Resin compositions, laminates, and packaging materials

Abstract

[Problem] To provide a resin composition which is capable of constituting a multilayer body that has excellent extrusion lamination processability, heat resistance and flexibility, and the like. [Solution] A resin composition which contains the four components described below at a specific content ratio. (A) A propylene polymer that satisfies the following requirements: (A-1) the MFR is 0.1 to 60 g / 10 minutes; (A-2) the density is 886 to 930 kg / m3; and (A-3) the melting point is 130 to 170°C. (B) A propylene polymer that satisfies the following requirements: (B-1) the MFR is 0.1 to 60 g / 10 minutes; (B-2) the density is 855 to 885 kg / m3; (B-3) the melting point is 130 to 170°C; and (B-4) the Shore A hardness is 65 to 90. (C) An ethylene polymer that satisfies the following requirements: (C-1) the MFR is 0.2 to 10 g / 10 minutes; (C-2) the density is 855 to 913 kg / m3; and (C-3) the melting point is less than 130°C. (D) A low-density polyethylene that satisfies the following requirements: (D-1) the MFR is 0.1 to 50 g / 10 minutes; and (D-2) the density is 914 to 935 kg / m3.

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a laminate having a layer containing the resin composition, and a packaging material. [Background technology]

[0002] Due to the diverse range of applications for sealant films, which are included in the raw materials of packaging materials, research into olefin resin compositions that make up the films is actively underway to impart functions suitable for each application. Among these, films using polypropylene are excellent in terms of flexibility and heat resistance. However, polypropylene films are inferior in terms of extrusion lamination processability, low-temperature sealing properties, and blocking resistance, and improvements are needed. In particular, extrusion lamination, one of the lamination methods for substrates, is a widely used technology that allows thin layers of resin to be laminated onto sheet-like substrates, and improving the extrusion lamination processability of polypropylene films is important in the field of sealant films.

[0003] Polypropylene films used for packaging materials include, for example, resin compositions containing polypropylene, ethylene polymers, and low-density polyethylene, and the effects of each resin composition, such as improved extrusion lamination properties (see Patent Document 1), ease of peeling (see Patent Document 2), and low-temperature sealing properties (see Patent Document 3), are described. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 52-24553 [Patent Document 2] Japanese Patent Publication No. 2017-066305 [Patent Document 3] Japanese Patent Application Publication No. 56-40549 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Generally, for imparting extrusion lamination processability, a method of blending low-density polyethylene with polypropylene may be used. Patent Document 1 describes a resin composition in which the extrusion lamination processability is improved by further adding an ethylene-based polymer, but it has been difficult to maintain the heat resistance and flexibility, which are the characteristics of polypropylene resin. Also, regarding the resin compositions described in Patent Documents 2 and 3, problems remained with respect to heat resistance and flexibility.

[0006] An object of the present invention is to provide a resin composition capable of forming a laminate and a packaging material that are excellent in extrusion lamination processability and have an excellent balance of heat resistance and flexibility, by focusing on the problems of the polypropylene film as described above.

Means for Solving the Problems

[0007] The present invention relates to, for example, the following [1] to [3]. [1] A propylene-based polymer (A) satisfying the following requirements (A-1) to (A-3), A propylene-based polymer (B) satisfying the following requirements (B-1) to (B-4), An ethylene-based polymer (C) satisfying the following requirements (C-1) to (C-3), A resin composition containing a low-density polyethylene (D) satisfying the following requirements (D-1) and (D-2), where the content of the polymer (A) is in the range of 30.0% by mass or more and 95.0% by mass or less, the content of the polymer (B) is in the range of 2.0% by mass or more and 50.0% by mass or less, the content of the polymer (C) is in the range of 1.0% by mass or more and 20.0% by mass or less, the content of the low-density polyethylene (D) is in the range of 1.0% by mass or more and 20.0% by mass or less (however, the total content of the polymer (A), the polymer (B), the polymer (C), and the low-density polyethylene (D) is 100% by mass), resin composition: (A-1) It complies with JIS K 7210 and has a melt flow rate measured at a temperature of 230 °C and a load of 2.16 kg of 0.1 to 60 g / 10 min; (A-2) The density measured in accordance with JIS K 7112 is 886 to 930 kg / m 3 ; (A-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is 130 to 170 °C; (B-1) It complies with JIS K 7210 and has a melt flow rate measured at a temperature of 230 °C and a load of 2.16 kg of 0.1 to 60 g / 10 min; (B-2) The density measured in accordance with JIS K 7112 is 855 to 885 kg / m 3 ; (B-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is 130 to 170 °C; (B-4) The Shore A hardness measured in accordance with ASTM D2240 is 65 to 90; (C-1) It complies with JIS K 7210 and has a melt flow rate measured at a temperature of 230 °C and a load of 2.16 kg of 0.2 to 10 g / 10 min; (C-2) The density measured in accordance with JIS K 7112 is 855 to 913 kg / m 3 ; (C-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is less than 130 °C; (D-1) It complies with JIS K 7210 and has a melt flow rate measured at a temperature of 190 °C and a load of 2.16 kg of 0.1 to 50 g / 10 min; (D-2) The density measured in accordance with JIS K 7112 is 914 to 935 kg / m 3 . [2] A laminate having a layer containing the resin composition described in [1]. [3] A packaging material having a layer containing the resin composition described in [1]. [Advantages of the Invention]

