Branched propylene-based polymer

Abstract

To provide a branched propylene-based polymer excellent in ductility when melted while holding melt tension necessary when processing.SOLUTION: A branched propylene-based polymer includes 0-11 mol% of at least one co-monomer selected from propylene, ethylene, and α-olefin having a carbon number of 4 or more where the polymer has the following characteristics (1), (2-1), and (3). Characteristic (1): The MFR is 0.1 g / 10 min.-100 g / 10 min. Characteristic (2-1): The melting point (Tm) measured by differential thermal scanning calorimetry (DSC) is lower than 155.0°C. Characteristic (3): A fluidization activation energy (Ea kJ / mol) obtained by measuring a dynamic viscoelasticity and an MFR satisfy the following formula (1). Formula (1): Ea≥-12.5×log(MFR)+66.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In recent years, much research has been conducted into introducing a branched structure into polypropylene to improve its suitability for sheet molding, blow molding, thermoforming, foam molding, and other applications that require a material with a relatively high melt tension. Recently, a macromonomer copolymerization method mainly using a metallocene catalyst has been proposed as a method for introducing a branched structure into polypropylene. Compared with crosslinked polypropylene modified with a crosslinking aid by peroxide, branched polypropylene produced by the macromonomer copolymerization method has the advantage that it has fewer problems such as gel generation due to excessively crosslinked components and deterioration of extensibility due to components with high molecular weight due to crosslinking.

[0003] As a branched propylene polymer produced by such a macromonomer copolymerization method, for example, a polyolefin composition essentially consisting of isotactic polypropylene and, if desired, one or more comonomers, in which the total comonomer content of the polyolefin composition is 0-20 mol%, and further, the weight average branching index g' for the low molecular weight region of the polyolefin composition is less than 0.93 has been disclosed (see Patent Document 1). Also, (a) the melt index MI5 (g / 10 min) at a load of 5.0 kg and the melt index MI at a load of 2.16 kg measured at a temperature of 230°C are 2.16 (g / 10min) compared to MI5 / MI 2.16 and the ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn measured by gel permeation chromatography (GPC) is expressed by the formula MI5 / MI 2.16 ≧0.240×Mw / Mn+3.1 (I) and (b) the melt tension MS (g) measured at 230°C and the intrinsic viscosity [η] (dL / g) measured in tetralin solvent at 135°C satisfy the relationship shown by the formula: logMS≧3.17×log〔η〕-0.68 (II) and the intrinsic viscosity [η] is in the range of 0.1 to 15.0 dL / g. The obtained branched propylene polymer is shown to have high melt strength and melt tension (see Patent Document 2).

[0004] Also disclosed is a branched polypropylene composition having a polydispersity of 4.0 or less and a melting point above 90° C., wherein the branched polypropylene composition has a weight average branching index g of less than 0.95. The resulting branched propylene-based polymer has been shown to exhibit improved melt strength (see Patent Document 3). Furthermore, a method for multi-stage polymerization using a catalyst containing two specific metallocene compounds, specifically, a catalyst combining metallocene compounds such as rac-SiMe2[2-Me-4-Ph-lnd]2ZrC12 and rac-SiMe2[2-Me-4-Ph-lnd]2HfC12 and silica carrying methylaluminoxane (MAO) has been disclosed. It has been shown that the obtained branched propylene-based polymer exhibits a relatively high melt tension (see Patent Document 4).

[0005] In addition, the propylene homopolymer has the following characteristics (1) to (6). (1) The weight average molecular weight (Mw) obtained by GPC is 200,000 to 1,000,000. (2) The ratio (Q value) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) obtained by GPC is 3.5 to 10.5. (3) In the molecular weight distribution curve obtained by GPC, the common logarithm of the molecular weight corresponding to the peak position is Tp, and the common logarithm of the molecular weight at the position where the peak height is 50% is L 50 and H 50 (L 50 is on the lower molecular weight side than Tp, H 50 is higher than Tp), and α and β are α=H50 -Tp, β=Tp-L 50 When defined as above, α / β is 1.2 or more. (4) 13 The mm fraction of propylene unit triads determined by C-NMR analysis is 90% or more. (5) In a temperature rising elution fractionation (TREF) measurement using orthodichlorobenzene as a solvent, the amount of components eluting at temperatures of 90°C or less is 6.0% by weight or less. (6) Propylene polymer 13 It is disclosed that in C-NMR analysis, three methylene carbons (Ca, Cb, Cc) are observed at 44.0-44.1 ppm, 44.7-44.8 ppm, and 44.8-44.9 ppm, and a methine carbon (Cbr) is observed at 31.6-31.7 ppm, and the methine carbon is 0.1 or more per 1000 total backbone carbons (wherein the total backbone carbons means all carbon atoms other than methyl carbons). It is also disclosed that the propylene homopolymer has good melt tension (see Patent Document 5).

[0006] In addition, a method for producing a propylene-based polymer having a strain hardening factor (λmax) of 2.0 or more in melt tension measurement using a catalyst containing specific multiple metallocene compounds has been disclosed. The obtained branched polypropylene has been shown to have good melt tension (see Patent Document 6).

[0007] Patent Document 7 also describes a polypropylene having a multi-branching index (MBI) of at least 0.15, the multi-branching index (MBI) being defined as the slope of the strain hardening index (SHI) as a function of the base 10 logarithm of the Henky strain rate (lg(dε / dt)), where dε / dt is the deformation rate and ε is the Henky strain, and the strain hardening index (SHI) is measured at 180°C, and the strain hardening index (SHI) is the base 10 logarithm (lg(ηE + )) is defined as the slope of polypropylene. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Special Publication No. 2001-525460 [Patent Document 2] Japanese Patent Application Publication No. 10-338717 [Patent Document 3] Special Publication No. 2002-523575 [Patent Document 4] JP 2001-64314 A [Patent Document 5] JP 2007-154121 A [Patent Document 6] JP 2009-57542 A [Patent Document 7] Special Publication No. 2009-533540 Summary of the Invention [Problem to be solved by the invention]

[0009] However, although the branched propylene-based polymers obtained by the macromonomer copolymerization methods disclosed in the above Patent Documents 1 to 6 have high melt tension and are highly suitable for sheet molding, blow molding, thermoforming, foam molding, and the like, there is still a problem that the extensibility of the melt is insufficient. In addition, the branched propylene polymer obtained by the method disclosed in Patent Document 7 has improved mechanical properties by increasing the content of the non-crystalline region, but the strain hardening (SHI@1s -1 ) is not so high that various moldability properties are not fully satisfactory.

[0010] An object of the present invention is to provide a branched propylene polymer which has excellent extensibility when molten while maintaining a melt tension necessary for molding. [Means for solving the problem]

[0011] The present invention relates to the following: <1> ~ <10> Regarding. <1> A branched propylene polymer comprising propylene and 0 mol % to 11 mol % of at least one comonomer selected from ethylene and an α-olefin having 4 or more carbon atoms, the branched propylene polymer having the following properties (1), (2-1) and (3): Property (1): The melt flow rate (MFR) measured at a temperature of 230°C under a load of 2.16 kg is 0.1 g / 10 min to 100 g / 10 min. Property (2-1): The melting point (Tm) measured by differential scanning calorimetry (DSC) is less than 155.0°C. Property (3): The flow activation energy (Ea) kJ / mol and MFR obtained by measuring the dynamic viscoelasticity satisfy the following formula (1). Ea≧-12.5×log(MFR)+66 Equation (1) <2> 2. The branched propylene polymer according to claim 1, further having the following property (2-2): Property (2-2): The difference (Tm-Tc) between the melting point (Tm) and the crystallization temperature (Tc) measured by differential scanning calorimetry (DSC) is greater than 34.0°C and less than 40.0°C. <3> The above-mentioned further has the following characteristic (4-1): <1> or <2> 2. The branched propylene polymer according to claim 1. Characteristic (4-1): In the molecular weight distribution curve obtained by 3D-GPC, the absolute molecular weight M abs The branching index g'(million) is 0.60~0.75. <4> The above-mentioned further has the following characteristic (5-1): <1> ~ <3> 13. The branched propylene polymer according to claim 12. Property (5-1): The ratio (Mz / Mw) of z-average molecular weight (Mz) to weight-average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is 2.0 to 4.0. <5> The above-mentioned further has the following characteristic (5-2): <1> ~ <4> 13. The branched propylene polymer according to claim 12. Property (5-2): In the integrated molecular weight distribution curve obtained by GPC, the ratio (W2 million / W1 million) of the proportion of components having a molecular weight of 2 million or more (W2 million) to the proportion of components having a molecular weight of 1 million or more (W1 million) and the MFR satisfy the following formula (2). (W2 million / W1 million)<-0.05×log(MFR)+0.34 Formula (2) <6> The above-mentioned further has the following properties (6-1) and (6-2). <1> ~ <5> 13. The branched propylene polymer according to claim 12. Characteristics (6-1): 13 The meso triad fraction measured by C-NMR is 95.0% or more and less than 99.0%. Characteristic (6-2): The amount of hetero bonds (2,1 bonds) is in the range of 0 mol % to 0.30 mol %, and the amount of hetero bonds (1,3 bonds) is in the range of 0 mol % to 0.25 mol %. <7> The above-mentioned further has the following characteristic (7): <1> ~ <6> 13. The branched propylene polymer according to claim 12. Characteristics (7): 13 The number of long chain branches measured by C-NMR is 0.1 to 0.5 per 1000 monomers. <8> The above-mentioned further has the following characteristic (8): <1> ~ <7> 13. The branched propylene polymer according to claim 12. Property (8): In an elution curve obtained by temperature rising elution fractionation measurement using o-dichlorobenzene, the amount of components eluted at a temperature of 40° C. or lower is 0.1% by mass to 4.0% by mass. <9> The above-mentioned further has the following characteristic (9): <1> ~ <8> 13. The branched propylene polymer according to claim 12. Property (9): The strain hardening coefficient at a strain rate (dε / dt) of 1.0 / sec is 0.70 to 2.50. <10> The above-mentioned further has the following characteristic (10): <1> ~ <9> 13. The branched propylene polymer according to claim 12. Property (10): The branching index is 0.10 to 1.00. Effect of the Invention

[0012] According to the present invention, there is provided a branched propylene polymer which has excellent extensibility when molten while maintaining the melt tension required for molding. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a graph in which the horizontal axis represents the logarithm of MFR (log(MFR)) and the vertical axis represents Ea, and data on the branched propylene polymers obtained in each of the Examples and Comparative Examples are plotted. [Diagram 2] FIG. 2 is a diagram illustrating the baseline and intervals of a chromatogram in GPC. [Diagram 3] FIG. 3 is a graph in which the horizontal axis represents the logarithm of MFR (log(MFR)) and the vertical axis represents W2 million / W1 million, and data on the branched propylene polymers obtained in each of the Examples and Comparative Examples are plotted. [Figure 4] FIG. 4 is a diagram showing an example of an integrated molecular weight distribution curve. [Diagram 5] FIG. 5 is a graph in which the horizontal axis represents the logarithm of MFR (log(MFR)) and the vertical axis represents the maximum winding speed (MaxDraw) at 230° C., and data on the branched propylene polymers obtained in each Example and Comparative Example are plotted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present inventors specified a branched propylene polymer based on the relationship between the flow activation energy (Ea) and MFR, which is obtained by measuring dynamic viscoelasticity as an index of suitable branching properties, and succeeded in obtaining a branched propylene polymer that has excellent extensibility when molten while maintaining the fluidity and melt tension required for molding.

[0015] The branched propylene polymer of the present invention is a branched propylene polymer comprising propylene and 0 mol % to 11 mol % of at least one comonomer selected from ethylene and an α-olefin having 4 or more carbon atoms, and is characterized by having the following properties (1), (2-1), and (3): Property (1): The melt flow rate (MFR) measured at a temperature of 230°C under a load of 2.16 kg is 0.1 g / 10 min to 100 g / 10 min. Property (2-1): The melting point (Tm) measured by differential scanning calorimetry (DSC) is less than 155.0°C. Property (3): The flow activation energy (Ea) kJ / mol and MFR obtained by measuring the dynamic viscoelasticity satisfy the following formula (1). Ea≧-12.5×log(MFR)+66 Equation (1)

[0016] The branched propylene polymer of the present invention has the above-mentioned properties (1) to (3) and has a high Ea corresponding to the MFR, and therefore is a branched propylene polymer having excellent extensibility when molten while retaining the fluidity and melt tension required for molding.

[0017] When a branched propylene polymer contains a large amount of components that do not relax or components that take a long time to relax, the melt tension increases, but on the other hand, oriented crystallization progresses locally from entanglement points of molecular chains at many points in the polymer, making the oriented crystallization non-uniform, which is thought to result in poor extensibility. In the present invention, the relationship between Ea and MFR has been focused on and specified as an index representing the branching characteristics of a branched propylene polymer that has excellent ductility when molten while maintaining a melt tension necessary for molding. The branched propylene polymer of the present invention has the above properties (1) to (3) and has a high Ea in proportion to the MFR. Although the reason is unclear, it is presumed that the branched propylene polymer of the present invention contains multi-branched molecules having a molecular structure in which many branch chains are introduced in the medium to high molecular weight region, but at the same time has a branching distribution in which the content of components that do not relax or components with long relaxation times is low. The branched propylene polymer of the present invention specified as above shows a relaxation time distribution in which there are many components with a relatively short relaxation time and few components with an extremely long relaxation time, so that local oriented crystallization originating from the entanglement points of molecular chains is unlikely to occur, and it is possible to suppress non-uniformity of oriented crystallization, which is presumed to improve extensibility.

[0018] The present invention will be described in detail below. In this specification, the use of "to" indicating a range of values ​​means that the values ​​before and after the range include the lower limit and upper limit. In this specification, the upper and lower limit values ​​of the numerical ranges may be arbitrarily combined, and the preferred ranges of the respective properties may be arbitrarily combined. In the present invention, logarithms are expressed in the common logarithm sense, ie, to the base 10. In the present invention, "stretchability" refers to the property of a resin being able to stretch widely and thinly and uniformly, or thinly and long and uniformly, in a molten state.

[0019] The branched propylene polymer of the present invention may be a homopolymer of propylene, or a copolymer of propylene and at least one comonomer selected from ethylene and an α-olefin having 4 or more carbon atoms. In the case of a copolymer of propylene and a comonomer, the content of the comonomer in the total monomers is more than 0 mass% and not more than 11 mol%, and the upper limit may be 7.5 mol% or less and the lower limit may be 0.5 mol% or more. The comonomer is, for example, selected from ethylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, and the like.

[0020] I. Physical properties of branched propylene polymers Characteristics (1): The branched propylene polymer of the present invention has a melt flow rate (MFR) of 0.1 g / 10 min to 100 g / 10 min, measured at a temperature of 230° C. under a load of 2.16 kg.

[0021] In the branched propylene polymer of the present invention, if the MFR is too small, the fluidity of the molten resin deteriorates, making it difficult to perform heat molding. Therefore, the MFR is 0.1 g / 10 min or more, preferably 1.0 g / 10 min or more, and more preferably 3.0 g / 10 min or more. On the other hand, if the MFR is too high, it will cause a decrease in melt tension, and therefore the MFR is 100 g / 10 min or less, preferably 80 g / 10 min or less, more preferably 60 g / 10 min or less, and even more preferably 40 g / 10 min or less, and may be 32 g / 10 min or less, or may be 30 g / 10 min or less. In the present invention, the MFR is a value measured by pelletizing a branched propylene polymer and measuring the MFR at 230° C. and a load of 2.16 kgf in accordance with JIS K7210-1:2014 “Plastics - Determination of melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics - Part 1: Standard test method”. The pelletization is performed in the same manner as the “granulation” described in the examples below. The MFR can be adjusted by varying the polymerization temperature and pressure and / or by adding hydrogen or other chain transfer agents during the polymerization.

[0022] Characteristics (2-1): The branched propylene polymer of the present invention has a melting point (Tm) measured by differential scanning calorimetry (DSC) of less than 155.0° C. When the melting point is in this range, the solidification of the molten resin during molding is delayed, and the extensibility during molding is improved. Furthermore, if the melting point (Tm) is less than 155.0° C., the heat sealing temperature can be controlled when the composition is used as a heat sealing material. Tm is preferably 150.0° C. or less, more preferably 145.0° C. or less, and even more preferably 135.0° C. or less. On the other hand, from the viewpoint of heat resistance, Tm is preferably 105.0° C. or higher, more preferably 110.0° C. or higher, even more preferably 115.0° C. or higher, and even more preferably 120.0° C. or higher.

[0023] In the present invention, Tm can be measured using a Seiko Instruments Inc. DSC (DSC6200) by packing 5 mg of a sheet-like sample piece into an aluminum pan, heating it from room temperature to 200°C at a heating rate of 100°C / min, holding it at 200°C for 5 minutes, and then cooling it from 200°C to 40°C at a heating rate of 10°C / min to crystallize it, and determining the maximum crystallization peak temperature (°C) as the crystallization temperature (Tc), and then heating it to 200°C at a heating rate of 10°C / min to melt it, and determining the maximum melting peak temperature (°C) as the melting point (Tm). The sheet-like sample can be obtained by sandwiching the branched propylene polymer powder between press plates, preheating it at 190°C for 2 minutes, pressing it at 5 MPa for 2 minutes, and then cooling it at 0°C and 10 MPa for 2 minutes.

[0024] In the case of a propylene-based polymer, the melting point can be controlled by controlling the crystal thickness, and the crystal thickness is proportional to the regularly inserted propylene chains. In other words, the melting point is lowered by the insertion of ethylene units or regioregular defects. In order to obtain the melting point of the propylene-based polymer of the present invention, the crystal thickness can be controlled and the melting point can be controlled by selecting an optimal complex for regioregular defects as a polymerization catalyst, selecting a combination of multiple complexes, or by selecting the polymerization temperature and pressure, or by inserting a comonomer such as ethylene during polymerization.

