Polypropylene resin composition, film, and method for producing the same

Abstract

To provide a polypropylene resin composition that yields a film exhibiting excellent transparency and excellent resistance to whitening due to bending at low-temperature processing, without an ultraviolet absorber bleeding out to a surface.SOLUTION: A polypropylene resin composition containing a propylene-based polymer (A) satisfying (a1) to (a3), a propylene-based thermoplastic elastomer (B) satisfying (b1) and (b2), and a triaryltriazine-based compound (C) having a predetermined structure, wherein proportions of components (A), (B), and (C) relative to a total amount of (A) to (C) are 45.0 to 79.9 mass%, 20.0 to 50.0 mass%, and 0.1 to 5.0 mass%, respectively, wherein (a1) the propylene-based polymer is a metallocene catalyst-based propylene-based polymer; (a2) an MFR is 1 to 50 g / 10 min; (a3) a flexural modulus is more than 100 MPa and 1,500 MPa or less; (b1) an MFR is 1 to 30 g / 10 min; and (b2) a flexural modulus is 5 to 100 MPa.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polypropylene resin composition and film that provide a film excellent in transparency and resistance to whitening due to folding without causing an ultraviolet absorber to bleed out to the surface, and a method for producing the same. [Background technology]

[0002] It is widely practiced to incorporate an ultraviolet absorber into a polyolefin-based thermoplastic resin sheet or film in order to improve the weather resistance of the sheet or film. In particular, high weather resistance is required for agricultural films and films and sheets for construction and civil engineering applications. Such films and sheets are based on polyethylene or polypropylene and contain various ultraviolet absorbers. Various developments have been made with ultraviolet absorbers to prevent deterioration of films and sheets and to obtain films and sheets with longer life and better performance.

[0003] Films and sheets deteriorate when exposed to ultraviolet rays in sunlight in the presence of oxygen in the air, resulting in a decrease in strength and elongation and breakage. To address this issue, various ultraviolet absorbers are incorporated into resins. While nickel-based compounds have traditionally been the main UV absorbers, in recent years, benzophenone-based, benzotriazole-based, and triazine-based UV absorbers have been developed and are being used in a variety of applications. Furthermore, sterically hindered amine-based light stabilizers have been developed, and due to their excellent performance, they are now the mainstream weather-resistant stabilizers.

[0004] For example, Patent Document 1 discloses a resin composition in which a specific triaryltriazine-type ultraviolet absorber is added to a mixture of an ethylene-propylene random copolymer having an ethylene content of 1.0 to 6.0% by weight, a low-density polyethylene having specific physical properties, and the like, and shows that problems such as bleed-out when processed into a film or sheet are improved. Patent Document 2 discloses a propylene-based resin film in which a predetermined amount of a benzotriazole-based ultraviolet absorber and / or a benzophenone-based ultraviolet absorber and a hindered amine-based light stabilizer are added to a propylene-α-olefin copolymer having specific physical properties, and it is shown that the film has improved whitening resistance and the like. Furthermore, Patent Document 3 discloses a decorative sheet in which at least an adhesive layer and one or more resin layers mainly made of transparent polypropylene are laminated on a base sheet, and at least one of the resin layers is a layer made of a mixture of a specific homopolypropylene and a specific elastomer to which a predetermined amount of a hydroxyphenyltriazine-based ultraviolet absorber has been added. It is shown that the decorative sheet does not whiten in the folded areas and has high weather resistance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-43596 [Patent Document 2] Japanese Patent Application Publication No. 11-147981 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-51167 Summary of the Invention [Problem to be solved by the invention]

[0006] The composition disclosed in Patent Document 1 improved the problem of bleed-out when processed into a film, but was poor in transparency and resistance to whitening upon bending, and whitening occurred particularly during bending at low temperatures. The film disclosed in Patent Document 2 improved resistance to whitening upon bending, but was poor in resistance to bleed-out of the UV absorber. The decorative sheet disclosed in Patent Document 3 improved transparency and resistance to whitening upon bending, but did not solve the problem of bleed-out of the UV absorber when used for a long period of time.

[0007] An object of the present invention is to provide a polypropylene resin composition that provides a film having excellent transparency and resistance to whitening due to bending during low-temperature processing without causing an ultraviolet absorber to bleed out to the surface, and to provide an unstretched film containing the same. [Means for solving the problem]

[0008] The triaryltriazine-based ultraviolet absorber disclosed in Patent Document 1 has excellent bleed-out resistance when formed into a film, and is therefore used as a weather resistance improver for polyolefin-based resins. However, films obtained from the composition of Patent Document 1 have a problem of poor resistance to whitening on bending. The inventors have conducted studies and found that adding an elastomer component to the composition of Patent Document 1 improves the whitening resistance of the film on bending, but also deteriorates the bleed-out resistance of the triaryltriazine-based ultraviolet absorber. The present inventors have conducted extensive research to achieve both resistance to bleed-out of an ultraviolet absorber and resistance to whitening on bending. As a result, they have found that by blending a specific propylene-based polymer, a specific propylene-based thermoplastic elastomer, and a specific ultraviolet absorber in specific ratios, a polypropylene resin composition can be obtained that is excellent in transparency and resistance to whitening on bending during low-temperature processing without causing the ultraviolet absorber to bleed out to the surface when processed into a film or sheet, and have completed the present invention. The present invention relates to the following [1] to [6].

