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

Abstract

To provide an unoriented film composed of a polypropylene resin composition which achieves improvement in one or more of rigidity, optical properties and tear strength.SOLUTION: A polypropylene resin composition for unoriented films comprises a polypropylene resin (X) having a branched structure and a polypropylene resin (Y) having an MFR (230°C, load 2.16 kgf) of 1-30 g / 10 min. When the total mass of the polypropylene resin (X) and the polypropylene resin (Y) is 100 mass%, the polypropylene resin (X) is 3-50 mass% and the propylene resin (Y) is 97-50 mass%.

Description

[Technical Field]

[0001] This invention relates to a polypropylene film, and more specifically, to an unoriented polypropylene film produced by a T-die. [Background technology]

[0002] Polypropylene is a representative general-purpose resin. Its films are widely used in the packaging field due to their good balance of optical properties, mechanical properties, and packaging suitability, and are particularly often used in food packaging. In recent years, there has been a demand for thinner films to reduce raw material costs, improve productivity through high-speed film formation, and address cost reductions such as weight reduction and environmental concerns. However, excessive thinning can lead to a decrease in the film's stiffness, or rigidity. As a result, not only are there adverse effects on the transportability and unwinding from the roll during film processing, but it also leads to a decline in the functions that the final product, the packaging, should inherently possess, such as protecting the contents and maintaining its shape.

[0003] To solve this problem, the film needs to be made more rigid. The main methods for increasing rigidity include adding nucleating agents, which are crystallization accelerators, and adding resin-reinforced fillers such as talc, carbon nanofibers, and cellulose nanofibers. However, when inorganic nucleating agents are added, they are considered foreign substances and can cause defects in the film's appearance known as "fish eyes." When organic network-based nucleating agents are added, there is a concern that the low molecular weight components derived from the nucleating agent may contaminate the contents of the packaging. Furthermore, adding resin-reinforced fillers not only causes significant changes in texture, feel, and optical properties, but also increases the specific gravity, making it unsuitable for weight reduction purposes.

[0004] Although methods involving the addition of alicyclic hydrocarbon resins such as petroleum resins have been proposed, alicyclic hydrocarbon resins are expensive and unsuitable for the purpose of increasing rigidity to reduce costs through improved productivity and weight reduction.

[0005] While it is possible to increase rigidity by adjusting film formation conditions, such as promoting oriented crystallization by lowering the extrusion temperature or promoting crystal growth by raising the cooling and solidification temperature, this is not a preferred method because it results in a deterioration of the thickness accuracy of the resulting film and changes in its optical properties.

[0006] Therefore, while it is preferable to achieve high rigidity through the composition of the polymer itself, no film made of a polypropylene composition that can achieve high rigidity while retaining necessary functions such as optical properties has yet been found. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 8-3364 [Patent Document 2] Japanese Patent Application Publication No. 9-118776 [Patent Document 3] Japanese Patent Publication No. 2008-127487 [Patent Document 4] Japanese Patent Publication No. 2011-236357 [Patent Document 5] Japanese Patent Publication No. 2016-11380 [Patent Document 6] Japanese Patent Publication No. 2021-4359 [Overview of the project] [Problems that the invention aims to solve]

[0008] The object of the present invention is to improve the rigidity of an unoriented film made of a polypropylene resin composition, the optical properties of the film, the tear strength of the film, or the ease of opening the film packaging, or a combination thereof. [Means for solving the problem]

[0009] The present invention has the following embodiments. Embodiment 1 is, Taking the total mass of the polypropylene-based resin (X) and the propylene-based resin (Y) as 100% by mass, (1) The following characteristics (1-i) to (1-v): (1-i) The MFR (230 °C, load 2.16 kgf) is 10 to 70 g / 10 min. (1-ii) Mw / Mn is 2.0 to 5.0. (1-iii) W 1M is 0.5 to 4.0. (1-iv) g’ is 0.70 to 0.95. (1-v) (mm) is 95% or more. A polypropylene-based resin (X) having a branched structure of 3 to 50% by mass, and (2) The following characteristic (2-i): (2-i) The MFR (230 °C, load 2.16 kgf) is 1 to 30 g / 10 min. 97 to 50% by mass of a propylene-based resin (Y) A polypropylene-based resin composition for an unstretched film containing the above.

[0010] Aspect 2 is The polypropylene-based resin composition for an unstretched film according to Aspect 1, wherein the propylene-based resin (Y) is a propylene homopolymer.

[0011] Aspect 3 is The polypropylene-based resin composition for an unstretched film according to Aspect 1, wherein the propylene-based resin (Y) is a propylene-α-olefin copolymer having a melting point of from 110 to 155 °C.

[0012] Aspect 4 is The polypropylene-based resin composition for an unstretched film according to Aspect 1, wherein the propylene-based resin (Y) is a propylene-ethylene block copolymer.

[0013] Aspect 5 is An unstretched film comprising the polypropylene-based resin composition according to Aspects 1 to 4.

[0014] A Aspect 6 is This is a multilayer film comprising a layer made of the polypropylene resin composition described in embodiments 1 to 4.

[0015] Embodiment 7 is, This packaging includes a layer made of the polypropylene resin composition described in Embodiments 1 to 4.

[0016] Embodiment 8 is, This is a method for manufacturing a multilayer film according to embodiment 6 by multilayer co-extrusion molding using a T-die. [Effects of the Invention]

[0017] In films obtained from the polypropylene resin compositions for unoriented films according to embodiments 1 to 4, the rigidity of the film, the optical properties of the film, the tear strength of the film, or the ease of opening the film packaging, or a combination thereof, is improved. In the unstretched film of embodiment 5, its rigidity, optical properties, tear strength, or ease of opening of the film packaging, or a combination thereof, is improved. In the multilayer film of embodiment 6, its rigidity, optical properties, tear strength, or ease of opening of the film packaging, or a combination thereof, is improved. In the packaging of embodiment 7, the rigidity of the film (layer) contained in the packaging, the optical properties of the film, the tear strength of the film, or the ease of opening the film packaging, or a combination of these, is improved. In a multilayer film manufactured according to embodiment 8, its rigidity, optical properties, tear strength, or ease of opening of the film packaging, or a combination thereof, is improved. [Modes for carrying out the invention]

[0018] In this disclosure, "propylene-based resin (Y)" means a polymer obtained by polymerizing α-olefins containing propylene. Propylene-based resin (Y) also includes propylene homopolymers. In this disclosure, "propylene homopolymer" means (1) a polymer obtained by polymerizing monomers consisting solely of propylene, and (2) a composition identical to said polymer, regardless of the polymerization method.