[0025] Characteristics (2-2): The branched propylene polymer of the present invention preferably has a difference (Tm-Tc) between the melting point (Tm) and the crystallization temperature (Tc) measured by differential scanning calorimetry (DSC) of more than 34.0°C and less than 40.0°C. If the difference (Tm-Tc) is too small, the polymer will not remain molten for long during molding, narrowing the moldable temperature range. Therefore, from the viewpoint of widening the moldable temperature range, the difference (Tm-Tc) is preferably greater than 34.0°C, more preferably 34.5°C or more, and even more preferably 35.0°C or more. On the other hand, if the difference (Tm-Tc) is too large, the polymer tends to remain in a molten state during molding for a long time, which tends to cause deposits to accumulate, for example, in areas of the mold that are easily heated. Therefore, from the viewpoint of further suppressing deposition, the difference (Tm-Tc) is preferably 39.0°C or less, more preferably 38.0°C or less.

[0026] The melting point (Tm) and crystallization temperature (Tc) are controlled by the amount of heterogeneous bonds (stereoregularity, regioregularity), the isotactic sequence length, and the comonomer content. On the other hand, the fact that the crystallization temperature (Tc) corresponding to the melting point (Tm) is high is due to the contribution of the primary structure other than the amount of heterogeneous bonds (steric regularity, regioregularity) and the isotactic sequence length. In particular, when the polymer has a branched structure, it is believed that the branching points promote crystallization, and the more branches there are, the smaller the difference (Tm-Tc) becomes. Therefore, in order to obtain the above difference (Tm-Tc) in the branched propylene polymer of the present disclosure, the degree of supercooling can be controlled by selecting a complex that optimizes the amount of heterogeneous bonds (stereoregularity, regioregularity), the isotactic sequence length, and the amount of branching, or by using a comonomer.

[0027] Characteristics (3): The branched propylene polymer of the present invention has a flow activation energy (Ea) kJ / mol and MFR obtained by measuring the dynamic viscoelasticity, which satisfy the following formula (1). Ea≧-12.5×log(MFR)+66 Equation (1)

[0028] In general, the viscosity of an object decreases as its temperature increases, and the logarithm of viscosity, lnη, is proportional to the reciprocal of absolute temperature, 1 / T, and it has long been known empirically that it can be expressed by the following formula (Chemical Dictionary, 2nd Edition, "Andrade's Viscosity Formula").

[0029]

number

[0030] This energy term Ea corresponds to the activation energy when the reaction rate in an Arrhenius chemical reaction is considered to be a flow, and is called the flow activation energy. "High Ea" means "the energy required to make the polymer flow is large." In the case of branched propylene polymers, if the amount of branches is large or the branch length is long, the molecular chains become more entangled, and the energy required to make the molecular chains flow is large. In other words, Ea is considered to depend mainly on the amount and length of long chain branches in the polymer. In the present invention, in order to obtain a branched propylene polymer having excellent ductility when melted while maintaining the fluidity and melt tension required for molding, attention is focused on Ea as an index for obtaining appropriate branching properties, and the relationship between Ea and MFR is specified.

[0031] From the viewpoint of branching properties that improve extensibility when melted, the branched propylene polymer of the present invention may have an Ea of 55.0 kJ / mol or more, or 58.0 kJ / mol or more, or on the other hand, may have an Ea of 70.0 kJ / mol or less.

[0032] Satisfying the formula (1) means that the branched propylene polymer of the present invention has an Ea obtained by measuring the dynamic viscoelasticity of at least a specific value in proportion to the MFR. The branched propylene polymer of the present invention has an Ea value corresponding to the MFR different from that of conventional propylene polymers, that is, satisfies formula (1). If Ea is too small in relation to MFR, the ductility during melting is poor. Therefore, the branched propylene polymer of the present invention satisfies the above formula (1). More preferably, it may satisfy the following formula (1-2). Ea≧-12.5×log(MFR)+67 Equation (1-2)

[0033] Generally, when the fluidity of a molten resin is increased, Ea decreases, so it is desirable to have a propylene-based polymer that has both the necessary fluidity and Ea, which is an index of branching characteristics suitable for improving extensibility when melted. A branched propylene-based polymer that has excellent fluidity and satisfies formula (1) is a polymer that could not be achieved with conventional propylene-based polymers, and it can be said that the fluidity and branching characteristics of a molten resin are highly balanced. In addition, the above formula is considered to be a function in which Ea is negatively correlated with an increase in MFR, and an approximate relational expression between Ea and MFR that distinguishes between Examples that can solve the problem and Comparative Examples of the prior art that cannot solve the problem was determined based on the data of Examples and Comparative Examples 1, 2, and 3 that have the same level of fluidity as Examples (see Figure 1).

[0034] The branched propylene polymer of the present invention is presumed to have a high flow activation energy (Ea) relative to the MFR due to branching characteristics including the amount of branching, branching length and branching distribution not found in conventional propylene polymers. It is believed that when Ea is high relative to MFR, the extrusion load during molding can be reduced more than that of a branched propylene polymer having the same MFR. Since the branched propylene polymer of the present invention satisfies the above formula (1), it is possible to reduce the extrusion load during molding and to increase the extensibility.

[0035] The upper limit of Ea in relation to the MFR is not particularly limited, but may satisfy the following formula (1-3) or may satisfy the following formula (1-4). Ea≦-12.5×log(MFR)+82 Equation (1-3) Ea≦-12.5×log(MFR)+72 Equation (1-4)

[0036] Ea is a value calculated from the shift factor (aT) when creating a master curve based on the temperature-time superposition principle in the measurement of melt viscoelasticity by the Arrhenius equation. In the present invention, the master curve is a curve showing the angular frequency (unit: rad / sec) dependency of the melt complex viscosity (unit: Pa·sec) at 200°C. Ea can be determined by the following method. First, for three temperatures of 180°C, 200°C, and 220°C, the melt complex viscosity-angular frequency curve of the branched propylene polymer at each temperature (T, unit: °C) is obtained. Based on the temperature-time superposition principle, each melt complex viscosity-angular frequency curve is superimposed on the melt complex viscosity-angular frequency curve at 200°C to obtain each shift factor (aT). From each temperature (T) and aT at each temperature (T), a linear approximation equation (the following equation (3-1)) of [ln(aT)] and [1 / (T+273.16)] is calculated by the least squares method. Next, Ea is obtained from the slope m of the linear equation and the following equation (3-2). ln(aT)=m(1 / (T+273.16))+n Formula (3-1) Ea = |0.008314 × m| Equation (3-2) aT: Shift factor Ea: Flow activation energy (unit: kJ / mol) T: Temperature (unit: ℃) The above calculations may be carried out using commercially available software, such as Trios manufactured by TA Instruments. Note that aT is the amount of movement in the x-axis direction when the log-log curve of melt complex viscosity vs. angular frequency at each temperature (T) is moved in the x-axis (angular frequency) and y-axis (melt complex viscosity) directions and superimposed on the melt complex viscosity vs. angular frequency curve at 200°C. The melt complex viscosity-angular frequency curve is measured using a viscoelasticity measuring device (for example, ARES-G2 manufactured by TA Instruments) under a nitrogen atmosphere under the following conditions. The propylene polymer is compression molded at 180°C for 5 minutes while being careful not to trap air bubbles, to obtain a disk-shaped measurement sample having a thickness of 2.0 mm and a diameter of 25 mm. Measurements of the sample are performed at three temperatures, 180°C, 200°C, and 220°C, using parallel disks having a diameter of 25 mm that are kept at each temperature, after which the measurement sample having a thickness of 2.0 mm is compressed to a thickness of 1.5 mm. Geometry: Parallel plate Plate diameter: 25mm Plate spacing: 2mm Strain: 5% Angular frequency: 0.01~100rad / sec

[0037] In the present invention, the Ea and MFR of the branched propylene polymer can satisfy the above formula (1) by adjusting the polymerization conditions, such as the selection of the catalyst type, the polymerization temperature, the monomer concentration, the amount of hydrogen, etc., as described in detail later. Among these, the adjustment is preferably performed by selecting the catalyst type, and although there is no particular limitation, it is appropriate to adjust the Ea and MFR by selecting the catalyst type in a macromonomer copolymerization method using a catalyst containing a plurality of metallocene compounds. On the other hand, when a single catalyst is used, it is considered very difficult to satisfy all of the following: high macromonomer copolymerizability, high molecular weight of macromonomer, and high production ratio of macromonomer. Therefore, when the above single catalyst is used, the amount of long chain branch (LCB) in the polymer is small, or the length of the branch is short, so that Ea is considered to be small. For example, as shown in Reference Example 2, when the terminal vinyl ratio is low, that is, when the production ratio of macromonomer in the polymer is low and the amount of LCB is small, Ea is small.

[0038] Characteristics (4-1): The branched propylene polymer of the present invention has an absolute molecular weight M abs It is preferable that the branching index g' (1 million) is 0.60 to 0.75. The branching index g' is the intrinsic viscosity [η] of a polymer with a long chain branching structure. br Intrinsic viscosity [η] of a linear polymer with the same molecular weight lin Ratio to ([η] br / [η] lin) When a polymer molecule has long chain branches, it has a smaller radius of gyration and a smaller intrinsic viscosity than a linear polymer molecule of the same molecular weight, so g' is smaller than 1.0. Also, even if the amount of branching is the same, if the branch length is long, it has a smaller radius of gyration and a smaller intrinsic viscosity than a linear polymer molecule of the same molecular weight, so g' is smaller than 1.0. Linear polymers, by definition, have a g' of 1.0. The definition of g' is described in "Developments in Polymer Characterization-4" (JV Dawkins ed. Applied Science Publishers, 1984), and is a known indicator for those skilled in the art. g' was determined by using 3D-GPC. abs can be obtained as a function of In this specification, 3D-GPC refers to a GPC apparatus to which three detectors are connected. The three detectors are a differential refractometer (RI), a viscosity detector (Viscometer) and a multi-angle laser light scattering detector (MALLS).

[0039] The branched propylene polymer of the present invention has an absolute molecular weight M abs Weight average molecular weight (Mw abs ) may be less than 1 million, and Mw abs From M abs It is considered that a branched structure in the high molecular weight region of 1,000,000 is preferable in terms of having a high melt tension. Therefore, the branched propylene polymer of the present invention has a g' (1 million) of preferably 0.75 or less, more preferably 0.74 or less, and further preferably 0.72 or less. abs If the branched structure is present in an appropriate amount in the high molecular weight region of g'(1 million) and the branched chain length of the introduced branched structure is appropriate, it is considered that the amount of components with extremely long relaxation times is prevented from increasing too much, and extensibility can be maintained. Therefore, g'(1 million) is preferably 0.60 or more, more preferably 0.62 or more, and even more preferably 0.65 or more. The branched propylene polymer of the present invention has M abs It is believed that the amount of components with branched structures in the molecular weight region of 100,000,000 is appropriately large within a specific range, which increases the melt strength and increases the strain hardening index (SHI) and melt tension (MT) in the measurement of extensional viscosity as nonlinear viscoelastic properties. Even if the number of branches is large as a whole polymer, the amount of M corresponding to the high molecular weight component is abs If the amount of components having branches in the M = 1 million portion is small, it is difficult to increase the SHI. abs = 1 million, and further, if the branched chain length of the introduced branched structure is not too long, it is believed that deterioration of ductility can be suppressed.

[0040] Characteristics (4-2): It is believed that the branched propylene polymer of the present invention can maintain extensibility by the moderate presence of components having a long relaxation time, as in the case of the above characteristic (4-1). abs Branching index g'(Mw abs ) may be 0.70 to 0.90. g'(Mw abs The lower limit of may be 0.73 or more, or 0.75 or more, and the upper limit may be 0.87 or less, or 0.86 or less.

[0041] Characteristics (4-3): The branched propylene polymer of the present invention has a molecular weight distribution curve obtained by 3D-GPC, and has a molecular weight distribution curve of g'(Mw abs ) and g' (1 million) may satisfy the following formula (4-1). 0.10≦g'(Mw abs )-g'(1 million) Formula (4-1) As described above, in the branched propylene polymer of the present invention, g'(Mw abs It is believed that the large difference between g(1) and g'(1 million) results in a larger number of components with longer relaxation times, which in turn increases the melt strength. Furthermore, the branched propylene polymer of the present invention has a molecular weight distribution curve obtained by 3D-GPC, in which g'(Mw abs ) and g' (1 million) may satisfy the following formula (4-2). g'(Mw abs )-g'(1 million)≦0.20 Formula (4-2) As described above, in the branched propylene polymer of the present invention, g'(Mw abs It is considered preferable that the difference between g(1) and g'(1 million) is not too large, since this prevents the proportion of components with extremely long relaxation times from becoming too high, thereby improving extensibility. In addition, the branched polypropylene polymer of the present invention is considered to be preferable since the branching distribution is within the above range, making it possible to maintain a balance between melt strength and extensibility as a whole.

[0042] M abs The method for measuring the molecular weight distribution and the branching index at each molecular weight is as follows: The detectors are connected in the order of MALLS, RI, and Viscometer. Equipment: Alliance GPCV2000 (GPC equipped with RI and Viscometer) manufactured by Waters, DAWN-E (MALLS) manufactured by Technology Column: Tosoh GMHHR-H(S)HT (2 columns) Mobile phase solvent: 1,2,4-trichlorobenzene (with antioxidant Irganox 1076 (BASF Japan) added at a concentration of 0.5 mg / mL) ·Measurement temperature: 140℃ ·Flow rate: 1mL / min Sample concentration: 1mg / mL ·Injection volume: 0.2175mL M obtained from MALLS abs The root mean square radius of gyration (Rg) and the intrinsic viscosity ([η]) obtained from the Viscometer are calculated using the data processing software ASTRA (version 4.73.04) attached to MALLS, with reference to the following literature. References: 1.Developments in Polymer Characterization, vol.4. Essex: Applied Science; 1984. Chapter1. 2.Polymer, 45, 6495-6505(2004) 3.Macromolecules, 33, 2424-2436(2000) 4.Macromolecules, 33, 6945-6952(2000) g' is the intrinsic viscosity ([η] br ) and the intrinsic viscosity ([η] obtained by separately measuring a linear polymer lin ) and the ratio ([η] br / [η] lin ) is calculated as follows. Here, a commercially available homopolypropylene (Novatec PP (registered trademark) manufactured by Japan Polypropylene Corporation, grade name: FY6) was used as the linear polymer, and [η] lin [η] of linear polymer lin The logarithm of [η] has a linear relationship with the logarithm of the molecular weight, as known from the Mark-Houwink-Sakurada equation. lin can be obtained by extrapolating to the low molecular weight side or the high molecular weight side as appropriate.

[0043] In the present invention, the g'(million) and g'(Mw abs ), g'(Mw abs As explained in the characteristic (3), )-g' (million) can be adjusted by adjusting the polymerization conditions, such as the selection of the catalyst type, the polymerization temperature, the monomer concentration, the amount of hydrogen, etc. Among them, it is preferable to adjust it by selecting the catalyst type, and although there is no particular limitation, it is appropriate to adjust it by selecting the catalyst type in a macromonomer copolymerization method using a catalyst containing a plurality of metallocene compounds.

[0044] Among them, g'(Mw absIt is preferable that the condition where (g)-g' (million) satisfies the formula (4-1) or (4-2) is adjusted by selecting a catalyst from a plurality of catalyst species or a plurality of metallocene compounds. For example, when a catalyst consisting of a single catalyst type or a single metallocene compound (hereinafter, collectively referred to as a single catalyst) is used instead of a catalyst consisting of multiple catalyst types or multiple metallocene compounds, it is considered that formula (4-1) or formula (4-2) is not satisfied. With a single catalyst, the molecular weight distribution of the macromonomer produced is narrow, and macromonomers with significantly different molecular weights are not supplied, so the value of formula (4-1) is expected to be small, or the value of formula (4-2) to be large. To explain this using Reference Example 2 as an example (see Table 2), g'(Mw abs ) is large, so Mw abs Since there are no components with short branched chains, it is estimated that the molecular weight of the macromonomer produced by this catalyst is high. On the other hand, since g' (1 million) is small, it is assumed that the molecular weight of the macromonomer produced by this catalyst is high. abs It is estimated that there are branched components due to macromonomers with large molecular weights in the range of g'(Mw = 1 million). Thus, in a single catalyst that produces macromonomers with a narrow molecular weight distribution, for example, abs )-g' (million) becomes large and equation (4-2) is not satisfied.

[0045] Characteristics (5-1): The branched propylene polymer of the present invention preferably has a ratio (Mz / Mw) of z-average molecular weight (Mz) to weight-average molecular weight (Mw) obtained by gel permeation chromatography (GPC) of 2.0 to 4.0. Mz, Mw, and number average molecular weight (Mn) are each indices that represent the average molecular weight of a polymer. Mz is an index of the average molecular weight with a high specific gravity on the high molecular weight side, Mn is an index of the average molecular weight with a high specific gravity on the low molecular weight side, and Mw is an index of the average molecular weight in between. In addition, the respective ratios, Mw / Mn and Mz / Mw, are indices of the spread of the molecular weight distribution of the polymer.

