Branched propylene polymer and method for producing same

Abstract

Provided is a branched propylene polymer having the following properties (1) to (5).　Property (1): MFR is 10-100 g / 10 min.　Property (2): Mw / Mn is not less than 2.5 but less than 3.5, Mz / Mw is 3.0-4.7, and Mz is 50.0-94.0.　Property (3): In an integral molecular weight distribution curve obtained by GPC, the proportion of components having a molecular weight of 1,000,000 or more is 1.5-4.0 mass%.　Property (4): In a molecular weight distribution curve obtained by 3D-GPC, the branch index g'(1,000,000) for which absolute molecular weight Mabs is 1,000,000 is greater than 0.70 but not more than 0.85.　Property (5): The ratio η*(0.01) / η*(100) of complex viscosity η*(0.01) to complex viscosity η*(100) in a dynamic viscoelasticity measurement is 4.0-20, and η*(0.01) / η*(100) and MFR satisfy a specific relational expression.

Description

[Technical Field]

[0001] The present invention relates to a branched propylene polymer and a production method thereof, and more particularly to a branched propylene polymer that exhibits reduced strain hardening in a low deformation rate region and a large difference between strain hardening in a low deformation rate region and strain hardening in a high deformation rate region while maintaining a melt tension required for molding, and a production method thereof. [Background technology]

[0002] Polypropylene has advantages such as a low specific gravity, excellent chemical resistance, excellent recyclability, and no toxic gases when incinerated. However, its melt tension is low, and there is still room for improvement in its formability in extrusion molding, thermoforming, and other processes. In recent years, much research has been conducted into improving the moldability of polypropylene in processes such as sheet molding, sheet foam molding, injection foam molding, blow molding, extrusion lamination molding, and thermoforming by increasing the melt tension through the introduction of branched structures.

[0003] Recently, a macromer copolymerization method using a metallocene catalyst has been proposed as a method for introducing a branched structure into polypropylene. The branched propylene polymer obtained by the macromer copolymerization method has advantages such as less generation of gel due to crosslinking reactions compared to polypropylene in which a branched structure is introduced by irradiation with an electron beam or the like.

[0004] As a branched propylene polymer produced by such a macromer copolymerization method, for example, a polymer having a branching index g' of less than 0.93 has been disclosed (see Patent Document 1), which is produced by a method in which a propylene macromer having a vinyl structure at the end is produced in the first polymerization stage (macromer synthesis step), and then propylene and the propylene macromer are copolymerized in the second polymerization stage (macromer copolymerization step). Furthermore, 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 are 2.16 (g / 10 min) and the ratio (MI5 / MI 2.16) and the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn measured by gel permeation chromatography is MI5 / MI 2.16 ≧0.240×Mw / Mn+3.1, and the melt tension MS (g) and the intrinsic viscosity [η] (dL / g) satisfy the relation logMS≧3.17×log[η]-0.68, and the intrinsic viscosity [η] is in the range of 0.1 to 15.0 dL / g (see Patent Document 2).

[0005] Also disclosed is a branched polypropylene having a polydispersity of 4.0 or less, a melting point exceeding 90°C, and a branching index g' of less than 0.95, which is obtained by a single-stage polymerization method in which a macromer synthesis step and a macromer copolymerization step are carried out simultaneously (see Patent Document 3).

[0006] In addition, a propylene homopolymer having the properties (1) to (6) has been disclosed, which was obtained by a method in which the production of terminal vinyl and copolymerization were carried out on a single supported catalyst by using a catalyst containing a specific single metallocene compound and an ion-exchange layered silicate (see Patent Document 4). (1) The weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is 200,000 to 1,000,000. (2) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) obtained by GPC is 3.5 to 10.5. (3) The common logarithm of the molecular weight corresponding to the peak position of the molecular weight distribution curve obtained by GPC 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 respectively α = H 50 -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 temperature rising elution fractionation (TREF) measurements using orthodichlorobenzene as the solvent, the amount of components eluting at temperatures of 90°C or less is 6.0% by mass or less. (6) Propylene polymer 13 In C-NMR analysis, three methylene carbons (Ca, Cb, Cc) were observed at 44.0 to 44.1 ppm, 44.7 to 44.8 ppm, and 44.8 to 44.9 ppm, and a methine carbon (Cbr) was observed at 31.6 to 31.7 ppm, and the number of methine carbons was 0.1 or more per 1,000 total skeletal carbons (wherein "total skeletal carbons" means all carbon atoms other than methyl carbons).

[0007] Furthermore, a propylene-based polymer that satisfies the requirements (i) to (vi) and is obtained by a method using a catalyst containing specific plural metallocene compounds has been disclosed (see Patent Document 5). (i) The melt flow rate (MFR) (temperature 230°C, load 2.16 kg) is 0.1 g / 10 min or more and 100 g / 10 min or less. (ii) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 3.5 or more and 10.5 or less. (iii) In a molecular weight distribution curve obtained by GPC, the proportion of components having a molecular weight (M) of 2 million or more is 0.4% by mass or more and less than 10% by mass relative to the total mass. (iv) In temperature rising elution fractionation (TREF) using orthodichlorobenzene (ODCB), the content of components eluting at a temperature of 40°C or less is 3.0% by mass or less. (v) The isotactic triad fraction (mm) measured by 13C-NMR is 95% or more. (vi) The strain hardening coefficient (λmax) in the extensional viscosity measurement is 6.0 or more.

[0008] Furthermore, in order to obtain high stability of the melt under elongational flow, polypropylene having a multibranching index (MBI) of at least 0.15, which indicates strain rate thickening, has been disclosed (see Patent Document 6). Separately, a propylene-based copolymer that satisfies the requirements (i) to (iv) has been devised using a catalyst containing specific multiple metallocene compounds in order to improve dispersibility when blended with other resins and to improve the melt-cut heat seal strength and appearance (see Patent Document 7). (i) The melt flow rate (MFR) (temperature 230°C, load 2.16 kg) is 0.1 g / 10 min or more and 80 g / 10 min or less. (ii) The ratio (Q value) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 2.5 to 5.5. (iii) The proportion of components soluble in p-xylene at 25°C (CXS) is 0.1% by weight or more and less than 5.0% by weight. (iv) The strain hardening coefficient (λmax) in the extensional viscosity measurement is 1.5 or more and less than 6.0. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Special Publication No. 2001-525460 [Patent Document 2] Japanese Patent Application Publication No. 10-338717 [Patent Document 3] Special Publication No. 2002-523575 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-154121 [Patent Document 5] Japanese Patent Application Laid-Open No. 2009-275207 [Patent Document 6] Special Publication No. 2009-533540 [Patent Document 7] Japanese Patent Application Laid-Open No. 2015-193827 Summary of the Invention [Problem to be solved by the invention]

[0010] The branched propylene polymers disclosed in the above Patent Documents 1 to 5 all have improved melt tension. However, these branched propylene polymers are prone to problems caused by unstable flow of the molten resin during molding. For example, they are prone to the occurrence of draw resonance in extrusion molding, poor appearance due to relaxation of stress concentration during molding of the raw material in thermoforming, and weld lines in injection molding. Such defects are thought to be caused by the presence of a large number of components with extremely long relaxation times in the polymer. When a polymer contains a large number of components with extremely long relaxation times, strain hardening is not only large in the high deformation rate region, but also large in the low deformation rate region. Therefore, the difference between strain hardening in the low deformation rate region and the high deformation rate region becomes small, which is thought to cause defects. The branched propylene polymer disclosed in Patent Document 6 has a large multi-branching index, but does not have sufficient strain hardening in the high deformation rate range and does not have sufficient melt tension. The branched propylene polymer disclosed in Patent Document 7 has good dispersibility when blended with other resins, but the melt tension is sacrificed, and the degree of strain hardening in the high deformation rate region is also small, thereby reducing the difference with the strain hardening in the low deformation rate region.

[0011] Therefore, an object of the present invention is to provide a branched propylene polymer that exhibits reduced strain hardening in a low deformation rate region and a large difference between strain hardening in a low deformation rate region and strain hardening in a high deformation rate region while maintaining a melt tension required for molding, and a method for producing the branched propylene polymer. [Means for solving the problem]

[0012] As a result of extensive research, the present inventors have found the following: A branched propylene polymer has a structure, particularly a molecular weight distribution and a branching distribution, that is different from conventional propylene polymers, and has a complex viscosity η in dynamic viscoelasticity measurement. *When the angular frequency ω dependence of (ω) and the MFR satisfy a specific formula, the components with extremely long relaxation times are reduced. Such a branched propylene polymer exhibits reduced strain hardening in the low deformation rate region while maintaining the melt tension required for molding, and the difference between strain hardening in the low deformation rate region and strain hardening in the high deformation rate region is large.

[0013] The branched propylene polymer of the present invention has the following properties (1) to (5). Property (1): The melt flow rate (MFR) measured at a temperature of 230°C under a load of 2.16 kg is 10 g / 10 min or more and 100 g / 10 min or less. Property (2): The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), as determined by gel permeation chromatography (GPC), is 2.5 or more and less than 3.5, the ratio (Mz / Mw) of the z average molecular weight (Mz) to the weight average molecular weight (Mw) is 3.0 or more and 4.7 or less, and the z average molecular weight (Mz) is 500,000 or more and 940,000 or less. Property (3): In an integrated molecular weight distribution curve obtained by GPC, the proportion of components having a molecular weight of 1 million or more (W1 million) is 1.5% by mass or more and 4.0% by mass or less. Property (4): In the molecular weight distribution curve obtained by 3D-GPC, the absolute molecular weight M abs The branching index g'(million) is greater than 0.70 and less than 0.85. Property (5): Complex viscosity η at angular frequency ω = 0.01 rad / s in dynamic viscoelasticity measurement * (0.01) and the complex viscosity η at angular frequency ω=100rad / s * (100) [η * (0.01) / η * (100)] is 4.0 or more and 20 or less, and η * (0.01) / η * (100) and MFR satisfy the following formulas (1) and (2). η * (0.01) / η * (100)≦-21×Log(MFR)+45 Equation (1) η *(0.01) / η * (100) ≧ -21×Log(MFR)+38 Equation (2)

[0014] The branched propylene polymer of the present invention may further have the following property (4') in that it relatively reduces components having extremely long relaxation times. Characteristic (4'): Weight average molecular weight (Mw) of absolute molecular weight obtained by 3D-GPC abs ) is less than 1 million, and in the molecular weight distribution curve obtained by 3D-GPC, the weight average molecular weight Mw abs The branching index g'(Mw abs ) and the branching index g' (1 million) satisfy the following formula (3). 0≦g'(Mw abs )-g'(1 million)≦0.10...Equation (3)

[0015] The branched propylene polymer of the present invention may further have the following property (6) in terms of the fluidity and melt strength of the resin during molding. Characteristics (6): 13 The mesotriad fraction (mm) measured by C-NMR is 95% or more and less than 99%, the heterogeneous bond content (2,1 bond) is 0.05 mol% or more and 0.50 mol% or less, and the heterogeneous bond content (1,3 bond) is 0.05 mol% or more and 0.50 mol% or less.

