JP2019172730A - Polypropylene resin composition - Google Patents

Abstract

To provide a polypropylene resin composition of which productivity is improved by shortening molding time while maintaining physical properties by increasing crystallization rate without deteriorating flexibility, and which generate no stain in a mold or a roll even with long run molding.SOLUTION: There is provided a polypropylene resin composition containing 50 to 99.9 pts.mass of a propylene polymer (A) with (mmmm)of 84.9 to 95.0 mol% and content of olefin with 2, 4 to 20 of 0 to 2 mass%, and 0.1 to 50 pts.mass of a propylene polymer (B) with (mmmm)of 95.0 to 99.9 mol% and content f olefin with 2, 4 to 20 carbon atoms of 0 to 20 mass% (total of (A) and (B) is 100 pts.mass) and having (mmmm)-(mmmm)of 1 mol% or more.SELECTED DRAWING: None

Description

  The present invention relates to a polypropylene resin composition. More specifically, the present invention relates to a polypropylene resin composition that can shorten the molding time while maintaining the physical properties and does not generate stains on the mold or roll even when long run molding is performed.

  Polypropylene-based resin compositions are used in various fields such as household goods, kitchenware, packaging films, sheets, household appliances, electrical parts, and automobile parts because of their excellent flexibility and heat resistance. Depending on the application, there is appropriate rigidity.

  In general, in order to improve the productivity of a molded article, for example, in the case of injection molding, a molding cycle is shortened, specifically, a mold cooling time is shortened. In extrusion molding for forming a film or sheet, it is possible to increase the roll take-up speed. However, since the polypropylene-based resin composition is a crystalline resin, it is molded in a molten state and crystallized by cooling with a mold or a roll. It cannot be improved.

  Therefore, in order to increase the crystallization rate, a crystal nucleating agent is often added (for example, Patent Documents 1 and 2). In addition, a small amount of 3-methylbutene-1 polymer is also polymerized (Patent Document 3).

International Publication No. 2010/024191 JP 2017-190440 A Japanese Patent Laid-Open No. 1-229056

  By adding the crystal nucleating agent in this way, the crystallization speed of the polypropylene resin composition is increased, but at the same time, the rigidity is increased and the desired physical properties are not achieved. In addition, when a low molecular weight crystal nucleating agent is added, the nucleating agent component adheres to a mold or a roll when forming a long run, which causes poor appearance.

  The object of the present invention is to increase the crystallization speed without impairing flexibility, thereby improving the productivity by shortening the molding time while maintaining the physical properties. An object of the present invention is to provide a polypropylene resin composition that does not generate dirt.

  As a result of various investigations, the present inventors have blended a propylene homopolymer having a specific structure and a propylene / α-olefin copolymer having a specific structure at a specific ratio, thereby forming a molded product. It was found that the crystallization temperature was higher than the additivity and the crystallization speed was increased (half-crystallization time was shortened) while maintaining the flexibility of the present invention, and the present invention was completed.

That is, the present invention includes the following aspects [1] to [6].
[1] Isotactic pentad (mmmm) 50 to 50 of propylene-based polymer (A) having an _A of 84.9 to 95.0 mol%, an olefin content of 2 to 4 to 20 carbon atoms, and 0 to 2 mass%. 99.9 parts by mass and isotactic pentad (mmmm) of propylene-based polymer (B) having an olefin content of 0 to 20% by mass with _B of 95.0 to 99.9 mol%, carbon number 2 and 4 to 20 0.1 to 50 parts by mass (provided that the total of the propylene polymer (A) and the propylene polymer (B) is 100 parts by mass),
(Mmmm) _B- (mmmm) _A is 1 mol% or more,
Polypropylene resin composition.
[2] The polypropylene resin composition according to [1], wherein the half crystallization time at 130 ° C. is less than 1,000 seconds.
[3] An extruded sheet using the polypropylene resin composition according to [1] or [2].
[4] A uniaxially or biaxially stretched film of the extruded sheet of [3].
[5] An injection-molded article of the polypropylene resin composition according to [1] or [2].
[6] A hollow molded body of the polypropylene resin composition according to [1] or [2].

  The polypropylene resin composition according to the present invention can increase the crystallization speed without impairing flexibility, and the productivity is improved by shortening the molding time while maintaining the physical properties. Further, even if long run molding is performed, the mold and the roll are not contaminated, and a molded article having a good appearance can be provided.

The additivity evaluation of the crystallization temperature (FIG. 1 (A)) and the additivity evaluation of ΔH (FIG. 1 (B)) by the blending ratio of the propylene polymer (B) in the examples are shown.

Hereinafter, each structure of the polypropylene resin composition, the extruded sheet, the stretched film, and the injection-molded body according to one embodiment of the present invention will be specifically described.
The polypropylene resin composition according to this embodiment contains 50 to 99.9 parts by mass of the following propylene polymer (A) and 0.1 to 50 parts by mass of the propylene polymer (B). The total of the propylene polymer (A) and the propylene polymer (B) is 100 parts by mass.

[Propylene polymer (A)]
The propylene-based polymer (A) that can be used in this embodiment has an isotactic pentad (mmmm) _A of 84.9 mol% or more and 95.0 mol% or less, preferably 86.0 mol% or more, 93 It is a polymer showing 0.0 mol% or less. In addition, the propylene polymer (A) has an olefin content of 2 to 4 to 20 carbon atoms of 0 to 2% by mass, and is preferably a propylene homopolymer.