[0046] In the branched propylene polymer, from the viewpoints of the presence of an appropriate amount of components having a long relaxation time and suppressing a decrease in melt tension, Mz / Mw is preferably 2.0 to 4.0. The upper limit of Mz / Mw of the branched propylene polymer of the present invention is more preferably 3.6 or less, further preferably 3.4 or less, and even more preferably 3.2 or less. The lower limit of Mz / Mw of the branched propylene polymer of the present invention is more preferably 2.3 or more, further preferably 2.8 or more, and even more preferably 2.9 or more. It is believed that the branched propylene polymer of the present invention has the above-mentioned molecular weight distribution characteristics, and therefore the amount of components having an extremely long relaxation time can be reduced, thereby improving the extensibility. The branched propylene polymer of the present invention may have a ratio of Mw to Mn (Mw / Mn) obtained by GPC of 3.0 to 7.0. When Mw / Mn is in this range, the amount of components having an extremely long relaxation time is prevented from increasing too much, and the melt tension is maintained. Thus, the upper limit of Mw / Mn of the branched propylene polymer of the present invention may be 7.0 or less, 6.0 or less, 5.0 or less, 4.5 or less, or 4.3 or less. On the other hand, the lower limit of Mw / Mn may be 3.0 or more, 3.2 or more, or 3.3 or more, from the viewpoint of preventing a decrease in melt tension. Furthermore, from the viewpoint of fluidity of the molten resin, the Mw of the branched propylene polymer of the present invention may be 150,000 to 350,000, 180,000 to 330,000, or 190,000 to 320,000.

[0047] The values ​​of Mz, Mw, Mn, Mw / Mn, and Mz / Mw are all obtained by GPC. The details of the measurement method and measuring equipment are as follows. Apparatus: Waters GPC (ALC / GPC, 150C) Detector: FOXBORO MIRAN, 1A, IR detector (measurement wavelength: 3.42 μm) Column: Showa Denko AT-806MS (3 columns) Mobile phase solvent: o-dichlorobenzene (ODCB) ·Measurement temperature: 140℃ ·Flow rate: 1.0mL / min ·Injection volume: 0.2mL The measurement sample is prepared as follows: A 1 mg / mL solution is prepared using the sample and ODCB (containing 0.5 mg / mL dibutylhydroxytoluene (BHT)), and the sample is dissolved at 140° C. for about 1 hour to prepare the measurement sample. The baseline and intervals of the obtained chromatogram are defined as shown in Figure 2. The retention volume obtained by GPC measurement is converted to molecular weight using a calibration curve prepared in advance using standard polystyrenes, all of which are the following brands manufactured by Tosoh Corporation: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, and A1000. Each standard was dissolved in ODCB (containing 0.5 mg / mL BHT) to a concentration of 0.5 mg / mL, and 0.2 mL of the solution was injected to create a calibration curve. The calibration curve was calculated using a cubic equation obtained by approximating the curve using the least squares method. Viscosity formula used for conversion to molecular weight: [η] = K × M α The following numerical values ​​are used: PS:K=1.38×10 -4 , α=0.7 PP:K=1.03×10 -4 , α=0.78

[0048] The average molecular weight, molecular weight distribution (Mz, Mw, Mn, Mw / Mn, Mz / Mw) and balance thereof of the branched propylene polymer measured by GPC can be adjusted by the polymerization conditions, such as the selection of catalyst type, polymerization temperature, monomer concentration, amount of hydrogen, etc., as described in the characteristic (3).

[0049] Characteristics (5-2): In the branched propylene polymer of the present invention, in an integrated molecular weight distribution curve obtained by GPC, the ratio (W2 million / W1 million) of the proportion of components having a molecular weight of 2 million or more (W2 million) to the proportion of components having a molecular weight of 1 million or more (W1 million) and the MFR preferably satisfy the following formula (2): (W2 million / W1 million)<-0.05×log(MFR)+0.34 Formula (2) W2 million / W1 million is the ratio of the amount of components in the high molecular weight region to the amount of components with even higher molecular weights. The above formula (2) is considered to be a function in which W2 million / W1 million is negatively correlated with an increase in MFR, and based on data from examples and comparative examples having the same level of MFR as the examples, an approximate relationship between W2 million / W1 million and MFR that distinguishes between examples that can solve the problem and comparative examples of the prior art that cannot solve the problem was determined (see FIG. 3). Satisfying the formula (2) means that W2 million / W1 million is less than a specific value in terms of MFR. In other words, it means that the amount of components with a molecular weight of 2 million or more, which is higher than the amount of components with a molecular weight of 1 million or more, is relatively small. When W2 million / W1 million is in the above range in terms of MFR, it is considered that the amount of components having a long relaxation time is prevented from becoming too large, and extensibility is maintained. Therefore, it is preferable that the branched propylene polymer of the present invention satisfies the above formula (2). The branched propylene polymer of the present invention more preferably satisfies the following formula (2-2), and further preferably satisfies the following formula (2-3). (W2 million / W1 million)<-0.05×log(MFR)+0.28 Formula (2-2) (W2 million / W1 million)<-0.05×log(MFR)+0.20 Formula (2-3)

[0050] In addition, the branched propylene polymer of the present invention may have a W1 million of 1.00% by mass or more and 9.50% by mass or less. It is believed that the melt tension of the branched propylene polymer of the present invention is increased due to the presence of components in the high molecular weight range. Therefore, in the present invention, attention is focused on components having a molecular weight of 1 million or more, and the branched propylene polymer of the present invention may have a W1 million of 1.00 mass% or more, or may have a W1 million of 2.00 mass% or more. On the other hand, it is believed that the presence of an appropriate amount of components in the high molecular weight range maintains an appropriate amount of components with long relaxation times and maintains extensibility. Therefore, W1 million may be 9.50 mass% or less, 8.00 mass% or less, 6.00 mass% or less, or 5.00 mass% or less.

[0051] Furthermore, the branched propylene polymer of the present invention may have a W2 million of 2.00 mass % or less. As in the above, it is believed that the presence of an appropriate amount of components in the very high molecular weight range maintains the components with extremely long relaxation times appropriately, and also maintains extensibility. Therefore, in the present invention, attention is focused on components with a molecular weight of 2 million or more, and the branched propylene-based polymer of the present invention may have a W2 million of 2.00 mass% or less, 1.00 mass% or less, or 0.70 mass% or less. The branched propylene-based polymer of the present invention may have a W2 million of 0.05 mass% or more.

[0052] Furthermore, in the branched propylene polymer of the present invention, W2 million / W1 million may be 0.25 or less, 0.20 or less, or 0.17 or less. As mentioned above, when W2 million / W1 million is within the above range, it is believed that the components with long relaxation times are prevented from becoming too numerous, and ductility is maintained. In the branched propylene polymer of the present invention, W2 million / W1 million may be 0.02 or more, 0.03 or more, or 0.05 or more.

[0053] In the present invention, W1 million and W2 million are defined as the value obtained by subtracting from 1 the integral value up to a molecular weight (M) of 1 million (Log(M)=6.0) and up to a molecular weight (M) of 2 million (Log(M)=6.3) in an integrated molecular weight distribution curve (total amount normalized to 1) obtained by GPC, and multiplying the result by 100. An example of an integrated molecular weight distribution curve is shown in FIG. In the present invention, W1 million and W2 million of the branched propylene polymer can be adjusted by polymerization conditions such as the selection of catalyst type, polymerization temperature, monomer concentration, amount of hydrogen, etc., as explained in the characteristic (3).

[0054] Characteristics (6-1): The branched propylene polymer of the present invention is 13 The meso triad fraction (mm) measured by C-NMR is preferably 95.0% or more and less than 99.0%. Characteristics (6-2): In addition, the branched propylene polymer of the present invention preferably has a heterogeneous bond ([2,1 bond]) content of 0 mol % to 0.30 mol %, and a heterogeneous bond ([1,3 bond]) content of 0 mol % to 0.25 mol %.

[0055] The crystallinity of branched propylene polymers is affected by stereoregularity, which is indicated by the mesotriad fraction (mm) and mesopentad fraction (mmmm), and by regioregularity, which is indicated by [2,1 bond] and [1,3 bond]. In other words, crystallization proceeds by folding back lamellae from the irregularity-defective parts (sterically irregular bonds and heterogeneous bonds). When the branched propylene polymer of the present invention has stereoregularity and regioregularity within the above ranges, it is believed that the fluidity of the resin during gradual cooling and solidification during molding and the melt tension during solidification are improved due to a crystallization process caused by shear or elongation deformation.

[0056] In order to improve the melt tension of the branched propylene polymer when solidified, the mm of the branched propylene polymer of the present invention is preferably 95.0% or more, more preferably 96.0% or more, and even more preferably 97.0% or more. On the other hand, if mm is too high, the rigidity and Young's modulus become high, and the film may become too stiff. Therefore, mm of the branched propylene polymer of the present invention is preferably less than 99.0%, preferably 98.5% or less, and more preferably 98.2% or less.

[0057] Similarly, from the viewpoint of improving the melt tension during solidification, the amount of [2,1 bond] in the branched propylene polymer of the present invention is preferably 0 mol% to 0.30 mol%, more preferably 0 mol% to 0.25 mol%, even more preferably 0 mol% to 0.20 mol%, even more preferably 0.030 mol% to 0.25 mol%, and particularly preferably 0.05 mol% to 0.20 mol%. The upper limit of the amount of [2,1 bond] may be 0.15 mol% or less. In combination with the amount of [2,1 bond], the amount of [1,3 bond] in the branched propylene polymer of the present invention is preferably 0 mol% to 0.25 mol%, more preferably 0 mol% to 0.20 mol%, even more preferably 0 mol% to 0.15 mol%, even more preferably 0.05 mol% to 0.20 mol%, and particularly preferably 0.10 mol% to 0.15 mol%.

[0058] 13 The methods for measuring and calculating the amounts of mm, [2,1 bond] and [1,3 bond] measured by C-NMR are as follows. A 200 mg sample is placed in an NMR sample tube with an inner diameter of 10 mm together with 2.4 ml of o-dichlorobenzene / deuterated bromide benzene (C6D5Br) = 3 / 1 (volume ratio) and hexamethyldisiloxane, a chemical shift standard substance, and dissolved uniformly in a block heater at 150 °C to prepare a measurement sample. ( 1 H-NMR) Equipment: Bruker Biospin AV400 NMR system Probe: 10mmφ cryo-probe Sample temperature: 120℃ Pulse angle: 4.5° Pulse Interval: 2 seconds Number of times of accumulation: 1024 times Chemical shift: The chemical shift is set to 0.09 ppm for the proton signal of hexamethyldisiloxane, and the chemical shifts of the signals due to other protons are based on this. ( 13 C-NMR) Equipment: Bruker Biospin AV400 NMR system Probe: 10mmφ cryo-probe Sample temperature: 120℃ Pulse angle: 45° Pulse Interval: 18.0 seconds Number of times: 3072 Decoupling conditions: Broadband decoupling method Chemical shift: Chemical shifts of hexamethyldisiloxane 13 The C signal was set to 1.98 ppm, and the other 13 The chemical shifts of the C signals are based on this.

[0059] <stereoregularity> The meso triad fraction (mm) of three propylene units is 13 Measured by C-NMR 13 The integrated intensity of the C signal is calculated by substituting it into the following equation (5). mm(%)=I mm ×100 / (I mm +I mr+rm +I rr ) Formula (5) Here I mm is assigned to the mm bonding mode of three propylene units. 13 The integrated intensity of the C signal is shown in Fig. 1. The integrated intensity of the signal with a chemical shift in the range of 23.6 to 21.1 ppm (hereinafter referred to as "I 23.6~21.1 " is used as the calculation. Spectral assignment can be done with reference to Polymer Jounral, vol. 16, p. 717 (1984), Asakura Publishing, Macromolecules, vol. 8, p. 687 (1975), and Polymer, vol. 30, p. 1350 (1989). The chemical shift range shifts slightly depending on the molecular weight of the polymer, but it is easy to distinguish the regions.

[0060] A specific method for determining the mesotriad fraction (mm) is described below. The signals derived from the methyl group of the central propylene unit of the head-to-tail (1,2 bond) triplet chain centered on a propylene unit occur in three regions depending on their configuration. I mm =:I 24.3~21.1 I mr+rm =:I 21.1~20.5 I rr =:I 20.5~19.8 Although the chemical shift range of each region shifts slightly depending on the molecular weight and monomer composition of the copolymer, the above three regions are easily distinguishable. Here, mm, mr+rm and rr are represented by the following structural formulas (1-a) to (1-c), respectively.

[0061] [ka]

[0062] In addition, the following structural formulae (2-a) to (2-d) may be present as partial structures containing positionally irregular units resulting from heterogeneous bonds such as 2,1 bonds and 1,3 bonds. Structural formulas (2-a), (2-a), and (2-a) are structures based on a 1,2 bond, and structural formula (2-d) is a structure based on a 1,3 bond.

[0063] [ka]

[0064] Of these, the carbon A, A', A'', and T signals appear in the mr+rm region, and the carbon B and B' signals appear in the rr region. It should be noted that the carbon C and C' signals appear in the vicinity of 17.5 to 17.1 ppm, but since they are not related to the mm, mr+rm, and rr regions of interest, they need not be taken into consideration. Therefore, when calculating the mm fraction according to the above formula (5), it is necessary to subtract the signal areas based on carbons A, A', A'', B, B', and T that are not based on head-to-tail bonded triads from the signal areas in the mr+rm region and the rr region, respectively.

[0065] The signal area based on carbon A can be evaluated from formula (6-1) using the signal areas of carbon C (resonating at about 17.1 ppm), carbon C' (resonating at about 17.5 ppm), carbon E (resonating at about 35.7 ppm), carbon G (resonating at about 35.8 ppm), and carbon D (resonating at about 42.1 ppm) in the positional irregular partial structure [structural formula (2-a)]. I A =(I C +I C’ +I E +I G +I D ) / 5 formula (6-1)

[0066] The signal area based on carbon A' can be evaluated from formula (6-2) using the signal areas of carbons H and I (resonating near 34.7 to 34.5 ppm) of the regioregular partial structure [structural formula (2-b)]. I A’ =(I H +I I ) / 2 formula (6-2)

[0067] The signal area based on carbon B can be evaluated from formula (6-3) using the signal areas of carbons H and I (resonating near 34.7 to 34.5 ppm) of the regioirregular partial structure [structural formula (2-b)]. I B =(I H +I I ) / 4 formula (6-3) The signal areas based on carbon A″ and carbon B′ can be evaluated from formula (6-4) using the signal areas of carbons O and N (resonating at around 34.9 ppm) of the regioirregular partial structure [structural formula (2-c)]. I A” =I B’ =I O,N / 2 formula (6-4) The signal area due to carbon T can be evaluated using the signal area of ​​carbon L (resonating at around 27.6 ppm) from equation (6-5). I T =I L Formula (6-5)

[0068] The branched propylene polymer of the present invention may have a partial structure represented by the following structural formulas (3-a) to (3-b).

[0069] [ka]

[0070] The methyl group of the central propylene unit of the partial structure PPE+EPP (PPE+EPP-methyl group) resonates in the mr+rm region, and the methyl group of the central propylene unit of the partial structure EPE (EPE-methyl group) resonates in the rr region. Therefore, when such partial structures are present, it is necessary to subtract the signal areas based on the PPE+EPP-methyl group and the EPE-methyl group from the signal areas in the mr+rm and rr regions. The signal area based on the PPE+EPP-methyl groups can be evaluated from the signal area of ​​the corresponding methine group (resonating at about 30.8 ppm), and the signal area based on the EPE-methyl group can be evaluated from the signal area of ​​the corresponding methine group (resonating at about 33.2 ppm).

[0071] From the above, the signal areas of mm, mr+rm, and rr can be evaluated, and the mm fraction of the three-unit sequence consisting of head-to-tail bonds with the propylene unit at the center can be calculated according to the above formula (5).

[0072] <Positional regularity> The amount of [2,1 bond] and [1,3 bond] is 13 Measured by C-NMR 13 It is calculated using the integrated intensity of the C signal according to the following formula. [2,1 bond] amount (mol%)=I 2,1-P ×100 / (I 1,2-P +I 2,1-P +I1,3-P ) [1,3 bond] amount (mol%)=I 1,3-P ×100 / (I 1,2-P +I 2,1-P +I 1,3-P ) Here, I 1,2-P Resonates in the 49.0-44.4 ppm region, which is assigned to the [1,2 bond] of the propylene unit. 13 Integrated intensity of C signal, I 2,1-P is the signal intensity assigned to the [2,1 bond] represented by structural formulas (2-a) to (2-c), I 1,3-P can be evaluated from formulas (7-1) to (7-3) based on the signal intensity assigned to the [1,3 bond] represented by structural formula (2-d). I 1,2-P =I 49.0~44.4 Formula (7-1) I 2,1-P =I A +I B +I A’’ Formula (7-2) I 1,3-P =I T / 2 formula (7-3)

[0073] Characteristics (6-3): In addition, the branched propylene polymer of the present invention preferably has an ethylene content of 0 mol % to 11 mol %. The ethylene content can be calculated by the following formula. Ethylene content (mol%) = I E ×100 / (I E +I P ) Here, I P is the value calculated using formulas (7-1) to (7-3). I P =I 1,2-P +I 2,1-P +I 1,3-P ) I E represents a characteristic value of ethylene based on bonding with ethylene, and is the quantity shown by the following formula: I E =(I 25.0~24.0 +I 30.0~29.8 +I O,N ) / 2+(I38.2~37.2 -I T +3×I 27.3~27.1 +I 30.5.~30.2 -I A -I npr +I H +I I ) / 4

[0074] Characteristics (7): The branched propylene polymer of the present invention is 13 The number of long chain branches measured by C-NMR is preferably 0.1 to 0.5 per 1000 monomers.

