Branched propylene polymer

Abstract

To provide a branched propylene polymer that has excellent ductility during melting while holding the melt tension required for molding.SOLUTION: The inventive branched propylene polymer has the following properties (1) and (2). (1): The multi-branch index (MBI) is 0.15 or more and 1.00 or less. (2): The strain hardening index (SHI@1 s-1) is 0.70 or more and 3.00 or less at a strain rate (dε / dt) of 1.0 / second.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a branched propylene polymer. [Background technology]

[0002] In recent years, much research has been conducted into introducing branched structures into polypropylene to improve its suitability for sheet molding, blow molding, thermoforming, foam molding, and other applications that require a material with a relatively high melt tension. Recently, a macromer copolymerization method using a metallocene catalyst has been proposed as a method for introducing branched structures into polypropylene. Branched polypropylene obtained by the macromer copolymerization method has advantages such as less gel generation due to crosslinking reactions compared to polypropylene in which branched structures are introduced by irradiation with electron beams or the like.

[0003] As such a macromer copolymerization method, for example, a method has been proposed in which a propylene macromer having a vinyl structure at its terminal is produced using a specific catalyst and specific polymerization conditions in the first polymerization stage (macromer synthesis step), and then propylene and the propylene macromer are copolymerized using a specific catalyst and specific polymerization conditions in the second polymerization stage (macromer copolymerization step). It has been shown that the resulting branched polypropylene has high melt strength and melt tension (see, for example, Patent Documents 1 and 2). Furthermore, a single-stage polymerization method has been proposed in which a macromer synthesis step and a macromer copolymerization step are carried out simultaneously using a specific metallocene catalyst, and it has been shown that the resulting branched polypropylene exhibits improved melt strength (see, for example, Patent Document 3). In addition, a multi-stage polymerization method has been proposed using a catalyst that combines a catalyst containing two specific metallocene compounds, specifically, metallocene compounds such as rac-SiMe2[2-Me-4-Ph-lnd]2ZrC12 and rac-SiMe2[2-Me-4-Ph-lnd]2HfC12, with silica supporting methylaluminoxane (MAO). It has been reported that the resulting branched polypropylene exhibits a relatively high melt tension (see Patent Document 4). In addition, a method has been devised that uses a catalyst containing a specific metallocene compound and an ion-exchange layered silicate, and it has been reported that the resulting branched polypropylene has a broad molecular weight distribution, a large amount of branching, and good melt tension (see Patent Document 5).

[0004] In addition, a method has been devised for producing a propylene-based polymer having a strain hardening coefficient (λmax) of 2.0 or more in melt tension measurement using a catalyst containing specific multiple metallocene compounds, and it has been reported that the obtained branched polypropylene has good melt tension (see Patent Document 6).

[0005] Furthermore, Patent Document 7 discloses that by polymerizing propylene using a single metallocene catalyst supported on silica with very low porosity, short chain branches with a specific degree of branching and a relatively large amount of amorphous regions are introduced, thereby obtaining a branched polypropylene having a better balance between mechanical properties and processability. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2001-525460 [Patent Document 2] Japanese Patent Application Publication No. 10-338717 [Patent Document 3] Special Publication No. 2002-523575 [Patent Document 4] Japanese Patent Application Laid-Open No. 2001-64314 [Patent Document 5] Japanese Patent Application Laid-Open No. 2007-154121 [Patent Document 6] Japanese Patent Application Laid-Open No. 2009-57542 [Patent Document 7] Special Publication No. 2009-542872 Summary of the Invention [Problem to be solved by the invention]

[0007] However, although the branched polypropylenes obtained by the macromer copolymerization methods disclosed in the above Patent Documents 1 to 6 have high melt tension and are highly suitable for sheet molding, blow molding, thermoforming, foam molding, and the like, they have a problem in that the extensibility of the melt is not excellent. In addition, the branched polypropylene obtained by the method disclosed in Patent Document 7 has improved mechanical properties by increasing the content of amorphous regions, but the strain hardening at a high strain rate (SHI@1 sec) is -1 ) is not so high, and therefore the moldability during various molding processes is not fully satisfactory.

[0008] An object of the present invention is to provide a branched propylene polymer which has excellent extensibility when molten while maintaining the melt tension necessary for molding. [Means for solving the problem]

[0009] The branched propylene polymer provided by the present invention is characterized by having the following properties (1) and (2). Property (1): Multi-branching index (MBI) is 0.15 or more and 1.00 or less. Property (2): Strain hardening at a strain rate (dε / dt) of 1.0 / s (SHI@1s -1 ) is greater than or equal to 0.70 and less than or equal to 3.00. Here, the multibranching index (MBI) is the slope of a plot of strain hardening index (SHI) at strain rates (dε / dt) of 0.01 / s to 1.0 / s, with the logarithm of strain rate (log(dε / dt)) on the horizontal axis and strain hardening index (SHI) at strain rates of 0.01 / s to 1.0 / s on the vertical axis. The strain hardening index (SHI) is the slope of a plot of the logarithm of the Hencky strain (ε) (log(ε)) on the horizontal axis and the logarithm of the extensional viscosity (ηE) (log(ηE)) on the vertical axis in the Hencky strain (ε) range between 1 and 3, when the extensional viscosity is measured at a temperature of 180°C and a predetermined strain rate (dε / dt). [Effects of the Invention]

[0010] According to the present invention, there is provided a branched propylene polymer which has excellent extensibility when melted while maintaining the melt tension necessary for molding. [Brief explanation of the drawings]

[0011] [Figure 1A] FIG. 1A is a schematic diagram illustrating that when a branched propylene polymer has many branches with short branch chain lengths in the high molecular weight region of the molecular weight distribution, entanglement points of molecular chains do not appear so frequently. [Figure 1B] FIG. 1B is a schematic diagram illustrating that when a branched propylene polymer has many branches with long branch chain lengths in the high molecular weight region of the molecular weight distribution, many entanglement points of molecular chains appear. [Figure 2] FIG. 2 is an example of a plot diagram for determining strain hardening index (SHI). [Figure 3] FIG. 3 is an example of a plot diagram for determining the branching index. [Figure 4] FIG. 4 is a diagram illustrating the baseline and intervals of a chromatogram in GPC. [Figure 5] FIG. 5 is a graph plotting data on the branched propylene polymers obtained in each example and comparative example, with MFR (MFR 230° C., 2.16 kg load) on the horizontal axis and multi-branching index (MBI) on the vertical axis. [Figure 6] FIG. 6 is a graph in which the horizontal axis represents MFR (MFR 230°C, 2.16 kg load) and the vertical axis represents the maximum take-up speed (MaxDraw) at 230°C, and data on the branched propylene polymers obtained in each example and comparative example are plotted. [Figure 7] FIG. 7 is a graph in which the data of the branched propylene polymers obtained in each Example and Comparative Example are plotted, with the melt tension (MT230°C) on the horizontal axis and the maximum take-up speed (MaxDraw) at 230°C on the vertical axis. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present inventors synthesized a branched propylene polymer based on the design concept that, in order to improve the extensibility of a branched propylene polymer, a branched propylene polymer can be obtained having a relaxation time distribution in which many components have a relatively short relaxation time and few components have an extremely long relaxation time by incorporating multi-branched molecules having a molecular structure in which many branched chains, each having a branched chain length shorter than that of conventional branched propylene polymers, are introduced per molecule in the high molecular weight region of the molecular weight distribution of the branched propylene polymer, and they have succeeded in obtaining a branched propylene polymer with improved extensibility. As shown in FIG. 1A , when a branched propylene polymer contains hyperbranched molecules having many branches with short branch chain lengths in the high molecular weight region of the molecular weight distribution, when strain is applied to the branched propylene polymer, an appropriate number of entanglement points of molecular chains appear, and the branched propylene polymer exhibits a relaxation time distribution in which many components have a relatively short relaxation time and few components have an extremely long relaxation time. This makes it difficult for local oriented crystallization originating from the entanglement points of molecular chains to occur, making it possible to suppress non-uniformity of oriented crystallization, which is thought to improve extensibility. In contrast, as shown in FIG. 1B , when a branched propylene polymer contains, in a high molecular weight region, hyperbranched molecules having many branches with excessively long branch chain lengths, many entanglement points of molecular chains appear when the branched propylene polymer is strained, resulting in the presence of many components that do not relax or components that take a long time to relax. As a result, oriented crystallization proceeds locally at many points in the polymer starting from the entanglement points of molecular chains, resulting in non-uniform oriented crystallization and poor extensibility. That is, the branched propylene polymer of the present invention is presumed to have a molecular structure in accordance with the design concept of introducing a large number of relatively short long-chain branches into the high molecular weight region of the molecular weight distribution, and on the other hand, has the following properties and exhibits excellent extensibility in a melt state while maintaining the melt tension required for molding. The present invention will be described in detail below. In this specification, the use of "to" to indicate a range of values ​​means that the values ​​before and after the "to" range include the lower limit and upper limit. In the present invention, logarithms are expressed in the sense of common logarithms, that is, with a base of 10. In the present invention, the term "stretchability" refers to the property of a resin in a molten state that allows it to be stretched uniformly in a wide, thin, or long, thin, or long shape.

[0013] I. Branched propylene polymer of the present invention The branched propylene polymer of the present invention has the following properties (1) and (2), and preferably further has one or more of the following properties (3) to (10). The multi-branching index (MBI) defined in property (1) can be used as an index for determining the degree of ductility of a molten resin, and the strain hardening index (SHI) defined in property (2) can be used as an index for determining the degree of melt tension of a molten resin. In the present invention, by specifying the multi-branching index (MBI) and the strain hardening index (SHI) each within a certain range, a branched propylene polymer that has excellent ductility in the melt while maintaining the melt tension necessary for molding can be provided.

[0014] Characteristics (1): The branched propylene polymer of the present invention has a multi-branching index (MBI) of 0.15 or more and 1.00 or less. Here, the multi-branching index (MBI) is the slope of a plot of the strain hardening index (SHI) of a polymer at strain rates (dε / dt) of 0.01 / sec to 1.0 / sec, with the logarithm of the strain rate (log(dε / dt)) on the horizontal axis and the strain hardening index (SHI) at strain rates of 0.01 / sec to 1.0 / sec on the vertical axis. The strain hardening of a polymer changes depending on the strain rate (dε / dt). The multi-branching index (MBI) indicates the dependency of the strain hardening index (SHI) on the strain rate (dε / dt). A larger value of the multi-branching index (MBI) means that the strain hardening index (SHI) increases more significantly as the strain rate (dε / dt) increases.

[0015] The strain hardening index (SHI) is the slope of a plot of the logarithm of the Hencky strain (ε) (log(ε)) on the horizontal axis and the logarithm of the extensional viscosity (ηE) (log(ηE)) on the vertical axis in the Hencky strain (ε) range from 1 to 3, when the extensional viscosity of a polymer is measured at a temperature of 180°C and a predetermined strain rate (dε / dt). Strain hardening index (SHI) indicates the strain hardening of a polymer when strain is applied to the polymer at a given strain rate (dε / dt). A polymer with a high strain hardening index (SHI) at a given strain rate (dε / dt) does not relax when strain is applied to the polymer at that given strain rate (dε / dt), and its extensional viscosity increases with increasing strain.

[0016] (Method for measuring extensional viscosity and calculation of strain hardening index (SHI) and multi-branching index (MBI) at each strain rate (dε / dt)) The strain hardening index (SHI) and multi-branching index (MBI) can be determined by measuring uniaxial extensional viscosity using the measuring device and measuring method described in, for example, Polymer, Vol. 42, p. 8663 (2001). In the present invention, the strain hardening index (SHI) at each strain rate (dε / dt) can be measured by the following measurement and method. Equipment: Rheometorics Ares Jig: TA Instruments Extentional Viscosity Fixture ·Measurement temperature: 180℃ ·Strain rate: 1.0 / sec, 0.1 / sec, 0.01 / sec Preparation of test specimen: Press mold a sheet of 18mm x 10mm and 0.7mm thick.

[0017] Figure 2 shows an example of a plot diagram for determining strain hardening index (SHI). Using the above measurement method, data on the time change in extensional viscosity (ηE) at a predetermined constant strain rate (dε / dt) was obtained. The measurement data was plotted on a graph with the logarithm (log(ε)) of Hencky strain (ε) on the horizontal axis and the logarithm (log(ηE)) of extensional viscosity (ηE) on the vertical axis. The slope of the extensional viscosity in the Hencky strain (ε) range from 1 to 3 was identified from the graph, and this slope was taken as the strain hardening index (SHI) at the strain rate (dε / dt) under the measurement conditions. Figure 3 is an example of a plot diagram for determining the multi-branching index. Using the above measurement method, the strain hardening index (SHI) is measured at multiple strain rates in the strain rate (dε / dt) range from 0.01 / s to 1.0 / s. The strain hardening index (SHI) at each strain rate is plotted on a graph with the logarithm of the strain rate (log(dε / dt)) on the horizontal axis and the strain hardening index (SHI) on the vertical axis. The slope of the graph in the strain rate range from 0.01 / s to 1.0 / s is identified, and this slope is taken as the multi-branching index (MBI). In the example of Figure 3, SHI@0.01s -1 , SHI@0.1s -1 , SHI@1.0s -1 The three plots were plotted on a graph, and the slope of the line approximating the three plots was taken as the multi-branching index (MBI).

