JP2022024535A - Branched propylene polymer - Google Patents

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

The present invention relates to a method for producing a branched propylene-based polymer.

In recent years, many studies have been conducted to improve the suitability for sheet molding, blow molding, thermoforming, foam molding and the like, which require a material having a relatively high melt tension, by introducing a branched structure into polypropylene.
Recently, as a method for introducing a branched structure into polypropylene, a macromer copolymerization method mainly using a metallocene catalyst has been proposed. The branched polypropylene obtained by the macromer copolymerization method has an advantage that the generation of gel due to the cross-linking reaction is less than that of polypropylene in which a branched structure is introduced by irradiating with an electron beam or the like.

As such a macromer copolymerization method, for example, in the first stage of polymerization (macromer synthesis step), propylene macromer having a vinyl structure at the terminal is produced by a specific catalyst and specific polymerization conditions, and the second stage of polymerization (macromer). In the copolymerization step), a method of copolymerizing propylene and propylene macromer with a specific catalyst and specific polymerization conditions has been proposed, and it has been shown that the obtained branched polypropylene has high melt strength and melt tension. (See, for example, Patent Documents 1 and 2).
In addition, a single-stage polymerization method in which a macromer synthesis step and a macromer copolymerization step are simultaneously performed using a specific metallocene catalyst has also been proposed, and it has been shown that the obtained branched polypropylene exhibits improved melt strength. (See, for example, Patent Document 3).
In addition, a catalyst containing two specific metallocene compounds, specifically, rac-SiMe ₂ [2-Me-4-Ph-lnd] ₂ ZrC1 ₂ and rac-SiMe ₂ [2-Me-4-Ph-]. lnd] A method of multi-stage polymerization using a catalyst in which a metallocene compound such as ₂ HfC1 ₂ and silica carrying methylaluminoxane (MAO) are combined has been proposed, and the obtained branched polypropylene has a relatively high melting rate. It has been reported to exhibit tension (see Patent Document 4).
In addition, a method using a catalyst containing a specific metallocene compound and an ion-exchangeable layered silicate has been devised, and it has been reported that the obtained branched polypropylene has a wide molecular weight distribution and a large amount of branching, and has a good melt tension. (See Patent Document 5).

Further, a method for producing a propylene-based polymer having a strain hardening degree (λmax) of 2.0 or more in the measurement of melt tension using a catalyst containing a plurality of specific metallocene compounds has been devised, and the obtained branching has been devised. It has been reported that polypropylene has a good melt tension (see Patent Document 6).

Further, Patent Document 7 describes short-chain branching with a specific degree of branching and a relatively large amount of non-branching by polymerizing propylene using a catalyst in which a single metallocene catalyst is supported on silica having very low porosity. It is disclosed that by introducing a crystalline region, a branched polypropylene having a better balance between mechanical properties and manufacturing properties can be obtained.

Special Table 2001-525460 Gazette Japanese Unexamined Patent Publication No. 10-338717 Special Table 2002-523575 Publication No. Japanese Unexamined Patent Publication No. 2001-64314 Japanese Unexamined Patent Publication No. 2007-154121 Japanese Unexamined Patent Publication No. 2009-57542 Special Table 2009-542872

However, although the branched polypropylene obtained by the macromer copolymerization method disclosed in Patent Documents 1 to 6 has a high melt tension and is highly suitable for sheet molding, blow molding, thermoforming, foam molding and the like. , There is a problem that the spreadability of the melt is not excellent.
Further, the branched polypropylene obtained by the method disclosed in Patent Document 7 has improved mechanical properties by increasing the content of the amorphous region, but the strain hardening degree at a high strain rate (SHI @ 1 sec ^-1 ). ) Is not so high, so that the formability at the time of various moldings cannot be sufficiently satisfied.

An object of the present invention is to provide a branched propylene-based polymer having excellent ductility during melting while maintaining the melt tension required for molding.

The branched propylene-based polymer provided by the present invention is characterized by having the following properties (1) and (2).
Characteristic (1): The multi-branch index (MBI) is 0.15 or more and 1.00 or less.
Characteristic (2): The strain hardening degree (SHI @ 1s ^-1 ) at a strain rate (dε / dt) of 1.0 / sec is 0.70 or more and 3.00 or less.
Here, the multi-branch index (MBI) is the strain hardening degree (SHI) when the strain rate (dε / dt) is 0.01 / sec to 1.0 / sec, and the log of the strain rate is on the horizontal axis. (Dε / dt)), and is the slope when the strain hardening degree (SHI) at a strain rate of 0.01 / sec to 1.0 / sec is plotted on the vertical axis.
Further, the strain hardening degree (SHI) is a section in which the henky strain (ε) is between 1 and 3 in the measurement of the extensional viscosity at a temperature of 180 ° C. and one predetermined strain rate (dε / dt). , The horizontal axis is the logarithm of Henky strain (ε) (log (ε)), and the vertical axis is the logarithm of extensional viscosity (ηE) (log (ηE)).

According to the present invention, there is provided a branched propylene-based polymer having excellent ductility at the time of melting while maintaining the melting tension required for molding.

FIG. 1A is a schematic diagram illustrating that when the branched propylene polymer has a large number of branches having a short branched chain length in the high molecular weight region of the molecular weight distribution, so many entanglement points of the molecular chains do not appear. FIG. 1B is a schematic diagram illustrating that a large number of entangled points of a molecular chain appear when the branched propylene polymer has a large number of branches having a long branched chain length in the high molecular weight region of the molecular weight distribution. FIG. 2 is an example of a plot diagram for determining the degree of strain hardening (SHI). FIG. 3 is an example of a plot diagram for obtaining a multi-branch index. FIG. 4 is a diagram illustrating a chromatogram baseline and interval in GPC. In FIG. 5, the horizontal axis is MFR (MFR 230 ° C., 2.16 kg load), the vertical axis is multi-branched index (MBI), and the data of the branched propylene-based polymer obtained in each Example and Comparative Example. It is a graph plotting. In FIG. 6, the horizontal axis is MFR (MFR 230 ° C., 2.16 kg load), and the vertical axis is the maximum take-up speed (MaxDraw) at 230 ° C., and the branched propylene system obtained in each Example and Comparative Example. It is a graph which plotted the data of a polymer. In FIG. 7, the horizontal axis represents the melt tension (MT230 ° C.) and the vertical axis represents the maximum winding speed (MaxDraw) at 230 ° C., and the data of the branched propylene-based polymer obtained in each Example and Comparative Example. It is a graph plotting.

In order to improve the spreadability of the branched propylene polymer, the present inventors set the branched chain length of the conventional branched propylene polymer in the high molecular weight region of the molecular weight distribution of the branched propylene polymer. By containing a multi-branched molecule having a molecular structure introduced in large numbers per molecule, the branched chain having a shorter branched chain length has many components having a somewhat short relaxation time, and the components having an extremely long relaxation time are When a branched propylene polymer was synthesized based on the design concept that a branched propylene polymer having a small relaxation time distribution could be obtained, it was successful in obtaining a branched propylene polymer having improved spreadability. did.
As shown in FIG. 1A, when the branched propylene-based polymer contains a multi-branched molecule having a large number of branches with short branched chain lengths in the high molecular weight region of the molecular weight distribution, the branched propylene-based polymer is strained. When the above occurs, an appropriate number of molecular chain entanglement points appear, and many components have a somewhat short relaxation time, and many components have an extremely long relaxation time, and the molecular chain entanglement shows a small relaxation time distribution. It is considered that the spreadability is improved because local orientation crystallization starting from a point is less likely to occur and non-uniformity of orientation crystallization can be suppressed.
On the other hand, as shown in FIG. 1B, when the high molecular weight region of the branched propylene polymer contains a multi-branched molecule having a large number of branches having a branched chain length of too long, the branched propylene polymer may be used. Since many molecular chain entanglement points appear when strain occurs, there are many components that are not relaxed or have a long relaxation time, and many components in the polymer start from the molecular chain entanglement points locally. It is considered that the orientation crystallization becomes non-uniform due to the progress of the orientation crystallization, and the spreadability is inferior.
That is, it is presumed that the branched propylene-based polymer of the present invention has a molecular structure that follows 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 on the one hand, and the properties described below on the other hand. It has a value and is excellent in ductility at the time of melting while maintaining the melting tension required for the molding process.
Hereinafter, the present invention will be described in detail. In addition, in this specification, "-" indicating a numerical range is used in the sense that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.
In the present invention, the logarithm is expressed as the meaning of the common logarithm, that is, the base is 10.
Further, in the present invention, "ductility" means a property that the resin can be spread widely, thinly and uniformly, or thinly and longly and uniformly in a molten state.

I. Branched Propylene Polymer of the Present Invention The branched propylene polymer of the present invention has the following properties (1) and (2), preferably one or more of the following properties (3) to (10). Have.
The multi-branch index (MBI) specified in the characteristic (1) can be used as an index for knowing the degree of ductility of the molten resin, and the strain hardening degree (SHI) specified in the characteristic (2) is the molten resin. It can be used as an index to know the degree of melting tension of. In the present invention, by specifying the multi-branch index (MBI) and the strain hardening degree (SHI) in a certain range, the branched propylene excellent in ductility at the time of melting while maintaining the melt tension required for the molding process. The system polymer is provided.

Characteristic (1):
The branched propylene-based polymer of the present invention has a multi-branched index (MBI) of 0.15 or more and 1.00 or less.
Here, the multi-branch index (MBI) is the strain rate (SHI) of the polymer when the strain rate (dε / dt) is 0.01 / sec to 1.0 / sec, and the strain rate is on the horizontal axis. It is the slope when plotting the log (log (dε / dt)) and the strain hardening degree (SHI) when the strain rate is 0.01 / sec to 1.0 / sec on the vertical axis.
The strain hardening degree of the polymer changes depending on the strain rate (dε / dt). The multi-branch index (MBI) indicates the dependence of the strain hardening degree (SHI) on the strain rate (dε / dt). The larger the value of the multi-branch index (MBI), the larger the strain hardening degree (SHI) means that the strain rate (dε / dt) increases.

The strain hardening degree (SHI) is a measurement in which the extensional viscosity of the polymer is measured at a temperature of 180 ° C. and a predetermined strain rate (dε / dt), and the henky strain (ε) is between 1 and 3. In the section of, the horizontal axis is the log of Henky strain (ε) (log (ε)), and the vertical axis is the log of extensional viscosity (ηE) (log (ηE)).
The strain hardening degree (SHI) indicates the strain hardening property of the polymer when the polymer is strained at a predetermined strain rate (dε / dt). A polymer having a large strain hardening degree (SHI) at a predetermined strain rate (dε / dt) relaxes the strain when the polymer is strained at the predetermined strain rate (dε / dt). The extensional viscosity increases as the amount of strain increases.

(Measurement method of extensional viscosity, calculation of strain hardening degree (SHI) at each strain rate (dε / dt), and calculation of multi-branch index (MBI))
The strain hardening degree (SHI) and the multi-branch index (MBI) are determined by, for example, Polymer, Vol. 42, p. It can be obtained by measuring the uniaxial extensional viscosity by a measuring instrument and a measuring method as described in 8663 (2001). In the present invention, the strain hardening degree (SHI) at each strain rate (dε / dt) can be measured by the following measurements and methods.
-Device: Ares manufactured by Rheometrics
・ Jig: Extental Viscosity Fixture manufactured by TA Instruments Co., Ltd.
・ Measurement temperature: 180 ℃
-Strain rate: 1.0 / sec, 0.1 / sec, 0.01 / sec-Preparation of test piece: Press-mold to prepare a sheet of 18 mm x 10 mm and thickness of 0.7 mm.

FIG. 2 is an example of a plot diagram for determining the degree of strain hardening (SHI). By the above measurement method, time change data of extensional viscosity (ηE) is acquired at a predetermined constant strain rate (dε / dt), and the measurement data is displayed on the horizontal axis as the log of Henky strain (ε). ε))), plot on a graph with the log of extensional viscosity (ηE) on the vertical axis, and calculate the slope of extensional viscosity in the section between 1 and 3 for Henky strain (ε) from the graph. The inclination is defined as the strain hardening degree (SHI) at the strain rate (dε / dt) under the measurement conditions.
FIG. 3 is an example of a plot diagram for obtaining a multi-branch index. By the above measurement method, the strain hardening degree (SHI) at a plurality of strain rates is measured in the range of strain rate (dε / dt) of 0.01 / sec to 1.0 / sec, and the strain hardening degree at each strain rate is measured. (SHI) is plotted on a graph with the strain rate log (log (dε / dt)) on the horizontal axis and the strain hardening degree (SHI) on the vertical axis, and the strain rate starts from 0.01 / sec from the graph. A slope in the range of 1.0 / sec is specified, and the slope is defined as a multi-branch index (MBI). In the example of FIG. 3, SHI @ 0.01s ^-1 , SHI @ 0.1s ^-1 , and SHI @ 1.0s ^-1 are plotted on a graph, and the slopes when the three-point plot is approximated by a straight line are large. The branch index (MBI) was used.