[0008] The resin composition of the present invention, by adding an ethylene polymer (C) and a propylene polymer (B) (different from the polypropylene resin) to a polypropylene resin (propylene polymer (A)) and low-density polyethylene (D), improves the compatibility between the polypropylene resin and the low-density polyethylene, and the laminate using this resin composition exhibits significantly improved extrusion lamination processability. Furthermore, the laminate using this resin composition is a well-balanced laminate with excellent extrusion lamination processability, flexibility, and heat resistance without significantly impairing the heat resistance, which is a property derived from propylene resin. [Modes for carrying out the invention]

[0009] The resin composition and other aspects of the present invention will be described in detail below. The present invention is not limited to the following embodiments and can be implemented with various modifications within the scope of its gist. In the present invention, "~" includes both ends of the value. For example, "0.1~60g / 10min" includes both values ​​of 0.1g / 10min and 60g / 10min, indicating a range of "0.1g / 10min or more and 60g / 10min or less".

[0010] [Resin composition] The resin composition of the present invention comprises a propylene polymer (A), a propylene polymer (B), an ethylene polymer (C), and low-density polyethylene (D), wherein the content of polymer (A) is 30.0% by mass or more and 95.0% by mass or less, the content of polymer (B) is 2.0% by mass or more and 50.0% by mass or less, the content of polymer (C) is 1.0% by mass or more and 20.0% by mass or less, and the content of low-density polyethylene (D) is 1.0% by mass or more and 20.0% by mass or less (provided that the total content of polymer (A), polymer (B), polymer (C), and low-density polyethylene (D) is 100% by mass).

[0011] Furthermore, each of the four components mentioned above satisfies the following requirements. (A) Propylene polymers that satisfy the following requirements (A-1) to (A-3) (A-1) In accordance with JIS K 7210, the melt flow rate measured at a temperature of 230°C and a load of 2.16 kg is 0.1 to 60 g / 10 min. (A-2) Density measured in accordance with JIS K 7112 is 886-930 kg / m³ 3 That is the case. (A-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is 130-170°C.

[0012] (B) Propylene polymers that satisfy the following requirements (B-1) to (B-4) (B-1) In accordance with JIS K 7210, the melt flow rate measured at a temperature of 230°C and a load of 2.16 kg is 0.1 to 60 g / 10 min. (B-2) Density measured in accordance with JIS K 7112 is 855-885 kg / m³ 3 That is the case. (B-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is 130-170°C. (B-4) The Shore A hardness measured in accordance with ASTM D2240 is 65-90.

[0013] (C) Ethylene polymers that satisfy the following requirements (C-1) to (C-3) (C-1) In accordance with JIS K 7210, the melt flow rate measured at a temperature of 230°C and a load of 2.16 kg is 0.2 to 10 g / 10 min. (C-2) Densities measured in accordance with JIS K 7112 were 855-913 kg / m³ 3 That is the case. (C-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is less than 130°C.

[0014] (D) Low-density polyethylene that meets the following requirements (D-1) and (D-2) (D-1) In accordance with JIS K 7210, the melt flow rate measured at a temperature of 190°C and a load of 2.16 kg was 0.1 to 50 g / 10 min. (D-2) Density measured in accordance with JIS K 7112 is 914-935 kg / m³3 That is the case.

[0015] <Propylene-based polymer (A)> The resin composition of the present invention contains a propylene-based polymer (A) that satisfies the above requirements (A-1) to (A-3). Examples of the polymer (A) include a propylene homopolymer, a random copolymer of propylene and an α-olefin having 2 or 4 to 20 carbon atoms, and a propylene block copolymer, preferably a propylene homopolymer or a random copolymer of propylene and an α-olefin having 2 or 4 to 20 carbon atoms. The polymer (A) used in the present invention may be one type of (co)polymer or two or more types of (co)polymers.

[0016] In the resin composition of the present invention, from the viewpoint of imparting heat resistance and rigidity to the sealant film, it is particularly preferable to use a propylene homopolymer, while from the viewpoint of imparting flexibility and transparency to the sealant film, it is particularly preferable to use a random copolymer of propylene and an α-olefin having 2 or 4 to 20 carbon atoms.

[0017] Examples of α-olefins having 2 or 4 to 20 carbon atoms that copolymerize with propylene include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Among these, ethylene, 1-butene, 1-hexene, and 1-octene are preferred, and ethylene and 1-butene are even more preferred.

[0018] (Requirement (A-1)) The polymer (A) complies with JIS K 7210 and has a melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg of 0.1 to 60 g / 10 min, preferably 0.2 to 55 g / 10 min, more preferably 0.3 to 50 g / 10 min. By using the polymer (A) within the above range, the extrusion lamination processability of the resin composition can be improved.

[0019] (Requirement (A-2)) The polymer (A) has a density measured in accordance with JIS K 7112 of 886 to 930 kg / m 3 and preferably 890 to 920 kg / m 3 more preferably 900 to 915 kg / m 3 By using the polymer (A) within the above range, heat resistance and flexibility can be imparted to the film using the resin composition. In addition, all densities in the present invention are values calculated by rounding the first decimal place of the measured value.

