Polypropylene-based resin composition and molded article

Abstract

The present invention addresses the problem of providing: a polypropylene-based resin composition which has excellent antistatic properties and enables the achievement of a molded body in which the amount of emission of VOC, especially the amount of emission of acetaldehyde and acrolein is relatively reduced; and a molded body.　A polypropylene-based resin composition according to the present invention contains a polypropylene-based resin which is composed of a propylene-based polymer and serves as a resin component, talc which serves as an inorganic filler, and a monoglycerol fatty acid ester compound and a diglycerol fatty acid ester compound, which serve as antistatic agents. With respect to a total of 100 parts by mass of the content of the resin component and the content of the talc, the content of the polypropylene-based resin is 50 parts by mass to 99.9 parts by mass, the content of the talc is 0.1 part by mass to 50 parts by mass, and the total content of the monoglycerol fatty acid ester compound and the diglycerol fatty acid ester compound is 0.20 part by mass to 0.39 part by mass. The ratio of the monoglycerol fatty acid ester compound to the diglycerol fatty acid ester compound is 30 / 70 to 49 / 51.

Description

Polypropylene resin composition and molded body

[0001] The present invention relates to a polypropylene resin composition and a molded article containing the polypropylene resin composition.

[0002] Molded articles containing polypropylene-based resin compositions are used for automobile interior and exterior materials, electrical component boxes, etc. Such polypropylene-based resin compositions contain an antistatic agent, and a method for improving the antistatic properties of the molded articles by adjusting the amount and ratio of the agent is known.

[0003] For example, Patent Document 1 discloses a polypropylene resin composition containing a glycerin fatty acid ester and a polyglycerin fatty acid ester as antistatic agents in specific amounts and in specific ratios, and a molded article thereof.

[0004] Japanese Patent Application Laid-Open No. 2020-143240

[0005] However, the molded article containing the polypropylene-based resin composition described in Patent Document 1 cannot sufficiently reduce the amount of volatile organic compounds (hereinafter referred to as VOCs), particularly the amount of acetaldehyde and acrolein emitted.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a polypropylene-based resin composition that has excellent antistatic properties and from which a molded article can be obtained in which the amount of VOC emission, particularly the amount of acetaldehyde and acrolein emission, is relatively reduced, and a molded article containing the polypropylene-based resin composition.

[0007] The polypropylene-based resin composition according to the present invention contains a polypropylene-based resin made of a propylene-based polymer as a resin component, talc as an inorganic filler, and a monoglycerin fatty acid ester compound and a diglycerin fatty acid ester compound as antistatic agents, wherein, relative to 100 parts by mass of the total of the resin component content and the talc content, the content of the polypropylene-based resin is 50 parts by mass or more and 99.9 parts by mass or less, the content of the talc is 0.1 parts by mass or more and 50 parts by mass or less, the total content of the monoglycerin fatty acid ester compound and the diglycerin fatty acid ester compound is 0.20 parts by mass or more and 0.39 parts by mass or less, and the ratio of the monoglycerin fatty acid ester compound to the diglycerin fatty acid ester compound is 30 / 70 or more and 49 / 51 or less.

[0008] The molded article according to the present invention contains the polypropylene resin composition described above.

[0009] According to the present invention, it is possible to provide a polypropylene-based resin composition that has excellent antistatic properties and from which a molded article can be obtained in which the amount of VOC emission, particularly the amount of acetaldehyde and acrolein emission, is relatively reduced, and a molded article containing the polypropylene-based resin composition.

[0010] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0011] 1. Polypropylene Resin Composition The polypropylene resin composition according to this embodiment contains a polypropylene resin made of a propylene polymer as a resin component, talc as an inorganic filler, and a monoglycerin fatty acid ester compound and a diglycerin fatty acid ester compound as antistatic agents.

[0012] [Polypropylene Resin] The polypropylene resin is made of a propylene polymer.

[0013] <Propylene-Based Polymer> The propylene-based polymer is a polymer containing 50% by mass or more of a monomer unit derived from propylene. Examples of the propylene-based polymer include a propylene homopolymer, a random copolymer of propylene and a monomer other than propylene, and a heterophasic propylene polymer material. The polypropylene-based resin may contain only one type of propylene-based polymer, or may contain two or more types of propylene-based polymers.

[0014] From the viewpoint of improving the rigidity and impact resistance of the molded body, the polypropylene-based resin preferably contains, as a propylene-based polymer, at least one selected from the group consisting of a propylene homopolymer and a heterophasic propylene polymer material, and more preferably contains a heterophasic propylene polymer material.

[0015] The isotactic pentad fraction of the propylene polymer is preferably 0.961 or more, more preferably 0.975 or more, and even more preferably 0.980 or more. The isotactic pentad fraction of the propylene polymer is preferably 1.000 or less, and more preferably 0.995 or less.

[0016] The isotactic pentad fraction means the isotactic fraction in pentad units. That is, the isotactic pentad fraction indicates the content of a structure in which five consecutive propylene-derived monomer units are meso-bonded when viewed in pentad units. When the target component is a copolymer, the isotactic pentad fraction refers to a value measured for a chain of propylene-derived monomer units.

[0017] The isotactic pentad fraction is １３ It is a value measured by C-NMR spectrum. １３ The ratio of the area of ​​the mmmm peak to the area of ​​all absorption peaks in the methyl carbon region obtained by C-NMR spectrum is defined as the isotactic pentad fraction. １３The method for measuring the isotactic pentad fraction by C-NMR spectroscopy is described, for example, in A. Zambelli et al., Macromolecules, 6, 925 (1973). １３ The assignment of absorption peaks obtained by C-spectrometry is based on the description in Macromolecules, 8, 687 (1975).

[0018] The isotactic pentad fraction of the propylene polymer can be adjusted to fall within the above range by appropriately selecting a catalyst, a donor, polymerization conditions, etc. Alternatively, a propylene polymer having a desired isotactic pentad fraction can be obtained from commercially available products.

[0019] From the viewpoint of improving the molding processability of the polypropylene resin composition, the melt flow rate (MFR) of the propylene polymer is preferably 0.1 g / 10 min or more and 300 g / 10 min or less, more preferably 1 g / 10 min or more and 300 g / 10 min or less. The melt flow rate (MFR) of the propylene polymer may be 5 g / 10 min or more and 100 g / 10 min or less, or 10 g / 10 min or more and 50 g / 10 min or less.

