Process for producing propylene-based block copolymer

Abstract

To provide a method for producing a propylene-based block copolymer containing a propylene-ethylene-based copolymer at a high catalyst efficiency while reducing a gel without unnecessarily increasing the number of reactors in a multistage continuous polymerization method.SOLUTION: A production method of a propylene-based block copolymer includes a first step for polymerizing a crystalline propylene-based copolymer in the presence of a specific solid catalyst component and an organic aluminum compound using one or two or more vapor phase polymerization reactors and a second step for polymerizing an amorphous propylene-ethylene-based copolymer in the presence of the crystalline propylene-based copolymer using one or two or more vapor phase polymerization reactors. A mixed reaction inhibitor made of a mixture of a specific polyoxyalkylene-based compound and a specific alcohol compound is supplied under a specific condition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a propylene-based block copolymer. [Background technology]

[0002] Crystalline polypropylene, obtained by polymerizing propylene in the presence of a stereoregular catalyst, is a thermoplastic resin that is lightweight, has excellent rigidity and heat resistance, and is easily recycled, and is therefore widely used. On the other hand, in order to improve the impact resistance, which is a drawback of crystalline polypropylene, a widely known method is to produce crystalline polypropylene in the first polymerization stage, and then copolymerize propylene with another α-olefin, such as ethylene, in the second polymerization stage to contain amorphous propylene-ethylene copolymers to produce propylene-based block copolymers. For the production of such propylene-based block copolymers, a multi-stage continuous polymerization method is most commonly adopted from the viewpoint of economic efficiency. However, in the multi-stage continuous polymerization method, a distribution occurs in the residence time of the catalyst in each polymerization tank, which results in a distribution in the amount of polymerization per catalyst, and this non-uniformity causes a problem of a defective appearance called gel in the product. Furthermore, the intrinsic viscosity η of propylene-ethylene copolymers may be increased to give propylene-based block copolymers properties such as improved melt tension, reduced flow marks, and reduced surface gloss (matte finish), but it is known that such polymers are particularly susceptible to gel problems. As one of the countermeasures, a method is known in which the number of reactors for the crystalline propylene-based resin in the front stage is increased to narrow the residence time distribution (for example, Patent Document 1). As another countermeasure, a method is known in which a specific mesh is used in the process of melt-kneading a propylene-based block copolymer to physically break down the gel into fine particles or filter and remove the gel (eg, Patent Documents 2 to 3). Also known is a method of adding a specific electron donating compound as a reaction inhibitor to the reaction system in the latter or subsequent stages of propylene-ethylene copolymerization (for example, Patent Documents 4 to 7). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 62-149711 [Patent Document 2] Patent Publication 2016-199699 [Patent Document 3] Special table 2000-511967 [Patent Document 4] Patent Publication No. 2015-003981 [Patent Document 5] Patent Publication No. 2004-262993 [Patent Document 6] Patent Publication No. 63-251411 [Patent Document 7] Patent Publication No. 2001-261720 Summary of the Invention [Problem to be solved by the invention]

[0004] As mentioned above, propylene-based block copolymers containing propylene-ethylene copolymers with high intrinsic viscosity have excellent properties and are used in industrial sheets and automotive components, but there have been concerns about poor product appearance due to the generation of gel. The solution of increasing the number of reactors disclosed in Patent Document 1 leads to increased plant construction costs and complicated operation due to an increase in plant operation management items, so further technical improvements were required. The mesh-based refinement and filtration removal disclosed in Patent Documents 2 and 3 can be difficult to use in applications where fillers such as talc, carbon fiber, or glass fiber are added because the mesh becomes clogged. In addition, the finer the mesh openings used to improve the effect, the greater the pressure on the mesh becomes, making it necessary to reduce the production volume per unit time. As a result, there are economically disadvantageous problems. Therefore, the development of an improvement method based on a different principle was desired. The addition of electron donor compounds disclosed in Patent Documents 4 to 7 is effective, but there is a problem that the catalytic activity in propylene-ethylene copolymerization is significantly reduced depending on the type of electron donor compound and the supply method. Because of this problem, in order to achieve the target propylene-ethylene copolymer content, the average polymerization amount per unit catalyst in the upstream reactor must be intentionally suppressed, which is economically disadvantageous, and further improvement has been desired.

[0005] In view of the above-mentioned problems in the prior art, an object of the present invention is to provide a method for producing a propylene-based block copolymer containing a propylene-ethylene-based copolymer in a multi-stage continuous polymerization method while reducing gel and with high catalytic efficiency without increasing the number of reactors more than necessary. [Means for solving the problem]

[0006] The inventors predicted that the main cause of gel formation is that small particles, such as catalyst particles that pass through the first step with a short residence time and catalyst particles that contain a small amount of the product from the first step, undergo a polymerization reaction in the second step, resulting in the generation of particles that contain a higher than average amount of propylene-ethylene copolymer, which is difficult to disperse. Based on this prediction, the inventors conducted extensive research based on the idea that it may be possible to selectively prevent the polymerization of small particles by using a reaction inhibitor that is unevenly distributed at a relatively shallow depth of the particles, thereby suppressing the polymerization of the entire small particles and only the surface portions of large particles. As a result, the inventors have found that in a method for continuously producing a propylene-based block copolymer containing a propylene-ethylene copolymer, when an electron-donating mixture of a polyoxyalkylene compound represented by general formula (1) and an alcohol compound represented by general formula (2) is supplied as a reaction inhibitor in a specific ratio and by a specific method in a propylene-ethylene copolymerization step, small particles can inhibit polymerization in the entire particle, and large particles can inhibit polymerization only in the surface portion, while the large particles, which account for the majority of the catalytic activity, remain, thereby suppressing a decrease in catalytic activity and exhibiting an excellent effect of inhibiting gel formation, and have completed the present invention based on these findings.

[0007] That is, the method for producing a propylene-based block copolymer of the present invention comprises the steps of: in a first step, polymerizing a crystalline propylene-based polymer in the presence of an olefin polymerization catalyst containing a solid catalyst component containing magnesium, titanium, a halogen and an electron-donating compound as an internal donor and an organoaluminum compound, using one or more gas phase polymerization reactors; and in a second step, polymerizing an amorphous propylene-ethylene-based copolymer in the presence of the crystalline propylene-based polymer, using one or more gas phase polymerization reactors; The method is characterized in that a mixed reaction inhibitor consisting of a mixture of a polyoxyalkylene compound represented by general formula (1) and an alcohol compound represented by general formula (2) is supplied while satisfying the following conditions (α) to (γ). [General formula (1)] HO-[CH 2 -CH 2 -O]p -[CH 2 -CH(CH 3 )-O] q -[CH 2 -CH 2 -O] r -R 1 (In the general formula (1), p, q, and r are integers and satisfy the relational expressions of 0≦p≦30, 0≦q≦70, 0≦r≦30, 1≦p+r≦60, and 2≦p+q+r. R 1 represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms. [General formula (2)] H.O.R. 2 (In general formula (2), R 2 represents a saturated hydrocarbon group having 1 to 10 carbon atoms. (α): The polyoxyalkylene compound is mixed in a ratio of 10 to 150 parts by mass with respect to 100 parts by mass of the alcohol compound. (β): The polyoxyalkylene compound is supplied in an amount of 0.1 to 10 g per 1 g of the solid catalyst component. (γ): The mixed reaction inhibitor is supplied to the gas-phase polymerization reactor in the second step as a mixed flow with liquefied propylene.

[0008] In the method for producing the propylene-based block copolymer of the present invention, it is preferable to supply the alcohol compound in a molar ratio of 0.5 to 3.0 relative to the organoaluminum compound supplied in the first step in order to suppress the generation of gel.

[0009] In the method for producing the propylene-based block copolymer of the present invention, it is preferable from the viewpoint of productivity that the gas-phase polymerization reactor is a horizontal polymerization reactor in which the heat of polymerization is removed by using the heat of evaporation of liquefied propylene and which has an internal agitator rotating around a horizontal axis.

[0010] In the method for producing a propylene-based block copolymer of the present invention, it is preferable from the viewpoint of productivity to produce 40,000 g or more of a crystalline propylene-based polymer per 1 g of the olefin polymerization catalyst in the first step.

[0011] In the method for producing the propylene-based block copolymer of the present invention, it is preferable that the propylene-based block copolymer satisfies the conditions (a) to (d) from the viewpoint of suppressing the generation of gel. (a) When the propylene-based block copolymer is formed into an extruded sheet having a thickness of 2 mm, the number of gels having a major diameter of 300 μm or more is 3 / cm 2 Is less than or equal to (b) The intrinsic viscosity [η] of the propylene-ethylene copolymer is in the range of 7 to 12 dL / g. (c) The ethylene content in the propylene-ethylene copolymer is in the range of 15 to 90 mass %. (d) When the propylene-based block copolymer is taken as 100% by mass, the propylene-ethylene-based copolymer is 10 to 30% by mass, and the crystalline propylene-based polymer is 70 to 90% by mass.

[0012] In the method for producing the propylene-based block copolymer of the present invention, it is preferable to produce the copolymer in the presence of an olefin polymerization catalyst containing a solid component containing magnesium, titanium, a halogen, and an electron-donating compound as an internal donor, a vinylsilane compound, an organoaluminum compound, and an organosilicon compound other than the vinylsilane compound, in terms of increasing catalytic activity. Effect of the Invention

[0013] According to the present invention, there is provided a method for producing a propylene-based block copolymer containing a propylene-ethylene-based copolymer in a multi-stage continuous polymerization method while reducing gels and with high catalytic efficiency without increasing the number of reactors more than necessary. [Brief description of the drawings]

[0014] [Figure 1]FIG. 1 is a schematic explanatory diagram showing an example of the arrangement of a continuous horizontal gas phase reaction apparatus. [Diagram 2] FIG. 2 is a schematic explanatory diagram showing an example of the arrangement of a continuous vertical gas phase reaction apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The method for producing a propylene-based block copolymer of the present invention comprises, in a first step, polymerizing a crystalline propylene-based polymer in the presence of an olefin polymerization catalyst containing a solid catalyst component containing magnesium, titanium, a halogen and an electron-donating compound as an internal donor and an organoaluminum compound, using one or more gas phase polymerization reactors, and then, in a second step, polymerizing an amorphous propylene-ethylene-based copolymer in the presence of the crystalline propylene-based polymer, using one or more gas phase polymerization reactors, The method is characterized in that a mixed reaction inhibitor consisting of a mixture of a polyoxyalkylene compound represented by general formula (1) and an alcohol compound represented by general formula (2) is supplied while satisfying the following conditions (α) to (γ). [General formula (1)] HO-[CH 2 -CH 2 -O] p -[CH 2 -CH(CH 3 )-O] q -[CH 2 -CH 2 -O] r -R 1 (In the general formula (1), p, q, and r are integers and satisfy the relational expressions of 0≦p≦30, 0≦q≦70, 0≦r≦30, 1≦p+r≦60, and 2≦p+q+r. R 1 represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms. [General formula (2)] H.O.R. 2 (In general formula (2), R 2 represents a saturated hydrocarbon group having 1 to 10 carbon atoms. (α): The polyoxyalkylene compound is mixed in a ratio of 10 to 150 parts by mass with respect to 100 parts by mass of the alcohol compound. (β): The polyoxyalkylene compound is supplied in an amount of 0.1 to 10 g per 1 g of the solid catalyst component. (γ): The mixed reaction inhibitor is supplied to the gas-phase polymerization reactor in the second step as a mixed flow with liquefied propylene.

[0016] The method for producing a propylene-based block copolymer of the present invention comprises, in a first step, using at least one gas-phase polymerization reactor to homopolymerize propylene or copolymerize propylene with at least one monomer selected from ethylene and α-olefins having 4 to 8 carbon atoms to produce a crystalline propylene-based resin, and in a second step, using a gas-phase polymerization reactor to copolymerize propylene with ethylene and at least one monomer optionally selected from α-olefins having 4 to 8 carbon atoms to continuously produce an amorphous propylene-ethylene-based copolymer, and by supplying the specific mixed reaction inhibitor in a specific ratio and in a specific manner in the second step, it is possible to suppress a decrease in catalyst activity and to exhibit an excellent effect of suppressing gel generation. Therefore, the method for producing a propylene-based block copolymer of the present invention can produce a propylene-based block copolymer containing a high intrinsic viscosity propylene-ethylene-based copolymer with high catalyst efficiency while reducing gel without increasing the number of reactors more than necessary in a multi-stage continuous polymerization method. By supplying the specific mixed reaction inhibitor in a specific ratio and in a specific manner in the second step of gas-gas-phase polymerization, polymerization tends to be inhibited in the entire particles of small particles such as catalyst particles, and in only the surface portions of large polypropylene particles, while the large particles, which account for most of the catalytic activity, remain, and it is presumed that this exhibits an excellent effect of inhibiting gel formation while inhibiting a decrease in catalytic activity.

[0017] The following describes in detail an embodiment of the present invention. However, the description of the components described below is an example of an embodiment of the present invention, and the present invention is not limited to the contents described below as long as it does not go beyond the gist of the present invention. In this specification, the use of "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0018] I. Olefin Polymerization Catalysts The olefin polymerization catalyst used in the present invention is preferably a so-called Ziegler catalyst, which comprises component (A): a solid catalyst component containing magnesium, titanium, a halogen, and an electron donor compound as an internal donor, and component (B): an organoaluminum compound.

[0019] 1. Component (A): Solid catalyst component The solid catalyst component containing magnesium, titanium, halogen, and an electron donor compound as an internal donor may be a known one. The solid catalyst component may contain any component in any form other than the above four components as long as the effect of the present invention is not impaired.

