JP6144045B2 - Polypropylene resin composition and method for producing the same, polypropylene sheet and biaxially oriented polypropylene film - Google Patents

Description

  The present invention relates to a propylene-based resin composition for a sheet and a biaxially stretched film. More specifically, the present invention relates to a propylene-based resin composition suitable for a biaxially stretched film that provides a sheet and a film having improved rigidity and clarity and is excellent in moldability during sheet formation.

  Polypropylene, which is inexpensive and has excellent rigidity, moisture resistance, and heat resistance, is widely used in various industrial fields. In particular, the propylene-based resin composition is excellent in appearance, mechanical properties, packaging suitability, and the like, and is therefore used for producing molded products, particularly sheets and film-shaped molded products in packaging applications such as food packaging and fiber packaging. ing. The propylene resin composition is mainly composed of crystalline polypropylene having different characteristics or a mixture of crystalline polypropylene and an amorphous (rubbery) propylene copolymer. Attempts have been made to provide a resin composition suitable for an end use by changing the characteristics and blending ratio of the copolymer. In particular, attempts have been made to improve the rigidity and moldability of resin compositions by introducing a small amount of a high molecular weight polymer component, but a high molecular weight polymer component having a sufficiently high molecular weight is obtained. In addition, there are disadvantages such as insufficient dispersibility of the high molecular weight polymer component, and it may not be possible to contribute to the improvement of the performance of the resin composition.

  Patent Document 1 describes crystallinity obtained by polymerization using a Ziegler-Natta type catalyst that satisfies a specific intrinsic viscosity range (in 135 ° C. decalin), a specific molecular weight distribution (gel permeation chromatography method), and a specific conditional expression. Polypropylene and its manufacturing method are disclosed. Cited Document 1 states that the object is to obtain a polypropylene resin for use in a thermoformed article that requires particularly high hardness and high rigidity.

  Patent Document 2 discloses a polypropylene resin composition having a specific range of melt flow rate, intrinsic viscosity, and first normal stress. Cited Document 2 states that the object is to obtain a foam having a uniform foamed cell structure at a high foaming ratio and having a light weight and excellent balance of mechanical properties such as impact strength and rigidity.

  In Patent Document 3, a crystalline propylene polymer component having a specific intrinsic viscosity range is produced in the first stage, and a crystalline propylene polymer component having a particular intrinsic viscosity range is produced in the second stage and thereafter. A propylene-based polymer obtained in this manner is disclosed. Patent Document 3 states that the object is to obtain a foamed molded product made of a propylene-based polymer.

  Patent Document 4 discloses a propylene-based polymer component having a specific intrinsic viscosity (in 135 ° C. tetralin) and a melting peak temperature (inspection scanning calorimeter), and a propylene having a specific intrinsic viscosity (in 135 ° C. tetralin). A polypropylene resin composition comprising a polymer component is disclosed. Patent Document 4 states that the object is to provide a polypropylene resin composition for injection molding having a good balance between rigidity and toughness.

  Patent Document 5 discloses a propylene homopolymer or propylene copolymer having a specific intrinsic viscosity (in 135 ° C. tetralin) and a propylene homopolymer or propylene copolymer having a specific intrinsic viscosity (in 135 ° C. tetralin). A propylene-based multistage polymer containing a specific amount of a polymer is disclosed. Patent Document 5 states that the purpose is to use a propylene-based polymer as a foam sheet.

  Patent Document 6 discloses a polypropylene resin composition having a specific melt flow rate, including propylene homo- or copolymer having a specific intrinsic viscosity (in 135 ° C. tetralin) range. Patent Document 6 discloses that a sheet is formed from a thermoforming polypropylene resin composition having excellent thermoformability and excellent transparency.

  In the examples of the above-mentioned patent documents, propylene is polymerized using a Ziegler-Natta type solid catalyst system (phthalate catalyst) containing diisobutyl phthalate as an internal electron donor compound. The polymer polymerized using the phthalate catalyst has a problem that the molecular weight distribution is not sufficiently high and the molecular weight distribution is slightly narrow.

WO97 / 45463 JP-A-11-181178 JP-A-11-228629 JP 2002-332387 A WO2005 / 097842 JP 2008-184560 A WO2009 / 069483 WO2009 / 057747 JP-A-2005-306910 JP 2004-131537 A Special table 2002-542347

  The present invention relates to a resin composition produced using a Ziegler-Natta type catalyst containing a solid catalyst component having a succinate compound as an electron donor compound, and an ultrahigh molecular weight polymer having a high molecular weight and a wide molecular weight distribution is used as a resin. An object of the present invention is to provide an improved resin composition capable of obtaining a sheet and a biaxially stretched film excellent in moldability, rigidity and transparency by being introduced at the production stage of the composition. .

  That is, the present invention is a specific product obtained by polymerizing in the presence of a solid catalyst component containing Mg, Ti, and a halogen containing a succinate electron donor compound, an alkylaluminum cocatalyst, and a catalyst system containing a silicon compound. A polypropylene resin composition having a specific molecular weight distribution, a melt flow rate value, and an excellent sheet moldability and secondary processability, including a high molecular weight polypropylene polymer having a melting peak of The propylene resin composition produced using a specific catalyst is also suitable for producing a suitable biaxially stretched film.

