Polypropylene composition

Abstract

A polypropylene composition including: as a component (A), a propylene (co)polymer that includes 0-2 wt% of a comonomer-derived unit selected from the group consisting of ethylene, a C4-C10-α-olefin, and a combination of these; and as a component (B), a phosphoric acid ester-based nucleating agent with an average grain size of 1-10 μm as measured by an image analysis method. The component (A) is a polymer that is obtained by using a solid catalyst and an organic aluminum compound-including catalyst to polymerize corresponding monomers, said solid catalyst including, as required components, Mg, Ti, a halogen, and an electron donor compound selected from succinate compounds. The MFR (temperature 230°C, load 2.16 kg) of the component (A) is 0.3-10 g / 10 min, and the polydispersity index (PI) of the component (A) is 5-10. The polypropylene composition includes 0.02-0.15 parts by weight of the component (B) per 100 parts by weight of the component (A).

Description

[Technical Field]

[0001] The present invention relates to a polypropylene composition, and more particularly to a polypropylene composition suitable for molding into a highly transparent sheet. [Background technology]

[0002] Polypropylene is used as a packaging sheet because it has excellent physical properties and is hygienic. The sheet is required to have excellent mechanical properties and appearance. For example, Patent Documents 1 and 2 disclose polypropylene compositions that can be molded into transparent sheets having high rigidity and sufficient impact strength. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 125504 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-960 Summary of the Invention [Problem to be solved by the invention]

[0004] The aforementioned patent documents disclose polypropylene compositions containing a phosphate ester-based nucleating agent. However, the inventors have found that there is still room for improvement in the transparency of the sheets described in the aforementioned patent documents. In view of these circumstances, an object of the present invention is to provide a polypropylene composition that can give a molded article, preferably a sheet, having high rigidity and high transparency. [Means for solving the problem]

[0005] The inventors have found that the above-mentioned problems can be solved by using a phosphate ester-based nucleating agent having a specific particle size. That is, the above-mentioned problems are solved by the following invention. (1) as component (A), a propylene (co)polymer containing 0 to 2% by weight of a comonomer-derived unit selected from the group consisting of ethylene, C4 to C10 α-olefins, and combinations thereof; The component (B) contains a phosphate ester-based nucleating agent having an average particle size of 1 to 10 μm as measured by image analysis, Component (A) is a polymer obtained by polymerizing a corresponding monomer using a solid catalyst containing, as essential components, Mg, Ti, a halogen, and an electron donor compound selected from succinate-based compounds, and a catalyst containing an organoaluminum compound; The MFR of component (A) (temperature 230°C, load 2.16 kg) is 0.3 to 10 g / 10 min, The polydispersity index (PI) of component (A) is 5 to 10; Contains 0.02 to 0.15 parts by weight of component (B) per 100 parts by weight of component (A), Polypropylene composition. (2) The polypropylene composition according to (1), which contains, as component (C), 0.1 to 0.5 parts by weight of a nonitol-based nucleating agent or a sorbitol-based nucleating agent per 100 parts by weight of component (A). (3) A molded article produced from the polypropylene composition according to (1) or (2) above, which has a gamma crystal peak ratio of 0.60 or less as determined by wide-angle X-ray diffraction. (4) A sheet produced from the polypropylene composition according to (1) or (2). (5) A secondary processed molded product obtained by processing the sheet described in (4) above. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a polypropylene composition that gives a molded article, preferably a sheet, having high rigidity and high transparency. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 10 is a diagram showing the relationship between the circular integrated intensity at the azimuthal angle of a wide-angle X-ray diffraction two-dimensional pattern and 2θ, and the peak height used to calculate the γ crystal peak ratio in Example 2. [Figure 2] FIG. 10 is a diagram showing the relationship between the circular integrated intensity at the azimuthal angle and 2θ of the wide-angle X-ray diffraction two-dimensional pattern in Comparative Example 3, and the peak height used to calculate the γ crystal peak ratio. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described in detail below. In the present invention, "X to Y" includes both end values, that is, X and Y.

[0009] 1. Polypropylene composition (1) Propylene (co)polymer (component (A)) The propylene (co)polymer of the present invention contains 0 to 2% by weight of comonomer-derived units selected from the group consisting of ethylene, C4 to C10 α-olefins, and combinations thereof. When a comonomer is contained, ethylene is preferred from the viewpoint of economic efficiency. For example, a propylene copolymer containing 2% by weight of ethylene-derived units is a copolymer having a weight ratio of ethylene-derived units to propylene-derived units of 2:98. The same applies to other copolymers. A large amount of comonomer-derived units can reduce the rigidity of the polypropylene composition. From this viewpoint, it is preferable that the content of comonomer-derived units is 0% by weight, i.e., component (A) is a propylene homopolymer. Furthermore, when the content of comonomer-derived units exceeds 0% by weight, the upper limit is preferably 1.0% by weight or less, more preferably 0.5% by weight or less.

[0010] The MFR of component (A) (temperature 230°C, load 2.16 kg) is 0.3 to 10 g / 10 min. If the MFR is below the lower limit, the load on the molding machine during sheet molding increases, resulting in poor moldability, while if the MFR is above the upper limit, drawdown is likely to occur, resulting in poor secondary processability. From this perspective, the upper limit of the MFR is preferably 6 g / 10 min or less, and the lower limit is preferably 0.5 g / 10 min or more.

[0011] The polydispersity index (PI) of component (A) is 5 to 10. PI is an index of molecular weight distribution and is determined by viscoelasticity measurement and the complex modulus of elasticity, specifically the crossover modulus of elasticity. If the PI is below the lower limit, drawdown is likely to occur and rigidity is reduced, while if the PI is above the upper limit, the surface of the sheet becomes rough and transparency is reduced. From this perspective, the upper limit of PI is preferably 8 or less, and the lower limit is preferably 5.5 or more.

[0012] Component (A) is produced by a method of polymerizing the corresponding monomer using a solid catalyst containing, as essential components, Mg, Ti, a halogen, and an electron donor compound selected from succinate-based compounds, and a catalyst containing an organoaluminum compound.

[0013] (1-1) Solid catalyst (component (i)) Polymers polymerized using a catalyst containing a succinate compound as an internal electron donor (hereinafter referred to as "Suc catalyst") have a broad molecular weight distribution (high PI) and a uniform distribution of high and low molecular weight components. The molecular weight distribution is a physical quantity that can be determined by measurement. However, this measurement does not represent the degree of dispersion of the high and low molecular weight components. For example, by melt-kneading high and low molecular weight components in powder or pellet form using an extruder, or by multi-stage polymerization of components with different molecular weights using a catalyst other than a Suc catalyst, it is possible to obtain polymers with molecular weight distributions (measured values) that appear to be equivalent to those obtained by polymerization using a Suc catalyst. However, the degree of dispersion of the high and low molecular weight components differs between polymers obtained in this manner and those polymerized using a Suc catalyst, with the latter achieving a uniform degree of dispersion. This difference is significant in properties such as stiffness, impact resistance, processability, and appearance.

[0014] Component (i) can be prepared by known methods, for example, by contacting a magnesium (Mg) compound, a titanium (Ti) compound and an electron donor compound with each other.

