Film and laminate

Abstract

To provide a film excellent in heat resistance and impact resistance.SOLUTION: A film comprising an ethylene-based polymer (X) satisfying the following requirements (a1) to (a3): (a1) 190 °C, 2. MFR measured under 16kg load is 0.5 to 10g / 10 min, (a2) the temperature at which the ratio of the melting heat amount to Δ H is 55% is 111 °C. or higher, where Δ H is the total amount of the melting heat amount observed in the second temperature rise when the temperature is raised from - 30 °C. to 230 °C. at a rate of 10 °C. / min, held at 230 °C. for 10 minutes, lowered to - 30 °C. at a rate of 10 °C. / min, held at - 30 °C. for 1 minute, and then raised to 230 °C. at a rate of 10 °C. / min, (a3) the temperature at which the ratio of the melting heat amount to Δ H is 55% is 150 °C. or higher, the ratio of Δ H (90) to Δ H is 14% or more, where Δ H is the total amount of heat of melting observed when measured under the same conditions as in (a2) above, and Δ H (90) is the amount of heat of melting observed during heating from - 30 °C. to 90 °C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to films and laminates. [Background technology]

[0002] To enable long-term storage, packaging bags containing medical products or food products are sometimes sterilized at high temperatures of approximately 100 to 140°C after filling and sealing. For example, a bag-shaped laminate (laminated film) made by laminating multiple resin films is used as the packaging bag. Such packaging bags are required to have heat resistance that can withstand sterilization treatment under high temperature and pressure, and strength (impact resistance) that prevents the bag from breaking even if dropped during distribution. Furthermore, such packaging bags are also required to have excellent transparency and a glossy appearance.

[0003] Patent Document 1 describes a bag-shaped medical container using a resin film, which is a laminate having at least an inner layer, an intermediate layer, and an outer layer, in which the inner layer is made of a resin material containing high-density polyethylene, and the intermediate layer is made of an ethylene-α-olefin copolymer obtained by copolymerizing ethylene with an α-olefin having 3 to 20 carbon atoms, and has a density of 0.920 g / cm 3 The present invention discloses a laminate and a container characterized in that the laminate and the container are made of a resin material mainly composed of a polyethylene-based resin having physical properties such as a viscosity of less than 100 psig, and the outer layer is made of a resin material containing high-density polyethylene.

[0004] Furthermore, Patent Document 2 discloses that an ethylene-based resin composition that satisfies specific requirements can provide a film that has an excellent balance of strength to protect the contents and rigidity (e.g., ease of opening when filling the contents into the packaging material, self-standing ability, etc.). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-237002 [Patent Document 2] International Publication No. 2021 / 200991 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional packaging bags have a problem in that improving heat resistance leads to a decrease in impact resistance, making it difficult to achieve both heat resistance and impact resistance. Furthermore, there is room for further improvement in the transparency and appearance of packaging bags. In view of the above-mentioned problems in the conventional art, an object of the present disclosure is to provide a film that is excellent in heat resistance and impact resistance. [Means for solving the problem]

[0007] For example, the present disclosure includes the following aspects.

[0008] [1] A film comprising an ethylene polymer (X) that satisfies the following requirements (a1) to (a3): (a1) The melt flow rate measured in accordance with JIS K 7210 at 190°C under a load of 2.16 kg is 0.5 to 10 g / 10 min. (a2) Using a differential scanning calorimeter, the sample is heated from -30°C to 230°C at a rate of 10°C / min, held at 230°C for 10 minutes, cooled to -30°C at a rate of 10°C / min, held at -30°C for 1 minute, and then heated to 230°C at a rate of 10°C / min for the second time. When the total heat of fusion observed is ΔH, the temperature at which the ratio of the heat of fusion to ΔH is 55% is 111°C or higher. (a3) Using a differential scanning calorimeter, the sample is heated from -30°C to 230°C at a rate of 10°C / min, held at 230°C for 10 minutes, cooled to -30°C at a rate of 10°C / min, held at -30°C for 1 minute, and then heated to 230°C at a rate of 10°C / min for the second time. When the total heat of fusion observed during the temperature rise from -30°C to 90°C is ΔH and ΔH(90) is the heat of fusion observed during the temperature rise from -30°C to 90°C, the ratio of ΔH(90) to ΔH is 14% or more.

