Propylene-based polymer composition and molded body of same

Abstract

Provided is a propylene-based polymer composition which is capable of reducing odor that may occur when exposed to high temperatures in the interior of a vehicle.　Specifically provided is a propylene-based polymer composition which contains a propylene-based polymer and talc, wherein: if the total of the content of the propylene-based polymer and the content of the talc is taken as 100 parts by mass, the content of the propylene-based polymer is 98.5 parts by mass to 55 parts by mass, and the content of the talc is 1.5 parts by mass to 45 parts by mass; the average particle diameter of the talc is 2 μm to 13 μm as measured by a wet laser diffraction method; and the first heating loss in the range of 450°C to 590°C in a differential curve obtained by differential thermogravimetric measurement (DTG) using 10 mg of the talc that is extracted from the propylene-based polymer composition is 60 μg or more and less than 230 μg, and the second heating loss in the range of 620°C to 730°C is more than 0 μg and less than 300 μg.

Description

Propylene polymer composition and molded article thereof

[0001] The present invention relates to a propylene polymer composition and a molded article thereof.

[0002] A propylene-based polymer composition containing a propylene-based polymer has good mechanical properties and can be used in various applications. The propylene-based polymer composition can be suitably used, for example, as a material for forming automotive components.

[0003] As a propylene-based polymer composition that can be used as a material for forming automobile parts (automotive members), for example, a composition that has good moldability during injection molding and is formulated with a propylene-ethylene block copolymer having a high polymer rubber content and an inorganic filler, for the purpose of improving physical properties such as flexural modulus, low-temperature impact resistance, and linear expansion characteristics, is known (see Patent Document 1).

[0004] Since the interior of an automobile can be a closed space, odors generated inside the interior can cause discomfort to the driver and passengers.

[0005] If the temperature inside the vehicle cabin becomes high, for example, at 50°C to 60°C, due to various factors such as the external environment, odors may be emitted from components inside the vehicle cabin that are exposed to high temperatures.

[0006] Japanese Patent Application Laid-Open No. 2002-97337

[0007] A propylene-based polymer composition containing a propylene-based polymer has good mechanical properties and is used for various applications, and is suitably used as a material for forming members to be provided in the interior of an automobile, which may be a closed space at high temperatures of 50°C to 60°C.

[0008] Furthermore, if an odor is generated in the vehicle interior, it may cause discomfort to the driver and passengers. Therefore, it is preferable that the propylene-based polymer composition and, further, the automobile interior parts that are molded articles obtained by molding the propylene-based polymer composition, generate less odor when exposed to high temperatures.

[0009] Therefore, there is a demand for a propylene-based polymer composition that generates little odor, particularly when exposed to high temperatures, and a molded article made from the propylene-based polymer composition.

[0010] The present inventors have conducted extensive research to solve the above problems and have found that the above problems can be solved by using specific components in specific amounts, thereby completing the present invention.

[0011] That is, the present invention provides the following [1] to

[10] : [1] A propylene polymer composition containing a propylene polymer and talc, wherein, when the total of the propylene polymer content and the talc content is 100 parts by mass, the propylene polymer content is 98.5 parts by mass to 55 parts by mass and the talc content is 1.5 parts by mass to 45 parts by mass, the talc has an average particle size measured by wet laser diffraction method of 2 μm to 13 μm, and a derivative curve obtained by differential thermogravimetry (DTG) using 10 mg of the talc extracted from the propylene polymer composition shows a first loss on heating in the range of 450°C to 590°C of 60 μg or more and less than 230 μg, and a second loss on heating in the range of 620°C to 730°C of more than 0 μg and less than 300 μg. [2] The propylene polymer composition according to [1], wherein the first loss on heating is 90 μg to 200 μg. [3] The propylene polymer composition according to [1] or [2], wherein the second loss on heating is 40 μg to 270 μg. [4] The propylene polymer composition according to any one of [1] to [3], wherein the calcium content of the talc is 0.3 parts by mass to 2.0 parts by mass, relative to 100 parts by mass of the talc. [5] The propylene polymer composition according to any one of [1] to [4], wherein the average particle size of the talc is 4 μm to 13 μm. [6] The propylene polymer composition according to any one of [1] to [5], wherein the propylene polymer is a heterophasic propylene polymerization material. [7] The propylene polymer composition according to any one of [1] to [6], further comprising an ethylene-α-olefin copolymer. [8] The propylene-based polymer composition according to [7], wherein the ethylene-α-olefin copolymer is an ethylene-1-butene copolymer. [9] A molded article obtained by molding the propylene-based polymer composition according to any one of [1] to [8].

[10] The molded article according to [9], which is an automobile interior part.

[0012] According to the present invention, it is possible to provide a propylene-based polymer composition capable of reducing odors that may be generated when exposed to high temperatures in a vehicle cabin, and a molded article obtained by molding the propylene-based polymer composition, i.e., various automotive interior parts.

[0013] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the embodiments and examples shown below.

[0014] In this specification, "AA to BB" means AA or more and BB or less. Here, AA and BB each represent a numerical value, and AA<BB. The unit of AA is the same as the unit written immediately after BB, unless otherwise specified.

[0015] As used herein, the term "monomer unit" refers to a structural unit formed when a monomer is polymerized, and having a structure derived from the monomer.

[0016] As used herein, the term "α-olefin" refers to an olefin having a terminal carbon-carbon double bond.

[0017] As used herein, the term "intrinsic viscosity number (unit: dL / g)" refers to a value measured at 135°C using tetralin as a solvent by the following method. Specifically, this method involves measuring the reduced viscosity at multiple concentrations using an Ubbelohde viscometer, plotting the reduced viscosity against the concentration, and determining the intrinsic viscosity by an "extrapolation method" in which the concentration is extrapolated to zero. More specifically, this method is described on page 491 of "Polymer Solutions, Polymer Experiments 11" (published by Kyoritsu Shuppan Co., Ltd. in 1982), in which the reduced viscosity is measured at three concentrations of 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL, the reduced viscosity is plotted against the concentration, and the concentration is extrapolated to zero.

[0018] 1. Propylene-Based Polymer Composition The propylene-based polymer composition according to this embodiment comprises a propylene-based polymer and talc, wherein, when the total of the propylene-based polymer content and the talc content is taken as 100 parts by mass, the propylene-based polymer content is 98.5 parts by mass to 55 parts by mass and the talc content is 1.5 parts by mass to 45 parts by mass, the talc content has an average particle size measured by wet laser diffraction of 2 μm to 13 μm, and a derivative curve obtained by differential thermogravimetry (DTG) using 10 mg of the talc extracted from the propylene-based polymer composition shows a first loss on heating of 60 μg or more and less than 230 μg in the range of 450° C. to 590° C., and a second loss on heating of more than 0 μg and less than 300 μg in the range of 620° C. to 730° C.

[0019] The propylene polymer composition (and molded article thereof) according to this embodiment can reduce odors that may be generated when exposed to high temperatures in the interior of an automobile, for example.

[0020] Components that can be contained in the propylene polymer composition of the present embodiment will be described below.

[0021] (1) Propylene-Based Polymer The propylene-based polymer composition of this embodiment contains a propylene-based polymer. The propylene-based polymer is a polymer containing more than 50% by mass of propylene units, which are structural units derived from propylene, when the total amount of all structural units of the propylene-based polymer is 100% by mass. The content of propylene units that can be contained in the propylene-based polymer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, and is usually 100% by mass or less, and may be 100% by mass.

[0022] The propylene-based polymer includes a propylene homopolymer and a copolymer of propylene and another monomer copolymerizable with propylene. The copolymer with such another monomer may be a random copolymer (hereinafter also referred to as a propylene-based random copolymer) or a block copolymer.

[0023] Here, preferred examples of "other monomers copolymerizable with propylene" include α-olefins (eg, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene).

[0024] The propylene polymer that can be contained in the propylene polymer composition of the present embodiment can be produced by any suitable conventionally known method.

[0025] The propylene polymer composition of the present embodiment may contain one kind of propylene polymer alone, or may contain two or more kinds of propylene polymers in any combination and in any ratio.

[0026] Examples of the single propylene polymer include a propylene homopolymer and a propylene random copolymer.

[0027] Examples of combinations of two or more propylene polymers include combinations of two or more propylene homopolymers differing in weight average molecular weight, as well as combinations of polymer (I) and polymer (II) described below.

[0028] In this embodiment, the propylene-based polymer may be a heterophasic propylene polymer material. That is, the propylene-based polymer composition of this embodiment may contain a heterophasic propylene polymer material as the propylene-based polymer.

[0029] Here, the heterophasic propylene polymer material refers to a material containing two or more types of propylene polymers, in which the two or more types of propylene polymers are not compatible with each other and form separate phases.

[0030] Examples of heterophasic propylene polymer materials include materials containing polymer (I) and polymer (II) described below.

[0031] Here, polymer (I) is a polymer containing propylene units in an amount of more than 80% by mass and not more than 100% by mass, where the total amount of the structural units contained is taken as 100% by mass.

[0032] Furthermore, polymer (II) is a copolymer of propylene units and at least one monomer unit selected from the group consisting of ethylene units and α-olefin units having 4 or more carbon atoms. When the total amount of structural units is taken as 100 mass%, polymer (II) is preferably a polymer containing propylene units in a content of more than 0 mass% and not more than 90 mass%, more preferably a polymer containing propylene units in a content of more than 0 mass% and not more than 80 mass%.

[0033] Here, the α-olefin units that can constitute the polymer (II) are preferably α-olefin units derived from 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, and more preferably α-olefin units derived from 1-butene, 1-hexene, and 1-octene.

[0034] The polymer (I) may be a propylene homopolymer or a copolymer of propylene and another monomer copolymerizable with propylene as described above. The polymer (I) and the polymer (II) may each be a single polymer or a combination of two or more polymers.

[0035] From the viewpoint of improving the rigidity and impact resistance of a molded article obtained by molding the propylene polymer composition of the present embodiment, the propylene polymer is preferably at least one selected from the group consisting of propylene homopolymers and heterophasic propylene polymer materials.

[0036] The propylene polymer is used from the viewpoint of improving the rigidity of a molded article obtained by molding the propylene polymer composition. １３The isotactic pentad fraction (also referred to as the [mmmm] fraction) measured by C-NMR is preferably 0.97 or more, more preferably 0.98 or more. The closer the isotactic pentad fraction of a propylene polymer is to 1, the higher the stereoregularity of the molecular structure of the propylene polymer and the higher the crystallinity of the propylene polymer. When the propylene polymer is a copolymer, the isotactic pentad fraction can be measured for the chain of propylene units in the copolymer.