Here, isotactic pentad indicates the abundance of isotactic chains in pentad units in a polypropylene molecular chain measured using ¹³ C-NMR. It is the fraction (mmmm) of propylene monomer at the center of the linked chain. Specifically, it is a value determined as the mmmm peak fraction in the total absorption peak in the methyl carbon region in the ¹³ C-NMR spectrum.

  The propylene polymer (A) has a melt flow rate (MFR) measured in accordance with ASTM D-1238 at 230 ° C. under a load of 2.16 kg, usually 0.5 to 100 g / 10 min, preferably It is in the range of 1-30 g / 10 minutes. When the MFR is within this range, a composition having excellent mechanical strength and moldability can be obtained.

  Such a propylene polymer (A) can be produced by polymerizing propylene in the presence of an α-olefin stereoregular polymerization catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst. An example of such a polymerization catalyst is a catalyst system comprising (a) a solid catalyst component containing magnesium, titanium, halogen and an electron donor as essential components, (b) an organoaluminum compound, and (c) an electron donor. Is described in detail below.

  The magnesium component may be a compound having reducibility or a compound having no reducibility. As an example of the compound having reducibility, a magnesium compound having a magnesium-carbon bond or a magnesium-hydrogen bond can be given. Specific examples thereof include dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium, diamyl magnesium, dihexyl magnesium, didecyl magnesium, ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, amyl magnesium chloride, Examples thereof include butyl ethoxy magnesium, ethyl butyl magnesium, and butyl magnesium hydride.

  Specific examples of non-reducing magnesium compounds include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, magnesium fluoride; methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy Alkoxymagnesium halides such as magnesium chloride and octoxymagnesium chloride; aryloxymagnesium halides such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium, 2-ethyl Alkoxymagnesium such as hexoxymagnesium; phenoxymagnesium, dimethylphenoxymer Aryloxy (aryloxy) magnesium as Neshiumu; magnesium laurate, carboxylic acid magnesium salts such as magnesium stearate and the like.

  These magnesium compounds can be used alone or may form a complex compound with an organometallic compound described later. In addition, they may be liquid or solid, may be derived by reacting metal magnesium with a corresponding compound, and are derived from metal magnesium by the above-mentioned method during catalyst preparation. You can also Among these magnesium compounds, magnesium compounds having no reducing property are preferable, halogen-containing magnesium compounds are more preferable, and magnesium chloride, alkoxy magnesium chloride, and aryloxy magnesium chloride are particularly preferable.

Examples of the titanium component include tetravalent titanium compounds represented by the following formula.
Ti (OR) _n X _4-n
(In the formula, R is a hydrocarbon group, X is a halogen atom, and n is 0 ≦ n ≦ 4)

Specific examples of such titanium compounds include titanium tetrahalides such as TiCl ₄ , TiBr ₄ , and TiI ₄ ; Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , and Ti (On). _{-C 4 H 9) Cl 3,} Ti (OC 2 H 5) Br 3, Ti ( trihalogenated alkoxy titanium such as _{O-iso-C 4 H 9} ) Br 3; Ti (OCH 3) 2 Cl 2, Ti Dihalogenated dialkoxytitanium such as (OC ₂ H ₅ ) ₂ Cl ₂ , Ti (On-C ₄ H ₉ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Br ₂ ; Ti (OCH ₃ ) ₃ Cl Monohalogenated trialkoxytitanium such as Ti (OC ₂ H ₅ ) ₃ Cl, Ti (On-C ₄ H ₉ ) ₃ Cl, Ti (OC ₂ H ₅ ) ₃ Br; Ti (OCH ₃ ) ₄ , Ti _{OC 2 H 5) 4, Ti} (O-n-C 4 H 9) 4, Ti (O-iso-C 4 H 9) 4, Ti (O-2- _{ethylhexyl) 4} tetraalkoxy illustrative and titanium, such as can do.

Electron donors that can be used in preparing the solid catalyst component (a) include alcohols, phenols, ketones, aldehydes, carboxylic acids, organic acid halides, organic acid or inorganic acid esters, ethers , Acid amides, acid anhydrides, ammonia, amines, nitriles, isocyanates, nitrogen-containing cyclic compounds, oxygen-containing cyclic compounds, and the like. Among these, carboxylic acids, carboxylic acid anhydrides, carboxylic acid esters, carboxylic acid halides, alcohols, and ethers are preferably used.
Next, specific examples of the electron donor will be given.

  (1) Alcohols: methanol, ethanol, propanol, butanol, pentanol, hexanol, 2-ethylhexanol, octanol, dodecanol, octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropyl alcohol, isopropylbenzyl C1-C18 alcohols, such as alcohol; C1-C18 halogen-containing alcohols, such as trichloromethanol, trichloroethanol, and trichlorohexanol.

  (2) Phenols: Phenols having 6 to 20 carbon atoms which may have a lower alkyl group such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, cumylphenol, naphthol as a substituent.

  (3) Ketones: C3-C15 ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, benzoquinone and the like.

  (4) Aldehydes: C2-C15 aldehydes such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde, naphthaldehyde and the like.