[0020] (A1a: Magnesium source) As the magnesium source of the solid catalyst component, any magnesium compound can be used. Representative examples of the magnesium compound include the compounds disclosed in JP-A-3-234707. In general, magnesium halide compounds such as magnesium chloride, alkoxy magnesium compounds such as diethoxy magnesium, metallic magnesium, oxymagnesium compounds such as magnesium oxide, hydroxymagnesium compounds such as magnesium hydroxide, Grignard compounds such as butyl magnesium chloride, organomagnesium compounds such as butyl ethyl magnesium, magnesium salt compounds of inorganic and organic acids such as magnesium carbonate and magnesium stearate, and mixtures thereof and compounds whose average composition formula is a mixture of these (e.g., Mg(OEt)m Cl 2-m ; compounds such as those where 0 < m < 2, etc.) can be used. Among these, preferred are magnesium chloride, diethoxymagnesium, metallic magnesium, and butylmagnesium chloride.

[0021] (A1b: titanium source) As the titanium source for the solid catalyst component, any titanium compound can be used. Typical examples of titanium compounds include those disclosed in JP-A-3-234707. Regarding the valence of titanium, titanium compounds having any valence of tetravalent, trivalent, divalent, or zero-valent can be used, but preferably tetravalent and trivalent titanium compounds, and more preferably tetravalent titanium compounds are used. Specific examples of tetravalent titanium compounds include titanium halide compounds typified by titanium tetrachloride, alkoxytitanium compounds typified by tetrabutoxytitanium, alkoxytitanium condensation compounds having a Ti-O-Ti bond typified by tetrabutoxytitanium dimer (BuO) 3 Ti-O-Ti(OBu) 3 and organometallic titanium compounds typified by dicyclopentadienyltitanium dichloride, etc. Among these, titanium tetrachloride and tetrabutoxytitanium are particularly preferred. Specific examples of trivalent titanium compounds include titanium halide compounds typified by titanium trichloride. Titanium trichloride can be a compound produced by any known method such as hydrogen reduction type, metal aluminum reduction type, metal titanium reduction type, or organoaluminum reduction type. The above titanium compounds are not only used alone, but it is also possible to use a plurality of compounds in combination. Also, mixtures of the above titanium compounds and compounds having an average composition formula that is a mixed formula thereof (for example, Ti(OBu) m Cl 4-m ; compounds such as those where 0 < m < 4, etc.), and complexes with other compounds such as phthalic acid esters (for example, Ph(CO 2 Bu)2 TiCl 4 Compounds such as , etc. can be used.

[0022] (A1c: Halogen) The halogen in the solid catalyst component may be fluorine, chlorine, bromine, iodine or a mixture thereof, with chlorine being particularly preferred. As the halogen source for the solid catalyst component, the above-mentioned magnesium halide, titanium halide, etc. are usually used, but other halogen sources, such as AlCl 3 , AlBr 3 ,AlI 3 Aluminum halides such as BCl 3 , BBr 3 , B.I. 3 Boron halides such as SiCl 4 Silicon halides such as PCl 3 , PCl 5 Phosphorus halides such as WCl 6 Tungsten halides such as MoCl 5 Also usable are known halogen compounds such as halides of molybdenum such as those mentioned above.

[0023] (A1d: Electron-donating compound as internal donor) In polymerization techniques using Ziegler catalysts, it is generally believed that the functions of internal donors and external donors are different. The internal donor is a donor that is used simultaneously when the titanium compound is supported on the magnesium compound to form an active site, and it controls the location where the titanium atom is coordinated or changes the electronic state of the coordinated titanium atom. On the other hand, an external donor changes the properties of an active site that has already been formed. For example, by further using an external donor on a prepared solid catalyst component, it is possible to change the active site to a highly stereospecific one or to poison an active site that produces an amorphous component, thereby making it possible to produce a propylene-based polymer with higher stereoregularity and less amorphous components. Examples of the electron donor compound (internal donor) include oxygen-containing electron donor compounds such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, and acid anhydrides, nitrogen-containing electron donor compounds such as ammonia, amines, nitriles, and isocyanates, and sulfur-containing electron donor compounds such as sulfonic acid esters, etc. Specific examples include the compounds described in paragraph 0037 of JP2010-70584A. Among these, preferred are phthalate ester compounds represented by diethyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, and diheptyl phthalate; phthalate halide compounds represented by phthaloyl dichloride; malonate compounds having one or two substituents at the 2-position such as 2-n-butyl-diethyl malonate; succinate compounds having one or two substituents at the 2-position or one or more substituents at each of the 2-position and the 3-position such as 2-n-butyl-diethyl succinate; aliphatic polyvalent ether compounds represented by 1,3-dimethoxypropane having one or two substituents at the 2-position such as 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane; and polyvalent ether compounds having an aromatic free radical in the molecule such as 9,9-bis(methoxymethyl)fluorene. These electron donor compounds can be used alone or in combination of two or more compounds.

[0024] The solid catalyst component of the present invention can be prepared by contacting the above-mentioned magnesium compound, titanium compound, halogen compound and electron donor compound as an internal donor to form a solid component (A1). The amount of the titanium compound used is preferably within a range of 0.0001 to 1,000, particularly preferably 0.01 to 10, in terms of molar ratio (number of moles of titanium compound / number of moles of magnesium compound) relative to the amount of the magnesium compound used. When a halogen compound is used in addition to a magnesium compound and a titanium compound, the amount of the halogen compound used is preferably in the range of 0.01 to 1,000, particularly preferably in the range of 0.1 to 100, in terms of molar ratio (number of moles of halogen compound / number of moles of magnesium compound) to the amount of the magnesium compound used, regardless of whether the magnesium compound and the titanium compound each contain a halogen or not. The amount of the electron donor compound used as an internal donor is preferably within a range of 0.001 to 10, particularly preferably 0.01 to 5, in terms of molar ratio (number of moles of electron donor compound / number of moles of magnesium compound) relative to the amount of the magnesium compound used.

[0025] The solid catalyst component of the present invention may be one which, after the formation of the solid component (A1), has been further contacted with an organoaluminum compound (A2), an alkoxysilane compound (A3), a vinylsilane compound (A4), etc. For example, after the formation of the solid component (A1), it may be further contacted with an organoaluminum compound (A2) and an alkoxysilane compound (A3), or after the formation of the solid component (A1), it may be further contacted with an organoaluminum compound (A2), an alkoxysilane compound (A3), and a vinylsilane compound (A4).

[0026] (A2: Organoaluminum compounds) As the organoaluminum compound (A2) used in the solid catalyst component of the present invention, it is preferable to use a compound represented by the following general formula (3). [General formula (3)] R 3 s AIX t (OR 4 ) u (In general formula (3), R 3 is a hydrocarbon group, X is a halogen or a hydrogen atom, and R 4 is a hydrocarbon group having 1 to 20 carbon atoms or an aluminum bridging group, and s, t, and u are 1≦s≦3, 0≦t<2, 0≦u≦2, and s+t+u=3, respectively.

[0027] In general formula (3), R 3 R is a hydrocarbon group, preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 8 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 6 carbon atoms. 3 Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a hexyl group, an octyl group, etc. Among these, a methyl group, an ethyl group, and an isobutyl group are most preferred. In the formula, X is a halogen or a hydrogen atom. Examples of halogen usable as X include fluorine, chlorine, bromine, and iodine. Among these, chlorine is particularly preferred. In the formula, R 4 is a hydrocarbon group having 1 to 20 carbon atoms or an aluminum crosslinking group. R 4 When R is a hydrocarbon group, 3 Examples of hydrocarbon groups from the same group are 4 can be selected. In addition, alumoxane compounds such as methylalumoxane can be used as the organoaluminum compound. In this case, R 4 represents an aluminum bridging group. Here, the crosslinking group by Al is R 4 or R 4 It means an aluminum atom bridging a hydrocarbon group with a residue having a structure obtained by removing the group.

[0028] Specific examples of the organoaluminum compound include (a) trialkylaluminums such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and tri-n-decylaluminum, (b) alkylaluminum halides such as diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride, and ethylaluminum dichloride, (c) alkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride, and (d) alkylaluminum alkoxides such as diethylaluminum ethoxide and diethylaluminum phenoxide. Among these, triethylaluminum and triisobutylaluminum are preferred. The organoaluminum compound may be used not only as a single compound, but also as a combination of two or more compounds. The amount of the organoaluminum compound used is preferably within the range of 0.1 to 100, particularly preferably 1 to 50, in terms of the atomic ratio of aluminum to titanium (molar number of aluminum atoms / molar number of titanium atoms).

[0029] (A3: Alkoxysilane compound) As the alkoxysilane compound used in the solid catalyst component of the present invention, it is preferable to use a compound represented by the following general formula (4). [General formula (4)] R 5 R 6 f Si(OR 7 ) g (R 5 R represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. 6 R represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a heteroatom-containing hydrocarbon group. 7 represents a hydrocarbon group. f and g are numbers that satisfy 0≦f≦2, 1≦g≦3, and f+g=3.)

[0030] In the general formula (4), R5 represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. R 5 When R is a hydrocarbon group, it generally has 1 to 20 carbon atoms, and preferably has 3 to 10 carbon atoms. Specific examples include linear aliphatic hydrocarbon groups such as n-propyl groups, branched aliphatic hydrocarbon groups such as i-propyl groups and t-butyl groups, alicyclic hydrocarbon groups such as cyclopentyl groups and cyclohexyl groups, and aromatic hydrocarbon groups such as phenyl groups. More preferably, R 5 As the alkyl group, it is preferable to use a branched aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and in particular, it is preferable to use an i-propyl group, an i-butyl group, a t-butyl group, a thexyl group (1,1,2-trimethylpropyl group), a cyclopentyl group, a cyclohexyl group, or the like. R 5 When R is a heteroatom-containing hydrocarbon group, the heteroatom is preferably selected from nitrogen, oxygen, sulfur, phosphorus, and silicon, and is particularly preferably nitrogen or oxygen. 5 The backbone structure of the heteroatom-containing hydrocarbon group is R 5 is a hydrocarbon group. In particular, an N,N-diethylamino group, a quinolino group, an isoquinolino group, etc. are preferred. R 5 When is a heteroatom-containing hydrocarbon group, the heteroatom-containing hydrocarbon group may be bonded to Si via any atom, be it a carbon atom or a heteroatom, constituting the heteroatom-containing hydrocarbon group.

[0031] In the general formula (4), R 6 R represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a heteroatom-containing hydrocarbon group. 6 Examples of halogen atoms that can be used as the halogen atom include fluorine, chlorine, bromine, and iodine. R 6When is a hydrocarbon group, it generally has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. Specific examples include linear aliphatic hydrocarbon groups such as methyl and ethyl groups, branched aliphatic hydrocarbon groups such as i-propyl and t-butyl groups, alicyclic hydrocarbon groups such as cyclopentyl and cyclohexyl groups, and aromatic hydrocarbon groups such as phenyl groups. Among these, it is preferable to use methyl, ethyl, n-propyl, i-propyl, i-butyl, s-butyl, t-butyl, thexyl, cyclopentyl, and cyclohexyl groups. R 6 When R is a heteroatom-containing hydrocarbon group, 5 is a heteroatom-containing hydrocarbon group. In particular, an N,N-diethylamino group, a quinolino group, an isoquinolino group, etc. are preferred. R 6 When is a heteroatom-containing hydrocarbon group, the heteroatom-containing hydrocarbon group may be bonded to Si via any atom, be it a carbon atom or a heteroatom, constituting the heteroatom-containing hydrocarbon group. If the value of f is 2, there are two R 6 may be the same or different. Regardless of the value of f, R 6 is R 5 may be the same as or different from.

[0032] In the general formula (4), R 7 R represents a hydrocarbon group. 7 R generally has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms. 7 Specific examples of R include linear aliphatic hydrocarbon groups such as methyl and ethyl groups, and branched aliphatic hydrocarbon groups such as i-propyl and t-butyl groups. Among these, methyl and ethyl groups are preferred. When the value of g is 2 or more, multiple R 7 may be the same or different.

[0033] A preferred example of an alkoxysilane compound that can be used in the present invention is t-Bu(Me)Si(OMe). 2 , t-Bu(Me)Si(OEt) 2 , t-Bu(Et)Si(OMe) 2 , t-Bu(n-Pr)Si(OMe) 2 , c-Hex(Me)Si(OMe) 2 , c-Hex(Et)Si(OMe) 2 , c-Pen 2 Si(OMe) 2 , i-Pr 2 Si(OMe) 2 , i-Bu 2 Si(OMe) 2 , i-Pr(i-Bu)Si(OMe) 2 , n-Pr(Me)Si(OMe) 2 , t-BuSi(OEt) 3 , (Et 2 N) 2 Si(OMe) 2 , Et 2 N-Si(OEt) 3 , (Et 2 N) 2 (c-Pen)Si(OMe) and the like. Here, Me represents methyl, Et represents ethyl, t-Bu represents t-butyl, n-Pr represents n-propyl, i-Pr represents isopropyl, c-Hex represents cyclohexyl, and c-Pen represents cyclopentyl. The alkoxysilane compound can be used not only alone but also in combination of two or more compounds.

[0034] The amount of the alkoxysilane compound used may be any amount as long as the effects of the present invention are not impaired; however, the molar ratio of the alkoxysilane compound to titanium (moles of alkoxysilane compound / moles of titanium atoms) is preferably within the range of 0.01 to 1,000, and more preferably within the range of 0.1 to 100. The alkoxysilane compound used in the present invention is considered to be coordinated near the titanium atom that can be the active center, for example, Lewis acid sites on the magnesium support, and to control the catalytic performance such as catalytic activity and polymer regularity. However, such an action mechanism does not limit the technical scope of the present invention.