[0016] The branched propylene polymer of the present invention may further have the following property (7) in terms of heat resistance, rigidity and touch of the product. Property (7): In an elution curve obtained by temperature rising elution fractionation (TREF) measurement using o-dichlorobenzene (ODCB), the content of components eluting at a temperature of 40°C or less is 0.1% by mass or more and 3.0% by mass or less.

[0017] The branched propylene polymer of the present invention may further have the following property (8) in terms of heat resistance, rigidity and touch of the product. Property (8): The melting point (Tm) measured by differential scanning calorimetry (DSC) is greater than 150.0°C and less than 160.0°C.

[0018] The branched propylene polymer of the present invention may further have the following property (9) in order to maintain high melt tension during molding. Characteristics (9): 13 The number of long chain branches measured by C-NMR is 0.1 or more and 0.5 or less per 1000 monomers.

[0019] The present invention also provides a method for producing the branched propylene polymer of the present invention, which comprises homopolymerizing propylene or copolymerizing propylene with a comonomer in the presence of a propylene polymerization catalyst containing the following components [A-1], [A-2], [B], and [C]: Component [A-1]: a metallocene compound that, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-1 having a terminal vinyl ratio (Rv) of 0.5 or more; Component [A-2]: a metallocene compound that, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-2 having a weight average molecular weight greater than that of the propylene homopolymer a-1 and a terminal vinyl ratio (Rv) of 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

[0020] In the method for producing the branched propylene polymer of the present invention, propylene may be homopolymerized or propylene and a comonomer may be copolymerized at a constant hydrogen concentration, in order to maintain the melt tension required for molding while avoiding the inclusion of an excessive amount of components having an extremely long relaxation time. In the method for producing a branched propylene polymer of the present invention, in order to avoid excessively increasing the amount of components having an extremely long relaxation time, hydrogen and propylene may be continuously introduced into a polymerization reactor, the ratio of the amounts of hydrogen and propylene introduced may be kept constant, and propylene may be homopolymerized or propylene and a comonomer may be copolymerized at a constant hydrogen concentration. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a branched propylene polymer that exhibits reduced strain hardening in a low deformation rate region and a large difference between strain hardening in a low deformation rate region and strain hardening in a high deformation rate region while maintaining a melt tension required for molding, and a method for producing the branched propylene polymer. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram illustrating the baseline and intervals of a chromatogram in GPC. [Figure 2] FIG. 2 is a diagram showing an example of an integrated molecular weight distribution curve. [Figure 3] FIG. 3 is a graph showing the relationship between the ratio of the complex viscosity on the low frequency side to the complex viscosity on the high frequency side [η*(0.01 rad / s) / η*(100 rad / s)] and the MFR (unit: g / 10 min) for the propylene-based polymers of Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0023] The branched propylene polymer of the present invention has the following properties (1) to (5). Property (1): The melt flow rate (MFR) measured at a temperature of 230°C under a load of 2.16 kg is 10 g / 10 min or more and 100 g / 10 min or less. Property (2): The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), as determined by gel permeation chromatography (GPC), is 2.5 or more and less than 3.5, the ratio (Mz / Mw) of the z average molecular weight (Mz) to the weight average molecular weight (Mw) is 3.0 or more and 4.7 or less, and the z average molecular weight (Mz) is 500,000 or more and 940,000 or less. Property (3): In an integrated molecular weight distribution curve obtained by GPC, the proportion of components having a molecular weight of 1 million or more (W1 million) is 1.5% by mass or more and 4.0% by mass or less. Property (4): In the molecular weight distribution curve obtained by 3D-GPC, the absolute molecular weight M abs The branching index g'(million) is greater than 0.70 and less than 0.85. Property (5): Complex viscosity η at angular frequency ω = 0.01 rad / s in dynamic viscoelasticity measurement * (0.01) and the complex viscosity η at angular frequency ω=100rad / s * (100) [η * (0.01) / η * (100)] is 4.0 or more and 20 or less, and η * (0.01) / η * (100) and MFR satisfy the following formulas (1) and (2). η * (0.01) / η * (100)≦-21×Log(MFR)+45 Equation (1) η * (0.01) / η * (100) ≧ -21×Log(MFR)+38 Equation (2)

[0024] The branched propylene polymer of the present invention has the above-mentioned properties (1) to (5), and has a branched propylene structure different from conventional ones, particularly a molecular weight distribution and a branching distribution, and a complex viscosity η in a dynamic viscoelasticity measurement. * When the angular frequency ω dependence of (ω) and the MFR satisfy a specific formula, components with extremely long relaxation times are reduced. Therefore, the branched propylene polymer of the present invention exhibits reduced strain hardening in a low deformation rate region while maintaining the melt tension required for molding. As a result, the branched propylene polymer of the present invention is a propylene polymer in which the difference between strain hardening in a low deformation rate region and strain hardening in a high deformation rate region is large.

[0025] Hereinafter, the physical properties and production method of the branched propylene polymer of the present invention will be described in detail for each item. In this specification, the use of "to" to indicate a range of values ​​means that the values ​​before and after it are included as the lower and upper limits. Any combination of upper and lower limits in the numerical range can be adopted.

[0026] 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 an α-olefin having 2 to 20 carbon atoms other than propylene, such as ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene.

[0027] I. Physical properties of branched propylene polymers Characteristics (1): The branched propylene polymer of the present invention has a melt flow rate (MFR) of 10 g / 10 min or more and 100 g / 10 min or less, measured at a temperature of 230° C. under a load of 2.16 kg. MFR is an index that indicates the fluidity of a molten resin, and as the molecular weight of a polymer increases, this value decreases. Conversely, as the molecular weight decreases, this value increases. In the branched propylene polymer, if the MFR is too small, the fluidity of the molten resin will be low, making it difficult to perform thermoforming. Therefore, the MFR is 10 g / 10 min or more, preferably 13 g / 10 min or more, more preferably 15 g / 10 min or more, and even more preferably 20 g / 10 min or more. The MFR may be 30 g / 10 min or more. On the other hand, if the MFR is too high, it will cause a decrease in melt tension. Therefore, the MFR is 100 g / 10 min or less, preferably 90 g / 10 min or less, more preferably 80 g / 10 min or less, and even more preferably 70 g / 10 min or less. The MFR may be 60 g / 10 min or less. In the present invention, the melt flow rate (MFR) is a value measured in accordance with JIS K7210 "Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastics - thermoplastics" under test conditions of 230°C and a load of 2.16 kgf. The melt flow rate (MFR) can be increased by increasing the polymerization temperature, decreasing the monomer concentration, or, more commonly, by adding hydrogen as a chain transfer agent during polymerization. When the temperature and monomer concentration are fixed, the MFR can be easily adjusted by adjusting the amount of hydrogen. The melt flow rate (MFR) can also be increased by appropriately degrading the polymer.

[0028] Characteristics (2): The branched propylene polymer of the present invention has a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) obtained by gel permeation chromatography (GPC) of 2.5 or more and less than 3.5, a ratio (Mz / Mw) of z average molecular weight (Mz) to weight average molecular weight (Mw) of 3.0 or more and 4.7 or less, and a z average molecular weight (Mz) of 500,000 or more and 940,000 or less. Mz, Mw, and Mn are indices that represent the average molecular weight of a polymer, with Mz being an index of the average molecular weight with a higher specific gravity on the high molecular weight side, Mn being an index of the average molecular weight with a higher specific gravity on the low molecular weight side, and Mw being an index of the average molecular weight in between. The ratios Mw / Mn and Mz / Mw are indices of the breadth of the molecular weight distribution of the polymer.

[0029] In a branched propylene polymer, if Mz is too large, the amount of components with extremely long relaxation times increases. Therefore, the Mz of the branched propylene polymer of the present invention is 940,000 or less, preferably 900,000 or less, more preferably 860,000 or less, and even more preferably 800,000 or less. The Mz may be 700,000 or less. On the other hand, a smaller Mz results in a lower melt tension. Therefore, the Mz of the branched propylene polymer of the present invention is 500,000 or more, preferably 540,000 or more, and more preferably 600,000 or more.

[0030] If the branched propylene polymer has an excessively large Mz / Mw ratio, the amount of components with extremely long relaxation times will be excessively large. Therefore, the Mz / Mw ratio of the branched propylene polymer of the present invention is 4.7 or less, preferably 4.5 or less, and more preferably 4.3 or less. On the other hand, if the Mz / Mw is too small, the melt tension decreases. Therefore, the Mz / Mw of the branched propylene polymer of the present invention is 3.0 or more, preferably 3.3 or more, and more preferably 3.5 or more.

[0031] If the branched propylene polymer has too large a Mw / Mn ratio, the amount of components with extremely long relaxation times will be too large. Therefore, the Mw / Mn ratio of the branched propylene polymer of the present invention is less than 3.5, preferably 3.4 or less, and more preferably 3.3 or less. On the other hand, if the Mw / Mn is too small, the fluidity of the molten resin decreases during high-shear and high-speed molding. Therefore, the Mw / Mn of the branched propylene polymer of the present invention is 2.5 or more, preferably more than 2.8, and more preferably more than 3.0.

[0032] In order to improve the fluidity of the molten resin while reducing the viscosity during high-shear and high-speed molding, the number-average molecular weight (Mn) of the branched propylene polymer of the present invention is preferably 40,000 or more, more preferably 45,000 or more, and is preferably 60,000 or less, more preferably 55,000 or less. The Mn may be 48,000 or more, or may be 50,000 or more. In view of the fluidity of the molten resin, the weight-average molecular weight (Mw) of the branched propylene polymer of the present invention is preferably 140,000 or more, more preferably 150,000 or more, even more preferably 160,000 or more, and is preferably 300,000 or less, more preferably 250,000 or less, even more preferably 230,000 or less. The Mw may be 200,000 or less.