[0018] Generally, the more components with long relaxation times there are in a polymer, the greater the strain hardening that polymer exhibits even at slow strain rates. The relaxation time of a polymer depends on the structure of the polymer molecule, such as molecular weight, the presence or absence of branches, the amount of branches, and the length of the branched chains. In particular, in the case of a branched propylene polymer, the relaxation time increases as the branch chain length increases. When the branched chain length of the branched propylene polymer is very long, the relaxation time of the branched propylene polymer is very long, and therefore the branched propylene polymer exhibits high strain hardening even at a slow strain rate. On the other hand, when the branch chain length is short, the relaxation time of the branched propylene polymer is short, and therefore the branched propylene polymer does not relax and exhibits high strain hardening at a fast strain rate, but the branched propylene polymer relaxes and exhibits reduced strain hardening at a slow strain rate. Therefore, the dependency of strain hardening on strain rate, i.e., the multi-branching index (MBI), of a branched propylene polymer as a polymer assembly varies depending on the combination of components with long relaxation times and components with short relaxation times and the content ratio of each component. When a branched propylene polymer contains a large number of components that do not relax or components that take a long time to relax, oriented crystallization proceeds locally at many locations in the polymer, starting from entanglement points of molecular chains, resulting in non-uniform oriented crystallization and poor extensibility. In contrast, when a branched propylene polymer contains many multi-branched molecules having many branches with short branch chain lengths per molecule in the high molecular weight region of the molecular weight distribution, the polymer exhibits a relaxation time distribution in which there are many components with a relatively short relaxation time and few components with extremely long relaxation times. This makes it difficult for local oriented crystallization originating from entanglement points of molecular chains to occur, making it possible to suppress non-uniformity of oriented crystallization, and is therefore thought to improve extensibility.

[0019] In order to provide the branched propylene polymer of the present invention with excellent extensibility when melted, the lower limit of the multi-branching index (MBI) of the branched propylene polymer is set to 0.15 or more, preferably 0.16 or more, and more preferably 0.17 or more. In order to provide stable melt tension by suppressing the strain rate dependency of strain hardening, the upper limit of the multi-branching index (MBI) of the branched propylene polymer of the present invention is set to 1.00 or less, preferably 0.80 or less, and more preferably 0.50 or less. By setting the multi-branching index (MBI) of the branched propylene polymer to 0.15 or more and 1.0 or less, the polymer does not relax at a fast strain rate (1.0 / sec) and has a large strain hardening degree (SHI@0.1 / sec), but relaxes at a slow strain rate (0.01 / sec) and has a small strain hardening degree (SHI@0.01 / sec). Therefore, the branched propylene polymer of the present invention exhibits a relaxation time distribution in which many components have a relatively short relaxation time and few components have an extremely long relaxation time, and therefore has excellent extensibility. The branched propylene polymer has a strain hardening coefficient (SHI@1s) in a specific range defined in the following property (2). -1 ), if the multibranching index (MBI) is less than 0.15, the strain rate dependency of the strain hardening index (SHI) is too small, so that even at a slow strain rate such as 0.01 s or 0.1 s, the strain hardening at a strain rate of 1 s (SHI@1s -1 ) shows a large strain hardening degree that is not so different from that of the branched propylene polymer. Therefore, in this case, the branched propylene polymer contains many components with long relaxation times, and has poor ductility. On the other hand, the branched propylene polymer has a strain hardening coefficient (SHI@1s) in a specific range defined in the following property (2). -1 ), if the multi-branching index (MBI) is more than 1.0, the strain rate dependency of the strain hardening (SHI) is too high, and even a slight change in the strain rate changes the strain hardening, making the melt tension unstable. Therefore, in this case, when the branched propylene polymer is molded, problems such as molding defects occur and it becomes difficult to control the conditions for the molding process are raised.

[0020] The strain hardening and the multi-branching index (MBI), which is indicated by the strain rate dependency of the strain hardening, can be adjusted by controlling the amount and length of branched chains in the branched propylene polymer. For example, the molecular weight of the macromer in the macromer synthesis step correlates with the length of the branched chain. Therefore, in a combination of a metallocene complex that mainly contributes to the synthesis of the macromer and a metallocene complex that mainly contributes to the copolymerization of propylene and the macromer, the molecular weight of the macromer can be adjusted by selecting the metallocene complex that contributes to the synthesis of the macromer. Specifically, the molecular weight of the macromer can be adjusted by selecting a combination of bulkier substituents at the 2- and 4-positions of the indene skeleton of the metallocene. In addition, macromers are produced through β-hydrogen elimination from the ends of growing chains. By increasing the polymerization temperature, the β-hydrogen elimination reaction can be accelerated relative to the propylene insertion / growth reaction, thereby reducing the molecular weight of the macromer. Regarding the amount of branching, the ratio of propylene to macromer in the macromer copolymerization step correlates with the amount of branched chains. Specifically, the amount of macromer incorporation can be adjusted by selecting the activity of the metallocene complex that contributes to the synthesis of the macromer and the activity of the metallocene complex that contributes mainly to the copolymerization of propylene and macromer. As another method, the amount of macromer incorporated can be adjusted by selecting the amount of metallocene complex used that contributes to the synthesis of the macromer and the amount of metallocene complex used that mainly contributes to the copolymerization of propylene and the macromer.

[0021] Characteristics (2): The branched propylene polymer of the present invention has a strain hardening coefficient (SHI@1s) at a strain rate (dε / dt) of 1.0 / s. -1 ) is preferably 0.70 or more and 3.00 or less. Here, the strain hardening rate at 1.0 / s (SHI@1s -1 ) is the slope of a plot of the logarithm of Hencky strain (ε) (log(ε)) on the horizontal axis and the logarithm of extensional viscosity (ηE) (log(ηE)) on the vertical axis in the Hencky strain (ε) range from 1 to 3, when measuring extensional viscosity at a temperature of 180°C and a strain rate (dε / dt) of 1.0 / s. From the viewpoint of increasing the melt tension to improve moldability and also improving the extensibility, the branched propylene polymer of the present invention has a strain hardening index (SHI@1s -1 ) is preferably 0.70 or more, more preferably 0.80 or more, and even more preferably 1.0 or more, while the strain hardening (SHI@1s -1 ) is preferably 3.00 or less, more preferably 2.00 or less, and even more preferably 1.70 or less. Branched propylene polymers show a high strain hardening rate (SHI@1s -1When the strain hardening coefficient (SHI@1s) is relatively large, the polymer contains components that do not relax at high strain rates, which increases the elongational viscosity. -1 ) compared to polymers with a smaller elongational viscosity, the melt tension is increased due to the higher elongational viscosity, which improves moldability in sheet molding, blow molding, thermoforming, and foam molding. From this viewpoint, the branched propylene polymer of the present invention has a strain hardening index (SHI@1s -1 ) is preferably 0.70 or more. On the other hand, the branched propylene polymer exhibits a high strain hardening rate (SHI@1s -1 If the strain hardening (SHI@1s) is too large, the number of components that do not relax or components that relax for a long time is large, and therefore, oriented crystallization proceeds locally from the entanglement points of molecular chains, resulting in a problem of deterioration in ductility. From this viewpoint, the branched propylene polymer of the present invention is -1 ) is preferably 3.00 or less.

[0022] Characteristics (3): In the branched propylene polymer of the present invention, the proportion of components soluble in p-xylene at 25° C. (CXS) is less than 0.5% by mass. CXS is used as an index of the proportion of low-regularity and low-molecular-weight components in branched propylene polymers. If CXS is too high, the amount of low-molecular-weight and low-stereoregular components increases, which affects various physical properties. The CXS is preferably 0.4% by mass or less, and more preferably 0.3% by mass or less. There is no set lower limit for CXS, but from the viewpoint of the feel of the molded article, it is preferably 0.1% by mass or more, and more preferably 0.2% by mass or more.

[0023] In the present invention, the CXS measurement method is as follows. 2 g of the sample is dissolved in 300 ml of p-xylene (containing 0.5 mg / ml of BHT) at 130°C to form a solution, which is then left to stand at 25°C for 48 hours. The precipitate and filtrate are then separated by filtration. The p-xylene is evaporated from the filtrate, which is then dried under reduced pressure at 100°C for 12 hours, and the components dissolved in the p-xylene at 25°C are recovered. The percentage of the mass of the recovered components relative to the mass of the sample is defined as CXS.

[0024] To control the amount of CXS, it is best to select a bridged indene or azulene complex as the metallocene catalyst component, so that the amount of low-molecular-weight components is relatively low and the stereoregularity is high. In particular, the amount of CXS can be controlled by adjusting the bulkiness of the substituents at the 2- or 4-positions. Furthermore, when combining two complexes, the overall amount of CXS can be controlled by selecting a complex with high stereoregularity and adjusting the ratio of the complexes. Furthermore, increasing the amount of organoaluminum compound, which is a catalyst component, coordinates with part of the complex, causing it to change, resulting in an increase in low molecular weight components and a decrease in stereoregularity. Therefore, by optimizing the amount of organoaluminum compound, it is possible to control the amount of CXS.

[0025] Characteristics (4): In the branched propylene polymer of the present invention, the molecular weight of the branched side chain of the branched propylene polymer is preferably 11,000 or more and 53,000 or less in terms of Mn. Reference: Macromolecules, Vol. 31, p. 1335 (1998) states that the entanglement molecular weight of isotactic polypropylene was found to be 6900 g / mol. Further, in the reference: Macromolecules, Vol. 35, p. 10062 (2002), it is stated that when the branch length of a propylene polymer is 7000 g / mol or less, there is little effect on viscoelasticity. In light of these documents, the manifestation of viscoelastic behavior such as strain hardening requires that the length of the branched chains be 6900 to 7000 g / mol or more in terms of the entanglement molecular weight of polypropylene. This corresponds to a skeleton carbon number of approximately 400 or more. Here, skeleton carbon refers to all carbons other than methyl carbons when propylene alone or when propylene and ethylene are copolymerized. Furthermore, when butene is used in addition to the above monomers, skeleton carbon refers to all carbon atoms other than methyl carbons and ethyl carbons. Therefore, at a high strain rate, the degree of strain hardening increases, and in order to obtain the melt tension required for molding, the length of the branched chains of the branched propylene polymer of the present invention is preferably 500 or more (11,000 or more in terms of the molecular weight of polypropylene), more preferably 700 or more (15,000 or more in terms of the molecular weight of polypropylene), and even more preferably 1,000 or more (21,000 or more in terms of the molecular weight of polypropylene), in terms of the number of carbon atoms in the backbone. Regarding the branch length of the branched propylene polymer of the present invention, at a high strain rate, the strain hardening is large and a melt tension required for molding is obtained, but at a low strain rate, the strain is sufficiently relaxed and the strain hardening is reduced. Therefore, the number of carbon atoms in the backbone is preferably 2500 or less (polypropylene molecular weight equivalent: 53,000 or less), more preferably 2200 or less (polypropylene molecular weight equivalent: 46,000 or less), and even more preferably 2000 or less (polypropylene molecular weight equivalent: 42,000 or less).

[0026] The polypropylene molecular weight equivalent value referred to here is, strictly speaking, different from the molecular weight value measured by GPC, but is close to the number average molecular weight (Mn) measured by GPC. Furthermore, although the length of the branches on a branched propylene polymer cannot be measured directly, a macromer corresponding to the branched portion can be synthesized by polymerizing propylene under the same conditions as those for producing the branched propylene polymer of the present invention, and the number average molecular weight (Mn) of the macromer measured by GPC using the method shown in the Examples can be estimated to be the branch length. Therefore, the lower limit of the branched chain length of the branched propylene polymer of the present invention is preferably 11,000 or more, more preferably 15,000 or more, and even more preferably 21,000 or more, in terms of the number average molecular weight (Mn) measured by GPC. On the other hand, the upper limit of the branched chain length of the branched propylene polymer of the present invention is preferably 53,000 or less, more preferably 46,000 or less, and even more preferably 42,000 or less, in terms of the number average molecular weight (Mn) measured by GPC.

