Heat-fusible laminate film

Abstract

To provide a polyolefin-based laminate film containing polypropylene and has reduced environmental loads by using a biomass-derived resin which achieves good heat sealability, and enables film formation at a lower resin pressure.SOLUTION: A laminate film has (A) a seal layer, (B) a core layer and (C) a laminate layer, where (A) the seal layer and (C) the laminate layer contain polypropylene, (B) the core layer contains linear low-density polyethylene and biomass-derived low-density polyethylene, and crystal heat of fusion ΔH observed in a temperature range of 110-140°C in a second heating process of a DSC curve is 18.0 to 21.7 J / g.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyolefin-based laminate film containing polypropylene, and more specifically to a laminate film that is suitable for use in films for medicine bags, etc., and that reduces the environmental impact by using a biomass-derived resin and can effectively suppress the generation of burnt foreign matter scraped off during film production. [Background technology]

[0002] In recent years, with the aim of reducing the environmental impact, studies have been conducted to replace some of the materials constituting the resin films used in various packaging materials from resins derived from fossil fuels such as petroleum with plant-derived resins. For example, a laminated film has been proposed in which a surface layer (A), an intermediate layer (B), and a heat-sealing layer (C) are laminated together, and the surface layer (A) and the heat-sealing layer (C) each contain a propylene-based resin, and the intermediate layer (B) contains a plant-derived linear low-density polyethylene and a fossil fuel-derived linear low-density polyethylene in a predetermined ratio (see, for example, Patent Document 1).

[0003] Laminated films having a configuration such as that described in Patent Document 1 are used in a wide range of applications, including packaging containers, but in recent years their use has expanded as films for medicine bags. When used as films for medicine bags, from the viewpoint of excellent appearance, it is required to effectively suppress the generation of burnt foreign matter scraped off. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-102277 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above technical background, the present invention aims to provide a polyolefin-based laminated film containing polypropylene, which has a reduced environmental impact due to the use of biomass-derived resin, and which achieves good heat sealing properties and can effectively suppress the generation of burnt foreign matter scraped off during film production. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have discovered that in a laminate film having (A) a seal layer, (B) a core layer, and (C) a laminate layer, in which the (A) seal layer and the (C) laminate layer contain polypropylene and the (B) core layer contains linear low-density polyethylene and biomass-derived linear low-density polyethylene, respectively, when the heat of crystalline fusion ΔH observed in the temperature range of 110 to 140°C in the second heating stroke of the DSC curve is within a predetermined numerical range, the generation of scorched foreign matter scraped off during film production can be effectively suppressed while maintaining good heat-sealability, leading to the completion of the present invention. That is, the present invention provides: [1] A laminated film having (A) a seal layer, (B) a core layer, and (C) a laminate layer, (A) the sealing layer and (C) the laminate layer contain polypropylene; (B) the core layer contains linear low-density polyethylene and biomass-derived linear low-density polyethylene; The laminated film has a heat of crystal fusion ΔH of 18.0 to 21.7 J / g observed in the temperature range of 110 to 140° C. in the second heating stroke of the DSC curve.

[0007] Below, [2] to [4] are each a preferred aspect or embodiment of the present invention. [2] (B) The laminated film according to [1], wherein the content of biomass-derived linear low-density polyethylene in the core layer is 12 to 31 mass %. [3] The laminated film according to [1] or [2], wherein the polypropylene is a random polypropylene. [4] The laminated film according to any one of [1] to [3], which is used as a film for a medicine bag. [Effects of the Invention]

[0008] The laminated film of the present invention maintains the excellent properties and good heat sealability inherent to the propylene polymer, while effectively suppressing the generation of scorched foreign matter scraped off during film production, and by using a biomass-derived resin, the environmental impact of its production, etc. is reduced. Thus, the laminated film of the present invention combines these properties, which are of great practical value, at a high level that goes beyond the limits of conventional technology, and can be suitably used in a variety of applications, including films for medicine bags. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention provides a laminated film having (A) a seal layer, (B) a core layer, and (C) a laminate layer, (A) the sealing layer and (C) the laminate layer contain polypropylene; (B) the core layer contains linear low-density polyethylene and biomass-derived linear low-density polyethylene; The laminated film has a heat of crystal fusion ΔH of 18.0 to 21.7 J / g observed in the temperature range of 110 to 140° C. in the second heating stroke of the DSC curve. That is, the laminated film of the present invention contains polypropylene in its (A) sealing layer and (C) laminating layer. The laminated film of the present invention also contains linear low-density polyethylene and biomass-derived linear low-density polyethylene in its core layer (B). Each of the above components will be described in detail below.

[0010] polypropylene The polypropylene used in at least the (A) seal layer and (C) laminate layer of the laminated film of the present invention is a resin generally manufactured and sold under the names of polypropylene, propylene polymer, and propylene-based polymer, and usually has a density of 890 to 930 kg / m 3 The polypropylene may be a homopolymer of propylene (homopolypropylene) or a propylene copolymer, i.e., a copolymer derived from propylene and at least one comonomer selected from other α-olefins in a small amount. In the present invention, either homopolypropylene or propylene copolymer may be used, but the use of propylene copolymer is preferred.

[0011] In the case of a copolymer, it may be a random copolymer or a block copolymer, but a random copolymer is particularly preferred. In the case of a copolymer of propylene, examples of the other α-olefin include ethylene and an α-olefin having about 4 to 20 carbon atoms, such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, and 4-methyl-1-pentene. Such other α-olefins may be copolymerized alone or in combination with two or more α-olefins.

[0012] Among these polypropylenes, propylene polymers having a melting point measured by a differential scanning calorimeter (DSC) in the range of 110 to 170°C, particularly 115 to 165°C, are preferably used in view of the balance between the heat resistance of the resulting laminated film and the compatibility with the core layer (B).

[0013] As long as the polypropylene used in the present invention has film-forming ability, either alone or in a blend with other resins such as an ethylene polymer, an ethylene-α-olefin random copolymer, or a tackifying resin, its melt flow rate (MFR) is not particularly limited. However, from the viewpoint of extrusion processability and the like, the melt flow rate (MFR) (ASTM D1238, 230°C, 2160 g load) is usually in the range of 0.01 to 100 g / 10 min, preferably 0.1 to 70 g / 10 min.