[0037] From the viewpoint of improving the moldability of the propylene polymer composition, the propylene polymer preferably has a melt flow rate (MFR) of 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, even more preferably 1 g / 10 min or more, particularly preferably 3 g / 10 min or more, and is preferably 500 g / 10 min or less, more preferably 300 g / 10 min or less, and even more preferably 3 g / 10 min to 300 g / 10 min, as measured in accordance with JIS K7210-1:2014 and K7210-2:2014 under conditions of 230°C and a load of 2.16 kgf.

[0038] The propylene polymer can be produced, for example, by a polymerization method described later using a polymerization catalyst described later.

[0039] Specific examples of the polymerization catalyst include a Ziegler-type catalyst system; a Ziegler-Natta-type catalyst system; a catalyst system containing a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane; a catalyst system containing a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that reacts with the compound to form an ionic complex, and an organoaluminum compound; and a catalyst system in which a catalyst component (e.g., a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that forms an ionic complex, or an organoaluminum compound) is supported on inorganic particles (e.g., silica, clay minerals) and modified. Furthermore, a prepolymerization catalyst prepared by prepolymerizing a monomer such as ethylene or an α-olefin in the presence of the polymerization catalyst already described can also be used.

[0040] 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] Examples of the polymerization catalyst include the catalysts described in JP-A-61-218606, JP-A-5-194685, JP-A-7-216017, JP-A-9-316147, JP-A-10-212319, and JP-A-2004-182981.

[0042] Examples of polymerization methods include bulk polymerization, solution polymerization, and gas-phase polymerization. Here, bulk polymerization refers to a method in which polymerization is carried out using, for example, liquid propylene as a medium at the polymerization temperature. Solution 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 the medium.

[0043] Examples of the polymerization method include a batch method, a continuous method, and a combination thereof. The polymerization method may be a multi-stage method in which the polymerization is carried out using a plurality of polymerization reactors connected in series.

[0044] Various conditions in the polymerization step included in the polymerization method (polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, polymerization time, etc.) can be appropriately determined depending on the desired propylene-based polymer.

[0045] In the method for producing a propylene polymer, a step of holding the obtained propylene polymer at a temperature at which the impurities can volatilize but which is lower than the temperature at which the obtained propylene polymer melts may be carried out in order to remove impurities such as residual solvent contained in the obtained propylene polymer and ultralow molecular weight oligomers by-produced during the production. Examples of the method (step) for removing such impurities include the methods described in JP-A-55-75410 and JP-A-2565753.

[0046] In the propylene homopolymer, from the viewpoint of improving the fluidity of the propylene polymer composition when melted and the toughness of a molded article obtained by molding the propylene polymer composition, the intrinsic viscosity number [η] is preferably 0.1 to 5 dL / g, more preferably 0.5 to 5 dL / g, and most preferably 0.7 to 4 dL / g. Here, the intrinsic viscosity number [η] is a value measured in tetralin at 135°C.

[0047] From the viewpoint of improving the fluidity of the propylene homopolymer composition when melted and the toughness of a molded article obtained by molding the propylene homopolymer composition, the molecular weight distribution Mw / Mn of the propylene homopolymer is preferably 2 or more and less than 10, more preferably 3 to 8, and even more preferably 3 to 7. Here, Mw represents the weight-average molecular weight, and Mn represents the number-average molecular weight. The molecular weight distribution Mw / Mn is a value measured by gel permeation chromatography (also referred to as GPC).

[0048] Examples of propylene-based random copolymers include a random copolymer containing propylene units and ethylene units (hereinafter also referred to as random copolymer (1)); a random copolymer containing propylene units and α-olefin units having 4 or more carbon atoms (hereinafter also referred to as random copolymer (2)); and a random copolymer containing propylene units, ethylene units, and α-olefin units having 4 or more carbon atoms (hereinafter also referred to as random copolymer (3)).

[0049] The α-olefin having 4 or more carbon atoms that can constitute the propylene-based random copolymer is preferably an α-olefin having 4 to 10 carbon atoms. Examples of the α-olefin having 4 to 10 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, and preferably 1-butene, 1-hexene, and 1-octene.

[0050] Examples of the random copolymer (2) include propylene-1-butene random copolymer, propylene-1-hexene random copolymer, propylene-1-octene random copolymer, and propylene-1-decene random copolymer.

[0051] Examples of the random copolymer (3) include propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer, and propylene-ethylene-1-decene copolymer.

[0052] When the total amount of structural units in the random copolymer (1) is taken as 100% by mass, the content of ethylene units is preferably 0.1 to 60% by mass, and more preferably 10 to 50% by mass.

[0053] When the total amount of structural units in the random copolymer (2) is taken as 100% by mass, the content of α-olefin units having 4 or more carbon atoms is preferably 0.1 to 80% by mass, more preferably 1 to 75% by mass, and even more preferably 5 to 72% by mass.

[0054] When the total amount of structural units in the random copolymer (3) is taken as 100% by mass, the total content of ethylene units and α-olefin units having 4 or more carbon atoms is preferably 0.1 to 80% by mass, more preferably 1 to 75% by mass, and even more preferably 5 to 50% by mass.

[0055] When the total amount of the constituent units in each of the random copolymers (1) to (3) is taken as 100% by mass, the content of the propylene unit is preferably 20 to 99.9% by mass.

[0056] As already explained, the polymer (I) that can be contained in the heterophasic propylene polymerization material is a polymer containing more than 80% by mass and not more than 100% by mass of propylene units, when the total amount of constituent units is taken as 100% by mass. The total content of monomer units other than propylene units in the polymer (I), when the mass of the polymer (I) is taken as 100% by mass, is usually 0% by mass or more and less than 20% by mass, and may be 0% by mass or more, or may be 0.01% by mass or more.

[0057] Examples of the monomer unit other than the propylene unit that may be contained in the polymer (I) include an ethylene unit and an α-olefin unit having 4 or more carbon atoms.

[0058] The α-olefin having 4 or more carbon atoms that can constitute the polymer (I) is preferably an α-olefin having 4 to 10 carbon atoms, more preferably 1-butene, 1-hexene, and 1-octene, and even more preferably 1-butene.

[0059] Examples of the polymer (I) include propylene homopolymer, 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.

[0060] Among these, 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 from the viewpoint of improving the rigidity of a molded article obtained by molding the propylene-based polymer composition, a propylene homopolymer is particularly preferred.

[0061] As already explained, the polymer (II) that the heterophasic propylene polymerization material may contain is a copolymer of a propylene unit and at least one monomer unit selected from the group consisting of an ethylene unit and an α-olefin unit having 4 or more carbon atoms.

[0062] The total content of ethylene units and α-olefin units having 4 or more carbon atoms in polymer (II) is preferably 20 to 80% by mass, and more preferably 20 to 60% by mass, when the mass of polymer (II) is taken as 100% by mass.

[0063] The α-olefin having 4 or more carbon atoms that can constitute polymer (II) is preferably an α-olefin having 4 to 10 carbon atoms, and examples thereof include the same as the examples of α-olefins that can constitute polymer (I) already described above.

[0064] Examples of the polymer (II) include a propylene-ethylene copolymer, a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, a propylene-ethylene-1-octene copolymer, a propylene-ethylene-1-decene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer, a propylene-1-octene copolymer, and a propylene-1-decene copolymer, of which a propylene-ethylene copolymer, a propylene-1-butene copolymer, and a propylene-ethylene-1-butene copolymer are preferred, and a propylene-ethylene copolymer is more preferred.

[0065] The content of polymer (II) in the heterophasic propylene polymerization material is preferably 1 to 50 mass%, more preferably 1 to 45 mass%, even more preferably 5 to 40 mass%, and particularly preferably 8 to 32 mass%, when the total mass of polymer (I) and polymer (II) is 100 mass%.

[0066] Examples of heterophasic propylene polymer materials include the following combinations in which polymer (I) is a propylene homopolymer: a combination of a propylene homopolymer and a (propylene-ethylene) copolymer; a combination of a propylene homopolymer and a (propylene-ethylene-1-butene) copolymer; a combination of a propylene homopolymer and a (propylene-ethylene-1-hexene) copolymer; a combination of a propylene homopolymer and a (propylene-ethylene-1-octene) copolymer; a combination of a propylene homopolymer and a (propylene-1-butene) copolymer; a combination of a propylene homopolymer and a (propylene-1-hexene) copolymer; a combination of a propylene homopolymer and a (propylene-1-octene) copolymer; a combination of a propylene homopolymer and a (propylene-1-decene) copolymer.

[0067] Another example of a heterophasic propylene polymer material is the following combination, in which polymer (I) is a polymer containing propylene units and monomer units other than propylene units: Here, polymer (I) is described first, and polymer (II) is described after it. a combination of a (propylene-ethylene) copolymer and a (propylene-ethylene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-ethylene-1-butene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-ethylene-1-hexene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-ethylene-1-octene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-ethylene-1-decene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-1-butene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-1-hexene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-1-octene) copolymer; a combination of a (propylene-ethylene) copolymer and a (propylene-1-decene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-ethylene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-ethylene-1-butene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-ethylene-1-hexene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-ethylene-1-octene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-ethylene-1-decene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-1-butene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-1-hexene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-1-octene) copolymer; a combination of a (propylene-1-butene) copolymer and a (propylene-1-decene) copolymer; a combination of a (propylene-1-hexene) copolymer and a (propylene-1-hexene) copolymer;a combination of a (propylene-1-hexene) copolymer and a (propylene-1-octene) copolymer; a combination of a (propylene-1-hexene) copolymer and a (propylene-1-decene) copolymer; a combination of a (propylene-1-octene) copolymer and a (propylene-1-octene) copolymer; and a combination of a (propylene-1-octene) copolymer and a (propylene-1-decene) copolymer;

[0068] The heterophasic propylene polymer material that can be contained in the propylene-based polymer composition of the present embodiment is preferably a combination of a propylene homopolymer and a (propylene-ethylene) copolymer, a combination of a propylene homopolymer and a (propylene-ethylene-1-butene) copolymer, a combination of a (propylene-ethylene) copolymer and a (propylene-ethylene) copolymer, a combination of a (propylene-ethylene) copolymer and a (propylene-ethylene-1-butene) copolymer, or a combination of a (propylene-1-butene) copolymer and a (propylene-1-butene) copolymer, more preferably a combination of a propylene homopolymer and a (propylene-ethylene) copolymer.