[0015] The titanium compound used in the preparation of component (i) is represented by the general formula: Ti(OR) g X 4-g In the formula, R is a hydrocarbon group, X is a halogen, and 0≦g≦4. More specifically, the titanium compound includes titanium tetrahalides such as TiCl4, TiBr4, and TiI4; Ti(OCH3)Cl3, Ti(OC2H5)Cl3, and Ti(O n -C4H9)Cl3, Ti(OC2H5)Br3, Ti(OisoC4H9)Br3, and other alkoxytitanium trihalides; Ti(OCH3)2Cl2, Ti(OC2H5)2Cl2, Ti(O n -C4H9)2Cl2, Ti(OC2H5)2Br2, and other alkoxytitanium dihalides; Ti(OCH3)3Cl, Ti(OC2H5)3Cl, Ti(O n -C4H9)3Cl, Ti(OC2H5)3Br, etc.; monohalogenated trialkoxy titanium compounds such as Ti(OCH3)4, Ti(OC2H5)4, Ti(O n Among these, preferred are halogen-containing titanium compounds, particularly titanium tetrahalides, and particularly preferred is titanium tetrachloride.

[0016] Examples of magnesium compounds used in preparing component (i) include magnesium compounds having a magnesium-carbon bond or a magnesium-hydrogen bond, such as dimethylmagnesium, diethylmagnesium, dipropylmagnesium, dibutylmagnesium, diamylmagnesium, dihexylmagnesium, didecylmagnesium, ethylmagnesium chloride, propylmagnesium chloride, butylmagnesium chloride, hexylmagnesium chloride, amylmagnesium chloride, butylethoxymagnesium, ethylbutylmagnesium, butylmagnesium hydride, etc. These magnesium compounds can also be used in the form of a complex compound with, for example, organoaluminum, and may be in either liquid or solid form. Further preferred magnesium compounds include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; alkoxymagnesium halides such as methoxymagnesium chloride, ethoxymagnesium chloride, isopropoxymagnesium chloride, butoxymagnesium chloride, and octoxymagnesium chloride; allyloxymagnesium halides such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; alkoxymagnesiums such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium, and 2-ethylhexoxymagnesium; dialkoxymagnesiums such as dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium, dibutoxymagnesium, and ethoxymethoxymagnesium; and allyloxymagnesiums such as ethoxypropoxymagnesium, butoxyethoxymagnesium, phenoxymagnesium, and dimethylphenoxymagnesium.

[0017] The electron donor compound used in the preparation of component (i) is generally called an “internal electron donor compound.” In the present invention, an internal electron donor compound selected from succinate-based compounds that provide a broad molecular weight distribution is used.

[0018] The succinate compound refers to a diester of succinic acid or a diester of a substituted succinic acid. The succinate compound preferably used in the present invention is represented by the following formula (I):

[0019] [ka]

[0020] wherein the groups R1 and R2 are identical or different and may be C1-C, optionally containing heteroatoms. 20 and the groups R3 to R6 are the same or different and are hydrogen or C1 to C6, optionally containing heteroatoms. 20 and R3 to R6 are linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl groups, and groups R3 to R6 bonded to the same carbon atom or different carbon atoms may be bonded together to form a ring.

[0021] R1 and R2 are preferably C1-C8 alkyl, cycloalkyl, aryl, arylalkyl, and alkylaryl groups. Compounds in which R1 and R2 are selected from primary alkyls, especially branched primary alkyls, are particularly preferred. Examples of suitable R1 and R2 groups are C1-C8 alkyl groups, such as methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, and 2-ethylhexyl groups. Ethyl, isobutyl, and neopentyl groups are particularly preferred.

[0022] A preferred group of compounds represented by formula (I) is one in which R3 to R5 are hydrogen and R6 is a branched alkyl, cycloalkyl, aryl, arylalkyl, and alkylaryl group having 3 to 10 carbon atoms. Preferred examples of such monosubstituted succinate compounds include diethyl sec-butylsuccinate, diethyl thexylsuccinate, diethyl cyclopropylsuccinate, diethyl norbornylsuccinate, diethylperihydrosuccinate, diethyl trimethylsilylsuccinate, diethyl methoxysuccinate, diethyl p-methoxyphenylsuccinate, diethyl p-chlorophenylsuccinate, diethyl phenylsuccinate, diethyl cyclohexyl ... Ethyl benzyl succinate, diethyl cyclohexyl methyl succinate, diethyl t-butyl succinate, diethyl isobutyl succinate, diethyl isopropyl succinate, diethyl neopentyl succinate, diethyl isopentyl succinate, diethyl (1-trifluoromethylethyl) succinate, diethyl fluorenyl succinate, 1-ethoxycarbodiisobutylphenyl succinate, diisobutyl sec-butyl succinate, diisobutyl thixyl succinate nate, diisobutyl cyclopropyl succinate, diisobutyl norbornyl succinate, diisobutyl perihydrosuccinate, diisobutyl trimethylsilyl succinate, diisobutyl methoxysuccinate, diisobutyl-p-methoxyphenyl succinate, diisobutyl-p-chlorophenyl succinate, diisobutyl cyclohexyl succinate, diisobutyl benzyl succinate, diisobutyl cyclohexyl methyl succinate, diisobutyl t-butyl succinate , diisobutyl isobutylsuccinate, diisobutyl isopropyl succinate, diisobutyl neopentyl succinate, diisobutyl isopentyl succinate, diisobutyl (1-trifluoromethylethyl) succinate, diisobutyl fluorenyl succinate, dineopentyl-sec-butylsuccinate, dineopentyl thexyl succinate, dineopentyl cyclopropyl succinate, dineopentyl norbornyl succinate, dineopentyl perhydrosuccinate,Dineopentyl trimethylsilyl succinate, dineopentyl methoxysuccinate, dineopentyl-p-methoxyphenyl succinate, dineopentyl-p-chlorophenyl succinate, dineopentyl phenyl succinate, dineopentyl cyclohexyl succinate, dineopentyl benzyl succinate, dineopentyl cyclohexyl methyl succinate, dineopentyl-t-butyl succinate, dineopentyl isobutyl succinate, dineopentyl isopropyl succinate, dineopentyl neopentyl succinate, dineopentyl isopentyl succinate, dineopentyl (1-trifluoromethylethyl) succinate, and dineopentyl fluorenyl succinate.

[0023] Another preferred group of compounds within the scope of formula (I) is a C1-C6 alkyl group in which at least two groups from R3 to R6 are different from hydrogen and optionally contain heteroatoms. 20The alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl groups are selected from the group consisting of linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, and alkylaryl groups. Compounds in which two groups other than hydrogen are bonded to the same carbon atom are particularly preferred. Specifically, R3 and R4 are groups other than hydrogen, and R5 and R6 are hydrogen atoms. Preferred examples of such disubstituted succinates include diethyl-2,2-dimethylsuccinate, diethyl-2-ethyl-2-methylsuccinate, diethyl-2-benzyl-2-isopropylsuccinate, diethyl-2-cyclohexylmethyl-2-isobutylsuccinate, diethyl-2-cyclopentyl-2-n-butylsuccinate, diethyl-2,2-diisobutylsuccinate, diethyl-2-cyclohexyl-2-ethylsuccinate, diethyl-2-isopropyl-2-methylsuccinate, diethyl-2-tetradecyl-2-ethylsuccinate, diethyl-2-isobutyl-2-ethylsuccinate, diethyl-2-(1-trifluoromethylethyl)-2-methylsuccinate, diethyl-2-isopentyl-2-isobutylsuccinate, diethyl-2-phenyl-2-n-butylsuccinate, diisobutyl -2,2-dimethylsuccinate, diisobutyl-2-ethyl-2-methylsuccinate, diisobutyl-2-benzyl-2-isopropylsuccinate, diisobutyl-2-cyclohexylmethyl-2-isobutylsuccinate, diisobutyl-2-cyclopentyl-2-n-butylsuccinate, diisobutyl-2,2-diisobutylsuccinate, diisobutyl-2-cyclohexyl-2-ethylsuccinate, diisobutyl-2-isopropyl-2-methylsuccinate, diisobutyl-2-tetradecyl-2-ethylsuccinate, diisobutyl-2-isobutyl-2-ethylsuccinate, diisobutyl-2-(1-trifluoromethylethyl)-2-methylsuccinate, diisobutyl-2-isopentyl-2-isobutylsuccinate, diisobutyl-2-phenyl-2-n-butylsuccinate, dineopentyl-2,2-dimethylsuccinate, dineopentyl-2-ethyl-2-methylsuccinate, dineopentyl-2-benzyl-2-isopropylsuccinate, dineopentyl-2-cyclohexylmethyl-2-isobutylsuccinate, dineopentyl-2-cyclopentyl-2-n-butylsuccinate, dineopentyl-2,2-diisobutylsuccinate, dineopentyl-2-cyclohexyl-2-ethylsuccinate, dineopentyl-2-isopropyl-2-methylsuccinate, dineopentyl-2-tetradecyl-2-ethylsuccinate, dineopentyl-2-isobutyl-2-ethylsuccinate, dineopentyl-2-(1-trifluoromethylethyl)-2-methylsuccinate, dineopentyl-2-isopentyl-2-isobutylsuccinate, and dineopentyl-2-phenyl-2-n-butylsuccinate. ,