[0009] [1] A propylene-based polymer (A) satisfying the following requirements (a1) to (a3); a propylene-based thermoplastic elastomer (B) satisfying the following requirements (b1) and (b2); and at least one compound (C) selected from the group of triaryltriazine-based compounds represented by formula (1): [ka] (In the formula, R 1 is an isooctyl group) The polypropylene resin composition contains the above-mentioned formula, wherein the proportions of components (A), (B) and (C) relative to the total amount of components (A) to (C) are 45.0 to 79.9% by weight, 20.0 to 50.0% by weight and 0.1 to 5.0% by weight, respectively. (a1) A metallocene catalyst-based propylene polymer. (a2) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 50 g / 10 min. (a3) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is greater than 100 MPa and less than 1,500 MPa. (b1) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 30 g / 10 min. (b2) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is 5 to 100 MPa. [2] The polypropylene resin composition according to [1], wherein the component (A) satisfies the following requirements (a4) to (a6): (a4) A propylene-ethylene copolymer containing 1% by weight or more and less than 5% by weight of units derived from ethylene. (a5) The melting point is 110 to 155°C. (a6) The ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is 1.5 to 3.5. [3] The polypropylene resin composition according to [1] or [2], wherein component (B) satisfies the following requirement (b3): (b3) A propylene-ethylene copolymer or a propylene-ethylene-1-butene copolymer containing 5 to 20% by weight of units derived from ethylene and 0 to 20% by weight of units derived from 1-butene, wherein the total amount of units derived from ethylene and 1-butene is 5 to 40% by weight. [4] An unstretched film comprising the polypropylene resin composition according to any one of [1] to [3]. [5] A propylene-based polymer (A) satisfying the following requirements (a1) to (a3); a propylene-based thermoplastic elastomer (B) satisfying the following requirements (b1) and (b2); and at least one compound (C) selected from the group of triaryltriazine-based compounds represented by formula (1): [ka] (In the formula, R 1 is an isooctyl group) The method for producing a polypropylene resin composition comprising the above, comprising a step of mixing components (A) to (C) so that the proportions of components (A), (B) and (C) relative to the total amount of components (A) to (C) are 45.0 to 79.9% by weight, 20.0 to 50.0% by weight and 0.1 to 5.0% by weight, respectively. (a1) A metallocene catalyst-based propylene polymer. (a2) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 50 g / 10 min. (a3) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is greater than 100 MPa and less than 1,500 MPa. (b1) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 30 g / 10 min. (b2) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is 5 to 100 MPa. [6] A method for producing an unstretched film, comprising a step of melt-extrusion molding the polypropylene resin composition according to any one of [1] to [3]. [Effects of the Invention]

[0010] The polypropylene resin composition of the present invention is suitable for forming a film or sheet-like molded product having excellent transparency and resistance to whitening on bending during low-temperature processing, by combining a specific propylene-based polymer, a specific propylene-based thermoplastic elastomer, and a specific ultraviolet absorber, in which bleed-out of the ultraviolet absorber is suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0011] The polypropylene resin composition contains a propylene polymer (A) that satisfies the following requirements (a1) to (a3); a propylene thermoplastic elastomer (B) that satisfies the following requirements (b1) and (b2); and at least one compound (C) selected from the group of triaryltriazine compounds represented by formula (1), wherein the proportions of components (A), (B), and (C) relative to the total amount of components (A), (B), and (C) are 45.0 to 79.9% by weight, 20.0 to 50.0% by weight, and 0.1 to 5.0% by weight, respectively. (a1) A metallocene catalyst-based propylene polymer. (a2) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 50 g / 10 min. (a3) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is greater than 100 MPa and less than 1,500 MPa. (b1) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 30 g / 10 min. (b2) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is 5 to 100 MPa. By using the polypropylene resin composition, it is possible to obtain a film that is excellent in transparency and resistance to whitening due to bending during low-temperature processing, without the ultraviolet absorber bleeding out to the surface.

[0012] In this specification, the propylene polymer (A) and the propylene thermoplastic elastomer (B) are polymers each containing 50% by weight or more of polymer units derived from propylene. Hereinafter, each component, production method, and application will be described.

[0013] <Polypropylene resin composition> The polypropylene resin composition contains a propylene polymer (A), a propylene thermoplastic elastomer (B), and at least one compound (C) selected from the group of triaryltriazine compounds represented by formula (1).

[0014] [Propylene polymer (A)] The propylene polymer (A) is a polymer selected from the group consisting of propylene homopolymers and copolymers of propylene with ethylene or an α-olefin having 4 to 20 carbon atoms, and satisfies the following requirements (a1) to (a3). Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and mixtures thereof. Among these, from the viewpoint of resistance to whitening upon bending, the propylene polymer (A) is preferably a propylene-ethylene copolymer. The propylene polymer (A) may be used alone or in combination of two or more.

[0015] In this specification, the content of units derived from ethylene in a propylene-ethylene copolymer is a value calculated based on the following formula. Content of ethylene-derived units (%) = Weight of ethylene-derived units / (Weight of units derived from propylene + Weight of units derived from ethylene) x 100 The content of units derived from each monomer in other copolymers such as propylene-ethylene-1-butene copolymer can also be calculated in the same manner as above.

[0016] (a1) A metallocene catalyst-based propylene polymer. The propylene polymer (A) is a so-called metallocene-catalyzed propylene polymer polymerized using a metallocene catalyst. The propylene polymer (A) polymerized using a metallocene catalyst has high crystallinity and improves bleed-out resistance even in a system containing an elastomer component such as a propylene-based thermoplastic elastomer (B).

[0017] The metallocene catalyst is a catalyst comprising (i) a transition metal compound of Group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton (a so-called metallocene compound), (ii) a co-catalyst capable of activating the metallocene compound to a stable ionic state by reacting with the metallocene compound, and, if necessary, (iii) an organoaluminum compound, and any known catalyst can be used. The metallocene compound is preferably a bridged metallocene compound capable of stereoregular polymerization of propylene, and more preferably a bridged metallocene compound capable of isoregular polymerization of propylene.

[0018] (i) As the metallocene compound, for example, those disclosed in JP-A-60-35007, JP-A-61-130314, JP-A-63-295607, JP-A-1-275609, JP-A-2-41303, JP-A-2-131488, JP-A-2-76887, JP-A-3-163088, JP-A-4-300887, JP-A-4-211694, JP-A-5-43616, JP-A-5-209013, JP-A-6-239914, JP-T-7-504934, and JP-A-8-85708 can be preferably used.