Aspects of the present invention are as follows:
1. (A) a solid catalyst containing, as an essential component, an electron donor compound selected from magnesium, titanium, halogen and succinate compounds;
A polypropylene resin composition obtained using a catalyst comprising (B) an organoaluminum compound; and (C) an external electron donor compound selected from silicon compounds, wherein:
High molecular weight polypropylene polymer (a) 0 having a xylene-soluble content of 5% by mass or less, an intrinsic viscosity of 6 to 20 dl / g, a melting peak temperature of 160 ° C. or higher by inspecting thermal analysis, and no single fluidity 1-10% by mass;
Contains a polypropylene polymer (b) 90.0-99.9% by mass having a lower intrinsic viscosity than (a), further having an intrinsic viscosity of 0.5 to 4 dl / g, and a xylene-soluble content of 25% by mass or less. And (i) to (iii) below:
(I) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) by gel permeation chromatography (GPC) of the polypropylene resin composition is 10 or more;
(Ii) The proportion of the component having a molecular weight of 2 million or more determined by the GPC method of the polypropylene resin composition is 2.5% or more; and (iii) the melt flow rate (MFR) of the polypropylene resin composition is 1.0 to 50 g. The said polypropylene resin composition characterized by satisfy | filling the condition for / 10 minutes.
2. 2. The polypropylene resin composition according to any one of the above 1, wherein the polypropylene polymer (a) and the polypropylene polymer (b) are obtained by a polymerization method in which two or more polymerization steps are carried out sequentially or continuously. .
3. 3. The polypropylene resin composition as described in 1 or 2 above, wherein the prepolymerization step includes a prepolymerization step.
4). A biaxially stretched polypropylene film comprising a layer made of the polypropylene resin composition according to any one of 1 to 3 above.
5). A polypropylene sheet comprising a layer made of the polypropylene resin composition according to any one of 1 to 3 above.
6). 6. The polypropylene sheet according to 5 above, wherein the β crystal fraction is 5% or more, and the diffuse transmitted light value when the thickness of the sheet is 500 μm is 30 or less.

  Hereinafter, the present invention will be described in detail.

First, the propylene resin composition of the present invention will be described. The present invention provides (A) a solid catalyst containing, as an essential component, an electron donor compound selected from magnesium, titanium, halogen, and a succinate compound;
A polypropylene resin composition obtained using a catalyst comprising (B) an organoaluminum compound; and (C) an external electron donor compound selected from silicon compounds, wherein:
High molecular weight polypropylene polymer (a) 0 having a xylene-soluble content of 5% by mass or less, an intrinsic viscosity of 6 to 20 dl / g, a melting peak temperature of 160 ° C. or higher by inspecting thermal analysis, and no single fluidity 1-10% by mass;
Contains a polypropylene polymer (b) 90.0-99.9% by mass having a lower intrinsic viscosity than (a), further having an intrinsic viscosity of 0.5 to 4 dl / g, and a xylene-soluble content of 25% by mass or less. And (i) to (iii) below:
(I) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) by gel permeation chromatography (GPC) of the polypropylene resin composition is 10 or more;
(Ii) The proportion of the component having a molecular weight of 2 million or more determined by the GPC method of the polypropylene resin composition is 2.5% or more; and (iii) the melt flow rate (MFR) of the polypropylene resin composition is 1.0 to 50 g. The present invention relates to the polypropylene resin composition, characterized by satisfying a condition of / 10 minutes.

  The catalyst used for the production of the polypropylene resin composition of the present invention is (A) a solid catalyst containing as an essential component an electron donor compound selected from magnesium, titanium, halogen and succinate compounds; (B) an organoaluminum compound And (C) an external electron donor compound selected from silicon compounds.

  The solid catalyst component which is the component (A) used in the production of the propylene resin composition of the present invention contains magnesium, titanium, halogen and an electron donor compound as essential components. Regarding this solid catalyst component, many prior art documents have proposed the manufacturing method. Specifically, this solid catalyst component can be obtained by bringing a magnesium compound, a titanium compound and an electron donor compound into contact with each other. For example, (1) an electron donor compound without pulverizing or pulverizing a magnesium compound or a complex compound of a magnesium compound and an electron donor compound in the presence or absence of an electron donor compound, a grinding aid or the like And / or a pretreatment with a reaction aid such as an organoaluminum compound or a halogen-containing silicon compound, or a reaction with a solid obtained without pretreatment and a titanium compound that forms a liquid phase under reaction conditions; (2) A method of depositing a solid titanium complex by reacting a liquid magnesium compound with a liquid titanium compound in the presence or absence of an electron donor compound; (3) a solid magnesium compound and liquid titanium; A method of reacting a compound and an electron donor compound; (4) a titanium compound is further reacted with the product obtained in (2) or (3) above; (5) A method of further reacting an electron donor compound and a titanium compound with those obtained in (1), (2) and (3) above; (6) Magnesium compound or magnesium compound and electron donor compound The complex 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 a reaction such as an electron donor compound and / or an organoaluminum compound or a halogen-containing silicon compound is performed. A method in which a solid obtained by pretreatment with an auxiliary agent or without pretreatment is treated with a halogen, a halogen compound or an aromatic hydrocarbon; and (7) the compound obtained in the above (1) to (5) is treated with a halogen or The solid catalyst component that is the component (A) used in the present invention can be obtained by various methods such as a method of treating with a halogen compound or an aromatic hydrocarbon. Kill.

  The titanium compound used for the preparation of the solid catalyst component (A) used in the production of the propylene resin composition of the present invention has the general formula:

A tetravalent titanium compound represented by (R is a hydrocarbon group, X is a halogen, and 0 ≦ g ≦ 4) is preferable. More specifically, titanium tetrahalides such as TiCl ₄ , TiBr ₄ , TiI ₄ ; Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (O _n —C ₄ H ₉ ) Cl ₃ , Ti (OC ₂ H ₅ ) Br ₃ , Ti (OisoC ₄ H ₉ ) Br ₃ and other trihalogenated alkoxytitanium; 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) monohalide trialkoxy titanium such as _{3 Br; Ti (OCH 3)} 4, Ti (OC 2 H 5) 4, Ti (O n - C ₄ H _{9) 4} such as tetraalkoxy titanium can be mentioned, such as, preferred are halogen-containing titanium compound among these, a particularly titanium tetrahalides, particularly preferred , It is titanium tetrachloride.