[0020] (Requirement (A-3)) The polymer (A) has a melting point (Tm) measured by differential scanning calorimetry (DSC) of 130°C or higher and 170°C or lower, preferably 131°C or higher and 165°C or lower, more preferably 132°C or higher and 160°C or lower. By using the polymer (A) within the above range, heat resistance and flexibility can be imparted to the film using the resin composition.

[0021] The melting point (Tm) of the polymer (A) is, for example, measured using a differential scanning calorimeter , Nitrogen in a nitrogen atmosphere (20 mL / min), after heating about 5 mg of the sample to 200°C and holding for 10 minutes, cooling to -30°C at 10°C / min and holding for 5 minutes, and then heating to 200°C at 10°C / min, the temperature at the peak of the crystal melting peak is taken as the melting point (Tm) of the polymer. When multiple peaks are detected, the peak detected on the highest temperature side is adopted.

[0022] (Method for producing polymer (A)) The polymer (A) can be produced by polymerizing monomers in the presence of known catalysts such as Ziegler-Natta catalysts and metallocene catalysts using known polymerization methods such as gas-phase, bulk, and slurry methods.

[0023] The polymer (A) is not particularly limited as long as it satisfies the requirements (A-1) to (A-3) above, and may be a commercially available product. Examples of commercially available products include the "Prime Polypro (registered trademark)" series manufactured by Prime Polymer Co., Ltd.

[0024] <Propylene-based polymer (B)> The resin composition of the present invention contains a propylene-based polymer (B) that satisfies the above requirements (B-1) to (B-4). Examples of polymer (B) are similar to those of polymer (A), and are preferably a propylene homopolymer or a random copolymer of propylene and an α-olefin having 2 or 4 to 20 carbon atoms. The copolymer (B) used in the present invention may be one type of copolymer or two or more types of copolymers.

[0025] In the resin composition of the present invention, from the viewpoint of imparting heat resistance and rigidity to the sealant film, it is particularly preferable to use a propylene homopolymer, while from the viewpoint of imparting flexibility and transparency to the sealant film, it is particularly preferable to use a random copolymer of propylene and an α-olefin having 2 or 4 to 20 carbon atoms.

[0026] Examples of α-olefins having 2 or 4 to 20 carbon atoms copolymerized with propylene include the same α-olefins as those listed in polymer (A) above, most preferably ethylene, 1-butene, 1-hexene, and 1-octene, and more preferably ethylene and 1-butene.

[0027] (Requirement (B-1)) The polymer (B) has a melt flow rate (MFR) of 0.1 to 60 g / 10 min, preferably 0.2 to 55 g / 10 min, and more preferably 0.3 to 50 g / 10 min, measured in accordance with JIS K 7210 at a temperature of 230°C and a load of 2.16 kg. By using polymer (B) with an MFR within the above range, the extrusion lamination processability of the resin composition can be improved.

[0028] (Requirement (B-2)) The aforementioned polymer (B) has a density of 855-885 kg / m³, as measured in accordance with JIS K 7112. 3 The preferred weight is 858-880 kg / m³. 3 , more preferably 860-875 kg / m 3 Yes. By using a polymer (B) whose density is within the aforementioned range, heat resistance and flexibility can be imparted to a film using a resin composition.

[0029] (Requirement (B-3)) The polymer (B) has a melting point (Tm) of 130 to 170°C, preferably 131 to 165°C, and more preferably 132 to 160°C, as measured by differential scanning calorimetry (DSC). By using polymer (B) with a Tm within the above range, heat resistance and flexibility can be imparted to the film using the resin composition. The melting point (Tm) of polymer (B) is measured by the same method as described for polymer (A).

[0030] (Requirement (B-4)) The polymer (B) has a Shore A hardness of 65 to 90, preferably 67 to 89, and more preferably 70 to 88, as measured in accordance with ASTM D2240. By using polymer (B) with a Shore A hardness within the above range, heat resistance and flexibility can be imparted to films using the resin composition. The Shore A hardness is obtained by heating and melting the sample at 190 to 230°C, then press-molding it at a cooling temperature of 15 to 25°C, storing the test specimen in an environment of 23±2°C for 72 hours or more, and reading the scale immediately after contact with the indenter using a Type A measuring instrument.

[0031] (Method for producing polymer (B)) The polymer (B) can be produced by polymerizing monomers using known polymerization methods such as gas-phase, bulk, or slurry methods in the presence of known catalysts such as Ziegler-Natta catalysts or metallocene catalysts.

[0032] The polymer (B) is not particularly limited as long as it satisfies the requirements (B-1) to (B-4) above, and may be a commercially available product. Examples of commercially available products include the "Tafmer® PN" series manufactured by Mitsui Chemicals, Inc.

[0033] <Ethylene-based polymer (C)> The resin composition of the present invention contains an ethylene-based polymer (C) that satisfies the above requirements (C-1) to (C-3). Examples of the polymer (C) include an ethylene homopolymer, a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and an ethylene block copolymer, preferably an ethylene homopolymer or a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Used in the present invention heavy The combined copolymer (C) may be one type of copolymer or two or more types of copolymers.

[0034] In the resin composition of the present invention, from the viewpoint of imparting heat resistance and rigidity to the sealant film, it is particularly preferable to use an ethylene homopolymer, while from the viewpoint of imparting flexibility and transparency to the sealant film, it is particularly preferable to use a random copolymer of ethylene and a carbon atom having 3 to 20 atoms.

