Resin composition, molded body, and method for producing said molded body

Abstract

Provided are: a resin composition which comprises a 3-methyl-1-butene-based polymer and a polypropylene-based resin, wherein the content of the 3-methyl-1-butene-based polymer is 10-90 mass% in 100 mass%, i.e., the total amount, of resin components in the resin composition, and the content of the polypropylene-based resin is 10-90 mass% in 100 mass%, i.e., the total amount, of the resin components in the resin composition; a molded body which is produced by using said resin composition; and a method for producing said molded body.

Description

Resin composition, molded article, and method for producing the molded article

[0001] The present invention relates to a resin composition, a molded article, and a method for producing the molded article.

[0002] Thermoplastic polyolefins are suitable for extrusion-molded products such as film products and injection-molded products, and are generally used. However, typical thermoplastic polyolefins are not suitable for use in higher temperature environments, for example, at temperatures exceeding 200°C. Therefore, development is underway for plastic films formed from thermoplastic polyolefins that can be used in higher temperature environments. For example, Patent Document 1 discloses a plastic film having a melt viscosity of 1 x 10 measured under conditions of 330°C and a shear rate of 0.1 (1 / sec). ４ Patent Document 2 discloses a stretched film obtained by stretching an unstretched film formed from a homopolymer of 3-methylbutene-1 or a copolymer of 3-methylbutene-1 and an α-olefin and / or polyene having 2 to 12 carbon atoms, having a viscosity of 0.05 poise or more, at a stretch ratio of 2 or more. Patent Document 2 also discloses a release film comprising a uniaxially stretched film formed from a composition containing 5 to 95 parts by weight of a 3-methyl-1-butene polymer (A) and 5 to 95 parts by weight of a 4-methyl-1-pentene polymer (B) (the total amount of components (A) and (B) is 100 parts by weight), and at least one surface of the uniaxially stretched film is roughened by embossing.

[0003] JP 60-176741 A JP 2002-137231 A

[0004] As mentioned above, thermoplastic polyolefins are required to have good heat resistance so that they can be used in high-temperature environments. On the other hand, thermoplastic polyolefins are required to have good moldability because they are subjected to various molding processes, such as stretching, compression molding, pressure molding, and vacuum molding, in order to produce the desired molded article. However, it has been difficult to achieve both good heat resistance and moldability. Therefore, an object of the present invention is to provide a resin composition having good heat resistance and moldability, a molded article using the resin composition, and a method for producing the molded article.

[0005] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by preparing a resin composition having a specific composition. That is, the present invention encompasses the following inventions. [1] A resin composition containing a 3-methyl-1-butene polymer and a polypropylene resin, wherein the content of the 3-methyl-1-butene polymer is 10 to 90 mass% relative to 100 mass% of the total amount of resin components in the resin composition, and the content of the polypropylene resin is 10 to 90 mass% relative to 100 mass% of the total amount of resin components in the resin composition. [2] The resin composition according to [1] above, wherein the yellowness index (YI) when formed into a 50 μm-thick film is 3.50 or less. [3] The resin composition according to [1] or [2] above, wherein the 3-methyl-1-butene polymer is at least one selected from the group consisting of a 3-methyl-1-butene homopolymer and a copolymer of 3-methyl-1-butene with at least one selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms other than 3-methyl-1-butene. [4] The resin composition according to any one of [1] to [3] above, further comprising an antioxidant. [5] The resin composition according to [4] above, wherein the antioxidant is at least one selected from the group consisting of a phenolic antioxidant and a phosphorus-based antioxidant. [6] The resin composition according to any one of [1] to [5] above, wherein the absolute value of the linear expansion coefficient at 160 to 260°C is 2,000 ppm / °C or less. [7] A molded article formed from the resin composition according to any one of [1] to [6] above. [8] The molded article according to [7] above, wherein the yellowness index (YI) is 3.50 or less. [9] The molded article according to [7] or [8] above, which contains 1 to 100% by mass of recycled raw materials.

[10] The molded article according to any one of [7] to [9] above, which is a film.

[11] A method for producing a molded article, which includes step (I) of melt-extruding the resin composition according to any one of [1] to [6] above.

[12] A method for producing a molded article according to

[11] above, wherein the resin composition is melted in an inert atmosphere or in a low-oxygen state during step (I).

[13] A method for producing a molded article according to

[11] or

[12] above, wherein the resin composition is melted at 270 to 323°C during step (I).

[14] A method for producing a molded article according to any one of

[11] to

[13] above, comprising a step (II) of contacting the molten extrudate of the resin composition obtained in the step (I) with a casting drum, wherein the temperature of the casting drum is 40 to 250° C.

[15] A method for producing a molded article according to any one of

[11] to

[14] above, wherein in the step (I), the molten resin composition is extruded through a T-die, and a draft ratio [Tt / Ft], which is the ratio of the gap thickness (Tt) of the lip portion of the T-die to the thickness (Ft) of the obtained molded article, is 1 to 30.

[0006] According to the present invention, it is possible to provide a resin composition having good heat resistance and moldability, a molded article using the resin composition, and a method for producing the molded article.

[0007] The following describes examples of embodiments of the present invention (hereinafter also referred to as "one aspect of the present invention"). However, each embodiment described below is merely an example for embodying the technical concept of the present invention, and the present invention is not limited to the following description. The present invention also includes embodiments in which the details described herein are arbitrarily selected or arbitrarily combined. Although preferred embodiments are described herein, combinations of two or more of the individual preferred embodiments are also preferred. Preferred specifications can be selected arbitrarily; for example, combinations of preferred specifications can be considered more preferable. Unless otherwise specified, the term "XX to YY" used herein as a numerical range means "XX or more and YY or less" (XX represents the lower limit and YY represents the upper limit). For example, simply describing a numerical range as "10 to 90" means a range of 10 or more and 90 or less. In this specification, the lower and upper limits described in stages for numerical ranges (such as each characteristic value, each component content, each structural unit content, each production condition, and values ​​calculated therefrom, each characteristic, and each condition) can be independently combined. For example, from a description of "preferably 10 to 90, more preferably 30 to 60" for the same item, the "preferable lower limit (10)" and the "more preferable upper limit (60)" can be combined to form "10 to 60." Furthermore, for a numerical range, for example, based on the description of "preferably 10 to 90, more preferably 30 to 60," the upper limit can be specified as "10 or more" or "30 or more" without a particular upper limit. Similarly, the upper limit can be specified as "90 or less" or "60 or less" without a particular lower limit. The same applies when the upper end of the numerical range is "less than" or when the lower limit is "over." Similarly, for example, from a description of "preferably 10 or more, more preferably 30 or more" for the same item and "preferably 90 or less, more preferably 60 or less," the "preferable lower limit (10)" and the "more preferable upper limit (60)" can be combined to form "10 or more and 60 or less." Similarly, the lower limit value alone can be specified as "10 or more" or "30 or more," and similarly, the upper limit value alone can be specified as "90 or less" or "60 or less."The same applies when the expressions "more than or equal to" and "less than or equal to" in the above description are written as "more than" and "less than," respectively. That is, for example, based on the description "preferably more than 10 and less than 90, more preferably 30 or more and 60 or less," the upper and lower limits can be combined to form "more than 10 and 60 or less" or "30 or more and less than 90."

[0008] [Resin Composition] The resin composition of the present invention is a resin composition containing a 3-methyl-1-butene polymer and a polypropylene resin, wherein the content of the 3-methyl-1-butene polymer is 10 to 90 mass% relative to 100 mass% of the total amount of resin components in the resin composition, and the content of the polypropylene resin is 10 to 90 mass% relative to 100 mass% of the total amount of resin components in the resin composition.

[0009] The resin composition of the present invention, which satisfies the above-mentioned composition, can have good heat resistance and moldability. This is presumably due in part to the fact that the 3-methyl-1-butene polymer and the polypropylene resin have adequate miscibility, allowing the characteristics of both to be well exhibited.

[0010] <3-Methyl-1-butene Polymer> The 3-methyl-1-butene polymer (hereinafter also abbreviated as "P3MB") may be a 3-methyl-1-butene homopolymer or a copolymer of 3-methyl-1-butene and an unsaturated hydrocarbon other than 3-methyl-1-butene. Examples of the unsaturated hydrocarbon include ethylene or an α-olefin other than 3-methyl-1-butene. From the viewpoint of good copolymerizability, an α-olefin having 3 to 20 carbon atoms other than 3-methyl-1-butene is preferred. From the viewpoint of optimally exhibiting the physical properties of 3-methyl-1-butene, the P3MB is preferably at least one selected from the group consisting of a 3-methyl-1-butene homopolymer and a copolymer of 3-methyl-1-butene and at least one α-olefin selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms other than 3-methyl-1-butene. Hereinafter, in this specification, unless otherwise specified, the term "α-olefin" refers to an α-olefin other than 3-methyl-1-butene.

