Propylene-based resin composition, composite molded body, and method for producing composite molded body

Abstract

A propylene-based resin composition including an essential resin component comprising (a) 99-1 mass% propylene-based polymer and (b) 1-99 mass% hydroxyl-group-containing polyolefin (the total of the propylene-based polymer (a) and the hydroxyl-group-containing polyolefin (b) being taken as 100 mass%), said propylene-based resin composition satisfying the following requirements (i) to (iii): (i) a molded article obtained from the propylene-based resin composition has a concentration of hydroxyl groups on the surface of 0.15-1.9 mass% (in terms of maleic-acid-modified polypropylene); (ii) the ratio X (=Mw(b) / Mw(a)) between the weight-average molecular weight Mw(a) of the propylene-based polymer (a) and the weight-average molecular weight Mw(b) of the hydroxyl-group-containing polyolefin (b) is 0.025≤X≤0.47; and (iii) the hydroxyl-group-containing polyolefin (b) has an Mw / Mn of 1.5-2.9.

Description

Propylene resin composition, composite molded article, and method for producing the composite molded article

[0001] This invention relates to a propylene-based resin composition.

[0002] Polypropylene-containing resin molded articles are used as automotive parts, including bumpers. In such applications, resin molded articles are generally painted, and it has been proposed to incorporate polyolefins containing hydroxyl groups, such as hydroxyl-containing polypropylene, to improve the adhesion of the paint film to the resin molded article (see, for example, Patent Document 1). On the other hand, the above-mentioned resin molded articles may require mechanical properties, such as rigidity, and there is a need for resin molded articles that combine excellent paint film adhesion with superior mechanical properties.

[0003] Japanese Patent Publication No. 2005-264033

[0004] Under these circumstances, the problem that the present invention aims to solve is to provide a propylene-based resin composition that can produce a resin molded article having both high coating adhesion and excellent mechanical properties.

[0005] In light of this background, the inventors conducted thorough research and found that a propylene-based resin composition having a specific composition and physical properties can solve the above problems, thus completing the present invention. In other words, the present invention relates to a propylene resin composition containing an essential resin component consisting of (a) 99% to 1% by mass of a propylene polymer and (b) 1% to 99% by mass of a polyolefin containing hydroxyl groups (provided that the total of (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups is 100% by mass), wherein the propylene resin composition satisfies the following requirements (i) to (iii): (i) The hydroxyl group concentration (in terms of maleic acid-modified polypropylene) on the surface of a molded article obtained from the propylene resin composition is 0.15% by mass or more and 1.9% by mass or less; (ii) The ratio X = Mw(b) / Mw(a) of the weight-average molecular weight Mw(a) of (a) the propylene polymer and the weight-average molecular weight Mw(b) of (b) the polyolefin containing hydroxyl groups is 0.025 ≤ X ≤ 0.47; (iii) (b) The Mw / Mn of the polyolefin containing hydroxyl groups is 1.5 to 2.9.

[0006] Hereinafter, [2] to [9] are preferred embodiments or models of the present invention. [2] A propylene-based resin composition according to [1], comprising 1 to 65 parts by mass of (c) elastomer per 100 parts by mass of the essential resin component. [3] A propylene-based resin composition according to [1] or [2], comprising 0.1 to 75 parts by mass of (d) inorganic filler per 100 parts by mass of the essential resin component. [4] A propylene-based resin composition according to any one of [1] to [3], wherein (a) the propylene polymer comprises (a3) ​​a heterophagic propylene polymerization material. [5] A composite molded article having (1) a coating film and (2) a polyolefin molded article, wherein (1) the coating film is formed directly on at least a portion of the surface of (2) the polyolefin molded article, and (2) the polyolefin molded article contains the propylene-based resin composition according to any one of [1] to [4]. [6] The composite molded article according to [5], which is an exterior part for automobiles. [7] A method for manufacturing a composite molded article, comprising the steps of: I) providing a polyolefin molded article (2), and II) forming a coating film (1) on at least a portion of the surface of the polyolefin molded article (2), wherein the polyolefin molded article (2) contains the propylene resin composition according to any one of [1] to [4]. [8] The method for manufacturing a composite molded article according to [7], wherein in the step of I) providing a polyolefin molded article (2), the polyolefin molded article is manufactured by injection molding. [9] The method for manufacturing a composite molded article according to [8], wherein the step of II) forming a coating film (1) on at least a portion of the surface of the polyolefin molded article (2) is performed in the mold used for injection molding in step I).

[0007] According to the present invention, it is possible to provide a propylene-based resin composition that can produce resin molded articles possessing both high coating adhesion and excellent mechanical properties.

[0008] The present invention relates to a propylene-based resin composition containing essential resin components consisting of (a) 99% to 1% by mass of a propylene-based polymer and (b) 1% to 99% by mass of a polyolefin containing hydroxyl groups (provided that the total of (a) the propylene-based polymer and (b) the polyolefin containing hydroxyl groups is 100% by mass), and satisfying the following requirements (i) to (iii): (i) The hydroxyl group concentration (in terms of maleic acid-modified polypropylene) on the surface of a molded article obtained from the propylene-based resin composition is 0.15% by mass or more and 1.9% by mass or less. (ii) The ratio X = Mw(b) / Mw(a) of the weight-average molecular weight Mw(a) of (a) the propylene-based polymer to the weight-average molecular weight Mw(b) of (b) the polyolefin containing hydroxyl groups is 0.025 ≤ X ≤ 0.47. (iii) (b) The Mw / Mn of the polyolefin containing hydroxyl groups is 1.5 to 2.9. That is, the propylene resin composition of the present invention contains, as essential components, an essential resin component consisting of a predetermined amount of (a) a propylene polymer and (b) a polyolefin containing hydroxyl groups. The propylene resin composition of the present invention may consist only of the above essential resin component, or it may contain optional components in addition to the above essential resin component portion. Examples of optional components include (c) elastomers and (d) inorganic fillers. The above components will be described below.

[0009] (a) Propylene Polymers The (a) propylene polymers (excluding those corresponding to (b) polypropylene containing hydroxyl groups) preferably used in the present invention are polymers in which the main part of the main chain is composed of structural units derived from propylene and which do not correspond to (b) polyolefins containing hydroxyl groups, and there are no other particular restrictions. Therefore, (a) propylene polymers are polymers in which the main part of the main chain is composed of structural units derived from propylene and which do not have hydroxyl groups. Here, "the main part of the main chain is composed of structural units derived from propylene" means that it has structural units derived from propylene in amounts exceeding 50% by mass and not exceeding 100% by mass. The (a) propylene polymer (hereinafter sometimes referred to as component (a)) preferably contained in the propylene resin composition of the present invention is a propylene (co)polymer having structural units derived from propylene in amounts exceeding 50% by mass and not exceeding 100% by mass, as described above. Component (a) may have structural units derived from monomers other than propylene.

[0010] Monomers other than propylene include ethylene and α-olefins having 4 or more carbon atoms, with ethylene and α-olefins having 4 to 20 carbon atoms being preferred. Examples of α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene, and 2,2,4-trimethyl-1-pentene. (a) The proportion of constituent units derived from propylene, the proportion of constituent units derived from ethylene, and the proportion of constituent units derived from at least one monomer selected from the group consisting of α-olefins with four or more carbon atoms in a propylene polymer can be determined by infrared spectroscopy. More specifically, the infrared absorption spectrum of (a) the propylene polymer can be measured using an infrared spectrophotometer and measured according to the method described in "Characterization of Polyethylene by Infrared Absorption Spectroscopy (by Takayama, Usami, et al.)" or "Die Makromolekulare Chemie, 177, 461 (1976) (by McRae, M.A., Madam S, W.F., et al.)".

[0011] (a) There are no particular restrictions on the molecular weight of the propylene polymer, but (ii) from the viewpoint of making it easier to satisfy the condition that the ratio X = Mw(b) / Mw(a) of the weight-average molecular weight Mw(a) of the propylene polymer and (b) the weight-average molecular weight Mw(b) of the polyolefin containing hydroxyl groups is 0.025 ≤ X ≤ 0.47, and from the viewpoint of exhibiting good mechanical properties and coating adhesion, the weight-average molecular weight Mw is 1.0 × 10⁻⁶. 5 ~6.0 x 10 5 Preferably, it is 1.0 × 10 5 ~3.0 x 10 5It is more preferable that (a) the molecular weight of the propylene polymer (number average molecular weight Mn and weight average molecular weight Mw) can be measured by methods conventionally used in the art, such as gel permeation chromatography (GPC), and more specifically, by the method described in the examples of this application. (a) The molecular weight of the propylene polymer can be adjusted by methods conventionally known in the art, and can be adjusted appropriately by appropriately adjusting and selecting all or part of the polymerization conditions, such as polymerization method, polymerization temperature, type and amount of catalyst, presence or absence of co-catalyst, type and amount.

[0012] (a) Examples of propylene polymers include (a1) propylene homopolymer, (a2) propylene random copolymer, and (a3) ​​heterophagic propylene polymerization material. The propylene resin composition according to the present invention may contain only one type of (a) propylene polymer, or it may contain two or more types.

[0013] Preferred (a2) propylene random copolymers include, for example, (a2-1) a propylene-ethylene random copolymer in which the proportion of constituent units derived from propylene is 90% by mass or more and 99.5% by mass or less, and the proportion of constituent units derived from ethylene is 0.5% by mass or more and 10% by mass or less (the total amount of constituent units derived from propylene and ethylene is 100% by mass); (a2-2) a propylene-ethylene-α-olefin random copolymer in which the proportion of propylene units is 81% by mass or more and 99% by mass or less, the proportion of constituent units derived from ethylene is 0.5% by mass or more and 9.5% by mass or less, and the proportion of constituent units derived from α-olefins having 4 to 10 carbon atoms is 0.5% by mass or more and 9.5% by mass or less (the total amount of constituent units derived from propylene, ethylene and α-olefins having 4 to 10 carbon atoms is 100% by mass); (a2-3) A propylene-α-olefin random copolymer is provided in which the proportion of constituent units derived from propylene is 90% by mass or more and 99.5% by mass or less, and the proportion of constituent units derived from α-olefins having 4 to 10 carbon atoms is 0.5% by mass or more and 10% by mass or less (provided that the total amount of constituent units derived from propylene and constituent units derived from α-olefins having 4 to 10 carbon atoms is 100% by mass). Examples of α-olefins having 4 to 10 carbon atoms in (a2-1) and (a2-2) above include linear α-olefins such as 1-butene, 1-pentene, 1-hexene, 1-octene, and 1-decene; and branched α-olefins such as 3-methyl-1-butene and 3-methyl-1-pentene. In the preparation of (a2-1) and (a2-2) above, α-olefins having 4 to 10 carbon atoms may be used alone or in combination of two or more.

[0014] (a1) Propylene homopolymer and (a2) Propylene random copolymer can be produced by polymerizing propylene (and other monomers as needed) in the presence of a Ziegler-Natta catalyst or a complex catalyst, such as a metallocene complex or a non-metallocene complex. Examples of polymerization methods include slurry polymerization, solution polymerization, bulk polymerization, and gas-phase polymerization.