[0033] The branched propylene polymer of the present invention has the above-described molecular weight and molecular weight distribution characteristics, and therefore can reduce components with extremely long relaxation times. As a result, the branched propylene polymer of the present invention can improve the fluidity of the molten resin, particularly under high shear stress, prevent breakage of the molten resin due to insufficient melt tension, and suppress instability when the molten resin flows during molding. Furthermore, the branched propylene polymer of the present invention tends to exhibit a large difference between strain hardening in a low deformation rate region and strain hardening in a high deformation rate region.

[0034] 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 by adjusting the polymerization conditions, such as the selection of catalyst type, polymerization temperature, monomer concentration, and amount of hydrogen. In the method for producing a branched propylene polymer of the present invention, as described below, it is preferable to use a polymerization catalyst containing component [A-1] (metallocene compound) that produces a macromer and component [A-2] (metallocene compound) that copolymerizes a propylene monomer with the macromer. In this case, it is generally preferable that, in the relationship between component [A-1] and component [A-2], component [A-1] acts as a catalyst component that produces relatively low molecular weight components, and component [A-2] acts as a catalyst component that produces relatively high molecular weight components. As a result, the rate of change in Mz is greater than the rate of change in Mw with respect to a change in the amount of hydrogen, so Mz / Mw can be changed without significantly changing Mw / Mn. For example, increasing the amount of hydrogen increases the rate of molecular weight reduction of the polymer produced from component [A-2], which produces a high molecular weight component, compared to the polymer produced from component [A-1], which produces a low molecular weight component. Furthermore, component [A-1] becomes relatively more activated than component [A-2], and the molecular weight distribution changes so that the proportion of polymer produced from component [A-1] is higher than that of polymer produced from component [A-2]. This change in molecular weight distribution allows for smaller Mz and Mz / Mw without significantly changing Mw and Mw / Mn. 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 the high molecular weight component increases relative to the polymer produced from the component [A-1] that produces the low molecular weight component. By changing the molecular weight distribution in this way, it is possible to increase Mz and Mz / Mw without significantly changing Mw and Mw / Mn. Furthermore, by using component [A-1] and component [A-2], selecting batch polymerization as the polymerization method, and changing the hydrogen concentration over time, it is possible to increase Mz / Mw and Mz, for example, without significantly changing Mw or Mw / Mn, due to the difference in the rate of change relative to hydrogen. Furthermore, by selecting continuous polymerization as the polymerization method and keeping the hydrogen concentration constant, it is possible to reduce Mz / Mw and Mz without significantly changing Mw or Mw / Mn.

[0035] The values ​​of Mz, Mw, Mn, Mw / Mn, Mz / Mw, and the W1 million and W2 million values ​​described below are all obtained by gel permeation chromatography (GPC), and 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℃ Solvent flow rate: 1.0 mL / min Sample concentration: 1 mg / mL Sample injection volume: 0.2 mL The sample is prepared by preparing a 1 mg / mL solution using the sample and ODCB (containing 0.5 mg / mL of dibutylhydroxytoluene (BHT)) and dissolving the sample at 140° C. for about 1 hour. The baseline and intervals of the obtained chromatogram are determined as shown in Figure 1. The conversion from the retention volume obtained by GPC measurement to molecular weight is performed using a calibration curve prepared in advance using standard polystyrenes. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation. Brand Name: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000 A 0.2 mL solution of each compound dissolved in ODCB (containing 0.5 mg / mL BHT) was injected to prepare a calibration curve. The calibration curve was calculated using a cubic equation obtained by approximating the curve using the least squares method. Viscosity formula used to convert to molecular weight: [η] = K × M α The following values ​​are used: PS:K = 1.38 × 10 -4 , α=0.7 PP:K = 1.03 × 10 -4 , α=0.78

[0036] Characteristics (3): In the branched propylene polymer of the present invention, the proportion of components having a molecular weight of 1 million or more (W1 million) is 1.5% by mass or more and 4.0% by mass or less in an integrated molecular weight distribution curve obtained by GPC. Characteristics (3'): In the branched propylene polymer of the present invention, the proportion of components having a molecular weight of 2 million or more (W2 million) is preferably 0.2% by mass or more and 1.5% by mass or less in an integrated molecular weight distribution curve obtained by GPC. The branched propylene polymer of the present invention has an increased melt tension due to the presence of components in the high molecular weight region. Therefore, the present invention focuses on components having a molecular weight of 1 million or more, and the branched propylene polymer of the present invention has a proportion of components having a molecular weight of 1 million or more (W1 million) of 1.5% by mass or more, preferably 1.6% by mass or more, and more preferably 1.7% by mass or more. W1 million may be 1.9% by mass or more, or may be 2.0% by mass or more. Furthermore, the branched propylene polymer of the present invention has a higher melt tension due to the presence of components in the extremely high molecular weight range. Therefore, the present invention focuses on components having a molecular weight of 2 million or more, and the proportion of components having a molecular weight of 2 million or more (W2 million) in the branched propylene polymer of the present invention is preferably 0.2 mass% or more, more preferably 0.25 mass% or more, and even more preferably 0.3 mass% or more. On the other hand, if the amount of components in the high molecular weight region is too large, the amount of components with extremely long relaxation times will be too large, and the difference between the strain hardening at a strain rate of 10 / sec (SHI@10) and the strain hardening at a strain rate of 1.0 / sec (SHI@1) will become small in the measurement of extensional viscosity. Therefore, the branched propylene polymer of the present invention has a W1 million of 4.0 mass% or less, preferably 3.8 mass% or less, more preferably 3.5 mass% or less, and even more preferably 2.5 mass% or less. For the same reason, W2 million is preferably 1.5 mass % or less, more preferably 1.2 mass % or less, and even more preferably 1.1 mass % or less.

[0037] In the present invention, W1 million and W2 million are defined as the value obtained by subtracting 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 from 1, and multiplying the result by 100. An example of an integrated molecular weight distribution curve is shown in FIG. 2.

[0038] In the present invention, the W1 million and W2 million of the branched propylene polymer 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., in the same manner as described in the property (2).

[0039] Characteristics (4): The branched propylene polymer of the present invention has an absolute molecular weight M abs The branching index g'(million) is greater than 0.70 and less than 0.85. The branching index g' is the intrinsic viscosity [η] of a polymer with a long-chain branching structure. br Intrinsic viscosity [η] of a linear polymer with the same molecular weight lin The ratio ([η] br / [η] lin ) When a polymer molecule has long-chain branches, its radius of gyration becomes smaller than that of a linear polymer molecule of the same molecular weight, resulting in a smaller intrinsic viscosity. Therefore, the branching index g' is smaller than 1.0. For linear polymers, the g' is 1.0 by definition. The definition of the branching index g' is described in, for example, "Developments in Polymer Characterization-4" (JV Dawkins ed., Applied Science Publishers, 1984), and is an index known to those skilled in the art. The branching index g' is calculated by using 3D-GPC to obtain the absolute molecular weight M abs can be obtained as a function of In this specification, 3D-GPC refers to a GPC device 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).

[0040] The branched propylene polymer of the present invention has an absolute molecular weight (M abs By having a branched structure in the high molecular weight region where the absolute molecular weight is 1 million (M abs The branching index g' (1 million) of the absolute molecular weight (M abs If there are too many branched structures in the high molecular weight region where the branching index g' (1 million) is 1 million, the number of components with extremely long relaxation times will be too large. Therefore, the lower limit of the branching index g' (1 million) is greater than 0.70, preferably 0.72 or more, and more preferably 0.74 or more. Thus, the branched propylene polymer of the present invention has an absolute molecular weight of 1 million (M abs A large amount of components with branches in the region of 1 million (M = 1 million) increases the melt strength, and the strain hardening index (SHI) increases in the measurement of extensional viscosity as a nonlinear viscoelastic property. On the other hand, even if the number of branches is large as a whole polymer, if the absolute molecular weight corresponding to the high molecular weight region is 1 million (M abs If the amount of components with branches in the region (=1 million) is not large, the strain hardening index (SHI) will not be large.

[0041] The branched propylene polymer of the present invention has a weight average molecular weight (Mw abs ) is preferably less than 1 million, and the absolute molecular weight (M abs ) weight average molecular weight (Mw abs ) region to the absolute molecular weight (Mw abs ) preferably has a branched structure in the high molecular weight region of 1 million in terms of having high melt strength. Therefore, the weight average molecular weight (Mw abs ) branching index g'(Mw abs ) is preferably 0.90 or less, more preferably 0.85 or less, and even more preferably 0.84 or less. On the other hand, the lower limit is preferably 0.75 or more, more preferably 0.76 or more, and even more preferably 0.77 or more. The lower limit may be 0.80 or more.

[0042] The strain hardening index (SHI) correlates with the relaxation time distribution and is dependent on the strain rate. That is, even if the melt strength is the same, if there are many branched components with extremely long relaxation times, the strain hardening will be large from high to low strain rates. On the other hand, if there are few branched components with extremely long relaxation times, the strain hardening will be large at high strain rates but small at low strain rates. The relaxation time of branched components is sufficiently long compared to linear molecules due to their branched structure, but the higher the molecular weight, the longer the relaxation time becomes. In other words, if the molecular weight becomes too large, the component will have an extremely long relaxation time. That is, in the branched propylene polymer of the present invention, Mw abs < 1 million, the molecular weight is greater than M abs The branched components present in 1 million are Mw abs The relaxation time is longer than that of the branched component present in the Therefore, it is preferable that the compound has the following characteristic (4'), from the viewpoint of having a component with an extremely long relaxation time, while preventing the relaxation time from being too extremely long.

[0043] Characteristics (4'): The branched propylene polymer of the present invention has a weight average molecular weight (Mw abs ) is less than 1 million, and in the molecular weight distribution curve obtained by 3D-GPC, the weight average molecular weight Mw abs The branching index g'(Mw abs ) and the branching index g' (million) preferably satisfy the following formula (3): 0≦g'(Mw abs )-g'(1 million)≦0.10...Equation (3) When the formula (3) is satisfied, the branched propylene polymer of the present invention has a branching index g' (Mw abs Since the difference between SHI@10 and the branching index g' (million) is small, the amount of components with extremely long relaxation times is relatively small. Therefore, the polymer is more likely to relax at a slower strain rate than a branched propylene polymer having the same melt strength, which is preferable in that it has the effect of increasing the difference between SHI@10 and SHI@1. The branched propylene polymer of the present invention is preferred in that the branching distribution is within the above range, since it can maintain a balance between the overall melt strength, particularly the extensional viscosity and the fluidity of the molten resin.