[0035] (A4: Vinylsilane compound) The vinylsilane compound used in the solid catalyst component of the present invention is monosilane (SiH 4 ) is a compound having a structure in which at least one hydrogen atom of the above-mentioned formula (1) is substituted with a vinyl group and some or all of the remaining hydrogen atoms are substituted with other free radicals. It is preferable to use a compound represented by the following general formula (5). [General formula (5)] [CH 2 =CH-] m Six n R 8 j (OR 9 ) k (In the general formula (5), X represents a halogen. R 8 R represents a hydrogen atom or a hydrocarbon group. 9 represents a hydrogen atom, a hydrocarbon group, or an organosilicon group. 1≦m≦4, 0≦n≦3, 0≦j≦3, 0≦k≦2, and m+n+j+k=4.

[0036] In the general formula (5), m represents the number of vinyl groups and takes a value of 1 or more and 4 or less. More preferably, the value of m is 1 or 2, and particularly preferably 2. In the general formula (5), X represents a halogen, and examples thereof include fluorine, chlorine, bromine, and iodine. When a plurality of halogens are present, they may be the same or different. Among these, chlorine is particularly preferred. n represents the number of halogens, and takes a value of 0 or more and 3 or less. More preferably, the value of n is 0 or more and 2 or less, and particularly preferably 0. In general formula (5), R 8represents a hydrogen atom or a hydrocarbon group, preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. 8 Examples of R include a hydrogen atom, an alkyl group such as a methyl group or a butyl group, a cycloalkyl group such as a cyclohexyl group, and an aryl group such as a phenyl group. 8 Examples of j include a hydrogen atom, a methyl group, an ethyl group, and a phenyl group. 8 and takes a value of 0 to 3. More preferably, the value of j is 1 to 3, even more preferably 2 to 3, and particularly preferably 2. When j is 2 or more, a plurality of R 8 may be the same or different. In general formula (5), R 9 R represents a hydrogen atom, a hydrocarbon group, or an organosilicon group. 9 When R is a hydrocarbon group, 8 can be selected from the same exemplary group as R 9 When R is an organosilicon group, it is preferably an organosilicon group having a hydrocarbon group having 1 to 20 carbon atoms. 9 Specific examples of organosilicon groups that can be used as the substituent include alkyl group-containing silicon groups such as trimethylsilyl groups, aryl group-containing silicon groups such as dimethylphenylsilyl groups, vinyl group-containing silicon groups such as dimethylvinylsilyl groups, and silicon groups formed by combining these groups, such as propylphenylvinylsilyl groups. k is R 9k represents the number of R and takes a value of 0 or more and 2 or less. In the case of a compound with k value of 3 such as vinyltriethoxysilane, the performance as a vinylsilane compound in the present invention is not exhibited, but the performance as an alkoxysilane compound in the present invention is exhibited, and therefore it is not suitable to use it as a vinylsilane compound. This is thought to be because it behaves in the same manner as t-butyltriethoxysilane, which is structurally similar (this t-butyltriethoxysilane is effective as an organosilicon compound having an alkoxy group in the present invention). More preferably, the value of k is 0 or more and 1 or less, and particularly preferably 0. When the value of k is 2, the two R 9 may be the same or different. Regardless of the value of k, R 8 and R 9 may be the same or different. These vinylsilane compounds can be used not only alone but also in combination of two or more compounds.

[0037] Preferred examples of vinylsilane compounds include CH 2 =CH-SiMe 3 , [CH 2 =CH-] 2 Sim 2 , C.H. 2 =CH-Si(Cl)Me 2 , C.H. 2 =CH-Si(Cl) 2 Me, C.H. 2 =CH-SiCl 3 , [CH 2 =CH-] 2 Si(Cl)Me,[CH 2 =CH-] 2 SiCl 2 , C.H. 2 =CH-Si(Ph)Me 2 , C.H. 2 =CH-Si(Ph) 2 Me, C.H. 2 =CH-SiPh 3 , [CH 2 =CH-] 2 Si(Ph)Me,[CH 2 =CH-] 2 SiPh2 , C.H. 2 =CH-Si(H)Me 2 , C.H. 2 =CH-Si(H) 2 Me, C.H. 2 =CH-SiH 3 , [CH 2 =CH-] 2 Si(H)Me,[CH 2 =CH-] 2 SiH 2 , C.H. 2 =CH-SiEt 3 , C.H. 2 =CH-SiBu 3 , C.H. 2 =CH-Si(Ph)(H)Me, CH 2 =CH-Si(Cl)(H)Me, CH 2 =CH-Si(Me) 2 (OMe), CH 2 =CH-Si(Me) 2 (OSiMe 3 ), C.H. 2 CH-Si(Me) 2 -OSi(Me) 2 -CH=CH 2 Among these, divinylsilane compounds in which m=2 are preferred, and divinyldimethylsilane ([CH 2 =CH-] 2 Sim 2 ) is particularly preferred. Here, Ph represents a phenyl group, and other symbols such as Me, Et, and Bu are as defined above.

[0038] The amount of the vinylsilane compound used may be any amount within a range that does not impair the effects of the present invention, but the molar ratio of the vinylsilane compound to titanium (moles of vinylsilane compound / moles of titanium atoms) is preferably within a range of 0.001 to 1000, and particularly preferably within a range of 0.01 to 100. The vinylsilane compound used in the present invention has a very high charge density at the carbon-carbon double bond, and is considered to be very fast in coordination with the titanium atom, which is the active center.Therefore, it is considered that the vinylsilane compound has an effect of preventing the over-reduction of the titanium atom by the organoaluminum compound and the deactivation of the active site by impurities.However, this mechanism of action does not limit the technical scope of the present invention.

[0039] (Method for preparing solid catalyst component) The solid catalyst component used in the present invention can be obtained by contacting the above-mentioned components constituting the solid catalyst component to form a solid component. The contact conditions for the components must be such that oxygen is not present, but any conditions can be used as long as the effects of the present invention are not impaired. In general, the following conditions are preferred: The contact temperature is about -50 to 200°C, preferably 0 to 150°C. Examples of the contact method include a mechanical method using a rotating ball mill or a vibrating mill, and a method in which the mixture is contacted by stirring in the presence of an inert diluent.

[0040] In preparing the solid catalyst component, intermediate and / or final washing with an inert solvent may be carried out. Preferred examples of the inert solvent include aliphatic hydrocarbon compounds such as heptane, aromatic hydrocarbon compounds such as toluene and xylene, and halogen-containing hydrocarbon compounds such as 1,2-dichloroethylene and chlorobenzene.

[0041] As a method for preparing the solid catalyst component, any method can be used. Specifically, the following methods (i) to (viii) can be exemplified.

[0042] (i) Co-grinding method The co-grinding method is a method in which a halogen-containing magnesium compound, typified by magnesium chloride, is co-grinded with a titanium compound to support the titanium compound on the magnesium compound. An electron donor compound may be co-grinded at the same time or in a separate step. A dry grinding method that does not use a solvent, a wet grinding method that co-grinds in the presence of an inert solvent, etc. can be used for grinding. Any grinding machine such as a rotary ball mill or a vibration mill can be used for grinding.

[0043] (ii) Heat treatment method The heat treatment method is a method in which a halogen-containing magnesium compound, typically magnesium chloride, and a titanium compound are heated by stirring in an inert solvent to carry out a contact treatment, thereby supporting the titanium compound on the magnesium compound. The contact treatment with an electron-donor compound may be carried out simultaneously or in a separate step. When a liquid compound such as titanium tetrachloride is used as the titanium compound, the contact treatment can be carried out without using an inert solvent. If necessary, an optional component such as a silicon halide compound may be contacted simultaneously or in a separate step. There is no particular limitation on the contact temperature, but it is often preferable to carry out the contact treatment at a relatively high temperature of about 90°C to 130°C.

[0044] (iii) Elution method The dissolution-precipitation method is a method in which a halogen-containing magnesium compound, such as magnesium chloride, is dissolved by contacting it with an electron-donating compound, and the resulting solution is brought into contact with a precipitating agent to cause a precipitation reaction, thereby forming particles. Among the above-mentioned electron donating compounds, examples of compounds that can be used for dissolution include alcohols and ethers. Examples of the precipitating agent include titanium halide compounds, silicon halide compounds, hydrogen chloride, halogen-containing hydrocarbon compounds, siloxane compounds having a Si-H bond (including polysiloxane compounds), aluminum compounds, and the like. The method for bringing the dissolving solution into contact with the precipitating agent may be to add the precipitating agent to the dissolving solution, or to add the dissolving solution to the precipitating agent. In either the dissolution or precipitation step, when a titanium compound is not used, the particles formed by the precipitation reaction are further contacted with a titanium compound, thereby supporting the titanium compound on the magnesium compound. If necessary, the particles formed by the above method may be contacted with an optional component such as a titanium halide compound or a silicon halide compound, or with an electron donor compound, which may be different from or the same as the compound used for dissolution. The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps or may be contacted together during dissolution, precipitation and contact with titanium compounds. An inert solvent may be present in any of the steps of dissolution, precipitation, and contact with an optional component.

[0045] (iv) Granulation method The granulation method is a method in which, like the dissolution-precipitation method, a halogen-containing magnesium compound, such as magnesium chloride, is dissolved by contacting it with an electron donor compound, and the resulting solution is granulated mainly by a physical method. Examples of the electron donor compound used for dissolution are the same as those in the dissolution-precipitation method. Examples of granulation techniques include a method of dropping a high-temperature solution into a low-temperature inert solvent, a method of spraying a solution from a nozzle toward a high-temperature gas phase and drying it, and a method of spraying a solution from a nozzle toward a low-temperature gas phase and cooling it. The particles formed by granulation are brought into contact with a titanium compound, thereby supporting the titanium compound on the magnesium compound. If necessary, the mixture may be contacted with an optional component such as a silicon halide compound or an electron donor compound. In this case, the electron donor compound may be different from or the same as that used for dissolution. The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps or may be contacted together when dissolving or contacting with the titanium compound. An inert solvent may be present in any of the steps of dissolution, contact with the titanium compound, and contact with the optional components.

[0046] (v) Halogenation of magnesium (Mg) compounds The halogenation method of a magnesium (Mg) compound is a method in which a halogen-free magnesium compound is contacted with a halogenating agent to halogenate the compound, and an electron donor compound may be contacted with the compound simultaneously or in a separate step. Examples of halogen-free magnesium compounds include dialkoxymagnesium compounds, magnesium oxide, magnesium carbonate, and magnesium salts of fatty acids. When a dialkoxymagnesium compound is used, it is also possible to use one prepared in situ by reacting metallic magnesium with an alcohol. When using this preparation method, it is common to form particles by granulation or the like at the stage of the starting material, the magnesium compound not containing a halogen. Examples of the halogenating agent include titanium halide compounds, silicon halide compounds, and phosphorus halide compounds. When a titanium halide compound is not used as the halogenating agent, the halogen-containing magnesium compound formed by halogenation is further contacted with a titanium compound to support the titanium compound on the magnesium compound. If necessary, the particles formed by the above method may be contacted with an optional component such as a titanium halide compound or a silicon halide compound, or may be contacted with an electron donating compound. The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps, or they may be contacted together with the halogenation of a halogen-free magnesium compound or the contact with a titanium compound. An inert solvent may be present in either step of contacting with the titanium halide compound or the step of contacting with the optional component.

[0047] (vi) Precipitation from organomagnesium compounds The precipitation method from an organomagnesium compound is a method in which a precipitating agent is brought into contact with a solution of an organomagnesium compound, such as a Grignard reagent represented by butylmagnesium chloride or a dialkylmagnesium compound, and the electron donor compound may be contacted with the organomagnesium compound simultaneously or in a separate step. Examples of the precipitating agent include titanium compounds, silicon compounds, and hydrogen chloride. When a titanium compound is not used as the precipitating agent, the particles formed by the precipitation reaction are further contacted with a titanium compound, thereby supporting the titanium compound on the magnesium compound. If necessary, the particles formed by the above method may be contacted with an optional component such as a titanium halide compound or a silicon halide compound, or may be contacted with an electron donating compound. There is no particular restriction on the order of contacting these optional components, and they may be contacted as independent steps or together during precipitation or contact with a titanium compound. An inert solvent may be present in any of the steps of precipitation, contact with the titanium compound, and contact with the optional component.

[0048] (vii) Impregnation method The impregnation method is a method in which a solution of an organomagnesium compound or a solution in which a magnesium compound is dissolved in an electron donor compound is impregnated into an inorganic compound support or an organic compound support. Examples of the organomagnesium compound are the same as those in the example of the precipitation method from an organomagnesium compound. The magnesium compound used for dissolving the magnesium compound may or may not contain a halogen, and examples of the electron donor compound are the same as those in the example of the dissolution-precipitation method. Examples of inorganic carriers include silica, alumina, and magnesia. Examples of organic carriers include polyethylene, polypropylene, polystyrene, and the like. After the impregnation treatment, the carrier particles are subjected to a chemical reaction with a precipitating agent or a physical treatment such as drying to precipitate and immobilize the magnesium compound. Examples of the precipitating agent are the same as those in the dissolution-precipitation method. When a titanium compound is not used as a precipitating agent, the particles thus formed are further contacted with a titanium compound to support the titanium compound on the magnesium compound. If necessary, the particles thus formed may be further contacted with an optional component such as a titanium halide compound or a silicon halide compound, or may be contacted with an electron donor compound. The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps, or they may be contacted together during impregnation, precipitation, drying, and contact with a titanium compound. In addition, an inert solvent may be present in any of the steps of impregnation, precipitation, contact with a titanium compound, and contact with an optional component.