[0014] As the polypropylene used in the present invention, two or more kinds of polypropylenes can be used in combination.

[0015] The polypropylene used in the present invention can be produced by various known production methods, specifically, using an olefin polymerization catalyst such as a Ziegler-Natta catalyst or a single-site catalyst. In particular, it can be produced using a single-site catalyst. A single-site catalyst is a catalyst with a uniform (single-site) active site, such as a metallocene catalyst (also known as a Kaminsky catalyst) or a Brookhart catalyst. The metallocene catalyst is a catalyst comprising a metallocene transition metal compound and at least one compound selected from the group consisting of an organoaluminum compound and a compound that reacts with the metallocene transition metal compound to form an ion pair, and may be supported on an inorganic material.

[0016] Various additives such as inorganic fillers such as silica and talc, antioxidants, weather stabilizers, antistatic agents, antifogging agents, antiblocking agents, slip agents, and pigments may be blended into the polypropylene as long as they do not contradict the object of the present invention.

[0017] Linear low-density polyethylene In the present invention, the linear low-density polyethylene used in at least the core layer (B) may be any of those generally known in the art as linear low-density polyethylene. Such linear low-density polyethylene may be a copolymer of ethylene and an α-olefin, and may be synthesized by a production method using a known catalyst such as a Ziegler catalyst or a metallocene catalyst.

[0018] The α-olefin may be a compound having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, 4-methyl-1-hexene, or a mixture thereof. The α-olefin is preferably a compound having 4, 6, or 8 carbon atoms, or a mixture thereof, such as 1-butene, 1-hexene, 1-octene, or a mixture thereof. However, ethylene can also be polymerized in the polymerization process to produce α-olefins, in which case ethylene can be produced essentially alone as a raw material.

[0019] The linear low-density polyethylene may be a commercially available product, for example, 2040F (C6-LLDPE, MFR: 4.0, density: 0.918 g / cm) manufactured by Ube Maruzen Polyethylene Co., Ltd. 3 ), Evolue (registered trademark) manufactured by Prime Polymer Co., Ltd., etc. can be used.

[0020] The density of the linear low-density polyethylene is preferably 890 to 940 kg / m 3 and more preferably 900 to 930 kg / m 3 is. The density of the linear low-density polyethylene can be adjusted appropriately by adjusting the comonomer content, and can also be adjusted appropriately by selecting and adjusting the polymerization conditions such as the catalyst and polymerization temperature.

[0021] The MFR (190°C, 2160g load) of the linear low-density polyethylene is preferably 0.1 to 15g / 10min, more preferably 0.5 to 12g / 10min, and particularly preferably 0.7 to 11g / 10min. The MFR (190°C, 2160 g load) of the linear low-density polyethylene can be appropriately adjusted by a conventionally known method, for example, by adjusting polymerization conditions such as polymerization temperature or by introducing a molecular weight modifier.

[0022] The linear low-density polyethylene can be produced by a conventionally known production method using a conventionally known catalyst, including a multi-site catalyst such as a Ziegler catalyst, or a single-site catalyst such as a metallocene catalyst. From the viewpoint of obtaining a linear low-density polyethylene having a narrow molecular weight distribution and capable of forming a high-strength film, it is preferable to use a single-site catalyst.

[0023] The single-site catalyst is a catalyst capable of forming a uniform active species, and is usually prepared by contacting a metallocene transition metal compound or a non-metallocene transition metal compound with an activating co-catalyst. Single-site catalysts are preferred because they have a more uniform active site structure than multi-site catalysts, making it possible to polymerize polymers with high molecular weights and highly uniform structures. Metallocene catalysts are particularly preferred as single-site catalysts. Metallocene catalysts are catalysts containing the following catalytic components: a transition metal compound of Group IV of the periodic table containing a ligand with a cyclopentadienyl skeleton, a co-catalyst, and optionally an organometallic compound and a carrier.

[0024] In the above-mentioned transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, or the like. The substituted cyclopentadienyl group has at least one substituent selected from a hydrocarbon group having 1 to 30 carbon atoms, a silyl group, a silyl-substituted alkyl group, a silyl-substituted aryl group, a cyano group, a cyanoalkyl group, a cyanoaryl group, a halogen group, a haloalkyl group, a halosilyl group, and the like. The substituted cyclopentadienyl group may have two or more substituents, and the substituents may be bonded to each other to form a ring, such as an indenyl ring, a fluorenyl ring, an azulenyl ring, or a hydrogenated product thereof. The rings formed by bonding the substituents to each other may further have substituents.

[0025] In a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the transition metal may be zirconium, titanium, hafnium, or the like, with zirconium and hafnium being particularly preferred. The transition metal compound typically contains two ligands having a cyclopentadienyl skeleton, and the ligands having the cyclopentadienyl skeleton are preferably bonded to each other via a bridging group. Examples of the bridging group include alkylene groups having 1 to 4 carbon atoms, silylene groups, substituted silylene groups such as dialkylsilylene groups and diarylsilylene groups, and substituted germylene groups such as dialkylgermylene groups and diarylgermylene groups. A substituted silylene group is preferred.

[0026] In the transition metal compounds of Group IV of the periodic table, representative examples of the ligand other than the ligand having a cyclopentadienyl skeleton include hydrogen, hydrocarbon groups having 1 to 20 carbon atoms (such as alkyl groups, alkenyl groups, aryl groups, alkylaryl groups, aralkyl groups, and polyenyl groups), halogens, metaalkyl groups, and metaaryl groups.

[0027] The above-mentioned compounds of transition metals of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton can be used as a catalyst component either singly or in combination of two or more kinds.

[0028] The co-catalyst refers to a catalyst that can effectively use the above-mentioned transition metal compound of Group IV of the periodic table as a polymerization catalyst or that can balance the ionic charge in a catalytically activated state. Examples of the co-catalyst include benzene-soluble aluminoxanes of organoaluminum oxy compounds and benzene-insoluble organoaluminum oxy compounds, ion-exchangeable layered silicates, boron compounds, ionic compounds consisting of a cation with or without an active hydrogen group and a non-coordinating anion, lanthanoid salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing a fluoro group.

