Resin composition and molded article thereof

Abstract

The present invention addresses the problem of providing: a resin composition having excellent hardness and spiral flow characteristics in a well-balanced manner; and a molded body formed from the resin composition.　The resin composition according to the present invention contains: 50-94 parts by mass of a crystalline propylene / ethylene block copolymer (A) that satisfies specific requirements; 1-25 parts by mass of an ethylene polymer (B) having a density of 915-980 kg / m3 and a melt flow rate (190 °C, 2.16 kg load) of 0.1-30 g / 10 min; and 5-25 parts by mass of an inorganic filler (C) (where the total amount of the crystalline propylene / ethylene block copolymer (A), the ethylene-based polymer (B), and the inorganic filler (C) is 100 parts by mass).

Description

[Technical Field]

[0001] The present invention relates to a resin composition comprising a propylene-ethylene block copolymer, and a molded article formed from the resin composition. [Background technology]

[0002] Polypropylene resin compositions are easy to mold, and the resulting molded articles have excellent rigidity and impact resistance, making them widely used in various applications such as automotive interior and exterior parts and electrical component housings.

[0003] For example, Patent Document 1 describes a polypropylene-based resin composition containing a specific propylene-ethylene block copolymer, an ethylene-butene-1 copolymer elastomer, and an inorganic filler, which can produce molded articles with low gloss and excellent rigidity.

[0004] Furthermore, Patent Document 2 describes a polypropylene-based resin composition that can produce molded articles with improved flow mark appearance, excellent toughness, and a good balance of rigidity and surface hardness, and contains a specific polypropylene resin, an ethylene-α-olefin copolymer rubber having a specific density and MFR, and an inorganic filler. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-92049 [Patent Document 2] Japanese Patent Publication No. 2008-239971 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, for automotive parts such as bumpers, instrument panels (dashboards), door trims, and pillars, there is a need for resin compositions that offer an even better balance of hardness and spiral flow. The object of the present invention is to provide a resin composition that exhibits a good balance of hardness and spiral flow characteristics, and a molded article formed from the resin composition. [Means for solving the problem]

[0007] As a result of diligent research to solve the aforementioned problems, the inventors have found that the aforementioned problems can be solved by the following specific resin composition, and have completed the present invention. The present invention relates, for example, to the following [1] to [9].

[0008] [1] 50 to 94 parts by mass of a crystalline propylene-ethylene block copolymer (A) that satisfies the following requirements (1) to (3), Density of 915-980 kg / m³ 3 The mixture comprises 1 to 25 parts by mass of an ethylene-based polymer (B), which is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, with a melt flow rate (MFR) of 0.1 to 30 g / 10 min measured at a temperature of 190°C and a load of 2.16 kg. A resin composition comprising 5 to 25 parts by mass of inorganic filler (C) (provided that the total of crystalline propylene-ethylene block copolymer (A), ethylene polymer (B), and inorganic filler (C) is 100 parts by mass). Requirement (1): A block copolymer comprising a crystalline propylene polymer component and a propylene-based copolymer component, wherein the amount of the propylene-based copolymer component is 10 to 50% by mass, the intrinsic viscosity [η] of the propylene-based copolymer component measured in tetralin at 135°C is 2.0 to 6.0 dl / g, and the proportion of ethylene-derived constituent units in the propylene-based copolymer component is 30 to 80 mol%. Requirement (2): The propylene copolymer component contains copolymer component (EP-1) and copolymer component (EP-2), The copolymer component (EP-1) contains 40 to 80 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] measured in tetralin at 135 °C of 1.5 to 4.0 dl / g. The copolymer component (EP-2) contains 30 to 50 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] measured in tetralin at 135 °C of 5.0 to 10 dl / g. Requirement (3): The mass ratio (EP-1 / EP-2) of the copolymer component (EP-1) to the copolymer component (EP-2) is 10 / 1 to 1 / 1.

[0009] 〔2〕 The copolymer component (EP-1) contains 51 to 58 mol% of ethylene-derived structural units. The resin composition according to 〔1〕, wherein the copolymer component (EP-2) contains 38 to 48 mol% of ethylene-derived structural units.

[0010] 〔3〕 The resin composition according to 〔1〕 or 〔2〕, wherein the crystalline propylene-ethylene block copolymer (A) further satisfies the following requirements (4) to (6). Requirement (4): The melt flow rate (MFR) measured at a temperature of 230 °C and a load of 2.16 kg is 1 to 500 g / 10 min. Requirement (5): The melting point measured by a differential scanning calorimeter (DSC) is 155 to 170 °C. Requirement (6): The 13 meso pentad fraction (mmmm fraction) measured by C-NMR of the crystalline propylene polymer component is 96.0 to 99.9%.

[0011] 〔4〕 The resin composition according to any one of 〔1〕 to 〔3〕, wherein the crystalline propylene-ethylene block copolymer (A) further satisfies at least one of the following requirements (7) and (8). Requirement (7): ΔC2, which is the difference between the ethylene-derived structural unit content of the copolymer component (EP-1) and the ethylene-derived structural unit content of the copolymer component (EP-2), is 1.0 to 13 mol%. Requirement (8): The difference Δη between the intrinsic viscosity [η] of copolymer component (EP-1) measured in tetralin at 135°C and the intrinsic viscosity [η] of copolymer component (EP-2) measured in tetralin at 135°C is 5.8 to 8.5 dl / g.

[0012] [5] A copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, with a density of 850 to 910 kg / m³. 3 The copolymer rubber (D) has a melt flow rate (MFR) of 0.2 g / 10 min or more and less than 40 g / 10 min, measured at a temperature of 190°C and a load of 2.16 kg. A resin composition according to any one of [1] to [4], comprising 25 parts by mass or less per 100 parts by mass of the total of a crystalline propylene-ethylene block copolymer (A), an ethylene polymer (B), and an inorganic filler (C).

[0013] [6] A molded article formed from any of the resin compositions described in [1] to [5]. [7] The molded article described in [6] is an injection-molded article.

[0014] [8] A molded body as described in [6], which is an automobile part. [9] The molded body described in [8], wherein the automobile part is a bumper. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a resin composition that exhibits a good balance of hardness and spiral flow characteristics, and a molded article formed from the resin composition. [Modes for carrying out the invention]

[0016] The present invention will be described in more detail below. [Resin composition] The resin composition of the present invention is a resin composition comprising a crystalline propylene-ethylene block copolymer (A), an ethylene polymer (B), and an inorganic filler (C), and in one embodiment, the resin composition further comprises a copolymer rubber (D).

[0017] <Crystalline propylene-ethylene block copolymer (A)> The crystalline propylene-ethylene block copolymer (A) according to the present invention satisfies all of the following requirements (1) to (3), preferably further satisfies one or more of the following requirements (4) to (6), and more preferably satisfies all of the following requirements (4) to (6).

[0018] Requirement (1) A block copolymer comprising a crystalline propylene polymer component and a propylene-based copolymer component, wherein the amount of the propylene-based copolymer component is 10 to 50% by mass, the intrinsic viscosity [η] of the propylene-based copolymer component measured in tetralin at 135°C is 2.0 to 6.0 dl / g, and the proportion of ethylene-derived constituent units in the propylene-based copolymer component is 30 to 80 mol%.

[0019] In the crystalline propylene-ethylene block copolymer (A) according to the present invention, the crystalline propylene polymer component is a component consisting only of propylene-derived structural units, or a component consisting of propylene-derived structural units and a small amount of ethylene-derived structural units, and is considered to have crystalline properties and high rigidity. In the crystalline propylene-ethylene block copolymer (A), the crystalline propylene polymer component is insoluble in n-decane at 23°C (D insol ) can be extracted as such.

[0020] The amount of crystalline propylene polymer component in the crystalline propylene-ethylene block copolymer (A) is 50 to 90% by mass, preferably 60 to 90% by mass, more preferably 65 to 85% by mass, and particularly preferably 75 to 83% by mass. The total amount of crystalline propylene polymer component and propylene-based copolymer component is 100% by mass. In the present invention, the amounts of crystalline propylene polymer component and propylene-based copolymer component are those measured by the method used in the examples described later.

[0021] In the crystalline propylene-ethylene block copolymer (A) according to the present invention, the propylene-based copolymer component is a component consisting of propylene-derived structural units and ethylene-derived structural units, and is a component that does not exhibit crystallinity or has low crystallinity, has a low glass transition temperature, exhibits impact resistance, and is thought to exhibit compatibility with other polymers when mixed with other polymers. This is sometimes called a rubber component. In the crystalline propylene-ethylene block copolymer (A), the propylene-based copolymer component is n-decane soluble at 23°C (D sol ) can be extracted as such.

[0022] The amount of propylene-based copolymer component in the crystalline propylene-ethylene block copolymer (A) is 10 to 50% by mass, preferably 10 to 40% by mass, and more preferably 15 to 35% by mass. When the amount of propylene-based copolymer component in the crystalline propylene-ethylene block copolymer (A) falls below the lower limit of the above range, the impact resistance of the molded article obtained from the resin composition containing it tends to decrease. This is thought to be because the absorption energy of the crystalline propylene-ethylene block copolymer (A) against impact decreases as the proportion of propylene-based copolymer component decreases.

[0023] On the other hand, if the amount of propylene copolymer component in the crystalline propylene-ethylene block copolymer (A) exceeds the upper limit of the above range, the high-speed moldability of the resin composition containing it may be poor, and the rigidity (buckling strength) of the molded article obtained from the resin composition may be poor.