[0009] [2] The film according to [1], wherein the ethylene polymer (X) has a melt flow rate of 1.0 to 10 g / 10 min, measured in accordance with JIS K 7210 at 190° C. under a load of 2.16 kg.

[0010] [3] The film according to [1] or [2], wherein the ethylene polymer (X) satisfies the following requirement (a4) in addition to the requirements (a1) to (a3): (a4) Density is 918 to 950 kg / m 3 is.

[0011] [4] The ethylene polymer (X) Density: 906-921 kg / m 3 and 10 to 99 mass% of an ethylene polymer (P) having a density of 940 to 960 kg / m 3 and 1 to 90 mass% of an ethylene polymer (Q) represented by the formula (wherein the total amount of the ethylene polymer (P) and the ethylene polymer (Q) is 100 mass%),

[0012] [5] A laminate comprising the film according to any one of [1] to [4].

[0013] [6] A laminate having an outer layer, an intermediate layer, and an inner layer, wherein the intermediate layer comprises the film according to any one of [1] to [4]. [Effects of the Invention]

[0014] According to one embodiment of the present disclosure, a film having excellent heat resistance and impact resistance can be provided. According to another embodiment of the present disclosure, a film having excellent heat resistance, impact resistance, and transparency, and also having a glossy appearance, can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0015] In the present disclosure, the expressions "XX or more and YY or less" and "XX to YY" that represent a numerical range mean a numerical range that includes the lower and upper limits that are the endpoints, unless otherwise specified. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0016] The present disclosure will be described in detail below. [film] The film of the present disclosure is characterized by containing an ethylene polymer (X) that satisfies the following requirements (a1) to (a3).

[0017] <Ethylene polymer (X)> Requirement (a1) The melt flow rate (MFR) measured under conditions of 190°C and a load of 2.16 kg in accordance with JIS K 7210 is 0.5 to 10 g / 10 min, preferably 1.0 to 10 g / 10 min, and more preferably 1.0 to 4.5 g / 10 min. When the MFR is within the above range, a film having excellent transparency and a glossy appearance can be easily obtained.

[0018] The MFR is strongly dependent on the molecular weight; the smaller the MFR, the higher the molecular weight, and the higher the MFR, the lower the molecular weight. It is also known that the molecular weight of an ethylene polymer is determined by the composition ratio of hydrogen to ethylene (hydrogen / ethylene) in the polymerization system (for example, Kazuo Soga et al., "Catalytic Olefin Polymerization," Kodansha Scientific, 1990, p. 376). Therefore, the MFR of an ethylene polymer can be increased or decreased by increasing or decreasing the hydrogen / ethylene ratio.

[0019] Requirements(a2) Using a differential scanning calorimeter, the sample is heated from -30°C to 230°C at a rate of 10°C / min, held at 230°C for 10 minutes, cooled to -30°C at a rate of 10°C / min, held at -30°C for 1 minute, and then heated to 230°C at a rate of 10°C / min for the second time. When the total heat of fusion observed during this second heating is ΔH, the temperature at which the ratio of the heat of fusion to ΔH is 55% (hereinafter also referred to as the "ΔH55% melting temperature") is 111°C or higher. The ΔH55% melting temperature is preferably 112° C. or higher, more preferably 115° C. or higher, and even more preferably 118° C. or higher, and although there is no particular upper limit, it is preferably 137° C. or lower, for example, 111 to 137° C. When the ΔH55% melting temperature is within the above range, a film having excellent heat resistance and impact resistance can be easily obtained.

[0020] The ΔH55% melting temperature can be measured according to the method described in the Examples below.

[0021] The ΔH55% melting temperature can be adjusted to the above range by changing the density or melting point distribution of the ethylene polymer, or by appropriately mixing two or more ethylene polymers having different densities. For example, when the ethylene polymer (X) has a density of 906 to 921 kg / m 3 and an ethylene polymer (P) having a density of 940 to 960 kg / m 3 When a mixture of the ethylene polymer (Q) having a higher density is used, the ΔH55% melting temperature can be increased by increasing the content of the ethylene polymer (Q) having a higher density.

