JP6384019B2 - Polypropylene resin composition and method for producing the same - Google Patents

Description

  The present invention relates to a polypropylene resin composition and a method for producing the same.

Polypropylene-based resin compositions containing polypropylene as a main component are inexpensive and have excellent mechanical properties, and thus are used in various applications. For example, an injection-molded product of a polypropylene resin composition is used for automobile interior materials, daily necessities, housings for electrical products, and the like.
Since polypropylene is a resin having no electrical conductivity, static electricity is generated on the surface of the molded product of the polypropylene resin composition, and dust may adhere to the static electricity. If dust adheres to the surface of the molded product, the appearance is impaired, and an antistatic agent is sometimes added to the polypropylene resin composition for the purpose of preventing the generation of static electricity (Patent Document 1).

Japanese Patent No. 5443603

However, when an antistatic agent is contained in the polypropylene resin composition to such an extent that sufficient antistatic properties are obtained, in the molded product obtained from the polypropylene resin composition, the antistatic agent spreads on the surface of the molded product. There was a tendency for so-called bleeding to occur. In particular, bleeding tends to occur more easily when the molded product is heated. When the antistatic agent bleeds, the appearance of the molded product may be impaired.
In recent years, resin compositions for injection molding have been demanded that can shorten the molding cycle of injection molding in order to improve the productivity of molded products. As a method for shortening the molding cycle, a method for improving the fluidity of the resin composition can be considered. However, simply improving the fluidity of the resin composition does not prevent bleeding of the antistatic agent, and mechanical properties such as rigidity and impact strength tend to be impaired, resulting in lower utility. Therefore, it is required to shorten the molding cycle while preventing bleeding of the antistatic agent and ensuring sufficient mechanical properties.
The present invention relates to a polypropylene resin composition having a high antistatic property, preventing bleeding of an antistatic agent, having a short injection molding cycle, and obtaining a molded product having sufficient mechanical properties, and a method for producing the same. The purpose is to provide.

The present invention has the following aspects.
[1] A polypropylene resin composition containing a propylene resin, an antistatic agent, and an organic nucleating agent,
The propylene-based resin comprises a propylene homopolymer and an ethylene / α-olefin copolymer having an ethylene unit and one or more kinds of α-olefin units of 3 to 12 carbons,
The content ratio of the ethylene / α-olefin copolymer in the polypropylene resin composition is 18 to 30% by mass, the content ratio of the antistatic agent is 0.3 to 0.7% by mass,
A polypropylene resin composition having a melt flow rate of 50 to 120 g / 10 min measured under conditions of a temperature of 230 ° C. and a load of 21.18 N according to JIS K7210.
[2] The polypropylene resin composition according to [1], wherein the propylene resin is produced using a catalyst containing the following components (A) to (C).
(A) Solid catalyst containing magnesium, titanium, halogen and an electron donor compound containing a succinate compound (B) External electron donor compound containing an organoaluminum compound (C) organosilicon compound [3] The polypropylene resin The polypropylene resin composition according to [1] or [2], wherein the content of the nucleating agent including the organic nucleating agent in the composition is 0.01 to 0.50% by mass.
[4] The polypropylene resin composition according to any one of [1] to [3], wherein an ethylene unit ratio in the ethylene / α-olefin copolymer is 25 to 40% by mass.
[5] The intrinsic viscosity in 135 ° C. tetrahydronaphthalene of the xylene-soluble component of the propylene-based resin is 1.4 to 2.4 dl / g, according to any one of [1] to [4]. Polypropylene resin composition.
[6] The polypropylene resin composition according to any one of [1] to [5], wherein the ethylene / α-olefin copolymer is an ethylene / propylene copolymer.
[7] A method for producing a polypropylene resin composition in which a propylene resin, an antistatic agent, and an organic nucleating agent are mixed and melt-kneaded,
As the propylene-based resin, a propylene homopolymer, and an ethylene / α-olefin copolymer having an ethylene unit and one or more kinds of α 3 -olefin units of 3 to 12 carbon atoms,
While the content ratio of the ethylene / α-olefin copolymer in the polypropylene resin composition is 18 to 30% by mass and the content ratio of the antistatic agent is 0.3 to 0.7% by mass,
Propylene resin, antistatic agent, and organic so that the melt flow rate of the obtained polypropylene resin composition measured in accordance with JIS K7210 at a temperature of 230 ° C. and a load of 21.18 N is 50 to 120 g / 10 min. A method for producing a polypropylene resin composition, which comprises a nucleating agent.
[8] The method for producing a polypropylene resin composition according to [7], wherein a catalyst containing the following components (A) to (C) is used when obtaining the propylene resin.
(A) Solid catalyst containing an electron donor compound containing magnesium, titanium, halogen and a succinate compound (B) Organoaluminum compound (C) External electron donor compound containing an organosilicon compound

  The polypropylene resin composition of the present invention has high antistatic properties, prevents bleeding of the antistatic agent, has a short injection molding cycle, and provides a molded product having sufficient mechanical properties.

The polypropylene resin composition of the present invention contains a propylene resin, an antistatic agent, and an organic nucleating agent.
The polypropylene resin composition of the present invention has a melt flow rate (hereinafter referred to as “MFR”) of 50 to 120 g / 10 minutes measured under conditions of a temperature of 230 ° C. and a load of 21.18 N according to JIS K7210. 60 to 100 g / 10 min is more preferable, and 65 to 90 g / 10 min is further preferable. If the MFR of the polypropylene resin composition is less than the lower limit, the molding cycle when the polypropylene resin composition is injection-molded may be long. If the upper limit is exceeded, the polypropylene resin composition The mechanical properties of a molded product obtained by injection molding may be lowered.

(Propylene resin)
The propylene-based resin is a block polypropylene composed of a propylene homopolymer and an ethylene / α-olefin copolymer having an ethylene unit and one or more types of α-olefin units of 3 to 12 carbon atoms. The ethylene / α-olefin copolymer in the propylene-based resin has a rubber component.
Examples of the α-olefin include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-dodecene. The α-olefin is preferably propylene in terms of high mechanical properties and lower cost. That is, the ethylene / α-olefin copolymer is preferably an ethylene / propylene copolymer.

  The ethylene unit ratio in the ethylene / α-olefin copolymer is preferably 25 to 40% by mass, and more preferably 30 to 35% by mass. If the ethylene unit content in the ethylene / α-olefin copolymer is within the above range, sufficiently high impact resistance can be obtained.

  The intrinsic viscosity of the propylene-based resin in xylene solubles in tetrahydronaphthalene at 135 ° C. is preferably 1.4 to 2.4 dl / g, more preferably 1.6 to 2.2 dl / g. preferable. If the intrinsic viscosity of the propylene-based resin in xylene solubles is not less than the lower limit, the impact resistance is higher, and if it is not more than the upper limit, the fluidity and impact resistance are higher.