  Magnesium compounds used in the preparation of the solid catalyst component (A) used in the production of the propylene resin composition of the present invention include magnesium compounds having a magnesium-carbon bond or a magnesium-hydrogen bond, such as dimethylmagnesium, diethylmagnesium, 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, butyl ethoxy magnesium, ethyl butyl magnesium, butyl magnesium hydride, etc. It is done. 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 suitable 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 magnesium chloride, octoxy magnesium chloride, and the like. Alkoxymagnesium halides; aryloxymagnesium halides such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; alkoxymagnesiums such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium and 2-ethylhexoxymagnesium; Allyloxymagnesium such as sigmamagnesium and dimethylphenoxymagnesium; Lau Magnesium phosphate, such as carboxylic acid salts of magnesium such as magnesium stearate and the like.

  The electron donor compound used for the preparation of the solid catalyst component (A) used in the production of the propylene resin composition of the present invention is generally referred to as “internal electron donor”. Examples of such electron donor compounds include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, oxygenated electron donors such as acid anhydrides, ammonia, amines, Nitrogen-containing electron donors such as nitriles and isocyanates are known. In the present invention, succinate electron donor compounds are used.

  Suitable succinate compounds are those of formula I:

Wherein the groups R ₁ and R ₂ are the same or different from each other, optionally containing a heteroatom, a C ₁ -C ₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or An alkylaryl group; the groups R _{3 to} R ₆ are the same or different from each other and contain C _{1 to} C ₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl, which are the same or different and contain hydrogen or optionally a heteroatom , Arylalkyl or alkylaryl groups, the groups R _{3 to} R ₆ bonded to the same or different carbon atoms may be bonded together to form a ring)
Selected from compounds having a succinate (succinate) structure.

R ₁ and R ₂ are preferably C ₁ -C ₈ alkyl, cycloalkyl, aryl, arylalkyl, and alkylaryl groups. Particularly preferred are compounds wherein R ₁ and R ₂ are selected from primary alkyls, especially branched primary alkyls. Examples of suitable R ₁ and R ₂ groups are methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, 2-ethylhexyl. Ethyl, isobutyl, and neopentyl are particularly preferred.

One preferred group of compounds represented by 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 an alkylaryl group. Specific examples of suitable mono-substituted succinate compounds include diethyl-sec-butyl succinate, diethyl hexyl succinate, diethyl cyclopropyl succinate, diethyl norbornyl succinate, diethyl perihydrosuccinate, diethyl trimethylsilyls. Succinate, diethyl methoxy succinate, diethyl-p-methoxyphenyl succinate, diethyl-p-chlorophenyl succinate, diethyl phenyl succinate, diethyl cyclohexyl succinate, diethyl benzyl succinate, diethyl cyclohexyl methyls 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 texyl succinate, diisobutyl cyclopropyl succinate , Diisobutyl norbornyl succinate, diisobutyl perhydrosuccinate, diisobutyl trimethylsilyl succinate, diisobutyl methoxy succinate, diisobutyl-p-methoxyphenyl succinate, diisobutyl-p-chlorophenyl succinate, diisobutyl cyclohexyl succinate , Diisobutyl benzyl succinate, diisobutyl cyclohexyl methyl succinate, diisobutyl-t-butyl succinate, di Sobutyl 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, dineopenty Lucyclohexyl succinate, dineopentyl benzyl succinate, dineopentyl cyclohexyl methyl succinate, dineopentyl-t-butyl succinate, dineopentyl isobutyl succinate, dineopentyl isopropyl succinate, dineo Pentyl neopentyl succinate, dineopentyl isopentyl succinate, dineopentyl (1-trifluoromethylethyl) succinate, dineopentyl fluorenyl succinate.

Another preferred group of compounds within the scope of formula (I) are C ₁ -C ₂₀ linear, wherein at least two groups from R _{3 to} R ₆ are different from hydrogen and optionally contain heteroatoms. Or a branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl group. Particularly preferred are compounds in which two groups different from hydrogen are bonded to the same carbon atom. Specific examples of suitable disubstituted succinates 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-diisobutyl succinate Diethyl-2-cyclohexyl-2-ethylsuccinate, diethyl-2-isopropyl-2-methylsuccinate, diethyl-2-tetradecyl-2-ethylsuccinate, diethyl-2-isobutyl-2-ethyls Cuccinate, 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-tetradecyl-2 Ethyl succinate, diisobutyl-2-isobutyl-2-ethyl succinate, diisobutyl-2- (1-trifluoromethylethyl) -2-methyl succinate, 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-dimethyls 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 succinate 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-ethylsuccinate, dineopentyl-2-isobutyl-2-ethylsuccinate, dineopentyl-2- (1-trifluoromethylethyl) -2-methylsuccinate, dineopentyl- 2,2-diisopropyl succinate, dineopentyl-2-isopentyl-2-isobutyl succinate, dineopentyl-2-phenyl-2-n-butyl succinate.

Further particularly preferred are compounds in which at least two groups different from hydrogen, ie R ₃ and R ₅ , or R ₄ and R ₆ are bonded to different carbon atoms. Specific examples of suitable compounds are 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-diisobu Rusuccinate, 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, diethyl -2,2,3,3-tetramethylsk , 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, dii Butyl-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-iso Propyl-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-methyl Xinate, dineopentyl-2- (3,3,3-trifluoropropyl) -3-methylsuccinate, 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-Dineopentyl succine , Dineopentyl-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, di Neopentyl-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.

Among the compounds of formula I, compounds in which some of the groups R _{3 to} R ₆ are bonded together to form a ring can also be preferably used. As such compounds, compounds listed in Patent Document 11, 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 Can do. In addition, for example, a cyclic succinate compound as disclosed in Patent Document 7 can also be suitably used.

As another example of the cyclic succinate compound, a compound disclosed in Patent Document 8 is also preferable.
Of the compounds of formula I, when the groups R _{3 to} R ₆ contain heteroatoms, the heteroatoms are preferably group 15 atoms including nitrogen and phosphorus atoms or group 16 atoms including oxygen and sulfur atoms. Examples of the compound in which the groups R _{3 to} R ₆ include a Group 15 atom include compounds disclosed in Patent Document 9. On the other hand, examples of the compound in which the groups R _{3 to} R ₆ include a Group 16 atom include compounds disclosed in Patent Document 10.