[0069] The heterophasic propylene polymer material can be produced by a multi-stage polymerization process including a first polymerization step of producing polymer (I) and a second polymerization step of producing polymer (II) in the presence of polymer (I) produced in the first polymerization step. The polymerization can be carried out using a catalyst that can be used for producing propylene polymers as described above.

[0070] The intrinsic viscosity number (hereinafter referred to as [η]I) of the polymer (I) is preferably 0.1 to 5 dL / g, more preferably 0.5 to 5 dL / g, and even more preferably 0.7 to 4 dL / g. Here, the intrinsic viscosity number [η]I is a value measured in tetralin at 135°C.

[0071] The intrinsic viscosity number (hereinafter referred to as [η]II) of the polymer (II) is preferably 1 to 10 dL / g, more preferably 2 to 10 dL / g, and even more preferably 2.5 to 8 dL / g. Here, the intrinsic viscosity number [η]II is a calculated value calculated by the formula described below.

[0072] The ratio of [η]II to [η]I ([η]II / [η]I) is preferably 0.5 to 20, more preferably 0.8 to 10, and even more preferably 0.9 to 9.

[0073] When the propylene-based polymer is a material composed of polymer (I) and polymer (II) formed by multistage polymerization, a portion of the polymer formed in the first polymerization step is extracted from the polymerization vessel in which the first polymerization step has been carried out, and the intrinsic viscosity of the polymer is determined. The intrinsic viscosity of the polymer material finally obtained by further carrying out the second polymerization step (hereinafter, referred to as ([η] Total)) is determined, and the intrinsic viscosity of the polymer formed in the second polymerization step is calculated using these limiting viscosity values ​​and the content of each polymer.

[0074] Furthermore, when a polymer material composed of polymer (I) and polymer (II) is produced by a method in which polymer (I) is obtained in an earlier polymerization step and polymer (II) is obtained in a later polymerization step, the procedures for measuring and calculating the contents and limiting viscosity numbers ([η] Total, [η] I, and [η] II) of each of polymer (I) and polymer (II) are as follows.

[0075] The intrinsic viscosity number [η]II of polymer (II) is calculated from the intrinsic viscosity number ([η]I) of polymer (I) obtained in the previous polymerization step, the intrinsic viscosity number ([η]Total) of the polymer finally obtained after the subsequent polymerization step (i.e., the polymer material consisting of polymer (I) and polymer (II), hereinafter simply referred to as the final polymer) measured by the method already described above, and the content of polymer (II) contained in the final polymer, using the following formula:

[0076] [η]II = ([η]Total - [η]I × XI) / XII [η]Total: intrinsic viscosity number of the final polymer (unit: dL / g) [η]I: intrinsic viscosity number of polymer (I) (unit: dL / g) XI: mass ratio of polymer (I) to the final polymer XII: mass ratio of polymer (II) to the final polymer XI and XII are determined from the mass balance during polymerization.

[0077] The mass ratio XII of polymer (II) to the final polymer may be calculated using the following formula using the heat of crystalline fusion of each of polymer (I) and the final polymer: XII=1-(ΔHf)T / (ΔHf)P, where (ΔHf)T: heat of fusion of the final polymer (polymer (I) and polymer (II)) (unit: cal / g) (ΔHf)P: heat of fusion of polymer (I) (unit: cal / g).

[0078] The molecular weight distribution (Mw / Mn) of the polymer (I) measured by GPC is preferably 1 or more and less than 10, more preferably 2-7, and even more preferably 3-5.

[0079] In the propylene polymer composition of the present embodiment, the content of the propylene polymer is preferably 98.5% by mass (parts by mass) to 55% by mass (parts by mass), more preferably 95% by mass (parts by mass) to 60% by mass (parts by mass), and even more preferably 90% by mass to 75% by mass, when the total amount of the propylene polymer (and ethylene-α-olefin copolymer) content and the talc content is 100% by mass (100 parts by mass).

[0080] (2) Ethylene-α-olefin copolymer The propylene polymer composition may further contain an ethylene-α-olefin copolymer in addition to the propylene polymer already described. Specifically, the propylene polymer composition may further contain an olefin copolymer containing ethylene units and α-olefin units having 4 or more carbon atoms. Hereinafter, the olefin copolymer containing ethylene units and α-olefin units having 4 or more carbon atoms is also referred to as an ethylene-α-propylene copolymer (4).

[0081] The propylene polymer composition may contain one type of ethylene-α-olefin copolymer (4) alone, or may contain two or more types in any ratio.

[0082] The content of the ethylene-α-olefin copolymer (4) in the propylene polymer composition of the present embodiment is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, and even more preferably 5 to 25% by mass, based on 100% by mass of the total amount of the propylene polymer composition.

[0083] In the propylene polymer composition of the present embodiment, the content of the ethylene-α-olefin copolymer (4) is preferably 0% by mass (parts by mass) to 40% by mass (parts by mass), more preferably 5% by mass (parts by mass) to 30% by mass (parts by mass), and even more preferably 10% by mass (parts by mass) to 25% by mass (parts by mass), based on 100% by mass (parts by mass) of the total amount of the propylene polymer and the ethylene-α-olefin copolymer (4), from the viewpoint of improving impact resistance.

[0084] The total content of ethylene units and α-olefin units having 4 or more carbon atoms in the ethylene-α-olefin copolymer (4) is preferably 95% by mass or more, more preferably 98% by mass or more, and even more preferably 99% by mass or more, when the total amount of the ethylene-α-olefin copolymer (4) is taken as 100% by mass, and is usually 100% by mass or less, and may be 100% by mass.

[0085] Examples of the α-olefin having 4 or more carbon atoms that can constitute the ethylene-α-olefin copolymer (4) include α-olefins having 4 to 12 carbon atoms (e.g., 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene).

[0086] In this embodiment, the α-olefins having 4 or more carbon atoms that can constitute the ethylene-α-olefin copolymer (4) are preferably 1-butene, 1-hexene, and 1-octene.

[0087] The α-olefin having 4 or more carbon atoms may be an α-olefin having a cyclic structure and having 4 or more carbon atoms including the carbon atoms constituting the cyclic structure (e.g., vinylcyclopropane, vinylcyclobutane).

[0088] Examples of the ethylene-α-olefin copolymer (4) include 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. From the viewpoint of improving impact resistance, it is preferable to use an ethylene-1-butene copolymer or an ethylene-1-octene copolymer as the ethylene-α-olefin copolymer (4).

[0089] The content of α-olefin units having 4 or more carbon atoms in the ethylene-α-olefin copolymer (4) is preferably 1 to 80 mass%, more preferably 1 to 75 mass%, and even more preferably 10 to 72 mass%, when the total mass of the ethylene-α-olefin copolymer (4) is taken as 100 mass%.

[0090] The ethylene-α-olefin copolymer (4) preferably has a melt flow rate (MFR) of 0.1 g / 10 min to 80 g / 10 min, more preferably 0.2 to 40 g / 10 min, and even more preferably 0.2 to 35 g / 10 min, as measured in accordance with JIS K7210-1:2014 and K7210-2:2014 under conditions of 190°C and a load of 2.16 kgf.

[0091] The density of the ethylene-α-olefin copolymer (4) is preferably 0.850 to 0.930 g / cm from the viewpoint of improving the impact resistance of a molded article obtained by molding the propylene-based polymer composition. ３ and more preferably 0.850 to 0.900 g / cm ３ is.

[0092] The ethylene-α-olefin copolymer (4) can be produced, for example, by polymerizing ethylene and an α-olefin having 4 or more carbon atoms using a polymerization catalyst. Examples of the polymerization catalyst include the polymerization catalysts already described as examples of the polymerization catalyst for producing a propylene-based polymer.

[0093] Commercially available ethylene-α-propylene copolymers (4) may be used, 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., and "Excellent FX (registered trademark)," "Sumikathen (registered trademark)," and "Esprene SPO (registered trademark)" manufactured by Sumitomo Chemical Co., Ltd.

[0094] (3) Talc The propylene-based polymer composition of the present embodiment contains talc, which is a plate-like silicate mineral, from the viewpoints of improving the rigidity, impact resistance, and dimensional stability of a molded article obtained by molding the propylene-based polymer composition and further reducing odor.

[0095] The propylene polymer composition of the present embodiment contains a predetermined amount of talc having predetermined properties and characteristics, thereby effectively reducing odors that may be generated from components exposed to high temperatures, particularly temperatures of 50°C to 60°C, or even higher, which can be reached in an automobile cabin.

[0096] Talc that can be suitably used in the propylene-based polymer composition of the present embodiment will be specifically described below.

[0097] First, in the propylene polymer composition of the present embodiment, from the viewpoint of improving rigidity and more effectively reducing odor, the talc content is preferably 1.5% by mass (parts by mass) to 45% by mass (parts by mass), more preferably 5% by mass (parts by mass) to 40% by mass (parts by mass), and even more preferably 10% by mass (parts by mass) to 35% by mass (parts by mass), when the total of the propylene polymer content and the talc content described above is taken as 100% by mass (parts by mass).

[0098] In the propylene polymer composition of the present embodiment, from the viewpoint of more effectively reducing odor, when the talc content is taken as 100 mass% (parts by mass), the calcium content (Ca content) of the talc is preferably 0.3 mass% (parts by mass) to 2.0 mass% (parts by mass), more preferably 0.35 mass% (parts by mass) to 1.93 mass% (parts by mass), and even more preferably 0.40 mass% (parts by mass) to 1.8 mass% (parts by mass).

[0099] Here, the "calcium content (Ca amount) contained in talc" can be measured using any suitable conventionally known XRF measuring device that uses, for example, X-ray fluorescence analysis (fundamental parameter method).

[0100] Here, the "calcium content contained in the talc" can be adjusted to be particularly reduced by, for example, reducing the particle size by pulverization and classifying the talc once or repeatedly using any suitable conventional method.

[0101] Here, the pulverization and classification of talc can be carried out, specifically, by a dry method employing any suitable conventionally known conditions, for example, primary pulverization by a friction-pulverization method using any suitable conventionally known friction-pulverizer, secondary pulverization by a collision-pulverization method using any suitable conventionally known collision-pulverizer, and classification using any suitable conventionally known classifier.

