Polypropylene resin composition and molded article thereof

Abstract

The present invention provides a propylene-based resin composition with excellent uniformity of wall thickness. [Solution] A propylene resin composition comprising a propylene-based random copolymer (A) having a specific melt flow rate (MFR), a polypropylene resin (B) having a long-chain branched structure having a specific MFR and melt tension (MT), and a polypropylene resin (C) having a specific MFR, wherein the propylene resin composition contains 30 to 98% by weight of the propylene-based random copolymer (A), 1 to 50% by weight of the polypropylene resin (B) having a long-chain branched structure, and 1 to 20% by weight of the polypropylene resin (C) (provided that the total of the propylene-based random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C) is 100% by weight).

Description

[Technical Field]

[0001] The present invention relates to a polypropylene resin composition and a molded article thereof, and more particularly to a polypropylene blow-molded article with excellent uniformity of wall thickness. [Background technology]

[0002] Polyolefin resins such as polyethylene and polypropylene have traditionally been widely used as blow-molded articles made of resin. In recent years, blow-molded articles have increasingly been required to have more complex shapes due to the need for greater design flexibility and a wider range of applications. However, conventional materials have poor ductility during melting and poor drawdown properties, making it difficult to obtain good blow-molded articles. In particular, areas that are greatly stretched, such as corners, tend to become thin, making it difficult to obtain molded articles with uniform wall thickness and good quality.

[0003] To address these issues, mixtures of propylene polymers having specific physical properties have been proposed to improve the uniformity of wall thickness (see, for example, Patent Document 1). However, further improvements are needed in propylene resin compositions suitable for injection blow molding. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2009-299017 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a propylene resin composition and a molded article thereof that, in response to the above points, can be molded over a wide temperature range and can produce a molded article with excellent uniformity of wall thickness. [Means for solving the problem]

[0006] As a result of diligent research to solve the above problems, the inventors have found that a propylene resin composition comprising a propylene-based random copolymer (A) having a specific melt flow rate (hereinafter sometimes abbreviated as MFR), a polypropylene resin (B) having a specific MFR, melt tension (hereinafter sometimes abbreviated as MT), and a long-chain branched structure, and a polypropylene resin (C) having a specific MFR, wherein the composition contains 30 to 98% by weight of the propylene-based random copolymer (A), 1 to 50% by weight of the polypropylene resin (B) having a long-chain branched structure, and 1 to 20% by weight of the polypropylene resin (C) (however, the total of the propylene-based random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C) is 100% by weight), solves the above problems, and based on these findings, the inventors have completed the present invention.

[0007] In other words, the present invention has the following configuration.

[0008] [1] A propylene resin composition characterized by comprising a propylene-based random copolymer (A) satisfying the following condition (Ai), a polypropylene resin (B) having a long-chain branched structure satisfying the following conditions (Bi) to (B-iii), and a polypropylene resin (C) satisfying the following condition (Ci), and satisfying the following requirement (X). Condition(Ai) The propylene-based random copolymer (A) is a propylene-α-olefin random copolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 200 g / 10 min. Condition (Bi) Polypropylene resin (B) having a long-chain branched structure has a melt flow rate (MFR) (230°C, 2.16 kg load) in the range of 0.1 to 35 g / 10 min. Condition (B-ii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) of 1 to 50 g. Condition (B-iii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) (unit: g) log(MT)≧-0.9×log(MFR)+0.7 It satisfies the condition. Condition (Ci) Polypropylene resin (C) is a propylene homopolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 100 g / 10 min. Requirements(X) The propylene resin composition contains 30-98% by weight of a propylene-based random copolymer (A), 1-50% by weight of a polypropylene resin (B) having a long-chain branched structure, and 1-20% by weight of a polypropylene resin (C) (provided that the total of the propylene-based random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C) is 100% by weight). [2] The propylene resin composition according to [1], wherein the propylene random copolymer (A) further satisfies the following conditions (A-ii) to (A-iii). (A-ii) The propylene-based random copolymer (A) is a metallocene polymer. (A-iii) The propylene-based random copolymer (A) has a melting peak temperature (Tm) in the range of 110°C to 155°C, as measured by DSC. [3] The propylene resin composition according to [1] or [2], further comprising a copolymer (P) that satisfies the following condition (Pi), and satisfying the following requirement (Z). Condition (Pi) The copolymer (P) is at least one copolymer selected from the group consisting of a propylene-α-olefin copolymer (D) that satisfies the following condition (Di) and an ethylene-α-olefin copolymer (E) that satisfies the following condition (Ei). Condition (Di) The propylene-α-olefin copolymer (D) is a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms (excluding α-olefins having 3 carbon atoms). Condition (E-i) The ethylene-α-olefin copolymer (E) is a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms. Requirement (Z) The propylene resin composition contains 1 to 20 parts by weight of the copolymer (P) with respect to a total of 100 parts by weight of the propylene random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C). [4] The propylene resin composition according to [3], wherein the copolymer (P) satisfies the following condition (P-ii). Condition (P-ii) The copolymer (P) has an intrinsic viscosity (η) measured in decalin at 135°C in the range of 0.1 to 20 dl / g. [5] The propylene resin composition according to [3] or [4], wherein the copolymer (P) is the propylene-α-olefin copolymer (D) and the polypropylene resin (C) and the propylene-α-olefin copolymer (D) are continuous polymers. [6] The propylene resin composition according to [1] to [5], further comprising a nucleating agent (F) and satisfying the following requirement (Y). Requirement (Y) The propylene resin composition contains 0.001 to 1 part by weight of the nucleating agent (F) with respect to a total of 100 parts by weight of the propylene random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C). [7] An injection blow molded article containing the propylene resin composition according to any one of [1] to [6].

Advantages of the Invention

[0009] The present invention makes it possible to provide a propylene resin composition and a molded article thereon that exhibits high transparency, can be molded over a wide temperature range, and has excellent uniformity of wall thickness. [Modes for carrying out the invention]

[0010] The present invention is a propylene resin composition characterized by comprising a propylene-based random copolymer (A) satisfying the following condition (Ai), a polypropylene resin (B) having a long-chain branched structure satisfying the following conditions (Bi) to (B-iii), and a polypropylene resin (C) satisfying the following condition (Ci), and satisfying the following requirement (X). Condition(Ai) The propylene-based random copolymer (A) is a propylene-α-olefin random copolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 200 g / 10 min. Condition (Bi) Polypropylene resin (B) having a long-chain branched structure has a melt flow rate (MFR) (230°C, 2.16 kg load) in the range of 0.1 to 35 g / 10 min. Condition (B-ii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) of 1 to 50 g. Condition (B-iii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) (unit: g) log(MT)≧-0.9×log(MFR)+0.7 It satisfies the condition. Condition (Ci) Polypropylene resin (C) is a propylene homopolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 100 g / 10 min. Requirements(X) The propylene resin composition contains 30-98% by weight of a propylene-based random copolymer (A), 1-50% by weight of a polypropylene resin (B) having a long-chain branched structure, and 1-20% by weight of a polypropylene resin (C) (provided that the total of the propylene-based random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C) is 100% by weight).

[0011] The details of each item regarding the propylene resin composition of the present invention are described below.

[0012] 1. Propylene resin composition The propylene resin composition of the present invention satisfies the following requirement (X).

[0013] Requirements(X) The propylene resin composition contains 30-98% by weight of a propylene-based random copolymer (A), 1-50% by weight of a polypropylene resin (B) having a long-chain branched structure, and 1-20% by weight of a polypropylene resin (C) (provided that the total of the propylene-based random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C) is 100% by weight). Details of the propylene-based random copolymer (A), the polypropylene resin having a long-chain branched structure (B), and the polypropylene resin (C) will be described later.

[0014] The propylene resin composition of the present invention must contain 30 to 98% by weight of a polypropylene random copolymer (A), preferably 37 to 96% by weight, more preferably 44 to 94% by weight, more preferably 50 to 90% by weight, particularly preferably 56 to 85% by weight, and most preferably 62 to 82% by weight. The polypropylene resin (B) having a long-chain branched structure must contain 1 to 50% by weight, preferably 2 to 45% by weight, more preferably 3 to 40% by weight, more preferably 5 to 35% by weight, particularly preferably 8 to 30% by weight, and most preferably 10 to 25% by weight. The polypropylene resin (C) must contain 1 to 20% by weight, preferably 2 to 18% by weight, more preferably 3 to 16% by weight, more preferably 5 to 15% by weight, particularly preferably 7 to 14% by weight, and most preferably 8 to 13% by weight. However, the total amount of propylene-based random copolymer (A), polypropylene resin having a long-chain branched structure (B), and polypropylene resin (C) is 100% by weight.

[0015] By setting the content of the propylene-based random copolymer (A), the long-chain branched polypropylene resin (B), and the polypropylene resin (C) within these ranges, it becomes possible to provide a propylene resin composition that is optimal for blow molding, which can produce molded articles with excellent uniformity of wall thickness.

[0016] The propylene resin composition of the present invention preferably further contains a nucleating agent (F) in addition to a propylene-based random copolymer (A), a polypropylene resin having a long-chain branched structure (B), and a polypropylene resin (C). Including the nucleating agent (F) makes it possible to obtain a molded article with higher transparency. Furthermore, when the propylene resin composition of the present invention contains a nucleating agent (F), it is preferable that it satisfies the following requirement (Y).

[0017] Requirement (Y) The propylene resin composition contains 0.001 to 1 part by weight of a crystal nucleating agent (F) per 100 parts by weight of a total of a propylene-based random copolymer (A), a polypropylene resin having a long-chain branched structure (B), and a polypropylene resin (C). Details of the nucleating agent (F) will be described later.

[0018] When the propylene resin composition of the present invention contains a nucleating agent (F), the nucleating agent (F) is usually contained in an amount of 0.001 to 1 part by weight, preferably 0.05 to 0.8 parts by weight, more preferably 0.1 to 0.6 parts by weight, and particularly preferably 0.2 to 0.5 parts by weight, as described above.

[0019] By setting the content of the nucleating agent (F) within the range described above, better rigidity and transparency can be obtained, and bleeding (dissolution) onto the surface of the molded product can be reduced. Specifically, if the content of the nucleating agent (F) is less than 0.001 parts by weight, good rigidity and transparency may not be obtained, and if it exceeds 1 part by weight, bleeding (dissolution) onto the surface of the molded product may occur. Furthermore, setting the content of the nucleating agent (F) within the range described above is advantageous in terms of cost-effectiveness regarding rigidity and transparency, as well as dissolution onto the surface of the molded product.