[0011] When P3MB is a copolymer of 3-methyl-1-butene and at least one selected from the group consisting of ethylene and an α-olefin, from the viewpoint of more easily obtaining good heat resistance and moldability, the content of structural units derived from at least one selected from the group consisting of ethylene and an α-olefin in the copolymer is preferably more than 0 mol% and 20 mol% or less, based on 100 mol% of the total amount of structural units derived from the monomers. Furthermore, from the viewpoint of favorably exhibiting the physical properties of the at least one selected from the group consisting of ethylene and an α-olefin, the content of structural units derived from at least one selected from the group consisting of ethylene and an α-olefin in the copolymer is more preferably 0.1 mol% or more, even more preferably 0.3 mol% or more, and still more preferably 0.5 mol% or more, based on 100 mol% of the total amount of structural units derived from the monomers. From the viewpoint of easily maintaining the physical properties of 3-methyl-1-butene and more easily obtaining good heat resistance and moldability, the content of structural units derived from at least one selected from the group consisting of ethylene and an α-olefin in the copolymer is more preferably 15 mol% or less, even more preferably 10 mol% or less, and still more preferably 5 mol% or less, based on 100 mol% of the total amount of structural units derived from monomers. From the viewpoints above, the content of structural units derived from at least one selected from the group consisting of ethylene and an α-olefin in the copolymer is more preferably 0.1 to 15 mol%, even more preferably 0.3 to 10 mol%, and still more preferably 0.5 to 5 mol%, based on 100 mol% of the total amount of structural units derived from monomers. Here, in this specification, the "total amount of structural units derived from monomers" means, for example, structural units contained due to impurities in the polymerization solvent and monomers when polymerizing a polymer, as well as components necessary for polymer polymerization such as catalysts, polymerization initiators, chain transfer agents, and coupling agents, but does not include structural units derived from components other than the monomers. Here, the content of structural units derived from at least one selected from the group consisting of ethylene and α-olefins in the copolymer can be determined using a Fourier transform infrared spectrophotometer (FT-IR). Specifically, it can be measured by the method described in the Examples below.

[0012] When P3MB is a copolymer of 3-methyl-1-butene and at least one selected from the group consisting of ethylene and an α-olefin, the content of structural units derived from 3-methyl-1-butene in the copolymer is preferably 80 mol% or more but less than 100 mol%, based on 100 mol% of the total amount of structural units derived from the monomers, from the viewpoint of more easily obtaining good heat resistance and moldability. Furthermore, the content of structural units derived from 3-methyl-1-butene in the copolymer is more preferably 85 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, based on 100 mol% of the total amount of structural units derived from the monomers, from the viewpoint of more easily maintaining the physical properties of 3-methyl-1-butene and more easily obtaining good heat resistance and moldability. From the viewpoint of favorably exhibiting the properties of at least one selected from the group consisting of ethylene and α-olefins, the content of structural units derived from 3-methyl-1-butene in the copolymer is more preferably 99.9 mol% or less, even more preferably 99.7 mol% or less, and still more preferably 99.5 mol% or less, based on 100 mol% of the total amount of structural units derived from monomers. From the viewpoint above, the content of structural units derived from 3-methyl-1-butene is more preferably 85 to 99.9 mol%, even more preferably 90 to 99.7 mol%, and still more preferably 95 to 99.5 mol%, based on 100 mol% of the total amount of structural units derived from monomers.

[0013] From the viewpoint of suitably exhibiting the physical properties of 3-methyl-1-butene, the α-olefin having 3 to 20 carbon atoms is preferably an α-olefin having 4 to 16 carbon atoms, more preferably an α-olefin having 4 to 12 carbon atoms, and even more preferably an α-olefin having 4 to 10 carbon atoms. The α-olefin having 3 to 20 carbon atoms may be linear or branched. Examples of the α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc. One type of the α-olefins having 3 to 20 carbon atoms may be used alone, or two or more types may be used in combination.

[0014] From the viewpoint of a balance between heat resistance and moldability, the melting point of P3MB is preferably 260 to 310° C., more preferably 265 to 305° C., even more preferably 270 to 300° C., still more preferably 275 to 295° C., and even more preferably 280 to 290° C. The melting point can be measured by the method described in the examples below.

[0015] From the viewpoint of the balance between the fluidity during molding of the resin composition of the present invention and the mechanical strength of the resulting molded article, the melt viscosity of P3MB is preferably 10 to 9,500 Pa s, more preferably 50 to 5,000 Pa s, even more preferably 100 to 2,000 Pa s, and still more preferably 200 to 1,000 Pa s. The melt viscosity can be measured by the method described in the examples below.

[0016] The method for producing P3MB is not particularly limited, and it can be produced using well-known catalysts such as Ziegler-Natta catalysts and metallocene catalysts. P3MB can be obtained as a powder by homopolymerizing 3-methyl-1-butene or copolymerizing 3-methyl-1-butene with the above-mentioned α-olefins in the presence of a catalyst, as described in JP-A-61-103910. The stereoregularity of P3MB may be isotactic or syndiotactic. The copolymer may be a random copolymer, a block copolymer, or an alternating copolymer.

[0017] (P3MB Content) The P3MB content in the resin composition of the present invention is 10 to 90% by mass, based on 100% by mass of the total amount of resin components in the resin composition. When the P3MB content in the resin composition of the present invention is 10% by mass or more, good heat resistance can be obtained. From this perspective, the P3MB content in the resin composition of the present invention is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and even more preferably 40% by mass or more, based on 100% by mass of the total amount of resin components in the resin composition. Furthermore, when the P3MB content in the resin composition of the present invention is 90% by mass or less, good moldability can be obtained. From these viewpoints, the content of P3MB in the resin composition of the present invention is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, even more preferably 73% by mass or less, even more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, based on 100% by mass of the total amount of resin components in the resin composition. Also from these viewpoints, the content of P3MB in the resin composition of the present invention is preferably 15 to 85% by mass, more preferably 20 to 80% by mass, even more preferably 30 to 75% by mass, even more preferably 40 to 73% by mass, even more preferably 40 to 70% by mass, even more preferably 40 to 65% by mass, and even more preferably 40 to 60% by mass, based on 100% by mass of the total amount of resin components in the resin composition. Note that, in the present invention, "resin component" refers to a polymer.

[0018] <Polypropylene-based resin> Known polypropylene-based resins can be used as the polypropylene-based resin. The content of structural units derived from propylene in the polypropylene-based resin is preferably 65 to 100 mol%, more preferably 80 to 100 mol%, even more preferably 85 to 100 mol%, still more preferably 90 to 100 mol%, and even more preferably 95 to 100 mol%, based on 100 mol% of the total amount of structural units derived from monomers.

[0019] The polypropylene-based resin may contain structural units derived from a monomer other than propylene. Examples of structural units derived from a monomer other than propylene include structural units derived from ethylene, and structural units derived from α-olefins such as 1-butene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, 1-nonene, and 1-decene. When the polypropylene-based resin contains structural units derived from a monomer other than propylene, the polypropylene-based resin may be a random copolymer or a block copolymer.

[0020] Examples of polypropylene-based resins include homopolypropylene, propylene-ethylene random copolymers, propylene-ethylene block copolymers, propylene-butene random copolymers, propylene-butene block copolymers, propylene-ethylene-butene random copolymers, propylene-pentene random copolymers, propylene-hexene random copolymers, propylene-octene random copolymers, propylene-ethylene-pentene random copolymers, propylene-ethylene-hexene random copolymers, and modified products thereof. One type of polypropylene-based resin may be used alone, or two or more types may be used in combination.

[0021] The melt flow rate (MFR) of the polypropylene resin measured under conditions of 230°C and 21.6N is preferably 0.05 to 20 g / 10 min, more preferably 0.1 to 5 g / 10 min, even more preferably 0.2 to 3 g / 10 min, and still more preferably 0.3 to 1 g / 10 min, from the viewpoint of more easily obtaining good heat resistance and moldability. The melt flow rate (MFR) of the polypropylene resin measured under conditions of 230°C and 21.6 N can be measured in accordance with JIS K 7210:1999.

[0022] The melting point of the polypropylene resin is preferably 120 to 180° C., more preferably 130 to 176° C., even more preferably 140 to 174° C., and still more preferably 150 to 170° C. The melting point of the polypropylene resin can be measured in accordance with JIS K 7121:2012.

[0023] (Polypropylene Resin Content) The content of the polypropylene resin in the resin composition of the present invention is 10 to 90% by mass, based on 100% by mass of the total amount of resin components in the resin composition. When the content of the polypropylene resin in the resin composition of the present invention is 10% by mass or more, good moldability can be obtained. From this perspective, the content of the polypropylene resin in the resin composition of the present invention is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, still more preferably 27% by mass or more, even more preferably 30% by mass or more, still more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on 100% by mass of the total amount of resin components in the resin composition. Furthermore, when the content of the polypropylene resin in the resin composition of the present invention is 90% by mass or less, good heat resistance can be obtained. From this perspective, the content of the polypropylene resin in the resin composition of the present invention is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on 100% by mass of the total amount of resin components in the resin composition. From the above viewpoints, the content of the polypropylene resin in the resin composition of the present invention is preferably 15 to 85% by mass, more preferably 20 to 80% by mass, even more preferably 25 to 70% by mass, still more preferably 27 to 60% by mass, still more preferably 30 to 60% by mass, still more preferably 35 to 60% by mass, and still more preferably 40 to 60% by mass, based on 100% by mass of the total amount of resin components in the resin composition.

[0024] <Alkyl Radical Scavenger> The resin composition of the present invention preferably contains an alkyl radical scavenger. The inclusion of an alkyl radical scavenger makes it easier to obtain good heat resistance and moldability. It is also preferable from the viewpoint of further improving the planarity and yellowness index (YI) of molded articles obtained from the resin composition. In this specification, "alkyl radical scavenger" refers to a compound that reacts with an alkyl radical derived from P3MB and stabilizes the alkyl radical. By stabilizing the alkyl radical, the function of suppressing a chain reaction of carbon-carbon bond dissociation reactions initiated by the alkyl radical is achieved. The resin composition of the present invention preferably contains, as the alkyl radical scavenger, at least one selected from the group consisting of an acrylic phenol compound and a benzofuranone compound. One alkyl radical scavenger may be used alone, or two or more may be used in combination.