In general, the more components having a long relaxation time are present in a polymer, the greater the strain curability of the polymer even at a slow strain rate. The relaxation time of the polymer depends on the structure of the polymer molecule such as the molecular weight, the presence or absence of branching, the amount of branching, and the length of the branched chain.
In particular, in the case of a branched propylene-based polymer, the longer the branched chain length, the longer the relaxation time. When the branched chain length of the branched propylene polymer is very long, the relaxation time of the branched propylene polymer is very long, so that high strain curability is exhibited even when the strain rate is slow.
On the other hand, when the branched chain length is short, the relaxation time of the branched propylene polymer is short, so that the branched propylene polymer does not relax at a high strain rate and exhibits high strain curability, but at a slow strain rate, it exhibits high strain curability. The branched propylene-based polymer is relaxed and the strain curability is lowered.
Therefore, in the branched propylene-based polymer as a polymer aggregate, the degree of strain hardening depends on the combination of the component having a long relaxation time and the component having a short relaxation time and the content ratio of each component, that is, the strain rate. The multi-branch index (MBI) is different.
When there are many components that are not relaxed or have a long relaxation time in the branched propylene-based polymer, orientation crystallization proceeds locally starting from the entanglement point of the molecular chain at many points in the polymer. Therefore, it is considered that the spreadability is inferior because the orientation crystallization becomes non-uniform.
On the other hand, when the branched propylene-based polymer contains many multi-branched molecules having a large number of branches with short branched chain lengths per molecule in the high molecular weight region of the molecular weight distribution, the component having a somewhat short relaxation time. Since components with a large number and an extremely long relaxation time show a small relaxation time distribution, local orientation crystallization starting from the entanglement point of the molecular chain is less likely to occur, and non-uniformity of orientation crystallization is suppressed. It is thought that the spreadability will be improved because it will be possible.

In the branched propylene-based polymer of the present invention, the lower limit of the multi-branch index (MBI) of the branched propylene-based polymer is preferably 0.15 or more in order to improve the ductility at the time of melting. It is 0.16 or more, more preferably 0.17 or more. Further, in the branched propylene-based polymer of the present invention, the upper limit of the multi-branch index (MBI) is set to 1.00 or less in order to obtain the stability of the melt tension by suppressing the strain rate dependence of the strain hardening degree. It is preferably 0.80 or less, and more preferably 0.50 or less.
By setting the multi-branch index (MBI) of the branched propylene-based polymer to 0.15 or more and 1.0 or less, the strain hardening degree (SHI @ 0) is not relaxed at a high strain rate (1.0 / sec). .1 / sec) is large, but at a slow strain rate (0.01 / sec), it becomes relaxed and the strain hardening degree (SHI @ 0.01 / sec) is small.
Therefore, the branched propylene-based polymer of the present invention has many components having a somewhat short relaxation time, and the components having an extremely long relaxation time show a small relaxation time distribution, so that excellent ductility can be obtained.
Even if the branched propylene-based polymer has a strain hardening degree (SHI @ 1s ^-1 ) in a specific range specified in the following property (2), the multi-branched index (MBI) is less than 0.15. In some cases, the strain rate dependence of the strain rate (SHI) is too small, so that even at a slow strain rate such as 0.01 seconds or 0.1 seconds, the strain rate is 1 second (strain rate). It shows a large degree of strain hardening that is not so different from SHI @ 1s ^-1 ). Therefore, in this case, the branched propylene-based polymer contains many components having a long relaxation time and has poor ductility.
On the other hand, even if the branched propylene-based polymer has a strain hardening degree (SHI @ 1s ^-1 ) in a specific range specified in the following characteristic (2), the multi-branched index (MBI) exceeds 1.0. In the case of, since the strain rate dependence of the strain hardening degree (SHI) is too large, the strain hardening degree changes even if the strain rate changes slightly, and the melt tension tends to become unstable. Therefore, in this case, when the branched propylene-based polymer is molded, there are problems such as molding defects and difficulty in controlling the conditions of the molding process.

The degree of strain hardening and the multi-branched index (MBI) indicated by the strain rate dependence of the degree of strain hardening are adjusted by controlling the amount of branched chains and the length of the branched chains in the branched propylene-based polymer. be able to.
For example, the magnitude of the molecular weight of macromer in the macromer synthesis step correlates with the magnitude of the length of the branched chain.
Therefore, in the combination of the metallocene complex that mainly contributes to the synthesis of macromer and the metallocene complex that mainly contributes to the copolymerization of propylene and macromer, the molecular weight of macromer can be determined by selecting the metallocene complex that contributes to the synthesis of macromer. Can be adjusted. Specifically, the magnitude of the molecular weight of macromer can be adjusted by selecting a combination of bulky substituents at the 2- and 4-position positions of the metallocene indene skeleton.
In addition to this, macromer is produced from the end of the growth chain via β-hydrogen desorption, but by raising the polymerization temperature, the β-hydrogen desorption reaction is accelerated relative to the insertion growth reaction of propylene. Can reduce the molecular weight of.
Regarding the amount of branching, the magnitude of the ratio of propylene to macromer in the macromer copolymerization step correlates with the magnitude of the amount of branched chains. Specifically, the amount of macromer uptake can be adjusted by selecting the activity of the metallocene complex that contributes to the synthesis of macromer and the activity of the metallocene complex that mainly contributes to the copolymerization of propylene and macromer.
As another method, the amount of macromer uptake can be adjusted by selecting the amount of the metallocene complex that contributes to the synthesis of macromer and the amount of the metallocene complex that mainly contributes to the copolymerization of propylene and macromer.

Characteristic (2):
The branched propylene-based polymer of the present invention has a strain rate (dε / dt) of 1.0 / sec and a strain curing degree (SHI @ 1s ^-1 ) of 0.70 or more and 3.00 or less. preferable.
Here, the strain hardening degree (SHI @ 1s ^-1 ) at 1.0 / sec means the henky strain in the measurement of the extensional viscosity at a temperature of 180 ° C. and a strain rate (dε / dt) of 1.0 / sec. When plotting the logarithm of Henky strain (ε) on the horizontal axis and the logarithm of extensional viscosity (ηE) on the vertical axis in the section where (ε) is between 1 and 3. The inclination of.
From the viewpoint of increasing melt tension to improve moldability and improving ductility, the branched propylene-based polymer of the present invention has a lower limit of strain hardening degree (SHI @ 1s ^-1 ) in measuring extensional viscosity. It is preferably 0.70 or more, more preferably 0.80 or more, still more preferably 1.0 or more, while the upper limit of the strain hardening degree (SHI @ 1s ^-1 ) is 3. It is preferably 0.00 or less, more preferably 2.00 or less, and even more preferably 1.70 or less.
When the strain hardening degree (SHI @ 1s ^-1 ) is large to some extent at a high strain rate, the branched propylene-based polymer has a large extensional viscosity due to the presence of components in the polymer that are not relaxed at a high strain rate. Become. Therefore, the melt tension increases due to the higher extensional viscosity compared to linear polymers that do not have strain curability at a high strain rate and polymers that have a small strain cure (SHI @ 1s ^-1 ). Therefore, the formability in sheet molding, blow molding, thermal molding, and foam molding is improved. From this point of view, the branched propylene-based polymer of the present invention preferably has a strain hardening degree (SHI @ 1s ^-1 ) of 0.70 or more.
On the other hand, if the strain hardening degree (SHI @ 1s ^-1 ) is too large at a high strain rate, the branched propylene-based polymer has many components that are not relaxed or have long relaxation, and therefore are oriented starting from the entanglement point of the molecular chain. There arises a problem that crystallization progresses locally and the ductility deteriorates. From this point of view, the branched propylene-based polymer of the present invention preferably has a strain hardening degree (SHI @ 1s ^-1 ) of 3.00 or less.

Characteristic (3):
The branched propylene-based polymer of the present invention has a component ratio (CXS) that is soluble in p-xylene at 25 ° C. of less than 0.5% by mass.
CXS is used as an index of the ratio of the low regularity component and the low molecular weight component contained in the branched propylene-based polymer. If the amount of CXS is too large, the number of low molecular weight components and low stereoregular components will increase, which will affect various physical properties.
CXS is preferably 0.4% by mass or less, more preferably 0.3% by mass or less. Although the lower limit of CXS is not set, it is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, from the viewpoint of the tactile sensation of the molded product.

In the present invention, the method for measuring CXS is as follows.
A 2 g sample is dissolved in 300 ml of p-xylene (containing 0.5 mg / ml BHT) at 130 ° C. to make a solution, and then allowed to stand at 25 ° C. for 48 hours. Then, the precipitate and the filtrate are separated by filtration. P-xylene is evaporated from the filtrate and further dried under reduced pressure at 100 ° C. for 12 hours to recover the components dissolved in p-xylene at 25 ° C. The value of the percentage of the mass of the recovered component with respect to the mass of the sample is defined as CXS.

In order to control the amount of CXS, it is preferable to select a crosslinked indene complex or an azulene complex as the metallocene complex of the catalyst component so that the amount of low molecular weight component is relatively small and the stereoregularity is high. It is possible to control the amount of CXS by adjusting the bulkiness of the substituent at the 2-position or 4-position. Further, when the two complexes are combined, the total amount of CXS can be controlled by selecting the complex having high stereoregularity and adjusting the ratio of the complex.
Further, when the amount of the organoaluminum compound which is a catalyst component is increased, the low molecular weight component is increased or the stereoregularity is lowered by coordinating to a part of the complex and altering the quality. Therefore, the amount of CXS can be controlled by optimizing the amount of organoaluminum compound.

Characteristic (4):
In the branched propylene-based polymer of the present invention, the molecular weight of the branched side chain of the branched propylene-based polymer is preferably 11,000 or more and 53,000 or less in terms of Mn.
References: Macromolecules, Vol. 31, p. 1335 (1998) states that isotactic polypropylene was found to have an entangled molecular weight of 6900 g / mol.
References: Macromolecules, Vol. 35, p. According to 10062 (2002)), when the branch length of the propylene-based polymer is 7000 g / mol or less, the effect on viscoelasticity is small.
In light of these documents, the length of the branched chain needs to be 6900 to 7000 g / mol or more as the entangled molecular weight of polypropylene in order to develop viscoelastic behavior such as strain hardening.
This corresponds to about 400 or more in terms of the number of carbon atoms in the skeleton. The skeletal carbon as used herein means all carbons other than methyl carbon when propylene is used alone or when propylene and ethylene are copolymerized. When butene is used in addition to the above-mentioned monomer, it means all carbon atoms other than methyl carbon and ethyl carbon.
Therefore, in order to obtain the melt tension required for molding because the strain hardening degree increases at a high strain rate, the length of the branched chain of the branched polypropylene polymer of the present invention is preferably 500 or more as the skeleton carbon number. (Polypropylene molecular weight conversion: 11,000 or more), more preferably 700 or more (polypropylene molecular weight conversion: 15,000 or more), still more preferably 1000 or more (polypropylene molecular weight conversion: 21,000) or more.
Further, regarding the branch length of the branched polypropylene polymer of the present invention, the strain hardening degree is large at a high strain rate and the melt tension required for molding can be obtained, but at a slow strain rate, the strain is sufficiently relaxed and strain hardening is obtained. The skeleton carbon number is preferably 2500 or less (polypropylene molecular weight conversion: 53,000 or less), more preferably 2200 or less (polypropylene molecular weight conversion: 46,000 or less), and further preferably 2000 or less (polypropylene molecular weight conversion: 46,000 or less) so as to reduce the property. Molecular weight conversion: 42,000 or less).

Strictly speaking, the polypropylene molecular weight conversion value referred to here is different from the molecular weight value measured by GPC, but is close to the number average molecular weight (Mn) measured by GPC. Further, although the length of the branch on the branched propylene polymer cannot be directly measured, the branched portion is formed by polymerizing propylene under the same conditions as for producing the branched propylene polymer of the present invention. It is possible to estimate that the number average molecular weight (Mn) of the macromer corresponding to the above is the length of the branch, which is measured by GPC by synthesizing the macromer corresponding to the above.
Therefore, the lower limit of the length of the branched chain of the branched propylene polymer of the present invention is preferably 11,000 or more, more preferably 15,000 or more, and further preferably 15,000 or more as the number average molecular weight (Mn) measured by GPC. It is preferably 21,000 or more. On the other hand, the upper limit of the length of the branched chain of the branched propylene polymer of the present invention is preferably 53,000 or less, more preferably 46,000 or less, and further preferably the number average molecular weight (Mn) measured by GPC. It is preferably 42,000 or less.