[0027] (Method for measuring molecular weight) The molecular weight is obtained by gel permeation chromatography (GPC) as the number average molecular weight (Mn), weight average molecular weight (Mw), and Q value (Mw / Mn). Details of the measurement method and measuring equipment are as follows. Apparatus: Waters GPC (ALC / GPC, 150°C) Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42 μm) Column: Showa Denko AD806M / S (3 columns) Mobile phase solvent: o-dichlorobenzene (ODCB) ·Measurement temperature: 140℃ ·Flow rate; 1.0mL / min ·Injection volume; 0.2mL The sample is prepared by mixing the sample with ODCB (containing 0.5 mg / mL of dibutylhydroxytoluene (BHT)) at a sample concentration of 1 mg / mL, and dissolving the mixture at 140° C. for about 1 hour. The baseline and interval of the obtained chromatogram are as shown in Figure 4. The conversion from the retention volume obtained by GPC measurement to molecular weight is performed using a calibration curve prepared in advance using standard polystyrenes. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation. Brand Name: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000 A 0.2 mL solution of each standard dissolved in ODCB (containing 0.5 mg / mL BHT) was injected to prepare a calibration curve. The calibration curve was calculated using a cubic equation obtained by approximating the curve using the least squares method. Viscosity formula used to convert to molecular weight: [η] = K × M α The following values ​​are used: PS:K=1.38×10 -4 , α=0.7 PP:K=1.03×10 -4 , α=0.78

[0028] Characteristics (5): The branched propylene polymer of the present invention preferably has a melt flow rate (MFR) measured at a temperature of 230° C. under a load of 2.16 kg of 1 to 10 g / 10 min. MFR is an index that indicates the fluidity of a polymer when melted. As the molecular weight of the polymer increases, the MFR decreases. If the MFR is too small, the fluidity of the polymer when melted decreases, making it difficult to mold the polymer under heat. On the other hand, as the molecular weight of the polymer decreases, the MFR increases. If the MFR is too large, the melt tension decreases. Furthermore, if the MFR is large, the fluidity of the polymer when melted improves, but the impact strength may decrease. From the viewpoint of thermoformability, the MFR of the propylene polymer of the present invention is preferably 1 g / 10 min or more, more preferably 2 g / 10 min or more, and even more preferably 3 g / 10 min or more. On the other hand, from the viewpoints of melt tension and impact strength, the MFR of the propylene polymer of the present invention is preferably 10 g / 10 min or less, more preferably 8 g / 10 min or less, and even more preferably 6 g / 10 min or less. Among these, a particularly preferred range of MFR is 1 g / 10 min or more and 6 g / 10 min or less. In the present invention, the melt flow rate (MFR) is a value measured in accordance with JIS K6921-2 "Plastics - Polypropylene (PP) materials for molding and extrusion - Part 2: Preparation of test specimens and determination of properties" under test conditions of 230°C and a load of 2.16 kgf. The melt flow rate (MFR) can be easily adjusted by changing the temperature or pressure of the polymerization, or, as a general method, by adding a chain transfer agent such as hydrogen during the polymerization.

[0029] Characteristics (6): The branching amount of the branched propylene polymer of the present invention is as follows: 13 It can be measured as an average value for the entire polymer using C-NMR, and the relative degree of branching at each absolute molecular weight can be determined as an index from the relationship between the absolute molecular weight (Mabs) and the branching index (g') using 3D-GPC. In the branched propylene polymer of the present invention, the ratio of components having a molecular weight M of 1 million or more to the total amount of the polymer (W1 million) is preferably 0.070 or more and 0.100 or less in a molecular weight distribution curve measured by GPC. W1 million is an index showing the ratio of high molecular weight components contained in a polymer. W1 million is defined as the value obtained by subtracting from 1 the integral value up to a molecular weight M of 1 million or less (Log(M)=6.0) in an integrated molecular weight distribution curve measured by GPC (total amount normalized to 1 on a mass basis). The branched propylene polymer of the present invention preferably has a branching index g' (1 million) of 0.80 or more and 0.90 or less when the absolute molecular weight Mabs measured by 3D-GPC is 1 million.

[0030] The branching index g' is the intrinsic viscosity [η] of a polymer with a long-chain branching structure. br Intrinsic viscosity [η] of a linear polymer with the same molecular weight lin The ratio ([η] br / [η] lin ) and takes a value less than 1.0 when long-chain branching structures are present. The definition is described, for example, in "Developments in Polymer Characterization-4" (JV Dawkins ed., Applied Science Publishers, 1983), and is a guide known to those skilled in the art. The branching index g' can be calculated by using, for example, the absolute molecular weight M abs can be obtained as a function of In the present invention, 3D-GPC refers to a GPC apparatus connected with three detectors: a differential refractometer (RI), a viscometer, and a multi-angle laser light scattering detector (MALLS). The GPC apparatus used is an Alliance GPCV2000 manufactured by Waters, equipped with a differential refractometer (RI) and a viscometer, and a multi-angle laser light scattering detector (MALLS) manufactured by Wyatt Technology, DAWN-E, as the light scattering detector. The detectors are connected in the following order: MALLS, RI, and Viscometer. The mobile phase solvent was 1,2,4-trichlorobenzene (to which the antioxidant Irganox 1076 manufactured by BASF Japan Ltd. was added at a concentration of 0.5 mg / mL). The flow rate is 1 mL / min, and two columns, GMHHR-H(S)HT manufactured by Tosoh Corporation, are connected in series. The temperatures of the column, the sample injection port, and each detector were 140°C. The sample concentration was 1 mg / mL, and the injection volume (sample loop volume) was 0.2175 mL. Absolute molecular weight (M abs ), the root mean square radius of gyration (Rg) and the intrinsic viscosity ([η]) obtained from the Viscometer are calculated using the data processing software ASTRA (version 4.73.04) attached to MALLS, with reference to the following literature. References: 1.Developments in Polymer Characterization, vol.4. Essex: Applied Science; 1984. Chapter1. 2.Polymer, 45, 6495-6505(2004) 3.Macromolecules, 33, 2424-2436(2000) 4.Macromolecules, 33, 6945-6952(2000) The branching index g' is the intrinsic viscosity ([η] br ) and the intrinsic viscosity ([η] obtained by separately measuring a linear polymer lin ) and the ratio ([η] br / [η] lin ) is calculated as

[0031] When long chain branching is introduced into a polymer molecule, the radius of gyration becomes smaller compared to a linear polymer molecule of the same molecular weight. As the radius of gyration becomes smaller, the intrinsic viscosity also becomes smaller. Therefore, as long chain branching is introduced, the intrinsic viscosity ([η]) of a linear polymer of the same molecular weight decreases. lin ) versus the intrinsic viscosity of branched polymers ([η] br ) ratio ([η] br / [η] lin ) becomes smaller. Therefore, for polymers with long chain branching, the branching index g'([η] br / [η] lin ) is less than 1.0, and linear polymers, by definition, have a branching index g' of 1.0. Here, a commercially available homopolypropylene (Novatec PP (registered trademark) manufactured by Japan Polypropylene Corporation, grade name: FY6) was used as the linear polymer, and [η] lin [η] of linear polymer lin The logarithm of [η] has a linear relationship with the logarithm of molecular weight, as known from the Mark-Houwink-Sakurada equation. lin can be obtained by extrapolating to the low molecular weight side or the high molecular weight side as appropriate. A branching index g' of less than 1.0 can be achieved by introducing a large amount of long-chain branches, or by increasing the branch chain length when the number of branches is the same. This can be achieved by controlling the selection of catalysts, their combination and amount ratio, and the prepolymerization conditions during polymerization. Each branching index g' can be set within the above-mentioned specific range by appropriately adjusting the amount of hydrogen during polymerization in addition to selecting catalysts, their combinations and their quantitative ratios, as described below.

[0032] Characteristics (7): The branched propylene polymer has a melting point (Tm) of 150°C or higher and 157°C or lower as measured by differential scanning calorimetry (DSC). The higher the Tm of the branched propylene polymer, the more improved its heat resistance and rigidity become. Therefore, the Tm is preferably 150°C or higher, and more preferably 151°C or higher. On the other hand, if the Tm of the branched propylene polymer is too high, the rigidity may become too high, resulting in poor feel to the touch, etc. Therefore, the Tm is preferably 157°C or lower, more preferably 155°C or lower. In the case of polypropylene, Tm decreases due to the insertion of ethylene units or regioregular defects. The Tm of the branched propylene polymer of the present invention can be controlled by selecting a complex with an optimal regioregular defect as a polymerization catalyst, selecting a combination of multiple complexes, and further controlling the polymerization temperature and polymerization pressure. The melting point (Tm) of a branched propylene polymer can be measured by the following method: Using a DSC6200 manufactured by Seiko Instruments Inc., a 5 mg sheet-shaped sample piece is placed in an aluminum pan, heated from room temperature to 200°C at a heating rate of 100°C / min, held for 5 minutes, and then cooled to 20°C at a rate of 10°C / min to crystallize the sample, and the crystallization temperature (Tc) is determined as the maximum crystallization peak temperature (°C).Then, the temperature is raised to 200°C at a rate of 10°C / min to determine the melting point (Tm) as the maximum melting peak temperature (°C). The sheet-like sample can be obtained by sandwiching the branched propylene polymer powder between press plates, preheating at 190°C for 2 minutes, pressing at 5 MPa for 2 minutes, and then cooling at 0°C and 10 MPa for 2 minutes.

[0033] Characteristics (8): The branched propylene polymer of the present invention may have a long chain branched (LCB) structural portion represented by the following structural formula (A).

[0034] [ka]

[0035] [In Structural Formula (A), P1, P2, and P3 are residues generated at the terminals of the branched propylene polymer, each having one or more propylene units, Cbr represents a methine carbon at the base of a branched chain having 7 or more carbon atoms, and Ca, Cb, and Cc represent methylene carbons adjacent to the methine carbon (Cbr)] In the structural formula (A), the main chain of the branched propylene polymer is P 1 -Cbr-P 2 Line, P 1 -Cbr-P 3 Line or P 2 -Cbr-P 3 There are three types of lines. 3 Line, Cbr-P 2 Line or Cbr-P 1 The line can be the branched chain. 1 , P 2 , P 3 may itself contain a branch carbon (Cbr) other than the Cbr described in structural formula (A). Here, the LCB structure is assigned to the branched propylene polymer. 13 By C-NMR, three methylene carbons (Ca, Cb, Cc) are observed at 44.0-44.1 ppm, 44.7-44.8 ppm, and 44.8-44.9 ppm, and a methine carbon (Cbr) is observed at 31.6-31.8 ppm. A characteristic feature of this compound is that the three methylene carbons adjacent to Cbr are observed as three diastereotopic, unequal carbons. Also, the LCB number is 13 It is the number of branched chains with 7 or more carbon atoms per 1000 monomer units (1000p) calculated by C-NMR. Branched chains with more than six carbon atoms can be distinguished from branched chains with six or fewer carbon atoms by the difference in the peak position of the methine carbon at the base of the branch (Macromolecules, Vol. 35, No. 10, 2002). In the present invention, the LCB number is not particularly limited, but is preferably 1.0 or less per 1000 p.

[0036] 13 Details of the method for measuring the long chain branching (LCB) structure calculated by C-NMR are as follows. [Sample preparation] Approximately 200 mg of sample is placed in an NMR sample tube with an inner diameter of 10 mm, together with 2.4 ml of o-dichlorobenzene / deuterated bromide benzene (CDBr) = 2 / 1 (volume ratio) and hexamethyldisiloxane, a chemical shift reference substance, and the tube is purged with nitrogen, sealed, and heated to dissolve to make a homogeneous solution. [Apparatus and measurement method] NMR measurements were performed using a Bruker Biospin AVANCE400 NMR instrument equipped with a 10 mm diameter cryoprobe. Probe temperature 120°C, pulse angle 45°, pulse interval 4.2 seconds, accumulation number more than 20,000, proton broadband decoupling method 13 Perform C-NMR measurement. The chemical shifts are those of hexamethyldisiloxane. 13 The C signal was set to 1.98 ppm, and the other 13 The chemical shifts of the C signals were referenced to this. [Calculation method for the number of long chain branches (LCB number)] When the intensity of methylene carbon in the propylene main chain from 44.4 to 49.0 ppm is normalized to 1000, the average of the methylene carbon intensity from 44.0 to 44.1 ppm and the methine carbon (Cbr) intensity from 31.6 to 31.8 ppm is defined as the number of long chain branches per 1000 propylene monomer units.

[0037] Characteristics (9): In order to obtain a propylene polymer having excellent extensibility while maintaining the melt tension necessary for molding, the propylene polymer produced by the present invention has a melt tension at 230°C (MT230°C) of preferably 4.0 g or more, more preferably 5.0 g or more, and particularly preferably 6.0 g or more, and an upper limit of MT230°C of preferably 19.0 g or less, more preferably 18.0 g or less, and particularly preferably 17.0 g or less. The melt tension at 230°C (MT230°C) is measured using a melt tension tester (for example, Capirograph 1B manufactured by Toyo Seiki Seisaku-sho, Ltd.) by extruding resin into a string shape at a resin temperature of 230°C under the following conditions, and winding it up around a roller. The tension detected on the pulley is taken up as the melt tension (MT230°C). Capillary: diameter 2.0 mm, length 40 mm Cylinder diameter: 9.55mm Cylinder extrusion speed: 20mm / min · Winding speed: 4.0m / min If breakage occurs at a winding speed of 4.0 m / min, it is determined that "melt tension cannot be evaluated."

[0038] Characteristics (10): The branched propylene polymer produced by the present invention has a controlled branch structure (amount of branches, branch length, branch distribution), and therefore has high melt tension and improved melt extensibility. The melt extensibility was measured by the melt tension measurement method described above. The resin was extruded into a string shape under the following conditions and wound around a roller. The winding speed was gradually increased from 4.0 m / min (acceleration: 5.4 cm / s 2 ), the winding speed just before the string-like material breaks is measured, and the maximum winding speed (MaxDraw) thus measured can be used as an index for evaluation. Note that a larger MaxDraw means better extensibility.

