Propylene resin composition

Abstract

A propylene resin composition comprising: a propylene resin (A) including a heterophasic propylene polymer material (A-1) which comprises a polymer (I) comprising 80 mass% or more monomer units derived from propylene and a polymer (II) comprising monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins each having 4-12 carbon atoms and monomer units derived from propylene; ethylene / α-olefin copolymers (B) comprising an ethylene / α-olefin copolymer (B-1) having a melt flow rate of 0.8 g / 10 min or less and an ethylene / α-olefin copolymer (B-2) having a melt flow rate of 10 g / 10 min or greater; an inorganic filler (C) excluding carbon black; 0.5-5.0 parts by weight of carbon black (D) having a pH higher than 5; and 0.1-1.0 parts by weight of a modified polypropylene (E).

Description

[Technical Field]

[0001] The present invention relates to a propylene resin composition. [Background technology]

[0002] Molded articles obtained by molding propylene resin compositions are used in various applications such as automobile interior materials, home appliance materials, etc. These applications require impact resistance, scratch resistance, etc., and a propylene resin composition containing a propylene resin, a copolymer of ethylene and an α-olefin having 4 or more carbon atoms, an inorganic filler, a fatty acid amide, and carbon black in specific proportions has been proposed as a molding composition that is excellent in these properties (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-34614 Summary of the Invention [Problem to be solved by the invention]

[0004] Injection molding is a widely used method for producing the above-mentioned molded articles. Injection molding can cause streaky appearance defects on the surface of injection-molded articles, which require prevention. Furthermore, automotive interior materials and the like are often used in harsh temperature environments, and further improvement in heat degradation resistance is required. Under these circumstances, the problem to be solved by the present invention is to provide a propylene resin composition that can be used to produce injection-molded articles that have good surface appearance and excellent heat degradation resistance while maintaining the excellent properties of conventional propylene resin compositions. [Means for solving the problem]

[0005] The present inventors have conducted extensive research in light of the above background and have completed the present invention. That is, the present invention provides: [1] a propylene resin (A) containing a heterophasic propylene polymerization material (A-1) containing a polymer (I) containing 80% by mass or more of monomer units derived from propylene (where the total mass of the polymer (I) is taken as 100% by mass), and a polymer (II) containing monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms, and monomer units derived from propylene; an ethylene-α-olefin copolymer (B) containing an ethylene-α-olefin copolymer (B-1) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less and an ethylene-α-olefin copolymer (B-2) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 10 g / 10 min or more; an inorganic filler other than carbon black (C); Carbon black (D) having a pH greater than 5; Contains modified polypropylene (E), The propylene resin composition has a carbon black (D) content of 0.5 parts by weight or more and 5.0 parts by weight or less, and a modified polypropylene (E) content of 0.1 parts by weight or more and 1.0 part by weight or less, relative to 100 parts by weight of the total weight of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C).

[0006] Below, [2] to [ 7 ] are each preferred aspects or embodiments of the present invention. [2] The propylene resin composition according to [1], wherein the content of the propylene resin (A) is 50% by weight or more and 75% by weight or less, the content of the ethylene-α-olefin copolymer (B) is 10% by weight or more and 25% by weight or less, and the content of the inorganic filler (C) is 15% by weight or more and 25% by weight or less, where the total weight of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C) is 100% by weight. [3] The ethylene-α-olefin copolymer (B-1) is an ethylene-1-octene copolymer (B-1-1) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less; an ethylene-1-butene copolymer (B-1-2) having a melt flow rate (190°C, 2.16 kgf load, compliant with JIS-K-7210) of 0.8 g / 10 min or less; The propylene resin composition according to [1] or [2], comprising: [4] The propylene resin composition according to any one of [1] to [3], wherein the ethylene-α-olefin copolymer (B-2) contains an ethylene-1-octene copolymer. [5] The propylene resin composition according to any one of [1] to [4], further comprising a lubricant (F). [6] The propylene resin composition according to [5], wherein the lubricant (F) is at least one selected from the group consisting of fatty acid amide-based lubricants and silicone-based lubricants. [7] A molded article comprising the propylene resin composition according to any one of [1] to [6]. [Effects of the Invention]

[0007] According to the present invention, it is possible to produce injection-molded articles having a good surface appearance and excellent resistance to heat deterioration, and it is possible to provide a propylene resin composition suitable as an injection-molding material. DETAILED DESCRIPTION OF THE INVENTION

[0008] The propylene resin composition of the present invention comprises: a propylene resin (A) containing a heterophasic propylene polymerization material (A-1) containing a polymer (I) containing 80% by mass or more of monomer units derived from propylene (where the total mass of the polymer (I) is taken as 100% by mass), and a polymer (II) containing monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms, and monomer units derived from propylene; an ethylene-α-olefin copolymer (B) containing an ethylene-α-olefin copolymer (B-1) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less and an ethylene-α-olefin copolymer (B-2) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 10 g / 10 min or more; an inorganic filler other than carbon black (C); Carbon black (D) having a pH greater than 5; Contains modified polypropylene (E), The propylene resin composition has a carbon black (D) content of 0.5 parts by weight or more and 5.0 parts by weight or less, and a modified polypropylene (E) content of 0.1 parts by weight or more and 1.0 part by weight or less, relative to 100 parts by weight of the total weight of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C). That is, the propylene resin composition of the present invention contains the following components (A), (B), (C), (D), and (E).

[0009] Propylene resin (A) The propylene resin composition of the present invention contains a propylene resin (A). The propylene resin composition of the present invention preferably contains 50% by weight or more and 75% by weight or less of the propylene resin (A), where the total weight of the components (A), (B), and (C) is 100% by weight. The propylene resin (A) is a propylene resin containing a heterophasic propylene polymerization material (A-1) that contains a polymer (I) containing 80% by mass or more of monomer units derived from propylene (where the total mass of the polymer (I) is 100% by mass), and a polymer (II) containing monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms, and monomer units derived from propylene.

[0010] From the viewpoint of the balance between rigidity and impact resistance of the resin composition, the propylene resin (A) preferably has an isotactic pentad fraction of 0.97 or more, more preferably 0.98 or more, as measured by C-NMR. The closer the isotactic pentad fraction of the propylene resin (A) is to 1, the more highly crystalline the propylene resin (A) is, with a molecular structure that exhibits high stereoregularity. Furthermore, when the propylene resin (A) is the heterophasic propylene polymer material (A-1), the value measured for the chain of propylene units of the polymer (I) in the heterophasic propylene polymer material is used as the isotactic pentad fraction herein.

[0011] Heterophasic propylene polymer material (A-1) From the viewpoint of achieving a good balance between the rigidity and impact resistance of the propylene resin composition, the heterophasic propylene polymer material (A-1) is preferably a propylene-ethylene heterophasic propylene polymer material containing 55 to 95 wt% of polymer (I) and 5 to 45 wt% of polymer (II) (where the total amount of the heterophasic propylene polymer material (A-1) is taken as 100 wt%). More preferably, the heterophasic propylene polymer material (A-1) is a heterophasic propylene polymer material containing 65 to 92 wt% of polymer (I) and polymer (II), and even more preferably, a heterophasic propylene polymer material containing 70 to 90 wt% of polymer (I) and 10 to 30 wt% of polymer (II).