[0022] Requirements(a3) Using a differential scanning calorimeter, the sample is heated from -30°C to 230°C at a rate of 10°C / min, held at 230°C for 10 minutes, cooled to -30°C at a rate of 10°C / min, held at -30°C for 1 minute, and then heated to 230°C at a rate of 10°C / min. During the second heating cycle, the total heat of fusion observed is ΔH, and the heat of fusion observed during the temperature rise from -30°C to 90°C is ΔH(90). The ratio of ΔH(90) to ΔH is 14% or more. The ratio of ΔH(90) to ΔH represents the amount of components at 90°C or less relative to the total heat of fusion, and is preferably 15% or more, more preferably 16% or more, and even more preferably 18% or more. There is no upper limit, but it is preferably 95% or less, for example, 14 to 95%. When the ratio of ΔH(90) to ΔH is within the above range, a film with excellent heat resistance and impact resistance can be easily obtained.

[0023] The ratio of ΔH(90) to ΔH can be measured according to the method described in the Examples below.

[0024] The ratio of ΔH(90) to ΔH can be adjusted within the above range by changing the density or melting point distribution of the ethylene polymer, or by appropriately mixing two or more ethylene polymers having different densities. For example, when the ethylene polymer (X) has a density of 906 to 921 kg / m 3 and an ethylene polymer (P) having a density of 940 to 960 kg / m 3 When a mixture of the ethylene polymer (P) and the ethylene polymer (Q) having a density of 0.01 or less is used, the ratio of ΔH(90) to ΔH can be adjusted within the above range by increasing the content of the ethylene polymer (P) having a lower density. Also, by selecting the ethylene polymer (P) and the ethylene polymer (Q) so that the difference in density between them is large, an ethylene polymer (X) satisfying both of the requirements (a2) and (a3) ​​can be obtained.

[0025] During the second temperature increase, the melting peak temperature (the temperature giving the melting peak in the DSC curve) is preferably 123.6 to 137°C.

[0026] The ethylene polymer (X) preferably satisfies the following requirements (a4) to (a5) in addition to the above requirements (a1) to (a3).

[0027] Requirements(a4) Density 918-950kg / m 3 and preferably 922 to 945 kg / m 3, more preferably 925 to 940 kg / m 3 , and more preferably 925 to 935 kg / m 3 When the density is within the above range, a film having excellent heat resistance and impact resistance can be easily obtained.

[0028] The density is measured as follows. In accordance with JIS K7112, the strand obtained during the MFR measurement is measured using the density gradient tube method.

[0029] Requirements(a5) The molecular weight distribution (Mw / Mn) is not more than 10, preferably not more than 8, and more preferably not more than 5. When Mw / Mn is within the above range, a film having excellent heat resistance, impact resistance, and transparency and a glossy appearance can be easily obtained.

[0030] Mw / Mn can be measured by the method described in the examples below.

[0031] The ethylene polymer (X) may be a homopolymer of ethylene or an ethylene copolymer of ethylene and another monomer. The ethylene copolymer is preferably a copolymer of ethylene and an α-olefin having 3 or more carbon atoms (ethylene-α-olefin copolymer). The α-olefin in the ethylene-α-olefin copolymer is preferably an α-olefin having 3 to 20 carbon atoms, and specific examples include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Among these, 1-hexene and 1-octene are preferred, and 1-hexene is more preferred. The α-olefin may be one type or two or more types.

[0032] The proportion of ethylene-derived structural units relative to 100 mol% of all structural units in the ethylene polymer (X) is preferably 90 mol% or more, more preferably 95 mol% or more.

[0033] The method for producing the ethylene polymer (X) is not particularly limited, and it can be produced using a known catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst.

[0034] The ethylene polymer (X) may contain structural units derived from one or more biomass-derived monomers (e.g., ethylene, α-olefins, etc.). The monomers constituting the ethylene polymer (X) may be only biomass-derived monomers, only fossil fuel-derived monomers, or both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers are monomers derived from any renewable natural raw materials and their residues, such as plant or animal origin, including fungi, yeast, algae, and bacteria, and contain carbon. 14 C isotope at 1×10 -12 The biomass-derived monomer is contained in a proportion of about 100 (pMC) as measured in accordance with ASTM D 6866. The biomass-derived monomer can be obtained by a conventionally known method. It is preferable that the ethylene polymer (X) contains a biomass-derived monomer from the viewpoint of reducing the environmental load (mainly reducing greenhouse gases). If the polymer production conditions, such as the polymerization catalyst, polymerization process, and polymerization temperature, are the same, even if the raw material monomer contains a biomass-derived olefin, 14 C isotope at 1×10 -12 ~1×10 -14 Other than the proportion of ethylene in the polymer, its molecular structure is the same as that of ethylene polymers made from fossil fuel-derived monomers, and its performance is therefore said to be the same.