[0020] The melt flow rate (MFR) of the propylene polymer is measured by Method A under conditions of a temperature of 230°C and a load of 2.16 kg in accordance with the method specified in JIS K7210-1:2014 and K7210-2:2014.

[0021] (Propylene Homopolymer) From the viewpoint of improving the fluidity of the polypropylene resin composition when melted and the toughness of a molded product, the intrinsic viscosity number ([η]) of the propylene homopolymer is preferably 0.10 dL / g or more and 4.00 dL / g or less, more preferably 0.50 dL / g or more and 3.00 dL / g or less, and even more preferably 0.70 dL / g or more and 2.00 dL / g or less.

[0022] In this specification, the intrinsic viscosity (unit: dL / g) is a value measured at a temperature of 135°C using tetralin as a solvent by the following method.

[0023] Using an Ubbelohde viscometer, the reduced viscosity is measured at three concentrations: 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL. The reduced viscosity is plotted against the concentration, and the intrinsic viscosity is calculated by extrapolation, extrapolating the concentration to zero. The method for calculating the intrinsic viscosity by extrapolation is described, for example, on page 491 of "Polymer Solutions, Polymer Experiments 11" (published by Kyoritsu Shuppan Co., Ltd. in 1982).

[0024] The molecular weight distribution (Mw / Mn) of the propylene homopolymer is preferably 3.0 or more, more preferably 4.0 or more. The molecular weight distribution of the propylene homopolymer is preferably 15.0 or less, more preferably 10.0 or less. The molecular weight distribution of the propylene homopolymer is preferably 3.0 or more and 15.0 or less, more preferably 4.0 or more and 10.0 or less.

[0025] In this specification, the molecular weight distribution refers to the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), calculated using the weight average molecular weight (Mw) and number average molecular weight (Mn) measured by gel permeation chromatography (GPC) under the following conditions: Apparatus: HLC-8121 GPC / HT manufactured by Tosoh Corporation Separation column: Three GMHHR-H(S)HT manufactured by Tosoh Corporation Measurement temperature: 140°C Carrier: orthodichlorobenzene Flow rate: 1.0 mL / min Sample concentration: Approximately 1 mg / mL Sample injection amount: 400 μL Detector: Differential refractometry Calibration curve creation method: Standard polystyrene was used

[0026] The propylene homopolymer can be produced, for example, by carrying out a polymerization step in which propylene is polymerized using a polymerization catalyst.

[0027] Examples of the polymerization catalyst include Ziegler catalysts; Ziegler-Natta catalysts; catalysts containing a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane; catalysts containing a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that forms an ionic complex upon reaction with the transition metal compound, and an organoaluminum compound; and modified catalysts obtained by supporting a catalyst component (a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that forms an ionic complex, an organoaluminum compound, etc.) on inorganic particles (silica, clay mineral, etc.).

[0028] Examples of the polymerization catalyst include those described in JP-A-61-218606, JP-A-5-194685, JP-A-7-216017, JP-A-9-316147, JP-A-10-212319, JP-A-2004-182981, JP-A-2010-168545, and JP-A-2011-246699.

[0029] Furthermore, a polymer obtained by prepolymerizing propylene in the presence of the above polymerization catalyst can also be used as the polymerization catalyst.

[0030] 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 an olefin that is liquid at the polymerization temperature as a medium. 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.

[0031] The polymerization method may be, for example, a batch method, a continuous method, or a combination thereof. The polymerization method may be a multi-stage method in which a plurality of polymerization reactors are connected in series.

[0032] From the viewpoint of industrial and economical excellence, the polymerization method is preferably a continuous gas phase polymerization method or a bulk-gas phase polymerization method in which bulk polymerization and gas phase polymerization are carried out continuously.

[0033] Various conditions in the polymerization step (polymerization conditions such as polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, and polymerization time) may be appropriately determined depending on the molecular structure of the target polymer.

[0034] In the method for producing a propylene homopolymer, other steps may be carried out before or after the polymerization step. For example, after the polymerization step, the polymer may be dried at a temperature equal to or lower than the melting point of the polymer, as necessary, in order to remove residual solvent contained in the polymer and ultralow molecular weight oligomers produced as by-products during production. Examples of drying methods include those described in JP-A-55-75410 and JP-A-2565753.

[0035] (Random copolymer of propylene and a monomer other than propylene) The random copolymer of propylene and a monomer other than propylene contains monomer units derived from propylene and monomer units derived from a monomer other than propylene. The random copolymer preferably contains 0.01% by mass or more and 20% by mass or less of the monomer units derived from a monomer other than propylene, relative to the total mass of the copolymer (100% by mass).

[0036] Examples of monomers other than propylene include ethylene and α-olefins having 4 to 12 carbon atoms. In this specification, α-olefins are aliphatic unsaturated hydrocarbons having a carbon-carbon unsaturated double bond at the α-position. Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 4-methyl-1-hexene.

[0037] The monomer other than propylene is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, and 1-octene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0038] Examples of random copolymers of propylene and a monomer other than propylene include propylene-ethylene random copolymers, propylene-1-butene random copolymers, propylene-1-hexene random copolymers, propylene-1-octene random copolymers, propylene-ethylene-1-butene random copolymers, propylene-ethylene-1-hexene random copolymers, and propylene-ethylene-1-octene random copolymers.

[0039] The random copolymer of propylene and a monomer other than propylene has an intrinsic viscosity ([η]) of preferably 0.10 dL / g or more and 4.00 dL / g or less, more preferably 0.50 dL / g or more and 3.00 dL / g or less, and even more preferably 0.70 dL / g or more and 2.00 dL / g or less, from the viewpoint of improving the fluidity of the polypropylene resin composition when melted.

[0040] The random polymer of propylene and a monomer other than propylene has a molecular weight distribution (Mw / Mn) of preferably 3.0 or more, more preferably 4.0 or more. The molecular weight distribution is preferably 10.0 or less, more preferably 7.0 or less. The molecular weight distribution of the random polymer of propylene and a monomer other than propylene is preferably 3.0 or more and 10.0 or less, more preferably 4.0 or more and 7.0 or less.