  Examples of the halogen atom constituting the solid catalyst component used for the production of the propylene resin composition of the present invention include fluorine, chlorine, bromine, iodine or a mixture thereof, and chlorine is particularly preferable.

The organoaluminum compound which is component (B) used in the production of the propylene resin composition of the present invention includes, for example, trialkylaluminum such as triethylaluminum and tributylaluminum, trialkenylaluminum such as triisoprenylaluminum, diethylaluminum ethoxy a de, dialkylaluminum alkoxides such as dibutyl aluminum butoxide, ethyl aluminum sesqui ethoxide, in addition to alkylaluminum sesqui alkoxides such as butyl sesquichloride butoxide, an average composition represented by such _{^{R 1 2.5 Al (OR 2)}} 0. 5 Dialkyls such as partially alkoxylated alkylaluminum, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide Alkylaluminum sesquihalides such as luminium halide, ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquichloride, alkylaluminum dihalogenides such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromide, etc. Partially hydrogenated alkylaluminum, partially hydrogenated alkylaluminum such as dialkylaluminum hydride such as diethylaluminum hydride, dibutylaluminum hydride, alkylaluminum dihydride such as ethylaluminum dihydride, propylaluminum dihydride, Ethyl aluminum ethoxy chloride, butyl aluminum butoxy chloride, It can be selected from partially alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxybromide.

  The electron donor compound which is the component (C) used in the production of the propylene resin composition of the present invention is generally referred to as “external electron donor”. As such an electron donor compound, an organosilicon compound is preferably used. 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-amino Propyltriethoxysilane, Chlortriethoxysilane, Ethyltriisopropoxysilane, Vinyltributoxysilane, Cyclohexyltrimethoxysilane, Cyclohexyltriethoxysilane 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, ethyl silicate, butyl butyl, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris (β-methoxyethoxysilane), Vinyl triacetoxysilane, dimethyltetraethoxydisiloxane, etc., among others, ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, texyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane , Vinyltributoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, phenylmethyldi Methoxysilane, bis p-tolyldimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, 2-nonebornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, diphenyldiethoxysilane, ethyl silicate Etc. are preferable.

The polypropylene resin composition of the present invention has a xylene-soluble content of 5% by mass or less, an intrinsic viscosity of 6 to 20 dL / g, a melting peak temperature of 160 ° C. or higher in an analytical thermal analysis, and exhibits fluidity by itself. High molecular weight polypropylene polymer (a) 0.1-10% by mass, intrinsic viscosity is smaller than (a), intrinsic viscosity is 0.5-4 dl / g, xylene solubles is 25% by mass or less The polypropylene polymer (b) is 90.0-99.9% by mass. The polypropylene resin composition of the present invention is a mixture of two types of polypropylene polymers (a) and polypropylene polymers (b) having different intrinsic viscosities, that is, different molecular weights. In particular, a preferable range of the intrinsic viscosity of the polypropylene polymer (a) is 7 to 15 dL / g, and a more preferable range is 8 to 13 dL / g. When the intrinsic viscosity of the polypropylene polymer (a) is less than 6, improvement of moldability and physical properties is not sufficient, and production of those exceeding 20 is difficult. In addition, when the xylene soluble content of the polypropylene polymer (a) exceeds 5% by mass and / or when the melting peak temperature of the analytical thermal analysis is less than 160 ° C., the effect of promoting crystallization is not sufficient. A small amount of a high molecular weight polypropylene polymer (a) is blended with a low molecular weight polypropylene polymer (b) and adjusted so as to satisfy the following properties necessary for forming a sheet or a biaxially stretched film:
(I) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) by gel permeation chromatography (GPC) of the polypropylene resin composition is 10 or more;
(Ii) The proportion of the component having a molecular weight of 2 million or more determined by the GPC method of the polypropylene resin composition is 2.5% or more; and (iii) The melt flow rate (MFR) of the polypropylene resin composition is 1.0 to 50 g. / 10 minutes.

  The polypropylene resin composition of the present invention has a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) by GPC of 10 or more, that is, a relatively broad molecular weight distribution. As a result of using a succinate-based Ziegler-Natta type polymerization catalyst, a polypropylene resin composition having a relatively broad molecular weight distribution can be obtained. If the molecular weight distribution is narrow, the melt tension becomes insufficient, resulting in difficulty in forming a sheet or a biaxially stretched film. Even when molding is possible, the resulting molded article has insufficient rigidity and clarity, and drawdown during secondary molding of the sheet also increases. The molecular weight distribution of the resin composition is preferably 12 or more, more preferably 13 or more. Furthermore, in the polypropylene resin composition of the present invention, the proportion of components having a molecular weight of 2 million or more determined by the GPC method is 2.5% or more, preferably 2.8% or more, and more preferably 3.1% or more. The influence of the high molecular weight component becomes significant due to the formation of an entangled network between molecules. The higher the molecular weight of the high molecular weight component, the greater the component amount, and the better the dispersibility, the easier the formation of the entanglement network. In particular, when the amount of a component having a molecular weight of 2 million or more is 2.5% or more, the improvement in rigidity and clarity, which seems to be due to the promotion of melt tension and orientation crystallization, becomes remarkable. In particular, in the sheet, with an increase in the high molecular weight component of 2 million or more, the proportion of β-type crystals that are one of the polymorphs of polypropylene increases. The MFR (fluidity index) at 230 ° C. of the polypropylene resin composition of the present invention is 1.0 to 50 g / 10 minutes, preferably 2.0 to 30 g / 10 minutes, more preferably 3.0 to 20 g / 10. Minutes. MFR is an index of fluidity. The higher the MFR, the higher the discharge rate in the extruder attached to the molding machine and the higher the productivity. On the other hand, increasing the MFR leads to a decrease in molecular weight. As a result, the formability of the sheet and the biaxially stretched film is lowered, and the strength of the obtained molded product is also lowered. The MFR of a general sheet and a polypropylene resin for a biaxially stretched film is 0.5 to 10/10 minutes. Since the polypropylene resin composition of the present invention has a high melt tension despite a high MFR, it is possible to obtain a sheet or a biaxially stretched film with high productivity.