[0049] (viii) Combined method The above methods (i) to (vii) can also be used in combination. Examples of the combination include "a method of co-grinding magnesium chloride with an electron donor compound, followed by heat treatment with a titanium halide compound", "a method of co-grinding a magnesium chloride compound with an electron donor compound, followed by dissolving it with another electron donor compound, and then precipitating it with a precipitating agent", "a method of dissolving a dialkoxy magnesium compound with an electron donor compound, contacting it with a titanium halide compound to precipitate and simultaneously halogenate the magnesium compound", and "a method of contacting a dialkoxy magnesium compound with carbon dioxide to generate and simultaneously dissolve a magnesium carbonate ester compound, impregnating silica with the resulting solution, then contacting it with hydrogen chloride to halogenate the magnesium compound, simultaneously precipitating and fixing it, and further contacting it with a titanium halide compound to support the titanium compound".

[0050] When the solid catalyst component is a solid component (A1) that has been formed and then contacted with an organoaluminum compound (A2), an alkoxysilane compound (A3), a vinylsilane compound (A4), etc., the method for contacting each component is not particularly limited, but generally, the above components can be contacted with each other while stirring in the presence of an inert solvent. Examples of the inert solvent include liquid saturated hydrocarbons such as hexane, heptane, octane, decane, dodecane, and liquid paraffin, and silicone oils having a dimethylpolysiloxane structure. These inert solvents may be used alone or in combination of two or more. It is preferable to use the inert solvent after removing impurities such as oxygen, moisture, and sulfur compounds that adversely affect polymerization. Any contact conditions can be adopted as long as the effects of the present invention are not impaired. The contact temperature is usually about -50°C to 200°C, preferably -10°C to 100°C, more preferably 0°C to 70°C, and further preferably 10°C to 60°C.

[0051] When the solid catalyst component is a solid component (A1) that has been formed and then contacted with an organoaluminum compound (A2) and an alkoxysilane compound (A3), any procedure can be used for the contact procedure of the solid component (A1), the organoaluminum compound (A2), and the alkoxysilane compound (A3). Specific examples include the following procedures (i) to (iv), among which procedures (i) and (ii) are preferred. Step (i): A method in which a solid component (A1) is contacted with an alkoxysilane compound (A3) and then with an organoaluminum compound (A2). Procedure (ii): A method in which the solid component (A1) is contacted with an organoaluminum compound (A2) and then with an alkoxysilane compound (A3). Step (iii): A method in which an alkoxysilane compound (A3) is contacted with an organoaluminum compound (A2), and then contacted with a solid component (A1). Step (iv): All components are contacted simultaneously.

[0052] The number of contacts between the solid component (A1), the organoaluminum compound (A2), and the alkoxysilane compound (A3) can be any number of times. In this case, the components used multiple times may be the same or different from each other. In addition, although the preferred range of the amount of each component to be used was given above, this is the amount used per contact. When the components are contacted multiple times, the components may be contacted any number of times as long as the amount used per contact falls within the range of the amount used above. When the solid catalyst component is contacted with other components, any contacting method, contacting conditions and contacting procedures can be employed.

[0053] When the solid catalyst component is a solid component (A1) that has been formed and then contacted with an organoaluminum compound (A2), an alkoxysilane compound (A3) and a vinylsilane compound (A4), any procedure can be used for the contact procedure of the solid component (A1), the organoaluminum compound (A2), the alkoxysilane compound (A3) and the vinylsilane compound (A4). Specific examples include the following procedures (iv) to (vii), among which procedures (iv) and (v) are preferred. Procedure (iv): A method in which the solid component (A1) is contacted with a vinylsilane compound (A4), then with an alkoxysilane compound (A3), and then with an organoaluminum compound (A2). Step (v): A method of contacting an alkoxysilane compound (A3) with a vinylsilane compound (A4), then contacting the solid component (A1), and then contacting an organoaluminum compound (A2). Step (vi): A method in which the solid component (A1) is contacted with a vinylsilane compound (A4), and then with an alkoxysilane compound (A3) and an organoaluminum compound (A2). Step (vii): All components are contacted simultaneously.

[0054] The number of times that the solid component (A1) is contacted with the organoaluminum compound (A2), the alkoxysilane compound (A3), and the vinylsilane compound (A4) can be any number of times. In this case, the components used multiple times may be the same or different from each other. In addition, although the preferred range of the amount of each component to be used was given above, this is the amount used per contact. When the components are contacted multiple times, the components may be contacted any number of times as long as the amount used per contact falls within the range of the amount used above. When the solid catalyst component is contacted with other components, any contacting method, contacting conditions and contacting procedures can be employed.

[0055] (Prepolymerization of solid catalyst component) The solid catalyst component may be prepolymerized. In the presence of the solid catalyst component, a compound having an ethylenic double bond is polymerized in small amounts as a monomer (prepolymerized monomer) under mild conditions, so that a part or all of the prepolymerized monomer is polymerized to become a polymer (prepolymerized polymer) of the compound having an ethylenic double bond, and the solid catalyst component suitable for polymerization of a propylene-based block copolymer can be obtained.

[0056] Examples of the prepolymerization monomer include olefins such as ethylene, propylene, 1-butene, 3-methylbutene-1, 4-methylpentene-1, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 4-methyl-1-pentene, and 3-methyl-1-pentene; styrene analogs such as styrene, α-methylstyrene, allylbenzene, and chlorostyrene; and diene compounds such as 1,3-butadiene, isoprene, 1,3-pentadiene, 1,5-hexadiene, 2,6-octadiene, dicyclopentadiene, 1,3-cyclohexadiene, 1,9-decadiene, and divinylbenzenes. Among these, ethylene, propylene, 3-methylbutene-1, 4-methylpentene-1, styrene, divinylbenzenes, etc. are preferable. These may be used alone or in combination of two or more. In order to adjust the molecular weight of the polymer formed by the prepolymerization, a molecular regulator such as hydrogen can also be used in combination. The solid catalyst component obtained by prepolymerization contains a polymer (prepolymerized polymer) of a compound having an ethylenic double bond. When propylene is homopolymerized or copolymerized using this solid catalyst component, the prepolymerized polymer functions as a shell, which has the effect of suppressing the generation of fine powder due to cracking of catalyst particles in the main polymerization. The amount of the prepolymerized monomer used is preferably 0.1 part by mass or more, more preferably 0.2 part by mass or more, even more preferably 0.4 part by mass or more, and still more preferably 0.5 part by mass or more, per part by mass of the solid catalyst component before prepolymerization, from the viewpoint of producing a sufficient amount of prepolymerized polymer in the prepolymerization process. The upper limit of the amount of the prepolymerized monomer used is not limited, but from the viewpoint of preventing the production amount of the prepolymerized polymer from being unnecessarily large, the amount of the prepolymerized monomer used is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and further preferably 10 parts by mass or less, per part by mass of the solid catalyst component before prepolymerization. The amount of the prepolymerized polymer contained in the solid catalyst component after the prepolymerization, i.e., the prepolymerization amount, is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, even more preferably 0.4 parts by mass or more, and even more preferably 0.5 parts by mass or more, per part by mass of the solid catalyst component before the prepolymerization. When the prepolymerization amount is within the above range, the effect of suppressing the generation of fine powder due to cracking of catalyst particles can be obtained. Although there is no upper limit for the amount of prepolymerization, from the viewpoints of productivity and economic efficiency, the amount is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per part by mass of the solid catalyst component before prepolymerization, because if the amount of prepolymerization is larger than the above range, the performance of the catalyst will reach a plateau.

[0057] The method of prepolymerization is not particularly limited, but generally, prepolymerization is performed while stirring in the presence of an inert solvent. Examples of the inert solvent include liquid saturated hydrocarbons such as hexane, heptane, octane, decane, dodecane, and liquid paraffin, and silicone oils having a dimethylpolysiloxane structure. These inert solvents may be either one type or a mixed solvent of two or more types. It is preferable to use the inert solvent after removing impurities such as oxygen, moisture, and sulfur compounds that adversely affect polymerization. As the conditions for the prepolymerization, any conditions can be adopted as long as the effects of the present invention are not impaired. The reaction temperature for the prepolymerization is usually about -50°C to 200°C, preferably -10°C to 100°C, and more preferably 0°C to 70°C.

[0058] The prepolymerization may be carried out in the presence of an organoaluminum compound. As the organoaluminum compound, the same as the above-mentioned organoaluminum compound (A2) can be mentioned. The amount of the organoaluminum compound in the prepolymerization step is preferably in the range of 0.1 to 40 mol, more preferably 0.3 to 20 mol, per mol of titanium atom in the solid catalyst component. The prepolymerization may be carried out in the presence of an alkoxysilane compound. Examples of the alkoxysilane compound include the same as the alkoxysilane compound (A3) described above. The amount of the alkoxysilane compound in the prepolymerization step is preferably in the range of 0.01 to 10 moles per mole of titanium contained in the solid catalyst component. The prepolymerization may be carried out in several separate steps, and the prepolymerized monomers used in these steps may be the same or different. After the prepolymerization, the catalyst may be washed with an inert solvent such as hexane or heptane. After the prepolymerization, the catalyst may be used as it is, or may be dried, depending on the form of use of the catalyst. Furthermore, as long as the effects of the present invention are not impaired, optional components may be added during or after washing or drying after the prepolymerization. Examples of optional components include polymers such as polyethylene, polypropylene, and polystyrene, and inorganic oxide solids such as silica and titania.

[0059] 2. Component (B): Organoaluminum compound In the present invention, the organoaluminum compound (B) usable as the olefin polymerization catalyst in the main polymerization may include the compounds disclosed in JP-A-2004-124090, etc. Preferably, it may be selected from the same group as the examples of the organoaluminum compound (A2) given as a component for preparing the solid catalyst component (A). The organoaluminum compound (B) may be the same as or different from the organoaluminum compound (A2) used in preparing the solid catalyst component (A). The organoaluminum compound (B) may be used either alone or in combination of two or more kinds. The amount of the organoaluminum compound (B) used is, in terms of a molar ratio to the titanium component constituting the solid catalyst component (A) (number of moles of organoaluminum compound / number of moles of titanium atoms in the solid catalyst component), preferably within the range of 1 to 5,000, particularly preferably within the range of 10 to 500.

[0060] 3. Electron-donating compounds as external donors In the present invention, the olefin polymerization catalyst may contain an electron donating compound as an external donor as a constituent component. In the polymerization technique using a Ziegler catalyst, as described above, the external donor changes the properties of the already formed active sites. For example, by further using an external donor on a prepared solid catalyst component, it is possible to change the active sites to highly stereospecific ones or to poison the active sites which generate amorphous components, so that it is possible to produce a propylene-based polymer with higher stereoregularity and less amorphous components. Examples of the electron donor compound (external donor) include an organosilicon compound (C), a compound having at least two ether bonds (D), a compound having a C(=O)N bond in the molecule (E), a sulfite compound (F), etc. The electron donor compound may be used alone or in combination of two or more kinds.

[0061] (Organosilicon Compounds (C)) As the organosilicon compound (C), compounds disclosed in JP-A-2004-124090 and the like can be used. Preferably, it can be selected from the same group as the examples of the alkoxysilane compound (A3) used in preparing the solid catalyst component (A). The organosilicon compound (C) may be the same as or different from the alkoxysilane compound (A3) used in preparing the solid catalyst component (A). The organosilicon compound (C) may be used either alone or in combination of two or more kinds.

[0062] (Compound (D) having at least two ether bonds) As the compound (D) having at least two ether bonds, compounds disclosed in JP-A-3-294302 and JP-A-8-333413 can be used. In general, it is preferable to use a compound represented by the following formula: [General formula (6)] R 13 OC(R 12 ) 2 -C(R 11 ) 2 -C(R 12 ) 2 -OR 13 (In general formula (6), R 11 and R 12 R represents any radical selected from a hydrogen atom, a hydrocarbon group, or a heteroatom-containing hydrocarbon group. 13 represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. Specific examples of the compound having at least two ether bonds include 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 9,9-bis(methoxymethyl)fluorene, etc. The compound having at least two ether bonds can be used not only alone but also in combination with a plurality of compounds.

[0063] (Compound (E) having a C(=O)N bond in the molecule) As the compound having a C(=O)N bond in the molecule, the compounds disclosed in JP-A-2004-124090 and the like can be used. Preferable examples include tetramethylurea, 1,3-dimethyl-2-imidazolidinone, and 1-ethyl-2-pyrrolidinone.

[0064] (Sulfite Compounds (F)) As the sulfite compound, the compounds disclosed in JP-A-2006-225449 and the like can be used. Preferred examples include dimethyl sulfite and diethyl sulfite.

[0065] The amount of the electron donor compound (external donor) used is preferably in the range of 0.01 to 10,000, particularly preferably in the range of 0.5 to 500, in terms of the molar ratio to the titanium constituting the solid catalyst component (number of moles of electron donor compound / number of moles of titanium atoms in the solid catalyst component).

[0066] II. Method for producing propylene-based block copolymer 1. Polymerization process In the production method of the present invention, in the first step, a crystalline propylene-based polymer is polymerized in the presence of an olefin polymerization catalyst containing a solid catalyst component (A) and an organoaluminum compound (B) using one or more gas phase polymerization reactors, and in the subsequent second step, an amorphous propylene-ethylene-based copolymer is polymerized in the presence of the crystalline propylene-based polymer using one or more gas phase polymerization reactors, thereby producing a propylene-based block copolymer. In the present invention, the crystalline propylene-based polymer means one that has stereoregularity and can form lamellae, and means a polymer having a propylene skeleton with a relatively small comonomer content in a (co)polymer. At least one selected from the group consisting of ethylene and linear or branched α-olefins having 4 to 8 carbon atoms can be used as the comonomer, and generally ethylene or 1-butene is preferred. The comonomer content is preferably in the range of 0 to 10 mass%, more preferably 0 to 3 mass%, and even more preferably 0 to 0.3 mass%. If it is out of this range, there is a risk of losing crystallinity. The crystalline propylene-based polymer is preferably a propylene homopolymer or propylene / α-olefin copolymer having a comonomer content of 0 to 10 mass%, more preferably a propylene homopolymer or propylene / α-olefin copolymer having a comonomer content of 0 to 3 mass%, and even more preferably a propylene homopolymer or propylene / α-olefin copolymer having a comonomer content of 0 to 0.3 mass%. On the other hand, in the present invention, the amorphous propylene-ethylene polymer means a component that is dissolved and extracted at a temperature lower than the temperature range at which the crystalline propylene-based polymer dissolves, in various methods for separating an olefin-based polymer such as CFC-IR into various temperature ranges using a solvent, which will be described later. That is, the amorphous propylene-ethylene polymer is a propylene copolymer having a relatively high comonomer content in a (co)polymer, and as the comonomer, at least one selected from the group consisting of ethylene and linear or branched α-olefins having 4 to 8 carbon atoms can be used, and ethylene or butene is generally selected. The comonomer content is preferably in the range of 15 to 90% by mass, more preferably in the range of 20 to 80% by mass. The amorphous propylene-ethylene polymer is preferably a propylene-ethylene copolymer having a comonomer content of 15 to 90% by mass, more preferably a propylene-ethylene copolymer having a comonomer content of 20 to 80% by mass.