[0025] (Acrylphenol Compound) As the acrylic phenol compound, for example, a compound represented by the following general formula (I) can be used.

[0026]

[0027] In general formula (I), R １ represents a hydrogen atom or a methyl group, and R ２ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ３ , R ４ , R ５ and R ６each independently represents an alkyl group having 1 to 9 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. The alkyl group having 1 to 9 carbon atoms may be linear or branched. Examples of the alkyl group having 1 to 9 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, a 2,2-dimethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, and an n-nonyl group. R １ is preferably a hydrogen atom. ２ is preferably a hydrogen atom or a methyl group, more preferably a methyl group. ３ , R ４ , R ５ and R ６ are each independently preferably an alkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 5 carbon atoms, and even more preferably a 1,1-dimethylpropyl group.

[0028] Examples of the acrylic phenol compound represented by general formula (I) include 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate, 2,4-di-t-butyl-6-[1-(3,5-di-t-butyl-2-hydroxyphenyl)ethyl]phenyl acrylate, and 2-t-butyl-6-[(3-t-butyl-2-hydroxy-5-methylphenyl)methyl]-4-methylphenyl acrylate. Commercially available alkyl radical scavengers may be used, and examples of the acrylic phenol compound represented by general formula (I) include those available under the trade names "Sumilizer (registered trademark) GS" and "Sumilizer (registered trademark) GM" manufactured by Sumitomo Chemical Co., Ltd.

[0029] (Benzofuranone Compound) As the benzofuranone compound, for example, a compound represented by the following general formula (II) can be used.

[0030]

[0031] In general formula (II), R ７ and R ８ each independently represents an alkyl group having 1 to 4 carbon atoms; R ９ and R １０ each independently represents an alkyl group having 1 to 9 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a s-butyl group, and a t-butyl group. The alkyl group having 1 to 9 carbon atoms may be linear or branched. Examples of the alkyl group having 1 to 9 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a s-butyl group, a t-butyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, a 2,2-dimethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, and an n-nonyl group. R ７ and R ８ are each independently preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. ９ and R １０ are each independently preferably an alkyl group having 1 to 4 carbon atoms, more preferably a t-butyl group.

[0032] Examples of the benzofuranone compound represented by general formula (II) include 5,7-di-t-butyl-3-(3,4-di-methyl-phenyl)-3H-benzofuran-2-one, 5,7-di(t-butyl)-3-(3,4-di-propyl-phenyl)-3H-benzofuran-2-one, and 4-t-butyl-2-(5-t-butyl-2-oxo-3H-benzofuran-3-yl)phenyl-3,5-di-t-butyl-4-hydroxybenzoate. Commercially available alkyl radical scavengers may be used, and examples of the benzofuranone compound represented by general formula (II) include "Irganox (registered trademark) HP-136" manufactured by BASF and "Revonox 501" manufactured by Chitec.

[0033] From the viewpoint of more easily achieving the effects of the present invention, the content of the alkyl radical scavenger in the resin composition of the present invention is preferably 0.01 to 1.00 parts by mass, more preferably 0.02 to 0.80 parts by mass, and even more preferably 0.05 to 0.70 parts by mass, relative to 100 parts by mass of the total amount of resin components in the resin composition. When the resin composition contains two or more types of alkyl radical scavengers, the content of the alkyl radical scavengers means the total content of the alkyl radical scavengers.

[0034] <Antioxidant> The resin composition of the present invention preferably further contains an antioxidant. By including an antioxidant, good heat resistance and moldability can be more easily obtained. This is also preferable from the viewpoint of further improving the flatness and yellowness index (YI) of a molded article obtained from the resin composition. The antioxidant is preferably at least one selected from the group consisting of phenolic antioxidants and phosphorus-based antioxidants. One type of antioxidant may be used alone, or two or more types may be used in combination. In this specification, an antioxidant that also acts as an alkyl radical scavenger is considered to be an alkyl radical scavenger.

[0035] (Phenol-Based Antioxidants) Examples of phenol-based antioxidants include pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-t-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and o- octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, thiodiethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], 3,3',3'',5,5',5''-hexa-t-butyl-α,α',α''-(mesitylene-2,4,6-triyl)tri-p-cresol, ethylenediamine bis(oxyethylene)bis[3-(5-t-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,6-di-t-butyl-4-[4,6-bis(octylthio)-1,3,5-triazin-2-ylamino]phenol, 3,9-bis[2-(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl]-2, Examples include 4,8,10-tetraoxaspiro(5,5)undecane, 4,4',4''-(1-methylpropanyl-3-ylidene)tris(6-t-butyl-m-cresol), 6,6'-di-t-butyl-4,4'-butylidene-m-cresol, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, and benzenepropionic acid 3,5-bis-(1,1-dimethylethyl)-4-hydroxy-C7-C9 branched alkyl ester.

[0036] As the phenolic antioxidant, commercially available products may be used, such as "ADEKA STAB (registered trademark) AO series" manufactured by ADEKA Corporation and "Irganox (registered trademark) series" manufactured by BASF Japan Ltd.

[0037] (Phosphorus-Based Antioxidants) Examples of phosphorus-based antioxidants include 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tetrakis(2,4-di-t-butyl-phenyl)-4,4′-biphenylenephosphonite, 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite, tris(2,4-di-t-butylphenyl)phosphonite, and the like. phosphite, bis(2,4-bis(1,1-dimethylethyl)-6-methylphenyl)ethyl ester phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, di-t-butyl-m-cresyl-phosphonite, diethyl[(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl]phosphite phosphonate, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite, 3,9-bis(octadecyoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tris(2,4-di-t-butylphenyl)phosphite, tris(nonylphenyl)phosphite, tetra-C12-15-alkyl Examples of suitable phosphite compounds include 2-ethylhexyl(propane-2,2-diylbis(4,1-phenylene))bis(phosphite), 2-ethylhexyldiphenyl phosphite, isodecyldiphenyl phosphite, trisisodecyl phosphite, triphenyl phosphite, and 3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane.

[0038] As the phosphorus-based antioxidant, commercially available products may be used, and examples thereof include "ADK STAB (registered trademark) PEP series" and "ADK STAB (registered trademark) HP series" manufactured by ADEKA Corporation, "Irgafos (registered trademark) series" manufactured by BASF Japan Ltd., and "HOSTANOX (registered trademark) P-EPQ" manufactured by Clariant.

[0039] (Other Antioxidants) The resin composition of the present invention may contain other antioxidants other than the phenolic antioxidant and the phosphorus-based antioxidant, as long as the effects of the present invention are exhibited. Examples of other antioxidants other than the phenolic antioxidant and the phosphorus-based antioxidant include sulfur-based antioxidants and amine-based antioxidants.

[0040] From the viewpoint of more easily achieving the effects of the present invention, the content of the antioxidant in the resin composition of the present invention is preferably 0.01 parts by mass or more, more preferably 0.10 parts by mass or more, per 100 parts by mass of the total amount of resin components in the resin composition. Furthermore, from the viewpoint of being able to suppress bleed-out and sublimation of the antioxidant, as well as from the viewpoint of economic efficiency, the content of the antioxidant in the resin composition of the present invention is preferably 1.00 parts by mass or less, more preferably 0.80 parts by mass or less, per 100 parts by mass of the total amount of resin components in the resin composition. From the above viewpoints, the content of the antioxidant in the resin composition of the present invention is preferably 0.01 to 1.00 parts by mass, more preferably 0.10 to 0.80 parts by mass, per 100 parts by mass of the total amount of resin components in the resin composition. When the resin composition of the present invention contains two or more antioxidants, the content of the antioxidants refers to the total content of the antioxidants.

[0041] <Other Additives> The resin composition of the present invention may contain additives other than the alkyl radical scavenger and the antioxidant, as long as the effects of the present invention are not impaired. Examples of other additives include antacids, fillers, light stabilizers, antistatic agents, flame retardants, pigments, polymerization inhibitors, heavy metal deactivators, UV absorbers, nucleating agents, clarifying agents, lubricants, fluorescent brighteners, rust inhibitors, and sliding agents. One type of other additive may be used alone, or two or more types may be used in combination.

[0042] (Antacid Agent) The resin composition of the present invention preferably contains an antacid from the viewpoint of suppressing deterioration due to acid components generated from residual metals and the like during melt-kneading. Examples of antacid agents include barium laurate, calcium stearate, zinc stearate, magnesium stearate, aluminum stearate, zinc oleate, and magnesium 12-hydroxystearate. One type of antacid may be used alone, or two or more types may be used in combination. When the resin composition contains an antacid, the content of the antacid in the resin composition can be determined appropriately. For example, the content may be 0.01 to 200 parts by mass, 0.01 to 100 parts by mass, 0.01 to 50 parts by mass, 0.01 to 10 parts by mass, 0.01 to 1.00 parts by mass, or 0.1 to 0.80 parts by mass, relative to 100 parts by mass of the total amount of resin components in the resin composition.