[0024] Furthermore, compounds in which at least two groups other than hydrogen are bonded to different carbon atoms are particularly preferred. Specifically, compounds in which R3 and R5 are groups other than hydrogen. In this case, R4 and R6 may be hydrogen atoms or groups other than hydrogen, but it is preferred that one of them is a hydrogen atom (trisubstituted succinate). Preferred examples of such compounds include diethyl-2,3-bis(trimethylsilyl)succinate, diethyl-2,2-sec-butyl-3-methylsuccinate, diethyl-2-(3,3,3-trifluoropropyl)-3-methylsuccinate, diethyl-2,3-bis(2-ethylbutyl)succinate, diethyl-2,3-diethyl-2-isopropylsuccinate, diethyl-2,3-diisopropyl-2-methylsuccinate, and diethyl-2,3 -Dicyclohexyl-2-methyldiethyl-2,3-dibenzylsuccinate, diethyl-2,3-diisopropylsuccinate, diethyl-2,3-bis(cyclohexylmethyl)succinate, diethyl-2,3-di-t-butylsuccinate, diethyl-2,3-diisobutylsuccinate, diethyl-2,3-dineopentylsuccinate, diethyl-2,3-diisopentylsuccinate, diethyl-2,3-(1-trifluoromethylethyl)succinate succinate, diethyl-2,3-tetradecylsuccinate, diethyl-2,3-fluorenylsuccinate, diethyl-2-isopropyl-3-isobutylsuccinate, diethyl-2-tert-butyl-3-isopropylsuccinate, diethyl-2-isopropyl-3-cyclohexylsuccinate, diethyl-2-isopentyl-3-cyclohexylsuccinate, diethyl-2-tetradecyl-3-cyclohexylmethylsuccinate, diethyl-2 -Cyclohexyl-3-cyclopentylsuccinate, diisobutyl-2,3-diethyl-2-isopropylsuccinate, diisobutyl-2,3-diisopropyl-2-methylsuccinate, diisobutyl-2,3-dicyclohexyl-2-methylsuccinate, diisobutyl-2,3-dibenzylsuccinate, diisobutyl-2,3-diisopropylsuccinate, diisobutyl-2,3-bis(cyclohexylmethyl)succinate, diisobutyl-2,3-Di-t-butylsuccinate, diisobutyl-2,3-diisobutylsuccinate, diisobutyl-2,3-dineopentylsuccinate, diisobutyl-2,3-diisopentylsuccinate, diisobutyl-2,3-(1-trifluoromethylethyl)succinate, diisobutyl-2,3-tetradecylsuccinate, diisobutyl-2,3-fluorenylsuccinate, diisobutyl-2-isopropyl-3-isobutylsuccinate, diisobutyl-2-te rt-Butyl-3-isopropylsuccinate, diisobutyl-2-isopropyl-3-cyclohexylsuccinate, diisobutyl-2-isopentyl-3-cyclohexylsuccinate, diisobutyl-2-tetradecyl-3-cyclohexylmethylsuccinate, diisobutyl-2-cyclohexyl-3-cyclopentylsuccinate, dineopentyl-2,3-bis(trimethylsilyl)succinate, dineopentyl-2,2-sec-butyl-3-methylsuccinate ester, dineopentyl-2-(3,3,3-trifluoropropyl)-3-methylsuccinate, dineopentyl-2,3-bis(2-ethylbutyl)succinate, dineopentyl-2,3-diethyl-2-isopropylsuccinate, dineopentyl-2,3-diisopropyl-2-methylsuccinate, dineopentyl-2,3-dicyclohexyl-2-methylsuccinate, dineopentyl-2,3-dibenzylsuccinate, dineopentyl-2,3-diisopropyl succinate, dineopentyl-2,3-bis(cyclohexylmethyl)succinate, dineopentyl-2,3-di-t-butylsuccinate, dineopentyl-2,3-diisobutylsuccinate, dineopentyl-2,3-dineopentylsuccinate, dineopentyl-2,3-diisopentylsuccinate, dineopentyl-2,3-(1-trifluoromethylethyl)succinate, dineopentyl-2,3-tetradecylsuccinate, 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, and dineopentyl-2-cyclohexyl-3-cyclopentyl succinate.

[0025] Among the compounds of formula (I), compounds in which some of the groups R3 to R6 are bonded together to form a ring can also be preferably used. Examples of such compounds include those listed in JP-A-2002-542347, such as 1-(ethoxycarbonyl)-1-(ethoxyacetyl)-2,6-dimethylcyclohexane, 1-(ethoxycarbonyl)-1-(ethoxyacetyl)-2,5-dimethylcyclopentane, 1-(ethoxycarbonyl)-1-(ethoxyacetylmethyl)-2-methylcyclohexane, and 1-(ethoxycarbonyl)-1-(ethoxy(cyclohexyl)acetyl)cyclohexane. Other suitable compounds include cyclic succinate compounds such as diisobutyl 3,6-dimethylcyclohexane-1,2-dicarboxylate and diisobutyl cyclohexane-1,2-dicarboxylate, as disclosed in WO 2009 / 069483. Other preferred examples of cyclic succinate compounds include the compounds disclosed in WO 2009 / 057747.

[0026] In the compound of formula (I), when groups R3 to R6 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 compounds in which groups R3 to R6 contain Group 15 atoms include the compounds disclosed in JP 2005-306910 A. On the other hand, examples of compounds in which groups R3 to R6 contain Group 16 atoms include the compounds disclosed in JP 2004-131537 A.

[0027] (1-2) Organoaluminum compound (component (ii)) The organoaluminum compounds of component (ii) include the following: trialkylaluminum such as triethylaluminum and tributylaluminum; Trikenylaluminum such as triisoprenylaluminum: dialkylaluminum alkoxides such as diethylaluminum ethoxide and dibutylaluminum butoxide; alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide;

[0028] Partially halogenated alkylaluminums such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromide, diethylaluminum chloride, dipropylaluminum chloride, dibutylaluminum chloride, etc.; Dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride; partially hydrogenated alkylaluminums such as alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride; Partially alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxychloride, butylaluminum butoxychloride, and ethylaluminum ethoxybromide.