[0020] The propylene resin composition of the present invention preferably further comprises a propylene-based random copolymer (A), a polypropylene resin having a long-chain branched structure (B), a polypropylene resin (C), and preferably a nucleating agent (F), in addition to a copolymer (P). The inclusion of copolymer (P) imparts flexibility, and when stretched, a propylene polymer with excellent uniformity of wall thickness can be obtained. Furthermore, if the propylene resin composition of the present invention contains a copolymer (P), it is preferable that it satisfies the following requirement (Z).

[0021] Requirements(Z) The propylene resin composition contains 1 to 20 parts by weight of copolymer (P) for a total of 100 parts by weight of a propylene-based random copolymer (A), a polypropylene resin having a long-chain branched structure (B), and a polypropylene resin (C). Details of the copolymer (P) will be described later.

[0022] When the propylene resin composition of the present invention contains copolymer (P), the copolymer (P) is usually contained in amounts of 1 to 20 parts by weight, preferably 2 to 18 parts by weight, more preferably 3 to 16 parts by weight, and particularly preferably 4 to 14 parts by weight, as described above.

[0023] By setting the copolymer (P) content within this range, it becomes possible to provide a propylene resin composition that offers excellent moldability while providing sufficient flexibility and low-temperature impact resistance. However, if the copolymer (P) content is less than 1 part by weight, the low-temperature impact resistance may be insufficient, and if it exceeds 20 parts by weight, the moldability and processability necessary for blow molding may decrease.

[0024] (1) Propylene-based random copolymer (A) The details of the propylene-based random copolymer (A) used in the present invention will be described below. The propylene-based random copolymer (A) used in the present invention satisfies the above condition (Ai), and preferably also has the properties described in conditions (A-ii) to (A-iv). The following will explain each item in order.

[0025] (1-1) Condition (Ai) The propylene-based random copolymer (A) used in the present invention is a propylene-α-olefin random copolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 200 g / 10 min.

[0026] (1-1-1) Properties of propylene-based random copolymer (A) The propylene-based random copolymer (A) used in the present invention is a propylene-α-olefin random copolymer. A preferred propylene-α-olefin random copolymer is a random copolymer of propylene and α-olefin, with structural units derived from propylene as the main component. The α-olefin used as a comonomer is preferably ethylene or an α-olefin having 4 to 18 carbon atoms. Specifically, examples include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methylpentene-1, 4-methylhexene-1, 4,4-dimethylpentene-1, etc. In addition, the α-olefin may be one type or a combination of two or more types.

[0027] Specific examples of such propylene-α-olefin random copolymers include propylene-ethylene random copolymer, propylene-1-butene random copolymer, propylene-1-hexene random copolymer, propylene-ethylene-1-octene random copolymer, and propylene-ethylene-1-butene random copolymer. In the propylene-based resin composition of the present invention, the use of propylene-ethylene random copolymer is particularly preferred from the viewpoint of the mechanical properties and transparency of the resulting molded article.

[0028] There are no particular restrictions on the amount of propylene units in a propylene-α-olefin random copolymer, but it is usually 88 to 99.5% by weight, preferably 91 to 99% by weight. By setting the amount of propylene units in the propylene-α-olefin random copolymer within this range, it becomes easier to obtain blow-molded articles with good rigidity and transparency. That is, if the amount of propylene units is significantly less than 88% by weight, the rigidity of the blow-molded article tends to decrease, while if it is more than 99.5% by weight, the transparency of the molded article may decrease. Here, the propylene units and α-olefin units are, for example, defined under the following conditions: 13 This value is measured by the 1C-NMR method, but it can also be measured using other instruments with equivalent performance. Equipment: JEOL-GSX270 manufactured by JEOL Ltd. Concentration: 300mg / 2mL Solvent: Orthodichlorobenzene

[0029] (1-1-2) Melt flow rate (MFR) of propylene-based random copolymer (A) The propylene-based random copolymer (A) used in the present invention is required to be a propylene-α-olefin random copolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 200 g / 10 min, as specified by condition (Ai).

[0030] The melt flow rate (MFR) of the propylene-based random copolymer (A) is 1 to 200 g / 10 min, preferably 2 to 90 g / 10 min, more preferably 2.5 to 80 g / 10 min, and particularly preferably 5 to 70 g / 10 min. By setting the MFR within this range, the stretchability of the propylene resin composition of the present invention becomes uniform, and the fluidity and mechanical properties are also improved. In other words, if the MFR is less than 1g / 10min, fluidity decreases, and rigidity may also decrease. Furthermore, if the MFR exceeds 200g / 10min, melt processability decreases, and injection blow molding may become particularly difficult. In this application, the melt flow rate (MFR) for all samples was measured according to Method A, Condition M (230°C, 2.16 kg load) of JIS K7210:1999 "Plastics - Test methods for melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastic plastics". The melt flow rate (MFR) of a propylene-based random copolymer (A) can be easily adjusted by controlling the polymerization conditions of the propylene-based random copolymer (A), such as temperature and pressure, or by controlling the amount of hydrogen added during polymerization to which a chain transfer agent such as hydrogen is added.

[0031] (1-2) Condition (A-ii) The propylene-based random copolymer (A) used in the present invention is not particularly limited, but it is preferable that it is a polymer obtained using a stereoregular catalyst. Examples of stereoregular catalysts include Ziegler catalysts and metallocene catalysts, but a metallocene polymer polymerized using a metallocene catalyst is more preferable because it makes it easier to further improve the effects of the present invention.

[0032] In other words, the propylene-based random copolymer (A) used in the present invention is more preferably a metallocene polymer polymerized using a metallocene catalyst. Using a polypropylene-based random copolymer polymerized with a metallocene catalyst, i.e., a metallocene polymer, results in a narrow molecular weight distribution and a uniform compositional distribution, which improves the transparency of the molded article. In other words, using a polypropylene-based random copolymer polymerized with a catalyst other than a metallocene catalyst results in a wider molecular weight distribution and a non-uniform compositional distribution compared to a metallocene polymer, which may result in a deterioration of the transparency of the molded article compared to a polymer polymerized using a metallocene catalyst.

[0033] Examples of Ziegler catalysts used for polymerization of the propylene-based random copolymer (A) used in the present invention include two-component catalysts comprising titanium halide compounds such as titanium trichloride, titanium tetrachloride, and trichloroethoxytitanium, transition metal components such as contacts of the titanium halide compounds with magnesium compounds such as magnesium halides, and organometallic components such as alkylaluminum compounds or their halides, hydrides, and alkoxides, and three-component catalysts to which electron-donating compounds containing nitrogen, carbon, phosphorus, sulfur, oxygen, silicon, etc. are added.

[0034] The metallocene catalyst used in the polymerization of the propylene-based random copolymer (A) in the present invention is a catalyst comprising (i) a transition metal compound of Group 4 of the periodic table (a so-called metallocene compound) containing a ligand having a cyclopentadienyl skeleton, (ii) a co-catalyst that can be activated to a stable ionic state by reacting with the metallocene compound, and optionally (iii) an organoaluminum compound. Any known catalyst can be used. The metallocene compound is preferably a crosslinked metallocene compound capable of stereoregular polymerization of propylene, and more preferably a crosslinked metallocene compound capable of isoregular polymerization of propylene. Each component will be described below.

[0035] (i) Examples of metallocene compounds include Japanese Patent Publication Nos. 60-35007, 61-130314, 63-295607, 1-275609, 2-41303, 2-131488, 2-76887, 3-163088, and 4-300887. It is disclosed in various publications such as Japanese Patent Publication No. 4-211694, Japanese Patent Publication No. 5-43616, Japanese Patent Publication No. 5-209013, Japanese Patent Publication No. 6-239914, Japanese Patent Publication No. 7-504934, Japanese Patent Publication No. 8-85708, Japanese Patent Publication No. 2011-126813, Japanese Patent Publication No. 2014-111568, and Japanese Patent Publication No. 2017-178786.

[0036] Furthermore, specifically, methylenebis(2-methylindenyl)zirconium dichloride, ethylenebis(2-methylindenyl)zirconium dichloride, ethylene 1,2-(4-phenylindenyl)(2-methyl-4-phenyl-4H-azlenyl)zirconium dichloride, isopropylidene(cyclopentadienyl)(fluorenyl)zirconium dichloride, isopropylidene(4-methylcyclopentadienyl)(3-t-butylindenyl)zirconium dichloride, dimethylsilylene(2-methyl-4-t-butyl-cyclopentadienyl)(3'-t-butyl-5'-methyl-cyclopentadienyl)zirconium dichloride, dimethylsilylenebis(indenyl) Zirconium dichloride (nyl), dimethylsilylenebis(4,5,6,7-tetrahydroindenyl) zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4-phenylindenyl)] zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-phenylindenyl)] zirconium dichloride, dimethylsilylenebis[4-(1-phenyl-3-methylindenyl)] zirconium dichloride, dimethylsilylene(fluorenyl)t-butylamide zirconium dichloride, methylphenylsilylenebis[1-(2-methyl-4,(1-naphthyl)-indenyl)] zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4,5-Benzoindenyl) Zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4-phenyl-4H-azlenyl)] Zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azlenyl)] Zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-naphthyl-4H-azlenyl)] Zirconium dichloride, diphenylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azlenyl)] Zirconium dichloride, diphenylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azlenyl] Examples of zirconium compounds include phenyl)-4H-azlenyl) zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-(3-fluorobiphenylyl)-4H-azlenyl)] zirconium dichloride, dimethylgermylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azlenyl)] zirconium dichloride, and dimethylgermylenebis[1-(2-ethyl-4-phenylindenyl)] zirconium dichloride. Compounds in which zirconium is replaced with titanium or hafnium can also be used in the same way. In some cases, mixtures of zirconium compounds and hafnium compounds can also be used. Furthermore, the chloride can be replaced with other halogen compounds, hydrocarbon groups such as methyl, isobutyl, and benzyl, amide groups such as dimethylamide and diethylamide, alkoxide groups such as methoxy and phenoxy groups, and hydride groups. Of these, metallocene compounds in which an indenyl group or an azlenyl group is crosslinked with silicon or a gelmyl group are preferred.