[0067] The polymerization method of the present invention employs a gas phase polymerization method in which each monomer is kept in a gaseous state without using a liquid solvent so that the olefin polymerization catalyst and the monomer are efficiently contacted with each other and the production efficiency per catalyst is improved. The polymerization method may be a continuous or batch type. The number of polymerization reactors may be one or more than one for both the first and second steps. The first step is carried out in one or more gas phase polymerization reactors, and the second step is carried out in one or more gas phase polymerization reactors. When there are multiple polymerization reactors, they may be connected in series or in parallel. Examples of the gas phase polymerization reactor include a fluidized bed reactor, a horizontal reactor having an internal agitator rotating about a horizontal axis, etc. Among them, from the viewpoint of productivity, it is preferable that the gas phase polymerization reactor is a horizontal polymerization reactor in which the heat of polymerization is removed by using the heat of evaporation of liquefied propylene and which has an internal agitator rotating about a horizontal axis.

[0068] The polymerization temperature is preferably from 0 to 90° C., more preferably from 30 to 85° C., and further preferably from 45 to 80° C. The polymerization pressure is preferably from 0.1 to 5 MPaG, and more preferably from 0.5 to 4 MPaG. Generally, by selecting a higher temperature and a higher pressure, it is possible to increase the productivity per gram of catalyst, but on the other hand, it becomes impossible to remove localized heat generation, and fine powder is generated due to the collapse of grown particles, and aggregates and lumps are generated due to fusion. Therefore, the above temperature and pressure ranges are set in consideration of the balance between the productivity per gram of catalyst and the removal of localized heat generation. The residence time can be arbitrarily adjusted according to the configuration of the polymerization tank, and is generally set within the range of 30 minutes to 10 hours. The preferred residence time is within 4 hours, and more preferably within 3 hours. In general, by selecting a longer residence time, it is possible to increase the productivity per gram of catalyst, but if the residence time is too long, the increase rate of the productivity per gram of catalyst relative to the increase in residence time decreases. Therefore, the above residence time range is set in consideration of the productivity per gram of catalyst. In the method for producing a propylene-based block copolymer of the present invention, in the first step, it is preferable to produce 40,000 g or more of a crystalline propylene-based polymer per 1 g of the olefin polymerization catalyst in terms of productivity, and it is more preferable to produce 45,000 g or more, and further more preferably 50,000 g or more of a crystalline propylene-based polymer per 1 g of the olefin polymerization catalyst.

[0069] 2. Mixed reaction inhibitors (1) Polyoxyalkylene compounds The polyoxyalkylene compound used in the mixed reaction inhibitor of the present invention is a compound represented by the following general formula (1). [General formula (1)] HO-[CH 2 -CH 2 -O] p -[CH 2 -CH(CH 3 )-O] q -[CH 2 -CH 2 -O] r -R 1 (In the general formula (1), p, q, and r are integers and satisfy the relational expressions of 0≦p≦30, 0≦q≦70, 0≦r≦30, 1≦p+r≦60, and 2≦p+q+r. R 1represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms. Since the polyoxyethylene skeleton is hydrophilic, it is considered that it produces low permeability to polypropylene particles and a surface potential resistance reducing effect as a surfactant, so p+r is set to 1≦p+r. From the viewpoint of hydrophilic function, the range of p+r is preferably 2≦p+r, and more preferably 3≦p+r. On the other hand, since the polyoxyethylene skeleton is highly hydrophilic, if p or r is increased, the solubility in organic solvents may decrease, or the polymer may become solid at room temperature, which may cause restrictions on handling during production. Therefore, p≦30 and r≦30. The range of p+r is preferably p+r≦30, more preferably p+r≦20, and even more preferably p+r≦10. The polyoxypropylene skeleton functions as a hydrophobic group, improving the solubility or compatibility with alcohol compounds described later, and producing properties such as low permeability to polypropylene particles and reduced surface potential resistance as a surfactant. q may be 0, or 0≦q≦70, but is preferably q≦69, more preferably q≦50, and even more preferably q≦40, in view of the possibility of restrictions on handling during production, such as increased viscosity. q may also be q≦30. In addition, in order to provide properties such as low permeability to polypropylene particles and a decrease in surface potential resistance as a surfactant, and to avoid problems in handling during production, the range of p+q+r is 2≦p+q+r, and preferably 3≦p+q+r. On the other hand, if p+q+r is too large, there is a risk of problems in handling during production, such as becoming solid at room temperature and increasing viscosity. Therefore, the range of p+q+r is preferably p+q+r≦120, more preferably p+q+r≦100, and even more preferably p+q+r≦80. p+q+r may be ≦40. R in the general formula (1) 1 represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms. R 1R is preferably a hydrocarbon group having 5 to 20 carbon atoms, more preferably a saturated hydrocarbon group having 5 to 20 carbon atoms, even more preferably a saturated hydrocarbon group having 10 to 20 carbon atoms, and still more preferably a saturated hydrocarbon group having 10 to 20 carbon atoms. 1 When the amount of the hydrophobic group falls within this range, the hydrophobic group tends to provide properties such as low permeability to polypropylene particles and a reduced surface potential resistance as a surfactant.

[0070] Specific examples of polyoxyalkylene compounds that can be used in the present invention include polyoxyethylene (3) lauryl ether, polyoxyethylene (4) lauryl ether, polyoxyethylene (5) lauryl ether, polyoxyethylene (3) stearyl ether, polyoxyethylene (4) stearyl ether, polyoxyethylene (5) stearyl ether, polyoxyethylene (4) oleyl ether, polyoxyethylene (6) oleyl ether, polyoxyethylene (1) polyoxypropylene (16) polyoxyethylene (1 ), polyoxyethylene (2) polyoxypropylene (16) polyoxyethylene (2), polyoxyethylene (2) polyoxypropylene (30) polyoxyethylene (2), polyoxyethylene (6) polyoxypropylene (35) polyoxyethylene (6), polyoxyethylene (5) polyoxypropylene (69) polyoxyethylene (5), polyoxyethylene (3) polyoxypropylene (2) polyoxyethylene (3) lauryl ether, polyoxyethylene (3) polyoxypropylene (3) lauryl ether, etc. The numbers in parentheses indicate the degree of polymerization of polyoxyalkylene. The polyoxyalkylene compound used in the mixed reaction inhibitor of the present invention may be a single component or a mixture of multiple components.

[0071] (2) Alcohol compounds The alcohol compound used in the mixed reaction inhibitor of the present invention is a compound represented by the following general formula (2). [General formula (2)] HO‐R 2 (In general formula (2), R 2 represents a saturated hydrocarbon group having 1 to 10 carbon atoms. In the alcohol compound represented by the general formula (2), R 2 R is a saturated hydrocarbon group having 1 to 10 carbon atoms. 2 is more preferably a saturated hydrocarbon group having 2 to 8 carbon atoms, and even more preferably a saturated hydrocarbon group having 2 to 3 carbon atoms. R 2 If the number of carbon atoms exceeds 10, drying and removal becomes difficult, and there is a possibility that problems such as odor may occur in the final product. The most suitable alcohol compound is ethanol, which has two carbon atoms. When using methanol, which has one carbon atom, attention must be paid to its toxicity to the human body.

[0072] (3) Mixing ratio of reaction inhibitor In the mixed reaction inhibitor used in the present invention, the polyoxyalkylene compound and the alcohol compound are mixed in a ratio of 10 to 150 parts by mass of the polyoxyalkylene compound to 100 parts by mass of the alcohol compound (condition (α)). The lower limit of the polyoxyalkylene compound is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 70 parts by mass or more, relative to 100 parts by mass of the alcohol compound, and the upper limit of the polyoxyalkylene compound may be 140 parts by mass or less, or may be 130 parts by mass or less. By making the polyoxyalkylene compound and the alcohol compound coexist in the above-mentioned appropriate ratio, unlike when each of them acts as an independent reaction inhibitor, the alcohol can prevent / inhibit the self-aggregation of micelles, etc., caused by the hydrophobic interaction of the polyoxyalkylene compound, and the supplied polyoxyalkylene compound can be more efficiently present on the surface of the polypropylene particles, so that a unique gel suppression effect can be obtained in the case of a specific mixing ratio range. However, such an action mechanism does not limit the technical scope of the present invention.

[0073] (4) Supply of mixed reaction inhibitors The polyoxyalkylene compound and the alcohol compound are mixed in advance before being supplied to the polymerization reactor, and the resulting mixture is supplied to the gas-phase polymerization reactor in the second step through a supply line as a mixed reaction inhibitor. A mixture of the alcohol compound and the polyoxyalkylene compound may be supplied to the supply line, or the alcohol compound and the polyoxyalkylene compound may be supplied separately to the supply line to form a mixture of the alcohol compound and the polyoxyalkylene compound in the supply line, or a combination of these may be used. In addition, the mixed reaction inhibitor is supplied to the gas phase polymerization reactor in the second step as a mixed flow with liquefied propylene (condition (γ)). By supplying the mixed flow with liquefied propylene, it is possible to uniformly supply a polyoxyalkylene compound having a high boiling point or being poorly soluble in organic solvents to the gas phase polymerization reactor even when the polymerization temperature is equal to or lower than the boiling point of the polyoxyalkylene compound. The position of the gas phase polymerization reactor to which the mixed reaction inhibitor is supplied may be any position if the gas phase polymerization reactor is a mixing tank type reactor, but is preferably on the upstream side if the gas phase polymerization reactor is a plug flow type reactor. The mixed reaction inhibitor is supplied so that the polyoxyalkylene compound is in the range of 0.1 to 10 g per 1 g of the solid catalyst component (A) supplied to the first step (condition (β)). By satisfying the above ratio, there is an advantage in that the generation of gel can be suppressed without decreasing the catalytic activity. The mixed reaction inhibitor is preferably 0.5 g or more, more preferably 1 g or more, and even more preferably 3 g or more, and may be 8 g or less, or 5 g or less, of the polyoxyalkylene compound per 1 g of the solid catalyst component (A) supplied to the first step. The mixed reaction inhibitor is preferably supplied so that the polyoxyalkylene compound is in the range of 10 to 90,000% by weight, and more preferably in the range of 2,000 to 85,000% by weight, based on the titanium in the solid catalyst component (A) supplied in the first step. In the present invention, the mixed reaction inhibitor is supplied in a specific manner in the second step of the gas-gas phase polymerization process, so that the decrease in catalytic activity is easily suppressed. Therefore, in the present invention, the polyoxyalkylene compound can be added in a relatively large amount based on the titanium in the solid catalyst component (A), and the effect of suppressing gel generation can be enhanced by the action with the alcohol compound. The mixed reaction inhibitor is preferably supplied in a molar ratio of 0.5 to 3.0 relative to the organoaluminum compound (B) supplied to the first step. By satisfying the above ratio, there is an advantage in that the generation of gel can be suppressed without decreasing the catalytic activity. The mixed reaction inhibitor is more preferably 0.6 or more molar ratio, and may be 0.8 or more molar ratio, more preferably 2.0 or less molar ratio, and even more preferably 1.5 or less molar ratio, relative to the organoaluminum compound (B) supplied to the first step.

[0074] 3. Propylene-based block copolymer produced The propylene block copolymer produced by the present invention can control the melt flow rate (MFR) of the crystalline propylene polymer by using a molecular weight regulator such as hydrogen in the polymerization process in the propylene homopolymer or copolymerization of propylene with other α-olefin produced in the first step. The MFR of the crystalline propylene polymer is set depending on the molding method and application, and the MFR value (unit: g / 10 min) measured under the measurement conditions of 230°C and 2.16 kg load is usually 0.1 or more, preferably 0.5 or more, more preferably 1 or more, and 500 or less, preferably 100 or less, more preferably 50 or less. If the MFR is too small, the fluidity of the polymer is significantly reduced, making molding difficult, and if it is too large, the tensile properties are reduced.