  (5) Carboxylic acids: aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, pivalic acid, acrylic acid, methacrylic acid, crotonic acid; malonic acid, succinic acid, glutar Aliphatic dicarboxylic acids such as acid, adipic acid, sebacic acid, maleic acid and fumaric acid; aliphatic oxycarboxylic acids such as tartaric acid; cyclohexane monocarboxylic acid, cyclohexene monocarboxylic acid, cis-1,2-cyclohexanedicarboxylic acid, cis Alicyclic carboxylic acids such as -4-methylcyclohexene-1,2-dicarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, anisic acid, p-tert-butylbenzoic acid, naphthoic acid, cinnamic acid Acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalic acid, trimellitic acid, hemimellitic acid, trimesic acid, Romerito acid, aromatic polycarboxylic acids such as mellitic acid. As the carboxylic acid anhydrides, acid anhydrides of the carboxylic acids can be used.

  (6) Organic acid halides: Acid halides having 2 to 15 carbon atoms such as acetyl chloride, benzoyl chloride, toluic acid chloride, and anisic acid chloride.

  (7) Organic acid or inorganic acid esters: methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate, dichloroacetic acid Ethyl, methyl methacrylate, ethyl crotonic acid, ethyl cyclohexanecarboxylate, dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di-n-amyl phthalate, diisoamyl Phthalate, ethyl-n-butyl phthalate, ethyl isobutyl phthalate, ethyl-n-propyl phthalate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, benzoic acid Rohexyl, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, γ-butyrolactone, δ-valerolactone, coumarin , Esters of organic or inorganic acids having 2 to 30 carbon atoms such as phthalide and ethyl carbonate.

  (8) Ethers: methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diamyl ether, diisoamyl ether, dineopentyl ether, dihexyl ether, dioctyl Ether, methyl butyl ether, methyl isoamyl ether, ethyl isobutyl ether, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-bis (cyclohexylmethyl) -1,3-dimethoxypropane, 2-isopropyl-3,7-dimethyloctyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, -Isopropyl-2-cyclohexylmethyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisopropyl-1 , 3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2, , 2-dicyclopentyl-1,3-dimethoxypropane, 2-heptyl-2-pentyl-1,3-dimethoxypropane.

Next, several specific methods for producing the solid catalyst component (a) will be described.
(1) A method in which a solution comprising a magnesium compound, an electron donor, and a hydrocarbon solvent is contacted with an organometallic compound to precipitate a solid, or contacted with a titanium compound while being precipitated.
(2) A method in which a complex composed of a magnesium compound and an electron donor is contacted with an organometallic compound and then contacted with a titanium compound.
(3) A method in which a titanium compound and preferably an electron donor are contacted with a contact product between an inorganic carrier and an organic magnesium compound. At this time, the contact product may be previously contacted with a halogen-containing compound and / or an organometallic compound.
(4) After obtaining an inorganic or organic carrier carrying a magnesium compound from a mixture of a magnesium compound, an electron donor, and optionally a solution containing a hydrocarbon solvent, and an inorganic or organic carrier, the titanium compound is then contacted. How to make.

(5) A method of obtaining a solid catalyst component carrying magnesium or titanium by contacting a magnesium compound, a titanium compound, an electron donor, and optionally a solution containing a hydrocarbon solvent, with an inorganic or organic carrier.
(6) A method in which a liquid organic magnesium compound is contacted with a halogen-containing titanium compound. At this time, the electron donor is used once.
(7) A method in which a liquid organic organomagnesium compound is contacted with a halogen-containing compound and then contacted with a titanium compound. At this time, the electron donor is used once.
(8) A method in which an alkoxy group-containing magnesium compound is contacted with a halogen-containing titanium compound. At this time, the electron donor is used once.

(9) A method in which a complex comprising an alkoxy group-containing magnesium compound and an electron donor is contacted with a titanium compound.
(10) A method in which a complex comprising an alkoxy group-containing magnesium compound and an electron donor is contacted with an organometallic compound and then contacted with a titanium compound.
(11) A method in which a magnesium compound, an electron donor, and a titanium compound are contacted and reacted in an arbitrary order. In this reaction, each component may be pretreated with an electron donor and / or a reaction aid such as an organometallic compound or a halogen-containing silicon compound. In this method, it is preferable to use the electron donor at least once.
(12) A method of depositing a solid magnesium-titanium complex by reacting a liquid magnesium compound having no reducing ability with a liquid titanium compound, preferably in the presence of an electron donor.

  In the preparation of the solid catalyst component, the electron donor is used in an amount of 0.01 to 5 mol, preferably 0.1 to 1 mol, and the titanium compound is 0.01 to 1000 mol, preferably 1 mol, per mol of the magnesium compound. Used in an amount of 0.1 to 200 mol. The halogen / titanium (atomic ratio) is about 2 to 200, preferably about 4 to 100, and the electron donor / titanium (molar ratio) is about 0.01 to 100, preferably about 0.2 to 10. It is desirable that the magnesium / titanium (atomic ratio) is about 1-100, preferably about 2-50.

Such a solid catalyst component can be used alone, but can also be used by being supported on a porous material such as an inorganic oxide or an organic polymer. The porous inorganic oxide _{used, SiO 2, Al 2 O 3} , MgO, TiO 2, ZrO 2, SiO 2 -Al 2 O 3 composite oxide, _MgO-Al 2 _{O 3} composite oxide, MgO-SiO Examples include _2- Al ₂ O ₃ composite oxide.