[0037] Furthermore, metallocene compounds may be used supported on an inorganic or organic compound carrier. Preferred carriers are porous inorganic or organic compounds, specifically including inorganic compounds such as ion-exchangeable layered silicates, zeolites, SiO2, Al2O3, silica alumina, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, and ThO2; organic compounds consisting of porous polyolefins, styrene-divinylbenzene copolymers, olefin-acrylic acid copolymers, or mixtures thereof.

[0038] (ii) Examples of co-catalysts that can react with metallocene compounds to activate them into a stable ionic state include organoaluminum oxy compounds (e.g., aluminoxane compounds), ion-exchangeable layered silicates, Lewis acids, boron-containing compounds, ionic compounds, and fluorine-containing organic compounds.

[0039] (iii) Examples of organoaluminum compounds include trialkylaluminum such as triethylaluminum, triisopropylaluminum, and triisobutylaluminum, dialkylaluminum halides, alkylaluminum sesquihalides, alkylaluminum dihalides, alkylaluminum hydrides, and organoaluminum alkoxides.

[0040] Polymerization methods include slurry methods using an inert solvent in the presence of the above-mentioned catalyst, solution methods, gas-phase methods that substantially do not use a solvent, or bulk polymerization methods using polymerization monomers as a solvent. As a method for obtaining the propylene-based random copolymer (A) used in the present invention, particularly the propylene-α-olefin random copolymer, the desired polymer can be obtained by appropriately controlling the distribution of molecular weight and crystallinity by adjusting the polymerization temperature and the amount of comonomers. Such propylene-α-olefin random copolymers can be appropriately selected and used from commercially available products, such as the "Wintec" and "Novatec" series manufactured by Nippon Polypropylene Co., Ltd.

[0041] (1-3) Condition (A-iii) The propylene-based random copolymer (A) preferably has a melting peak temperature (hereinafter sometimes abbreviated as Tm or melting point) measured by DSC method in the range of 110°C to 155°C.

[0042] (1-3-1) Melting peak temperature (Tm) of propylene-based random copolymer (A) The propylene-based random copolymer (A) used in the present invention typically has a melting peak temperature (Tm) measured by DSC, as defined in condition (A-iii), in the range of 110°C to 155°C, more preferably 112°C to 145°C, even more preferably 115°C to 140°C, and particularly preferably 120°C to 135°C. By setting Tm within this range, molding becomes possible at relatively low temperatures, enabling molding over a wide temperature range, and also allowing for good transparency and mechanical properties of the resulting molded product. Specifically, Tm below 110°C is undesirable because it may reduce the rigidity of the molded article, and Tm above 155°C is undesirable because it may worsen the transparency of the molded article. Tm can be easily adjusted by controlling the amount of α-olefin supplied to the polymerization reaction system. Here, Tm is specifically measured using a differential scanning calorimeter (DSC). A sample of 5 mg is taken, held at 200°C for 5 minutes, then crystallized at a cooling rate of 10°C / min down to 40°C, and finally melted at a heating rate of 10°C / min. The peak position of the curve drawn at this time is defined as the melting peak temperature Tm (°C).

[0043] (1-4) Condition (A-iv) Propylene-based random copolymer (A) typically has a molecular weight distribution Mw / Mn (Q value) of 2 to 5 as determined by gel permeation chromatography (GPC), and its isotactic triad fraction is typically 96% or higher.

[0044] (1-4-1) Molecular weight distribution Mw / Mn (Q value) obtained by gel permeation chromatography (GPC) The propylene-based random copolymer (A) used in the present invention typically has a molecular weight distribution Mw / Mn (hereinafter sometimes abbreviated as Q value) of 2 to 5 as determined by gel permeation chromatography (GPC), as defined in the above condition (A-iv). Within this range, it is preferably 2.1 to 4.5, more preferably 2.2 to 4, and particularly preferably 2.3 to 3.5. By setting the Q value within this range, a molded article with higher transparency can be obtained. On the other hand, polymers with a molecular weight distribution (Mw / Mn) of less than 1.5 are difficult to obtain with current polymerization technology, and if the Q value exceeds 5, the transparency of the molded product may deteriorate due to the influence of high molecular weight components.

[0045] The molecular weight distribution Mw / Mn (Q value) of the propylene-based random copolymer (A) can be adjusted by selecting the catalyst and polymerization method. For example, when using a metallocene catalyst as specified in condition (A-ii) above, it can be controlled by polymerizing using a catalyst system that uses two or more metallocene catalyst components or a catalyst system that uses two or more metallocene complexes, or by performing multi-stage polymerization of two or more stages during polymerization. Conversely, to narrow the molecular weight distribution, it can be adjusted by using a single metallocene catalyst, or by melt-kneading the propylene polymer with an organic peroxide after polymerization.

[0046] Here, the molecular weight distribution is determined by the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) (Q value: Mw / Mn), and is obtained by measurement using gel permeation chromatography (GPC). The definitions of Mn, Mw, and Mz are described in "Fundamentals of Polymer Chemistry" (edited by the Society of Polymer Science, Japan, Tokyo Kagaku Dojin, 1978), etc., and can be calculated from the molecular weight distribution curve obtained by GPC. Details of the specific GPC measurement method and measuring instrument used in the examples of this specification are as follows.

[0047] Equipment: Waters GPC (ALC / GPC, 150C) Detector: FOXBORO MIRAN, 1A, IR detector (measurement wavelength: 3.42 μm) Columns: Showa Denko AD806M / S (3 in series) Mobile phase solvent: o-dichlorobenzene (ODCB) Measurement temperature: 140℃ Flow rate: 1.0ml / min Injection amount: 0.2ml Sample preparation: Prepare a 1 mg / mL solution of the sample using ODCB (containing 0.5 mg / mL of BHT), and dissolve it at 140°C for approximately 1 hour. The conversion from retention capacity obtained by GPC measurement to molecular weight is performed using a calibration curve prepared in advance using standard polystyrene (PS). The standard polystyrene used is the following brand manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000 Calibration curves are created by injecting 0.2 mL of a solution prepared by dissolving each component in ODCB (containing 0.5 mg / mL of BHT) so that each component is at 0.5 mg / mL. The calibration curves are approximated using a cubic equation obtained by the least squares method. The viscosity formula used for conversion to molecular weight is [η] = K × M α The following values ​​are used. PS: K = 1.38 × 10 -4 α=0.7 PP:K = 1.03 × 10 -4 α = 0.78 Furthermore, molecular weight distribution can be measured by GPC using equipment, detectors, columns, etc., that have equivalent performance.

[0048] (2) Polypropylene resin having a long-chain branched structure (B) The details of the polypropylene resin (B) used in the present invention will be described below. The polypropylene resin (B) used in the present invention preferably has the properties described in the above conditions (Bi) to (B-iii). The following will explain each item in turn.

[0049] (2-1) Condition (Bi) Polypropylene resin (B) having a long-chain branched structure has a melt flow rate (MFR) (230°C, 2.16 kg load) in the range of 0.1 to 35 g / 10 min.

[0050] (2-1-1) Properties of polypropylene resin (B) having a long-chain branched structure In the polypropylene resin (B) having a long-chain branched structure used in the present invention, the long-chain branching refers to a branched structure in which the carbon skeleton (main chain of the branch) constituting the branch has tens or more carbon atoms and a molecular weight of hundreds or more, in order to exhibit high melt tension and strain hardening properties, and is distinguished from short-chain branching which is formed by copolymerization with α-olefins such as 1-butene.

[0051] Methods for introducing long-chain branched structures into polypropylene resins include using high-energy ionization radiation (Japanese Patent Publication No. 62-121704), using organic peroxides (Japanese Patent Publication No. 2001-524565), and forming long-chain branches by producing macromonomers having terminal unsaturated bonds and copolymerizing them with propylene (Japanese Patent Publication No. 2001-525460). Regardless of the method used, the degree of strain hardening of the polypropylene resin can be increased.

[0052] As a method for producing a polypropylene resin (B) having a long-chain branched structure, a macromer copolymerization method that has a comb-like chain structure and forms a long-chain branched structure during polymerization is preferred because it can efficiently produce a polypropylene resin (B) having a long-chain branched structure that can exhibit the properties of the present invention. Examples of such methods include, for example, the methods disclosed in Japanese Patent Publication No. 2001-525460, Japanese Patent Application Publication No. 10-338717, Japanese Patent Publication No. 2002-523575, Japanese Patent Application Publication No. 2009-57542, Japanese Patent Publication No. 05027353, and Japanese Patent Application Publication No. 10-338717. In particular, the macromer copolymerization method of Japanese Patent Application Publication No. 2009-57542 is suitable for the present invention because it can obtain a long-chain branched polypropylene resin without the generation of gel.

[0053] Having long chain branches in polypropylene can be confirmed by methods based on the rheological properties of the resin, methods for calculating the branching index g’ using the relationship between molecular weight and viscosity, 13 methods using C-NMR, etc. In this specification, as shown below 13 the presence or absence of long chain branching structures is determined by C-NMR.

[0054] 13 [C-NMR] 13 C-NMR can distinguish between short chain branching structures and long chain branching structures. There is a detailed explanation in Macromol.Chem.Phys.2003, vol.204, 1738, as follows. Propylene-based polymers having long chain branching structures have specific branching structures as shown in the following structural formula (I). In structural formula (1), Ca, Cb, Cc represent methylene carbons adjacent to the branched carbon, Cbr represents the methine carbon at the root of the branched chain, and P1, P2, P3 represent propylene-based polymer residues. P1, P2, P3 may themselves contain a branched carbon (Cbr) different from the Cbr described in structural formula (I). [Chemical formula]

[0055] Such a branching structure 13 is identified by C-NMR analysis. The assignment of each peak can refer to the description in Macromolecules, Vol.35, No.10, 2002, pages 3839 - 3842. That is, one methylene carbon (Ca, Cb, Cc) each is observed at 43.9~44.1 ppm, 44.5~44.7 ppm, and 44.7~44.9 ppm, for a total of three, and a methine carbon (Cbr) is observed at 31.5~31.7 ppm. The methine carbon observed at 31.5~31.7 ppm above may hereinafter be abbreviated as branched methine carbon (Cbr). ​A distinctive feature is that the three methylene carbons adjacent to the branched methine carbon Cbr are observed to be separated into three distinct diastereotopic segments, which is non-equivalent.