(Measurement method of molecular weight)
The molecular weight is obtained by gel permeation chromatography (GPC) as a number average molecular weight (Mn), a weight average molecular weight (Mw), and a Q value (Mw / Mn).
The details of the measuring method and measuring equipment are as follows.
-Device: Waters GPC (ALC / GPC, 150C)
-Detector: MIRAN, 1A, IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
-Column: Showa Denko AD806M / S (3)
-Mobile phase solvent; o-dichlorobenzene (ODCB)
-Measurement temperature; 140 ° C
・ Flow rate: 1.0 mL / min ・ Injection amount: 0.2 mL
The sample is prepared by mixing the sample and ODCB (containing 0.5 mg / mL dibutylhydroxytoluene (BHT)) at a sample concentration of 1 mg / mL and dissolving at 140 ° C. for about 1 hour. ..
The baseline and section of the obtained chromatogram are as shown in FIG.
Further, the conversion from the holding capacity obtained by GPC measurement to the molecular weight is performed using a calibration curve using standard polystyrene prepared in advance. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
Brands: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000
A calibration curve is created by injecting 0.2 mL of solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each sample is 0.5 mg / mL. The calibration curve uses a cubic equation obtained by approximating with the least squares method.
Viscosity formula used for conversion to molecular weight: [η] = K × M ^α uses the following numerical values.
・ PS: K = 1.38 × 10 ^-4 , α = 0.7
-PP: K = 1.03 × 10 ^-4 , α = 0.78

Characteristic (5):
The branched propylene-based polymer of the present invention preferably has a melt flow rate (MFR) of 1 to 10 g / 10 minutes as measured at a temperature of 230 ° C. and a load of 2.16 kg.
MFR is an index showing fluidity at the time of melting. When the molecular weight of the polymer is large, the MFR becomes small, and when the MFR is too small, the fluidity at the time of melting becomes poor and heat molding becomes difficult. On the other hand, when the molecular weight of the polymer is small, the MFR becomes large, and when the MFR is too large, the melt tension is lowered. Further, when the MFR is large, the fluidity at the time of melting is improved, but the impact strength may be lowered.
From the viewpoint of heat moldability, the MFR of the propylene-based polymer of the present invention is preferably 1 g / 10 minutes or more, more preferably 2 g / 10 minutes or more, and preferably 3 g / 10 minutes or more. Even more preferable. On the other hand, the MFR of the propylene-based polymer of the present invention is preferably 10 g / 10 minutes or less, more preferably 8 g / 10 minutes or less, and 6 g / 10 minutes or less from the viewpoint of melt tension and impact strength. Is even more preferable. Among them, the particularly preferable range of MFR is 1 g / 10 minutes or more and 6 g / 10 minutes or less.
In the present invention, the melt flow rate (MFR) is based on JIS K6921-2 "Plastic-Polypropylene (PP) molding and extrusion materials-Part 2: How to make test pieces and how to determine their properties". Test conditions: Values measured at 230 ° C. and a load of 2.16 kgf.
The melt flow rate (MFR) can be easily adjusted by changing the temperature and pressure of the polymerization, or by adding a chain transfer agent such as hydrogen at the time of polymerization as a general method.

Characteristic (6):
The branching amount of the branched propylene-based polymer of the present invention can be measured as the average value of the entire polymer using ¹³ C-NMR, and the absolute molecular weight (Mabs) and the branching index (Mabs) using 3D-GPC. From the relationship of g'), the relative outline of the degree of branching at each absolute molecular weight can be obtained as an index.
In the branched propylene-based polymer of the present invention, in the molecular weight distribution curve measured by GPC, the ratio of the components having a molecular weight M of 1 million or more (W1 million) to the total amount of the polymer is 0.070 or more and 0.100 or less. It is preferable to have. W1 million is an index showing the ratio of high molecular weight components contained in the polymer. W1 million is an integral value from 1 to an integral molecular weight M of 1 million (Log (M) = 6.0) or less in the integrated molecular weight distribution curve measured by GPC (normalized to 1 for the total amount based on mass). Defined as a subtracted value.
The branched propylene-based polymer of the present invention preferably has a branch index g'(1,000,000) of 0.80 or more and 0.90 or less when the absolute molecular weight Mabs measured by 3D-GPC is 1,000,000.

The branching index g'is given by the ratio of the intrinsic viscosity [η] _lin of the linear polymer having the same molecular weight as the intrinsic viscosity [η] _br of the polymer having a long-chain branched structure ([η] _br / [η] _lin ). In the presence of long-chain branched structures, the value is less than 1.0.
Definitions are described, for example, in "Developments in Polymer Characation-4" (JV Dawkins ed. Applied Science Publics, 1983) and are known to those of skill in the art.
The branching index _g'can be obtained as a function of absolute molecular weight Mabs, for example, by using a 3D-GPC equipped with a light scatterometer and a viscometer as described below.
In the present invention, the 3D-GPC refers to a GPC device to which three detectors are connected. The three detectors concerned are a differential refractometer (RI), a viscosity detector (Viscometer) and a multi-angle laser light scattering detector (MALLS).
As a GPC apparatus equipped with a differential refractometer (RI) and a viscosity detector (Viscometer), an Alliance GPCV2000 manufactured by Waters is used. Further, as the light scattering detector, a DAWN-E manufactured by Wyatt Technology, a multi-angle laser light scattering detector (MALLS) is used.
The detector is connected in the order of MALLS, RI, and Viscometer.
The mobile phase solvent is 1,2,4-trichlorobenzene (addition of the antioxidant Irganox 1076 manufactured by BASF Japan, Inc. at a concentration of 0.5 mg / mL).
The flow rate is 1 mL / min, and two MHHR-H (S) HTs manufactured by Tosoh Corporation are connected in series for the column.
The temperature of the column, the sample injection part and each detector is 140 ° C.
The sample concentration is 1 mg / mL, and the injection amount (sample loop volume) is 0.2175 mL.
To obtain the absolute molecular weight (Mabs) obtained from MALLS, the root mean square inertia radius (Rg), and the intrinsic viscosity ([η]) obtained from Viscometer, use the data processing software ASTRA (version _4.73.04 ) attached to MALLS. Use it and calculate with reference to the following documents.
References:
1. 1. Developments in Composer Characation, vol. 4. Essex: Applied Science; 1984. Chapter1.
2. 2. Polymer, 45, 6495-6505 (2004)
3. 3. Macromolecules, 33, 2424-2436 (2000)
4. Macromolecules, 33, 6945-6952 (2000)
The branching index g'is the ratio ([η] lin) of the intrinsic viscosity ([η] _br ) obtained by measuring the sample with the above Viscometer and the intrinsic viscosity ([η] _lin ) obtained by separately measuring the linear polymer. η] _br / [η] _lin ).

When a long-chain branched structure is introduced into a polymer molecule, the radius of inertia becomes smaller as compared with a linear polymer molecule having the same molecular weight. Since the intrinsic viscosity decreases as the radius of inertia decreases, the intrinsic viscosity of the branched polymer ([η] lin) with respect to the intrinsic viscosity ([η] _lin ) of the linear polymer having the same molecular weight as the long-chain branched structure is introduced. The ratio of _br ) ([η] _br / [η] _lin ) becomes smaller. Therefore, a polymer having a long-chain branched structure has a branching index g'([η] _br / [η] _lin ) of less than 1.0, and a linear polymer has a branching index g'of 1 by definition. It becomes 0.0.
Here, [η] _lin is obtained by using a commercially available homopolypropylene (Novatec PP (registered trademark) grade name: FY6 manufactured by Japan Polypropylene Corporation) as the linear polymer. Since it is known as the Mark-Houwink-Sakurada equation that the logarithm of [η] _lin of a linear polymer has a linear relationship with the logarithm of molecular weight, [η] _lin is suitable for the low molecular weight side and the high molecular weight side. It can be extrapolated to get a numerical value.
The branch index g'can be made smaller than 1.0 by introducing many long-chain branches, and in the case of the same number of branches, it can be achieved by lengthening the branch chain length. This is possible by controlling the combination, amount ratio, and prepolymerization conditions.
Each branching index g'can be set within the above-mentioned specific range by appropriately adjusting the amount of hydrogen at the time of polymerization in addition to the selection of catalysts, their combinations and the amount ratios, as described later.

Characteristic (7):
The branched propylene-based 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-based polymer, the better the heat resistance and rigidity. Therefore, Tm is preferably 150 ° C. or higher, more preferably 151 ° C. or higher.
On the other hand, if the Tm of the branched propylene-based polymer is too high, the rigidity may be too high and the tactile sensation such as the touch may be deteriorated. Therefore, Tm is preferably 157 ° C. or lower, more preferably 155 ° C. or lower.
In the case of polypropylene, Tm is reduced by the insertion of ethylene units and positional regularity defects. In the branched propylene-based polymer of the present invention, Tm is controlled by selecting the optimum complex having a positional regularity defect as a polymerization catalyst, selecting a combination of a plurality of complexes, and further controlling the polymerization temperature and the polymerization pressure. can.
The melting point (Tm) of the branched propylene-based polymer can be measured by the following method. Using DSC6200 manufactured by Seiko Instruments, a sheet-shaped sample piece was packed in a 5 mg aluminum pan, the temperature was once raised from room temperature to 200 ° C. at a heating rate of 100 ° C./min, and after holding for 5 minutes, 10 ° C./min. The temperature was lowered to 20 ° C. to obtain the crystallization temperature (Tc) as the maximum crystal peak temperature (° C.) when crystallized, and then the maximum melting peak when the temperature was raised to 200 ° C. at 10 ° C./min. The melting point (Tm) is obtained as the temperature (° C.).
The sheet-shaped sample is prepared by sandwiching a powder of a branched propylene polymer 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. ,Obtainable.

Characteristic (8):
The branched propylene-based polymer of the present invention may have a long-chain branched (LCB) structural portion represented by the following structural formula (A).

[However, in the structural formula (A), P ₁ , P ₂ , and P ₃ are residues generated at the end of the branched propylene-based polymer, each having one or more propylene units, and Cbr is carbon. The methine carbon at the root of the branched chain having a number of 7 or more is shown, and Ca, Cb, and Cc indicate the methylene carbon adjacent to the methine carbon (Cbr). ]
In the structural formula (A), there are ^three main chains of the branched propylene polymer: P1 ^- Cbr-P2 line, P1 ^- Cbr-P3 line, or P2 ^{- Cbr -} P3 line. Exists. Therefore, corresponding to each, the Cbr-P ³ line, the Cbr-P ² line, or the Cbr-P ¹ line can be the above-mentioned branched chain. P1, P2 ^, and P3 may contain ^a branched carbon ( ^Cbr ) different from that of Cbr described in the structural formula (A) in itself.
Here, the attribution of the LCB structure is 3 methylene carbons (44.0 to 44.1 ppm, 44.7 to 44.8 ppm and 44.8 to 44.9 ppm) by ¹³ C-NMR of the branched propylene polymer. Ca, Cb, Cc) is observed, and it is observed as methine carbon (Cbr) at 31.6 to 31.8 ppm. It is characterized by the fact that three methylene carbons in the vicinity of Cbr are observed in three non-equivalent parts of the diastereotopic.
The number of LCBs is the number of branched chains having 7 or more carbon atoms per 1000 monomer units (1000p) calculated by ¹³ C-NMR.
A branched chain having more than 6 carbon atoms and a branched chain having 6 or less carbon atoms can be distinguished by the difference in the peak position of the methine carbon at the root of the branch (Macromolecules, Vol. 35, No. 10, 2002).
In the present invention, the number of LCBs is not particularly limited, but is usually preferably 1.0 or less per 1000 p.

¹³ Details of the method for measuring the long-chain branched (LCB) structure calculated by C-NMR are as follows.
[Sample preparation]
About 200 mg of a sample, along with o-dichlorobenzene / deuterated benzene (C ₆ D ₅ Br) = 2/1 (volume ratio) 2.4 ml and hexamethyldisiloxane, which is a reference substance for chemical shift, has an inner diameter of 10 mmφ. Place in an NMR sample tube, replace with nitrogen, seal the tube, and heat-dissolve to obtain a uniform solution.
[Apparatus and measurement method]
For the NMR measurement, an AVANCE 400 type NMR device of Bruker Biospin Co., Ltd. equipped with a 10 mmφ cryoprobe was used.
The probe temperature is 120 ° C., the pulse angle is 45 °, the pulse interval is 4.2 seconds, the number of integrations is 20000 times or more, and ¹³ C-NMR measurement is performed by the proton broadband decoupling method.
The chemical shift was set to 1.98 ppm for the ¹³ C signal of hexamethyldisiloxane, and the chemical shift of the other ¹³ C signals was based on this.
[Calculation method of the number of long chain branches (LCB number)]
When the strength of methylene carbon in the propylene main chain of 44.4 to 49.0 ppm is standardized to 1000, the strength of methylene carbon is 44.0 to 44.1 ppm and the strength of methylene carbon is 31.6 to 31.8 ppm (Cbr). The average strength is the number of long chain branches per 1000 propylene monomer units.

Characteristic (9):
The lower limit of the melt tension (MT230 ° C.) at 230 ° C. is set from the viewpoint that the propylene-based polymer produced in the present invention can obtain a propylene-based polymer having excellent ductility while maintaining the melt tension required for molding. It is preferably 4.0 g or more, more preferably 5.0 g or more, particularly preferably 6.0 g or more, and the upper limit of MT230 ° C. is preferably 19.0 g or less, still more preferably 18.0 g or less. It is particularly preferably 17.0 g or less.
As a method for measuring the melt tension (MT230 ° C.) at 230 ° C., a melt tension tester (for example, Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd.) is used, the resin is extruded into a string shape at a resin temperature of 230 ° C. under the following conditions, and a roller is used. The tension detected in the pulley when it is wound up is defined as the melt tension (MT230 ° C.).
・ Capillary: diameter 2.0 mm, length 40 mm
・ Cylinder diameter: 9.55 mm
・ Cylinder extrusion speed: 20 mm / min ・ Winding speed: 4.0 m / min If a break occurs at a take-up speed of 4.0 m / min, “melt tension cannot be evaluated”.

Characteristic (10):
Since the branched propylene-based polymer produced in the present invention has a controlled branch structure (branch amount, branch length, branch distribution), it is possible to improve melt ductility while having a high melt tension.
For melt ductility, in the above method for measuring melt tension, the winding speed is gradually increased from 4.0 m / min while extruding the resin into a string shape and winding it on a roller under the following conditions (acceleration: 5. 4 cm / s ² ), the take-up speed immediately before the string-like object is cut can be measured, and the maximum take-up speed (MaxDraw) measured in this way can be used as an index for evaluation.
It should be noted that the larger the MaxDraw, the better the ductility.

