4-methyl-1-pentene copolymer, molded article, and film

Abstract

To provide a copolymer capable of obtaining a molded article excellent in dielectric breakdown strength and transparency even after drawing.SOLUTION: There is provided a 4-methyl-1-pentene copolymer having a content of a constitutional unit derived from 4-methyl-1-pentene of 90 to 99 mol% and a content of a constitutional unit derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene of 1 to 10 mol%, and satisfying the following requirements (A) and (B). Requirement (A) is that (σ) determined by formula (1) and formula (2) in a temperature range of -20 to 150°C in an elution curve obtained by crystallization elution fractionation chromatography is 5 to 40. Requirement (B) is that the crystallization temperature (Tc) is 150°C or higher and lower than 200°C. In the formulas, Ci represents a concentration of polymer in solution at an ith data point, Ti represents a temperature (°C) at the ith data point, and Tw represents a weight average crystallization temperature.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a 4-methyl-1-pentene copolymer, a molded article, and a film. [Background technology]

[0002] 4-methyl-1-pentene polymers are superior to polyethylene and polypropylene in terms of heat resistance, electrical properties, and other characteristics, and are widely used in a variety of applications (see, for example, Patent Document 1).

[0003] In recent years, metallized film capacitors, which have electrical properties such as high withstand voltage and low loss, have been attracting attention from the perspective of energy conservation and high efficiency. As a capacitor film having electrical properties in which the rate of capacitance decrease during long-term voltage application at high temperatures is small and the dielectric loss (hereinafter also referred to as "tan δ") characteristics are stable, for example, a capacitor film has been disclosed which is obtained by biaxially stretching a film containing a 4-methyl-1-pentene copolymer (A) having specific physical properties, and in which the ratio V(130°C) / V(23°C) of the breakdown voltage V(23°C) at 23°C to the breakdown voltage V(130°C) at 130°C is 0.5 or more (see, for example, Patent Document 2). Furthermore, it is generally known that in order to improve uniform stretchability, a component having a branched structure or a high molecular weight component is introduced as a component with high melt tension (see, for example, Patent Document 3). In addition, as a capacitor film suitable as an insulating film for film capacitors, the intrinsic viscosity [η] measured in decalin at 135°C X A biaxially stretched film containing a 4-methyl-1-pentene copolymer (X) that satisfies the above specific requirements has been disclosed (see, for example, Patent Document 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 050817 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-11182 [Patent Document 3] Patent No. 6260472 [Patent Document 4] Patent Publication No. 2021-155595 Summary of the Invention [Problem to be solved by the invention]

[0005] As disclosed in the above Patent Documents 1 to 4, films have been improved to have high dielectric breakdown strength at high temperatures and reduced shrinkage at high temperatures so that they can maintain sufficient quality even when used in harsh high-temperature environments. However, there is a demand for the development of films that have excellent dielectric breakdown strength and maintain transparency even after stretching.

[0006] An object of one embodiment of the present invention is to provide a copolymer from which a molded article having excellent dielectric breakdown strength and transparency can be obtained even after stretching. Another problem to be solved by one embodiment of the present invention is to provide a molded article and a film that are excellent in dielectric breakdown strength and transparency even after stretching. [Means for solving the problem]

[0007] The means for solving the above problems include the following aspects. <1> The content of structural units derived from 4-methyl-1-pentene is 90 to 99 mol %, the content of structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene is 1 to 10 mol% (provided that the total content of the structural units derived from 4-methyl-1-pentene and the structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene is 100 mol%), and A 4-methyl-1-pentene copolymer satisfying the following requirements (A) and (B): Requirement (A): The σ (σ) calculated from equations (1) and (2) in the temperature range of -20 to 150°C of the elution curve obtained by crystallization elution fractionation (CEF) chromatography is 5 to 40;

[0008]

number

[0009] In the above formulas (1) and (2), Ci represents the polymer concentration in the solution at the i-th data point, Ti represents the temperature (°C) at the i-th data point, and T w represents the weight average crystallization temperature. Requirement (B): The crystallization temperature (Tc) measured by a differential scanning calorimeter (DSC) is 150°C or higher and lower than 200°C. <2> the structural unit derived from an α-olefin having 3 to 20 carbon atoms other than ethylene or 4-methyl-1-pentene is a structural unit derived from ethylene; <1> The 4-methyl-1-pentene copolymer described in 1. <3> Further satisfy requirements (C), (D), and (E); <1> or <2> 4-methyl-1-pentene copolymer according to Requirement (C): The melting point (Tm) measured by differential scanning calorimetry (DSC) is 180 to 230°C; Requirement (D): The intrinsic viscosity [η] measured in decalin at 135°C is 1.0 to 5.0 dL / g; Requirement (E): The molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) is 1.0 to 5.0. <4> <1> ~ <3> 1. A molded article containing the 4-methyl-1-pentene copolymer according to any one of 1 to 8. <5> <1> ~ <3> A film containing the 4-methyl-1-pentene copolymer according to any one of the above items. <6> The stretching ratio is 1.1 to 100 times in terms of area. <5> The film according to claim 1. <7> The thickness is 1 to 20 μm. <5> or <6> The film according to claim 1. <8> For capacitors, <5> ~ <7> 10. The film according to any one of the preceding items. <9> The breakdown voltage at 100°C is 300 to 450 V / μm. <5> ~ <8> 10. The film according to any one of the preceding items. [Effects of the Invention]