  In addition, the polypropylene resin composition of the present invention is a commonly used additive (nucleating agent, antioxidant, hydrochloric acid absorbent, heat stabilizer, light stabilizer, oil-extended and other olefin polymers). UV absorbers, internal lubricants, external lubricants, anti-static agents, flame retardants, dispersants, copper damage inhibitors, neutralizers, plasticizers, foaming agents, antifoaming agents, crosslinking agents, peroxides) and pigments (organic) Alternatively, inorganic) may be added.

  According to the present invention, a polypropylene resin composition that can be stably processed into a sheet and a biaxially stretched film with high moldability can be obtained. Sheets and biaxially stretched films formed from the polypropylene resin composition had excellent rigidity and transparency.

Next, the manufacturing method of the polypropylene resin composition of this invention is demonstrated concretely.
The high molecular weight polypropylene polymer (a) as a raw material for the polypropylene resin composition of the present invention can be obtained by an existing slurry process (polymerization in a liquid monomer), gas phase polymerization or the like. In addition, the polypropylene polymer (b) used as the raw material of the polypropylene resin composition of the present invention supplies propylene monomer, hydrogen, and catalyst to the polymerization vessel in the presence of the high molecular weight polypropylene polymer formed in the previous step, and is necessary And a monomer (comonomer) other than propylene is polymerized. (A) and (b) preferably use a sequential polymerization method comprising at least two sequential polymerization stages in which each subsequent polymerization is carried out in the presence of a polymerizable material formed during the immediately preceding polymerization reaction. . Furthermore, since (a) may be a small amount, it may be polymerized in the prepolymerization stage.

  Moreover, as a method of obtaining each polypropylene polymer, the method performed using the polymerizer which has the gradient of a 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 connected 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 the above polymerization method, for example, the method described in JP-T-2002-520426 can be applied.
The polymerization stage is carried out in the presence of a stereospecific Ziegler-Natta type catalyst. According to a preferred embodiment, the entire polymerization stage comprises (A) a solid catalyst containing as an essential component an electron donor compound selected from magnesium, titanium, halogen and succinate-based compounds; (B) an organoaluminum compound; C) It is carried out in the presence of a catalyst component comprising an external electron donor compound selected from silicon compounds. Catalysts having the above characteristics are well known from the patent literature. The polymerization stage may occur in the liquid phase, in the gas phase, or in the liquid-gas phase. The reaction temperature in the polymerization stage for the preparation of the polypropylene polymer may be the same or different and is preferably in the range of 40-100 ° C; more preferably 50-90 ° C. The polymerization stage pressure to prepare the polypropylene polymer, if performed in liquid monomer, is a pressure that competes with the vapor pressure of liquid propylene at the operating temperature used and is used to supply the catalyst mixture. It may be regulated by the vapor pressure of a small amount of inert diluent, by any monomer overpressure and by hydrogen used as a molecular weight regulator.

The polymerization pressure is preferably in the range of 33 to 43 bar when carried out in the liquid phase and in the range of 5 to 30 bar when carried out in the gas phase. Conventional molecular weight regulators known in the art such as chain transfer agents (eg hydrogen or ZnEt ₂ ) may be used.

The present invention will be further described below with reference to examples. In addition, each analysis in an Example was performed with the following method.
[MFR]
According to JIS K 7210, the measurement was performed under conditions of a temperature of 230 ° C. and a load of 21.18 N.

[Xylene solubles (XS)]
2.5 g of the polypropylene resin composition was placed in a flask containing 250 mL of o-xylene (solvent), and stirred for 30 minutes at 135 ° C. while purging with nitrogen using a hot plate and a reflux apparatus. After completely dissolving the product, it was cooled at 25 ° C. for 1 hour. The resulting solution 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. Further, after adding acetone to the residue (mixture of xylene-insoluble component and solvent) remaining on the filter paper and filtering, the unfiltered component was evaporated to dryness in a vacuum drying oven set at 80 ° C. Insoluble matter was obtained.
In addition, XS of (b) component manufactured by superposition | polymerization was computed by calculation from XS of (a) component and a polymer mixture by the following formula | equation.
XS of (b) = (XS of polymer mixture (c) −XS of (a) × fraction of (a)) / fraction of (b)

[Intrinsic viscosity (IV)]
The intrinsic viscosity was measured in 135 ° C. tetrahydronaphthalene using an Ubbelohde viscometer. In addition, IV of (b) component manufactured by superposition | polymerization was computed by calculation from IV of (a) component and a polymer mixture by the following formula | equation.
IV of (b) = (IV of polymer mixture (c) −IV of (a) × fraction of (a)) / (b) fraction IV is an index of molecular weight.

[Ethylene content (C2)]
A sample dissolved in a mixed solvent of 1,2,4-trichlorobenzene / deuterated benzene was measured with a ¹³ C-NMR method using JNM LA-400 (13C resonance frequency 100 MHz) manufactured by JEOL Ltd. And the following formula. In addition, C2 of (b) component manufactured by superposition | polymerization was computed by calculation from C2 of (a) component and a polymer mixture by the following formula | equation.
C2 of (b) = (C2 of the polymer mixture (c) C2 × (a) C2 × (a) fraction) / (b) fraction

[Mw / Mn of polypropylene resin composition]
PL GPC220 manufactured by Polymer Laboratories is used as an apparatus, 1,2,4-trichlorobenzene containing an antioxidant is used as a mobile phase, and UT-G (1) and UT-807 (1) manufactured by Showa Denko KK are used as columns. ), UT-806M (two) connected in series was used, and a differential refractometer was used as a detector. The solvent for the sample solution of the polypropylene resin composition was the same as that of the mobile phase, and the sample for measurement was prepared by dissolving at a sample concentration of 1 mg / mL for 2 hours while shaking at a temperature of 150 ° C. 500 μL of the sample solution thus obtained was injected into the column and measured at a flow rate of 1.0 mL / min, a temperature of 145 ° C., and a data acquisition interval of 1 second. For column calibration, a polystyrene standard sample (Shodex STANDARD, manufactured by Showa Denko KK) having a molecular weight of 580 to 7.45 million was used and approximated by a cubic equation. The Mark-Houkins coefficients are K = 1.21 × 10 ⁻⁴ and α = 0.707 for the polystyrene standard sample, and K = 1.37 × 10 ⁻⁴ and α = 0. 75 was used.