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

The branched propylene polymer produced by the present invention can have a large MaxDraw while maintaining a high melt tension by controlling the branch component and the branched chain length, and the balance between the melt tension and the melt ductility can be achieved. Has been improved.
In the branched propylene-based polymer produced by the present invention, the maximum take-up speed (MaxDraw) is preferably 55 m / min or more, more preferably 65 m / min or more, still more preferably 75 m / min or more.

In the branched propylene-based polymer produced by the present invention, the relationship between the maximum take-up speed (MaxDraw) (unit: m / min) and MFR (unit: g / 10 minutes) is represented by the following formula (1). Satisfying is preferable from the viewpoint of durability.
(MaxDraw) ≧ 62 × log (MFR) +7 ・ ・ ・ Equation (1)
Generally, when the fluidity is increased, the ductility becomes excellent, but the melt tension decreases, and when the fluidity is increased so as to improve the ductility, there is a problem that the melt tension becomes insufficient, which is necessary for molding. It is desired that the propylene-based polymer has both melt tension and excellent ductility. The above formula (1) shows that the branched propylene-based polymer produced in the present invention is superior in ductility to match the fluidity as compared with the conventional propylene-based polymer.
That is, in order to distinguish the branched propylene-based polymer of the present invention from the conventional one, the maximum take-up rate (MaxDraw) is considered to be a function having a positive correlation with the increase in fluidity (MFR). The maximum take-up rate (MaxDraw) of the branched propylene-based polymer produced in the present invention by setting the parameters of the function is higher than the maximum take-up rate (MaxDraw) of the conventional propylene-based polymer defined by the function. Also shows that it is large in terms of fluidity. Specifically, based on the examples and comparative example data, the maximum take-up speed (MaxDraw) and fluidity (MFR) values that distinguish between the examples and the comparative examples of the prior art are assumed, and the maximum take-up speed is assumed. For the relational expression established between (MaxDraw) and liquidity (MFR), the parameters of the relational expression are determined by the least squares method.
Since the branched propylene-based polymer produced by the present invention is excellent in ductility in terms of fluidity, it retains the melt tension required for molding and exhibits excellent ductility even if the fluidity is low. ..

II. Method for Producing Branched Propylene Polymer The method for producing the branched propylene polymer of the present invention is a method for obtaining a branched propylene polymer satisfying the above-mentioned physical characteristics, which is a feature of the present invention. Well, there are no particular restrictions. For example, a macromer copolymerization method using a metallocene catalyst can be mentioned, and preferably a method using a catalyst containing a plurality of metallocene compounds as described below to obtain a long-chain branched propylene-based polymer can be mentioned.
As a method for producing a branched propylene-based polymer of the present invention, among them, a method for producing a branched propylene-based polymer using the following catalyst components (A), (B) and (C) as a catalyst for propylene polymerization. Is mentioned as a suitable one.
(A): At least one kind from the component [A-1] which is a compound represented by the following general formula (a1), and at least one kind from [A-2] which is a compound represented by the general formula (a2). Two or more kinds of transition metal compounds of Group 4 of the periodic table selected from: Component [A-1]: Compound represented by the general formula (a1) Component [A-2]: Compound represented by the general formula (a2) (B): A compound that reacts with the component (A) to form an ion pair or an ion-exchangeable layered silicate (C): an organic aluminum compound.

Hereinafter, the catalyst components (A), (B) and (C) will be described in detail.
1. 1. Catalyst component (A)
1-1. Component [A-1]: Compound represented by the general formula (a1) The component [A-1] is represented by the following general formula (a1) from the viewpoint of producing a propylene-based polymer having a high terminal vinyl ratio. Metallocene compounds are preferably used.

[In the general formula (a1), R ¹¹ and R ¹² each independently represent a heterocyclic group having 4 to 16 carbon atoms and containing nitrogen, oxygen or sulfur. R ¹³ and R ¹⁴ are aryl groups having 6 to 30 carbon atoms, which may independently contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus or a plurality of heteroelements selected from these. Alternatively, it represents a heterocyclic group having 6 to 16 carbon atoms containing nitrogen, oxygen or sulfur. Q ¹¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or a germanium group which may have a hydrocarbon group having 1 to 20 carbon atoms, and M ¹¹ represents zirconium or hafnium. Represented, X ¹¹ and Y ¹¹ independently have 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, and 1 to 20 carbon atoms. Represents a halogenated hydrocarbon group, an amino group or an alkylamino group having 1 to 20 carbon atoms. ]

The nitrogen, oxygen or sulfur-containing heterocyclic groups of R ¹¹ and R ¹² having 4 to 16 carbon atoms are preferably a 2-furyl group, a substituted 2-furyl group, a substituted 2-thienyl group, or a substituted group. It is a modified 2-furfuryl group, more preferably a substituted 2-furyl group.
By using R ¹¹ and R ¹² as a group selected from a heterocyclic group having 4 to 16 carbon atoms containing nitrogen, oxygen or sulfur, the terminal vinyl ratio (Rv) can be increased, and among them, the heterocycle. By introducing a substituent of appropriate size on the group, the coordination field on the heterocycle and the transition metal, and the relative positional relationship with the growth polymer chain are made appropriate, so that the terminal vinyl ratio (Rv) is obtained. Can be made higher, and the molecular weight of the polymer can be lowered.
The substituents of the substituted 2-furyl group, the substituted 2-thienyl group and the substituted 2-fulfuryl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group and an n-butyl. Alkyl groups having 1 to 6 carbon atoms such as groups, i-butyl groups and t-butyl groups, halogen atoms such as fluorine atoms and chlorine atoms, alkoxy groups having 1 to 6 carbon atoms such as methoxy groups and ethoxy groups, and trialkyls. Cyril group, can be mentioned. Of these, a methyl group, a trimethylsilyl group and a t-butyl group are preferable, and a methyl group and a t-butyl group are particularly preferable.
Further, as R ¹¹ and R ¹² , particularly preferably, a 5-t-butyl-2-furyl group and a 5-methyl-2-furyl group are used. Further, it is preferable that R ¹¹ and R ¹² are the same as each other.

Each of the above R ¹³ and R ¹⁴ is an aryl group having 6 to 30 carbon atoms which may independently 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 containing nitrogen, oxygen or sulfur.
In particular, by making R ¹³ and R ¹⁴ bulkier, it is possible to obtain a propylene polymer having higher stereoregularity, less heterogeneous bonds, and a higher terminal vinyl ratio.
Therefore, R ¹³ and R ¹⁴ have one or more hydrocarbon groups having 1 to 6 carbon atoms and a hydrocarbon group having 1 to 6 carbon atoms on the aryl cyclic skeleton within the range of 6 to 16 carbon atoms. A silyl group having a silyl group, a halogen-containing hydrocarbon group having 1 to 6 carbon atoms, or an aryl group which may have a halogen atom as a substituent is preferable, and specific examples of such R ¹³ and R ¹⁴ are 4-t. Examples thereof include a butylphenyl group, a 2,3-dimethylphenyl group, a 3,5-dit-butylphenyl group, a 4-chlorophenyl group, a 4-trimethylsilylphenyl group, a 1-naphthyl group and a 2-naphthyl group.
Further, R ¹³ and R ¹⁴ more preferably have one or more hydrocarbon groups having 1 to 6 carbon atoms and a hydrocarbon group having 1 to 6 carbon atoms in the range of 6 to 16 carbon atoms. It is a silyl group, a halogen-containing hydrocarbon group having 1 to 6 carbon atoms, or a phenyl group having a halogen atom as a substituent. The position to be substituted is preferably the 4-position on the phenyl group. Specific examples of such R ¹³ and R ¹⁴ are 4-t-butylphenyl group, 4-biphenylyl group, 4-chlorophenyl group and 4-trimethylsilylphenyl group. Further, it is preferable that R ¹³ and R ¹⁴ are the same as each other.

The X ¹¹ and Y ¹¹ are co-ligands and react with the component (B) to produce an active metallocene having an olefin polymerization ability. Therefore, as long as this purpose is achieved, X ¹¹ and Y ¹¹ are not limited in the type of ligand, and are independently hydrogen atoms, halogen atoms, and hydrocarbon groups having 1 to 20 carbon atoms, respectively. 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. Represents.

The above ^Q11 is a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or a gelmilene group which may have a hydrocarbon group having 1 to 20 carbon atoms, which bonds two five-membered rings. show. When two hydrocarbon groups are present on the above-mentioned silylene group or gelmilene group, they may be bonded to each other to form a ring structure.
Specific examples of the above ^Q11 include an alkylene group such as methylene, methylmethylene, dimethylmethylene and 1,2-ethylene; an arylalkylene group such as diphenylmethylene; a silylene group; a methylsilylene, a dimethylsilylene, a diethylsilylene and a di (n). -Alkylylylene groups such as propyl) silylene, di (i-propyl) silylene, di (cyclohexyl) silylene, (alkyl) (aryl) silylene groups such as methyl (phenyl) silylene; arylcyrylene groups such as diphenylsilylene; tetramethyl Alkyl-oligosilylene group such as disylylene; gelmilene group; alkyl gelmilene group in which silicon of the above-mentioned silylene group having a divalent hydrocarbon group having 1 to 20 carbon atoms is replaced with germanium; (alkyl) (aryl) gelmilene group. ; Aryl gelmilene group and the like can be mentioned.
Among these, a silylene group having a hydrocarbon group having 1 to 20 carbon atoms or a gelmilene group having a hydrocarbon group having 1 to 20 carbon atoms is preferable, and an alkylcilylene group and an alkylgelmilene group are particularly preferable.

Among the compounds represented by the general formula (a1), the 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'-dimethylgelmilenebis {2- (5-methyl-2-furyl) -4-phenyl-indenyl}] hafnium,
(6) Dichloro [1,1'-dimethylgelmilenebis {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,

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.

Also particularly preferred is
(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.

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 macromer and propylene.

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

The R ²¹ and R ²² are independently hydrocarbon groups 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 and the like, and methyl is preferable. , Ethyl, n-propyl.

Further, the R ²³ and R ²⁴ may each independently contain a halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus or a plurality of heteroelements selected from these, having 6 to 30 carbon atoms. , Preferably an aryl group having 6 to 24 carbon atoms. Examples of such an aryl group are a phenyl group, a biphenylyl group, and a naphthyl group which may have a substituent. Preferred examples are 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, Examples thereof include 5-dimethyl-4-t-butylphenyl, 3,5-dimethyl-4-trimethylsilylphenyl and 3,5-dichloro-4-trimethylsilylphenyl.

Q21 is a divalent hydrocarbon group having ¹ to 20 carbon atoms or carbon that bonds two 5-membered rings and bridges two conjugated five-membered ring ligands via carbon having 1 or 2 carbon atoms. It represents either a silylene group or a gelmilene group which may have a hydrocarbon group of several 1 to 20. When two hydrocarbon groups are present on the above-mentioned silylene group or gelmilene group, they may be bonded to each other to form a ring structure.
Specific examples of the above Q ²¹ include an alkylene group such as methylene, methylmethylene, dimethylmethylene and 1,2-ethylene; an arylalkylene group such as diphenylmethylene; a silylene group; Alkylylylene group such as n-propyl) silylene, di (i-propyl) silylene, di (cyclohexyl) silylene, (alkyl) (aryl) silylene group such as methyl (phenyl) silylene; arylcyrylene group such as diphenylsilylene; tetra Alkyloligosilylene group such as methyldicyrylene; gelmilene group; alkyl gelmilene group in which silicon of the silylene group having a divalent hydrocarbon group having 1 to 20 carbon atoms is replaced with germanium; (alkyl) (aryl) gelmilene Group; An arylgelmyrene group and the like can be mentioned.
Among these, a silylene group having a hydrocarbon group having 1 to 20 carbon atoms or a gelmilene group having a hydrocarbon group having 1 to 20 carbon atoms is preferable, and an alkylcilylene group and an alkylgelmilene group are particularly preferable.
Further, the M ²¹ is zirconium or hafnium, preferably hafnium.

The X ²¹ and Y ²¹ are co-ligands and react with the component (B) as a co-catalyst to generate an active metallocene having an olefin polymerization ability. Therefore, as long as this purpose is achieved, the types of ligands of X ²¹ and Y ²¹ are not limited, and each of them independently contains a hydrogen atom, a halogen atom, and 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. Represents.