[0041] A random copolymer of propylene and a monomer other than propylene can be produced, for example, by polymerizing propylene and a monomer other than propylene in accordance with the polymerization catalyst, polymerization method, polymerization system, and polymerization conditions that can be used in the production of the above-mentioned propylene homopolymer.

[0042] (Heterophagic Propylene Polymerization Material) The heterophasic propylene polymerization material is a mixture containing a polymer I containing 80% by mass or more of monomer units derived from propylene (where the total mass of the polymer I is taken as 100% by mass), and a polymer II containing monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms and monomer units derived from propylene.

[0043] The heterophasic propylene polymer material can be produced, for example, by carrying out a first polymerization step of polymerizing polymer I and a second polymerization step of polymerizing polymer II. These polymerization steps can be carried out using the same polymerization catalyst, polymerization method, polymerization system, and polymerization conditions as those usable in the production of the above-mentioned propylene homopolymer.

[0044] The heterophasic propylene polymer material may be such that the sum of polymer I and polymer II contained in the heterophasic propylene polymer material is 100% by mass relative to the total mass of the heterophasic propylene polymer material (100% by mass).

[0045] As described above, polymer I contains 80% by mass or more of monomer units derived from propylene (where the total mass of polymer I is 100% by mass). Polymer I may be, for example, a propylene homopolymer, or may contain monomer units derived from a monomer other than propylene. When polymer I contains monomer units derived from a monomer other than propylene, the content of such units may be, for example, 0.01% by mass or more and less than 20% by mass, relative to the total mass of polymer I (100% by mass).

[0046] Examples of the monomer other than propylene include ethylene and α-olefins having 4 or more carbon atoms. Examples of the α-olefins having 4 or more carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 4-methyl-1-hexene.

[0047] The monomer other than propylene is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, and 1-octene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0048] Examples of polymer I containing a monomer unit derived from a monomer other than propylene include a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer, a propylene-1-octene copolymer, a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, and a propylene-ethylene-1-octene copolymer.

[0049] From the viewpoint of improving the dimensional stability of the molded article, polymer I is preferably a propylene homopolymer, a propylene-ethylene copolymer, a propylene-1-butene copolymer, or a propylene-ethylene-1-butene copolymer, and more preferably a propylene homopolymer.

[0050] The isotactic pentad fraction of Polymer I is preferably 1.000 or less, and may be, for example, 0.998 or less, 0.995 or less, 0.990 or less, or 0.985 or less. The lower limit of the isotactic pentad fraction is not particularly limited, and may be, for example, 0.900 or more, 0.925 or more, 0.930 or more, 0.961 or more, 0.965 or more, or 0.968 or more.

[0051] The content of polymer I is preferably 50% by mass or more and 99% by mass or less, more preferably 60% by mass or more and 95% by mass or less, based on 100% by mass of the total mass of the heterophasic propylene polymer material.

[0052] As described above, polymer II contains monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms, and monomer units derived from propylene. Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 4-methyl-1-hexene.

[0053] Polymer II preferably contains 30% by mass or more of monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms, and also contains monomer units derived from propylene (where the total mass of Polymer II is taken as 100% by mass).

[0054] In Polymer II, the content of monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms may be 30% by mass or more and 70% by mass or less, or 35% by mass or more and 60% by mass or less (where the total mass of Polymer II is taken as 100% by mass).

[0055] In Polymer II, the at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, 1-octene, and 1-decene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0056] Examples of polymer II include propylene-ethylene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer, propylene-ethylene-1-decene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, propylene-1-decene copolymer, etc. Among these, polymer II is preferably a propylene-ethylene copolymer, a propylene-1-butene copolymer, or a propylene-ethylene-1-butene copolymer, and more preferably a propylene-ethylene copolymer.

[0057] The content of polymer II is preferably 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, relative to the total mass (100% by mass) of the heterophasic propylene polymer material.

[0058] In the heterophasic propylene polymerization material, the content of monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms may be 0.3% by mass or more and 35% by mass or less, or 0.7% by mass or more and 24% by mass or less (where the total mass of the heterophasic propylene polymerization material is 100% by mass).

[0059] The content of xylene-insoluble components (CXIS components) in the heterophasic propylene polymerization material is preferably 50% by mass or more and 99% by mass or less, and more preferably 60% by mass or more and 95% by mass or less, relative to the total mass of the heterophasic propylene polymerization material (100% by mass).

[0060] The content of xylene soluble components (CXS components) in the heterophasic propylene polymerization material is preferably 1% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 40% by mass or less, relative to the total mass of the heterophasic propylene polymerization material (100% by mass).

[0061] In this specification, the xylene-insoluble component (CXIS component) refers to a component contained in a polymer that is insoluble in p-xylene and is a solid obtained by the following method: dissolving about 2 g of a polymer in boiling p-xylene for 2 hours to obtain a solution, and then cooling the solution to 20°C to precipitate a solid.

[0062] In this specification, the xylene soluble component (CXS component) means a component other than the "CXIS component" in the polymer.

[0063] In this embodiment, it is believed that the CXIS component in the heterophasic propylene polymer material is mainly composed of polymer I, and the CXS component in the heterophasic propylene polymer material is mainly composed of polymer II.

[0064] Examples of heterophasic propylene polymer materials include (propylene)-(propylene-ethylene) polymer materials, (propylene)-(propylene-ethylene-1-butene) polymer materials, (propylene)-(propylene-ethylene-1-hexene) polymer materials, (propylene)-(propylene-ethylene-1-octene) polymer materials, (propylene)-(propylene-1-butene) polymer materials, (propylene)-(propylene-1-hexene) polymer materials, (propylene)-(propylene-1-octene) polymer materials, and (propylene)-(propylene- (propylene-ethylene)-(propylene-ethylene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-butene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-hexene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-octene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-decene) polymerization material, (propylene-ethylene)-(propylene-1-butene) polymerization material, (propylene-ethylene)-(propylene-1-hexene) (propylene-ethylene)-(propylene-1-octene) polymerization material, (propylene-ethylene)-(propylene-1-decene) polymerization material, (propylene-1-butene)-(propylene-ethylene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-butene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-hexene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-octene) polymerization material, (propylene-1-butene)-(propylene-ethylene- (propylene-1-decene) polymerization material, (propylene-1-butene)-(propylene-1-butene) polymerization material, (propylene-1-butene)-(propylene-1-hexene) polymerization material, (propylene-1-butene)-(propylene-1-octene) polymerization material, (propylene-1-butene)-(propylene-1-decene) polymerization material, (propylene-1-hexene)-(propylene-1-hexene) polymerization material, (propylene-1-hexene)-(propylene-1-octene) polymerization material, (propylene-1-hexene)-(propylene-1-decene) polymerization material,Examples include (propylene-1-octene)-(propylene-1-octene) polymer materials, (propylene-1-octene)-(propylene-1-decene) polymer materials, etc.