[0075] [ka] [In structural formula (A), P 1 , P 2 , P 3 are propylene-based polymer residues, each having more than one propylene unit, C br indicates the methine carbon at the root of a branched chain having 7 or more carbon atoms, and C a , C b , C c is the methine carbon (C br ) to indicate the methylene carbon adjacent to the

[0076] In the structural formula (A), the main chain of the propylene polymer is P 1 -C br -P 2 Line, P 1 -C br -P 3 Line or P 2 -C br -P 3 Therefore, there are three types of lines, C br -P 3 Line C br -P 2 Line or C br -P 1 The line can be the branched chain. 1 , P 2 , P 3 In itself, C described in structural formula (A)br Another branched carbon (C br ) may also be included. Here, the assignment of the LCB structure is 13 C-NMR revealed three methylene carbons (C a , C b , C c ) was observed, and methine carbon (C br ) is observed as C br It is characterized by the fact that the three adjacent methylene carbons are observed to be separated into three diastereotopic, unequal carbons.

[0077] Also, the LCB number is: 13 The methine carbon at the base of a branched chain with 7 or more carbon atoms per 1,000 monomer units (C br ) is the number of Branched chains with more than 6 carbon atoms can be distinguished from branched chains with 6 or fewer carbon atoms by the difference in the peak position of the methine carbon at the base of the branch (see Macromol. Chem. Phys. 2003, Vol. 204, p. 1738).

[0078] [How to calculate the number of long chain branches (LCB number)] The number of long chain branches (LCB number) is the number of three methylene carbons (C a , C b , C c ) and the average of the signal integrated intensities of the methine carbon (Cbr) at 31.8 to 31.6 ppm, calculated using the following formula, and expressed as the number per 1,000 propylene monomer units. LCB=[(I 44.1~43.9 +I 44.8~44.7 +I 44.9~44.8 +I 31.8~31.6 ) / 4] / I 49.0~44.4

[0079] The characteristic (7) can be satisfied by adjusting the polymerization conditions, such as the selection of the catalyst type, the polymerization temperature, the monomer concentration, the amount of hydrogen, etc., in the same manner as explained for the characteristic (3).

[0080] Characteristics (8): In the branched propylene polymer of the present invention, the amount of components eluted at a temperature of 40° C. or lower is preferably 0.1 to 4.0% by mass in an elution curve obtained by temperature rising elution fractionation (TREF) measurement by ODCB. The components that dissolve at 40° C. or less are low-crystalline components, and if the amount of these components in a branched propylene polymer is large, the crystallinity decreases, and the heat resistance and rigidity of the product may decrease. Also, if the amount of these components is small, the rigidity of the film formed may be too high or the touch may be poor. Therefore, the amount of components eluted at a temperature of 40° C. or less from the branched propylene polymer of the present invention is preferably 4.0 mass% or less, more preferably 2.5 mass% or less, even more preferably 2.0 mass% or less, still more preferably 1.0 mass% or less, and particularly preferably 0.7 mass% or less. On the other hand, if the amount of components eluted at 40° C. or less is too small, for example, when laminated, the rigidity may become too high, resulting in poor tactile sensation such as touch, etc. Therefore, the amount of components eluted at temperatures of 40° C. or less from the branched propylene polymer of the present invention is preferably 0.1% by mass or more, more preferably 0.2% by mass or more.

[0081] Details of the method for measuring the eluted components using TREF are as follows. The sample is dissolved in ODCB at 140°C to obtain a solution. This is introduced into a TREF column at 140°C, and then cooled to 100°C at a rate of 8°C / min, and then cooled to 40°C at a rate of 4°C / min, and then held for 10 minutes. The column is then maintained at 40°C for 10 minutes, and then heated linearly from 40°C to 140°C at a rate of 100°C / 60 minutes, while the solvent ODCB is passed through the column at a flow rate of 1mL / min for 60 minutes to elute the sample and obtain an elution curve. The ratio of the amount of components eluted at 40°C to the total amount of elution is taken as the amount (mass%) of components eluted at temperatures below 40°C. Column size: 4.3mmφ×150mm Column packing material: 100μm surface deactivated glass beads Solvent:ODCB Sample concentration: 5mg / mL Sample injection volume: 0.1mL Solvent flow rate: 1mL / min Detector: FOXBORO MIRAN, 1A, IR detector (measurement wavelength: 3.42 μm)

[0082] The soluble content of branched propylene polymers at 40°C or less in TREF by ODCB can generally be kept low by using a metallocene compound as a polymerization catalyst component. In addition to keeping the content of isomers of the complex in the catalyst low, it is preferable to gently contact the metallocene catalyst with the organoaluminum compound during the production of the catalyst and not to set the reaction conditions during polymerization at extremely high temperatures.

[0083] Characteristics (9): The branched propylene polymer of the present invention has a strain hardening coefficient (SHI@1s -1 ) is preferably 0.70 to 2.50. Here, SHI@1s -1 is the extensional viscosity (η E In the measurement of the Hencky strain (ε) between 1 and 3, the horizontal axis is the logarithm of the Hencky strain (log(ε)) and the vertical axis is the logarithm of the extensional viscosity (log(η E ) is the slope when plotting From the viewpoint of increasing the melt tension to improve moldability and improving extensibility, the SHI@1s of the branched propylene polymer of the present invention is -1 is preferably from 0.70 to 2.50, more preferably from 0.80 to 2.00, and further preferably from 1.00 to 1.80. The branched propylene polymer is SHI@1s -1When SHI@1s is relatively large, the extensional viscosity increases due to the presence of components in the polymer that do not relax at high strain rates. Therefore, linear polymers that do not have strain hardening at high strain rates and SHI@1s -1 Compared to polymers with a smaller elongational viscosity, the melt tension is increased due to the higher elongational viscosity, which is thought to improve moldability in sheet molding, blow molding, thermoforming, and foam molding. From this viewpoint, the branched propylene polymer of the present invention is SHI@1s -1 It is preferable that the ratio is 0.70 or more. The branched propylene polymer is SHI@1s -1 When SHI@1s is appropriately large, the amount of components that do not relax or components that relax for a long time is appropriately maintained, and the local progression of oriented crystallization starting from the entanglement points of molecular chains is suppressed, and extensibility is maintained. From this viewpoint, the branched propylene polymer of the present invention has SHI@1s -1 It is preferable that the ratio is 2.50 or less.

[0084] The strain hardening index (SHI) can be determined by measuring the uniaxial extensional viscosity as described in Polymer, Vol. 42, p. 8663 (2001). In the present invention, SHI@1s -1 is measured by the following method. Equipment: TA Instruments ARES-G2 Fixture: TA Instruments Extensional Viscosity Fixture ·Measurement temperature: 180℃ ·Strain rate: 1.0 / sec - Preparation of test specimen: A sheet of 18 mm x 10 mm and 0.7 mm thick was prepared by press molding.

[0085] To calculate the SHI, the above measurement method is used to obtain data on the time change in elongational viscosity at a predetermined constant strain rate, and the measurement data is plotted as log(ε) on the horizontal axis and log(η) on the vertical axis. E) is plotted on a graph. Then, the slope of the extensional viscosity in the Hencky strain range between 1 and 3 is identified from the graph, and this slope is taken as the SHI at the strain rate under the measurement conditions.

[0086] The characteristic (9) can be satisfied by adjusting the polymerization conditions, such as the selection of the catalyst type, the polymerization temperature, the monomer concentration, the amount of hydrogen, etc., in the same manner as explained for the characteristic (3).

[0087] Characteristics (10): The branched propylene polymer of the present invention preferably has a multi-branching index of 0.10 to 1.00. The branched propylene polymer of the present invention preferably has a multi-branching index (MBI) of 0.10 or more in order to provide excellent extensibility when melted, and preferably has an MBI of 1.00 or less in order to obtain stability in melt tension by suppressing the strain rate dependency of strain hardening. The lower limit of the MBI is more preferably 0.18 or more, and the upper limit is more preferably 0.80 or less, and further preferably 0.60 or less. Here, MBI is the slope of a plot of the SHI of a polymer at strain rates of 0.1 / sec to 10 / sec, with the logarithm of the strain rate (log(dε / dt)) on the horizontal axis and the SHI at strain rates of 0.1 / sec to 10 / sec on the vertical axis. The SHI of a polymer changes with strain rate. The MBI indicates the dependence of the SHI on the strain rate. A larger MBI value means that the SHI increases more with increasing strain rate. To obtain the MBI, SHI is measured at multiple strain rates in the range of 0.1 / sec to 10 / sec, and the SHI at each strain rate is plotted on a graph with log(dε / dt) on the horizontal axis and SHI on the vertical axis. The slope of the approximation line of the plot in the range of strain rates from 0.1 / sec to 10 / sec is defined as the MBI. -1 , SHI@1.0s -1 , SHI@10.0s -1 The slope of the line obtained by approximating the plot of the three points using the least squares method was determined as the MBI.

[0088] The characteristic (10) can be satisfied by adjusting the polymerization conditions, such as the selection of the catalyst type, the polymerization temperature, the monomer concentration, the amount of hydrogen, etc., in the same manner as explained for the characteristic (3).

[0089] Characteristics (11): In order to obtain a propylene polymer having excellent extensibility while maintaining a melt tension necessary for molding, the branched propylene polymer of the present invention may have a melt tension at 230°C (MT230) of 0.3 g to 15 g or 0.5 g to 15 g. MT230 is the tension detected at a pulley when a resin is extruded in a string-like shape and wound around a roller under the following conditions using a melt tension tester (for example, Capilograph 1B manufactured by Toyo Seiki Seisakusho). ·Resin temperature: 230℃ Capillary: diameter 2.0mm, length 40mm Cylinder diameter: 9.55mm Cylinder extrusion speed: 20mm / min · Winding speed: 4.0m / min If the resin breaks at a winding speed of 4.0 m / min, the melt tension is deemed "unable to evaluate."

[0090] Characteristics (12): The branched propylene polymer of the present invention may have a maximum draw-up speed (MaxDraw) m / min at 230° C. and an MFR that satisfy the relationship represented by the following formula (8). (MaxDraw)>200×log(MFR)-38 Equation (8) Here, MaxDraw is the melt tension measurement, in which the resin is extruded into a string shape and wound around a roller, and the winding speed is increased from 4.0 m / min to an acceleration of 18.1 mm / sec. 2 This is the winding speed just before the string-shaped resin breaks when the winding speed is gradually increased. If the resin breaks at a winding speed of 4.0 m / min, it is deemed "evaluation not possible." The melt extensibility can be evaluated using MaxDraw as an index, and the larger MaxDraw is, the better the extensibility is. In the present invention, MaxDraw was measured under the following conditions. Equipment: INSTRON capillary rheometer CEAST SR50 Capillary: diameter 2.0mm, length 40mm Barrel diameter: 15mm Barrel length: 290mm Cylinder extrusion speed: 20mm / min ·Resin temperature: 230℃

[0091] Generally, increasing the fluidity leads to excellent extensibility, but the melt tension decreases. Increasing the fluidity to achieve excellent extensibility leads to the problem that the melt tension becomes insufficient. Therefore, a propylene-based polymer that has both the melt tension required for molding and excellent extensibility is desired. The relationship between MaxDraw and MFR defined by the above formula (8) can be used as an index of extensibility commensurate with fluidity. Satisfying the above formula (8) indicates that the branched propylene-based polymer of the present invention has excellent extensibility commensurate with fluidity, compared to conventional propylene-based polymers. That is, in order to distinguish the branched propylene polymer of the present invention from the conventional ones, the melt extensibility (MaxDraw) is considered to be a function positively correlated with an increase in fluidity (MFR), the parameters of the function are set, and it is shown that the MaxDraw of the branched propylene polymer of the present invention is larger in proportion to the MFR than the MaxDraw of the conventional propylene polymer defined by the function. Specifically, based on the data of the examples and comparative examples, the values ​​of MaxDraw and MFR that distinguish the examples from the comparative examples of the prior art are assumed, and the parameters of the relational equation that holds between the MaxDraw and MFR are determined by the least squares method (see FIG. 5).

[0092] II. Method for producing branched propylene polymer The method for producing the branched propylene polymer of the present invention is not particularly limited as long as it is a method that can produce a branched propylene polymer having the above-mentioned properties that are characteristic of the present invention. However, a macromonomer copolymerization method using a catalyst containing a plurality of metallocene compounds is suitable. The present inventors speculate that the mechanism of the macromonomer copolymerization method using a catalyst containing a plurality of metallocene compounds is as follows. When polymerization is performed using a catalyst containing a metallocene compound (referred to as compound 1) that forms a catalyst that mainly produces a macromonomer and a metallocene compound (referred to as compound 2) that forms a catalyst that mainly copolymerizes a macromonomer and a propylene monomer to produce a polymer having a branched chain, the following polymerization behavior is observed. By using a propylene polymerization catalyst containing compound 1 and compound 2, it is possible to obtain a polymer having a molecular weight range that includes a molecular weight distribution that is a combination of the molecular weight and molecular weight distribution of a polymer produced from a catalyst containing compound 1 (catalyst 1) and the molecular weight and molecular weight distribution of a polymer produced from a catalyst containing compound 2 (catalyst 2). In the process of forming the branched structure, when the polymer produced from catalyst 1 has a terminal vinyl group, such a polymer containing a terminal vinyl group becomes a macromonomer (referred to as macromonomer 1), and further, a copolymer of propylene and macromonomer 1 is produced from catalyst 1, and a copolymer of propylene and macromonomer 1 is produced from catalyst 2. When the polymer produced from catalyst 2 has a terminal vinyl group, such a polymer containing a terminal vinyl group becomes a macromonomer (referred to as macromonomer 2), and further, a copolymer of propylene and macromonomer 2 is produced from catalyst 1, and a copolymer of propylene and macromonomer 2 is produced from catalyst 2. Furthermore, when the polymer produced from catalyst 1 is macromonomer 1 and the polymer produced from catalyst 2 is macromonomer 2, furthermore, a copolymer of propylene, macromonomer 1 and macromonomer 2 is produced from catalyst 1, and a copolymer of propylene, macromonomer 1 and macromonomer 2 is produced from catalyst 2. In this way, depending on the molecular weight, molecular weight distribution, terminal vinyl ratio and copolymerizability of catalyst 1 of the polymer produced from catalyst 1, the molecular weight, molecular weight distribution, terminal vinyl ratio and copolymerizability of catalyst 2 of the polymer produced from catalyst 2, the ratio of the amounts of catalyst 1 and catalyst 2, the steric positional relationship, etc., the average molecular weight, high molecular weight, and very high molecular weight of the branched propylene polymer as the final product will vary, as well as the amount and branch distribution. That is, Mn, Mw, Mz, W 1 million, W 2 million, g' (1 million), g' (Mw abs ), [g'(Mw abs )-g'(million)], Ea, SHI, MBI, and MT are expected to change.

[0093] A preferred method for producing the branched propylene polymer of the present invention is, but is not limited to, the following. In the method for producing a branched propylene-based polymer of the present invention, from the viewpoint of easily satisfying the above-mentioned characteristics, it is preferable to carry out polymerization using a polymerization catalyst in which two catalyst components, component [A-1] and component [A-2], which generate a macromonomer, are used and the types, amounts and amount ratio of the components [A-1] and [A-2] are selected and combined so that the following conditions are satisfied: a) The molecular weight of the polymer produced from component [A-2] is higher than that of the polymer produced from component [A-1], b) The proportion of terminal vinyl in the polymer produced from component [A-1] is greater than the proportion of terminal vinyl in the polymer produced from component [A-2]; c) Component [A-2] has better copolymerizability with the macromonomer than component [A-1].

[0094] By using a polymerization catalyst comprising a combination of the component [A-1] and the component [A-2] that satisfy the above a), b), and c), it is easy to produce the branched propylene polymer of the present invention, which has the above properties (1) to (3) and is likely to have a branched propylene structure different from conventional structures, particularly a molecular weight distribution and a branching distribution, and has a high Ea relative to the MFR. By using a polymerization catalyst comprising a combination of the components [A-1] and [A-2] that satisfy the above a), b), and c), it is possible to produce the branched propylene polymer of the present invention, which contains multi-branched molecules having a molecular structure in which a large number of branched chains are introduced into the medium to high molecular weight region, while having a branching distribution with a small content of components that do not relax or components that have a long relaxation time.

[0095] By using a polymerization catalyst comprising a combination of the components [A-1] and [A-2] that satisfy the above a), b), and c), the branched propylene polymer of the present invention has a Mw measured using a light scattering detector (MALLS). abs From the area of ​​M abs = 1 million region, the high molecular weight side, M abs In the Mw = 1 million region, the ratio of polymers produced from component [A-2] is high, while in the low molecular weight region, Mw abs In the region, the ratio of the polymer produced from component [A-1] is high. Since the above conditions a) and b) are satisfied, a large amount of macromonomer with a relatively small molecular weight (macromonomer 1) is produced from component [A-1], and a large amount of macromonomer with a relatively large molecular weight (macromonomer 2) is produced from component [A-2]. In addition, when we focus on the branching components, M abs In the Mw = 1 million region, the proportion of branched components formed by copolymerizing propylene with macromonomer 1 and macromonomer 2 due to component [A-2] is high. abs In the region, the ratio of branched components formed by copolymerizing propylene with Macromonomer 1 and Macromonomer 2 increases due to the component [A-1]. Furthermore, since c) above is satisfied, Mw abs In the region, the copolymerization of the macromonomer by component [A-1] is poor, so g'(Mw abs ) can be suppressed. On the other hand, M abs= 1 million, g' (1 million) decreases as component [A-2] more efficiently copolymerizes both Macromonomer 1 and Macromonomer 2. As a result, it is believed that a branched propylene polymer that satisfies Property (4-3) in addition to Property (4-1) and Property (4-2) can be produced.