[0056] 13 Such branched chains, as assigned by 1C-NMR, represent propylene polymer residues with 5 or more carbon atoms that branch off from the main chain of the propylene polymer. These branched chains can be distinguished from branches with 4 or fewer carbon atoms by the difference in the peak positions of the branched carbons. Therefore, in this invention, the presence or absence of a long-chain branched structure can be determined by confirming the peak of this branched methine carbon. Furthermore, in this specification 13 The measurement method for 1C-NMR is as follows, but it is also possible to perform the measurement using other instruments with equivalent performance.

[0057] [ 13 C-NMR measurement method] 200 mg of the sample was dissolved in 2.4 ml of o-dichlorobenzene / deuterated bromidebenzene (C6D5Br) = 4 / 1 (volume ratio) and hexamethyldisiloxane, the reference substance for chemical shifts, in an NMR sample tube with an inner diameter of 10 mmφ. 13 Perform 1C-NMR measurement. 13 ¹ The measurement will be performed at a sample temperature of 120°C using the proton complete decoupling method. Other conditions are as follows: Pulse angle: 90° Pulse interval: 4 seconds Total number of times: 20,000 The chemical shift was set with the methyl carbon peak of hexamethyldisiloxane at 1.98 ppm, and the chemical shifts of peaks due to other carbon atoms were based on this. The amount of long-chain branching can be calculated using the peak around 44 ppm.

[0058] Polypropylene resin (B) having a long-chain branched structure, 13 Preferably, the long-chain branching amount quantified from the peak around 44 ppm in the 1C-NMR spectrum is 0.01 branches / 1000 total propylene or more, more preferably 0.03 branches / 1000 total propylene or more, and even more preferably 0.05 branches / 1000 total propylene or more. Preferably, it is 1.00 branches / 1000 total propylene or less, more preferably 0.50 branches / 1000 total propylene or less, and even more preferably 0.30 branches / 1000 total propylene or less. Within this range, a polypropylene resin with little to no gel and a high degree of strain hardening can be obtained.

[0059] (2-1-2) Melt flow rate (MFR) of polypropylene resin (B) having a long-chain branched structure The polypropylene resin (B) having a long-chain branched structure has a melt flow rate (MFR) (230°C, 2.16 kg load) in the range of 0.1 to 35 g / 10 min, as specified in the above conditions (Bi).

[0060] The melt flow rate (MFR) of the polypropylene resin (B) having a long-chain branched structure must be 0.1 to 35 g / 10 min, preferably 0.5 to 33 g / 10 min, more preferably 1 to 30 g / 10 min, and particularly preferably 1.5 to 25 g / 10 min. By setting the MFR within this range, good fluidity and melt processability can be obtained, making it possible to manufacture good molded articles. On the other hand, an MFR of less than 0.1 g / 10 min is undesirable because it tends to reduce fluidity, and an MFR exceeding 35 g / 10 min is also undesirable because it reduces melt processability, making injection blowing particularly difficult. As mentioned above, the melt flow rate (MFR) was measured according to Method A, Condition M (230°C, 2.16 kg load) of JIS K7210:1999 "Plastics - Test methods for melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastic plastics". One specific method for adjusting the MFR to the above range is to change the amount of hydrogen added during polymerization. Since hydrogen acts as a chain transfer agent in the polymerization of propylene, increasing the amount of hydrogen added will raise the MFR, and conversely, decreasing the amount will lower the MFR. The value of the MFR with respect to the hydrogen concentration inside the polymerization tank varies depending on the catalyst used and other polymerization conditions, but it is extremely easy for a person skilled in the art to understand the relationship between hydrogen concentration and MFR in advance according to the type of catalyst and other polymerization conditions, and to adjust the hydrogen concentration to obtain the desired MFR value.

[0061] The polypropylene resin (B) having a long-chain branched structure used in the present invention preferably has high stereoregularity, which results in high rigidity of the molded article and a low amount of low molecular weight components, making it possible to produce a propylene resin composition with less eye discharge, stickiness, and bleed-out. The polypropylene resin (B) having a long-chain branched structure may be homopolypropylene (propylene homopolymer), or it may be a propylene-α-olefin random copolymer with a small amount of ethylene or α-olefins or other comonomers having about 2 to 8 carbon atoms, such as 1-butene or 1-hexene, as long as various properties are satisfied.

[0062] (2-2) Condition (B-ii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) of 1 to 50 g.

[0063] (2-2-1) Melt tension (MT) of polypropylene resin (B) having a long-chain branched structure The polypropylene resin (B) having a long-chain branched structure used in the present invention requires a melt tension (MT) of 1 to 50 g, preferably 1.5 g to 49 g, more preferably 2 g to 48 g, and particularly preferably 2.5 g to 47 g. By setting the MT within this range, a polypropylene resin with excellent ductility can be obtained, resulting in a uniform wall thickness of the molded product and a good molded article. On the other hand, if the melt tension (MT) is less than 1g or more than 50g, the ductility of the polypropylene resin deteriorates, and in both cases, the wall thickness of the molded product becomes uneven, which is undesirable. Further details regarding the melt tension (MT) will be discussed later.

[0064] Specific methods for controlling MT within the above range include adjusting the MFR, adjusting the catalyst manufacturing method (especially the complex loading ratio), performing electron beam irradiation, or changing the number of long-chain branches by adding peroxides or the like during the granulation process. Increasing the number of long-chain branches or lowering the MFR will increase MT. Conversely, to lower MT, the opposite is true; that is, adjustments should be made to increase the MFR. In this specification, the melt tension (MT) is defined as the value measured under the following conditions, but it may also be measured using other devices with equivalent performance.

[0065] [MT measurement conditions] Measuring device: Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd. Capillary: Diameter 2.0mm, Length 40mm Cylinder diameter: 9.55mm Cylinder extrusion speed: 20 mm / min Pulling speed: 4.0 m / min (However, if the MT is too high and the resin breaks, reduce the pulling speed and measure at the highest possible pulling speed.) Temperature: 230℃

[0066] (2-3) Condition (B-iii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) (unit: g) log(MT)≧-0.9×log(MFR)+0.7 It satisfies the condition.

[0067] (2-3-1) Relationship between MT and MFR in polypropylene resin (B) having a long-chain branched structure The polypropylene resin (B) having a long-chain branched structure used in the present invention has a melt tension (MT) (unit: g) log(MT)≧-0.9×log(MFR)+0.7 It is necessary to satisfy the following conditions. In the examples described herein, the measurement conditions for MT are as described above. The measurement conditions and units for MFR are also as described above.

[0068] This regulation is an indicator for polypropylene resin (B) having a long-chain branched structure to exhibit sufficient drawdown resistance during blow molding. Generally, MT correlates with MFR, and therefore is described by a relationship formula with MFR. Thus, defining MT in relation to MFR is a common practice for those skilled in the art. For example, Japanese Patent Publication No. 2003-25425 proposes the following relation as a definition of polypropylene having high melt tension. log(MS)>-0.61×log(MFR)+0.82 (230℃) (Here, MS is synonymous with MT.) Furthermore, Japanese Patent Publication No. 2003-64193 proposes the following relational expression as a definition of polypropylene having high melt tension. 11.32 × MFR - 0.7854 ≤ MT (230℃) Furthermore, Japanese Patent Publication No. 2003-94504 proposes the following relational expression as a definition of polypropylene having high melt tension. MT≧7.52×MFR-0.576 (MT values ​​were measured at 190°C, and MFR values ​​at 230°C.)

[0069] If a polypropylene resin (B) having a long-chain branched structure satisfies the above formula, it can be said to be a resin with sufficiently high melt tension. In other words, a polypropylene resin (B) having a long-chain branched structure that satisfies the above formula is a resin with excellent drawdown resistance, and is therefore particularly useful as a material for injection blow molding when combined with a propylene-based random copolymer (A) or polypropylene resin (C). Furthermore, it is more preferable that the following condition (B-iii)' is satisfied, and even more preferable that condition (B-iii)'' is satisfied. ·Condition (B-iii)' log(MT)≧-0.9×log(MFR)+0.9 ·Condition (B-iii)” log(MT)≧-0.9×log(MFR)+1.1 The preferred range for MT is as described in condition (B-ii). By setting the relationship between MT and MFR under these conditions, the propylene resin composition of the present invention, which has good fluidity and excellent ductility, can be obtained.

[0070] The polypropylene resin (B) having a long-chain branched structure used in the present invention preferably has a melting point of 145°C or higher, and more preferably 150°C or higher, as determined by differential scanning calorimetry (DSC). A melting point higher than 145°C is preferable from the viewpoint of the heat resistance of the product, but the upper limit of the melting point of polypropylene resin (B) is usually 170°C. The melting point of the polypropylene resin (B) having a long-chain branched structure used in the present invention is determined by differential scanning calorimetry (DSC). The temperature is first raised to 200°C to erase the thermal history, then the temperature is lowered to 40°C at a cooling rate of 10°C / min, and the endothermic peak top temperature is measured again at a heating rate of 10°C / min. The specific equipment used in the examples of this specification is as described in the Examples section below, but it is also possible to perform measurements using other equipment with equivalent performance.

[0071] (3) Polypropylene resin (C) The details of the polypropylene resin (C) used in the present invention are described below. The polypropylene resin (C) used in the present invention has the properties described in the following condition (Ci).

[0072] (3-1) Condition (Ci) Polypropylene resin (C) is a propylene homopolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 100 g / 10 min.

[0073] (3-1-1) Properties of polypropylene resin (C) The polypropylene resin (C) used in this invention is a propylene homopolymer. Compared to other polypropylenes, propylene homopolymers have a higher melting point. Because the polypropylene resin (C) is a propylene homopolymer, molding is possible at relatively high temperatures, allowing for molding over a wide temperature range, and resulting in improved mechanical properties for the resulting molded articles.