[0035] The ethylene polymer (X) may contain a chemically recycled monomer (e.g., ethylene, α-olefin, etc.). The monomers constituting the ethylene polymer (X) may consist solely of chemically recycled monomers, or may consist solely of fossil fuel-derived monomers, or may contain a chemically recycled monomer, a fossil fuel-derived monomer, and / or a biomass-derived monomer. The chemically recycled monomers can be obtained by a conventionally known method. It is preferable for the ethylene polymer (X) to contain a chemically recycled monomer from the viewpoint of reducing the environmental load (mainly waste reduction). The chemically recycled monomer is a monomer obtained by depolymerizing or pyrolyzing a polymer such as waste plastics back into a monomer unit such as ethylene, or a monomer produced using such a monomer as a raw material. Therefore, even if the chemically recycled monomer is contained as a raw material monomer for the ethylene polymer, the molecular structure will be equivalent to that of an ethylene polymer composed of a fossil fuel-derived monomer, provided that the polymer production conditions, such as the polymerization catalyst, polymerization process, and polymerization temperature, are equivalent. Therefore, the performance is also considered to be unchanged.

[0036] The ethylene polymer (X) may be one type or a mixture of two or more types of ethylene polymers. In the case of a mixture of two or more types of ethylene polymers, the mixture only needs to satisfy the above requirements (a1) to (a3), and each copolymer before mixing does not necessarily have to satisfy the above requirements (a1) to (a3). Alternatively, one or a combination of two or more polyethylenes satisfying the above requirements (a1) to (a3) ​​may be selected from commercially available polyethylene resins and used as the ethylene polymer (X).

[0037] A preferred example of the ethylene polymer (X) is a mixture containing the ethylene polymer (P) and the ethylene polymer (Q) described below. When the ethylene polymer (X) is the mixture, a film having excellent heat resistance, impact resistance, and transparency and a glossy appearance can be easily obtained.

[0038] The mixture contains the ethylene polymer (P) and the ethylene polymer (Q) in proportions such that the mixture as a whole satisfies the requirements (a1) to (a3), for example, 10 to 99 mass %, preferably 20 to 90 mass %, and more preferably 30 to 80 mass % of the ethylene polymer (P) and 1 to 90 mass %, preferably 10 to 80 mass %, and more preferably 20 to 70 mass % of the ethylene polymer (Q) (where the total amount of the ethylene polymer (P) and the ethylene polymer (Q) is 100 mass %). When the content ratios of the ethylene polymer (P) and the ethylene polymer (Q) are within the above ranges, a film having excellent heat resistance and impact resistance can be easily obtained.

[0039] [Ethylene polymer (P)] The density of the ethylene polymer (P) is 906 to 921 kg / m from the viewpoint of being able to obtain a film excellent in heat resistance, impact resistance, and blocking resistance. 3 and preferably 908 to 920 kg / m 3 , more preferably 910 to 920 kg / m 3 is.

[0040] The melt flow rate (MFR) of the ethylene polymer (P), measured at 190°C under a load of 2.16 kg in accordance with JIS K 7210, is preferably 0.01 to 10 g / 10 min, more preferably 0.1 to 10 g / 10 min, and even more preferably 0.7 to 10 g / 10 min. When the MFR is within the above range, a film having excellent transparency and a glossy appearance can be easily obtained.

[0041] The ethylene polymer (P) may be an ethylene homopolymer or a copolymer of ethylene and another monomer (ethylene copolymer).

[0042] As the ethylene-based copolymer, a copolymer of ethylene and an α-olefin having 3 or more carbon atoms (ethylene-α-olefin copolymer) is particularly preferred. Examples of the α-olefin include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene, and 1-butene, 1-hexene, and 1-octene are preferred.

[0043] The method for producing the ethylene polymer (P) is not particularly limited.

[0044] [Ethylene polymer (Q)] The density of the ethylene polymer (Q) is 940 to 960 kg / m from the viewpoint of obtaining a film excellent in heat resistance and impact resistance. 3 and preferably 943 to 960 kg / m 3 , more preferably 945 to 960 kg / m 3 is.