[0012] The melt flow rate (MFR) of the heterophasic propylene polymer material (A-1), measured in accordance with JIS-K-7210 at 230°C under a load of 2.16 kgf, is preferably 10 to 200 g / 10 min, more preferably 30 to 150 g / 10 min, from the viewpoint of improving moldability and impact resistance.

[0013] The heterophasic propylene polymerization material (A-1) can be produced by the following method using a polymerization catalyst. Examples of the polymerization catalyst include a Ziegler-type catalyst system, a Ziegler-Natta-type catalyst system, a catalyst system consisting of a Group 4 transition metal compound having a cyclopentadienyl ring and an alkylaluminoxane, a catalyst system consisting of a Group 4 transition metal compound having a cyclopentadienyl ring, a compound that reacts with the metal compound to form an ionic complex, and an organoaluminum compound, and a catalyst system in which inorganic particles such as silica or a clay mineral are supported and modified with catalytic components such as a Group 4 transition metal compound having a cyclopentadienyl ring, a compound that forms an ionic complex, and an organoaluminum compound. Furthermore, a prepolymerization catalyst prepared by prepolymerizing ethylene or an α-olefin in the presence of the above-mentioned catalyst system may also be used. Examples of the catalyst system include those described in JP-A Nos. 61-218606, 5-194685, 7-216017, 9-316147, 10-212319, and 2004-182981.

[0014] Polymerization methods include, for example, bulk polymerization, solution polymerization, slurry polymerization, and gas-phase polymerization. Here, bulk polymerization refers to a method in which polymerization is carried out using an olefin that is liquid at the polymerization temperature as a medium, and solution polymerization or slurry polymerization refers to a method in which polymerization is carried out in an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, or octane. Gas-phase polymerization refers to a method in which gaseous monomers are used as a medium and the gaseous monomers are polymerized in that medium. These polymerization methods may be either a batch method or a multistage method in which a plurality of polymerization reactors are connected in series, or these polymerization methods may be combined arbitrarily. From an industrial and economical viewpoint, a continuous gas-phase polymerization method or a bulk-gas-phase polymerization method in which a bulk polymerization method and a gas-phase polymerization method are carried out continuously is preferred. The various conditions in the polymerization step (polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, polymerization time, etc.) may be appropriately determined depending on the physical properties of the target heterophasic propylene polymer material (A-1).

[0015] In the production of the heterophasic propylene polymerization material (A-1), the heterophasic propylene polymerization material (A-1) may be dried at a temperature below the melting point of the heterophasic propylene polymerization material (A-1) as necessary to remove residual solvent contained in the heterophasic propylene polymerization material (A-1) and ultralow molecular weight oligomers produced as by-products during the production. Examples of drying methods include those described in JP-A-55-75410 and JP-A-2565753.

[0016] The polymer (I) containing 80% by mass or more of propylene-derived monomer units contained in the heterophasic propylene polymerization material (A-1) may be, for example, a propylene homopolymer, or may contain monomer units derived from a monomer other than propylene. When the polymer (I) contains monomer units derived from a monomer other than propylene, the content of such units may be, for example, 0.01% by mass or more and less than 20% by mass based on the total mass of the polymer (I).

[0017] Examples of the monomer other than propylene include ethylene and α-olefins having 4 or more carbon atoms. Among them, at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms is preferred, at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, and 1-octene is more preferred, and at least one selected from the group consisting of ethylene and 1-butene is even more preferred.

[0018] Examples of polymers containing monomer units derived from a monomer other than propylene include propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, and propylene-ethylene-1-octene copolymer.

[0019] From the viewpoint of dimensional stability of the molded article, the polymer (I) is preferably a propylene homopolymer, a propylene-ethylene copolymer, a propylene-1-butene copolymer, or a propylene-ethylene-1-butene copolymer, and more preferably a propylene homopolymer.

[0020] The intrinsic viscosity of polymer (I) measured in tetralin at 135°C (hereinafter referred to as [η] I From the viewpoint of achieving a good balance between the fluidity of the propylene resin composition when melted and the toughness of a molded article made thereof, the viscosity is preferably 0.7 to 1.3 dL / g, and more preferably 0.8 to 1.1 dL / g. Furthermore, the molecular weight distribution (Q value, the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn)) of the polymer (I) contained in the heterophasic propylene polymerization material (A-1) measured by gel permeation chromatography (GPC) is preferably 3 or more and less than 7, more preferably 3 to 5.

[0021] The polymer (II) contained in the heterophasic propylene polymerization material (A-1) and containing monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms and monomer units derived from propylene preferably contains 20 mass% or more of monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms, and also contains monomer units derived from propylene.

[0022] In polymer (II), the content of monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms may be 20 to 70 mass%, 20 to 60 mass%, or 25 to 40 mass%.

[0023] In polymer (II), the at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, 1-octene, and 1-decene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0024] Examples of the polymer (II) include propylene-ethylene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer, propylene-ethylene-1-decene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, and propylene-1-decene copolymer. Among them, propylene-ethylene copolymer, propylene-1-butene copolymer, and propylene-ethylene-1-butene copolymer are preferred, and propylene-ethylene copolymer is more preferred.

[0025] The ratio of the weight of the structural units derived from propylene (propylene content) to the weight of the structural units derived from ethylene (ethylene content) in the polymer (II) (propylene content / ethylene content (weight / weight)) is preferably 80 / 20 to 30 / 70, more preferably 80 / 20 to 40 / 60, and particularly preferably 75 / 25 to 60 / 40, from the viewpoint of obtaining a good balance between rigidity and impact resistance.

[0026] The intrinsic viscosity (hereinafter referred to as [η]) of the polymer (II) contained in the heterophasic propylene polymerization material (A-1), which contains monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms and monomer units derived from propylene, measured in tetralin at 135°C, is II The solubility (dl / g) is 4.5 to 7.5 dl / g, preferably 4.5 to 6.5 dl / g, and more preferably 5.0 to 6.0 dl / g.

[0027] In addition, the intrinsic viscosity number ([η] I ) to the intrinsic viscosity number ([η] II ) ratio ([η] II / [η] I ) is preferably 1 to 20, more preferably 2 to 10, and even more preferably 2 to 9.

[0028] The intrinsic viscosity number (unit: dl / g) in the present invention is a value measured at a temperature of 135° C. using tetralin as a solvent by the following method. The reduced viscosity is measured at three concentrations of 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL using an Ubbelohde viscometer. The intrinsic viscosity number is calculated using the calculation method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (published by Kyoritsu Shuppan Co., Ltd. in 1982), that is, by plotting the reduced viscosity against the concentration and extrapolating the concentration to zero. When the heterophasic propylene polymerization material (A-1) is a polymer obtained by multistage polymerization of polymer (I) and polymer (II), the intrinsic viscosity of polymer (I) or polymer (II) can be determined from a polymer powder partially extracted from a polymerization vessel in a previous stage, and the intrinsic viscosity of the remaining components can be calculated using the value of the intrinsic viscosity and the contents of each component.