The propylene-based resin can be produced by multistage polymerization. For example, propylene homopolymer is polymerized in the first stage polymerization reactor, and the resulting propylene homopolymer is supplied to the second stage polymerization reactor and ethylene · A propylene-based resin can be obtained by polymerizing the α-olefin copolymer. In this method, the propylene homopolymer and the ethylene / α-olefin copolymer to be produced are mixed in the second stage polymerization reactor.
By polymerizing the ethylene / α-olefin copolymer in the presence of the propylene homopolymer, productivity is increased and the dispersibility of the ethylene / α-olefin copolymer is increased, so that the balance of physical properties is also improved.
The multistage polymerization is not limited to the above method, and a propylene homopolymer may be polymerized in a plurality of polymerization reactors, or an ethylene / α-olefin copolymer may be polymerized in a plurality of polymerization reactors. Good. Moreover, as a method of obtaining a propylene-type resin, the method of performing using the superposition | polymerization device which has a gradient of monomer concentration and superposition | polymerization conditions is mentioned. In such a polymerization vessel, for example, a monomer in which at least two polymerization regions are joined can be used, and the monomer can be polymerized by gas phase polymerization. Specifically, in the presence of a catalyst, a monomer is supplied and polymerized in a polymerization region including a riser, and a monomer is supplied and polymerized in a downcomer connected to the riser. The polymer product is recovered while circulating. This method comprises means for completely or partially preventing the gas mixture present in the riser from entering the downcomer. Also, a gas and / or liquid mixture having a different composition from the gas mixture present in the riser is introduced into the downcomer. As this polymerization method, for example, the method described in JP-T-2002-520426 can be applied.
Moreover, in the case of superposition | polymerization, you may add hydrogen for adjustment of molecular weight as needed.
In block polypropylene in which a propylene homopolymer and an ethylene / α-olefin copolymer are mixed by polymerization, the propylene homopolymer and the ethylene / α-olefin copolymer are mixed in a state close to a molecular level. Therefore, block polypropylene is different from a simple blend of a propylene homopolymer and an ethylene / α-olefin copolymer.

  Although it does not restrict | limit especially as a catalyst used when superposing | polymerizing propylene-type resin, (A) Solid catalyst containing magnesium, titanium, a halogen, and an electron donor compound; (B) Organoaluminum compound; (C) External electron donation Those containing body compounds are preferred. When a catalyst containing these (A), (B) and (C) is used, a swell is increased, sink marks are reduced, and a molded product having a uniform thickness can be easily obtained. Demonstrated.

The solid catalyst (A) can be obtained by various methods. For example, the method shown to following (1)-(7) is mentioned.
(1) A magnesium compound or a complex compound of a magnesium compound and an electron donor compound is pulverized or not pulverized in the presence or absence of an electron donor compound, a grinding aid or the like, and / or Alternatively, a method of pretreatment with a reaction aid such as an organoaluminum compound or a halogen-containing silicon compound, or reacting with a solid obtained without pretreatment with a titanium compound that forms a liquid phase under reaction conditions.
(2) A method of depositing a solid titanium composite by reacting a magnesium compound liquid with a liquid titanium compound in the presence or absence of an electron donor compound.
(3) A method of reacting a solid magnesium compound with a liquid titanium compound and an electron donor compound.
(4) A method in which a titanium compound is further reacted with the product obtained in (2) or (3) above.
(5) A method in which an electron donor compound and a titanium compound are further reacted with the product obtained in any one of the above (1), (2), and (3).
(6) A magnesium compound or a complex compound of a magnesium compound and an electron donor compound is pulverized in the presence or absence of an electron donor compound, a grinding aid or the like, and in the presence of a titanium compound, and an electron donor compound and A method of treating a solid obtained by pretreatment with a reaction aid such as an organoaluminum compound or a halogen-containing silicon compound or without pretreatment with a halogen or a halogen compound or an aromatic hydrocarbon.
(7) A method of treating the compound obtained in the above (1) to (5) with a halogen, a halogen compound or an aromatic hydrocarbon.

The titanium compound used for the preparation of the solid catalyst component (A) is a tetravalent compound represented by the general formula: Ti (OR) _g X _4-g (R is a hydrocarbon group, X is a halogen, 0 ≦ g ≦ 4). These titanium compounds are preferred. Examples of the hydrocarbon group include methyl, ethyl, propyl, butyl and the like, and examples of the halogen include Cl, Br and the like.
More specific titanium compounds include titanium halides such as TiCl ₄ , TiBr ₄ , and TiI ₄ ; Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , and Ti (O _n —C ₄ H). _{9) Cl 3, Ti (OC} 2 H 5) Br 3, Ti (O-isoC 4 H 9) trihalide, alkoxy titanium such as _{Br 3; Ti (OCH 3)} 2 Cl 2, Ti (OC 2 H 5) _{2 Cl 2, Ti (O n} -C 4 H 9) 2 Cl 2, Ti (OC 2 H 5) 2 dihalogenated alkoxy titanium such as _{Br 2; Ti (OCH 3)} 3 Cl, Ti (OC 2 H 5) _{3 Cl, Ti (O n -C} 4 H 9) 3 Cl, Ti (OC 2 H 5) 3 monohalogenated trialkoxy titanium such as _{Br; Ti (OCH 3) 4} , Ti (OC 2 H 5) 4, Ti Tet such _{(O n -C 4 H 9)} 4 Such as alkoxy titanium, and the like. These titanium compounds may be used individually by 1 type, and may use 2 or more types together.
Among the above titanium compounds, preferred are halogen-containing titanium compounds, particularly titanium tetrahalides, and particularly preferred is titanium tetrachloride (TiCl ₄ ).

As the magnesium compound used for the preparation of the solid catalyst component (A), a magnesium compound having a magnesium-carbon bond or a magnesium-hydrogen bond, such as dimethylmagnesium, diethylmagnesium, dipropylmagnesium, dibutylmagnesium, diamylmagnesium, dihexylmagnesium, Examples include didecyl magnesium, ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, amyl magnesium chloride, butyl ethoxy magnesium, ethyl butyl magnesium, butyl magnesium hydride and the like.
These magnesium compounds can be used, for example, in the form of a complex compound with organic aluminum or the like, and may be in a liquid state or a solid state.
Further preferred magnesium compounds include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide and magnesium fluoride; alkoxy such as methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy magnesium chloride and octoxy magnesium chloride. Magnesium halides; aryloxymagnesium halides such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; alkoxymagnesiums such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium and 2-ethylhexoxymagnesium; phenoxymagnesium and dimethyl Allyloxymagnesium such as phenoxymagnesium; Magnesium laurate , And the like carboxylates of magnesium such as magnesium stearate.
These magnesium compounds may be used individually by 1 type, and may use 2 or more types together.