[0035] Examples of α-olefins having 3 to 20 carbon atoms that copolymerize with ethylene include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Among these, α-olefins having 3 to 10 carbon atoms are preferred, and more preferably α-olefins having 3 to 8 carbon atoms, such as propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

[0036] (Requirement (C-1)) The polymer (C) has a melt flow rate (MFR) of 0.2 to 10 g / 10 min, preferably 0.3 to 9 g / 10 min, and more preferably 0.4 to 8.5 g / 10 min, measured in accordance with JIS K 7210 at a temperature of 230°C and a load of 2.16 kg. (C) By using this method, the extrusion lamination processability of the resin composition can be improved.

[0037] (Requirement (C-2)) The aforementioned polymer (C) has a density of 855-913 kg / m³, as measured in accordance with JIS K 7112. 3 Preferably 856-910 kg / m 3 More preferably 857-905 kg / m 3 Therefore, by using a polymer (C) whose density is within the aforementioned range, the extrusion lamination processability of the resin composition can be improved.

[0038] (Requirement (C-3)) The polymer (C) has a melting point (Tm) of less than 130°C, preferably less than 120°C, and more preferably less than 110°C, as measured by differential scanning calorimetry (DSC). By using a polymer (C) with a Tm within the above range, flexibility can be imparted to a film using a resin composition. The melting point (Tm) of polymer (C) can be measured using the same method as described for polymer (A).

[0039] (Method for producing polymer (C)) The polymer (C) can be produced by polymerizing monomers using known polymerization methods such as gas-phase, bulk, or slurry methods in the presence of known catalysts such as Ziegler-Natta catalysts or metallocene catalysts.

[0040] The polymer (C) is not particularly limited as long as it satisfies the requirements (C-1) to (C-3) above, but it may be a commercially available product. Examples of commercially available products include the "Tafmer P" series and "Tafmer® A" series manufactured by Mitsui Chemicals, Inc., the "Evolu®" series manufactured by Prime Polymer Co., Ltd., and the "SABIC® COHERE S" series manufactured by Saudi Basic Industries Corporation.

[0041] before Record Copolymer (C) can be produced by polymerizing monomers using known polymerization methods such as gas-phase, bulk, or slurry methods in the presence of known catalysts such as Ziegler-Natta catalysts or metallocene catalysts. One example of a method to set the melting point to, for example, less than 120°C is to control polymerization conditions such as the amount of monomer feed, and by this method, copolymers having a target melting point can be obtained.

[0042] <Low-density polyethylene (D)> The resin composition of the present invention contains low-density polyethylene (D) that satisfies the above requirements (D-1) and (D-2). Examples of the low-density polyethylene (D) include ethylene homopolymers, random copolymers of ethylene and α-olefins having 3 to 20 carbon atoms, and ethylene block copolymers, preferably ethylene homopolymers or random copolymers of ethylene and α-olefins having 3 to 20 carbon atoms. The low-density polyethylene (D) used in the present invention may be one copolymer or two or more copolymers.

[0043] In the resin composition of the present invention, from the viewpoint of imparting heat resistance and rigidity to the sealant film, it is particularly preferable to use an ethylene homopolymer, while from the viewpoint of imparting flexibility and transparency to the sealant film, it is particularly preferable to use a random copolymer of ethylene and a carbon atom having 3 to 20 atoms.

[0044] Examples of α-olefins having 3 to 20 carbon atoms that copolymerize with ethylene include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Among these, ethylene, 1-butene, 1-hexene, and 1-octene are preferred, and ethylene, 1-butene, and 1-hexene are even more preferred.

[0045] (Requirement (D-1)) The low-density polyethylene (D) has a melt flow rate (MFR) of 0.1 to 50 g / 10 min, preferably 0.2 to 45 g / 10 min, and more preferably 0.3 to 40 g / 10 min, measured in accordance with JIS K 7210 at a temperature of 190°C and a load of 2.16 kg. By using low-density polyethylene (D) with an MFR within the above range, the extrusion lamination processability of the resin composition can be improved.

[0046] (Requirement (D-2)) The aforementioned low-density polyethylene (D) has a density of 914-935 kg / m³, as measured in accordance with JIS K 7112. 3 The load is preferably 915-933 kg / m³. 3 A comfortable 916-930 kg / m 3 Therefore, by using low-density polyethylene (D) with a density within the aforementioned range, the extrusion lamination processability of the resin composition can be improved.

[0047] (Method for manufacturing low-density polyethylene (D)) Generally, polyethylene with a density within the above range is called low-density polyethylene, and in the present invention, for example, high-pressure low-density polyethylene can be used. The high-pressure method is a method of polymerizing ethylene using oxygen or a radical initiator as a catalyst under conditions of approximately 1,000 to 4,000 atmospheres and 100 to 350°C.

[0048] The polymer (D) is not particularly limited as long as it satisfies requirements (D-1) and (D-2), but it may be a commercially available product. Examples of commercially available products include the "Mirazon®" series manufactured by Mitsui Dow Polychemical Co., Ltd.