[0075] In the second step, the intrinsic viscosity [η] of the propylene-ethylene copolymer can be controlled by using a molecular weight regulator such as hydrogen during the polymerization step. From the viewpoints of improving melt tension, reducing flow marks, and improving the appearance of the product by suppressing the number of gels, the intrinsic viscosity [η] of the propylene-ethylene copolymer is preferably in the range of 7 to 12 dL / g, more preferably in the range of 8 to 11 dL / g. In addition, from the viewpoint of improving impact resistance and improving the appearance of the product by suppressing the number of gels, the ethylene content in the propylene-ethylene copolymer is preferably in the range of 15 to 90% by mass, and more preferably in the range of 20 to 80% by mass. If the ethylene content is lower than this, the impact resistance of the product may be impaired due to loss of amorphousness, which is not preferable. If the ethylene content is higher than this, the degree of compatibility with crystalline propylene decreases, resulting in an increase in the number of gels, which may impair the appearance of the product, which is not preferable. From the viewpoint of suppressing the generation of gel, when the propylene-based block copolymer is taken as 100% by mass, the propylene-ethylene-based copolymer is preferably 10 to 30% by mass and the crystalline propylene-based resin is 70 to 90% by mass, more preferably the propylene-ethylene-based copolymer is 12 to 28% by mass and the crystalline propylene-based resin is 72 to 88% by mass, and even more preferably the propylene-ethylene-based copolymer is 14 to 26% by mass and the crystalline propylene-based resin is 74 to 86% by mass. Furthermore, in order to improve the appearance of the product, when the propylene-based block copolymer is made into an injection sheet having a thickness of 2 mm, the number of gels having a major axis of 300 μm or more is 3 / cm 2 It is preferable that the number of particles is 0 to 2 / cm or less. 2 It is more preferable that: The propylene-based block copolymer can be formed into an extrusion sheet having a thickness of 2 mm by, for example, the method described in the Examples below. EXAMPLES

[0076] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Measurement methods for each physical property value in the present invention are shown below. [Measurement of various physical properties] (1)MFR The propylene-based polymers obtained in the examples were evaluated under the conditions in accordance with JIS K7210 (230° C., 2.16 kg load).

[0077] (2) Analytical method for propylene block copolymers The ratio of propylene-ethylene copolymer moiety (Wc), ethylene content (Gv), and intrinsic viscosity (η) in the propylene block copolymer were measured using the following apparatus and conditions.

[0078] (2-1) Analytical equipment used (i) Cross-sorting device Dia Instruments CFC T-100 (abbreviated as CFC) (ii) Fourier transform infrared absorption spectroscopy FT-IR, PerkinElmer 1760X The fixed wavelength infrared spectrophotometer that was attached as a CFC detector is removed and instead an FT-IR is connected, and this FT-IR is used as a detector. The transfer line between the outlet of the solution eluted from the CFC and the FT-IR is 1 m long, and the temperature is maintained at 140°C throughout the measurement. The flow cell attached to the FT-IR has an optical path length of 1 mm and an optical path width of 5 mmφ, and the temperature is maintained at 140°C throughout the measurement. (iii) Gel Permeation Chromatography (GPC) The GPC column used in the latter stage of the CFC is three Showa Denko AD806MS columns connected in series.

[0079] (2-2) Measurement conditions for CFCs (i) Solvent: orthodichlorobenzene (ODCB) (ii) Sample concentration: 4 mg / mL (iii) Injection volume: 0.4mL (iv) Crystallization: The temperature is lowered from 140°C to 40°C over about 40 minutes. (v) Separation method: The fractionation temperatures during temperature rising elution fractionation are 40, 100, and 140°C, and the sample is fractionated into three fractions in total. The elution ratios (unit: mass%) of the components eluted at 40°C or less (fraction 1), the components eluted at 40-100°C (fraction 2), and the components eluted at 100-140°C (fraction 3) are defined as W40, W100, and W140, respectively. W40+W100+W140=100. Each fraction is automatically transported directly to the FT-IR analyzer. (vi) Solvent flow rate during elution: 1 mL / min

[0080] (2-3) FT-IR measurement conditions After the sample solution starts to elute from the GPC subsequent to the CFC, FT-IR measurement is carried out under the following conditions, and GPC-IR data is collected for each of the above-mentioned fractions 1 to 3. (i) Detector: MCT (ii) Resolution: 8cm -1 (iii) Measurement interval: 0.2 minutes (12 seconds) (iv) Number of integrations per measurement: 15

[0081] (2-4) Post-processing and analysis of measurement results The amount of eluted components and the molecular weight distribution at each temperature were measured using FT-IR. -1 The absorbance of the eluted components is calculated as a chromatogram. The elution volume is normalized so that the total of the elution volumes of each eluted component is 100%. The retention volume is converted to molecular weight using a calibration curve prepared in advance using standard polystyrene. The standard polystyrene used is the following brand manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000. A calibration curve is created by injecting 0.4 mL of a solution in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. A cubic equation obtained by approximating with the least squares method is used for the calibration curve. A general-purpose calibration curve is used for conversion to molecular weight, based on "Size Exclusion Chromatography" by Mori Sadao (Kyoritsu Shuppan). The following values ​​are used for the viscosity formula ([η] = K × Mα). (i) When creating a calibration curve using standard polystyrene K=0.000138, α=0.70 (ii) When measuring a propylene block copolymer sample K=0.000103, α=0.78 The ethylene content distribution of each elution component (distribution of ethylene content along the molecular weight axis) was measured by FT-IR at 2956 cm -1 and 2927cm -1 The ratio of the absorbance of polyethylene, polypropylene, 13 The ethylene content is converted to ethylene content (mass%) using a calibration curve prepared in advance using ethylene-propylene rubber (EPR) and mixtures thereof whose ethylene content is known by C-NMR measurement or the like.

[0082] (2-5) Proportion of propylene-ethylene random copolymer (Wc) The ratio (Wc) of the propylene-ethylene random copolymer portion in the propylene-based block copolymer of the present invention is theoretically defined by the following formula (I) and can be determined by the following procedure. Wc (mass%)=W 40 ×A 40 / B 40 +W 100 ×A 100 / B 100 ...(I) In formula (I), W 40 , W 100 is the elution ratio (unit: mass%) in each fraction mentioned above, and A 40 , A 100 is W 40 , W 100 is the average ethylene content (unit: mass%) actually measured in each fraction corresponding to B40 , B 100 is the ethylene content (unit: mass%) of the propylene-ethylene random copolymer portion contained in each fraction. A 40 , A 100 , B 40 , B 100 The method for calculating this will be described later.

[0083] The meaning of formula (I) is as follows. That is, the first term on the right side of formula (I) is a term for calculating the amount of propylene-ethylene random copolymer parts contained in fraction 1 (part soluble at 40°C). When fraction 1 contains only propylene-ethylene random copolymers and does not contain crystalline propylene-based polymer parts, W40 directly contributes to the content of propylene-ethylene random copolymer parts derived from fraction 1 in the whole. However, since fraction 1 contains a small amount of components derived from crystalline propylene-based polymer parts (extremely low molecular weight components and atactic polypropylene) in addition to components derived from propylene-ethylene random copolymers, it is necessary to correct for these components. Therefore, W 40 A 40 / B 40 For example, the average ethylene content of fraction 1 (A 40 ) is 30% by mass, and the ethylene content of the propylene-ethylene random copolymer contained in fraction 1 (B 40 ) is 40% by mass, 30 / 40=3 / 4 (i.e. 75% by mass) of fraction 1 is derived from propylene-ethylene random copolymer, and 1 / 4 is derived from crystalline propylene-based polymer portion. 40 / B 40 The multiplication is the mass% of fraction 1 (W 40 ) to calculate the contribution of the propylene-ethylene random copolymer. The second term on the right-hand side is similar, and the contribution of the propylene-ethylene random copolymer is calculated for each fraction and added together to obtain the content of the propylene-ethylene random copolymer portion.

[0084] (i) As described above, the average ethylene content corresponding to fractions 1 and 2 obtained by the CFC measurement is A 40 , A 100 (All units are % by mass.) The method for determining the average ethylene content will be described later. (ii) The ethylene content corresponding to the peak position in the differential molecular weight distribution curve of fraction 1 is defined as B40 (unit: mass%). As for fraction 2, the propylene-ethylene random copolymer portion is considered to be completely eluted at 40°C, and therefore it cannot be defined by the same definition. Therefore, in the present invention, B 100 = 100. B 40 , B 100 is the ethylene content of the propylene-ethylene random copolymer portion contained in each fraction, but it is practically impossible to determine this value analytically. The reason is that there is no means to completely separate and fractionate the propylene homopolymer and propylene-ethylene random copolymer that are mixed in the fraction. As a result of investigations using various model samples, B 40 It was found that the improvement effect of the material properties can be well explained by using the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1. 100 has crystallinity derived from ethylene chains, and the amount of propylene-ethylene random copolymer contained in these fractions is relatively small compared to the amount of propylene-ethylene random copolymer contained in fraction 1. For these reasons, approximating B to 100 is closer to reality and causes almost no error in calculation. 100 The analysis will be performed assuming =100.

[0085] (iii) For the above reasons, the ratio of the propylene-ethylene random copolymer portion (Wc) is calculated according to the following formula. Wc (mass%)=W 40 ×A 40 / B 40 +W 100 ×A 100 / 100 …(II) In other words, the first term on the right side of equation (II) is W 40 ×A 40 / B 40 indicates the content (mass%) of propylene-ethylene random copolymer that is not crystalline, and the second term W 100 ×A 100 / 100 indicates the content (mass%) of crystalline propylene-ethylene random copolymer moieties. Here, B 40 and the average ethylene content A of each fraction 1 and 2 obtained by CFC measurement 40 , A 100 is calculated as follows: The ethylene content corresponding to the peak position of the differential molecular weight distribution curve is B 40 The sum of the products of the mass fraction of each data point and the ethylene content of each data point, which are taken as data points during measurement, is the average ethylene content A of fraction 1. 40 It becomes. Average ethylene content of fraction 2 A 100 is also required in the same way.

[0086] The significance of setting the above three types of fractionation temperatures is as follows. In the CFC analysis of the present invention, 40°C is a temperature condition necessary and sufficient for fractionating only polymers that do not have crystallinity (for example, most of the propylene-ethylene random copolymer, or extremely low molecular weight components and atactic components in the crystalline propylene-based polymer portion). 100°C is a temperature necessary and sufficient for eluting only components that are insoluble at 40°C but soluble at 100°C (for example, components in the propylene-ethylene random copolymer that have crystallinity due to ethylene and / or propylene chains, and the crystalline propylene-based polymer portion). 140°C is a temperature necessary and sufficient for eluting only components that are insoluble at 100°C but soluble at 140°C (for example, components with particularly high crystallinity in the crystalline propylene-based polymer portion, and components in the propylene-ethylene random copolymer that have extremely high molecular weight and extremely high ethylene crystallinity), and for recovering the entire amount of the propylene-based block copolymer used in the analysis. W 140 Since propylene-ethylene random copolymer components are not contained at all or, if they are present, they are present in extremely small amounts and can be practically ignored, they are excluded from the calculation of the propylene-ethylene random copolymer ratio and the ethylene content of the propylene-ethylene random copolymer.

[0087] (2-6) Ethylene content in propylene-ethylene random copolymer The ethylene content of the propylene-ethylene random copolymer portion in the propylene-based block copolymer of the present invention can be calculated from the following formula using the values ​​explained above. Ethylene content of propylene-ethylene random copolymer part (mass%) = (W 40 ×A 40 +W 100 ×A 100 ) / Wc Here, Wc is the proportion (mass%) of the propylene-ethylene random copolymer portion calculated previously.

[0088] (2-7) Measurement of intrinsic viscosity The intrinsic viscosity [η]p of the crystalline propylene polymer portion and the propylene-ethylene random copolymer portion in the propylene block copolymer of the present invention is measured at a temperature of 135°C using an Ubbelohde viscometer and decalin as a solvent. First, after the polymerization of the crystalline propylene-based polymer portion is completed, a portion is sampled from the polymerization tank and the intrinsic viscosity [η]p is measured. Next, after the polymerization of the crystalline propylene-based polymer portion, the intrinsic viscosity [η]F of the final polymer (F) obtained by polymerizing the propylene-ethylene random copolymer is measured. [η]c is calculated from the following relationship. [η]F=(100-Wc) / 100×[η]p+Wc / 100×[η]c

[0089] (3) Gel evaluation method 100 parts by mass of propylene block copolymer granules were dry-blended with 0.5 parts by mass of blue pigment, and the mixture was molded at a molding temperature of 240°C and a primary injection pressure of 55kgf / cm using a Niigata Iron Works NN30-H4000 injection molding machine with a clamping pressure of 30 tons and a mold with a film gate of 2mm width. 2 , Secondary pressure=45kgf / cm 2 An injection sheet of 50mm square x 2mm thickness is molded using the method. The size of the gels on one surface of each of the 10 molded sheets is visually measured using a transmission optical microscope, and the number of gels is counted. Among all gels counted visually, gels with a major axis of 50 μm or more were counted as "total gels" and converted into the number per square centimeter. The major axis here refers to the maximum length of the straight line connecting two points on the periphery of the observed gel. Gels with a major axis of 300 μm or more are considered "large gels" and are evaluated by converting the number of gels per square centimeter.