[0044] Absolute molecular weight M abs The molecular weight distribution and the branching index at each molecular weight are measured as follows. The GPC apparatus used is an Alliance GPCV2000 manufactured by Waters, equipped with a differential refractometer (RI) and a viscometer, and a DAWN-E manufactured by Wyatt Technology, equipped with a multi-angle laser light scattering detector (MALLS). The detectors are connected in the following order: MALLS, RI, and Viscometer. The mobile phase solvent was 1,2,4-trichlorobenzene (to which the antioxidant IRGANOX 1076 manufactured by BASF Japan Ltd. was added at a concentration of 0.5 mg / mL). The flow rate is 1 mL / min, and two columns, GMHHR-H(S)HT manufactured by Tosoh Corporation, are connected in series. The temperatures of the column, the sample injection port, and each detector were 140°C. The sample concentration was 1 mg / mL, and the injection volume (sample loop volume) was 0.2175 mL. Absolute molecular weight (M abs ), the root mean square radius of gyration (Rg) and the intrinsic viscosity ([η]) obtained from the Viscometer are calculated using the data processing software ASTRA (version 4.73.04) attached to MALLS, with reference to the following literature. References: 1.Developments in Polymer Characterization, vol.4. Essex: Applied Science; 1984. Chapter1. 2.Polymer, 45, 6495-6505(2004) 3.Macromolecules, 33, 2424-2436(2000) 4.Macromolecules, 33, 6945-6952(2000) The branching index g' is the intrinsic viscosity ([η] br ) and the intrinsic viscosity ([η] obtained by separately measuring a linear polymer lin ) and the ratio ([η] br / [η] lin ) is calculated as Here, a commercially available homopolypropylene (Novatec PP (registered trademark) manufactured by Japan Polypropylene Corporation, grade name: FY6) was used as the linear polymer, and [η] lin [η] of linear polymer lin The logarithm of [η] has a linear relationship with the logarithm of molecular weight, as known from the Mark-Houwink-Sakurada equation. lin can be obtained by extrapolating to the low molecular weight side or the high molecular weight side as appropriate.

[0045] In the present invention, the g' (million) and g' (Mw abs ), g'(Mw abs )-g' (million) can be adjusted by adjusting the polymerization conditions, such as the selection of catalyst type, polymerization temperature, monomer concentration, amount of hydrogen, etc., as explained in the characteristic (2).

[0046] Characteristics (5): Complex viscosity η at angular frequency ω = 0.01 rad / s in dynamic viscoelasticity measurements * (0.01) and the complex viscosity η at angular frequency ω=100rad / s * (100) [η * (0.01) / η * (100)] is 4.0 or more and 20 or less, and η * (0.01) / η * (100) and MFR satisfy the following formulas (1) and (2). η * (0.01) / η * (100)≦-21×Log(MFR)+45 Equation (1) η * (0.01) / η * (100) ≧ -21×Log(MFR)+38 Equation (2)

[0047] Generally, in the non-Newtonian properties exhibited by polymer melts, the presence of components with long relaxation times increases the storage modulus on the low frequency side, and also increases the loss modulus. Here, the complex viscosity η *is expressed by the following formula using the storage modulus G' and loss modulus G'', and as the storage modulus and loss modulus increase, the complex viscosity also increases.

[0048]

number

[0049] η is the complex viscosity at ω=100 rad / s in dynamic viscoelasticity measurements * (100) is the viscosity under high shear and correlates with the fluidity of the molten resin in molding accompanied by rapid deformation. From the viewpoint of increasing strain hardening in the high deformation rate region, the branched propylene polymer of the present invention has a η * (100) is preferably 100 Pa.s or more, more preferably 120 Pa.s or more, and preferably 350 Pa.s or less, more preferably 300 Pa.s or less. * (100) may be 150 Pa.s or more, further 180 Pa.s or more, or may be 250 Pa.s or less. η is the complex viscosity at ω=0.01 rad / s in dynamic viscoelasticity measurements * (0.01) is a viscosity under low shear and correlates with the fluidity of the molten resin in molding accompanied by slow deformation. From the viewpoint of reducing strain hardening in the low deformation rate region, the branched propylene polymer of the present invention has a viscosity of η * (0.01) is preferably 500 Pa.s or more, more preferably 1000 Pa.s or more, and preferably 4000 Pa.s or less, more preferably 3000 Pa.s or less. * (0.01) may be 2500 Pa.s or less. The branched propylene polymer of the present invention has a strain hardening ratio of η 2 / μm to reduce the difference between strain hardening in a low deformation rate region and strain hardening in a high deformation rate region. * (0.01) / η * (100) is 4.0 or more and 20.0 or less, preferably 4.5 or more, more preferably 5.0 or more, and preferably 15.0 or less, more preferably 9.0 or less.

[0050] Furthermore, satisfying the formula (1) and formula (2) means that the branched propylene polymer of the present invention has a ratio η of the complex viscosity on the low frequency side to the complex viscosity on the high frequency side. * (0.01) / η * (100) is shown to be within the range of a specific relationship in terms of MFR. The branched propylene polymer of the present invention has a complex viscosity ratio η * (0.01) / η * (100) is in a range corresponding to MFR different from that of conventional propylene-based polymers, that is, it satisfies formula (1) and formula (2). Ratio of complex viscosity to MFR η * (0.01) / η * If the (100) is too large, components with extremely long relaxation times will be present, causing instability in the flowing molten resin. Specifically, for example, in extrusion lamination molding, draw resonance increases during high-speed molding. Therefore, the branched propylene polymer of the present invention satisfies the following formula (1): η * (0.01) / η * (100)≦-21×Log(MFR)+45 Equation (1) More preferably, the following formula (1') is satisfied. η * (0.01) / η * (100)≦-21×Log(MFR)+43 Equation (1') On the other hand, the ratio of complex viscosity to MFR is η * (0.01) / η * If the (100) is too small, the melt tension will be insufficient. Specifically, for example, in extrusion lamination molding, the neck-in phenomenon will become significant during high-speed molding. Therefore, the branched propylene polymer of the present invention satisfies the following formula (2): η * (0.01) / η * (100) ≧ -21×Log(MFR)+38 Equation (2) More preferably, the following formula (2') is satisfied. η * (0.01) / η *(100) ≧ -21×Log(MFR)+40 Equation (2')

[0051] Generally, there is a problem that increasing the fluidity of a molten resin reduces the melt strength, and therefore, a propylene polymer that has both the necessary fluidity and excellent melt strength is desired. A branched propylene polymer that has excellent melt strength and satisfies the formulas (1) and (2) is a polymer that could not be achieved with conventional branched propylene polymers, and can be said to have a high balance between the fluidity and melt strength of the molten resin. The above formula is expressed by the ratio of complex viscosities η * (0.01) / η * Considering that (100) is a function that has a negative correlation with an increase in MFR, based on the data of the Example and Comparative Examples 1, 2, and 3, which have a branching index g' (1 million) at the same level as the Example and high melt tension, an approximate relationship between the ratio of complex viscosities and MFR that distinguishes between the Example, which can solve the problem, and the Comparative Examples of the prior art, which cannot solve the problem, was determined (see Figure 3).

[0052] η * (0.01), η * (100), and η * (0.01) / η * When the (100) is in the above-mentioned specific range, it is easy to suppress the instability phenomenon when the molten resin flows during molding, improve the fluidity of the molten resin especially under high shear, and it is easy to prevent the molten resin from breaking due to insufficient melt tension. In addition, the difference between the strain hardening at low deformation rates and at high deformation rates tends to be large.

[0053] The complex viscosity (η * ) can be measured using a conventional device for measuring dynamic viscoelasticity. An example of a device for measuring dynamic viscoelasticity is the ARES-G2 manufactured by TA Instruments. The propylene polymer is compression-molded at 180°C for 5 minutes, taking care to prevent the inclusion of air bubbles, to obtain a disk-shaped measurement sample having a thickness of 2.0 mm and a diameter of 25 mm. The sample is measured using parallel disks having a diameter of 25 mm kept at 180°C, after compressing the 2.0 mm thick measurement sample to a thickness of 1.5 mm. The storage modulus (G') and loss modulus (G") of the measurement sample are measured at 180°C using parallel disks having a diameter of 25 mm arranged with a gap of 1.5 mm, at a strain of 0.1% to 40%, in a frequency range of 0.01 rad / sec to 100 rad / sec, with five measurement points per ω digit.

[0054] The property (5) can be satisfied by adjusting the polymerization conditions, such as the selection of catalyst type, polymerization temperature, monomer concentration, amount of hydrogen, etc., in the same manner as described for the property (2).

[0055] Characteristics (6): The branched propylene polymer of the present invention is 13 It is preferable that the mesotriad fraction (mm) measured by C-NMR is 95% or more and less than 99%, the amount of heterogeneous bonds (2,1 bonds) is 0.05 mol% or more and 0.50 mol% or less, and the amount of heterogeneous bonds (1,3 bonds) is 0.05 mol% or more and 0.50 mol% or less. The crystallinity of branched propylene polymers is affected by the stereoregularity indicated by the mesotriad fraction (mm) and mesopentad fraction (mmmm), and the regioregularity indicated by hetero bonds (2,1 bonds) and hetero bonds (1,3 bonds). In other words, crystallization proceeds by folding back lamellae from the irregularity defects (sterically irregular bonds and hetero 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 strength during solidification are improved due to a crystallization process caused by the stereoregularity and regioregularity in a shear or elongation deformation field. Therefore, the branched propylene polymer of the present invention 13The mesotriad fraction (mm) measured by C-NMR is preferably 95% or more, more preferably 96% or more, and even more preferably 97% or more, from the viewpoint of improving the melt strength during solidification. In order to improve the melt strength during solidification, the branched propylene polymer of the present invention preferably has a heterogeneous bond content (2,1 bond) of 0.05 mol % or more and 0.50 mol % or less, more preferably 0.10 mol % or more and 0.40 mol % or less, and even more preferably 0.20 mol % or more and 0.30 mol % or less. In order to improve the melt strength during solidification, the amount of heterogeneous bonds (1,3 bonds) in the branched propylene polymer of the present invention is preferably 0.05 mol % or more and 0.50 mol % or less, more preferably 0.10 mol % or more and 0.40 mol % or less, and even more preferably 0.20 mol % or more and 0.30 mol % or less.