[Melting peak temperature]
Using a DSC made by Perkin Elmer, the polypropylene molded body was held at 30 ° C. for 5 minutes, and then heated to 230 ° C. at a heating rate of 20 ° C./min. Melting peak temperature.

[Ratio of components having a molecular weight of 2 million or more in the polypropylene resin composition]
In the molecular weight distribution curve obtained by the above GPC measurement (relationship between log M and the standardized elution amount when the molecular weight is M), the area of the region having a molecular weight of 2 million or more was determined from the ratio to the area of the entire region.

[Melt tension]
Polypropylene composition under conditions of cylinder temperature 230 ° C., orifice L / D = 8.0 / 2.095 mm, piston lowering speed 20 mm / min, take-off speed 6.28 m / min using RCT-50KRAF manufactured by Toyo Seiki Seisakusho The load (gf) when discharging the melt was measured.

[Production of biaxially oriented polypropylene (PP)]
A biaxially stretched film was obtained as follows. An unstretched sheet having a thickness of 10 cm × 10 cm and a thickness of 500 μm was obtained using a T-die molding machine (multilayer T-die molding machine manufactured by Yoshii Tekko Co., Ltd., screw diameter 25 mm) under conditions of a roll temperature of 30 ° C. (using an air knife). Thereafter, the film was stretched in two directions at the same time by a biaxial stretching apparatus (small biaxial stretching apparatus manufactured by Iwamoto Seisakusho Co., Ltd.) at a stretching ratio of 6 × 6 times, a molding temperature of 155 ° C., and a stretching speed of 50 mm / sec. A biaxially stretched film was obtained.

[Young's modulus of biaxially stretched film]
Young's modulus is a universal testing machine Autocom type tester AC-5kN-C, conforming to JIS K7127, sample shape conforming to No. 1 type test piece (test piece length 200mm, width 10mm, distance between chucks 100 mm), and the MD direction (longitudinal direction of the film) was measured at 23 ° C. under the condition of a pulling speed of 5 mm / min. Higher Young's modulus means higher rigidity.

[Manufacture of sheets]
The sheet was obtained as follows. An unstretched sheet having a thickness of 10 cm × 10 cm and a thickness of 500 μm was obtained using a T-die molding machine (multilayer T-die molding machine manufactured by Yoshii Tekko Co., Ltd., screw diameter 25 mm) under conditions of a roll temperature of 30 ° C. (using an air knife). .

[Haze]
Haze measurement was performed according to JIS K 7136.
[Clarity]
Clarity measurement was performed according to ASTM D 1746.

[Taper stiffness of sheet]
Five test pieces were prepared by punching an unstretched sheet having a thickness of 500 μm used for the evaluation of the moldability into 2.75 inches in length and 1.5 inches in width.

  About each test piece, the Stiffness of the forming direction (MD direction) was measured using a V-5 stiffness tester (model 150-B) manufactured by Taber Instrument Corporation. The measurement conditions at that time were measurement range: 50-500, range weight: 500 units, warpage angle: 15 °, measurement span: 5 cm, scale magnification: 5 times, holding time 3 minutes, measurement temperature: 23 ° C. The stiffness was obtained by reading the values at the left and right warping angles of 15 ° for each test piece and averaging them.

And the Taber stiffness of the unstretched sheet | seat was calculated | required by the following Formula.
E = 9.83 × T _su / t ³
(E: Taber stiffness [MPa] of sheet, T _su is average value of stiffness [gf · cm], t is thickness of test piece [mm])
It means that rigidity is so high that the value of Taber stiffness is large.

[Diffuse transmitted light value (LSI)]
The diffuse transmitted light value (LSI: Light Scattering Index) was measured using a visual transparency tester manufactured by Toyo Seiki Seisakusho. The smaller this LSI, the higher the transparency. While the haze is the ratio of scattered light having an angle of 4 ° or more, the LSI corresponds to the intensity of scattered light having an angle of 0.4 to 1.2 °. Become.

[Β crystal fraction]
Wide angle X-ray scattering (manufactured by Rigaku Corporation, RAD-3R system, X-ray source: CuKα ray monochromatized by Ni filter) was measured for the unstretched sheet obtained in the measurement of the Taber stiffness. In the case of having a β-type crystal, in the obtained X-ray diffraction profile, a scattering peak based on (300) reflection peculiar to the β-type crystal is observed in the vicinity of 2θ = 16 °. The calculation of β crystal fraction is as follows. Turner Jones et al. Macromol. Chem. 75, 134 (1964).

(1) Preparation of solid catalyst component The solid catalyst component was prepared according to the preparation method as described in the Example of Unexamined-Japanese-Patent No. 2011-500907. 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 the method described in Example 2 of USP-4,399,054, but operating at 3000 rpm instead of 10000 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. The following procedure was then repeated twice: 250 mL of fresh TiCl ₄ was added and the mixture was allowed to react at 120 ° C. for 60 minutes and the supernatant was siphoned off. The solid was washed 6 times with anhydrous hexane (6 × 100 mL) at 60 ° C.