[0015] In this specification, the term "heterophasic propylene polymerization material" means a mixture having a structure in which copolymers (β) (hereinafter sometimes simply referred to as "polymer (β)") are dispersed in a matrix of polymer (α) (where the total mass of the polymer is 100% by mass) (where the total mass of the polymer is 100% by mass) (where the total mass of the copolymer is 100% by mass), wherein copolymers (β) (where the total mass of the copolymer is 100% by mass) (where the total mass of the copolymer is 100% by mass) (where the total mass of the copolymer is 100% by mass) have constituent units derived from ethylene at a rate of 20% to 90% by mass and constituent units derived from at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms. The heterophasic propylene polymerization material (a3) ​​as component (a) has a total amount of propylene of 50% by mass or more. (a3) The amount of polymer (α) contained in the heterophagic propylene polymerization material is preferably 70% by mass or more and 90% by mass or less, and more preferably 75% by mass or more and 90% by mass or less (provided that the total amount of (a3) ​​heterophagic propylene polymerization material is 100% by mass). The amount of copolymer (β) contained in (a3) ​​heterophagic propylene polymerization material is preferably 10% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 25% by mass or less (provided that the total amount of (a3) ​​heterophagic propylene polymerization material is 100% by mass).

[0016] Examples of α-olefins having 3 or more carbon atoms in the copolymer (β) include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene, and 2,2,4-trimethyl-1-pentene. The α-olefins having 3 or more carbon atoms are preferably α-olefins having 3 to 20 carbon atoms, more preferably α-olefins having 3 to 10 carbon atoms, and even more preferably propylene, 1-butene, 1-hexene, or 1-octene. In the copolymer (β), the α-olefin having 3 or more carbon atoms may be used alone or in combination of two or more types.

[0017] The proportion of constituent units derived from ethylene in the copolymer (β) is preferably 22% by mass or more and 80% by mass or less, more preferably 25% by mass or more and 70% by mass or less, and even more preferably 27% by mass or more and 60% by mass or less (wherein the total amount of constituent units derived from at least one selected from the group consisting of α-olefins having 3 or more carbon atoms and constituent units derived from ethylene is 100% by mass). The proportion of constituent units derived from at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms in the copolymer (β) is preferably 20% by mass or more and 78% by mass or less, more preferably 30% by mass or more and 75% by mass or less, and even more preferably 40% by mass or more and 73% by mass or less (wherein the total amount of constituent units derived from at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms and constituent units derived from ethylene is 100% by mass).

[0018] Examples of copolymer (β) include propylene-ethylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, and propylene-ethylene-1-octene copolymer, with propylene-ethylene copolymer or propylene-ethylene-1-butene copolymer being preferred. Copolymer (β) is usually a random copolymer.

[0019] As a method for producing the (a3) ​​heterophagous propylene polymerization material as component (a), a multi-stage polymerization method is used in the presence of a polymerization catalyst, for example, by polymerizing monomers containing propylene and ethylene. For example, a method is used in which, in a first polymerization step, a monomer containing propylene is polymerized in the presence of a polymerization catalyst to produce a polymer (α), and in a second polymerization step, in the presence of the polymer (α) obtained in the first polymerization step, ethylene and at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms are copolymerized to produce a copolymer (β). Examples of polymerization catalysts used in the production of the (a3) ​​heterophagous propylene polymerization material include Ziegler catalysts, Ziegler-Natta catalysts, catalysts consisting of a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane, and catalysts consisting of a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that reacts with the transition metal compound to form an ionic complex, and an organoaluminum compound. Furthermore, a prepolymerization catalyst may be used in the presence of the above-mentioned polymerization catalyst. Examples of prepolymerization catalysts include those described in Japanese Patent Publication No. 61-218606, Japanese Patent Publication No. 61-287904, Japanese Patent Publication No. 5-194685, Japanese Patent Publication No. 7-216017, Japanese Patent Publication No. 9-316147, Japanese Patent Publication No. 10-212319, and Japanese Patent Publication No. 2004-182981.

[0020] Examples of the polymerization method for producing the heterophasic propylene polymerization material (a3) as component (a) include bulk polymerization, solution polymerization, slurry polymerization, and gas phase polymerization. Examples of the inert hydrocarbon solvent used in solution polymerization and slurry polymerization include propane, butane, isobutane, pentane, hexane, heptane, and octane. Two or more of these polymerization methods may be combined, and may be either batch-type or continuous-type. As the polymerization method for producing the heterophasic propylene polymerization material (B2), continuous gas phase polymerization, and bulk-gas phase polymerization in which bulk polymerization and gas phase polymerization are continuously performed are preferred.

[0021] The melt flow rate (MFR) of the propylene-based polymer (a), which is measured under the conditions of a temperature of 230°C and a load of 21.18 N (2.16 kg) in accordance with JIS K7210, is not particularly limited, but from the viewpoint of bondability with other members and the like, it is preferably 0.3 g / 10 min or more and 200 g / 10 min or less. The melt flow rate of the propylene-based polymer (a) is more preferably 2.5 g / 10 min or more and 150 g / 10 min or less, and further preferably 10 g / 10 min or more and 150 g / 10 min or less.

[0022] The intrinsic viscosity (hereinafter, [η ｃｘｉｓThere are no particular restrictions on the viscosity (which is written as ], but it is preferably 0.1 dl / g or more and 6.0 dl / g or less, more preferably 0.3 dl / g or more and 5.0 dl / g or less, and even more preferably 0.3 dl / g or more and 3.1 dl / g or less. The intrinsic viscosity can be determined according to the following procedure. The reduced viscosity is measured in tetralin at 135°C using an Ubbelohde viscometer, and the intrinsic viscosity is determined from the obtained reduced viscosity by extrapolation according to the calculation method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (Kyoritsu Shuppan Co., Ltd., 1982). Here, the CXS portion and the CXIS portion are obtained by the following method. (a) Completely dissolve about 5 g of propylene polymer in 500 ml of boiling xylene. Slowly cool the obtained xylene solution to 20°C, condition it at 20°C for 4 hours or more, and filter the precipitate from the solution. The precipitate is the CXIS portion. The substance obtained by removing the solvent from the solution is the xylene-soluble portion (CXS portion) at 20°C.

[0023] (a) The propylene polymer is preferably (a1) a propylene homopolymer, (a2) a propylene random copolymer such as a propylene-ethylene random copolymer or a propylene-ethylene-1-butene random copolymer, or (a3) ​​a heterophagic propylene polymerization material, more preferably (a1) a propylene homopolymer or (a3) ​​a heterophagic propylene polymerization material, and particularly preferably (a3) ​​a heterophagic propylene polymerization material.

[0024] (b) Polyolefin containing hydroxyl groups The polyolefin containing hydroxyl groups that constitutes the propylene resin composition of the present invention may be any polymer in which the main part of its main chain is composed of structural units derived from olefins, has at least one hydroxyl group, and has a predetermined molecular weight distribution (Mw / Mn), and there are no other particular restrictions. Here, "the main part of the main chain is composed of structural units derived from olefins" means having structural units derived from olefins in proportion to more than 50% by mass and up to 100% by mass.

[0025] (b) The molecular weight of the hydroxyl group-containing polyolefin is not particularly limited, but from the perspectives of facilitating satisfaction of the condition that the ratio X = Mw(b) / Mw(a) of (ii) the weight average molecular weight Mw(a) of (a) the propylene-based polymer to the weight average molecular weight Mw(b) of (b) the hydroxyl group-containing polyolefin satisfies 0.025≦X≦0.47, and exhibiting good mechanical properties and coating film adhesion, the weight average molecular weight Mw is preferably 0.5 to 1.0×10 ４ , more preferably 0.5 to 0.9×10 ４ , even more preferably 0.7 to 0.9×10 ４ . The molecular weight (number average molecular weight Mn and weight average molecular weight Mw) of (b) the hydroxyl group-containing polyolefin can be measured by a method conventionally commonly used in the art, for example, gel permeation chromatography (GPC), and more specifically, can be measured by, for example, the method described in the Examples of the present application.

[0026] The molecular weight of (b) the hydroxyl group-containing polyolefin can be appropriately adjusted by appropriately adjusting the molecular weight of the polyolefin resin used for its production (by using a polyolefin resin with a desired molecular weight). When producing the polyolefin resin, the molecular weight of the polyolefin resin can be appropriately adjusted by appropriately adjusting and selecting all or part of the production conditions, such as the polymerization method, polymerization temperature, type and amount of catalyst, presence or absence of co-catalyst, type and amount of co-catalyst, and then the molecular weight of (b) the hydroxyl group-containing polyolefin obtained therefrom can be appropriately adjusted. In addition, the molecular weight of (b) the hydroxyl group-containing polyolefin can also be appropriately adjusted by appropriately selecting and adjusting the conditions for introducing hydroxyl groups into the polyolefin resin, such as the type and amount of organic peroxide, the temperature during grafting, and the kneading time.

[0027] (b) The polyolefin containing hydroxyl groups has a predetermined molecular weight distribution, and more specifically, satisfies the condition that (iii) Mw / Mn is 1.5 to 2.9. The propylene resin composition of the present invention satisfies the condition that the molecular weight distribution Mw / Mn of the polyolefin containing hydroxyl groups, which is one of its constituent components, is 1.5 to 2.9, and also possesses the other technical features defined in the present invention, thereby providing a propylene resin composition that can produce a resin molded article having both coating adhesion and excellent mechanical properties. The molecular weight distribution Mw / Mn of the polyolefin containing hydroxyl groups is preferably 1.5 to 2.9, more preferably 1.5 to 2.7, and even more preferably 2.0 to 2.7.

[0028] (b) The molecular weight distribution Mw / Mn of a polyolefin containing hydroxyl groups can be calculated by measuring its number-average molecular weight Mn and weight-average molecular weight Mw. (b) As stated above, the number-average molecular weight Mn and weight-average molecular weight Mw of a polyolefin containing hydroxyl groups can be measured by methods conventionally used in the industry, such as gel permeation chromatography (GPC), and more specifically, by the method described in the examples of this application.

[0029] (b) The molecular weight distribution of a polyolefin containing hydroxyl groups can be appropriately adjusted by appropriately adjusting the molecular weight distribution of the polyolefin resin used in its production (by using a polyolefin resin with a desired molecular weight distribution). When producing the polyolefin resin, the molecular weight distribution of the polyolefin resin can be appropriately adjusted by appropriately adjusting and selecting all or part of the production conditions, such as the polymerization method, polymerization temperature, type and amount of catalyst, and presence, type and amount of co-catalyst, thereby appropriately adjusting the molecular weight distribution of the (b) polyolefin containing hydroxyl groups obtained therefrom. For example, when a single-site catalyst is used when producing a polyolefin resin, the molecular weight distribution of the polyolefin resin tends to become narrower (Mw / Mn becomes smaller), and this can narrow the molecular weight distribution of the (b) polyolefin containing hydroxyl groups obtained therefrom. In addition, the molecular weight distribution of the (b) polyolefin containing hydroxyl groups can also be appropriately adjusted by appropriately selecting and adjusting the conditions when introducing hydroxyl groups into the polyolefin resin, such as the type and amount of organic peroxide, the temperature during grafting, and the kneading time.

[0030] (b) The method for producing polyolefins containing hydroxyl groups is not particularly limited, but for example, one production method is to melt-knead a mixture containing a polyolefin resin, such as the propylene polymer described above (a), a hydroxyl group-containing monomer, and an organic peroxide. The polyolefin resin preferably used in the melt-kneading method is an ultra-high molecular weight crystalline polypropylene resin having a melting point measured by differential scanning calorimeter preferably of 150°C to 168°C and an intrinsic viscosity [η] measured in decalin at 135°C preferably of 5 dl / g to 15 dl / g, more preferably of 5.5 dl / g to 12 dl / g. The amount of hydroxyl group-containing monomer and organic peroxide used is preferably in the range of 0.3 to 10 parts by mass of hydroxyl group-containing monomer and 0.001 to 10 parts by mass of organic peroxide per 100 parts by weight of polyolefin resin.