[0096] II-1. Polymerization catalysts The propylene polymerization catalyst for producing the branched propylene polymer of the present invention preferably contains the following components [A-1], [A-2], [B] and [C]. Component [A-1]: a metallocene compound that gives a propylene homopolymer a-1 having a terminal vinyl ratio (Rv) of 0.5 or more when propylene homopolymerized at 70°C; Component [A-2]: A metallocene compound which, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-2 having a larger Mn than that of the propylene homopolymer a-1 and an Rv of 0.1 or more and less than 0.5. Component [B]: a compound or layered silicate that reacts with component [A-1] and component [A-2] to form an ion pair Component [C]: Organoaluminum compound

[0097] II-1-1. Component [A-1] Component [A-1] is a metallocene compound that gives a propylene homopolymer a-1 with an Rv of 0.5 or more when propylene homopolymerization is performed at 70°C. Component [A-1] is a metallocene compound with an Rv of preferably 0.65 or more, more preferably 0.75 or more, and ideally 1.0 (one end of all molecular chains is a vinyl structure). By using a metallocene compound that forms a polymerization catalyst that produces a propylene homopolymer with a higher Rv, a more efficient macromonomer synthesis process can be performed. Here, the terminal vinyl ratio (Rv) and the terminal vinylidene ratio (Rvd) are defined by the following formulas. Rv = [Vi] / {(total number of terminals - number of LCBs)÷2} Rvd = [Vd] / {(total number of terminals - number of LCBs)÷2} (However, [Vi] and [Vd] are1 The number of terminal vinyl groups and the number of terminal vinylidene groups per 1,000 monomers calculated by H-NMR. The total number of terminals is 1 H-NMR and 13 The total number of terminals per 1000 monomers calculated by C-NMR. The number of LCBs is 13 The number of LCBs per 1000 monomers calculated by C-NMR.)

[0098] [Relationship between reaction mechanism and terminal structure] The relationship between the reaction mechanism of propylene homopolymerization and the terminal structure will be explained below. In the polymerization of propylene, a chain transfer reaction generally called β-hydrogen elimination occurs as a termination reaction, and a polymer with a propyl-vinylidene structure (vinylidene structure) at the termination end shown in structural formula (4-b) is produced. When hydrogen is used, chain transfer usually occurs preferentially to hydrogen, and a polymer with an i-butyl structure at the termination end shown in structural formula (4-c) is produced. When a catalyst containing a metallocene compound with a specific structure is used, a special chain transfer reaction called β-methyl elimination occurs, and a polymer with a 1-propenyl structure (vinyl structure) at the termination end shown in structural formula (4-a) is produced (Reference: Macromol. Rapid Commun. 2000, 21, 1103-1107). In addition, as a terminal end, in rare cases, when propylene undergoes random insertion and then chain transfer with hydrogen, the n-butyl structure shown in structural formula (4-e) is generated. Furthermore, as a terminal end, when propylene undergoes random insertion and then β-hydrogen elimination occurs, a very small amount of the 1-butenyl structure shown in structural formula (4-f) or the terminal vinylene structure (2-butenyl structure) shown in structural formula (4-g) is thought to be generated. The initiation end becomes an n-propyl structure shown in structural formula (4-h) when the first propylene is inserted into the central metal after chain transfer with hydrogen or after β-hydrogen elimination as a termination reaction, or an i-butyl structure shown in structural formula (4-c) when the first propylene is inserted into the central metal after β-methyl elimination as a termination reaction. In addition, as the initiation end, after the chain transfer with hydrogen or after β-hydrogen elimination as a termination reaction, the first propylene rarely randomly inserts into the central metal, resulting in a 2,3 dimethylbutyl structure as shown in structural formula (4-i), or after β-methyl elimination as a termination reaction, the first propylene rarely randomly inserts into the central metal, resulting in a 3,4 dimethylpentyl structure as shown in structural formula (4-j). All of these initial ends are saturated, so one polymer chain cannot have two unsaturated ends at the same time. Furthermore, a polymer having an i-butenyl structure at the end, as shown in structural formula (4-d), may be produced by isomerization. The internal vinylidene structure shown in structural formula (4-k) is an olefin structure formed inside the polymer chain when propylene is inserted into an intermediate formed by the elimination of hydrogen after the generation of an unsaturated terminal. From the above, among the above, the main saturated ends resulting from the main reaction are structural formula (4-c) and structural formula (4-h), the main unsaturated ends are structural formula (4-a) and structural formula (4-b), and the other end structures are minute in number compared to the above main end structures.

[0099] Among these terminal structures, polymers having the structures shown in structural formula (4-a) and structural formula (4-f) at their terminals can become macromonomers. Structural formula (4-a) and structural formula (4-f) are the same in that the two carbon atoms at the extreme ends have vinyl structures, and there is no difference in their function of being copolymerizable. However, the 1-propenyl structure is a terminal formed as a result of β-methyl elimination after regular insertion of propylene, whereas the 1-butenyl structure is a structure formed as a side reaction of β-hydrogen elimination after extremely rare irregular insertion of propylene. Therefore, the amount of 1-butenyl structures can be estimated to be extremely small compared to the amount of 1-propenyl structures. The ratio of 1-butenyl structures formed to the 1-propenyl structures is roughly the same as or less than the probability of heterogeneous bonds being formed. In other words, it can be estimated that most of the number of terminal vinyl groups [Vi] above is the 1-propenyl structure formed as a result of β-methyl elimination after regular insertion of propylene.

[0100] [ka]

[0101] [ka]

[0102] It is calculated by dividing the number of terminal vinyl groups [Vi] and the number of terminal vinylidene groups [Vd], which are unsaturated ends, by the total number of polymers. The specific calculation method is shown below.

[0103] <How to calculate the number of saturated ends> The number of major saturated ends per 1000 monomers is as follows: 13 It is calculated using the integrated intensity of the C signal according to the following formula. Structural formula (4-c): [i-Butyl]=I i-butyl ×1000 / I total-C Structural formula (4-e): [n-butyl]=I nbu ×1000 / I total-C Structural formula (4-h): [n-propyl]=I npr ×1000 / I total-C Structural formula (4-i): [2,3-dimethylbutyl]=I 2,3-dime ×1000 / I total-C Structural formula (4-j): [3,4-dimethylpentyl]=I 3,4-dime ×1000 / I total-C When saturated ends other than the above-mentioned major saturated ends are detected, the number is calculated in the same manner as above, using known literature values, as the number per 1000 monomers. Here, I i-butyl , I nbu , I npr , I 2,3-dime , I 3,4-dimerepresent characteristic values ​​of signals based on structural formula (4-c), structural formula (4-e), structural formula (4-h), structural formula (4-i), and structural formula (4-j), respectively, and are quantities represented by the following formulas. I i-butyl =I 23.80~23.65 I nbu =I 36.99~36.88 I npr =I 39.71~39.61 I 2,3-dime =(I 16.30~16.20 +I 43.05~43.00 ) / 2 I 3,4-dime =I 12.0~11.60 Also, I total-C is the quantity shown in the following formula: I total-C =I i-butyl +I nbu +I npr +I 2,3-dime +I 3,4-dime +I 1,2―P +I 2,1―P +I 1,3―P Furthermore, when there are other saturated structures in addition to the above-mentioned main saturated structures, the number of all detected structures is added to the above formula. I 1,2―P is the characteristic value of the signal based on the 1,2-inserted propylene bond, I 2,1―P is the characteristic value of the signal based on the 2,1 inserted propylene bond, I 1,3―P represents a characteristic value of a signal based on the 1,3-inserted propylene bond, and is a quantity represented by the following formula: I 1,2-P =I 48.80~44.50 I 2,1-P =(I 34.68~34.63 +I 35.47~35.40 +I 35.94~35.70 ) / 2 I 1,3-P =I 37.50~37.20 / 2

[0104] <How to calculate the number of unsaturated ends> The number of unsaturated ends per 1000 monomers is: 1It is calculated using the integrated intensity of the H signal as follows: 1 In H-NMR, the proton signals of the unsaturated bonds of the 1-propenyl structure shown in structural formula (4-a) and the 1-butenyl structure shown in structural formula (4-f) are as follows: 1 It is detected overlapping with the signals at 5.08 ppm to 4.85 ppm and 5.86 ppm to 5.69 ppm in the H-NMR spectrum. Therefore, the number of terminal vinyl groups [Vi] is the total number of 1-propenyl structures and 1-butenyl structures. Structural formula (4-a) + Structural formula (4-f):[Vi]=I vi ×1000 / I total Similarly, the number of terminal vinylidene groups [Vd], the number of i-butenyl groups [i-butenyl], the number of vinylene terminals [terminal vinylene], and the number of internal vinylidenes [internal vinylidene] can be calculated from the following formulas. Structural formula (4-b):[Vd]=I vd ×1000 / I total Structural formula (4-d): [i-butenyl] = I ibu ×1000 / I total Structural formula (4-g): [Terminal vinylene] = I vnl ×1000 / I total Structural formula (4-k): [internal vinylidene] = I ivd ×1000 / I total Here, I vi , I vd , I ibu , I vnl , I ivd represent characteristic values ​​of signals based on structural formula (4-a)+structural formula (4-f), structural formula (4-b), structural formula (4-d), structural formula (4-g), and structural formula (4-k), respectively, and are quantities represented by the following formulas. I vi =(I 5.08~4.85 +I 5.86~5.69 ) / 3 I vd =(I 4.78~4.65 ) / 2 I ibu =I 5.26~5.08 I vnl =(I 5.58~5.26 ) / 2 I ivd =(I 4.85~4.78 ) / 2 Also, I total is the quantity represented by the following formula. I total =I main / 6 + I vi + I vd + I ibu + I vnl + I ivd Also, when there are other unsaturated structures in addition to the above main unsaturated structure, all the detected terminal numbers are added to the above formula. I main means 1 the total integrated intensity of the proton signals bonded to the saturated carbons of the polymer chains including the terminals, detected at 4.00 ppm to 0.00 ppm in the 1H-NMR spectrum.

[0105] <Calculation method of the number of LCBs> The number of LCBs is determined as the number per 1000 monomers by the method described in property (7). <Calculation method of the total number of terminals> The total number of terminals is 1 the total number of terminals per 1000 monomers calculated by 1H-NMR and 13 13C-NMR. <Calculation method of the terminal vinyl ratio (Rv) and the terminal vinylidene ratio (Rvd)> Using [Vi], [Vd], the total number of terminals, and the number of LCBs obtained above, the following formula is used for calculation. Rv = [Vi] / {(total number of terminals - number of LCBs) ÷ 2} Rvd = [Vd] / {(total number of terminals - number of LCBs) ÷ 2}

[0106] Examples of the component [A-1] include a bisindenyl complex having a bulky heterocyclic group at the 2-position of the indenyl group and an aryl group which may be substituted at the 4-position or a heterocyclic group containing a nitrogen, oxygen or sulfur atom, etc. As one of the non-limiting preferred embodiments, the following structure can be mentioned.

[0107] [ka] [In general formula (a1), R 11 and R 12 R each independently represents a heterocyclic group containing a nitrogen, oxygen or sulfur atom and having 4 to 16 carbon atoms. 13 and R 14 Q each independently represents an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroatoms selected from these, or a heterocyclic group having 6 to 16 carbon atoms which contains a nitrogen, oxygen, or sulfur atom. 11 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms; M 11 represents zirconium or hafnium, and X 11 and Y 11 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.]

[0108] Above R 11 and R 12 The nitrogen-, oxygen- or sulfur-atom-containing heterocyclic group having 4 to 16 carbon atoms is preferably a 2-furyl group, a substituted 2-furyl group, a substituted 2-thienyl group or a substituted 2-furfuryl group, and more preferably a substituted 2-furyl group. R 11 and R 12 is a group selected from heterocyclic groups having 4 to 16 carbon atoms and containing a nitrogen, oxygen, or sulfur atom, the terminal vinyl ratio (Rv) can be increased. In particular, by introducing a substituent of an appropriate size onto the heterocyclic group, the relative positional relationship between the heterocycle and the coordination field on the transition metal and the growing polymer chain can be made appropriate, thereby making it possible to further increase Rv. Moreover, as the substituent of the substituted 2-furyl group, the substituted 2-thienyl group and the substituted 2-furfuryl group, a hydrocarbon group having 1 to 4 carbon atoms is preferable. In addition, R 11 and R 12 Particularly preferred as R is a 5-methyl-2-furyl group. 11 and R 12 are preferably identical to each other.

[0109] Above R 13 and R 14 are each independently an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroatoms selected from these, or a heterocyclic group having 6 to 16 carbon atoms which contains a nitrogen, oxygen, or sulfur atom. In particular, R 13 and R 14 By making the copolymer bulkier, it is possible to obtain a propylene polymer having higher stereoregularity, fewer heterogeneous bonds, and a higher terminal vinyl ratio. So, R 13 and R 14 is preferably, in the range of 6 to 16 carbon atoms, one or more hydrocarbon groups having 1 to 6 carbon atoms, silyl groups having a hydrocarbon group having 1 to 6 carbon atoms, halogen atom-containing hydrocarbon groups having 1 to 6 carbon atoms, or aryl groups which may have a halogen atom as a substituent on an aryl ring skeleton. 13 and R 14 Specific examples of the aryl group include a 4-t-butylphenyl group, a 2,3-dimethylphenyl group, a 3,5-di-t-butylphenyl group, a 4-chlorophenyl group, a 4-trimethylsilylphenyl group, a 1-naphthyl group, and a 2-naphthyl group. Also, R 13 and R 14 More preferably, R is one or more of a hydrocarbon group having 1 to 6 carbon atoms, a silyl group having a hydrocarbon group having 1 to 6 carbon atoms, a halogen atom-containing hydrocarbon group having 1 to 6 carbon atoms, or a phenyl group having a halogen atom as a substituent, with the carbon number being in the range of 6 to 16. The position of substitution is preferably the 4-position on the phenyl group. 13 and R14 Specific examples of R include a 4-t-butylphenyl group, a 4-biphenylyl group, a 4-chlorophenyl group, and a 4-trimethylsilylphenyl group. 13 and R 14 are preferably identical to each other.

[0110] Above X 11 and Y 11 is an auxiliary ligand, and reacts with component [B] to produce an active metallocene capable of olefin polymerization. Therefore, as long as this purpose is achieved, X 11 and Y 11 There are no limitations on the type of ligand, and each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen atom-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0111] Above Q 11 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms, which bonds two five-membered rings. When two hydrocarbon groups are present on the above-mentioned silylene group or germylene group, they may be bonded to each other to form a ring structure. Above Q 11Specific examples of the alkylene group include alkylene groups such as methylene, methylmethylene, dimethylmethylene, and 1,2-ethylene; aryl alkylene groups such as diphenylmethylene; silylene groups; alkyl silylene groups such as methylsilylene, dimethylsilylene, diethylsilylene, di(n-propyl)silylene, di(i-propyl)silylene, and di(cyclohexyl)silylene; (alkyl)(aryl)silylene groups such as methyl(phenyl)silylene; aryl silylene groups such as diphenylsilylene; alkyl oligosilylene groups such as tetramethyldisilylene; germylene groups; alkylgermylene groups in which the silicon of the silylene group having the above-mentioned divalent hydrocarbon group having 1 to 20 carbon atoms is replaced with germanium; (alkyl)(aryl)germylene groups; and arylgermylene groups. Among these, a silylene group having a hydrocarbon group of 1 to 20 carbon atoms or a germylene group having a hydrocarbon group of 1 to 20 carbon atoms is preferred, with an alkylsilylene group and an alkylgermylene group being particularly preferred.

[0112] Among the compounds represented by the above general formula (a1), preferred compounds are specifically exemplified below. (1) dichloro[1,1'-dimethylsilylenebis{2-(2-furyl)-4-phenylindenyl}]hafnium, (2) dichloro[1,1'-dimethylsilylenebis{2-(2-thienyl)-4-phenylindenyl}]hafnium, (3) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-phenylindenyl}]hafnium, (4) dichloro[1,1'-diphenylsilylenebis{2-(5-methyl-2-furyl)-4-phenylindenyl}]hafnium, (5) dichloro[1,1'-dimethylgermylenebis{2-(5-methyl-2-furyl)-4-phenylindenyl}]hafnium, (6) dichloro[1,1'-dimethylgermylenebis{2-(5-methyl-2-thienyl)-4-phenylindenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-phenylindenyl}]hafnium, (8) dichloro[1,1'-dimethylsilylenebis{2-(5-trimethylsilyl-2-furyl)-4-phenylindenyl}]hafnium, (9) dichloro[1,1'-dimethylsilylenebis{2-(5-phenyl-2-furyl)-4-phenylindenyl}]hafnium, (10) dichloro[1,1'-dimethylsilylenebis{2-(4,5-dimethyl-2-furyl)-4-phenylindenyl}]hafnium, (11) dichloro[1,1'-dimethylsilylenebis{2-(2-benzofuryl)-4-phenylindenyl}]hafnium, (12) dichloro[1,1'-dimethylsilylenebis{2-(2-furfuryl)-4-phenylindenyl}]hafnium, (13) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-chlorophenyl)indenyl}]hafnium, (14) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-chlorophenyl)indenyl}]hafnium, (15) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-fluorophenyl)indenyl}]hafnium, (16) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trifluoromethylphenyl)indenyl}]hafnium, (17) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)indenyl}]hafnium, (19) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-i-propylphenyl)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-methyl-2-furyl)-4-(4-trimethylsilylphenyl)indenyl}]hafnium, (22) dichloro[1,1'-dimethylsilylenebis{2-(2-furyl)-4-(1-naphthyl)indenyl}]hafnium, (23) dichloro[1,1'-dimethylsilylenebis(2-(2-furyl)-4-(2-naphthyl)indenyl)]hafnium, (24) dichloro[1,1'-dimethylsilylenebis(2-(2-furyl)-4-(2-phenanthryl)indenyl)]hafnium, (25) dichloro[1,1'-dimethylsilylenebis(2-(2-furyl)-4-(9-phenanthryl)indenyl)]hafnium, (26) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-biphenylyl)indenyl}]hafnium, (27) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(1-naphthyl)indenyl}]hafnium, (28) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(2-naphthyl)indenyl}]hafnium, (29) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(1-naphthyl)indenyl}]hafnium, (30) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(2-naphthyl)indenyl}]hafnium, etc. can be mentioned.