[0065] Here, the expression "(propylene)-(propylene-ethylene) polymer material" means "a heterophasic propylene polymer material in which polymer I is a propylene homopolymer and polymer II is a propylene-ethylene copolymer." The same applies to other similar expressions.

[0066] The heterophasic propylene polymeric material is preferably a (propylene)-(propylene-ethylene) polymeric material, a (propylene)-(propylene-ethylene-1-butene) polymeric material, a (propylene-ethylene)-(propylene-ethylene) polymeric material, a (propylene-ethylene)-(propylene-ethylene-1-butene) polymeric material, or a (propylene-1-butene)-(propylene-1-butene) polymeric material, and more preferably a (propylene)-(propylene-ethylene) polymeric material.

[0067] The intrinsic viscosity number ([η]I) of Polymer I is preferably 0.10 dL / g or more and 4.00 dL / g or less, more preferably 0.50 dL / g or more and 3.00 dL / g or less, and even more preferably 0.70 dL / g or more and 2.00 dL / g or less.

[0068] The intrinsic viscosity number ([η]II) of Polymer II is preferably 1.00 dL / g or more and 10.00 dL / g or less, more preferably 2.00 dL / g or more and 10.00 dL / g or less, and even more preferably 2.00 dL / g or more and 9.00 dL / g or less.

[0069] The ratio ([η]II / [η]I) of the intrinsic viscosity number ([η]II) of Polymer II to the intrinsic viscosity number ([η]I) of Polymer I is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less.

[0070] The intrinsic viscosity number ([η]I) of polymer I can be measured, for example, by extracting polymer I from a reactor in which polymer I is polymerized and measuring the intrinsic viscosity number of the polymer.

[0071] The intrinsic viscosity number ([η]II) of polymer II can be calculated, for example, by the following formula (i) using the intrinsic viscosity number ([η]Total) of the heterophasic propylene polymerization material, the intrinsic viscosity number ([η]I) of polymer I, and the contents of polymer II and polymer I.

[0072] [η]II=([η]Total-[η]I×XI) / XII (i) [η]Total: intrinsic viscosity number (dL / g) of the heterophasic propylene polymerization material [η]I: intrinsic viscosity number (dL / g) of polymer I XI: ratio of the mass of polymer I to the total mass of the heterophasic propylene polymerization material (mass of polymer I / mass of heterophasic propylene polymerization material) XII: ratio of the mass of polymer II to the total mass of the heterophasic propylene polymerization material (mass of polymer II / mass of heterophasic propylene polymerization material)

[0073] Here, XI and XII can be determined from the material balance during polymerization.

[0074] XII may be calculated by measuring the heat of fusion of polymer I and the heat of fusion of the heterophasic propylene polymer material and using the following formula: XII=1-(ΔHf)T / (ΔHf)P, where (ΔHf)T: heat of fusion of heterophasic propylene polymer material (J / g), (ΔHf)P: heat of fusion of polymer I (J / g).

[0075] The intrinsic viscosity number ([η]CXIS) of the CXIS component is preferably 0.10 dL / g or more and 4.00 dL / g or less, more preferably 0.50 dL / g or more and 3.00 dL / g or less, and even more preferably 0.70 dL / g or more and 2.00 dL / g or less.

[0076] The intrinsic viscosity number ([η]CXS) of the CXS component is preferably 1.00 dL / g or more and 10.00 dL / g or less, more preferably 2.00 dL / g or more and 10.00 dL / g or less, and even more preferably 2.00 dL / g or more and 9.00 dL / g or less.

[0077] The ratio ([η]CXS / [η]CXIS) of the intrinsic viscosity number of the CXS component ([η]CXS) to the intrinsic viscosity number of the CXIS component ([η]CXIS) is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less.

[0078] The molecular weight distribution (Mw(I) / Mn(I)) of Polymer I is preferably 3.0 or more, and more preferably 4.0 or more.

[0079] The molecular weight distribution of the CXIS component (Mw(CXIS) / Mn(CXIS)) is preferably 3.0 or more, more preferably 4.0 or more.

[0080] From the viewpoint of obtaining good mechanical strength for automotive materials, industrial materials, and the like, the content of the polypropylene-based resin is 50 parts by mass or more and 99.9 parts by mass or less, preferably 60 parts by mass or more and 99.9 parts by mass or less, more preferably 70 parts by mass or more and 99.9 parts by mass or less, and even more preferably 75 parts by mass or more and 99.9 parts by mass or less, relative to 100 parts by mass of the total of the content of the resin component and the content of talc.

[0081] [Ethylene-α-olefin copolymer] In one aspect, the polypropylene resin composition according to this embodiment further includes an ethylene-α-olefin copolymer as a resin component. The ethylene-α-olefin copolymer may be an ethylene-α-olefin random copolymer. The ethylene-α-olefin copolymer refers to a copolymer containing monomer units derived from ethylene and monomer units derived from an α-olefin having 4 or more carbon atoms, and is substantially free of monomer units derived from propylene.

[0082] In the ethylene-α-olefin copolymer, the total content of the monomer units derived from ethylene and the monomer units derived from the α-olefin having 4 or more carbon atoms may be 100% by mass, relative to 100% by mass of the total mass of the copolymer.

[0083] Examples of α-olefins having 4 or more carbon atoms include α-olefins having 4 to 12 carbon atoms. Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. The α-olefins having 4 to 12 carbon atoms are preferably 1-butene, 1-hexene, or 1-octene. The α-olefins having 4 to 12 carbon atoms may also be α-olefins having a cyclic structure, such as vinylcyclopropane and vinylcyclobutane.