[0029] The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton may be used by being supported on a carrier of an inorganic or organic compound. The carrier is preferably a porous oxide of an inorganic or organic compound, specifically an ion-exchangeable oxide such as montmorillonite. Examples include layered silicates, SiO2, Al2O3, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, ThO2, and mixtures thereof.

[0030] Furthermore, examples of organometallic compounds that may be used if necessary include organoaluminum compounds, organomagnesium compounds, organozinc compounds, etc. Of these, organoaluminum compounds are preferably used.

[0031] From the viewpoint of obtaining linear low-density polyethylene having a wide molecular weight distribution and excellent flexibility and moldability, it is preferable to use a multi-site catalyst such as a Ziegler catalyst or a Phillips catalyst. Preferred Ziegler catalysts may be those generally known as Ziegler catalysts used in the coordination polymerization of ethylene and α-olefins, such as catalysts containing a titanium compound and an organoaluminum compound, and examples thereof include catalysts consisting of a titanium halide compound and an organoaluminum compound, and catalysts consisting of a solid catalyst component consisting of titanium, magnesium, chlorine, etc., and an organoaluminum compound. More specifically, examples of such catalysts include a catalyst comprising a catalyst component (ai) obtained by reacting a titanium compound with a reaction product of an alcohol pre-treated anhydrous magnesium dihalide and an organometallic compound, and an organometallic compound (bi); a catalyst comprising a catalyst component (aii) obtained by reacting magnesium metal with an organic hydroxide compound or an oxygen-containing organic compound such as magnesium, an oxygen-containing organic compound of a transition metal, and an aluminum halide, and an organometallic compound catalyst component (bii); and a catalyst comprising a solid catalyst component (aiii) obtained by reacting (i) metallic magnesium with at least one member selected from an organic hydroxide compound, an oxygen-containing organic compound of magnesium, and a halogen-containing compound, (ii) at least one member selected from an oxygen-containing organic compound of a transition metal and a halogen-containing compound, and (iii) a silicon compound, with (iv) an aluminum halide compound, and an organometallic compound catalyst component (biii).

[0032] The Phillips catalyst may be any of those generally known as Phillips catalysts used in the coordination polymerization of ethylene and α-olefins, such as a catalyst system containing a chromium compound such as chromium oxide. Specific examples include catalysts in which a chromium compound such as chromium trioxide or a chromate ester is supported on a solid oxide such as silica, alumina, silica-alumina, or silica-titania.

[0033] Biomass-derived linear low-density polyethylene In the present invention, the biomass-derived linear low-density polyethylene used in at least the core layer (B) is a polyethylene having a density of 900 to 940 kg / m obtained by polymerizing ethylene produced using a biomass-derived raw material. 3This refers to linear low-density polyethylene. The biomass-derived linear low-density polyethylene preferably has 10 to 30 SCBs (side chains having 1 to 5 carbon atoms, also called "short chain branches") per 1000 carbon atoms.

[0034] The density of the biomass-derived linear low-density polyethylene is preferably 905 to 935 kg / m 3 , more preferably 910 to 930 kg / m 3 is. There are no particular restrictions on the MFR (2.16 kg, 190°C) of the biomass-derived linear low-density polyethylene, but from the viewpoint of moldability and the like, it is preferably 0.5 to 20.0 g / 10 min, more preferably 0.6 to 15.0 g / 10 min, even more preferably 0.7 to 10.0 g / 10 min, and particularly preferably 0.8 to 5.0 g / 10 min.

[0035] There are no particular limitations on the molecular weight distribution of the biomass-derived linear low-density polyethylene, but from the viewpoint of better film-forming properties, flexibility, moldability, etc., the molecular weight distribution (expressed as the ratio of weight-average molecular weight: Mw to number-average molecular weight: Mn: Mw / Mn) is preferably 2.5 to 10.0, more preferably 3.0 to 9.0, and even more preferably 3.5 to 8.0. This Mw / Mn can be measured by gel permeation chromatography (GPC), and more specifically, for example, can be measured by the method described in the Examples of the present application.

[0036] The biomass-derived linear low-density polyethylene has one or more sharp peaks as determined from an endothermic curve measured with a differential scanning calorimeter (DSC) at a heating rate of 10°C / min, and the maximum temperature of the peak, i.e., the melting point, is preferably in the range of 90 to 140°C, and more preferably 100 to 130°C.

[0037] The biomass-derived linear low-density polyethylene may be a commercially available product, such as that manufactured and sold by Braskem. Specific brands that can be suitably used include SLH118 and SLL118. The biomass-derived linear low-density polyethylene used in the present invention is obtained by polymerizing monomers containing biomass-derived ethylene (and / or biomass-derived comonomer). The biomass-derived ethylene is preferably obtained by the production method described below, but is not limited thereto. Since biomass-derived ethylene (and / or biomass-derived comonomer) is used as the raw material monomer, the polymerized linear low-density polyethylene is biomass-derived. Note that the raw material monomer for polyethylene does not have to contain 100% by mass of biomass-derived ethylene (and biomass-derived comonomer), and may contain ethylene that is not biomass-derived or raw material monomers other than ethylene.

[0038] The method for producing biomass ethylene, which is a raw material for biomass-derived linear low-density polyethylene, is not particularly limited, and can be obtained by a conventionally known method. An example of a method for producing biomass ethylene will be described below.

[0039] Biomass ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. The plant raw material is not particularly limited, and conventionally known plants can be used. Examples include corn, sugarcane, beet, and manioc.

[0040] In the present invention, biomass-derived fermented ethanol refers to ethanol produced by contacting a culture solution containing a carbon source obtained from plant raw materials with an ethanol-producing microorganism or a product derived from its disruption, and then purifying the ethanol. Conventional methods such as distillation, membrane separation, and extraction can be used to purify ethanol from the culture solution. Examples of such methods include adding benzene, cyclohexane, or the like and removing water by azeotropy or membrane separation. In order to obtain biomass ethylene, further advanced purification may be carried out at this stage, such as reducing the total amount of impurities in the ethanol to 1 ppm or less.