[0031] (b) The polyolefin resin used in the production of polyolefins containing hydroxyl groups may be any polymer having structural units derived from olefins with two or more carbon atoms, and is not particularly limited in any other respect. However, preferred examples include the above-mentioned (a) propylene polymers, low-density ethylene resins, medium-density ethylene resins, ultra-low-density ethylene resins, 1-butene (co)polymers, 4-methylpentene-1 (co)polymers, ethylene-α-olefin copolymers, ethylene-cyclic olefin copolymers, ethylene-α-olefin-cyclic olefin copolymers, ethylene-α-olefin-non-conjugated polyene copolymers, ethylene-α-olefin-conjugated polyene copolymers, ethylene-aromatic vinyl copolymers, and ethylene-α-olefin-aromatic vinyl copolymers. Furthermore, in the present invention, hydrides of conjugated diene polymers, such as hydrides of isoprene polymers, and hydrogenated polybutadiene can also be used as polyolefin resins in a broad sense in the production of (b) polyolefins containing hydroxyl groups. (b) The polyolefin resins used in the production of polyolefins containing hydroxyl groups are particularly preferably the propylene polymers, isoprene polymers, and hydrogenated polybutadienes mentioned above (a). (b) The polyolefin resins used in the production of polyolefins containing hydroxyl groups may be used individually or in combination of two or more types.

[0032] (b) As a polyolefin containing hydroxyl groups derived from the hydrogenated isoprene polymer, one obtained by hydrogenating a hydroxyl group-containing liquid isoprene polymer may be used. In this case, any known hydroxyl group-containing liquid isoprene polymer can be used, or it can be easily produced by known methods. For example, a hydroxyl group-containing liquid polyisoprene can be obtained by radical polymerization of isoprene monomer with hydrogen peroxide, a hydroxyl group-containing azo compound (e.g., 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide]), or a hydroxyl group-containing peroxide (e.g., cyclohexanone peroxide) as polymerization initiators.

[0033] (b) Preferred examples of hydroxyl group-containing monomers used in the production of hydroxyl group-containing polyolefins include (meth)acrylic acid esters, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, glycerin mono(meth)acrylate, pentaerythritol mono(meth)acrylate, trimethylolpropane (meth)acrylate, tetramethylolethane mono(meth)acrylate, butanediol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, and 2-(6-hydroxyhexanoyloxy)ethyl acrylate. "(meth)acrylate" means "acrylate" and / or "methacrylate".

[0034] Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate are preferred, and 2-hydroxyethyl methacrylate is particularly preferred. The hydroxyl group-containing monomer may be used alone or in combination of two or more.

[0035] As the organic peroxide, any known organic peroxide can be used without particular limitation. Specific examples of preferred organic peroxides include peroxyketals, such as 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)octane, n-butyl-4,4-bis(tert-butylperoxy)valate, 2, and 2-bis(tert-butylperoxy)butane; and dialkylperoxides, such as di-tert-butylperoxide, dicumylperoxide, tert-butylperoxide. Chilcumyl peroxide, α,α′-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyn-3; diacyl peroxides, e.g., acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,5-dichlorobenzene Dimethyl peroxides and m-trioyl peroxides; peroxyesters, e.g., tert-butyloxyacetate, tert-butylperoxyisobutyrate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxylaurylate, tert-butylperoxybenzoate, di-tert-butylperoxyisophthalate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butylperoxymalic acid, tert-butylperoxyisophthalate Examples include pyruvic carbonates and cumyl peroxyoctate; peroxydicarbonates, such as di(2-ethylhexyl)peroxydicarbonate, di(3-methyl-3-methoxybutyl) and peroxydicarbonate; and hydroperoxides, such as tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide.Particularly preferred examples among these include benzoyl peroxide, m-trioyl peroxide, tert-butylperoxy-2-ethylhexanoate, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and tert-butylperoxybenzoate. These may be used individually or in combination of two or more.

[0036] A preferred example of the above-mentioned (b) method for producing polyolefins containing hydroxyl groups is that various known methods for mixing resins with each other or with solid or liquid additives can be employed. A preferred example is a method in which all or some of the components are combined and mixed separately, for example, using a Henschel mixer, ribbon blender, or blender to obtain a homogeneous mixture, and then kneaded. Conventional kneading means such as Banbury mixers, Plastmills, Brabender plastographs, and single-screw or twin-screw extruders can be widely used. The temperature when kneading in the kneader (for example, the cylinder temperature in the case of an extruder) is, for example, 100°C to 300°C, preferably 160°C to 250°C. A temperature of 100°C or higher improves the graft amount, and a temperature of 300°C or lower effectively suppresses the decomposition of the resin. The kneading time is usually 0.1 minutes to 30 minutes, preferably 0.5 minutes to 5 minutes. A mixing time of 0.1 minutes or more ensures a sufficient graft volume, while a mixing time of 30 minutes or less effectively suppresses resin degradation.

[0037] (b) There are no particular restrictions on the graft modification rate of polyolefins containing hydroxyl groups, but (i) it is preferable to satisfy the condition that the hydroxyl group concentration on the surface of the molded article obtained from the propylene resin composition (calculated on a maleic acid-modified polypropylene basis) is 0.15% by mass or more and 1.9% by mass or less, and from the viewpoint of achieving excellent coating adhesion, it is preferable to have a rate of 0.5% or more, and particularly preferable to have a rate of 0.7% or more. On the other hand, from the viewpoint of suppressing the decomposition of polypropylene and maintaining mechanical properties, (b) the graft modification rate of polyolefins containing hydroxyl groups is preferable to be 5.0% or less, and particularly preferable to be 3.0% or less. The graft modification rate is defined by the following formula: Graft modification rate (%) = 100 × (mass of graft chains) / (mass of base material)

[0038] (b) In polyolefins containing hydroxyl groups, the "mass of grafted chains" in the formula is the total mass of the side chains containing hydroxyl groups. When polyolefins containing hydroxyl groups (b) are produced by the above production method, the "mass of hydroxyl group-containing monomers" is the total mass of those grafted onto the main chain from the hydroxyl group-containing monomers used in the above production method (if substantially all of the hydroxyl group-containing monomers are grafted onto the main chain, the "mass of hydroxyl group-containing monomers" is the total mass of the hydroxyl group-containing monomers used in the above production method). Similarly, in polyolefins containing hydroxyl groups (b), the "mass of base material" in the formula is the mass of the polyolefin main chain. When polyolefins containing hydroxyl groups (b) are produced by the above production method, the "mass of polyolefin resin" is the total mass of the polyolefin resin used in the above production method. The graft modification rate of polyolefins containing hydroxyl groups (b) can be measured by nuclear magnetic resonance (NMR) measurement. The graft modification rate of polyolefins containing hydroxyl groups (b) can be appropriately adjusted by selecting and adjusting the amount of hydroxyl group-containing monomers and organic peroxides used, and the conditions of the graft modification process, such as the kneading conditions.

[0039] (b) The MFR of the hydroxyl group-containing polyolefin is not particularly limited, but from the viewpoint of molding processability and the like, the MFR measured at 230°C under a load of 2.16 kg is preferably 0.5 g / 10 min or more, more preferably 1 g / 10 min or more, and particularly preferably 5 g / 10 min or more. On the other hand, from the viewpoint of tensile strength and the like, the MFR of the hydroxyl group-containing polyolefin (b) measured at 230°C under a load of 2.16 kg is preferably 1000 g / 10 min or less, and particularly preferably 500 g / 10 min or less. The MFR of the hydroxyl group-containing polyolefin (b) can be appropriately adjusted by selecting and adjusting the type and physical properties of the polypropylene used for its production, and the conditions of the above-mentioned graft modification step.

[0040] The aforementioned hydroxyl group-containing polyolefin (b) may contain various additives such as phenolic, sulfur-based, phosphorus-based and other antioxidants, lubricants, antistatic agents, dispersants, copper damage inhibitors, neutralizing agents, foaming agents, plasticizers, anti-foaming agents, flame retardants, crosslinking agents, peroxides, flow improvers, ultraviolet absorbers, and / or light stabilizers.

[0041] (c) Elastomer The propylene-based resin composition of the present invention preferably contains 1 part by mass to 65 parts by mass of (c) an elastomer, in addition to (a) the propylene-based polymer and (b) the hydroxyl group-containing polyolefin that constitute the essential resin components (provided that the total of (a) the propylene-based polymer and (b) the hydroxyl group-containing polyolefin is 100 parts by mass). By containing the elastomer (c), the propylene-based resin composition of the present embodiment can achieve further excellent flexibility and impact resistance. The elastomer (c) preferably used in the present invention has a density of 0.900 kg / m ３ or less, and there are no particular other restrictions, but (c1) an ethylene-α-olefin copolymer and (c2) an aromatic vinyl-based copolymer can be particularly preferably used. As the elastomer (c), only one type may be used alone, or two or more types may be used in combination.

[0042] (c1) Ethylene-α-olefin copolymer A preferred example of the elastomer (c) preferably used in the propylene resin composition of the present invention is an ethylene-α-olefin copolymer having constituent units derived from ethylene and constituent units derived from α-olefin, and having 50% by mass or more of constituent units derived from ethylene. (c1) Ethylene-α-olefin copolymer is preferably an ethylene copolymer having 50% by mass or more and 99% by mass of constituent units derived from ethylene and constituent units derived from at least one monomer selected from the group consisting of α-olefins having 3 to 10 carbon atoms (provided that the total amount of the ethylene copolymer is 100% by mass). (c1) Ethylene-α-olefin copolymer is preferably a random copolymer. (c1) Ethylene-α-olefin copolymer may have constituent units derived from monomers other than ethylene and α-olefin.

[0043] Examples of α-olefins having 3 to 10 carbon atoms include propylene, 1-butene, 2-methylpropene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. (c1) In the preparation of the ethylene-α-olefin copolymer, the α-olefin having 3 to 10 carbon atoms may be used alone or in combination of two or more. More preferably, the constituent units derived from at least one selected from the group consisting of α-olefins having 3 to 10 carbon atoms are constituent units derived from propylene, 1-butene, or 1-octene.

[0044] The proportion of constituent units derived from ethylene in the (c1) ethylene-α-olefin copolymer is preferably 50% by mass or more and 99% by mass or less, more preferably 55% by mass or more and 90% by mass or less, and particularly preferably 60% by mass or more and 85% by mass or less (provided that the total amount of the (c1) ethylene-α-olefin copolymer is 100% by mass). The proportion of constituent units derived from at least one selected from the group consisting of α-olefins having 3 to 10 carbon atoms in the (c1) ethylene-α-olefin copolymer is preferably 1% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, and particularly preferably 15% by mass or more and 40% by mass or less (provided that the total amount of the (c1) ethylene-α-olefin copolymer is 100% by mass).

[0045] (c1) The proportion of constituent units derived from ethylene and the proportion of constituent units derived from at least one monomer selected from the group consisting of α-olefins having 3 to 10 carbon atoms in an ethylene-α-olefin copolymer can be determined by infrared spectroscopy. Specifically, by measuring the infrared absorption spectrum of the (c1) ethylene-α-olefin copolymer using an infrared spectrophotometer, the proportion of constituent units derived from ethylene and the proportion of constituent units derived from at least one monomer selected from the group consisting of α-olefins having 3 to 10 carbon atoms can be calculated according to the method described in "Characterization of Polyethylene by Infrared Absorption Spectroscopy (by Takayama, Usami, et al.)" or "Die Makromolekulare Chemie, 177, 461 (1976) (by McRae, M.A., Madam S, W.F., et al.)".