[0019] In this disclosure, "propylene-α-olefin copolymer" means (1) a polymer obtained by polymerizing propylene with a monomer consisting of ethylene and / or an α-olefin having 4 to 20 carbon atoms, and (2) a composition identical to said polymer, regardless of the polymerization method.

[0020] In this disclosure, "propylene-ethylene block copolymer" means (1) a polymer obtained by polymerizing a propylene-based resin (A) and a propylene-ethylene random copolymer (B) by a stepwise polymerization method or by melt kneading using a mixing apparatus, and (2) a composition identical to the polymer, regardless of the polymerization method or mixing method.

[0021] In this disclosure, "Mw / Mn" means the value obtained by dividing the weight-average molecular weight (hereinafter referred to as "Mw") by the number-average molecular weight (hereinafter referred to as "Mn").

[0022] In this disclosure, "W 1M " refers to the proportion of components with a molecular weight of 1 million or more.

[0023] In this disclosure, "MT170℃" means the melt tension expressed in units of gf at 170℃.

[0024] In this disclosure, "MT230℃" means the melt tension expressed in units of gf at 230℃.

[0025] In this disclosure, "MFR" means melt flow rate.

[0026] In this disclosure, “neck-in” means the difference between the width of the film or sheet as it is being extruded from the die of the extruder and the width of the film or sheet as it exits the die.

[0027] In this disclosure, "g'" means [η]br / [η]lin This is the value obtained. Here, [η]br is the intrinsic viscosity of a polymer having a long-chain branched structure (hereinafter referred to as "br"), and [η]lin is the intrinsic viscosity [η]lin of a similar linear polymer having the same molecular weight as br. g' takes a smaller value as the number of long-chain branched structures increases. An explanation of g' is provided in "Developments in Polymer Characterization-4" (JV Dawkins ed. Applied Science Publishers, 1983).

[0028] In this disclosure, "(mm)" represents the proportion of polypropylene units in a 3-chain of propylene units in the polypropylene resin (X) in which the direction of methyl branching in each propylene unit is the same.

[0029] In this disclosure, unless otherwise specified, the content of polypropylene resin (X) and propylene resin (Y) in the resin composition is expressed as a mass ratio when the total mass of polypropylene resin (X) and propylene resin (Y) is set to 100% by mass.

[0030] In this disclosure, "ductility" means the highest processing speed at which film breakage does not occur and draw resonance does not occur during extrusion lamination.

[0031] 1-1. Polypropylene resin (X) Due to the ease of melt extrusion molding of the polypropylene resin composition, the MFR (230°C, load 2.16 kgf) of the polypropylene resin (X) in the polypropylene resin composition is preferably 10 to 70 g / 10 min, more preferably 15 to 60 g / 10 min, even more preferably 20 to 50 g / 10 min, and most preferably 30 to 50 g / 10 min.

[0032] The MFR of polypropylene resins can be adjusted by (i) changing the temperature and / or pressure during polymerization of the polypropylene resin and / or (ii) adding hydrogen or other chain transfer agents to the monomer during polymerization of the polypropylene resin.

[0033] Due to the ease of melt extrusion molding of the polypropylene resin composition, the Mw / Mn ratio of the polypropylene resin (X) in the polypropylene resin composition is preferably 2.0 to 5.0, more preferably 2.1 to 4.6, and even more preferably 2.2 to 4.2. The Mw, Mn, and Mw / Mn of the polypropylene resin (X) can be adjusted by changing the polymerization temperature and pressure, adding hydrogen or other chain transfer agents during polymerization and their amounts, and / or by the type of catalyst and the ratio of the amounts of each catalyst during polymerization. Due to the ease of melt extrusion molding of the polypropylene resin composition, the Mw of the polypropylene resin (X) in the polypropylene resin composition is preferably 160,000 to 280,000, more preferably 170,000 to 260,000, and even more preferably 180,000 to 240,000.

[0034] For ease of melt extrusion molding of polypropylene resin compositions and / or reduction of fisheye formation and other appearance improvements, W of polypropylene resin (X) 1M The amount is preferably 0.5 to 4.0% by mass, more preferably 1.0 to 3.5% by mass, and even more preferably 1.5 to 3.0% by mass. Polymer W 1M This can be adjusted by adjusting the ratio of a catalyst that produces a higher molecular weight polymer than the one used during polymerization to a catalyst that produces a lower molecular weight polymer than the one used during polymerization, the amount of hydrogen added during polymerization, and the reaction temperature during polymerization.

[0035] When producing a film by melt molding of a polypropylene resin composition, for the sake of ductility, the MT170°C of the polypropylene resin (X) in the polypropylene resin composition is preferably 40 gf or less, more preferably 35 g or less, and even more preferably 30 g or less. The selection of metallocene catalysts, their combinations and ratios, and the prepolymerization conditions can be controlled to increase the long-chain branching of the polypropylene resin (X).

[0036] To improve the quality of films produced by melt molding of polypropylene resin compositions, the g' of the polypropylene resin (X) in the polypropylene resin composition is preferably 0.70 to 0.95, more preferably 0.72 to 0.90, even more preferably 0.75 to 0.88, and most preferably 0.80 to 0.85.

[0037] From the viewpoint of preventing a decrease in the moldability of the polypropylene resin composition during melt molding, the polypropylene resin (X) contained in the polypropylene resin composition is preferably a branched polymer having a comb-like chain structure.