[0074] (3-1-2) Melt flow rate (MFR) of polypropylene resin (C) The melt flow rate (MFR) of the polypropylene resin (C) used in the present invention is 1 to 100 g / 10 min, and within this range, preferably 1.1 to 90 g / 10 min, more preferably 1.3 to 80 g / 10 min, and particularly preferably 1.5 to 70 g / 10 min. If the MFR is above the lower limit of this range (1 g / 10 min), the fluidity is improved and the moldability is good, while if it is below the upper limit (100 g / 10 min), the productivity of the resin composition is good and is economically preferable. On the other hand, an MFR of less than 1g / 10min is undesirable because it can lead to decreased fluidity and, in some cases, reduced rigidity. As mentioned above, the melt flow rate (MFR) is the MFR at 230°C and a 2.16 kg load, in accordance with JIS K7210.

[0075] Furthermore, the melting point of the polypropylene resin (C) used in the present invention is usually 150°C or higher, preferably 155°C or higher, and particularly preferably 160°C or higher. There is no particular need to limit the upper limit, but it is usually 180°C or lower, preferably 170°C or lower. By setting the melting point within this range, a propylene resin composition with good operability during blow molding can be obtained. That is, if the melting point is below 150°C, it may be difficult to perform blow molding at high temperatures, and the blow molding temperature may be limited. Also, if the melting point exceeds 180°C, there is a risk of thermal degradation of the propylene resin composition.

[0076] The method for producing the polypropylene resin (C) of the present invention is not particularly limited, but a polymerization method using a stereoregular catalyst is preferred. Examples of stereoregular catalysts include Ziegler catalysts and metallocene catalysts. Furthermore, various polypropylene resins that can be used as polypropylene resin (C) are commercially available from many companies, such as the Novatec series manufactured by Nippon Polypropylene Co., Ltd. It is also possible to purchase and use a product with the desired physical properties from these commercially available products.

[0077] (4) Copolymer (P) The copolymer (P) used in the present invention is described in detail below. The copolymer (P) used in the present invention preferably has the properties described in the following conditions (Pi).

[0078] (4-1) Condition (Pi) The copolymer (P) is at least one copolymer selected from the group consisting of a propylene-α-olefin copolymer (D) that satisfies the following condition (Di) and an ethylene-α-olefin copolymer (E) that satisfies the following condition (Ei).

[0079] Conditions (Di) and (Ei) will be described later. By satisfying condition (Pi) of the copolymer (P), flexibility is imparted, and a molded article with excellent ductility can be obtained.

[0080] (4-2) Condition (P-ii) The copolymer (P) preferably has an intrinsic viscosity (η) measured in decalin at 135°C in the range of 0.1 to 20 dl / g.

[0081] (4-2-1) Intrinsic viscosity (η) measured in decalin at 135°C The copolymer (P) used in the present invention preferably has an intrinsic viscosity (η) measured in decalin at 135°C in the range of 0.1 to 20 dl / g, as defined by condition (P-ii). Within this range, it is more preferably 1 to 19 dl / g, even more preferably 2 to 18 dl / g, and particularly preferably 3 to 17 dl / g. By setting the intrinsic viscosity (η) within this range, a polypropylene resin with excellent ductility can be obtained, making it possible to obtain molded articles with uniform wall thickness. On the other hand, if the intrinsic viscosity (η) is less than 0.1 dl / g, the viscosity during melting may be insufficient, making it impossible to obtain molded products with uniform wall thickness. If the intrinsic viscosity (η) exceeds 20 dl / g, the viscosity during melting may be too high, potentially making it impossible to obtain molded products with uniform wall thickness. One specific method for adjusting the intrinsic viscosity of copolymer components is to change the hydrogen concentration during polymerization.

[0082] (5) Propylene-α-olefin copolymer (D) The details of the propylene-α-olefin copolymer (D) used in the present invention are described below. The propylene-α-olefin copolymer (D) used in the present invention has the properties described in the following conditions (Di).

[0083] (5-1) Condition (Di) Propylene-α-olefin copolymer (D) is a copolymer of propylene and α-olefins having 2 to 8 carbon atoms (excluding α-olefins having 3 carbon atoms).

[0084] (5-1-1) Properties of propylene-α-olefin copolymer (D)

[0085] The propylene-α-olefin copolymer (D) used in the propylene-based resin composition of the present invention is a copolymer obtained by copolymerizing propylene with one or more types of α-olefins having 2 to 8 carbon atoms (excluding α-olefins having 3 carbon atoms), wherein the α-olefins have 2 to 8 carbon atoms, such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene are preferred examples.

[0086] The α-olefin content of the propylene-α-olefin copolymer (D) is typically 10 to 90% by weight. The lower limit is preferably 15% by weight and 20% by weight, in that order, and the upper limit is preferably 70% by weight and 50% by weight, in that order.

[0087] The α-olefin content of the propylene-α-olefin copolymer (D) can be adjusted by appropriately adjusting the ratio of α-olefin to propylene supplied to the polymerization tank. A specific method for adjusting the intrinsic viscosity is to change the hydrogen concentration during polymerization. Furthermore, the propylene-α-olefin copolymer (D) can also be a continuous polymer of polypropylene resin (C) and propylene-α-olefin copolymer (D). In this case, the polypropylene resin (C) is polymerized in the first step of the continuous polymerization, and the propylene-α-olefin copolymer (D) is polymerized in the second step.

[0088] The propylene-α-olefin copolymer (D) has an intrinsic viscosity of typically 5 to 20 dl / g as measured in decalin at 135°C. The lower limit is preferably 6 dl / g, 7 dl / g, and 8 dl / g, in that order, and the upper limit is preferably 16 dl / g, 13 dl / g, and 12 dl / g, in that order. (6) Ethylene-α-olefin copolymer (E) The details of the ethylene-α-olefin copolymer (E) preferably used in the present invention are described below. The ethylene-α-olefin copolymer (E) preferably used in the present invention has the properties described in the following condition (Ei).

[0089] (6-1) Condition (Ei) Ethylene-α-olefin copolymer (E) is a copolymer of ethylene and α-olefins having 3 to 8 carbon atoms.

[0090] (6-1-1) Properties of ethylene-α-olefin copolymer (E) The ethylene-α-olefin copolymer (E) used in the propylene-based resin composition of the present invention (hereinafter sometimes referred to as component (E)) is a copolymer obtained by copolymerizing ethylene with one or more types of α-olefins having 3 to 8 carbon atoms, wherein the α-olefins have 3 to 8 carbon atoms and are preferably exemplified by propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, etc.

[0091] Ethylene-α-olefin copolymer (E) is a component that improves the low-temperature impact resistance of propylene-based resin compositions, but it also affects flexibility and transparency, so it is preferable that it further satisfies the following condition (a).

[0092] (a): Melt flow rate (MFR) of ethylene-α-olefin copolymer (E) The propylene resin composition of the present invention needs to have adequate fluidity to ensure moldability. Therefore, if the melt flow rate (MFR, 230°C, 2.16 kg) (hereinafter sometimes referred to as MFR(E)) of the ethylene-α-olefin copolymer (E) is too low, fluidity will be insufficient, leading to poor dispersion and a decrease in transparency. For this reason, the MFR(E) is usually 0.1 g / 10 min or higher, preferably 0.5 g / 10 min or higher, more preferably 1.5 g / 10 min or higher, and particularly preferably 2 g / 10 min or higher. On the other hand, if the MFR(E) is too high, the molding becomes unstable and variations (unevenness) occur in the wall thickness of the molded body during blow molding. Therefore, the MFR(E) is usually 20 g / 10 min or less, preferably 10 g / 10 min or less, and particularly preferably 9 g / 10 min or less. As mentioned above, MFR is a value measured at 230°C and a 2.16 kg load, in accordance with JIS K7210.

[0093] (6-1-2) Method for producing ethylene-α-olefin copolymer (E) In order to suppress stickiness and bleed-out when the ethylene-α-olefin copolymer (E) used in the present invention is incorporated into the propylene resin composition of the present invention, it is desirable that it has high crystallinity and a narrow molecular weight distribution. Therefore, it is desirable to use a metallocene catalyst that can increase crystallinity and narrow the molecular weight distribution in the production of the ethylene-α-olefin copolymer (E). The metallocene catalyst and polymerization method are described below.

[0094] (i) Metallocene catalysts As the metallocene catalyst, various known catalysts used in the polymerization of ethylene-α-olefin copolymers can be used. Specifically, examples include metallocene catalysts described in Japanese Patent Publication Nos. 58-19309, 59-95292, 60-35006, and 3-163088.

[0095] (ii) Polymerization method Specific polymerization methods include slurry methods, gas-phase fluidized bed methods, solution methods, or high-pressure bulk polymerization methods with a pressure of 200 kg / cm² (19.6 MPa) or higher and a polymerization temperature of 100°C or higher, in the presence of these catalysts. High-pressure bulk polymerization is a preferred manufacturing method. Furthermore, the ethylene-α-olefin copolymer (E) can be appropriately selected and used from among commercially available metallocene polyethylenes. Examples of commercially available products include DuPont-Dau's "AFFINITY" and "ENGAGE," Nippon Polyethylene's "KERNEL" and "HARMOREX," and ExxonMobil's "EXACT." From these, a grade with the desired physical properties can be appropriately selected. Furthermore, component (E) may consist of multiple ethylene-α-olefin copolymers, in which case it is sufficient that the mixture of multiple ethylene-α-olefin copolymers satisfies the requirements of ethylene-α-olefin copolymer (E). For example, multiple grades may be combined, and the mixture thereof may satisfy the requirements of ethylene-α-olefin copolymer (E).

[0096] (7) Nucleating agent (F) The following describes in detail the crystal nucleating agent (F) that is preferably used in the present invention. By incorporating a crystal nucleating agent (F) into the propylene resin composition of the present invention, molded articles with better transparency and impact resistance can be obtained. As crystallizing agents, organophosphate metal salts, organomonocarboxylate metal salts, organodicarboxylate metal salts, polymer nucleating agents, dibenzylidenesorbitol or its derivatives, and metal salts of diterpenic acids are used. The content of the crystallizing agent (F) is as described in condition (Y) above.