[0046] (c1) The ethylene-α-olefin copolymer may have constituent units derived from monomers other than ethylene and at least one selected from the group consisting of ethylene and α-olefins having 3 to 10 carbon atoms. Examples of such other monomers include conjugated dienes having 4 to 8 carbon atoms, such as 1,3-butadiene, 2-methyl-1,3-butadiene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene; unconjugated dienes having 5 to 15 carbon atoms, such as dicyclopentadiene, 5-ethylidene-2-norbornene, 1,4-hexadiene, 1,5-dicyclooctadiene, 7-methyl-1,6-octadiene, and 5-vinyl-2-norbornene; vinyl carboxylates, such as vinyl acetate; unsaturated carboxylic acid esters, such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, and ethyl methacrylate; and unsaturated carboxylic acids, such as acrylic acid and methacrylic acid. The other monomer is preferably a non-conjugated diene having 5 to 15 carbon atoms, more preferably 5-ethylidene-2-norbornene or dicyclopentadiene. (c1) The ethylene-α-olefin copolymer may contain two or more constituent units derived from the other monomer.

[0047] (c1) When the ethylene-α-olefin copolymer has constituent units derived from monomers other than ethylene and at least one selected from the group consisting of α-olefins having 3 to 10 carbon atoms, the proportion of constituent units derived from the other monomers is preferably 30% by mass or less, and more preferably 20% by mass or less (provided that the total amount of the (c1) ethylene-α-olefin copolymer is 100% by mass). The proportion of constituent units derived from the other monomers can be determined by infrared spectroscopy. Specifically, an infrared spectrophotometer is used to measure the peak intensity of the peak derived from the other monomer in the (c1) ethylene-α-olefin copolymer, and the proportion of constituent units derived from the other monomer in the (c1) ethylene-α-olefin copolymer is calculated from the peak intensity.

[0048] (c1) Preferred examples of ethylene-α-olefin copolymers include ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-propylene-1-butene copolymer, ethylene-propylene-1-hexene copolymer, ethylene-propylene-1-octene copolymer, ethylene-propylene-5-ethylidene-2-norbornene copolymer, ethylene-propylene-dicyclopentadiene copolymer, ethylene-propylene-1,4-hexadiene copolymer, and ethylene-propylene-5-vinyl-2-norbornene copolymer. It may also be an olefin-based block copolymer containing an ethylene polymerization block and an ethylene-α-olefin copolymer block. The ethylene-based copolymer as component (c1) may be used alone or in combination of two or more. Preferably, ethylene-octene copolymer or ethylene-propylene copolymer can be used as component (c1).

[0049] (c1) There are no particular restrictions on the density of the ethylene-α-olefin copolymer, but from the viewpoint of tensile strength and suppression of product stickiness, 0.830 g / cm³ is recommended. ３ Preferably, it is 0.840 g / cm³ or more. ３ It is more preferable that the amount be greater than or equal to 0.850 g / cm³. ３ The above is particularly preferable. On the other hand, from the viewpoint of product flexibility, impact resistance, etc., the density of (c1) ethylene-α-olefin copolymer is 0.900 g / cm³. ３ Preferably, it is 0.890 g / cm³. ３ It is more preferable that the following is the case: 0.880 g / cm³ ３ The following is particularly preferable: (c1) The density of the ethylene-α-olefin copolymer can be appropriately adjusted by selecting and adjusting, for example, the type and proportion of constituent units derived from α-olefin, and the polymerization conditions of the (c1) ethylene-α-olefin copolymer.

[0050] (c1) There are no particular restrictions on the MFR of the ethylene-α-olefin copolymer, but from the viewpoint of moldability, etc., it is preferable that the MFR measured at 190°C and a 2.16 kg load is 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, and particularly preferable 0.5 g / 10 min or more. On the other hand, from the viewpoint of impact resistance, etc., it is preferable that the MFR of the (c1) ethylene-α-olefin copolymer measured at 190°C and a 2.16 kg load is 30 g / 10 min or less, more preferably 25 g / 10 min or less, and particularly preferable 20 g / 10 min or less. The MFR of the (c1) ethylene-α-olefin copolymer can be appropriately adjusted, for example, by adjusting its molecular weight through the polymerization conditions of the (c1) ethylene-α-olefin copolymer.

[0051] (c1) There are no particular restrictions on the melting point of the ethylene-α-olefin copolymer, but it is especially preferable that it be 0°C or higher from the viewpoint of suppressing stickiness of the product. On the other hand, from the viewpoint of product flexibility and impact resistance, the melting point of the (c1) ethylene-α-olefin copolymer is preferably 100°C or lower, more preferably 80°C or lower, and particularly preferably 70°C or lower. The melting point of the (c1) ethylene-α-olefin copolymer can be measured by DSC (Differential Scanning Calorimetry). The melting point of the (c1) ethylene-α-olefin copolymer can be appropriately adjusted by adjusting the molecular structure and crystallinity of the (c1) ethylene-α-olefin copolymer through, for example, the type and proportion of constituent units derived from α-olefin and the polymerization conditions.

[0052] (c1) Ethylene-α-olefin copolymers can be obtained by polymerization using known methods. Examples of such polymerization methods include polymerization using polymerization catalysts such as Ziegler-Natta catalysts or metallocene catalysts in an inert solvent such as hexane, heptane, toluene, or xylene.

[0053] (c2) Aromatic vinyl copolymer The (c2) aromatic vinyl copolymer can be any copolymer having structural units derived from an aromatic vinyl compound, and there are no other particular restrictions, but it is preferable that it is a copolymer having structural units derived from an aromatic vinyl compound and structural units derived from a conjugated diene compound, for example aromatic vinyl compound-conjugated diene compound polymers, aromatic vinyl compound-conjugated diene compound-aromatic vinyl compound polymers, and hydrogenated versions thereof can be preferably used. Among these, hydrogenated versions of aromatic vinyl compound-conjugated diene compound-aromatic vinyl compound polymers are particularly preferred.

[0054] Examples of aromatic vinyl compounds in component (c2) include styrene, α-methylstyrene, o-, m-, or p-methylstyrene, 1,3-dimethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromstyrene, dibromstyrene, ethylstyrene, and vinylnaphthalene, with styrene being preferred among them.

[0055] Examples of conjugated diene compounds that are preferably used in component (c2) include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-neopentyl-1,3-butadiene, 2-chloro-1,3-butadiene, and 2-cyano-1,3-butadiene, with butadiene or isoprene being preferred.

[0056] The proportion of structural units derived from aromatic vinyl compounds is preferably 10% to 50% by mass, more preferably 15% to 45% by mass, and even more preferably 20% to 40% by mass, from the viewpoint of reducing mold contamination during molding and improving the tensile properties and appearance of the molded article. However, the total amount of copolymer having structural units derived from aromatic vinyl compounds and structural units derived from conjugated diene compounds is set to 100% by mass. The proportion of structural units derived from aromatic vinyl compounds can be determined by 1H-NMR measurement.

[0057] The proportion of structural units derived from the conjugated diene compound is preferably 50% to 90% by mass, more preferably 55% to 85% by mass, and even more preferably 60% to 80% by mass. However, the total amount of the copolymer having structural units derived from the aromatic vinyl compound and structural units derived from the conjugated diene compound is set to 100% by mass. The proportion of structural units derived from the conjugated diene compound can be determined by 1H-NMR measurement.

[0058] (c2) Component may be a hydrogenated product, in which case the hydrogenation rate is preferably 80% or more, and more preferably 90% or more. However, this is a molar ratio based on the amount of double bonds in structural units derived from the conjugated diene compound in the copolymer before hydrogenation being 100%.

[0059] (c2) As a method for producing the component, for example, the method described in Japanese Patent Publication No. 40-23798 can be cited. As a method for hydrogenating a copolymer having structural units derived from an aromatic vinyl compound and structural units derived from a conjugated diene compound, for example, the methods described in Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Unexamined Patent Publication No. 59-133203, Japanese Unexamined Patent Publication No. 60-79005, etc. (c2) As the aromatic vinyl copolymer, commercially available products such as "KRATON-G" from Kraton Polymers, "Septon" from Kuraray Co., Ltd., "ToughTec" from Asahi Kasei Corporation, and "TAIPOL" from TSRC Corporation may be used.

[0060] The components (a) to (c) described above all correspond to polyolefin resins, but all or part of these polyolefin resins may contain carbon-14 (14C) as a constituent element, and may be materially recycled (mechanically recycled).

[0061] The concentration of carbon-14 (¹⁴C) in polyolefin resins is determined as pMC (percentage of modern carbon: unit %) by the AMS (Accelerator mass spectrum) method specified in ISO 16620-2:2019. Since atmospheric carbon dioxide contains carbon-14 (¹⁴C) in a certain proportion, it is known that plants that grow by taking in atmospheric carbon dioxide, such as corn and trees, contain ¹⁴C. It is also known that petroleum and other fossil resources, which are thought to have been stored underground for long periods, contain almost no carbon-14 (¹⁴C). Therefore, by using plant-derived substances as raw materials for monomers used in the production of polyolefin resins, it is possible to include carbon-14 (¹⁴C) in the constituent elements of polyolefin resins.

[0062] In the production of polyolefin resins, monomers derived from fossil resources (e.g., ethylene, propylene, 1-butene, 1-hexene), monomers derived from plants (e.g., ethylene, propylene, 1-butene, 1-hexene), and chemically recycled monomers (e.g., ethylene, propylene, 1-butene, 1-hexene) can be used, and two or more of these may be used in combination. Specific monomer combinations include, for example, fossil resource-derived propylene / plant-derived propylene / chemically recycled propylene, fossil resource-derived propylene / plant-derived propylene / chemically recycled propylene / fossil resource-derived ethylene / plant-derived ethylene / chemically recycled ethylene, and fossil resource-derived ethylene / plant-derived ethylene / chemically recycled ethylene / fossil resource-derived 1-butene / plant-derived 1-butene / chemically recycled 1-butene.

[0063] Monomers derived from fossil resources originate from carbon in underground resources such as petroleum, coal, and natural gas, and generally contain very little carbon-14 (14C). Methods for producing fossil resource-derived monomers include known methods such as the cracking of petroleum-derived naphtha and ethane, and the dehydrogenation of ethane and propane to produce olefins.

[0064] Plant-derived monomers are derived from carbon that circulates on the Earth's surface as plants and animals, and generally contain a certain proportion of carbon-14 (14C). Methods for producing plant-derived monomers include known methods such as cracking of bionaphtha, vegetable oil, and animal oil; dehydrogenation of biopropane; separating alcohol from fermented products extracted from plant raw materials, such as sugarcane and corn, such as sugar, and then dehydrating them (see, for example, JP 2010-511634, JP 2011-506628, and JP 2013-503647); and a method of metathesis reaction between ethylene obtained from plant-derived ethanol and n-butene (see, for example, WO2007 / 055361).