[0102] The attrition-type pulverization method is a method of pulverizing talc by grinding it. Specific examples of devices that can be suitably used in the attrition-type pulverization method include stone mill-type pulverizers such as a VX roller mill, a 5R-type Raymond mill, a 4R-type Raymond mill, a vertical mill, and a mass colloider.

[0103] Collision milling is a method of pulverizing powdered talc by collision. Specific examples of devices that can be suitably used in collision milling include jet mills such as dry fluidized bed jet mills. When using a mill with a built-in classifier, classification may be performed while milling. Furthermore, in the primary or secondary milling, impact milling, i.e., a method of pulverizing powder by applying impact to it using a mill, may be used. Specific examples of devices that can be suitably used in impact milling include atomizers, pulverizers, hammer mills, micron mills, bevel impactors, pin mills, super micron mills, and pin mills.

[0104] In the secondary grinding and classification of talc, particularly when a collision grinding method such as a jet mill is used, from the viewpoint of preventing excessive destruction and excessive pulverization of the talc and improving the balance between rigidity due to high dispersibility and odor reduction, it is preferable to set the conditions such that, for example, the ratio of the talc (particle) supply rate to the air supply rate does not exceed 0.1 and the number of passes is at most 10 passes.

[0105] In the propylene polymer composition of the present embodiment, the average particle size of the talc measured by wet laser diffraction is preferably 2 μm to 13 μm, more preferably 4 μm to 13 μm, even more preferably 4.1 μm to 13 μm, and particularly preferably 4.1 μm to 5.2 μm, from the viewpoint of improving rigidity.

[0106] In this embodiment, the "average particle size" of talc is a volume-weighted average particle size, generally referred to simply as MV. Specifically, the average particle size (MV) of talc can be obtained in accordance with JIS R 1629-1997 by any suitable conventional wet laser diffraction method, in which talc is treated with a homogenizer for, for example, 10 minutes to prepare a sample dispersed with a surfactant, and the sample is irradiated with a laser beam to measure diffraction (scattering).

[0107] In this embodiment, in a differential curve obtained by differential thermogravimetry (DTG) using 10 mg of talc extracted from the propylene-based polymer composition, the first loss on heating in the range of 450°C to 590°C is 60 μg or more and less than 230 μg, and the second loss on heating in the range of 620°C to 730°C is more than 0 μg and less than 300 μg. A detailed description of the method for measuring the loss on heating will be given later.

[0108] In this embodiment, from the viewpoint of improving rigidity, it is necessary to pulverize the talc. On the other hand, from the viewpoint of further reducing odor generation, it is desirable to keep the first heat loss as small as possible.

[0109] In this embodiment, the first loss on heating is preferably as small as possible from the viewpoint of further reducing odor generation. Specifically, the first loss on heating is preferably 60 μg or more and less than 230 μg, more preferably 90 μg to 200 μg, even more preferably 90 μg to 192 μg, and particularly preferably 90 μg to 180 μg.

[0110] The first loss on heating is related to the Ca content, as described above. The first loss on heating correlates with the amount of the most thermally unstable crystal defects in talc, and these crystal defects are thought to be related to the generation of odor due to thermal decomposition of components of the propylene polymer composition, such as additives. Therefore, by repeatedly grinding and classifying talc, calcium, which is the origin of talc crystal defects, is shaken off, reducing the amount of residual calcium and increasing the talc crystal defects. As a result, it is thought that the first loss on heating, which corresponds to the amount of the most thermally unstable structural defects, increases. Therefore, the first loss on heating can be adjusted by the talc treatment (adjusting the particle size, including grinding and classification, and adjusting the Ca content) as described above.

[0111] In this embodiment, the second loss on heating is preferably larger from the viewpoint of further reducing odor generation. Specifically, the second loss on heating is preferably more than 0 μg and less than 300 μg, more preferably 40 μg to 270 μg, even more preferably 0 μg to 268 μg, still more preferably 42 μg to 268 μg, and particularly preferably 45 μg to 268 μg.

[0112] The second loss on heating, like the first loss on heating, represents the amount of crystal defects. The crystal defects in the second loss on heating are more thermally stable and do not contribute to the decomposition of the components contained in the propylene polymer composition, but rather serve to prevent the decomposition of the components. Therefore, it is believed that the odor can be reduced by increasing the second loss on heating.

[0113] According to the propylene polymer composition of this embodiment, as described above, it is preferable that the first loss on heating be smaller and the second loss on heating be larger, from the viewpoint of effectively reducing odor generation. Thus, according to the propylene polymer composition of this embodiment, the ratio of the first loss on heating to the second loss on heating, i.e., "first loss on heating / second loss on heating," is preferably smaller, is preferably 5 or less, is more preferably 4 or less, is further preferably 0.35 to 3.48, and is particularly preferably 0.35 to 3.40.

[0114] In addition, when a conventionally known dry grinding method is used in talc grinding, it is thought that as grinding progresses, two fracture modes simultaneously occur: structural fracture due to delamination of the layered structure of talc, and structural fracture due to non-delamination, i.e., in-plane fracture. This means that both the crystal defects associated with the first heat loss and the crystal defects associated with the second heat loss increase. On the other hand, when a wet grinding method is used, it is thought that the structural fracture of talc is mainly due to delamination, and the increase in crystal defects associated with the first heat loss predominantly progresses.

[0115] Therefore, in order to predominantly promote structural destruction related to the second heat loss that suppresses odor generation, it is necessary to mainly promote in-plane destruction accompanied by mechanochemical changes, and for this purpose it is preferable to apply a dry grinding method, and it is further preferable to adjust the air speed and rotation speed in the dry grinding method in a direction that particularly increases them, and it is particularly important to carry out grinding and classification while carefully adjusting the Ca content and heat loss ratio so that they fall within the preferred ranges already explained.

[0116] When the first and second heat losses of the talc extracted from the propylene polymer composition of the present embodiment are set as described above, odors that may be generated from components exposed to high temperatures, particularly temperatures of 50°C to 60°C, or even higher, which may be reached in the interior of an automobile, can be effectively reduced.

[0117] The origin of the talc that can be used in this embodiment is not particularly limited. The initial Ca content and the associated amount of crystal defects of commercially available talc may differ depending on the origin of the talc. However, various talcs that are commercially available regardless of origin can be used, provided that they satisfy the target Ca content conditions described above or can be processed to satisfy them.

[0118] Examples of producing regions of talc that can be suitably used in the propylene-based polymer composition of the present embodiment include China, France, India, Pakistan, and Australia.

[0119] In the propylene polymer composition of the present embodiment, when the total of the content of the propylene polymer already described and the content of the talc already described is taken as 100 mass% (parts by mass), the content of the propylene polymer is preferably 98.5 mass% (parts by mass) to 55 mass% (parts by mass), and more preferably 95 mass% (parts by mass) to 60 mass% (parts by mass), from the viewpoint of improving the balance between rigidity and impact resistance.

[0120] (4) Other Inorganic Fillers The propylene-based polymer composition of the present embodiment may contain, in addition to the talc already described, “other inorganic fillers.” The propylene-based polymer composition may contain one type of other inorganic filler alone, or two or more types of other inorganic fillers in any ratio.

[0121] Examples of other inorganic fillers include glass, silicate minerals, silicon dioxide (e.g., silica), titanium oxide, iron oxide, aluminum oxide (e.g., alumina), magnesium oxide, antimony oxide, barium ferrite, strontium ferrite, beryllium oxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, calcium carbonate, magnesium carbonate, carbonate minerals, calcium sulfate, magnesium sulfate, basic magnesium sulfate, calcium sulfite, and cadmium sulfide.

[0122] In the present embodiment, the shape of the other inorganic filler may be any suitable shape, specifically, for example, a plate shape, a needle shape, or a fiber shape.

[0123] The other inorganic filler may be treated with a surface treatment agent such as a silane coupling agent, a titanium coupling agent, a surfactant, etc. The "other inorganic filler" treated with the above-exemplified surface treatment agent can improve the interfacial adhesion with the propylene-based polymer contained in the propylene-based polymer composition and can also improve the dispersibility in the propylene-based polymer composition.

[0124] In the propylene-based polymer composition of the present embodiment, the content of the other inorganic filler is preferably 0.01 to 50% by mass, and more preferably 0.03 to 45% by mass, relative to 100% by mass of the total amount of the propylene-based polymer composition.

[0125] (5) Optional Components The propylene-based polymer composition of the present embodiment may further contain optional components for adjusting the properties and characteristics of the propylene-based polymer composition and a molded article thereof to desired states, in addition to the propylene-based polymer (propylene homopolymer, propylene-based random copolymer, heterophasic propylene polymer material), ethylene-α-olefin copolymer, talc, and other inorganic fillers already described above.

[0126] Examples of such optional components include modifiers, colorants which may include pigments (e.g., inorganic pigments, organic pigments), pigment dispersants, lubricants, neutralizing agents, antioxidants, weathering agents, ultraviolet absorbers, nucleating agents, light stabilizers, antistatic agents, antiblocking agents, processing aids, organic peroxides, foaming agents, foam nucleating agents, plasticizers, flame retardants, crosslinking agents, crosslinking aids, brightness enhancers, antibacterial agents, agents which improve fluidity and impact resistance by crosslinking, light diffusing agents, and even mold release agents.

[0127] The propylene polymer composition of the present embodiment may contain only one type of optional component, or may contain two or more types in any ratio.

[0128] In the propylene polymer composition of the present embodiment, among the optional components, antioxidants, neutralizing agents, ultraviolet absorbers, lubricants, weatherproofing agents, and colorants are preferably used. These will be specifically described below.

[0129] (i) Antioxidant The propylene polymer composition of the present embodiment may further contain an antioxidant. In the present embodiment, any suitable antioxidant known in the art may be used as the antioxidant. Two or more types of antioxidants may be used in combination.

[0130] From the viewpoint of effectively suppressing odor generation, the content of the antioxidant is usually 0.001 to 2 mass%, preferably 0.005 to 1.5 mass%, and more preferably 0.01 to 1 mass%, relative to 100 mass% of the total amount of the propylene polymer composition.

[0131] Examples of antioxidants include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, hydroxylamine-based antioxidants, and metal deactivators.