[0024] The propylene copolymer component has an intrinsic viscosity [η] measured in tetralin at 135°C of 2.0 to 6.0 dl / g, preferably 2.5 to 6.0 dl / g, more preferably 3.0 to 5.0 dl / g, even more preferably 3.1 to 4.5 dl / g, and particularly preferably 3.2 to 4.0 dl / g. If the intrinsic viscosity exceeds the upper limit of the above range or falls below the lower limit, the impact resistance of the molded article obtained from the resin composition may decrease. The intrinsic viscosity values ​​mentioned above were measured using the method employed in the examples described later.

[0025] The proportion of ethylene-derived structural units in the propylene copolymer component is 30-80 mol%, preferably 35-60 mol%, more preferably 40-55 mol%, and particularly preferably 45-54 mol%. The total of propylene-derived structural units and ethylene-derived structural units in the propylene copolymer component is 100 mol%.

[0026] If the proportion of ethylene-derived constituent units falls below the lower limit of the above range, the impact resistance of the molded article obtained from the resin composition tends to be poor. This is thought to be because a decrease in the ethylene content of the propylene copolymer component lowers the glass transition temperature, increases the degree of crystallinity, and reduces the energy absorbed by impact. Furthermore, if the proportion of ethylene-derived constituent units exceeds the upper limit of the above range, the high-speed moldability of the resin composition may be poor. The proportion of ethylene-derived structural units in the propylene copolymer component is as measured by the method used in the examples described later.

[0027] Requirement (2) The propylene copolymer component contains copolymer component (EP-1) and copolymer component (EP-2), The copolymer component (EP-1) contains 40-80 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] of 1.5-4.0 dl / g as measured in tetralin at 135°C. The copolymer component (EP-2) contains 30-50 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] of 5.0-10 dl / g as measured in tetralin at 135°C.

[0028] Specifically, the propylene-ethylene block copolymer (A) according to the present invention contains a copolymer component (EP-1) which contains 40 to 80 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] of 1.5 to 4.0 dl / g as measured in tetralin at 135°C, and a copolymer component (EP-2) which contains 30 to 50 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] of 5.0 to 10 dl / g as measured in tetralin at 135°C.

[0029] The ethylene-derived structural unit content of the copolymer component (EP-1) is 40 to 80 mol%, preferably 45 to 70 mol%, more preferably 50 to 60 mol%, and particularly preferably 51 to 58 mol%. The propylene-derived structural unit content and ethylene-derived structural unit content of the copolymer component (EP-1) are set to 100 mol%. If the ethylene-derived structural unit content of the copolymer component (EP-1) exceeds the upper limit of the above range, the rigidity and hardness may be insufficient. Furthermore, if the ethylene-derived structural unit content of the copolymer component (EP-1) falls below the lower limit of the above range, the impact resistance may be insufficient.

[0030] The intrinsic viscosity [η] of the copolymer component (EP-1), measured in tetralin at 135°C, is 1.5 to 4.0 dl / g, preferably 1.8 to 3.5 dl / g, and more preferably 2.0 to 3.0 dl / g. If the intrinsic viscosity [η] of the copolymer component (EP-1) exceeds the upper limit of the above range, the melt fluidity of the resin composition may decrease, and the moldability may deteriorate. Conversely, if the intrinsic viscosity [η] of the copolymer component (EP-1) falls below the lower limit of the above range, the rigidity and hardness of the molded article of the resin composition may be insufficient, or the toughness and impact resistance may be insufficient.

[0031] The ethylene-derived structural unit content of the copolymer component (EP-2) is 30 to 50 mol%, preferably 35 to 50 mol%, more preferably 38 to 48 mol%, and particularly preferably 40 to 47 mol%. The combined propylene-derived and ethylene-derived structural unit content of the copolymer component (EP-2) is assumed to be 100 mol%. If the ethylene-derived structural unit content of the copolymer component (EP-2) exceeds the upper limit or falls below the lower limit of the above range, the rigidity and impact resistance may be insufficient.

[0032] The intrinsic viscosity [η] of the copolymer component (EP-2), measured in tetralin at 135°C, is 5.0 to 10 dl / g, preferably 6.0 to 10 dl / g, more preferably 7.0 to 10 dl / g, even more preferably 8.0 to 9.9 dl / g, and particularly preferably 8.5 to 9.8 dl / g. If the intrinsic viscosity [η] of the copolymer component (EP-2) exceeds the upper limit of the above range, the resin composition may lack homogeneity, resulting in molded articles formed from the resin composition having surface irregularities or inferior mechanical properties such as rigidity.

[0033] Requirement (3) The mass ratio (EP-1 / EP-2) of the copolymer component (EP-1) to the copolymer component (EP-2) is between 10 / 1 and 1 / 1. The mass ratio (EP-1 / EP-2) of copolymer component (EP-1) to copolymer component (EP-2) is preferably 8 / 1 to 2 / 1, more preferably 6 / 1 to 3 / 1. If the mass ratio (EP-1 / EP-2) exceeds the upper limit of the above range, the molded article formed from the resin composition may have a poor balance between rigidity and impact resistance. Conversely, if the mass ratio (EP-1 / EP-2) falls below the lower limit of the above range, the fluidity of the resin composition may decrease, potentially leading to molding defects.

[0034] Requirement (4) The melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg is 1-500 g / 10 min. The melt flow rate (MFR; 230°C, 2.16 kg load) of this crystalline propylene-ethylene block copolymer (A) is preferably 10 to 300 g / 10 min, more preferably 20 to 150 g / 10 min, even more preferably 30 to 120 g / 10 min, and particularly preferably 40 to 70 g / 10 min. If this MFR exceeds the upper limit of the above range, burrs may form when resin-accompanied foreign matter is injection molded. Conversely, if this MFR falls below the lower limit of the above range, the fluidity of the resin composition may decrease, resulting in poor moldability.

[0035] Requirement (5) The melting point, as measured by differential scanning calorimetry (DSC), is 155-170°C. The melting point (Tm) of this crystalline propylene-ethylene block copolymer (A) is preferably 158 to 168°C, more preferably 160 to 165°C.

[0036] Specifically, this melting point (Tm) can be determined by measuring it using a differential scanning calorimetry (DSC) under the following conditions, in accordance with JIS K7121, and defining the temperature at the peak of the endothermic peak in step 3 as the melting point. If there are multiple endothermic peaks, the temperature at the peak of the largest endothermic peak is defined as the melting point. (Measurement conditions) Atmosphere: Nitrogen gas atmosphere Sample amount: 5 mg Sample shape: Pressed film (molded at 230°C, thickness 200-400 μm) Step 1: Increase the temperature from 30°C to 240°C at a rate of 10°C / min, and hold for 10 minutes. Step 2: Cool the temperature down to 60°C at a rate of 10°C / minute. Step 3: Increase the temperature to 240°C at a rate of 10°C / min.

[0037] Requirement (6) : The crystalline propylene polymer component 13 The mesopentade fraction (mmmm fraction) measured by 13C-NMR is 96.0–99.9%. Details of the measurement conditions, etc., are described in the Examples section below. The mesopentade fraction (mmmm fraction) is preferably 97.0 to 99.9%, more preferably 97.6 to 99.9%. When the crystalline propylene-ethylene block copolymer (A) according to the present invention satisfies requirement (6), the stereoregularity of the crystalline propylene polymer component is high, resulting in a high degree of crystallinity during crystallization. For this reason, the molded article formed from the resin composition tends to have high rigidity, which is preferable.

[0038] The crystalline propylene-ethylene block copolymer (A) according to the present invention preferably satisfies at least one of the following requirements (7) to (8), and more preferably satisfies both requirements (7) to (8).

[0039] Requirement (7): The difference between the ethylene-derived constituent unit content of copolymer component (EP-1) and the ethylene-derived constituent unit content of copolymer component (EP-2), ΔC2, is preferably 1.0 to 13 mol%, and more preferably 3.5 to 11 mol%. When the crystalline propylene-ethylene block copolymer (A) according to the present invention satisfies requirement (7), it is preferable because it exhibits an excellent balance between room temperature shock and low temperature shock.

[0040] Requirement (8): The difference Δη between the intrinsic viscosity [η] of copolymer component (EP-1) measured in tetralin at 135°C and the intrinsic viscosity [η] of copolymer component (EP-2) measured in tetralin at 135°C is preferably 5.0 to 8.5 dl / g, more preferably 5.8 to 8.5 dl / g, and even more preferably 6.3 to 8.0 dl / g. When the crystalline propylene-ethylene block copolymer (A) according to the present invention satisfies requirement (8), it is preferable because it can achieve both improved appearance and improved surface impact resistance.

[0041] <Method for producing crystalline propylene-ethylene block copolymer (A)> The crystalline propylene-ethylene block copolymer (A) used in the present invention described above can be suitably produced by a method comprising, for example, a step (1) of polymerizing propylene to produce a crystalline propylene polymer component (1), a step (2) of copolymerizing propylene and ethylene in the presence of the crystalline propylene polymer component (1) to produce a copolymer component (EP-1), and a step (3) of copolymerizing propylene and ethylene in the presence of the crystalline propylene polymer component (1) and the copolymer component (EP-1) to produce a copolymer component (EP-2).