[0097] Examples of the above organophosphate ester metal salts include sodium-2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate, lithium-2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate, lithium-2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-ethylidene-bis(4-i-propyl-6-t-butylphenyl)phosphate, lithium- 2,2'-methylene-bis(4-methyl-6-t-butylphenyl) phosphate, lithium-2,2'-methylene-bis(4-ethyl-6-t-butylphenyl) phosphate, sodium-2,2'-butylidene-bis(4,6-di-methylphenyl) phosphate, sodium-2,2'-butylidene-bis(4,6-di-t-butylphenyl) phosphate, sodium-2,2'-t-octylmethylene-bis(4,6-di-t-methylphenyl) phosphate, sodium-2,2'-t-octylmethylene-bis(4,6-di-t -butylphenyl) phosphate, calcium-bis[(2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate], magnesium-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate], barium-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate], sodium-2,2'-methylene-bis(4-methyl-6-t-butylphenyl) phosphate, sodium-2,2'-methylene-bis(4-ethyl-6-t-butylphenyl) phosphate , sodium-2,2'-ethylidene-bis(4-s-butyl-6-t-butylphenyl) phosphate, sodium-2,2'-methylene-bis(4,6-di-methylphenyl) phosphate, sodium-2,2'-methylene-bis(4,6-di-ethylphenyl) phosphate, potassium-2,2'-ethylidene-bis(4,6-di-t-butylphenyl) phosphate, calcium-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl) phosphate], magnesium-bis[2,2'-ethylidene-bis(4,Examples include [6-di-t-butylphenyl) phosphate], barium-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl) phosphate], aluminum-tris[2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate], aluminum-tris[2,2'-ethylidene-bis(4,6-di-t-butylphenyl) phosphate], aluminum-hydrooxy-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate], and aluminum-dihydrooxy-2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate.

[0098] Examples of the above-mentioned metal salts of organic monocarboxylic acids include metal salts of benzoic acid, allyl-substituted acetic acid, and specifically, benzoic acid, p-isopropylbenzoic acid, o-tertiary butylbenzoic acid, pt-butylbenzoic acid, monophenylacetic acid, diphenylacetic acid, phenyldimethylacetic acid, adipic acid, and their Li, Na, Mg, Ca, Ba, and Al salts. Examples of the above-mentioned metal salts of organic dicarboxylic acids include succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, phthalic acid, cyclohexanecarboxylic acid, norbornanedicarboxylic acid, and their Li, Na, Mg, Ca, Ba, and Al salts. Examples of the above-mentioned polymer nucleating agents include polyvinylcyclohexane and poly-3-methylbutene-1.

[0099] Examples of the above-mentioned dibenzylidene sorbitol or its derivatives include 1,3,2,4-dibenzylidene sorbitol, 1,3-benzylidene-2,4-p-methylbenzylidene sorbitol, 1,3-benzylidene-2,4-p-ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-benzylidene sorbitol, and 1,3-p-methylbenzylidene-2,4-p-ethyl Benzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3,2,4-di(p-methylbenzylidene) sorbitol, 1,3,2,4-di(p-ethylbenzylidene) sorbitol, 1,3,2,4-di(pn-propylbenzylidene) sorbitol, 1,3,2,4-di(pi-propylbenzylidene) sorbitol, 1,3,2,4-di(pn-butylbenzylidene) sorbitol, 1,3,2,4-di( ps-butylbenzylidene)sorbitol, 1,3,2,4-di(pt-butylbenzylidene)sorbitol, 1,3,2,4-di(p-methoxybenzylidene)sorbitol, 1,3,2,4-di(p-ethoxybenzylidene)sorbitol, 1,3-benzylidene-2,4-p-chlorbenzylidene sorbitol, 1,3-p-chlorbenzylidene-2,4-benzylidene sorbitol, 1,3-p-chlorbenzylidene-2,4-p-methylbenzylidene sorbitol Examples include thol, 1,3-p-chlorbenzylidene-2,4-p-ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-p-chlorbenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-chlorbenzylidene sorbitol, 1,3,2,4-di(p-chlorbenzylidene) sorbitol, and 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol.Particularly preferred examples include 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-di(p-methylbenzylidene) sorbitol, 1,3-p-chlorbenzylidene-2,4-p-methylbenzylidene sorbitol, and 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol.

[0100] The metal salts of the above-mentioned diterpenic acids are reaction products of diterpenic acids with specific metal compounds such as magnesium compounds and aluminum compounds. Diterpenic acids can generally be obtained from rosin, which is known as a natural resin obtained from pine plants, specifically natural rosin such as gum rosin, tall oil rosin, and wood rosin; various modified rosin such as disproportionated rosin, hydrogenated rosin, dehydrogenated rosin, polymerized rosin, and α,β-ethylenically unsaturated carboxylic acid modified rosin; and purified products of the above-mentioned natural rosin and modified rosin as raw materials. Examples of diterpenic acids include pimaric acid, sandaracopimalic acid, palastic acid, isopimaric acid, abietic acid, dehydroabietic acid, neoabietic acid, dihydropimalic acid, dihydroabietic acid, and tetrahydroabietic acid.

[0101] In the present invention, it is preferable to include a crystal nucleating agent (F) represented by the following formula (II) in order to achieve transparency.

[0102] [ka] (In the formula, n is an integer between 0 and 2, R1 to R5 are each independently, identical or different, hydrogen, halogen, C1 to C20 alkyl, C2 to C20 alkenyl, C1 to C20 alkoxy, C1 to C20 alkoxycarbonyl, or phenyl, and R6 is C1 to C20 alkyl.)

[0103] Among the crystal nucleating agents represented by formula (II), a representative commercially available product is Mirad NX8000J (manufactured by Milliken & Company). Its chemical structure is as shown in formula (III) below. The molecular weight of this crystal nucleating agent is 484. This substance has the excellent characteristic of being extremely stable both thermally and chemically, and therefore hardly decomposing even at molding temperatures. This is highly desirable because it does not cause the problem of decomposition products bleeding out onto the surface of the molded product and degrading its appearance.

[0104] [ka]

[0105] (8) Any component As long as the effects of the present invention are not impaired, the propylene resin composition of the present invention may also contain other thermoplastic resins such as polyethylene resins and elastomers.

[0106] Furthermore, the propylene resin composition of the present invention may contain various additives, such as antioxidants, neutralizing agents, light stabilizers, ultraviolet absorbers, inorganic fillers, antiblocking agents, lubricants, antistatic agents, metal deactivators, colorants, and other polymers that can be used with polypropylene, to the extent that the objectives of the present invention are not impaired. The amount of these additives is generally 0.0001 to 3 parts by weight, preferably 0.001 to 1 part by weight, per 100 parts by weight of the propylene resin composition of the present invention.

[0107] Examples of antioxidants include phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants; examples of neutralizing agents include higher fatty acid salts such as calcium stearate and zinc stearate; and examples of light stabilizers and ultraviolet absorbers include hindered amines, nickel complex compounds, benzotriazoles, and benzophenones.

[0108] The following are examples of typical compounds used as phenolic antioxidants. Examples of monophenol-type compounds include 2,6-di-t-butyl-4-methylphenol (commonly known as BHT), tocopherol (vitamin E), and n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate (trade names: Irganox1076, Sumirizer BP-76).

[0109] Examples of bisphenol-type compounds include 2,2'-methylenebis(4-methyl-6-t-butylphenol) (trade name: Sumirizer MDP-S), 1,1-bis(2'-methyl-4'-hydroxy-5'-t-butylphenyl)butane (trade names: Sumirizer BBM-S, Adekastab AO-40), and 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane (trade names: Sumirizer GA-80, Adekastab AO-80).

[0110] Examples of triphenol-type compounds include 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane (trade name: Adekastab AO-30), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene (trade names: Irganox1330, Adekastab AO-330), tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate (trade names: Irganox3114, Adekastab AO-20), 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate (trade names: Smirizer BP-179, Cyanox1790), and tris-(3,5-di-t-butyl-4-hydroxyphenyl)-isocyanurate (trade name: Cheminox314). An example of a tetraphenol-type compound is tetrakis{methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate}methane (trade name: Irganox1010).

[0111] The following are examples of typical phosphorus-based antioxidants. Examples of phosphite-type compounds include tris(2,4-di-t-butylphenyl) phosphite (trade names: Irgafos168, Smirizer P-16, Adekastab 2112), trisnonylphenyl phosphite (trade names: Smirizer TNP, Adekastab 1178), tris(mixed, mono-dinonylphenyl phosphite) (trade name: Adekastab 329K), tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylenediphosphonite (common name: P-EPQ), and cyclic neopentanetetraylbis(2,6-di-t-butyl-4-methylphenyl phosphite) (trade name: Adekastab PEP-36).

[0112] The following are examples of typical compounds used as sulfur-based antioxidants. Examples of sulfide-type compounds include dilauryl-3,3'-thio-dipropionate (commonly known as DLTDP), dimyristyl-3,3'-thio-dipropionate (commonly known as DMTDP), distearyl-3,3'-thio-dipropionate (commonly known as DSTDP), and pentaerythritol-tetrakis-(3-laurylthio-propionate) (trade names: Sumilyzer TP-D, Adekastab AO-412S).

[0113] Next, we will explain UV absorbers and light stabilizers. UV absorbers are compounds that have an absorption band in the ultraviolet region, and known types include triazoles, benzophenones, salicylates, cyanoacrylates, nickel chelates, and inorganic microparticles. Triazoles are preferred. The following are examples of typical compounds used as ultraviolet absorbers. Examples of triazole compounds include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (trade names: Sumisorb 200, Tinuvin P), 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole (trade names: Sumisorb 340, Tinuvin 399), 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole (trade names: Sumisorb 320, Tinuvin 320), 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole (trade names: Sumisorb 350, Tinuvin 328), and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole (trade names: Sumisorb 300, Tinuvin 326). Examples of benzophenone compounds include 2-hydroxy-4-methoxybenzophenone (trade name: Sumisorb 110) and 2-hydroxy-4-n-octoxybenzophenone (trade name: Sumisorb 130). Examples of salicylate compounds include 4-t-butylphenyl salicylate (trade name: Seesorb 202). Examples of cyanoacrylate compounds include ethyl (3,3-diphenyl) cyanoacrylate (trade name: Seesorb 501). Examples of nickel chelate compounds include nickel dibutyldithiocarbamate (trade name: Antigen NBC). Examples of inorganic particulate compounds include TiO2, ZnO2, and CeO2.