[0041] A catalyst is usually used to obtain ethylene by the dehydration reaction of ethanol, but the catalyst is not particularly limited and any conventionally known catalyst can be used. From the viewpoint of the process, a fixed-bed flow reaction is advantageous because it allows easy separation of the catalyst from the product, and for example, γ-alumina is preferred. This dehydration reaction is endothermic, so it is usually carried out under heated conditions. The heating temperature is not limited as long as the reaction proceeds, but is preferably 100° C. or higher, more preferably 250° C. or higher, and even more preferably 300° C. or higher. There is no particular upper limit to the temperature, but from the viewpoint of energy balance and equipment, it is preferably 500° C. or lower, more preferably 400° C. or lower. The reaction pressure is not particularly limited, but a pressure equal to or higher than atmospheric pressure is preferred to facilitate subsequent gas-liquid separation. From an industrial perspective, a fixed-bed flow reaction is preferred because it facilitates catalyst separation, but a liquid-phase suspension bed, a fluidized bed, or the like may also be used.

[0042] In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in the ethanol supplied as a raw material. Generally, when performing a dehydration reaction, it is preferable to eliminate water in order to improve the efficiency of water removal. However, in the case of ethanol dehydration using a solid catalyst, it has been found that the absence of water tends to increase the amount of other olefins, particularly butene, produced. This is presumably because the presence of a small amount of water is insufficient to suppress ethylene dimerization after dehydration. The allowable lower limit of the water content is 0.1% by mass or more, preferably 0.5% by mass or more. There are no particular limitations on the upper limit, but from the viewpoints of material balance and heat balance, it is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0043] By carrying out the dehydration reaction of ethanol in this manner, a mixture of ethylene, water, and a small amount of unreacted ethanol is obtained, but since ethylene is in a gaseous state at room temperature and below about 5 MPa, water and ethanol can be removed from this mixture by gas-liquid separation to obtain ethylene. This method can be carried out by any known method. The ethylene obtained by the gas-liquid separation is further distilled. The distillation method, operation temperature, residence time, etc. are not particularly limited, except that the operation pressure at this time must be atmospheric pressure or higher.

[0044] When the raw material is biomass-derived fermented ethanol, the resulting ethylene contains trace amounts of impurities introduced during the ethanol fermentation process, such as carbonyl compounds (e.g., ketones, aldehydes, and esters) and their decomposition products (e.g., carbon dioxide), as well as nitrogen-containing compounds (e.g., amines and amino acids) and their decomposition products (e.g., ammonia), which are enzymatic decomposition products and contaminants. These trace amounts of impurities can be problematic during the production and use of polyethylene, so they can be removed by purification. The purification method is not particularly limited, and conventionally known methods can be used. Suitable purification procedures include, for example, adsorption purification. The adsorbent used is not particularly limited, and conventionally known adsorbents can be used. For example, a material with a high surface area is preferred, and the type of adsorbent is selected depending on the type and amount of impurities in the ethylene obtained by the dehydration reaction of biomass-derived fermented ethanol.

[0045] A caustic water treatment may be used in combination as a method for purifying impurities in ethylene. When caustic water treatment is used, it is preferable to carry out the treatment before adsorption purification. In this case, it is necessary to carry out a water removal treatment after the caustic treatment and before adsorption purification.

[0046] The monomers that are raw materials for the biomass-derived linear low-density polyethylene may further contain ethylene and / or α-olefins derived from fossil fuels, or may further contain α-olefins derived from biomass.

[0047] The number of carbon atoms in the biomass-derived α-olefin is not particularly limited, but typically, those having 3 to 20 carbon atoms can be used, and butylene, hexene, or octene is preferred. This is because butylene, hexene, or octene can be produced by polymerizing ethylene, a biomass-derived raw material. Furthermore, by including such a biomass-derived α-olefin, the polymerized polyolefin has alkyl groups as a branched structure, making it more flexible than a simple linear one.

[0048] The concentration of biomass-derived ethylene in biomass-derived linear low-density polyethylene (hereinafter referred to as "biomass content") is determined by radiocarbon ( 14 C) The value measured is the amount of carbon derived from biomass. Carbon dioxide in the atmosphere contains: 14 Since it contains a certain percentage of carbon (105.5pMC), plants that grow by absorbing carbon dioxide from the atmosphere, such as corn, 14 The carbon content is also known to be about 105.5 pMC. 14 It is also known that polyethylene contains almost no carbon atoms. 14 By measuring the proportion of carbon, the proportion of carbon derived from biomass can be calculated. 14 The content of C is P 14C The content of biomass-derived carbon in this case is P bio can be calculated as follows: P bio (%)=P 14C / 105.5×100

[0049] In the biomass-derived linear low-density polyethylene that can be used in the present invention, theoretically, if all biomass-derived ethylene is used as the raw material for the polyethylene, the concentration of biomass-derived ethylene will be 100%, and the biomass degree of the biomass-derived polyethylene will be 100%. Note that the concentration of biomass-derived ethylene in fossil fuel-derived polyethylene produced only from fossil fuel-derived raw materials will be 0%, and the biomass degree of the fossil fuel-derived polyethylene will be 0%.

[0050] In the present invention, the biomass-derived linear low-density polyethylene does not need to have a biomass content of 100%. This is because if biomass-derived raw materials are used for even a part of the biomass-derived linear low-density polyethylene, the amount of fossil fuel used can be reduced compared to conventional methods.

[0051] In the biomass-derived linear low-density polyethylene that can be used in the present invention, the polymerization method of the monomer containing biomass-derived ethylene is not particularly limited, and can be carried out by a conventionally known method. The polymerization temperature and polymerization pressure can be adjusted appropriately depending on the polymerization method and polymerization apparatus. The polymerization apparatus is also not particularly limited, and a conventionally known apparatus can be used. It is preferable to use a multi-site catalyst such as a Ziegler catalyst or a Phillips catalyst, or a single-site catalyst such as a metallocene catalyst as the polymerization catalyst, and to carry out the polymerization in one stage or in two or more stages by any of gas phase polymerization, slurry polymerization, solution polymerization, and high pressure ionic polymerization.