As an electron donor compound used for the preparation of the solid catalyst component (A) used in the production of the above-mentioned propylene resin composition, alcohol, phenol, ketone, aldehyde, carboxylic acid, organic acid or inorganic acid ester, ether, Although oxygen-containing electron donors such as acid amides and acid anhydrides, nitrogen-containing electron donors such as ammonia, amines, nitriles, and isocyanates are known, the electron donor compound in the present invention contains dicarboxylic acid diesters. Is preferred. A dicarboxylic acid is a compound having two carboxyl groups. For example, succinic acid and substituted succinic acid having a substituent such as an alkyl group at the 1-position or 2-position of succinic acid are also included in the dicarboxylic acid. Of the dicarboxylic acid diesters, diesters of succinic acid, substituted succinic acid, phthalic acid, maleic acid, and substituted malonic acid are more preferred, and succinic acid ester (succinate) electron donor compounds are particularly preferred.
A suitable succinate compound is a compound having a succinate structure represented by the following chemical formula (I).

In formula (I), R ¹ and R ² are the same or different from each other, and may be a linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl having 1 to 20 carbon atoms that may contain a hetero atom. It is a group. Preferred R ¹ and R ² are alkyl, cycloalkyl, aryl, arylalkyl, and alkylaryl groups having 1 to 8 carbon atoms. R ¹ and R ² are particularly preferably compounds selected from primary alkyls, especially branched primary alkyls. Specific examples of suitable R ¹ and R ² include methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl and 2-ethylhexyl, with ethyl, isobutyl and neopentyl being particularly preferred.
R ^{3 to} R ⁶ are the same as or different from each other, hydrogen, or a linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl group having 1 to 20 carbon atoms that may contain a hetero atom. It is. R ³ and R ⁴ , R ⁵ and R ⁶ bonded to the same carbon atom may be bonded to each other to form a ring structure. Any two or more of R ^{3 to} R ⁶ bonded to different carbon atoms may be bonded to each other to form a ring structure.

One preferred group of compounds of formula (I) are branched alkyl, cycloalkyl, aryl, arylalkyl, wherein R ^{3 to} R ⁵ are hydrogen and R ⁶ has 3 to 10 carbon atoms. And monosubstituted succinate compounds of alkylaryl groups.
Specific examples of suitable mono-substituted succinate compounds include diethyl-sec-butyl succinate, diethyl texyl succinate, diethyl cyclopropyl succinate, diethyl norbornyl succinate, diethyl perhydrosuccinate, diethyl trimethylsilyl Succinate, diethyl methoxy succinate, diethyl-p-methoxyphenyl succinate, diethyl-p-chlorophenyl succinate, diethyl phenyl succinate, diethyl cyclohexyl succinate, diethyl benzyl succinate, diethyl cyclohexyl methyl Succinate, diethyl-t-butyl succinate, diethyl isobutyl succinate, diethyl isopropyl succinate, diethyl neopentyl succinate, diethyl isopentyl succinate , Diethyl (1-trifluoromethylethyl) succinate, diethyl fluorenyl succinate, 1- (ethoxycarbodiisobutylphenyl) succinate, diisobutyl-sec-butyl succinate, diisobutyl hexyl succinate, diisobutylcyclopropyl succinate , Diisobutyl norbornyl succinate, diisobutyl perhydrosuccinate, diisobutyltrimethylsilyl succinate, diisobutyl methoxy succinate, diisobutyl-p-methoxyphenyl succinate, diisobutyl-p-chlorophenyl succinate, diisobutyl cyclohexyls Succinate, diisobutylbenzyl succinate, diisobutylcyclohexylmethyl succinate, diisobutyl-t-butyl succinate , Diisobutyl isobutyl succinate, diisobutyl isopropyl succinate, diisobutyl neopentyl succinate, diisobutyl isopentyl succinate, diisobutyl (1-trifluoromethylethyl) succinate, diisobutyl fluorenyl succinate, dineopentyl-sec-butyl Succinate, dineopentyl texyl succinate, dineopentyl cyclopropyl succinate, dineopentyl norbornyl succinate, dineopentyl perhydrosuccinate, dineopentyl trimethylsilyl succinate, dineopentyl Methoxy succinate, dineopentyl-p-methoxyphenyl succinate, dineopentyl-p-chlorophenyl succinate, dineopentyl phenyl succinate, dineo Pentylcyclohexyl succinate, dineopentyl benzyl succinate, dineopentyl cyclohexyl methyl succinate, dineopentyl-t-butyl succinate, dineopentyl isobutyl succinate, dineopentyl isopropyl succinate, dineo Examples include pentyl neopentyl succinate, dineopentyl isopentyl succinate, dineopentyl (1-trifluoromethylethyl) succinate, and dineopentyl fluorenyl succinate.
These compounds may be used individually by 1 type, and may use 2 or more types together.

As another preferred compound of the compound represented by formula (I), at least two groups of R ^{3 to} R ⁶ are not hydrogen, but linear or branched alkyl having 1 to 20 carbon atoms which may contain a hetero atom, And disubstituted succinate compounds selected from alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl groups. Two groups that are not hydrogen are preferably bonded to the same carbon atom.
Specific examples of suitable disubstituted succinate compounds include diethyl-2,2-dimethyl succinate, diethyl-2-ethyl-2-methyl succinate, diethyl-2-benzyl-2-isopropyl succinate, diethyl -2-cyclohexylmethyl-2-isobutyl succinate, diethyl-2-cyclopentyl-2-n-propyl succinate, diethyl-2-cyclopentyl-2-n-butyl succinate, diethyl-2,2-diisobutyls Succinate, diethyl-2-cyclohexyl-2-ethylsuccinate, diethyl-2-isopropyl-2-methylsuccinate, diethyl-2-tetradecyl-2-ethylsuccinate, diethyl-2-isobutyl-2- Ethyl succinate, diethyl-2- (1-trifluoromethylethyl) 2-methyl succinate, diethyl-2-isopentyl-2-isobutyl succinate, diethyl-2-phenyl-2-n-butyl succinate, diisobutyl-2,2-dimethyl succinate, diisobutyl-2 -Ethyl-2-methyl succinate, diisobutyl-2-benzyl-2-isopropyl succinate, diisobutyl-2-cyclohexylmethyl-2-isobutyl succinate, diisobutyl-2-cyclopentyl-2-n-propyl succinate Diisobutyl-2-cyclopentyl-2-n-butyl succinate, diisobutyl-2,2-diisobutyl succinate, diisobutyl-2-cyclohexyl-2-ethyl succinate, diisobutyl-2-isopropyl-2-methyl Succinate, diisobutyl-2-teto Decyl-2-ethylsuccinate, diisobutyl-2-isobutyl-2-ethylsuccinate, diisobutyl-2- (1-trifluoromethylethyl) -2-methylsuccinate, diisobutyl-2-isopentyl-2- Isobutyl succinate, diisobutyl-2-phenyl-2-n-butyl succinate, diisobutyl-2,2-diisopropyl succinate, diisobutyl-2-phenyl-2-n-propyl succinate, dineopentyl-2, 2-dimethyl succinate, dineopentyl-2-ethyl-2-methyl succinate, dineopentyl-2-benzyl-2-isopropyl succinate, dineopentyl-2-cyclohexylmethyl-2-isobutyl succinate, dineopentyl-2 -Cyclopentyl-2-n-propyl Xinate, dineopentyl-2-cyclopentyl-2-n-butyl succinate, dineopentyl-2,2-diisobutyl succinate, dineopentyl-2-cyclohexyl-2-ethyl succinate, dineopentyl-2-isopropyl-2-methyl Succinate, dineopentyl-2-tetradecyl-2-ethyl succinate, dineopentyl-2-isobutyl-2-ethyl succinate, dineopentyl-2- (1-trifluoromethylethyl) -2-methyl succinate, Examples include dineopentyl-2,2-diisopropyl succinate, dineopentyl-2-isopentyl-2-isobutyl succinate, and dineopentyl-2-phenyl-2-n-butyl succinate.
These compounds may be used individually by 1 type, and may use 2 or more types together.