[0065] Chemical recycled monomers are derived from carbon generated by the decomposition or combustion of waste, and their carbon-14 (14C) content varies depending on the type of waste. Known methods for producing chemical recycled monomers include, for example, a method of thermal decomposition of waste plastics (see, for example, JP 2017-512246), a method of cracking waste vegetable oil and waste animal oil (see, for example, JP 2018-522087), and a method of gasification, alcohol conversion, and dehydration reaction of food waste, biomass waste, food waste, waste oil, waste wood, paper waste, and / or waste plastics (see, for example, JP 2019-167424, WO2021 / 006245).

[0066] When using two or more types of olefins derived from fossil resources, plant-derived olefins, and chemically recycled olefins, the olefins manufactured individually may be mixed in combinations such as fossil resource-derived olefin / plant-derived olefin, fossil resource-derived olefin / chemically recycled olefin, plant-derived olefin / chemically recycled olefin, or fossil resource-derived olefin / plant-derived olefin / chemically recycled olefin. Alternatively, a mixture of the above olefin combinations may be produced by using a mixture of combinations such as fossil resource-derived compound / plant-derived compound, fossil resource-derived compound / chemically recycled compound, plant-derived compound / chemically recycled compound, or fossil resource-derived compound / plant-derived compound / chemically recycled compound as a raw material or intermediate in the olefin manufacturing process.

[0067] As an example of a polyolefin resin containing carbon 14 (14C), commercially available polypropylene resins can be used. Examples include the "Bornewaves" series from Borealis, the "TRUCIRCLE" series from SABIC, and the "CirculenRenew" series from Lyondell Basell.

[0068] From the viewpoint of reducing environmental impact, the carbon-14 (14C) concentration of the polyolefin resin is preferably 0.2 pMC (%) or more, more preferably 0.5 pMC (%) or more, even more preferably 1 pMC (%) or more, even more preferably 5 pMC (%) or more, and particularly preferably 10 pMC (%) or more. From the viewpoint of cost, it is preferably 99 pMC (%) or less, more preferably 95 pMC (%) or less, even more preferably 90 pMC (%) or less, even more preferably 70 pMC (%) or less, and particularly preferably 50 pMC (%) or less.

[0069] The carbon-14 (14C) concentration of polyolefin resins can be adjusted by changing the ratio of fossil resource-derived olefins, plant-derived olefins, and chemically recycled olefins used in the production of polyolefin resins.

[0070] (d) Inorganic filler The propylene resin composition of the present invention may contain 0.1 to 75 parts by mass of (d) an inorganic filler (provided that the total of (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups is 100 parts by mass), in addition to (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups, which constitute the essential resin components. By containing (d) an inorganic filler, the propylene resin composition of this embodiment can achieve even better rigidity and dimensional stability.

[0071] Preferred examples of the inorganic fillers (d) used in the present invention include talc, calcium carbonate, calcined kaolin, glass fibers, hollow glass spheres, silica, metal soap, titanium dioxide, mica, potassium titanate fibers, hydrotalcite, zeolite, aluminum silicate, and magnesium silicate. Among these, talc, aluminum silicate, and magnesium silicate are particularly preferred. Talc is also preferred to have an average particle size of 1 to 20 μm, and more preferably 2 to 12 μm, as measured by laser analysis. The inorganic fillers (d) may be used individually or in combination of two or more types.

[0072] Propylene Resin Composition The propylene resin composition of the present invention contains an essential resin component consisting of (a) 99% to 1% by mass of a propylene polymer and (b) 1% to 99% by mass of a polyolefin containing hydroxyl groups (provided that the total of (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups is 100% by mass). The propylene resin composition of the present invention contains an essential resin component consisting of (a) 99% to 1% by mass of a propylene polymer and (b) 1% to 99% by mass of a polyolefin containing hydroxyl groups, and also possesses the other technical features (i) to (iii) of the present invention. As a result, the propylene resin composition of the present invention can produce resin molded articles that combine coating adhesion and excellent mechanical properties, thereby achieving a remarkable technical effect that has high practical value. (a) The proportion of the propylene polymer is preferably 4% to 99% by mass, more preferably 50% to 99% by mass, and even more preferably 90% to 99% by mass, when the total of (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups is 100% by mass. (b) The proportion of the polyolefin containing hydroxyl groups is preferably 1% to 98% by mass, more preferably 1% to 50% by mass, and even more preferably 1% to 10% by mass, when the total of (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups is 100% by mass.

[0073] The propylene-based resin composition of the present invention preferably contains (a) a propylene-based polymer and (b) a polyolefin containing hydroxyl groups as essential resin components, in addition to (c) an elastomer in an amount of 1 to 65 parts by mass (provided that the total mass of the essential resin components, i.e., the sum of (a) the propylene-based polymer and (b) the polyolefin containing hydroxyl groups, is 100 parts by mass). The amount of (c) elastomer used is preferably 25 to 65 parts by mass, more preferably 30 to 65 parts by mass, and even more preferably 30 to 50 parts by mass, based on 100 parts by mass of the total of (a) the propylene-based polymer and (b) the polyolefin containing hydroxyl groups.

[0074] The propylene resin composition of the present invention preferably contains (a) a propylene polymer and (b) a polyolefin containing hydroxyl groups as essential polyolefin components, in addition to (d) an inorganic filler in an amount of 0.1 to 75 parts by mass (provided that the total mass of the essential polyolefin components, i.e., (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups, is 100 parts by mass). The amount of (d) inorganic filler used is preferably 20 to 75 parts by mass, more preferably 30 to 75 parts by mass, and even more preferably 30 to 50 parts by mass, based on 100 parts by mass of the total of (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups.

[0075] The propylene-based resin composition of the present invention may contain components other than (a) a propylene-based polymer and (b) a polyolefin containing hydroxyl groups (and, if present, (c) an elastomer and (d) an inorganic filler as preferred components), as essential resin components. Examples of components other than components (a) to (d) above include various additives, other resin components, and organic fillers. There are no particular restrictions on the total amount of various additives, other resin components, organic fillers, etc., but it is preferable that it is 50% by mass or less of the total mass of the resin composition.

[0076] As additives, various known additives that can be used in polypropylene resin compositions, such as antioxidants, neutralizing agents, light stabilizers, ultraviolet absorbers, nucleating agents, antiblocking agents, mineral oils, crosslinking agents, crosslinking aids, antistatic agents, and / or metal deactivators, may be incorporated.

[0077] Examples of antioxidants include phenolic antioxidants, phosphite antioxidants, and thio antioxidants. Examples of neutralizing agents include higher fatty acid salts, such as calcium stearate and zinc stearate. Examples of light stabilizers and UV absorbers include hindered amines, benzotriazoles, and benzophenones.

[0078] Examples of crystal nucleating agents include aromatic carboxylic acid metal salts, aromatic phosphate metal salts, sorbitol derivatives, rosin metal salts, and amide nucleating agents. Among these crystal nucleating agents, examples include p-tert-butylbenzoate aluminum, 2,2'-methylenebis(4,6-di-tert-butylphenyl)sodium phosphate, 2,2'-methylenebis(4,6-di-tert-butylphenyl)aluminum phosphate, a complex of bis(2,4,8,10-tetra-tert-butyl-6-hydroxy-12H-dibenzo[d,g][1,2,3]dioxaphosphosin-6-oxide) aluminum hydroxide salt with an organic compound, p-methyl-benzylidene sorbitol, p-ethyl-benzylidene sorbitol, 1,2,3-trideoxy-4,6:5,7-bis-[(4-propylphenyl)methylene]-nonitol, and rosin sodium salts.

[0079] Examples of lubricants include higher fatty acid amides, such as stearate amide. Examples of mineral oils include high boiling fractions of petroleum, such as aromatic mineral oils, naphthenic mineral oils, and paraffinic mineral oils. Examples of crosslinking agents include organic peroxides, phenolic resins, sulfur, sulfur-containing compounds, p-quinones, derivatives of p-quinone dioxime, bismaleimide compounds, epoxy compounds, silane compounds, and amino resins. Examples of crosslinking aids include polyfunctional compounds such as sulfur-based, methacrylate-based, and maleimide-based compounds. Examples of antistatic agents include fatty acid partial esters, such as glycerol fatty acid monoesters. Examples of metal deactivators include triazines, phosphones, epoxys, triazoles, hydrazides, and oxamides.

[0080] Examples of organic fillers include cross-linked rubber microparticles, thermosetting resin microparticles, and thermosetting resin hollow microparticles. Examples of other resin components include various thermoplastic resins and thermosetting resins other than polyolefins and elastomers. Coloring is also possible to impart design appeal, and various colorants, such as inorganic pigments, organic pigments, or dyes, can be used for coloring. In addition, glossing materials, such as aluminum flakes, titanium dioxide flakes, and (synthetic) mica, can also be used.

[0081] There are no particular limitations on the method for producing the propylene-based resin composition of the present invention, but for example, it can be produced by melt-kneading predetermined amounts of (a) a propylene-based polymer and (b) a polyolefin containing hydroxyl groups (and, if used, (c) an elastomer, (d) an inorganic filler, and / or other components), or by dry-blending the other components with a melt-kneaded portion of the above components.

[0082] The propylene-based resin composition of the present invention satisfies the following conditions (i) to (iii): (i) The hydroxyl group concentration (in terms of maleic acid-modified polypropylene) on the surface of the molded article obtained from the propylene-based resin composition is 0.15% by mass or more and 1.9% by mass or less. (ii) The ratio X = Mw(b) / Mw(a) of the weight-average molecular weight Mw(a) of (a) the propylene-based polymer and (b) the weight-average molecular weight Mw(b) of the polyolefin containing hydroxyl groups is 0.025 ≤ X ≤ 0.47. (iii) The Mw / Mn ratio of the polyolefin containing hydroxyl groups is 1.5 to 2.9. By satisfying the above conditions (i) to (iii), the propylene-based resin composition of the present invention can produce a resin molded article that achieves both high coating adhesion and excellent mechanical properties at a high level that surpasses the limits of the conventional technology. For example, in a composite molded article containing a propylene-based resin composition, a coating film is directly formed (without using a primer) on the surface of the molded article, and it is possible to manufacture a resin molded article that achieves both high adhesion of the coating film to the molded article and excellent mechanical properties of the molded article itself at a level that surpasses the limitations of conventional technology.

[0083] The mechanism by which high coating adhesion and excellent mechanical properties are achieved by satisfying the above conditions (i) to (iii) is not entirely clear, but it is presumed that there is some relationship between the weight-average molecular weight ratio between the main constituent components, (a) propylene polymer and (b) polyolefin containing hydroxyl groups, and the molecular weight distribution of the polyolefin containing (b) hydroxyl groups, being within predetermined ranges (conditions (ii) and (iii)), which allows the phase mainly composed of the polyolefin containing (b) hydroxyl groups to disperse well, and the hydroxyl groups of the polyolefin containing (b) hydroxyl groups to be efficiently utilized to improve coating adhesion, thereby enabling the supply of sufficient hydroxyl groups to the molded surface to achieve high coating adhesion, and the existence of a hydroxyl group concentration range (condition (i)) in which the deterioration of mechanical properties due to excess hydroxyl groups is suppressed.

[0084] (i) Surface hydroxyl group concentration (i) The hydroxyl group concentration on the surface of a molded article obtained from the propylene resin composition of the present invention (calculated as maleic acid-modified polypropylene (MAH-PP)) is 0.15% by mass or more and 1.9% by mass or less. More specifically, a plate made by injection molding from the propylene resin composition of the present invention is used, and trifluoroacetic anhydride is used as a derivatization reagent to modify the hydroxyl groups. The plate and 150 mg of trifluoroacetic anhydride are placed in a 100 ml lidded vial, reacted at 45°C for 1 hour, the lid is opened, and the plate is vacuum dried for 6 hours. The hydroxyl group concentration obtained from the infrared spectroscopic spectrum measured on the resulting plate is 0.15% by mass or more and 1.9% by mass or less.