[0043] (Fillers) Examples of fillers include fibrous compounds such as glass fibers, alumina fibers, resin fibers, carbon fibers, and cellulose fibers; flat compounds such as mica, talc, montmorillonite, and tabular aluminum; spherical compounds such as glass beads, shirasu balloons, and acrylic balloons; acicular compounds such as acicular metal titanates, wollastonite, acicular silica, and tin oxide; and powdered compounds such as powdered metal titanates, finely powdered wood chips, titanium oxide, calcium carbonate, silica, and alumina. These fillers may be surface-treated with, for example, a silane coupling agent. A compatibilizer may also be used to enhance the dispersibility of the filler. One type of filler may be used alone, or two or more types may be used in combination. When the resin composition of the present invention contains a filler, the content of the filler in the resin composition can be determined appropriately. For example, it may be 0.01 to 300 parts by mass or 0.1 to 100 parts by mass per 100 parts by mass of the total amount of resin components in the resin composition.

[0044] <Total Content of Each Component, etc.> From the viewpoint of making it easier to obtain good heat resistance and moldability, the total content of P3MB and the polypropylene resin in the resin composition of the present invention is preferably 50.0 to 100 mass%, more preferably 60.0 to 100 mass%, even more preferably 70.0 to 100 mass%, still more preferably 80.0 to 100 mass%, still more preferably 90.0 to 100 mass%, still more preferably 95.0 to 100 mass%, and may even be 100 mass%, based on 100 mass% of the total amount of resin components in the resin composition.

[0045] From the viewpoint of more easily obtaining good heat resistance and moldability, the total content of the resin components in the resin composition of the present invention is preferably 50.0 to 100 mass%, more preferably 60.0 to 99.9 mass%, even more preferably 70.0 to 99.8 mass%, still more preferably 80.0 to 99.7 mass%, still more preferably 90.0 to 99.6 mass%, and still more preferably 95.0 to 99.5 mass%, based on 100 mass% of the total amount of the resin composition of the present invention.

[0046] The resin composition of the present invention preferably contains substantially no thermosetting resin. Specifically, "substantially no" here means that the content of the thermosetting resin in 100% by mass of the resin composition is 5.0% by mass or less, preferably 1.0% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, and even more preferably 0.01% by mass or less. In other words, the content of the thermosetting resin in the resin composition of the present invention is preferably 0 to 5.0% by mass, more preferably 0 to 1.0% by mass, even more preferably 0 to 0.1% by mass, even more preferably 0 to 0.05% by mass, even more preferably 0 to 0.01% by mass, and may even be 0% by mass.

[0047] Preferably, the resin composition of the present invention is substantially free of cyclic polyolefins. Here, "substantially free" specifically means that, based on 100% by mass of the resin composition, the cyclic polyolefin content is 5.0% by mass or less, preferably 1.0% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, and even more preferably 0.01% by mass or less. In other words, the content of cyclic polyolefins in the resin composition of the present invention is, based on 100% by mass of the resin composition, preferably 0 to 5.0% by mass, more preferably 0 to 1.0% by mass, even more preferably 0 to 0.1% by mass, even more preferably 0 to 0.05% by mass, even more preferably 0 to 0.01% by mass, and may even be 0% by mass. The term "cyclic polyolefin" refers to a polymer having an alicyclic structure (cycloolefin skeleton) in its main chain, which contains at least 10 mol% or more structural units derived from a monomer capable of introducing the alicyclic structure into the main chain of the polymer, based on 100 mol% of all structural units constituting the polymer. The monomer capable of introducing the alicyclic structure into the main chain of the polymer is not particularly limited, and examples thereof include substituted or unsubstituted norbornene, substituted or unsubstituted tetracyclododecene, and substituted or unsubstituted dicyclopentadiene. An example of the cyclic polyolefin is a polymer obtained by subjecting a cyclic olefin monomer such as substituted or unsubstituted norbornene to ring-opening metathesis polymerization (ROMP) to obtain a ring-opening polymer, and then hydrogenating the double bonds in the polymer. Another example is a copolymer obtained by addition polymerization of the cyclic olefin monomer with an olefin such as ethylene. Commercially available examples of the cyclic polyolefin include "ZEONEX (registered trademark)" and "ZEONOR (registered trademark)" manufactured by Zeon Corporation; "APEL (registered trademark)" manufactured by Mitsui Chemicals, Inc.; "ARTON (registered trademark)" manufactured by JSR Corporation; and "TOPAS (registered trademark)" manufactured by Topas Advanced Polymers GmbH.

[0048] <Yellowness Index (YI) of Resin Composition> When the resin composition of the present invention is formed into a film having a thickness of 50 μm, the yellowness index (YI) is preferably 3.50 or less, more preferably 2.80 or less, even more preferably 2.40 or less, even more preferably 2.00 or less, even more preferably 1.40 or less, even more preferably 1.00 or less, even more preferably 0.80 or less, and even more preferably 0.50 or less. The lower limit of the yellowness index (YI) is not particularly limited, but is preferably, for example, 0.00. In other words, the yellowness index (YI) of the resin composition of the present invention is preferably 0.00 to 3.50, more preferably 0.00 to 2.80, even more preferably 0.00 to 2.40, even more preferably 0.00 to 2.00, even more preferably 0.00 to 1.40, even more preferably 0.00 to 1.00, even more preferably 0.00 to 0.80, and even more preferably 0.00 to 0.50. The yellowness index (YI) of a 50 μm-thick film made from the resin composition of the present invention can be measured by the method described in the examples below.

[0049] <Linear expansion coefficient of resin composition> From the viewpoint of heat resistance, the absolute value of the linear expansion coefficient of the resin composition of the present invention at 160 to 260 ° C. is preferably 2,000 ppm / ° C. or less, more preferably 1,500 ppm / ° C. or less, even more preferably 1,300 ppm / ° C. or less, still more preferably 1,000 ppm / ° C. or less, and even more preferably 700 ppm / ° C. or less. Note that, when the absolute value of the linear expansion coefficient of the resin composition of the present invention at 160 to 260 ° C. cannot be measured due to melting of the resin composition, but the absolute value of the linear expansion coefficient at 160 to 240 ° C. can be measured, the absolute value of the linear expansion coefficient at 160 to 240 ° C. is preferably 3,500 ppm / ° C. or less, more preferably 3,000 ppm / ° C. or less, even more preferably 2,500 ppm / ° C. or less, and even more preferably 2,000 ppm / ° C. or less. The absolute value of the linear expansion coefficient at 160 to 260° C. and the absolute value of the linear expansion coefficient at 160 to 240° C. of the resin composition of the present invention can be measured by the method described in the examples below.

[0050] <Method for producing resin composition> The resin composition of the present invention can be produced by blending and kneading P3MB, a polypropylene resin, and, if necessary, other components. The method for blending the components is not particularly limited as long as the effects of the present invention are achieved, and for example, a method of melt-kneading using a twin-screw kneading extruder can be used. The conditions for obtaining the resin composition by melt-kneading are described below.

[0051] When the resin composition of the present invention is obtained by melt-kneading, the melt-kneading conditions are preferably such that the resin composition is melt-kneaded in an inert atmosphere or a low-oxygen state. Melt-kneading in an inert atmosphere or a low-oxygen state can suppress deterioration of the physical properties of the resin composition due to oxygen, making it easier to obtain good heat resistance and moldability. This is also preferable from the viewpoint of further improving the flatness and yellowness index (YI) of molded articles obtained from the resin composition. Here, the "low-oxygen state" refers to a state in which the oxygen concentration inside the melt-kneader is reduced by degassing the inside of the melt-kneader under reduced pressure compared to before degassing. Furthermore, in an "inert atmosphere" state, an inert gas is injected into the melt-kneader, thereby reducing the oxygen concentration inside the melt-kneader compared to before the inert gas was injected. Therefore, the concept of a "low-oxygen state" may also include a state in which an "inert atmosphere" state is used. In a "low-oxygen state," the oxygen concentration inside the melt-kneader is preferably 5% or less, more preferably 2% or less, and even more preferably 1% or less. The oxygen concentration can be measured using a diaphragm-type galvanic oxygen meter, such as the "XP-3180E" (diaphragm-type galvanic cell type) manufactured by New Cosmos Electric Co., Ltd., or its successor, the "XP-3380II-E" (galvanic cell type).

[0052] The method of melt-kneading by injecting an inert gas into the melt-kneader may, for example, be to introduce each component into the melt-kneader while injecting an inert gas into the melt-kneader and perform melt-kneading; after introducing each component into the melt-kneader, preferably before starting the temperature increase or before starting shearing, more preferably before starting the temperature increase and before starting shearing, and then perform melt-kneading; or, after injecting an inert gas into the melt-kneader, to introduce each component from a sealed supply unit and perform melt-kneading. Moreover, during melt-kneading, the inert gas may be continuously injected into the melt-kneader. The method of injecting the inert gas can be carried out according to the equipment provided in each melt-kneader and is not particularly limited. The inert gas may be injected, for example, from a gas supply unit such as an inert gas provided in the melt-kneader, from a supply unit for each component provided in the melt-kneader, or from a degassing vent provided in the melt-kneader. The inert gas is preferably injected into the entire area from the inert gas supply section to the heating section where melt-kneading is performed, thereby enabling melt-kneading. Examples of the inert gas include nitrogen gas, helium gas, neon gas, argon gas, krypton gas, and carbon dioxide gas, and nitrogen gas is preferred from the viewpoints of availability and versatility.