[0029] In addition, when the heterophasic propylene polymer material consisting of polymer (I) and polymer (II) is a copolymer produced by a method in which polymer (I) is obtained in a first polymerization step and polymer (II) is obtained in a second polymerization step, the contents of polymer (I) and polymer (II), the intrinsic viscosity number ([η] Total , [η] I , [η] II The procedure for measuring and calculating the intrinsic viscosity ([η]) is as follows: Total ) represents the overall intrinsic viscosity of the heterophasic propylene polymer material consisting of polymer (I) and polymer (II).

[0030] The intrinsic viscosity ([η]) of the polymer (I) obtained in the previous polymerization step I ), the intrinsic viscosity ([η] of the final polymer after the subsequent polymerization step, measured by the above-mentioned method Total ), and the content of polymer (II) in the final polymer, the intrinsic viscosity number ([η] II ) is calculated using the following formula: [η] II =([η] Total -[η] I ×X I ) / X II [η] Total : Intrinsic viscosity number (dl / g) of the final polymer after the second polymerization step [η] I : Intrinsic viscosity number (dl / g) of polymer powder extracted from the polymerization tank after the first polymerization step X I : Weight ratio of polymer (I) to the entire heterophasic propylene polymer material consisting of polymer (I) and polymer (II) X II : Weight ratio of polymer (II) to the entire heterophasic propylene polymer material consisting of polymer (I) and polymer (II) In addition, X I , X II is calculated from the mass balance during polymerization.

[0031] X IIThe weight ratio of polymer (II) to the entire heterophasic propylene polymerization material consisting of polymer (I) and polymer (II) may be calculated from the following formula by measuring the heat of crystalline fusion of each of polymer (I) and the final polymer. X II =1-(ΔHf) T / (ΔHf) P (ΔHf) T : Heat of fusion of the final polymer (cal / g) (ΔHf) P : Heat of fusion of polymer (I) (cal / g)

[0032] When the propylene resin (A) used in the present invention is a propylene polymer mixture containing a heterophasic propylene polymer material (A-1) and a propylene homopolymer (A-2) (hereinafter also referred to as a propylene polymer mixture (A-3)), the content of the heterophasic propylene polymer material (A-1) in the propylene polymer mixture (A-3) is preferably 30 to 99% by weight, and the content of the propylene homopolymer (A-2) is preferably 70 to 1% by weight. More preferably, the content of the heterophasic propylene polymer material (A-1) is 45 to 95% by weight, and the content of the propylene homopolymer (A-2) is 55 to 5% by weight.

[0033] Propylene homopolymer (A-2) The intrinsic viscosity of the propylene homopolymer (A-2) is less than 1.5 dl / g, preferably 0.1 to 1.2 dl / g, and more preferably 0.5 to 1.0 dl / g. The isotactic pentad fraction of the propylene homopolymer (A-2) is preferably 0.97 or more, more preferably 0.98 or more. The melt flow rate (MFR: 230° C., load: 2160 g) of the propylene homopolymer (A-2) is preferably 10 to 500 g / 10 min, more preferably 40 to 350 g / 10 min.

[0034] The propylene homopolymer (A-2) can be produced by a method using a catalyst system similar to that used in the production of the heterophasic propylene polymerization material (A-1), and the polymerization method can be, for example, bulk polymerization, solution polymerization, slurry polymerization, or gas phase polymerization.

[0035] Propylene polymer mixture (A-3) When the propylene resin (A) used in the present invention is a propylene polymer mixture (A-3) containing a heterophasic propylene polymer material (A-1) and a propylene homopolymer (A-2), the content of the heterophasic propylene polymer material (A-1) in the propylene polymer mixture (A-3) is preferably 30 to 99% by weight, and the content of the propylene homopolymer (A-2) is preferably 70 to 1% by weight. More preferably, the content of the heterophasic propylene polymer material (A-1) is 45 to 95% by weight, and the content of the propylene homopolymer (A-2) is 55 to 5% by weight. In this case, it is preferable to first produce a heterophasic propylene polymerization material (A-1) and blend it with a propylene homopolymer (A-2) to produce a propylene polymer mixture (A-3).More preferably, in one stage of multistage polymerization, polymer (I) is produced and in another stage polymer (II) is produced to first produce a heterophasic propylene polymerization material (A-1), which is then blended with a separately produced propylene homopolymer (A-2) to produce a propylene polymer mixture (A-3).

[0036] Ethylene-α-olefin copolymer (B) The propylene resin composition of the present invention contains an ethylene-α-olefin copolymer (B). The propylene resin composition of the present invention preferably contains 10% by weight or more and 25% by weight or less of the copolymer (B) of ethylene and an α-olefin having 3 or more carbon atoms, where the total weight of components (A), (B), and (C) is 100% by weight. The ethylene-α-olefin copolymer (B) contains an ethylene-α-olefin copolymer (B-1) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less, and an ethylene-α-olefin copolymer (B-2) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 10 g / 10 min or more. The ratio of the content of the ethylene-α-olefin copolymer (B-1) having a melt flow rate (190°C, 2.16 kgf load, according to JIS-K-7210) of 0.8 g / 10 min or less to the content of the ethylene-α-olefin copolymer (B-2) having a melt flow rate (190°C, 2.16 kgf load, according to JIS-K-7210) of 10 g / 10 min or more is not particularly limited, but the weight ratio of (B-1):(B-2) is preferably 99:1 to 1:99, more preferably 90:10 to 50:50, and particularly preferably 60:40 to 80:20. From the viewpoint of gloss of the molded article, it is preferable to increase the proportion of the ethylene-α-olefin copolymer (B-1), and from the viewpoint of flowability, it is preferable to increase the proportion of the ethylene-α-olefin copolymer (B-2).

[0037] The melt flow rate of the ethylene-α-olefin copolymer (B), measured in accordance with JIS-K-7210 at 190°C under a load of 2.16 kgf, is usually 50 g / 10 min or less, more preferably 0.01 to 50 g / 10 min, and even more preferably 0.05 to 40 g / 10 min. The density of the ethylene-α-olefin copolymer (B) is preferably 0.850 to 0.900 g / cm, more preferably 0.855 to 0.875 g / cm. 3 , and more preferably 0.860 to 0.872 g / cm 3 is.

[0038] The α-olefin used in the ethylene-α-olefin copolymer (B) is preferably an α-olefin having 4 to 10 carbon atoms. Specific examples include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and α-olefins having a cyclic structure such as vinylcyclohexane, and preferably 1-butene, 1-hexene, and 1-octene. Specific examples of the ethylene-α-olefin copolymer (B) include ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-1-decene copolymer, ethylene-(3-methyl-1-butene) copolymer, and copolymers of ethylene and an α-olefin having a cyclic structure.