Examples of the porous organic polymer include polystyrene, styrene-divinylbenzene copolymer, styrene-N, N′-alkylene dimethacrylamide copolymer, styrene-ethylene glycol dimethacrylate methyl copolymer, polyethyl acrylate, acrylic Methyl methacrylate-divinylbenzene copolymer, ethyl acrylate-divinylbenzene copolymer, polymethyl methacrylate, methyl methacrylate-divinylbenzene copolymer, polyethylene glycol dimethyl methacrylate, polyacrylonitrile, acrylonitrile-divinylbenzene copolymer Typical examples include coalescence, polyvinyl chloride, polyvinyl pyrrolidine, polyvinyl pyridine, ethyl vinyl benzene-divinyl benzene copolymer, polyethylene, ethylene-methyl acrylate copolymer, polypropylene, etc. Polystyrene, polyacrylate, polyacrylonitrile, polyvinyl chloride, mention may be made of the polymers of the polyolefin. Among these porous _{materials, SiO 2, Al 2 O 3} , a styrene - divinylbenzene copolymer are preferably used.

The organoaluminum compound used together with the solid catalyst component has at least one Al-carbon bond in the molecule. Next, a typical example is shown by a general formula.
R ¹ _m AlY _3-m
R ² R ³ Al—O—AlR ⁴ R ⁵
(Here, R ^{1 to} R ⁵ are hydrocarbon groups having 1 to 8 carbon atoms, and they may be the same or different from each other. Y represents a halogen, hydrogen or an alkoxy group.) m is 2 ≦ m ≦ 3.)

  Specific examples of the organoaluminum compound include trialkylaluminum such as triethylaluminum, triisobutylaluminum and trihexylaluminum, dialkylaluminum hydride such as diethylaluminum hydride and diisobutylaluminum hydride, and a mixture of triethylaluminum and diethylaluminum chloride. Examples thereof include a mixture of a trialkylaluminum and a dialkylaluminum halide, and an alkylalumoxane such as tetraethyldialumoxane and tetrabutyldialumoxane.

  Of these organoaluminum compounds, trialkylaluminum, a mixture of trialkylaluminum and dialkylaluminum halide, and alkylalumoxane are preferred, especially triethylaluminum, triisobutylaluminum, a mixture of triethylaluminum and diethylaluminum chloride, or tetraethyldichloride. Alumoxane is preferred.

Specific examples of the electron donor used together with the solid catalyst component and the organoaluminum compound include the following compounds.
(1) Compounds containing nitrogen atoms: 2,2,6,6-tetramethylpiperidine, 2,6-dimethylpiperidine, 2,6-diethylpiperidine, 2,6-diisopropylpiperidine, 2,6-diisobutyl-4- Methylpiperidine, 1,2,2,6,6-pentamethylpiperidine, 2,2,5,5-tetramethylpyrrolidine, 2,5-dimethylpyrrolidine, 2,5-diethylpyrrolidine, 2,5-diisopropylpyrrolidine, 1,2,2,5,5-pentamethylpyrrolidine, 2,2,5-trimethylpyrrolidine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2,6-diisopropylpyridine, 2,6-diisobutyl Pyridine, 1,2,4-trimethylpiperidine, 2,5-dimethylpiperidine, methyl nicotinate, nicotinic acid Chill, nicotinamide, benzoamide, 2-methylpyrrole, 2,5-dimethylpyrrole, imidazole, toluic acid amide, benzonitrile, acetonitrile, aniline, paratoluidine, orthotoluidine, metatoluidine, triethylamine, diethylamine, dibutylamine , Tetramethylenediamine, tributylamine.

(2) Compounds containing sulfur atoms: thiophenol, thiophene, ethyl 2-thiophenecarboxylate, ethyl 3-thiophenecarboxylate, 2-methylthiophene, methyl mercaptan, ethyl mercaptan, isopropyl mercaptan, butyl mercaptan, diethylthioether, diphenylthioether , Methyl benzenesulfonate, methyl sulfite, ethyl sulfite.

(3) Compounds containing oxygen atoms: tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 2-ethyltetrahydrofuran, 2,2,5,5-tetraethyltetrahydrofuran, 2,2,5,5-tetramethyltetrahydrofuran, 2 , 2,6,6-tetraethyltetrahydropyran, 2,2,6,6-tetramethyltetrahydropyran, dioxane, dimethyl ether, diethyl ether, dibutyl ether diisoamyl ether, diphenyl ether, anisole, acetophenone, acetone, methyl ethyl ketone, acetylacetone, o -Tolyl-t-butyl ketone, methyl-2,6-di-t-butylphenyl ketone, ethyl 2-furalate, isoamyl 2-furalate, methyl 2-furalate, 2-fural acid Pill.

(4) Organosilicon compound: A compound represented by the general formula RnSi (OR ') 4-n is preferred, and specific examples are shown below. (Here, R and R ′ are hydrocarbon groups, and n is a numerical value of 0 <n <4.)
Cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis o-Tolyldimethoxysilane, bism-tolyldimethoxysilane, bisp-tolyldimethoxysilane, bisp-tolyldiethoxysilane, bisethylphenyldimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyl Trimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltri Toxisilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, n-butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, Chlortriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetra Ethoxydisiloxane.

  The organoaluminum compound has a molar ratio of 5 to 1000 per mole of Ti atoms in the solid catalyst component, and the electron donor should have a molar ratio of 0.002 to 0.5 per mole of the organoaluminum compound. Is preferred.