[0042] In steps (1), (2), and (3), homopolymerization of propylene or copolymerization of propylene and ethylene is usually carried out in the presence of a metallocene compound-containing catalyst or a Ziegler-Natta catalyst, preferably in the presence of a Ziegler-Natta catalyst. Polymerization in the presence of a Ziegler-Natta catalyst easily yields a crystalline propylene-ethylene block copolymer (A) with a broad molecular weight distribution and good moldability.

[0043] (Catalyst containing metallocene compound) Examples of metallocene compound-containing catalysts include metallocene catalysts comprising a metallocene compound, at least one compound selected from organometallic compounds, organoaluminum oxy compounds, and compounds capable of forming ion pairs in reaction with metallocene compounds, and optionally a particulate support. Preferably, metallocene catalysts capable of stereoregular polymerization such as isotactic are used. Among the metallocene compounds, crosslinkable metallocene compounds exemplified in International Publication No. 01 / 27124 and metallocene compounds described in sections

[0068] to

[0076] of International Publication No. 2010 / 74001 are preferred. Furthermore, compounds that form ion pairs in reaction with organometallic compounds, organoaluminum oxy compounds, and transition metal compounds, and optionally a particulate support, can be used without limitation from compounds disclosed in International Publication No. 01 / 27124, Japanese Patent Application Publication No. 11-315109, etc.

[0044] (Ziegranata catalyst) Propylene-based block copolymers can be produced using a highly stereoregular Ziegler-Natta catalyst. Various known catalysts can be used as the highly stereoregular Ziegler-Natta catalyst. For example, a catalyst can be used comprising (a) a solid titanium catalyst component containing magnesium, titanium, a halogen, and an electron donor, (b) an organometallic compound catalyst component, and (c) an organosilicon compound catalyst component having at least one group selected from the group consisting of cyclopentyl, cyclopentenyl, cyclopentadienyl, and derivatives thereof. This catalyst component can be produced by known methods, for example, by the methods described in International Publication No. 2010 / 74001, sections

[0078] to

[0094] .

[0045] When polymerizing propylene using a catalyst consisting of the solid titanium catalyst component (a), organometallic compound catalyst component (b), and organosilicon compound catalyst component (c) as described above, prepolymerization can also be performed beforehand. Prepolymerization involves polymerizing an olefin in the presence of the solid titanium catalyst component (a), the organometallic compound catalyst component (b), and optionally the organosilicon compound catalyst component (c).

[0046] As the olefin for prepolymerization, α-olefins having 2 to 8 carbon atoms can be used. Specifically, linear olefins such as ethylene, propylene, 1-butene, and 1-octene; branched olefins such as 3-methyl-1-butene, 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, and 3-ethyl-1-hexene can be used. These may also be copolymerized.

[0047] Prepolymerization should be carried out so that approximately 0.1 to 1000 g, preferably 0.3 to 500 g, of polymer is produced per 1 g of solid titanium catalyst component (a). If the amount of prepolymerization is too large, the efficiency of (co)polymer formation in the main polymerization may decrease. In prepolymerization, the catalyst can be used at a considerably higher concentration than the catalyst concentration in the system during the main polymerization.

[0048] For this polymerization, it is desirable to use solid titanium catalyst component (a) (or prepolymerization catalyst) in an amount of approximately 0.0001 to 50 millimoles, preferably approximately 0.001 to 10 millimoles, of titanium atoms per liter of polymerization volume. For organometallic compound catalyst component (b), it is desirable to use an amount of approximately 1 to 2000 moles, preferably approximately 2 to 500 moles, of metal atoms per mole of titanium atoms in the polymerization system. For organosilicon compound catalyst component (c), it is desirable to use an amount of approximately 0.001 to 50 moles, preferably approximately 0.01 to 20 moles, of organometallic compound catalyst component (b) per mole of metal atoms.

[0049] Polymerization may be carried out by gas-phase polymerization, solution polymerization, suspension polymerization, or any other liquid-phase polymerization method, and steps (1), (2), and (3) may be carried out separately. Furthermore, it may be carried out in a continuous or semi-continuous manner, and each of the above steps may be divided and carried out in multiple polymerizers, for example, 2 to 10 polymerizers. Industrially, polymerization is most preferably carried out in a continuous manner.

[0050] Inert hydrocarbons may be used as the polymerization medium, or liquid propylene may be used as the polymerization medium. The polymerization conditions for each stage are appropriately selected within the range of atmospheric pressure to 10 MPa (gauge pressure), preferably 0.2 to 5 MPa (gauge pressure), with a polymerization temperature of approximately -50 to +200°C, preferably approximately 20 to 100°C, and a polymerization pressure of atmospheric pressure to 10 MPa (gauge pressure).

[0051] In the manufacturing method of the present invention, for example, steps (1), (2), and (3) are carried out continuously in a reaction apparatus in which three or more polymerizers are connected in series. Alternatively, step (1) may be carried out in each polymerization apparatus using a polymerization apparatus in which two or more reactors are connected in series, or step (2) may be carried out in each polymerization apparatus using a polymerization apparatus in which two or more reactors are connected in series, or step (3) may be carried out in each polymerization apparatus using a polymerization apparatus in which two or more reactors are connected in series.

[0052] Step (1) is a step in which propylene and optionally ethylene are polymerized at a polymerization temperature of 0 to 100°C and a polymerization pressure of atmospheric pressure to 5 MPa gauge pressure, and a crystalline propylene polymer component (1) is produced by supplying either no ethylene or a small amount of ethylene compared to the amount of propylene fed. The crystalline propylene polymer component (1) is the crystalline portion of the crystalline propylene-ethylene block copolymer (A), and the portion insoluble in 23°C n-decane (D) is obtained from the crystalline propylene-ethylene block copolymer (A). insol It can be extracted as a component that is usually composed mainly of propylene-derived structural units, possesses crystalline properties, and is thought to exhibit high rigidity. Furthermore, if necessary, a chain transfer agent such as hydrogen gas may be introduced to adjust the intrinsic viscosity [η] of the crystalline propylene polymer component (1) produced in step (1).

[0053] Steps (2) and (3) are steps for producing a propylene copolymer component, of which step (2) is a step for producing copolymer component (EP-1) and step (3) is a step for producing copolymer component (EP-2). In the present invention, the propylene copolymer component consists of copolymer component (EP-1) and copolymer component (EP-2). The propylene copolymer component is a component of the crystalline propylene-ethylene block copolymer (A) that does not exhibit crystallinity or has low crystallinity, and is a portion (D) that is soluble in n-decane at 23°C from the crystalline propylene-ethylene block copolymer (A). solIt can be extracted as a polymer and is typically composed mainly of propylene and ethylene-derived structural units. Propylene copolymer components have a low glass transition temperature, exhibit impact resistance, and are thought to exhibit compatibility with other polymers when mixed with them. This is sometimes referred to as a rubber component.

[0054] Step (2) is a step in which propylene and ethylene are copolymerized in the presence of a crystalline propylene polymer component (1) at a polymerization temperature of 0 to 100°C and a polymerization pressure of atmospheric pressure to 5 MPa gauge pressure, and the copolymer component (EP-1) is produced from among the propylene-based copolymer components that do not exhibit crystallinity or have low crystallinity by making the ratio of the amount of ethylene feed to the amount of propylene feed larger than in step (1). Furthermore, if necessary, a chain transfer agent, such as hydrogen gas, may be introduced to adjust the intrinsic viscosity [η] of the copolymer component (EP-1).

[0055] Step (3) is a step in which propylene and ethylene are copolymerized at a polymerization temperature of 0 to 100°C and a polymerization pressure of atmospheric pressure to 5 MPa gauge pressure in the presence of the crystalline propylene polymer component produced in step (1) and the copolymer component (EP-1) produced in step (2). This step is used to produce copolymer component (EP-2) from among the propylene-based copolymer components that do not exhibit crystallinity or have low crystallinity.

[0056] In requirement (1), the amount of propylene-based copolymer component in the crystalline propylene-ethylene block copolymer (A) is the ratio (mass%) of crystalline propylene polymer component (1) to the total of crystalline propylene polymer component (1) and propylene-based copolymer components (total of copolymer component (EP-1) and copolymer component (EP-2)). Therefore, it can be adjusted, for example, by adjusting the polymerization time of each step. In other words, the amount of propylene-based copolymer component can be increased by increasing the proportion of the polymerization time of steps (2) and (3) to the total polymerization time.

[0057] The ethylene content in requirement (1) or (2) can be adjusted by adjusting the ratio of ethylene feed to propylene feed when performing step (2) or step (3), respectively. In other words, increasing this ratio of feed will increase the ethylene content, and decreasing this ratio will decrease the ethylene content.

[0058] The intrinsic viscosity [η] in requirement (1) or (2) can be adjusted by the amount of hydrogen gas used as a chain transfer agent during step (2) or step (3), respectively. In other words, the intrinsic viscosity [η] can be decreased by increasing the ratio of hydrogen gas feed to monomer feed, and the intrinsic viscosity [η] can be increased by decreasing the ratio of hydrogen gas feed to monomer feed.

[0059] The mass ratio (EP-1 / EP-2) of copolymer component (EP-1) to copolymer component (EP-2) in requirement (3) can be adjusted, for example, by adjusting the polymerization time of each step. In other words, the mass ratio (EP-1 / EP-2) can be increased by increasing the proportion of the polymerization time of step (2) to the total polymerization time. Conversely, the mass ratio (EP-1 / EP-2) can be decreased by increasing the proportion of the polymerization time of step (3) to the total polymerization time.