[0010] According to one embodiment of the present invention, there is provided a copolymer from which a molded article having excellent dielectric breakdown strength and transparency can be obtained even after stretching. Furthermore, according to one embodiment of the present invention, there are provided a molded article and a film that are excellent in dielectric breakdown strength and transparency even after stretching. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, the term "polymer" is used to encompass homopolymers and copolymers unless otherwise specified. In addition, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower limit and upper limit. Furthermore, in this specification, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, it means the total amount of the multiple substances present in the composition, unless otherwise specified. In this specification, no particular distinction is made between films and sheets, and film is used as the general term for membranous (plate-like) bodies. As used herein, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, unless otherwise specified, each component in the composition or each structural unit in the polymer may be contained alone or in combination of two or more types. The present invention will be described in detail below.

[0012] [4-methyl-1-pentene copolymer] The 4-methyl-1-pentene copolymer according to the present invention has a content of structural units derived from 4-methyl-1-pentene of 90 to 99 mol % and a content of structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene of 1 to 10 mol % (provided that the total content of the structural units derived from 4-methyl-1-pentene and the structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene is 100 mol %), and satisfies the following requirements (A) and (B): Each component of the 4-methyl-1-pentene copolymer (hereinafter, sometimes simply referred to as "copolymer") will be described below.

[0013] <<Structural units derived from 4-methyl-1-pentene>> The content of structural units derived from 4-methyl-1-pentene is 90 to 99 mol%, preferably 92 to 99 mol%, and more preferably 93 to 99 mol%, provided that the total content of the structural units derived from 4-methyl-1-pentene and the structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene, which will be described later, is 100 mol%. When the content of structural units derived from 4-methyl-1-pentene is 90 mol % or more, the film has excellent gas permeability and also has good gas permeability for gas components with large molecular weights.Furthermore, when the content of structural units derived from 4-methyl-1-pentene is 99 mol % or less, a film having good mechanical properties such as film elongation can be obtained. The content of structural units derived from 4-methyl-1-pentene and structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene, which will be described later, can be determined by the measurement method described in the Examples.

[0014] <<Structural units derived from α-olefins having 3 to 20 carbon atoms other than 4-methyl-1-pentene>> The α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene (hereinafter, may also be simply referred to as "α-olefin having 3 to 20 carbon atoms") is not particularly limited, and examples thereof include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, and 3-methyl-1-pentene. Among these, from the viewpoint of obtaining a film with superior stretchability, as the α-olefin having 3 to 20 carbon atoms, an α-olefin having 5 to 20 carbon atoms is preferred, an α-olefin having 6 to 20 carbon atoms is more preferred, an α-olefin having 10 to 20 carbon atoms is even more preferred, and 1-decene, 1-tetradecene, 1-hexadecene, and 1-octadecene are particularly preferred. The copolymer may contain one type of structural unit derived from an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene, or may contain two or more types of structural units.

[0015] From the viewpoint of enabling high stretching and maintaining high dielectric breakdown voltage (BDV) and high transparency even after stretching, the structural unit derived from an α-olefin having 3 to 20 carbon atoms other than ethylene or 4-methyl-1-pentene is preferably a structural unit derived from ethylene or an α-olefin having 5 to 20 carbon atoms (more preferably an α-olefin having 6 to 20 carbon atoms, even more preferably an α-olefin having 10 to 20 carbon atoms, and particularly preferably 1-decene, 1-tetradecene, 1-hexadecene, or 1-octadecene), and more preferably a structural unit derived from ethylene. When the 4-methyl-1-pentene copolymer contains structural units derived from ethylene, ethylene easily penetrates into the crystalline phase of 4-methyl-1-pentene, and the resulting film has excellent flexibility, and is therefore presumably excellent in dielectric breakdown strength even after stretching.