[0084] Examples of the ethylene-α-olefin copolymer include an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, an ethylene-1-octene copolymer, an ethylene-1-decene copolymer, an ethylene-(3-methyl-1-butene) copolymer, and a copolymer of ethylene and an α-olefin having a cyclic structure.

[0085] In the ethylene-α-olefin copolymer, the content of monomer units derived from α-olefins having 4 or more carbon atoms is preferably 1% by mass or more and 49% by mass or less, more preferably 5% by mass or more and 49% by mass or less, and even more preferably 24% by mass or more and 49% by mass or less, relative to the total mass of the ethylene-α-olefin copolymer (100% by mass).

[0086] The density of the ethylene-α-olefin copolymer is preferably 0.85 g / cm from the viewpoint of impact resistance of the molded product. ３ 0.89g / cm or more ３ More preferably, it is 0.85 g / cm or less. ３ 0.88g / cm or more ３ More preferably, it is 0.85 g / cm or less. ３ 0.87g / cm or more ３ The following is the result.

[0087] The melt flow rate (MFR) of the ethylene-α-olefin copolymer is preferably 0.1 g / 10 min or more and 80 g / 10 min or less. The melt flow rate (MFR) of the ethylene-α-olefin copolymer is measured by Method A under conditions of a temperature of 190°C and a load of 2.16 kg in accordance with the method specified in JIS K7210-1:2014 and K7210-2:2014.

[0088] When the ethylene-α-olefin copolymer is contained, the content thereof is preferably 1 part by mass or more, more preferably 5 parts by mass or more, relative to 100 parts by mass of the polypropylene-based resin. The content of the ethylene-α-olefin copolymer is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, relative to 100 parts by mass of the polypropylene-based resin.

[0089] The ethylene-α-olefin copolymer can be produced by polymerizing ethylene and an α-olefin having 4 or more carbon atoms using a polymerization catalyst.

[0090] Examples of the polymerization catalyst include homogeneous catalysts such as metallocene catalysts, and Ziegler-Natta catalysts.

[0091] Examples of homogeneous catalysts include catalysts containing a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane; catalysts containing a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that reacts with the transition metal compound to form an ionic complex, and an organoaluminum compound; and modified catalysts in which a catalyst component (a compound of a transition metal of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that forms an ionic complex, an organoaluminum compound, etc.) is supported on inorganic particles (silica, clay mineral, etc.).

[0092] Examples of Ziegler-Natta catalysts include catalysts that combine a titanium-containing solid transition metal component with an organometallic component.

[0093] The ethylene-α-olefin copolymer may be a commercially available product. Examples of commercially available ethylene-α-olefin copolymers include 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 EXCELLEN FX (registered trademark), SUMIKACENE (registered trademark), and ESPRENE SPO (registered trademark) manufactured by Sumitomo Chemical Co., Ltd.

[0094] When an ethylene-α-olefin copolymer is contained, the content thereof is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more and 40 parts by mass or less, and even more preferably 15 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the total of the resin component content and the talc content, from the viewpoint of obtaining good mechanical strength for automotive materials, industrial materials, and the like.

[0095] [Inorganic Filler] The polypropylene resin composition according to this embodiment contains talc as an inorganic filler. Talc is hydrous magnesium silicate having a pyrophyllite-type three-layered crystal structure. The talc is preferably obtained by pulverizing hydrous magnesium silicate, and more preferably, is a plate-like particle obtained by finely pulverizing molecular crystals of hydrous magnesium silicate to the order of a unit layer.

[0096] The average particle size of talc is preferably 3 μm or less. Here, the average particle size of talc means the 50% equivalent particle size D50 determined from the integral distribution curve of the undersize method measured by suspending the talc in a dispersion medium such as water or alcohol using a centrifugal sedimentation particle size distribution analyzer.

[0097] Talc may be used without treatment, or may be surface-treated with various known surfactants to improve interfacial adhesion with polypropylene resins or to improve dispersibility in polypropylene resins. Examples of surfactants include silane coupling agents, titanium coupling agents, higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acid salts.

[0098] From the viewpoint of obtaining good mechanical strength for automotive materials, industrial materials, and the like while suppressing costs, the content of talc is 0.1 parts by mass or more and 50 parts by mass or less, preferably 0.1 parts by mass or more and 40 parts by mass or less, more preferably 0.1 parts by mass or more and 30 parts by mass or less, and even more preferably 0.1 parts by mass or more and 25 parts by mass or less, relative to 100 parts by mass of the total content of the resin component and the content of talc.

[0099] The polypropylene resin composition according to the present embodiment may contain inorganic fillers other than talc, such as calcium carbonate, barium sulfate, mica, crystalline calcium silicate, and fibrous magnesium oxysulfate.

[0100] [Antistatic Agent] The polypropylene resin composition according to this embodiment contains a monoglycerin fatty acid ester compound and a diglycerin fatty acid ester compound as antistatic agents.

[0101] The monoglycerin fatty acid ester compound is an ester compound obtained from monoglycerin and a fatty acid, and is preferably a monoglycerin fatty acid ester compound obtained from monoglycerin and one type of fatty acid. The monoglycerin fatty acid ester compound is more preferably a monoglycerin fatty acid ester compound obtained from monoglycerin and at least one type of fatty acid selected from the group consisting of fatty acids having 16 to 18 carbon atoms. In the monoglycerin fatty acid ester compound, the content of structural units derived from fatty acids having 16 to 18 carbon atoms is preferably 50% by mass or more, relative to the total mass (100% by mass) of the monoglycerin fatty acid ester compound. In one embodiment, the fatty acid in the monoglycerin fatty acid ester compound is at least one selected from the group consisting of stearic acid, palmitic acid, and lauric acid. The monoglycerin fatty acid ester compound is more preferably a monoglycerin monostearate compound (monoglycerin monostearate) or a monoglycerin monopalmitate compound, and particularly preferably a monoglycerin monostearate compound (monoglycerin monostearate). These monoglycerin fatty acid ester compounds may be used alone or in combination of two or more. Commercially available monoglycerin fatty acid ester compounds include, for example, "Electrostripper TS-5" manufactured by Kao Corporation and "MG-100" manufactured by Toho Chemical Co., Ltd.