[0039] The maximum winding speed can be measured using a Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd. under the following conditions: The initial winding speed is 4.0 m / min, and the speed is increased at a constant acceleration. The winding speed when the strand breaks is measured. Capillary: diameter 2.0 mm, length 40 mm Cylinder diameter: 9.55mm Cylinder extrusion speed: 20mm / min · Winding speed: 4.0m / min-200.0m / min ·Temperature: 230℃

[0040] The branched propylene polymer produced by the present invention can have a large MaxDraw while maintaining a high melt tension by controlling the branch components and the branch chain length, and thus has an improved balance between melt tension and melt extensibility. In the branched propylene polymer produced by the present invention, the maximum draw speed (MaxDraw) is preferably 55 m / min or more, more preferably 65 m / min or more, and even more preferably 75 m / min or more.

[0041] From the viewpoint of durability, it is preferable that the branched propylene polymer produced by the present invention has the maximum draw speed (MaxDraw) (unit: m / min) and the MFR (unit: g / 10 min) satisfy the relationship represented by the following formula (1): (MaxDraw)≧62×log(MFR)+7 Equation (1) Generally, increasing fluidity improves extensibility but reduces melt tension, and increasing fluidity to improve extensibility leads to the problem of insufficient melt tension, so a propylene polymer that satisfies both the melt tension required for molding and excellent extensibility is desired. The above formula (1) shows that the branched propylene polymer produced by the present invention has excellent extensibility commensurate with the fluidity, compared to conventional propylene polymers. That is, in order to distinguish the branched propylene polymer of the present invention from conventional ones, the maximum winding speed (MaxDraw) is considered to be a function positively correlated with an increase in fluidity (MFR), parameters of the function are set, and it is shown that the maximum winding speed (MaxDraw) of the branched propylene polymer produced by the present invention is greater in proportion to the fluidity than the maximum winding speed (MaxDraw) of a conventional propylene polymer defined by the function. Specifically, based on the data of Examples and Comparative Examples, values ​​of the maximum winding speed (MaxDraw) and fluidity (MFR) that distinguish the Examples from Comparative Examples of the prior art are assumed, and the parameters of the relational equation that holds between the maximum winding speed (MaxDraw) and fluidity (MFR) are determined by the least squares method. The branched propylene polymer produced by the present invention has excellent extensibility commensurate with its fluidity, and therefore maintains the melt tension necessary for molding and exhibits excellent extensibility even if its fluidity is low.

[0042] II. Method for producing branched propylene polymer The method for producing the branched propylene polymer of the present invention is not particularly limited as long as it is a method that can produce a branched propylene polymer that satisfies the above-mentioned physical properties that are the characteristic features of the present invention. For example, a macromer copolymerization method using a metallocene catalyst can be used. Preferably, a method using a catalyst containing multiple metallocene compounds such as those described below can be used to produce a long-chain branched propylene polymer. Among the methods for producing the branched propylene polymer of the present invention, a method for producing a branched propylene polymer using the following catalyst components (A), (B), and (C) as a propylene polymerization catalyst can be mentioned as a suitable method. (A): Two or more transition metal compounds of Group 4 of the periodic table, selected from at least one component [A-1], which is a compound represented by the following general formula (a1), and at least one component [A-2], which is a compound represented by the following general formula (a2): Component [A-1]: a compound represented by general formula (a1) Component [A-2]: a compound represented by general formula (a2) (B): A compound or ion-exchange layered silicate that reacts with component (A) to form an ion pair (C): Organoaluminum compounds

[0043] The catalyst components (A), (B) and (C) will be described in detail below. 1. Catalyst Component (A) 1-1. Component [A-1]: Compound represented by general formula (a1) As the component [A-1], a metallocene compound represented by the following general formula (a1) is preferably used, since it produces a propylene polymer with a high terminal vinyl ratio.

[0044] [ka]

[0045] [In general formula (a1), R 11 and R 12 R each independently represents a heterocyclic group containing nitrogen, oxygen, or sulfur and having 4 to 16 carbon atoms. 13 and R 14 Q each independently represents an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these, or a heterocyclic group having 6 to 16 carbon atoms which contains nitrogen, oxygen, or sulfur. 11 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms; M 11 represents zirconium or hafnium, and X 11 and Y 11 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0046] Above R 11 and R 12The nitrogen-, oxygen- or sulfur-containing heterocyclic group having 4 to 16 carbon atoms is preferably a 2-furyl group, a substituted 2-furyl group, a substituted 2-thienyl group or a substituted 2-furfuryl group, and more preferably a substituted 2-furyl group. R 11 and R 12 is a group selected from heterocyclic groups containing nitrogen, oxygen, or sulfur and having 4 to 16 carbon atoms, the terminal vinyl ratio (Rv) can be increased. In particular, by introducing a substituent of an appropriate size onto the heterocyclic group, the relative positional relationship between the heterocycle and the coordination field on the transition metal and the growing polymer chain can be optimized, thereby further increasing the terminal vinyl ratio (Rv) and reducing the molecular weight of the polymer. Furthermore, examples of the substituent on the substituted 2-furyl group, substituted 2-thienyl group, and substituted 2-furfuryl group include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and t-butyl groups; halogen atoms, such as fluorine and chlorine atoms; alkoxy groups having 1 to 6 carbon atoms, such as methoxy and ethoxy groups; and trialkylsilyl groups. Among these, methyl, trimethylsilyl, and t-butyl groups are preferred, with methyl and t-butyl being particularly preferred. Furthermore, R 11 and R 12 Particularly preferred as R are 5-t-butyl-2-furyl and 5-methyl-2-furyl. 11 and R 12 are preferably identical to each other.

[0047] Above R 13 and R 14 are each independently an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these, or a heterocyclic group having 6 to 16 carbon atoms which contains nitrogen, oxygen, or sulfur. In particular, R 13 and R 14By increasing the bulkiness, it is possible to obtain a propylene polymer having higher stereoregularity, fewer heterogeneous bonds, and a higher terminal vinyl ratio. So, R 13 and R 14 is preferably an aryl group having one or more hydrocarbon groups having 1 to 6 carbon atoms, silyl groups having a hydrocarbon group having 1 to 6 carbon atoms, halogen-containing hydrocarbon groups having 1 to 6 carbon atoms, or aryl groups which may have a halogen atom as a substituent on an aryl ring skeleton, within the range of 6 to 16 carbon atoms, and such R 13 and R 14 Specific examples of the group include a 4-t-butylphenyl group, a 2,3-dimethylphenyl group, a 3,5-di-t-butylphenyl group, a 4-chlorophenyl group, a 4-trimethylsilylphenyl group, a 1-naphthyl group, and a 2-naphthyl group. Also, R 13 and R 14 More preferably, R is a phenyl group having one or more hydrocarbon groups having 1 to 6 carbon atoms, silyl groups having hydrocarbon groups having 1 to 6 carbon atoms, halogen-containing hydrocarbon groups having 1 to 6 carbon atoms, or halogen atoms as substituents, with the carbon number being in the range of 6 to 16. The position of substitution is preferably the 4-position on the phenyl group. 13 and R 14 Specific examples of R include a 4-t-butylphenyl group, a 4-biphenylyl group, a 4-chlorophenyl group, and a 4-trimethylsilylphenyl group. 13 and R 14 are preferably identical to each other.

[0048] Above X 11 and Y 11 is an auxiliary ligand, and reacts with component (B) to generate an active metallocene capable of olefin polymerization. Therefore, as long as this purpose is achieved, X 11 and Y 11The types of ligands are not limited, and each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0049] The above Q 11 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms, which links two five-membered rings. When two hydrocarbon groups are present on the above-mentioned silylene group or germylene group, they may be bonded to each other to form a ring structure. The above Q 11 Specific examples of the alkylene group include alkylene groups such as methylene, methylmethylene, dimethylmethylene, and 1,2-ethylene; aryl alkylene groups such as diphenylmethylene; silylene groups; alkylsilylene groups such as methylsilylene, dimethylsilylene, diethylsilylene, di(n-propyl)silylene, di(i-propyl)silylene, and di(cyclohexyl)silylene; (alkyl)(aryl)silylene groups such as methyl(phenyl)silylene; arylsilylene groups such as diphenylsilylene; alkyloligosilylene groups such as tetramethyldisilylene; germylene groups; alkylgermylene groups in which the silicon atom of the silylene group having the above-mentioned divalent hydrocarbon group having 1 to 20 carbon atoms is substituted with germanium; (alkyl)(aryl)germylene groups; and arylgermylene groups. Among these, a silylene group having a hydrocarbon group with 1 to 20 carbon atoms or a germylene group having a hydrocarbon group with 1 to 20 carbon atoms is preferred, with an alkylsilylene group and an alkylgermylene group being particularly preferred.

[0050] Among the compounds represented by the above general formula (a1), preferred compounds are specifically exemplified below. (1) dichloro[1,1'-dimethylsilylenebis{2-(2-furyl)-4-phenyl-indenyl}]hafnium, (2) dichloro[1,1'-dimethylsilylenebis{2-(2-thienyl)-4-phenyl-indenyl}]hafnium, (3) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl}]hafnium, (4) dichloro[1,1'-diphenylsilylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl}]hafnium, (5) dichloro[1,1'-dimethylgermylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl}]hafnium, (6) dichloro[1,1'-dimethylgermylenebis{2-(5-methyl-2-thienyl)-4-phenyl-indenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-phenyl-indenyl}]hafnium, (8) dichloro[1,1'-dimethylsilylenebis{2-(5-trimethylsilyl-2-furyl)-4-phenyl-indenyl}]hafnium, (9) dichloro[1,1'-dimethylsilylenebis{2-(5-phenyl-2-furyl)-4-phenyl-indenyl}]hafnium, (10) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-chlorophenyl)-indenyl}]hafnium, (11) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropyl-phenyl)-indenyl}]hafnium, (12) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (13) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, (14) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-biphenylyl)-indenyl}]hafnium, (15) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(1-naphthyl)-indenyl}]hafnium, (16) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(2-naphthyl)-indenyl}]hafnium, (17) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(1-naphthyl)-indenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(2-naphthyl)-indenyl}]hafnium, (19) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-isopropyl-phenyl)-indenyl}]hafnium, (20) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (21) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium,

[0051] Of these, more preferred are: (3) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-phenyl-indenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-phenyl-indenyl}]hafnium, (11) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropyl-phenyl)-indenyl}]hafnium, (12) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (13) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, (19) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-isopropyl-phenyl)-indenyl}]hafnium, (20) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (21) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, is.

[0052] Also particularly preferred are: (11) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropyl-phenyl)-indenyl}]hafnium, (12) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (13) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, (19) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-isopropyl-phenyl)-indenyl}]hafnium, (20) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (21) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, is.

[0053] 1-2. Ingredient [A-2] As the component [A-2], a metallocene compound represented by the following general formula (a2) is preferably used from the viewpoint of efficiently copolymerizing the macromer and propylene.

[0054] [ka]

[0055] [In general formula (a2), R 21 and R 22 are each independently a hydrocarbon group having 1 to 6 carbon atoms. 23 and R 24 Q each independently represents an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these. 21 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms; M 21 represents zirconium or hafnium, and X 21 and Y 21 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0056] Above R 21 and R 22 are each independently a hydrocarbon group having 1 to 6 carbon atoms, preferably an alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms. Specific examples include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, n-pentyl, i-pentyl, n-hexyl, etc., and are preferably methyl, ethyl, or n-propyl.

[0057] Also, the above R 23 and R 24are each independently an aryl group having 6 to 30 carbon atoms, preferably 6 to 24 carbon atoms, which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroelements selected therefrom. Examples of such aryl groups include phenyl, biphenylyl, and naphthyl groups, each of which may have a substituent. Preferred examples include phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorophenyl, 4-fluorophenyl, 4-methylphenyl, 4-i-propylphenyl, 4-t-butylphenyl, 4-trimethylsilylphenyl, 4-(2-fluoro-4-biphenylyl), 4-(2-chloro-4-biphenylyl), 1-naphthyl, 2-naphthyl, 4-chloro-2-naphthyl, 3-methyl-4-trimethylsilylphenyl, 3,5-dimethyl-4-t-butylphenyl, 3,5-dimethyl-4-trimethylsilylphenyl, and 3,5-dichloro-4-trimethylsilylphenyl.

[0058] Q 21 represents either a divalent hydrocarbon group having 1 to 20 carbon atoms that links two five-membered rings or that bridges two conjugated five-membered ring ligands via a carbon atom having 1 or 2 carbon atoms, or a silylene group or germylene group that may have a hydrocarbon group having 1 to 20 carbon atoms. When two hydrocarbon groups are present on the above-mentioned silylene group or germylene group, they may be bonded to each other to form a ring structure. The above Q 21Specific examples of the alkylene group include alkylene groups such as methylene, methylmethylene, dimethylmethylene, and 1,2-ethylene; aryl alkylene groups such as diphenylmethylene; silylene groups; alkylsilylene groups such as methylsilylene, dimethylsilylene, diethylsilylene, di(n-propyl)silylene, di(i-propyl)silylene, and di(cyclohexyl)silylene; (alkyl)(aryl)silylene groups such as methyl(phenyl)silylene; arylsilylene groups such as diphenylsilylene; alkyloligosilylene groups such as tetramethyldisilylene; germylene groups; alkylgermylene groups in which the silicon atom of the silylene group having the above-mentioned divalent hydrocarbon group having 1 to 20 carbon atoms is substituted with germanium; (alkyl)(aryl)germylene groups; and arylgermylene groups. Among these, a silylene group having a hydrocarbon group with 1 to 20 carbon atoms or a germylene group having a hydrocarbon group with 1 to 20 carbon atoms is preferred, with an alkylsilylene group and an alkylgermylene group being particularly preferred. Furthermore, the above M 21 is zirconium or hafnium, preferably hafnium.