[0049] The polymers (A) to (C) and low-density polyethylene (D) used in the present invention may contain biomass-derived α-olefins in the α-olefins that constitute these polymers. That is, the α-olefins that constitute the polymers may consist solely of biomass-derived α-olefins, or they may contain both biomass-derived α-olefins and fossil fuel-derived α-olefins. Biomass-derived α-olefins are α-olefins made from any renewable natural raw materials and their residues, including fungi, yeasts, algae, and bacteria, which are of plant or animal origin, and which contain carbon as 14 C 10 isotopes -12 It contains a certain proportion, and the biomass carbon concentration (unit: pMC) measured in accordance with ASTM D 6866 is approximately 100 pMC. Biomass-derived α-olefins can be obtained by conventionally known methods.

[0050] It is preferable from the viewpoint of reducing environmental impact (mainly greenhouse gas reduction) that the α-olefins constituting the polymers (A) to (C) and low-density polyethylene (D) used in the present invention include biomass-derived α-olefins. If the polymer production conditions such as polymerization catalyst, polymerization process, and polymerization temperature are equivalent, it is preferable that the raw material α-olefins include biomass-derived α-olefins. 14 C 10 isotopes -12 ~10 -14Aside from the small proportion it contains, its molecular structure is equivalent to that of a propylene polymer made from fossil fuel-derived α-olefins. Therefore, its performance is considered to be the same.

[0051] The polymers (A) to (C) and low-density polyethylene (D) used in the present invention may contain chemically recycled α-olefins in the α-olefins constituting the polymer. That is, the α-olefins constituting the polymer may consist solely of chemically recycled α-olefins, or they may contain chemically recycled α-olefins, fossil fuel-derived α-olefins, and / or biomass-derived α-olefins. Chemically recycled α-olefins can be obtained by conventionally known methods.

[0052] The inclusion of chemically recycled α-olefins in the propylene-based polymer according to the present invention is preferable from the viewpoint of reducing environmental impact (mainly waste reduction). Even if the raw material monomers include chemically recycled monomers, chemically recycled monomers are monomers obtained by depolymerizing polymers such as waste plastics, by thermal decomposition, etc., back to monomer units such as propylene, and monomers produced using such monomers as raw materials. Therefore, if the polymer production conditions such as polymerization catalysts, polymerization processes, and polymerization temperatures are the same, the molecular structure is equivalent to that of polymers made from fossil fuel-derived monomers. Consequently, the performance is also considered to be unchanged.

[0053] <Resin composition> The resin composition of the present invention comprises polymer (A), polymer (B), polymer (C), and low-density polyethylene (D). The content of each component is described below, but the total content of the four components is 100% by mass.

[0054] The content of polymer (A) is 30.0% by mass or more and 95.0% by mass or less, preferably 40.0% by mass or more and 93.0% by mass or less, and more preferably 45.0% by mass or more and 90.0% by mass or less. When the content of polymer (A) is within the above range, the film has excellent processability and heat resistance.

[0055] The content of polymer (B) is 2.0% by mass or more and 50.0% by mass or less, preferably 3.0% by mass or more and 40.0% by mass or less, and more preferably 4.0% by mass or more and 30.0% by mass or less. When the content of polymer (B) is within the above range, the film exhibits excellent flexibility and heat resistance.

[0056] The content of polymer (C) is 1.0% by mass or more and 20.0% by mass or less, preferably 1.0% by mass or more and 15.0% by mass or less, and more preferably 1.0% by mass or more and 10.0% by mass or less. When the content of polymer (C) is within the above range, the resin composition exhibits excellent extrusion lamination properties and the film has excellent heat resistance.

[0057] The content of the low-density polyethylene (D) is 1.0% by mass or more and 20.0% by mass or less, preferably 2.0% by mass or more and 15.0% by mass or less, and more preferably 3.0% by mass or more and 10.0% by mass or less. When the content of low-density polyethylene (D) is within the above range, the resin composition exhibits excellent extrusion lamination processability and the film has excellent heat resistance.

[0058] The aforementioned resin composition has a melt flow rate (MFR) measured in accordance with JIS K 7210 at a temperature of 230°C and a load of 2.16 kg, preferably 1.0 to 20 g / 10 min, and more preferably 3.0 to 15 g / 10 min. An MFR within this range indicates that the resin composition has sufficient extrusion lamination properties. By including the above four components, each satisfying the requirements, within the above range, the compatibility of each component is increased, significantly improving the extrusion lamination properties.

[0059] The resin composition of the present invention may be manufactured by any method, but it is preferable to manufacture it by melt-kneading each of the above components. Specifically, for example, the above four components may be charged into a tumbler mixer, V-type mixer, ribbon mixer, Henschel mixer, etc., and kneaded, and then melt-kneaded in a single-screw extruder, multi-screw extruder, kneader, Banbury mixer, etc.

[0060] The resin composition of the present invention is useful as a sealant film, and a film can be manufactured by extruding the resin composition of the present invention. In the present invention, a film refers to a sheet-like molded product with a thickness of 800 μm or less. The thickness of the film is preferably 1 to 300 μm, and more preferably 3 to 200 μm.

[0061] The sealant film may optionally contain additives such as polymers (A) to (C) and low-density polyethylene (D), resins other than the polymers (A) to (C), tackifiers, weather stabilizers, heat stabilizers, antistatic agents, anti-slip agents, anti-blocking agents, lubricants, pigments, dyes, plasticizers, anti-aging agents, hydrochloric acid absorbers, antioxidants, and nucleating agents, to the extent that it does not impair the objectives of the present invention.