[0045] The melt flow rate (MFR) of the ethylene polymer (Q), measured at 190°C under a load of 2.16 kg in accordance with JIS K 7210, is preferably 0.01 to 10 g / 10 min, more preferably 0.01 to 6 g / 10 min, still more preferably 0.05 to 6 g / 10 min, and particularly preferably 0.07 to 4 g / 10 min. When the MFR is within the above range, a film having excellent transparency and a glossy appearance can be easily obtained.

[0046] The ethylene polymer (Q) may be an ethylene homopolymer or a copolymer of ethylene and another monomer (ethylene copolymer).

[0047] As the ethylene-based copolymer, a copolymer of ethylene and an α-olefin having 3 or more carbon atoms (ethylene-α-olefin copolymer) is particularly preferred. Examples of the α-olefin include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene, and 1-butene, 1-hexene, and 1-octene are preferred.

[0048] The method for producing the ethylene polymer (Q) is not particularly limited.

[0049] <Other polymers and other components> The film of the present disclosure may further contain a polymer other than the ethylene polymer (X) as long as the object of the present disclosure is not impaired. Examples of the other polymer include thermoplastic resins other than the ethylene polymer (X). Examples of the thermoplastic resin include olefin polymers other than the ethylene polymer (X), (meth)acrylic resins, polyvinyl chloride, polystyrene, polyester, polyamide, polyimide, polyacetal, polyvinyl alcohol, polyacrylonitrile, and polycarbonate. When the film of the present disclosure contains other polymers, the content of the other polymers is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, for example, 0.1 to 30 parts by mass, relative to 100 parts by mass of the total content of the ethylene polymer (X) and the other polymers.

[0050] The film of the present disclosure may contain at least one of various additives commonly used for polyolefin resins, such as a neutralizing agent, a weather stabilizer, a heat stabilizer, an antistatic agent, an antifogging agent, an antiblocking agent, a slip agent, a lubricant, a pigment, and a drip-repellent agent, which are added as needed within a range that does not impair the object of the present disclosure. When an additive is added to the film, the content thereof is preferably 5 parts by mass or less, more preferably 1 part by mass or less, per 100 parts by mass of the ethylene polymer (X).

[0051] 〔film〕 The film of the present disclosure can also be used as a stretched film. When used as a stretched film, it may be a uniaxially stretched film or a biaxially stretched film. The lower limit of the stretching ratio in the stretched film is preferably 2.0 times or more, more preferably 2.5 times or more, even more preferably 3.0 times or more, and particularly preferably 3.1 times or more. The upper limit is not particularly limited, but is preferably 10 times or less, more preferably less than 6 times, for example, 2.0 times or more and 10 times or less. When the stretching ratio is in the above range, the packaging bag has an excellent balance between rigidity and strength.

[0052] The thickness of the film of the present disclosure can be appropriately set depending on various applications, and the lower limit is preferably 5 μm or more, more preferably 10 μm or more, and the upper limit is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less, for example, 5 to 200 μm. When the film thickness is in the above range, the packaging bag has an excellent balance between rigidity and strength.

[0053] Methods for producing the films of the present disclosure include, but are not limited to, known melt extrusion methods.

[0054] When the film of the present disclosure is a stretched film, examples of methods for stretching the stretched raw sheet include a method of simultaneous or sequential biaxial stretching in the longitudinal and transverse directions using a tenter method, a method of simultaneous biaxial stretching in the longitudinal and transverse directions using a tubular method, and a method of uniaxial stretching in the flow direction of the film by using a difference in the rotation speed ratio of two or more rolls.

[0055] In the uniaxial stretching, the film is preferably fed to a roll stretching machine, preheated with a preheating roll, and then uniaxially stretched in the MD direction (take-up speed direction). From the viewpoint of improving production efficiency, it is preferable to preheat the raw film and then immediately uniaxially stretch it in the MD direction. In the present disclosure, uniaxial stretching refers to uniaxial stretching, but the film may be stretched in a direction different from the uniaxial direction to the extent that the effects of the present disclosure are not impaired. This is because, depending on the stretching equipment used, even if uniaxial stretching is attempted, the film may actually be stretched in a direction different from the uniaxial direction.