[0039] The content of the α-olefin contained in the ethylene-α-olefin copolymer (B) is preferably 1 to 49% by weight, more preferably 5 to 49% by weight, and even more preferably 10 to 49% by weight (each of the weights of the ethylene-α-olefin copolymer (B) being 100% by weight).

[0040] The ethylene-α-olefin copolymer (B) can be produced using a polymerization catalyst. Examples of the polymerization catalyst include homogeneous catalysts such as metallocene catalysts, and Ziegler-Natta catalysts. Examples of homogeneous catalyst systems include a catalyst system comprising a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane; a catalyst system comprising a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that reacts with the transition metal compound to form an ionic complex, and an organoaluminum compound; and a catalyst system in which inorganic particles such as silica or a clay mineral are supported and modified with catalyst components such as a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that forms an ionic complex, and an organoaluminum compound. Further examples include prepolymerization catalyst systems prepared by prepolymerizing ethylene or an α-olefin in the presence of the above catalyst systems. An example of a Ziegler-Natta type catalyst system is a catalyst system that uses a combination of a titanium-containing solid transition metal component and an organometallic component.

[0041] The ethylene-α-olefin copolymer (B) may be a commercially available product, such as Engage (registered trademark) manufactured by Dow Chemical Japan, Tafmer (registered trademark) manufactured by Mitsui Chemicals, Inc., Neozex (registered trademark) and Ultozex (registered trademark) manufactured by Prime Polymer Co., Ltd., Excellen FX (registered trademark), Sumikathen (registered trademark), and Esprene SPO (registered trademark) manufactured by Sumitomo Chemical Co., Ltd.

[0042] Ethylene-α-olefin copolymer (B-1) The ethylene-α-olefin copolymer (or ethylene-α-olefin-diene copolymer) that constitutes component (B-1) of ethylene-α-olefin copolymer (B) has a melt flow rate (190°C, 2.16 kgf load, according to JIS-K-7210) of 0.8 g / 10 min or less, preferably 0.05 to 0.6 g / 10 min. When component (B-1) has a melt flow rate of 0.8 g / 10 min or less, the surface gloss of the resulting molded article is unlikely to be excessive, and when the melt flow rate is 0.05 g / 10 min or more, a decrease in the fluidity of the resin composition can be effectively prevented.

[0043] Examples of the α-olefin constituting the ethylene-α-olefin copolymer (which may be an ethylene-α-olefin-diene copolymer) used as component (B-1) include α-olefins having 3 to 10 carbon atoms, and specific preferred embodiments include propylene, 1-butene, 1-hexene, and 1-octene. Among these, 1-octene and 1-butene are preferred, that is, the ethylene-α-olefin copolymer (B-1) is an ethylene-1-octene copolymer (B-1-1) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less; an ethylene-1-butene copolymer (B-1-2) having a melt flow rate (190°C, 2.16 kgf load, compliant with JIS-K-7210) of 0.8 g / 10 min or less; It is preferred that the compound contains: In this case, the content of the ethylene-1-octene copolymer (B-1-1) is preferably 0 to 50% by weight, particularly preferably 0 to 40% by weight, based on the entire ethylene-α-olefin copolymer (B-1). In this case, the content of the ethylene-1-butene copolymer (B-1-2) is preferably 50 to 100% by weight, particularly preferably 60 to 100% by weight, based on the entire ethylene-α-olefin copolymer (B-1).

[0044] Furthermore, when component (B-1) is an ethylene-α-olefin-diene copolymer, examples of the diene constituting it include cyclic non-conjugated dienes such as 5-ethylidene-2-norbornene, 5-propylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, and norbornadiene; and linear conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 6-methyl-1,7-octadiene, and 7-methyl-1,6 octadiene. Of these, 1,4-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene are preferably used.

[0045] Ethylene-α-olefin copolymer (B-2) The ethylene-α-olefin copolymer, which is component (B-2) constituting the ethylene-α-olefin copolymer (B), has a melt flow rate of 10 g / 10 min or more, preferably 10 to 50 g / 10 min, and more preferably 10 to 40 g / 10 min. When component (B-2) has a melt flow rate of 10 g / 10 min or more, a decrease in the fluidity of the resin composition can be effectively prevented. When the melt flow rate is 50 g / 10 min or less, the surface gloss of the molded article is unlikely to become excessive, and a decrease in the impact resistance of the molded article can be effectively prevented.

[0046] The ethylene-α-olefin copolymer used as component (B-2) includes copolymers of ethylene and an α-olefin having 3 to 10 carbon atoms, and preferred α-olefins include propylene, 1-butene, 1-hexene, and 1-octene. Of these, 1-octene is preferred, i.e., the ethylene-α-olefin copolymer (B-2) preferably contains an ethylene-1-octene copolymer. In this case, the content of the ethylene-1-octene copolymer is preferably 50 to 100% by weight, particularly preferably 60 to 100% by weight, based on the total weight of the ethylene-α-olefin copolymer (B-2).

[0047] Inorganic filler (C) The propylene resin composition of the present invention contains an inorganic filler (C). Preferably, the propylene resin composition of the present invention contains 15% by weight or more and 25% by weight or less of the inorganic filler (C), where the total weight of the components (A), (B), and (C) is 100% by weight. The inorganic filler (C) in the present invention is an inorganic filler other than carbon black. Specific examples of the inorganic filler (C) include talc, mica, calcium carbonate, barium sulfate, magnesium carbonate, clay, alumina, silica, calcium sulfate, silica sand, titanium oxide, magnesium hydroxide, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium hydroxide, calcium sulfite, sodium sulfate, bentonite, magnesium oxysulfate, potassium titanate, aluminum borate, calcium silicate, carbon fiber, glass fiber, and metal fiber. Among these, talc is preferably used. The inorganic filler (C) may be used alone or in combination of two or more kinds. The inorganic filler (C) may be in the form of powder, flakes, granules, fibers, or the like. The inorganic filler (C) may be used without treatment, or may be surface-treated with a silane coupling agent, a titanium coupling agent, or a surfactant to improve interfacial adhesion with component (A) and dispersibility. Examples of surfactants include higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acid salts.

[0048] The average particle diameter of the inorganic filler (C) is preferably 10 μm or less, more preferably 5 μm or less. Here, the "average particle diameter" in the present invention refers to the 50% equivalent particle diameter D obtained from an integral distribution curve obtained by laser diffraction using a Microtrac particle size analyzer (SPA method) manufactured by Nikkiso Co., Ltd., after a sample is placed in an ethanol solution and dispersed for 10 minutes using an ultrasonic cleaning device. 50 This means that...