[0059] Above X 21 and Y 21 is an auxiliary ligand, and reacts with component (B) as a cocatalyst to produce an active metallocene capable of olefin polymerization. Therefore, as long as this purpose is achieved, X 21 and Y 21 The types of ligands are not limited, and each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0060] Non-limiting examples of the metallocene compound represented by the above general formula (a2) include the following. However, to avoid a cumbersome and numerous list of examples, only representative exemplary compounds are listed. Also, although compounds with hafnium as the central metal are listed, similar zirconium compounds can also be used, and it is self-evident that various ligands, bridging groups, or auxiliary ligands can be used as desired. (1) dichloro{1,1'-dimethylsilylenebis(2-methyl-4-phenyl-4-hydroazulenyl)}hafnium, (2) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (3) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (4) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (5) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-chloro-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (6) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-methyl-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (8) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (9) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(1-naphthyl)-4-hydroazulenyl}]hafnium, (10) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(2-naphthyl)-4-hydroazulenyl}]hafnium, (11) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chloro-2-naphthyl)-4-hydroazulenyl}]hafnium, (12) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (13) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(2-chloro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (14) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(9-phenanthryl)-4-hydroazulenyl}]hafnium, (15) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (16) dichloro[1,1'-dimethylsilylenebis{2-n-propyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (17) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-chloro-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (19) dichloro[1,1'-dimethylgermylenebis{2-methyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (20) dichloro[1,1'-dimethylgermylenebis{2-methyl-4-(4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (21) dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (22) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chloro-2-naphthyl)-4-hydroazulenyl}]hafnium, (23) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (24) Dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, etc.

[0061] Among these, preferred are: (2) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (22) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chloro-2-naphthyl)-4-hydroazulenyl}]hafnium, (23) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (24) dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, is.

[0062] Also particularly preferably, (2) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (22) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (24) dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, is.

[0063] 2. Catalyst component (B) The catalyst component (B) used in the present invention is a compound or ion-exchangeable layered silicate that reacts with the catalyst component (A) to form an ion pair. The catalyst component (B) may be used alone or in combination of two or more thereof, and is preferably an ion-exchange layered silicate.

[0064] 2-1. Compounds that form ion pairs with catalyst component (A) Examples of the compound that reacts with the catalyst component (A) to form an ion pair include aluminum oxy compounds and boron compounds. Specific examples of the aluminum oxy compounds include compounds represented by the following general formulas (I) to (III).

[0065] [ka]

[0066] In the above general formulas (I), (II), and (III), R 91 , R 101 and R 111 represents a hydrogen atom or a hydrocarbon group, preferably a hydrocarbon group having 1 to 10 carbon atoms, particularly preferably a hydrocarbon group having 1 to 6 carbon atoms. 91 , R 101 and R 111 may be the same or different, and p represents an integer of 0 to 40, preferably 2 to 30. The compounds represented by general formulas (I) and (II) are also called aluminoxanes, and among them, methylaluminoxane or methylisobutylaluminoxane is preferred. The above aluminoxanes can be used in combination with one another within each group or between groups. The above aluminoxanes can be prepared under various known conditions. In general formula (III), R 112 represents a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. The compound represented by general formula (III) is a compound containing one kind of trialkylaluminum or two or more kinds of trialkylaluminum and a compound represented by general formula R 112 It can be obtained by reacting with an alkylboronic acid represented by B(OH)2 in a molar ratio of 10:1 to 1:1. Examples of boron compounds include complexes of cations such as carbonium cations and ammonium cations with organic boron compounds such as triphenylboron, tris(3,5-difluorophenyl)boron and tris(pentafluorophenyl)boron, as well as various organic boron compounds such as tris(pentafluorophenyl)boron.

[0067] 2-2. Ion-exchange layered silicate In the present invention, the ion-exchangeable layered silicate (hereinafter sometimes simply referred to as silicate) used as a raw material refers to a silicate compound that has a crystalline structure in which layers formed by ionic bonds or the like are stacked in parallel with each other through bonding forces, has interlayer ions between the layers, and the contained interlayer ions are exchangeable. Most silicates occur naturally as the main component of clay minerals. They are typically purified by dispersing / swelling them in water and measuring differences in sedimentation rate, but complete removal of impurities is not required, and they may contain impurities other than ion-exchange layered silicates (quartz, cristobalite, etc.). Depending on the type, amount, particle size, crystallinity, and dispersion state of these impurities, they may be preferable to pure silicates, and such complexes are also included in the ion-exchange layered silicates of catalyst component (B). Furthermore, the silicate used in the present invention is not limited to naturally occurring silicates, but may also be synthetic silicates.

[0068] Specific examples of ion-exchangeable layered silicates include layered silicates having a 1:1 structure or a 2:1 structure, as described in "Clay Mineralogy" by Shiramizu Haruo, Asakura Shoten (1988). The 1:1 type structure refers to a structure based on stacking of one layer of tetrahedral sheet and one layer of octahedral sheet, as described in the aforementioned "Clay Mineralogy" and the like. The 2:1 structure is a structure based on stacking two layers of tetrahedral sheets sandwiching one layer of octahedral sheet. Specific examples of ion-exchangeable layered silicates having a 1:1 type structure include kaolin group silicates such as dickite, nacrite, kaolinite, metahalloysite, and halloysite, and serpentine group silicates such as chrysotile, lisardite, and antigorite. Specific examples of ion-exchangeable layered silicates having a 2:1 structure include smectite group silicates such as montmorillonite, beidellite, nontronite, saponite, hectorite, and stevensite, vermiculite group silicates such as vermiculite, mica group silicates such as mica, illite, sericite, and glauconite, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, and chlorite groups, which may form mixed layers. Among these, those containing an ion-exchangeable layered silicate having a 2:1 structure as the main component are preferred, those containing a smectite silicate as the main component are more preferred, and those containing montmorillonite as the main component are even more preferred. The type of interlayer cation (the positive ion contained between the layers of the ion-exchangeable layered silicate) is not particularly limited, but preferred as the main component are alkali metals of Group 1 of the periodic table, such as lithium and sodium; alkaline earth metals of Group 2 of the periodic table, such as calcium and magnesium; or transition metals, such as iron, cobalt, copper, nickel, zinc, ruthenium, rhodium, palladium, silver, iridium, platinum, and gold, which are relatively easily available.

[0069] The ion-exchange layered silicate may be used in a dry state or in a liquid slurried state. The shape of the ion-exchange layered silicate is not particularly limited, and it may be a naturally occurring shape or the shape at the time of artificial synthesis, or it may be an ion-exchange layered silicate whose shape has been processed by operations such as pulverization, granulation, and classification. Among these, the use of granulated ion-exchange layered silicate is particularly preferred because it gives good polymer particle properties when used as a catalyst component. The ion-exchanged layered silicate can be used as it is without any particular treatment, but is preferably subjected to a chemical treatment. For the chemical treatment method of the ion-exchanged layered silicate, see paragraphs 0042 to 0071 of JP 2009-299046 A.

[0070] The catalyst component (B) preferably used in the present invention is a chemically treated ion-exchange layered silicate having an Al / Si atomic ratio of 0.01 to 0.25, preferably 0.03 to 0.24, and more preferably 0.05 to 0.23. The Al / Si atomic ratio is considered to be an index of the acid treatment strength of the clay portion. The aluminum and silicon in the ion-exchange layered silicate are measured by creating a calibration curve using chemical analysis according to the JIS method, and quantifying the amounts using fluorescent X-rays.

[0071] 3.Component (C) The catalyst component (C) used in the present invention is an organoaluminum compound, and preferably an organoaluminum compound represented by the following general formula (IV) is used. (AlR n X 3-n ) m ...General formula (IV) [In the above general formula (IV), R represents an alkyl group having 1 to 20 carbon atoms, X represents a halogen, hydrogen, an alkoxy group, or an amino group, n represents an integer of 1 to 3, and m represents an integer of 1 or 2.] When X is a halogen, it is preferably chlorine; when X is an alkoxy group, it is preferably an alkoxy group having 1 to 8 carbon atoms; and when X is an amino group, it is preferably an amino group having 1 to 8 carbon atoms. The organoaluminum compounds can be used alone or in combination of two or more. Specific examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, tri-normal propylaluminum, tri-normal butylaluminum, triisobutylaluminum, tri-normal hexylaluminum, tri-normal octylaluminum, tri-normal decylaluminum, diethylaluminum chloride, diethylaluminum sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, and diisobutylaluminum chloride. Among these, preferred are trialkylaluminums and alkylaluminum hydrides in which m=1 and n=3. More preferred are trialkylaluminums in which R has 1 to 8 carbon atoms.

[0072] 4. Catalyst Preparation The olefin polymerization catalyst used in the present invention contains the above-mentioned catalyst components. These can be obtained by contacting them in a polymerization vessel or outside a polymerization vessel. The olefin polymerization catalyst may be prepolymerized in the presence of an olefin. The catalyst components are usually contacted in an aliphatic or aromatic hydrocarbon solvent. The contact temperature is not particularly limited, but is preferably between -20°C and 150°C. The order of contact may be any combination suitable for the purpose, but the particularly preferred orders for each catalyst component are as follows: When catalyst component (C) is used, it is possible to contact catalyst component (C) with catalyst component (A), or catalyst component (B), or both catalyst component (A) and catalyst component (B) before contacting catalyst component (A) with catalyst component (B); to contact catalyst component (C) with catalyst component (A) and catalyst component (B) simultaneously; or to contact catalyst component (C) after contacting catalyst component (A) and catalyst component (B); however, a method in which catalyst component (C) is contacted with either catalyst component (A) or catalyst component (B) before contacting catalyst component (A) with catalyst component (B) is preferred. After contacting the catalyst components, they can be washed with an aliphatic hydrocarbon or aromatic hydrocarbon solvent.

[0073] The amounts of the catalyst components (A), (B), and (C) used in the present invention are arbitrary. For example, the amount of catalyst component (A) used relative to catalyst component (B) is preferably in the range of 0.1 μmol to 1000 μmol, more preferably 0.5 μmol to 500 μmol, per 1 g of catalyst component (B). The amount of catalyst component (C) used relative to catalyst component (A) is preferably 0.01 to 5×10 in terms of the molar ratio of aluminum in catalyst component (C) to the transition metal in catalyst component (A). 6 , more preferably 0.1 to 1 × 10 4 The range is.

[0074] The branched propylene polymer of the present invention can be produced by using a catalyst component capable of producing a macromer and a catalyst component capable of copolymerizing the macromer with propylene. Although it is possible to produce the polymer using a single catalyst component that simultaneously has the ability to produce the macromer and the ability to copolymerize the macromer with propylene, a method using separate catalyst components having each of the respective abilities can be selected to efficiently produce the branched propylene polymer of the present invention. That is, the method using a component [A-1] capable of producing a macromer and a component [A-2] capable of copolymerizing the macromer with propylene facilitates the production of a branched propylene polymer satisfying the requirements of the present invention. Therefore, the proportions of the component [A-1] and the component [A-2] used may be any within a range that satisfies the properties of the branched propylene polymer of the present invention, but the molar ratio of the transition metal in [A-1] to the total amount of the components [A-1] and [A-2] is preferably 0.30 or more and 0.99 or less. By varying this ratio, it is possible to adjust the balance between melt properties and catalytic activity. In other words, component [A-1] produces low-molecular-weight vinyl-terminated macromers, while component [A-2] produces high-molecular-weight polymers in which some of the macromers are copolymerized. Therefore, by varying the ratio of component [A-1], it is possible to control the average molecular weight, molecular weight distribution, bias toward low molecular weights in the molecular weight distribution, very high molecular weight components, and branching (amount, length, and distribution) of the resulting polymer, thereby controlling melt properties such as strain hardening and melt tension. The molar ratio of the transition metal in component [A-1] to the total amount of components [A-1] and [A-2] is preferably 0.30 or more, more preferably 0.40 or more, and even more preferably 0.50 or more. The upper limit is preferably 0.99 or less, more preferably 0.90 or less, and in order to efficiently obtain the polymer of the present invention with high catalytic activity, it is preferably 0.80 or less, more preferably 0.70 or less. Furthermore, by using component [A-1] within the above range, the balance between the average molecular weight and the catalytic activity can be adjusted.