[0056] The stretched film may be annealed, if necessary, by contacting the stretched sheet with a heated roll.

[0057] The film of the present disclosure is preferably an unstretched film.

[0058] [Laminate] The film of the present disclosure may be used as a laminate in which it is laminated with other layers, that is, examples of the laminate include a laminate in which a layer made of the above film is laminated with other layers. The laminate may have one or more layers made of the above film, and other layers constituting the laminate may be appropriately selected depending on the application.

[0059] The thickness of the layer made of the above film can be appropriately determined depending on the desired application, but is preferably 5 to 200 μm, more preferably 10 to 150 μm.

[0060] A preferred embodiment of the laminate is a laminate having an outer layer, an intermediate layer, and an inner layer, and it is particularly preferred that the intermediate layer contains the above-mentioned film. Materials constituting the outer layer and the inner layer other than the intermediate layer are preferably materials that can give a laminate having transparency, such as polyethylene. When the intermediate layer contains the above film, a laminate having excellent heat resistance, impact resistance, and transparency and a glossy appearance can be obtained. In particular, one embodiment of the film of the present disclosure contains an ethylene polymer (X) whose density satisfies the above requirement (a4), and therefore the heat resistance and impact resistance of the obtained laminate can be both achieved.

[0061] The other layers constituting the laminate include, for example, a substrate layer. The type of material constituting the substrate layer is not particularly limited. Various materials capable of exhibiting substrate functionality can be used, such as thermoplastic resins or stretched products thereof, inorganic oxide vapor-deposited films, metal vapor-deposited films, ceramic vapor-deposited films, metal foil, paper, and nonwoven fabric. When using resins, examples include polyamide resins such as nylon 11 and nylon 12; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyolefin resins such as polyethylene resin and polypropylene resin; polystyrene resin, polyvinylidene chloride resin, polycarbonate resin, saponified ethylene-vinyl acetate copolymer, and acrylic resin. Furthermore, the substrate layer can also be a two-layer film formed by dry-laminating a polyester film and a ceramic vapor-deposited polyester film, or a three-layer film formed by dry-laminating a polyester film and aluminum foil, with a polyester film further dry-laminated on the aluminum foil surface.

[0062] The thickness of the substrate layer is preferably 1 to 100 μm, more preferably 2 to 90 μm, and even more preferably 3 to 60 μm.

[0063] The laminate may have an adhesive or anchoring agent interposed between the layers as required. Metal oxides or the like may be vapor-deposited on the entire surface or a part of the surface, or an ink layer may be provided.

[0064] The method for producing the laminate is not particularly limited, but examples include a method of directly laminating by extrusion lamination, an ozone treatment in an oxidizing atmosphere (e.g., a gas containing oxygen, particularly ozone (air, etc.)), and a method of laminating via an adhesive by dry lamination, etc.

[0065] The laminate has an excellent balance of heat resistance and impact resistance, making it less susceptible to defects even when exposed to high temperatures and less susceptible to tearing when subjected to impact. Therefore, it is useful in a variety of applications requiring heat resistance and impact resistance, such as in the food and medical fields. Specifically, it can be suitably used as a packaging material for fluid or solid packaged items that require heat and sterilization, such as retort foods, pharmaceuticals, medical devices, and pet food. It is particularly useful as a material for packaging fluids (fluid packaging material). [Example]

[0066] The present disclosure will be explained in more detail below based on examples, but the present disclosure is not limited to these examples in any way.

[0067] [Raw materials] In the examples and comparative examples, the following ethylene polymers were used. Evolue (registered trademark) SP3210 manufactured by Prime Polymer Co., Ltd. Linear low-density polyethylene (ethylene-1-hexene copolymer), MFR: 0.59 g / 10 min, density: 929 kg / m 3 Evolue (registered trademark) SP3022 manufactured by Prime Polymer Co., Ltd. Linear low-density polyethylene (ethylene-1-hexene copolymer), MFR: 1.6 g / 10 min, density: 928 kg / m 3 Evolue (registered trademark) SP2040 manufactured by Prime Polymer Co., Ltd. Linear low-density polyethylene (ethylene-1-hexene copolymer), MFR: 3.8 g / 10 min, density: 918 kg / m 3 HI-ZEX (registered trademark) 3600F manufactured by Prime Polymer Co., Ltd. High density polyethylene, MFR: 1.0g / 10min, density: 958kg / m 3 Evolue (registered trademark) SP3530 manufactured by Prime Polymer Co., Ltd. Linear low-density polyethylene (ethylene-1-hexene copolymer), MFR: 3.1 g / 10 min, density: 931 kg / m 3 Evolue (registered trademark) GD1588 manufactured by Prime Polymer Co., Ltd. Linear low-density polyethylene (ethylene-1-hexene copolymer), MFR: 2.3 g / 10 min, density: 926 kg / m 3 HI-ZEX (registered trademark) 2200J manufactured by Prime Polymer Co., Ltd. High density polyethylene, MFR: 5.2g / 10min, density: 964kg / m 3 Evolue (registered trademark) SP4020 manufactured by Prime Polymer Co., Ltd. Linear low-density polyethylene (ethylene-1-hexene copolymer), MFR: 1.8 g / 10 min, density: 936 kg / m 3