Particularly preferred compounds of formula (I) are compounds in which at least two groups different from hydrogen, that is, R ³ and R ⁵ , or R ⁴ and R ⁶ are bonded to different carbon atoms. Also mentioned.
Specific examples of this compound include diethyl-2,3-bis (trimethylsilyl) succinate, diethyl-2,2-sec-butyl-3-methylsuccinate, diethyl-2- (3,3,3-trifluoro Propyl) -3-methylsuccinate, diethyl-2,3-bis (2-ethylbutyl) succinate, diethyl-2,3-diethyl-2-isopropylsuccinate, diethyl-2,3-diisopropyl-2-methyl Succinate, diethyl-2,3-dicyclohexyl-2-methylsuccinate, diethyl-2,3-dibenzylsuccinate, diethyl-2,3-diisopropylsuccinate, diethyl-2,3-bis ( (Cyclohexylmethyl) succinate, diethyl-2,3-di-t-butylsuccinate, diethyl-2,3-dii Butyl succinate, diethyl-2,3-dineopentyl succinate, diethyl-2,3-diisopentyl succinate, diethyl-2,3- (1-trifluoromethylethyl) succinate, diethyl-2 , 3-tetradecyl succinate, diethyl-2,3-fluorenyl succinate, diethyl-2-isopropyl-3-isobutyl succinate, diethyl-2-tert-butyl-3-isopropyl succinate, diethyl 2-isopropyl-3-cyclohexyl succinate, diethyl-2-isopentyl-3-cyclohexyl succinate, diethyl-2-tetradecyl-3-cyclohexylmethyl succinate, diethyl-2-cyclohexyl-3-cyclopentyl succinate Nate, diethyl-2,2,3,3-tetramethyl Succinate, diethyl-2,2,3,3-tetraethylsuccinate, diethyl-2,2,3,3-tetrapropylsuccinate, diethyl-2,3-diethyl-2,3-diisopropylsuccinate, Diisobutyl-2,3-bis (trimethylsilyl) succinate, diisobutyl-2,2-sec-butyl-3-methylsuccinate, diisobutyl-2- (3,3,3-trifluoropropyl) -3-methylsuccinate , Diisobutyl-2,3-bis (2-ethylbutyl) succinate, diisobutyl-2,3-diethyl-2-isopropyl succinate, diisobutyl-2,3-diisopropyl-2-methyl succinate, diisobutyl-2, 3-dicyclohexyl-2-methyl succinate, diisobutyl-2,3-dibenzyl succinate, Isobutyl-2,3-diisopropyl succinate, diisobutyl-2,3-bis (cyclohexylmethyl) succinate, diisobutyl-2,3-di-t-butyl succinate, diisobutyl-2,3-diisobutyl succinate, Diisobutyl-2,3-dineopentyl succinate, diisobutyl-2,3-diisopentyl succinate, diisobutyl-2,3- (1-trifluoromethylethyl) succinate, diisobutyl-2,3-n-propyl Succinate, diisobutyl-2,3-tetradecyl succinate, diisobutyl-2,3-fluorenyl succinate, diisobutyl-2-isopropyl-3-isobutyl succinate, diisobutyl-2-tert-butyl-3 -Isopropyl succinate, diisobutyl-2- Isopropyl-3-cyclohexyl succinate, diisobutyl-2-isopentyl-3-cyclohexyl succinate, diisobutyl-2-n-propyl-3- (cyclohexylmethyl) succinate, diisobutyl-2-tetradecyl-3-cyclohexylmethyl succinate , Diisobutyl-2,2,3,3-tetramethyl succinate, diisobutyl-2,2,3,3-tetraethyl succinate, diisobutyl-2,2,3,3-tetrapropyl succinate, diisobutyl -2,3-diethyl-2,3-diisopropyl succinate, diisobutyl-2-cyclohexyl-3-cyclopentyl succinate, dineopentyl-2,3-bis (trimethylsilyl) succinate, dineopentyl-2,2-sec-butyl -3-Me Rusuccinate, dineopentyl-2- (3,3,3-trifluoropropyl) -3-methyl succinate, dineopentyl-2,3-bis (2-ethylbutyl) succinate, dineopentyl-2,3-diethyl-2-isopropyl Succinate, dineopentyl-2,3-diisopropyl-2-methyl succinate, dineopentyl-2,3-dicyclohexyl-2-methyl succinate, dineopentyl-2,3-dibenzyl succinate, dineopentyl-2, 3-diisopropyl succinate, dineopentyl-2,3-bis (cyclohexylmethyl) succinate, dineopentyl-2,3-di-t-butyl succinate, dineopentyl-2,3-diisobutyl succinate, dineopentyl-2, 3-Dineopentylsk Dynepentyl-2,3-diisopentyl succinate, dineopentyl-2,3- (1-trifluoromethylethyl) succinate, dineopentyl-2,3-dineopentyl succinate, dineopentyl-2,3- Diisopentyl succinate, dineopentyl-2,3-tetradecyl succinate, dineopentyl-2,3-fluorenyl succinate, dineopentyl-2-isopropyl-3-isobutyl succinate, dineopentyl-2-tert- Butyl-3-isopropyl succinate, dineopentyl-2-isopropyl-3-cyclohexyl succinate, dineopentyl-2-isopentyl-3-cyclohexyl succinate, dineopentyl-2-tetradecyl-3-cyclohexylmethyl succinate Dineopentyl-2-n-propyl-3- (cyclohexylmethyl) succinate, dineopentyl-2-cyclohexyl-3-cyclopentyl succinate, dineopentyl-2,2,3,3-tetraethylsuccinate, dineopentyl-2,2 3,3-tetrapropyl succinate, dineopentyl-2,3-diethyl-2,3-diisopropyl succinate.
These compounds may be used individually by 1 type, and may use 2 or more types together.

In addition, as the compound represented by the formula (I), those in which at least two of R ^{3 to} R ⁶ are bonded to form a ring are also preferable.
As such compounds, compounds described in JP-T-2002-542347, for example, 1- (ethoxycarbonyl) -1- (ethoxyacetyl) -2,6-dimethylcyclohexane, 1- (ethoxycarbonyl)- 1- (ethoxyacetyl) -2,5-dimethylcyclopentane, 1- (ethoxycarbonyl) -1- (ethoxyacetylmethyl) -2-methylcyclohexane, 1- (ethoxycarbonyl) -1- (ethoxy (cyclohexyl) acetyl ) Cyclohexane. Moreover, the cyclic | annular succinate compound currently disclosed by the international publication 2009/069483 and the international publication 2009/057747 can also be used conveniently.