[0132] In this embodiment, the antioxidant is preferably a phenol-based antioxidant, a phosphorus-based antioxidant, or a sulfur-based antioxidant, which will be specifically described below.

[0133] Examples of phenolic antioxidants include tetrakis[methylene-3(3',5'di-tert-butyl-4-hydroxyphenyl)propionate]methane, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10- ...yloxy Examples of such an active ingredient include oxaspiro[5.5]undecane, triethylene glycol-N-bis-3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate, 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thiobis-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and tocopherols.

[0134] As the phenolic antioxidant, 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane is preferably used from the viewpoint of improving the color stability of the propylene polymer composition.

[0135] The amount of the phenolic antioxidant in the propylene polymer composition is usually 0.001 to 1 mass %, preferably 0.005 to 0.8 mass %, and more preferably 0.01 to 0.5 mass %, relative to 100 mass % of the total amount of the propylene polymer composition.

[0136] Examples of the phosphorus-based antioxidant, from the viewpoint of improving the processing stability of the propylene polymer composition, include tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and 2,4,8,10-tetra-tert-butyl-6-[3-(3-methyl-4-hydroxy-5-tert-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosphepine.

[0137] The amount of the phosphorus-based antioxidant added is usually 0.001 to 1 mass %, preferably 0.005 to 0.8 mass %, and more preferably 0.01 to 0.5 mass %, relative to 100 mass % of the total amount of the propylene-based polymer composition.

[0138] In the propylene polymer composition of the present embodiment, the mass ratio of di-tert-butylphenol to the phosphorus-based antioxidant (di-tert-butylphenol / phosphorus-based antioxidant) is preferably more than 0 and less than 0.5, more preferably 0.01 or more and 0.48 or less, and even more preferably 0.05 or more and 0.45 or less, from the viewpoint of suppressing odor generation.

[0139] Examples of sulfur-based antioxidants that can be used to improve the heat aging resistance of the propylene polymer composition include dimyristyl 3,3'-thiodipropionate, neopentanetetrayltetrakis(3-laurylthiopropionate), and bis[2-methyl-4-(3-n-alkyl(C12-C14)thiopropionyloxy)-5-tert-butylphenyl]sulfide. Here, "C12" indicates that the number of carbon atoms is 12, and "C14" indicates that the number of carbon atoms is 14.

[0140] The amount of the sulfur-based antioxidant added is usually 0.001 to 1 mass %, preferably 0.005 to 0.5 mass %, and more preferably 0.01 to 0.3 mass %, relative to 100 mass % of the total amount of the propylene-based polymer composition.

[0141] More specific preferred examples of the antioxidant include phenol-based antioxidants (e.g., Sumilizer GA80 (manufactured by Sumitomo Chemical Co., Ltd.) and IRGANOX 1010 (manufactured by BASF Corporation)), sulfur-based antioxidants (e.g., Sumilizer TPM (manufactured by Sumitomo Chemical Co., Ltd.)), and phosphorus-based antioxidants (e.g., SONGNOX 6260 (manufactured by Songwon Corporation) and IRGAFOS 168 (manufactured by BASF Corporation)).

[0142] (ii) Neutralizing Agent In the present embodiment, any suitable conventionally known antioxidant can be used as the neutralizing agent. Two or more neutralizing agents may be used in combination.

[0143] Specific examples of the neutralizing agent include metal salts of higher fatty acids (metal soaps), hydrotalcites, oxides or hydroxides of alkaline earth metals, etc. As the neutralizing agent, it is preferable to use hydrotalcite or calcium stearate, and it is more preferable to use calcium stearate (e.g., manufactured by Sakai Chemical Industry Co., Ltd.).

[0144] As the higher fatty acid constituting the metal salt of a higher fatty acid (metal soap), for example, a higher fatty acid having 10 to 30 carbon atoms is preferably used, and a higher fatty acid having 12 to 18 carbon atoms is more preferably used. As the metal salt, for example, calcium salt, sodium salt, magnesium salt, lithium salt, aluminum salt, or zinc salt is preferred, and calcium salt or zinc salt is more preferred. Calcium salt or zinc salt of stearic acid is preferred.

[0145] The hydrotalcites may be natural minerals or synthetic products, and their crystal structure, crystal particle size, water content, etc. may be appropriately determined. Furthermore, the hydrotalcites may be subjected to a surface treatment, if necessary.

[0146] The hydrotalcite is preferably a hydrotalcite represented by the following formula: Mg Ｙ Al ２ (OH) ２Ｙ＋４ CO ３ ・mH ２O (wherein Y is Y≧4, and m is a positive number). Furthermore, the hydrotalcites are more preferably the following hydrotalcites: Mg ４．５ Al ２ (OH) １３ CO ３ ・3H ２ O Mg ４．５ Al ２ (OH) １1 (CO ３ ) ０．８ ・O ０．２ Mg ４ Al ２ (OH) １２ CO ３ ・3H ２ O Mg ５ Al ２ (OH) １４ CO ３ ・4H ２ O Mg ６ Al ２ (OH) １６ CO ３ ・4H ２ O Mg ３ ZnAl ２ (OH) １２ CO ３ ・mH ２ O (m is 0 to 4).

[0147] The alkaline earth metal oxide or hydroxide is an oxide or hydroxide of a metal atom in Group 2 of the periodic table, and examples thereof include calcium oxide, magnesium oxide, calcium hydroxide, and magnesium hydroxide. Calcium hydroxide is preferred.

[0148] The amount of the neutralizing agent added is, for example, usually 0.001 to 1 mass %, preferably 0.005 to 0.8 mass %, and more preferably 0.01 to 0.5 mass %, when the total amount of the propylene polymer composition is taken as 100 mass %.

[0149] (iii) Ultraviolet Absorber In the present embodiment, any suitable conventionally known ultraviolet absorber can be used as the ultraviolet absorber. Two or more types of ultraviolet absorbers may be used in combination.

[0150] Examples of ultraviolet absorbers include phenyl salicylate, 4-tert-butylphenyl salicylate, 2,4-di-tert-butylphenyl 3',5'-di-tert-butyl-4'-hydroxybenzoate, myristyl 3,5-di-tert-butyl-4-hydroxybenzoate, lauryl 3,5-di-tert-butyl-4-hydroxybenzoate, palmityl 3,5-di-tert-butyl-4-hydroxybenzoate, stearyl 3,5-di-tert- butyl-4-hydroxybenzoate, behenyl 3,5-di-tert-butyl-4-hydroxybenzoate, montanyl 3,5-di-tert-butyl-4-hydroxybenzoate, 4-tert-octylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, bis(5-benzoyl-4-hydroxy- 2-methoxyphenyl)methane, 2,2',4,4'-tetrahydroxybenzophenone, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(3-tert-butyl-2-hydroxy 2-(3'-sec-butyl-2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzotriazole, and 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole.

[0151] In the present embodiment, the ultraviolet absorber is preferably 2,4-di-tert-butylphenyl 3',5'-di-tert-butyl-4'-hydroxybenzoate, lauryl 3,5-di-tert-butyl-4-hydroxybenzoate, palmityl 3,5-di-tert-butyl-4-hydroxybenzoate, stearyl 3,5-di-tert-butyl-4-hydroxybenzoate, or behenyl 3,5-di-tert-butyl-4-hydroxybenzoate, from the viewpoint of obtaining a propylene polymer composition excellent in hue.

[0152] The blending amount of the ultraviolet absorber is usually 0.01 to 2% by mass, preferably 0.01 to 1% by mass, and more preferably 0.01 to 0.5% by mass, relative to 100% by mass of the total amount of the propylene polymer composition.

[0153] In this embodiment, for example, "Sumisorb 400" manufactured by Sumika Chemtex Co., Ltd. can be used as the ultraviolet absorber.

[0154] (iv) Lubricant In the present embodiment, any suitable lubricant known in the art can be used. Two or more types of lubricants may be used in combination.

[0155] Specific examples of the lubricant include metal salts of higher fatty acids (metal soaps), ethylene bisstearamide, and ethylene bisoleamide.

[0156] In this embodiment, for example, "Alflow H-50P" manufactured by NOF Corporation can be used as the lubricant.

[0157] (v) Weathering Agent The propylene polymer composition of this embodiment may contain a hindered amine weathering agent as a weathering agent. The hindered amine weathering agent that can be used has the function of capturing radicals generated by light (ultraviolet rays) and preventing deterioration due to decomposition of hydroperoxide in the propylene polymer composition and its molded article. In this embodiment, the hindered amine weathering agent may be either a low-molecular-weight agent or a high-molecular-weight agent.

[0158] Specific examples of the hindered amine light stabilizer include: (1) bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, (2) a mixture containing bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate, (3) bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, (4) a reaction product of decanedioic acid bis(2,2,6,6-tetramethyl-1(octyloxy)-4-piperidyl)ester, 1,1-dimethylethyl hydroperoxide, and octane, and (5) 4-benzoyloxy-2,2,6,6-tetramethylpiperidine. (6) an ester mixture of 2,2,6,6-tetramethyl-4-piperidinol and a higher fatty acid, (7) tetrakis(2,2,6,6-tetra-methyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, (8) tetrakis(1,2,2,6,6-penta-methyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, (9) a polycondensate of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, (10) poly[{(6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl){(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}}], (11) Polycondensation product of dibutylamine / 1,3,5-triazine / N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, (12) N,N',N'',N'''-tetrakis-(4,6bis-(butyl-(N-methyl-2,2,6,6-tetramethylpiperidin-4-yl)amino)-triazin-2-yl)-4,7-diazadecane-1,10-diamine, (13) mixed{1,2,2,6,6-pentamethyl-4-piperidyl / β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]dimethyl}-1,2,3,4-butanetetracarboxylate, (14) N-(2,2,6,6-tetramethyl-4-piperidyl)maleimide, (15) bis(1-undecanoxy-2,2,6,6-tetramethylpiperidin-4-yl)carbonate, (16) 2,2,6,6-tetramethylpiperidin-4-yl hexadecanoate, (17) 2,2,6,6-tetramethylpiperidin-4-yl octadecanoate, and copolymers of α-olefins having 20 to 24 carbon atoms. These may be used alone or in combination of two or more.