[0075] 5. Prepolymerization The olefin polymerization catalyst is preferably subjected to prepolymerization, which involves contacting an olefin with the catalyst and polymerizing a small amount of the olefin. By carrying out the prepolymerization treatment, gel formation can be prevented during main polymerization. This is thought to be because long chain branches can be uniformly distributed among the polymer particles during main polymerization. The olefin used in the prepolymerization is not particularly limited, but examples thereof include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, and styrene, with propylene being preferred. The olefin may be fed to the prepolymerization reactor at a constant rate or at a constant pressure, or any combination thereof, or by stepwise change. The prepolymerization temperature and prepolymerization time are not particularly limited, but are preferably in the range of −20° C. to 100° C. and 5 minutes to 24 hours, respectively. The amount of prepolymerization is preferably 0.01 to 100, more preferably 0.1 to 50, in terms of the mass ratio of the prepolymerized polymer to the catalyst component (B). Furthermore, the catalyst component (C) can be added during the prepolymerization, and washing can also be carried out after the prepolymerization is completed. It is also possible to use a method in which a polymer such as polyethylene or polypropylene, or a solid inorganic oxide such as silica or titania is made to coexist during or after the contact of the above catalyst components. After the prepolymerization, the catalyst may be dried. The drying method is not particularly limited, and examples thereof include drying under reduced pressure, drying by heating, and drying by passing a dry gas through the catalyst. These methods may be used alone or in combination of two or more. In the drying step, the catalyst may be stirred, vibrated, or fluidized.

[0076] 6. Propylene polymerization Any polymerization mode can be adopted as long as the olefin polymerization catalyst and the monomer are brought into contact with each other efficiently. Specifically, a slurry polymerization method using an inert solvent, a bulk polymerization method using propylene as a solvent without substantially using an inert solvent, a solution polymerization method, or a gas phase polymerization method in which each monomer is kept in a gaseous state without substantially using a liquid solvent can be used. Furthermore, continuous polymerization and batch polymerization methods can also be applied. Although multi-stage polymerization of two or more stages can be carried out, single-stage polymerization is preferred. Among these, bulk polymerization is preferred, in which case the polymerization temperature can be from 50° C. to the temperature at which propylene becomes critical.

[0077] Furthermore, in order to produce the branched propylene polymer of the present invention, it is preferable to set the polymerization temperature to 65°C or higher. In the polymerization reaction mediated by the above-mentioned component [A-1], a β-methyl elimination reaction occurs as a termination reaction, forming a vinyl group at the end and producing a macromer that can copolymerize with propylene. The rate of the β-methyl elimination reaction is affected by the polymerization temperature; generally, the higher the polymerization temperature, the faster the β-methyl elimination rate, which results in a higher ratio to the propagation reaction rate and a lower molecular weight of the macromer. Therefore, in the method for producing the branched propylene polymer of the present invention, the polymerization temperature is preferably 65° C. or higher. By setting the polymerization temperature at 65°C or higher, the average molecular weight of the macromer falls within the range that is preferred in the present invention, and therefore branches with short branch chain lengths can be introduced into the branched propylene polymer. For the above reasons, the polymerization temperature is preferably 65° C. or higher, more preferably 70° C. or higher, and even more preferably 75° C. or higher. On the other hand, the upper limit must be equal to or lower than the critical temperature of propylene in order to carry out bulk polymerization, and is preferably 85° C. or lower, and even more preferably 83° C. or lower. In particular, when a compound represented by general formula (a1) is selected as component [A-1], if the substituent at the 2-position of the indenyl group is, for example, a methylfuryl group, the polymer of the present invention can be obtained by polymerization at a temperature of preferably 80°C or higher. However, if the substituent at the 2-position of the indenyl group is a bulkier substituent such as a t-butylfuryl group, the polymer of the present invention can be obtained at a lower polymerization temperature, such as 70°C. In this case, the pressure is more preferably 1.5 MPa or more, even more preferably 2.5 MPa or more, and preferably 3.5 MPa or more, and the upper limit is preferably 4.4 MPa or less, and more preferably 4.0 MPa or less. The polymerization may be a homopolymerization of propylene, or a copolymerization using, in addition to the propylene monomer, one or more α-olefin comonomers having 2 to 20 carbon atoms other than propylene, such as ethylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc. The amount of the comonomer is preferably 10 mol % or less, more preferably 5 mol % or less, as a copolymerization ratio in the branched propylene polymer, and is preferably 15 mol % or less, more preferably 7.5 mol % or less, as a charge amount during polymerization.

[0078] Furthermore, to produce the branched propylene polymer of the present invention, hydrogen is used as a molecular weight modifier. The range of hydrogen is 1.0×10 in terms of molar ratio to propylene. -5 More than 1.0×10 is preferable. -4 More preferably, 0.5 × 10 -3 The above is even more preferable. Also, the upper limit is 1.0 x 10 -2 Less than 0.5 x 10 is preferable. -2 Less than 0.2 × 10 is more preferable. -2 The following is even more preferred: The polymer produced via the above-mentioned component [A-1] has a very slow hydrogen-mediated chain transfer, while the polymer produced via the component [A-2] has a relatively fast hydrogen-mediated chain transfer, so that a high molecular weight polymer can be produced when there is little hydrogen. Therefore, when the amount of hydrogen used is small, the polymer produced by component [A-2] (i.e., a copolymer of polypropylene and vinyl-terminated macromer, a polymer corresponding to a branched propylene-based polymer) is on the higher molecular weight side than the polymer produced by component [A-1] (i.e., a vinyl-terminated macromer, a polymer that forms a branched chain). Therefore, when propylene is polymerized using a combination of component [A-1] and component [A-2] under conditions where a small amount of hydrogen is used, the molecular weight distribution of the branched propylene polymer can be broadened toward the high molecular weight side, and the branch chain length can be shortened.

[0079] Furthermore, component [A-1] produces vinyl-terminated macromers, which then mediate copolymerization of propylene with the macromer to produce branched vinyl-terminated macromers. On the other hand, component [A-2] does not produce macromers by itself; it mediates copolymerization of propylene with the macromer only when the macromer produced by component [A-1] approaches component [A-2] to produce branched polymers.

[0080] As described above, when a branched propylene polymer is produced by combining component [A-1] and component [A-2] and copolymerizing them, (1) by setting the polymerization temperature to 65°C or higher, it is possible to introduce branches with short branch chain lengths. Furthermore, (2) by reducing the amount of hydrogen used as a molecular weight modifier, it is possible to broaden the molecular weight distribution of the branched propylene polymer toward the high molecular weight side. Furthermore, (3) due to the difference in contact efficiency between component [A-1] and component [A-2] and the terminal vinyl macromer, macromers with many branched structures produced by component [A-1], which has a high contact efficiency with the macromer, are introduced into the high molecular weight branched polymer produced by component [A-2]. Therefore, the combined effects of (1), (2), and (3) above make it possible to introduce many branches with short branch chain lengths into the high molecular weight region of the molecular weight distribution of the branched propylene polymer. Specifically, the branching index g' at the component having a molecular weight M of 1 million or more in the molecular weight distribution and the absolute molecular weight Mabs of 1 million can be set to the preferred ranges described above. Therefore, the obtained branched propylene polymer can have a relaxation time distribution in which many components have a relatively short relaxation time and few components have an extremely long relaxation time.

[0081] III. Uses of branched propylene polymers The branched propylene polymer of the present invention can be heated, melt-kneaded using a melt kneader, and then cut into granular pellets to be used as a molding material. The branched propylene polymer of the present invention can be blended with various additives, such as known antioxidants, ultraviolet absorbers, antistatic agents, nucleating agents, lubricants, flame retardants, antiblocking agents, colorants, and inorganic or organic fillers, as well as various synthetic resins and natural resins, as needed. These pellet-like molding materials can be molded by various known polypropylene molding methods, such as injection molding, extrusion molding, foam molding, and blow molding, to produce various molded products such as industrial injection-molded parts, containers, unstretched films, uniaxially stretched films, biaxially stretched films, sheets, pipes, and fibers. Furthermore, the branched propylene polymer of the present invention has an excellent balance between melt fluidity and melt tension, and therefore can be suitably used in fields where uniformity of wall thickness is required in sheet molding, blow molding, etc., uniformity of foam cell diameter in foam molding, etc., and fine fiber diameter in melt spinning, etc. are required. The branched propylene polymer of the present invention can also be used by blending with other resins. [Example]

[0082] Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. (1) Synthesis of component (A) (1-1) Synthesis example of component [A-1] (Complex 1) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium: rac-Dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium was synthesized according to the methods described in Example 13 of JP-A 2009-299046 and Example 1 of JP-A 2009-91512. (Complex 2) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium: rac-Dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium was synthesized according to the method of Synthesis Example 1 in JP 2012-149160 A. (1-2) Synthesis example of component [A-2] (Complex 3) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium: rac-Dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium was synthesized according to the method described in Example 7 of JP-A-11-240909.

[0083] (2) Example of synthesis of component (B): Chemical treatment of ion-exchange layered silicate Into a 1 L three-necked flask equipped with a stirring blade and a reflux device, 645.1 g of distilled water and 82.6 g of 98% sulfuric acid were added, and the temperature was raised to 95°C. To this was added 100 g of commercially available montmorillonite (Benclay KK manufactured by Mizusawa Industrial Chemicals, Al=9.78 mass%, Si=31.79 mass%, Mg=3.18 mass%, Al / Si (molar ratio)=0.320, average particle size 14 μm), and the mixture was reacted at 95° C. for 320 minutes. After 320 minutes, 0.5 L of distilled water was added to stop the reaction, and the mixture was filtered to obtain 255 g of a cake-like solid. 1 g of this cake contained 0.31 g of chemically treated montmorillonite (intermediate), which had a chemical composition of Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, with an Al / Si (molar ratio) of 0.222. 1545 g of distilled water was added to the cake to form a slurry, and the temperature was raised to 40°C. 5.734 g of lithium hydroxide hydrate was added as a solid, and the reaction was carried out at 40°C for 1 hour. After 1 hour, the reaction slurry was filtered and washed three times with 1 L of distilled water, yielding another cake-like solid. The collected cake was dried to obtain 80 g of chemically treated montmorillonite, which had a chemical composition of Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, Al / Si (molar ratio) = 0.222, and Li = 0.53 mass%.

[0084] (3) Preparation of catalyst (3-1) Synthesis example of catalyst 1 10 g of the chemically treated montmorillonite obtained above was placed in a three-necked flask (volume 1 L), and heptane (66 mL) was added to form a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution with a concentration of 143 mg / mL) was added to the slurry and stirred for 1 hour. The mixture was then washed with heptane until the residual liquid ratio was 1 / 100, and the total volume was adjusted to 50 mL. In a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 1) (105 μmol) prepared in Synthesis Example 1 of the catalyst component [A-1] was dissolved in toluene (21 mL) to prepare solution 1. Furthermore, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (complex 3) (45 μmol) prepared in Synthesis Example 1 of the catalyst component [A-2] was dissolved in toluene (9 mL) to prepare solution 2.

[0085] Triisobutylaluminum (0.42 mmol: 0.6 mL of a heptane solution with a concentration of 143 mg / mL) was added to a 1 L flask containing the above-mentioned chemically treated montmorillonite, and then the above solution 1 (21 mL) was added and stirred at room temperature for 20 minutes. Thereafter, triisobutylaluminum (0.18 mmol: 0.25 mL of a heptane solution with a concentration of 143 mg / mL) was further added, and then the above solution 2 was added, followed by stirring at room temperature for 1 hour. Then, 170 mL of heptane was added, and the slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was raised to 40°C, propylene was fed at a rate of 5 g / h and prepolymerization was carried out while maintaining the temperature at 40°C for 4 hours. Thereafter, the propylene feed was stopped and residual polymerization was carried out for 1 hour. The supernatant of the obtained catalyst slurry was removed by decantation, and triisobutylaluminum (6 mmol: 8.5 mL of a heptane solution with a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes. This solid was dried under reduced pressure for 1 hour to obtain 29.9 g of a dried prepolymerized catalyst. The prepolymerization ratio (the value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) was 1.99. This prepolymerized catalyst was designated as Catalyst 1.