(2) Polymerization and Production of Polypropylene Resin Composition The polypropylene resin composition of the present invention was produced by the following method:
Example 1
The above solid catalyst, triethylaluminum (TEAL) and dicyclopentyldimethoxysilane (DCPMS) are mixed in an amount such that the mass ratio of TEAL to the solid catalyst is 18 and the mass ratio of TEAL / DCPMS is 10 at room temperature. Touched for a minute. 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, and propylene was fed at 50 ° C. in the absence of hydrogen to produce a high molecular weight propylene homopolymer (polypropylene (a ₁ ) in Table 1). After the obtained polymer was introduced into the second stage polymerization reactor, 0.510 mol% of hydrogen and propylene were fed to produce a propylene homopolymer (polypropylene (b ₅ ) in Table 1), By controlling the residence time of the first stage and the second stage, (a ₁ ) and (b ₅ ) are adjusted to the quantitative ratios shown in Table 2, and the polymerization pressure is adjusted at a polymerization temperature of 80 ° C. To obtain a polymer mixture (c). The obtained polymer mixture is blended with 0.2 parts by weight of B255 manufactured by BASF as an antioxidant and 0.05 parts by weight of calcium stearate manufactured by Tannan Chemical Co., Ltd. as a neutralizing agent. After stirring and mixing for a minute, it was extruded with a Nakatani NVC φ 50 mm single screw extruder at a cylinder temperature of 230 ° C., the strand was cooled in water, and then cut with a pelletizer to obtain a pellet-like propylene resin composition.

Examples 2-3
The hydrogen concentration in the second stage was 0.624 mol% in Example 2 and 0.355 mol% in Example 3, and the propylene homopolymers of (b ₆ ) and (b ₇ ) in Table 1 were respectively used in the first stage. And (a ₁ ) and (b ₆ ), (a ₁ ) and (b ₇ ) are adjusted to the quantitative ratios shown in Table 2, and the polymerization pressure is adjusted. As a result, a polymer mixture (c) was obtained. Other than that was carried out similarly to Example 1, and obtained the propylene resin composition.

Example 4
After the second stage hydrogen concentration was 0.451 mol% and a homopolymer that was a matrix of the propylene copolymer of (b ₉ ) in Table 1 was polymerized, the copolymer (ethylene / propylene copolymer) was further added in the third stage. Polymer). By controlling the residence time of the first stage and the second to third stages, (b ₉ ) is adjusted to the quantitative ratio shown in Table 2, and by adjusting the polymerization temperature and polymerization pressure, the polymer mixture ( c) was obtained. At that time, ethylene concentration (C2 / (C2 + C3)) and hydrogen concentration (used for the purpose of IV adjustment of XS of (b ₉ )) in the third-stage polymerization reactor were 0.246 mol / mol, 2. The residence time distributions of the second and third stages were adjusted so that the proportion of the ethylene / propylene copolymer in the propylene copolymer (b ₉ ) was 18.5 wt%. Other than that was carried out similarly to Example 1, and obtained the propylene resin composition.

Comparative Examples 1-2
A polymer composition was made that was not within the scope of the present invention. Comparative Examples 1 and 2 are examples in which propylene was polymerized using a phthalate-based solid catalyst. The solid catalyst used in Comparative Examples 1 and 2 is obtained by the method described in EP 6749991. Specifically, it was manufactured as follows:
The solid catalyst used for the polymerization was prepared by the method described in Example 1 of EP 6749991. The solid catalyst is one in which Ti and diisobutyl phthalate as an internal donor are supported on MgCl ₂ by the method described in the above-mentioned patent publication.

In the case of Comparative Example 1, TEAL and cyclohexylmethyldiethoxysilane (CHMMS), in the case of Comparative Example 2, TEAL and dicyclopentyldimethoxysilane (DCPMS) are used, and the mass ratio of TEAL to the solid catalyst is 11 In such an amount that the mass ratio of TEAL / CHMMS and TEAL / DCPMS is 3, it was contacted 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 a polymerization reactor, and 0.055 mol% (Comparative Example 1), 0.242 mol% (Comparative Example 2) of hydrogen and propylene were fed, and the polymerization pressure was set to 80 ° C. By adjusting, a propylene homopolymer (polypropylene in Table 1 (c _{ratio 1} ), (c _{ratio 2} )) was obtained. The obtained polymers were melt-kneaded in the same manner as in Example 1 to obtain compositions of Comparative Examples 1 and 2.

Comparative Example 3
A polymer composition was prepared in which the melting point and intrinsic viscosity of component (a) and component (b) were not within the scope of the present invention. RS1684 (polypropylene (a ₂ ) 5.0% by mass manufactured by Lyondell Basell and 95% by mass of the polypropylene resin composition obtained in Comparative Example 2 were mixed, and the resulting mixture was mixed with an extruder (manufactured by Nakatani, screw And melt kneading at 250 ° C. to obtain a polypropylene composition.

Comparative Example 4
A polymer composition was made that was not within the scope of the present invention. The same prepolymerization catalyst as in Example 1 was introduced into the polymerization reactor, 0.284 mol% of hydrogen and propylene were fed, and the polymerization pressure was adjusted at a polymerization temperature of 80 ° C. Polypropylene (c _{ratio 4} ) was obtained. The obtained polymer was melt-kneaded in the same manner as in Example 1 to obtain the composition of Comparative Example 4.

Comparative Example 5
A polymer composition was made that was not within the scope of the present invention. A propylene homopolymer (polypropylene in Table 1 (c _{ratio 5} )) was obtained in the same manner as in Comparative Example 2 except that the hydrogen concentration in the polymerization reactor was increased to 0.517 mol%. The obtained polymer was melt-kneaded in the same manner as in Example 1 to obtain a composition of Comparative Example 5.