[0052] From the viewpoint of obtaining biomass polyethylene with a wide molecular weight distribution and excellent flexibility and moldability, it is preferable to use a multi-site catalyst such as a Ziegler catalyst or a Phillips catalyst. Preferred Ziegler catalysts may be those generally known as Ziegler catalysts used in the coordination polymerization of ethylene and α-olefins, such as catalysts containing a titanium compound and an organoaluminum compound, and examples thereof include catalysts consisting of a titanium halide compound and an organoaluminum compound, and catalysts consisting of a solid catalyst component consisting of titanium, magnesium, chlorine, etc., and an organoaluminum compound. More specifically, examples of such catalysts include a catalyst comprising a catalyst component (a) obtained by reacting a titanium compound with a reaction product of an alcohol pre-treated anhydrous magnesium dihalide and an organometallic compound, and an organometallic compound (b); a catalyst comprising a catalyst component (A) obtained by reacting magnesium metal with an organic hydroxide compound or an oxygen-containing organic compound such as magnesium, an oxygen-containing organic compound of a transition metal, and an aluminum halide, and an organometallic compound catalyst component (B); and a catalyst comprising a solid catalyst component (A) obtained by reacting (i) metallic magnesium with at least one member selected from an organic hydroxide compound, an oxygen-containing organic compound of magnesium, and a halogen-containing compound, (ii) at least one member selected from an oxygen-containing organic compound of a transition metal and a halogen-containing compound, or (iii) a silicon compound, with (iv) an aluminum halide compound, and an organometallic compound catalyst component (B).

[0053] The Phillips catalyst may be any of those generally known as Phillips catalysts used in the coordination polymerization of ethylene and α-olefins, such as a catalyst system containing a chromium compound such as chromium oxide. Specific examples include catalysts in which a chromium compound such as chromium trioxide or a chromate ester is supported on a solid oxide such as silica, alumina, silica-alumina, or silica-titania.

[0054] Biomass-derived linear low-density polyethylene is usually a copolymer of ethylene and an α-olefin, but it can also be produced using only ethylene as a raw material by promoting ethylene polymerization during polymerization.

[0055] The α-olefin may be a compound having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, 4-methyl-1-hexene, or a mixture thereof. The α-olefin is preferably a compound having 4, 6, or 8 carbon atoms, or a mixture thereof, such as 1-butene, 1-hexene, 1-octene, or a mixture thereof.

[0056] The biomass-derived linear low-density polyethylene may be used alone or in combination with two or more other polymers, such as other ethylene-based polymers.

[0057] The biomass-derived linear low-density polyethylene may be blended with various known additives that are usually added to olefin polymers, such as antioxidants, weather stabilizers, antistatic agents, antifogging agents, antiblocking agents, slip agents (lubricants), etc., as needed, within the scope of the present invention.

[0058] The laminated film of the present invention has (A) a seal layer, (B) a core layer, and (C) a laminate layer, which will be explained below.

[0059] (A) Sealing layer The seal layer (A) constituting the laminate film of the present invention contains polypropylene. By containing polypropylene in the seal layer (A), the laminate film of the present invention can achieve favorable effects such as strength, transparency, lightness, and elastic modulus. From the viewpoint of achieving good heat sealability, it is preferable that the polypropylene contained in the seal layer (A) is partly or entirely random polypropylene. The content of polypropylene in the sealing layer (A) is preferably 80% by mass or more, more preferably 85 to 99.9% by mass, and particularly preferably 90 to 99.8% by mass.

[0060] The (A) sealing layer may contain a biomass-derived low density polyethylene, including a biomass-derived linear low density polyethylene. By including biomass-derived low-density polyethylene in the (A) sealing layer, the biomass content of the laminated film can be further improved, and the impact strength can also be further improved. The content of biomass-derived low-density polyethylene in the sealing layer (A) is preferably 0.5% by mass or more, more preferably 1 to 9% by mass, and particularly preferably 2 to 7% by mass. The method for measuring the biomass content of the (A) seal layer is the same as that described below for the biomass content of the (B) core layer.

[0061] There are no particular restrictions on the thickness of the (A) sealing layer, but from the viewpoint of elastic modulus and the like, it is preferably 1.3 μm or more, and particularly preferably 2.5 μm or more. On the other hand, from the viewpoint of transparency and the like, the thickness is preferably 25 μm or less, and particularly preferably 23 μm or less.

[0062] (B) Core layer The core layer (B) constituting the laminated film of the present invention contains linear low-density polyethylene and biomass-derived linear low-density polyethylene. (B) When the core layer contains linear low-density polyethylene, it is possible to achieve high compatibility with the biomass-derived linear low-density polyethylene, and thereby achieve favorable effects such as high transparency, a moist texture, and firmness. The content of linear low-density polyethylene in the core layer (B) is not particularly limited, but is preferably from 69 to 88% by mass, and particularly preferably from 70 to 86% by mass.

[0063] (B) By including a biomass-derived linear low-density polyethylene in the core layer, the biomass content is improved, reducing the environmental load, and achieving other desirable effects such as improved impact strength and improved heat sealability. The content of the biomass-derived linear low-density polyethylene in the (B) core layer is preferably 12 to 31% by mass, more preferably 14 to 30% by mass, and particularly preferably 16 to 29% by mass. By having the content of the biomass-derived linear low-density polyethylene in the (B) core layer be 12 to 31% by mass, a sufficient biomass content can be achieved, and desirable effects such as good heat-sealability and suppression of the generation of burnt, scraped-out foreign matter can be more significantly achieved. Furthermore, it becomes easier to keep the crystalline heat of fusion ΔH of the entire laminated film of the present invention between 110 and 140°C within the specified range described below.

[0064] To further enhance the desirable effects of the high biomass content, high transparency, and suppression of the generation of burnt foreign matter scraped off, the thickness of the (B) core layer is preferably greater than the thickness of the (A) seal layer and the (C) laminate layer, and is particularly preferably equal to or greater than the sum of the thicknesses of the (A) seal layer and the (C) laminate layer. Specifically, the thickness of the (B) core layer is preferably 55% or more, more preferably 70% to 240%, and particularly preferably 85% to 160% of the sum of the thicknesses of the (A) seal layer and the (C) laminate layer. The thickness of the core layer (B) is preferably 2.5 to 50 μm, more preferably in the range of 5.0 to 45 μm.