[0159] From the viewpoint of obtaining a propylene polymer composition (and a molded article thereof) having excellent light stability, the hindered amine weather resisting agent may be selected from the following: (1) bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, (4) a reaction product of decanedioic acid bis(2,2,6,6-tetramethyl-1(octyloxy)-4-piperidyl)ester, 1,1-dimethylethyl hydroperoxide, and octane, (7) tetrakis(2,2,6,6-tetra-methyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, (8) tetrakis(1,2,2,6,6-penta-methyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, (9) a polycondensate of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, (10) poly[{(6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl){(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}}], (14) a copolymer of N-(2,2,6,6-tetramethyl-4-piperidyl)maleimide and an α-olefin having 20 to 24 carbon atoms is preferably used.

[0160] In this embodiment, examples of the hindered amine weathering agent include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate represented by the following formula (e.g., ADEKASTAB LA-77 (manufactured by ADEKA Corporation)), a sterically hindered amine oligomer represented by the following formula: a copolymer of N-(2,2,6,6-tetramethyl-4-piperidyl)maleimide and an α-olefin having 20 to 24 carbon atoms (e.g., UVINUL (registered trademark) 5050H (manufactured by BASF Japan Ltd.)), and a butanediol, dimethylester, polymer with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol CAS. 65447-77-0 (e.g., TINUVIN It is more preferable to use 622 SF (manufactured by BASF).

[0161]

[0162]

[0163] The content of the hindered amine weathering agent in the propylene polymer composition of the present embodiment is preferably 1% by mass (parts by mass) or less, more preferably 0.5% by mass (parts by mass) or less, and usually more than 0% by mass (parts by mass), preferably 0.001% by mass (parts by mass) or more, more preferably 0.01% by mass (parts by mass) or more, and even more preferably 0.03% by mass (parts by mass) or more, when the total amount of the propylene polymer (and the ethylene-α-olefin copolymer) and talc contained in the propylene polymer composition is taken as 100% by mass (parts by mass).

[0164] When the content of the hindered amine light stabilizer is equal to or less than the upper limit, the odor of the molded article obtained by molding the propylene polymer composition can be effectively reduced and the thermal stability can be effectively improved.

[0165] (vi) Colorant In the present embodiment, any suitable colorant known in the art can be used as the colorant. Two or more types of colorants may be used in combination.

[0166] Examples of colorants include inorganic pigments and organic pigments. Examples of inorganic pigments include iron oxide, titanium oxide, zinc oxide, red iron oxide, cadmium red, cadmium yellow, ultramarine, cobalt blue, titanium yellow, white lead, red lead, lead yellow, and iron blue. Examples of organic pigments include carbon black, quinacridone, polyazo yellow, anthraquinone yellow, polyazo red, azo lake yellow, perylene, phthalocyanine green, phthalocyanine blue, and isoindolinone yellow. The colorant can be added as a masterbatch. The propylene polymer composition may contain only one type of colorant, or two or more types. Furthermore, a pigment dispersant may be further used to disperse the pigment in the propylene polymer composition.

[0167] As the pigment serving as the colorant, it is preferable to use, for example, carbon black, particularly when black coloring is required.

[0168] When a pigment is used as a colorant, the propylene polymer composition preferably contains 0.001 to 6 mass% of the pigment, more preferably 0.001 to 6 mass% of carbon black as the pigment, still more preferably 0.001 to 3 mass% of the pigment, and particularly preferably 0.001 to 3 mass% of carbon black as the pigment.

[0169] 2. Evaluation of Properties of Propylene-Based Polymer Composition (i) Melt Flow Rate (MFR) The melt flow rate of the propylene-based polymer composition of the present embodiment can be measured in accordance with JIS K7210-1:2014 and K7210-2:2014 under conditions of 230°C and a load of 2.16 kgf.

[0170] In the propylene polymer composition of the present embodiment, the melt flow rate is preferably 1 g / 10 min or more, more preferably 5 g / 10 min or more, even more preferably 10 g / 10 min or more, and particularly preferably 15 g / 10 min or more, from the viewpoint of improving moldability.

[0171] (ii) Odor Evaluation The odor of the propylene-based polymer composition of the present embodiment and a molded article thereof can be evaluated using a molded article sample obtained by molding the propylene-based polymer composition into a predetermined shape and size. Specifically, for example, the produced propylene-based polymer composition is supplied to an injection molding machine and molded under predetermined conditions to form a molded article sample.

[0172] Specifically, for example, a molded sample can be formed by supplying the propylene-based polymer composition to any suitable conventionally known injection molding machine, and then removing the sample at a temperature of 60°C or less under the following conditions: a molten resin temperature of 200°C, a mold temperature of 40°C, a filling pressure of 15 MPa, a dwell pressure of 4.3 MPa, a dwell time of 40 seconds, a total cycle time of 60 seconds, and a removal temperature of 60°C or less, and molding the sample into a predetermined size that allows odor measurement.

[0173] Next, the odor generated when the obtained molded sample is heat-treated at a predetermined temperature is scored by, for example, three or more panelists based on the following criteria. The scores given by all panelists are then totaled, and the average score is calculated by dividing the total score by the number of panelists, and the score is then rounded off to calculate a score. The level of odor is then evaluated based on the calculated score. Specifically, the smaller the calculated score, the less odor can be evaluated, and a score of 2 or less can be evaluated as acceptable. <Criteria> 0 points: No odor can be detected. 1 point: Odor can be detected but is acceptable. 2 points: Strong odor can be detected but is acceptable. 3 points: Unpleasant and unacceptable.

[0174] (iii) Evaluation of Acetone Amount The amount of acetone, which may cause odors emitted from the propylene-based polymer composition of the present embodiment and the molded article thereof, can be measured by gas chromatography (GC) using any suitable conventionally known device that uses a flame ionization detector (FID) as a detector.

[0175] Specifically, a molded body sample obtained in the same manner as in the "odor evaluation" already explained is heat-treated, and the volatile components thus produced are subjected to gas chromatography measurement. The area intensity (peak intensity) of the peak corresponding to acetone in the resulting histogram can be quantified, thereby measuring the amount of acetone generated (amount of acetone generated).

[0176] In the evaluation of the amount of acetone according to this embodiment, the amount of acetone is determined based on the peak intensity of 0 to 550×10 ３ It is sufficient, and furthermore, it is 0 to 500 × 10 ３ It is preferable that:

[0177] (iv) Evaluation of Tensile Modulus The tensile modulus can be measured and evaluated by measuring the tensile modulus in accordance with JIS K7161-2:2014 using a dumbbell-shaped test piece molded in the same manner as in the "Evaluation of Odor" described above, except that the propylene-based polymer composition described above is used to mold the dumbbell-shaped test piece.

[0178] In the evaluation of the tensile modulus according to this embodiment, from the viewpoint of resistance to deformation during use, the tensile modulus may be 1780 MPa or more.

[0179] (v) Evaluation of Loss on Heat of Talc In this embodiment, the evaluation of loss on heat of talc is carried out using talc for evaluation obtained by extracting only talc from the produced propylene-based polymer composition. Specifically, the evaluation can be carried out using talc extracted by the conventionally known Soxhlet extraction method using boiling xylene as the extraction solvent. More specifically, the talc for evaluation can be obtained by placing the propylene-based polymer composition in a filter thimble, refluxing for 5 hours at a set temperature of 130°C, for example, and vacuum-drying the extract remaining in the filter thimble for 1 hour.

[0180] The loss on heating of talc, i.e., the amount of weight loss of talc when heated under specified conditions, can be evaluated by differential thermogravimetry (DTG) using the evaluation talc obtained as described above and any suitable conventional thermal analyzer (e.g., "TG / DTA6200" manufactured by Hitachi High-Tech Science Corporation).

[0181] Specifically, the heat loss of talc can be measured under the following conditions: <Conditions> Sample amount: 10 mg Sample container: Pt open-type sample container, φ5.2 mm, H2.5 mm Heating rate: 12.5°C / min Temperature range: room temperature to 1100°C Isothermal: held at 1100°C for 10 minutes Measurement atmosphere: nitrogen (200 mL / min)

[0182] In this embodiment, a first heat loss, which is determined by the area intensity of the histogram in the range of 450°C to 590°C of a differential curve obtained by differential thermogravimetry (DTG), and a second heat loss, which is determined by the area intensity of the histogram in the range of 620°C to 730°C, are quantified, and the obtained first heat loss and second heat loss, as well as the ratio of the first heat loss to the second heat loss (first heat loss / second heat loss), are evaluated.

[0183] 3. Method for Producing Propylene-Based Polymer Composition The propylene-based polymer composition of the present embodiment can be produced by any suitable conventionally known method using the components already described above.

[0184] The propylene polymer composition of the present embodiment can be produced, for example, by mixing the components that can be contained in the propylene polymer composition already described, and melt-kneading the mixture using any suitable conventionally known apparatus.

[0185] In this embodiment, the temperature (cylinder temperature) when melt-kneading is carried out can be, for example, 180°C or higher, may be 180 to 300°C, or may be 180 to 250°C.

[0186] In the present embodiment, the oxygen concentration in the melt-kneading is preferably adjusted to, for example, 2% or less from the viewpoint of suppressing decomposition of components contained in the propylene polymer composition, such as the propylene polymer and additives, and improving long-term heat resistance. Specifically, for example, the oxygen concentration in the feed hopper of the apparatus may be measured by inserting a sensor equipped in a portable oxygen concentration meter into a purge resin inlet attached to the feed hopper, while circulating nitrogen gas through the feed hopper to adjust the oxygen concentration to 2%.

[0187] Examples of suitable devices that can be used for melt-kneading include a Banbury mixer, a single-screw extruder, and a twin-screw extruder (kneader) (for example, a twin-screw co-rotating extruder, "TEX44αII" manufactured by Japan Steel Works, Ltd.).

[0188] When the components that can be contained in the propylene-based polymer composition are mixed and kneaded, the order in which the components are added is not particularly limited.

[0189] The propylene polymer composition may be produced, for example, by previously mixing and kneading components other than the pigment to prepare a kneaded mixture, and then mixing and kneading the kneaded mixture with the pigment. The pigment that can be used here may be in an embodiment containing the pigment and components other than the pigment (e.g., a propylene polymer, a pigment dispersant), specifically, for example, a masterbatch.

[0190] The propylene polymer composition produced by melt-kneading can be adjusted to any shape and size, for example, a strand, a sheet, a plate, or a pellet.