[0056] 13 The methods for measuring and calculating the mesotriad fraction (mm), the amount of heterogeneous bonds (2,1 bonds), and the amount of heterogeneous bonds (1,3 bonds) measured by C-NMR are as follows. [Sample preparation and measurement conditions] 200 mg of sample was placed in an NMR sample tube with an inner diameter of 10 mm along with 2.4 mL of solvent (o-dichlorobenzene / deuterated bromide benzene (CDBr) = 2 / 1 (volume ratio)) and hexamethyldisiloxane, a chemical shift reference substance, and dissolved uniformly in a block heater at 150°C. ( 1 H-NMR) Equipment: Bruker BioSpin AV400 NMR instrument Probe: 10mmφ cryoprobe Sample temperature: 120℃ Pulse angle: 4.5° Pulse interval: 2 seconds Number of times accumulated: 1024 Chemical shift: The chemical shift is set to 0.09 ppm for the proton signal of hexamethyldisiloxane, and the chemical shifts of signals due to other protons are based on this. ( 13C-NMR) Equipment: Bruker BioSpin AV400 NMR instrument Probe: 10mmφ cryoprobe Sample temperature: 120℃ Pulse angle: 45° Pulse interval: 17.2 seconds Accumulation count: 3072 Decoupling conditions: Broadband decoupling method Chemical shift: Chemical shifts are those of hexamethyldisiloxane. 13 The C signal was set to 1.98 ppm, and the other 13 The chemical shift of the C signal was based on this.

[0057] [Calculation method of stereoregularity: mesotriad fraction (mm) and mesopentad fraction (mmmm)] The mesotriad fraction (mm) of three consecutive propylene units and the mesopentad fraction (mmmm) of five consecutive propylene units are: 13 Measured by C-NMR 13 The integrated intensity of the C signal is calculated by substituting it into the following formulas (4) and (4′). mm(%)=I mm ×100 / (I mm +3×I mrrm ) ···(4) mmmm(%)=(I mm -2× Imrrm )×100 / (I mm +3×I mrrm ) (4') Here I mm is attributed to the mm bonding mode of three propylene units. 13 This represents the integrated intensity of the C signal, and the integrated intensity of the signal with a chemical shift in the range of 23.6 ppm to 21.1 ppm (hereinafter referred to as "I 23.6~21.1 ") is calculated as follows. Similarly, the integrated intensity of the signal with a chemical shift in the range of X ppm to Y ppm is referred to as "I X~Y " should be written as follows. I mrrmThe 5-propylene unit sequence is assigned to the MRRM bonding mode. 13 represents the integrated intensity of the C signal, and I 19.9~19.7 The value is shown as: Spectral assignments can be made with reference to Polymer Jounral, Vol. 16, p. 717 (1984), Asakura Shoten, 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 the regions are easy to distinguish.

[0058] [Calculation method of regioregularity; heterogeneous bond amount (2,1 bond), heterogeneous bond amount (1,3 bond)] The branched propylene polymer of the present invention may have a structure based on regular 1,2 insertion of propylene (1,2 bond) as well as 2,1 bond and 1,3 bond based on irregular insertion of propylene (2,1 insertion, 1,3 insertion).

[0059] The heterogeneous bond amount (2,1 bond) (molar concentration) and the heterogeneous bond amount (1,3 bond) (molar concentration) are 13 Measured by C-NMR 13 The integrated intensity of the C signal is used to calculate the value using the following formula. Heterogeneous bond amount (2,1 bond) (mol%)=I 2,1-P ×100 / (I 1,2-P +I 2,1-P +I 1,3-P ) Heterogeneous bond amount (1,3 bond) (mol%)=I 1,3-P ×100 / (I 1,2-P +I 2,1-P +I 1,3-P ) where I 1,2-P , I 2,1-P , I 1,3-P are attributed to the bonding patterns of propylene units as 1,2 bonds, 2,1 bonds, and 1,3 bonds, respectively. 13 It represents the integrated intensity of the C signal and is calculated as follows: I 1,2-P =I 48.80~44.50 I 2,1-P =(I34.68~34.63 +I 35.47~35.40 +I 35.94~35.70 ) / 2 I 1,3-P =I 37.50~37.20 / 2

[0060] The characteristic (6) can be satisfied by adjusting the polymerization conditions, such as the selection of catalyst type, polymerization temperature, monomer concentration, and amount of hydrogen, in the same manner as described for the characteristic (2).

[0061] Characteristics (7): In the branched propylene polymer of the present invention, the amount of components eluting at a temperature of 40°C or lower is preferably 0.1% by mass or more and 3.0% by mass or less in an elution curve obtained by temperature rising elution fractionation (TREF) measurement using o-dichlorobenzene (ODCB). The components eluting at temperatures of 40° C. or lower are low-crystalline components, and if the amount of these components in a branched propylene polymer is large, the crystallinity decreases, which may result in a decrease in the heat resistance and rigidity of the product. Therefore, the amount of components eluting at temperatures of 40° C. or lower in the branched propylene polymer of the present invention is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, even more preferably 1.0% by mass or less, and particularly preferably 0.7% by mass or less. On the other hand, if the amount of components eluting at 40° C. or lower is too small, for example, when laminated, the rigidity may become too high, which may result in poor feel to the touch, etc. Therefore, the amount of components eluting at temperatures of 40° C. or lower 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, even more preferably 0.3% by mass or more, and particularly preferably 0.4% by mass or more. The content of branched propylene polymers soluble at 40°C or less in temperature rising elution fractionation (TREF) with o-dichlorobenzene (ODCB) can generally be kept low by using a metallocene compound as a polymerization catalyst component. Furthermore, it is preferable to keep the content of isomers contaminating the metallocene compound low, to gently contact the metallocene compound with the organoaluminum compound during catalyst production, and to avoid extremely high reaction temperatures during polymerization.

[0062] The details of the method for measuring the eluted components by temperature rising elution fractionation (TREF) are as follows. The sample was dissolved in ODCB at 140°C to form a solution. This was then loaded onto a TREF column at 140°C, which was then cooled to 100°C at a rate of 8°C / min, then cooled to 40°C at a rate of 4°C / min, and held at 40°C for 10 minutes. The column was 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 for 60 minutes. ODCB, the solvent, was then passed through the column at a flow rate of 1 mL / min to elute the sample, and an elution curve was obtained. The ratio of the amount of components eluted at 40°C to the total amount of components eluted is defined as the amount (mass%) of components eluted at temperatures of 40°C or lower. Column size: 4.3mmφ×150mm Column packing material: 100 μm surface-deactivated glass beads Solvent: o-dichlorobenzene (ODCB) Sample concentration: 5 mg / mL Sample injection volume: 0.1 mL Solvent flow rate: 1 mL / min Detector: FOXBORO MIRAN 1A, IR detector (measurement wavelength: 3.42 μm)

[0063] Characteristics (8): The branched propylene polymer of the present invention preferably has a melting point (Tm) measured by differential scanning calorimetry (DSC) of more than 150.0°C and less than 160.0°C. The branched propylene polymer of the present invention is believed not to lower the melt tension if it has a melting point (Tm) within the above range. Therefore, the Tm of the branched propylene polymer of the present invention is preferably higher than 150.0°C, more preferably 152.0°C or higher, even more preferably 154.0°C or higher, and preferably lower than 160.0°C, more preferably 158.0°C or lower, even more preferably 157.0°C or lower. The Tm of the branched propylene polymer of the present invention can be controlled by selecting a metallocene compound as a polymerization catalyst that reduces defects due to regioregularity, selecting a combination of multiple metallocene compounds, and further controlling the polymerization temperature, pressure conditions, and crystal thickness. In the present invention, Tm can be determined using a DSC (DSC6200) manufactured by Seiko Instruments Inc., by placing 5 mg of a sheet-like sample piece in an aluminum pan, heating it from room temperature to 200°C at a heating rate of 100°C / min, holding it for 5 minutes, and then cooling it to 40°C at a heating rate of 10°C / min, and determining the maximum peak temperature (°C) of crystallization as the crystallization temperature (Tc), and then heating it to 200°C at a heating rate of 10°C / min, and determining the maximum peak temperature (°C) of melting as the melting point (Tm). The sheet-like sample can be obtained by sandwiching the branched propylene polymer powder between press plates, preheating at 190°C for 2 minutes, pressing at 5 MPa for 2 minutes, and then cooling at 0°C and 10 MPa for 2 minutes.

[0064] Characteristics (9): The branched propylene polymer of the present invention preferably has a number of long chain branches of 0.1 to 0.5 per 1000 monomers in order to maintain high melt tension during molding. The branched propylene polymer of the present invention may have a number of long chain branches of 0.3 to 0.3 per 1000 monomers in order to avoid excessively increasing the content of components with extremely long relaxation times. [Calculation method for the number of long chain branches (LCB number)] The number of long chain branches (LCB number) is 13 The number per 1000 propylene monomer units is calculated by the following formula using the integrated signal intensities of the branch point carbon (methine carbon) at 31.72 ppm to 31.66 ppm and three methylene carbons bonded to the branch point carbons (methine carbon) at 44.09 ppm to 44.03 ppm, 44.78 ppm to 44.72 ppm, and 44.90 ppm to 44.84 ppm, when the intensity of the methylene carbon in the propylene main chain at 49.00 ppm to 44.33 ppm is normalized to 1000 by C-NMR. Number of long chain branches (LCB number) = [(I44.09~43.03 +I 44.78~44.72 +I 44.90~44.84 +I 31.72~31.66 ) / 4] / I 49.00~44.33

[0065] The property (9) can be satisfied by adjusting the polymerization conditions, such as the selection of catalyst type, polymerization temperature, monomer concentration, and amount of hydrogen, in the same manner as described for the property (2).

[0066] By satisfying the properties (1) to (5), the branched propylene polymer of the present invention can reduce components with extremely long relaxation times while maintaining a high melt tension, thereby increasing the difference in strain hardening depending on the strain rate. Since the branched propylene polymer of the present invention can increase the difference in strain hardening depending on the strain rate while maintaining a high melt tension, it is particularly preferable for it to have the following properties (10) and (11). Furthermore, the branched propylene polymer of the present invention is preferably one of the properties (6) to (9) because the performances resulting from each of the properties described above are improved.