[0065] The content of the biomass-derived linear low-density polyethylene can be appropriately increased or decreased, for example, by adjusting the blending of the resin composition when producing the core layer (B). The content of biomass-derived low-density polyethylene, such as biomass-derived linear low-density polyethylene, in the (B) core layer after production can be determined by, for example, radiocarbon ( 14 C) The content of biomass-derived carbon in the film is measured by measurement, and the content of biomass-derived carbon in the biomass-derived low-density polyethylene can be used for calculation.

[0066] (C) Laminate layer The laminate layer (C) constituting the laminate film of the present invention contains polypropylene. Polypropylene has high heat resistance, is lightweight, and is low cost, and by including it, the laminate layer (C) can be made high in heat resistance, lightweight, and low in cost. Furthermore, from the viewpoint of interlayer affinity, if polypropylene is used for the (C) laminate layer, it becomes easier to use polypropylene for the adjacent (B) core layer and, through it, for the (A) seal layer, making the entire laminated film highly heat-resistant, lightweight, and low-cost. The polypropylene content in the (C) laminate layer is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more. As the polypropylene in the (C) laminate layer, random polypropylene is particularly preferred.

[0067] The (C) laminate layer constituting the laminate film of the present invention can be laminated with other layers including the (D) substrate layer described below, as necessary or desired. Therefore, it is preferable to design the (C) laminate layer taking into consideration the lamination strength between it and other layers such as the (D) substrate layer. For example, it is preferable to use the same type of material as the other layers including the (D) base layer, and therefore it is preferable to use a polypropylene material or a polyester-based material that is preferably used for the (D) base layer. In addition, to further improve the lamination strength between other layers, the surface of the (C) laminate layer (the surface opposite to the surface laminated with the (B) core layer) may be subjected to treatment such as corona treatment or roughening treatment.

[0068] The (C) laminate layer may contain a biomass-derived low-density polyethylene, including a biomass-derived linear low-density polyethylene. (C) By including biomass-derived low-density polyethylene in the laminate layer, the biomass content of the laminate film can be further improved, and the impact strength can also be further improved. The content of biomass-derived low-density polyethylene in the (C) laminate layer is preferably 0.5% by mass or more, more preferably 0.8 to 20% by mass, even more preferably 1.5 to 15% by mass, and particularly preferably 2.0 to 12% by mass. The method for measuring the biomass content of the (C) laminate layer is the same as that described above for the biomass content of the (B) core layer.

[0069] From the viewpoint of preventing blocking during storage of the laminated film of the present invention, the laminate layer (C) may contain an anti-blocking agent. As the anti-blocking agent, powdered silica, preferably synthetic silica, etc., can be suitably used. From the viewpoint of uniformly dispersing the powdered silica in the (C) laminate layer, the powdered silica may be dispersed in a resin having excellent miscibility with the polypropylene constituting the (C) laminate layer, such as various polyolefins, to form a masterbatch, and then the masterbatch may be added to the polypropylene.

[0070] There are no particular restrictions on the thickness of the laminate layer (C), but it is preferably 1.3 to 25 μm, and more preferably in the range of 2.5 to 23 μm.

[0071] In addition to polypropylene, linear low-density polyethylene, and biomass-derived linear low-density polyethylene, any of the (A) seal layer, (B) core layer, and (C) laminate layer may contain various additives and fillers, such as heat stabilizers, antioxidants, light stabilizers, antistatic agents, antiblocking agents, lubricants, nucleating agents, flame retardants, pigments, dyes, calcium carbonate, barium sulfate, magnesium hydroxide, mica, talc, clay, antibacterial agents, and anti-fogging agents, as long as the addition does not violate the objectives of the present invention. Furthermore, other thermoplastic resins, thermoplastic elastomers, rubbers, hydrocarbon resins, petroleum resins, and the like may also be added as long as the addition does not violate the objectives of the present invention.

[0072] Laminated Film As described above, the laminate film of the present invention has the (A) seal layer, the (B) core layer, and the (C) laminate layer. In the laminate film of the present invention, the (C) laminate layer and the (A) seal layer are preferably laminated via the (B) core layer, but other layers may also be present.

[0073] The laminate film of the present invention can be produced by various known film forming methods, such as a method in which films to become the (C) laminate layer, (B) core layer, and (A) seal layer are first formed, and then the films are bonded together to form a laminate film; a method in which a multilayer film consisting of the (B) core layer and the (A) seal layer is obtained using a multilayer die, and then the (C) laminate layer is extruded onto the surface of the (B) core layer to form a laminate film; a method in which a multilayer film consisting of the (C) laminate layer and the (B) core layer is obtained using a multilayer die, and then the (A) seal layer is extruded onto the surface of the (B) core layer to form a laminate film; or a method in which a multilayer film consisting of the (C) laminate layer, (B) core layer, and (A) seal layer is obtained using a multilayer die.

[0074] As the film forming method, various known film forming methods, specifically, a T-die cast film forming method and an inflation film forming method can be used. The laminated film of the present invention and each of the layers constituting the film may be either a non-stretched film (unstretched film) or a stretched film.

[0075] The thickness of the laminated film of the present invention is not particularly limited, but is 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, from the viewpoint of ensuring practical strength, etc. On the other hand, from the viewpoint of maintaining practical flexibility even after being laminated with, for example, the (D) substrate layer, the thickness is usually 100 μm or less, preferably 90 μm or less, more preferably 80 μm or less.