[0016] The content of structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene is 1 to 10 mol %, preferably 1 to 8 mol %, and more preferably 1 to 7 mol %. However, the total content of the structural units derived from 4-methyl-1-pentene and the structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene is 100 mol %. When the content of each structural unit is within the above range, the stretchability of the obtained film is good, and as a result, the voltage resistance characteristics of the film tend to be improved, and for example, a decrease in the breakdown voltage in a high-temperature environment tends to be suppressed.

[0017] The copolymer may further contain structural units derived from polymerizable compounds other than 4-methyl-1-pentene, ethylene, and α-olefins having 3 to 20 carbon atoms other than 4-methyl-1-pentene (hereinafter, also referred to as "other polymerizable compounds"), within the scope of the present invention.

[0018] Other polymerizable compounds include, for example, vinyl compounds having a cyclic structure such as styrene, vinylcyclopentene, vinylcyclohexane, and vinylnorbornane; vinyl esters such as vinyl acetate; unsaturated organic acids or derivatives thereof such as maleic anhydride; conjugated dienes such as butadiene, isoprene, pentadiene, and 2,3-dimethylbutadiene; 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene; Examples of non-conjugated polyenes include dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylenenorbornene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, and 2-propenyl-2,2-norbornadiene.

[0019] In the copolymer, the content of structural units derived from other polymerizable compounds is usually 10 mol % or less, preferably 5 mol % or less, more preferably 3 mol % or less, relative to 100 mol % of all structural units constituting the copolymer, and it is even more preferable that they are substantially free of other polymerizable compounds. The structural unit derived from the other polymerizable compound may be contained either alone or in combination of two or more.

[0020] <<Requirements (A)>> The 4-methyl-1-pentene copolymer has an elution curve obtained by crystallization elution fractionation (CEF) in the temperature range of -20 to 150°C, and the σ calculated from equations (1) and (2) is 5 to 40, preferably 5 to 35, and more preferably 10 to 30.

[0021]

number

[0022] In the above formula (1) and formula (2), C i represents the polymer concentration in solution at the ith data point, and T i represents the temperature (℃) at the i-th data point, and T w represents the weight average crystallization temperature.

[0023] C i is the polymer concentration in the solution at the i-th data point. For example, if there are x data points in the temperature range of -20 to 150°C, the polymer concentration of the data point closest to -20°C among the x data points is C1, and the polymer concentration of the data point closest to 150°C is C x This becomes:

[0024] Crystallization Elution Fractionation (CEF) is a fractionation method that utilizes the difference in crystallinity of the polymer components contained in the copolymer being measured. The elution curve obtained by crystallization elution fractionation chromatography can be used to evaluate the composition distribution of 4-methyl-1-pentene copolymers. When the σ calculated from Equations (1) and (2) in the temperature range of -20 to 150°C in the elution curve obtained by crystallization elution fractionation (CEF) chromatography is 5 to 40, the copolymer composition distribution is narrow, and in the 4-methyl-1-pentene copolymer, structural units derived from the comonomer component ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene are presumably introduced appropriately and uniformly into the 4-methyl-1-pentene main chain. As a result, the resulting film is presumably excellent in flexibility and dielectric breakdown strength (BDV) even after stretching. The measurement conditions for crystallization elution fractionation (CEF) chromatography are described in the Examples below.

[0025] The peak temperature (hereinafter sometimes referred to as "CEF peak temperature") (°C) of the elution curve (composition distribution) obtained by crystallization elution fractionation (CEF) chromatography is preferably 95 to 120°C, more preferably 95 to 115°C. The "CEF peak temperature" refers to the temperature at which the response intensity is highest in an elution curve (composition distribution) observed in crystallization elution fractionation (CEF) chromatography, with the horizontal axis representing temperature and the vertical axis representing the response intensity of an IR detector. When the CEF peak temperature is within the above range, the resulting film has better heat resistance.

[0026] <<Requirements (B)>> The 4-methyl-1-pentene copolymer has a crystallization temperature (Tc) measured by differential scanning calorimetry (DSC) of 150°C or higher and lower than 200°C, preferably 160°C or higher and lower than 200°C, and more preferably 160 to 190°C. A 4-methyl-1-pentene copolymer having a crystallization temperature (Tc) within the above range has an appropriately narrow composition distribution, and therefore has excellent heat resistance, and a molded product having excellent dielectric breakdown strength (BDV) and transparency even after stretching can be obtained. The crystallization temperature (Tc) can be determined by a method described in the Examples below using a differential scanning calorimeter (DSC).

[0027] It is preferred that the 4-methyl-1-pentene copolymer further satisfies the requirements (C), (D) and (E).