[0067] Characteristics (10): In the branched propylene polymer of the present invention, the lower limit of the strain hardening index (SHI@10) at a high strain rate (10 / sec) in the measurement of extensional viscosity is preferably 1.00 or more, more preferably 1.10 or more, and even more preferably 1.20 or more. On the other hand, the upper limit of the strain hardening index (SHI@10) is preferably 1.70 or less, more preferably 1.60 or less, and even more preferably 1.50 or less. The upper limit of the strain hardening index (SHI@10) may be 1.40 or less, or may be 1.30 or less. The branched propylene polymer of the present invention has an upper limit of strain hardening (SHI@1) at a low strain rate (1.0 / sec) in the measurement of extensional viscosity of preferably 1.20 or less, more preferably 1.10 or less, and even more preferably 1.05 or less, while the lower limit of strain hardening (SHI@1) is preferably 0.70 or more, more preferably 0.80 or more, and even more preferably 0.90 or more. Furthermore, the branched propylene polymer of the present invention can increase the difference in strain hardening depending on the strain rate, and in addition to SHI@10 and SHI@1 being within the above ranges, the difference therebetween (SHI@10-SHI@1) can be preferably 0.10 or more and 0.25 or less. The difference (SHI@10-SHI@1) may be more preferably 0.12 or more, and even more preferably 0.15 or more and 0.20 or less. When a branched propylene polymer contains a large amount of components with extremely long relaxation times, both the strain hardening SHI@10 at high strain rates and the strain hardening SHI@1 at low strain rates increase, resulting in a small difference between SHI@10 and SHI@1. On the other hand, when a branched propylene polymer contains a small amount of components with extremely long relaxation times, SHI@10 exhibits a large value, but SHI@1 does not increase, resulting in a large difference between SHI@10 and SHI@1. The branched propylene polymer of the present invention does not relax at high strain rates (10 / s), as indicated by SHI@10, and has a large strain hardening (SHI@10). However, as indicated by SHI@1, it relaxes at low strain rates (1.0 / s), preventing excessive strain hardening (SHI@1). As a result, the difference between SHI@10 and SHI@1.0 can be as large as 0.10 or more. The upper limit of the difference can be 0.25 or less.

[0068] The method for measuring the extensional viscosity and the method for calculating the strain hardening index (SHI) at each strain rate (dε / dt) are as follows. The strain hardening index (SHI) can be determined by measuring the uniaxial extensional viscosity using the measuring device and measuring method described in, for example, Polymer, Vol. 42, p. 8663 (2001). In the present invention, the strain hardening index (SHI) at each strain rate (dε / dt) can be measured by the following measurement and method. Equipment: Rheometorics Ares Jig: TA Instruments Extentional Viscosity Fixture Measurement temperature: 180℃ Strain rate: 10 / sec, 1.0 / sec Preparation of test specimen: A sheet of 18 mm x 10 mm and 0.7 mm thick is prepared by press molding. Using the above measurement method, data on the change in elongational viscosity (ηE) over time is obtained at a predetermined constant strain rate (dε / dt), and the measurement data is plotted on a graph with the logarithm (Log(ε)) of Hencky strain (ε) on the horizontal axis and the logarithm (Log(ηE)) of extensional viscosity (ηE) on the vertical axis. From the graph, the slope of the elongational viscosity in the Hencky strain (ε) range from 1 to 3 is identified, and this slope is taken as the strain hardening index (SHI) at the strain rate (dε / dt) under the measurement conditions.

[0069] Characteristics (11): The lower limit of the melt tension at 190°C (MT190) of the branched propylene polymer of the present invention is generally 0.5 g or more, preferably 0.6 g or more, and the upper limit of MT190 is generally 5.0 g or less, preferably 4.0 g or less, more preferably 3.0 g or less. The melt tension at 190°C (MT190) is measured using a melt tension tester (for example, Capilograph 1B manufactured by Toyo Seiki Co., Ltd.). At a resin temperature of 190°C, resin is extruded into a string shape under the following conditions, and the tension detected on the pulley when the resin is wound up around a roller is taken up as the melt tension (MT190). Capillary: diameter 2.1 mm Cylinder diameter: 9.6mm Cylinder extrusion speed: 10 mm / min Winding speed: 4.0 m / min If breakage occurs at a winding speed of 4.0 m / min, the melt tension cannot be evaluated.

[0070] 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 macromer copolymerization method using a catalyst containing a plurality of metallocene compounds is suitable. The present inventors speculate that the mechanism of the macromer copolymerization method using a catalyst containing multiple metallocene compounds is as follows. When polymerization is carried out using a catalyst containing a metallocene compound (referred to as Compound 1) that forms a catalyst that mainly produces macromers and a metallocene compound (referred to as Compound 2) that forms a catalyst that mainly copolymerizes macromers with propylene monomers to produce polymers with branched chains, 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 range that is simply a combination of the molecular weight and molecular weight distribution of a polymer produced from a catalyst containing Compound 1 (referred to as Catalyst 1) and the molecular weight and molecular weight distribution of a polymer produced from a catalyst containing Compound 2 (referred to as Catalyst 2). Furthermore, in the process of forming the branched structure, if the polymer produced from catalyst 1 has a terminal vinyl group, such a polymer containing a terminal vinyl group becomes a macromer (referred to as macromer 1), and further, a copolymer of propylene and macromer 1 is produced from catalyst 1, and a copolymer of propylene and macromer 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 macromer (referred to as macromer 2), and further, a copolymer of propylene and macromer 2 is produced from catalyst 1, and a copolymer of propylene and macromer 2 is produced from catalyst 2. Furthermore, if the polymer produced from catalyst 1 is macromer 1 and the polymer produced from catalyst 2 is macromer 2, then catalyst 1 will produce a copolymer of propylene, macromer 1, and macromer 2, and catalyst 2 will produce a copolymer of propylene, macromer 1, and macromer 2. Thus, depending on the molecular weight, molecular weight distribution, terminal vinyl percentage, and copolymerizability of catalyst 1 of the polymer produced from catalyst 1, the molecular weight, molecular weight distribution, terminal vinyl percentage, and copolymerizability of catalyst 2 of the polymer produced from catalyst 2, the ratio of catalyst 1 to catalyst 2, and the steric positional relationship, the average molecular weight, high molecular weight, and very high molecular weight of the final product branched propylene polymer, as well as the number of branches and branch distribution, vary. That is, Mn, Mw, Mz, W (million), W (million), g' (million), g' (Mw abs ) is thought to change. A preferred method for producing the branched propylene polymer of the present invention is not limited to the above mechanism, and examples thereof include the following.

[0071] 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, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-1 having a terminal vinyl ratio (Rv) of 0.5 or more; Component [A-2]: a metallocene compound that, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-2 having a weight average molecular weight greater than that of the propylene homopolymer a-1 and a terminal vinyl ratio (Rv) of 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

[0072] II-1-1. Component [A-1] Component [A-1] is a metallocene compound that, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-1 having a terminal vinyl ratio (Rv) of 0.5 or more. Component [A-1] is a metallocene compound that preferably gives a terminal vinyl ratio (Rv) of 0.65 or more, more preferably 0.75 or more, and ideally 1.0 (one end of every molecular chain is a vinyl structure). By using a metallocene compound that forms a polymerization catalyst that produces a propylene homopolymer with a higher terminal vinyl ratio, a more efficient macromer synthesis process can be carried out. Here, the terminal vinyl ratio (Rv) and the terminal vinylidene ratio (Rvd) are defined by the following formulas. Terminal vinyl ratio (Rv) = [Vi] / {(total number of terminals - number of LCBs) ÷ 2} Terminal vinylidene ratio (Rvd) = [Vd] / {(total number of terminals - number of LCBs) ÷ 2} (However, [Vi] and [Vd] are 1The total number of terminal vinyl groups and terminal vinylidene groups per 1,000 monomer units is calculated by H-NMR. 1 H-NMR and 13 The total number of terminals per 1000 monomer units calculated by C-NMR. The number of LCBs is 13 The number of LCBs per 1000 monomer units is calculated by C-NMR.

[0073] [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 known as β-hydrogen elimination generally occurs as a termination reaction, resulting in the production of a polymer terminated at the propyl-vinylidene end (vinylidene end) shown in structural formula (1-b). When hydrogen is used, chain transfer usually occurs preferentially to hydrogen, resulting in the production of a polymer terminated at the i-butyl end (i-butyl end) shown in structural formula (1-c). When a catalyst containing a specific metallocene compound is used, a special chain transfer reaction known as β-methyl elimination occurs, resulting in the production of a polymer terminated at the 1-propenyl end (vinyl end) shown in structural formula (1-a) (Reference: Macromol. Rapid Commun. 2000, 21, 1103-1107). In addition, as a terminal end, after random insertion of propylene, chain transfer with hydrogen very rarely produces the n-butyl structure shown in structural formula (1-e).Furthermore, as a terminal end, after random insertion of propylene, β-hydrogen elimination occurs, and it is thought that a very small amount of the 1-butenyl structure shown in structural formula (1-f) or the terminal vinylene structure (2-butenyl structure) shown in structural formula (1-g) is produced. The initiation end is the n-propyl structure shown in structural formula (1-h) when the first propylene inserts into the central metal after chain transfer with hydrogen or β-hydrogen elimination as a termination reaction, or the i-butyl structure shown in structural formula (1-c) when the first propylene inserts into the central metal after β-methyl elimination as a termination reaction. The initiation end is a 2,3-dimethylbutyl structure shown in structural formula (1-i) due to the initial propylene being randomly inserted into the central metal after chain transfer with hydrogen or after β-hydrogen elimination as a termination reaction, or a 3,4-dimethylpentyl structure shown in structural formula (1-j) due to the initial propylene being randomly inserted into the central metal after β-methyl elimination as a termination reaction. 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 (1-d), may be produced by isomerization. The internal vinylidene structure shown in structural formula (1-k) is an olefin structure formed inside the polymer chain by the insertion of propylene 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 terminals resulting from the main reaction are structural formula (1-c) and structural formula (1-h), and the main unsaturated terminals are structural formula (1-a) and structural formula (1-b), and the number of other terminal structures is small compared to the number of the above main terminal structures.