[0090] (4) Qualitative method for polyoxyalkylene compounds in propylene block copolymers 70 ml of acetonitrile is added to 5.0 g of a propylene-based block copolymer sample, and the components are ultrasonically extracted at 30°C for 1 hour. The acetonitrile solution is filtered through filter paper (5C filter paper manufactured by ADVANTEC) to recover the filtrate, and the acetonitrile is removed by evaporating and vacuum drying (at 25°C for 1 hour). Then, 1.0 ml of orthodichlorobenzene / deuterated bromide benzene = 2 / 1 (volume ratio) is added to the dried filtrate to prepare a solution. The solution is placed in an NMR sample tube and NMR measurement is performed. 1 The presence or absence of a peak derived from polyoxyethylene (POE) detected at 3.8 to 3.2 ppm in the H-NMR spectrum is used to confirm the presence or absence of a polyoxyalkylene compound. <Equipment> JNM-ECS400 FT NMR manufactured by JEOL RESONANCE <probe>:5mm FG / TH autotune probe <Measurement temperature> Room temperature < 1 H-NMR measurement: Pre-saturation elimination of solvent, flip angle = 45°, spin on, flip angle = 45°, pulse interval = 9.8 seconds, number of accumulations = 256

[0091] [Catalyst manufacturing example] (1) Preparation of solid catalyst component for propylene polymerization Preparation of solid component A 10 L autoclave equipped with a stirrer was thoroughly purged with nitrogen, and 2 L of purified toluene was introduced. Mg(OEt) 2 200g of TiCl 4 The temperature was raised to 90°C, and 40 ml of di-n-butyl phthalate and 10 ml of diethyl phthalate were added. The temperature was then raised to 110°C and the reaction was carried out for 3 hours. The reaction product was thoroughly washed with purified toluene. Next, purified toluene was added to adjust the total liquid volume to 2 L. TiCl 4 The reaction was carried out at 110°C for 2 hours. The reaction product was thoroughly washed with purified toluene. Then, purified toluene was added to adjust the total liquid volume to 2 L. TiCl 4 1L of was added, and the temperature was raised to 110°C and the reaction was carried out for 2 hours. The reaction product was thoroughly washed with purified toluene. Furthermore, toluene was replaced with n-heptane using purified n-heptane to obtain a slurry of solid components. A part of this slurry was sampled, dried and analyzed, and the Ti content of the solid components was found to be 1.7 mass%. Next, a 20L autoclave equipped with a stirrer was thoroughly replaced with nitrogen, and 100g (0.036molTi) of the slurry of the solid components was introduced as a solid component. Purified n-heptane was introduced to adjust the concentration of the solid components to 25g / L. SiCl 4 The reaction was carried out at 90°C for 1 hour. The reaction product was thoroughly washed with purified n-heptane, and the liquid level was adjusted to 4 L by adding purified n-heptane. 2 =CH-] 2 Sim 2 25ml of (i-Pr) 2 Si(OMe) 2 18 ml of the above and 40 g (0.35 mol) of a diluted solution of triethylaluminum in n-heptane were added, and the reaction was carried out for 2 hours at 40° C. The reaction product was thoroughly washed with purified n-heptane. A portion of the resulting slurry was sampled, dried, and analyzed. catalyst The composition is Ti 1.2 mass%, (i-Pr) 2 Si(OMe) 2 was contained at 6.7 mass%.

[0092] (2) Preparation of prepolymerization catalyst for propylene polymerization The solid obtained above catalyst Using 100 g of the component (0.025 mol Ti), preliminary polymerization was carried out according to the following procedure. Purified n-heptane was added to the above slurry to obtain a solid. catalyst The concentration of the components was adjusted to 20 g / L. After cooling the slurry to 10°C, 15 g (0.132 mol) of a diluted solution of triethylaluminum in n-heptane was added as triethylaluminum, and 280 g of propylene was fed over 4 hours. After the propylene feed was completed, the reaction was continued for another 30 minutes. Next, the gas phase was thoroughly replaced with nitrogen, and the reaction product was thoroughly washed with refined n-heptane. The obtained slurry was extracted from the autoclave and vacuum dried. Prepolymerized solid catalyst component (Prepolymerization catalyst) I got this. Prepolymerized solid catalyst component (Prepolymerization catalyst) When the solid catalyst The solid catalyst component contained 2.0 g of polypropylene per 1 g of component. The portion of the solid catalyst component excluding polypropylene contained 1.2 mass% Ti, (i-Pr) 2 Si(OMe) 2 was contained at 6.4 mass%.

[0093] Example 1 Inner diameter D: 300mm, length L: 1540mm, internal volume: 0.10m 3 A propylene-based block copolymer was produced using a reactor consisting of two connected horizontal gas-phase reactors, each of which is a continuous horizontal gas-phase polymerizer equipped with a stirrer in the horizontal direction. Fig. 1 is a schematic explanatory diagram showing an example of the arrangement of a continuous horizontal gas phase reaction apparatus. Hereinafter, an explanation will be given with reference to the flow sheet shown in Fig. 1. After replacing the inside of the horizontal polymerization reactor (first reactor) 100 with nitrogen gas, 29 kg of seed powder was introduced and nitrogen gas was passed through for 3 hours. After that, the temperature was raised while introducing propylene and hydrogen, and when the polymerization conditions were met, the prepolymerization catalyst obtained in the above catalyst production example was fed from the catalyst component feed pipe 101. (Prepolymerized solid catalyst component) The solid was added so that the polymerization rate of the propylene polymer was 10 kg / hr. catalyst The catalyst component was supplied at a rate of 0.125 g / hr, and a 7 mass % n-hexane diluted solution of triethylaluminum was continuously supplied from the catalyst component supply pipe 102 at a rate of 27 mmol / hr in terms of triethylaluminum. When the position of the partition wall 100a of the first reactor is the upstream end of the reactor, the temperature is controlled by supplying liquefied propylene from the liquefied monomer-containing liquid supply pipes 107-1 to 5 so that the temperature of each thermometer installed at the same position as the recycle gas supply pipes 108-1 to 5 from the upstream end becomes 59°C, 59°C, 62°C, 64°C, and 65°C from the upstream end. The propylene partial pressure is controlled to 2.0 MPa, and hydrogen as a molecular weight control agent is supplied from the raw material hydrogen supply pipe 104-1 so that the hydrogen / propylene molar ratio is 0.017 mol / mol. The homopropylene polymer polymerized so that the powder mass inside the horizontal reactor 100 is kept at 23 kg is continuously extracted from the extraction pipe 113 to the vessel 114 at a rate of 10 kg / hr, and continuously transferred to the second reactor 200 through the transfer pipe 201. A portion of the homopropylene polymer obtained was extracted and analyzed, and it was found to have an MFR of 30 g / 10 min.

[0094] In the second reactor 200, the polymerization temperature was controlled at 60°C, the propylene partial pressure at 1.5 MPa, the ethylene partial pressure at 0.38 MPa, and hydrogen as a molecular weight regulator was supplied from the raw hydrogen supply pipe 204-1 so as to give a hydrogen / (ethylene+propylene) molar ratio of 0.00036 mol / mol, and the ratio of ethylene to propylene in the reaction gas was controlled at 0.253 mol / mol by supplying ethylene from the raw ethylene supply pipe 204-2. In addition, 200 g of polyoxyethylene (4) lauryl ether (purchased from Sigma-Aldrich, trade name: Brij L4) was added to 200 g of ethanol, and diluted with hexane to a total volume of 10 L to prepare a mixed reaction inhibitor having a ratio of 100 parts by mass of polyoxyethylene (4) lauryl ether to 100 parts by mass of ethanol. A hexane solution of the mixed reaction inhibitor was supplied from the reaction inhibitor supply pipe 215 so that the ratio of polyoxyethylene (4) lauryl ether was 7.69 g per 1 g of propylene polymerization catalyst (propylene polymerization prepolymerization catalyst excluding polypropylene) supplied to the first reactor. That is, the mixed reaction inhibitor is supplied to the gas-phase polymerization reactor (second reactor 200) in the second step as a mixed flow with liquefied propylene in the liquefied monomer-containing liquid supply pipe 207. In addition, ethanol is supplied at a molar ratio of 0.77 mol / mol to triethylaluminum supplied to the first reactor. The polymerized powder was continuously extracted from the extraction pipe 213 at a rate of 11.6 kg / hr so ​​that the powder mass inside the second reactor 200 was kept at 20 kg, and the reaction was stopped by supplying nitrogen gas containing moisture, thereby producing a propylene-based block copolymer-1. The analysis of the obtained propylene block copolymer showed that MFR = 3.5 g / 10 min, the ratio of the propylene-ethylene random copolymer part (Wc) = 14 mass%, and the ethylene content of the propylene-ethylene random copolymer part = 30 mass%. 1 In the H-NMR spectrum, a peak originating from bridge L4 was observed at 3.8 to 3.2 ppm.

[0095] Example 2 Propylene-based block copolymer-2 was obtained by making the following changes from Example 1. The prepolymerization catalyst to be supplied to the first reactor was changed to be supplied at 0.133 g / hr as a solid component so that the polymerization rate of the propylene-based polymer would be 8 kg / hr, and a 7 mass % n-hexane diluted solution of triethylaluminum was continuously supplied at a supply rate of 25 mmol / hr as triethylaluminum. The propylene partial pressure was changed to 1.9 MPa, and the hydrogen / propylene molar ratio in the first reactor was changed to 0.016 mol / mol. A part of the obtained homopropylene polymer was extracted and analyzed, and as a result, MFR was 16 g / 10 min. In the second reactor, the hydrogen was changed to a hydrogen / (ethylene+propylene) molar ratio of 0.00030 mol / mol. In addition, the mixed reaction inhibitor used was changed to a mixed reaction inhibitor in which 150 g of polyoxyethylene (2) polyoxypropylene (16) polyoxyethylene (2) (ADEKA PLURONIC (registered trademark) L-31 available from ADEKA CORPORATION) was added per 100 g of ethanol, and diluted with hexane to a total volume of 10 L, with the polyoxyalkylene compound being 150 parts by mass per 100 parts by mass of ethanol. The mixed reaction inhibitor was supplied so that the polyoxyalkylene compound contained in the mixed reaction inhibitor was 7.84 g per 1 g of propylene catalyst supplied to the first reactor. At this time, the ethanol was supplied at a molar ratio of 0.61 mol / mol to the triethylaluminum supplied to the first reactor. Also, the propylene-based block copolymer was continuously withdrawn from the withdrawal pipe at a rate of 9.4 kg / hr. A propylene-based block copolymer-2 was produced in the same manner as in Example 1 except for the above. The analysis of the obtained propylene block copolymer showed that MFR = 4.25 g / 10 min, the ratio of the propylene-ethylene random copolymer part (Wc) = 15 mass%, the ethylene content of the propylene-ethylene random copolymer part = 24 mass%, and the acetonitrile extract 1 In the H-NMR spectrum, peaks originating from L-31 were observed at 3.8 to 3.2 ppm.

[0096] Example 3 Propylene-based block polymer-3 was obtained by making the following changes from Example 1. The prepolymerization catalyst to be supplied to the first reactor was changed to be supplied at 0.204 g / hr as a solid component so that the polymerization rate of the propylene-based polymer would be 10 kg / hr, and the supply amount of a 7 mass % n-hexane diluted solution of triethylaluminum was continuously supplied at 39.9 mmol / hr as triethylaluminum. The propylene partial pressure was changed to 1.7 MPa, and the hydrogen / propylene molar ratio in the first reactor was changed to 0.127 mol / mol. A part of the obtained homopropylene polymer was extracted and analyzed, and as a result, MFR was 310 g / 10 min. In the second reactor, the propylene partial pressure was changed to 1.3 MPa, the ethylene partial pressure to 0.61 MPa, the hydrogen to a hydrogen / (ethylene+propylene) molar ratio of 0.00064 mol / mol, and the ratio of ethylene to propylene in the reaction gas to 0.463 mol / mol. In addition, the mixed reaction inhibitor used was changed to the same mixed reaction inhibitor as in Example 2. The mixed reaction inhibitor was supplied so that the ratio of the polyoxyalkylene compound contained in the mixed reaction inhibitor was 9.95 g per 1 g of the propylene polymerization catalyst supplied to the first reactor. At this time, ethanol was supplied to the first reactor at a molar ratio of 0.74 mol / mol relative to the triethylaluminum supplied to the first reactor. Also, the propylene-based block copolymer was continuously withdrawn from the withdrawal pipe at a rate of 12.8 kg / hr. A propylene-based block copolymer-3 was produced in the same manner as in Example 1 except for the above. The analysis of the obtained propylene block copolymer showed that MFR was 39.1 g / 10 min, the ratio of the propylene-ethylene random copolymer portion (Wc) was 22 mass%, and the ethylene content of the propylene-ethylene random copolymer portion was 37 mass%. 1 In the H-NMR spectrum, peaks due to L-31 were observed at 3.8 to 3.2 ppm.

[0097] Comparative Example 1 The mixed reaction inhibitor used was changed to a mixed reaction inhibitor with a ratio of 100 parts by mass of ethanol and 200 parts by mass of polyoxyethylene (4) lauryl ether by adding 200 g of polyoxyethylene (4) lauryl ether to 100 g of ethanol and diluting it with hexane so that the total volume became 10 L. In addition, ethanol was supplied at a molar ratio of 0.39 mol / mol to triethylaluminum. Also, the propylene-based block copolymer was continuously withdrawn from the withdrawal pipe at a rate of 11.8 kg / hr. Except for these, the same method as in Example 1 was used to produce a propylene-based block copolymer-C1. The analysis of the obtained propylene block copolymer showed that MFR = 3.5 g / 10 min, the ratio of the propylene-ethylene random copolymer part (Wc) = 15 mass%, the ethylene content of the propylene-ethylene random copolymer part = 30 mass%, and the acetonitrile extract 1 In the H-NMR spectrum, peaks derived from polyoxyethylene chains were observed at 3.8 to 3.2 ppm.

[0098] Comparative Example 2 2 is a schematic diagram showing an example of the arrangement of a continuous vertical gas phase reaction apparatus. The flow sheet shown in FIG. 2 will be used for explanation. Polymerization was carried out using a continuous reactor consisting of two connected fluidized bed reactors with an internal volume of 2000 L. In the first reactor 300, the polymerization temperature was 75°C, the propylene partial pressure was 1.8 MPa (absolute pressure), and hydrogen as a molecular weight control agent was continuously supplied from the pipe 306 and hydrogen from the pipe 308 so that the molar ratio of hydrogen / propylene was 0.028 mol / mol. At the same time, the catalyst of the above catalyst production example was supplied from the pipe 301 at 0.55 g / hr so ​​that the polymerization rate of the propylene-based polymer was 23 kg / hr, and a 7 mass % n-hexane diluted solution of triethylaluminum was continuously supplied from the pipe 310 at 46 mmol / hr. The polypropylene polymer polymerized in the first reactor was continuously extracted from the pipe 311 at a rate of 23 kg / hr so ​​that the powder amount in the reactor was 60 kg, and was continuously transferred to the second reactor 400 through the pipe 401.