[0049] Carbon Black (D) The propylene resin composition according to the present invention contains carbon black (D) in an amount of 0.5 parts by weight or more and 5.0 parts by weight or less, relative to 100 parts by weight of the total weight of components (A), (B), and (C). The content of carbon black (D) is preferably more than 0.5 parts by weight and 5.0 parts by weight or less, more preferably 1.0 parts by weight or more and 4.5 parts by weight or less, and particularly preferably 2.2 parts by weight or more and 4.0 parts by weight or less, relative to 100 parts by weight of the total weight of components (A), (B), and (C). Suitable examples of carbon black (D) include acetylene black, furnace black, channel black, ketjen black, thermal black, medium thermal black, lamp black (lamp black), etc. Among these, it is preferable to use furnace black and channel black, which have excellent coloring power. The average particle size of the carbon black (D) is preferably 50 nm or less, more preferably 30 nm or less, from the viewpoint of dispersibility, and is preferably 1 nm or more.

[0050] The pH of the carbon black (D) is greater than 5, preferably greater than 5 and less than 10, more preferably greater than 5 and less than 9, particularly preferably from 5.5 to 8, and particularly preferably from 6.5 to 8. When the carbon black (D) has a pH of more than 5, the propylene resin composition of the present invention exhibits excellent resistance to heat deterioration. There is no particular upper limit to the pH of the carbon black (D), but in consideration of cost, availability, etc., it is usually 10 or less, preferably 9 or less, and particularly preferably 8 or less.

[0051] The pH of carbon black (D) can be adjusted by methods conventionally used in the art, but a preferred method is to introduce functional groups such as -OH, -CO, and -COOH by, for example, oxidizing the surface of furnace carbon black, etc. In addition, products with various pH values ​​are available from various manufacturers. The pH of carbon black (D) can be measured by a method conventionally used in the art, for example, by measuring the pH of a mixture of carbon black and distilled water with a glass electrode pH meter.

[0052] The carbon black (D) may be surface-treated to improve its ability to be filled into resins. Examples of surface treatment agents include titanate-based and aluminum-based surface treatment agents. The carbon black (D) may be added to the propylene resin composition according to the present invention as a masterbatch in which the carbon black (E) is mixed with a component such as a resin. The carbon black (D) may be used alone or in combination of two or more kinds.

[0053] Modified Polypropylene (E) The modified polypropylene (E) used in the resin composition of the present invention is an acid-modified polypropylene and / or a hydroxy-modified polypropylene, and has the characteristic of contributing to improvement of scratch resistance and balance of physical properties in the resin composition of the present invention and in the molded article using the same.

[0054] The modified polypropylene of component (E) is not particularly limited except that it is polypropylene-based and has been acid-modified and / or hydroxy-modified, and any conventionally known modified polypropylene can be used. The acid-modified polypropylene is obtained by graft copolymerizing a polypropylene such as a propylene homopolymer or a propylene copolymer with an unsaturated carboxylic acid such as maleic acid or maleic anhydride. The graft copolymerization is carried out, for example, by reacting the polypropylene with an unsaturated carboxylic acid in a suitable solvent using a radical generator such as benzoyl peroxide. The unsaturated carboxylic acid or its derivative can also be introduced into the polymer chain by random or block copolymerization with a polypropylene monomer.

[0055] Examples of unsaturated carboxylic acids used for modification include compounds having a carboxyl group, such as maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid, and a polymerizable double bond into which a functional group, such as a hydroxyl group or an amino group, has been introduced as needed. Derivatives of unsaturated carboxylic acids include their acid anhydrides, esters, amides, imides, and metal salts, and specific examples thereof include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, fumaric acid monoamide, maleimide, N-butylmaleimide, and sodium methacrylate. Preferred is maleic anhydride.

[0056] The grafting reaction conditions include, for example, dialkyl peroxides such as di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, An example of a method is to use about 0.001 to 10 parts by weight of an organic peroxide, such as a peroxy ester such as 2,5-dimethyl-2,5-di(benzoylperoxy)hexyne-3, a diacyl peroxide such as benzoyl peroxide, or a hydroperoxide such as diisopropylbenzene hydroperoxide or 2,5-dimethyl-2,5-di(hydroperoxy)hexane, per 100 parts by weight of the polypropylene, and react it in a molten state or in a solution state at a temperature of about 80 to 300°C. The amount of acid modification (sometimes referred to as graft ratio) of the acid-modified polypropylene is not particularly limited, but the amount of acid modification is preferably 0.05 to 10% by weight, more preferably 0.07 to 5% by weight, calculated as maleic anhydride. A preferred example of the acid-modified polypropylene is maleic anhydride-modified polypropylene in terms of the magnitude of the effects of the present invention.

[0057] The hydroxy-modified polypropylene is a modified polypropylene containing a hydroxyl group. The modified polypropylene may have the hydroxyl group at an appropriate position, for example, at the end of the main chain or on a side chain. Examples of polypropylene constituting the hydroxy-modified polypropylene include propylene homopolymers, copolymers of propylene with α-olefins such as ethylene, butene, 4-methylpentene-1, hexene, octene, nonene, decene, and dodecene, and copolymers with copolymerizable monomers other than α-olefins.

[0058] Preferred examples of the hydroxy-modified polypropylene include polypropylene homopolymers such as isotactic polypropylene, random copolymers of propylene and α-olefins (e.g., ethylene, butene, hexane, etc.), and hydroxy-modified products such as propylene-α-olefin block copolymers. Examples of the monomer for introducing the reactive group include monomers having a hydroxyl group (e.g., allyl alcohol, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc.).

[0059] The amount of modification with a monomer having a hydroxyl group is 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the polypropylene resin. The average molecular weight of the hydroxy-modified polypropylene is not particularly limited. For example, in the case of a low-molecular-weight system, the hydroxy-modified polypropylene can be obtained by polymerizing a conjugated diene monomer by a known method such as anionic polymerization, hydrolyzing the polymer, and hydrogenating the resulting polymer. Two or more types of modified polypropylene (E) may be used in combination.

[0060] The blending ratio of the modified polypropylene (E) is 0.1 to 1.0 parts by weight, preferably 0.3 to 1.0 parts by weight, and more preferably 0.5 to 1.0 parts by weight, per 100 parts by weight of the total amount of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C). Since the blending amount of the modified polypropylene (E) is 0.1 part by weight or more, the resin composition of the present invention and the molded article obtained therefrom have excellent scratch resistance and a balance of physical properties (rigidity, heat resistance, etc.). Furthermore, since the blending amount is 1.0 part by weight or less, the balance of other physical properties (impact strength, etc.) and economy are excellent.

[0061] Other ingredients The propylene resin composition according to the present invention may contain known additives in addition to the components (A) to (E). Examples of additives include lubricants, nucleating agents, neutralizing agents, antioxidants, light stabilizers, weathering agents, UV absorbers, antistatic agents, antiblocking agents, processing aids, organic peroxides, colorants (inorganic pigments, organic pigments, pigment dispersants, etc.), foaming agents, foam nucleating agents, plasticizers, flame retardants, crosslinking agents, crosslinking aids, brightness enhancers, antibacterial agents, and light diffusing agents. These additives may be used alone or in combination of two or more. Furthermore, the resin composition according to the present invention may contain resins or rubbers other than the components (A), (B), and (E) as necessary.