[0038] The introduction of numerous long-chain branches into polypropylene resin (X) induces a branching index g' of 0.70 to 0.95. The selection of preferred metallocene catalysts, their combinations and ratios, and control of prepolymerization conditions adjust the branching index g'.

[0039] To improve the rigidity of molded products such as films made from polypropylene resin compositions, the (mm) of the polypropylene resin (X) in the polypropylene resin composition is preferably 95% or more, more preferably 96% or more, and even more preferably 97% or more.

[0040] The polypropylene resin (X) to be contained in the polypropylene resin composition has MFR, Mw / Mn, and W 1M In order to induce g' and (mm) to favorable values, and to induce a favorable relationship between log(MT170℃) and -1.1×log(MFR), a macromer copolymerization method utilizing a combination of metallocene catalysts is preferred as a method for producing polypropylene resin (X). Japanese Patent Publication No. 2009-57542, among others, discloses such a method.

[0041] The polypropylene resin (X) contained in the polypropylene resin composition is preferably a polymer (propylene homopolymer) obtained by polymerizing only propylene monomer.

[0042] The polypropylene resin (X) may be in powder or particulate form. Here, particulate polypropylene resin (X) includes granules of polypropylene resin (X).

[0043] The production of polypropylene resin (X) by mixing additional components can be carried out using Henschel mixers, V-blenders, ribbon blenders, kneaders and / or tumbler blenders, etc. The production of granules can be carried out using single-screw extruders, multi-screw extruders, kneaders, Banbury mixers, and other kneaders.

[0044] 1-2. Propylene resin (Y) To achieve the objectives of the present invention, the propylene resin (Y) is preferably one or more selected from the group consisting of propylene homopolymer, propylene-α-olefin copolymer, and propylene-ethylene block copolymer.

[0045] To improve moldability, such as preventing melt fracture and neck-in during film molding of polypropylene resin compositions, the MFR (230°C, load 2.16 kgf) of the propylene resin (Y) contained in the resin composition is preferably 1 to 30 g / 10 min, and more preferably 2 to 25 g / 10 min.

[0046] The MFR of the propylene-based resin (Y) can be adjusted by changing the temperature and pressure conditions of propylene polymerization, as well as by adding chain transfer agents such as hydrogen during polymerization.

[0047] Method for producing propylene resin (Y) Polymerization catalysts for producing propylene resin (Y) include Ziegler-Natta catalysts and / or metallocene catalysts, but other catalysts may also be used. The Ziegler-Natta catalyst is described in Section 2.3.1 (pages 20-57) of the "Polypropylene Handbook," edited by Edward P. Moore Jr., translated and supervised by Tetsuo Yasuda and Nobu Sakuma, published by Kogyo Chosakai (1998). The Ziegler-Natta catalyst includes (1) titanium trichloride catalysts, magnesium chloride, and titanium halides, which consist of titanium trichloride and organoaluminum halides; (2) magnesium-supported catalysts consisting of a solid catalyst component containing an electron-donating compound and organoaluminum and organosilicon compounds; and (3) catalysts that combine an organoaluminum compound component with an organosilicon-treated solid catalyst component formed by contacting a solid catalyst component with organoaluminum and organosilicon compounds.

[0048] Metallocene catalysts include (i) transition metal compounds of Group 4 of the periodic table containing ligands having a cyclopentadienyl skeleton, (ii) co-catalysts that can be activated to a stable ionic state by reacting with metallocene compounds, and (iii) catalysts consisting of co-catalysts that can be activated to a stable ionic state by reacting with metallocene compounds and organoaluminum compounds. To improve the mechanical properties of the propylene-based resin (Y), the metallocene catalyst used to synthesize the propylene-based resin (Y) is preferably a crosslinked metallocene compound capable of stereoregular polymerization of propylene, and more preferably a crosslinked metallocene compound capable of isoregular polymerization of propylene.

[0049] (i) Metallocene compounds are described in Japanese Patent Publication Nos. S60-35007, S61-130314, S63-295607, H1-275609, H2-41303, H2-131488, H2-76887, H3-163088, H4-300887, H4-211694, H5-43616, H5-209013, H6-239914, H7-504934 and H8-85708.

[0050] (i) Specific examples of metallocene compounds include: Methylenebis(2-methylindenyl)zirconium dichloride, Ethylenebis(2-methylindenyl)zirconium dichloride, Ethylene 1,2-(4-phenylindenyl)(2-methyl-4-phenyl-4H-azlenyl) 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)zirconium dichloride, Dimethylsilylenebis(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-butylamide 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-azlenyl)] zirconium dichloride, Dimethylsilylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azlenyl)] zirconium dichloride, Dimethylsilylenebis[1-(2-ethyl-4-naphthyl-4H-azlenyl)] zirconium dichloride, Diphenylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azlenyl)] zirconium dichloride, Dimethylsilylenebis[1-(2-ethyl-4-(3-fluorobiphenylyl)-4H-azlenyl)] zirconium dichloride, Dimethylgermylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azlenyl)] zirconium dichloride, and Dimethylgermylenebis[1-(2-ethyl-4-phenylindenyl)] zirconium dichloride These include zirconium compounds, etc.

[0051] (i) The metallocene compound in which zirconium is replaced with titanium or hafnium, and / or mixtures thereof, can also be used as polymerization catalysts for producing propylene resin (Y). (i) The metallocene compound in which chloride is 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 groups, hydride groups, etc., can also be used as polymerization catalysts for producing propylene resin (Y).

[0052] To improve the moldability of resin compositions containing propylene resin (Y), the metallocene compound (i), which is a polymerization catalyst for producing propylene resin (Y), is preferably a metallocene compound in which an indenyl group or an azlenyl group is crosslinked with silicon or a gelmyl group. The polymerization catalyst for producing the propylene resin (Y) may be supported on an inorganic or organic compound. To increase the yield of the propylene resin (Y), the support is preferably porous. The support is preferably an inorganic compound such as an ion-exchange layered silicate, zeolite, SiO2, Al2O3, silica alumina, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, ThO2, porous polyolefin, an organic compound such as a styrene-divinylbenzene copolymer, or an olefin-acrylic acid copolymer, or a mixture thereof.