[0086] (3-2) Synthesis example of catalyst 2 Internal volume 1m 3 150 kg of the chemically treated montmorillonite obtained above was placed in a reactor, and 2832 L of hexane was added to form a slurry. 74.4 kg (375 mol) of triisobutylaluminum was added over 85 minutes and stirred for 60 minutes. The mixture was then washed with hexane until the residual liquid ratio was 1 / 32, and the total volume was adjusted to 900 L. This slurry solution containing the chemically treated montmorillonite was kept at 50°C, and 0.65 kg of triisobutylaluminum (4.257 kg, 3.28 mol, of a hexane solution with a concentration of 15.3% by mass) was added thereto. After stirring for 5 minutes, 0.657 kg (0.81 mol) of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (complex 3) and 96 L of toluene were added, and stirring was continued for 60 minutes. Thereafter, 9.758 kg (26.61 mol) of tri-normal-octylaluminum was added and stirred for 6 minutes. Then, in another vessel equipped with a stirrer, 240 L of toluene was added to 0.064 kg of triisobutylaluminum (9.88 kg, 0.32 mol of a toluene solution with a concentration of 0.648 mass%), and a solution prepared by adding 1.768 kg (1.89 mol) of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 2) was added, 100 L of toluene was added, and stirring was continued for a further 20 minutes. Thereafter, 2387 L of hexane was added, the internal temperature of the reactor was raised to 40°C, and then 328.1 kg of propylene was fed over 240 minutes to carry out prepolymerization while maintaining the temperature at 40°C. Thereafter, the propylene feed was stopped, and the residual polymerization was carried out at 40°C for 80 minutes. After the completion of the residual polymerization, stirring was stopped, and the contents were allowed to settle and settle. The supernatant was removed so that the solution volume was 1500 L, and 12.7 kg of triisobutylaluminum was added, and 3974 L of hexane was added again, and after stirring, the contents were allowed to settle and settle, and the supernatant was removed so that the solution volume was 1500 L. To this solution, 8.9 kg of triisobutylaluminum (42.9 kg of a hexane solution with a concentration of 20.8% by mass) and 205 L of hexane were added. The reaction mixture was then transferred to a dryer and dried at 40°C for 9 hours. As a result, 465 kg of a dry prepolymerized catalyst was obtained. The prepolymerization ratio (the value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) was 2.10. This prepolymerized catalyst was designated as catalyst 2.

[0087] (4) Example [Example 1] (polymerization) A 3 L autoclave was thoroughly dried in advance by passing nitrogen through it under heating, and then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86 mL of a heptane solution of triisobutylaluminum (143 mg / mL) was added, and then 60 NmL of hydrogen was introduced. Next, 750 g of liquid propylene was introduced, and the temperature was then raised to 70°C. Then, 120 mg of the catalyst 1 (excluding the prepolymerized polymer) was pumped into the polymerization vessel using high-pressure argon to initiate polymerization. After maintaining the temperature at 70°C for 1 hour, 5 ml of ethanol was pumped in to terminate the polymerization. As a result, 216 g of polymer was obtained. (granulation) 100 parts by mass of the resulting branched propylene polymer were blended with 0.125 parts by mass of a phenolic antioxidant, IRGANOX 1010 (trade name, manufactured by BASF Japan Ltd., tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane), and 0.125 parts by mass of a phosphite antioxidant, IRGAFOS 168 (trade name, manufactured by BASF Japan Ltd., tris(2,4-di-t-butylphenyl)phosphite), and mixed for 3 minutes at room temperature using a high-speed agitation mixer, Henschel Mixer (trade name, manufactured by Nippon Coke and Engineering Co., Ltd.). The mixture was then melt-kneaded using a twin-screw extruder, KZW-15 (manufactured by Technovel Co., Ltd.), at a screw rotation speed of 400 rpm and temperatures of 80, 120, and 230°C from the bottom of the hopper (the same temperature was maintained from the bottom to the die outlet). The molten resin extruded from the strand die was taken up while being cooled and fixed in a cooling water bath, and the strands were cut and pelletized using a strand cutter. The MFR of the obtained pellets (MFR pellet )=1.4 g / 10 min. Other results are shown in Table 1.

[0088] [Example 2] The same polymerization as in Example 1 was carried out except that 130 mg of catalyst 1 (mass excluding the prepolymerized polymer) and 70 Nml of hydrogen were introduced, resulting in the production of 255 g of polymer. Granulation was carried out in the same manner as in Example 1. The MFR of the resulting pellets (MFR pellet )=1.8 g / 10 min. Other results are shown in Table 1.

[0089] [Example 3] The same polymerization as in Example 1 was carried out except that 90 mg of catalyst 1 (mass excluding the prepolymerized polymer) and 80 Nml of hydrogen were introduced, resulting in the production of 230 g of polymer. Granulation was carried out in the same manner as in Example 1. The MFR of the resulting pellets (MFR pellet )=3.2 g / 10 min. Other results are shown in Table 1.

[0090] [Example 4] The same polymerization as in Example 1 was carried out except that 80 mg of catalyst 1 (mass excluding the prepolymerized polymer) and 90 Nml of hydrogen were introduced, resulting in the production of 250 g of polymer. Granulation was carried out in the same manner as in Example 1. The MFR of the resulting pellets (MFR pellet )=4.1 g / 10 min. Other results are shown in Table 1.

[0091] [Reference Example 1]: Example of side chain homopolymerization method (Catalyst Preparation) 20 g of the chemically treated montmorillonite obtained above was placed in a 1 L three-necked flask, and 131 mL of heptane was added to form a slurry. 50 mmol of triisobutylaluminum (69 mL of a heptane solution with a concentration of 143.4 mg / mL) was added to the slurry, and the mixture was stirred for 60 minutes. Then, the mixture was washed with heptane to a volume of 1 / 100, and the total volume was adjusted to 100 mL. The slurry solution containing this chemically treated montmorillonite was kept at 50°C, and 4.2 mmol of tri-normal octylaluminum (10.7 mL of a heptane solution with a concentration of 143.4 mg / mL) was added thereto, followed by stirring for 20 minutes. To this was added 0.3 mmol of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 1) (slurried in 50 mL of toluene), and the mixture was stirred for 20 minutes while maintaining the temperature at 50°C. Then, 350 mL of heptane was added, and the slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was raised to 40° C., propylene was fed at a rate of 10 g / hour and prepolymerization was carried out for 4 hours while maintaining the temperature at 40° C. Thereafter, the propylene feed was stopped and residual polymerization was carried out for 1 hour while maintaining the temperature at 40° C. The supernatant of the resulting catalyst slurry was removed by decantation, and then heptane was added again and decanted to wash the prepolymerized catalyst. To the portion remaining after the decantation, 12 mmol of triisobutylaluminum (16.6 mL of a heptane solution with a concentration of 143.4 mg / mL) was added and stirred for 10 minutes. The solid was dried under reduced pressure at 40°C for 2 hours to obtain 57.6 g of a dried prepolymerized catalyst. The prepolymerization ratio (the amount of prepolymerized polymer divided by the amount of solid catalyst) was 1.88. This prepolymerized catalyst was designated Catalyst 3. (4) Polymerization A 3-L autoclave was thoroughly dried under heating by passing nitrogen through it, then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86 mL of a heptane solution of triisobutylaluminum (140 mg / mL) was added, followed by the introduction of 60 NmL of hydrogen. 750 g of liquid propylene was then introduced, and the temperature was raised to 70°C. 150 mg of the catalyst 3 (excluding the prepolymerized polymer) was then pumped into the polymerization vessel, and polymerization was carried out at 70°C for 1 hour. Finally, unreacted propylene was quickly purged to terminate the polymerization. Approximately 195 g of propylene homopolymer was obtained. The MFR was 620 g / 10 min. Mn was calculated by GPC and found to be 33,000, which can be estimated as 1,571 skeletal carbon atoms. The results are shown in Table 2.

[0092] [Reference Example 2]: Example of side chain homopolymerization method The same polymerization as in Reference Example 1 was carried out, except that 120 mg of catalyst 3 (excluding the prepolymerized polymer) and 90 Nml of hydrogen were introduced. As a result, 210 g of polymer was obtained. MFR = 680 / 10 min. Mn was calculated by GPC and found to be 32,000, which can be estimated as 1,524 skeletal carbon atoms. The results are shown in Table 2.

[0093] [Example 5] A 3 L autoclave was thoroughly dried in advance by passing nitrogen through it under heating, and then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86 mL of a heptane solution of triisobutylaluminum (143 mg / mL) was added, and then 120 NmL of hydrogen was introduced. Next, 750 g of liquid propylene was introduced, and the temperature was then raised to 80°C. Then, 50 mg of catalyst 2 (excluding the prepolymerized polymer) was pumped into the polymerization vessel using high-pressure argon to initiate polymerization. After maintaining the temperature at 80°C for 1 hour, 5 ml of ethanol was pumped in to terminate the polymerization. As a result, 250 g of polymer was obtained. Granulation was carried out in the same manner as in Example 1, and the MFR of the resulting pellets (MFRpellet) was 3.0 g / 10 min. Other results are shown in Table 1.

[0094] [Reference Example 3]: Example of side chain homopolymerization method (Catalyst Preparation) 20 g of the chemically treated montmorillonite obtained above was placed in a 1 L three-necked flask, and 131 mL of heptane was added to form a slurry. 50 mmol of triisobutylaluminum (69 mL of a heptane solution with a concentration of 143.4 mg / mL) was added to the slurry, and the mixture was stirred for 60 minutes. Then, the mixture was washed with heptane to a volume of 1 / 100, and the total volume was adjusted to 100 mL. The slurry solution containing this chemically treated montmorillonite was kept at 50°C, and 4.2 mmol of tri-normal octylaluminum (10.7 mL of a heptane solution with a concentration of 143.4 mg / mL) was added thereto, followed by stirring for 20 minutes. To this was added 0.3 mmol of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 2) (slurried in 50 mL of toluene), and the mixture was stirred for 20 minutes while maintaining the temperature at 50°C. Then, 350 mL of heptane was added, and the slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was raised to 40° C., propylene was fed at a rate of 10 g / hour and prepolymerization was carried out for 4 hours while maintaining the temperature at 40° C. Thereafter, the propylene feed was stopped and residual polymerization was carried out for 1 hour while maintaining the temperature at 40° C. The supernatant of the resulting catalyst slurry was removed by decantation, and then heptane was added again and decanted to wash the prepolymerized catalyst. To the portion remaining after the decantation, 12 mmol of triisobutylaluminum (16.6 mL of a heptane solution with a concentration of 143.4 mg / mL) was added and stirred for 10 minutes. The solid was dried under reduced pressure at 40°C for 2 hours to obtain 54.0 g of a dried prepolymerized catalyst. The prepolymerization ratio (the amount of prepolymerized polymer divided by the amount of solid catalyst) was 1.7. This prepolymerized catalyst was designated Catalyst 4. (polymerization) A 3-L autoclave was thoroughly dried under heating by passing nitrogen through it, then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86 mL of a heptane solution of triisobutylaluminum (140 mg / mL) was added, followed by the introduction of 80 NmL of hydrogen. 750 g of liquid propylene was then introduced, and the temperature was raised to 80°C. 165 mg of the above catalyst 4 (excluding the prepolymerized polymer) was then pumped into the polymerization vessel, and polymerization was carried out at 80°C for 1 hour. Finally, unreacted propylene was quickly purged to terminate the polymerization. Approximately 220 g of propylene homopolymer was obtained. MFR was 520 g / 10 min. Mn was calculated by GPC and found to be 36,000, which can be estimated as 1,714 skeletal carbon atoms. The results are shown in Table 2.

[0095] [Reference Example 4]: Example of side chain homopolymerization method The same polymerization as in Reference Example 3 was carried out, except that 150 mg of catalyst 4 (excluding the prepolymerized polymer) and 120 Nml of hydrogen were introduced. As a result, 240 g of polymer was obtained. MFR = 570 / 10 min. Mn was calculated by GPC and found to be 35,000, which can be estimated as 1,667 skeletal carbon atoms. The results are shown in Table 2.

[0096] [Comparative Example 1] A 3 L autoclave was thoroughly dried in advance by passing nitrogen through it under heating, and then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86 mL of a heptane solution of triisobutylaluminum (143 mg / mL) was added, and then 210 NmL of hydrogen was introduced. Next, 750 g of liquid propylene was introduced, and the temperature was raised to 70°C. Then, 60 mg of the catalyst 2 (excluding the prepolymerized polymer) was pumped into the polymerization vessel using high-pressure argon to initiate polymerization. After maintaining the temperature at 70°C for 1 hour, 5 ml of ethanol was pumped in to terminate the polymerization. As a result, 225 g of polymer was obtained. Granulation was carried out in the same manner as in Example 1. The MFR of the obtained pellets (MFR pellet )=1.4g / 10min.

[0097] Comparative Example 2 The same polymerization as in Comparative Example 1 was carried out, except that 45 mg of catalyst 2 (excluding the prepolymerized polymer) and 230 Nml of hydrogen were introduced. As a result, 240 g of polymer was obtained. Granulation was carried out in the same manner as in Example 1. The MFR of the obtained pellets (MFR pellet )=2.8g / 10min.

[0098] [Reference Example 5]: Example of side chain homopolymerization method A 3 L autoclave was thoroughly dried in advance by passing nitrogen through it under heating, and then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86 mL of a heptane solution of triisobutylaluminum (140 mg / mL) was added, and then 210 NmL of hydrogen was introduced. Next, 750 g of liquid propylene was introduced, and the temperature was raised to 70°C. Then, 150 mg of the catalyst 4 (excluding the prepolymerized polymer) was pumped into the polymerization vessel, and polymerization was carried out at 70°C for 1 hour. Finally, the unreacted propylene was quickly purged to terminate the polymerization. Approximately 225 g of propylene homopolymer was obtained. The MFR was 38 g / 10 min. Mn was calculated by GPC and found to be 63,000, which can be estimated as 3,000 skeletal carbon atoms. The results are shown in Table 2.

[0099] [Reference Example 6]: Example of side chain homopolymerization method The same polymerization as in Reference Example 3 was carried out, except that 130 mg of catalyst 4 (excluding the prepolymerized polymer) and 245 Nml of hydrogen were introduced. As a result, 230 g of polymer was obtained. MFR = 53 / 10 min. Mn was calculated by GPC and found to be 62,000, which can be estimated as 2,952 skeletal carbon atoms. The results are shown in Table 2.