[0062] [Laminated structure] The laminate of the present invention has a layer containing the above-described resin composition. That is, the laminate of the present invention comprises the sealant film as a sealant layer. A laminate is a structure in which a plurality of layers are laminated. The laminate of the present invention has a structure in which the sealant layer and the substrate layer are laminated.

[0063] <Base material layer> The resin composition constituting the base layer is preferably polypropylene. Examples of polypropylene include propylene homopolymers and copolymers with propylene as the main monomer. In the case of copolymers, they may be random copolymers or block copolymers. Examples of monomers copolymerized with propylene include α-olefins having 2 or 4 to 20 carbon atoms, and diene compounds. The polypropylene contains 85 to 100 mol%, preferably 90 to 99.5 mol%, of structural units derived from propylene, and 0 to 15 mol%, preferably 0.5 to 10 mol%, of structural units derived from other monomers (however, propylene-derived structure The sum of the units and structural units derived from other monomers is 100 mol%.

[0064] Examples of α-olefins having 2 or 4 to 20 carbon atoms that copolymerize with propylene include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and 1-tetradecene.

[0065] The polypropylene constituting the base layer can be produced by polymerizing monomers in the presence of known catalysts such as Ziegler-Natta catalysts and metallocene catalysts using known polymerization methods such as gas-phase, bulk, and slurry methods. The polypropylene contained in the base layer may be the same as or different from polymer (A) or (B) contained in the resin composition constituting the sealant layer described above.

[0066] The substrate layer may consist of a single layer or multiple layers. The substrate layer may optionally contain additives such as resins other than polypropylene, tackifiers, weather stabilizers, heat stabilizers, antistatic agents, anti-slip agents, anti-blocking agents, lubricants, pigments, dyes, plasticizers, anti-aging agents, hydrochloric acid absorbers, antioxidants, and nucleating agents, to the extent that it does not impair the objectives of the present invention.

[0067] When the sealant film is used as a sealant layer in the laminate of the present invention, its thickness is usually 3 to 30 μm, preferably 5 to 25 μm, and the thickness of the substrate layer is usually 10 to 100 μm, preferably 20 to 50 μm. If there are multiple sealant layers, it is preferable that the thickness of each sealant layer be within the above range. The overall thickness of the laminate of the present invention is usually 20 to 100 μm, preferably 25 to 70 μm.

[0068] The laminate of the present invention may be manufactured by laminating a sealant layer and a substrate layer by dry lamination, non-solvent lamination, sand lamination, etc., or by laminating a sealant layer and a substrate layer by melt extrusion lamination. Since the resin composition of the present invention has excellent extrusion lamination processability, the laminate of the present invention is preferably manufactured by melt extrusion lamination.

[0069] <Packaging materials> A layer containing the resin composition of the present invention can be suitably used in packaging materials. The packaging material of the present invention having a layer containing the resin composition of the present invention exhibits excellent processability, heat resistance, and flexibility.

[0070] The packaging material can be formed, for example, from a laminate having layers containing the resin composition of the present invention. Specifically, the packaging material can be manufactured by facing the sealant layers of the laminate toward each other, or facing the sealant layers of the laminate toward another film, and then heat-sealing at least a portion of the periphery from the outer surface side to form a desired container shape. Alternatively, a sealed packaging material can be manufactured by heat-sealing the entire periphery. This packaging material can be used in automatic packaging devices for solids such as snack foods and bread, powders, or liquid materials.

[0071] Furthermore, a container can be obtained by filling a container, such as one pre-formed into a cup shape by vacuum forming or pressure forming from a laminate or sheet, a container obtained by injection molding, or a container formed from a paper substrate, with contents, then covering it with the laminate of the present invention as a lid material, and heat-sealing the top or sides of the container. This container is suitable for packaging instant noodles, miso, jelly, pudding, snack foods, and the like. [Examples]

[0072] Next, the laminate of the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. The materials used in the examples and comparative examples are shown below.。

[0073] (A) Propylene polymer (a-1) Polypropylene resin: Prime Polypro (registered trademark) F113A (manufactured by Prime Polymer Co., Ltd., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 3g / 10min, Density (compliant with JIS K 7112): 910kg / m³ 3 Melting point: 159 ℃ ) (a-2) Polypropylene resin: Prime Polypro (registered trademark) F327 (manufactured by Prime Polymer Co., Ltd., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 7g / 10min, Density (compliant with JIS K 7112): 910kg / m³ 3 Melting point: 137 ℃ ) (a-3) Polypropylene resin: Prime Polypro (registered trademark) F-744NP (manufactured by Prime Polymer Co., Ltd., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 7g / 10min, Density (compliant with JIS K 7112): 910kg / m³ 3 Melting point: 134 ℃ )

[0074] (B) Propylene polymer (b-1) Propylene elastomer: Toughmer (registered trademark) PN-2060 (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 6g / 10min, Density (compliant with JIS K 7112): 868kg / m³) 3 Melting point: 160 ℃ Shore A hardness (according to ASTM D2240): 84) (b-2) Propylene elastomer: Toughmer (registered trademark) PN-2070 (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 7g / 10min, Density (compliant with JIS K 7112): 868kg / m³) 3 Melting point: 140 ℃ Shore A hardness (according to ASTM D2240): 75)