[0191] From the viewpoint of improving molding processability and production stability when molding the propylene polymer composition to produce a predetermined molded article, the propylene polymer composition is preferably in the form of pellets having a length in the major axis direction of 1 to 50 mm.

[0192]

[0033] 4. Uses of Propylene-Based Polymer Composition and Molded Article There are no particular limitations on the uses of the propylene-based polymer composition of the present embodiment and the molded article obtained by molding the propylene-based polymer composition. The propylene-based polymer composition of the present embodiment and the molded article thereof can effectively suppress the generation of unpleasant odors, and therefore can be suitably used in various applications requiring reduced generation of unpleasant odors, specifically, for example, in automobile interior parts.

[0193] 5. Molded Article The molded article according to this embodiment is a molded article obtained by molding the propylene polymer composition into a predetermined shape and size by the manufacturing method described below.

[0194] The molded article of the present embodiment may have any shape and size suitable for a selected application. Specifically, for example, the molded article may have a desired shape and size suitable for a selected automobile interior member.

[0195] 6. Method for producing a molded article from a propylene polymer composition

[0043] A preferred example of a method for producing a molded article from a propylene polymer composition is injection molding. Examples of injection molding methods include general injection molding, injection foam molding, supercritical injection foam molding, ultra-high speed injection molding, injection compression molding, gas-assisted injection molding, sandwich molding, sandwich foam molding, and insert-outsert molding.

[0196] The molded article produced by molding the propylene-based polymer composition of the present embodiment can be suitably used as, for example, automobile components, household electrical appliance components, and containers. In particular, the molded article can be suitably used as automobile interior components (automobile interior components) that require reduction of unpleasant odors that may occur when exposed to high temperatures. Suitable examples of automobile interior components include door trims, pillars, and instrument panels.

[0197] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples shown below.

[0198] The operations described below were carried out at room temperature and pressure unless otherwise specified.

[0199] [Measurement Method] (Melt Flow Rate) Measured in accordance with JIS K7210-1:2014 and K7210-2:2014 under conditions of 230°C and a load of 2.16 kgf, except for the ethylene-α-olefin copolymer (B-1), which was measured under conditions of 190°C and a load of 2.16 kgf.

[0200] (Intrinsic Viscosity Number) Using an Ubbelohde viscometer, reduced viscosities were measured for a plurality of concentrations, and the reduced viscosities were plotted against the concentrations, and the intrinsic viscosity number was determined by the "extrapolation method" in which the concentration was extrapolated to zero.

[0201] More specifically, the reduced viscosity was measured at three concentrations of 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL using the method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (published by Kyoritsu Shuppan Co., Ltd. in 1982), and the reduced viscosity was determined by plotting the reduced viscosity against the concentration and extrapolating the concentration to zero.

[0202] (Average particle size of talc measured by wet laser diffraction method) The average particle size was determined as the volume mean diameter (MV) in accordance with JIS R 1629-1997 by treating talc with a homogenizer for 10 minutes, dispersing it with a surfactant, irradiating the sample with a laser beam, and measuring the diffraction (scattering). Tween 20 was used as the surfactant. The average particle size of talc may also be measured on talc extracted by the Soxhlet extraction method described below.

[0203] (Calcium Content (Ca Amount) of Talc) Qualitative and semi-quantitative analysis of the calcium content (Ca amount) of talc was performed using an XRF measurement device (ZSX Primus II: manufactured by Rigaku Corporation) that uses the fundamental parameter method. Specifically, the talc was pulverized and pressure-molded into a predetermined shape, and then fixed in a holder with an irradiation diameter of 30 mmφ, and the Ca amount was measured. Note that when measuring the calcium content of talc, measurement may be performed on talc extracted by the Soxhlet extraction method described below.

[0204] [Components] The components used in the propylene polymer compositions according to the examples and comparative examples will be specifically described below.

[0205] (1) Propylene-Based Polymer (Propylene-Based Polymer (A-1): Heterophagic Propylene Polymerization Material) A heterophasic propylene polymerization material, which is a propylene-based polymer (A-1), containing 87 parts by mass of (a) a propylene homopolymer, which is a polymer (I), and 13 parts by mass of (b) an ethylene-propylene random copolymer, which is a polymer (II), was produced by a liquid-phase-gas phase polymerization method using a polymerization catalyst obtained by the method described in Example 1 of JP 2004-182981 A.

[0206] The melt flow rate of the produced propylene polymer (A-1) and the intrinsic viscosity of (a) the propylene homopolymer and (b) the ethylene-propylene random copolymer contained in the propylene polymer (A-1) were measured as described above. The results were as follows: Melt flow rate (230°C, load 2.16 kgf): 55 g / 10 min; (a) propylene homopolymer: 0.90 dL / g; (b) ethylene-propylene random copolymer: 6.0 dL / g; Content of ethylene-derived structural units: 32% by mass.

[0207] (Propylene Polymer (A-2): Propylene Homopolymer) A propylene homopolymer, propylene polymer (A-2), was produced by liquid-gas phase polymerization using a polymerization catalyst obtained by the method described in Example 1 of JP-A No. 2004-182981. The physical properties were as follows: Melt flow rate (230°C, load 2.16 kgf): 3.2 g / 10 min Intrinsic viscosity: 2.0 dL / g

[0208] (Ethylene-α-olefin copolymer (B-1)) An ethylene-1-butene copolymer ("Engage (registered trademark) 7447" manufactured by Dow Chemical Japan) was used as the ethylene-α-olefin copolymer (B-1). The composition, melt flow rate, and density of the ethylene-α-olefin copolymer (B-1) were as follows: Content of structural units derived from ethylene: 70% by mass (Content of structural units derived from 1-butene: 30% by mass) Melt flow rate (190°C, load 2.16 kgf): 5 g / 10 min Density: 0.865 g / cm

[0209] (2) Talc: CAS No. 14807-96-6 Seven types of talc (Talc 1 to 7) were produced by the following method. [Talc 1] Using raw ore A collected from a mine in Liaoning Province, China, primary pulverization was carried out using a so-called attrition-type pulverization method. Secondary pulverization and classification were then carried out by a dry method using a collision-type pulverization method. In the pulverization and classification, the ratio of the talc (particle) supply rate to the air supply rate was kept at no more than 0.1, and the number of passes was kept at no more than 10. The amount of calcium (Ca) was checked as a parameter each time and kept at no less than 0.3% by mass.

[0210] The Ca content (Ca amount) after the secondary pulverization was quantified by conventional X-ray fluorescence analysis. As a result, the Ca content in Talc 1 was 1.28 mass%. In addition, the average particle size measured by conventional wet laser diffraction was 5.2 μm.

[0211] [Talc 2] Rough ore B collected from a mine in Liaoning Province, China, was subjected to primary crushing in the same manner as for Talc 1 described above. Secondary crushing and classification were then carried out by a dry method in the same manner as for the production of Talc 1 described above. Crushing and classification were carried out in the same manner as for the production of Talc 1 described above, with the Ca content kept at not less than 0.3% by mass.

[0212] The Ca content after the secondary pulverization was quantified by X-ray fluorescence analysis in the same manner as for Talc 1, and was found to be 1.82% by mass. The average particle size measured by a conventional wet laser diffraction method was 4.1 μm.

[0213] [Talc 3] Rough ore C collected from a mine in Liaoning Province, China was used, and primary crushing was carried out in the same manner as for Talc 1 already described. Secondary crushing and classification were then carried out by a dry method in the same manner as for Talc 1 already described. Crushing and classification were carried out in the same manner as for the production of Talc 1 already described, with the Ca content kept at not less than 0.3% by mass.

[0214] The Ca content after the secondary pulverization was quantified by fluorescent X-ray analysis in the same manner as in the production of Talc 1 described above, and was found to be 0.63% by mass. The average particle size measured by a conventional wet laser diffraction method was 5.0 μm.

[0215] [Talc 4] Rough ore F collected from a mine in northwest India was used, and primary crushing was carried out in the same manner as for Talc 1 described above. Secondary crushing and classification were then carried out by a dry method in the same manner as for Talc 1 described above. Crushing and classification were carried out such that the Ca content did not fall below 0.3% by mass.

[0216] The Ca content after the secondary pulverization was quantified by X-ray fluorescence analysis in the same manner as for Talc 1, and was found to be 0.35% by mass. The average particle size measured by a conventional wet laser diffraction method was 5.2 μm.

[0217] [Talc 5] Rough ore D collected from a mine in Liaoning Province, China was used and subjected to primary crushing in the same manner as for Talc 1 described above. Secondary crushing and classification were not performed.

[0218] The Ca content after the primary pulverization was quantified by X-ray fluorescence analysis in the same manner as for Talc 1, and was found to be 1.93% by mass. The average particle size measured by a conventional wet laser diffraction method was 13 μm.

[0219] [Talc 6] Rough ore E collected from a mine in Liaoning Province, China was subjected to primary crushing and classification in the same manner as for Talc 1 described above. However, secondary crushing was not performed.

[0220] The Ca content after primary pulverization and classification was quantified by X-ray fluorescence analysis in the same manner as for Talc 1, and was found to be 0.22% by mass. It is presumed that Talc 6 was classified immediately after primary pulverization, and therefore, the coarse talc powder containing a large amount of calcium due to insufficient pulverization was largely removed at this stage, leaving behind fine powder with significant crushing as the dominant component, resulting in a reduced Ca content. The average particle size measured by conventional wet laser diffraction was 5.5 μm.

[0221] [Talc 7] Rough ore G collected from a mine in the Pyrenees region of southern France was subjected to primary crushing in the same manner as described above for Talc 1. Thereafter, secondary crushing and classification were carried out by any suitable wet method known in the art.

[0222] The Ca content after secondary pulverization and classification was quantified by fluorescent X-ray analysis to be 0.24% by mass, and the average particle size measured by conventional wet laser diffraction was 11 μm.

[0223] The Ca content and average particle size of Talc 1 to 7 are also summarized in Table 1 below.

[0224] (3) Lubricant (Ethylene bisstearic acid amide: CAS No. 324-27431) NOF Corporation "Alflo H-50S"

[0225] (4) Neutralizer 1 (Calcium stearate: CAS No. 1592-23-0) "Calcium stearate" manufactured by Sakai Chemical Industry Co., Ltd.

[0226] (5) Neutralizer 2 (Calcium hydroxide: CAS No. 1305-62-0) "Calcium hydroxide CLS-B" manufactured by Shiraishi Calcium Co., Ltd.