[0076] The laminated film of the present invention has a crystalline heat of fusion ΔH of 18.0 to 21.7 J / g at 110 to 140° C. calculated from the melting curve in the second heating step obtained by DSC measurement. By having the heat of crystalline fusion ΔH at 110°C to 140°C within the above range, the laminated film of the present invention effectively suppresses the generation of burnt foreign matter scraped off during film production, and can be suitably used in various packaging materials and container films, such as films for medicine bags, which combine a high biomass content with excellent appearance. The mechanism by which the above advantageous technical effect is achieved by having the heat of crystalline fusion ΔH at 110°C to 140°C in the range of 18.0 to 21.7 J / g is not entirely clear, but it can be assumed that there is some relationship between this and the fact that, when the amount of crystalline components that melt within the above temperature range, which is sufficiently lower than the film-forming temperature, is within an appropriate range, a fluidity can be achieved that suppresses resin scorching and scraping of the scorched material.

[0077] Measurement of the melting curve in the second heating step by DSC and measurement of the heat of fusion ΔH from the melting curve between 110°C and 140°C can be performed by a conventionally known method, and more specifically, can be performed by, for example, the method described in the Examples of the present application. The heat of crystal fusion ΔH at 110° C. to 140° C. is more preferably 18.2 to 21.5 J / g, and even more preferably 18.4 to 21.3 J / g. The heat of fusion ΔH at 110° C. to 140° C. can be increased by increasing the amount of biomass-derived linear low-density polyethylene added or by increasing the thickness of the layer to which it is added.

[0078] The laminate film of the present invention contains a biomass-derived linear low-density polyethylene in the (B) core layer, and preferably in the (A) seal layer and / or the (C) laminate layer, thereby reducing the amount of fossil fuel used in production and the environmental load. The biomass degree of the laminated film can be calculated by averaging the biomass degree of each layer weighted by the weight of each layer. The biomass degree of the laminated film can be increased or decreased as appropriate by adjusting the biomass degree of each layer, and the biomass degree of each layer can be increased or decreased as appropriate by adjusting the biomass degree and amount of resin used in each layer. The biomass ratio of the laminated film of the present invention is more preferably 0.05% by mass or more, and particularly preferably 0.07% by mass or more. The higher the biomass content of the laminated film of the present invention, the better, and there is no particular upper limit. However, in relation to the physical properties of the film, costs, etc., it is usually 60 mass % or less, and in many cases 50 mass % or less.

[0079] The laminated film of the present invention may be a stretched film or a non-stretched film. From the viewpoint of improving mechanical properties, a stretched film is preferred, and a biaxially stretched film is particularly preferred. As the biaxial stretching method, a method such as sequential biaxial stretching, simultaneous biaxial stretching, or multi-stage stretching is suitably adopted. The conditions for biaxial stretching may be the same as those for producing known biaxially stretched films, for example, in the case of a sequential biaxial stretching method, the longitudinal stretching temperature is 100 to 145°C, the stretching ratio is in the range of 4 to 7 times, and the transverse stretching temperature is 150 to 190°C, and the stretching ratio is in the range of 8 to 11 times.

[0080] (D) Base material layer If desired, the laminated film of the present invention can be laminated with a substrate layer (D) at its laminate layer (C).

[0081] There are no particular restrictions on the base layer (D), and for example, films that are normally used for plastic packaging can be suitably used. Preferred materials for the (D) substrate layer include, for example, plastic films made of thermoplastic resins such as various polyethylenes, crystalline polypropylene, crystalline propylene-ethylene copolymers, crystalline polybutene-1, crystalline poly-4-methylpentene-1, low-, medium-, or high-density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and ionically crosslinked olefin copolymers (ionomers); aromatic vinyl copolymers such as polystyrene and styrene-butadiene copolymer; halogenated vinyl polymers such as polyvinyl chloride and vinylidene chloride resin; nitrile polymers such as acrylonitrile-styrene copolymer and acrylonitrile-styrene-butadiene copolymer; polyamides such as nylon 6, nylon 66, and para- or meta-xylylene adipamide; polyesters such as polyethylene terephthalate (PET) and polytetramethylene terephthalate; various polycarbonates; and polyacetals such as polyoxymethylene. Furthermore, if the contents to be packaged are oxygen-sensitive, the above film may be coated with a film vapor-deposited with a metal oxide or the like, or a film coated with an organic compound, or a layer made of ethylene vinyl alcohol copolymer (EVOH) resin. Plastic films made of these materials are used in an unstretched, uniaxially stretched, or biaxially stretched state.

[0082] (D) As the base layer, these plastic films can be used as a single layer or as a laminate of two or more types. Also, one or two or more types of these plastic films can be laminated with a metal foil such as aluminum, paper, cellophane, etc. Preferred examples of the (D) substrate layer include single-layer films made of stretched nylon film or stretched polyester film, two-layer films made by laminating a polyolefin film such as low-density polyethylene or polypropylene with PET, and three-layer films made by laminating PET / nylon / polyethylene. When producing these laminated films, adhesives or anchoring agents can be interposed between the layers as needed. An ink layer for displaying a design can also be provided.

[0083] The method for laminating the (D) substrate layer to the (C) laminate layer is not particularly limited, but for example, the (D) substrate layer can be directly laminated to the (C) laminate layer by extrusion lamination or the like. Alternatively, the (D) substrate layer can be laminated to the (C) laminate layer via an adhesive by dry lamination or the like. Usable adhesives include conventional adhesives such as urethane-based adhesives, acid-modified polyolefin-based adhesives, polyester-based adhesives, polyether-based adhesives, and polyamide-based adhesives. The thickness of the (D) substrate layer can be set arbitrarily, but is usually selected within the range of 5 to 1000 μm, preferably 9 to 100 μm.

[0084] The laminate film of the present invention and a laminate film obtained by laminating a (D) substrate layer onto the (C) laminate layer of the laminate film of the present invention are preferably used in various applications, and are particularly suitable for use as packaging materials.