  The polymerization catalyst can also be used in the form of a prepolymerized catalyst obtained by prepolymerizing an olefin having 2 or more carbon atoms in advance. The following compounds can be illustrated as an olefin which can be used for prepolymerization.

(1) Linear chain such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene Α-olefin.
(2) Cycloolefins such as cyclopentene, cycloheptene, norbornene, 5-ethyl-2-norbornene, and tetracyclododecene.

(3) 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1 Branched α-olefins such as hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene.
(4) Vinyl compounds such as allylnaphthalene, allylnorbornane, styrene, dimethylstyrenes, vinylnaphthalenes, allyltoluenes, allylbenzene, vinylcyclohexane, vinylcyclopentane, vinylcycloheptane, and allyltrialkylsilanes.

  The homopolymerization of propylene can be produced by polymerizing propylene using the catalyst. The polymerization temperature is usually −50 to 100 ° C., preferably 0 to 90 ° C. in the case of suspension polymerization, and usually 0 to 250 ° C., preferably 20 to 150 ° C. in the case of solution polymerization. In the case of the polymerization method, it is usually 0 to 120 ° C, preferably 20 to 100 ° C. The polymerization pressure is usually normal pressure to 150 (kg / cm 2), preferably normal pressure to 100 (kg / cm 2), and the polymerization reaction can be performed in any of batch, semi-continuous and continuous methods. It can be carried out. Furthermore, the polymerization can be performed in two or more stages having different reaction conditions.

[Propylene polymer (B)]
The propylene polymer (B) as the second component constituting the polypropylene resin composition according to the present embodiment is a polymer having an olefin content of 0 to 20% by mass having 2 to 4 to 20 carbon atoms, A polymer obtained by random copolymerization of propylene and other α-olefins is preferable. Such a polymer can be produced using the same stereoregular polymerization catalyst as described above and using the same polymerization conditions and polymerization method.

  The α-olefin is an olefin having 2 to 4 to 20 carbon atoms, and examples thereof include ethylene, 1-butene, 1-hexene, 1-octene and 4-methyl-1-pentene. Among them, ethylene is preferable. . The α-olefin content in the copolymer is 0 to 20% by mass, preferably 1 to 10% by mass.

Moreover, isotactic pentad (mmmm) _B of this propylene polymer (B) is a polymer having high crystallinity of 95.0 mol% or more and 99.9 mol% or less, and (mmmm) _B- (mmmm) _A is 1 mol% or more. Here, the isotactic pentad can be measured by the same method as described in the section of the propylene polymer (A).

  Furthermore, this propylene-based polymer (B) has a melt flow rate (MFR) value of 0.5 to 100 g / 10 min measured at 230 ° C. under a load of 2.16 kg in accordance with ASTM D-1238. It is preferable that it is in the range of 1 to 30 g / 10 minutes.

The propylene-based polymer (A) and the propylene-based polymer (B) can be used after separately polymerizing and mixing at a predetermined ratio and, if necessary, adding melt kneading.
A series of polymerization apparatuses are prepared, for example, the propylene polymer (A) is produced in the first stage, and then the propylene polymer (B) is produced in the second stage, and directly mixed by a so-called multistage polymerization method. May be used.

  The polypropylene resin composition may further include an antioxidant, a heat stabilizer, a weather stabilizer, an antistatic agent, a slip agent, an antiblocking agent, an antifogging agent, as necessary, as long as the object of the present invention is not impaired. Agents, lubricants, nucleating agents, dyes, pigments, natural oils, synthetic oils, waxes, fillers and the like can be blended.

  As the antioxidant, a hindered phenol-based, sulfur-based, lactone-based, organic phosphite-based, organic phosphonite-based antioxidant, or an antioxidant obtained by combining several of these can be used.

  As the slip agent, amides of saturated or unsaturated fatty acids such as lauric acid, palmitic acid, oleic acid, stearic acid, erucic acid and hebenic acid, or bisamides of these saturated or unsaturated fatty acids can be used. Of these, erucic acid amide and ethylenebisstearic acid amide are preferable. It is preferable to mix | blend a slip agent in 0.01-5 mass parts with respect to 100 mass parts of polypropylene resin compositions.

  Antiblocking agents include finely powdered silica, finely powdered aluminum oxide, finely powdered clay, powdery or liquid silicon resin, polytetrafluoroethylene resin, finely powdered crosslinked resin such as crosslinked acrylic resin or methacrylic resin powder Can be mentioned. Of these, finely divided silica and finely powdered crosslinked resin are preferred.

  Various molded articles can be obtained by molding the polypropylene resin composition of the present invention according to a known molding technique. Examples of molding techniques include T-die film molding, stretched film molding, inflation film molding, sheet molding, calendar molding, pressure molding, vacuum molding, pipe molding, profile extrusion molding, hollow molding, laminate molding, injection molding, and injection stretch blow. Examples thereof include molding, compression molding, injection compression molding, and the like.

[Extruded sheet]
The extruded sheet according to the present invention can be obtained by extruding the polypropylene resin composition according to the present invention. Furthermore, this extruded sheet can be uniaxially or biaxially stretched to form a stretched film.