[0019] Specifically, methylenebis(2-methylindenyl)zirconium dichloride, ethylenebis(2-methylindenyl)zirconium dichloride, ethylene 1,2-(4-phenylindenyl)(2-methyl-4-phenyl-4H-azulenyl)zirconium dichloride, isopropylidene(cyclopentadienyl)(fluorenyl)zirconium dichloride, isopropylidene(4-methylcyclopentadienyl)(3-t-butylindenyl)zirconium dichloride, dimethylsilylene(2-methyl-4-t-butyl-cyclopentadienyl)(3'-t-butyl-5'-methyl-cyclopentadienyl)zirconium dichloride, dimethylsilylenebis(indenyl) methylsilylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4-phenylindenyl)]zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-phenylindenyl)]zirconium dichloride, dimethylsilylenebis[4-(1-phenyl-3-methylindenyl)]zirconium dichloride, dimethylsilylene(fluorenyl)t-butylamido zirconium dichloride, methylphenylsilylenebis[1-(2-methyl-4,(1-naphthyl)-indenyl)]zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4,5-benzoindenyl)] zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4-phenyl-4H-azulenyl)] zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azulenyl)] zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-naphthyl-4H-azulenyl)] zirconium dichloride, diphenylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azulenyl)] zirconium dichloride Examples of zirconium compounds include dimethylsilylenebis[1-(2-ethyl-4-(3-fluorobiphenyl)-4H-azulenyl)]zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-(3-fluorobiphenyl)-4H-azulenyl)]zirconium dichloride, dimethylgermylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azulenyl)]zirconium dichloride, and dimethylgermylenebis[1-(2-ethyl-4-phenylindenyl)]zirconium dichloride.

[0020] In the above, compounds in which zirconium is replaced with titanium, hafnium, etc. can also be used. It is also preferable to use a mixture of a zirconium compound and a hafnium compound. Chloride can also be replaced with other halogen compounds; hydrocarbon groups such as methyl, isobutyl, and benzyl; amide groups such as dimethylamide and diethylamide; alkoxide groups such as methoxy and phenoxy; and hydride groups. Among these, metallocene compounds in which an indenyl group or an azulenyl group is bridged with a silicon or germyl group are particularly preferred.

[0021] The metallocene compound may be supported on an inorganic or organic carrier. The carrier is preferably a porous inorganic or organic compound, and specific examples include inorganic compounds such as ion-exchangeable layered silicates, zeolites, SiO2, Al2O3, silica alumina, MgO, ZrO2, TiO2, BO3, CaO, ZnO, BaO, and ThO2; organic compounds such as porous polyolefins, styrene-divinylbenzene copolymers, and olefin-acrylic acid copolymers; and mixtures thereof.

[0022] (ii) Preferred examples of the co-catalyst capable of reacting with a metallocene compound to activate it to a stable ionic state include organoaluminum oxy-compounds (e.g., aluminoxane compounds), ion-exchangeable layered silicates, Lewis acids, boron-containing compounds, ionic compounds, and fluorine-containing organic compounds.

[0023] (iii) Preferred examples of organoaluminum compounds include trialkylaluminums such as triethylaluminum, triisopropylaluminum, and triisobutylaluminum, dialkylaluminum halides, alkylaluminum sesquihalides, alkylaluminum dihalides, alkylaluminum hydrides, and organoaluminum alkoxides.

[0024] (a2) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 50 g / 10 min. The propylene polymer (A) has a melt flow rate (MFR) of 1 to 50 g / 10 min, measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load). The MFR is preferably 3 to 40 g / 10 min, more preferably 5 to 30 g / 10 min. When the propylene polymer (A) has an MFR in the range of 1 to 50 g / 10 min, it has good compatibility with the propylene thermoplastic elastomer (B), and therefore good processability in film and sheet processing. Methods for controlling the MFR value are well known, and the MFR value can be easily adjusted by adjusting the temperature and pressure, which are polymerization conditions for the propylene polymer (A), or by controlling the amount of a chain transfer agent such as hydrogen added during polymerization.

[0025] (a3) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is greater than 100 MPa and less than 1,500 MPa. The propylene polymer (A) has a flexural modulus of greater than 100 MPa and not greater than 1,500 MPa, as measured at a test speed of 2 mm / min in accordance with JIS-K7171:2016. The flexural modulus is preferably greater than 200 MPa and not greater than 1,400 MPa, more preferably greater than 300 MPa and not greater than 1,300 MPa, and particularly preferably greater than 400 MPa and not greater than 1,200 MPa. If the flexural modulus is 100 MPa or less, the component (C) will bleed out, resulting in a deterioration in transparency. If the flexural modulus is greater than 1,500 MPa, the resistance to whitening upon bending will be impaired. The method for controlling the flexural modulus is well known, and it can be easily adjusted by controlling the content ratio of ethylene and / or α-olefin having 4 to 20 carbon atoms to be copolymerized.

[0026] The propylene polymer (A) preferably further satisfies the following requirements (a4) to (a6).

[0027] (a4) A propylene-ethylene copolymer containing 1% by weight or more and less than 5% by weight of units derived from ethylene. The propylene polymer (A) is preferably a propylene-ethylene copolymer containing 1% by weight or more and less than 5% by weight of units derived from ethylene. The content of units derived from ethylene is more preferably 1.2 to 4.0% by weight, and even more preferably 1.5 to 3.0% by weight. The content of units derived from ethylene can be calculated by the method described below.

[0028] (a5) The melting point is 110 to 155°C. The melting point of the propylene polymer (A) is preferably 110 to 155° C., more preferably 115 to 145° C., and even more preferably 120 to 140° C. By setting the melting point in the range of 110 to 155° C., it is possible to achieve a good balance between resistance to whitening upon bending and resistance to bleed-out. Methods for controlling the melting point are well known, and the melting point can be easily adjusted by controlling the content ratio of ethylene and / or α-olefin having 4 to 20 carbon atoms to be copolymerized.

[0029] In this specification, the melting point is measured as follows: Using a differential scanning calorimeter (DSC), a 5.0 mg sample is heated to 200°C, held at 200°C for 5 minutes, and then cooled to 40°C at a rate of 10°C / min. The sample is then heated at a rate of 10°C / min, and the top temperature of the endothermic peak is taken as the melting peak temperature (melting point / Tm).