[0085] A preferred example of such a packaging material is a film for a medicine bag. That is, the laminated film of the present invention has excellent heat sealing properties and can be formed without burning or scraping off foreign matter, so it can be particularly suitably used as a film for a medicine bag. The laminate film of the present invention (or a laminate film in which a (D) base layer is laminated onto a (C) laminate layer of the laminate film of the present invention) has an (A) seal layer on one outer layer, so that the laminate film can be folded in half at the center with the (A) seal layer facing inward, and then heat-sealed on all three sides to form a continuous heat-sealed section, thereby partitioning and forming a drug storage section. In other words, it can be used as a film for medicine bags to be made into medicine packaging bags. Furthermore, by using the laminate film of the present invention (or a laminate film in which a (D) base layer is laminated onto a (C) laminate layer of the laminate film of the present invention), it can also be made into a series of medicine packaging bags in which medicines are continuously packaged using a heat-sealed continuous packaging machine. There are no particular limitations on the drugs that can be packaged in medicine bags or drug packaging bags, and not only pharmaceuticals or their preparations, but also supplements, health foods, foods for specified health uses, and foods with nutrient functions can be packaged. [Example]

[0086] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples in any sense.

[0087] The physical properties and characteristics in the examples and comparative examples were evaluated by the following methods. (1) Molecular weight distribution (Mw / Mn) After pretreating a polymer sample under the following conditions, the molecular weight was measured by GPC, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) was taken as the molecular weight distribution. i) Pretreatment 20 mL of mobile phase for GPC measurement (o-dichlorobenzene) was added to a sample (30 mg) and dissolved by shaking at 145°C. The resulting solution was hot filtered through a sintered filter with a pore size of 1.0 µm and subjected to GPC measurement. ii) GPC Apparatus: Tosoh Corporation, gel permeation chromatograph HLC-8321 Column: Tosoh Corporation, inner diameter 7.5 mm x 30 cm, 4 columns (2 columns of TSKgel GMH6-HT and 2 columns of TSKgel GMH6-HTL) Column temperature: 140℃ Detector: differential refractometer Flow rate: 1mL / min Sampling interval: 0.5 seconds

[0088] (2) Heat of fusion A differential scanning calorimeter (DSC) Q100 manufactured by TA Instruments was used. Approximately 5 mg of sample was weighed out, and the thermal melting curve was measured by heating from -50°C to 250°C at a heating rate of 10°C / min under conditions of a nitrogen gas inflow of 50 ml / min, in accordance with JIS K7121. The heat of crystalline fusion ΔH of the sample from 110 to 140°C on the obtained thermal melting curve (at the second heating stage) was calculated.

[0089] (3) Scraping out burnt foreign matter The appearance of the film was visually inspected to see if any black burnt foreign matter (several mm in size) had appeared in the film.

[0090] (4) Heat seal strength The laminated film produced in each Example / Comparative Example was overlaid on a cellophane film having a thickness of 20 μm on the surface of the (C) laminate layer side to prepare a sample film (50 mm×150 mm). The seal surfaces of the above sample films were placed together, and heat-sealed for 1 second using a precision heat sealer (manufactured by Tester Sangyo) at a temperature of 130°C and a pressure of 0.2 MPa using a 5 mm wide sealing bar. The sample was then allowed to cool, and a 15 mm wide test piece was then cut from the heat-sealed sample. The sample was then peeled off in a 180-degree direction using a universal tensile tester (manufactured by A&D Co., Ltd.) at a tensile speed of 500 mm / min in a thermostatic chamber at 23°C and 50% RH, and the maximum load was measured, which was taken as the heat seal strength (N / 15 mm). The peeled surface was observed and the peeling state was evaluated as to which of the following conditions it fell under. Interfacial peeling Cohesion peeling Delamination Edge cut (cut at the boundary between the sealed and unsealed areas)

[0091] Details of each component such as resin used in the examples and comparative examples are as follows. Linear low-density polyethylene (LLDPE) Density: 910kg / m 3 MFR (2.16 kg, 190°C): 3.6 g / 10 min Melting point: 115℃ Biomass-derived linear low-density polyethylene (B-LLDPE) Braskem, product name: SLH118 MFR (2.16kg, 190℃): 1.0g / 10min Density: 916kg / m 3 Molecular weight distribution (Mw / Mn): 4.43 Random Polypropylene-1 (rPP-1) Density: 910kg / m 3 MFR (2.16 kg, 210 °C): 7.0 g / 10 min Melting point: 131°C Random Polypropylene-2 ​​(rPP-2) Density: 900kg / m 3 MFR (2.16 kg, 210 °C): 7.0 g / 10 min Melting point: 125℃

[0092] (Comparative Example 1) The components constituting each layer were fed into separate extruders in the formulations shown in Table 1, and a 50 μm-thick laminate film was formed using the T-die method. The three-layer coextruded film consisted of (A) seal layer, (B) core layer, and (C) laminate layer. The laminate layer was then corona-treated to obtain a laminate film. The thickness ratio of each layer was (A) seal layer:(B) core layer:(C) laminate layer = 25:50:25. The obtained laminated film was evaluated according to the above methods (2) to (4). The results are shown in Table 1.

[0093] (Examples 1 to 3 and Comparative Example 2) (B) A laminated film was produced in the same manner as in Comparative Example 1, except that the composition of the core layer was changed as shown in Table 1, and evaluated. The results are shown in Table 1.

[0094] [Table 1] [Industrial Applicability]

[0095] The laminated film of the present invention maintains the excellent properties and good heat sealability inherent to the propylene polymer, while effectively suppressing the generation of scorched foreign matter scraped off during film production, and the use of a biomass-derived resin reduces the environmental impact of its production, etc., and thus combines at a high level properties that are of great practical value.The laminated film is suitable for various packaging films, including films for medicine bags, and has high applicability in various industrial fields such as medicine, health care, nursing, caregiving, accommodation, agriculture, food, and distribution.

Claims

1. A laminated film having (A) a seal layer, (B) a core layer, and (C) a laminate layer, (A) the sealing layer and (C) the laminate layer contain polypropylene; (B) the core layer contains linear low-density polyethylene and biomass-derived linear low-density polyethylene; The above laminated film has a heat of crystalline fusion ΔH of 18.0 to 21.7 J / g observed in the temperature range of 110 to 140°C in the second heating stroke of the DSC curve.

2. The laminated film according to claim 1, wherein the content of the biomass-derived linear low-density polyethylene in the core layer (B) is 12 to 31 mass%.

3. The laminated film according to claim 1 or 2, wherein the polypropylene is a random polypropylene.

4. The laminated film according to claim 1 or 2, which is used as a film for a medicine bag.