[0099] In the second reactor 400, at a polymerization temperature of 70°C, propylene partial pressure was 1.5 MPa, ethylene partial pressure was 0.38 MPa, propylene and ethylene were continuously supplied from a pipe 406 and a pipe 407, respectively, so that the molar ratio of ethylene / propylene was 0.253, and hydrogen as a molecular weight control agent was continuously supplied from a pipe 408, so that the molar ratio of hydrogen / propylene was 0.00020. At the same time, a mixed reaction inhibitor diluted with hexane to a concentration of polyoxyethylene (4) lauryl ether (trade name: Bridge L4) of 100 g / L and a concentration of ethanol of 20 g / L was supplied to the circulation gas line from a pipe 409, so that the ratio of polyoxyethylene (4) lauryl ether was 13.34 g per 1 g of propylene polymerization catalyst supplied to the first reactor. That is, the molar ratio of ethanol supplied to the first reactor was 0.69 mol / mol relative to triethylaluminum. The polymerized powder was continuously extracted from the pipe 410 at a rate of 27 kg / hr so ​​that the volume occupied by the powder in the second reactor was kept at 60 kg, and the reaction was stopped by supplying nitrogen gas containing moisture, thereby producing a propylene-based block copolymer-C2. The analysis of the obtained propylene block copolymer showed that MFR = 3.5 g / 10 min, the ratio of the propylene-ethylene random copolymer part (Wc) = 14 mass%, and the ethylene content of the propylene-ethylene random copolymer part = 30 mass%. 1 In the 1 H-NMR spectrum, no peaks derived from polyoxyethylene chains were observed at 3.8 to 3.2 ppm.

[0100] Comparative Example 3 In Comparative Example 2, the polymerization temperature of the first reactor 100 was changed to 61°C, the catalyst supply amount was changed to 0.66g / hr, the propylene partial pressure of the second reactor was changed to 1.4MPa, and the ethylene / propylene molar ratio was changed to 0.295. Furthermore, the concentration of the reaction inhibitor supplied to the second reactor 200 was changed to a hexane diluted solution of 20g / L of ethanol, and the amount of triethylaluminum supplied to the first reactor was changed to a molar ratio of 1.49. A propylene-based block copolymer-C3 was produced in the same manner as in Comparative Example 2 except for the above.

[0101] Comparative Example 4 In Comparative Example 2, the temperature of the second reactor 200 was changed to 60°C, the propylene partial pressure was changed to 1.2MPa, and the molar ratio of ethylene / propylene was changed to 0.266. Furthermore, the reaction inhibitor supplied to the second reactor was changed to L-121 (polyoxyethylene (5)-polyoxypropylene (69)-polyoxyethylene (5)), available from Sigma-Aldrich, and L-121 was added at 1.32 g / g relative to the catalyst. A propylene-based block copolymer-C4 was produced in the same manner as in Comparative Example 2, except for the above.

[0102] Comparative Example 5 Propylene-based block copolymer-C5 was produced in the same manner as in Example 1, except that the reaction inhibitor used in Example 1 was changed to a hexane diluted solution having an ethanol concentration of 10 g / L, and was supplied to the first reactor in a molar ratio of 1.06 to the amount of triethylaluminum supplied thereto, and the propylene-based block copolymer was continuously withdrawn from the withdrawal pipe at a rate of 11.3 kg / hr.

[0103] Comparative Example 6 In Example 3, the prepolymerization catalyst to be supplied to the first reactor was changed to 0.222 g / hr as a solid component so that the polymerization rate of the propylene-based polymer was 10 kg / hr, and the supply amount of a 7 mass% n-hexane diluted solution of triethylaluminum was continuously supplied at 41 mmol / hr as triethylaluminum, the propylene partial pressure was changed to 2.0 MPa, and the hydrogen / propylene molar ratio in the first reactor was changed to 0.140 mol / mol. In addition, the reaction inhibitor used was changed to a hexane diluted solution with an ethanol concentration of 10 g / L, and the amount of triethylaluminum supplied to the first reactor was changed to a molar ratio of 1.28. A part of the obtained homopropylene polymer was extracted and analyzed, and the result was MFR=360 g / 10 min. In the second reactor, the propylene partial pressure was changed to 1.4 MPa, the ethylene partial pressure was changed to 0.57 MPa, the hydrogen molar ratio (hydrogen / (ethylene+propylene)) was changed to 0.00077 mol / mol, and the ratio of ethylene to propylene in the reaction gas was changed to 0.422 mol / mol. A propylene-based block copolymer-C6 was produced in the same manner as in Example 3, except that the propylene-based block copolymer was continuously withdrawn from the withdrawal pipe at a rate of 11.0 kg / hr.

[0104] [Granulation process] For 100 parts by mass of each of the propylene-based block copolymers obtained in the above Examples and Comparative Examples, the following antioxidants were used: 0.1 part by mass of 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione (manufactured by Nippon Cytec Industries Co., Ltd., product name: Cyanox 1790), 0.09 part by mass of tris(2,4-di-t-butylphenyl)phosphite (manufactured by Ciba-Geigy, product name: Irgaphos 168), 0.05 part by mass of 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (manufactured by ADEKA Corporation, product name: Adekastab PEP-36), and N,N-bis(octadecyl)hydroxylamine. 0.09 parts by mass of Irgastab FS042 (manufactured by Ciba-Geigy Co., Ltd.) and 0.03 parts by mass of calcium stearate as a neutralizing agent were added, and mixed and blended for 5 minutes using a Super Mixer (manufactured by Kawada Manufacturing Co., Ltd.) The resulting blend was used to obtain propylene-based block copolymer granules by underwater cutting granulation method under the following conditions and equipment. Kneading extruder: Inner diameter 110mm single screw extruder Die: TiC, φ2.5mm, 20 holes, heat channel type Cutter blade: TiC, 4 blades, rake angle 50° Granulation processing rate: 200kg / hr Screen pack filter: None

[0105] The polymerization results and evaluation results are shown in Tables 1 and 2.

[0106] [Table 1]

[0107] [Table 2]

[0108] From the results of Comparative Examples 2 and 4, when the mixed reaction inhibitor or polyoxyalkylene compound was supplied to the circulation gas line and not supplied to the polymerization reactor as a mixed flow with liquefied propylene, the presence of the polyoxyalkylene compound was not observed in the propylene block copolymer particles. Since the polyoxyalkylene compound used in the present invention is difficult to vaporize under general polypropylene gas polymerization reaction conditions, it is presumed that even if the mixed reaction inhibitor is supplied to the reactor by entraining it in the monomer gas flow, it is difficult for it to reach the polymer powder, and therefore the effect is not exhibited. Comparison of Examples 1 to 3 and Comparative Examples 1 to 6 shows that when a polyoxyalkylene compound is contained in the propylene block copolymer particles, the number of gels is reduced compared to when it is not contained. Also, in Examples 1 to 3 and Comparative Example 1, in which a mixed reaction inhibitor was supplied to the circulation gas line and supplied to the polymerization reactor as a mixed flow with liquefied propylene, it was shown that the production efficiency of the product per 1 g of catalyst could be improved. Furthermore, a comparison between Example 1 and Comparative Example 1 shows that, even if a polyoxyalkylene compound is present, the effect of inhibiting gel formation is poor when alcohol is not present at a specific ratio. In contrast, in Examples 1 to 3 of the present invention, it has been shown that a propylene-based block copolymer containing a high intrinsic viscosity propylene-ethylene-based copolymer can be produced with high catalytic efficiency while reducing gels and without unnecessarily increasing the number of reactors in a multi-stage continuous polymerization method by supplying a specific ratio of the mixed reaction inhibitor as a mixed flow with liquefied propylene to the polymerization reactor in the second step. As in Example 3 and Comparative Example 6, when a propylene-based block copolymer with high fluidity is produced by increasing the hydrogen / propylene molar ratio, a greater amount of gel tends to be generated. However, even in such cases, it has been shown that by supplying a specific ratio of a mixed reaction inhibitor to the polymerization reaction tank in the second step as a mixed flow with liquefied propylene, it is possible to produce the copolymer with high catalytic efficiency while reducing gels with a major axis of 300 μm or more, which particularly deteriorate the appearance. [Explanation of symbols]

[0109] 100 Horizontal polymerization reactor (first reactor) 100a,100b bulkhead 101 Catalyst component supply piping 102 Catalyst component supply pipe 103 Raw material monomer supply pipe 104-1, 104-2 Raw hydrogen supply pipe 105,106 Piping 107, 107-1, 107-2, 107-3, 107-4, 107-5 Liquefied monomer-containing liquid supply piping 108, 108-1, 108-2, 108-3, 108-4, 108-5 Recycle gas supply piping 109 Mixer 109a horizontal axis 109b Stirring blade 110 Unreacted gas extraction pipe 111 Recycled Drums 112 Compressor 113 Polymer withdrawal piping 114 Vessel 201 Transfer piping 200 Second Reactor 210a,210b Bulkhead 202 Catalyst component supply piping 203 Raw material monomer supply pipe 204-1 Hydrogen raw material supply pipe 204-2 Raw ethylene supply piping 205,206 Piping 207, 207-1, 207-2, 207-3, 207-4, 207-5 Liquefied monomer-containing liquid supply piping 208, 208-1, 208-2, 208-3, 208-4, 208-5 Recycled gas supply piping 209 Mixer 209a horizontal axis 209b Stirring blade 210 Unreacted gas extraction pipe 211 Recycled Drums 212 Compressor 213 Polymer withdrawal piping 214 Oxygen supply piping 215 Reaction inhibitor supply piping 300 First Reactor 301 Catalyst component supply piping 302 Gas distribution plate 303 Cycle gas extraction piping 304 Cycle Gas Compressor 305 Cycle Gas Cooler 306 Propylene supply piping 307 Ethylene supply piping 308 Hydrogen supply piping 309 External electron donor supply piping 310 Piping 311 Powder Discharge Case 400 Second Reactor 401 Resin Transfer Case 402 Gas distribution plate 403 Cycle gas extraction piping 404 Cycle Gas Compressor 405 Cycle Gas Cooler 406 Gas propylene supply piping 407 Gas ethylene supply piping 408 Hydrogen supply piping 409 Mixed reaction inhibitor supply piping 410 Polymer withdrawal pipe< / probe>

Claims

1. In the first step, using one or more gas-phase polymerization reactors, a crystalline propylene-based polymer is polymerized in the presence of a solid catalyst component containing magnesium, titanium, halogen, and an electron-donating compound as an internal donor, and a catalyst for olefin polymerization containing an organoaluminum compound. In the subsequent second step, using one or more gas-phase polymerization reactors, an amorphous propylene-ethylene copolymer is polymerized in the presence of the crystalline propylene-based polymer. In the method for producing a propylene-based block copolymer, a mixed reaction inhibitor composed of a mixture of a polyoxyalkylene-based compound represented by the general formula (1) and an alcohol compound represented by the general formula (2) is supplied while satisfying the following conditions (α) to (γ). A method for producing a propylene-based block copolymer, characterized in that. [General formula (1)] HO-[CH ２ -CH ２ -O] ｐ -[CH ２ -CH(CH ３ )-O] ｑ -[CH ２ -CH ２ -O] ｒ -R １ (In general formula (1), p, q, and r are integers, satisfying 0 ≦ p ≦ 30, 0 ≦ q ≦ 70, 0 ≦ r ≦ 30, 1 ≦ p + r ≦ 60, and all the relational expressions of 2 ≦ p + q + r. R １ represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms) [General formula (2)] HO-R ２ (In general formula (2), R ２ represents a saturated hydrocarbon group having 1 to 10 carbon atoms) (α): The polyoxyalkylene-based compound is mixed in a ratio of 10 to 150 parts by mass with respect to 100 parts by mass of the alcohol compound. (β): The polyoxyalkylene-based compound is supplied so as to be in the range of 0.1 to 10 g per 1 g of the solid catalyst component. (γ): The mixed reaction inhibitor is supplied as a mixed stream with liquefied propylene to the gas-phase polymerization reactor in the second step.

2. The method for producing a propylene-based block copolymer according to claim 1, wherein the alcohol compound is supplied so as to be in the range of 0.5 to 3.0 molar ratio with respect to the organoaluminum compound supplied in the first step.

3. The method for producing a propylene-based block copolymer according to claim 1 or 2, wherein the gas-phase polymerization reactor removes the heat of polymerization using the heat of vaporization of liquefied propylene and has a horizontal polymerization reactor having a stirrer rotating around a horizontal axis inside.

4. The method for producing a propylene-based block copolymer according to any one of claims 1 to 3, wherein in the first step, 40,000 g or more of a crystalline propylene-based polymer is produced per 1 g of the olefin polymerization catalyst.

5. The method for producing a propylene-based block copolymer according to any one of claims 1 to 4, wherein the propylene-based block copolymer satisfies (a) to (d). When the propylene-based block copolymer is made into an injection sheet with a thickness of 2 mm, the number of gels having a major axis of 300 μm or more is 3 pieces / cm ２ is as follows (b) The intrinsic viscosity [η] of the propylene-ethylene copolymer is in the range of 7 to 12 dL / g. (c) The content of ethylene in the propylene-ethylene copolymer is in the range of 15 to 90% by mass. (d) When the propylene block copolymer is 100% by mass, the propylene-ethylene copolymer is 10 to 30% by mass and the crystalline propylene polymer is 70 to 90% by mass.

6. The method for producing a propylene block copolymer according to any one of claims 1 to 5, wherein the solid catalyst component is obtained by contacting a solid component containing magnesium, titanium, a halogen, and an electron-donating compound as an internal donor with a vinylsilane compound, an organoaluminum compound, and an alkoxysilane compound excluding the vinylsilane compound.

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