Non-limiting examples of the metallocene compound represented by the above general formula (a2) include the following.
However, only representative exemplary compounds are described, avoiding a large number of complicated examples. Further, although the compound whose central metal is hafnium is described, it is obvious that a similar zirconium compound can be used, and various ligands, cross-linking groups or co-ligands can be arbitrarily used.
(1) Dichloro {1,1'-dimethylsilylenebis (2-methyl-4-phenyl-4-hydroazurenyl)} hafnium,
(2) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium,
(3) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazurenyl}] hafnium,
(4) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
(5) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-chloro-4-t-butylphenyl) -4-hydroazurenyl}] hafnium,
(6) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-methyl-4-t-butylphenyl) -4-hydroazurenyl}] hafnium,
(7) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
(8) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
(9) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (1-naphthyl) -4-hydroazurenyl}] hafnium,
(10) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (2-naphthyl) -4-hydroazurenyl}] hafnium,
(11) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chloro-2-naphthyl) -4-hydroazurenyl}] hafnium,
(12) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (2-fluoro-4-biphenylyl) -4-hydroazurenyl}] hafnium,
(13) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (2-chloro-4-biphenylyl) -4-hydroazurenyl}] hafnium,
(14) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (9-phenanthril) -4-hydroazurenyl}] hafnium,
(15) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium,
(16) Dichloro [1,1'-dimethylsilylenebis {2-n-propyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
(17) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (3-chloro-4-t-butylphenyl) -4-hydroazurenyl}] hafnium,
(18) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
(19) Dichloro [1,1'-dimethylgelmilenebis {2-methyl-4- (2-fluoro-4-biphenylyl) -4-hydroazurenyl}] hafnium,
(20) Dichloro [1,1'-dimethylgelmilenebis {2-methyl-4- (4-t-butylphenyl) -4-hydroazurenyl}] hafnium,
(21) Dichloro [1,1'-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium,
(22) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4-chloro-2-naphthyl) -4-hydroazurenyl}] hafnium,
(23) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (2-fluoro-4-biphenylyl) -4-hydroazurenyl}] hafnium,
(24) Dichloro [1,1'-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (3,5-dichloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium, And so on.

Of these, preferably
(2) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium,
(7) Dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-chloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
(18) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (3-methyl-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
(22) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4-chloro-2-naphthyl) -4-hydroazurenyl}] hafnium,
(23) Dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (2-fluoro-4-biphenylyl) -4-hydroazurenyl}] hafnium,
(24) Dichloro [1,1'-(9-silafluorene-9,9-diyl) bis {2-ethyl-4- (3,5-dichloro-4-trimethylsilylphenyl) -4-hydroazurenyl}] hafnium,
Is.

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

2. 2. Catalyst component (B)
The catalyst component (B) used in the present invention is a compound or an 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. It is preferably an ion-exchangeable layered silicate.

2-1. Compounds that form an ion pair with the catalyst component (A) Examples of the compound that forms an ion pair by reacting with the catalyst component (A) include an aluminum oxy compound and a boron compound, and specific examples of the aluminum oxy compound include aluminum oxy compounds. Specific examples thereof include compounds represented by the following general formulas (I) to (III).

In the above general formulas (I), (II) and (III), R ⁹¹ , R ¹⁰¹ and R ¹¹¹ are hydrogen atoms or hydrocarbon groups, preferably hydrocarbon groups having 1 to 10 carbon atoms, particularly preferably carbon. The number 1 to 6 hydrocarbon groups are shown. Further, the plurality of R ⁹¹ , R ¹⁰¹ and R ¹¹¹ may be the same or different from each other. Further, p represents an integer of 0 to 40, preferably 2 to 30.
The compounds represented by the general formulas (I) and (II) are compounds also referred to as aluminoxane, and among these, methylaluminoxane or methylisobutylaluminoxane is preferable. The above-mentioned aluminoxane can be used in combination within each group and between each group. The above aluminoxane can be prepared under various known conditions.
In the 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 the general formula (III) is 10: 1 to 10: 1 to one kind of trialkylaluminum or two or more kinds of trialkylaluminum and an alkylboronic acid represented by the general formula R ¹¹² B (OH) ₂ . It can be obtained by a 1: 1 (molar ratio) reaction.
The boron compound is a complex of a cation such as a carbonium cation or an ammonium cation with an organoboron compound such as triphenylboron, tris (3,5-difluorophenyl) boron or tris (pentafluorophenyl) boron, or a complex. Various organoboron compounds such as tris (pentafluorophenyl) boron can be mentioned.

2-2. Ion-exchangeable layered silicate In the present invention, the ion-exchangeable layered silicate used as a raw material (hereinafter, may be simply abbreviated as silicate) is a layer composed of ionic bonds or the like bonded to each other. A silicate compound having a crystal structure stacked in parallel by force, having interlayer ions between layers, and exchanging the contained interlayer ions.
Most silicates are naturally produced primarily as the main component of clay minerals. It is common to disperse / swell in water and purify according to the difference in sedimentation rate, but it is not necessary that the contaminants are completely removed, and contaminants other than ion-exchangeable layered silicate (contaminants other than ion-exchangeable layered silicate) ( Quartz, cristobalite, etc.) may be included. Depending on the type, amount, particle size, crystallinity, and dispersion state of these impurities, it may be preferable to pure silicate, and such a complex is also an ion-exchange layered silicate of the catalyst component (B). include.
Further, the silicate used in the present invention is not limited to a naturally produced silicate, and may be an artificial synthetic product.

Specific examples of ion-exchangeable layered silicates include layered silicic acids having a 1: 1 type structure or a 2: 1 type structure described in "Clay Minerals" by Haruo Shiramizu, Asakura Shoten (1988). Salt is mentioned.
The 1: 1 type structure refers to a structure based on a stack in which a one-layer tetrahedral sheet and a one-layer octahedral sheet are combined as described in the above-mentioned "Clay Minerals" and the like.
The 2: 1 type structure shows a structure based on a stack in which two layers of tetrahedral sheets sandwich one layer of octahedral sheets.
Specific examples of ion-exchangeable layered silicates having a 1: 1 type structure include kaolin-type silicates such as dikite, nacrite, kaolinite, metahaloysite, and halloysite, and serpentine subgroups such as chrysotile, lysaldite, and antigolite. Examples include group silicates.
Specific examples of ion-exchangeable layered silicates having a 2: 1 type structure include smectite silicates such as montmorillonite, byderite, nontronite, saponite, hectrite and stephensite, and vermiculite silicates such as vermiculite. Examples thereof include mica silicates such as salt, mica, illite, sericite, and vermiculite, attapargite, sepiolite, parigolskite, bentonite, pyrophyllite, talc, and green mudstones. These may form a mixed layer.
Among these, those in which the main component is an ion-exchangeable layered silicate having a 2: 1 type structure are preferable. More preferably, the main component is a smectite group silicate, and even more preferably, the main component is montmorillonite.
The type of interlayer cation (cation contained between the layers of the ion-exchangeable layered silicate) is not particularly limited, but the main components are alkali metals of Group 1 of the periodic table such as lithium and sodium, calcium and magnesium. Alkaline earth metals of Group 2 of the Periodic Table, or transition metals such as iron, cobalt, copper, nickel, zinc, ruthenium, rhodium, palladium, silver, iridium, platinum, and gold are relatively easily available. It is preferable in that it is.

The ion-exchangeable layered silicate may be used in a dry state or may be used in a liquid slurry state.
The shape of the ion-exchangeable layered silicate is not particularly limited, and may be a naturally produced shape, a shape at the time of artificial synthesis, or a shape by operations such as crushing, granulation, and classification. Ion-exchangeable layered silicates processed from the above may be used.
Of these, the granulated ion-exchangeable layered silicate is particularly preferable because it gives good polymer particle properties when the ion-exchangeable layered silicate is used as a catalyst component.
The ion-exchangeable layered silicate can be used as it is without any particular treatment, but it is preferably chemically treated. For the method for chemically treating the ion-exchangeable layered silicate, the description in paragraphs 0042 to 0071 of JP-A-2009-299046 can be referred to.

The catalyst component (B) preferably used in the present invention is a chemically treated ion-exchangeable layered silicate, and has an atomic ratio of Al / Si of 0.01 to 0.25, preferably 0.03 to 0. Those of .24 and further those in the range of 0.05 to 0.23 are preferable. The Al / Si atomic ratio is considered to be an index of the acid treatment strength of the clay portion.
Aluminum and silicon in the ion-exchangeable layered silicate are measured by a method of preparing a calibration curve by a method of chemical analysis by the JIS method and quantifying by fluorescent X-rays.

3. 3. Ingredient (C)
The catalyst component (C) used in the present invention is an organoaluminum compound, and an organoaluminum compound represented by the following general formula (IV) is preferably 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 is 1 to 3, and m is 1 to 2. Represents each of the integers of. ]
When it is a halogen, chlorine is preferable, when it is an alkoxy group, an alkoxy group having 1 to 8 carbon atoms is preferable, and when it is an amino group, an amino group having 1 to 8 carbon atoms is preferable.
The organoaluminum compound can be used alone or in combination of two or more.
Specific examples of the organic aluminum compound include trimethylaluminum, triethylaluminum, trinormalpropylaluminum, trinormalbutylaluminum, triisobutylaluminum, trinormalhexylaluminum, trinormalaloctylaluminum, trinormalaldecylaluminum, diethylaluminum chloride, diethylaluminum. Examples thereof include sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, diisobutylaluminum chloride and the like. Of these, trialkylaluminum and alkylaluminum hydrides with m = 1 and n = 3 are preferred. More preferably, it is trialkylaluminum in which R has 1 to 8 carbon atoms.

4. Preparation of catalyst The catalyst for olefin polymerization used in the present invention contains each of the above catalyst components. These can be obtained by contacting them inside or outside the polymerization tank. The catalyst for olefin polymerization may be prepolymerized in the presence of olefin.
Contact of each catalyst component is usually carried out in an aliphatic hydrocarbon or an aromatic hydrocarbon solvent. The contact temperature is not particularly limited, but is preferably between −20 ° C. and 150 ° C. The contact order can be any combination for the purpose of purpose, and particularly preferable ones are as follows for each catalyst component.
When the catalyst component (C) is used, the catalyst component (A) or the catalyst component (B), or the catalyst component (A) and the catalyst are used before the catalyst component (A) and the catalyst component (B) are brought into contact with each other. The catalyst component (C) is brought into contact with both of the components (B), or the catalyst component (A) and the catalyst component (B) are brought into contact with each other and the catalyst component (C) is brought into contact with the catalyst component (C) at the same time. It is possible to bring the catalyst component (C) into contact after contacting (A) with the catalyst component (B), but it is preferable that the catalyst is brought into contact with the catalyst component (A) and the catalyst component (B) before being brought into contact with each other. This is a method of contacting with any of the components (C).
Further, after contacting each catalyst component, it is possible to wash with an aliphatic hydrocarbon or an aromatic hydrocarbon solvent.

The amounts of the catalyst components (A), (B) and (C) used in the present invention are arbitrary. For example, the amount of the catalyst component (A) used with respect to the catalyst component (B) is preferably in the range of 0.1 μmol to 1000 μmol, more preferably 0.5 μmol to 500 μmol with respect to 1 g of the catalyst component (B).
The amount of the catalyst component (C) used with respect to the catalyst component (A) is the molar ratio of aluminum of the catalyst component (C) to the transition metal of the catalyst component (A), preferably 0.01 to 5 × ¹⁰⁶ . More preferably, it is in the range of 0.1 to 1 × 10 ⁴ .

The branched propylene-based polymer of the present invention can be produced by using a catalyst component having an ability to generate macromer and a catalyst component having an ability to copolymerize the macromer and propylene. Although it is possible to produce using a single catalyst component having the ability to generate this macromer and the ability to copolymerize macromer and propylene at the same time, the branched propylene-based polymer of the present invention can be efficiently produced. Can be selected from methods using different catalytic components having their respective abilities. That is, a branched propylene-based weight having the requirements of the present invention by a method using a component [A-1] having an ability to generate macromer and a component [A-2] having an ability to copolymerize macromer and propylene. Manufacture of coalescing is facilitated.
Therefore, the ratio of the component [A-1] and the component [A-2] to be used is arbitrary as long as the characteristics of the branched propylene-based polymer of the present invention are satisfied, but the components [A-1] and [A-1] are used. The molar ratio of the transition metal of [A-1] to the total amount of A-2] is preferably 0.30 or more and 0.99 or less.
By changing this ratio, it is possible to adjust the balance between melt properties and catalytic activity. That is, a low molecular weight terminal vinyl macromer is produced from the component [A-1], and a high molecular weight body obtained by partially copolymerizing the macromer is produced from the component [A-2]. Therefore, by changing the ratio of the component [A-1], the average molecular weight, the molecular weight distribution, the bias of the molecular weight distribution toward the low molecular weight side, the very high molecular weight component, the branch (amount, length, Distribution) can be controlled, thereby controlling the melt properties such as strain hardening degree and melt tension.
The molar ratio of the transition metal of the component [A-1] to the total amount of the component [A-1] and the component [A-2] is preferably 0.30 or more, more preferably 0.40 or more. More preferably, it is 0.50 or more. The upper limit is preferably 0.99 or less, more preferably 0.90 or less, and preferably 0.80 or less in order to efficiently obtain the polymer of the present invention with high catalytic activity. Yes, more preferably in the range of 0.70 or less.
Further, by using the component [A-1] in the above range, the balance between the average molecular weight and the catalytic activity can be adjusted.