[0085] The measurement conditions for the infrared spectroscopic spectrum are as follows: • FT-IR instrument: FTIR470plus, manufactured by JASCO Corporation (detector: TGS) • Measurement conditions: ATR: Pike MIRacre Single Reflection ATR (diamond crystal) Number of scans: 32 Resolution: 4 cm －１ Measurement range: 600 cm －１ ~4000 －１ Vertical axis: Absorbance

[0086] In the obtained infrared spectral spectrum, the peak height A was calculated using equation (1): A = (A3 - A2) × (1 / (A1 - A2)) - (1) where A1 is 2915 cm⁻¹ in the infrared spectral spectrum. －１ ~2925cm －１ The maximum height in the range (CH ２ (Antisymmetry stretching), A2 is 1900 cm² in the infrared spectroscopic spectrum. －１ ~1800m －１ The minimum height in the range, A3, is 1775 cm² in the infrared spectral spectrum. －１ ~1795cm －１ This is the maximum height within the range. The hydroxyl group concentration B, converted to MAH-PP (maleic acid-modified polypropylene), was calculated using the peak height A according to the following method and formula (2). A calibration curve was created using maleic acid-modified polypropylene (Yumex 1010, manufactured by Sanyo Chemical Industries, Ltd.). When the amount of MAH was calculated for MAH-PP by titration, the amount of MAH was 5.66 mass%. When the infrared spectroscopic spectrum of this sample was measured, the peak height A defined by the above method was 0.21. Therefore, the following relationship holds between the amount of MAH (hydroxyl group concentration converted to MAH-PP, mass%) B and the peak intensity A: B = 26.766 × A - (2)

[0087] With the propylene-based resin composition of the present invention, if the hydroxyl group concentration (MAH-PP equivalent) on the surface of the molded article obtained under the above conditions is 0.15% by mass or more and 1.9% by mass or less, it is possible to supply sufficient hydroxyl groups to the surface of the molded article to achieve high coating adhesion and to suppress a decrease in mechanical properties. Preferably, the hydroxyl group concentration (MAH-PP equivalent) on the surface of the molded article obtained under the above conditions from the propylene-based resin composition of the present invention is 0.15% by mass or more and 1.0% by mass or less, and more preferably 0.15% by mass or more and 0.7% by mass or less.

[0088] The hydroxyl group concentration (MAH-PP equivalent) on the surface of a molded article obtained from the propylene resin composition of the present invention under the above conditions can be appropriately increased or decreased by increasing or decreasing the amount of polyolefin containing hydroxyl groups and / or the graft modification rate. The method for measuring and adjusting the graft modification rate of polyolefin containing hydroxyl groups is as described above in relation to polyolefin containing hydroxyl groups.

[0089] (ii) Weight-average molecular weight ratio X (ii) The ratio X = Mw(b) / Mw(a) of the weight-average molecular weight Mw(a) of the (a) propylene polymer constituting the propylene resin composition of the present invention and the weight-average molecular weight Mw(b) of the (b) polyolefin containing hydroxyl groups is within the range of 0.025 ≤ X ≤ 0.47. When the weight-average molecular weight ratio X is 0.025 or more and 0.47 or less, and also possesses other technical features of the present invention, the propylene resin composition of the present invention can achieve a good microstructure and can achieve both high coating adhesion and excellent mechanical properties at a high level that exceeds the limits of the prior art. The weight-average molecular weight ratio X is preferably 0.03 or more and 0.45 or less, and more preferably 0.04 or more and 0.4 or less.

[0090] The weight-average molecular weight ratio X can be adjusted as appropriate by adjusting (a) the weight-average molecular weight Mw(a) of the propylene polymer and / or (b) the weight-average molecular weight Mw(b) of the polyolefin containing hydroxyl groups. The methods for adjusting (a) the weight-average molecular weight Mw(a) of the propylene polymer and (b) the weight-average molecular weight Mw(b) of the polyolefin containing hydroxyl groups are as described above, relating to (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups, respectively.

[0091] (iii) (b) Mw / Mn of polyolefin containing hydroxyl groups (iii) The polyolefin containing hydroxyl groups that constitutes the propylene resin composition of the present invention has a molecular weight distribution in which Mw / Mn is 1.5 to 2.9. The propylene resin composition of the present invention satisfies the condition that the molecular weight distribution Mw / Mn of the polyolefin containing hydroxyl groups that is a component thereof is 1.5 to 2.9, and also possesses the other technical features defined in the present invention, thereby providing a propylene resin composition that can produce a resin molded article having both coating adhesion and excellent mechanical properties. Details of the measurement method, preferred numerical range, and adjustment means for polyolefin containing hydroxyl groups are as described above in relation to polyolefin containing hydroxyl groups.

[0092] The propylene-based resin composition of the present invention makes it possible to produce resin molded articles that possess both high coating adhesion and excellent mechanical properties. An example of excellent mechanical properties is a high flexural modulus. There are no particular restrictions on the flexural modulus of a resin molded article produced from the propylene-based resin composition of the present invention, but it is preferable that the flexural modulus measured in accordance with JIS K7171, after cutting a dumbbell-shaped test piece obtained by injection molding the propylene-based resin composition of the present invention under the conditions described in JIS K7152 into a shape with a total length of 80 mm, a width of 10 mm, and a thickness of 4 mm, is 1300 MPa or higher. It is more preferable that the above flexural modulus be 1500 MPa or higher, and particularly preferable that it be 1600 MPa or higher. The higher the above flexural modulus, the better, and there is no particular upper limit, but when the propylene-based resin composition of the present invention is produced by ordinary means and at ordinary cost, it is often 3500 MPa or less.

[0093] Another example of excellent mechanical properties is high Charpy impact strength. While there are no particular limitations on the Charpy impact strength of resin molded articles produced from the propylene-based resin composition of the present invention, a dumbbell-shaped test piece obtained by injection molding the propylene-based resin composition of the present invention under the conditions described in JIS K7152 was cut to a shape with a total length of 80 mm, a width of 10 mm, and a thickness of 4 mm. Furthermore, a V-notch was applied to the surface formed by the 80 mm length and 4 mm thickness. The Charpy impact strength measured in accordance with JIS K 7111-1 was 10 kJ / m². ２ It is preferable that the above is true. The Charpy impact strength is 15 kJ / m ２ It is more preferable that the concentration be 20 kJ / m ２ The above is particularly preferable. The higher the Charpy impact strength, the better, and there is no particular upper limit, but when the propylene-based resin composition of the present invention is manufactured by ordinary means and at normal cost, 70 kJ / m ２ The following is often the case.

[0094] Composite molded article and method for manufacturing the same By using the propylene-based resin composition of the present invention, a composite molded article having (1) a coating film and (2) a polyolefin molded article can be manufactured, wherein the coating film (1) is directly formed on at least a portion of the surface of the polyolefin molded article (2). In the composite molded article, the polyolefin molded article (2) contains the propylene-based resin composition of the present invention. Since the propylene-based resin composition of the present invention has excellent coating adhesion, the coating adhesion is improved when the polyolefin molded article (2) contains the propylene-based resin composition of the present invention, and the coating film (1) can be directly formed on the polyolefin molded article (2) with high coating adhesion without requiring primer coating to improve the affinity of the coating film. As a result, the primer coating process can be reduced, leading to reduced environmental impact, lower costs, and labor savings.

[0095] (1) There are no particular restrictions on the components of the coating film, but in a resin molded article using the propylene-based resin composition of the present invention, hydroxyl groups are supplied to the surface at an appropriate concentration, and the hydroxyl groups have particularly excellent affinity with isocyanate groups, so (1) it is preferable that the coating film contains a paint having isocyanate groups, such as a urethane-based paint.

[0096] The composite molded product of this embodiment is low-cost and environmentally friendly because the coating (1) is directly formed on the (2) polyolefin molded body with high coating adhesion without requiring primer coating on the polypropylene-containing resin molded body. Furthermore, since the propylene-based resin composition of the present invention has excellent mechanical properties, such as high flexural modulus and high impact strength, the composite molded product of this embodiment can be suitably used in various applications where both mechanical properties and the appearance and design provided by the coating are required. More specifically, it can be suitably used in various automotive exterior parts, such as bumpers, fenders, back doors, side moldings, and rocker moldings, as well as various parts for home appliances, various housing equipment parts, various industrial parts, and various building material parts.

[0097] There are no particular limitations on the method for manufacturing the composite molded article of the above embodiment, but it is preferable to manufacture it by a method having the following steps I) and II). Step I): (2) A step of providing a polyolefin molded article. Step II): (2) A step of forming a coating film (1) on at least a part of the surface of the polyolefin molded article.

[0098] There are no particular restrictions on the method for providing the (2) polyolefin molded article in step I. A (2) polyolefin molded article of a desired shape may be produced from the propylene-based resin composition of the present invention, or a (2) polyolefin molded article that has been molded into a desired shape may be purchased. There are no particular restrictions on the method for producing the (2) polyolefin molded article of a desired shape. For example, injection molding or extrusion molding can be used. Among these, injection molding is preferred.

[0099] If the step of providing (2) a polyolefin molded article in step I) is performed by injection molding, then in step II), it is preferable from the viewpoint of low environmental impact to form (1) a coating film on the surface of (2) the polyolefin molded article within the mold used for the injection molding, i.e., to perform in-mold painting (IMC).

[0100] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples shown below.

[0101] In the following explanation, "%" and "parts" refer to mass unless otherwise specified. Furthermore, the operations described below were performed under normal temperature and pressure conditions unless otherwise specified.

[0102] <Measurement and Evaluation Methods> In the following examples / comparative examples, the physical properties and performance were measured and evaluated using the methods described below. (Melt Flow Rate) Measured under conditions of 230°C and a load of 2.16 kgf, in accordance with JIS K7210-1:2014 and K7210-2:2014.

[0103] (Intrinsic Viscosity Number) Using an Ubbelohde viscometer, the reduced viscosity was measured for multiple concentrations, and the intrinsic viscosity was determined by plotting the reduced viscosity against the concentration and extrapolating the concentration to zero. More specifically, the method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (Kyoritsu Shuppan Co., Ltd., 1982) was used to measure the reduced viscosity at three points with concentrations of 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL. The reduced viscosity was then plotted against the concentration and extrapolated to zero.

[0104] (Molecular Weight, Molecular Weight Distribution) The molecular weight distribution and various average molecular weights (number-average molecular weight Mn, weight-average molecular weight Mw, z-average molecular weight Mz) of the resin and composition were determined by gel permeation chromatography (GPC). GPC measurements were performed under the following conditions: • GPC instrument: HLC-8321GPC / HT (Tosoh Corporation) • Measurement conditions: GPC column: TSKgel GMHHR-H(S)HT 7.8 mm I.D. 300 mm x 300 mm (Tosoh Corporation) 3-column mobile phase: Orthodichlorobenzene (special grade) with added BHT (0.1 w / V%) Flow rate: 1 mL / min Column oven temperature: 145°C Autosampler temperature: 145°C System oven temperature: 40°C Detector: Differential refractive index detector (RID) RID cell temperature: 145°C Sample solution injection volume: 300 μL GPC column calibration standard: Tosoh Corporation standard polystyrene Sample solution preparation conditions Solvent: Orthodichlorobenzene (special grade) with added BHT at 0.12 w / V% Sample solution concentration: 1 mg / mL Automatic shaker for dissolution: DF-8020 (Tosoh Corporation) Dissolution conditions: 5 mg of the sample was sealed in a 1000 mesh stainless steel mesh bag. The mesh bag containing the sample was placed in a test tube, 5 mL of solvent was added to the test tube, the test tube was covered with aluminum foil, and the test tube was placed in an immersion chamber and shaken at 60 reciprocations / minute at 140°C for 120 minutes. Analysis method: In accordance with JIS K 7252-1.