[0060] Requirements (4) and (5), namely the MFR and melting point of the crystalline propylene-ethylene block copolymer (A), can be adjusted by adjusting the ratio of hydrogen gas feed as a chain transfer agent to the amount of monomer feed (i.e., propylene in the case of propylene homopolymerization, and propylene and ethylene in the case of copolymerization) during steps (1) to (3). In other words, increasing this ratio can increase the MFR and decrease the melting point, while decreasing this ratio can decrease the MFR and increase the melting point.

[0061] Requirement (6), namely the melting point of the crystalline propylene-ethylene block copolymer (A) and the mesopentad fraction (mmmm fraction) of the crystalline propylene polymer component, can be adjusted by adjusting the catalyst and external donor system used for polymerization.

[0062] After polymerization is complete, post-treatment steps such as known catalyst deactivation steps, catalyst residue removal steps, and drying steps may be performed as needed. This manufacturing method makes it possible to produce a crystalline propylene-ethylene block copolymer (A) suitable for resin compositions that can yield molded articles with excellent appearance and impact resistance. The reason for this is not entirely clear, but it is thought that the low molecular weight polymerized rubber component, which has a relatively high content of ethylene-derived constituent units and excellent impact modification performance, and the high molecular weight polymerized rubber component, which has excellent appearance improvement effects, are well dispersed at the polymerization powder stage, resulting in these effects.

[0063] In addition, the crystalline propylene-ethylene block copolymer (A) according to the present invention may contain a structural unit derived from biomass-derived propylene and / or a structural unit derived from biomass-derived ethylene. Further, it may contain a structural unit derived from chemically recycled propylene and / or a structural unit derived from chemically recycled ethylene. The monomers (propylene and / or ethylene) constituting the polymer may be only biomass-derived monomers (propylene and / or ethylene), only chemically recycled monomers (propylene and / or ethylene), only fossil fuel-derived monomers (propylene and / or ethylene), both biomass-derived monomers (propylene and / or ethylene) and fossil fuel-derived monomers (propylene and / or ethylene), both biomass-derived monomers (propylene and / or ethylene) and chemically recycled monomers (propylene and / or ethylene), both biomass-derived monomers (propylene and / or ethylene) and chemically recycled monomers (propylene and / or ethylene), or may contain all of biomass-derived monomers (propylene and / or ethylene), chemically recycled monomers (propylene and / or ethylene) and fossil fuel-derived monomers (propylene and / or ethylene).

[0064] Biomass-derived propylene and biomass-derived ethylene are monomers made from any renewable natural raw materials such as plant-derived or animal-derived, including fungi, yeast, algae and bacteria, and their residues, and contain 14C isotope as carbon at a ratio of about 1×10 -12 and the biomass carbon concentration (pMC) measured in accordance with ASTM D6866 is about 100 (pMC). Biomass-derived propylene and biomass-derived ethylene can be obtained, for example, by conventionally known methods.

[0065] It is preferable from the viewpoint of reducing environmental impact that the crystalline propylene-ethylene block copolymer (A) contains constituent units derived from biomass-derived propylene and / or biomass-derived ethylene. If the polymer production conditions such as polymerization catalyst and polymerization temperature are equivalent, even if the raw material propylene is a propylene-based block copolymer containing biomass-derived propylene and / or biomass-derived ethylene, the 14C isotope is 1 × 10⁻¹⁶. -12 Aside from the proportions it contains, its molecular structure is equivalent to that of propylene-ethylene block polymers, which consist of fossil fuel-derived propylene and fossil fuel-derived ethylene. Therefore, its performance is considered to be the same as these.

[0066] It is preferable from the viewpoint of reducing environmental impact (mainly waste reduction) that the crystalline propylene-ethylene block copolymer (A) contains chemically recycled propylene and chemically recycled ethylene. Even if the raw material propylene and / or ethylene contains chemically recycled monomers, the chemically recycled propylene and / or chemically recycled ethylene are monomers obtained by depolymerizing, thermally decomposing, etc., polymers such as waste plastics back into monomer units such as ethylene, and monomers produced using such monomers as raw materials. Therefore, if the polymer production conditions such as polymerization catalyst, polymerization process, and polymerization temperature are the same, the molecular structure is equivalent to that of a crystalline propylene-ethylene block copolymer made from fossil fuel-derived monomers. Consequently, the performance is also considered to be the same.

[0067] <Ethylene polymer (B)> The ethylene-based polymer (B) according to the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, with a density of 915 to 980 kg / m³. 3 The melt flow rate (MFR; 190°C, 2.16kg load) measured at a temperature of 190°C and a load of 2.16kg is 0.1 to 30g / 10min.

[0068] When the ethylene-based polymer (B) is a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, examples of α-olefins having 4 to 12 carbon atoms include butene-1, pentene-1, hexene-1, heptene-1, octene-1, decene-1, etc., and preferably butene-1, hexene-1, and octene-1. When the ethylene-based polymer (B) is a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, the content of ethylene-derived constituent units is 51 mol% or more and less than 100 mol%.

[0069] The density of the ethylene polymer (B) is preferably 910 to 965 kg / m³. 3 Comfortably 910-950 kg / m 3 More preferably 911-945 kg / m 3 The MFR (at 190°C, 2.16 kg load) of the ethylene polymer (B) is preferably 0.1 to 20 g / 10 min, more preferably 0.5 to 10 g / 10 min, and even more preferably 1 to 9 g / 10 min. When the ethylene polymer (B) has such MFR and density, it is preferable from the viewpoint of compatibility with the crystalline propylene-ethylene block copolymer (A). Ethylene polymers (B) can be produced by polymerizing ethylene alone using conventionally known methods, or by copolymerizing ethylene with an α-olefin having 4 to 12 carbon atoms, or commercially available products may be used.

[0070] <Inorganic filler (C)> The inorganic filler (C) according to the present invention is not particularly limited and any known inorganic filler can be used, but examples include talc, mica, calcium carbonate, barium sulfate, glass fiber, gypsum, magnesium carbonate, magnesium oxide, titanium oxide, iron oxide, and even metal powders such as zinc, copper, iron, and aluminum, or carbon fiber, which can be used alone or in mixtures. Among these, talc, mica, calcium carbonate, and glass fiber are preferred, and talc is particularly preferred. The average particle size of the talc is preferably in the range of 1 to 5 μm, more preferably 2.5 to 4.5 μm, based on volume measured by laser diffraction. The inorganic filler (C) may be used alone or in combination of two or more types.

[0071] <Copolymer rubber (D)> In addition to the above-mentioned crystalline propylene-ethylene block copolymer (A), ethylene polymer (B), and inorganic filler (C), the resin composition of the present invention may optionally contain copolymer rubber (D). The copolymer rubber (D) according to the present invention is a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, and has a density of 850 to 910 kg / m³. 3 The melt flow rate (MFR; 190°C, 2.16kg load) measured at a temperature of 190°C and a load of 2.16kg is between 0.2g / 10min and less than 40g / 10min.

[0072] Examples of α-olefins having 4 to 12 carbon atoms include butene-1, pentene-1, hexene-1, heptene-1, octene-1, and decene-1, with butene-1, hexene-1, and octene-1 being preferred. Examples of copolymer rubber (D) include ethylene-1-butene random copolymer rubber, ethylene-1-hexene random copolymer rubber, and ethylene-1-octene random copolymer rubber, with ethylene-1-octene random copolymer rubber or ethylene-1-butene random copolymer rubber being preferred. Alternatively, two or more types of ethylene-α-olefin random copolymer rubbers may be used in combination.

[0073] The density of copolymer rubber (D) is preferably 850-895 kg / m³. 3 A more preferable 855-875 kg / m 3 More preferably 862-874 kg / m 3 The MFR (at 190°C and a 2.16 kg load) of copolymer rubber (D) is preferably 0.2 to 20 g / 10 min, more preferably 0.2 to 10 g / 10 min, and even more preferably 1 to 9 g / 10 min.

[0074] When the copolymer rubber (D) has such MFR and density, it is preferable from the viewpoint of impact resistance and other properties of the molded article formed from the resin composition. Copolymer rubber (D) can be produced by copolymerizing ethylene with an α-olefin having 4 to 12 carbon atoms using conventionally known methods, or a commercially available product may be used.

[0075] <Other ingredients (E)> In addition to the components (A) to (C) described above and optionally component (D), the resin composition of the present invention may further optionally contain other components (E) to the extent that it does not impair the purpose of the present invention.

[0076] Other components (E) include, for example, nucleating agents, heat stabilizers, antistatic agents, weather stabilizers, light stabilizers, anti-aging agents, antioxidants, fatty acid metal salts, softeners, dispersants, fillers, colorants, lubricants, pigments, and various other additives. These additives may be used individually or in combination. When multiple types of additives are used, the mixing order of the additives is arbitrary; they may be mixed simultaneously, or a multi-stage mixing method may be employed, such as mixing some components before mixing others.