[0074] Of these terminal structures, polymers having the structures shown in structural formula (1-a) and structural formula (1-f) at their terminals can become macromers. Structural formula (1-a) and structural formula (1-f) are the same in that the two terminal carbon atoms have a vinyl structure, and there is no difference in their copolymerizable function. However, while 1-propenyl structures are terminals resulting from the regular insertion of propylene followed by β-methyl elimination, 1-butenyl structures are structures resulting from a side reaction in which propylene undergoes extremely rare irregular insertion followed by β-hydrogen elimination. Therefore, 1-butenyl structures can be estimated to be present in extremely small amounts relative to 1-propenyl structures. The ratio of 1-butenyl structures to 1-propenyl structures is roughly equivalent to or less than the probability of heterogeneous bond formation. In other words, it can be estimated that most of the number of terminal vinyl groups [Vi] above are 1-propenyl structures resulting from the regular insertion of propylene followed by β-methyl elimination.

[0075] [ka]

[0076] [ka]

[0077] [Method for evaluating terminal vinyl ratio (Rv) and terminal vinylidene ratio (Rvd)] Here, the propylene polymerization conditions for determining the terminal vinyl ratio (Rv) and terminal vinylidene ratio (Rvd) of the catalyst component will be described in detail. After replacing the inside of a 3L autoclave with propylene, 2.86mL of a heptane solution of triisobutylaluminum (143.4mg / mL) was added, 240mL of hydrogen was introduced, and 750g of liquefied propylene was introduced and the temperature was raised to 70°C. The catalyst was then pumped into the polymerization vessel and polymerization was carried out at 70°C for 1 hour. Finally, unreacted propylene was quickly purged to terminate the polymerization and obtain a propylene polymer. The terminal vinyl ratio (Rv) and terminal vinylidene ratio (Rvd) are indicators that indicate the ratio of the number of terminal vinyl groups and the number of terminal vinylidene groups to the total number of polymer chains, respectively. The calculation method is as follows: 1 H-NMR and 13 The number of unsaturated terminals and the number of saturated terminals per 1000 monomers were calculated using C-NMR, and the sum of these was taken as the total number of terminals. 13 The number of LCBs is calculated from C-NMR as the number per 1,000 monomers, and half (1 / 2) of this number is used as the total number of polymers. The number of terminal vinyl groups [Vi] and the number of terminal vinylidene groups [Vd] at the unsaturated end are then divided by the total number of polymers to calculate the number. The specific calculation method is shown below.

[0078] <How to calculate the number of saturated ends> The number of major saturated ends is as follows per 1000 monomers: 13The integrated intensity of the C signal is used to calculate the value using the following formula. Structural formula (1-c): [i-butyl]=I i-butyl ×1000 / I total-C Structural formula (1-e): [n-butyl]=I nbu ×1000 / I total-C Structural formula (1-h): [n-propyl]=I npr ×1000 / I total-C Structural formula (1-i): [2,3-dimethylbutyl]=I 2,3-dime ×1000 / I total-C Structural formula (1-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 per 1000 monomers is calculated in the same manner using known literature values. where I i-butyl , I nbu , I npr , I 2,3-dime , I 3,4-dime are structural formula (1-c), structural formula (1-e), structural formula (1-h), and structural formula ( 1-i), which represents the characteristic value of the signal based on structural formula (1-j), is the quantity shown by the following formula: 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 +I3,4-dime +I 1,2―P +I 2,1―P +I 1,3―P Furthermore, if 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 the characteristic value of the signal based on the 1,3 inserted propylene bond, and is the quantity shown 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

[0079] <How to calculate the number of unsaturated ends> The number of unsaturated ends per 1000 monomers is: 1 The integrated intensity of the H signal is used to determine the value as follows: 1 In H-NMR, the proton signals of the unsaturated bonds of the 1-propenyl structure shown in structural formula (1-a) and the 1-butenyl structure shown in structural formula (1-f) are 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 (1-a) + Structural formula (1-f):[Vi]=I vi ×1000 / I total Structural formula (1-b):[Vd]=I vd ×1000 / I total Similarly, 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 (1-d): [i-butenyl]=I ibu ×1000 / I total Structural formula (1-g): [Terminal vinylene] = I vnl ×1000 / I total Structural formula (1-k): [internal vinylidene] = I ivd ×1000 / I total where I vi , I vd , I ibu , I vnl , I ivd represent the characteristic values ​​of the signals based on structural formula (1-a) + structural formula (1-f), structural formula (1-b), structural formula (1-d), structural formula (1-g), and structural formula (1-k), respectively, and are quantities shown 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 shown in the following formula: I total =I main / 6+I vi +I vd +I ibu +I vnl +I ivd Furthermore, if there are other unsaturated structures in addition to the above-mentioned main unsaturated structure, the numbers of all detected ends are added to the above formula. I main What is 1 It is the sum of the integrated intensities of proton signals bonded to saturated carbons of the polymer chain, including the terminals, detected in the H-NMR spectrum from 4.00 ppm to 0.00 ppm.

[0080] <Calculation method of LCB number> The LCB number is determined as the number per 1000 monomers by the method described in property (9). <Calculation method of total terminal number> The total terminal number is 1 H-NMR and 13 the total number of terminals per 1000 monomer units calculated by C-NMR. <Calculation method of terminal vinyl ratio> It is calculated using the following formula with [Vi], the total terminal number, and the LCB number obtained above. Terminal vinyl ratio (Rv) = [Vi] / { (total terminal number - LCB number) ÷ 2} Terminal vinylidene ratio (Rvd) = [Vd] / { (total terminal number - LCB number) ÷ 2}

[0081] As component [A-1], for example, a bisindenyl complex having a bulky heterocyclic group at the 2-position of the indenyl group and an aryl group or a heterocyclic group containing nitrogen, oxygen or sulfur which may be substituted at the 4-position can be mentioned. As one of the non-limiting preferred embodiments, the following structure can be mentioned.

[0082]

Chemical formula

[0083] Above R 11 and R 12 The nitrogen-, oxygen- or sulfur-containing heterocyclic group having 4 to 16 carbon atoms is preferably a 2-furyl group, a substituted 2-furyl group, a substituted 2-thienyl group or a substituted 2-furfuryl group, and more preferably a substituted 2-furyl group. R 11 and R 12 is a group selected from heterocyclic groups containing nitrogen, oxygen, or sulfur and having 4 to 16 carbon atoms, the terminal vinyl percentage (Rv) can be increased. In particular, by introducing a substituent of an appropriate size onto the heterocyclic group, the relative positional relationship between the heterocycle and the coordination field on the transition metal and the growing polymer chain can be optimized, thereby further increasing the terminal vinyl percentage (Rv). Furthermore, the substituent of the substituted 2-furyl group, the substituted 2-thienyl group, and the substituted 2-furfuryl group is preferably a hydrocarbon group having 1 to 4 carbon atoms. Furthermore, 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.

[0084] Above R 13 and R 14 are each independently an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these, or a heterocyclic group having 6 to 16 carbon atoms which contains nitrogen, oxygen, or sulfur. In particular, R 13 and R 14 By increasing the bulkiness, it is possible to obtain a propylene polymer having higher stereoregularity, fewer heterogeneous bonds, and a higher terminal vinyl ratio. So, R 13 and R 14 is preferably an aryl group having one or more hydrocarbon groups having 1 to 6 carbon atoms, silyl groups having a hydrocarbon group having 1 to 6 carbon atoms, halogen-containing hydrocarbon groups having 1 to 6 carbon atoms, or aryl groups which may have a halogen atom as a substituent on an aryl ring skeleton, within the range of 6 to 16 carbon atoms, and such R 13 and R 14 Specific examples of the group include a 4-t-butylphenyl group, a 2,3-dimethylphenyl group, a 3,5-di-t-butylphenyl group, a 4-chlorophenyl group, a 4-trimethylsilylphenyl group, a 1-naphthyl group, and a 2-naphthyl group. Also, R 13 and R 14 More preferably, R is a phenyl group having one or more hydrocarbon groups having 1 to 6 carbon atoms, silyl groups having hydrocarbon groups having 1 to 6 carbon atoms, halogen-containing hydrocarbon groups having 1 to 6 carbon atoms, or halogen atoms as substituents, with the carbon number being in the range of 6 to 16. The position of substitution is preferably the 4-position on the phenyl group. 13 and R 14 Specific examples of R include a 4-t-butylphenyl group, a 4-biphenylyl group, a 4-chlorophenyl group, and a 4-trimethylsilylphenyl group. 13 and R 14 are preferably identical to each other.

[0085] Above X 11 and Y 11 is an auxiliary ligand, and reacts with component [B] to generate an active metallocene capable of olefin polymerization. Therefore, as long as this purpose is achieved, X 11 and Y 11 The types of ligands are not limited, and each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0086] The above Q11 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms, which links two five-membered rings. When two hydrocarbon groups are present on the above-mentioned silylene group or germylene group, they may be bonded to each other to form a ring structure. The above Q 11 Specific examples of the alkylene group include alkylene groups such as methylene, methylmethylene, dimethylmethylene, and 1,2-ethylene; aryl alkylene groups such as diphenylmethylene; silylene groups; alkylsilylene groups such as methylsilylene, dimethylsilylene, diethylsilylene, di(n-propyl)silylene, di(i-propyl)silylene, and di(cyclohexyl)silylene; (alkyl)(aryl)silylene groups such as methyl(phenyl)silylene; arylsilylene groups such as diphenylsilylene; alkyloligosilylene groups such as tetramethyldisilylene; germylene groups; alkylgermylene groups in which the silicon atom of the silylene group having the above-mentioned divalent hydrocarbon group having 1 to 20 carbon atoms is substituted with germanium; (alkyl)(aryl)germylene groups; and arylgermylene groups. Among these, a silylene group having a hydrocarbon group 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.

[0087] 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, Examples include:

[0088] 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, 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, is.

[0089] II-1-2. Component [A-2] Component [A-2] is a metallocene compound that, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-2 having a weight-average molecular weight greater than that of the propylene homopolymer a-1 and a terminal vinyl ratio (Rv) of less than 0.5. The component [A-2] is a metallocene compound that forms a polymerization catalyst capable of copolymerizing a propylene monomer and a propylene macromer. The component [A-2] is preferably a metallocene compound having a terminal vinyl ratio (Rv) of 0.30 or less, more preferably 0.10 or less, and ideally 0 (no vinyl structure is generated). Furthermore, component [A-2] produces a polymer with a higher molecular weight than component [A-1] when propylene homopolymerized at 70°C with the same amount of hydrogen. By using a metallocene compound as component [A-2], which forms a polymerization catalyst that produces a propylene homopolymer with a high molecular weight and a low terminal vinyl percentage, it is possible to suppress the production of high-molecular-weight branched components with long branches, and also to preferentially cause the reaction in which the short-molecular-weight macromer produced by component [A-1] is copolymerized with component [A-2]. The terminal vinyl percentage (Rv) and terminal vinylidene percentage (Rvd) are evaluated in the same manner as in the evaluation method for the component [A-1].