[0114] Light stabilizers commonly use hindered amine compounds, known as HALS. Typical HALS have a 2,2,6,6-tetramethylpiperidine skeleton and cannot absorb ultraviolet light, but they suppress photodegradation through a wide variety of functions. Their main functions are said to be radical scavenging, decomposition of hydroxyperoxide compounds, and scavenging of heavy metals that accelerate the decomposition of hydroxyperoxides. The following are examples of typical compounds that are HALS (Highly Acute Leaving Syndrome). Examples of sebacate-type compounds include bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (trade names: Adekastab LA-77, Tinuvin 770) and bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (trade name: Tinuvin 765). Examples of butanetetracarboxylate type compounds include tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate (trade name: Adekastab LA-57), tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate (trade name: Adekastab LA-52), a condensate of 1,2,3,4-butanetetracarboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol (trade name: Adekastab LA-67), and a condensate of 1,2,3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and tridecyl alcohol (trade name: Adekastab LA-62). Examples of succinic acid polyester-type compounds include condensation polymers of succinic acid and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine. Triazine-type compounds include N,N'-bis(3-aminopropyl)ethylenediamine·2,4-bis{N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino}-6-chloro-1,3,5-triazine condensate (trade name: Chimassorb199), poly{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl- Examples include 4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino} (trade name: Chimassorb 944) and poly(6-morpholino-s-triazine-2,4-diyl){(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino} (trade name: Chimasorb 3346).

[0115] Examples of inorganic fillers include calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, and magnesium silicate. The amount of inorganic filler added can be about 50 parts by weight or less per 100 parts by weight of the resin composition of the present invention.

[0116] Furthermore, examples of antistatic agents include fatty acid partial esters such as glycerol fatty acid monoesters, and examples of metal deactivators include triazines, phosphores, epoxys, triazoles, hydrazides, and oxamides.

[0117] Lubricants are additives used to improve moldability and fluidity, and they reduce friction between polymer molecules and between the polymer and the inner wall of the molding machine within the molding or extruder. Compounds used as lubricants include hydrocarbon compounds such as paraffin and wax, alcohols such as stearyl alcohol and propylene glycol, higher fatty acid esters such as n-butyl stearate, higher fatty acid amides such as oleamide and stearamide, higher fatty acid salts such as calcium stearate, partial esters of polyhydric alcohols such as monoglyceride stearate, and silicone oils. Specific examples of higher fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, erucinic acid amide, and behenic acid amide. Fatty acid amide compounds may have substituents on the alkyl chain or on the nitrogen atom. Examples of substituted fatty acid amide compounds include hydroxystearic acid amide, N-oleyl palmitic acid amide, N-stearyloleic acid amide, N-stearylerucinic acid amide, methylenebisstearic acid amide, and ethylenebisstearic acid amide.

[0118] The following are examples of typical compounds used as neutralizing agents. Examples of carboxylate salt compounds include calcium stearate and zinc stearate. Examples of inorganic compounds include hydrotalcite and inclusion products of aluminum hydroxide and lithium carbonate (trade name: Mizukarak).

[0119] 2. Method for producing propylene resin composition and molded article thereof (1) Method for preparing a propylene resin composition The method for preparing the propylene resin composition used in the present invention includes a propylene-based random copolymer (A) in powder or pellet form, a polypropylene resin (B) having a long-chain branched structure, and a polypropylene resin (C), and, if necessary, A method of mixing a copolymer (P) {(P) is a copolymer of a predetermined propylene-α-olefin copolymer (D) and / or an ethylene-α-olefin copolymer (E)}, a crystal nucleating agent (F), and / or any other component using a dry blender, Henschel mixer, or the like.

[0120] (2) Blow molding of propylene resin composition An injection blow molded article containing the propylene resin composition of the present invention can be obtained by injection blow molding using a known injection blow molding machine. The propylene resin composition of the present invention is particularly suitable for injection blow molding because it has good fluidity, melt tension, etc., which gives it excellent resistance to drawdown, and it is possible to obtain a molded article with uniform wall thickness.

[0121] The molding conditions for injection blow molding are a molding temperature of 120-250°C and an injection pressure of 2-10 kg / cm². 2 It is preferable that the procedure be carried out under conditions where the blow ratio is 1.2 to 5.0. In the case of polypropylene multilayer injection blow molded articles, propylene-based resin compositions can be used in any layer, such as the inner layer, intermediate layer, or outer layer. However, a three-type, five-layer configuration consisting of a propylene-based resin layer, an adhesive resin layer, a gas barrier resin layer, an adhesive resin layer, and a propylene-based resin layer is considered a suitable layer configuration.

[0122] Furthermore, in injection blow molded articles with a barrier layer, the propylene resin composition requires even higher melting properties (melt fluidity and melt ductility) than a single layer. If the melting properties of the main propylene resin composition are poor, the molten resin extruded during parison formation will draw down due to its own weight, resulting in a thinner upper layer and a thicker lower layer. Consequently, the upper barrier layer of the resulting blow molded article will not reach the minimum thickness required to maintain its barrier properties. Therefore, the barrier layer of the extruded molten resin must be made thicker, but this results in an even thicker lower barrier layer on the resulting blow-molded product. When the barrier layer, which has poor melt-ductility, becomes thicker on a polypropylene resin (B) having a long-chain branched structure, the injection blow moldability deteriorates, resulting in an injection blow-molded product of even lower quality.

[0123] Examples of resins used in the barrier layer include polyesters such as polyethylene terephthalate, polyamides such as nylon 6, nylon 66, and MX nylon, ethylene-vinyl alcohol copolymers, and polyvinyldenium chloride. It is possible to mix two or more types of resins or to use multiple layers. In addition, other resins can be mixed within a range that does not impair the effect. The resins used in the adhesive resin layer include polypropylene graft-modified with propylene-based unsaturated carboxylic acids such as maleic anhydride, acrylic acid, and methacrylic acid, or their anhydrides, as well as propylene-α-olefin copolymers.

[0124] (3) Applications of injection blow molded articles of propylene resin composition The injection blow molded articles containing the propylene resin composition of the present invention exhibit excellent physical properties such as rigidity and transparency, as well as excellent uniformity of wall thickness. Therefore, they are suitable not only for general small containers such as food containers, detergent containers, and baby bottles, but also for cosmetic containers and other applications where aesthetic design is required. [Examples]

[0125] The present disclosure will be described in detail below with reference to examples and comparative examples, but the present disclosure is not limited to these examples. In the examples and comparative examples, the physical properties of the propylene resin composition or its components were measured and evaluated according to the evaluation method described below, and the resins used were those listed below.

[0126] 1. Evaluation Method (I) Melt Flow Rate (MFR) [Unit: g / 10 min] The melt flow rate (MFR) of each component described in this example was measured in accordance with Method A, Condition M (230°C, 2.16 kg load) of JIS K7210:1999 "Plastics - Test methods for melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastic plastics".

[0127] (II) Measurement of molecular weight distribution (Mw / Mn and Mz / Mw) by GPC The specific GPC measurement methods used in this specification are as follows: • Equipment: Waters GPC (ALC / GPC 150C) • Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42 μm) • Columns: Showa Denko AD806M / S (3 pieces) Mobile phase solvent: Orthodichlorobenzene (ODCB) ·Measurement temperature: 140℃ ·Flow rate: 1.0ml / min ·Injection amount: 0.2ml • Sample preparation: A 1 mg / mL solution of the sample was prepared using ODCB (containing 0.5 mg / mL of BHT) and dissolved at 140°C for approximately 1 hour. The conversion from retention capacity obtained by GPC measurement to molecular weight was performed using a calibration curve prepared in advance using standard polystyrene (PS). The standard polystyrene used was the following brand manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000 Calibration curves were created by injecting 0.2 mL of a solution prepared by dissolving each component in ODCB (containing 0.5 mg / mL of BHT) so that each component was at a concentration of 0.5 mg / mL. The calibration curves were approximated using a cubic equation obtained by the least squares method. The viscosity formula [η] = K × Mα used for conversion to molecular weight was calculated using the following values. PS: K = 1.38 × 10⁻⁴, α = 0.7 PP:K = 1.03 × 10⁻⁴, α = 0.78

[0128] (III) Molten film tension (MT) Measurements were taken using a capillary graph manufactured by Toyo Seiki Seisakusho under the following conditions. • Capillary: 2.0mm diameter, 40mm length Cylinder diameter: 9.55mm Cylinder extrusion speed: 20 mm / min • Pickup speed: 4.0m / min ·Temperature: 230℃ When MT is extremely high, the resin may break at a pull-up speed of 4.0 m / min. In such cases, the pull-up speed is reduced, and the tension at the highest possible pull-up speed is defined as MT. The unit is grams.

[0129] (IV) Amount of paraxylene-soluble component (CXS) 2 g of the sample was dissolved in 300 ml of p-xylene (containing 0.5 mg / ml of BHT) at 130°C to form a solution, which was then left to stand at 25°C for 12 hours. The precipitated polymer was then filtered off, the p-xylene was evaporated from the filtrate, and the solution was further dried under reduced pressure at 100°C for 12 hours to recover the room-temperature xylene-soluble component. The ratio [weight %] of the weight of this recovered component to the weight of the initial sample was defined as CXS. (V) Melting peak temperature (Tm, melting point) Using a differential operating calorimeter (DSC, Seiko Instruments DSC6200), a 5.0 mg sample was first heated to 200°C to erase its thermal history, then the temperature was lowered to 40°C at a rate of 10°C / min, and the temperature was measured again at a rate of 10°C / min. The endothermic peak top temperature was defined as the melting peak temperature (Tm, melting point).

[0130] (VI) Melting behavior gradient (120~145℃) Using a Seiko Instruments differential scanning calorimeter (DSC6200), a 5.0 mg sample was taken, heated to 200°C to erase the thermal history, held at 200°C for 5 minutes, then cooled to 40°C at a rate of 10°C / min to induce crystallization, and finally melted at a heating rate of 10°C / min. The endothermic peak was defined as the heat of fusion, and after integrating the heat of fusion, the slope of the heat of fusion between 120°C and 145°C was defined as the melting behavior slope (120-145°C). A lower value of this slope tends to result in molded products with less variation in wall thickness across a wide temperature range.