[0029] (1-3) Electron donor compound (component (iii)) The catalyst for producing component (A) preferably contains an external electron donor compound as component (iii). Such a compound is preferably an organosilicon compound, and specific examples thereof include the following compounds: Trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane, bis-ethylphenyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltrimethoxysilane triethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, thexyltrimethoxysilane, n-butyltriethoxysilane, iso-butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris(β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, methyl(3,3,3-trifluoro-n-propyl)dimethoxysilane, cyclohexylethyldimethoxysilane, cyclopentyl-t-butoxydimethoxysilane, diisobutyldimethoxysilane, isobutylisopropyldimethoxysilane, n-propyltrimethoxysilane, di-n-propyldimethoxysilane, t-butylethyldimethoxysilane, t-butylpropyldimethoxysilane, t-butyl-t-butoxydimethoxysilane, isobutyltrimethoxysilane, cyclohexylisobutyldimethoxysilane, di-sec-butyldimethoxysilane, isobutylmethyldimethoxysilane, bis(decahydroisoquinolin-2-yl)dimethoxysilane, diethylaminotriethoxysilane, dicyclopentyl-bis(ethylamino)silane, tetraethoxysilane, tetramethoxysilane, isobutyltriethoxysilane. t-butyltrimethoxysilane, i-butyltrimethoxysilane, i-butylsec-butyldimethoxysilane, ethyl(perhydroisoquinolin-2-yl)dimethoxysilane, tri(isopropenyloxy)phenylsilane, i-butyli-propyldimethoxysilane, cyclohexyli-butyldimethoxysilane, cyclopentyli-butyldimethoxysilane, cyclopentylisopropyldimethoxysilane, phenyltriethoxysilane, p-tolylmethyldimethoxysilane,

[0030] Among these, ethyltriethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, t-butyltriethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-butylethyldimethoxysilane, t-butylpropyldimethoxysilane, t-butylt-butoxydimethoxysilane, t-butyltrimethoxysilane, i-butyltrimethoxysilane, isobutylmethyldimethoxysilane, i-butylsec-butyldimethoxysilane, ethyl(perhydroisoquinolin-2-yl)dimethoxysilane, bis(decahydroisoquinolin-2-yl)dimethoxysilane, tri(isopropenyloxy)phenylsilane, thexyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane , i-butyl i-propyl dimethoxysilane, cyclopentyl t-butoxy dimethoxysilane, dicyclopentyl dimethoxysilane, cyclohexyl methyl dimethoxysilane, cyclohexyl i-butyl dimethoxysilane, cyclopentyl i-butyl dimethoxysilane, cyclopentyl isopropyl dimethoxysilane, di-sec-butyl dimethoxysilane, diethylamino triethoxysilane, tetraethoxysilane, tetramethoxysilane, isobutyl triethoxysilane, phenyl methyl dimethoxysilane, phenyl triethoxysilane, bis p-tolyl dimethoxysilane, p-tolyl methyl dimethoxysilane, dicyclohexyl dimethoxysilane, cyclohexyl ethyl dimethoxysilane, 2-norbornane triethoxysilane, 2-norbornane methyl dimethoxysilane, diphenyl diethoxysilane, methyl (3,3,3-trifluoro-n-propyl) dimethoxysilane, ethyl silicate, and the like are preferred.

[0031] (1-4) Polymerization The raw material monomers are polymerized by contacting them with the catalyst prepared as described above. In this process, it is preferable to first perform prepolymerization using the catalyst. Prepolymerization is a process in which polymer chains, which serve as a foothold for the subsequent main polymerization of the raw material monomers, are formed on a solid catalyst component. Prepolymerization can be performed by a known method. Prepolymerization is usually performed at 40°C or below, preferably 30°C or below, and more preferably 20°C or below. The prepolymerized catalyst (prepolymerization catalyst) is then introduced into the polymerization reaction system to perform the main polymerization of the raw material monomers. Polymerization may be performed in a liquid phase, a gas phase, or a liquid-gas phase. The polymerization temperature is preferably room temperature to 150°C, more preferably 40°C to 100°C. The polymerization pressure is preferably in the range of 0.8 to 6.0 MPa when performed in the liquid phase and 0.5 to 3.0 MPa when performed in the gas phase. A conventional molecular weight modifier known in the art, such as a chain transfer agent (e.g., hydrogen or ZnEt2), may also be used.

[0032] A polymerization reactor having a gradient in monomer concentration or polymerization conditions may also be used. In such a polymerization reactor, for example, at least two polymerization zones may be connected, 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 zone consisting of a riser pipe, and another monomer is supplied and polymerized in a downcomer pipe connected to the riser pipe. The polymer product is recovered while circulating between the riser pipe and the downcomer pipe. This method includes a means for completely or partially preventing the gas mixture present in the riser pipe from entering the downcomer pipe. Furthermore, a gas or liquid mixture having a different composition from the gas mixture present in the riser pipe is introduced into the downcomer pipe. For example, the method described in JP-A-2002-520426 can be used as the polymerization method.

[0033] (2) Phosphate ester nucleating agent (component (B)) Nucleating agents are additives that promote or control the crystallization of resins. Examples include transparent nucleating agents, which are used to reduce the size of crystalline components in resins to increase transparency, and rigid nucleating agents, which are used to increase the amount of crystalline components in resins to increase rigidity. While the phosphate ester nucleating agents used in the present invention are typically rigid nucleating agents, the inventors have discovered that a phosphate ester nucleating agent with a specific average particle size can improve both transparency and rigidity. The inventors have also discovered that the formation of gamma crystals is suppressed by the phosphate ester nucleating agent. Because gamma crystal lamellae are less likely to thicken than alpha crystals and have a lower melting point, the formation of gamma crystals reduces heat resistance. Therefore, molded articles obtained from the compositions of the present invention have excellent heat resistance. These molded articles are particularly useful as injection-molded articles, sheets, and secondary processed sheet products (especially containers). This effect of suppressing gamma crystal formation is more pronounced when component (B) and component (C) are used in combination.

[0034] Component (B) can be any known material in the art. Among them, a phosphate ester or its metal salt in which an aromatic hydrocarbon group is bonded to a phosphate group is preferred. Specific examples of such phosphate ester-based nucleating agents include sodium 2,2-methylenebis(4,6-di-tert-butylphenyl) phosphate, aluminum 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate, and lithium 2,2'-methylenebis(4,6-di-tert-butylphenyl) phosphate.

[0035] The average particle size of component (B) is 1 to 10 μm, preferably 1 to 7 μm, and more preferably 2 to 6 μm. If the average particle size exceeds the upper limit, the transparency of the sheet decreases and fisheyes become noticeable, impairing the appearance. If the average particle size exceeds the lower limit, aggregation becomes more likely, which also causes fisheyes to occur and impairs the appearance.

[0036] In the present invention, the average particle diameter is measured by image analysis. Image analysis is a method in which two-dimensional images of each particle are processed, the diameters (circle-equivalent diameters) are measured by circular approximation, and the average value is calculated. This method preferably includes the following steps: 1) Place 10 mg of sample on a 100 cm2 area, taking care not to overlap particles. 2 The mixture is thinly dispersed in air onto a clean, colorless, transparent glass plate, and then sandwiched between two similar clean, colorless, transparent glass plates. 2) Images are obtained using a scanner (for example, GT-X8000 manufactured by Seiko Epson Corporation). 3) Using image analysis software (e.g., Asahi Kasei Engineering Corp.'s A-Zou-kun), images are captured and circular approximations are performed to measure the diameter of each particle. If component (B) is aggregated, the diameter of the aggregate is measured in the same manner as for individual particles, and the average diameter is calculated by combining this with the diameter of the individual particles.