[0030] (a6) The ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is 1.5 to 3.5. The propylene polymer (A) has a ratio (Mw / Mn) of weight average molecular weight Mw to number average molecular weight Mn of 1.5 to 3.5, more preferably 1.7 to 3.3, and even more preferably 2.0 to 3.0. The Mw / Mn can be controlled by changing the type of metallocene catalyst used in the polymerization of the propylene polymer (A) or by adjusting the combination and ratio of metallocene complexes that give propylene polymers with different molecular weights using a catalyst containing a plurality of metallocene compounds.

[0031] In this specification, Mw, Mn and integrated molecular weight distribution curves are those obtained by gel permeation chromatography (GPC). Details of the measurement method and measuring instrument are as described in the Examples.

[0032] The method for producing the propylene polymer (A) is not particularly limited as long as a metallocene catalyst is used, and the propylene polymer (A) can be produced by any of the conventionally known methods such as slurry polymerization, bulk polymerization, gas phase polymerization, etc. Furthermore, the propylene polymer (A) can also be produced by a multistage polymerization method as long as the above requirements (a1) to (a3) ​​are satisfied.

[0033] [Propylene-based thermoplastic elastomer (B)] The propylene-based thermoplastic elastomer (B) is a copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms, and satisfies the following requirements (b1) and (b2). Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and mixtures thereof. The propylene-based thermoplastic elastomer (B) may be used alone or in combination of two or more.

[0034] (b1) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 30 g / 10 min. The propylene-based thermoplastic elastomer (B) has an MFR of 1 to 30 g / 10 min, measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load). The MFR is preferably 2 to 20 g / 10 min, more preferably 5 to 15 g / 10 min. If the MFR of the propylene-based thermoplastic elastomer (B) is less than 1 g / 10 min, resistance to whitening due to bending deteriorates, and if it exceeds 30 g / 10 min, molding defects occur during film or sheet molding. Methods for controlling the MFR value are well known, and the MFR value can be easily adjusted by adjusting the temperature and pressure, which are polymerization conditions for the propylene-based thermoplastic elastomer (B), or by controlling the amount of a chain transfer agent such as hydrogen added during polymerization.

[0035] (b2) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is 5 to 100 MPa. The propylene-based thermoplastic elastomer (B) has a flexural modulus of 5 to 100 MPa measured at a test speed of 2 mm / min in accordance with JIS-K7171:2016. The flexural modulus is preferably 6 to 80 MPa, more preferably 7 to 50 MPa, and particularly preferably 10 to 45 MPa. If the flexural modulus is less than 5 MPa, molding defects will occur during film or sheet molding, and if it exceeds 100 MPa, resistance to whitening on bending will deteriorate. The method for controlling the flexural modulus is well known, and it can be easily adjusted by controlling the content ratio of ethylene and / or α-olefin having 4 to 20 carbon atoms to be copolymerized.

[0036] The propylene-based thermoplastic elastomer (B) preferably further satisfies the following requirements (b3) and (b4).

[0037] (b3) A propylene-ethylene copolymer or a propylene-ethylene-1-butene copolymer containing 5 to 20% by weight of units derived from ethylene and 0 to 20% by weight of units derived from 1-butene, wherein the total amount of units derived from ethylene and 1-butene is 5 to 40% by weight. From the viewpoint of a balance between resistance to whitening on bending, resistance to bleed-out, and moldability, the propylene-based thermoplastic elastomer (B) is preferably a propylene-ethylene copolymer or a propylene-ethylene-1-butene copolymer containing 5 to 20% by weight of units derived from ethylene and 0 to 20% by weight of units derived from 1-butene, with the total amount of units derived from ethylene and 1-butene being 5 to 40% by weight. The content of units derived from ethylene in the propylene-based thermoplastic elastomer (B) is more preferably 6 to 17% by weight, and even more preferably 7 to 15% by weight. The content of units derived from 1-butene in the propylene-based thermoplastic elastomer (B) is more preferably 0 to 19% by weight, and even more preferably 0 to 18% by weight. The total content of units derived from ethylene and 1-butene in the propylene-based thermoplastic elastomer (B) is more preferably 8 to 35% by weight, and even more preferably 10 to 30% by weight.

[0038] (b4) The content of units derived from propylene is 60 to 95% by weight. From the viewpoint of a balance between resistance to whitening upon bending, resistance to bleed-out, and moldability, the content of units derived from propylene in the propylene-based thermoplastic elastomer (B) is preferably 60 to 95% by weight, more preferably 65 to 92% by weight, and even more preferably 70 to 90% by weight.

[0039] Examples of the propylene-based thermoplastic elastomer (B) that can be used include the propylene-1-butene copolymers described in JP 2004-099909 A; the propylene-ethylene-1-butene copolymers described in JP 2004-315830 A, JP 2007-169666 A, and JP 2010-163626 A; and the propylene-α-olefin copolymers described in JP 2022-152305 A and JP 2022-152304 A.

[0040] (Method for calculating the content ratio of units derived from ethylene and α-olefins having 4 to 20 carbon atoms) The content ratio of units derived from ethylene and an α-olefin having 4 to 20 carbon atoms in the propylene-based polymer (A) and the propylene-based thermoplastic elastomer (B) is 13 It can be calculated from the integrated intensity of the spectrum obtained by C-NMR measurement. For example, in the case of a propylene-ethylene-1-butene copolymer, the ethylene and 1-butene contents (wt%) can be calculated from the following (Equation 1) and (Equation 2), respectively. Ethylene content (mol%) = IE × 100 / (IE + IP + IB) Ethylene content (wt%) = [Ethylene content (mol%) × Molecular weight of ethylene] / [Ethylene content (mol%) × Molecular weight of ethylene + Propylene content (mol%) × Molecular weight of propylene + 1-butene content (mol%) × Molecular weight of 1-butene] (Equation 1) 1-Butene content (mol%) = IB × 100 / (IE + IP + IB) 1-butene content (wt%) = [1-butene content (mol%) × molecular weight of 1-butene] / [ethylene content (mol%) × molecular weight of ethylene + propylene content (mol%) × molecular weight of propylene + 1-butene content (mol%) × molecular weight of 1-butene] (Equation 2) where IE, IP, and IB are the integrated intensities of carbons derived from ethylene, propylene, and 1-butene, respectively.