Among the compounds represented by formula (I), when R ^{3 to} R ⁶ contain a hetero atom, the hetero atom is a group 15 atom such as a nitrogen atom or a phosphorus atom, or a group 16 atom such as an oxygen atom or a sulfur atom. A group atom is preferred. Examples of the compound in which R ^{3 to} R ⁶ include a Group 15 atom include compounds disclosed in JP-A-2005-306910. Examples of the compound in which R ^{3 to} R ⁶ include a group 16 atom include compounds disclosed in JP-A-2004-131537.
Examples of the halogen atom constituting the solid catalyst component include fluorine, chlorine, bromine, iodine or a mixture thereof, and chlorine is particularly preferable.

Examples of the organoaluminum compound (B) include trialkylaluminum such as triethylaluminum and tributylaluminum, trialkenylaluminum such as triisoprenylaluminum, dialkylaluminum alkoxide such as diethylaluminum ethoxide and dibutylaluminum butoxide, and ethylaluminum sesquiethoxy. In addition to alkylaluminum sesquialkoxides such as butylaluminum sesquibutoxide, R ⁷ _2.5 Al (OR ⁸ ) _0.5 (R ⁷ and R ⁸ are each a hydrocarbon group that may be different or the same. A partially alkoxylated alkylaluminum, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum having an average composition represented by Dialkylaluminum halides such as mubromide, alkylaluminum sesquichlorides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, alkylaluminum sesquihalogenides such as ethylaluminum sesquichloride, alkylaluminum dihalogenides such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromide, etc. Partially hydrogenated alkylaluminums such as dialkylaluminum hydrides such as partially halogenated alkylaluminum, diethylaluminum hydride, dibutylaluminum hydride, ethylaluminum dihydride, propylaluminum dihydride, etc. , Ethyl aluminum ethoxy chloride, butyl aluminum butoxy Chlorides, alkylaluminum, and the like which are partially alkoxylated and halogenated, such as ethylaluminum ethoxy bromide.
The said organoaluminum compound (B) may be used individually by 1 type, and may use 2 or more types together.

The external electron donor compound (C) includes an organosilicon compound.
Preferred organosilicon compounds include, for example, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, and t-amylmethyldiethoxy. Silane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o-tolyldimethoxysilane, bism-tolyldimethoxysilane, bisp-tolyldimethoxysilane, bisp-tolyldiethoxysilane, bisethylphenyldimethoxysilane , Dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane , Ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane , Methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, texyltrimethoxysilane, n-butyltriethoxysilane, iso-butyltriethoxysilane, phenyltriethoxysilane, γ- Aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane Lan, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris (β-methoxyethoxysilane) ), Vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, and the like.
Among these, ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, texyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, diisopropyldimethoxy Silane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, phenylmethyldimethoxysilane, bis p-tolyldimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, 2-nonebornanetriethoxysilane, 2 -Norbornanemethyldimethoxysilane, diphenyldiethoxysilane, ethyl silicate are preferred.
The external electron donor compound (C) may be used alone or in combination of two or more.

  Among the above catalysts, the solid catalyst (A) is a solid catalyst containing magnesium, titanium, halogen, and an electron donor compound containing a succinate compound, and the organoaluminum compound (B) is a trialkylaluminum such as triethylaluminum or tributylaluminum. Aluminum and the external electron donor compound (C) are preferably organic silicon compounds such as dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, and diisopropyldimethoxysilane. With such a catalyst, a polymer having excellent productivity, high stereoregularity, and a wide molecular weight distribution can be obtained. As a result, a composition excellent in rigidity, heat resistance, and moldability can be easily produced.

(Antistatic agent)
The antistatic agent imparts conductivity to the propylene-based resin composition.
Examples of the antistatic agent include nonionic antistatic agents, anionic antistatic agents, cationic antistatic agents, and amphoteric antistatic agents.
Examples of the nonionic antistatic agent include glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene alkylamine fatty acid ester, N, N-bis (2-hydroxy And ethyl) alkylamine, polyoxyethylene fatty alcohol ether, polyoxyethylene alkylphenyl ether, polyethylene glycol fatty acid ester and the like.
Examples of the anionic antistatic agent include alkyl sulfonate, alkyl benzene sulfonate, alkyl sulfate, alkyl phosphate and the like.
Examples of the cationic antistatic agent include tetraalkylammonium salts and trialkylbenzylammonium salts.
Examples of amphoteric antistatic agents include alkylbetaines and imidazoline type derivatives.

Among the antistatic agents, nonionic antistatic agents are preferable, and among the nonionic antistatic agents, glycerin fatty acid esters are preferable because the effects of the present invention are particularly exerted.
Examples of the glycerol fatty acid ester include glycerol monolaurate, glycerol monomyristate, glycerol monopalmitate, glycerol monostearate, glycerol monooleate, and glycerol monoisostearate.
One antistatic agent may be used alone, or two or more antistatic agents may be used in combination.

  The content ratio of the antistatic agent in the propylene-based resin composition is 0.3 to 0.7% by mass, and more preferably 0.4 to 0.6% by mass. When the content ratio of the antistatic agent is less than the lower limit, the antistatic property of the molded product obtained by injection molding the propylene-based resin composition may be insufficient, and when the upper limit is exceeded, Bleed may not be suppressed.

(Organic nucleating agent)
An organic nucleating agent is an organic compound that promotes the formation of polypropylene crystal nuclei and improves the crystallinity of the resulting resin composition. By containing the nucleating agent, the rigidity of the molded product obtained from the resin composition is improved.
Specific examples of organic nucleating agents include aromatic phosphate ester compounds, sorbitol compounds, nonitol compounds, triaminobenzene derivative compounds, metal salts of carboxylic acids, etc. Phosphate ester compounds are preferred.

Examples of the aromatic phosphate compound include phosphoric acid-2,2′-methylenebis (4,6-di-tert-butylphenyl) sodium salt compound, phosphoric acid-2,2′-methylenebis (4, 6-di-tert-butylphenyl) lithium salt compounds, aluminum-bis (4,4 ′, 6,6′-tetra-tert-butyl-2,2′-methylenediphenyl-phosphate) -hydroxide, etc. Can be mentioned.
Examples of the sorbitol compound include dibenzylidene sorbitol, 1,3,2,4-di- (methylbenzylidene) sorbitol, 1,3,2,4-bis- (dimethylbenzylidene) sorbitol, 1,3,2,4 -(Ethylbenzylidene) sorbitol, 1,3,2,4- (methoxybenzylidene) sorbitol, 1,3,2,4- (ethoxybenzylidene) sorbitol and the like.
Examples of nonitol compounds include 1,2,3-trideoxy-4,6-5,7-bis-o-[(4-propylphenyl) methylene] nonitol.
Examples of the triaminobenzene derivative nucleating agent include 1,3,5-tris (2,2-dimethylpropanamide) benzene.
Examples of the metal salt of carboxylic acid include sodium adipate, potassium adipate, aluminum adipate, sodium sebacate, potassium sebacate, aluminum sebacate, sodium benzoate, aluminum benzoate, and di-para-t-butylbenzoate. Examples include aluminum acid, titanium di-para-t-butylbenzoate, chromium di-para-t-butylbenzoate, and aluminum hydroxy-di-t-butylbenzoate.
An organic nucleating agent may be used individually by 1 type, and may use 2 or more types together.
Among the organic nucleating agents, aromatic phosphate ester compounds are preferable because they contribute to rigidity and crystallization speed.