5. Prepolymerization The catalyst for olefin polymerization is preferably subjected to prepolymerization consisting of contacting olefins and polymerizing in a small amount. By performing the prepolymerization treatment, it is possible to prevent the formation of a gel when the main polymerization is performed. It is considered that the reason is that the long-chain branches can be uniformly distributed among the polymer particles at the time of the main polymerization.
The olefin used during the prepolymerization is not particularly limited, but ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, etc. Examples thereof include styrene, and propylene is preferable.
As the olefin feeding method, any method can be used, such as a feeding method for maintaining the olefin in the prepolymerization tank at a constant speed or a constant pressure state, a combination thereof, and a stepwise change.
The prepolymerization temperature and the prepolymerization time are not particularly limited, but are preferably in the range of −20 ° C. to 100 ° C., 5 minutes to 24 hours, respectively.
As for the amount of prepolymerization, the mass ratio of the prepolymerized polymer to the catalyst component (B) is preferably 0.01 to 100, more preferably 0.1 to 50.
Further, the catalyst component (C) can be added at the time of prepolymerization, and it is also possible to wash at the end of prepolymerization.
Further, a method such as coexistence of a polymer such as polyethylene or polypropylene or a solid of an inorganic oxide such as silica or titania is also possible at the time of or after the contact of each of the above catalyst components.
The catalyst may be dried after the prepolymerization. The drying method is not particularly limited, and examples thereof include vacuum drying, heat drying, and drying by circulating a drying gas, and these methods may be used alone or in combination of two or more methods. good. The catalyst may be agitated, vibrated and fluidized in the drying step.

6. Propylene polymerization As the polymerization mode, any mode can be adopted as long as the catalyst for olefin polymerization and the monomer are in efficient contact with each other.
Specifically, a slurry polymerization method using an inert solvent, a bulk polymerization method using propylene as a solvent without substantially using the inert solvent, a solution polymerization method, or a gas state of each monomer substantially without using a liquid solvent. A vapor phase polymerization method for keeping can be adopted.
Further, a method of performing continuous polymerization or batch polymerization is also applied.
Further, although it is possible to carry out multi-step polymerization of two or more steps, it is preferable to carry out single-step polymerization.
Above all, it is preferable to carry out the bulk polymerization method, in which case the polymerization temperature can be from 50 ° C. to a temperature at which propylene becomes critical.

Further, in order to produce the branched propylene-based polymer of the present invention, the polymerization temperature is preferably 65 ° C. or higher.
In the polymerization reaction mediated by the above-mentioned component [A-1], a β-methyl elimination reaction is carried out as a termination reaction to form a vinyl group at the terminal, and macromer capable of copolymerizing with propylene is produced. In addition, the rate of β-methyl desorption reaction is affected by the polymerization temperature. Generally, when the polymerization temperature is high, the β-methyl desorption rate increases, and as a result, the ratio to the growth reaction rate increases and the molecular weight of macromer increases. descend.
Therefore, as a method for producing the branched propylene-based polymer of the present invention, it is preferable to set the polymerization temperature to 65 ° C. or higher.
By setting the polymerization temperature to 65 ° C. or higher, the average molecular weight of macromer is in a range preferable in the present invention, so that a branch having a short branched chain length can be introduced into the branched propylene-based 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, regarding the upper limit, it is necessary to be below the critical temperature of propylene in order to carry out bulk polymerization, preferably 85 ° C. or lower, and more preferably 83 ° C. or lower.
In particular, the polymerization temperature when the compound represented by the general formula (a1) is selected as the component [A-1] is preferably 80 when 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 polymerizing at ° C or higher, but when the substituent at the 2-position of the indenyl group is a bulky substituent such as a t-butylfuryl group, the temperature is higher than 70 ° C. The polymer of the present invention can be obtained at a low polymerization temperature.
In that case, the pressure is more preferably 1.5 MPa or more, further preferably 2.5 MPa or more, and preferably 3.5 MPa or more. The upper limit is preferably 4.4 MPa or less, more preferably 4.0 MPa or less.
Further, the polymerization may be homopolymerization of propylene, and in addition to the propylene monomer, an α-olefin monomer having 2 to 20 carbon atoms excluding propylene, for example, ethylene, 1-butene, 1-hexene, 1-octene, 4-. It may be a copolymerization using one kind or two or more kinds selected from methyl-1-pentene and the like as a comonomer.
The amount of the comonomer is preferably 10 mol% or less, more preferably 5 mol% or less as the copolymerization ratio in the branched propylene-based polymer, and 15 mol as the charge amount at the time of polymerization. % Or less, more preferably 7.5 mol% or less.

Further, in order to produce the branched propylene-based polymer of the present invention, hydrogen is used as a molecular weight adjusting agent. The range is preferably 1.0 × 10 ^-5 or more, more preferably 1.0 × 10 ^-4 or more, and even more preferably 0.5 × 10 ^-3 or more in terms of molar ratio with respect to propylene. Further, regarding the upper limit, 1.0 × 10 ^-2 or less is preferable, 0.5 × 10 ^-2 or less is more preferable, and 0.2 × 10 ^-2 or less is further preferable.
The polymer produced mediated by the above-mentioned component [A-1] has a very slow chain transfer due to hydrogen, while the polymer produced mediated by the component [A-2] has a relatively slow chain transfer due to hydrogen. Therefore, when the amount of hydrogen is low, a high molecular weight polymer can be produced. Therefore, when the amount of hydrogen used is small, the polymer produced by the component [A-2] (that is, a polymer of polypropylene and terminal vinyl macromer, which corresponds to a branched propylene-based polymer). Is present on the higher molecular weight side than the polymer produced by the component [A-1] (that is, the terminal vinyl macromer and the polymer forming the branched chain).
Therefore, when propylene is polymerized under the condition that the amount of hydrogen used is small by using the component [A-1] and the component [A-2] in combination, the molecular weight distribution of the branched propylene-based polymer is widened to the high molecular weight side and , The branched chain length can be shortened.

Further, the component [A-1] produces a terminal vinyl macromer, and the component [A-1] that produced the macromer itself mediates the copolymerization of propylene and macromer to generate a branched macromer having a terminal vinyl group. On the other hand, the component [A-2] does not generate macromer by itself, and mediates the copolymerization of propylene and macromer only when the macromer produced by the component [A-1] approaches the component [A-2]. To produce a branched polymer.

As described above, when the branched propylene polymer is produced by the macromer copolymerization method by combining the component [A-1] and the component [A-2], (1) the polymerization temperature is set to 65 ° C. or higher. As a result, it is possible to introduce a branch having a short branch chain length, and (2) by reducing the amount of hydrogen used as a molecular weight adjuster, the molecular weight distribution of the branched propylene-based polymer can be widened toward the high molecular weight side. Further, due to the difference in the contact efficiency between each of the component [A-1] and the component [A-2] and the terminal vinyl macromer, many of the components [A-1] having a high contact efficiency with the macromer are generated. Since the macromer having a branched structure is introduced into the high molecular weight branched polymer produced by the component [A-2], the branched propylene is produced by the comprehensive action of the above (1), (2) and (3). It is possible to introduce a large number of branches having a short branch chain length into the high molecular weight region of the molecular weight distribution of the system polymer.
Specifically, the component having a molecular weight M of 1,000,000 or more in the molecular weight distribution and the branching index g'at an absolute molecular weight Mabs of 1,000,000 can be set in the above-mentioned preferable ranges.
Therefore, the obtained branched propylene-based polymer can have a relaxation time distribution in which many components have a somewhat short relaxation time and few components have an extremely long relaxation time.

III. Applications of the branched propylene-based polymer The branched propylene-based polymer of the present invention can be used as a molding material as pellets cut into granules after heat-melt-kneading using a melt-kneader. The branched propylene-based polymer of the present invention contains, if necessary, known antioxidants, ultraviolet absorbers, antistatic agents, nucleating agents, lubricants, flame retardants, antiblocking agents, colorants, and inorganic substances. Alternatively, various additives such as organic fillers, as well as various synthetic resins and natural resins can be blended.
These pellet-shaped molding materials are molded by various known molding methods of polypropylene, for example, injection molding, extrusion molding, foam molding, hollow molding, etc., and are used for industrial injection molded parts, containers, non-stretched films, and uniaxial moldings. Various molded products such as stretched films, biaxially stretched films, sheets, pipes, and fibers can be manufactured.
Further, since the branched propylene-based polymer of the present invention has an excellent balance between melt fluidity and melt tension, the thickness is uniform in sheet molding, blow molding, etc., and the foam cell diameter is uniform in foam molding, etc. , In melt spinning and the like, it can be suitably used in fields where finer fiber diameters are required.
Further, the branched propylene-based polymer of the present invention can also be used by blending with other resins.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.
(1) Synthesis of component (A) (1-1) Synthesis example of component [A-1] (complex 1)
rac-dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (4-isopropylphenyl) indenyl}] Hafnium synthesis:
rac-dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (4-isopropylphenyl) indenyl}] hafnium, Japanese Patent Application Laid-Open No. 2009-299046 It was synthesized according to the method of Example 13 and Example 1 of JP-A-2009-91512.
(Complex 2)
rac-dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-isopropylphenyl) indenyl}] Hafnium synthesis:
rac-dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-isopropylphenyl) indenyl}] hafnium, Synthetic Example 1 of JP2012-149160 It was synthesized according to the method of.
(1-2) Synthesis example of component [A-2] (complex 3)
rac-dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] Hafnium synthesis:
rac-dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazurenyl}] hafnium is synthesized according to the method of Example 7 of JP-A-11-240909. did.

(2) Example of synthesis of component (B): Chemical treatment of ion-exchangeable layered silicate In 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 placed. In addition, the temperature was raised to 95 ° C.
Commercially available montmorillonite (Benclay KK manufactured by Mizusawa Industrial Chemicals, Al = 9.78% by mass, Si = 31.79% by mass, Mg = 3.18% by mass, Al / Si (molar ratio) = 0.320, An average particle size of 14 μm) was added, 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). The chemical composition of the chemically treated montmorillonite (intermediate) was Al = 7.68% by mass, Si = 36.05% by mass, Mg = 2.13% by mass, and Al / Si (molar ratio) = 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 reacted at 40 ° C. for 1 hour. After 1 hour, the reaction slurry was filtered and washed 3 times with 1 L of distilled water to obtain a cake-like solid again.
When the recovered cake was dried, 80 g of chemically treated montmorillonite was obtained. The chemical composition of this chemically treated montmorillonite is Al = 7.68% by mass, Si = 36.05% by mass, Mg = 2.13% by mass, Al / Si (molar ratio) = 0.222, Li = 0.53. It was% by mass.

(3) Preparation of catalyst (3-1) Example of synthesis 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 prepare a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution having a concentration of 143 mg / mL) was added to the mixture, and the mixture was stirred for 1 hour and then washed with heptane until the residual liquid ratio became 1/100 to make the total volume 50 mL.
Further, in another flask (volume 200 mL), the rac-dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2) produced in Synthesis Example 1 of the catalyst component [A-1] was prepared. -Frill) -4- (4-isopropylphenyl) indenyl}] hafnium (complex 1) (105 μmol) was dissolved in toluene (21 mL) to prepare solution 1. Further, in another flask (volume 200 mL), rac-dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl)) prepared in the synthesis example of the catalyst component [A-2]. -4-hydroazurenyl}] Hafnium (complex 3) (45 μmol) was dissolved in toluene (9 mL) to prepare Solution 2.

After adding triisobutylaluminum (0.42 mmol: 0.6 mL of heptane solution having a concentration of 143 mg / mL) to the 1 L flask containing the chemically treated montmorillonite, add the above solution 1 (21 mL) and stir at room temperature for 20 minutes. did.
Then, after further adding triisobutylaluminum (0.18 mmol: 0.25 mL of a heptane solution having a concentration of 143 mg / mL), the above solution 2 was added, and the mixture was stirred 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 set to 40 ° C., propylene was fed at a rate of 5 g / hour, and prepolymerization was performed while maintaining 40 ° C. for 4 hours. Then, the propylene feed was stopped and residual polymerization was carried out for 1 hour. After removing the supernatant of the obtained catalyst slurry by decantation, triisobutylaluminum (6 mmol: 8.5 mL of heptane solution having a concentration of 143 mg / mL) was added to the remaining portion, and the mixture was stirred for 5 minutes.
This solid was dried under reduced pressure for 1 hour to obtain 29.9 g of a dry prepolymerization catalyst. The prepolymerization ratio (value obtained by dividing the amount of prepolymer by the amount of solid catalyst) was 1.99. This prepolymerization catalyst was designated as catalyst 1.

(3-2) Example of synthesis of catalyst 2 150 kg of the chemically treated montmorillonite obtained above was placed in a reactor having an internal volume of ¹ m3, and 2832 L of hexane was added to form a slurry, which was 74.4 kg (375 mol) of triisobutylaluminum. Was added over 85 minutes and stirred for 60 minutes. After that, it was washed with hexane until the residual liquid ratio became 1/32, and the total volume was set to 900 L.
The 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 having a concentration of 15.3% by mass) was added thereto.
After stirring for 5 minutes, rac-dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4-hydroazulenyl}] hafnium (complex 3) was added to 0.657 kg (0.81 mol). 96 L of toluene was added and stirring was continued for 60 minutes.
Then, 9.758 kg (26.61 mol) of trinormal octyl aluminum was added and stirred for 6 minutes, and then 0.064 kg of triisobutylaluminum (concentration: 0.648 mass%) of toluene was added to 240 L of toluene in a container with another stirring device. Rac-dichloro [1,1'-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-isopropylphenyl) toluene}] to the place where 9.88 kg, 0.32 mol) was added. The prepared solution was added by adding 1.768 kg (1.89 mol) of phenylium (complex 2), 100 L of toluene was added, and stirring was continued for another 20 minutes.
After that, 2387 L of hexane was added to bring the internal temperature of the reactor to 40 ° C., and then 328.1 kg of propylene was fed over 240 minutes to perform prepolymerization while maintaining 40 ° C. Then, the propylene feed was stopped and 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 settled. The supernatant was removed so that the solution volume became 1500 L, 12.7 kg of triisobutylaluminum was added, 3974 L of hexane was added again, and the mixture was stirred and then settled, and the supernatant was removed until the solution volume reached 1500 L.
To this, 8.9 kg of triisobutylaluminum (42.9 kg of a hexane solution having a concentration of 20.8 mass%) and 205 L of hexane were added.
Then, the reaction solution was transferred to a dryer and dried at 40 ° C. for 9 hours.
Then, 465 kg of the dry prepolymerization catalyst was obtained. The prepolymerization ratio (value obtained by dividing the amount of prepolymer by the amount of solid catalyst) was 2.10. This prepolymerization catalyst was designated as catalyst 2.