[0053] The method of melt-kneading while degassing the inside of the melt-kneader under reduced pressure may involve, for example, introducing each component into the melt-kneader while degassing the inside of the melt-kneader, and then melt-kneading. Alternatively, after introducing each component into the melt-kneader, degassing the inside of the melt-kneader under reduced pressure, preferably before starting the temperature increase or before starting shearing, more preferably before starting the temperature increase and before starting shearing, and then melt-kneading. Alternatively, after degassing the inside of the melt-kneader under reduced pressure, each component may be introduced from a sealed supply port and then melt-kneaded. Furthermore, degassing the inside of the melt-kneader under reduced pressure may be performed intermittently or continuously during melt-kneading. The method of degassing the inside of the melt-kneader under reduced pressure may be performed depending on the equipment provided in each melt-kneader, and may be performed, for example, through a vacuum vent. For example, a vacuum pump may be used for degassing the inside of the melt-kneader. There are no limitations on the method of degassing the inside of the melt-kneader under reduced pressure, as long as it is possible to perform melt-kneading under an inert atmosphere or in a low-oxygen environment. When degassing under reduced pressure, the inside of the melt kneader can be made into a vacuum state of, for example, 0.1 to 50 kPa.

[0054] The melt kneader may be a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer, or the like, which is equipped with equipment capable of melt-kneading by injecting an inert gas into the interior of the melt kneader, or equipment capable of melt-kneading by degassing the interior of the melt kneader under reduced pressure.

[0055] The injection of the inert gas and the degassing under reduced pressure may be used in combination. In this case, it is preferable to inject the inert gas upstream of the melt kneader before or together with the raw materials, and on the other hand, to carry out degassing under reduced pressure further downstream. It is also more preferable to inject the inert gas upstream of the melt kneader before or together with the raw materials, and on the other hand, to carry out degassing under reduced pressure further downstream, and to continue both the injection of the inert gas and the degassing under reduced pressure during melt kneading.

[0056] The temperature during melt-kneading is preferably 280 to 323°C. When the temperature during melt-kneading is 280°C or higher, for example, P3MB can be sufficiently melted and mixed with the polypropylene-based resin, and the aforementioned additives and the like can be easily dispersed in the resin components. From this perspective, the temperature during melt-kneading is more preferably 285°C or higher, even more preferably 290°C or higher, and even more preferably 292°C or higher. Furthermore, when the temperature during melt-kneading is 323°C or lower, decomposition of the components can be suppressed, and good heat resistance and moldability can be more easily obtained. Furthermore, the flatness and yellowness index (YI) of molded articles obtained from the resin composition can be further improved. From this perspective, the temperature during melt-kneading is more preferably 315°C or lower, even more preferably 305°C or lower, even more preferably 300°C or lower, and even more preferably 298°C or lower. From the above viewpoint, the temperature during melt-kneading is more preferably 285 to 315°C, even more preferably 290 to 305°C, still more preferably 290 to 300°C, and even more preferably 292 to 298°C.

[0057] [Molded Article] The molded article of the present invention is a molded article formed from the resin composition of the present invention. The molded article of the present invention has good heat resistance and moldability because it is obtained by molding the resin composition of the present invention.

[0058] <Yellowness Index (YI)> The yellowness index (YI) of the molded article of the present invention is preferably 3.50 or less, more preferably 2.70 or less, even more preferably 2.40 or less, still more preferably 1.80 or less, even more preferably 1.40 or less, even more preferably 1.00 or less, even more preferably 0.80 or less, and even more preferably 0.50 or less. The lower limit of the yellowness index (YI) is not particularly limited, but is preferably, for example, 0.00. In other words, the yellowness index (YI) of the molded article of the present invention is preferably 0.00 to 3.50, more preferably 0.00 to 2.70, even more preferably 0.00 to 2.40, even more preferably 0.00 to 1.80, even more preferably 0.00 to 1.40, even more preferably 0.00 to 1.00, even more preferably 0.00 to 0.80, and even more preferably 0.00 to 0.50. The yellowness index (YI) of the molded article of the present invention can be measured by the method described in the examples below.

[0059] <Recycled Raw Materials> The molded article of the present invention preferably contains recycled raw materials. The recycled raw materials refer to recycled raw materials recovered during the process of producing a molded article from the resin composition of the present invention. Specific examples include non-product parts such as film scraps and film edges generated during the process of producing a film from the resin composition of the present invention; non-standard products; and the like. These can be crushed and used as needed. The inclusion of recycled raw materials contributes to resource conservation and reduces fusion of raw materials in the process before being fed into the extruder, thereby improving the dispersion of the raw materials and improving extrusion stability during film production. As a result, thickness unevenness of the resulting film is suppressed, and the film quality is improved, thereby improving moldability and post-processability. The molded article of the present invention may contain recycled raw materials and one or more selected from the group consisting of P3MB, which is not a recycled raw material, and polypropylene-based resins, which are not recycled raw materials. In this case, for example, by appropriately adjusting the amount of one or more selected from the group consisting of P3MB that is not a recycled material and polypropylene-based resins that are not recycled materials depending on the composition and amount of recycled raw material used, the content of P3MB and polypropylene-based resin in the resin composition constituting the molded product can be adjusted to within the content range described above in the [Resin Composition] section. The content of recycled raw materials in the molded product of the present invention may be 1 to 100% by mass, 10 to 90% by mass, 20 to 80% by mass, or 30 to 70% by mass.

[0060] The shape of the molded article of the present invention is not particularly limited, and examples thereof include a film, a plate, a rod, a strip, a tube, a cylinder, a hollow body, etc. Among these, the molded article of the present invention is preferably a film.

[0061] <Film> The film, which is one embodiment of the molded article of the present invention, may be a single-layer film or a multi-layer film.

[0062] (Film Thickness) The thickness of the film, which is one embodiment of the molded article of the present invention, is not particularly limited and can be appropriately set depending on the application, but is preferably 1 to 1,000 μm, more preferably 5 to 500 μm, and even more preferably 10 to 100 μm from the viewpoints of film formability, handling properties in post-processing of the film, etc. The film thickness can be measured by the method described in the examples below.

[0063] (Film Curl Degree) The curl degree of the film, which is one embodiment of the molded article of the present invention, is preferably 26.0 mm or less, more preferably 22.0 mm or less, even more preferably 18.0 mm or less, even more preferably 14.0 mm or less, even more preferably 10.0 mm or less, even more preferably 6.0 mm or less, and even more preferably 2.0 mm or less. The lower limit of the curl degree is not particularly limited, but is preferably, for example, 0 mm. The curl degree of the film is preferably 0 to 26.0 mm, more preferably 0 to 22.0 mm, even more preferably 0 to 18.0 mm, even more preferably 0 to 14.0 mm, even more preferably 0 to 10.0 mm, even more preferably 0 to 6.0 mm, and even more preferably 0 to 2.0 mm. The curl degree used to evaluate the flatness of the film can be measured by the method described in the Examples below.

[0064] <Uses of Molded Article> The molded article of the present invention has good moldability and heat resistance, and therefore can be used in a variety of applications. The uses of the molded article of the present invention are not particularly limited, but it is suitable for use in, for example, films, sheets, fibers, electrical and electronic devices, home appliance parts, office automation equipment, information terminal equipment, machine parts, automotive materials, building materials, civil engineering materials, fishery materials, various containers, lighting equipment, etc. In addition, examples of the film include films for film capacitors, films for high-frequency circuit substrates, films for transparent substrates, insulating films, thermoforming films, packaging films, optical films, surface protection films, process films, release films, films for sanitary materials, agricultural films, construction films, and medical films.

[0065] [Method for Producing Molded Article] The method for producing a molded article of the present invention is a method for producing a molded article, which includes a step (I) of melt-extruding the resin composition of the present invention.

[0066] <Step (I)> Step (I) is a step of melt-extruding the resin composition of the present invention. As a method for melt-extruding the resin composition, it is preferable to use an extruder, from the viewpoint of facilitating production ease and obtaining a molded product with excellent dimensional accuracy. As the extruder, for example, a single-screw extruder or a multi-screw extruder such as a twin-screw kneading extruder can be used, and it is preferable to use a multi-screw extruder such as a twin-screw kneading extruder, from the viewpoint of sufficiently melt-kneading each component.

[0067] In step (I), the resin composition is preferably melted in an inert atmosphere or a low-oxygen state, more preferably in an inert atmosphere. Melting the resin composition in an inert atmosphere or a low-oxygen state can suppress deterioration of the physical properties of the resin composition due to oxygen, making it easier to obtain good heat resistance and moldability, and is also preferable from the viewpoint of further improving the flatness and yellowness index (YI) of the molded product. For example, when an extruder is used in step (I), it is preferable to melt the resin composition using at least one method selected from injecting an inert gas into the extruder to melt the resin composition, and degassing the inside of a melt-kneader under reduced pressure to melt the resin composition.