[0075] (C) Ethylene polymer (c-1) Ethylene-propylene random copolymer: Tuffmer® P-0375 (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 3g / 10min, Density (compliant with JIS K 7112): 859kg / m³ 3 、 Melting point (Tm): 29℃) (c-2) Ethylene-propylene random copolymer: Tuffmer® P-0775 (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 0.6g / 10min, Density (compliant with JIS K 7112): 858kg / m³ 3 、 Melting point: 43℃) (c-3) Ethylene-propylene random copolymer: Tuffmer® P-0480 (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 1.8g / 10min, Density (compliant with JIS K 7112): 869kg / m³) 3 (Melting point (Tm): 43℃) (c-4) Ethylene-propylene random copolymer: Tuffmer® P-0680 (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 0.8g / 10min, Density (compliant with JIS K 7112): 869kg / m³) 3 (Melting point (Tm): 44℃) (c-5) Ethylene-butene copolymer: Tuffmer® A-0550S (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 0.9g / 10min, Density (compliant with JIS K 7112): 861kg / m³ 3 (Melting point (Tm): less than 50℃) (c-6) Ethylene polymer: Tuffmer (registered trademark) A-0585X (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 0.9g / 10min, Density (compliant with JIS K 7112): 885kg / m³) 3 (Melting point (Tm): 68℃) (c-7) Ethylene-butene copolymer: Tuffmer® A-0250S (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 0.5g / 10min, Density (compliant with JIS K 7112): 861kg / m³ 3 (Melting point (Tm): less than 50℃) (c-8) Linear low-density polyethylene: Evolu (registered trademark) SP0510 Prime Polymer Co., Ltd. Manufacturing, MFR (230℃, 2.16kg load, compliant with JIS K 7210): 2.3g / 10min, Density (compliant with JIS K 7112): 904kg / m³ 3 (Melting point (Tm): 98℃) (c-9) Linear low-density polyethylene: SABIC® COHERE S100 (manufactured by Saudi Basic Industries Corporation, MFR (230℃, 2.16kg load, compliant with JIS K 7210): 1.8g / 10min, Density (compliant with JIS K 7112): 900kg / m³) 3 (Melting point (Tm): 107℃) (c'-1) Ethylene-butene copolymer: Tuffmer® A-6050 (manufactured by Mitsui Chemicals, Inc., MFR (230℃, 2.16kg load, compliant with JIS K 7210): 12g / 10min, Density (compliant with JIS K 7112): 864kg / m³) 3 (Melting point (Tm): 68℃)

[0076] (D) Low-density polyethylene (d-1) Mirason® 11P (manufactured by Mitsui Dow Polychemical Co., Ltd., MFR (190℃, 2.16kg load, compliant with JIS K 7210): 7.2g / 10min, Density (compliant with JIS K 7112): 917kg / m³ 3 ) (d-2) Mirason® 16P (manufactured by Mitsui Dow Polychemical Co., Ltd., MFR (190℃, 2.16kg load, compliant with JIS K 7210): 3.7g / 10min, Density (compliant with JIS K 7112): 923kg / m³ 3 )

[0077] The melting point (Tm) of the polymer, the processability of the film, the heat resistance, and the flexibility were measured using the following methods.

[0078] [Melting point (Tm)] Using a differential scanning calorimeter (DSCPyris1, PerkinElmer), approximately 5 mg of the sample (polymer) was heated to 200°C under a nitrogen atmosphere (20 mL / min) and held for 10 minutes. Then, it was cooled to -30°C at 10°C / min and held for 5 minutes, and subsequently heated to 200°C at 10°C / min. The temperature at which the peak of the crystal melting peak was observed was defined as the melting point (Tm) of polymers (A) to (C).

[0079] [Workability] A casting apparatus was used in which the temperature of the resin composition extruded from the T-die of a 75mm diameter extruder was set to 270°C. Films were produced under the following conditions: cooling roll surface temperature of 60°C, die width of 680mm, die lip opening of 0.8mm, and air gap of 80mm. The screw rotation speed was gradually increased, and the processing speed at which a 5mm tremor occurred at either end of the molten film was defined as the maximum take-up speed. When increasing the processing speed, the screw rotation speed was gradually increased, and the extrusion amount was adjusted to ensure that the film thickness was always 20μm. The processability during extrusion lamination was evaluated according to the following criteria. ○: Maximum pickup speed exceeds 40 m / min. ×: The maximum pickup speed is 40 m / min or less.

[0080] [Heat resistance] Two 20 μm thick films, prepared using the film-forming method described above under [Processability], were sealed for 1 second each at a sealing pressure of 0.2 MPa and sealing temperatures of 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 150°C, 160°C, or 170°C using a heat sealer to prepare test specimens. For each test specimen, the peel strength was measured when the heat-sealed portion was peeled off at a speed of 300 mm / min in a 180° direction relative to the film surface using a tensile testing machine (RTG-1310, manufactured by A&D Co., Ltd.), and this was defined as the heat seal strength at each temperature. If the heat seal strength exceeds 1.5 N / m, it is assumed that thermal blocking is occurring. The highest temperature at which the heat seal strength remains below 1.5 N / m is defined as the heat resistance temperature, and the heat resistance of the film was evaluated according to the following criteria. ○: Heat resistance temperature is 120℃ or higher. ×: The heat resistance temperature is less than 120°C.