[0105] (Coating Adhesion) The resin compositions of the examples and comparative examples were supplied to an injection molding machine (Sumitomo Heavy Industries "SE130DU"), and injection molding was performed under conditions of a melting temperature of 220°C and a mold temperature of 50°C to form a test plate with a length of 150 mm, a width of 90 mm, and a thickness of 3.0 mm. Subsequently, the plate was cut to a size of 50 mm in length, 45 mm in width, and 3.0 mm in thickness to prepare test pieces. Coating adhesion was evaluated by the following method. Nippon Paint's "R-215" was used as the color base paint, Nippon Paint's "R-271" as the hardener, and Nippon Paint's T-824S as the diluent thinner, all mixed in a ratio of 100:30:25. This mixture was applied to the test piece heated at 80°C, and the 80°C heating state was maintained for 60 minutes after application to cure the coating. The obtained coated test specimens were left to stand at 23°C and 50% Rh for at least 72 hours, after which a coating adhesion test was performed. The adhesion test was evaluated using a grid test (JIS K5400). The number of remaining coatings after tape removal per 100 grid squares is indicated as ○○ / 100.

[0106] (Flexural modulus and Charpy impact strength) - The resin compositions of the manufacturing examples or comparative examples of the molded articles for evaluation were injection molded under the following conditions within the range described in JIS K7152 to produce injection molded articles for evaluation of flexural modulus and Charpy impact strength. The propylene resin composition melted in the injection molding machine was supplied from the gate into the mold cavity by the injection molding machine. The material was supplied to an injection molding machine (Toshiba Machine "IS100EN"), and injection molding was performed under the conditions of a melting temperature of 197°C and a mold temperature of 38°C to create dumbbell-shaped test pieces.

[0107] - Flexural modulus: The above dumbbell-shaped test specimen was cut to a length of 80 mm, a width of 10 mm, and a thickness of 4 mm, and measured in accordance with JIS K7171.

[0108] Charpy Impact Test: The dumbbell-shaped test piece described above was cut to a shape with a total length of 80 mm, a width of 10 mm, and a thickness of 4 mm. A V-notch was then cut into the surface formed by the 80 mm length and 4 mm thickness. Measurements were taken in accordance with JIS K 7111-1.

[0109] (Hydroxygroup concentration (MAH-PP equivalent)) The hydroxylgroup concentration was determined by the following method. Using a plate prepared by injection molding from the resin composition of the example or comparative example, the hydroxyl groups were modified using trifluoroacetic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) as a derivatization reagent. The plate and 150 mg of trifluoroacetic anhydride were placed in a 100 ml lidded vial and reacted at 45°C for 1 hour. The lid was opened and the plate was vacuum dried for 6 hours. The infrared spectroscopic spectrum was measured from the obtained plate.

[0110] The measurement conditions are as follows: • FT-IR instrument: FTIR470plus manufactured by JASCO Corporation (detector: TGS) • Measurement conditions: ATR: Pike MIRacre Single Reflection ATR (diamond crystal) Number of scans: 32 Resolution: 4cm －１ Measurement range: 600 cm －１ ~4000 －１ Vertical axis: Absorbance. In the obtained infrared spectral spectrum, the peak height A was calculated using equation (1). A = (A3 - A2) × (1 / (A1 - A2)) - (1) Here, A1 is 2915 cm⁻¹ in the infrared spectral spectrum. －１ ~2925cm －１ The maximum height in the range (CH ２ (Antisymmetry stretching), A2 is 1900 cm² in the infrared spectroscopic spectrum. －１ ~1800m －１ The minimum height in the range, A3, is 1775 cm² in the infrared spectral spectrum. －１ ~1795cm －１This is the maximum height within the range. The hydroxyl group concentration B, converted to MAH-PP (maleic acid-modified polypropylene), was calculated using the peak height A according to the following method and formula (2). A calibration curve was created using maleic acid-modified polypropylene (Yumex 1010, manufactured by Sanyo Chemical Industries, Ltd.). When the amount of MAH was calculated for MAH-PP by titration, the amount of MAH was 5.66 mass%. When the infrared spectroscopic spectrum of this sample was measured, the peak height A defined by the above method was 0.21. Therefore, the following relationship holds between the amount of MAH (hydroxyl group concentration converted to MAH-PP, mass%) B and the peak intensity A: B = 26.766 × A - (2)

[0111] ((a) The ratio X of the weight-average molecular weight Mw(a) of the propylene polymer and (b) the weight-average molecular weight Mw(b) of the polyolefin containing hydroxyl groups) The ratio X was calculated using the following formula with (b) the weight-average molecular weight Mw(b) of the polyolefin containing hydroxyl groups and (a) the weight-average molecular weight Mw(a) of the propylene polymer: X = Mw(b) / Mw(a)

[0112] [Components used in the examples and comparative examples] The components used in the examples and comparative examples are shown below.

[0113] [(a) Propylene-based polymers] ・(a-1) Heterophasic propylene polymer material 1 Using a polymerization catalyst obtained by the method described in Example 1 of Japanese Patent Application Publication No. 2004-182981, a heterophasic propylene polymer material (A-1) containing 86% by mass of a propylene homopolymer component as polymer (I) and 14% by mass of an ethylene-propylene random copolymer as polymer (II) was obtained by liquid-phase-gas-phase polymerization and used as "(a-1) Heterophasic propylene polymer material 1", which is an example of (a) propylene-based polymer in the present invention. The physical properties of (a-1) Heterophasic propylene polymer material 1 were as follows: ・・Melt flow rate (230°C, load 2.16 kgf): 63 g / 10 min ・・Weight-average molecular weight Mw(a): 2.03 × 10 ５(α) Propylene homopolymer component intrinsic viscosity number: 0.86 dL / g (β) Ethylene-propylene random copolymer component intrinsic viscosity number: 5.10 dL / g Percentage of ethylene-derived constituent units: 30% by mass

[0114] - (a-2) Heterophasic propylene polymer material 2 Using a polymerization catalyst obtained by the method described in Example 1 of Japanese Patent Application Publication No. 2004-182981, a heterophasic propylene polymer material (A-2) containing 89% by mass of a propylene homopolymer component as polymer (I) and 11% by mass of an ethylene-propylene random copolymer as polymer (II) was obtained by liquid-phase-gas-phase polymerization and used as "(a-2) Heterophasic propylene polymer material 2", which is an example of (a) propylene-based polymer in the present invention. The physical properties of (a-2) Heterophasic propylene polymer material 2 were as follows: - Melt flow rate (230°C, load 2.16 kgf): 98 g / 10 min - Weight-average molecular weight Mw(a): 2.07 × 10 ５ • (α) Propylene homopolymer component intrinsic viscosity number: 0.79 dL / g • (β) Ethylene-propylene random copolymer component intrinsic viscosity number: 7.00 dL / g Percentage of constituent units derived from ethylene: 32% by mass

[0115] [(b) Polyolefin containing hydroxyl groups] ・(b-1) Hydroxyl group-containing polyolefin 1 (b-1) Hydroxyl group-containing polyolefin 1 was produced from propylene homopolymer (b0) according to the following method. A propylene homopolymer component having the following physical properties, obtained by liquid-gas-phase polymerization using a polymerization catalyst obtained by the method described in Example 1 of Japanese Patent Application Publication No. 2004-182981, was used as the propylene homopolymer (b0). ・・Melt flow rate (230°C, load 2.16 kgf): 0.47 g / 10 min ・・(α) Propylene homopolymer component Intrinsic viscosity number: 2.90 dL / g

[0116] 100 parts by mass of propylene homopolymer (b0) was mixed with 6.0 parts by mass of 2-hydroxyethyl methacrylate, 8.0 parts by mass of organic peroxide 1 (a mixture of Percadox 14 and ethylene-propylene copolymer, manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide, and 0.2 parts by mass of "Irganox 1010" (antioxidant 3) and "Irgafos 168" (antioxidant 4) as antioxidants. After pre-mixing in a tumbler, the mixture was introduced into a twin-screw kneader through the raw material inlet and melt-kneaded at a cylinder temperature of 180°C to obtain (b-1) hydroxyl group-containing polyolefin 1. The weight-average molecular weight Mw(b) of (b-1) hydroxyl group-containing polyolefin 1 is 8.3 × 10⁻⁶. ４ The molecular weight distribution Mw / Mn was 2.2.

[0117] (b-2) Hydroxyl group-containing polyolefin 2 was produced from propylene homopolymer (b0) according to the following method. 100 parts by mass of propylene homopolymer (b-2) were mixed with 8.0 parts by mass of 2-hydroxyethyl methacrylate, 4.0 parts by mass of "Trigonox C" (organic peroxide 2) as an organic peroxide, 0.2 parts by mass of "Irganox 1010" (antioxidant 3) and 0.2 parts by mass of "Irgafos 168" (antioxidant 4) as antioxidants. After pre-mixing in a tumbler, the mixture was introduced into a twin-screw kneader through the raw material inlet and melt-kneaded at a cylinder temperature of 180°C to obtain (b-2) hydroxyl group-containing polyolefin 2. The weight-average molecular weight Mw(b) of (b-2) hydroxyl group-containing polyolefin 2 is 9.6 × 10⁻⁶. ４ The molecular weight distribution Mw / Mn was 2.9.

[0118] • (b-3) Hydroxyl group-containing polyolefin 3 As the hydroxyl group-containing polyolefin 3, a hydride of hydroxyl group-containing liquid isoprene polymer was used. The hydride of hydroxyl group-containing liquid isoprene polymer has a number average molecular weight Mn of 3500 and a weight average molecular weight Mw(b) of 8.8 × 10 ３ The molecular weight distribution Mw / Mn was 2.5, and the hydrogenation rate was 98%.

[0119] • (b-4) Hydroxyl group-containing polyolefin 4. GI3000, a hydroxyl-hydrogenated polybutadiene manufactured by Nippon Soda Co., Ltd., was used. The weight-average molecular weight Mw(b) was 5.8 × 10⁻⁶. ３ The molecular weight distribution Mw / Mn was 1.5.

[0120] • (b-5) Hydroxyl group-containing polyolefin 5. GI2000, a hydroxyl-hydrogenated polybutadiene manufactured by Nippon Soda Co., Ltd., was used. The weight-average molecular weight Mw(b) was 4.5 × 10⁻⁶. ３ The molecular weight distribution Mw / Mn was 1.9.

[0121] [(c) Elastomers] - (c-1) Ethylene-α-olefin copolymer 1 was used, prepared by the method described in U.S. Patent No. 5,272,236 and No. 5,278,272. More specifically, an ethylene-α-olefin copolymer component was used, having an intrinsic viscosity η = 1.5 dL / g, a proportion of constituent units derived from ethylene = 59% by mass, and α-olefin being 1-octene, with a proportion of constituent units derived from 1-octene = 41% by mass.