[0053] To increase the production volume of propylene resin (Y), it is preferable to use a co-catalyst in combination with the metallocene compound (ii). Preferred co-catalysts include organoaluminum oxy compounds such as aluminoxane compounds, ion-exchange layered silicates, Lewis acids, boron-containing compounds, ionic compounds, and fluorine-containing organic compounds.

[0054] To increase the production volume of propylene resin (Y), the organoaluminum compound in (iii) is preferably trialkylaluminum such as triethylaluminum, triisopropylaluminum, and triisobutylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, alkylaluminum dihalide, alkylaluminum hydride, or organoaluminum alkoxide.

[0055] Propylene-based resin (Y) can be produced by slurry polymerization, bulk polymerization, gas-phase polymerization, etc. Furthermore, propylene-based resin (Y) can be produced by these multi-stage polymerization methods.

[0056] Propylene resin (Y) may be produced by mixing with necessary additional components using a Henschel mixer, V-blender, ribbon blender, tumbler blender, etc. Propylene resin (Y) may be produced by kneading using a kneader such as a single-screw extruder, multi-screw extruder, kneader, or Banbarri mixer.

[0057] The propylene-based resin (Y) is preferably a propylene homopolymer. Furthermore, the propylene-based resin (Y) is preferably a propylene-α-olefin copolymer, and more preferably a propylene-α-olefin copolymer with a melting point of 110 to 155°C. The propylene-α-olefin copolymer, propylene-based resin (Y), may also be a propylene-ethylene copolymer obtained by copolymerizing a propylene monomer and an ethylene comonomer. The propylene-based resin (Y) preferably contains 0 to 6.0% by mass of ethylene as a comonomer. More preferably, it contains 0 to 5.0% by mass of ethylene, and even more preferably, 0 to 4.0% by mass of ethylene. If the ethylene content exceeds 6.0% by mass, the crystallinity may decrease, and the heat resistance may decrease.

[0058] Furthermore, the propylene-based resin (Y) may also be a propylene-ethylene block copolymer. The propylene-ethylene block copolymer may be a propylene-ethylene block copolymer obtained by mixing a propylene-based resin (A) and a propylene-ethylene random copolymer (B). The mixing method may be a mixture produced by a step polymerization method, or a mixture produced by melt-kneading separately manufactured propylene-based resin (A) and propylene-ethylene random copolymer (B) using a mixing device such as a ribbon blender, Henschel mixer (trade name), Banbury mixer, drum tumbler, single-screw or twin-screw extruder, cone kneader, etc. However, it is more economical to produce it by a step polymerization method. To improve the heat resistance of the molded product, suppress stickiness and bleed-out, and prevent clogging during step polymerization, the comonomer content of the propylene-based resin (A) is preferably 0 to 15% by weight, more preferably 0 to 5% by weight, and particularly preferably 0 to 2% by weight.

[0059] The propylene resin (Y) may be in powder or particulate form. Here, particulate propylene resin (Y) includes granulated propylene resin (Y).

[0060] 1-3. Polypropylene resin compositions for unoriented films One embodiment of the present invention is a polypropylene resin composition for unstretched films comprising a polypropylene resin (X) and a propylene resin (Y) in a specific ratio detailed below (hereinafter also referred to as "the polypropylene resin composition of the present invention").

[0061] From the viewpoint of rigidity, optical properties, and tear strength, the amount of polypropylene resin (X) in the polypropylene resin composition for unoriented film is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 8 to 35% by mass. From the viewpoint of rigidity, optical properties, and tear strength, the amount of propylene resin (Y) in the polypropylene resin composition for unoriented film is preferably 50 to 97% by mass, more preferably 60 to 95% by mass, and even more preferably 65 to 92% by mass.

[0062] 1-3-2. Other ingredients The polypropylene resin composition of the present invention may further contain additives as needed, in addition to the polypropylene resin (X) and propylene resin (Y) described above. By appropriately selecting additives, the functionality of the propylene resin can be improved. Additives may be used individually or in combination of two or more. The content of additives in the polypropylene resin composition is preferably, for example, 0 to 10 parts by mass per 100 parts by mass of the total of the polypropylene resin (X) and propylene resin (Y).

[0063] Examples of additives include phenolic stabilizers such as 2,6-di-t-butyl-p-cresol, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, and n-octadecyl-3-(4'-hydroxy-3,5'-di-t-butylphenyl)propionate; phosphite stabilizers such as bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite and tris(2,4-di-t-butylphenyl)phosphite; lubricants such as higher fatty acid amides and higher fatty acid esters; antistatic agents such as glycerol esters and sorbitanic acid esters of fatty acids with 8 to 22 carbon atoms, and polyethylene glycol esters; and antiblocking agents such as silica, calcium carbonate, and talc.

[0064] Other examples include UV absorbers and light stabilizers. By incorporating UV absorbers and light stabilizers into the polypropylene resin composition, weather resistance can be imparted to the polypropylene resin composition. UV absorbers are compounds that have an absorption band in the ultraviolet region, and known types include triazoles, benzophenones, salicylates, cyanoacrylates, nickel chelates, and inorganic microparticles. Of these, triazoles are the most widely used. Examples of triazole-based UV absorbers include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole, and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole. Examples of benzophenone-based UV absorbers include 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone. Examples of salicylate-based UV absorbers include 4-t-butylphenyl salicylate. Examples of cyanoacrylate-based UV absorbers include ethyl (3,3-diphenyl) cyanoacrylate. Examples of nickel chelating UV absorbers include nickel dibutyldithiocarbamate. Examples of inorganic particulate UV absorbers include TiO2, ZnO2, and CeO2.