[0028] <<Requirements(C)>> The 4-methyl-1-pentene copolymer has a melting point (Tm) of 180 to 230°C, preferably 190 to 220°C, and more preferably 190 to 215°C, as measured by a differential scanning calorimeter (DSC). The melting point (Tm) can be determined using a differential scanning calorimeter (DSC) by the method described in the Examples below.

[0029] <<Requirements(D)>> The 4-methyl-1-pentene copolymer has an intrinsic viscosity [η] measured in decalin at 135°C of 1.0 to 5.0 dL / g, preferably 1.5 to 4.0 dL / g, more preferably 2.0 to 3.5 dL / g, and even more preferably 2.0 to 3.0 dL / g. A copolymer having an intrinsic viscosity [η] within the above range exhibits good fluidity during preparation and molding of a composition containing the copolymer, and also contributes to improving the stretchability of the film, which makes it easier to improve the voltage resistance characteristics of the film.

[0030] <<Requirements(E)>> The 4-methyl-1-pentene copolymer has a molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) of 1.0 to 5.0, preferably 1.5 to 4.0, and more preferably 1.5 to 3.0. When the molecular weight distribution (Mw / Mn) of the copolymer is within the above range, the stretchability of the resulting film is good, and as a result, the voltage resistance characteristics of the film tend to be improved. Therefore, the film is excellent in suppressing a decrease in breakdown voltage, for example, in high-temperature environments, and is more likely to exhibit the stable electrical characteristics required of a capacitor film. A copolymer having an Mw / Mn ratio in the above range can be obtained, for example, by using a metallocene catalyst described below. The molecular weight distribution (Mw / Mn) can be determined by the method described in the Examples below.

[0031] <<Production method of 4-methyl-1-pentene copolymer>> The 4-methyl-1-pentene copolymer can be obtained by polymerizing 4-methyl-1-pentene with the above-mentioned α-olefin having 3 to 20 carbon atoms other than ethylene or 4-methyl-1-pentene, and, if necessary, with the above-mentioned other polymerizable compound. Furthermore, by carrying out the polymerization in the presence of a metallocene catalyst, a 4-methyl-1-pentene copolymer that satisfies the above-mentioned requirements can be suitably obtained.

[0032] Examples of the metallocene catalyst include those described in WO 2001 / 27124, WO 2005 / 121192, WO 2014 / 050817, and the like.

[0033] [Molded body] The molded article according to the present invention contains the 4-methyl-1-pentene copolymer described above. The molded article may further contain other polymers and / or other components described below within the scope of the present invention. The molded article can be produced into a desired shape by a conventional molding method such as heat press molding, compression molding, injection molding, and extrusion molding using a resin composition containing the copolymer and, if necessary, other polymers and / or other components described below.

[0034] The shape of the molded product is not particularly limited, and may be, for example, any of a film shape (including a sheet shape and a plate shape), a cylindrical shape, a prismatic shape, etc. Among these, the shape of the molded product containing the 4-methyl-1-pentene copolymer is preferably a film shape, since a molded product excellent in dielectric breakdown strength (BDV) and transparency can be obtained even after stretching.

[0035] 〔film〕 The film according to the present invention contains the above-mentioned 4-methyl-1-pentene copolymer. The film may be a single-layer film, or a multilayer film in which a film (layer) containing the copolymer is laminated with a film other than the film containing the copolymer (hereinafter also referred to as "other film"), or a multilayer film in which a plurality of films containing the copolymer are laminated. The other film is not particularly limited, and may be a film containing a polymer other than the above-mentioned 4-methyl-1-pentene copolymer, or may be a metal film (for example, metal foil). The film and the other film may or may not be in contact with each other. If the adhesive strength between the layers of the laminated film is insufficient, an adhesive layer may be provided between the film and the other film.

[0036] Furthermore, the film may contain polymers other than ethylene, 4-methyl-1-pentene, and α-olefins having 3 to 20 carbon atoms (excluding 4-methyl-1-pentene) (hereinafter also referred to as "other polymers"), and / or additives, within the scope of the present invention.

[0037] Examples of the additives include secondary antioxidants, heat stabilizers, weather stabilizers, antistatic agents, slip agents, antiblocking agents, antifogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, fillers, and hydrochloric acid absorbers. When the film contains an additive, the content of the additive is not particularly limited, but is usually 0.1 to 50 parts by mass, and preferably 0.1 to 10 parts by mass, per 100 parts by mass of the copolymer. The additives may be used alone or in combination of two or more.

[0038] Examples of other polymers include polyethylene, poly-1-butene, styrene-based resins, and polyolefin-based polymers such as ethylene-α-olefin copolymers. The other polymers may be used alone or in combination of two or more. The content of the other polymer is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less, based on 100 parts by mass of the 4-methyl-1-pentene copolymer.