[0041] [at least one compound (C) selected from the group of triaryltriazine compounds represented by formula (1)] At least one compound (C) selected from the group of triaryltriazine compounds represented by formula (1) is an ultraviolet absorber. Since the compound (C) has excellent compatibility with the propylene polymer (A) and the propylene thermoplastic elastomer (B), the compound (C) is unlikely to bleed out onto the surface of a film obtained from the polypropylene resin composition even after long-term use. The compound (C) may be used alone or in combination of two or more.

[0042] [ka] In formula (1), R 1 is an isooctyl group.

[0043] The triaryltriazine compound represented by the formula (1) includes R 1The isooctyl group may be one type of isooctyl group or a mixture of two or more types of isooctyl groups, but a mixture of two or more types of isooctyl groups is preferred. The isooctyl groups used include 2-octyl group, 2-methyl-1-heptyl group, 3-methyl-1-heptyl group, 4-methyl-1-heptyl group, 5-methyl-1-heptyl group, 6-methyl-1-heptyl group, 3-octyl group, 2-ethyl-1-hexyl group, 3-ethyl-1-hexyl group, 4-ethyl-1-hexyl group, 4-octyl group, 2-propyl-1-pentyl group, 2-methyl-3-heptyl group, 2-isopropyl-1-pentyl group, 2-methyl-2-heptyl group, 3- Methyl-2-heptyl group, 4-methyl-2-heptyl group, 5-methyl-2-heptyl group, 6-methyl-2-heptyl group, 2,2-dimethyl-1-hexyl group, 2,3-dimethyl-1-hexyl group, 2,4-dimethyl-1-hexyl group, 2,5-dimethyl-1-hexyl group, 3,3-dimethyl-1-hexyl group, 3,4-dimethyl-1-hexyl group, 3,5-dimethyl-1-hexyl group, 4,4-dimethyl-1-hexyl group, 4,5-dimethyl-1-hexyl group, 5,5-dimethyl- 1-hexyl group, 3-methyl-3-heptyl group, 3-ethyl-2-hexyl group, 4-ethyl-2-hexyl group, 2-methyl-2-ethyl-1-pentyl group, 2-methyl-3-ethyl-1-pentyl group, 3-methyl-3-ethyl-1-pentyl group, 4-methyl-3-heptyl group, 5-methyl-3-heptyl group, 6-methyl-3-heptyl group, 2-ethyl-3-methyl-1-pentyl group, 2-ethyl-4-methyl-1-pentyl group, 3-ethyl-4-methyl-1-pentyl group, 3-ethyl Examples include butyl-3-hexyl group, 4-ethyl-3-hexyl group, 2,2-diethyl-1-butyl group, 4-methyl-4-heptyl group, 3-methyl-4-heptyl group, 2-methyl-4-heptyl group, 2,3-dimethyl-3-hexyl group, 2,4-dimethyl-3-hexyl group, 2,5-dimethyl-3-hexyl group, 2,3-dimethyl-2-ethyl-1-butyl group, 2-isopropyl-3-methyl-1-butyl group, 3,3,4-trimethyl-1-pentyl group, and 2-methyl-3-heptyl group.

[0044] The triaryltriazine compound represented by the formula (1) can be easily synthesized by a conventional method for synthesizing triaryltriazines. For example, 2 moles of xylene and 1 mole of a 3-alkoxyphenol may be added to 2,4,6-trichlorotriazine in the presence of a Lewis acid catalyst. Alternatively, 2-hydroxy-4,6-diaryltriazine may be synthesized from a hydrohalide salt of 2,6-dimethylbenzamidine and a halogenated formate, which may then be treated with thionyl chloride to form 2-chloro-4,6-diaryltriazine, which may then be reacted with a 3-alkoxyphenol in the presence of a Lewis acid catalyst. Moreover, commercially available triaryltriazine compounds represented by the above formula (1) can also be used.

[0045] The triaryltriazine compound may contain R 1 R may contain a triaryltriazine compound in which the alkyl group, alkenyl group, or alkynyl group is other than an isooctyl group. 1 The allowable amount of triaryltriazine compounds in which the alkyl group, alkenyl group, or alkynyl group other than an isooctyl group is different depending on the type of triaryltriazine compound, but is generally less than 30 mol % of all triaryltriazine compounds.

[0046] [Other ingredients] The polypropylene resin composition may contain components other than components (A) to (C) within the range that does not impair the effects of the present invention. Examples of such optional components include resins other than components (A) and (B), ultraviolet absorbers other than component (C), antioxidants used in ordinary polyolefin resin materials, crystal nucleating agents, clarifying agents, lubricants, antiblocking agents, antistatic agents, antifogging agents, neutralizing agents, light stabilizers, metal deactivators, colorants, dispersants, peroxides, fillers, and fluorescent brightening agents.

[0047] Specifically, examples of the antioxidant include phosphorus-based antioxidants such as bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-diphosphite, di-stearyl-pentaerythritol-diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol-diphosphite, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene-diphosphonite, and tetrakis(2,4-di-t-butyl-5-methylphenyl)-4,4'-biphenylene-diphosphonite; phenolic antioxidants such as 2,6-di-t-butyl-p-cresol, tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, and tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate; thio-based antioxidants such as di-stearyl-β,β'-thio-dipropionate, di-myristyl-β,β'-thio-dipropionate, and di-lauryl-β,β'-thio-dipropionate, and the like.

[0048] As the crystal nucleating agent, known nucleating agents can be used. Specific examples thereof include, for example, sorbitol-based clarifying nucleating agents, amine / amide-based clarifying nucleating agents, organic phosphate-based clarifying nucleating agents, aromatic phosphate esters, talc, and the like.