[0100] (5) Measurement and evaluation methods The physical properties and extensibility of the branched propylene polymers obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were measured or evaluated by the following methods. (5-1) Elongational viscosity (ηE), strain hardening index (SHI), and multi-branching index (MBI) The extensional viscosity was measured at each strain rate (1.0 / s, 0.1 / s, 0.01 / s) using the method described above in the description of properties (1) and (2). The strain hardening index (SHI) at each strain rate (dε / dt) was calculated using the measured values ​​of extensional viscosity. The multi-branching index (MBI) was also calculated using the calculated SHI values ​​at each strain rate (dε / dt). The apparatus and conditions used for measuring the extensional viscosity are as follows. <Measurement equipment and conditions> Equipment: Rheometorics Ares Jig: TA Instruments Extentional Viscosity Fixture ·Measurement temperature: 180℃ ·Strain rate: 1.0 / sec, 0.1 / sec, 0.01 / sec Preparation of test specimen: Press mold a sheet of 18mm x 10mm and 0.7mm thick.

[0101] (5-2) Percentage of components soluble in p-xylene at 25°C (CXS) The proportion of p-xylene soluble matter (CXS) contained in the branched propylene polymer was measured by the method described above in the description of property (3).

[0102] (5-3) Molecular weight of branched side chains The catalysts (catalysts 1 and 2) used in the examples and comparative examples were a combination of complex 1 or complex 2, which is component [A-1] capable of synthesizing a macromer, and complex 3, which is component [A-2] capable of copolymerizing propylene with a macromer. In order to measure or estimate the molecular weight of the branched side chain, Reference Examples 1 to 6 were carried out using only complex 1 (catalyst 3) or complex 2 (catalyst 4), which is capable of synthesizing a macromer, and the molecular weight (Mn) of the resulting macromer was measured. The molecular weight (Mn) of the macromer was measured by gel permeation chromatography (GPC) using the method described above in the description of property (4). The apparatus and conditions used for measuring the macromer molecular weight (Mn) are as follows. <Measurement equipment and conditions> Apparatus: Waters GPC (ALC / GPC, 150°C) Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42 μm) Column: Showa Denko AD806M / S (3 columns) Mobile phase solvent: o-dichlorobenzene (ODCB) ·Measurement temperature: 140℃ ·Flow rate; 1.0mL / min ·Injection volume; 0.2mL

[0103] (5-4) Melt flow rate (MFR) at 230°C and 2.16 kg load The MFR of the branched propylene polymer in a powder state and the MFR of the branched propylene polymer in a pelletized state were measured. Also, the MFR of the macromers obtained in Reference Examples 1 to 6 was measured. As described above in the description of property (5), MFR was measured in accordance with JIS K6921-2 "Plastics - Polypropylene (PP) materials for molding and extrusion - Part 2: Preparation of test specimens and determination of properties" under test conditions of 230°C and a load of 2.16 kgf.

[0104] (5-5) Components with molecular weight M of 1 million or more (W1 million) and branching index g' (1 million) for absolute molecular weight Mabs of 1 million The branched propylene polymer was measured for the component (W1 million) having a weight average molecular weight Mw of 1 million or more and the branching index g' (1 million) for the absolute molecular weight Mabs of 1 million by the method described above in the description of property (6).

[0105] (5-6) Melting point (Tm) The melting point (Tm) of the branched propylene polymer was measured by the method described above in the description of property (7).

[0106] (5-7) Number of long chain branches (LCB) The number of long chain branches (LCB) having 7 or more carbon atoms per 1000 monomer units was measured by the method described above in the description of property (8).

[0107] (5-8) Melt tension The melt tension MT230°C (unit: g / 10 min) of the branched propylene polymer at 230°C was measured by the method described above in the description of property (9).

[0108] (5-9) Spreadability The maximum take-up speed MaxDraw (unit: m / min) of the branched propylene polymer at 170° C. was measured by the method described above in the description of property (10).

[0109] (6) Evaluation results The results of each example and comparative example are shown in Tables 1 to 4. Table 1 shows the polymerization conditions for synthesizing branched propylene polymers in each of the Examples and Comparative Examples, as well as the MFR, the proportion of xylene-soluble components, the components with a molecular weight M of 1 million or more (W1 million), the branching index g' (1 million) at an absolute molecular weight Mabs of 1 million, the number of long-chain branches (LCBs) having 7 or more carbon atoms per 1,000 monomer units, the melting point (Tm), and the macromers of Reference Examples corresponding to the branched chains of the branched propylene polymers. Table 2 shows the polymerization conditions of Reference Examples in which macromers corresponding to the branched chains of the branched propylene polymers obtained in the Examples and Comparative Examples were synthesized, as well as the MFR, number average molecular weight (Mn), and number of carbon atoms in the skeleton of the obtained macromers. Table 3 shows the MFR, the elongational viscosity ηE at each strain rate (0.01 / sec, 0.1 / sec, 1.0 / sec), the strain hardening index (SHI) at each strain rate (0.01 / sec, 0.1 / sec, 1.0 / sec), and the multi-branching index (MBI) calculated from the strain hardening index (SHI) at strain rates from 0.01 / sec to 1.0 / sec for the branched propylene polymers obtained under the polymerization conditions of each Example and Comparative Example. The graph in FIG. 5 is a graph in which the data of the branched propylene polymers obtained in each example and comparative example are plotted, with MFR (MFR 230°C, 2.16 kg load) on the horizontal axis and multi-branching index (MBI) on the vertical axis. Table 4 shows the MFR, melt tension at 230°C (MT230°C), and maximum draw speed at 230°C (MaxDraw) for the branched propylene polymers obtained under the polymerization conditions of each Example and Comparative Example. The graph in FIG. 6 is a graph in which the data of the branched propylene polymers obtained in each Example and Comparative Example are plotted, with the MFR (MFR 230°C, 2.16 kg load) on the horizontal axis and the maximum take-up speed (MaxDraw) at 170°C on the vertical axis. The graph in FIG. 7 is a graph in which the data of the branched propylene polymers obtained in each Example and Comparative Example are plotted, with the melt tension (MT230°C) on the horizontal axis and the maximum take-up speed (MaxDraw) at 230°C on the vertical axis.

[0110] [Table 1]

[0111] [Table 2]

[0112] [Table 3]

[0113] [Table 4]

[0114] As shown in Table 3, the branched propylene polymers of Examples 1 to 5 have a multi-branching index (MBI) of 0.15 to 0.43, which falls within the range of property (1), and a strain hardening index (SHI@1.0 -1 ) was 1.14 to 1.75, which was within the range of property (2). As shown in Table 4, the branched propylene polymers of Examples 1 to 5 had a melt tension at 230°C of 6.0 to 16.6 g, and while maintaining the melt tension necessary for molding, the maximum winding speed (230°C) was 66 to 119 m / s, and they also had excellent extensibility when molten. In contrast, as shown in Table 3, the branched propylene polymers of Comparative Examples 1 and 2 had a strain hardening coefficient (SHI@1.0 -1 ) was 1.75 to 1.88, which was within the range of property (2), but the multi-branching index (MBI) was 0.05 to 0.08, which was smaller than the lower limit of the range of property (1). As shown in Table 4, the branched propylene polymers of Comparative Examples 1 and 2 had a melt tension at 230°C of 8.6 to 16.6 g, which was sufficient for molding, but the maximum winding speed (230°C) was 31 to 53 m / s, which meant that the polymers had poor extensibility when molten. As shown in FIG. 5, when a graph was prepared by plotting the data of the branched propylene polymers obtained in each Example and Comparative Example, with MFR on the horizontal axis and multi-branching index (MBI) on the vertical axis, it was confirmed that the branched propylene polymers of the Examples had a larger MBI than the branched propylene polymers of the Comparative Examples. As shown in FIG. 6, a graph was prepared by plotting data of the branched propylene polymers obtained in each Example and Comparative Example, with MFR (MFR 230°C, 2.16 kg load) on the horizontal axis and maximum take-up speed (MaxDraw) at 230°C on the vertical axis. It was confirmed that the branched propylene polymers of the Examples were superior in extensibility to the branched propylene polymers of the Comparative Examples. As shown in FIG. 7, a graph was prepared by plotting data of the branched propylene polymers obtained in each Example and Comparative Example, with melt tension (MT230°C) on the horizontal axis and maximum take-up speed at 230°C (MaxDraw) on the vertical axis. It was confirmed that the branched propylene polymers of the Examples were superior in extensibility to the branched propylene polymers of the Comparative Examples.

[0115] As shown in Table 1, in the branched propylene polymers of Examples 1 to 5, the component with a molecular weight M of 1 million or more (W1 million) was 0.070 to 0.100 in the molecular weight distribution curve. In contrast, the branched propylene polymers of Comparative Examples 1 and 2 had a component with a molecular weight Mw of 1 million or more (W1 million) of 0.067 to 0.068. Therefore, the branched propylene polymers of Examples 1 to 5 have a larger high molecular weight region than the branched propylene polymers of Comparative Examples.

[0116] Furthermore, as shown in Table 1, the branched propylene polymers of Examples 1 to 5 had a branching index g' (1 million) of 0.88 to 0.89 when the absolute molecular weight Mabs was 1 million. In contrast, the branching index g' (1 million) of Comparative Examples 1 and 2 was 0.89. The branched propylene polymers of Examples 1 to 5 are equivalent to those of Comparative Examples 1 and 2 when only the branching index g' (1 million) is compared. However, as described above, the amount of branched chains introduced into the high molecular weight region represented by components having a weight average molecular weight Mw of 1 million or more (W1 million) is greater than that of Comparative Examples 1 and 2.

[0117] Furthermore, as shown in Tables 1 and 2, the length of the side chain introduced into the branched propylene polymers of Examples 1 to 5 is estimated to be a molecular weight Mn of 33,000 (1,571 in terms of the number of backbone carbon atoms) to 36,000 (1,714 in terms of the number of backbone carbon atoms) based on the results of Reference Examples 1 to 4. In contrast, the length of the side chain introduced into the branched propylene polymers of Comparative Examples 1 to 3 is estimated to be a molecular weight Mn of 62,000 to 63,000 based on the results of Reference Examples 5 and 6. Therefore, the branched propylene polymers of Examples 1 to 5 have shorter side chains than the branched propylene polymers of Comparative Examples.

[0118] As shown in Table 1, the branched propylene polymers of Examples 1 to 5 had a low number of long chain branches (LCB) having 7 or more carbon atoms per 1,000 monomer units of 1.0 or less. The branched propylene polymers of Comparative Examples 1 and 2 also had a low number of long chain branches (LCB) of 1.0 or less.

[0119] From the above-described analysis of the molecular structure, it was confirmed that the branched propylene polymers obtained in Examples 1 to 5 contain many multi-branched molecules having many branches with short branch chain lengths per molecule in the high molecular weight region, and have molecular structures with relaxation time distributions in which there are many components with a relatively short relaxation time and few components with extremely long relaxation times.

Claims

1. A method for producing a branched propylene polymer by a macromer copolymerization method using a metallocene catalyst, comprising: The metallocene catalyst comprises a component [A-1] consisting of a compound represented by the following general formula (a1) and a component [A-2] consisting of a compound represented by the following general formula (a2), and the method for producing a branched propylene polymer comprises performing bulk polymerization at a polymerization temperature of 80°C or higher: 【Chemical 1】 [In general formula (a1), R １１ and R １２ R each independently represents a substituted 2-furyl group, a substituted 2-thienyl group, or a substituted 2-furfuryl group. The substituents of the substituted 2-furyl group, the substituted 2-thienyl group, and the substituted 2-furfuryl group are a methyl group, an ethyl group, an n-propyl group, or an i-propyl group. １３ and R １４ Q each independently represents an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroelements selected from these, or a heterocyclic group having 6 to 16 carbon atoms which contains nitrogen, oxygen, or sulfur. １１ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms; M １１ represents zirconium or hafnium, and X １１ and Y １１ each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms. 【Chemistry 2】 [In general formula (a2), R 21 and R 22 each independently represent a hydrocarbon group having 1 to 6 carbon atoms. R 23 and R 24 each independently represent a halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or an aryl group having 6 to 30 carbon atoms which may contain a plurality of heteroelements selected therefrom. Q 21 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms; M 21 represents zirconium or hafnium; and X 21 and Y 21 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.]

2. 2. The method for producing a branched propylene polymer according to claim 1, wherein the molar ratio of the transition metal of the component [A-1] to the total amount of the transition metals of the component [A-1] and the component [A-2] is 0.30 or more and 0.99 or less.

3. Hydrogen was used as a molecular weight modifier at a molar ratio of 1.0 × 10 to propylene. －５ Above, 0.2 x 10 －２ The method for producing a branched propylene polymer according to claim 1 or 2, wherein the following ranges are used:

4. The method according to any one of claims 1 to 3, wherein a branched propylene polymer having a multi-branching index (MBI) of 0.15 or more and 1.00 or less is produced.

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