[0039] The thickness of the film can be appropriately set depending on the purpose, but is preferably 1 to 20 μm, more preferably 2 to 15 μm, and even more preferably 3 to 15 μm.

[0040] The stretching ratio of the film is preferably 1.1 to 100 times, in terms of area, more preferably 2 to 90 times, and even more preferably 4 to 80 times. When the stretching ratio is within the above range, the withstand voltage characteristics required for a film capacitor are easily exhibited, making it suitable as a film for a capacitor.

[0041] The dielectric breakdown voltage of the film at 100° C. (hereinafter, sometimes referred to as "dielectric breakdown voltage (100° C.)") is preferably 300 to 450 V / μm, and more preferably 320 to 440 V / μm. The breakdown voltage (100° C.) is determined by the method described in the Examples below.

[0042] <<Film manufacturing method>> The film can be produced by preparing a resin composition containing the copolymer and, if necessary, other polymers and / or additives, and then molding the resin composition using a T-die extrusion molding method or the like at a temperature in the range of 180 to 300°C.

[0043] Examples of methods for preparing the resin composition include mixing the copolymer and, if necessary, other polymers and / or additives by various known mixing methods, such as a method of mixing the components using equipment such as a Plastomill, a Henschel mixer, a V-blender, a ribbon blender, a tumbler, a blender, or a kneader-ruder, and then melt-kneading the resulting mixture in various known kneading equipment, such as a single-screw extruder, a twin-screw extruder, a kneader, or a Banbury mixer, and granulating or pulverizing the resulting kneaded product.

[0044] When the film is a stretched film, the resulting film may be further stretched. The stretching may be uniaxial or biaxial. When the film is a biaxially stretched film, the obtained film may be biaxially stretched. The stretching method is not particularly limited, but examples thereof include batch stretching, sequential biaxial stretching, and simultaneous biaxial stretching. The stretching temperature is usually in the range of 180 to 300°C.

[0045] [Application] The film can be used for, for example: Oriented films: for example, films for capacitors; Semiconductor process films: such as dicing tape, back grinding tape, die bonding film, polarizing plate film; Packaging films: for example, food packaging films, stretch films, cling films, breathable films, shrink films, easy-peel films; Separators: such as battery separators, separators for lithium-ion batteries, electrolyte membranes for fuel cells, adhesive separators; Films for electronic components: for example, diffusion films, reflective films, radiation-resistant films, gamma-ray-resistant films, porous films; Release films: for example, release films for flexible printed circuit boards, ACM substrates, rigid-flexible substrates, advanced composite materials, curing carbon fiber composites, curing glass fiber composites, curing aramid fiber composites, curing nanocomposites, curing filler materials, curing urethane, curing epoxy, semiconductor encapsulation, polarizing plates, diffusion sheets, prism sheets, reflective sheets, fuel cells, or various rubber sheets; Surface protection films: for example, protective films for polarizing plates, liquid crystal panels, optical components, lenses, electrical components and appliances, mobile phones, personal computers or touch panels, masking films; Building material films: such as building window films, laminated glass films, bulletproof materials, bulletproof glass films, heat-shielding sheets, heat-shielding films; Examples include:

[0046] From the viewpoint of being excellent in dielectric breakdown strength (BDV) and transparency even after stretching, the film according to the present invention can be suitably used for capacitors. [Example]

[0047] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to these examples.

[0048] 〔composition〕 The content (mol %) of structural units derived from 4-methyl-1-pentene and ethylene and α-olefins having 3 to 20 carbon atoms (excluding 4-methyl-1-pentene) in the copolymer was determined by the following apparatus and conditions: 13 Calculated from C-NMR spectrum. ~Measurement conditions~ Measurement equipment: Nuclear magnetic resonance equipment (ECP500 type, manufactured by JEOL Ltd.) Observation kernel: 13 C(125MHz) Sequence: Single pulse proton decoupling Pulse width: 4.7 μsec (45° pulse) Repeat time: 5.5 seconds Accumulation count: 10,000 times or more Solvent: orthodichlorobenzene / deuterated benzene (volume ratio: 80 / 20) mixed solvent Sample concentration: 55 mg / 0.6 mL Measurement temperature: 120℃ Chemical shift reference value: 27.50 ppm

[0049] [Intrinsic viscosity [η]] The intrinsic viscosity [η] of the copolymer was measured at 135°C in decalin solvent using an Ubbelohde viscometer. Specifically, approximately 20 mg of powdered copolymer was dissolved in 25 mL of decalin, and the specific viscosity ηsp was measured using an Ubbelohde viscometer in an oil bath at 135°C. This decalin solution was diluted with 5 mL of decalin, and the specific viscosity ηsp was measured in the same manner as above. This dilution procedure was repeated two more times, and the value of ηsp / C when the concentration (C) was extrapolated to 0 was calculated as the limiting viscosity [η] (unit: dl / g) (see the following formula). [η]=lim(ηsp / C) (C→0)