[0102] The diglycerin fatty acid ester compound is an ester compound obtained from diglycerin and a fatty acid, preferably a diglycerin mono-fatty acid ester compound obtained from diglycerin and one fatty acid. The diglycerin fatty acid ester compound is more preferably a diglycerin mono-fatty acid ester compound obtained from diglycerin and at least one fatty acid selected from the group consisting of fatty acids having 16 to 18 carbon atoms. In the diglycerin mono-fatty acid ester compound, the content of structural units derived from fatty acids having 16 to 18 carbon atoms is preferably 50% by mass or more, based on the total mass (100% by mass) of the diglycerin mono-fatty acid ester. In one embodiment, the fatty acid in the diglycerin fatty acid ester compound is at least one selected from the group consisting of stearic acid, palmitic acid, and lauric acid. The diglycerin fatty acid ester compound is more preferably a diglycerin mono-stearate ester compound (diglycerin monostearate) or a diglycerin mono-palmitate ester compound. These diglycerin fatty acid ester compounds may be used alone or in combination of two or more. Commercially available diglycerin fatty acid ester compounds include "Rikemal S-71-D" manufactured by Riken Vitamin Co., Ltd.

[0103] From the viewpoint of reducing the amount of VOCs emitted in the molded body and achieving good bleed resistance and antistatic properties, the total content of the monoglycerin fatty acid ester compound and the diglycerin fatty acid ester compound is 0.20 parts by mass or more and 0.39 parts by mass or less, preferably 0.25 parts by mass or more and 0.39 parts by mass or less, and more preferably 0.30 parts by mass or more and 0.39 parts by mass or less, relative to 100 parts by mass of the total of the resin component content and the talc content.

[0104] The ratio of the monoglycerin fatty acid ester compound to the diglycerin fatty acid ester compound is 30 / 70 or more and 49 / 51 or less, preferably 40 / 60 or more and 49 / 51 or less, and more preferably 45 / 55 or more and 49 / 51 or less, from the viewpoint of reducing the amount of VOCs emitted in the molded product and obtaining good bleed resistance and antistatic properties.

[0105] [Lubricant] In one aspect, the polypropylene resin composition according to this embodiment further contains a lubricant. Examples of lubricants include higher fatty acid amides. The higher fatty acid amide may be at least one selected from the group consisting of higher fatty acid monoamides and higher fatty acid bisamides. Examples of higher fatty acid monoamides include lauric acid amide, stearic acid amide, oleic acid amide, behenic acid amide, and erucic acid amide. Examples of higher fatty acid bisamides include methylene bisstearic acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, and hexamethylene bisstearic acid amide.

[0106] The content of the lubricant is preferably 0.01 part by mass or more and 1.0 part by mass or less, and more preferably 0.01 part by mass or more and 0.5 part by mass or less, relative to 100 parts by mass of the total of the content of the resin component and the content of the talc.

[0107] [Pigment] In one aspect, the polypropylene resin composition according to the present embodiment further contains at least one pigment selected from the group consisting of carbon black, titanium oxide, fatty acid metal salts, phthalocyanine metal compounds, red iron oxide, ultramarine, and polyolefin wax. The pigment may be in the form of a dry color or a masterbatch type.

[0108] The pigment content is preferably 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more and 6 parts by mass or less, even more preferably 0.2 parts by mass or more and 3 parts by mass or less, and particularly preferably 0.4 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the total of the resin component content and the talc content.

[0109] [Other Additives] The polypropylene resin composition according to the present embodiment may contain other additives as needed, such as a neutralizing agent, an antioxidant, a processing stabilizer, an ultraviolet absorber, a nucleating agent, a transparent nucleating agent, a processing aid, a metal soap, a foaming agent, an antibacterial agent, a plasticizer, a flame retardant, a crosslinking agent, a crosslinking aid, and a brightness enhancer.

[0110] The polypropylene resin composition according to the present embodiment can be produced by, for example, melt-kneading the components using a kneader such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, or a heated roll.

[0111] The melt-kneading temperature is preferably 170° C. or higher and 250° C. or lower, and the melt-kneading time is preferably 1 minute or higher and 20 minutes or lower. The melt-kneading of the components may be carried out simultaneously or sequentially.

[0112] 2. Molded Article The molded article according to this embodiment contains the polypropylene-based resin composition described above. The molded article is a molded article molded by a conventionally known method. Examples of such molded articles include injection molded articles, press molded articles, vacuum molded articles, vacuum press molded articles, pressure molded articles, foam molded articles, and extrusion molded articles. Examples of molding methods for such molded articles include injection molding, press molding, vacuum molding, vacuum press molding, pressure molding, foam molding, and extrusion molding.

[0113] The molded article according to the present embodiment is preferably an injection-molded article. Examples of the injection molding method for molding the injection-molded article include general injection molding, injection foam molding, supercritical injection foam molding, ultra-high speed injection molding, injection compression molding, injection press molding, gas-assisted injection molding, sandwich molding, sandwich foam molding, and insert-outsert molding.

[0114] The molded article according to this embodiment is preferably used as an automobile interior part, such as a door trim, a pillar, an instrument panel, a console, a rocker panel, an armrest, a door panel, or a spare tire cover.

[0115] In one aspect, the molded article according to the present embodiment may be obtained by the method described in the following steps (A') and (B'): Step (A'): A step of pulverizing a molded article containing the polypropylene-based resin composition to obtain a pulverized product; and Step (B'): A step of molding the pulverized product to obtain a molded article containing the polypropylene-based resin composition.