[0065] Hindered amine compounds are commonly used as light stabilizers, and these are known as HALS. HALS include sebacate-type compounds, butanetetracarboxylate-type compounds, succinate polyester-type compounds, and triazine-type compounds. Examples of sebacate-type compounds include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate and bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate. Examples of butanetetracarboxylate-type compounds include tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, condensates of 1,2,3,4-butanetetracarboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol, and condensates of 1,2,3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and tridecyl alcohol. Examples of succinic acid polyester-type compounds include condensation polymers of succinic acid and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine. Examples of triazine-type compounds include N,N'-bis(3-aminopropyl)ethylenediamine·2,4-bis{N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino}-6-chloro-1,3,5-triazine condensate, poly{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino, and poly(6-morpholino-s-triazine-2,4-diyl){(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino.

[0066] 1-3-3. Other Polymers Modifiers can be added to polypropylene resin compositions to improve their performance or adjust their properties. Examples of modifiers include elastomers and polyethylene resins. Elastomers include ethylene-α-olefin copolymers, binary random copolymer resins of propylene and α-olefins having 4 to 12 carbon atoms, and ternary random copolymer resins of propylene, ethylene, and α-olefins having 4 to 12 carbon atoms.

[0067] Styrene-based elastomers are also elastomers. Examples of styrene-based elastomers include hydrogenated styrene-butadiene block copolymers, hydrogenated styrene-isoprene block copolymers, hydrogenated styrene-vinylated polyisoprene block copolymers, and hydrogenated styrene-butadiene random copolymers.

[0068] The polyethylene resin includes ethylene-α-olefin copolymers such as low-density polyethylene and linear low-density polyethylene. For transparency of the product formed from the composition, the density of the polyethylene resin in the composition is 0.860 to 0.910 g / cm³. 3 Preferably, 0.870~0.905 g / cm³ 3 More preferably, 0.875~0.895 g / cm³ 3 That is even more preferable. The density is measured at 23°C in accordance with JIS K7112. The α-olefin monomer used as a raw material for the ethylene / α-olefin copolymer is preferably an α-olefin having 3 to 18 carbon atoms. This α-olefin includes propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methylpentene-1, 4-methylhexene-1, and 4,4-dimethylpentene-1, as well as mixtures thereof. The ethylene / α-olefin copolymer includes ethylene-based elastomers, ethylene-propylene rubber, and the like. From the viewpoint of transparency, ethylene-α-olefin copolymers produced using metallocene catalysts are preferred.

[0069] From the viewpoint of film processability and film transparency, the amount of polyethylene resin in the polypropylene resin is preferably 2 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of polypropylene resin.

[0070] When blending components other than the polypropylene resin in the polypropylene resin composition for unoriented film of the present invention, mixing methods such as using a Henschel mixer, V-blender, ribbon blender, or tumbler blender, as well as melt kneading using a kneader such as a single-screw extruder, multi-screw extruder, kneader, or Banbarri mixer, can be used.

[0071] 1-4. Film Manufacturing Unstretched films can be manufactured by methods such as melt extrusion molding using a T-die.

[0072] Film molding machines for producing unoriented films include those that form films by melt extrusion from a T-die. Preferably, film molding machines for producing unoriented films are T-die film processing machines and T-die extrusion laminating machines, with T-die film processing machines being more preferable. From the viewpoint of film processability, the resin temperature during the manufacture of the T-die film processing apparatus is preferably 160 to 260°C. From the viewpoint of film transparency, the cooling roll temperature during the manufacture of the T-die film processing apparatus is preferably 20 to 80°C.

[0073] Another aspect of the present invention is an unoriented film made from the polypropylene resin composition of the present invention (hereinafter also referred to as "the unoriented film of the present invention"). The unoriented film of the present invention may be a single-layer film, or it may be a multilayer film containing at least one layer made of the polypropylene resin composition of the present invention. The unoriented film of the present invention is used for food packaging such as bread and vegetables, clothing packaging such as shirts, and industrial parts packaging. Furthermore, this film can be used as a base material for films laminated to cellophane, paper, textiles, cardboard, aluminum foil, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and stretched polypropylene by lamination methods such as dry lamination and sand lamination.

[0074] Another aspect of the present invention is a packaging body comprising a layer made of the polypropylene resin composition of the present invention. Examples of packaging materials of the present invention include packaging for beverages, solid or semi-solid food products, packaging for hair products, shampoos, cosmetics, paper cartons, packaging for tubes, bags, cups, standing packs, trays, and the like. [Examples]

[0075] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In this embodiment, "room temperature" means 20-30°C.

[0076] 1. Evaluation Method (1) MFR The MFR is measured according to the method of JIS K6921-1:2018.

[0077] (2)Molecular weight distribution: The Mw, Mn, and integral molecular weight distribution curves are obtained using GPC. Equipment: Waters GPC (ALC / GPC, 150C) Detector: FOXBORO MIRAN, 1A, IR detector (measurement wavelength: 3.42 μm) Columns: Showa Denko AD806M / S (3 pieces) Mobile phase solvent: 0.5 mg / mL dibutylhydroxytoluene solution in o-dichlorobenzene (hereinafter referred to as "ODCB+BHT"). Measurement temperature: 140℃ Flow rate: 1.0 mL / min Injection volume: 0.2 mL The sample is an ODCB + BHT solution containing a 1 mg / mL sample that was dissolved at 140 °C for approximately 1 hour. The conversion from retention volume to molecular weight obtained by GPC is performed using a calibration curve with standard polystyrene prepared in advance. All of the standard polystyrenes used are the following brands manufactured by Tosoh Corporation: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000. [[ID=ll]]A calibration curve is created by injecting 0.2 mL of a solution dissolved in ODCB + BHT so that each standard polystyrene has a concentration of 0.5 mg / mL. The calibration curve uses a cubic equation approximated by the least squares method. Viscosity formula used for conversion to molecular weight: [η]=K×M α The following numerical values are used. For polystyrene: K = 1.38×10 -4 , α = 0..7 For polypropylene: K = 1.03×10 -4 , α = 0.78

[0078] In this example, W 1M is a value calculated as a percentage (%) by dividing the ratio obtained by excluding the integrated value up to a molecular weight of 1 million from the integrated molecular weight distribution curve obtained by GPC by 100.