[0068] Examples of methods for melting the resin composition by injecting an inert gas into an extruder include a method in which the resin composition prepared in advance by the method described above in the "Method for Producing a Resin Composition" section is introduced into the extruder through a raw material inlet such as a hopper while injecting an inert gas into the extruder, and the resin composition is melted in the extruder; or a method in which the resin composition is introduced into the extruder through a raw material inlet such as a hopper, and then an inert gas is injected into the extruder, preferably before the start of heating or before the start of shearing, more preferably before the start of heating and before the start of shearing, and then the resin composition is melted in the extruder. Furthermore, the inert gas may be continuously injected into the extruder while the resin composition is melting, and it is preferable to continuously inject the inert gas into the extruder while the resin composition is melting. The method for injecting the inert gas can be performed depending on the equipment of the extruder used and is not particularly limited. The inert gas may be injected, for example, from a gas supply unit such as an inert gas provided in the extruder, or from a supply unit for each component such as a hopper provided in the extruder. The inert gas is preferably injected into the entire extruder from the inert gas supply section to the heating section where melt-kneading is performed, thereby enabling melt-kneading. Examples of the inert gas include nitrogen gas, helium gas, neon gas, argon gas, krypton gas, and carbon dioxide gas, and nitrogen gas is preferred from the viewpoints of availability and versatility.

[0069] Examples of methods for melting the resin composition by degassing the inside of an extruder under reduced pressure include a method in which the resin composition prepared in advance by the method described above in the "Method for Producing a Resin Composition" section is introduced into a raw material inlet such as a hopper while degassing the inside of the extruder under reduced pressure and melted therein; or a method in which the resin composition is introduced into the extruder through a raw material inlet such as a hopper, and then the inside of the extruder is degassed under reduced pressure and melted therein, preferably before starting the temperature increase or before starting shearing, more preferably before starting the temperature increase and before starting shearing. Furthermore, while the resin composition is being melted, degassing under reduced pressure inside the extruder may be performed intermittently or continuously. It is preferable to perform degassing under reduced pressure continuously while the resin composition is being melted. There are no limitations on the method for degassing the inside of the extruder under reduced pressure, as long as the resin composition can be melt-kneaded under an inert atmosphere or a low-oxygen state. For example, in one embodiment of the production method, degassing under reduced pressure inside the extruder can be performed depending on the equipment provided in the extruder used, and may be performed, for example, through a vacuum vent. For the degassing under reduced pressure, for example, a decompression pump such as a vacuum pump can be used. Furthermore, by performing degassing under reduced pressure inside the extruder, it is possible to remove moisture remaining in the resin composition and organic solvents that evaporate at the melting temperature, and therefore, when the melt is extruded from a T-die or the like, foaming of the melt due to moisture, etc. can be suppressed, which is preferable. From this viewpoint, the degassing under reduced pressure is preferably performed after the resin composition is melted and before it is extruded, and may be performed, for example, from a vent provided in a barrel corresponding to the position of the shearing section of the extruder.

[0070] The injection of the inert gas and the degassing under reduced pressure may be used in combination. In this case, it is preferable to inject the inert gas upstream of the extruder before or together with the raw materials, and to carry out the degassing under reduced pressure downstream of the inert gas injection. It is more preferable to continue both the injection of the inert gas and the degassing under reduced pressure during the melt-kneading.

[0071] As described above, the resin composition used in the step (I) may be a resin composition prepared in advance by the method described above in the section "Method for producing a resin composition," or a method may be used in which, during the step (I), for example, a twin-screw kneading extruder is used as the extruder, the components described above are kneaded in the extruder to prepare the resin composition, and the molten resin composition is directly extruded from the extruder.

[0072] In step (I), the resin composition is preferably melted at 280 to 323°C. When the temperature during melt-kneading in step (I) is 280°C or higher, the resin composition can be sufficiently melted, and good moldability can be obtained. From this perspective, the temperature during melt-kneading in step (I) is more preferably 285°C or higher, even more preferably 290°C or higher, and even more preferably 292°C or higher. Furthermore, when the temperature during melt-kneading is 323°C or lower, thermal decomposition of each component can be suppressed. Furthermore, good heat resistance and moldability can be more easily obtained, and the flatness and yellowness index (YI) of the molded product can also be further improved. From these perspectives, the temperature during melt-kneading in step (I) is more preferably 315°C or lower, even more preferably 305°C or lower, even more preferably 300°C or lower, and even more preferably 298°C or lower. From the above viewpoints, the temperature during melt-kneading in step (I) is more preferably 285 to 315°C, even more preferably 290 to 305°C, still more preferably 290 to 300°C, and still more preferably 292 to 298°C.

[0073] In step (I), after the resin composition is melted, the resin composition is extruded, for example, through a die attached to the tip of an extruder, and then cooled. The die is not particularly limited and may be appropriately selected depending on the desired molded product. When producing a film, it is preferable to use a T-die from the viewpoint of making it easier to produce a film with excellent manufacturing ease and dimensional accuracy. The cooling method is not particularly limited, but it is preferable to cool using a casting drum as shown in the following step (II).

[0074] <Step (II)> The production method preferably includes step (II) of contacting the molten extrudate of the resin composition obtained in step (I) with a casting drum. The temperature of the casting drum is not particularly limited, but is preferably 40 to 250°C. A casting drum temperature of 40°C or higher makes it easier to obtain good heat resistance and moldability, and also results in more excellent flatness and yellowness index (YI) of the molded article. From these viewpoints, the casting drum temperature is more preferably 50°C or higher, even more preferably 60°C or higher, even more preferably 80°C or higher, even more preferably 100°C or higher, even more preferably 120°C or higher, even more preferably 125°C or higher, even more preferably 130°C or higher, and even more preferably 135°C or higher. Furthermore, a casting drum temperature of 250°C or lower can prevent the molten extrudate from fusing to the casting drum. From this viewpoint, the temperature of the casting drum is preferably 250°C or less, more preferably 240°C or less, even more preferably 230°C or less, still more preferably 220°C or less, still more preferably 210°C or less, still more preferably 205°C or less, still more preferably 200°C or less, and still more preferably 190°C or less. Also, from the above viewpoint, the temperature of the casting drum in step (II) is more preferably 50 to 240°C, even more preferably 60 to 230°C, still more preferably 80 to 220°C, still more preferably 100 to 210°C, still more preferably 120 to 210°C, still more preferably 125 to 205°C, still more preferably 130 to 200°C, and still more preferably 135 to 190°C. Here, the "temperature of the casting drum" refers to the temperature of the surface of the casting drum.

[0075] The molded body solidified by cooling through the step (II) may then be wound into a roll using a winder or the like, if necessary. Also, if necessary, it may be further stretched using a stretching machine or the like.

[0076] In step (I), the melt of the resin composition is extruded through a T-die, and the draft ratio [Tt / Ft], which is the ratio of the gap thickness (Tt) of the lip of the T-die to the thickness (Ft) of the molded article extruded from the lip, is preferably 1 to 30. A draft ratio [Tt / Ft] of 1 or more makes it easier to obtain good heat resistance and moldability, and also improves the flatness and yellowness index (YI) of the film. From these perspectives, the draft ratio [Tt / Ft] is more preferably 2 or more, even more preferably 3 or more, even more preferably 4 or more, and even more preferably 5 or more. Furthermore, a draft ratio [Tt / Ft] of 30 or less can prevent film breakage during film formation and post-processing. Furthermore, it is easier to suppress unevenness in the film thickness and to suppress shrinkage during thermoforming. From these viewpoints, the draft ratio [Tt / Ft] is more preferably 28 or less, even more preferably 25 or less, still more preferably 20 or less, still more preferably 15 or less, and still more preferably 10 or less. Also, from the above viewpoints, the draft ratio [Tt / Ft] is more preferably 2 to 28, even more preferably 2 to 25, still more preferably 3 to 20, still more preferably 4 to 15, and still more preferably 5 to 10.

[0077] The method for producing a molded article of the present invention may further include a step of processing the molded article obtained through the above steps, such as forming the molded article into a desired shape by stretching, compression molding, pressure forming, vacuum forming, or the like.

[0078] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples.

[0079] The physical properties of the P3MB obtained in Production Example 1 were measured or evaluated by the following methods.

[0080] [Content of structural units derived from comonomer (1-decene)] The content of structural units derived from 1-decene in P3MB obtained in Production Example 1 was determined by IR measurement using an FT-IR analyzer ("Cary 600 series FTIR spectrometer" manufactured by Agilent Technologies) by the ATR method, as follows: 3-methyl-1-butene homopolymer and 1-decene homopolymer were mixed in any ratio, and the bending vibration of 1,461 cm derived from the main chain methylene group of each polymer was measured. －１ and a bending vibration of 727 cm due to the side chain methylene group derived from 1-decene. －１ A calibration curve was created from the ratio of the peak area of ​​P3MB obtained in Production Example 1 to the peak area of ​​P3MB obtained in Production Example 1, and the resulting measured values ​​were inserted into the calibration curve to determine the content of structural units derived from 1-decene.

[0081] [Melting Point] Using a differential scanning calorimeter ("DSC25" manufactured by TA Instruments) the P3MB obtained in Production Example 1 was heated from 30°C to 320°C at a rate of 10°C / min under a nitrogen atmosphere (nitrogen flow rate 100 mL / min), held at 320°C for 5 minutes, and then cooled to -70°C at a rate of 10°C / min. After holding at -70°C for 5 minutes, the peak temperature was measured when the temperature was raised to 320°C at 10°C / min, and this temperature was defined as the melting point of P3MB.

[0082] [Melt Viscosity] The melt viscosity (Pa·s) of P3MB obtained in Production Example 1 was measured using a capillary rheometer ("Capilograph (registered trademark) 1C" manufactured by Toyo Seiki Seisaku-sho, Ltd.) at a barrel temperature of 320°C and a shear rate of 100 sec. －１ The measurement was carried out under the following conditions: (capillary: inner diameter 1.0 mm x length 10 mm, extrusion speed 10 mm / min).