[0037] The reason why the use of a phosphate ester-based nucleating agent having the above average particle size can improve both the transparency and rigidity of the sheet is not limited, but it is thought that the reduction in size increases the number of nucleating agent particles, thereby increasing the total surface area, increasing the number of crystal nuclei generated and increasing the degree of crystallization, and also suppressing light scattering due to the reduction in size of the nucleating agent and crystals, resulting in improved rigidity and transparency of the sheet. The average particle size of component (B) can be controlled by known methods. For example, in small-scale production, the desired average particle size can be achieved by manually grinding component (B) using a mortar, taking appropriate samples and checking the particle size while continuing the grinding process. Alternatively, in large-scale industrial production, component (B) can be mechanically ground using various grinders (mills) to achieve the desired average particle size. Examples of mills include high-speed rotary mills (hammer type, cage type, screen type, disc pin type), high-speed rotary mills with built-in classifiers (fixed impact plate type, turbo type, centrifugal classifier type, annular type), container-driven media mills (rolling ball type, pot type, tube type, conical type), vibration ball mills (circular vibration type, gyratory vibration type, centrifugal type), planetary mills, planetary ball mills, centrifugal fluidization mills, media stirring mills (tower type, stirring tank type, horizontal flow tank type, vertical flow tank type, annular type), air flow mills (air flow suction type, nozzle passage type, collision type, fluidized bed jet injection type), and consolidation shear mills (high-speed centrifugal roller type, inner piece type).

[0038] The amount of component (B) is 0.02 to 0.15 parts by weight per 100 parts by weight of component (A). If the amount exceeds the upper limit, not only is it difficult to obtain the effect of improving transparency, but the cost increases and economic efficiency decreases. If the amount exceeds the lower limit, the effect is insufficient. From this perspective, the lower limit of the amount of component (B) is preferably 0.03 parts by weight, and the upper limit is preferably 0.10 parts by weight, more preferably 0.06 parts by weight.

[0039] (3) Nonitol-based or sorbitol-based nucleating agent (ingredient (C)) To further enhance the transparency of the sheet, the polypropylene composition of the present invention may contain a nonitol-based nucleating agent or a sorbitol-based nucleating agent as component (C). These nucleating agents are generally known as transparent nucleating agents, and those known in the art can be used in the present invention. Specific examples of nonitol-based nucleating agents include 1,2,3-trideoxy-4,6:5,7-bis-[(4-propylphenyl)methylene]-nonitol. Also, examples of sorbitol-based nucleating agents include bis-1,3:2,4-(4'-ethylbenzylidene)1-allyl sorbitol, bis-1,3:2,4-(3'-methyl-4'-fluoro-benzylidene)1-propyl sorbitol, bis-1,3:2,4-(3',4'-dimethylbenzylidene)1'-methyl-2'-propenyl sorbitol, bis-1,3,2,4-dibenzylidene 2',3'-dibromopropyl sorbitol, bis-1,3,2,4-dibenzylidene 2'-bromo-3'-hydroxypropyl sorbitol, bis-1,3:2,4-(3'-bromo-4'-ethylbenzylidene) Examples of suitable sorbitols include 1,3:2,4-bis-o-(4-methylbenzylidene)-D-sorbitol, 1,3:2,4-bis-o-(benzylidene)-D-sorbitol, 1,3:2,4-bis-o-(3,4-dimethylbenzylidene)-D-sorbitol, 1,3:2,4-bis-o-(3,4-dimethylbenzylidene)-D-sorbitol, and 1,3:2,4-bis-o-(3,4-dimethylbenzylidene)-D-sorbitol. These may be used alone or in combination of two or more.

[0040] The amount of component (C) is preferably 0.1 to 0.5 parts by weight per 100 parts by weight of component (A). If the amount exceeds this upper limit, not only is it difficult to obtain an improved transparency effect, but the cost is high and economic efficiency is reduced. The amount of component (C) is the total amount of the nonitol-based nucleating agent and the sorbitol-based nucleating agent.

[0041] (4) Other ingredients The polypropylene composition of the present invention may contain a nucleating agent other than component (B) and component (C) to the extent that the effects of the present invention are not impaired. Examples of nucleating agents other than component (B) and component (C) include organic crystal nucleating agents such as triaminobenzene derivative nucleating agents, metal carboxylate nucleating agents, xylitol-based nucleating agents, and rosin-based nucleating agents. Examples of triaminobenzene derivative nucleating agents include 1,3,5-tris(2,2-dimethylpropanamido)benzene. Examples of metal carboxylate nucleating agents include sodium adipate, potassium adipate, aluminum adipate, sodium sebacate, potassium sebacate, aluminum sebacate, sodium benzoate, aluminum benzoate, aluminum di-para-t-butylbenzoate, titanium di-para-t-butylbenzoate, chromium di-para-t-butylbenzoate, and aluminum hydroxy-di-t-butylbenzoate. Examples of xylitol-based nucleating agents include bis-1,3:2,4-(5',6',7',8'-tetrahydro-2-naphthaldehyde benzylidene) 1-allyl xylitol and bis-1,3:2,4-(3',4'-dimethylbenzylidene) 1-propyl xylitol. Examples of rosin-based nucleating agents include rosin acid metal salt compounds or rosin acid partial metal salt compounds (e.g., rosin acid partial calcium salts) obtained by reacting rosin acid with metals such as calcium and magnesium. Examples of rosin acids include pimaric acid, sandaracopimaric acid, palustric acid, isopimaric acid, abietic acid, dehydroabietic acid, neoabietic acid, dihydropimaric acid, dihydroabietic acid, and tetrahydroabietic acid. The polypropylene composition of the present invention may contain one or more of these nucleating agents in addition to component (B) and component (C). The amount is more preferably 0.03 to 0.15 parts by weight per 100 parts by weight of component (A).

[0042] In the present invention, conventional additives commonly used in olefin polymers, such as antioxidants, chlorine absorbers, heat stabilizers, light stabilizers, UV absorbers, antiblocking agents, antistatic agents, antifogging agents, flame retardants, dispersants, copper inhibitors, neutralizing agents, plasticizers, antifoaming agents, crosslinking agents, peroxides, oil extenders, lubricants, and other organic and inorganic pigments, may be added. The amount of each additive may be a known amount. Furthermore, in the present invention, a masterbatch of component (B) or component (C), or a masterbatch of component (B) and a nucleating agent other than component (C), may be mixed with component (A). When the matrix polymer of the masterbatch is different from component (A), the polypropylene composition of the present invention contains the matrix polymer as another component.

[0043] The polypropylene composition of the present invention may contain a resin or elastomer other than the main component, as long as the effects of the present invention are not impaired. The polypropylene composition may contain only one type of resin or elastomer, or two or more types of resins or elastomers. The content may be a known amount. When an elastomer is blended with the polypropylene composition of the present invention to improve the impact resistance, it is preferable to use a copolymer of ethylene and an α-olefin having 3 or more carbon atoms, taking into account its affinity with polypropylene.

[0044] The polypropylene composition of the present invention may contain a filler to the extent that the effects of the present invention are not impaired. Fillers are added mainly for the purpose of improving the rigidity of the material, and examples thereof include organic fillers such as carbon fiber and cellulose fiber, as well as various inorganic fillers. In terms of classification by substance, examples of inorganic fillers include natural silicates or silicates such as talc, kaolinite, clay, bilophyllite, selinite, wollastonite, and mica; synthetic silicates or silicates such as hydrous calcium silicate, hydrous aluminum silicate, hydrous silica, and anhydrous silicic acid; carbonates such as calcium carbonate, heavy calcium carbonate, and magnesium carbonate; hydroxides such as aluminum hydroxide and magnesium hydroxide; and oxides such as zinc oxide and magnesium oxide.