Comparative Example 6
A polymer composition was made that was not within the scope of the present invention. In the same manner as in Example 2, except that the phthalate-based solid catalyst used in Comparative Example 2 and the prepolymerized catalyst obtained from TEAL / DCPMS were used, the high-molecular weight propylene monopolymer was used in the first stage polymerization reactor. After polymerizing the polymer (polypropylene (a ₄ ) in Table 1), a propylene homopolymer (polypropylene (b ₈ ) in Table 1) was polymerized in a second stage polymerization reactor to obtain a polymer mixture (c). It was. At that time, the hydrogen concentration in the second stage polymerization reactor was changed to 0.536 mol%. The propylene resin composition of Comparative Example 6 was obtained from the obtained polymer mixture in the same manner as in Example 1.

Comparative Example 7
A polymer composition was made that was not within the scope of the present invention. In the same manner as in Example 4, except that the phthalate-based solid catalyst used in Comparative Example 2 and the prepolymerized catalyst obtained from TEAL / DCPMS were used, a high-molecular weight propylene monopolymer was used in the first stage polymerization reactor. After polymerizing the polymer (polypropylene (a ₄ ) in Table 1), a polymer comprising a propylene homopolymer and an ethylene / propylene copolymer (polypropylene (b ₁₀ ) in Table 1) in the second and third stage polymerization reactors. ) To obtain a polymer mixture (c). At that time, the hydrogen concentration in the second-stage polymerization reactor was changed to 0.710 mol%, and the hydrogen concentration and ethylene concentration (C2 / (C2 + C3)) in the third-stage polymerization reactor were changed to 5. They were changed to 52 mol% and 0.390 mol / mol. The propylene resin composition of Comparative Example 7 was obtained from the obtained polymer mixture in the same manner as in Example 1.

Comparative Example 8
A polymer composition was produced in which the intrinsic viscosity of component (a) was not within the scope of the present invention. The same procedure as in Example 2 was conducted except that 0.003 mol% of hydrogen was introduced into the first stage polymerization reactor at 80 ° C. to polymerize a high molecular weight propylene homopolymer (polypropylene (a ₃ ) in Table 1). A polymer mixture (c) was obtained. The propylene resin composition of Comparative Example 8 was obtained from the obtained polymer mixture in the same manner as in Example 1.

Comparative Example 9
A polymer composition was produced in which the intrinsic viscosity of component (b) was not within the scope of the present invention. In the same manner as in Example 2 except that the propylene homopolymer (polypropylene (b ₁₁ ) in Table 1) was polymerized by changing the hydrogen concentration in the second stage polymerization reactor to 0.003 mol%, the polymer mixture ( c) was obtained. The propylene resin composition of Comparative Example 9 was obtained in the same manner as Example 1 from the obtained polymer mixture.

[Characteristics of polypropylene resin composition]
Table 3 shows the MFR, melting peak temperature, Mw / Mn, ratio of components having a molecular weight of 2 million or more, and melt tension of each obtained polypropylene resin composition. In addition, biaxially stretched PP and sheets were produced from each of the obtained polypropylene resin compositions, and the respective characteristics were measured as described above. Table 3 shows the characteristics of each biaxially stretched PP and sheet. The composition of Comparative Example 5 was unable to form a biaxially stretched PP and sheet due to insufficient melt tension. The composition of Comparative Example 7 was unable to form biaxially stretched PP due to insufficient melt tension. The compositions of Comparative Example 8 and Comparative Example 9 each had an MFR exceeding the preferred range of the present invention (Comparative Example 8) and less than the range of the present invention (Comparative Example 9). It was not suitable for.

  When the composition which consists of the polypropylene homopolymer of Examples 1-3 and a comparative example is compared, the rigidity of the biaxially stretched PP and sheet of the composition of the present invention is improved. Also in the comparison of the composition containing the propylene copolymer of Example 4 and Comparative Example 7, the sheet of the composition of the present invention has improved rigidity.

  When Examples 1 to 3 are compared with the sheets relating to the comparative examples, all have characteristics that the haze value is large, the clarity is high, and the diffuse transmitted light value (LSI) is small. It can be seen that the sheets of Examples 1 to 3 are “white and transparent”.

Claims (6)

(A) a solid catalyst containing, as an essential component, an electron donor compound selected from magnesium, titanium, halogen and succinate compounds;
A polypropylene resin composition obtained using a catalyst comprising (B) an organoaluminum compound; and (C) an external electron donor compound selected from silicon compounds, wherein:
High molecular weight polypropylene polymer (a) 0 having a xylene-soluble content of 5% by mass or less, an intrinsic viscosity of 6 to 20 dl / g, a melting peak temperature of 160 ° C. or higher by inspecting thermal analysis, and no single fluidity 1-10% by mass;
A polypropylene polymer having a lower intrinsic viscosity than (a), an intrinsic viscosity of 0.5 to 4 dl / g, and a xylene-soluble content of 25% by mass or less (b) 90.0-99.9% by mass And the following (i) to (iii):
(I) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) by gel permeation chromatography (GPC) of the polypropylene resin composition is 10 or more;
(Ii) The proportion of the component having a molecular weight of 2 million or more determined by the GPC method of the polypropylene resin composition is 2.5% or more; and (iii) The melt flow rate (MFR) at 230 ° C. of the polypropylene resin composition is 1 The polypropylene resin composition is characterized by satisfying a condition of 0 to 50 g / 10 minutes.   2. The polypropylene resin composition according to claim 1, wherein the polypropylene polymer (a) and the polypropylene polymer (b) are obtained by a polymerization method in which two or more polymerization steps are sequentially or continuously performed. object. The polypropylene resin composition according to claim 1, wherein the polymerization step includes a prepolymerization step.   It has a layer which consists of a polypropylene resin composition in any one of Claims 1-3, The biaxially stretched polypropylene film characterized by the above-mentioned.   It has a layer which consists of a polypropylene resin composition in any one of Claims 1-3, The polypropylene sheet characterized by the above-mentioned.   6. The polypropylene sheet according to claim 5, wherein the β-crystal fraction is 5% or more, and the diffuse transmission value at a sheet thickness of 500 μm is 30 or less.