[0049] Specific examples of the neutralizing agent include fatty acid metal salts such as calcium stearate, zinc stearate, and magnesium stearate, and hydrotalcite (trade name: DHT-4A, a magnesium aluminum composite hydroxide salt represented by the following general formula (2) manufactured by Kyowa Chemical Industry Co., Ltd.). Mg 1-x Al x (OH)2(CO3) x / 2 ·mH2O ···(2) (In the formula, x satisfies 0 < x ≤ 0.5, and m is a number of 3 or less.)

[0050] As the lubricant, known lubricants can be used, and preferred examples thereof include fatty acid amides such as oleic acid amide, stearic acid amide, erucic acid amide, and behenic acid amide; butyl stearate; and silicone oil.

[0051] Examples of the antistatic agent include glycerin esters, sorbitan acid esters, and polyethylene glycol esters of fatty acids having 8 to 22 carbon atoms. Examples of the antiblocking agent include silica, calcium carbonate, and talc.

[0052] [Composition ratio of each ingredient] The blending ratio of the components (A) to (C) in the polypropylene resin composition is within the following ranges relative to the total amount of the components (A) to (C). The proportion of the propylene polymer (A) is 45.0 to 79.9% by weight, preferably 55.0 to 74.9% by weight. If the proportion of the component (A) is within the above range, the bleed-out resistance and the resistance to whitening on bending are excellent. The proportion of the propylene-based thermoplastic elastomer (B) is 20.0 to 50.0% by weight, preferably 25.0 to 44.0% by weight. If the proportion of component (B) is within the above range, the bleed-out resistance and the resistance to whitening on bending are excellent. The proportion of compound (C) is 0.1 to 5.0% by weight, preferably 0.1 to 2.0% by weight. If the proportion of component (C) is within the above range, the weather resistance and bleed-out resistance are excellent, and it is also preferable from the standpoint of economy.

[0053] <Method of producing polypropylene resin composition> The polypropylene resin composition can be produced by mixing components (A) to (C) so that the proportions of components (A), (B), and (C) relative to the total amount of components (A) to (C) are 45.0 to 79.9% by weight, 20.0 to 50.0% by weight, and 0.1 to 5.0% by weight, respectively. When mixing, any other component may be added in addition to components (A) to (C). Components (A) and (B) can be in the form of pellets, powder, etc. Component (C) is usually in powder form. Component (C) can also be melt-kneaded with component (A) or (B) to form pellets, etc. One embodiment of the present invention is a mixture such as pellets obtained by dry-blending components (A), (B), and (C) in the above-mentioned ratio.

[0054] The mixture obtained as described above may be further melt-kneaded to produce a polypropylene resin composition. The melt-kneading is carried out using raw materials such as powder or pellet-like components, using a kneading machine such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader blender, a Brabender plastograph, a small batch mixer, a continuous mixer, or a mixing roll. The kneading temperature is generally 180 to 270°C. Two or more of the above kneading machines can also be combined.

[0055] <Uses of polypropylene resin composition> The polypropylene resin composition has excellent film processability and is formulated to be less susceptible to bleed-out, and therefore has excellent long-term weather resistance, transparency, and resistance to whitening upon bending. Therefore, the polypropylene resin composition is suitable for applications in which the product is exposed to the natural environment for a long period of time or for applications in which the product is subjected to bending. The polypropylene resin composition is suitable for film applications, particularly for non-oriented films.

[0056] Another aspect of the present invention is a method for producing a non-stretched film, which includes a step of melt-extrusion molding a polypropylene resin composition. Any conventionally known method may be used as a method for processing the polypropylene resin composition into a non-stretched film. For example, a method may be used in which the polypropylene resin composition is heated, melted, and kneaded in an extruder, and then extruded into a film form through a T-die or round die. The heating temperature is preferably, for example, 180 to 270°C. [Example]

[0057] The present invention will be described in detail below using examples, but the present invention is not limited to these examples. The raw materials used in the examples and the evaluation methods of the obtained films are as follows.

[0058] 1. Evaluation Method (1) MFR The MFR of components (A) and (B) was measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load).

[0059] (2) Melting point (Tm) For component (A), a differential scanning calorimeter (DSC) was used. A 5.0 mg sample was heated to 200°C, held at 200°C for 5 minutes, and then cooled to 40°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the top temperature of the endothermic peak was taken as the melting point (Tm).

[0060] (3) Flexural modulus For components (A) and (B), injection-molded test specimens measuring 4.0 mm thick, 10.0 mm wide, and 80 mm long were prepared. Dumbbell-shaped tensile test specimens (Type A) were molded using a Toshiba Machine IS80G injection molding machine at a molding temperature of 200°C and a mold temperature of 40°C. The flexural modulus of the test specimens thus obtained was measured in accordance with JIS-K7171:2016 (ISO178) at a test speed of 2 mm / min.

[0061] (4) Ethylene and 1-butene content The ethylene and 1-butene contents in components (A) and (B) are 13 The intensity was calculated from the integrated intensity of the spectrum obtained by C-NMR measurement. The sample preparation and NMR measurement conditions are as follows. 200 mg of component (A) or (B) was dissolved in an NMR sample tube with an inner diameter of 10 mm together with 2.4 ml of o-dichlorobenzene / deuterated bromide benzene (C6D5Br) = 4 / 1 (volume ratio) and hexamethyldisiloxane as a chemical shift reference substance. NMR measurements were performed using a Bruker Biospin AV400 NMR instrument equipped with a 10 mm diameter cryoprobe. 13 The C-NMR measurement was performed at a sample temperature of 120°C, a pulse angle of 90°, a pulse interval of 15 seconds, and an accumulation count of 512. The ethylene content (wt%) and 1-butene content (wt%) of components (A) and (B) are 13 The integrated intensities of the spectra obtained by C-NMR measurement were used to calculate the values ​​using the following formulas (1) and (2). Ethylene content (mol%) = IE × 100 / (IE + IP + IB) Ethylene content (wt%) = [Ethylene content (mol%) × Molecular weight of ethylene] / [Ethylene content (mol%) × Molecular weight of ethylene + Propylene content (mol%) × Molecular weight of propylene + 1-butene content (mol%) × Molecular weight of 1-butene] (Equation 1) 1-Butene content (mol%) = IB × 100 / (IE + IP + IB) 1-butene content (wt%) = [1-butene content (mol%) × molecular weight of 1-butene] / [ethylene content (mol%) × molecular weight of ethylene + propylene content (mol%) × molecular weight of propylene + 1-butene content (mol%) × molecular weight of 1-butene] (Equation 2) where IE, IP, and IB are the integrated intensities of carbons derived from ethylene, propylene, and 1-butene, respectively.