[0045] Furthermore, examples of inorganic fillers that can be classified according to shape include the following: Powdered fillers such as synthetic silicates or silicates such as hydrous calcium silicate, hydrous aluminum silicate, hydrous silica, and anhydrous silica; plate-like fillers such as talc, kaolinite, clay, and mica; whisker-like fillers such as basic magnesium sulfate whiskers, calcium titanate whiskers, aluminum borate whiskers, sepiolite, PMF (Processed Mineral Filler), xonotlite, potassium titanate, and ellestadite; balloon-like fillers such as glass balloons and fly ash balloons; and fibrous fillers such as glass fiber.

[0046] To improve the dispersibility of these fillers, the fillers may be subjected to a surface treatment in advance, if necessary. The fillers used in the present invention are not limited, but considering their affinity with polypropylene, ease of procurement as raw materials, and economic efficiency, talc, calcium carbonate, mica, etc. are preferred. These fillers may be used alone or in combination of two or more. However, since a high filler content can reduce the transparency of the sheet, from this perspective, the upper limit of the content of these fillers is preferably 0.15 parts by weight or less, more preferably 0.10 parts by weight or less, and even more preferably 0.06 parts by weight or less, per 100 parts by weight of component (A), and the lower limit is preferably 0 parts by weight or more.

[0047] 2. Molded article of the present invention In the present invention, the term "sheet" refers to a member having a thickness of 150 μm or more. The sheet of the present invention can be produced by extrusion molding the polypropylene composition of the present invention. Alternatively, the sheet of the present invention can be produced by dry blending components (A) and (B), and optionally other components, followed by extrusion molding. The molding temperature may be as known, but a cylinder set temperature of 180 to 250°C is preferred. The sheet obtained in this manner can also be subjected to secondary processing such as vacuum forming or biaxial stretching. The temperature in the secondary processing is not particularly limited, but a temperature of 140 to 170°C is preferred. Secondary processing refers to processing a sheet, which is a primary processed molded product, and includes processing into a molded product having a different shape by compression molding, vacuum forming, pressure forming, vacuum pressure forming, etc., or fusing and joining sheets together. The resulting molded product is also referred to as a secondary processed molded product.

[0048] The sheet of the present invention preferably has a haze (as a measure of transparency) of 10% or less, more preferably 5% or less. The haze is measured in accordance with JIS K7136 using a haze measuring device (HM-150 model, manufactured by Murakami Color Research Laboratory Co., Ltd.), and the value (total haze) obtained by measuring the test piece as is is used as the haze, which is an index of transparency in the present invention. Furthermore, the sheet of the present invention preferably has a stiffness (as a measure of rigidity) of 1600 MPa or more, more preferably 1700 MPa or more.

[0049] The γ-crystal peak ratio of the molded article (preferably a sheet or injection-molded article) of the present invention, as determined by wide-angle X-ray diffraction, is preferably 0.60 or less. A γ-crystal peak ratio in this range results in a molded article with excellent heat resistance. From this perspective, the upper limit of the γ-crystal peak ratio is more preferably 0.55 or less. The lower limit is not limited, but in practice it is approximately 0.40 or more. The γ-crystal peak ratio is determined using a sample cut out from a test piece prepared according to the method described in JIS K6758. Specifically, the peak height (Hγ) of the γ-crystal 117 reflection (2θ=20.1°) and the peak height (Hα) of the α-crystal 130 reflection (2θ=18.5°) are measured by wide-angle X-ray diffraction, and the ratio is calculated using the following formula: γ crystal peak ratio = Hγ / Hα

[0050] The sheet of the present invention can be used for various purposes. For example, the sheet can be formed into a desired shape by die cutting, or can be subjected to secondary processing such as vacuum forming into containers. In particular, the sheet of the present invention has excellent transparency and rigidity, making it useful as a packaging material for food containers and lids for boxed lunches, noodles, salads, side dishes, frozen foods, ice, frozen desserts, chilled drinks, and the like. [Example]

[0051] (1) Production of polypropylene composition [Propylene homopolymer 1] A solid catalyst component (1) was prepared according to the method described in the examples of JP 2011-500907 A. Specifically, the procedure is as follows: Into a nitrogen-purged 500 mL four-neck round-bottom flask, 250 mL of TiCl4 was introduced at 0 °C. With stirring, 10.0 g of microspherical MgCl2·1.8C2H5OH and 9.1 mmol of diethyl-2,3-(diisopropyl)succinate were added. The microspherical MgCl2·1.8C2H5OH was prepared according to the method described in Example 2 of U.S. Pat. No. 4,399,054, except that it was operated at 3000 rpm instead of 10,000 rpm.

[0052] The temperature in the flask was raised to 100°C and maintained for 120 minutes. Then, the 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 TiCl4 was added, the mixture was reacted at 120°C for 60 minutes, and the supernatant liquid was siphoned off. The solid was washed six times with anhydrous hexane (6 x 100 mL) at 60°C.

[0053] The solid catalyst (1) was contacted with triethylaluminum (TEAL) and dicyclopentyldimethoxysilane (DCPMS) for 5 minutes at room temperature in amounts such that the weight ratio of TEAL to the solid catalyst was 18 and the weight ratio of TEAL / DCPMS was 10. The obtained catalyst system was suspended in liquid propylene and maintained at 20°C for 5 minutes to carry out prepolymerization.

[0054] The obtained prepolymerization catalyst (1-1) was introduced into a polymerization reactor to obtain propylene homopolymer 1. During the polymerization, the temperature and pressure were adjusted, and hydrogen was used as a molecular weight modifier. The polymerization temperature was 80°C, and the hydrogen concentration was 0.05 mol%. The MFR of the polymer (temperature 230°C, load 2.16 kg) was 0.8 g / 10 min, and the polydispersity index (PI) was 5.9.

[0055] [Propylene homopolymer 2] The prepolymerization catalyst (1-1) was introduced into a polymerization reactor to obtain propylene homopolymer 2. During polymerization, the temperature and pressure were adjusted, and hydrogen was used as a molecular weight modifier. The polymerization temperature was 80°C, and the hydrogen concentration was 0.10 mol%. The MFR of the polymer (temperature 230°C, load 2.16 kg) was 2.0 g / 10 min, and the polydispersity index (PI) was 6.0.

[0056] [Propylene homopolymer 3] The prepolymerization catalyst (1-1) was introduced into a polymerization reactor to obtain propylene homopolymer 3. During polymerization, the temperature and pressure were adjusted, and hydrogen was used as a molecular weight modifier. The polymerization temperature was 80°C, and the hydrogen concentration was 0.17 mol%. The MFR of the polymer (temperature 230°C, load 2.16 kg) was 5.0 g / 10 min, and the polydispersity index (PI) was 6.1.

[0057] [Propylene homopolymer 4] A solid catalyst component (2) was prepared by the method described in Example 1 of European Patent No. 674991. This solid catalyst was prepared by supporting Ti and diisobutyl phthalate as an internal donor on MgCl2 using the method described in the above patent. Hereinafter, a catalyst containing a phthalate compound such as diisobutyl phthalate as an internal electron donor compound will also be referred to as a "Ph catalyst." The solid catalyst (2) obtained above was contacted with TEAL and DCPMS at a weight ratio of 11 to the solid catalyst and a weight ratio of 10 to the TEAL / DCPMS at -5°C for 5 minutes. The resulting catalyst system was suspended in liquid propylene and maintained at 20°C for 5 minutes to undergo prepolymerization, resulting in a prepolymerized catalyst (2-1).