[0079] (3) MT170 °C and MT230 °C: With a Capillograph 1B manufactured by Toyo Seiki Seisaku-sho, Ltd., MT170 °C is measured under the following conditions. · Capillary: diameter 2.0 mm, length 40 mm · Cylinder diameter: 9.55 mm · Cylinder extrusion speed: 20 mm / min · Take-up speed: 4.0 m / min · Temperature: 170 °C However, if MT170℃ is a high value, the sample may break at a pull-up speed of 4.0 m / min. In such cases, the pull-up speed should be reduced, and the tension at the highest possible pull-up speed should be set to MT170℃. MT230℃ is measured using the same method as MT170℃, except that the temperature is set to 230℃.

[0080] (4) g' g' is calculated using the following method. A Waters Alliance GPCV2000 GPC instrument equipped with a differential refractometer (RI) and a viscometer will be used. A Wyatt Technology DAWN-E multi-angle laser light scattering detector (hereinafter referred to as "MALS") will be used as the light scattering detector. The detectors will be connected in the order of MALS, RI, and viscometer. The mobile phase solvent will be 1,2,4-trichlorobenzene (with BASF Japan's antioxidant Irganox 1076 added at a concentration of 0.5 mg / mL). The flow rate is 1 mL / min, and two Tosoh GMHHR-H(S) HT columns are used in conjunction. The temperature of the columns, sample injection section, and each detector is 140°C. The sample concentration is 1 mg / mL, and the injection volume, i.e., the sample loop volume, is 0.2175 mL. The absolute molecular weight (Mabs), mean square radius of inertia (Rg), and intrinsic viscosity ([η]) obtained from the viscometer are obtained using ASTRA (version 4.73.04), the data processing software included with MALS. Using Novatec PP (registered trademark) manufactured by Nippon Polypropylene Co., Ltd., with the grade name FY6 as the standard, we obtain [η]lin by extrapolating using the Mark-Houwink-Sakurada formula. In calculating g', matters not described in this specification were based on the following references: 1. “Developments in Polymer Characterization-4” (JV Dawkins ed. Applied Science Publishers, 1983.Chapter1.) 2. Polymer, 45, 6495-6505 (2004) 3.Macromolecules,33,2424-2436(2000) 4. Macromolecules, 33, 6945-6952 (2000). If it is confirmed that g' exceeds 0.95, write ">0.95".

[0081] (5) mm fraction: 13 From the results of the ¹³C-NMR measurement, (mm) is calculated using formula m. (mm)=Imm×100 / (Imm+3×Imrrm) (formula m) Be, Imm is I 23.6~21.1 of 13 The integrated intensity of the C signal, Imrrm, is I 19.8~19.7 of 13 This is the integrated intensity of the C signal. 375 mg of the sample was completely dissolved in 2.5 ml of deuterated 1,1,2,2-tetrachloroethane in an NMR sample tube (10φ), and then measured by proton complete decoupling at 125°C. The chemical shift was set to 74.2 ppm, with the middle peak of the three peaks of deuterated 1,1,2,2-tetrachloroethane being used as the reference point for the chemical shifts of the other carbon peaks. • Flip angle: 90 degrees • Pulse interval: 10 seconds ·Resonance frequency: 100MHz or more • Total number of times: 10,000 or more • Observation range: -20 ppm to 179 ppm • Number of data points: 32768

[0082] Referencing Polymer Journal, Vol. 16, p. 717 (1984), Asakura Shoten; Macromolecules, Vol. 8, p. 687 (1975); Polymer, Vol. 30, p. 1350 (1989), etc., the spectral assignments are determined. (6) Ethylene content: In accordance with the method described in paragraphs

[0120] to

[0125] of Japanese Patent Publication No. 2013-199642, a GSX-400 manufactured by JEOL Ltd. 13 The ethylene content is determined by analyzing the 1C-NMR spectrum. However, if the JEOL Ltd. GSX-400 is unavailable, use a device with a carbon nucleus resonance frequency of 100 MHz or higher.

[0083] (7)λmax: We will find λmax under the following conditions: • Device: Ares, manufactured by Rheometorics Corporation. • Fixture: Extensional Viscosity Fixture manufactured by TA Instruments Inc. ·Measurement temperature: 180℃ • Distortion rate: 0.1 / sec • Preparation of test specimens: Press-form a sheet measuring 18mm x 10mm with a thickness of 0.7mm. Unless otherwise specified, λmax measurements shall conform to Polymer 42(2001)8663. (8) Transparency (LSI): The film's LSI (Luminous Score) is measured using an LSI meter (N207) manufactured by Toyo Seiki Seisakusho. LSI measures the amount of light scattering at small angles and serves as an indicator of the film's transparency, which is consistent with visual perception. A higher value indicates poorer transparency, while a lower value indicates better transparency. (9) Total HAZE (in %): All haze will be measured in accordance with JIS K7136. A low overall haze level indicates high transparency. (10) Internal HAZE (in %): In accordance with JIS K 7136, oil is placed in two standard glass pieces, a film is inserted into them, and the internal haze is measured. Low internal haze indicates high transparency. (11) LSI (unit: %) The glossiness (hereinafter referred to as "LSI") of a 60° mirror surface is measured in accordance with JIS K7105-1981. A higher glossiness value indicates better glossiness, i.e., higher gloss. (12) Melting point, crystallization temperature (unit: °C): Measurements will be taken in accordance with JIS K 7121. (13) Young's modulus MD, TD (unit: N): The Young's modulus in the film's flow direction (hereinafter referred to as "MD") (hereinafter referred to as "Young's modulus MD") is measured in accordance with JIS K 7127. Similarly, the Young's modulus in the direction perpendicular to the film flow (hereinafter referred to as "TD") (hereinafter referred to as "Young's modulus TD") is measured. A high Young's modulus indicates high rigidity. (14) Tear strength MD, TD (unit: N / mm): The tear strength of the MD (hereinafter referred to as "MD tear strength") is measured in accordance with JIS K 7128. Similarly, the tear strength of the TD (hereinafter referred to as "TD tear strength") is measured. The lower the tear strength of the film, the easier the film packaging is to open.