[0050] [Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)] The weight-average molecular weight (Mw) of the copolymer and the molecular weight distribution (Mw / Mn), which is the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), were calculated by a standard polystyrene conversion method using gel permeation chromatography (GPC) under the following measurement conditions:

[0051] ~Measurement conditions~ Measurement equipment: CFC2 type cross fractionation chromatograph (Polymer Char) Detector (built-in): IR4 type infrared spectrophotometer (Polymer Char) Detection wavelength: 3.42 μm (2,920 cm -1 ) fixed Sample concentration: 45mg / 30mL Injection volume: 0.5mL Elution range: 140 (single GPC injection) Column: Shodex HT-806M x 3 (Showa Denko K.K.) Column temperature: 140℃ Column calibration: Monodisperse polystyrene (Tosoh Corporation) Molecular weight calibration method: Standard calibration method (polystyrene equivalent)

[0052] [Melting point (Tm) and crystallization temperature (Tc)] The melting point (Tm) of the copolymer was measured using a differential scanning calorimeter (DSC8000 model, manufactured by PerkinElmer Co., Ltd.) as a measuring device. Approximately 5 mg of copolymer was sealed in a measurement aluminum pan and heated from room temperature to 280°C at 10°C / min. To completely melt the copolymer, it was held at 280°C for 5 minutes and then cooled to -40°C at 10°C / min. After leaving it at -40°C for 5 minutes, it was heated a second time to 280°C at 10°C / min. The peak temperature (°C) during this second heating was taken as the melting point (Tm) of the copolymer. When multiple peaks were detected, the peak detected at the highest temperature was used. The peak temperature (°C) at the first cooling was taken as the crystallization temperature (Tc) of the copolymer.

[0053] [Crystallization elution fractionation] The peak temperature (°C) (CEF peak temperature) of the elution curve (composition distribution) obtained by crystallization elution fractionation (CEF) chromatography was measured by the following method. Also, σ of the elution curve (composition distribution) in the temperature range of -20 to 150°C was calculated using equations (1) and (2) with reference to DM Sarzotti, JBP Soares, and A. Penlidis, J. Polym. Sci. Part B: Polym. Phys., 40: 2595-2611, 2002. Measurement equipment: High-throughput composition distribution analyzer CEF (Polymer Char) Detector (built-in): IR5 MCT Infrared Detector Polymer Char Detection wavelength Methylene sensor CH2νa 3.42μm (2,920cm -1 concentration Methyl sensor CH3νa 3.38μm 2,960cm -1 composition Column: CEF column (Polymer Char), length 150 mm, volume 2.3 mL Mobile phase: o-dichlorobenzene (ODCB) with BHT Sample concentration: 16mg / 8mL Dissolution conditions: 150°C, 60 min (under N2 atmosphere) Sample filtration: 10 μm in-line filter Injection volume: 0.2mL Temperature lowering conditions: 95℃→-20℃, 1.0℃ / min, flow rate 0.012mL / min Temperature rise conditions: -20°C → 140°C, 4.0°C / min, flow rate 1.0mL / min

[0054]

number

[0055] In the above formula (1) and formula (2), C i represents the polymer concentration in solution at the ith data point, and T i represents the temperature (℃) at the i-th data point, and T w represents the weight average crystallization temperature.

[0056] [Example 1 (Copolymer (1)] [Synthesis Example 1-1: Production of Olefin Polymerization Catalyst] At 30°C, 30 mL of purified decane and 30 mL of particulate D were added to a 200 mL three-necked flask equipped with a stirrer and thoroughly purged with nitrogen under a nitrogen stream. 50A suspension was prepared using 14.65 mmol of solid polymethylaluminoxane (synthesized using the method described in WO 2014 / 123212) with a diameter of 28 μm and an aluminum atom content of 43% by mass. To the suspension was added 50.0 mg (0.0586 mmol) of (8-octamethylfluoren-12'-yl-(2-(adamantan-1-yl)-8-methyl-3,3b,4,5,6,7,7a,8-octahydrocyclopenta[a]indene))zirconium dichloride (4.58 mmol / L toluene solution) with stirring. After 1 hour, stirring was stopped, and the resulting mixture was washed with 100 mL of decane by decantation. Decane was then added to prepare a 50 mL slurry (zirconium atom loading: 98%).