(4) Example [Example 1]
(polymerization)
The 3 L autoclave was heated and dried well in advance by circulating nitrogen, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 mL of a heptane solution of triisobutylaluminum (143 mg / mL), 60 Nml of hydrogen was introduced.
Then, after introducing 750 g of liquid propylene, the temperature was raised to 70 ° C.
Then, 120 mg of the catalyst 1 excluding the prepolymerized polymer was pressure-fed to the polymerization tank with high-pressure argon to start polymerization. After holding at 70 ° C. for 1 hour, 5 ml of ethanol was press-fitted to terminate the polymerization. As a result, 216 g of the polymer was obtained.
(Granulation)
For 100 parts by mass of the obtained branched propylene polymer, the phenolic antioxidant IRGANOX1010 (trade name, manufactured by BASF Japan, Inc., tetrakis [methylene-3- (3', 5'-di-t-butyl-4)) '-Hydroxyphenyl) propionate] methane) 0.125 parts by mass, phosphite-based antioxidant IRGAFOS168 (trade name, manufactured by BASF Japan, Tris (2,4-di-t-butylphenyl) phosphite) 0.125 The parts by mass were mixed and mixed at room temperature for 3 minutes using a high-speed stirring type mixer Henshell mixer (trade name, manufactured by Nippon Coke Industries, Ltd.). Then, using a twin-screw extruder KZW-15 (manufactured by Technobel Co., Ltd.), the screw was melt-kneaded at a screw rotation speed of 400 rpm and kneading temperatures of 80, 120, and 230 ° C. (hereinafter, the same temperature up to the die outlet) from the bottom of the hopper. The molten resin extruded from the strand die was taken up while being cooled and fixed in a cooling water tank, and the strands were cut and pelletized using a strand cutter.
The MFR (MFR _pellet ) of the obtained pellet was 1.4 g / 10 minutes. Other results are shown in Table 1.

[Example 2]
In the polymerization of Example 1, the same polymerization was carried out except that the catalyst 1 was introduced with 130 mg by mass excluding the prepolymerized polymer and 70 Nml of hydrogen. As a result, 255 g of the polymer was obtained.
When granulation was carried out in the same manner as in Example 1, the obtained pellets had MFR (MFR _pellet ) = 1.8 g / 10 minutes. Other results are shown in Table 1.

[Example 3]
In the polymerization of Example 1, the same polymerization was carried out except that 90 mg of the catalyst 1 was introduced by mass excluding the prepolymerized polymer and 80 Nml of hydrogen was introduced. As a result, 230 g of the polymer was obtained.
When granulation was carried out in the same manner as in Example 1, the obtained pellets had MFR (MFR _pellet ) = 3.2 g / 10 minutes. Other results are shown in Table 1.

[Example 4]
In the polymerization of Example 1, the same polymerization was carried out except that the catalyst 1 was introduced with a mass of 80 mg excluding the prepolymerized polymer and 90 Nml of hydrogen. As a result, 250 g of the polymer was obtained.
When granulation was carried out in the same manner as in Example 1, the obtained pellets had MFR (MFR _pellet ) = 4.1 g / 10 minutes. Other results are shown in Table 1.

[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, 131 mL of heptane was added to form a slurry, and 50 mmol of triisobutylaluminum (69 mL of a heptane solution having a concentration of 143.4 mg / mL) was added thereto. The mixture was stirred for 60 minutes. Then, it was washed with heptane to 1/100 to make the total volume 100 mL.
The slurry solution containing this chemically treated montmorillonite was kept at 50 ° C., 4.2 mmol of trinormal octyl aluminum (10.7 mL of a heptane solution having a concentration of 143.4 mg / mL) was added thereto, and the mixture was stirred for 20 minutes.
There, rac-dichloro [1,1'-dimethylsilylenebis {2- (5-t-butyl-2-furyl) -4- (4-isopropylphenyl) indenyl}] hafnium (complex 1) 0.3 mmol ( (Slurry made with 50 mL of toluene) was added, 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 set to 40 ° C., propylene was fed at a rate of 10 g / hour, and prepolymerization was performed for 4 hours while maintaining 40 ° C. Then, the propylene feed was stopped and residual polymerization was carried out at 40 ° C. for 1 hour.
After removing the supernatant of the obtained catalyst slurry by decantation, the prepolymerization catalyst was washed by adding heptane again and decanting. To the portion remaining by the decantation, 12 mmol of triisobutylaluminum (16.6 mL of a heptane solution having a concentration of 143.4 mg / mL) was added, and the mixture was stirred for 10 minutes. This solid was dried under reduced pressure at 40 ° C. for 2 hours to obtain 57.6 g of a dry prepolymerization catalyst. The prepolymerization ratio (value obtained by dividing the amount of prepolymer by the amount of solid catalyst) was 1.88. This prepolymerization catalyst was designated as catalyst 3.
(4) Polymerization A 3 L autoclave was heated and dried well in advance by circulating nitrogen, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 mL of a heptane solution of triisobutylaluminum (140 mg / mL), 60 Nml of hydrogen was introduced. Then, 750 g of liquid propylene was introduced and the temperature was raised to 70 ° C. Then, the catalyst 3 having a mass of 150 mg excluding the prepolymerized polymer was pressure-fed to the polymerization tank and polymerized at 70 ° C. for 1 hour. Finally, unreacted propylene was quickly purged to terminate polymerization. As a result, about 195 g of a propylene homopolymer was obtained. MFR = 620 g / 10 minutes.
When Mn was calculated by GPC, it was Mn = 33000. This can be estimated to be 1571 as skeletal carbon. The results are shown in Table 2.

[Reference Example 2]: Example of homopolymerization method of side chain In the polymerization of Reference Example 1, the same polymerization was carried out except that 120 mg of the catalyst 3 was introduced by mass excluding the prepolymerized polymer and 90 Nml of hydrogen was introduced. As a result, 210 g of the polymer was obtained. MFR = 680/10 minutes.
When Mn was calculated by GPC, it was Mn = 32000. This can be estimated to be 1524 as skeletal carbon. The results are shown in Table 2.

[Example 5]
The 3 L autoclave was heated and dried well in advance by circulating nitrogen, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 mL of a heptane solution of triisobutylaluminum (143 mg / mL), 120 Nml of hydrogen was introduced.
Then, after introducing 750 g of liquid propylene, the temperature was raised to 80 ° C.
Then, 50 mg of the catalyst 2 excluding the prepolymerized polymer was pressure-fed to the polymerization tank with high-pressure argon to start the polymerization. After holding at 80 ° C. for 1 hour, 5 ml of ethanol was press-fitted to terminate the polymerization. As a result, 250 g of the polymer was obtained.
When granulation was carried out in the same manner as in Example 1, the obtained pellets had MFR (MFR pellet) = 3.0 g / 10 minutes. Other results are shown in Table 1.

[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, 131 mL of heptane was added to form a slurry, and 50 mmol of triisobutylaluminum (69 mL of a heptane solution having a concentration of 143.4 mg / mL) was added thereto. The mixture was stirred for 60 minutes. Then, it was washed with heptane to 1/100 to make the total volume 100 mL.
The slurry solution containing this chemically treated montmorillonite was kept at 50 ° C., 4.2 mmol of trinormal octyl aluminum (10.7 mL of a heptane solution having a concentration of 143.4 mg / mL) was added thereto, and the mixture was stirred for 20 minutes.
There, rac-dichloro [1,1'-dimethylsylylenebis {2- (5-methyl-2-furyl) -4- (4-isopropylphenyl) indenyl}] hafnium (complex 2) 0.3 mmol (toluene 50 mL) (Slurry made in 1) was added, 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 set to 40 ° C., propylene was fed at a rate of 10 g / hour, and prepolymerization was performed for 4 hours while maintaining 40 ° C. Then, the propylene feed was stopped and residual polymerization was carried out at 40 ° C. for 1 hour.
After removing the supernatant of the obtained catalyst slurry by decantation, the prepolymerization catalyst was washed by adding heptane again and decanting. To the portion remaining by the decantation, 12 mmol of triisobutylaluminum (16.6 mL of a heptane solution having a concentration of 143.4 mg / mL) was added, and the mixture was stirred for 10 minutes. This solid was dried under reduced pressure at 40 ° C. for 2 hours to obtain 54.0 g of a dry prepolymerization catalyst. The prepolymerization ratio (value obtained by dividing the amount of prepolymer by the amount of solid catalyst) was 1.7. This prepolymerization catalyst was designated as catalyst 4.
(polymerization)
The 3 L autoclave was heated and dried well in advance by circulating nitrogen, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 mL of a heptane solution of triisobutylaluminum (140 mg / mL), 80 Nml of hydrogen was introduced. Then, 750 g of liquid propylene was introduced and the temperature was raised to 80 ° C. Then, the catalyst 4 having a mass of 165 mg excluding the prepolymerized polymer was pressure-fed to the polymerization tank and polymerized at 80 ° C. for 1 hour. Finally, unreacted propylene was quickly purged to terminate polymerization. As a result, about 220 g of a propylene homopolymer was obtained. MFR = 520 g / 10 minutes.
When Mn was calculated by GPC, it was Mn = 36000. This can be estimated to be 1714 as skeletal carbon. The results are shown in Table 2.

[Reference Example 4]: Example of homopolymerization method of side chain In the polymerization of Reference Example 3, the same polymerization was carried out except that 150 mg of the catalyst 4 was introduced in a mass excluding the prepolymerized polymer and 120 Nml of hydrogen was introduced. As a result, 240 g of the polymer was obtained. MFR = 570/10 minutes.
When Mn was calculated by GPC, it was Mn = 35000. This can be estimated to be 1667 as skeletal carbon. The results are shown in Table 2.

[Comparative Example 1]
The 3 L autoclave was heated and dried well in advance by circulating nitrogen, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 mL of a heptane solution of triisobutylaluminum (143 mg / mL), 210 Nml of hydrogen was introduced.
Then, after introducing 750 g of liquid propylene, the temperature was raised to 70 ° C. Then, 60 mg of the catalyst 2 excluding the prepolymerized polymer was pressure-fed to the polymerization tank with high-pressure argon to start polymerization. After holding at 70 ° C. for 1 hour, 5 ml of ethanol was press-fitted to terminate the polymerization. As a result, 225 g of the polymer was obtained.
When granulation was carried out in the same manner as in Example 1, the obtained pellets had MFR (MFR _pellet ) = 1.4 g / 10 minutes.

[Comparative Example 2]
In the polymerization of Comparative Example 1, the same polymerization was carried out except that 45 mg of the catalyst 2 excluding the prepolymerized polymer and 230 Nml of hydrogen were introduced. Then, when granulation was carried out in the same manner as in Example 1 in which 240 g of the polymer was obtained, the MFR (MFR _pellet ) of the obtained pellets was 2.8 g / 10 minutes.

[Reference Example 5]: Example of homopolymerization method of side chain The 3L autoclave was dried well in advance by circulating nitrogen under heating, and then the inside of the tank was replaced with propylene and cooled to room temperature. After adding 2.86 mL of a heptane solution of triisobutylaluminum (140 mg / mL), 210 Nml of hydrogen was introduced.
Then, 750 g of liquid propylene was introduced and the temperature was raised to 70 ° C. Then, the catalyst 4 having a mass of 150 mg excluding the prepolymerized polymer was pressure-fed to the polymerization tank and polymerized at 70 ° C. for 1 hour. Finally, unreacted propylene was quickly purged to terminate polymerization. As a result, about 225 g of a propylene homopolymer was obtained. MFR = 38 g / 10 minutes.
When Mn was calculated by GPC, it was Mn = 63000. This can be estimated to be 3000 as skeletal carbon. The results are shown in Table 2.

[Reference Example 6]: Example of homopolymerization method of side chain In the polymerization of Reference Example 3, the same polymerization was carried out except that 130 mg of the catalyst 4 was introduced in a mass excluding the prepolymerized polymer and 245 N ml of hydrogen was introduced. As a result, 230 g of the polymer was obtained. MFR = 53/10 minutes.
When Mn was calculated by GPC, it was Mn = 62000. This can be estimated to be 2952 as skeletal carbon. The results are shown in Table 2.