  In the propylene-based resin composition, the content of the nucleating agent including the organic nucleating agent is preferably 0.01 to 0.50 mass%, more preferably 0.05 to 0.30 mass%. preferable. When the content of the nucleating agent including the organic nucleating agent exceeds the upper limit, it is not suitable for food use, and when it is less than the lower limit, the rigidity is low and the crystallization rate may be slow.

Moreover, you may add an inorganic filler to the polypropylene resin composition of this invention in the range which does not impair antistatic property. Examples of the inorganic filler include natural silicic acid or silicate such as talc, kaolinite, calcined clay, virophilite, serinite, and wollastonite; carbonates such as precipitated calcium carbonate, heavy calcium carbonate, and magnesium carbonate; Hydroxides such as aluminum hydroxide and magnesium hydroxide; oxides such as zinc oxide and magnesium oxide; and powder filler such as hydrous calcium silicate, hydrous aluminum silicate, hydrous silicic acid and anhydrous silicic acid Flake filler such as mica, basic magnesium sulfate whisker, calcium titanate whisker, aluminum borate whisker, sepiolite, PMF (Processed Mineral Filler), zonotlite, potassium titanate, and elastite Fibrous fillers; and it can be used Garasubarun, the balloon-like filler or the like, such as fly ash balloon.
In general, an inorganic filler exhibiting a nucleating effect such as talc may be used as a nucleating agent for polypropylene. In the present invention, the content of the inorganic filler is 0.50% by mass or less. Is preferably 0.30% by mass or less, and more preferably 0.10% by mass or less. When the content of the inorganic filler exceeds the upper limit, the antistatic property may be insufficient.

(Other additives)
In the polypropylene resin composition of the present invention, as an optional component, for example, an antioxidant, a hydrochloric acid absorbent, a heat stabilizer, a light stabilizer, an ultraviolet absorber, an internal lubricant, an external lubricant, a flame retardant, a dispersant, copper Other additives such as harm inhibitors, neutralizers, plasticizers, foaming agents, foam inhibitors, crosslinking agents, peroxides and pigments (organic or inorganic) may be included.

(Production method)
Examples of the method for producing a polypropylene resin composition include a method in which the propylene resin, the antistatic agent, and the organic nucleating agent are mixed and melt-kneaded. If necessary, other resins other than the propylene resin, additives and the like may be further mixed. There is no restriction | limiting in the order of addition of each component. However, when producing a propylene-based resin composition, the propylene-based resin, the antistatic agent, and the organic structure are adjusted so that the MFR (JIS K7210, temperature 230 ° C., load 21.18 N) is 50 to 120 g / 10 minutes. Combine with nucleating agent.
There is no restriction | limiting in particular as the method of melt-kneading, For example, the method of using mixers, such as a Henschel mixer and a tumbler mixer, is mentioned.
After mixing, the obtained mixture may be melt-kneaded and further pelletized. As the melt-kneading apparatus, a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader, a roll mill, or the like can be used.

(Function and effect)
The polypropylene-based resin composition uses the specific block polypropylene having a high MFR and defines the content ratio of the antistatic agent. Such a polypropylene resin composition has a high antistatic property, can prevent bleeding of the antistatic agent, has a short injection molding cycle, and can provide a molded product having sufficient mechanical properties.
The polypropylene resin composition has high fluidity and can prevent short shots without increasing the molding temperature even when injection molding a thin molded product.

In the polypropylene resin composition of the present invention, the surface resistivity measured using an electric resistance meter is preferably 1.0 × 10 ^{11 to} 3.0 × 10 ¹⁴ Ω, and 1.0 × 10 6. More preferably, it is ^{11 to} 1.0 × 10 ¹⁴ Ω.
In the polypropylene resin composition of the present invention, the flexural modulus measured at 25 ° C. is preferably 1200 to 1600 MPa and more preferably 1250 to 1600 MPa in accordance with JIS K6921-2.
In the polypropylene resin composition of the present invention, it is preferable that the surface impact strength measured at −20 ° C. is 12 to 20 J using a puncture impact tester in accordance with JIS K7211-2, and 13 to 20 J. More preferably.

(Molding)
The polypropylene resin composition can be processed into a molded product by injection molding. In particular, the polypropylene resin composition is suitable as a molding material for thin-walled molded products. Here, the term “thin” means that the thickness is 1.0 mm or less.
Since the polypropylene resin composition is excellent in moldability, even when a thin molded product is obtained by injection molding, the resin does not reach a part of the mold cavity without increasing the molding temperature. It is difficult to cause molding defects.
In addition, a molded product obtained by injection molding the polypropylene resin is less prone to molding defects called so-called sinks in which dents are formed on the surface. When sink marks are less likely to occur, the thickness of the molded product can be prevented from becoming non-uniform, so that the molded product can be prevented from cracking.
A molded product obtained by injection molding of the polypropylene resin composition can be used as, for example, an automobile interior material, daily necessities, a casing of an electric product, a food packaging container, and the like.

Examples and Comparative Examples are shown below, but the present invention is not limited to the following Examples.
In each example, the ethylene unit content in the ethylene / α-olefin copolymer, the intrinsic viscosity of the propylene-based xylene-soluble component, and the MFR of the polypropylene-based resin composition were measured as follows.
1) Content of ethylene unit in copolymer component:
The ethylene unit content of the copolymer was determined by using JNM LA-400 ( ^13C resonance frequency 100 MHz) manufactured by JEOL Ltd. for a sample dissolved in a mixed solvent of 1,2,4-trichlorobenzene / deuterated benzene. , Measured by ¹³ C-NMR method.
2) Intrinsic viscosity of propylene-based xylene solubles:
The xylene-soluble content of the propylene-based resin can be obtained by the following method.
Place 2.5 g of sample in a flask containing 250 ml of o-xylene (solvent), and stir for 30 minutes at 135 ° C. while purging with nitrogen using a hot plate and reflux apparatus to completely dissolve the resin composition. Then, it was cooled at 25 ° C. for 1 hour. The solution thus obtained was filtered using filter paper. 100 ml of the filtrate after filtration was collected, transferred to an aluminum cup or the like, evaporated and dried at 140 ° C. while purging with nitrogen, and allowed to stand at room temperature for 30 minutes to obtain a xylene-soluble component.
The intrinsic viscosity was measured in tetrahydronaphthalene at 135 ° C. using a capillary automatic viscometer (SS-780-H1, manufactured by Shibayama Scientific Instruments).
3) MFR:
The MFR of the polypropylene resin composition was measured under the conditions of a temperature of 230 ° C. and a load of 21.18 N according to JIS K7210.