[0057] [Synthesis Example 1-2: Preparation of prepolymerization catalyst component] To the slurry prepared in Synthesis Example 1-1, 1.0 mL of a decane solution of triisobutylaluminum (TIBAL) (0.5 mmol / mL in terms of aluminum atom) was added under a nitrogen stream at 25°C. After cooling to 15°C, 10 mL of 4-methyl-1-pentene was added to the reactor over 60 minutes. The start of the 4-methyl-1-pentene addition marked the start of prepolymerization. 2.0 hours after the start of prepolymerization, stirring was stopped, and the resulting mixture was washed three times with 100 mL of decane by decantation. The prepolymerization catalyst component was a decane slurry (9.5 g / L, 0.56 mmol / L in terms of zirconium atom).

[0058] [Production of copolymer (1)] At room temperature under a nitrogen stream, 425 mL of purified decane was placed in a 1 L stainless steel polymerization vessel equipped with a stirrer, and the temperature was raised to 40°C. After reaching 40°C, 0.8 mL (0.4 mmol in terms of aluminum atoms) of a decane solution of triisobutylaluminum (TIBAL) (0.5 mmol / mL in terms of aluminum atoms) was added, followed by 0.0020 mmol in terms of zirconium atoms of a decane slurry of the prepolymerized catalyst component from Synthesis Example 1-2 above. 15 NmL of hydrogen was added, and then 252 mL of 4-methyl-1-pentene was continuously added to the polymerization vessel at a constant rate over 2 hours. The start of the addition of the mixed solution marked the start of polymerization, and the temperature was maintained at 45°C for 4.5 hours. 94 NmL of ethylene was charged every 15 minutes from 15 minutes after the start of polymerization to 60 minutes after the start of polymerization, and 260 NmL of ethylene was charged every 15 minutes from 75 minutes after the start of polymerization to 240 minutes after the start of polymerization. 15 NmL of hydrogen was charged 1 hour and 2 hours after the start of polymerization. 4.5 hours after the start of polymerization, the temperature was lowered to room temperature, the pressure was released, and the polymerization liquid containing a white solid was immediately filtered to obtain a solid substance. This solid substance was dried under reduced pressure at 80°C for 8 hours to obtain copolymer (1). The physical properties of the obtained copolymer (1) are shown in the table below.

[0059] [Production of Resin Composition (1)] The copolymer (1) was produced multiple times to prepare a sufficient amount of copolymer (1) for pelletization. 0.1 parts by mass of tri(2,4-di-t-butylphenyl)phosphate as a secondary antioxidant and 0.1 parts by mass of n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate as a heat stabilizer were blended with 100 parts by mass of the prepared copolymer (1) to obtain a mixture. The obtained mixture was melt-extruded and granulated using a twin-screw extruder (manufactured by Technovel Co., Ltd., model number: KZW-15) (screw diameter 15 mmφ, L / D 30) under conditions of a set temperature of 270 to 290°C, a resin extrusion rate of 30 g / min, and a rotation speed of 200 rpm, to obtain pellets of resin composition (1).

[0060] [Production of film (1)] The pellets of resin composition (1) obtained above were fed to a single-screw extruder (manufactured by Toyo Seiki Seisakusho, Ltd.), melt-kneaded at a cylinder temperature of 280° C., and melt-extruded into a film from a T-slit die at a die temperature of 290° C. Next, the obtained film was tightly attached to a metal cooling roll controlled at 80° C. by air pressure and taken up at a take-up speed of 0.6 m / min, to obtain a cooled and solidified unstretched film (1) having a thickness of 200 μm. Next, the unstretched film (1) obtained above was used as a raw film, and this raw film was preheated for 1 minute at a temperature of 150 to 190°C using a batch-type biaxial stretching machine (KARO IV, manufactured by Bruckner-Maschinenbau GmbH), and then sequentially biaxially stretched at a stretching speed of 104% / sec to obtain a biaxially stretched film (1). The stretching ratio was 3 times in the machine direction (MD) of the film and 5 times in the transverse direction (TD) of the film.

[0061] <Evaluation of stretched film> [Evaluation of dielectric breakdown voltage (BDV) at 100℃] The dielectric breakdown voltage (BDV) (V / μm) of the biaxially stretched film (1) obtained above was measured in accordance with ASTM-D149 using a dielectric breakdown tester (manufactured by Yamayo Test Instruments Co., Ltd.). The biaxially stretched film (1) was cut into a size of 21 cm × 29.7 cm to prepare a sample for evaluation. A voltage was applied to the sample for evaluation at 100°C at a voltage increase rate (500 V / sec), and the maximum voltage value was recorded as the dielectric breakdown voltage value (dielectric breakdown strength) (V / μm). The measurement was performed X times, and the average value and standard deviation of the breakdown voltage values ​​were calculated for the X number of data obtained. The average value + standard deviation value was entered in the "Breakdown voltage (BDV) @ 100°C" column of the table.