[0083] [Catalyst Preparation] The catalyst component used in Production Example 1 was prepared by the following method. (Preparation of Titanium Catalyst Component) 47.6 g (500 mmol) of anhydrous magnesium chloride, 250 ml of decane, and 234 ml (1.5 mol) of 2-ethylhexyl alcohol were heated and reacted at 130°C for 2 hours to obtain a homogeneous solution. The resulting homogeneous solution was cooled to room temperature (23°C) and then added dropwise over 1 hour to 2 L (18 mol) of titanium tetrachloride maintained at -20°C to obtain a mixed solution. After completion of the dropwise addition of the homogeneous solution, the temperature of the resulting mixed solution was raised to 90°C over 2 hours. When the temperature reached 90°C, 11.4 mL (80 mmol) of ethyl benzoate was added and the mixture was maintained at the same temperature for 2 hours with stirring. After completion of the 2-hour reaction, the mixture was allowed to stand and the supernatant was removed. Decane and hexane were added, and the solids were washed three times. After that, the solids were resuspended in 2 L of titanium tetrachloride and again subjected to a heated reaction at 90°C for 2 hours. After the reaction was complete, the mixture was again left to stand using decane and hexane, and the supernatant was repeatedly removed, followed by thorough washing until no free titanium compound was detected in the washings. The resulting suspension was dried under reduced pressure at room temperature for 6 hours to obtain a titanium catalyst component. The composition of the resulting titanium catalyst component was 4.0% by mass of titanium, 56.0% by mass of chlorine, 17.0% by mass of magnesium, 10.4% by mass of ethyl benzoate, and 12.6% by mass of a hydrocarbon solvent consisting of decane and hexane.

[0084] [Production Example 1] (Production of P3MB) 8.0 kg of 3-methyl-1-butene, 0.6 kg of 1-decene, 50 g of triethylaluminum diluted with hexane to a concentration of 1 mol / L, and 4 g of the titanium catalyst component prepared in the above [Catalyst Preparation] were added to a 20 L stainless steel autoclave, and a polymerization reaction was carried out at 70°C for 4 hours. Hydrogen was continuously supplied at a rate of 40 mL / min during the polymerization reaction. After 4 hours, 200 g of 3-methyl-1-butanol was injected to stop the reaction and expel excess unreacted monomer. Next, 2 kg of normal heptane was introduced, and the mixture was stirred at 60°C for 30 minutes. The solids were then filtered off using a pressure filter. This procedure was repeated twice, and then the solvent was changed from 2 kg of normal heptane to 3 kg of 2-propanol, and the same procedure was repeated twice. 7.7 kg of the resulting crude polymer was placed in a 50 L vessel equipped with a stirrer, followed by the addition of 8 kg of 1 mol / L hydrochloric acid and 16 kg of 2-propanol, followed by stirring for 1 hour. This suspension was filtered by vacuum filtration and washed with 10 kg of 2-propanol. The crude polymer obtained from this first wash was placed in a 50 L vessel equipped with a stirrer, followed by the addition of 20 kg of 2-propanol, followed by stirring for 1 hour. This suspension was filtered by vacuum filtration and washed with 10 kg of 2-propanol. The resulting washed polymer was dried under reduced pressure at 80°C for 2 days, yielding 3.2 kg of P3MB, a copolymer of 3-methyl-1-butene and 1-decene. The aforementioned measurements were performed on the resulting P3MB, revealing a melting point of 286°C and a melt viscosity of 596 Pa·s. Furthermore, the content of structural units derived from the comonomer 1-decene in P3MB was 1.1 mol%.

[0085] [Example 1] (1) Preparation of Resin Composition 85 parts by mass of P3MB (obtained in Production Example 1), polypropylene (product name "Prime Polypro (registered trademark) PP E701G", JIS K 7210:1999) = 0.5 g / 10 min at 230 ° C., measured in accordance with Prime Polymer Co., Ltd. (15 parts by mass), pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (antioxidant "ADK STAB (registered trademark) AO-60", manufactured by ADEKA Corporation) 0.2 parts by mass, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (antioxidant "ADK STAB (registered trademark) PEP-36", manufactured by ADEKA Corporation) 0.2 parts by mass, 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)propionate] (antioxidant "ADK STAB (registered trademark) PEP-36", manufactured by ADEKA Corporation) After dry-blending 0.1 parts by weight of [(2-hydroxyphenyl)ethyl]phenyl acrylate (alkyl radical scavenger "Sumilizer (registered trademark) GS", manufactured by Sumitomo Chemical Co., Ltd.), and 0.25 parts by weight of zinc stearate (antacid), a nitrogen purge was performed using 99.99% pure nitrogen from the raw material inlet to prevent external oxygen contamination. While eliminating oxygen as much as possible, the dry-blended materials were charged into the raw material inlet and melted at a cylinder temperature of 295 ° C using a vented twin-screw kneading extruder "KZW15-45" (manufactured by Technovel Co., Ltd.). The extruder was then evacuated using a vacuum pump from the shear section of the extruder to remove moisture, yielding a pellet-shaped resin composition (M1). The visual appearance of the resulting resin composition (M1) was uniform, and no separation of P3MB and polypropylene was observed.

[0086] (2) Film Production The pellet-shaped resin composition (M1) obtained was molded under the following film-forming conditions to obtain a film. Specifically, as a measure to prevent oxygen contamination from the outside, nitrogen purging was performed using 99.99% pure nitrogen from the raw material inlet, and while eliminating oxygen as much as possible, the pellet-shaped resin composition (M1) was introduced into the raw material inlet, and a vented twin-screw kneading extruder "KZW15-45" (manufactured by Technovel Co., Ltd.) was used to melt the resin composition at a cylinder temperature of 295 ° C., and then the extruder was evacuated from the shear section using a vacuum pump to remove moisture. The melt was extruded into a film from a T-die (gap thickness (Tt) of the lip of the T-die: 300 μm), and solidified on a casting drum maintained at a surface temperature of 160 ° C. to obtain a film with a thickness (Ft) of 50 μm. The draft ratio [Tt / Ft] was 6.

[0087] Examples 2 to 11 Films were obtained in the same manner as in Example 1, except that the resin composition and film molding conditions were changed as shown in Table 1.

[0088] [Example 12] A film was obtained in the same manner as in Example 1, except that all of the P3MB and polypropylene were recycled raw materials. The P3MB and polypropylene contained in the recycled raw materials were obtained by recovering film edge portions generated during the production of the film in Example 4, pulverizing them in a pulverizer, solidifying them in a granulator, and molding them into pellets.

[0089] Comparative Examples 1 and 2 Films were obtained in the same manner as in Example 1, except that the resin composition and film molding conditions were changed as shown in Table 1.

[0090] Comparative Example 3 An attempt was made to form a film in the same manner as in Comparative Example 2, except that the surface temperature of the casting drum during film formation was set to 160° C. However, the molten material extruded from the T-die fused to the surface of the casting drum, making it impossible to form a film.

[0091] Comparative Example 4 Preparation of a resin composition was attempted in the same manner as in Example 2, except that 30 parts by mass of polypropylene (trade name "Prime Polypro (registered trademark) PP E701G" manufactured by Prime Polymer Co., Ltd.) in Example 2 was changed to 30 parts by mass of polyethylene (trade name "Hi-Zex 7000F" manufactured by Prime Polymer Co., Ltd.) and the film molding conditions were changed as shown in Table 1. However, significant separation occurred between the P3MB and the polyethylene, and a film could not be formed.

[0092] Comparative Example 5 A film was obtained in the same manner as in Comparative Example 2, except that 100 parts by mass of polypropylene (trade name "Prime Polypro (registered trademark) PP E701G" manufactured by Prime Polymer Co., Ltd.) was replaced with 100 parts by mass of polymethylpentene (trade name "TPX (registered trademark) DX845" manufactured by Mitsui Chemicals, Inc.) and the film molding conditions were changed as shown in Table 1.

[0093] The physical properties of the films obtained in the examples and comparative examples were measured or evaluated by the following methods.

[0094] [Film Thickness] The film was cut from the center of the TD direction to a size of 100 mm in the TD direction x 100 mm in the MD direction to prepare a film sample. The thickness was measured at 11 points at 10 mm intervals from both ends of the TD film using a dial gauge thickness meter (JIS B 7503:2017 compliant, manufactured by Ozaki Seisakusho Co., Ltd., "PEACOCK (registered trademark) UPRIIGHT DIAL GAUGE (graduation 0.001 mm, measurement range 2 mm, model No. 25, 5 mmφ flat probe)"), and the average value was used as the film thickness. The MD direction ("MD" is an abbreviation for Machine Direction) corresponds to the longitudinal direction of the film roll during film production. The TD direction ("TD" is an abbreviation for Transverse Direction) refers to the direction perpendicular to the MD direction. The same applies below.