[0113] Of these, the preferred ones are: (3) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-phenylindenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-phenylindenyl}]hafnium, (13) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-chlorophenyl)indenyl}]hafnium, (14) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-chlorophenyl)indenyl}]hafnium, {furyl)-4-(4-t-butylphenyl)indenyl}]hafnium, (17) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)indenyl}]hafnium, (19) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium, (20) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-(21)dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trimethylsilylphenyl)indenyl}]hafnium, (26) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-biphenylyl)indenyl}]hafnium, (28) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(2-naphthyl)indenyl}]hafnium, (30) dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-furyl)-4-(2-naphthyl)indenyl}]hafnium, It is. Also, more preferably, (13) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-chlorophenyl)indenyl}]hafnium, (17) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-t-butylphenyl)indenyl}]hafnium, (21) dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-trimethylsilylphenyl)indenyl}]hafnium, It is.

[0114] II-1-2. Component [A-2] The component [A-2] is a metallocene compound which, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-2 having a larger Mn and an Rv of 0.1 or more and smaller than 0.5 than those of the propylene homopolymer a-1.

[0115] The component [A-2] is a metallocene compound that forms a polymerization catalyst for copolymerizing a propylene monomer and a propylene macromonomer and for producing a propylene macromonomer. Therefore, the component [A-2] is a metallocene compound having an Rv of 0.1 or more, preferably 0.15 or more, and more preferably 0.2 or more. On the other hand, as the component [A-2], a metallocene compound that has a high molecular weight and a low Rv but forms a polymerization catalyst that efficiently copolymerizes a macromonomer is used, thereby making it possible to suppress the generation of high molecular weight branched components with long branches. Therefore, the component [A-2] is a metallocene compound having an Rv of less than 0.5, preferably 0.45 or less, and more preferably 0.3 or less.

[0116] In order to obtain an average molecular weight, a molecular weight distribution and a branching distribution that are characteristic of the branched propylene polymer of the present invention and have the above-mentioned properties (1), (2-1) and (3) and preferably satisfy the above-mentioned properties (4-1) to (10), it is necessary that the component [A-2] produces a polymer having a higher molecular weight than the component [A-1]. Therefore, component [A-2] is a metallocene compound that produces a higher molecular weight polymer than component [A-1] when propylene homopolymerization is performed at 70°C with the same amount of hydrogen.

[0117] In order to obtain an average molecular weight, molecular weight distribution and branching distribution such that the branched propylene polymer of the present invention satisfies the above-mentioned properties, it is preferable that the component [A-2] has a better copolymerizability with the macromonomer than the component [A-1]. Therefore, it is preferable that component [A-2] is a metallocene compound in which, when propylene is homopolymerized at 70°C, the proportion of the number of terminal vinyls produced that are copolymerized into LCBs {LCB number / ([Vi]+LCB number)} is greater than that of component [A-1].

[0118] By selecting the component [A-2] as described above, it is possible to preferentially cause the reaction in which the macromonomer with a relatively small molecular weight produced in the component [A-1] is copolymerized with the component [A-2]. The evaluation method for Rv and Rvd is the same as that for component [A-1], except that 100 mg of a catalyst containing component [A-2] (excluding the prepolymerized polymer) is used and 1.19 NL of hydrogen is introduced to polymerize. In addition, the Mw characteristics can be evaluated in the same manner as in the evaluation of Rv and Rvd, by performing bulk polymerization at 70°C, measuring the polymers produced from component [A-2] and component [A-1] by GPC, and comparing the Mw values ​​obtained. Furthermore, the copolymerization characteristics of the macromonomer can be evaluated by performing bulk polymerization at 70°C in the same manner as in the evaluation of Rv and Rvd, and comparing the proportion of the number of terminal vinyls produced that have copolymerized into LCBs {LCB number / ([Vi]+LCB number)} obtained by NMR measurement of the polymer produced from component [A-2] and component [A-1].

[0119] As described above, the ratio of the macromonomer in the polymer produced from component [A-2] is lower than the ratio of the macromonomer in the polymer produced from component [A-1], so that the amount of copolymerization of macromonomer 2 is suppressed. On the other hand, since macromonomer copolymerization is better than that of component [A-1], the branch chain length can be adjusted in the branched structure introduced into the branched propylene-based polymer by efficiently copolymerizing macromonomer 1. By utilizing this branch chain length adjustment, a branched propylene-based polymer having the above properties (1), (2-1) and (3), which are characteristic of the branched propylene-based polymer of the present invention, and preferably satisfying the above properties (4-1) to (10) can be obtained.

[0120] The component [A-2] can be a metallocene compound represented by the following general formula (a2).

[0121] [ka] [M is a transition metal atom selected from groups 3, 4, 5, 6 or the lanthanides or actinides of the periodic table; preferably, M is titanium, zirconium or hafnium; p is 0, 1, 2 or 3, preferably p is 2, which is equal to the formal oxidation state of the metal M minus 2; X may be the same or different and is a hydrogen atom, a halogen atom, or R a , OR a , OSO2CF3, OCOR a , S.R. a , N.R. a 2 or PR a 2 groups (where R ais a linear or branched, cyclic or acyclic alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, R a is a linear or branched alkyl group having 1 to 20 carbon atoms); or two X's may form a substituted or unsubstituted butadienyl group or an OR'O group (wherein R' is a divalent group selected from an alkylidene group having 1 to 40 carbon atoms, an arylidene group having 6 to 40 carbon atoms, an alkylarylidene group having 7 to 40 carbon atoms, and an arylalkylidene group having 7 to 40 carbon atoms); preferably, X's are a hydrogen atom, a halogen atom, or R a group; more preferably, X is a chlorine atom or an alkyl group having 1 to 10 carbon atoms, such as a methyl or ethyl group; L is a divalent hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table, or a divalent silylene group containing up to five silicon atoms; preferably, L is a divalent bridging group selected from alkylidene having 1 to 40 carbon atoms, cycloalkylidene having 3 to 40 carbon atoms, arylidene having 6 to 40 carbon atoms, alkylarylidene having 7 to 40 carbon atoms, or arylalkylidene group having 7 to 40 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table, and a silylene group containing up to five silicon atoms such as SiMe2 and SiPh2; preferably, L is (Z(R")2) n group (wherein Z is a carbon or silicon atom, n is 1 or 2, and R" is a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, R" is a linear or branched, cyclic or acyclic alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, aryl group having 6 to 20 carbon atoms, alkylaryl group having 7 to 20 carbon atoms, or arylalkyl group having 7 to 20 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table); more preferably, (Z(R")2). nThe group is Si(CH3)2, SiPh2, SiPhMe, SiMe(SiMe3), CH2, (CH2)2 or C(CH3)2; R 1 and R 2 are the same or different and are hydrocarbon groups having 1 to 40 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, they are linear or branched, cyclic or acyclic alkyl groups having 1 to 40 carbon atoms, alkenyl groups having 2 to 40 carbon atoms, alkynyl groups having 2 to 40 carbon atoms, aryl groups having 6 to 40 carbon atoms, alkylaryl groups having 7 to 40 carbon atoms, or arylalkyl groups having 7 to 40 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; more preferably, R 1 and R 2 is a linear or branched alkyl group having 1 to 20 carbon atoms; more preferably, R 1 and R 2 is a methyl or ethyl group; T are the same or different and are represented by the formula (a2-T1) or (a2-T2):

[0122] [ka] (wherein an atom marked with a symbol "*" is bonded to an atom marked with the same symbol in a compound of formula (a2); R 3 is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, R 3 is a linear or branched, cyclic or acyclic alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; more preferably, R 3 is a linear or branched alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms; more preferably, R 3represents an aryl group having 6 to 20 carbon atoms which may be substituted with one or more alkyl groups each having 1 to 10 carbon atoms; R 4 and R 6 are the same or different and each is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, R 4 and R 6 are the same or different and each represents a straight-chain or branched, cyclic or acyclic alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, which may contain a hydrogen atom or a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, R 4 and R 6 is a hydrogen atom; R 5 is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, R 5 is a linear or branched, cyclic or acyclic alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, which may contain a heteroatom belonging to Groups 13 to 17 of the periodic table; more preferably, R 5 is a linear or branched, saturated or unsaturated alkyl group having 1 to 20 carbon atoms; more preferably, R 5 is a methyl or ethyl group; R 7 and R 8 are the same or different and each is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom belonging to Groups 13 to 17 of the periodic table; R 7 and R 8 may form a saturated or unsaturated 5- or 6-membered ring, and the ring may have an alkyl group having 1 to 20 carbon atoms as a substituent; preferably, R 7 and R 8represents a linear or branched, cyclic or acyclic alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, which may contain a hydrogen atom or a heteroatom belonging to Groups 13 to 17 of the periodic table; Preferably, R 8 is a hydrogen atom or a linear or branched, saturated or unsaturated alkyl group having 1 to 20 carbon atoms; more preferably, R 8 is a methyl or ethyl group; Preferably, R 7 is an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms; more preferably, R 7 is the formula (a2-R7):

[0123] [ka] (In the formula, R 7a , R 7b , R 7c , R 7d and R 7e are the same or different and each is a straight-chain or branched, cyclic or acyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms, which may contain a hydrogen atom or a heteroatom belonging to Groups 13 to 17 of the periodic table; preferably, R 7a and R 7d is a hydrogen atom; R 7b , R 7c and R 7e is preferably a hydrogen atom or a linear or branched, cyclic or acyclic alkyl group having 1 to 10 carbon atoms.)]

[0124] In one embodiment, the compound represented by general formula (a2) may be a compound represented by the following general formula (a3):

[0125] [ka] (In the formula, M, X, p, L, R 1 , R 2 , R 7 , and R 8 has the same meaning as in formula (a2). In formula (a3), M is preferably hafnium, since it produces vinyl groups at the terminals at a certain ratio and can produce long chain branches by copolymerizing macromonomers.

[0126] Specific examples of the metallocene complex represented by the general formula [a3] are shown below, but the invention is not limited thereto. Dimethylsilylenebis(cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(5-methyl-cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(2,5-dimethyl-cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(2,3,5-trimethyl-cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(2,5-dimethyl-3-phenyl-cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(2,5-dimethyl-3-(4-t-butylphenyl)-cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(2,5-dimethyl-3-(2,5-dimethylphenyl)-cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(2,5-dimethyl-3-(3,5-dimethylphenyl)-cyclopenta[b]thienyl)hafnium dichloride Dimethylsilylenebis(2,5-dimethyl-3-(3,5-di-t-butylphenyl)-cyclopenta[b]thienyl)hafnium dichloride

[0127] Other examples include compounds in which one or both of the two Xs in the above-exemplified compounds are replaced with a bromine atom, an iodine atom, a methyl group, a phenyl group, a dimethylamino group, a diethylamino group, etc. In addition, when an asymmetric carbon is generated in these metallocene complexes, unless otherwise specified, one of the stereoisomers or a mixture thereof (including a racemic mixture) is shown.

[0128] The metallocene complex represented by the general formula [a2] can be synthesized by appropriately selecting from conventionally known synthesis methods. For example, the metallocene complex can be synthesized by referring to JP-A-2007-528925. The metallocene complex represented by the general formula [a3] can be synthesized by appropriately selecting from conventionally known synthesis methods. For example, the metallocene complex can be synthesized by referring to JP-A-2021-152155.

[0129] II-1-3. Component [B] Component [B] is a compound or layered silicate that reacts with component [A-1] and component [A-2] to form an ion pair. Component [B] may be used alone or in combination of two or more thereof. Component [B] is preferably a layered silicate.

[0130] II-1-3-1. Compounds that form ion pairs with component [A-1] and component [A-2] Examples of the compound that reacts with component [A-1] and component [A-2] to form an ion pair include aluminum oxy compounds, boron compounds, etc., and specific examples of the aluminum oxy compounds include compounds represented by the following general formulas (I) to (III).

[0131] [ka]

[0132] In the above general formulas (I), (II), and (III), R 91 , R 101 and R 111represents a hydrogen atom or a hydrocarbon group, preferably a hydrocarbon group having 1 to 10 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 6 carbon atoms. 91 , R 101 and R 111 may be the same or different, and p represents an integer of 0 to 40, preferably 2 to 30. The compounds represented by the general formulas (I) and (II) are also called aluminoxanes. Among the aluminoxanes, methylaluminoxane or methylisobutylaluminoxane is preferred. The above aluminoxanes can be used in combination in each group or between groups. In general formula (III), R 112 represents a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Examples of the boron compound include complexes of cations such as carbonium cation and ammonium cation with organic boron compounds such as triphenyl boron, tris(3,5-difluorophenyl) boron, and tris(pentafluorophenyl) boron, as well as various organic boron compounds such as tris(pentafluorophenyl) boron.

[0133] II-1-3-2. Layered silicates Layered silicate (hereinafter sometimes simply referred to as silicate) refers to a silicate compound that has a sheet-like crystal structure stacked in parallel by ionic bonds or the like, and further, multiple sheet-like crystals form a layer with interlayer ions between the layers. Specific examples of layered silicates include layered silicates having a 1:1 type structure based on the stacking of one layer of tetrahedral sheet and one layer of octahedral sheet, as described in "Clay Mineralogy" by Shiramizu Haruo, Asakura Publishing (1988), and a 2:1 type structure based on the stacking of one layer of octahedral sheet sandwiched between two layers of tetrahedral sheets. Specific examples of layered silicates having a 1:1 type structure include kaolin group silicates such as dickite, nacrite, kaolinite, metahalloysite, and halloysite, and serpentine group silicates such as chrysotile, lisardite, and antigorite. Specific examples of layered silicates having a 2:1 type structure include smectite group silicates such as montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, etc., vermiculite group silicates such as vermiculite, mica group silicates such as mica, illite, sericite, glauconite, etc., attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group, etc. These may form mixed layers.

[0134] Among these, it is preferable that the main component is a layered silicate having a 2:1 type structure based on stacking of two layers of tetrahedral sheets mainly made of silicon oxide sandwiching one layer of octahedral sheet mainly made of aluminum oxide, more preferably the main component is a smectite silicate, and even more preferably the main component is montmorillonite. The layered silicate can contain exchangeable ions (interlayer ions) between the layers, and such layered silicates in which the interlayer ions are exchangeable are called ion-exchangeable layered silicates. The interlayer ions are preferably interlayer cations, in which the ions are cations. The type of interlayer cation is not particularly limited, but examples of the main components include alkali metals in Group 1 of the periodic table, such as lithium and sodium, alkaline earth metals in Group 2 of the periodic table, such as calcium and magnesium, and transition metals, such as iron, cobalt, copper, nickel, zinc, ruthenium, rhodium, palladium, silver, iridium, platinum, and gold.

[0135] The layered silicate may be a natural product or an artificially synthesized product. The shape of the layered silicate is not particularly limited, and it may be the shape as it occurs in nature, or an artificially synthesized spherical shape. In addition, naturally occurring layered silicates can be processed into a spherical shape by operations such as pulverization and granulation, and among these, it is preferable to process the shape into a spherical shape by granulation. Furthermore, it is particularly preferable to narrow the particle size distribution of the layered silicates processed into a spherical shape by operations such as classification, since this gives good polymer particle properties.

[0136] It is desirable to chemically treat the layered silicate in order to convert the interlayer ions of the layered silicate into alkali metal ions. For the chemical treatment method of the layered silicate, for example, the description in paragraphs 0048 to 0066 of JP2018-162391A can be referred to.

[0137] The component [B] preferably used in the present invention is a chemically treated layered silicate. From the viewpoint of the amount and distribution of the catalyst components [A-1] and [A-2] supported, the molar ratio of aluminum atoms to silicon atoms (Al / Si) contained in the layered silicate is preferably in the range of 0.01 to 0.25, more preferably 0.03 to 0.24, and even more preferably 0.05 to 0.23. The Al and Si in the layered silicate are measured by creating a calibration curve by chemical analysis according to the JIS method with reference to the description in paragraph 0089 of JP 2018-162391 A, and quantifying with fluorescent X-rays.

[0138] II-1-4.Component [C] The component [C] used in the present invention is an organoaluminum compound, and preferably an organoaluminum compound represented by the following general formula (IV) is used. (AlR b n X 3-n ) m ...General formula (IV) [In the above general formula (IV), R b represents an alkyl group having 1 to 20 carbon atoms, X represents a halogen, a hydrogen, an alkoxy group or an amino group, n represents an integer of 1 to 3, and m represents an integer of 1 or 2.] The organoaluminum compounds may be used alone or in combination of two or more kinds. Specific examples of the organoaluminum compound include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, diethylaluminum chloride, diethylaluminum sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, diisobutylaluminum chloride, etc. Among these, preferred are trialkylaluminums with m=1 and n=3 and dialkylaluminum hydrides with m=2, n=1, and X being hydrogen. More preferred are trialkylaluminums with R having 1 to 8 carbon atoms.