[0077] <Resin composition> The resin composition of the present invention contains, when the total of the above-mentioned crystalline propylene-ethylene block copolymer (A), ethylene polymer (B), and inorganic filler (C) is 100 parts by mass, 50 to 94 parts by mass of crystalline propylene-ethylene block copolymer (A), 1 to 25 parts by mass of ethylene polymer (B), and 5 to 25 parts by mass of inorganic filler (C). Preferably, the resin composition of the present invention contains, when the total of the crystalline propylene-ethylene block copolymer (A), ethylene polymer (B), and inorganic filler (C) is 100 parts by mass, 55 to 89 parts by mass of crystalline propylene-ethylene block copolymer (A), 1 to 20 parts by mass of ethylene polymer (B), and 10 to 25 parts by mass of inorganic filler (C). More preferably, it contains 60 to 84 parts by mass of crystalline propylene-ethylene block copolymer (A), 1 to 15 parts by mass of ethylene polymer (B), and 15 to 25 parts by mass of inorganic filler (C).

[0078] The resin composition of the present invention may further contain the copolymer rubber (D) described above. The content of copolymer rubber (D) is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 18 parts by mass or less, and particularly preferably 17 parts by mass or less, based on 100 parts by mass of the total of the crystalline propylene-ethylene block copolymer (A), the ethylene polymer (B), and the inorganic filler (C). When the resin composition of the present invention contains copolymer rubber (D), the lower limit of the content of copolymer rubber (D) is, for example, 0.1 parts by mass, preferably 1 part by mass, and more preferably 2 parts by mass, based on 100 parts by mass of the total of the crystalline propylene-ethylene block copolymer (A), the ethylene polymer (B), and the inorganic filler (C). When the resin composition of the present invention contains copolymer rubber (D) in such amounts, the impact resistance of the molded article obtained from the resin composition can be improved.

[0079] The resin composition of the present invention may further contain the above-mentioned other component (E) to the extent that it does not impair the purpose of the present invention. The content of the other component (E) in the resin composition of the present invention is, for example, 10 parts by mass or less, preferably 5 parts by mass or less, and more preferably 3 parts by mass or less, based on 100 parts by mass of the total of the crystalline propylene-ethylene block copolymer (A), the ethylene polymer (B), and the inorganic filler (C).

[0080] The resin composition of the present invention can be manufactured by blending the above-mentioned components in a desired proportion. Specifically, the resin composition of the present invention can be obtained by simultaneously or sequentially mixing or melt-kneading the above-mentioned crystalline propylene-ethylene block copolymer (A), ethylene polymer (B), and inorganic filler (C), along with copolymer rubber (D) and other components (E) using a mixing device such as a Banbury mixer, single-screw extruder, twin-screw extruder, or high-speed twin-screw extruder.

[0081] The resin composition of the present invention does not particularly limit its properties, but it is desirable that it has fluidity suitable for injection molding, preferably a melt flow rate (MFR) of 10 to 50 g / 10 min, more preferably 15 to 45 g / 10 min, measured at a temperature of 230°C and a load of 2.16 kg. In addition, the spiral flow, measured by the method specified in the examples described later, is preferably 130 to 160 cm, more preferably 135 to 150 cm.

[0082] The resin composition of the present invention can be molded by conventionally known molding methods for molding resin compositions, thereby enabling the production of molded articles. The propylene polymer composition of the present invention is particularly suitable for use in injection molding, extrusion molding, and the like.

[0083] Such resin compositions of the present invention can be suitably used in various fields such as automotive interior and exterior parts, home appliance parts, and food containers. Molded articles made from the resin compositions of the present invention exhibit mechanical properties suitable for use in automotive interior and exterior parts, etc., and have particularly excellent rigidity, as well as suppressing flow mark formation and having a superior appearance.

[0084] Molded body The molded article of the present invention is a molded article formed from the resin composition of the present invention described above. The molded article of the present invention is preferably an injection molded article, an extruded article, or a press molded article, and more preferably an injection molded article.

[0085] The molded articles of the present invention can be suitably used for various applications. In particular, they have excellent mechanical properties such as hardness, impact resistance, and rigidity, as well as excellent spiral flow identification during injection molding, making them less prone to flow marks and giving them a superior appearance. Therefore, they can be suitably used for automotive parts such as instrument panels, door trims, pillars and other automotive interior parts, and bumpers and other automotive exterior parts.

[0086] Other automotive parts applications include, for example, exterior automotive parts such as side moldings and aerodynamic undercovers, body panels such as fenders, door panels, and steps, and engine peripheral parts such as engine covers, fans, and fan shrouds.

[0087] As food containers, they can be used for, for example, tableware, retort containers, freezer storage containers, retort pouches, microwave-safe containers, frozen food containers, frozen dessert cups, cups, beverage bottles, and other food containers, retort containers, bottle containers, etc.

[0088] Other applications of the molded articles of the present invention include, for example, housings for home appliances, wire insulation materials, insulators for high-voltage power lines, tubes for cosmetic and perfume sprays, medical tubes, infusion tubes, pipes, wire harnesses, interior materials for motorcycles, railway vehicles, aircraft, ships, etc., instrument panel surfaces, door trim surfaces, rear package trim surfaces, ceiling surfaces, rear pillar surfaces, seat back garnishes, console boxes, armrests, airbag case lids, shift knobs, assist grips, side step mats, reclining covers, trunk seats, seat belt buckles, molding materials such as inner and outer moldings, roof moldings, belt moldings, door seals, body seals, and other automotive sealing materials, glass run channels, mudguards, kicking plates, step mats, license plate housings, automotive hose components, air duct hoses, air duct covers, air intake pipes, air dam skirts, timing belt cover seals, bonnet cushions, door cushions, and other automotive interior and exterior materials, vibration-damping tires, static tires, racing tires, radio-controlled car tires, and other special tires, packing, etc. Automotive dust covers, lamp seals, automotive boot materials, rack and pinion boots, timing belts, wire harnesses, grommets, emblems, air filter gaskets, surface materials for furniture, footwear, clothing, bags, building materials, etc., building sealants, waterproof sheets, building material sheets, building material gaskets, building material window films, steel core protection components, gaskets, doors, door frames, window frames, moldings, baseboards, opening frames, etc., flooring materials, ceiling materials, wallpaper, health products (e.g., anti-slip mats / sheets, fall prevention films / mats / sheets), health equipment components, shock-absorbing pads, protectors / protective gear ( Examples: helmets, guards), sports equipment (e.g., sports grips, protectors), sports protective gear, rackets, mouthguards, balls, golf balls, transport equipment (e.g., shock-absorbing transport grips, shock-absorbing sheets), vibration-damping pallets, shock-absorbing dampers, insulators, shock-absorbing materials for footwear, shock-absorbing foam, shock-absorbing films and other shock-absorbing materials, grip materials, general merchandise, toys, shoe midsoles, insoles, outsoles, sandals, suction cups, toothbrushes, flooring materials, gymnastics mats, power tool components, agricultural machinery components, heat dissipation materials, transparent substrates, soundproofing materials, cushioning materials,Examples include electric wires and cables, shape memory materials, gaskets, packing materials for applications requiring high-temperature processing such as high-pressure steam sterilization, industrial sealing materials, industrial sewing machine tables, license plate housings, cap liners such as PET bottle cap liners, stationery, office supplies, OA printer legs, fax machine legs, sewing machine legs, motor support mats, audio vibration damping materials and other precision equipment and OA equipment support components, heat-resistant packing for OA use, clothing cases, and desk mats. [Examples]

[0089] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0090] (Measurement method and evaluation method) (1) Polymer or resin composition: [Melt Flow Rate (MFR)] The melt flow rate (MFR) was measured under a 2.16 kg load according to ASTM D-1238. The measurement temperature was 230°C for propylene-based polymers such as crystalline propylene-ethylene block copolymer (A) and resin compositions containing propylene-based polymers, and 190°C for ethylene-based polymers such as ethylene-based polymers (B) and copolymer rubber (D).

[0091] [Intrinsic viscosity [η]] Approximately 25 mg of the sample was dissolved in 25 ml of tetralin, and the specific viscosity η was measured in an oil bath at 135°C. sp The specific viscosity η was measured. After diluting this tetralin solution by adding 5 ml of tetralin solvent, the specific viscosity η was measured in the same manner. sp The following was measured. This dilution procedure was repeated two more times, and the η obtained by extrapolating the concentration (C) to 0 was obtained. sp The value of / C was determined as the intrinsic viscosity, and this value was defined as the intrinsic viscosity [η].

[0092] [Percentage of ethylene-derived constituent units] Regarding the measurement sample, under the following conditions: 13 13C-NMR measurements were performed. ( 13 C-NMR measurement conditions) Measurement device: JEOL LA400 nuclear magnetic resonance spectrometer Measurement mode: BCM (Bilevel Complete decoupling) Observation frequency: 100.4MHz Observation range: 17006.8Hz Pulse width: 45° of the C nucleus (7.8 μsec) Pulse repetition time: 5 seconds Sample tube: 5mmφ Sample tube rotation speed: 12Hz Total number of times: 20,000 Measurement temperature: 125℃ Solvent: 1,2,4-Trichlorobenzene: 0.35 ml / Deuterated benzene: 0.2 ml Sample quantity: approximately 40 mg

[0093] From the spectra obtained by measurement, the ratio of monomer chain distributions (triad distributions) was determined in accordance with the following reference (1), and the mole fraction (mol%) of ethylene-derived constituent units (hereinafter referred to as E(mol%)) and the mole fraction (mol%) of propylene-derived constituent units (hereinafter referred to as P(mol%)) in the measurement sample were calculated. From the obtained E(mol%) and P(mol%), the proportion (mass%) of ethylene-derived constituent units (hereinafter referred to as E(mass%)) in the measurement sample was calculated according to the following formula (Equation 1).

