: 88 mol% "Copolymer (A2-2)": Acid-modified ethylene-1-butene copolymer, malee anhydride modified product of copolymer (A1-2), amount of acid modification after malee anhydride modification: 0.7% by mass, MFR 2.16 (230℃, 2.16kg, compliant with ASTM D1238): 23g / 10min, Density (compliant with ASTM D1505): 896kg / m³ 3

[0094] <Propylene-based polymer (B)> "hPP(B-1)": Propylene homopolymer (MFR 2.16 (230℃, 2.16kg load, compliant with ASTM D1238): 7g / 10min, melting point: 160℃

[0095] The evaluation methods for the materials used in the examples and comparative examples are shown below. <Content (composition) of constituent units derived from comonomers> The content of constituent units derived from comonomers was measured using a nuclear magnetic resonance (NMR) analyzer (JEOL Ltd., JNM GX-400 model). 0.35 g of the sample was heated and dissolved in 2.0 mL of hexachlorobutadiene. After filtering this solution through a glass filter (G2), 0.5 mL of deuterated benzene was added, and the solution was placed in a 10 mm inner diameter NMR tube and analyzed at 120°C. 13 ¹ 13The content (mol%) of ethylene-derived constituent units in the ethylene-1-butene copolymer was quantified using 1C-NMR spectroscopy.

[0096] <Melting point> Using a differential scanning calorimeter (DSCPyris1, PerkinElmer), approximately 5 mg of the sample was heated to 200°C under a nitrogen atmosphere (20 mL / min) and held for 10 minutes. Then, it was cooled to 30°C at 10°C / min and held for 5 minutes, and subsequently heated to 200°C at 10°C / min. The temperature at the peak of the crystal melting peak was defined as the melting point (Tm).

[0097] [Example 1] A resin composition for skin layer preparation was prepared by blending 5 parts by mass of copolymer (A1-1) and 95 parts by mass of hPP (B-1). Using two extruders connected to T-dies, the resin composition for skin layer production and hPP(B-1) for base layer production were supplied to each extruder. The die and resin temperatures were set to 230°C, and the extrusion amount of each extruder was adjusted to produce an unoriented film by co-extrusion molding, consisting of an unoriented skin layer with a thickness of 20 μm and an unoriented base layer with a thickness of 50 μm. Next, aluminum was deposited onto the skin layer surface of the obtained unoriented film using a vacuum deposition machine (ULVAC, Inc.) (under 1 × 10⁻⁶ Pa vacuum conditions, RH method) to form an inorganic vapor deposition layer with a thickness of 65 nm. Then, a stretched PET film (Toray Industries, Inc.) with a thickness of 25 μm was laminated onto the inorganic vapor deposition layer surface of the obtained unoriented film via an adhesive layer using the dry lamination method to produce a laminate. The vapor deposition strength of the obtained laminate was determined by the method shown below. The results are shown in Table 1.

[0098] <Method for measuring vapor deposition intensity> The resulting laminate was cut to a width of 15 mm and a length of 80 mm (with the film formation direction and the longer side direction coinciding), and a tensile test was performed using a tensile testing machine with the 180-degree peel test method at a tensile speed of 300 mm / min. The peel strength during the peeling process was defined as the vapor deposition strength.

[0099] [Examples 2-7, Comparative Examples 1-3] Laminates were manufactured in the same manner as in Example 1, except that the composition of the resin composition for skin layer fabrication was changed to the composition shown in Table 1. The vapor deposition strength of each of these laminates was determined according to the method described above. The results are shown in Table 1.

[0100] [Table 1]

Claims

1. A film having an inorganic layer, a skin layer, and a substrate layer, The inorganic layer, the skin layer, and the substrate layer are laminated in that order. The skin layer comprises an ethylene copolymer (A) and a propylene polymer (B), The ethylene copolymer (A) is one or more selected from the group consisting of unmodified ethylene-α-olefin copolymer (A1) and acid-modified ethylene-α-olefin copolymer (A2). The ethylene copolymer (A) has a melt flow rate (MFR) measured at 230°C and a 2.16 kg load in accordance with ASTM D1238. 2.16 ) is in the range of 15-50g / 10 minutes. The substrate layer is a film containing the propylene polymer (B).

2. The film according to claim 1, wherein the inorganic layer is deposited.

3. The film according to claim 1, wherein at least one of the skin layer and the substrate layer is an unstretched layer.

4. The film according to claim 1, wherein the skin layer contains 1 to 40 parts by mass of the ethylene copolymer (A) and 60 to 99 parts by mass of the propylene polymer (B) (provided that the total of the ethylene copolymer (A) and the propylene polymer (B) is 100 parts by mass).

5. The density of the ethylene copolymer (A) measured at 25°C in accordance with ASTM D1505 was 870–905 kg / m³. 3 The film according to claim 1, which is within the range.

6. A laminate comprising a stretched film and a film according to any one of claims 1 to 5.

7. A laminate comprising a stretched film, a film according to any one of claims 1 to 5, and a sealant film layer, laminated in this order.

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