[0131] (V) Melting ratio (135℃) The melting ratio was determined using a differential scanning calorimeter (DSC6200) manufactured by Seiko Instruments, similar to the melting behavior slope described above. A sample of 5.0 mg was taken, the temperature was raised to 200°C to erase the thermal history, it was held at 200°C for 5 minutes, and then the temperature was lowered to 40°C at a cooling rate of 10°C / min to induce crystallization. The endothermic peak at which the sample melted was measured was taken as the heat of fusion, and after integrating the heat of fusion, the ratio of the "heat of fusion at 135°C" to the "heat of fusion obtained by integration" was calculated and defined as the melting ratio (135°C).

[0132] (VI) Thickness The wall thickness of the cylindrical bottle obtained using the method described later was measured at equal intervals in 15 vertical directions and 8 circumferential directions at the center of the body (20 to 110 cm from the bottom) using an Olympus Magna microphone. The average of these wall thicknesses was defined as the "average wall thickness (mm)". The standard deviation of these wall thicknesses (hereinafter referred to as the "wall thickness standard deviation") was also calculated. ·Average wall thickness ×: Average wall thickness is 0.6mm or less △: Average wall thickness is greater than 0.6 mm and less than 0.65 mm. ○: Average wall thickness is 0.65 mm or more ·Thickness standard deviation ×: Standard deviation of wall thickness is 0.12 or higher △: Standard deviation of wall thickness is greater than 0.1 and less than 0.12. ○: Standard deviation of wall thickness is 0.1 or less • Presence or absence of cracks If cracks occur in molded products at molding temperatures of 125°C, 130°C, 135°C, and 140°C, it is marked as "×". If cracks have not yet occurred but are close to it, it is marked as "△". If no cracks occur, it is marked as "〇". The overall evaluation (overall crack occurrence) is as follows: ×: If the molding temperature is 135°C or higher, there is an "×". △: If there is a "×" when the molding temperature is 140℃ or higher. ○: No "×" marks at any molding temperature. • Overall molding evaluation ×: If there is at least one "×" in the evaluation of average wall thickness, standard deviation of wall thickness, and overall crack occurrence. △: The evaluation of average wall thickness, standard deviation of wall thickness, and overall crack occurrence does not include "×", and there are two or more "△" marks. ○: The evaluation of average wall thickness, standard deviation of wall thickness, and overall crack occurrence does not include any "×" marks, and there is one or fewer "△" marks.

[0133] 2.Material • Polypropylene-based random copolymer (A) (A-1) Wintec WFW4M manufactured by Nippon Polypropylene Co., Ltd. (propylene-ethylene random copolymer polymerized using a metallocene catalyst, MFR = 7g / 10min, melting peak temperature: 135℃) (A-2) Wintec WFX4M manufactured by Nippon Polypropylene Co., Ltd. (propylene-ethylene random copolymer polymerized using a metallocene catalyst, MFR = 7g / 10min, melting peak temperature: 125℃) • Polypropylene resin having a long-chain branched structure (B) (B-1) Waymax MFX3 manufactured by Nippon Polypropylene Co., Ltd. (MFR=8g / 10min, MT=6g, log(MT)=0.8, -0.9×log(MFR)+0.7=-0.1), 13 1C-NMR measurements confirmed the presence of long-chain branching in this polypropylene. • Polypropylene resin (C) (C-1) Novatec FL4 manufactured by Nippon Polypropylene Co., Ltd. (propylene homopolymer polymerized using Ziegler catalyst, MFR = 4.2 g / 10 min, melting peak temperature: 164°C) (C-2) Novatec SA06GA manufactured by Nippon Polypropylene Co., Ltd. (propylene homopolymer polymerized using Ziegler catalyst, MFR = 60 g / 10 min, melting peak temperature: 162°C) (C-3) Novatec FA3KM manufactured by Nippon Polypropylene Co., Ltd. (propylene homopolymer polymerized using Ziegler catalyst, MFR = 10g / 10min, melting peak temperature: 162℃) (C-4) and (D-1) From the propylene-ethylene block copolymer (ICP) manufactured by Nippon Polypropylene Co., Ltd., an ICP with the following physical properties was selected, and the first stage of the ICP was used as (C-4) and the second stage of the ICP as (D-1). (C-4) Polypropylene homopolymer (propylene homopolymer polymerized using Ziegler catalyst, MFR = 30 g / 10 min, melting peak temperature: 162°C) • Propylene-α-olefin copolymer (D) (D-1) Propylene-ethylene copolymer (Propylene-ethylene random copolymer polymerized using Ziegler catalyst, ethylene content = 27.4% by weight, intrinsic viscosity = 10.2 dl / g) • Ethylene-α-olefin copolymer (E) (E-1) Kernel KS261 manufactured by Nippon Polyethylene Co., Ltd. (ethylene-1-hexene copolymer, MFR = 4.4g / 10 min) • Nucleating agent (F) (F-1)1,2,3-Trideoxy-4,6:5,7-Bis-[(4-Propylphenyl)methylene]-Nonitol, manufactured by Milliken & Company, product name "Mirad NX8000J" • Neutralizing agent "CaSt": Calcium stearate, manufactured by Nitto Kasei Co., Ltd.

[0134] 3. Preparation of various propylene resin compositions and injection blow molding [Examples 1-16 and Comparative Examples 1-3] According to the formulations described in Tables 1 and 2, the components of propylene-based random copolymer (A), polypropylene resin having a long-chain branched structure (B), and polypropylene resin (C) were mixed (the values ​​for (A), (B), and (C) shown in Table 1 are the values ​​when the sum of (A), (B), and (C) is 100% by weight). Furthermore, for those containing propylene-α-olefin copolymer (D), ethylene-α-olefin copolymer (E), a crystal nucleating agent (F), and / or a neutralizing agent, the respective parts by weight shown in Table 1 were added and mixed with 100 parts by weight of the total of components (A), (B), and (C). These mixtures were stirred for 3 minutes at room temperature in a high-speed agitator mixer (Henschel mixer, trade name), and then melt-kneaded in an extruder to obtain pellets of each propylene resin composition.

[0135] Each of the obtained pellets was supplied to a Sumitomo Heavy Industries, Ltd. SE180 injection molding machine, and injection blow molding preforms weighing 20-25 g were molded under the following conditions: primary injection pressure of 30 MPa, injection speed of 150 mm / s, molding temperature of 220°C, and mold cooling water temperature of 70°C. Subsequently, cylindrical bottles (height 151.5 mm, diameter 55.5 mm) were molded using Frontier Corporation's FRB-1NP at temperatures of 125°C, 130°C, 135°C, and 140°C. The evaluation results of each molded blow-molded body are shown in Tables 1 and 2.

[0136] [Table 1]

[0137] [Table 2]

[0138] 4. Evaluation Results From these examples and comparative examples, it can be seen that in order to obtain a propylene-based resin composition and its molded article with excellent thickness uniformity as required by this application, the resin composition obtained within the scope of the claims of this application is necessary.

Claims

1. A propylene resin composition characterized by comprising a propylene-based random copolymer (A) satisfying the following condition (A-i), a polypropylene resin (B) having a long-chain branched structure satisfying the following conditions (B-i) to (B-iii), and a polypropylene resin (C) satisfying the following condition (C-i), and satisfying the following requirement (X). Condition (A-i) The propylene-based random copolymer (A) is a propylene-α-olefin random copolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 200 g / 10 min. Condition (B-i) Polypropylene resin (B) having a long-chain branched structure has a melt flow rate (MFR) (230°C, 2.16 kg load) in the range of 0.1 to 35 g / 10 min. Condition (B-ii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) of 1 to 50 g. Condition (B-iii) Polypropylene resin (B) having a long-chain branched structure has a melt tension (MT) (unit: g) log(MT)≧−0.9×log(MFR)+0.7 It satisfies the condition. Condition (C-i) The polypropylene resin (C) is a propylene homopolymer with a melt flow rate (MFR) (230°C, 2.16 kg load) of 1 to 100 g / 10 min. Requirements (X) The propylene resin composition contains 30 to 98% by weight of a propylene-based random copolymer (A), 1 to 50% by weight of a polypropylene resin (B) having a long-chain branched structure, and 1 to 20% by weight of a polypropylene resin (C) (provided that the total of the propylene-based random copolymer (A), the polypropylene resin (B) having a long-chain branched structure, and the polypropylene resin (C) is 100% by weight).

2. The propylene resin composition according to claim 1, wherein the propylene random copolymer (A) further satisfies the following conditions (A-ii) to (A-iii). (A-ii) The propylene-based random copolymer (A) is a metallocene polymer. (A-iii) The propylene-based random copolymer (A) has a melting peak temperature (Tm) in the range of 110°C to 155°C, as measured by the DSC method.

3. The propylene resin composition according to claim 1, further comprising a copolymer (P) that satisfies the following condition (P-i), and satisfying the following requirement (Z). Condition (P-i) The copolymer (P) is at least one copolymer selected from the group consisting of a propylene-α-olefin copolymer (D) that satisfies the following condition (D-i) and an ethylene-α-olefin copolymer (E) that satisfies the following condition (E-i). Condition (D-i) Propylene-α-olefin copolymer (D) is a copolymer of propylene and α-olefins having 2 to 8 carbon atoms (excluding α-olefins having 3 carbon atoms). Condition (E-i) Ethylene-α-olefin copolymer (E) is a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms. Requirements (Z) The propylene resin composition contains 1 to 20 parts by weight of copolymer (P) per 100 parts by weight of the total of a propylene-based random copolymer (A), a polypropylene resin (B) having a long-chain branched structure, and a polypropylene resin (C).

4. The propylene resin composition according to claim 3, wherein the copolymer (P) satisfies the following condition (P-ii). Condition (P-ii) The copolymer (P) has an intrinsic viscosity (η) measured in decalin at 135°C in the range of 0.1 to 20 dl / g.

5. The propylene resin composition according to claim 3, wherein the copolymer (P) is a propylene-α-olefin copolymer (D), and the polypropylene resin (C) and the propylene-α-olefin copolymer (D) are a continuous polymer.

6. The propylene resin composition according to claim 1, further comprising a crystal nucleating agent (F) and satisfying the following requirement (Y). Requirement (Y) The propylene resin composition contains 0.001 to 1 part by weight of a crystal nucleating agent (F) per 100 parts by weight of a total of a propylene-based random copolymer (A), a polypropylene resin having a long-chain branched structure (B), and a polypropylene resin (C).

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

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