[0094] Literature (1): Kakugo, M.; Naito, Y.; Mizunuma, K.; Miyatake, T., Carbon-13 NMR determination of monomer sequence distribution in ethylene-propylene copolymers prepared with delta-titanium trichloride-diethylaluminum chloride. Macromolecules 1982, 15, (4), 1150-1152 E(mass%)=E(mol%)×28×100 / [P(mol%)×42+E(mol%)×28](Formula 1)

[0095] [Melting point] In accordance with JIS K7121, measurements were performed using a differential scanning calorimeter (DSC, PerkinElmer (Diamond DSC)) under the following conditions, and the temperature at the peak of the endothermic peak in step 3 was defined as the melting point (Tm). If there were multiple endothermic peaks, the temperature at the peak of the largest endothermic peak was defined as the melting point (Tm). (Measurement conditions) Atmosphere: Nitrogen gas atmosphere Sample amount: 5 mg Sample shape: Pressed film (molded at 230°C, thickness 200-400 μm) Step 1: Increase the temperature from 30°C to 240°C at a rate of 10°C / min, and hold for 10 minutes. Step 2: Cool the temperature down to 60°C at a rate of 10°C / minute. Step 3: Increase the temperature to 240°C at a rate of 10°C / min.

[0096] [Mesopentad fraction (mmmm fraction)] Mesopentad fraction (mmmm fraction, %), which is one of the indicators of stereoregularity of polymers and indicates their microtacticity, is a value determined by attribution based on Macromolecules 8,687 (1975) by A. Zambelli et al. for propylene homopolymers. 13 The mesopentade fraction was measured by 13C-NMR under the following conditions, and the mesopentade fraction was calculated as (peak area at 21.7 ppm) / (peak area at 19-23 ppm) × 100. (Measurement conditions) Device: Bruker BioSpin AVANCE III cryo-500 type nuclear magnetic resonance spectrometer Nucleus for measurement: 13 C(125MHz) Measurement mode: Single-pulse proton broadband decoupling Pulse width: 45° (5.00 microseconds) Repeat time: 5.5 seconds Total number of times: 256 Measurement solvent: o-dichlorobenzene / deuterated benzene (80 / 20 vol%) mixed solvent Sample concentration: 50 mg / 0.6 mL Measurement temperature: 120℃ Chemical shift standard: 21.59 ppm

[0097] [Amount of crystalline propylene polymer component and amount of propylene-based copolymer component] 23℃ n-decane insoluble portion (D insol ) consists of a crystalline propylene polymer component, and a 23°C n-decane soluble portion (D sol The amount (mass%) of each component was measured using the following method, with ) as the propylene copolymer component. 5 g of the sample was mixed with 200 ml of n-decane and heated at 145°C for 30 minutes to dissolve and obtain solution (1). Next, solution (1) was cooled to 23°C over approximately 2 hours, and then left to stand at 23°C for 30 minutes to obtain solution (2) containing precipitate (α). Subsequently, precipitate (α) was filtered from solution (2) using a filter cloth with a mesh size of approximately 15 μm, and after drying precipitate (α), the mass of precipitate (α) was measured. The mass of precipitate (α) was divided by the sample mass (5 g) to obtain the 23°C n-decane insoluble portion (D insol The proportion of crystalline propylene polymer component (mass%) was determined. Furthermore, the solution (2) from which precipitate (α) was filtered was placed in approximately three times the volume of acetone to precipitate the components dissolved in n-decane, thereby obtaining precipitate (β). Subsequently, precipitate (β) was filtered using a glass filter (G2, mesh size approximately 100-160 μm), dried, and the mass of precipitate (β) was measured. The mass of precipitate (β) divided by the sample mass (5 g) was used to determine the n-decane soluble portion (D) at 23°C. sol The proportion of the propylene copolymer component was used to determine the amount (mass%) of the propylene copolymer component.

[0098] (2) Evaluation of the molded product: [Flexural modulus] In accordance with JIS K7171, test specimens were prepared from the resin compositions obtained in the examples and comparative examples, and the flexural modulus was measured under the following conditions. (Measurement conditions) Test specimen: 10mm (width) x 80mm (length) x 4.0mm (thickness) Bending speed: 2 mm / min Bending span: 64mm

[0099] [Charpy impact strength] In accordance with JIS K7111, test specimens were prepared from the resin compositions obtained in the examples and comparative examples, and the notched Charpy impact strength was measured under the following conditions. (Measurement conditions) Temperature: -30°C and 23°C Test specimen: 10mm (width) x 80mm (length) x 4mm (thickness) The notch is a machining process.

[0100] [Rockwell hardness] Measurements were taken using the R scale in accordance with JIS K7202. [High-speed surface impact test] At -30°C, a load cell-equipped impinger with a 1 / 2-inch tip diameter was impacted at a speed of 5 m / s onto a 3 mm thick rectangular plate specimen. A support stand with a 3-inch tip diameter (receiving diameter) was used on the back of the specimen. The total absorbed energy (J) of the specimen was then determined.

[0101] [Spiral Flow] A mold for measuring resin flow length was used, which had a spiral channel with a thickness of 3 mm and a width of 10 mm. The measurement was performed under the spiral flow measurement injection molding conditions described below. Injection molding machine: J110AD, manufactured by Japan Steel Works Ltd. Cylinder temperature: 230℃ Mold temperature: 40℃ Injection time: 10 seconds (no holding pressure setting)

[0102] [Preparation Example 1] (Preparation of Solid Titanium Catalyst Component) According to the preparation of <Solid Titanium Catalyst Component (i-1)> in Production Example 3 of Japanese Patent Publication No. 2020-114909, a solid titanium catalyst component containing 1.3% by weight of titanium, 20% by weight of magnesium, 13.8% by weight of diisobutyl phthalate, and 0.8% by weight of diethyl phthalate was obtained.

[0103] [Preparation Example 2] (Preparation of Prepolymerization Catalyst) 112.0 g of the solid titanium catalyst component synthesized in Preparation Example 1, 83.0 mL of triethylaluminum, 23.6 mL of diethylaminotriethoxysilane, and 10 L of heptane were placed in a 20 L autoclave equipped with a stirrer. Maintaining an internal temperature of 15-20°C, 672 g of propylene was added, and the mixture was reacted with stirring for 120 minutes. After polymerization was complete, the solid component was allowed to settle, and the supernatant was removed and washed twice with heptane. The obtained prepolymerization catalyst was resuspended in purified heptane, and the concentration of the solid titanium catalyst component was adjusted by adding heptane to 0.7 g / L. This prepolymerization catalyst contained 6 g of polypropylene per gram.

[0104] [Manufacturing Example 1] (Manufacturing of Propylene-Ethylene Block Copolymer (A-1)) <Process (1)> 300 L of propylene was charged into a 1000 L capacity vessel polymerizer equipped with a stirrer. While maintaining this liquid level, propylene was continuously supplied at a rate of 118 kg / h, the pre-polymerization catalyst obtained in Preparation Example 2 as a solid catalyst component at a rate of 1.2 g / h, triethylaluminum at a rate of 13.3 mL / h, diethylaminotriethoxysilane at a rate of 5.1 mL / h, and hydrogen at a rate of 6.6 mol% in the gas phase. Polymerization was carried out at a temperature of 73.5 °C, a pressure of 3.39 MPa-G, and an average residence time of 1.1 hours.

[0105] The obtained slurry was sent to a second polymerizer, a vessel equipped with a stirrer with a capacity of 500 L, and further polymerization was carried out. In the second polymerizer, 300 L of propylene was charged, and while maintaining this liquid level, propylene was supplied at a rate of 14.5 kg / h, dicyclopentadienyldichlorotitanium at a rate of 3.2 g / h, and hydrogen was continuously supplied so that the hydrogen concentration in the gas phase was 7.3 mol%. Polymerization was carried out at a temperature of 73.5°C, a pressure of 3.27 MPa-G, and an average residence time of 1.0 hour to obtain homopropylene polymer (H-1).

[0106] <Process (2A)> The obtained homopropylene polymer (H-1) slurry was sent to a 500L capacity vessel polymerizer with a stirrer (No. 3 polymerizer) for further polymerization. In No. 3 polymerizer, 260L of propylene was charged, and while maintaining this liquid level, propylene was supplied at a rate of 16.9 kg / h, ethoxyethoxyethyl acetate as an activity regulator at a rate of 0.28 ml / h, ethylene was supplied so that the concentration of ethylene dissolved in the propylene liquid phase was 0.198 mol per 1 mol of propylene, and hydrogen was supplied so that the hydrogen concentration in the gas phase was 5.9 mol%. Polymerization was carried out at a temperature of 53.2°C, a pressure of 3.24 MPa-G, an average residence time of 0.75 hours, and an ethylene concentration in the gas phase of 29.1 mol% to obtain block copolymer (B-1).

[0107] <Process (2B)> The copolymer slurry containing the obtained block copolymer (B-1) was sent to a 500L capacity vessel polymerizer No. 4 equipped with a stirrer for further polymerization. In the No. 4 polymerizer, 260L of propylene was charged, and while maintaining this liquid level, polymerization was carried out by continuously supplying propylene at a rate of 52.1 kg / h, dicyclopentadienyldichlorotitanium at a rate of 35.2 mg / h, ethylene at a rate of 0.129 mol per mol of propylene, and hydrogen at a concentration of 0.16 mol% in the gas phase. The temperature at this time was 60.4°C, the pressure was 3.16 MPa-G, the average residence time was 0.55 hours, and the ethylene concentration in the gas phase was 19.7 mol%.