  In the manufacturing method, the following steps are generally taken. First, after a polypropylene resin composition is melted with an extruder, it is extruded into a sheet form from a T-die and cooled and solidified with a cooling roll. Next, the obtained sheet is passed through a number of heating rolls and stretched in the longitudinal direction to obtain a uniaxially stretched film. Subsequently, a biaxially stretched film is obtained by stretching in a transverse direction through a heating furnace composed of a preheating section, a stretching section, and a heat treatment section. Then, it winds up, after performing a corona discharge process etc. as needed. Although the melting temperature of polypropylene varies depending on the molecular weight, the resin temperature in the extruder is usually adjusted to a range of 200 ° C to 290 ° C. The longitudinal stretching is usually adjusted at 130 to 160 ° C, and the lateral stretching is usually performed at 145 to 165 ° C. The stretching ratio in the longitudinal stretching and the lateral stretching may be appropriately set in accordance with the properties of the polypropylene resin composition to be used, but can be set to 4 to 10 times, respectively. The biaxial stretching area ratio (longitudinal stretching ratio × lateral stretching ratio) may be 16 times or more.

  The film thus stretched exhibits excellent mechanical strength, rigidity characteristics and optical characteristics, and has a good appearance. Therefore, the stretched film can be suitably used as industrial-purpose materials such as protective films and optical films, or general-purpose packaging materials such as food packaging, filling packaging, and fiber packaging.

[Injection molded body]
The injection molded body according to the present invention can be obtained by injection molding the polypropylene resin composition according to the present invention.
In the manufacturing method, the following steps are generally taken. First, a polypropylene resin composition is melt-extruded to produce pellets, and the pellets are charged from a hopper of an injection molding machine and injection molded into a desired mold. The cylinder temperature and mold temperature of the injection molding machine can be optimized as appropriate according to the fluidity of the resin to be injected, the gate structure in the mold, and the like.
The injection-molded body can be a hollow molded body such as a preform or a bottle that forms various containers. Also, various containers such as bottles can be formed by blow-drawing from the preform.

Next, the present invention will be described more specifically through examples and comparative examples, but the present invention is not limited to these examples.
The production method of the propylene homopolymer and the propylene / ethylene random copolymer used in Examples and Comparative Examples will be described.

(Reference Example 1)
<Production of propylene homopolymer>
[Preparation of solid titanium catalyst component]
Anhydrous magnesium chloride (7.14 kg, 75 mol), decane (37.5 liters), and 2-ethylhexyl alcohol (35.1 liters, 225 mol) were heated at 130 ° C. for 2 hours to obtain a homogeneous solution. Thereafter, 1.67 kg (11.3 mol) of phthalic anhydride was added to the solution, and the mixture was further stirred and mixed at 130 ° C. for 1 hour to dissolve the phthalic anhydride in the homogeneous solution. After cooling the homogeneous solution thus obtained to room temperature, the whole amount was dropped into 200 liters (1800 mol) of titanium tetrachloride maintained at −20 ° C. over 1 hour. After dripping, the temperature of the obtained solution was raised to 110 ° C. over 4 hours, and when it reached 110 ° C., 5.03 liters (18.8 mol) of diisobutyl phthalate was added. Further, stirring was continued at 110 ° C. for 2 hours, and then the solid part was recovered by hot filtration. This solid part was resuspended in 275 liters of TiCl ₄ and again heated at 110 ° C. for 2 hours. After completion of the reaction, the solid part was again collected by hot filtration and washed with decane and hexane at 110 ° C. This washing operation was performed until no titanium compound was detected in the washing solution.

  The synthesized solid titanium catalyst component was then made into a hexane slurry. A part of this catalyst was collected and dried, and the composition of the dried product was analyzed. As a result, it was 2.5% by mass of titanium, 58% by mass of chlorine, 18% by mass of magnesium, and 13.8% by mass of diisobutyl phthalate.

[Preliminary polymerization]
In a 500 liter reactor equipped with a stirrer, 3.5 kg of the solid titanium catalyst component obtained above and 300 liters of n-heptane were placed in a nitrogen gas atmosphere, and cooled to -5 ° C while stirring. Next, 6 liters of an n-heptane solution of triethylaluminum (2.0 mol / liter) and an n-heptane solution of cyclohexylmethyldimethoxysilane (0.01 mol / liter) were added to 60 (mmol / liter) and 10 (mmol / liter), respectively. Liter) and stirring was continued for 5 minutes.

  Next, after reducing the pressure in the system, propylene was continuously supplied to polymerize propylene for 4 hours. After completion of the polymerization, propylene was purged with nitrogen gas, and the solid phase part was washed with 10 liters of n-hexane three times at room temperature. Further, the solid phase part was dried under reduced pressure at room temperature for 1 hour to prepare a catalyst component. As a result of measuring the amount of magnesium contained in the catalyst component, the amount of prepolymerization was 1.8 g per gram of the solid titanium catalyst component.

[Main polymerization]
In a 500 liter stainless steel autoclave equipped with a stirrer, in a nitrogen gas atmosphere, 6 liters of triisobutylaluminum n-heptane solution (0.1 mol / liter) and n-heptane solution of cyclohexylmethyldimethoxysilane (0.01 mol) / Liter) A mixture of 0.6 liter mixed and held for 5 minutes was added. Next, 100 liters of hydrogen gas as a molecular weight control agent and 300 liters of liquid propylene were injected, and then the reaction system was heated to 70 ° C. After 4.2 g of the catalyst component obtained above was charged into the reaction system, propylene was polymerized for 1 hour. After the polymerization, unreacted propylene was purged to obtain 50.5 kg of white polypropylene powder. The amount of propylene homopolymer produced per gram of the solid titanium catalyst component was 33.5 kg. This propylene homopolymer had an isotactic pentad of 91.8 mol% and an MFR of 3.0 g / 10 min.