[0062] (5) Molecular weight distribution (Mw / Mn) The Mw, Mn and integrated molecular weight distribution curve of component (A) were determined by GPC measurement using the following apparatus and measurement conditions: Apparatus: Waters GPC (ALC / GPC, 150C) Detector: FOXBORO MIRAN 1A, IR detector (measurement wavelength: 3.42 μm) Column: Showa Denko AD806M / S (3 columns) Mobile phase solvent: 0.5 mg / mL o-dichlorobenzene solution of dibutylhydroxytoluene (hereinafter referred to as "ODCB + BHT") Measurement temperature: 140℃ Flow rate: 1.0mL / min Injection volume: 0.2mL The sample was an ODCB+BHT solution containing 1 mg / mL of component (A) that was dissolved at 140° C. for about 1 hour. The conversion from the retention volume obtained by GPC measurement to molecular weight was performed using a calibration curve prepared in advance using standard polystyrenes. The standard polystyrenes used were all the following brands manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000. A 0.2 mL solution of each standard polystyrene dissolved in ODCB and BHT was injected to prepare a calibration curve, which was approximated by a cubic equation using the least squares method. Viscosity formula used to convert to molecular weight: [η] = K × M α The following values ​​were used: For polystyrene: K = 1.38 x 10 -4 , α=0.7 For polypropylene: K = 1.03 x 10 -4 , α=0.78

[0063] (6) Transparency The haze of the films obtained in the examples and comparative examples was measured in accordance with JIS K7105:1981 and evaluated according to the following criteria: A rating of ◯ is desirable. ○: Haze is less than 10% △: Haze is less than 10-20% ×: Haze is 20% or more

[0064] (7) Bleed-out resistance The films obtained in the examples and comparative examples were subjected to aging treatment at 60°C for 30 days. After aging, the haze was measured in accordance with JIS K7105:1981 and evaluated according to the following criteria. A rating of ◯ in this evaluation is desirable. ○: (Haze after aging) - (Haze before aging) < 10% △: 10%≦(haze after aging)-(haze before aging)<20% ×: (Haze after aging) - (Haze before aging) ≥ 20%

[0065] (8) Low-temperature bending whitening resistance The films obtained in the Examples and Comparative Examples were cut into a size of 1 cm in the width direction and 10 cm in the machine direction. The cut films were stored in an atmosphere of 0°C for 24 hours and then folded in half in the machine direction under the same environment. The state of the fold was evaluated for resistance to fold whitening according to the following criteria. A rating of ○ in this evaluation was desirable. ○: No whitening at the crease △: The crease is slightly whitened ×: The crease is significantly whitened

[0066] 2.Raw materials [Component (A)] A-1: Wintec (registered trademark) WFW4M (propylene-ethylene copolymer produced by metallocene catalyst), manufactured by Japan Polypropylene Corporation MFR=7.0 g / 10 min, Tm=125°C, flexural modulus=1,050 MPa, ethylene content=1.9 wt%, Mw / Mn=2.5 A-2: Novatec (registered trademark) EG6D (propylene-ethylene copolymer produced by Ziegler-Natta catalyst), manufactured by Japan Polypropylene Corporation MFR=1.9 g / 10 min, Tm=140°C, flexural modulus=950 MPa, ethylene content=3.1 wt%, Mw / Mn=4.7

[0067] [Component (B)] B-1: Vistamaxx (registered trademark) VM3000 (propylene-ethylene copolymer), manufactured by ExxonMobil Corporation MFR=8g / 10min, flexural modulus=40MPa, ethylene content=11% by weight B-2: Dow Chemical Company, trade name: Versify® 3300 [propylene-ethylene copolymer] MFR=8g / 10min, flexural modulus=39MPa, ethylene content=12wt% B-3: Mitsui Chemicals, Inc., trade name: Tafmer (registered trademark) PN2070 [propylene-ethylene-1-butene copolymer] MFR=7 g / 10 min, flexural modulus=14 MPa, ethylene content=9.4 wt%, 1-butene content=16.5 wt%

[0068] [Component (C)] C-1: Cytec Corporation, product name: Cyasorb (registered trademark) UV-1164G R in Equation (1) 1 A composition containing 49 mol% of compounds in which 3-ethyl-1-hexyl groups are present, 20 mol% of compounds in which 4-methyl-1-heptyl groups are present, 19 mol% of compounds in which 3-ethyl-4-methyl-1-pentyl groups are present, and 10 mol% of compounds in which 2-ethyl-1-hexyl groups are present, with the total amount of isooctyl derivatives being 98 mol%.