(Each Example and Comparative Example)
Propylene-based resin containing propylene homopolymer and ethylene / propylene copolymer, anti-static agent (glycerin monostearate), nucleating agent containing aromatic phosphate-based organic nucleating agent (ADEKA STAB NA-18 manufactured by ADEKA) ), An inorganic filler (talc) having a nucleating effect was mixed in the formulations shown in Tables 1 and 2 to obtain a mixture. Tables 1 and 2 show the types of solid catalysts used in polymerizing propylene resins, the content of ethylene / propylene copolymer in the resin composition, the ethylene unit content in the copolymer, and the propylene resin. The intrinsic viscosity of xylene is also shown.
Next, the mixture is further blended with 0.2% by weight of B225 manufactured by BASF as an antioxidant and 0.05% by weight of calcium stearate manufactured by Tamnan Chemical Co., Ltd. Stir and mix. Thereafter, the mixture was melt-kneaded using a same-direction twin-screw extruder (KTX-30 manufactured by Kobe Steel) set to a screw temperature of 180 ° C. and a screw rotation speed of 300 rpm, and pelletized to obtain a polypropylene resin composition. Obtained.

  In addition, the solid catalyst A and the solid catalyst B used when polymerizing a propylene-type resin were obtained with the following preparation methods.

Solid catalyst A: A solid catalyst component A was prepared according to the preparation method described in Examples of JP2011-500907A. Specifically:
In a 500 mL 4-neck round bottom flask purged with nitrogen, 250 mL of TiCl ₄ was introduced at 0 ° C. While stirring, 10.0 g of fine spherical MgCl ₂ .1.8 C ₂ H ₅ OH (produced according to Example 2 of US Pat. No. 4,399,054 except that the stirring speed was changed to 3000 rpm instead of 10,000 rpm) And 9.1 mmol of diethyl-2,3- (diisopropyl) succinate. The temperature was raised to 100 ° C. and held for 120 minutes. Next, stirring was stopped, the solid product was allowed to settle, and the supernatant liquid was siphoned off. Next, the following operation was repeated twice.
To the solid product, 250 mL of fresh TiCl ₄ was added, the mixture was allowed to react at 120 ° C. for 60 minutes, and the supernatant liquid was siphoned off. The solid was washed 6 times with anhydrous hexane (6 × 100 mL) at 60 ° C.
Solid catalyst B: prepared by the method described in Example 1 of European Patent No. 6749991. The solid catalyst B is obtained by supporting Ti and diisobutyl phthalate as an electron donor compound on MgCl ₂ by the method described in the above-mentioned patent publication.

<Polymerization of propylene resin>
The propylene-based resins used in the propylene resin compositions of Examples 1-4 and Comparative Examples 2, 3, 5-7 were polymerized by the following method:
The solid catalyst A, triethylaluminum (TEAL) and dicyclopentyldimethoxysilane (DCPMS) are mixed in such an amount that the mass ratio of TEAL to the solid catalyst is 18 and the mass ratio of TEAL / DCPMS is 10, at room temperature. Contacted for 5 minutes. The resulting catalyst system was prepolymerized by holding it in liquid propylene in suspension for 5 minutes at 20 ° C.
The obtained prepolymer was introduced into the first stage polymerization reactor to obtain a propylene homopolymer, and then the obtained polymer was introduced into the second stage polymerization reactor to obtain a copolymer (propylene -Ethylene copolymer) was polymerized. At that time, the polymerization temperature, hydrogen concentration, and C2 / (C2 + C3) in the second stage polymerization reactor were set to 85 ° C., 3.0 mol%, and 0.28 mol ratio, respectively, and the polymerization pressure was adjusted. In addition, the polymerization temperature in the first stage polymerization reactor was adjusted to 70 ° C., the polymerization pressure was adjusted, the residence time distribution in the first and second stages and the hydrogen concentration in the first stage polymerization reactor were The component content was controlled to 33.0% by mass and the MFR of the resin compositions shown in Tables 1 and 2.
In the propylene resins of Examples 5 to 7 and Comparative Examples 4 and 8, the residence time distributions of the first stage and the second stage and the hydrogen concentration in the first stage polymerization reactor were determined according to the rubber component content and the resin composition. Polymerization was carried out in the same manner as in Example 1 except that the MFR of the product was controlled to the values shown in Tables 1 and 2.
The propylene-based resin of Comparative Example 9 has a C2 / (C2 + C3) ratio of 0.29 in the second-stage polymerization reactor, a residence time distribution in the first and second stages, and the first-stage polymerization reactor. The polymerization was carried out in the same manner as in Example 1 except that the hydrogen concentration was controlled so that the rubber component content and the MFR of the resin composition were as shown in Table 2.
The propylene resin used in the propylene resin composition of Comparative Example 1 was polymerized by the following method:
The solid catalyst B was brought into contact with TEAL and DCPMS in an amount such that the mass ratio of TEAL to the solid catalyst was 11, and the mass ratio of TEAL / DCPMS was 3, at −5 ° C. for 5 minutes. The resulting catalyst system was prepolymerized by holding it in liquid propylene in suspension for 5 minutes at 20 ° C.
The obtained prepolymer was introduced into the first stage polymerization reactor to obtain a propylene homopolymer, and then the obtained polymer was introduced into the second stage polymerization reactor to obtain a copolymer (propylene -Ethylene copolymer) was polymerized. At that time, the polymerization temperature, hydrogen concentration, and C2 / (C2 + C3) in the second-stage polymerization reactor were set to 85 ° C., 2.5 mol%, and 0.39 mol ratio, respectively, and the polymerization pressure was adjusted. The polymerization temperature in the first stage polymerization reactor was adjusted to 70 ° C., the polymerization pressure was adjusted, and the residence time distributions in the first and second stages and the hydrogen concentration in the first stage polymerization reactor were displayed. The content ratio of the rubber component shown in 2 and the MFR of the resin composition were controlled.

<Evaluation>
About each Example and each comparative example, surface specific resistivity, bending elastic modulus, and surface impact strength were measured, and bleeding prevention property and moldability were evaluated. Moreover, the cooling time at the time of injection molding in each Example and each comparative example was calculated | required. These results are shown in Tables 1 and 2.
In addition, about the surface intrinsic resistivity, bending elastic modulus, surface impact strength, and bleed prevention, a test piece molded as follows was used.
Using an injection molding machine (α100C, manufactured by Fanuc Co., Ltd.), a polypropylene resin composition is molded into a 130 mm square flat plate with a thickness of 2 mm under conditions of a cylinder set temperature of 220 ° C and a mold temperature of 40 ° C. The flat plate was used as a test piece. The test piece was stored for 48 hours in a room with a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5% before being subjected to the test.