(Reference Example 2)
<Production of propylene / ethylene random copolymer>
Using dicyclopentyldimethoxysilane in place of cyclohexylmethyldimethoxysilane described in Reference Example 1,
A copolymer was produced in the same manner as in Reference Example 1, except that 300 liters of liquid propylene and 0.5 kg of ethylene were injected into the autoclave instead of 300 liters of liquid propylene. The isotactic pentad of the propylene chain portion of the obtained propylene / ethylene random copolymer was 98.2 mol%, MFR was 2.4 g / 10 min, and ethylene content was 2.7 mass%. .

(Reference Example 3)
<Production of propylene / ethylene random copolymer>
In the main polymerization described in Reference Example 1, a copolymer was produced in the same manner as in Reference Example 1, except that 300 liter of liquid propylene and 0.5 kg of ethylene were injected into the autoclave instead of 300 liter of liquid propylene. . The resulting propylene / ethylene random copolymer had a propylene chain isotactic pentad of 92.5 mol%, an MFR of 2.3 g / 10 min, and an ethylene content of 2.7 mass%. .

Example 1
The polymer of Reference Example 1 and the copolymer of Reference Example 2 were blended at a ratio of 97: 3, and tetrakis [methylene-3- (3 ′, 5′-di-t-) as an antioxidant as an additive. Butyl-4′-hydroxyphenyl) propionate] methane was mixed with 500 ppm, phosphorus antioxidant [Tris (2,4-di-t-butylphenyl) phosphite] was mixed with 1000 ppm, and calcium stearate was mixed with 1000 ppm with a Henschel mixer. Then, it was put into a twin screw extruder (30 mmφ) and kneaded at a die temperature of 200 ° C. and a screw rotation speed of 200 rpm to obtain a polypropylene resin composition pellet. This composition had an isotactic pentad of 91.8 mol%, an MFR of 3.0 g / 10 min, and an ethylene content of 0.1 mass%. The results are shown in Table 1.

(Examples 2 to 6)
Similar to Example 1, except that the propylene polymer (A) of Reference Example 1 and the propylene polymer (B) of Reference Example 2 (propylene / ethylene random copolymer) were blended in the proportions shown in Table 1. Preparation of a resin composition, molding of an extruded sheet, and injection molding were performed. The results are shown in Table 1.

(Comparative Example 1)
A resin composition was prepared, an extruded sheet was molded, and injection molded in the same manner as in Example 3 except that Reference Example 3 was used instead of Reference Example 2.
The results are shown in Table 1.

(Comparative Example 2)
2,000 ppm of nucleating agent (1,3: 2,4-bis-O- (4-methylbenzylidene) -D-sorbitol, manufactured by Shin Nippon Rika Co., Ltd., trade name “Gelol MD”) is added to the additive. In the same manner as in Example 3, preparation of the resin composition, molding of the extruded sheet, and injection molding were performed. The results are shown in Table 1.

Evaluation method and MFR
Measured according to ASTM D-1238 (measuring temperature 230 ° C., load 2.16 kg).

・ Ethylene content (C2) and isotactic pentad (mmmm)
The content (ethylene content) of the skeleton derived from ethylene in the propylene polymer (A), the propylene polymer (B), and the polypropylene resin composition was measured by ¹³ C-NMR method. Moreover, isotactic pentad (mmmm) was taken as the value calculated | required as a mmmm peak fraction in all the absorption peaks in the methyl carbon area | region in a ¹³ C-NMR spectrum.
( ^13C -NMR measurement conditions)
Measuring device: LA400 type nuclear magnetic resonance device manufactured by JEOL Measurement mode: BCM (Bilevel Complete decoupling)
Observation frequency: 100.4 MHz
Observation range: 17006.8Hz
Pulse width: C nucleus 45 ° (7.8 μsec)
Pulse repetition time: 5 seconds Sample tube: 5 mmφ
Sample tube rotation speed: 12Hz
Integration count: 20000 times Measurement temperature: 125 ° C
Solvent: 1,2,4-trichlorobenzene: 0.35 ml / heavy benzene: 0.2 ml
Sample amount: about 40mg

Melting point, heat of fusion (ΔH) and crystallization temperature The melting point and heat of fusion of the polypropylene resin composition were measured by differential scanning calorimetry (DSC).
The measurement was performed using a Diamond DSC manufactured by PerkinElmer.
The temperature at the maximum peak position in the endothermic curve was determined by the following method.
The obtained polypropylene resin composition was heated at 230 ° C. using a press molding machine and processed into a sheet. The sample cut out from the sample was packed in an aluminum pan having a flat bottom, heated to 230 ° C. in a nitrogen atmosphere and held for 10 minutes. Thereafter, the temperature was lowered from 230 ° C. to −30 ° C. at −10 ° C./min and held for 1 minute, and then heated to 230 ° C. at 10 ° C./min. The peak of the endothermic peak at the time of temperature rise was defined as the melting point, and when there were a plurality of endothermic peaks, the peak of the endothermic peak was defined as the melting point.
On the other hand, the heat of fusion (J / g) was determined from the peak area of the endothermic curve. The endothermic curve at the temperature after melting was adjusted to be horizontal, and the line connecting the point where the melting peak disappeared and 40 ° C. was used as the baseline.
In addition, the temperature is lowered from 230 ° C. to −30 ° C. at 10 ° C./min, and the top of the exothermic peak accompanying crystallization at the time of the temperature reduction is defined as the crystallization temperature. It was defined as the crystallization temperature.