[0227] (6) Antioxidants (Antioxidant 1: CAS No. 90498-90-1) "Sumilizer GA80" manufactured by Sumitomo Chemical Co., Ltd. (Antioxidant 2: CAS No. 26741-53-7) "SONGNOX 6260" manufactured by Songwon Co., Ltd. (Antioxidant 3: CAS No. 16545-54-3) "Sumilizer TPM" manufactured by Sumitomo Chemical Co., Ltd.

[0228] (7) Weathering agent (hindered amine weathering agent (HALS): CAS No. 16545-54-3) "ADEKASTAB LA-77" manufactured by ADEKA Corporation

[0229] (8) Ultraviolet absorber (Ultraviolet absorber: CAS No. 4221-80-1) "Sumisorb 400" manufactured by Sumika Chemtex Co., Ltd.

[0230] [Examples 1 to 5, Comparative Examples 1 and 2] Raw materials corresponding to components selected from the components already described were weighed out so as to obtain the compositions (unit: parts by mass (PHR)) shown in Tables 2 and 3 below, and these were mixed uniformly to obtain mixtures.

[0231] The components (raw materials) corresponding to the symbols (abbreviations) shown in Tables 2 and 3 below are as follows: "A-1": Propylene polymer (A-1) (heterophagic propylene polymer material) "A-2": Propylene polymer (A-2) (propylene homopolymer) "B-1": Ethylene-α-olefin copolymer (B-1) (ethylene-1-butene copolymer, "Engage (registered trademark) 7447" manufactured by Dow Chemical Japan) "Ca(OH) ２ ": Calcium hydroxide "EBS": Ethylene bis stearic acid amide "CaSt ２ ": Calcium stearate "GA80": "Sumilizer GA80" manufactured by Sumitomo Chemical Co., Ltd. "6260": "SONGNOX 6260" manufactured by Songwon Co., Ltd. "TPM": "Sumilizer TPM" manufactured by Sumitomo Chemical Co., Ltd. "LA77": "ADEKASTAB LA-77" manufactured by ADEKA Corporation "S400": "Sumisorb 400" manufactured by Sumika Chemtex Co., Ltd.

[0232] The resulting mixture was then fed into a twin-screw kneader (twin-screw extruder) (manufactured by The Japan Steel Works, Ltd., "TEX44αII") from the most upstream raw material inlet and melt-kneaded to obtain a propylene polymer composition.

[0233] The melt kneading was carried out under the conditions of a cylinder temperature of 200° C., a discharge rate of 50 kg / hour, a screw rotation speed of 200 rpm, and an oxygen concentration of 2% in the feed hopper.

[0234] The oxygen concentration in the feed hopper of the twin-screw kneader was measured by inserting a sensor equipped with a portable oxygen concentration meter into the purge resin inlet attached to the feed hopper. The melt-kneading was carried out while adjusting the oxygen concentration to 2% by circulating nitrogen gas through the feed hopper.

[0235] The obtained propylene polymer compositions were evaluated for various parameters by the evaluation methods described below. Specifically, odor measurement and evaluation, acetone quantification and evaluation, tensile modulus measurement and evaluation, and each peak of heat loss of extracted talc were measured and evaluated. The evaluation results are shown in Tables 4 and 5 below.

[0236] [Evaluation] (Evaluation of odor) The propylene polymer compositions prepared in the above-described Examples and Comparative Examples were supplied to an injection molding machine (Meiki M70 injection molding machine) and molded under the conditions of a molten resin temperature of 200°C, a mold temperature of 40°C, a filling pressure of 15 MPa, a dwell pressure of 4.3 MPa, a dwell time of 40 seconds, a total cycle time of 60 seconds, and a molded product removal temperature of 60°C or less, thereby obtaining a plate-like molded product having a length of 60 mm, a width of 60 mm, and a thickness of 2.0 mm. The obtained plate-like molded product was then cut to a length of 60 mm, a width of 30 mm, and a thickness of 2.0 mm, thereby obtaining molded product sample 1.

[0237] A total of three pieces of the obtained molded sample 1 were placed in a 0.5 L odorless glass bottle, the lid was closed, and heated in an oven at 80° C. for 2 hours. Thereafter, the glass bottle was left to stand at 60° C. for a while.

[0238] Next, an odor test was carried out by three or more panelists on the molded product sample 1 in the glass bottle according to the following method. The panelists rated the odor level based on the following criteria: <Criteria> 0 points: No odor detected. 1 point: Odor detected but tolerable. 2 points: Strong odor detected but tolerable. 3 points: Unpleasant and unacceptable.

[0239] The scores given by all panelists were totaled, the total score was divided by the number of panelists to calculate an average score, and the average score was rounded off to calculate a score. The resin compositions of the Examples and Comparative Examples were evaluated for odorlessness based on the score. The lower the score, the less odor they were evaluated to have, and a score of 2 or less was evaluated as acceptable.

[0240] (Evaluation of Acetone Amount) The acetone amount in the propylene polymer compositions according to the Examples and Comparative Examples was measured by gas chromatography (GC) according to the following procedure.

[0241] Specifically, a gas chromatograph flash GC nose Heracles (manufactured by Alphamos) was used as the apparatus, a Tenax TA (solid adsorbent trap) was used as the trap, and an MXT-5 (packing material: diphenyl dimethyl polysiloxane, length 10 m, inner diameter 0.18 mm, thickness 0.14 μm) was used as the column.

[0242] A flame ionization detector (FID) was used as the detector, and hydrogen gas was used as the carrier gas.

[0243] The propylene-based polymer compositions according to the Examples and Comparative Examples were molded into flat plate-like molded articles having a length of 60 mm, a width of 60 mm and a thickness of 2.0 mm in the same manner as in the "Evaluation of Odor" already described above. The molded articles were then cut into a size of a length of 20 mm, a width of 10 mm and a thickness of 2.0 mm to prepare molded article sample 2.

[0244] A total of three pieces of the obtained molded body sample 2 were sealed in a sample bottle (volume 20 mL). The sample bottle was heated at 100°C for 5 minutes, and the volatile components were injected into the injection port of a GC and cooled and collected in a trap. The trap was heated to introduce the volatile components into the column, and the generated acetone was quantified.

[0245] The GC measurement conditions were an injection volume of 5000 μL, an injection port temperature of 220°C, a trap temperature of 70°C, a trap desorption temperature of 240°C, and a column oven temperature of 40°C, held for 10 seconds, heated at 1.5°C / sec, and held at 250°C for 90 seconds. The split ratio was 10:1. The FID detector temperature was 260°C.

[0246] After the measurement, the area intensity of the peak corresponding to acetone in the obtained histogram was quantified and evaluated.

[0247] (Evaluation of Tensile Modulus) In Examples and Comparative Examples, the propylene polymer compositions were supplied to an injection molding machine (Meiki M70 injection molding machine), and dumbbell-shaped test specimens were molded under the following conditions: molten resin temperature 200° C., mold temperature 40° C., filling pressure 15 MPa, dwell pressure 4.3 MPa, dwell time 40 seconds, total cycle time 60 seconds, and molded product removal temperature 60° C. or lower. Two days after molding, the tensile modulus of the dumbbell-shaped test specimens was measured and evaluated under conditions of 23° C. and 50% Rh in accordance with JIS K7161-2:2014.

[0248] (Evaluation of Loss on Heat of Talc) Talc alone was extracted from the propylene polymer compositions according to the Examples and Comparative Examples by Soxhlet extraction. Specifically, boiling xylene was used as an extraction solvent, and 5 g of the propylene polymer composition was placed in a filter thimble, refluxed at a set temperature of 130°C for 5 hours, and the extract remaining in the filter thimble was vacuum-dried for 1 hour to obtain talc for evaluation.

[0249] The resulting talc for evaluation was used to measure and evaluate the weight loss (heat loss) of the talc under the following conditions using a thermal analyzer ("TG / DTA6200" manufactured by Hitachi High-Tech Science Corporation). <Conditions> Sample amount: Approximately 10 mg Sample container: Pt open-type sample container φ5.2 mm, H2.5 mm (manufactured by Hitachi High-Tech Science Corporation) Heating rate: 12.5°C / min Temperature range: Room temperature to 1100°C Isothermal: Hold at 1100°C for 10 minutes Measurement atmosphere: Nitrogen (200 mL / min)

[0250]

[0251]

[0252]

[0253]

[0254]

[0255] As is clear from Table 4, the propylene polymer compositions of Examples 1 to 5 reduced the amount of acetone generated (peak intensity) by 129×10 compared to Comparative Examples 1 and 2, which do not satisfy the requirements of the present invention. ３ ~479 x 10 ３ As a result, the generation of odor was suppressed.

Claims

1. A propylene polymer composition comprising a propylene polymer and talc, wherein, when the total of the propylene polymer content and the talc content is 100 parts by mass, the propylene polymer content is 98.5 parts by mass to 55 parts by mass and the talc content is 1.5 parts by mass to 45 parts by mass, the talc content has an average particle size of 2 μm to 13 μm as measured by wet laser diffraction, and a derivative curve obtained by differential thermogravimetry (DTG) using 10 mg of the talc extracted from the propylene polymer composition shows a first heat loss of 60 μg or more and less than 230 μg in the range of 450°C to 590°C, and a second heat loss of more than 0 μg and less than 300 μg in the range of 620°C to 730°C.

2. The propylene polymer composition according to claim 1, wherein the first heat loss is 90 μg to 200 μg.

3. The propylene polymer composition according to claim 1 or 2, wherein the second loss on heating is 40 μg to 270 μg.

4. The propylene polymer composition according to claim 1 or 2, wherein the calcium content of the talc is 0.3 to 2.0 parts by mass relative to 100 parts by mass of the talc.

5. The propylene polymer composition according to claim 1 or 2, wherein the average particle size of the talc is 4 μm to 13 μm.

6. The propylene polymer composition according to claim 1 or 2, wherein the propylene polymer is a heterophasic propylene polymer material.

7. The propylene polymer composition according to claim 1 or 2, further comprising an ethylene-α-olefin copolymer.

8. The propylene polymer composition according to claim 7, wherein the ethylene-α-olefin copolymer is an ethylene-1-butene copolymer.

9. A molded article obtained by molding the propylene polymer composition according to claim 1 or 2.

10. The molded article according to claim 9, which is an automobile interior part.

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