[0081] [Flexibility] Using a 20 μm thick film prepared by the film-forming method described above under [Processability], strip test pieces were prepared in accordance with JIS K 7161. Tensile testing was performed using a tensile testing machine (RTG-1310, manufactured by A&D Co., Ltd.) at a speed of 300 mm / min in the direction of resin flow (MD) or perpendicular direction (TD) at 180° to the film surface, and the elastic modulus of the film was measured in each direction. The flexibility of the film was evaluated according to the following criteria. ○: The modulus of elasticity in each direction is less than 1200 MPa. ×: The modulus of elasticity in each direction is 1200 MPa or higher.

[0082] [Example 1] The various raw materials used were mixed in the proportions listed in Table 1-1 using a mixer (Henschel mixer FM-150, manufactured by Mitsui Miike Seisakusho Co., Ltd.). The mixture was then melted and kneaded at 200°C with a discharge rate of 50 kg / h using a 65 mm single-screw extruder (manufactured by Tommy Machinery Industry Co., Ltd.). The molten resin extruded from the stand die was taken up while being cooled and solidified in a water tank, and then cut using a strand cutter to prepare a pellet-shaped resin composition with a diameter of approximately 3 mm. Using the aforementioned resin composition, a film was prepared by the film-forming method described in [Processability] above, and its processability, heat resistance, and flexibility were determined by the measurement method described above. The results are shown in Table 1-1.

[0083] [Examples 2-13, Comparative Examples 1-4] Pellet-shaped resin compositions were manufactured in the same manner as in Example 1, except that the various raw materials used in the resin composition were changed to the amounts shown in Table 1-1 or Table 1-2. Processability, heat resistance, and flexibility were determined for each of these resin compositions using the measurement method described above. The results are shown in Table 1-1 or Table 1-2.

[0084] [Example 14] The various raw materials used were mixed in the proportions listed in Table 1-2 using a mixer (Henschel mixer FM-150, manufactured by Mitsui Miike Seisakusho Co., Ltd.). The mixture was then melted and kneaded at 200°C at a discharge rate of 50 kg / h using a twin-screw extruder (manufactured by Ikegai Co., Ltd.). The molten resin extruded from the stand die was taken up while being cooled and solidified in a water tank, and cut using a strand cutter to prepare a pellet-shaped resin composition with a diameter of approximately 3 mm. Using the aforementioned resin composition, a film was prepared by the film-forming method described in [Processability] above, and its processability, heat resistance, and flexibility were determined by the measurement method described above. The results are shown in Table 1-2.

[0085] [Example 15, Comparative Example 5] The resin composition was prepared in the same manner as in Example 14, except that the various raw materials used were changed to the amounts shown in Table 1-2. resin composition They manufactured these. resin composition Using these materials, processability, heat resistance, and flexibility were determined according to the measurement method described above. The results are shown in Table 1-2.

[0086] Table 1-1

[0087] Table 1-2

Claims

1. A propylene polymer (A) that satisfies the following requirements (A-1) to (A-3), A propylene polymer (B) that satisfies the following requirements (B-1) to (B-4), An ethylene polymer (C) that satisfies the following requirements (C-1) to (C-3), A resin composition comprising low-density polyethylene (D) that satisfies the following requirements (D-1) and (D-2), The content of the polymer (A) is in the range of 30.0% by mass or more and 95.0% by mass or less. The content of the polymer (B) is in the range of 2.0% by mass or more and 50.0% by mass or less. The content of the polymer (C) is in the range of 1.0% by mass or more and 20.0% by mass or less. A resin composition having a content of low-density polyethylene (D) in the range of 1.0% by mass or more and 20.0% by mass or less (provided that the total content of polymer (A), polymer (B), polymer (C), and low-density polyethylene (D) is 100% by mass): (A-1) The melt flow rate measured in accordance with JIS K 7210 at a temperature of 230°C and a load of 2.16 kg is 0.1 to 60 g / 10 min; (A-2) Density measured in accordance with JIS K 7112 is 886-930 kg / m³ 3 It is; (A-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is 130 to 170°C; (B-1) The melt flow rate measured in accordance with JIS K 7210 at a temperature of 230°C and a load of 2.16 kg is 0.1 to 60 g / 10 min; (B-2) Density measured in accordance with JIS K 7112 is 855-885 kg / m³ 3 It is; (B-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is 130 to 170°C; (B-4) The Shore A hardness measured in accordance with ASTM D2240 is 65 to 90; (C-1) The melt flow rate measured in accordance with JIS K 7210 at a temperature of 230°C and a load of 2.16 kg is 0.2 to 10 g / 10 min; (C-2) Densities measured in accordance with JIS K 7112 are 855-913 kg / m³ 3 It is; (C-3) The melting point (Tm) determined by differential scanning calorimetry (DSC) is less than 130°C; (D-1) The melt flow rate measured in accordance with JIS K 7210 at a temperature of 190°C and a load of 2.16 kg is 0.1 to 50 g / 10 min; (D-2) Densities measured in accordance with JIS K 7112 are 914-935 kg / m³ 3 That is the case.

2. A laminate having a layer containing the resin composition described in claim 1.

3. A packaging material having a layer containing the resin composition described in claim 1.

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