[0116] The present invention includes the following aspects: [1] A polypropylene-based resin composition comprising a polypropylene-based resin made of a propylene-based polymer as a resin component, talc as an inorganic filler, and a monoglycerin fatty acid ester compound and a diglycerin fatty acid ester compound as antistatic agents, wherein, relative to 100 parts by mass of the total of the resin component and the talc content, the content of the polypropylene-based resin is 50 parts by mass or more and 99.9 parts by mass or less, the content of the talc is 0.1 parts by mass or more and 50 parts by mass or less, the total content of the monoglycerin fatty acid ester compound and the diglycerin fatty acid ester compound is 0.20 parts by mass or more and 0.39 parts by mass or less, and the ratio of the monoglycerin fatty acid ester compound to the diglycerin fatty acid ester compound is 30 / 70 or more and 49 / 51 or less. [2] The polypropylene-based resin composition according to [1], wherein the total content of the monoglycerin fatty acid ester compound and the diglycerin fatty acid ester compound is 0.30 parts by mass or more and 0.39 parts by mass or less. [3] The polypropylene-based resin composition according to [1] or [2], further comprising a lubricant. [4] The polypropylene-based resin composition according to any one of [1] to [3], further comprising at least one pigment selected from the group consisting of carbon black, titanium oxide, fatty acid metal salts, phthalocyanine-based metal compounds, red iron oxide, ultramarine, and polyolefin-based wax. [5] The polypropylene-based resin composition according to any one of [1] to [4], wherein the fatty acids in the monoglycerin fatty acid ester compound and the diglycerin fatty acid ester compound are at least one selected from the group consisting of stearic acid, palmitic acid, and lauric acid. [6] The polypropylene-based resin composition according to any one of [1] to [5], wherein the polypropylene-based resin contains a heterophasic propylene polymerization material as the propylene-based polymer. [7] The polypropylene-based resin composition according to any one of [1] to [6], wherein the propylene-based polymer has a melt flow rate (temperature: 230°C, load: 2.16 kg) of 0.1 g / 10 min or more and 300 g / 10 min or less.[8] The polypropylene resin composition according to any one of [1] to [7], further comprising an ethylene-α-olefin copolymer as a resin component. [9] A molded article comprising the polypropylene resin composition according to any one of [1] to [8].

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

[0117] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples. In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified. Furthermore, the operations described below were carried out under conditions of room temperature and normal pressure unless otherwise specified.

[0118] [Methods for measuring physical properties] (Melt flow rate) Measured in accordance with JIS K7210-1:2014 and K7210-2:2014 under conditions of a temperature of 230°C and a load of 2.16 kg, except for the olefin polymer (B), which was measured under conditions of a temperature of 190°C and a load of 2.16 kg.

[0119] (Intrinsic viscosity number) Using an Ubbelohde viscometer, the reduced viscosity was measured for a plurality of concentrations, the reduced viscosity was plotted against the concentration, and the intrinsic viscosity was determined by the "extrapolation method" in which the concentration was extrapolated to zero. More specifically, the reduced viscosity was measured for 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 plotted against the concentration, and the intrinsic viscosity number was determined by the method in which the concentration was extrapolated to zero.

[0120] [Components Used in Examples and Comparative Examples] The components used in the examples and comparative examples are shown below.

[0121] (1) Resin Component <Propylene-Based Polymer: Heterophagic Propylene Polymer Material (A)> A heterophasic propylene polymer material (A) containing 87 parts by mass of (a) a propylene homopolymer component as polymer (I) and 13 parts by mass of (b) an ethylene-propylene random copolymer component as 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.

[0122] The physical properties of the heterophasic propylene polymer material (A) were as follows: Melt flow rate (temperature 230°C, load 2.16 kg): 55 g / 10 min Isotactic pentad fraction: 0.983 (a) Propylene homopolymer component Intrinsic viscosity number: 0.90 dL / g (b) Ethylene-propylene random copolymer component Intrinsic viscosity number: 6.0 dL / g Content of ethylene-derived structural units: 32% by mass

[0123] <Olefin Polymer: Ethylene-α-Olefin Copolymer (B)> "Engage (registered trademark) 8200" and "Engage (Tonryoku trademark) 8842" (both ethylene-1-octene copolymers) manufactured by Dow Chemical Japan were used.

[0124] The physical properties of the ethylene-α-olefin copolymer (B) were as follows: Content of structural units derived from ethylene EG8200: 65% by mass (content of structural units derived from 1-octene: 35% by mass) EG8842: 44% by mass (content of structural units derived from 1-octene: 56% by mass) Melt flow rate (temperature 190°C, load 2.16 kg) EG8200: 5 g / 10 min EG8842: 1 g / 10 min Density EG8200: 0.870 g / cm ３ EG8842: 0.857g / cm ３

[0125] (2) Inorganic Filler <Talc: CAS No. 14807-96-6> MW UPN TT-H manufactured by Hayashi Kasei Co., Ltd. was used.

[0126] (3) Lubricant <Lubricant 1: Ethylene bisstearic acid amide: CAS No. 324-27431> "Alflo H-50S" manufactured by NOF Corp. was used. <Lubricant 2: Erucic acid amide: CAS No. 112-84-5> "Neutron S" manufactured by Nippon Fine Chemical Co., Ltd. was used.

[0127] (4) Neutralizing Agent <Neutralizing Agent 1 Calcium stearate: CAS No. 1592-23-0> Calcium stearate manufactured by Sakai Chemical Industry Co., Ltd. was used.

[0128] (5) 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.

[0129] (6) Antistatic Agent <Antistatic Agent 1: CAS No. 31566-31-1> Monoglycerin fatty acid ester compound "Electrostripper TS-5" manufactured by Kao Corporation <Antistatic Agent 2: CAS 168075-67-0> Diglycerin fatty acid ester compound "Rikemal S-71-D" manufactured by Riken Vitamin Co., Ltd.

[0130] (7) Other Additives <Hindered amine weathering agent (HALS): CAS No. 19788-83-9> "ADEKASTAB LA-52" manufactured by ADEKA Corporation was used. <Ultraviolet absorber: CAS No. 4221-80-1> "Sumisorb 400" manufactured by Sumika Chemtex Co., Ltd. was used. <Organic peroxide: 8% masterbatch of di(2-tert-butylperoxyisopropyl)benzene> Perkadox 14, manufactured by Kayaku Akzo Co., Ltd., a mixture of 8% mass concentration of organic peroxide, 88 mass% of propylene homopolymer, and 4 mass% of SiO ２ A mixture of was used.

[0131] [Evaluation] (Method for measuring aldehyde) The resin compositions of the examples and comparative examples were supplied to an injection molding machine ("SE130DU" manufactured by Sumitomo Heavy Industries, Ltd.), and a flat plate of the resin composition measuring 150 mm in length, 90 mm in width, and 3.0 mm in thickness was molded under the following conditions: molten resin temperature 220° C., mold temperature 50° 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 less. The flat plate was then cut to a size of 111 mm in length, 90 mm in width, and 3.0 mm in thickness.