[0062] For example, propylene resins other than component (A) and component (E), copolymers of ethylene and α-olefins having 3 or more carbon atoms other than component (B), ethylene-propylene-diene copolymer (EPDM), styrene resin, ABS (acrylonitrile / butadiene / styrene copolymer) resin, AAS (special acrylic rubber / acrylonitrile / styrene copolymer) resin, ACS (acrylonitrile / chlorinated polyethylene / styrene copolymer) resin, polychloroprene, chlorinated rubber, polyvinyl chloride, polyvinylidene chloride, acrylic resin, ethylene / vinyl alcohol Examples of the thermoplastic resin include copolymer resin, fluororesin, polyacetal, phenylene ether resin, polyurethane, polyamide, ester resin, polycarbonate, polysulfone, polyether ether ketone, polyether sulfone, and aromatic polyester resin; epoxy resin, diallyl phthalate prepolymer, silicone resin, silicone rubber, polybutadiene, 1,2-polybutadiene, polyisoprene, styrene / butadiene copolymer, butadiene / acrylonitrile copolymer, epichlorohydrin rubber, acrylic rubber, and natural rubber. The diene monomer used in EPDM is not particularly limited, but examples thereof include ethylidene norbornene (ENB), 1,4-hexadiene (1,4-HD), and dicyclopentadiene (DCPD). Commercially available EPDM products may be used, such as Esprene (registered trademark) manufactured by Sumitomo Chemical Co., Ltd. and Nordel (registered trademark) manufactured by Dow Chemical Japan.

[0063] Lubricant (F) From the viewpoint of moldability and scratch resistance of the molded product, it is particularly preferable to contain a lubricant (F) as another component. As the lubricant, any lubricant conventionally known in the art can be used as appropriate. Preferred examples include silicone-based lubricants such as fatty acid amides, silicone oils, and silicone gums, fatty acid metal salts, and higher alcohols. Of these, fatty acid amides and silicone-based lubricants are particularly preferred. The amount of lubricant (F) to be added is not particularly limited and can be set appropriately depending on the type of lubricant, the purpose of addition, etc., but it is preferably 0.2 parts by weight or more and 3.0 parts by weight or less, and more preferably 0.3 parts by weight or more and 1.5 parts by weight or less, per 100 parts by weight of the total amount of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C).

[0064] fatty acid amides The fatty acid amide preferably used as a lubricant in this embodiment is preferably a compound represented by RCONH2 (wherein R represents an alkyl or alkenyl group having 5 to 21 carbon atoms), and examples thereof include lauric acid amide, stearic acid amide, oleic acid amide, behenic acid amide, erucic acid amide, etc. Among these, erucic acid amide is particularly preferred. Examples of commercially available products include Diamid Y manufactured by Nippon Kasei Chemical Co., Ltd., Armid HT-P manufactured by Lion Akzo Co., Ltd., Neutron manufactured by Nippon Fine Chemical Co., Ltd., Diamid KN manufactured by Nippon Kasei Chemical Co., Ltd., and Neutron S manufactured by Nippon Fine Chemical Co., Ltd. The fatty acid amides may be used alone or in combination of two or more. The amount of fatty acid amide is preferably 0.2 parts by weight or more and 1.0 parts by weight or less, and more preferably 0.3 parts by weight or more and 0.5 parts by weight or less, per 100 parts by weight of the total amount of propylene resin (A), ethylene-α-olefin copolymer (B), and inorganic filler (C).

[0065] Silicone lubricant Suitable examples of silicone-based lubricants that are preferably used as the lubricant in this embodiment include silicone oil, high molecular weight silicone (silicone gum), silicone powder, and the like. Suitable examples of silicone oils include dimethylsilicone oil, phenylmethylsilicone oil, alkylsilicone oil, fluorosilicone oil, tetramethyltetraphenyltrisiloxane, modified silicone oil, and the like.

[0066] High molecular weight silicone (silicone gum) typically has a weight-average molecular weight of 100,000 or more. By using such high molecular weight silicone (silicone gum), it becomes entangled with the molecules of the constituent materials, making it possible to maintain the surface condition for a long period of time. The weight-average molecular weight of the silicone gum is preferably 100,000 to 800,000, more preferably 450,000 to 650,000. Furthermore, non-crosslinked high molecular weight silicone (silicone gum) is preferred. The silicone-based lubricant may be used alone or in combination of two or more kinds. The amount of the silicone-based lubricant is preferably 0.5 parts by weight or more and 3.0 parts by weight or less, and more preferably 1.0 parts by weight or more and 1.5 parts by weight or less, per 100 parts by weight of the total amount of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C).

[0067] Propylene resin composition The propylene resin composition according to the present invention contains the above-mentioned component (A), component (B), component (C), component (D), and component (E). The content of the propylene resin (A) in the propylene resin composition is usually 50 to 75% by weight, preferably 53 to 70% by weight, and more preferably 55 to 65% by weight, where the total weight of the components (A), (B), and (C) is 100% by weight. The content of the ethylene-α-olefin copolymer (B) in the propylene resin composition is usually 10 to 25% by weight, preferably 12 to 20% by weight, and more preferably 14 to 20% by weight, where the total weight of components (A), (B), and (C) is 100% by weight. The content of the inorganic filler (C) other than carbon black in the propylene resin composition is usually 15 to 25% by weight, preferably 20 to 26% by weight, and more preferably 20 to 24% by weight, where the total weight of components (A), (B), and (C) is 100% by weight.

[0068] The melt flow rate (230°C, 2.16 kgf load, in accordance with JIS-K-7210) of the entire propylene resin composition according to the present invention is preferably 0.1 to 400 g / 10 min, more preferably 1 to 200 g / 10 min, and even more preferably 10 to 100 g / 10 min, from the viewpoint of improving molding processability.

[0069] The propylene resin composition according to the present invention is obtained by melt-kneading the raw material components preferably at 180° C. or higher, more preferably from 180 to 300° C., and even more preferably from 180 to 250° C. Examples of the melt-kneading method include a Banbury mixer, a single-screw extruder, and a twin-screw co-rotating extruder.

[0070] The propylene resin composition may be in the form of a strand, a sheet, a plate, a pellet obtained by cutting a strand to an appropriate length, etc. In order to mold the resin composition according to the present invention, the preferred form is a pellet having a length of 1 to 50 mm, from the viewpoint of production stability of the obtained molded article.

[0071] The raw material components are preferably blended and kneaded in the following order. Method 1: A method in which components (A) to (E) (and optionally component (F)) are kneaded together. Method 2: A method in which components (A) to (C) and component (E) (and optionally component (F)) are kneaded, and then a masterbatch of carbon black (D) is added and kneaded. Method 3: A method in which a portion of component (A) and carbon black (D) are preliminarily mixed and pelletized, and the pellets, a portion of component (A), components (B) to (C) and component (E) (and optionally component (F)) are all mixed together and kneaded. Method 4: After kneading components (A) to (C) and component (E), component (F) such as a fatty acid amide and carbon black (D) are added and kneaded. Method 5: A method in which a portion of component (A), component (F) such as a fatty acid amide, and carbon black (D) are pre-mixed and pelletized, and the pellets, a portion of component (A), component (B), component (C), and component (E) are then kneaded all at once.