[0084] 4.Materials used (1) Polypropylene resin (X) The polymers (X1) to (X4) produced in the following manufacturing examples 1 to 4 are used.

[0085] [Manufacturing Example 1 (Manufacturing of PP1)] <Catalyst Synthesis Example 1> (1) Synthesis of complexes rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium is synthesized according to the method of Synthesis Example 1 in Japanese Patent Application Publication No. 2012-149160.

[0086] rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium is synthesized according to the method of Example 7 in Japanese Patent Publication No. 11-240909.

[0087] (2) Preparation of catalyst (2-a) Chemical treatment of ion-exchange layered silicates Add 645.1 g of distilled water and 82.6 g of 98 wt% sulfuric acid to a 1 L three-necked flask equipped with a stirring blade and reflux device, and heat to 95°C. Add 100g of montmorillonite and react at 95°C for 320 minutes. After 320 minutes from the start of the reaction, add 0.5L of distilled water to stop the reaction, filter, and obtain 255g of solid. The montmorillonite in question is Benclay KK, manufactured by Mizusawa Chemical Industries, Ltd., with Al=9.78% by mass, Si=31.79% by mass, Mg=3.18% by mass, Al / Si (molar ratio)=0.320, and an average particle size of 14 μm. One gram of the solid contains 0.31 grams of the intermediate. The chemical composition of the intermediate is Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, and Al / Si (molar ratio) = 0.222. Add 1545g of distilled water to the solid to form a slurry, and raise the temperature to 40°C. Add 5.734g of lithium hydroxide hydrate in solid form and react at 40°C for 1 hour. After 1 hour, filter the reaction slurry, wash it three times with 1L of distilled water, and obtain a solid. The solid material is dried to obtain 80 g of chemically treated montmorillonite. The chemical composition of this chemically treated montmorillonite is Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, Al / Si (molar ratio) = 0.222, and Li = 0.53 mass%.

[0088] (2-b) Prepolymerization Internal volume 1m 3150 kg of the solid material is placed in the reactor, and 2832 L of hexane is added to form a slurry. 74.4 kg (375 mol) of triisobutylaluminum is then added over 85 minutes and stirred for 60 minutes. Afterwards, the mixture is washed with hexane to 1 / 32 of its original volume, bringing the total volume to 900 L. The slurry solution containing this chemically treated montmorillonite is kept at 50°C, and 0.65 kg of triisobutylaluminum (4.257 kg, 3.28 mol, of a hexane solution with a concentration of 15.3% by mass) is added to it. After stirring for 5 minutes, add 0.657 kg (0.81 mol) of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium and 96 L of toluene, and continue stirring for 60 minutes. Then, 9.758 kg (26.61 mol) of trin-normal octylaluminum was added and stirred for 6 minutes. In a separate container equipped with a stirring device, 0.064 kg of triisobutylaluminum (9.88 kg, 0.32 mol) of 0.648 mass% toluene solution was added to 240 L of toluene, to which 1.768 kg (1.89 mol) of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium was added to prepare the solution. 100 L of toluene was then added, and stirring continued for another 20 minutes. Subsequently, 2387 L of hexane was added, and the internal temperature of the reactor was raised to 40°C. Then, 328.1 kg of propylene was fed over 240 minutes, and prepolymerization was carried out while maintaining the temperature at 40°C. Afterward, the propylene feed is stopped, and residual polymerization is carried out at 40°C for 80 minutes. After the remaining polymerization is complete, stop stirring and allow the contents to settle and stand. Remove the supernatant of the contents until the solution volume is 1500 L, add 12.7 kg of triisobutylaluminum, add 3974 L of hexane again, stir, and then stand. Repeat removing the supernatant until the solution volume is 1500 L to obtain the pure product. To the clean material, 42.9 kg of a 20.8% by mass triisobutylaluminum hexane solution (containing 8.9 kg of triisobutylaluminum in the solution) and 205 L of hexane were added to obtain the reaction solution. The reaction solution is transferred to a dryer and dried at 40°C for 9 hours to obtain 465 kg of dried prepolymerization catalyst, which is named Catalyst 1. The prepolymerization ratio of the dry prepolymerization catalyst is 281. The prepolymerization ratio is calculated as the weight of the prepolymerization polymer divided by the weight of the solid catalyst.

[0089] <Polymerization> A 20L autoclave is heated and thoroughly dried by circulating nitrogen, then the contents of the chamber are replaced with propylene and cooled to room temperature. 18.7 mL of heptane solution of triisobutylaluminum (140 mg / mL) and 1.02 NL of H2 are introduced, followed by the introduction of 5000 g of liquid propylene, and the temperature is raised to 63°C. Then, 300 mg of catalyst 1, excluding the prepolymerized polymer, is pumped into the polymerization chamber with high-pressure argon to start polymerization, and the temperature is rapidly raised to 70°C. The temperature is maintained at 70°C, and 1 hour after the start of polymerization, unreacted propylene is quickly purged to stop the polymerization. This yields 2922 g of polymer powder (hereinafter referred to as "PP1"). The catalytic activity of PP1 (PP1 / catalyst) is 9740 g / g. The MFR of PP1 is 32 g / 10 min.

[0090] In the method for producing PP1, the amount of H2 introduced is changed to 1.28 NL, and the amount of catalyst 1 is changed to 220 mg, with the mass of catalyst 1 excluding the prepolymerized polymer being changed to obtain 1730 g of polymer powder (hereinafter referred to as "PP2"). The catalytic activity of PP2 (PP2 / catalyst) is 11400 g / g. The MFR of PP2 is 60 g / 10 min.

[0091] In the method for producing PP1, the amount of H2 introduced is changed to 0.95 NL, and the amount of catalyst 1, specifically the mass of catalyst 1 excluding the prepolymerized polymer, is changed to 200 mg to obtain 1583 g of polymer powder (hereinafter referred to as "PP3"). The catalytic activity of PP3 (PP3 / catalyst) is 7915 g / g. The MFR of PP3 is 15 g / 10 min.