[0068] [Physical properties of ethylene polymers] <Melt flow rate (MFR: [g / 10 min])> Measurement was carried out in accordance with JIS K7210 under conditions of 190°C and a load of 2.16 kg (kgf).

[0069] <Density [kg / m 3 ]> The MFR was measured by the density gradient tube method in accordance with JIS K7112 using the strand obtained during the MFR measurement.

[0070] <Melting point [℃]> Using a differential scanning calorimeter, the sample was heated from -30°C to 230°C at a rate of 10°C / min under the following measurement conditions, held at 230°C for 10 minutes, cooled to -30°C at a rate of 10°C / min, held at -30°C for 1 minute, and then heated to 230°C at a rate of 10°C / min. The temperature at which an endothermic peak was observed during the second heating was taken as the melting point (°C). If there were multiple endothermic peaks, the temperature at which the peak height was greatest was taken as the melting point (°C). To determine the magnitude of peak height, a baseline was drawn in the temperature range from 20°C to 150°C, as in the case of requirements (a2) (ΔH 55% melting temperature [°C]) and (a3) ​​(amount of components with ΔH of 90°C or less) below. The value of this baseline was subtracted from the heat of fusion curve, and the magnitude of the peak height was determined. (Measurement conditions) Differential scanning calorimeter: (PerkinElmer Diamond DSC) Measurement environment: Nitrogen gas atmosphere Sample amount: 5 mg

[0071] <ΔH55% melting temperature [℃]> The ΔH55% melting temperature is the temperature at which the ratio of the heat of fusion to ΔH becomes 55%, when the total amount of heat of fusion observed during the second temperature rise in the DSC measurement is ΔH. Specifically, a baseline was drawn in the temperature range from 20°C to 150°C on the DSC curve during the second heating, and the value of that baseline was subtracted from the DSC curve. The remaining area was taken as the total heat of fusion (ΔH). It was determined whether the temperature at which that area became 55% (ΔH55% melting temperature) was 110°C or higher.

[0072] <Amount of components below ΔH90℃ [%]> The total heat of fusion observed during the second temperature rise in the DSC measurement was defined as ΔH, and the heat of fusion observed during the temperature rise from -30°C to 90°C was defined as ΔH(90), and the ratio of ΔH(90) to ΔH was calculated. In Table 1, the ratio of ΔH(90) to ΔH is referred to as the amount of ΔH below 90°C.

[0073] <Molecular weight distribution (Mw / Mn)> The weight average molecular weight (Mw) and number average molecular weight (Mn) of each ethylene polymer were measured by gel permeation chromatography (GPC), and calculations were performed in terms of polyethylene. The molecular weight distribution (Mw / Mn) was calculated from the obtained Mw and Mn. The GPC measurement conditions were as follows: (Measurement conditions) Measurement equipment: Gel permeation chromatograph GPC / HT type (Tosoh Corporation) Analysis software: Data processing software Empower3 (Waters) Column: 2 x TSKgel GMH6-HT + 2 x TSKgel GMH6-HTL (Both have an inner diameter of 7.5 mm and a length of 30 cm, manufactured by Tosoh Corporation)

[0074] [Physical properties of film and dry laminate] <Dart impact strength [g]> Measurement was carried out according to ASTM D 1709 Method A under the following conditions. Test pieces (80 μm thick) cut from the films obtained in the Examples and Comparative Examples were clamped with an air clamp, and a hemispherical dart was dropped from a fixed height to determine the load (g) at which the test piece broke 50%. The number of drops per level was 10.