[0069] [Example 1] 59.5 wt% of a propylene-based polymer (A-1), 40.0 wt% of a propylene-based thermoplastic elastomer (B-1), and 0.5 wt% of a triaryltriazine-based compound (C-1) were thoroughly mixed in a blender and then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded through a T-die attached to a 35mm diameter extruder at a resin temperature of 240°C and a width of 320mm to produce a 100µm thick film. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0070] [Example 2] 69.5 wt% of a propylene-based polymer (A-1), 30.0 wt% of a propylene-based thermoplastic elastomer (B-2), and 0.5 wt% of a triaryltriazine-based compound (C-1) were thoroughly mixed in a blender and then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded through a T-die attached to a 35mm diameter extruder at a resin temperature of 240°C and a width of 320mm to produce a 100µm thick film. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0071] [Example 3] 69.5 wt% of a propylene-based polymer (A-1), 30.0 wt% of a propylene-based thermoplastic elastomer (B-3), and 0.5 wt% of a triaryltriazine-based compound (C-1) were thoroughly mixed in a blender and then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded through a T-die attached to a 35mm diameter extruder at a resin temperature of 240°C and a width of 320mm to produce a 100µm thick film. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0072] [Comparative Example 1] 59.5 wt% of a propylene-based polymer (A-2), 40.0 wt% of a propylene-based thermoplastic elastomer (B-1), and 0.5 wt% of a triaryltriazine-based compound (C-1) were thoroughly mixed in a blender and then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded through a T-die attached to a 35mm diameter extruder at a resin temperature of 240°C and a width of 320mm to produce a 100µm thick film. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0073] Comparative Example 2 69.5 wt% of a propylene-based polymer (A-2), 30.0 wt% of a propylene-based thermoplastic elastomer (B-2), and 0.5 wt% of a triaryltriazine-based compound (C-1) were thoroughly mixed in a blender and then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded through a T-die attached to a 35mm diameter extruder at a resin temperature of 240°C and a width of 320mm to produce a 100µm thick film. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0074] Comparative Example 3 69.5 wt% of propylene-based polymer (A-2), 30.0 wt% of propylene-based thermoplastic elastomer (B-3), and 0.5 wt% of triaryltriazine-based compound (C-1) were thoroughly mixed in a blender and then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded through a T-die attached to a 35mm diameter extruder at a resin temperature of 240°C and a width of 320mm to produce a 100µm thick film. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0075] Comparative Example 4 99.5 wt% of a propylene polymer (A-1) and 0.5 wt% of a triaryltriazine compound (C-1) were thoroughly mixed in a blender, then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded at a resin temperature of 240°C and a width of 320 mm through a T-die attached to an extruder with a 35 mm diameter to produce a film with a thickness of 100 μm. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0076] Comparative Example 5 99.5 wt% of a propylene polymer (A-2) and 0.5 wt% of a triaryltriazine compound (C-1) were thoroughly mixed in a blender, then melt-extruded at 230°C to form pellets. The resulting pellets were melt-extruded through a T-die attached to a 35mm diameter extruder at a resin temperature of 240°C and a width of 320mm to produce a 100µm thick film. The resulting film was evaluated for transparency, bleed-out resistance, and low-temperature fold whitening resistance. The evaluation results are shown in Table 1.

[0077] [Table 1]

[0078] As is clear from Table 1, the films of Examples 1 to 3 according to the present invention are excellent in transparency, bleed-out resistance, and low-temperature bending whitening resistance. Comparative Example 4, which contained a propylene-ethylene copolymer polymerized using a metallocene catalyst but no propylene-based thermoplastic elastomer, was poor in low-temperature bending whitening resistance. The results of Comparative Example 5 show that the film using a propylene-ethylene copolymer polymerized using a Ziegler-Natta catalyst had good bleed-out resistance but poor transparency and low-temperature bending whitening resistance. Furthermore, the results of Comparative Examples 1 to 3 show that while component (B) is effective in improving low-temperature bending whitening resistance, it also causes the problem of poor bleed-out resistance. [Industrial Applicability]

[0079] The polypropylene resin composition can be suitably used as a raw material for non-oriented films.

Claims

1. A propylene polymer (A) that satisfies the following requirements (a1) to (a3): A propylene-based thermoplastic elastomer (B) that satisfies the following requirements (b1) and (b2), and At least one compound (C) selected from the group of triaryltriazine compounds represented by formula (1): 【Chemistry 1】 (In the formula, R １ is an isooctyl group) A polypropylene resin composition comprising: A polypropylene resin composition, wherein the proportions of components (A), (B) and (C) relative to the total amount of components (A) to (C) are 45.0 to 79.9% by weight, 20.0 to 50.0% by weight and 0.1 to 5.0% by weight, respectively. (a1) A metallocene catalyst-based propylene polymer. (a2) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 50 g / 10 min. (a3) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is greater than 100 MPa and less than 1,500 MPa. (b1) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 30 g / 10 min. (b2) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is 5 to 100 MPa.

2. The polypropylene resin composition according to claim 1, wherein the component (A) satisfies the following requirements (a4) to (a6): (a4) A propylene-ethylene copolymer containing 1% by weight or more and less than 5% by weight of units derived from ethylene. (a5) The melting point is 110 to 155°C. (a6) The ratio of the weight average molecular weight Mw to the number average molecular weight Mn (Mw / Mn) is 1.5 to 3.

5.

3. The polypropylene resin composition according to claim 1, wherein the component (B) satisfies the following requirement (b3): (b3) A propylene-ethylene copolymer or a propylene-ethylene-1-butene copolymer containing 5 to 20% by weight of units derived from ethylene and 0 to 20% by weight of units derived from 1-butene, wherein the total amount of units derived from ethylene and 1-butene is 5 to 40% by weight.

4. An unstretched film comprising the polypropylene resin composition according to any one of claims 1 to 3.

5. A propylene polymer (A) that satisfies the following requirements (a1) to (a3): A propylene-based thermoplastic elastomer (B) that satisfies the following requirements (b1) and (b2), and At least one compound (C) selected from the group of triaryltriazine compounds represented by formula (1): 【Chemistry 2】 (In the formula, R １ is an isooctyl group) A method for producing a polypropylene resin composition comprising: A production method comprising the step of mixing components (A) to (C) so that the proportions of components (A), (B), and (C) relative to the total amount of components (A) to (C) are 45.0 to 79.9 wt %, 20.0 to 50.0 wt %, and 0.1 to 5.0 wt %, respectively. (a1) A metallocene catalyst-based propylene polymer. (a2) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 50 g / 10 min. (a3) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is greater than 100 MPa and less than 1,500 MPa. (b1) The MFR measured in accordance with JIS-K6921-2:1997 Appendix (230°C, 2.16 kg load) is 1 to 30 g / 10 min. (b2) The flexural modulus measured in accordance with JIS-K7171:2016 at a test speed of 2 mm / min is 5 to 100 MPa.

6. A method for producing an unstretched film, comprising a step of melt-extrusion molding the polypropylene resin composition according to any one of claims 1 to 3.

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