[Surface resistivity]
A voltage was applied to the test piece at 1000 V for 1 minute using an electrical resistance measuring instrument (manufactured by Hewlett-Packard, 4329A, High Resistance Meter). After turning off the applied voltage, the surface resistivity was measured. The smaller the surface resistivity value, the better the antistatic property.

[Bending elastic modulus]
Using the test piece, the flexural modulus was measured in accordance with JIS K6921-2 under conditions of a temperature of 25 ° C., a span interval of 64 mm, and a bending speed of 2.0 mm / min. The greater the value of the flexural modulus, the better the rigidity.

[Surface impact strength]
Using a puncture impact tester (Hydroshot HITS-P10, manufactured by Shimadzu Corporation), the surface impact strength at −20 ° C. of the test piece was measured according to JIS K7211-2. The greater the value of surface impact strength, the better the impact resistance.

[Bleed prevention]
The test piece was placed in an oven set at 60 ° C., taken out after 6 days, and the appearance of the test piece was visually observed and evaluated according to the following criteria.
A: No trace of bleed is observed.
○: The bleed can be visually recognized partially, but there is no problem.
Δ: Bleed can be visually recognized in a wide range.
X: Bleed can be confirmed as easily visible over the entire surface.

[Formability]
The molded product when the test piece was molded was observed and evaluated according to the following criteria.
○: No short shots, sink marks or cracks are observed.
Δ: At least one of short shot, sink mark and crack is observed.

[Cooling time during injection molding]
A mold for producing a drink container (depth 150 mm, upper diameter 71 mm) was attached to an injection molding machine (α100C, manufactured by FANUC CORPORATION). Using the injection molding machine, a polypropylene resin composition was molded under conditions of a cylinder set temperature of 220 ° C. and a mold temperature of 40 ° C., and the cooling time at that time was determined.
Specifically, first, the mold cooling time after resin injection is set to 5 seconds, the polypropylene resin composition is molded, the molded product after the mold is opened is taken out, and the molded product is sufficiently It was confirmed by visual observation whether it was solidified by cooling. If it is determined that the molded product has been cooled and solidified, the mold cooling time is reduced by 0.5 seconds, and the polypropylene resin composition is injection molded again, so that the molded product is sufficiently cooled and solidified. It was confirmed visually.
The mold cooling time was shortened by 0.5 seconds until the molded article was not cooled and solidified, the shortest cooling time that could be cooled and solidified was determined, and this time was taken as the cooling time during injection molding. The cooling time at the time of injection molding becomes an index of the molding cycle, and the shorter the cooling time, the shorter the molding cycle and the higher the productivity.

[result]
The polypropylene resin compositions of the examples had high antistatic properties, bleed was suppressed, and the molding cycle was short. Furthermore, the polypropylene resin compositions of the examples were sufficiently ensured in moldability and mechanical properties.
The polypropylene resin composition of Comparative Example 1 having a low MFR and containing an inorganic filler having a nucleating effect but not containing an organic nucleating agent had low antistatic property, anti-bleeding property, rigidity and moldability.
The polypropylene resin composition of Comparative Example 2 containing an inorganic filler having a nucleating effect but not containing an organic nucleating agent had low antistatic properties.
The polypropylene resin composition of Comparative Example 3 containing no organic nucleating agent and no inorganic filler having a nucleating effect had a long molding cycle and low rigidity.
The polypropylene resin composition of Comparative Example 4 in which the content ratio of the ethylene / α-olefin copolymer was small had low bleed prevention properties and surface impact strength.
The polypropylene resin composition of Comparative Example 5 containing no antistatic agent had low antistatic properties.
Although the antistatic agent was included, the polypropylene resin composition of Comparative Example 6 having a content ratio of less than 0.3% by mass had low antistatic properties.
The polypropylene resin composition of Comparative Example 7 in which the content of the antistatic agent exceeded 0.7% by mass had low bleeding prevention properties.
The polypropylene resin composition of Comparative Example 8 in which the MFR exceeded 120 g / 10 minutes had a low surface impact strength.
The polypropylene resin composition of Comparative Example 9 in which the content ratio of the ethylene / α-olefin copolymer was large had low rigidity.

Claims (7)

A polypropylene resin composition containing a propylene resin, an antistatic agent, and an organic nucleating agent,
The propylene resin comprises a propylene homopolymer and an ethylene / α-olefin copolymer having an ethylene unit and one or more types of α-olefin units of 3 to 12 carbon atoms, and the propylene homopolymer and The ethylene / α-olefin copolymer is a block polypropylene mixed by polymerization and manufactured using a catalyst containing the following components (A) to (C):
The content ratio of the ethylene / α-olefin copolymer in the polypropylene resin composition is 18 to 30% by mass, the content ratio of the antistatic agent is 0.3 to 0.7% by mass,
A polypropylene resin composition having a melt flow rate of 50 to 120 g / 10 min measured under conditions of a temperature of 230 ° C. and a load of 21.18 N according to JIS K7210.
(A) Solid catalyst containing magnesium, titanium, halogen and electron donor compound including succinate compound
(B) Organoaluminum compound
(C) External electron donor compound containing an organosilicon compound The polypropylene resin composition according to claim 1 , wherein the content of the nucleating agent including the organic nucleating agent in the polypropylene resin composition is 0.01 to 0.50 mass%. The polypropylene resin composition according to claim 1 or 2 , wherein an ethylene unit ratio in the ethylene / α-olefin copolymer is 25 to 40% by mass. The polypropylene resin according to any one of claims 1 to 3 , wherein an intrinsic viscosity in tetrahydronaphthalene at 135 ° C of a xylene-soluble component of the propylene resin is 1.4 to 2.4 dl / g. Composition. The polypropylene resin composition according to any one of claims 1 to 4 , wherein the ethylene / α-olefin copolymer is an ethylene / propylene copolymer. A method for producing a polypropylene resin composition in which a propylene resin, an antistatic agent, and an organic nucleating agent are mixed and melt-kneaded,
As the propylene-based resin, a homopolymer of propylene and an ethylene / α-olefin copolymer having an ethylene unit and one or more kinds of α 3 -olefin units of carbon 3 to 12 are mixed by polymerization, and the following (A) Using block polypropylene produced using a catalyst containing the component of (C) ,
While the content ratio of the ethylene / α-olefin copolymer in the polypropylene resin composition is 18 to 30% by mass and the content ratio of the antistatic agent is 0.3 to 0.7% by mass,
Propylene resin, antistatic agent, and organic so that the melt flow rate of the obtained polypropylene resin composition measured in accordance with JIS K7210 at a temperature of 230 ° C. and a load of 21.18 N is 50 to 120 g / 10 min. A method for producing a polypropylene resin composition, which comprises a nucleating agent.
(A) Solid catalyst containing magnesium, titanium, halogen and electron donor compound including succinate compound
(B) Organoaluminum compound
(C) External electron donor compound containing an organosilicon compound The polypropylene resin composition according to claim 2, which is a composition for a food packaging container for forming a food packaging container.