[0092] In the method for producing PP1, the amount of H2 introduced is changed to 0.85 NL, and the amount of catalyst 1, specifically the mass of catalyst 1 excluding the prepolymerized polymer, is changed to 230 mg to obtain 1730 g of polymer powder (hereinafter referred to as "PP4"). The catalytic activity of PP4 (PP4 / catalyst) is 7520 g / g. The MFR of PP4 is 8.5 g / 10 min.

[0093] <Pellet manufacturing> [Manufacturing of pellets (X1) to (X4)] Each of 100 parts by mass of polymer powders (PP1) to (PP3) is mixed with 0.125 parts by mass of IRGANOX1010 and 0.125 parts by mass of IRGAFOS 168. After mixing in a high-speed agitator for 3 minutes at room temperature, the mixture is melt-kneaded in a twin-screw extruder to obtain polypropylene resin pellets (X1) to (X4) (in the table, they are simply referred to as "X1," etc.). IRGANOX1010 is the trade name for tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, a phenol-based antioxidant manufactured by BASF Japan Ltd. IRGAFOS 168 is tris(2,4-di-t-butylphenyl) phosphite, a phosphite-based antioxidant manufactured by BASF Japan Ltd. In this context, the high-speed agitator is a Henschel mixer. The twin-screw extruder used here is a Technovel KZW-25. The screw rotation speed for melt mixing is set to 400 RPM, and the mixing temperature for melt mixing is set to 80°C, 160°C, and 210°C from the bottom of the hopper, and then to 230°C up to the die outlet.

[0094] Regarding pellets (X1) to (X4), MFR, 13 We evaluated the 1C-NMR spectrum, GPC, branching index g', and melt tension (MT). The evaluation results are shown in Table 1.

[0095] [Table 1]

[0096] (2) Propylene resin (Y) As the propylene resin (Y), polypropylene (Y1) to (Y4) is used (in the table, it is simply referred to as "Y1," etc.).

[0097] (Y1): Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec® FL4", propylene homopolymer, MFR = 4.2g / 10 min. (Y2): [Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec (registered trademark) SA4L", propylene homopolymer, MFR = 5.3g / 10 min. (Y3): Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec (Registered Trademark) FY6H", propylene homopolymer, MFR = 1.9g / 10 min. (Y4): Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec (registered trademark) FA3KM", propylene homopolymer, MFR = 10.0g / 10 min. (Y5): Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec (Registered Trademark) EA9HD", propylene homopolymer, MFR = 0.4g / 10 min. (Y6): Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec (product registration) SA04M", propylene homopolymer, MFR = 40.0g / 10 min. (Y7): Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec (registered product) FW4BA", propylene-α-olefin copolymer, MFR = 7.0g / 10min, Tm = 138℃. (Y8): Manufactured by Nippon Polypropylene Co., Ltd., product name "Novatec (registered product name) BC5FA", propylene-ethylene block copolymer, MFR = 2.5g / 10min.

[0098] [Examples 1-10][Comparative Examples 1-11] Polypropylene resin (X) and propylene resin (Y) are mixed in a Henschel mixer in the mass ratio shown in Table 2, and then pelletized by melt extrusion at a temperature of 220°C using an extruder with a screw diameter of 50 mmΦ. "0" in the table indicates that the corresponding resin was not mixed. The obtained pellets are introduced into a single-layer T-die (die width 330 mm, die lip opening 0.8 mm) using an extruder with a diameter of 35 mm, set to a resin temperature of 220°C, and melt-extruded. The pellets are then cooled and solidified on a cooling roll with a #200 textured surface, which is temperature-controlled at 30°C and rotates at 20 m / min, to obtain a single-layer unstretched film with a thickness of 30 μm. Table 3 shows the physical properties of the pellets and films of the examples and comparative examples.

[0099] [Table 2]

[0100] [Table 3]

[0101] Table 3 shows that the films of Examples 1 to 10 solve the problems of the present invention. The polypropylene resin composition for melt extrusion film molding of the present invention exhibits a small neck-in, excellent moldability, high film transparency, and superior rigidity. Therefore, it is useful as a material for various types of films, particularly for high-speed film molding aimed at improving productivity. The resulting film is suitable for various packaging materials and can be widely used as packaging for beverages, solid or semi-solid food products, hair products, shampoos, cosmetics, paper cartons, tubes, bags, cups, standing packs, trays, and other packaging materials.

Claims

1. Based on the total mass of polypropylene resin (X) and propylene resin (Y) being 100% by mass, (1) The following characteristics (1-i) to (1-v): (1-i) MFR (230°C, load 2.16 kgf) is 10 to 70 g / 10 min (1-ii) Mw / Mn is 2.0 to 5.0 (1-iii) W １Ｍ is 0.5 to 4.0% by mass (1-iv) g' is 0.70 to 0.95 (1-v) (mm) is 95% or more 3 to 50% by mass of polypropylene resin (X) having a branched structure, and (2) The following characteristic (2-i): (2-i) MFR (230°C, load 2.16 kgf) is 1 to 30 g / 10 min 97 to 50% by mass of propylene resin (Y) A polypropylene resin composition for an unstretched film containing the same.

2. The polypropylene resin composition for an unstretched film according to Claim 1, wherein the propylene resin (Y) is a propylene homopolymer.

3. The polypropylene resin composition for an unstretched film according to Claim 1, wherein the propylene resin (Y) is a propylene / α-olefin copolymer having a melting point of 110 to 155°C.

4. The polypropylene resin composition for an unstretched film according to Claim 1, wherein the propylene resin (Y) is a propylene / ethylene block copolymer.

5. An unstretched film made of the polypropylene resin composition according to Claims 1 to 4.

6. A multilayer film containing a layer made of the polypropylene resin composition according to Claims 1 to 4.

7. A package containing a layer made of the polypropylene resin composition according to Claims 1 to 4.

8. A method for manufacturing the multilayer film according to Claim 6 by multi-layer coextrusion molding using a T-die.