[0139] II-1-5. Preparation of catalyst The olefin polymerization catalyst preferably used in the present invention includes the above-mentioned components [A-1], [A-2], [B] and [C]. These can be obtained by contacting them in or outside a polymerization vessel. The olefin polymerization catalyst may be prepolymerized in the presence of an olefin. The amounts of component [A-1], component [A-2], component [B] and component [C] used are arbitrary. For example, the total amount of the components [A-1] and [A-2] used may be 0.1 μmol to 1000 μmol, or may be in the range of 0.5 μmol to 500 μmol, per 1 g of the component [B]. Regarding the ratio of component [A-1] to component [A-2], the ratio of the molar amount of [A-1] to the total molar amount of component [A-1] and component [A-2] is preferably 0.30 or more and 0.99 or less. The change in the molar amount ratio changes the average molecular weight, high molecular weight, very high molecular weight, branch number and branch distribution. This change makes it possible to obtain the branched propylene polymer of the present invention that has a small amount of components with extremely long relaxation times while maintaining the necessary branch structure. The amount of component [C] used is, in terms of the molar ratio of aluminum in component [C] to the total transition metals in components [A-1] and [A-2], 0.01 to 5 × 106 may be 0.1 to 1 × 10 4 The range may be:

[0140] The order in which the components [A-1], [A-2], [B] and [C] are contacted is arbitrary. The following orders can be mentioned. (1) Either component [A-1] or component [A-2] is contacted with component [B], and then the resulting mixture is contacted with component [C], and then with the remaining either component [A-1] or component [A-2]. (2) Both component [A-1] and component [A-2] are contacted with component [B], either separately or simultaneously, and then contacted with component [C]. (3) After component [C] and component [B] are contacted with each other, components [A-1] and [A-2] are contacted with each other sequentially or simultaneously. (4) In the presence of component [B], components [A-1] and [A-2] are simultaneously contacted with component [C]. Of these, (4) is preferred.

[0141] In the contact, a solvent may be used to ensure sufficient contact. Examples of the solvent include aliphatic saturated hydrocarbons, aromatic hydrocarbons, aliphatic unsaturated hydrocarbons, halides thereof, and prepolymerized monomers. Specific examples of the aliphatic saturated hydrocarbons and aromatic hydrocarbons include hexane, heptane, and toluene. As the prepolymerized monomer, propylene can be used as a solvent.

[0142] II-1-6. Prepolymerization The olefin polymerization catalyst may be a prepolymerized catalyst in which an olefin is brought into contact with the catalyst to polymerize a small amount of the olefin. The prepolymerized catalyst has improved catalytic activity and can produce a propylene-based polymer at low cost. The olefin to be used is not particularly limited, but examples thereof include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, styrene, etc., and preferably propylene. The olefin used may be an olefin derived from a fossil fuel, an olefin derived from biomass, an olefin derived from chemical recycling, or a mixture thereof. The olefin may be fed to the prepolymerization reactor by any method, such as a method for maintaining the olefin at a constant rate or at a constant pressure, a combination of these, or a method for changing the rate stepwise. The prepolymerization temperature and prepolymerization time are not particularly limited, but are preferably in the range of −20° C. to 100° C. and 5 minutes to 24 hours, respectively. The prepolymerization ratio may be 0.01-100, more preferably 0.1-50, as the mass ratio of the prepolymerized polymer to the component [B]. Also, the component [C] can be added during the prepolymerization. During or after the prepolymerization, a polymer such as polyethylene or polypropylene or a solid inorganic oxide such as silica or titania may be allowed to coexist.

[0143] II-2. Polymerization method for propylene-based polymers The polymerization method for the branched propylene polymer of the present invention may include a method of homopolymerizing propylene or copolymerizing propylene with a comonomer in the presence of a propylene polymerization catalyst containing the components [A-1], [A-2], [B] and [C]. The polymerization method may be any method such as solution polymerization, gas phase polymerization, bulk polymerization using propylene as a solvent without substantially using an inert solvent, etc. Among these, bulk polymerization is preferred.

[0144] For example, the polymerization temperature in the bulk polymerization may be 40° C. to 80° C., or 50° C. to 75° C. The polymerization pressure in the bulk polymerization may be 1.0 MPa to 5.0 MPa, 1.5 MPa to 4.0 MPa, or 2.0 MPa to 3.5 MPa. As for the polymerization method, a method of carrying out continuous polymerization or batch polymerization can be adopted. With regard to the number of polymerization stages, single-stage polymerization or multi-stage polymerization of two or more stages can be used.

[0145] The polymerization may be homopolymerization of propylene, or copolymerization of propylene with an α-olefin comonomer having 2 to 20 carbon atoms other than propylene. Examples of the α-olefin comonomer include at least one comonomer selected from ethylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc. Homopolymerization of propylene gives a propylene homopolymer, and copolymerization of propylene with a comonomer gives a propylene copolymer. The propylene and comonomers that can be used are derived from fossil fuels, biomass, chemical recycling, and mixtures thereof.

[0146] [Use of hydrogen] The branched propylene polymer of the present invention can also be obtained by using hydrogen in the presence of the above catalyst and adjusting the amount of hydrogen used. By adjusting the amount of hydrogen used, etc., the average molecular weight, molecular weight distribution (Mz, Mw, Mn, Mw / Mn, Mz / Mw) and balance thereof of the branched propylene polymer measured by GPC can be adjusted, for example, as follows. In the method for producing a branched propylene polymer of the present invention, it is preferable that the component [A-1] acts as a catalyst component that produces a relatively low molecular weight component in relation to the component [A-1] and the component [A-2]. On the other hand, it is preferable that the component [A-2] acts as a catalyst component that produces a relatively high molecular weight component. As a result, the rate of change of Mz relative to the change in the amount of hydrogen is greater than the rate of change of Mw. Therefore, it is possible to change Mz / Mw without changing Mw / Mn too much. For example, when the amount of hydrogen is increased, the rate of change in molecular weight reduction of the polymer produced from the component [A-2] that produces a high molecular weight is greater than that of the polymer produced from the component [A-1] that produces a low molecular weight. Also, since the component [A-1] is relatively more activated than the component [A-2], the molecular weight distribution changes so that the ratio of the polymer produced from the component [A-1] is higher than that of the polymer produced from the component [A-2]. By changing the molecular weight distribution as described above, it is possible to reduce Mz and Mz / Mw without changing Mw and Mw / Mn much. On the other hand, when the amount of hydrogen is reduced, the rate of change in the molecular weight of the polymer produced from the component [A-2] that produces high molecular weight increases compared to the polymer produced from the component [A-1] that produces low molecular weight. By changing the molecular weight distribution in this way, it is possible to increase Mz and Mz / Mw without changing Mw and Mw / Mn much.

[0147] [How to use the catalyst] In the case of continuously polymerizing the branched propylene polymer of the present invention, it is preferable to continuously introduce the catalyst when at least hydrogen and propylene are continuously introduced into a polymerization reactor.

[0148] [Polymer slurry concentration] When the branched propylene polymer of the present invention is produced, for example, by bulk continuous polymerization, the amount of polymer held in the polymerization reactor can be kept constant (steady state) by adjusting the amount of propylene introduced into the polymerization reactor and the amount of the produced polymer and unreacted propylene recovered. At this time, the ratio of the polymer amount to the propylene mass in the polymerization reactor (polymer slurry concentration) also becomes constant. However, even if the polymer slurry concentration is constant, if the polymer tends to settle, the polymer concentration will vary depending on the height of the position in the propylene liquid, and the hydrogen consumption rate will differ depending on the position, resulting in a broadening of the molecular weight and branching distribution. Therefore, in the method for producing a branched propylene polymer of the present invention, the polymer slurry concentration is preferably 55% by mass or less, more preferably 50% by mass or less, and further preferably 45% by mass or less. From the viewpoint of productivity, it is preferable to adjust the polymer slurry concentration. In the method for producing a branched propylene polymer of the present invention, the polymer slurry concentration is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more.

[0149] III. Uses of branched propylene polymers The branched propylene polymer of the present invention can be used as a molding material in the form of powder, pellets cut into granular form after heat-melting and kneading, or the like. The branched propylene polymer of the present invention can be blended with additives and resins. Examples of various additives include antioxidants, ultraviolet absorbers, antistatic agents, nucleating agents, lubricants, flame retardants, antiblocking agents, colorants, inorganic fillers, organic fillers, etc. Examples of resins include various synthetic resins, natural resins, etc. The branched propylene polymer of the present invention can be molded by various polypropylene molding methods. Examples of the molding methods include injection molding, extrusion molding, foam molding, blow molding, etc. Examples of molded products that can be produced include various molded products such as industrial injection molded parts, containers, non-stretched films, uniaxially stretched films, biaxially stretched films, sheets, pipes, and fibers. In addition, the branched propylene polymer of the present invention has a required melt tension and contains few components having an extremely long relaxation time, and therefore has excellent extensibility when melted, and can be suitably used in applications requiring extensibility. The branched propylene polymer of the present invention can also be used by blending with other resins. EXAMPLES

[0150] Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as it does not depart from the gist of the present invention. In the following examples, the autoclave was thoroughly dried in advance by passing nitrogen through it under heating before use, and the catalyst preparation and polymerization were all carried out under an inert gas.

[0151] (1) Synthesis of catalyst component (A) (1-1) Synthesis Example 1: Synthesis of catalyst component [A-1] (Complex 1) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium: rac-Dichloro[1,1′-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium was synthesized according to the method of Synthesis Example 1 in JP2012-149160A.

[0152] (1-2) Synthesis Example 2: Synthesis of catalyst component [A-2] (Complex 2) 1) Synthesis of rac-dimethylsilylenebis(2,5-dimethyl-3-phenyl-cyclopenta[b]thienyl)hafnium dichloride (complex 2): (1-a) Synthesis of 2,5-dimethyl-3-phenyl-hydrocyclopenta[b]thiophene: The synthesis was carried out with reference to the method described in Example 1 of JP-A-2003-517010. (1-b) Synthesis of dimethylbis(2,5-dimethyl-3-phenyl-hydrocyclopenta[b]thiophene)silane: 2,5-Dimethyl-3-phenyl-hydrocyclopenta[b]thiophene (8.8g, 39mmol) and THF (200ml) were added to a 500ml glass reaction vessel and cooled to -70℃. n-Butyllithium-n-hexane solution (1.55mol / L, 25ml, 39mmol) was added dropwise. After the addition, the mixture was stirred for 2 hours while gradually returning to room temperature. The mixture was cooled again to -70℃, 1-methylimidazole (0.15ml, 1.9mmol) was added, and a THF solution (30ml) containing dimethyldichlorosilane (2.5g, 19mmol) was added dropwise. After the addition, the mixture was stirred overnight while gradually returning to room temperature. Distilled water was added to the reaction solution obtained, which was then transferred to a separatory funnel and washed with saline until neutral. Sodium sulfate was added and the reaction solution was left overnight to dry. The sodium sulfate was filtered off, the solvent was removed under reduced pressure, and the resulting solid was purified using a silica gel column to obtain a white powder of dimethylbis(2,5-dimethyl-3-phenyl-hydrocyclopenta[b]thiophene)silane (9.8 g, 99% yield). (1-c) Synthesis of rac-dimethylsilylenebis(2,5-dimethyl-3-phenyl-cyclopenta[b]thienyl)hafnium dichloride (complex A): Dimethylbis(2,5-dimethyl-3-phenyl-hydrocyclopenta[b]thiophene)silane (6.1g, 12mmol) and 200ml of diethyl ether were added to a 500ml glass reaction vessel, and the vessel was cooled to -70℃ in a dry ice-methanol bath. A n-butyllithium-n-hexane solution (1.55mol / L, 16ml, 24mmol) was added dropwise to the vessel. After the addition, the mixture was returned to room temperature and stirred for 2 hours. The solvent of the reaction solution obtained was concentrated under reduced pressure to about 20ml, after which 250ml of toluene and 10ml of THF were added, and the mixture was cooled to -70℃ in a dry ice-methanol bath. 3.8g (12mmol) of hafnium tetrachloride was added to the vessel. The mixture was then gradually returned to room temperature and stirred overnight. The solvent was distilled off under reduced pressure and the resulting solid was recrystallized from toluene / hexane to obtain 0.87 g (yield 10%) of racemic dimethylsilylenebis(2,5-dimethyl-3-phenyl-cyclopenta[b]thienyl)hafnium dichloride (purity 97%) as yellow crystals.

[0153] The racemic mixture was analyzed by proton nuclear magnetic resonance ( 1 The identified values ​​by H-NMR are shown below. 1 H-NMR (CDCl3) Identification Results Racemic: δ1.06(s,6H), δ2.42(s,6H), δ2.59(s,6H), δ8.51(s,2H), δ7.28~δ7.33(m,2H), δ7.39~δ7.43(m,4H), δ7.46~δ7.50(m,4H)

[0154] (1-3) Synthesis Example 3: Synthesis of Comparative Catalyst Component [CA-2] (Complex 3) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium: rac-Dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium was synthesized according to the method of Example 7 of JP-A-11-240909.

[0155] (2) Synthesis example of component (B): Chemical treatment of ion-exchangeable layered silicate Into a 1 L three-neck flask equipped with a stirring blade and a reflux device, 645.1 g of distilled water and 82.6 g of 98% sulfuric acid were added and heated to 95°C. 100 g of commercially available montmorillonite (Benclay KK manufactured by Mizusawa Chemical Industry Co., Ltd., Al=9.78% by mass, Si=31.79% by mass, Mg=3.18% by mass, Al / Si (molar ratio)=0.320, average particle size 14 μm) was added thereto, and the mixture was reacted for 320 minutes at 95° C. After 320 minutes, 0.5 L of distilled water was added to stop the reaction, and 255 g of a cake-like solid was obtained by filtration. This cake (1 g) contained 0.31 g of the chemically treated montmorillonite (intermediate). The chemical composition of the chemically treated montmorillonite (intermediate) was Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, and Al / Si (molar ratio) = 0.222. 1545g of distilled water was added to the cake to make a slurry, and the temperature was raised to 40℃. 5.734g of lithium hydroxide hydrate was added as a solid to the slurry, and the reaction was carried out at 40℃ for 1 hour. After 1 hour, the reaction slurry was filtered and washed three times with 1L of distilled water, and a cake-like solid was obtained again. The cake-like solid obtained was pre-dried overnight at 90°C or higher under normal pressure, and then dried under reduced pressure for 2 hours or more after the bumping subsided using an oil bath at 200°C to obtain 80 g of chemically treated montmorillonite. The chemical composition of this chemically treated montmorillonite was Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, Al / Si (molar ratio) = 0.222, Li = 0.53 mass%.

[0156] (3) Preparation of catalyst (3-1) Synthesis example of catalyst 1 10 g of the chemically treated montmorillonite obtained above was placed in a three-neck flask (volume 1 L) and heptane (66 mL) was added to make a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution with a concentration of 143 mg / mL) was added to the slurry and stirred for 1 hour, and then washed with heptane until the residual liquid ratio was 1 / 100, and the total volume was made 50 mL. In another flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 1) (105 μmol) prepared in the synthesis example of the catalyst component [A-1] was dissolved in toluene (21 mL) to prepare solution 1. Furthermore, in another flask (volume 200 mL), rac-dimethylsilylenebis(2,5-dimethyl-3-phenyl-cyclopenta[b]thienyl)hafnium dichloride (complex 2) (45 μmol) prepared in the synthesis example of the catalyst component [A-2] was dissolved in toluene (9 mL) to prepare solution 2.

[0157] To the 1 L flask containing the above-mentioned chemically treated montmorillonite, triisobutylaluminum (0.42 mmol: 0.6 mL of a heptane solution with a concentration of 143 mg / mL) was added, and then the above-mentioned solution 1 (21 mL) was added and stirred at room temperature for 20 minutes. Thereafter, triisobutylaluminum (0.18 mmol: 0.25 mL of a heptane solution with a concentration of 143 mg / mL) was further added, and then the above solution 2 was added, followed by stirring at room temperature for 1 hour. Then, 170 mL of heptane was added to the mixture, and the slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was brought to 40°C, propylene was fed at a rate of 5g / hour, and prepolymerization was carried out while maintaining 40°C for 4 hours. Thereafter, 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 (6mmol: 8.5mL of heptane solution with a concentration of 143mg / mL) was added to the remaining portion and stirred for 5 minutes. The catalyst slurry was dried under reduced pressure for 1 hour to obtain 28.2 g of a prepolymerized catalyst (Catalyst 1). The prepolymerization ratio (value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) was 1.82.

[0158] (3-2) Synthesis example of catalyst 2 10 g of the chemically treated montmorillonite obtained above was placed in a three-neck flask (volume 1 L) and heptane (66 mL) was added to make a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution with a concentration of 143 mg / mL) was added to the slurry and stirred for 1 hour, and then washed with heptane until the residual liquid ratio was 1 / 100, and the total volume was made 50 mL. In another flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 1) (105 μmol) prepared in the synthesis example of the catalyst component [A-1] was dissolved in toluene (21 mL) to prepare solution 1. Furthermore, in another flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (complex 3) (45 μmol) prepared in the synthesis example of the comparative catalyst component [CA-2] was dissolved in toluene (9 mL) to prepare solution 2.

[0159] Triisobutylaluminum (0.42 mmol: 0.6 mL of a heptane solution with a concentration of 143 mg / mL) was added to a 1 L flask containing the above-mentioned chemically treated montmorillonite, and then the above solution 1 (21 mL) was added and stirred at room temperature for 20 minutes. Thereafter, triisobutylaluminum (0.18 mmol: 0.25 mL of a heptane solution with a concentration of 143 mg / mL) was further added, and then the above solution 2 was added, followed by stirring at room temperature for 1 hour. Then, 170 mL of heptane was added to the mixture, and the slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was brought to 40°C, propylene was fed at a rate of 5g / hour, and prepolymerization was carried out while maintaining 40°C for 4 hours. Thereafter, 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 (6mmol: 8.5mL of heptane solution with a concentration of 143mg / mL) was added to the remaining portion and stirred for 5 minutes. The catalyst slurry was dried under reduced pressure for 1 hour to obtain 30.9% prepolymerized catalyst (catalyst 2). The prepolymerization rate was 2.09%.