[0132] Aldehydes (acetaldehyde and acrolein) were measured by the following method. First, 5 L of nitrogen gas and the test strip were sealed in a 10 L Tedlar bag and heated at 80°C for 1 hour. 2 L of the resulting sample gas was collected on a 2,4-dinitrophenylhydrazine (DNPH) cartridge. After collection, the cartridge was eluted with acetonitrile, and the components eluted from the cartridge were measured using a high-performance liquid chromatograph (HPLC; Shimadzu Corporation, Model: LC-20AD). The detection limit for acetaldehyde and acrolein was 0.15 μg / test strip, and emissions of acetaldehyde and acrolein of 0.15 μg / test strip were considered "below the detection limit."

[0133] (Method for measuring surface resistivity) A flat plate of the resin composition having a length of 150 mm, a width of 90 mm, and a thickness of 3.0 mm was molded in the same manner as in the preparation of the test piece for the aldehyde measurement described above. Thereafter, measurement was performed using a HIOKI SM7110 (manufactured by Hioki E.E. Corporation) in accordance with JIS-K-6911.

[0134] [Example 1] (1) A resin composition containing 63 parts by mass of a propylene polymer: heterophasic propylene polymerization material (A) and 26 parts by mass of an olefin polymer: ethylene-α-olefin copolymer (B) as resin components, and (2) 11 parts by mass of talc as an inorganic filler, was added with: (3) 0.05 parts by mass of "Alflow H-50S" and 0.2 parts by mass of "Neutron S" as lubricants; (4) 0.05 parts by mass of calcium stearate as a neutralizer; (5) 0.05 parts by mass of "Sumilizer GA80" and 0.05 parts by mass of "SONGNOX6260" as antioxidants; and 0.03 parts by mass of "Sumilizer TPM" as anti-oxidants. (7) Other additives included 0.05 parts by mass of a hindered amine weathering agent (HALS) "ADEKASTAB LA-52," 0.05 parts by mass of an ultraviolet absorber "Sumisorb 400," and 0.02 parts by mass of an 8% masterbatch of organic peroxide di(2-tert-butylperoxyisopropyl)benzene.

[0135] The mixture was then uniformly pre-blended in a tumbler, and the resulting mixture was then melt-kneaded into a twin-screw extruder ("TEX44αII" manufactured by Japan Steel Works) through the most upstream raw material inlet to obtain a resin composition. The melt-kneading conditions were a cylinder temperature of 230°C, a discharge rate of 50 kg / h, a screw rotation speed of 200 rpm, and an oxygen concentration of 2% in the feed hopper. The oxygen concentration in the feed hopper was measured by inserting a sensor equipped with a portable oxygen concentration meter into the purge resin inlet attached to the feed hopper. The 2% oxygen concentration condition was achieved by flowing nitrogen gas into the feed hopper. The resulting resin composition was used to measure aldehydes and surface resistivity according to the evaluation methods described above.

[0136] [Examples 2 to 3, Comparative Examples 1 to 4] (6) The same procedure as in Example 1 was carried out, except that the amounts of the antistatic agents "Electrostripper TS-5" and "Rikemal S-71-D" were changed as shown in Table 1.

[0137] Table 1 shows the blending amount of (6) antistatic agent in each example and each comparative example, as well as the measurement results of aldehyde and surface resistivity of injection molded articles of the polypropylene resin compositions obtained by granulation.

[0138] The abbreviations in Table 1 have the following meanings: "TS-5": "Electrostripper TS-5" manufactured by Kao Corporation; "S-71-D": "Rikemal S-71-D" manufactured by Riken Vitamin Co., Ltd.

[0139]

[0140] As can be seen from Table 1, the injection-molded articles of each example that satisfy all of the constituent requirements of the present invention are excellent in antistatic properties and can relatively reduce the amount of VOCs emitted, particularly the amount of acetaldehyde and acrolein emitted.

Claims

1. A polypropylene-based resin composition comprising a polypropylene-based resin made of a propylene-based polymer as a resin component, talc as an inorganic filler, and a monoglycerin fatty acid ester compound and a diglycerin fatty acid ester compound as antistatic agents, wherein, relative to a total of 100 parts by mass of the resin component content and the talc content, the content of the polypropylene-based resin is 50 parts by mass or more and 99.9 parts by mass or less, the content of the talc is 0.1 parts by mass or more and 50 parts by mass or less, the total content of the monoglycerin fatty acid ester compound and the diglycerin fatty acid ester compound is 0.20 parts by mass or more and 0.39 parts by mass or less, and the ratio of the monoglycerin fatty acid ester compound to the diglycerin fatty acid ester compound is 30 / 70 or more and 49 / 51 or less.

2. The polypropylene resin composition according to claim 1, wherein the total content of the monoglycerin fatty acid ester compound and the diglycerin fatty acid ester compound is 0.30 parts by mass or more and 0.39 parts by mass or less.

3. The polypropylene resin composition according to claim 1, further comprising a lubricant.

4. The polypropylene resin composition according to claim 1, further comprising at least one pigment selected from the group consisting of carbon black, titanium oxide, fatty acid metal salts, phthalocyanine metal compounds, red iron oxide, ultramarine blue, and polyolefin wax.

5. The polypropylene resin composition according to claim 1, wherein the fatty acid in said monoglycerin fatty acid ester compound and said diglycerin fatty acid ester compound is at least one selected from the group consisting of stearic acid, palmitic acid, and lauric acid.

6. The polypropylene resin composition according to claim 1, wherein the polypropylene resin contains a heterophasic propylene polymer material as the propylene polymer.

7. The polypropylene resin composition according to claim 1, wherein the propylene polymer has a melt flow rate (temperature: 230° C., load: 2.16 kg) of 0.1 g / 10 min or more and 300 g / 10 min or less.

8. The polypropylene resin composition according to claim 1, further comprising an ethylene-α-olefin copolymer as a resin component.

9. A molded article comprising the polypropylene resin composition according to any one of claims 1 to 8.

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

Images