・ Semi-crystallization time (T1 / 2)
The measurement was performed using DSC7 manufactured by PerkinElmer.
The obtained polypropylene resin composition was heated at 230 ° C. with a press molding machine to form a sheet. The sample cut out from there was packed in an aluminum pan with a flat bottom. The temperature was raised to 230 ° C. in a nitrogen atmosphere and held for 10 minutes, and then lowered to 130 ° C. at a rate of 320 ° C./minute, half the time (second) during which crystal saturation occurred, so-called T1 / 2 (semi-crystallization) Time).

-Composition evaluation The polypropylene resin composition was evaluated for the presence or absence of increase in crystallization temperature, ΔH maintenance, and flexibility retention by comparison with the propylene polymer (A).
(Presence of increase in crystallization temperature)
○: Increased ×: No increase or decrease (ΔH maintainability)
○: No increase in ΔH ×: Increase in ΔH (flexibility retention)
○: The propylene polymer (A) was kept flexible, and the performance of the propylene polymer (A) was kept. ×: The propylene polymer (A) was not kept flexible and increased in rigidity or It was too flexible to maintain performance.

Extrudability Using a GM engineering T-die molding machine, a 0.8 mm thick sheet was prepared under conditions of a die temperature of 250 ° C., a chill roll temperature of 30 ° C., and a take-off speed of 0.8 m / min.
(Roll dirt)
100 kg was continuously extruded under the above molding conditions, and the occurrence of dirt on the chill roll surface was observed and judged.
○: Soil on the surface of the chill roll or take-up roll hardly occurs, and there is no practical problem.
X: Dirt on the surface of the chill roll or take-up roll occurs, and there is a practical problem.
(Followability to increase molding speed)
The degree of adhesion to the chill roll when the take-up speed was OOm / min was visually evaluated.
○: Even when the take-up speed was increased and the molding speed was increased, the degree of adhesion to the chill roll was maintained and the separation of the chill roll was good. ×: The degree of adhesion to the chill roll was unstable and / or the separation of the chill roll was poor. The taking over was unstable.

-Injection moldability Using an electric injection molding machine (Robot Shot S-2000i-100B manufactured by FANUC) with a clamping force of 100 tons, cylinder temperature 270 ° C, mold temperature 20 ° C, injection primary pressure 180MPa, injection speed 120mm / Sec, injection speed 120mm / sec, pressure holding pressure, 70MPa, pressure holding time 1.0sec, injection molding of polypropylene resin composition pellets, height 62mm, diameter 86mm, side wall thickness 0.7mm The container was injection molded.
(High-speed formability)
In continuous molding under the above molding conditions, the determination was made based on whether or not the cycle time enabling molding with zero trouble such as mold release failure and container deformation during 100 shots was shortened.
○: In continuous molding under the above molding conditions, the cycle time that enables molding with zero troubles such as mold release failure and container deformation during 100 shots was shortened.
X: The cycle time was not shortened.
(Mold dirt)
Furthermore, it was determined by observing the degree of contamination on the mold surface.
○: In the continuous molding of 100 shots under the above molding conditions, the mold surface is hardly contaminated and there is no practical problem.
X: In continuous molding, contamination on the mold surface occurs, and there is a practical problem.

  FIG. 1 shows the crystallization temperature additivity evaluation (FIG. 1 (A)) and ΔH additivity evaluation (FIG. 1 (B)) according to the blending ratio of the propylene polymer (B) in the examples. As shown in FIG. 1 (B), ΔH decreases depending on the blending ratio of the propylene-based polymer (B), and it can be seen that there is an additivity. On the other hand, as shown to FIG. 1 (A), it turns out that the crystallization temperature does not have the additivity with respect to the compounding ratio of a propylene polymer (B). Thus, in the present invention, while maintaining the flexibility of the molded product without using a nucleating agent, the crystallization temperature becomes higher than the additivity and the crystallization speed becomes faster (half-crystallization time becomes shorter). It was confirmed. There is no need to use a nucleating agent, so that a roll or mold is not soiled, and a molded product having an excellent appearance can be provided.

Claims (6)

Isotactic pentad (mmmm) 50-99.9 of propylene-based polymer (A) in which _A is 84.9-95.0 mol%, C2, 4-20, and olefin content is 0-2 mass%. Part by mass and isotactic pentad (mmmm) 0.1 of propylene-based polymer (B) having _B of 95.0 to 99.9 mol%, olefin content of 2 to 4 to 20 carbon atoms and 0 to 20 mass% -50 mass parts (however, the sum of (A) and (B) is 100 mass parts),
(Mmmm) _B- (mmmm) _A is 1 mol% or more,
Polypropylene resin composition.   The polypropylene resin composition according to claim 1, wherein the half crystallization time at 130 ° C is less than 1,000 seconds.   An extruded sheet using the polypropylene resin composition according to claim 1 or 2.   A uniaxially or biaxially stretched film of the extruded sheet according to claim 3.   An injection-molded article of the polypropylene resin composition according to claim 1 or 2.   The hollow molded object of the polypropylene resin composition of Claim 1 or 2.

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