[0108] The obtained slurry was deactivated, vaporized, and then subjected to gas-solid separation, followed by vacuum drying at 80°C. This yielded propylene-ethylene block copolymer (A-1). The properties of the obtained homopropylene polymer (H-1), block copolymer (B-1), and propylene-ethylene block copolymer (A-1) were as follows.

[0109] • Homopropylene polymer (H-1) Intrinsic viscosity [η]=0.78dl / g MFR (2.16kg load, 230℃) = 240g / 10min Mesopentadol fraction (mmmm fraction) = 98.1 mol% • Block copolymer (B-1) Intrinsic viscosity [η]=1.04dl / g MFR (2.16kg load, 230℃) = 127g / 10min Ethylene content = 13.0% by mass Percentage of n-decane soluble portion at 23°C = 16.7% by mass Ethylene content of n-decane soluble portion at 23°C = 53.6 mol% Intrinsic viscosity [η] of the n-decane soluble portion at 23℃ = 2.1 dl / g • Propylene-ethylene block copolymer (A-1) Intrinsic viscosity [η]=1.39dl / g MFR (2.16kg load, 230℃) = 54g / 10min Ethylene content = 15.4% by mass Percentage of n-decane soluble portion at 23°C = 19.3% by mass Ethylene content of n-decane soluble portion at 23°C = 52.3 mol% Intrinsic viscosity [η] of the n-decane soluble portion at 23℃ = 3.3 dl / g

[0110] Table 1 shows the properties of the propylene-ethylene block copolymer (A-1) determined based on these characteristics. Note that the propylene polymer component (PP-1) was considered to be the n-decane-insoluble portion at 23°C, while the propylene copolymer components (EP-1) and (EP-2) were considered to be the n-decane-soluble portion at 23°C.

[0111] [Comparative Manufacturing Example 1] (Manufacturing of Polymer Mixture (A'-1)) <Production of block copolymer (a-1)> In an 8L tubular polymerizer, propylene was continuously supplied at a rate of 20 kg / h, hydrogen at 0.5 NL / h, the pre-polymerization catalyst obtained in Preparation Example 2 at a rate of 0.38 g / h per solid catalyst component, triethylaluminum at 2.1 mL / h, and diethylaminotriethoxysilane at 1.6 mL / h. Polymerization was carried out in a completely liquid state without a gas phase. The temperature of the tubular polymerizer was 16°C and the pressure was 3.6 MPa-G.

[0112] The resulting slurry was sent to a tubular polymerizer with a capacity of 58 L for further polymerization. Propylene was continuously supplied to the polymerizer at a rate of 23 kg / h and hydrogen at a rate of 172 NL / h, at a temperature of 70°C, a pressure of 3.6 MPa-G, and an average residence time of 0.61 hours.

[0113] The obtained slurry was sent to a 70L vessel polymerizer equipped with a stirrer for further polymerization. Propylene was supplied to the polymerizer at a rate of 45 kg / h, and hydrogen was continuously supplied to maintain a hydrogen concentration of 9.6 mol% in the gas phase. Polymerization was carried out at a temperature of 68.0°C, a pressure of 3.2 MPa-G, and an average residence time of 0.35 hours to obtain homopropylene polymer (h-1).

[0114] The obtained slurry was transferred to a 2.4 L transfer tube, and in the transfer tube, an activity regulator (Atomer 163, manufactured by Croda Japan Co., Ltd.) was supplied at 1.83 g / h and an anti-adhesion agent (L-71 (trade name), manufactured by ADEKA Corporation) was supplied at 0.51 g / h, bringing the slurry into contact with the solvent. The slurry that had come into contact with the solvent was gasified, and after gas-solid separation was performed, 12.4 kg of homopropylene polymer (h-1) powder was sent to a 480 L gas-phase polymerizer. Then, propylene, ethylene, and hydrogen were continuously supplied so that the gas composition in the gas-phase polymerizer was ethylene / (ethylene + propylene) = 0.3295 (molar ratio) and hydrogen / ethylene = 0.1460 (molar ratio). Polymerization was carried out at a temperature of 70°C, a pressure of 1.2 MPa-G, and a residence time of 0.68 hours.

[0115] Subsequently, gas-solid separation was performed, and vacuum drying was carried out at 80°C to obtain block copolymer (a-1), which is a polymer for blending. The properties of the obtained homopropylene (h-1) and block copolymer (a-1) were as follows.

[0116] • Homopropylene polymer (h-1) Intrinsic viscosity [η]=0.74dl / g MFR (2.16kg load, 230℃) = 252g / 10min Mesopentadione fraction (mmmm fraction) = 98.2 mol% • Block copolymer (a-1) Intrinsic viscosity [η]=0.94dl / g MFR (2.16kg load, 230℃) = 90g / 10min Ethylene content = 15.1% by mass Percentage of n-decane soluble portion at 23°C = 19.5% by mass Ethylene content of n-decane soluble portion at 23℃ = 53 mol% Intrinsic viscosity [η] of the n-decane soluble portion at 23℃ = 2.1 dl / g

[0117] <Production of block copolymer (a-2)> In an 8L tubular polymerizer, 20 kg / h of propylene, 0.5 NL / h of hydrogen, 0.30 g / h of the pre-polymerization catalyst obtained in Preparation Example 2 per solid catalyst component, 1.7 mL / h of triethylaluminum, and 1.3 mL / h of diethylaminotriethoxysilane were continuously supplied, and polymerization was carried out in a completely liquid state without a gas phase. The temperature of the tubular polymerizer was 16°C and the pressure was 3.2 MPa-G. The resulting slurry was sent to a 58L tubular polymerizer for further polymerization. Propylene was continuously supplied to the polymerizer at 23 kg / h and hydrogen at 172 NL / h, the temperature was 63°C, the pressure was 3.2 MPa-G, and the average residence time was 0.60 hours.

[0118] The obtained slurry was sent to a 70L vessel polymerizer equipped with a stirrer for further polymerization. Propylene was supplied to the polymerizer at a rate of 45 kg / h, and hydrogen was continuously supplied to maintain a hydrogen concentration of 9.5 mol% in the gas phase. Polymerization was carried out at a temperature of 62.0°C, a pressure of 2.8 MPa-G, and an average residence time of 0.35 hours to obtain homopropylene polymer (h-2).

[0119] The obtained slurry was transferred to a 2.4 L transfer tube, and 0.32 g / h of an anti-fouling agent (L-71 (product name), manufactured by ADEKA Corporation) was supplied into the transfer tube and brought into contact with the slurry. The slurry that came into contact with the slurry was gasified and gas-solid separation was performed. Then, homopropylene polymer (h-2) powder was sent to a 480 L gas-phase polymerizer so that the amount of powder was 20.6 kg. Subsequently, propylene, ethylene, and hydrogen were continuously supplied so that the gas composition in the gas-phase polymerizer was ethylene / (ethylene + propylene) = 0.158 (molar ratio) and hydrogen / ethylene = 0.0030 (molar ratio). Polymerization was carried out at a polymerization temperature of 75°C, a pressure of 1.6 MPa-G, and a residence time of 1.42 hours.

[0120] Subsequently, gas-solid separation was performed, and the mixture was vacuum-dried at 80°C to obtain block copolymer (a-2). The properties of the obtained homopropylene polymer (h-2) and block copolymer (a-2) were as follows.

[0121] • Homopropylene polymer (H-2) Intrinsic viscosity [η]=0.77dl / g MFR (2.16kg load, 230℃) = 250g / 10min Mesopentadione fraction (mmmm fraction) = 98.2 mol% • Block copolymer (a-2) Intrinsic viscosity [η]=4.06dl / g MFR (2.16 kg load, 230°C) = 0.8 g / 10 min Ethylene content = 23.8% by mass Percentage of n-decane soluble portion at 23°C = 39.7% by mass Ethylene content of n-decane soluble portion at 23℃ = 45 mol% Intrinsic viscosity [η] of the n-decane soluble portion at 23℃ = 8.0 dl / g

[0122] <Production of polymer mixture (A'-1)> 83 parts by mass of the block copolymer (a-1) obtained above, 7.8 parts by mass of block copolymer (a-2), 9.2 parts by mass of homopropylene polymer (Prime Polypro® J137G (product name), manufactured by Prime Polymer Co., Ltd.), 0.1 parts by mass of calcium stearate (manufactured by NOF Corporation), and as antioxidants, 0.1 parts by mass of IRGANOX® 1010 (manufactured by BASF Japan Ltd.), 0.1 parts by mass of IRGAFOS 168 (manufactured by BASF Japan Ltd.), and 0.1 parts by mass of H-BHT (manufactured by Honshu Chemical Industry Co., Ltd.) were blended and dry-blended in a tumbler mixer. Subsequently, the mixture was melt-kneaded using a twin-screw extruder (manufactured by Nakatani Machinery Co., Ltd.: NR-II, co-rotating twin-screw extruder) under the conditions of a barrel temperature (kneading temperature) of 190°C, a screw rotation speed of 200 rpm, and an extrusion rate of 20 kg / h to obtain polymer mixture (A'-1).