[0075] <Gross [%]> In accordance with JIS Z 8741, light from a standard light source was directed at the test piece at an angle of 20°, and the specular reflection component was measured with a photoreceiver.

[0076] <Haze [%]> The total haze of the resulting film was measured in accordance with ASTM D1003.

[0077] <Heat-resistant temperature [℃]> When the dry laminate was sterilized at any temperature for 5 minutes, the temperature at which no wrinkles or fusion occurred was determined as the heat resistance temperature.

[0078] [Example 1, Comparative Example 3] Each ethylene polymer was subjected to inflation molding under the following molding conditions to obtain a film having a thickness of 80 μm. The resulting film was tested for dart impact strength, gloss, and haze, and the results are shown in Table 1. (Film molding conditions) Molding machine: Modern Machinery Co., Ltd., 65mmφ inflation molding machine Molding temperature: 190℃ Extrusion rate: 80 kg / h

[0079] Next, a substrate (thickness 12 μm) made of a biaxially stretched PET film (OPET) was attached as a substrate layer to the film obtained above using an anchor coating agent, to obtain a dry laminate. The dry laminate obtained as described above was subjected to a heat resistance temperature test. The results are shown in Table 1.

[0080] [Examples 2 and 3, Comparative Examples 1 and 2] Each ethylene polymer was cast under the following conditions to obtain a film having a thickness of 80 μm. The resulting film was tested for dart impact strength, gloss, and haze, and the results are shown in Table 1. (Film molding conditions) Molding machine: Modern Machinery Co., Ltd., 65mmφ cast molding machine Molding temperature: 230℃, cooling temperature: 40℃ Extrusion rate: 72 kg / h

[0081] Next, a substrate (thickness 15 μm) made of a biaxially stretched Ny film (ONy) was attached as a substrate layer to the film obtained above using an anchor coating agent, to obtain a dry laminate. The dry laminate obtained as described above was subjected to a heat resistance temperature test. The results are shown in Table 1.

[0082] [Table 1]

Claims

1. A film containing an ethylene polymer (X) that satisfies the following requirements (a1) to (a3): (a1) The melt flow rate measured in accordance with JIS K 7210 at 190°C under a load of 2.16 kg is 0.5 to 10 g / 10 min. (a2) Using a differential scanning calorimeter, the sample is heated from -30°C to 230°C at a rate of 10°C / min, held at 230°C for 10 minutes, cooled to -30°C at a rate of 10°C / min, held at -30°C for 1 minute, and then heated to 230°C at a rate of 10°C / min for the second time. When the total amount of heat of fusion observed during this second heating is ΔH, the temperature at which the ratio of the heat of fusion to ΔH is 55% is 111°C or higher. (a3) Using a differential scanning calorimeter, the sample is heated from -30°C to 230°C at a rate of 10°C / min, held at 230°C for 10 minutes, cooled to -30°C at a rate of 10°C / min, held at -30°C for 1 minute, and then heated to 230°C at a rate of 10°C / min. During the second heating cycle, the total amount of heat of fusion observed is ΔH, and the heat of fusion observed during the heating cycle from -30°C to 90°C is ΔH(90). The ratio of ΔH(90) to ΔH is 14% or more.

2. 2. The film according to claim 1, wherein the ethylene polymer (X) has a melt flow rate of 1.0 to 10 g / 10 min as measured in accordance with JIS K 7210 at 190°C under a load of 2.16 kg.

3. The film according to claim 1, wherein the ethylene polymer (X) satisfies the following requirement (a4) in addition to the requirements (a1) to (a3): (a4) Density is 918 to 950 kg / m 3 is.

4. The ethylene polymer (X) Density: 906 to 921 kg / m 3 and 10 to 99 mass% of an ethylene polymer (P) having a density of 940 to 960 kg / m 3 and 1 to 90 mass% of an ethylene-based polymer (Q) represented by the formula (I) (wherein the total amount of the ethylene-based polymer (P) and the ethylene-based polymer (Q) is 100 mass%).

5. A laminate comprising the film according to any one of claims 1 to 4.

6. A laminate having an outer layer, an intermediate layer, and an inner layer, wherein the intermediate layer comprises the film according to any one of claims 1 to 4.

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