[0122] • (c-2) Ethylene-α-olefin copolymer 2: An ethylene-α-olefin copolymer was used, with an intrinsic viscosity η = 1.5 dL / g, a proportion of constituent units derived from ethylene = 67% by mass, and α-olefin being 1-butene, with a proportion of constituent units derived from 1-butene = 33% by mass.

[0123] • (c-3) Ethylene-α-olefin copolymer 3: An ethylene-α-olefin copolymer was used in which the intrinsic viscosity η = 0.9 dL / g, the proportion of constituent units derived from ethylene = 60% by mass, the α-olefin is 1-octene, and the proportion of constituent units derived from 1-octene = 40% by mass.

[0124] (c-4) Styrene-ethylene-butene-styrene block copolymer 1. Asahi Kasei Corporation's product name "ToughTec H1062" was used. MFR (230℃) = 17g / 10min. Percentage of styrene constituent units = 18% by weight

[0125] (c-5) Polyolefin elastomers, product name "ENGAGE 11547" manufactured by Dow Chemical Co., Ltd. were used. MFR (190°C) = 5g / 10min

[0126] [(d) Inorganic filler] ・(d-1) Talc 1 Talc: CAS No. 14807-96-6) MW UPN TT-H manufactured by Hayashi Chemical Co., Ltd. was used.

[0127] (d-2) Talc 2 Talc: CAS No. 14807-96-6) Luzenac Har T84 manufactured by Imerys was used.

[0128] [Neutralizing agent] ・Neutralizing agent 1 (Calcium stearate CAS No. 1592-23-0) Calcium stearate manufactured by Sakai Chemical Industry Co., Ltd. was used.

[0129] [Antioxidants] The following antioxidants were used: • Antioxidant 1 (CAS No. 90498-90-1) Sumitomo Chemical Co., Ltd. "SumiLizer GA80" • Antioxidant 2 (CAS No. 26741-53-7) Songwon Co., Ltd. "SONGNOX 6260" • Antioxidant 3 (CAS No. 6683-19-8) BASF "Irganox 1010" • Antioxidant 4 (CAS No. 31570-04-4) BASF "Irgafos 168"

[0130] [Organic Peroxides] The following organic peroxides were used: • Organic peroxide 1: 20% masterbatch of di(2-tert-butylperoxyisopropyl)benzene (Parcadox 14, manufactured by Kayaku Akzo Co., Ltd., a mixture of 20% by mass organic peroxide and 80% by mass ethylene-propylene copolymer)

[0131] • Organic peroxide 2: CAS No. 614-45-9 "Trigonox C" manufactured by Kayaku Nurion Co., Ltd.

[0132] - Sorbitol-based nucleating agent 1: "Gelol DXR" manufactured by Shin Nippon Rika Co., Ltd. was used.

[0133] [Example 1] A propylene-based resin composition was obtained by blending the following materials in the following proportions: (a) 2.0% by mass of (a-2) heterophagic propylene polymerization material 2 as a propylene-based polymer, (c) 25% by mass of (c-1) ethylene-α-olefin copolymer 1 and (c-2) ethylene-α-olefin copolymer 2 as elastomers ((c-1):(c-2) = 56:44 (by mass)), and (c-4) 5% by mass of styrene-ethylene-butene-styrene block copolymer 1, (d) 21% by mass of (d-1) talc 1 as an inorganic filler, and (b) 47% by mass of (b-1) hydroxyl group-containing polyolefin 1 as a hydroxyl group-containing polyolefin. When the total of (a) propylene-based polymer and (b) hydroxyl group-containing polyolefin was 100 parts by mass, the proportion of (a) propylene-based polymer was 4.1 parts by mass and the proportion of (b) hydroxyl group-containing polyolefin was 95.9 parts by mass. Furthermore, to the above resin composition, 0.05 parts by mass of calcium stearate (neutralizing agent 1) was added as a neutralizing agent, 0.05 parts by mass of "Sumiriser GA80" (antioxidant 1) and 0.1 parts by mass of "SONGNOX 6260" (antioxidant 2) were added as antioxidants, and other additives such as stabilizers used in automotive PP compound materials were added. After uniform pre-mixing in a tumbler, the resulting mixture was further introduced into a twin-screw kneader (twin-screw extruder) through the raw material inlet and melt-mixed to obtain a resin composition. Using the obtained resin composition, the coating adhesion, flexural modulus, and Charpy impact test were evaluated according to the evaluation method described above. The results are shown in Table 1.

[0134] [Example 2] (a) As a propylene polymer, (a-2) Heterophagic propylene polymerization material 2 was replaced with (a-1) Heterophagic propylene polymerization material 1 at 56.2% by mass; (b-1) Hydroxyl group-containing polyolefin 1 was replaced with (b-3) Hydroxyl group-containing polyolefin 3 at 2.3% by mass; (c-1) Ethylene-α-olefin copolymer 1 and (c-2) Ethylene-α-olefin copolymer 2 were used in a total of 20% by mass ((c-1):(c-2) = 52.5:47.5 (by mass)); and the amount of talc 1 was changed to 21.5% by mass; (c-4) Styrene-ethylene-butene-styrene block copolymer 1 was not used; otherwise, a resin composition was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0135] [Example 3] A resin composition was prepared and evaluated in the same manner as in Example 2, except that (a) 55.6% by mass of (a-1) heterophagic propylene polymerization material 1 was used as the propylene polymer, (b-3) hydroxyl group-containing polyolefin 3 was replaced with (b-4) hydroxyl group-containing polyolefin 4 at 5.7% by mass, the total amount of (c-1) ethylene-α-olefin copolymer 1 and (c-2) ethylene-α-olefin copolymer 2 used was 18.4% by mass ((c-1):(c-2) = 51:49 (by mass)), and the amount of talc 1 used was changed to 20.3% by mass. The results are shown in Table 1.

[0136] [Example 4] A resin composition was prepared and evaluated in the same manner as described in Example 2, except that (a) 58.4% by mass of (a-1) heterophagic propylene polymerization material 1 was used as the propylene polymer, (b-3) the amount of hydroxyl group-containing polyolefin 3 used was changed to 1.5% by mass, and (c) a total of 18.6% by mass of (c-1) ethylene-α-olefin copolymer 1 and (c-3) ethylene-α-olefin copolymer 3 ((c-1):(c-3) = 50:50 (by mass)) was used as the elastomer. The results are shown in Table 1.

[0137] [Example 5] (a) As a propylene polymer, (a-2) heterophagic propylene polymerization material 2 was used at 48.1% by mass, and the amount of (b-3) hydroxyl group-containing polyolefin 3 used was changed to 1.1% by mass. (c) As elastomers, (c-1) ethylene-α-olefin copolymer 1 and (c-3) ethylene-α-olefin copolymer 3 were used in a total of 15.8% by mass ((c-1):(c-3) = 51:49 (by mass)), polyolefin elastomer (c-5) was used at 2.0% by mass, talc was changed to (d-2) talc 2, and the amount used was changed to 33% by mass. For every 100 parts by mass of the above components, 0.2 parts by mass of sorbitol-based nucleating agent 1 was added. Otherwise, the resin composition was produced and evaluated in the same manner as described in Example 2. The results are shown in Table 1.

[0138] [Example 6] (a) A resin composition was prepared and evaluated in the same manner as described in Example 5, except that (a-2) heterophagic propylene polymerization material 2 was used as the propylene polymer at 48.2% by mass, and (b-3) the amount of hydroxyl group-containing polyolefin 3 used was changed to 1.0% by mass. The results are shown in Table 1.

[0139] [Comparative Example 1] A resin composition was prepared and evaluated in the same manner as in Example 2, except that (a) 56.8% by mass of (a-1) heterophagic propylene polymerization material 1 was used as the propylene polymer, (b-3) hydroxyl group-containing polyolefin 3 was replaced with 3.7% by mass of (b-5) hydroxyl group-containing polyolefin 5 as the hydroxyl group-containing polyolefin, the total amount of (c-1) ethylene-α-olefin copolymer 1 and (c-2) ethylene-α-olefin copolymer 2 used was changed to 18.8% by mass ((c-1):(c-2) = 51:49 (by mass)), and the amount of talc 1 used was changed to 20.7% by mass. The results are shown in Table 1.

[0140] [Comparative Example 2] As the polyolefin containing hydroxyl groups, (b-1) hydroxyl group-containing polyolefin 1 was replaced with 50% by mass of (b-2) hydroxyl group-containing polyolefin 2, the amount of heterophagic propylene (a-2) used was maintained at 2.0% by mass, and the total amount of (c-1) ethylene-α-olefin copolymer 1 and (c-2) ethylene-α-olefin copolymer 2 used was changed to 22% by mass ((c-1):(c-2) = 59:41 (by mass)). Otherwise, the resin composition was produced and evaluated in the same manner as described in Example 1. The results are shown in Table 1.

[0141]

[0142] The propylene-based resin composition, composite molded article, and method for manufacturing the composite molded article of the present invention and its embodiments can produce resin molded articles that combine excellent coating adhesion and superior mechanical properties. Therefore, they are suitable for use in various applications, such as various parts for home appliances, various parts for housing equipment, various industrial parts, and various building material parts, and have high applicability in various industrial fields, such as the transportation machinery industry, the electrical and electronics industry, and the building construction industry.

Claims

1. A propylene resin composition containing essential resin components consisting of (a) 99% to 1% by mass of a propylene polymer and (b) 1% to 99% by mass of a polyolefin containing hydroxyl groups (where the total of (a) the propylene polymer and (b) the polyolefin containing hydroxyl groups is 100% by mass), wherein the propylene resin composition satisfies the following requirements (i) to (iii): (i) The hydroxyl group concentration (in terms of maleic acid-modified polypropylene) on the surface of a molded article obtained from the propylene resin composition is 0.15% by mass or more and 1.9% by mass or less; (ii) The ratio X = Mw(b) / Mw(a) of the weight-average molecular weight Mw(a) of (a) the propylene polymer to the weight-average molecular weight Mw(b) of (b) the polyolefin containing hydroxyl groups is 0.025 ≤ X ≤ 0.47; (iii) (b) The polyolefin containing hydroxyl groups has a Mw / Mn ratio of 1.5 to 2.

9.

2. The propylene resin composition according to claim 1, comprising 1 to 65 parts by mass of (c) elastomer per 100 parts by mass of the essential resin component.

3. The propylene resin composition according to claim 1 or 2, comprising 0.1 to 75 parts by mass of (d) an inorganic filler per 100 parts by mass of the essential resin component.

4. The propylene resin composition according to claim 1 or 2, wherein (a) the propylene polymer contains (a3) ​​a heterophagic propylene polymerization material.

5. A composite molded article having (1) a coating film and (2) a polyolefin molded article, wherein (1) the coating film is formed directly on at least a portion of the surface of (2) the polyolefin molded article, and (2) the polyolefin molded article contains the propylene resin composition described in claim 1 or 2.

6. The composite molded body according to claim 5, which is an exterior part for an automobile.

7. A method for producing a composite molded article, comprising the steps of: I) providing a polyolefin molded article (2), and II) forming a coating film (1) on at least a portion of the surface of the polyolefin molded article (2), wherein the polyolefin molded article (2) contains the propylene resin composition described in claim 1 or 2.

8. I) (2) The method for manufacturing a composite molded article according to claim 7, wherein in the step of providing a polyolefin molded article, the polyolefin molded article is manufactured by injection molding.

9. II) The method for manufacturing a composite molded article according to claim 8, wherein the step of forming a coating film (1) on at least a portion of the surface of the polyolefin molded article is performed in the mold used for injection molding in step I).

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