[0123] Table 1 shows the properties of the polymer mixture (A'-1) determined based on the properties of the homopropylene polymer (h-1) and other materials described above.

[0124] [Table 1]

[0125] [Example 1] 65 parts by mass of the propylene-based block copolymer (A-1) obtained in Production Example 1, and ethylene polymer (B-1) (manufactured by Prime Polymer Co., Ltd., Evolu SP4030 (MFR (190℃, 2.16kg) = 3.8g / 10min, density 938kg / m³)) 314 parts by mass of )), 21 parts by mass of talc (JM-209(C) (trade name), manufactured by Asada Flour Milling Co., Ltd.), 0.1 parts by mass of calcium stearate (manufactured by NOF Corporation), and 0.1 parts by mass of IRGANOX1010 (trade name, manufactured by BASF Japan Ltd.) and IRGAFOS168 (trade name, manufactured by BASF Japan Ltd.) as antioxidants were mixed and dry blended in a tumbler mixer. Then, the mixture was melt-kneaded and pelletized using a twin-screw extruder (manufactured by Japan Steel Works Ltd., TEX(registered trademark) 30α) under the conditions of cylinder temperature 180°C, screw rotation 750 rpm, and extrusion rate 60 kg / h. These pellets were molded into test pieces using an injection molding machine and the above evaluation was performed. The results are shown in Table 2.

[0126] [Example 2] In Example 1, the amount of ethylene polymer (B-1) was 10 parts by mass, and copolymer rubber (D) (ethylene-1-octene copolymer (EOR), manufactured by Dow Chemical, ENGAGE8200 (MFR (190℃, 2.16kg) = 5.0g / 10min, density 870kg / m³) 3 Except for the addition of 4 parts by weight of )), resin composition pellets and test pieces were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0127] [Example 3] In Example 1, the amount of ethylene polymer (B-1) was 7 parts by mass, and copolymer rubber (D) (ethylene-1-octene copolymer (EOR), manufactured by Dow Chemical, ENGAGE8200 (MFR (190℃, 2.16kg) = 5.0g / 10min, density 870kg / m³) 3 Except for the addition of 7 parts by weight of )), resin composition pellets and test pieces were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0128] [Example 4] In Example 1, the amount of ethylene polymer (B-1) was 4 parts by mass, and copolymer rubber (D) (ethylene-1-octene copolymer (EOR), manufactured by Dow Chemical, ENGAGE8200 (MFR (190℃, 2.16kg) = 5.0g / 10min, density 870kg / m³)3 Except for the addition of 10 parts by weight of )), resin composition pellets and test pieces were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0129] [ Reference example 5] In Example 1, the amount of ethylene polymer (B-1) was 2 parts by mass, and copolymer rubber (D) (ethylene-1-octene copolymer (EOR), manufactured by Dow Chemical, ENGAGE8200 (MFR (190℃, 2.16kg) = 5.0g / 10min, density 870kg / m³) 3 Except for the addition of 12 parts by weight of )), resin composition pellets and test pieces were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0130] [Comparative Example 1] In Example 3, the resin composition pellets and test pieces were prepared and evaluated in the same manner as in Example 3, except that 65 parts by mass of propylene-based block copolymer (A-1) was replaced with 65 parts by mass of polymer mixture (A'-1). The evaluation results are shown in Table 2.

[0131] [Comparative Example 2] In Example 1, pellets and test pieces of the resin composition were manufactured and evaluated in the same manner as in Example 1, except that 14 parts by mass of ethylene polymer (B-1) was replaced with 14 parts by mass of copolymer rubber (D). The evaluation results are shown in Table 2.

[0132] [Table 2]

[0133] [Example 6] In Example 3, 7 parts by mass of ethylene polymer (B-1) and 7 parts by mass of ethylene polymer (B-2) (manufactured by Prime Polymer Co., Ltd., Evolu SP1540 (MFR (190℃, 2.16kg) = 3.8g / 10min, density 913kg / m³) 3 )) Changed Except for the exceptions, resin composition pellets and test pieces were manufactured and evaluated in the same manner as in Example 3. The evaluation results are shown in Table 3.

[0134] [Example 7] In Example 3, 7 parts by mass of ethylene polymer (B-1) was mixed with 7 parts by mass of ethylene polymer (B-3) (manufactured by Prime Polymer Co., Ltd., Evolu SP4020 (MFR (190℃, 2.16kg) = 1.8g / 10min, density 937kg / m³)). 3 Except for the change made to ), resin composition pellets and test pieces were manufactured and evaluated in the same manner as in Example 3. The evaluation results are shown in Table 3.

[0135] [Example 8] In Example 3, 7 parts by mass of ethylene polymer (B-1) was mixed with 7 parts by mass of ethylene polymer (B-4) (Milason 11P, manufactured by Mitsui DuPont Polychemical Co., Ltd. (MFR (190℃, 2.16kg) = 7.2g / 10min, density 917kg / m³)). 3 Except for the change made to ), resin composition pellets and test pieces were manufactured and evaluated in the same manner as in Example 3. The evaluation results are shown in Table 3.

[0136] [Comparative Example 3] In Example 6, the resin composition pellets and test pieces were prepared and evaluated in the same manner as in Example 6, except that 65 parts by mass of propylene-based block copolymer (A-1) was replaced with 65 parts by mass of polymer mixture (A'-1). The evaluation results are shown in Table 3.

[0137] [Comparative Example 4] In Example 8, the resin composition pellets and test pieces were prepared and evaluated in the same manner as in Example 8, except that 65 parts by mass of propylene-based block copolymer (A-1) was replaced with 65 parts by mass of polymer mixture (A'-1). The evaluation results are shown in Table 3.

[0138] [Table 3]

Claims

1. 50 to 90.6 parts by mass of a crystalline propylene-ethylene block copolymer (A) that satisfies the following requirements (1) to (3), Density of 915-980 kg / m³ 3 The mixture comprises 4.4 to 25 parts by mass of an ethylene-based polymer (B), which is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, with a melt flow rate (MFR) of 0.1 to 30 g / 10 min measured at a temperature of 190°C and a load of 2.16 kg. A resin composition comprising 5 to 25 parts by mass of an inorganic filler (C) (provided that the total of the crystalline propylene-ethylene block copolymer (A), the ethylene polymer (B), and the inorganic filler (C) is 100 parts by mass). Requirement (1): A block copolymer comprising a crystalline propylene polymer component and a propylene copolymer component, wherein the amount of the propylene copolymer component is 10 to 50% by mass, the intrinsic viscosity [η] of the propylene copolymer component measured in tetralin at 135°C is 2.0 to 6.0 dl / g, and the proportion of ethylene-derived constituent units in the propylene copolymer component is 30 to 80 mol%. Requirement (2): The propylene copolymer component contains copolymer component (EP-1) and copolymer component (EP-2), The copolymer component (EP-1) contains 40 to 80 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] of 1.5 to 4.0 dl / g as measured in tetralin at 135°C. The copolymer component (EP-2) contains 30 to 50 mol% of ethylene-derived structural units and has an intrinsic viscosity [η] of 5.0 to 10 dl / g as measured in tetralin at 135°C. Requirement (3): The mass ratio (EP-1 / EP-2) of the copolymer component (EP-2) to the copolymer component (EP-1) is between 10 / 1 and 1 / 1.

2. The copolymer component (EP-1) contains 51 to 58 mol% of ethylene-derived structural units. The resin composition according to claim 1, wherein the copolymer component (EP-2) contains 38 to 48 mol% of ethylene-derived structural units.

3. The resin composition according to claim 1, wherein the crystalline propylene-ethylene block copolymer (A) further satisfies the following requirements (4) to (6). Requirement (4): The melt flow rate (MFR), measured at a temperature of 230°C and a load of 2.16 kg, is between 1 and 500 g / 10 min. Requirement (5): The melting point, as measured by a differential scanning calorimetry (DSC), is 155 to 170°C. Requirement (6): The crystalline propylene polymer component 13 The mesopentad fraction (mmmm fraction) measured by 13C-NMR is 96.0–99.9%.

4. The resin composition according to claim 1, wherein the crystalline propylene-ethylene block copolymer (A) further satisfies at least one of the following requirements (7) and (8). Requirement (7): The difference between the ethylene-derived constituent unit content of copolymer component (EP-1) and the ethylene-derived constituent unit content of copolymer component (EP-2), ΔC2, is 1.0 to 13 mol%. Requirement (8): The difference between the intrinsic viscosity [η] of copolymer component (EP-1) measured in tetralin at 135°C and the intrinsic viscosity [η] of copolymer component (EP-2) measured in tetralin at 135°C, Δη, is 5.8 to 8.5 dl / g.

5. A copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, with a density of 850 to 910 kg / m³. 3 The copolymer rubber (D) has a melt flow rate (MFR) of 0.2 g / 10 min or more and less than 40 g / 10 min, measured at a temperature of 190°C and a load of 2.16 kg. The resin composition according to claim 1, comprising 25 parts by mass or less per 100 parts by mass of the total of a crystalline propylene-ethylene block copolymer (A), an ethylene polymer (B), and an inorganic filler (C).

6. A molded article formed from the resin composition according to any one of claims 1 to 5.

7. The molded article according to claim 6, which is an injection-molded article.

8. A molded article according to claim 6, which is an automobile part.

9. The molded body according to claim 8, wherein the automobile part is a bumper.

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