[0072] Furthermore, from the viewpoint of increasing the impact resistance and improving the appearance of a molded article obtained by molding the resin composition, it is preferable that the propylene resin composition according to the present invention has few fish eyes (point-like protrusions or dents) on the surface of the molded article (film, sheet, injection molded article, etc.). Therefore, in order to prevent the occurrence of fisheyes, when producing a resin composition, it is preferable to pass the components through a filter after melt-kneading. The filter may be a single-stage or multi-stage filter.

[0073] The molded article obtained by molding the propylene resin composition according to the present invention is preferably an injection-molded article produced by an injection molding method, in which the occurrence of blue streaks is effectively suppressed. Examples of the injection molding method include general injection molding, injection foam molding, supercritical injection foam molding, ultra-high speed injection molding, injection compression molding, injection press molding, gas-assisted injection molding, sandwich molding, sandwich foam molding, and insert-outsert molding. The molded article can be used, for example, as an automobile part, a home appliance part, a container, etc. Among these, it is particularly suitable as an automobile interior part. [Example]

[0074] The present invention will be described in more detail below with reference to examples and comparative examples, but the technical scope of the present invention is not limited to these examples in any sense.

[0075] The physical properties and characteristics in the examples and comparative examples were evaluated by the following methods. (1) Melt flow rate (MFR, unit: g / 10 min) Measurement was carried out under a load of 2.16 kg according to the method specified in JIS K 6758. The MFR of component (A) and the propylene resin composition was measured at a temperature of 230°C, and the MFR of component (B) was measured at a temperature of 190°C.

[0076] (2) Intrinsic viscosity (unit: dL / g) Measurement was carried out at a temperature of 135°C using tetralin as a solvent according to the following method. Using an Ubbelohde viscometer, the reduced viscosity is measured at three concentrations: 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL. The reduced viscosity is plotted against the concentration, and the intrinsic viscosity is calculated by extrapolation, extrapolating the concentration to zero. The method for calculating the limiting viscosity by extrapolation is described, for example, on page 491 of "Polymer Solutions, Polymer Experiments 11" (published by Kyoritsu Shuppan Co., Ltd. in 1982).

[0077] (3) The ratio of polymer (I) to polymer (II) in the heterophasic propylene polymer material (A-1), the intrinsic viscosity ([η] I , [η] II ) measurement and calculation The intrinsic viscosity ([η]) of the polymer (I) obtained in the previous polymerization step, measured by the method (2) above, I ), and the intrinsic viscosity ([η] of the final polymer (total of polymer (I) and polymer (II)) after the subsequent polymerization step, measured by the above-mentioned method. Total), and the content (weight ratio) of polymer (II) contained in the final polymer, the intrinsic viscosity ([η] II ) was calculated using the following formula: [η] II =([η] Total -[η] I ×X I ) / X II [η] Total : Intrinsic viscosity number (dl / g) of the final polymer after the second polymerization step [η] I : Intrinsic viscosity number (dl / g) of polymer powder extracted from the polymerization tank after the first polymerization step X I : Weight ratio of components polymerized in the previous step X II : Weight ratio of the component polymerized in the subsequent step (X I and X II The sum of

[0078] where X I , X II can be determined from the mass balance during polymerization in each stage.

[0079] In addition, X II The heat of fusion may be measured for the components polymerized in the first step and the heat of fusion of the final polymer after the second step of polymerization, and calculated using the following formula: X II =1-(ΔHf) Total / (ΔHf) I (ΔHf) Total : Heat of fusion of the final polymer after the second polymerization step (J / g) (ΔHf) I : Heat of fusion of the component polymerized in the previous step (J / g)

[0080] (4) Ethylene content in propylene-ethylene random copolymer The ethylene content of the ethylene-α-olefin copolymer in the propylene polymer composition ((C 2’ ) II) is the ethylene content ((C 2’ ) Total ) and compare the measurement results with the above X II It was calculated using the following formula: (C 2’ ) II =(C 2’ ) Total / X II where: (C 2’ ) Total : Ethylene content (mass%) of the entire propylene polymer composition (C 2’ ) II : Ethylene content (mass%) of ethylene-α-olefin copolymer

[0081] (5) Carbon black content (unit: parts by weight) The carbon black content was measured from the heat loss in the third stage under the analytical conditions shown in Table 1 below using a TG / DTA-200 manufactured by Seiko Instruments Inc. [Table 1]

[0082] (6) Thermal stability evaluation The press-molded body produced by the method described below was placed in a gear oven at 160°C and a gear oven life (GOL) test was conducted. Every day, the press-molded body was removed and bent with the fingers to check for cracks. If cracks occurred in the press-molded body during this test, the GOL test for that sample was terminated at that point, and the total time spent in the oven up to that point was recorded as the gear oven life (hereinafter referred to as GOL, unit: hours). A longer GOL indicates better thermal stability.

[0083] - Manufacturing of press-molded products The press-molded articles for the thermal stability evaluation were prepared according to the following method. The propylene resin composition was heated at 230°C for 5 minutes under normal pressure using a heat press, then pressed at 230°C for 5 minutes under 3 MPa, and further cooled at normal temperature for 5 minutes under 5 MPa to obtain a pressed sheet with a thickness of 1 mm. This sheet was punched out with a punching blade to obtain a disk-shaped press-molded product (test piece) with a diameter of 25 mm and a thickness of 1 mm.

[0084] (7) Poor blue streaks -Method of manufacturing a molded body for evaluating blue streak defects The propylene resin composition was injection molded under the following conditions to produce an injection-molded article for evaluation: The propylene resin composition was melted in an injection molding machine and supplied from the gate into a mold cavity by the injection molding machine. Molding conditions: Mold cavity shape: 100mm (width) x 150mm (length) x 3mm (thickness) Gate: 1 gate in the center of the 100mm side Cylinder temperature: 220℃ Mold temperature: 50℃

[0085] ·Evaluation method for blue streak defects Thirty of the above-mentioned molded bodies were molded in succession under the above molding conditions, and the number of molded bodies in which blue streaks were observed out of the 30 was used as a score. If no blue streaks were observed, the score was 0.

[0086] Details of each component / raw material used in the examples / comparative examples are as follows.

[0087] (Propylene resin (A)) As the propylene resin (A), the following two types were used, which were produced by polymerizing a propylene homopolymer in a first polymerization step and polymerizing an ethylene-propylene copolymer in a second polymerization step in the presence of a polymerization catalyst obtained by the method described in Example 1 of JP-A-2004-182981.