(5) Measurement and Evaluation Method The physical characteristics and ductility of the branched propylene-based polymers obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were measured or evaluated by the following methods.
(5-1) Extensional viscosity (ηE), strain hardening degree (SHI) and multi-branching index (MBI)
The extensional viscosity at each strain rate (1.0 / sec, 0.1 / sec, 0.01 / sec) was measured by the method described above in the description of the characteristic (1) and the characteristic (2), and the obtained elongation was obtained. The strain hardening degree (SHI) at each strain rate (dε / dt) was calculated using the measured value of viscosity. In addition, the multi-branch index (MBI) was calculated using the value of the strain hardening degree (SHI) at each calculated strain rate (dε / dt).
The equipment and conditions used for measuring the extensional viscosity are as follows.
<Measuring equipment and conditions>
-Device: Ares manufactured by Rheometrics
・ Jig: Extental Viscosity Fixture manufactured by TA Instruments Co., Ltd.
・ Measurement temperature: 180 ℃
-Strain rate: 1.0 / sec, 0.1 / sec, 0.01 / sec-Preparation of test piece: Press-mold to prepare a sheet of 18 mm x 10 mm and thickness of 0.7 mm.

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

(5-3) Molecular Weight of Branch Side Chain The catalysts (catalysts 1 and 2) used in Examples and Comparative Examples are complex 1 or complex 2 which is a component [A-1] having a macromer synthesizing ability, and propylene and macromer. Complex 3 which is a component [A-2] having a copolymerization ability of the above was used in combination. Reference Examples 1 to 6 were carried out using only the complex 1 (catalyst 3) or the complex 2 (catalyst 4) having the ability to synthesize macromer in order to measure or estimate the molecular weight of the branched side chain, and the obtained macromer molecular weight (Mn) was carried out. ) Was measured.
The molecular weight (Mn) of macromer was measured by gel permeation chromatography (GPC) by the method described above in the description of the characteristic (4).
The equipment and conditions used for the measurement of macromer molecular weight (Mn) are as follows.
<Measuring equipment and conditions>
-Device: Waters GPC (ALC / GPC, 150C)
-Detector: MIRAN, 1A, IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
-Column: Showa Denko AD806M / S (3)
-Mobile phase solvent; o-dichlorobenzene (ODCB)
-Measurement temperature; 140 ° C
・ Flow rate: 1.0 mL / min ・ Injection amount: 0.2 mL

(5-4) Melt flow rate (MFR) at a temperature of 230 ° C. and a load of 2.16 kg.
The MFR of the branched propylene-based polymer in the powder state and the MFR in the pelletized state were measured. Moreover, the MFR of the macromer obtained in Reference Examples 1 to 6 was measured.
As described above in the description of property (5), MFR complies with JIS K6921-2 "Plastic-Polypropylene (PP) molding and extrusion materials-Part 2: How to make test pieces and how to determine properties". The test conditions were measured at 230 ° C. and a load of 2.16 kgf.

(5-5) A component having a molecular weight M of 1 million or more (W1 million) and a branch index g'(1 million) having an absolute molecular weight Mabs of 1 million.
By the method described above in the description of the property (6), the component (W1 million) having a weight average molecular weight Mw of 1 million or more and the branch index g'(1 million) having an absolute molecular weight Mabs of 1 million. ) Was measured.

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

(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 the characteristic (8).

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

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

(6) Evaluation Results The results of each Example and Comparative Example are shown in Tables 1 to 4.
Table 1 shows the polymerization conditions of each Example and Comparative Example in which the branched propylene-based polymer was synthesized, and the obtained branched propylene-based polymer having MFR, the ratio of the xylene-soluble component, and the molecular weight M of 1 million or more. Component (W1 million), branch index g'(1 million) with absolute molecular weight Mabs of 1 million, number of long-chain branches (LCB) with 7 or more carbon atoms per 1000 monomer units, melting point (Tm), branched propylene The macromer of the reference example corresponding to the branched chain of the system polymer is summarized.
Table 2 shows the polymerization conditions of the reference example in which the macromer corresponding to the branched chain of the branched propylene polymer obtained in each Example and Comparative Example was synthesized, and the MFR and number average molecular weight (Mn) of the obtained macromer. ), The number of carbon atoms in the skeleton is summarized.
Table 3 shows the MFR and strain rates (0.01 / sec, 0.1 / sec, 1.0 / sec) of the branched propylene-based polymers obtained under the polymerization conditions of each Example and Comparative Example. Extensional viscosity ηE, strain hardening degree (SHI) at each strain rate (0.01 / sec, 0.1 / sec, 1.0 / sec,), strain rate from 0.01 / sec to 1.0 / sec The multi-branch index (MBI) obtained from the strain hardening degree (SHI) in.
In the graph of FIG. 5, the horizontal axis is MFR (MFR 230 ° C., 2.16 kg load), the vertical axis is multi-branched index (MBI), and the branched propylene-based polymer obtained in each Example and Comparative Example. It is a graph plotting the data of.
Table 4 summarizes the MFR, the melt tension at 230 ° C. (MT230 ° C.), and the maximum take-up speed (MaxDraw) at 230 ° C. for the branched propylene-based polymers obtained under the polymerization conditions of each Example and Comparative Example.
In the graph of FIG. 6, MFR (MFR 230 ° C., 2.16 kg load) is taken on the horizontal axis, and the maximum take-up speed (MaxDraw) at 170 ° C. is taken on the vertical axis. It is a graph which plotted the data of the propylene-based polymer.
In the graph of FIG. 7, the horizontal axis represents the melt tension (MT230 ° C.) and the vertical axis represents the maximum winding speed (MaxDraw) at 230 ° C., and the branched propylene-based polymer obtained in each Example and Comparative Example. It is a graph plotting the data of.

As shown in Table 3, the branched propylene-based polymers of Examples 1 to 5 have a multi-branched index (MBI) of 0.15 to 0.43, fall within the range of the characteristic (1), and are strained. The degree of curing (SHI @ ^1.0-1 ) was 1.14 to 1.75, which was within the range of the characteristic (2). As shown in Table 4, the branched propylene-based polymers of Examples 1 to 5 have a melt tension of 6.0 to 16.6 g at 230 ° C., while maintaining the melt tension required for molding. The maximum take-up speed (230 ° C.) was 66 to 119 m / s, and the ductility during melting was also excellent.
On the other hand, as shown in Table 3, the branched propylene-based polymers of Comparative Examples 1 and 2 have a strain hardening degree (SHI @ ^1.0-1 ) of 1.75 to 1.88 and have characteristics (characteristics (SHI @ 1.0-1). Although it was in the range of 2), the polybranched index (MBI) was 0.05 to 0.08, which was smaller than the lower limit of the range of the characteristic (1). As shown in Table 4, the branched propylene-based polymers of Comparative Examples 1 and 2 had a melt tension of 8.6 to 16.6 g at 230 ° C. and maintained the melt tension required for molding. However, the maximum take-up speed (230 ° C.) was 31 to 53 m / s, and the ductility at the time of melting was inferior.
As shown in FIG. 5, the horizontal axis is MFR, the vertical axis is multi-branch index (MBI), and a graph is created by plotting the data of the branched propylene-based polymer obtained in each Example and Comparative Example. Then, it was confirmed that the branched propylene-based polymer of the example group had a larger MBI than the branched propylene-based polymer of the comparative example group.
As shown in FIG. 6, MFR (MFR 230 ° C., 2.16 kg load) is taken on the horizontal axis, and the maximum take-up speed (MaxDraw) at 230 ° C. is taken on the vertical axis, and the branches obtained in each Example and Comparative Example are taken. When a graph plotting the data of the propylene-based polymer was created, it was confirmed that the branched propylene-based polymer of the example group was superior in spreadability to the branched propylene-based polymer of the comparative example group. Was done.
As shown in FIG. 7, the horizontal axis is the melt tension (MT230 ° C.), the vertical axis is the maximum winding speed (MaxDraw) at 230 ° C., and the branched propylene-based weights obtained in each Example and Comparative Example are taken. When a graph plotting the coalescence data was created, it was confirmed that the branched propylene-based polymer of the example group was superior in spreadability to the branched propylene-based polymer of the comparative example group.

As shown in Table 1, the branched propylene-based polymers of Examples 1 to 5 had 0.070 to 0.100 as components (W1 million) having a molecular weight M of 1 million or more in the molecular weight distribution curve. On the other hand, in the branched propylene-based polymers of Comparative Examples 1 and 2, the components (W1 million) having a molecular weight Mw of 1 million or more were 0.067 to 0.068.
Therefore, the branched propylene-based polymers of Examples 1 to 5 have a larger high molecular weight region than the branched propylene-based polymers of Comparative Examples.

Further, as shown in Table 1, the branched propylene-based polymers of Examples 1 to 5 had a branch index g'(1 million) of 0.88 to 0.89 when the absolute molecular weight Mabs was 1 million. On the other hand, in Comparative Examples 1 and 2, the branch index g'(1 million) was 0.89.
The branched propylene-based polymers of Examples 1 to 5 are equivalent to those of Comparative Examples 1 and 2 as long as only the branch index g'(1 million) is compared, but the weight average molecular weight Mw is 100 as described above. Since the high molecular weight region represented by more than 10,000 components (W1 million) is larger than that of Comparative Examples 1 and 2, the amount of the branched chain introduced into the high molecular weight region is that of Comparative Examples 1 and 2. Many compared to.

Further, as shown in Tables 1 and 2, the length of the side chains introduced into the branched propylene-based polymers of Examples 1 to 5 has a molecular weight Mn of 33000 (skeleton) from the results of Reference Examples 1 to 4. It is estimated to be 1571) to 36000 in terms of carbon number (1714 in terms of skeletal carbon number). On the other hand, the length of the side chain introduced into the branched propylene-based polymer of Comparative Examples 1 to 3 has a molecular weight Mn of 62000 to 63000 from the results of Reference Examples 5 to 6.
Therefore, the branched propylene-based polymers of Examples 1 to 5 have shorter side chains than the branched propylene-based polymers of Comparative Examples.

Further, as shown in Table 1, the branched propylene-based polymers of Examples 1 to 5 have a long chain branch (LCB) having 7 or more carbon atoms per 1000 monomer units, which is 1.0 or less. The number of chain branches is small. The branched propylene-based polymers of Comparative Examples 1 and 2 also had a number of long-chain branches (LCB) of 1.0 or less.

From the analysis of the molecular structure described above, the branched propylene-based polymers obtained in Examples 1 to 5 contain a large number of multi-branched molecules having a large number of branches with short branched chain lengths per molecule in the high molecular weight region. It was confirmed that many components have a short relaxation time to some extent, and components having an extremely long relaxation time have a molecular structure having a small relaxation time distribution.

Claims (8)

A branched propylene-based polymer having the following properties (1) and (2).
Characteristic (1): The multi-branch index (MBI) is 0.15 or more and 1.00 or less.
Characteristic (2): The strain hardening degree (SHI @ 1s ^-1 ) at a strain rate (dε / dt) of 1.0 / sec is 0.70 or more and 3.00 or less.
Here, the multi-branch index (MBI) is the strain hardening degree (SHI) when the strain rate (dε / dt) is 0.01 / sec to 1.0 / sec, and the log of the strain rate is on the horizontal axis. (Dε / dt)), and is the slope when the strain hardening degree (SHI) at a strain rate of 0.01 / sec to 1.0 / sec is plotted on the vertical axis.
Further, the strain hardening degree (SHI) is a section in which the henky strain (ε) is between 1 and 3 in the measurement of the extensional viscosity at a temperature of 180 ° C. and one predetermined strain rate (dε / dt). , The horizontal axis is the logarithm of Henky strain (ε) (log (ε)), and the vertical axis is the logarithm of extensional viscosity (ηE) (log (ηE)). The branched propylene-based polymer according to claim 1, further satisfying the following property (3).
Property (3): The ratio (CXS) of the component soluble in p-xylene at 25 ° C. is less than 0.5% by mass. The branched propylene-based polymer according to claim 1 or 2, further satisfying the following property (4).
Property (4): The molecular weight of the branched side chain is Mn of 11,000 or more and 53,000 or less. The branched propylene-based polymer according to any one of claims 1 to 3, further satisfying the following property (5).
Characteristic (5): The melt flow rate (MFR) measured at a temperature of 230 ° C. and a load of 2.16 kg is 1 to 10 g / 10 minutes. The branched propylene-based polymer according to any one of claims 1 to 4, further satisfying the following property (6-1).
Characteristic (6-1): In the molecular weight distribution curve measured by GPC, the component (W1 million) having a molecular weight M of 1 million or more is 0.070 or more and 0.100 or less. The branched propylene-based polymer according to any one of claims 1 to 5, further satisfying the following property (6-2).
Characteristic (6-2): The branch index g'(1,000,000) when the absolute molecular weight Mabs measured by 3D-GPC is 1,000,000 is 0.80 or more and 0.90 or less. The branched propylene-based polymer according to any one of claims 1 to 6, further satisfying the following property (7).
Characteristic (7): The melting point (Tm) measured by differential scanning calorimetry (DSC) is 150 ° C. or higher and 157 ° C. or lower. The branched propylene-based polymer according to any one of claims 1 to 7, further satisfying the following property (8).
Property (8): The branched propylene-based polymer has a long-chain branched structural portion represented by the following structural formula (A).

[However, in the structural formula (A), P ₁ , P ₂ , and P ₃ are residues generated at the end of the branched propylene-based polymer, each having one or more propylene units, and Cbr is carbon. The methine carbon at the root of the branched chain having a number of 7 or more is shown, and Ca, Cb, and Cc indicate the methylene carbon adjacent to the methine carbon (Cbr). ]

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