[0058] The resulting prepolymerization catalyst (2-1) was introduced into a polymerization reactor, and propylene was supplied as the monomer. Hydrogen was also supplied as a molecular weight modifier so that the hydrogen concentration in the polymerization reactor was 0.02 mol%. The polymerization temperature was set to 80°C, and the polymerization pressure was adjusted to synthesize a propylene homopolymer. The MFR (temperature 230°C, load 2.16 kg) of the polymer was 0.8 g / 10 min, and the polydispersity index (PI) was 4.0.

[0059] [Propylene copolymer 1] The solid catalyst (1) used in the production of propylene homopolymer 1 was contacted with TEAL and diisopropyldimethoxysilane (DIPMS) for 24 minutes at 12°C in amounts such that the weight ratio of TEAL to solid catalyst (1) was 11 and the weight ratio of TEAL / DIPMS was 3. The obtained catalyst system was prepolymerized by maintaining it in a suspended state in liquid propylene at 20°C for 5 minutes, and this was used as prepolymerization catalyst (1-2).

[0060] The prepolymerization catalyst (1-2) was introduced into a polymerization reactor, and propylene was fed as the monomer. A small amount of ethylene and hydrogen as a molecular weight modifier were also fed to the reactor so that the ethylene concentration in the reactor was 0.12 mol% and the hydrogen concentration was 0.09 mol%. The polymerization temperature was set to 70°C, and the polymerization pressure was adjusted to synthesize a propylene-ethylene copolymer. The polymer had an ethylene-derived unit content of 0.5 wt%, an MFR (temperature 230°C, load 2.16 kg) of 5.0 g / 10 min, and a polydispersity index (PI) of 5.9.

[0061] (2) Nucleating agent masterbatch [Nucleating Agent Masterbatch B-1 and B-2] As the phosphate ester-based nucleating agent for component (B), 2,2-methylenebis(4,6-di-tert-butylphenyl)phosphate sodium salt (CAS No. 85209-91-2) was prepared and pulverized in a mortar. Sampling was performed appropriately during pulverization, and the pulverization process was continued while checking the average particle size until the desired average particle size was achieved. 80 parts by weight of the masterbatch matrix polymer described below and 20 parts by weight of the pulverized phosphate ester-based nucleating agent were mixed by stirring for 1 minute in a Henschel mixer. The mixture was melt-kneaded and extruded using a Nakatani Machinery Co., Ltd. NVC φ50 mm single-screw extruder at a cylinder setting temperature of 230°C. The strands were cooled in water and then cut using a pelletizer to produce pellet-like nucleating agent masterbatch B-1.

[0062] Similarly, 70 parts by weight of a masterbatch matrix polymer described below, 20 parts by weight of a ground phosphate ester-based nucleating agent, and 10 parts by weight of talc (Neotalc UNI05 manufactured by Neolite Industries Co., Ltd., with an average particle size of 5 μm measured by laser diffraction) were mixed by stirring for 1 minute in a Henschel mixer. The mixture was melt-kneaded and extruded using an NVC φ50 mm single-screw extruder manufactured by Nakatani Machinery Co., Ltd., with a cylinder temperature set at 230°C. The strands were cooled in water and then cut with a pelletizer to produce nucleating agent masterbatch B-2 in the form of pellets.

[0063] [Nucleating Agent Masterbatches C-1 and C-2] Nucleating agent masterbatch C-1 in pellet form was produced in the same manner as in the production of nucleating agent masterbatch B-1, except that a commercially available nonitol-based nucleating agent (Millad NX8000J manufactured by Milliken) was used as component (C) instead of the phosphate ester-based nucleating agent of component (B) without being crushed. Similarly, a commercially available sorbitol-based nucleating agent (Millad 3988 manufactured by Milliken) was used to produce nucleating agent masterbatch C-2 in pellet form.

[0064] [Matrix polymer for masterbatch] Propylene homopolymer 4 was obtained by supplying hydrogen as a molecular weight modifier to a polymerization reactor so that the hydrogen concentration was 0.23 mol%, setting the polymerization temperature to 80°C, and adjusting the polymerization pressure. The MFR of this polymer (temperature 230°C, load 2.16 kg) was 7.0 g / 10 min, and the polydispersity index (PI) was 4.0.

[0065] [Example 1] To 100 parts by weight of propylene homopolymer 1, 0.2 wt% of BASF B225 as an antioxidant, 0.05 wt% of Dannan Chemical Industry Co., Ltd. calcium stearate as a neutralizing agent, masterbatch B-1 so that the amount of component (B) was the amount shown in Table 1, and masterbatch C-1 so that the amount of component (C) was the amount shown in Table 1 were blended, and the mixture was stirred and mixed for 1 minute using a Henschel mixer. The mixture was then extruded using a single-screw extruder (NVC, Nakatani Machinery Co., Ltd.) with a screw diameter of 50 mm at a cylinder set temperature of 230°C, and the strand was cooled in water and then cut using a pelletizer to obtain a polypropylene composition.

[0066] Test pieces were prepared by injection molding according to the method described in JIS K6758 and used to measure the γ crystal peak ratio and the deflection temperature under load (HDT), which will be described later.

[0067] Using a sheet molding machine equipped with a 40 mmφ single-screw extruder (manufactured by Tanabe Plastics Machinery Co., Ltd.) and a 375 mm wide T-die, the polypropylene composition was extruded under conditions of a cylinder set temperature of 230°C, a die set temperature of 230°C, a screw rotation speed of 30 rpm, and a discharge rate of 7 kg / h, and treated with an 80°C roll (nip pressure of 0.1 MPa) to produce a sheet with a thickness of 0.40 mm.

[0068] The resulting sheet was cut into 250 mm square pieces and then molded into tray-shaped containers using a small vacuum / compressed air molding machine (model FVS-500) manufactured by Wakisaka Engineering Co., Ltd., under conditions of a heater setting temperature of 360°C (both top and bottom), a heating time of 36 seconds, and a compressed air pressure of 0.6 MPa. The container shape as the molded product was 130 mm long, 100 mm wide, and 25.4 mm deep, with a flat portion (bottom) of 90 mm long, 60 mm wide, and 0.30 mm thick. The container was molded so that the longitudinal direction of the sheet was the MD. The sheet and container were evaluated as described below. Test specimens taken from the 0.30 mm thick flat portion (bottom) were used to measure the transparency and stiffness of the containers described below.

[0069] [Examples 2 and 3] Injection-molded articles, sheets and containers were produced and evaluated in the same manner as in Example 1, except that Propylene Homopolymer 1 was replaced with Propylene Homopolymers 2 and 3, respectively.

[0070] [Example 4] An injection-molded article, a sheet and a container were produced and evaluated in the same manner as in Example 1, except that Propylene Copolymer 1 was used instead of Propylene Homopolymer 1.

[0071] [Examples 5 and 6] Injection-molded articles, sheets, and containers were produced and evaluated in the same manner as in Example 2, except that the average particle size of component (B) was changed as shown in Table 1.

[0072] [Examples 7 and 8] Injection-molded articles, sheets, and containers were produced and evaluated in the same manner as in Example 2, except that the content of component (B) was changed as shown in Table 1.

[0073] [Example 9] Injection-molded articles, sheets, and containers were produced and evaluated in the same manner as in Example 2, except that nucleating agent masterbatch C-2 (sorbitol-based nucleating agent) was used instead of nucleating agent masterbatch C-1 (nonitol-based nucleating agent).

[0074] [Example 10] An injection-molded article, a sheet and a container were produced and evaluated in the same manner as in Example 2, except that component (C) (nucleating agent masterbatch C-1) was not used.