[0062] [Variation in breakdown voltage (m)] Using the breakdown voltage values ​​obtained from the above BDV evaluation, a correlation analysis (Weibull distribution analysis) between the breakdown voltage values ​​and the breakdown probability was performed with reference to the description in "Kaneko, Sugiyama, Transactions of the Institute of Electrical Engineers of Japan, 94-A(4):137-144, 1972." The variation (m) of the breakdown voltage values ​​was calculated and listed in a table. A larger value of m means less variation in breakdown voltage. The smaller the variation in breakdown voltage value, the easier it is to stretch the film uniformly, and even after stretching, the film tends to have excellent stability in properties such as heat resistance.

[0063] [Observation of film appearance] The appearance of the biaxially stretched film (1) obtained above was visually observed and evaluated according to the following criteria. The results are shown in the table below. If the biaxially stretched film obtained has a transparent appearance, voids (gaps) do not occur when the unstretched film is stretched, and therefore, the BDV tends to be less variable. -Evaluation criteria- A: The appearance of the biaxially stretched film is transparent. B: The biaxially stretched film appears cloudy.

[0064] [Example 2: Copolymer (2)] Polymerization was carried out in the same manner as in Example 1, except that the amount of ethylene charged every 15 minutes from 75 minutes after the start of polymerization to 240 minutes was changed to 180 NmL, to obtain copolymer (2). The physical properties of the obtained copolymer (2) are shown in Table 1. In addition, a resin composition and a biaxially stretched film were prepared and evaluated in the same manner as in Example 1, except that the obtained copolymer (2) was used. The obtained results are shown in the table.

[0065] [Comparative Example 1: Copolymer (3)] Copolymer (3) was obtained in the same manner as in Example 5 of WO 2013 / 099876. The physical properties of the obtained copolymer (3) are shown in the table below. In addition, a resin composition and a film were prepared and evaluated in the same manner as in Example 1, except that the obtained copolymer (3) was used. The obtained results are shown in the table.

[0066] [Comparative Example 2: Copolymer (4)] Copolymer (4) was obtained in the same manner as in Example 36 of WO 2013 / 099876. The physical properties of the obtained copolymer (4) are shown in the table below. In addition, a resin composition and a film were prepared and evaluated in the same manner as in Example 1, except that the obtained copolymer (4) was used. The obtained results are shown in the table.

[0067] [Table 1]

[0068] In Table 1, "ND" means not detected or measurable. It can be seen that the films of Examples 1 and 2 are superior to the films of Comparative Examples 1 and 2 in dielectric breakdown strength (BDV) and transparency even after stretching.

Claims

1. the content of structural units derived from 4-methyl-1-pentene is 90 to 99 mol %, the content of structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene is 1 to 10 mol% (provided that the total content of the structural units derived from 4-methyl-1-pentene and the structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene is 100 mol%), and A 4-methyl-1-pentene copolymer satisfying the following requirements (A) and (B): Requirement (A): The σ (σ) calculated from the elution curve obtained by crystallization elution fractionation (CEF) chromatography in the temperature range of −20 to 150° C. using equations (1) and (2) is 5 to 40; [Equation 1] In the above formula (1) and formula (2), C ｉ represents the polymer concentration in the solution at the i-th data point, and T ｉ represents the temperature (°C) at the i-th data point, and T ｗ represents the weight average crystallization temperature. Requirement (B): The crystallization temperature (Tc) measured by a differential scanning calorimeter (DSC) is 150°C or higher and lower than 200°C.

2. 2. The 4-methyl-1-pentene copolymer according to claim 1, wherein the structural units derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene are structural units derived from ethylene.

3. 4-methyl-1-pentene copolymer according to claim 1, further satisfying requirements (C), (D) and (E); Requirement (C): The melting point (Tm) measured by a differential scanning calorimeter (DSC) is 180 to 230°C; Requirement (D): The intrinsic viscosity [η] measured in decalin at 135°C is 1.0 to 5.0 dL / g; Requirement (E): The molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) is 1.0 to 5.

0.

4. A molded article comprising the 4-methyl-1-pentene copolymer according to any one of claims 1 to 3.

5. A film containing the 4-methyl-1-pentene copolymer according to any one of claims 1 to 3.

6. The film according to claim 5, wherein the stretching ratio is 1.1 to 100 times in terms of area.

7. The film of claim 5, having a thickness of 1 to 20 μm.

8. The film of claim 5 for use in a capacitor.

9. 6. The film according to claim 5, having a breakdown voltage at 100° C. of 300 to 450 V / μm.

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