[0088] (A-1-i) Propylene-(ethylene-propylene) polymer material A heterophasic propylene polymer material containing 88.0% by weight of the following polymer (I) and 12.0% by weight of polymer (II), and having an overall MFR (230° C., 2.16 kgf load) of 65 g / 10 min, was used. Polymer (I) Intrinsic viscosity number ([η] I ):0.90dl / g Polymer (II) Ethylene content: 30% by weight Intrinsic viscosity number ([η] II ): 5.1dl / g

[0089] (A-1-ii) Propylene-(ethylene-propylene) polymer material A heterophasic propylene polymer material containing 86.0% by weight of the following polymer (I) and 14.0% by weight of polymer (II), and having an overall MFR (230° C., 2.16 kgf load) of 63 g / 10 min, was used. Polymer (I) Intrinsic viscosity number ([η] I ):0.86dl / g Polymer (II) Ethylene content: 30% by weight Intrinsic viscosity number ([η] II ): 5.1dl / g

[0090] (Ethylene-α-olefin copolymer (B)) (B-1-i) Ethylene-octene random copolymer Product name: ENGAGE EG8150 (manufactured by Dow Chemical Japan Co., Ltd.) Density: 0.868(g / cm 3 ) MFR (190°C, 21.18N load): 0.5g / 10min (B-1-ii) Ethylene-butene random copolymer Product name: ENGAGE EG7387 (manufactured by Dow Chemical Japan Co., Ltd.) Density: 0.870(g / cm 3 ) MFR (190°C, 21.18N load): 0.3g / 10min (B-2-i) Ethylene-octene random copolymer Product name: ENGAGE EG8137 (manufactured by Dow Chemical Japan Co., Ltd.) Density: 0.870(g / cm 3 ) MFR (190°C, 21.18N load): 13g / 10min (B-2-ii) Ethylene-octene random copolymer Product name: ENGAGE EG8407 (manufactured by Dow Chemical Japan Co., Ltd.) Density: 0.870(g / cm 3 ) MFR (190°C, 21.18N load): 30g / 10min

[0091] (Inorganic filler (C)) talc Average particle size (laser diffraction method, 50% equivalent particle size D 50 ): 5.6 μm

[0092] (Carbon black (D)) A pigment masterbatch (D') containing carbon black was used.

[0093] (D'-i) Pigment masterbatch Carbon black (Di) content: 50% Carbon black pH: 7.5

[0094] (D'-ii) Pigment masterbatch Carbon black (D-ii) content: 51% Carbon black pH: 7.5

[0095] (D'-iii) Pigment masterbatch Carbon black (D-iii) content: 4.5% Carbon black pH: 2.5

[0096] (Modified polypropylene (E)) Maleic anhydride modified PP Product name: TPPP9112 (BYK)

[0097] (Lubricant (F)) Erucic acid amide Product name: Neutron-S (manufactured by Nippon Fine Chemical Co., Ltd.)

[0098] Example 1 [Production of Propylene Resin Composition] Propylene resin (A), ethylene-α-olefin copolymer (B), and inorganic filler (C) were blended in the proportions shown in Table 2 below (where the total amount of components (A), (B), and (C) is 100% by weight). Additionally, pigment masterbatch (D'-1), modified PP (E), and fatty acid amide (F) were blended in the proportions (parts by mass) also shown in Table 2 with 100 parts by weight of the total amount of components (A), (B), and (C) (where the pigment masterbatch (D'-i) was blended in an amount such that the carbon black (Di) content was as shown in Table 2). The blended mixture was kneaded and extruded under vent suction using a twin-screw kneading extruder to produce a resin composition. The thermal stability and appearance (blue streaks) of the resulting propylene resin composition were evaluated, and the results are shown in Table 2 below.

[0099] [Examples 2-3 and Comparative Examples 1-2] Propylene resin compositions were produced in the same manner as in Example 1, except that the components and blending amounts of the propylene resin compositions were changed to those shown in Table 2 (however, the pigment masterbatches (D'-ii) and (D'-iii) were blended in amounts such that the contents of carbon black (D-ii) and (D-iii) were the contents shown in Table 2), and the thermal stability and appearance (poor blue streaks) were evaluated. The results are shown in Table 2.

[0100] [Table 2]

[0101] As a reference example, a propylene resin composition for injection molding different from the propylene resin composition of the present invention is shown, which contains 60% by weight of (A-1-ii), 3% by weight of (B-1-i), 15% by weight of (B-1-ii), and 22% by weight of an inorganic filler (C), and further contains 0.4 parts by weight of a lubricant (F) per 100 parts by weight of the total weight of these components. [Industrial Applicability]

[0102] The propylene resin composition of the present invention has excellent properties, such as the ability to produce injection-molded articles having good surface appearance and excellent resistance to heat degradation, and is therefore particularly preferably used as an injection molding material, and is suitably used for various automobile interior and exterior parts such as instrument panels, glove boxes, trims, housings, pillars, bumpers, fenders, and back doors, as well as various parts for home appliances, various housing equipment parts, various industrial parts, and various building material parts, and has high applicability in various industrial fields such as the transportation machinery industry, the electrical and electronics industry, and the building and construction industry.

Claims

1. a propylene resin (A) containing a heterophasic propylene polymerization material (A-1) containing 65 to 95 mass% of a polymer (I) containing 80 mass% or more of monomer units derived from propylene (wherein the total mass of the polymer (I) is 100 mass%) and a polymer (II) containing monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having from 4 to 12 carbon atoms and monomer units derived from propylene; an ethylene-α-olefin copolymer (B) containing an ethylene-α-olefin copolymer (B-1) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less and an ethylene-α-olefin copolymer (B-2) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 10 g / 10 min or more, wherein the proportion of structural units derived from the α-olefin is 1 to 49 mass%; an inorganic filler (C) other than carbon black; Carbon black (D) having a pH greater than 5; and a modified polypropylene (E), A propylene resin composition, wherein the content of carbon black (D) is 0.5 parts by weight or more and 5.0 parts by weight or less, and the content of modified polypropylene (E) is 0.1 parts by weight or more and 1.0 part by weight or less, relative to 100 parts by weight of the total weight of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C).

2. 2. The propylene resin composition according to claim 1, wherein the content of the propylene resin (A) is 50% by weight or more and 75% by weight or less, the content of the ethylene-α-olefin copolymer (B) is 10% by weight or more and 25% by weight or less, and the content of the inorganic filler (C) is 15% by weight or more and 25% by weight or less, where the total weight of the propylene resin (A), the ethylene-α-olefin copolymer (B), and the inorganic filler (C) is 100% by weight.

3. The ethylene-α-olefin copolymer (B-1) is an ethylene-1-octene copolymer (B-1-1) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less; an ethylene-1-butene copolymer (B-1-2) having a melt flow rate (190°C, 2.16 kgf load, in accordance with JIS-K-7210) of 0.8 g / 10 min or less; The propylene resin composition according to claim 1 or 2, comprising:

4. The propylene resin composition according to any one of claims 1 to 3, wherein the ethylene-α-olefin copolymer (B-2) contains an ethylene-1-octene copolymer.

5. The propylene resin composition according to any one of claims 1 to 4, further comprising a lubricant (F).

6. 6. The propylene resin composition according to claim 5, wherein the lubricant (F) is at least one selected from the group consisting of fatty acid amide-based lubricants and silicone-based lubricants.

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

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