[0075] [Example 11] A sheet, an injection-molded article, and a container were produced and evaluated in the same manner as in Example 2, except that nucleating agent masterbatch B-2 was used instead of nucleating agent masterbatch B-1.

[0076] [Comparative Example 1] An injection-molded article, a sheet and a container were produced and evaluated in the same manner as in Example 1, except that Propylene Homopolymer 4 was used instead of Propylene Homopolymer 1.

[0077] Comparative Example 2 Injection-molded articles, sheets, and containers were produced and evaluated in the same manner as in Example 2, except that component (B) (nucleating agent masterbatch B-1) and component (C) (nucleating agent masterbatch C-1) were not used.

[0078] Comparative Example 3 An injection-molded article, a sheet and a container were produced and evaluated in the same manner as in Example 2, except that component (B) (nucleating agent masterbatch B-1) was not used.

[0079] Comparative Example 4 Injection-molded articles, sheets, and containers were produced and evaluated in the same manner as in Example 2, except that the amount of component (B) was changed as shown in Table 1.

[0080] Comparative Example 5 Injection-molded articles, sheets, and containers were produced and evaluated in the same manner as in Example 10, except that the average particle size of component (B) was changed as shown in Table 1.

[0081] [Table 1]

[0082] [Table 2]

[0083] The molded article of the present invention has high heat resistance. It is clear that the sheet and container of the present invention have a good appearance and have high transparency and high rigidity. It is also clear that the container, which is a secondary molded article of the sheet of the present invention, has a good appearance and has high transparency and high rigidity. The evaluation was carried out as follows:

[0084] [Average particle size of component (B)] For component (B), 10 mg of sample was placed on an area of ​​100 cm, taking care not to overlap particles. 2 The powder was thinly dispersed in air onto a clean, colorless, transparent glass plate, and then sandwiched between two clean, colorless, transparent glass plates. The particles were observed using a scanner (GT-X8000, manufactured by Seiko Epson Corporation) and images were obtained. The images were then imported using image analysis software (Asahi Kasei Engineering Co., Ltd., A-Image-kun), and the diameter of each particle was measured using a circular approximation. The average value was calculated and used as the average particle size of component (B). If component (B) was aggregated, the diameter of the aggregates and the diameter of the individual particles were averaged to calculate the average diameter.

[0085] [MFR] For propylene homopolymer or propylene copolymer, 0.05 g of H-BHT manufactured by Honshu Chemical Industry Co., Ltd. was added to 5 g of sample, and after homogenization with a dry bland, measurement was carried out at a temperature of 230°C and a load of 2.16 kg according to JIS K6921-2.

[0086] [Polydispersity index (PI)] For propylene homopolymers or propylene copolymers, 1 part by weight of H-BHT (Honshu Chemical Industry Co., Ltd.) was added, homogenized with a dry bland, and then measured at a temperature of 190°C using a PaarPhysica UDS200 operated at frequencies increasing from 0.1 rad / s to 100 rad / s. The polydispersity index (PI) was derived from the crossover modulus using the equation: PI=10 5 / Gc where Gc is the crossover modulus defined as the value (expressed as Pa) at which G' = G'', where G' is the storage modulus and G'' is the loss modulus.

[0087] [Content of ethylene-derived units] A sample of propylene homopolymer or propylene copolymer dissolved in a mixed solvent of 1,2,4-trichlorobenzene / deuterated benzene was measured using a Bruker AVANCEIII HD400 (13C resonance frequency 100MHz) under the following conditions: measurement temperature 120°C, flip angle 45°, pulse interval 7 seconds, sample rotation speed 20Hz, and cumulative number of 5000. 13 C-NMR spectra were obtained. Using the spectrum obtained above, the content (wt%) of ethylene-derived units in the propylene copolymer was determined by the method described in Kakugo, Y. Naito, K. Mizunuma and T. Miyatake, Macromolecules, 15, 1150-1152 (1982).

[0088] [γ-crystal peak ratio] Samples were cut from the surface of test pieces prepared by injection molding according to the method described in JIS K6758, and the gamma crystal content was evaluated by wide-angle X-ray diffraction. Since gamma crystal lamellae are less likely to thicken than alpha crystals and have a lower melting point, the formation of gamma crystals reduces heat resistance. The gamma crystal content was evaluated using the gamma crystal peak ratio according to the following equation. γ crystal peak ratio = Hγ / Hα Here, Hγ is the peak height of the 117 reflection (2θ=20.1°) of the γ crystal, and Hα is the peak height of the 130 reflection (2θ=18.5°) of the α crystal. X-ray diffraction was performed under the following measurement conditions. After removing the background from the obtained two-dimensional pattern, circular integration was performed at the azimuthal angle to eliminate the influence of orientation, and the 2θ (diffraction angle) dependence of the diffraction intensity was determined. X-ray diffractometer: Rigaku MicroMax and Rapid Wavelength: 0.154nm (Cu Kα) Output: 40kV, 30mA Exposure time: 300 seconds X-ray beam diameter: 0.8 μmφ (pinhole collimator) Detector; Imaging Plate The peak heights mentioned above include not only the reflections from the γ and α crystals but also the scattering from the amorphous phase common to both. Therefore, even in Example 2 (Fig. 1) where there is almost no reflection from the γ crystal, the γ crystal peak ratio shows a value of 0.52.

[0089] [HDT: Deflection temperature under load] The test piece was prepared according to the method described in JIS K6758 and measured according to JIS K7207.

[0090] [Transparency: Haze] According to JIS K7136, the haze of the sheet or container was measured using a haze measuring device (HM-150 model, manufactured by Murakami Color Research Laboratory Co., Ltd.) to evaluate transparency. For the container, the central part of the flat part (bottom) was used for measurement. The value obtained by measuring the sheet or container as is was taken as the total haze.

[0091] [Rigidity: Stiffness] Using sheets or containers as test specimens, Taber stiffness was measured at room temperature of 23°C in accordance with JIS P8125 using a Taber stiffness tester (TB-150). For sheets, 0.40 mm thick test specimens were cut into 7 cm x 3.8 cm pieces with the longitudinal direction in the take-off direction (MD) or its perpendicular direction (TD), and N=4 were measured, and the average values ​​of MD and TD were calculated. For containers, 0.30 mm thick test specimens were cut into 7 cm x 3.8 cm pieces with the longitudinal direction in the direction corresponding to the MD of the sheet from the flat part (bottom), and N=4 were measured, and the average values ​​were calculated.

[0092] [exterior] The sheet or container was visually inspected for the presence or absence of fish eyes.

Claims

1. Component (A) is a propylene polymer, The component (B) contains a phosphate ester-based nucleating agent having an average particle size of 1 to 10 μm as measured by image analysis, As component (C), a nonitol-based nucleating agent or a sorbitol-based nucleating agent is contained in an amount of 0.1 to 0.5 parts by weight per 100 parts by weight of component (A), Component (A) is a polymer obtained by polymerizing a corresponding monomer using a solid catalyst containing, as essential components, Mg, Ti, a halogen, and an electron donor compound selected from succinate-based compounds, and a catalyst containing an organoaluminum compound; The MFR of component (A) (temperature: 230°C, load: 2.16 kg) is 0.3 to 10 g / 10 min, The polydispersity index (PI) of component (A) is 5 to 10; Contains 0.02 to 0.15 parts by weight of component (B) per 100 parts by weight of component (A), Polypropylene composition.

2. A molded article produced from the polypropylene composition according to claim 1, wherein the molded article has a gamma crystal peak ratio of 0.60 or less as determined by wide-angle X-ray diffraction.

3. A sheet made from the polypropylene composition of claim 1.

4. A secondary molded product obtained by processing the sheet according to claim 3.

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