[0160] (4) Examples [Example 1] (polymerization) The 20L autoclave was used after replacing the inside of the tank with propylene and cooling to room temperature. 18.7mL of a heptane solution of triisobutylaluminum (140mg / mL), 107g of ethylene, 0.34NL of hydrogen, and 5000g of liquid propylene were introduced into the polymerization tank, and the temperature was raised to 63°C. Then, 160mg of the catalyst 1, excluding the prepolymerized polymer, was pumped into the polymerization tank with high-pressure argon to start polymerization, and the temperature inside the tank was quickly raised to 70°C. The temperature was kept at 70°C, and after 1 hour from the start of polymerization, the unreacted propylene was quickly purged to stop the polymerization. As a result, 2172g of branched propylene-based polymer particles were obtained. The obtained polymer particles were used for GPC, 3D-GPC, 13 C-NMR and DSC measurements were performed.

[0161] (granulation) 100 parts by mass of the obtained branched propylene-based polymer particles were blended with 0.125 parts by mass of a phenol-based antioxidant IRGANOX1010 (manufactured by BASF Japan, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane) and 0.125 parts by mass of a phosphite-based antioxidant IRGAFOS168 (manufactured by BASF Japan, tris(2,4-di-t-butylphenyl)phosphite) and mixed for 3 minutes at room temperature using a high-speed stirring mixer Henschel mixer (manufactured by Nippon Coke and Engineering Co., Ltd.). Then, using a twin-screw extruder KZW-15 (manufactured by Technobel Co., Ltd.), the screw rotation speed was 400 rpm and the kneading temperature was 80, 120, and 230 ° C. from the bottom of the hopper (the same temperature from then to the die outlet). 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 of the obtained pellets was 3.9g / 10min. The obtained pellets were used to measure Ea, MT, extensional viscosity, TREF, and MaxDraw. The evaluation results of each property are shown in Table 1.

[0162] [Example 2] Polymerization was carried out in the same manner as in Example 1, except that the catalyst 1 was introduced in an amount of 120 mg (mass excluding the prepolymerized polymer) and 0.60 NL of hydrogen was introduced in the polymerization of Example 1. As a result, 1750 g of branched propylene polymer particles were obtained. The obtained polymer particles were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 7.8 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0163] [Example 3] Polymerization was carried out in the same manner as in Example 1, except that 138 g of ethylene, 400 mg of catalyst 1 (mass excluding the prepolymerized polymer), and 0.34 NL of hydrogen were introduced in the polymerization of Example 1. As a result, 2226 g of branched propylene polymer particles were obtained. . The polymer particles obtained above were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 3.0 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0164] [Example 4] Polymerization was carried out in the same manner as in Example 1, except that the amount of catalyst 1 introduced was 120 mg (mass excluding the prepolymerized polymer) and 1.68 NL of hydrogen was introduced in the polymerization of Example 1. As a result, 2390 g of branched propylene polymer particles were obtained. The polymer particles obtained above were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 7.8 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0165] [Example 5] Polymerization was carried out in the same manner as in Example 1, except that the catalyst 1 was introduced in an amount of 90 mg (mass excluding the prepolymerized polymer) and 1.02 NL of hydrogen was introduced. As a result, 1502 g of branched propylene polymer particles was obtained. The polymer particles obtained above were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 23.4 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0166] [Example 6] Polymerization was carried out in the same manner as in Example 1, except that 60 mg of catalyst 1 (mass excluding the prepolymerized polymer) and 0.68 NL of hydrogen were introduced, the temperature inside the tank was raised to 65° C., and the temperature was maintained at 65° C. As a result, 1852 g of branched propylene polymer particles were obtained. The polymer particles obtained above were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 7.8 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0167] [Comparative Example 1] The 20L autoclave was used after replacing the inside of the tank with propylene and cooling to room temperature. 18.7mL of a heptane solution of triisobutylaluminum (140mg / mL) and 0.68NL of hydrogen were introduced into the polymerization tank, followed by 5000g of liquid propylene, and the temperature was raised to 63°C. Then, 310mg of the catalyst 2, excluding the prepolymerized polymer, was pumped into the polymerization tank with high-pressure argon to start polymerization, and the temperature inside the tank was quickly raised to 70°C. The temperature was kept at 70°C, and after 1 hour from the start of polymerization, the unreacted propylene was quickly purged to stop the polymerization. As a result, 2288g of branched propylene-based polymer particles were obtained. The polymer particles obtained above were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 3.3 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0168] [Comparative Example 2] Polymerization was carried out in the same manner as in Comparative Example 1, except that 230 mg of catalyst 2 (mass excluding the prepolymerized polymer) and 1.02 NL of hydrogen were introduced, resulting in 1978 g of branched propylene polymer particles. The polymer particles obtained above were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 9.9 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0169] [Comparative Example 3] Polymerization was carried out in the same manner as in Comparative Example 1, except that 220 mg of catalyst 2 (mass excluding the prepolymerized polymer) and 1.11 NL of hydrogen were introduced, resulting in 1,936 g of branched propylene polymer particles. The polymer particles obtained above were granulated in the same manner as in Example 1, and the MFR of the obtained pellets was 15.0 g / 10 min. The properties were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0170] [Reference Example 1]: Performance evaluation of complex 1 as catalyst component (A) (Preparation of Catalyst R1) 10 g of the chemically treated montmorillonite obtained above was placed in a three-neck flask (volume 1 L) and heptane (65 mL) was added to make a slurry. Triisobutylaluminum (25 mmol: 35 mL of heptane solution with a concentration of 143 mg / mL) was added to the slurry and stirred for 1 hour, and then washed with heptane until the residual liquid ratio was 1 / 100, and the total volume was made 50 mL. In addition, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 1) (0.15 mmol) synthesized in Synthesis Example 1 was dissolved in toluene (30 mL) to prepare a solution.

[0171] To the 1 L flask containing the above-mentioned chemically treated montmorillonite, triisobutylaluminum (0.60 mmol: 0.85 mL of a heptane solution with a concentration of 143 mg / mL) was added, and then the above solution was added and stirred at room temperature for 60 minutes. Then, 170 mL of heptane was added to the mixture, 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 5g / hour, and prepolymerization was carried out 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 a heptane solution with a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes. The catalyst slurry was dried under reduced pressure for 40 minutes to obtain 29.5 g of a prepolymerized catalyst (Catalyst R1). The prepolymerization rate was 1.95.

[0172] (polymerization) The 20L autoclave was used after replacing the inside of the tank with propylene and cooling to room temperature. 18.7mL of a heptane solution of triisobutylaluminum (140mg / mL) and 0.51NL of hydrogen were introduced into the polymerization tank, followed by 5000g of liquid propylene, and the temperature was raised to 63°C. Then, 300mg of the catalyst R1, excluding the prepolymerized polymer, was pumped into the polymerization tank with high-pressure argon to start polymerization, and the temperature was quickly raised to 70°C. The temperature was kept at 70°C, and after 1 hour from the start of polymerization, the unreacted propylene was quickly purged to stop the polymerization. As a result, 1740g of propylene homopolymer was obtained. Table 2 shows the results of MFR, GPC, and NMR measurements using the obtained polymer.

[0173] [Reference Example 2]: Performance evaluation of complex 2 as catalyst component (A) (Preparation of Catalyst R2) 10 g of the chemically treated montmorillonite obtained above was placed in a three-neck flask (volume 1 L) and heptane (66 mL) was added to make a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution with a concentration of 143 mg / mL) was added to the slurry and stirred for 1 hour, and then washed with heptane until the residual liquid ratio was 1 / 100, and the total volume was made 50 mL. In addition, in a separate flask (volume 200 mL), rac-dimethylsilylenebis(2,5-dimethyl-3-phenyl-cyclopenta[b]thienyl)hafnium dichloride (complex 2) (0.15 mmol) synthesized in Synthesis Example 2 was dissolved in toluene (30 mL) to prepare a solution.

[0174] To the 1 L flask containing the above-mentioned chemically treated montmorillonite, triisobutylaluminum (0.60 mmol: 0.85 mL of a heptane solution with a concentration of 143 mg / mL) was added, and then the above solution was added and stirred at room temperature for 60 minutes. Then, 170 mL of heptane was added to the mixture, 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 5g / hour, and prepolymerization was carried out 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 a heptane solution with a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes. The catalyst slurry was dried under reduced pressure for 1 hour to obtain 32.0 g of a prepolymerized catalyst (Catalyst R2). The prepolymerization rate was 2.20.

[0175] (polymerization) Polymerization was carried out in the same manner as in Reference Example 1, except that catalyst R2 was used instead of catalyst R1, 100 mg of the mass excluding the prepolymerized polymer, and 1.19 NL of hydrogen was introduced. As a result, 1153 g of polymer was obtained. The results of MFR, GPC, and NMR measurements of the obtained polymer are shown in Table 2.

[0176] [Reference Example 3]: Performance evaluation of complex 3 as catalyst component (A) (Preparation of catalyst R3) 10 g of the chemically treated montmorillonite obtained above was placed in a three-neck flask (volume 1 L) and heptane (66 mL) was added to make a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution with a concentration of 143 mg / mL) was added to the slurry and stirred for 1 hour, and then washed with heptane until the residual liquid ratio was 1 / 100, and the total volume was made 50 mL. In addition, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (complex 3) (0.15 mmol) synthesized in Synthesis Example 3 was dissolved in toluene (30 mL) to prepare a solution.

[0177] To the 1 L flask containing the above-mentioned chemically treated montmorillonite, triisobutylaluminum (0.60 mmol: 0.85 mL of a heptane solution with a concentration of 143 mg / mL) was added, and then the above solution was added and stirred at room temperature for 60 minutes. Then, 170 mL of heptane was added to the mixture, and the slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was brought to 40°C, propylene was fed at a rate of 5g / hour, and prepolymerization was carried out while maintaining 40°C for 4 hours. Thereafter, 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 (6mmol: 8.5mL of heptane solution with a concentration of 143mg / mL) was added to the remaining portion and stirred for 5 minutes. The catalyst slurry was dried under reduced pressure for 1 hour to obtain 31.0 g of a prepolymerized catalyst (Catalyst R3). The prepolymerization rate was 2.10.

[0178] (polymerization) Polymerization was carried out in the same manner as in Reference Example 1, except that catalyst R3 was used instead of catalyst R1, 300 mg of the mass excluding the prepolymerized polymer, and 0.51 NL of hydrogen was introduced. As a result, 1570 g of polymer was obtained. The results of MFR, GPC, and NMR measurements of the obtained polymer are shown in Table 2.

[0179] From the results of Reference Examples 1 to 3 in Table 2, it was shown that complex 1 of Synthesis Example 1 can be used as a metallocene compound that gives a propylene homopolymer a-1 having a terminal vinyl ratio (Rv) of 0.5 or more when propylene homopolymerization is performed at 70°C using component [A-1], and complex 2 of Synthesis Example 2 can be used as a metallocene compound that gives a propylene homopolymer a-2 having a number average molecular weight (Mn) larger than that of the propylene homopolymer a-1 and an Rv of 0.1 or more and smaller than 0.5 when propylene homopolymerization is performed at 70°C using component [A-2], and the propylene homopolymer a-2 can be used as a metallocene compound in which the ratio of the number of terminal vinyls produced that are copolymerized into LCBs {LCB number / ([Vi]+LCB number)} is larger than that of the propylene homopolymer a-1. Complex 3 in Synthesis Example 3 was a metallocene compound that gave a propylene homopolymer having a larger Mn than the propylene homopolymer a-1 but an Rv of 0 when propylene homopolymer was subjected to propylene homopolymerization at 70°C.

[0180] (5) Measurement and evaluation methods For the branched propylene polymers obtained in Examples 1 to 6 and Comparative Examples 1 to 3, and the propylene polymers obtained in Reference Examples 1 to 3, the following (5-1) to (5-14) were measured and calculated by the methods described in this specification. (5-1) MFR Furthermore, the measured MFR values ​​were used to calculate the values ​​on the right-hand sides of the above formulas (1), (2) and (8). (5-2) Tm and Tc measured by DSC (5-3) Ea in dynamic viscoelasticity measurement

[0181] (5-4) Mn, Mw, Mz, Mw / Mn, and Mz / Mw Obtained by GPC (5-5) W1 million, W2 million, and W2 million / W1 million in the integral molecular weight distribution curve obtained by GPC (5-6) Mw obtained by 3D-GPC abs , g'(million), g'(Mw abs ), and [g'(Mw abs )-g'(1 million)] (5-7) 13 Ethylene content measured by C-NMR (5-8) 13 mm, [2,1 bond] amount, and [1,3 bond] amount measured by C-NMR (5-9) 13 LCB number measured by C-NMR (5-10) The amount of components eluted at temperatures below 40°C in the elution curve obtained by TREF (TREF 40°C solubles) (5-11) SHI@1.0s obtained from extensional viscosity measurement -1 and MBI (5-12) Melt tension (MT230) (5-13) MaxDraw (5-14)[Vi], terminal vinyl ratio, number of LCBs / ([Vi]+number of LCBs)

[0182] (6) Evaluation results The results of each of the Examples, Comparative Examples, and Reference Examples are shown in Tables 1 and 2, as well as FIGS.

[0183] [Table 1]

[0184] [Table 2]

[0185] As shown in Table 1, the branched propylene polymers of Comparative Examples 1 to 3 have low Ea in proportion to MFR. The branched propylene polymers of Comparative Examples 1 to 3 do not have the preferred molecular weight distribution and branching distribution specified in the present invention. abs Although the amount of components with branches in the 1,000,000 part is small, it has a high melt tension, so it is presumed that there are many components with extremely long relaxation times. As a result, it is thought that the ductility when melted is poor. In contrast, as shown in Table 1, all of the branched propylene polymers of Examples 1 to 6 satisfied the above-mentioned properties (1) to (3), and had a branched propylene structure, particularly a branching distribution and a molecular weight distribution, different from conventional structures. The branched propylene polymers of Examples 1 to 6 had an MFR of 3.0 g / 10 min to 23.4 g / 10 min and an MT230 of 1.1 g to 4.2 g, and had a MaxDraw of 138 m / min to 385 m / min while maintaining a melt tension required for molding. Thus, the branched propylene polymers of Examples 1 to 6 had excellent extensibility when melted while maintaining the fluidity and melt tension required for molding. All of the branched propylene polymers of Examples 1 to 6 had MaxDraw and MFR satisfying the relationship represented by the above formula (8), and were shown to have excellent extensibility in proportion to the MFR.

Claims

1. A branched propylene polymer comprising propylene and 0 mol % to 11 mol % of at least one comonomer selected from ethylene and an α-olefin having 4 or more carbon atoms, the branched propylene polymer having the following properties (1), (2-1) and (3): Property (1): The melt flow rate (MFR) measured at a temperature of 230° C. under a load of 2.16 kg is 0.1 g / 10 min to 100 g / 10 min. Property (2-1): The melting point (Tm) measured by differential scanning calorimetry (DSC) is less than 155.0°C. Property (3): The flow activation energy (Ea) kJ / mol and MFR obtained by measuring dynamic viscoelasticity satisfy the following formula (1). Ea≧−12.5×log(MFR)+66 Formula (1)

2. The branched propylene polymer according to claim 1, further having the following property (2-2): Property (2-2): The difference (Tm-Tc) between the melting point (Tm) and the crystallization temperature (Tc) measured by differential scanning calorimetry (DSC) is greater than 34.0°C and less than 40.0°C.

3. The branched propylene polymer according to claim 1 or 2, further having the following property (4-1): Characteristic (4-1): In the molecular weight distribution curve obtained by 3D-GPC, the absolute molecular weight M ａｂｓ The branching index g' (million) is 0.60 to 0.

75.

4. The branched propylene polymer according to claim 1 or 2, further having the following property (5-1): Property (5-1): The ratio (Mz / Mw) of z-average molecular weight (Mz) to weight-average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is 2.0 to 4.

0.

5. The branched propylene polymer according to claim 1 or 2, further having the following property (5-2): Property (5-2): In an integrated molecular weight distribution curve obtained by GPC, the ratio (W2 million / W1 million) of the proportion of components having a molecular weight of 2 million or more (W2 million) to the proportion of components having a molecular weight of 1 million or more (W1 million) satisfies the following formula (2): (W2 million / W1 million) <-0.05×log(MFR)+0.34 Formula (2)

6. The branched propylene polymer according to claim 1 or 2, further having the following properties (6-1) and (6-2): Characteristics (6-1): １３ The meso triad fraction measured by C-NMR is 95.0% or more and less than 99.0%. Characteristic (6-2): The amount of heterogeneous bonds (2,1 bonds) is in the range of 0 mol % to 0.30 mol %, and the amount of heterogeneous bonds (1,3 bonds) is in the range of 0 mol % to 0.25 mol %.

7. The branched propylene polymer according to claim 1 or 2, further having the following property (7): Characteristic (7): １３ The number of long chain branches measured by C-NMR is 0.1 to 0.5 per 1000 monomers.

8. The branched propylene polymer according to claim 1 or 2, further having the following property (8): Property (8): In an elution curve obtained by temperature rising elution fractionation measurement using o-dichlorobenzene, the amount of components eluted at a temperature of 40° C. or less is 0.1% by mass to 4.0% by mass.

9. The branched propylene polymer according to claim 1 or 2, further having the following property (9): Property (9): The strain hardening degree at a strain rate (dε / dt) of 1.0 / sec is 0.70 to 2.

50.

10. The branched propylene polymer according to claim 1 or 2, further having the following property (10): Property (10): The branching index is 0.10 to 1.00.

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