[0095] [Heat Resistance] A test piece measuring 4 mm in the TD direction and 25 mm in the MD direction was cut out from the center of the TD direction of the film obtained in each example. A thermomechanical analyzer TMA ("Q400" manufactured by TA Instruments) was used as the measuring device, and the dimensional change of the test piece was measured in a temperature range of 25 to 300 ° C. in accordance with JIS K 7197:1991 under the conditions of a chuck distance L of 8 mm, a load of 0.01 N, and a heating rate of 10 ° C. / min. The absolute value of the linear expansion coefficient from 160 to 260 ° C. or 160 to 240 ° C. was calculated according to the following formula. In the formula, L (260 ° C.) means the chuck distance (mm) of the test piece at 260 ° C., L (160 ° C.) means the chuck distance (mm) of the test piece at 160 ° C., and L (240 ° C.) means the chuck distance (mm) of the test piece at 240 ° C. The smaller the absolute value of the linear expansion coefficient, the better the heat resistance. Measurement was performed only in the MD direction of the film, and the average value of the results of three measurements was taken as the absolute value of the linear expansion coefficient. Absolute value of linear expansion coefficient from 160 to 260°C (ppm / °C) = 10 ６ × |L(260°C)-L(160°C)| / {8×(260-160)} Absolute value of linear expansion coefficient from 160 to 240°C (ppm / °C) = 10 ６ × |L(240°C) - L(160°C)| / {8 x (240 - 160)} [Judgment: Criteria] "S": The absolute value of the linear expansion coefficient from 160 to 260°C is 700 ppm / °C or less. "A": The absolute value of the linear expansion coefficient from 160 to 260°C is more than 700 ppm / °C and 1,300 ppm / °C or less. "B": The absolute value of the linear expansion coefficient from 160 to 260°C is more than 1,300 ppm / °C and 2,000 ppm / °C or less. "C": The absolute value of the linear expansion coefficient from 160 to 240°C is 2,000 ppm / °C or less. (The absolute value of the linear expansion coefficient from 160 to 260°C could not be calculated because the film melted.) "D": The absolute value of the linear expansion coefficient from 160 to 240°C is more than 2,000 ppm / °C and is 3,000 ppm / °C or less. (The absolute value of the linear expansion coefficient from 160 to 260°C could not be calculated because the film melted.) "E": The absolute value of the linear expansion coefficient from 160 to 240°C and the absolute value of the linear expansion coefficient from 160 to 260°C could not be calculated because the film melted.

[0096] [Moldability] A test piece measuring 75 mm in TD x 75 mm in MD was cut out from the center of the TD of the film obtained in each example, and a stretching test was performed using a stretching machine (manufactured by Ever Sokki Co., Ltd., product name "Biaxial Stretching Birefringence Retardation Measurement Device") under the following conditions, and the results were used as an index of moldability. [Measurement Conditions] - Preheating temperature: 150°C - Preheating time: 30 seconds - Stretching speed: 2.6 mm / min - Stretching temperature: 150°C - Stretching direction: uniaxial stretching in MD direction - Stretching ratio: 2 to 7 times [Evaluation: Criteria] "S": No tear was observed at a stretching ratio of 6 times. "A": Tearing was observed at a stretching ratio of 6 times, and no tear was observed at a stretching ratio of 5 times. "B": Tearing was observed at a stretching ratio of 5 times, and no tear was observed at a stretching ratio of 3.5 times. "C": Tearing was observed at a stretching ratio of 3.5 times, and no tear was observed at a stretching ratio of 2 times. "D": Breaking was observed at a stretching ratio of 2 times.

[0097] [Flatness (Curling)] The film was cut into a size of 100 mm x 100 mm to prepare a film sample, which was then left for 24 hours under an atmospheric condition of 25°C and 65% RH without any load being applied to the film sample, thereby conditioning the film sample. After conditioning, the film sample was placed on a flat surface without any tape on all four sides (the casting drum surface of the film sample was the surface in contact with the desk), and the "floating" of the film from the desk was measured to evaluate the flatness. The "floating" refers to the height (distance) of the most raised part of the film placed on the desk from the contact surface, with the contact surface between the desk and the film being set at 0 mm. This "floating" was used as the "curling" value (unit: mm), which is an index for evaluating flatness. A smaller curling value indicates better flatness.

[0098] [Transmission YI (D65)] The yellowness index (YI value) of the film was measured using a spectrophotometer "SD7000" manufactured by Nippon Denshoku Industries Co., Ltd. under the condition of a D65 light source (viewing angle 10 degrees). After background measurement was performed without a sample, the film was set in a sample holder and transmittance measurement was performed for light of 380 nm to 780 nm to determine the tristimulus values ​​(X, Y, Z). The YI value was calculated based on the following formula. Three measurements were performed, and the average of the results of each of the three measurements was taken as the yellowness index (YI value) of the film. This value is shown in Table 1 below as the transmission YI (D65). The smaller the yellowness index (YI value) of the film, the better. YI = 100 × (1.2769X - 1.0592Z) / Y

[0099]

[0100] In Table 1, "P3MB" in the "Resin Composition" column refers to the P3MB obtained in Production Example 1, and "PP" refers to polypropylene (trade name "Prime Polypro (registered trademark) PP E701G", manufactured by Prime Polymer Co., Ltd.). In Table 1, the numbers in parentheses in the "Resin Composition" column refer to the content (mass%) of each component in 100% by mass of the total resin components in the resin composition. For example, "P3MB (50) + PP (50)" means that the content of P3MB is 50% by mass and the content of the polypropylene is 50% by mass, out of 100% by mass of the total resin components in the resin composition. In Table 1, "antioxidants, etc." refers to antioxidants, alkyl radical scavengers, and antacids. Therefore, the notation "present" for "antioxidant, etc." indicates that each antioxidant, alkyl radical scavenger, and antacid are contained in the same manner, and the notation "absent" for "antioxidant, etc." indicates that none of the antioxidant, alkyl radical scavenger, and antacid are contained. In Table 1, the "extrusion temperature" and "nitrogen purge" for each example refer to the "extrusion temperature" and "presence or absence of nitrogen purge" in "(1) Preparation of resin composition" and "(2) Production of film." In Table 1, the notation "(*1)" indicates that the molten material after extrusion was fused to the casting drum, making film formation impossible, and therefore evaluation was not possible. In Table 1, the notation "(*2)" indicates that the resin components were largely separated, making it impossible to form a film, and therefore evaluation was not possible.

[0101] From the results in Table 1, it was confirmed that the resin compositions of Examples 1 to 12 were able to achieve both good heat resistance and moldability compared to the resin compositions of each comparative example.

[0102] On the other hand, the resin composition of Comparative Example 1 had poor moldability because the polypropylene resin content was less than 10% by mass, based on 100% by mass of the total resin components in the resin composition. The resin composition of Comparative Example 2 had poor heat resistance because the P3MB content was less than 10% by mass, based on 100% by mass of the total resin components in the resin composition. The resin composition of Comparative Example 3 also had poor heat resistance because the P3MB content was less than 10% by mass, based on 100% by mass of the total resin components in the resin composition. When the surface temperature of the casting drum during film molding was set to 160°C, the molten material extruded from the T-die fused to the casting drum surface, making it impossible to form a film. In Comparative Example 4, the P3MB and polyethylene separated, making it impossible to form a film. In addition, the resin composition of Comparative Example 5 had poor heat resistance and moldability because the contents of P3MB and polypropylene resin were both less than 10% by mass, based on 100% by mass of the total amount of resin components in the resin composition.

Claims

1. A resin composition comprising a 3-methyl-1-butene polymer and a polypropylene resin, wherein the content of the 3-methyl-1-butene polymer is 10 to 90% by mass relative to 100% by mass of the total amount of resin components in the resin composition, and the content of the polypropylene resin is 10 to 90% by mass relative to 100% by mass of the total amount of resin components in the resin composition.

2. The resin composition according to claim 1, which has a yellowness index (YI) of 3.50 or less when formed into a film having a thickness of 50 μm.

3. The resin composition according to claim 1, wherein the 3-methyl-1-butene polymer is at least one selected from the group consisting of 3-methyl-1-butene homopolymers and copolymers of 3-methyl-1-butene with at least one selected from the group consisting of ethylene and α-olefins having 3 to 20 carbon atoms other than 3-methyl-1-butene.

4. The resin composition according to claim 1, further comprising an antioxidant.

5. The resin composition according to claim 4, wherein the antioxidant is at least one selected from the group consisting of phenol-based antioxidants and phosphorus-based antioxidants.

6. The resin composition according to claim 1, wherein the absolute value of the linear expansion coefficient at 160 to 260°C is 2,000 ppm / °C or less.

7. A molded article formed from the resin composition according to any one of claims 1 to 6.

8. The molded article according to claim 7, having a yellowness index (YI) of 3.50 or less.

9. The molded article according to claim 7, which contains 1 to 100% by mass of recycled raw materials.

10. The molded article according to claim 7, which is a film.

11. A method for producing a molded article, comprising step (I) of melt-extruding the resin composition according to any one of claims 1 to 6.

12. The method for producing a molded article according to claim 11, wherein the resin composition is melted in an inert atmosphere or in a low-oxygen state during step (I).

13. The method for producing a molded article according to claim 11, wherein the resin composition is melted at 280 to 323°C in step (I).

14. The method for producing a molded article according to claim 11, further comprising a step (II) of contacting the molten extrudate of the resin composition obtained in the step (I) with a casting drum, wherein the temperature of the casting drum is 40 to 250°C.

15. The method for producing a molded article according to claim 11, wherein in step (I), the melt of the resin composition is extruded through a T-die, and the draft ratio [Tt / Ft], which is the ratio of the gap thickness (Tt) of the lip portion of the T-die to the thickness (Ft) of the molded article extruded from the lip portion, is 1 to 30.

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