[0090] As described above, the efficiency of branch formation when the macromer produced from component [A-1] is copolymerized with component [A-2] is lower than the efficiency of branch formation when component [A-1] is copolymerized with itself. Therefore, the branched polymer of the present invention can be produced by utilizing the fact that the branch density of the branched polymer derived from component [A-2] is lower than that of the branched polymer derived from component [A-1]. The branched propylene polymer of the present invention has the characteristics of Mn, Mw, Mz, W 1 million, g' (1 million), preferably W 2 million, g' (Mw abs ), [g'(Mw abs In order to obtain an average molecular weight, molecular weight distribution, and branching distribution such that (g')-(g'(million)) satisfies formula (3), it is necessary for component [A-2] to produce a polymer with a higher molecular weight than component [A-1]. The above properties can be evaluated in the same manner as in the evaluation of the terminal vinyl percentage (Rv) and terminal vinylidene percentage (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 weight average molecular weights (Mw) of the polymers.

[0091] An example of the component [A-2] is a metallocene compound represented by the following general formula (a2).

[0092] [ka] [In general formula (a2), E 21 and E 22Q each independently represents a cyclopentadienyl group, an indenyl group, a fluorenyl group, or an azulenyl group, each of which may have a substituent (provided that the substituent is not a heterocyclic group containing nitrogen, oxygen, or sulfur and having 4 to 16 carbon atoms). 21 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms; M 21 represents zirconium or hafnium, and X 21 and Y 21 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0093] Above E 21 and E 22 are each independently a cyclopentadienyl group, an indenyl group, a fluorenyl group, or an azulenyl group, each of which may have a substituent. However, the substituent is not a heterocyclic group containing nitrogen, oxygen or sulfur and having 4 to 16 carbon atoms. Of these, a substituted cyclopentadienyl group, a substituted indenyl group, and a substituted azulenyl group are preferred. Examples of the substituent include a hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected therefrom, a halogen atom, an alkoxy group, and a trialkylsilyl group. The hydrocarbon group having 1 to 6 carbon atoms includes R 21 and R 22 The aryl group having 6 to 30 carbon atoms and optionally containing halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected therefrom may be the same as the hydrocarbon group having 1 to 6 carbon atoms in the general formula (a3) ​​described below. 23 and R 24The aryl group may be the same as the aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these in the above. Examples of the halogen atom include a fluorine atom and a chlorine atom, examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group and an ethoxy group, and examples of the trialkylsilyl group include a trimethylsilyl group.

[0094] Above X 21 and Y 21 is an auxiliary ligand, and reacts with component [B] to generate an active metallocene capable of olefin polymerization. Therefore, as long as this purpose is achieved, X 21 and Y 21 The types of ligands are not limited, and each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0095] Q 21 represents either a divalent hydrocarbon group having 1 to 20 carbon atoms that links two five-membered rings or that bridges two conjugated five-membered ring ligands via a carbon atom having 1 or 2 carbon atoms, or a silylene group or germylene group that may have a hydrocarbon group having 1 to 20 carbon atoms. When two hydrocarbon groups are present on the above-mentioned silylene group or germylene group, they may be bonded to each other to form a ring structure. The above Q 21Specific examples of the alkylene group include alkylene groups such as methylene, methylmethylene, dimethylmethylene, and 1,2-ethylene; aryl alkylene groups such as diphenylmethylene; silylene groups; alkylsilylene groups such as methylsilylene, dimethylsilylene, diethylsilylene, di(n-propyl)silylene, di(i-propyl)silylene, and di(cyclohexyl)silylene; (alkyl)(aryl)silylene groups such as methyl(phenyl)silylene; arylsilylene groups such as diphenylsilylene; alkyloligosilylene groups such as tetramethyldisilylene; germylene groups; alkylgermylene groups in which the silicon atom of the silylene group having the above-mentioned divalent hydrocarbon group having 1 to 20 carbon atoms is substituted with germanium; (alkyl)(aryl)germylene groups; and arylgermylene groups. Among these, a silylene group having a hydrocarbon group of 1 to 20 carbon atoms or a germylene group having a hydrocarbon group of 1 to 20 carbon atoms is preferred, and an alkylsilylene group having 1 to 20 carbon atoms or an alkylgermylene group having 1 to 20 carbon atoms is particularly preferred. Furthermore, the above M 21 is zirconium or hafnium, preferably hafnium.

[0096] An example of such a compound is a metallocene compound represented by the following general formula (a3).

[0097] [ka] [In general formula (a3), R 21 and R 22 are each independently a hydrocarbon group having 1 to 6 carbon atoms. 23 and R 24 Q each independently represents an aryl group having 6 to 30 carbon atoms which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these. 21 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, or a silylene group or germylene group which may have a hydrocarbon group having 1 to 20 carbon atoms; M 21represents zirconium or hafnium, and X 21 and Y 21 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms.

[0098] Above R 21 and R 22 are each independently a hydrocarbon group having 1 to 6 carbon atoms, preferably an alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, an n-pentyl group, an i-pentyl group, an n-hexyl group, and the like, and are preferably a methyl group, an ethyl group, or an n-propyl group.

[0099] Also, the above R 23 and R 24 are each independently an aryl group having 6 to 30 carbon atoms, preferably 6 to 24 carbon atoms, which may contain halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of hetero elements selected from these. Examples of such an aryl group include a phenyl group, a biphenylyl group, and a naphthyl group, which may have a substituent. Preferred examples include a phenyl group, a 3-chlorophenyl group, a 4-chlorophenyl group, a 3-fluorophenyl group, a 4-fluorophenyl group, a 4-methylphenyl group, a 4-i-propylphenyl group, a 4-t-butylphenyl group, a 4-trimethylsilylphenyl group, a 4-(2-fluoro-4-biphenylyl) group, a 4-(2-chloro-4-biphenylyl) group, a 1-naphthyl group, a 2-naphthyl group, a 4-chloro-2-naphthyl group, a 3-methyl-4-trimethylsilylphenyl group, a 3,5-dimethyl-4-t-butylphenyl group, a 3,5-dimethyl-4-trimethylsilylphenyl group, and a 3,5-dichloro-4-trimethylsilylphenyl group. In general formula (a3), Q 21 , M 21 , X 21 and Y 21are Q in general formula (a2), respectively. 21 , M 21 , X 21 and Y 21 It may be the same as:

[0100] Non-limiting examples of the metallocene compound represented by the above general formula (a3) ​​include the following. However, to avoid a cumbersome and numerous list of examples, only representative exemplary compounds are listed. Also, although compounds with hafnium as the central metal are listed, similar zirconium compounds can also be used, and it is self-evident that various ligands, bridging groups, or auxiliary ligands can be used as desired. (1) dichloro{1,1'-dimethylsilylenebis(2-methyl-4-phenyl-4-hydroazulenyl)}hafnium, (2) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (3) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (4) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (5) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-chloro-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (6) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-methyl-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (8) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (9) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(1-naphthyl)-4-hydroazulenyl}]hafnium, (10) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(2-naphthyl)-4-hydroazulenyl}]hafnium, (11) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chloro-2-naphthyl)-4-hydroazulenyl}]hafnium, (12) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (13) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(2-chloro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (14) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(9-phenanthryl)-4-hydroazulenyl}]hafnium, (15) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (16) dichloro[1,1'-dimethylsilylenebis{2-n-propyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (17) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-chloro-4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (19) dichloro[1,1'-dimethylgermylenebis{2-methyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (20) dichloro[1,1'-dimethylgermylenebis{2-methyl-4-(4-t-butylphenyl)-4-hydroazulenyl}]hafnium, (21) dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (22) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chloro-2-naphthyl)-4-hydroazulenyl}]hafnium, (23) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (24) Dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, etc.

[0101] Among these, preferred are: (2) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (7) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (23) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (22) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chloro-2-naphthyl)-4-hydroazulenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (24) Dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium.

[0102] More preferably, (2) dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (23) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (18) dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium, (24) Dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazulenyl}]hafnium.

[0103] 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. Component [B] is preferably a layered silicate.

[0104] II-1-3-1. Compounds that form ion pairs with component [A-1] and component [A-2] Examples of compounds that react with component [A-1] and component [A-2] to form ion pairs include aluminum oxy compounds and boron compounds. Specific examples of aluminum oxy compounds include compounds represented by the following general formulas (I) to (III).

[0105] [ka]

[0106] In the above general formulas (I), (II), and (III), R 91 , R 101 and R 111 represents a hydrogen atom or a hydrocarbon group, preferably a hydrocarbon group having 1 to 10 carbon atoms, particularly preferably a hydrocarbon group having 1 to 6 carbon atoms.91 , R 101 and R 111 may be the same or different, and p represents an integer of 0 to 40, preferably 2 to 30. The compounds represented by general formulas (I) and (II) are also called aluminoxanes. Among the aluminoxanes, methylaluminoxane or methylisobutylaluminoxane is preferred. The above aluminoxanes can be used in combination within 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 boron compounds include complexes of cations such as carbonium cations and ammonium cations with organic boron compounds such as triphenylboron, tris(3,5-difluorophenyl)boron and tris(pentafluorophenyl)boron, as well as various organic boron compounds such as tris(pentafluorophenyl)boron.

[0107] II-1-3-2. Layered silicates Layered silicates (hereinafter sometimes simply referred to as silicates) are silicate compounds having a sheet-like crystal structure in which the crystals are stacked in parallel by ionic bonds, etc. In the silicate compounds, a plurality of the sheet-like crystals form one layer, and the layers may have interlayer ions between them. Specific examples of layered silicates include layered silicates with a 1:1 structure based on stacking of one layer of tetrahedral sheet and one layer of octahedral sheet, as described in "Clay Mineralogy" by Shiramizu Haruo, Asakura Shoten (1988), and a 2:1 structure based on 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 structure include smectite group silicates such as montmorillonite, beidellite, nontronite, saponite, hectorite, and stevensite, vermiculite group silicates such as vermiculite, mica group silicates such as mica, illite, sericite, and glauconite, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, and chlorite groups, etc. These may form mixed layers.

[0108] Among these, preferred are layered silicates whose main component is a 2:1 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 smectite silicates whose main component is montmorillonite, and even more preferably 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 thereof include, as a main component, alkali metals of Group 1 of the periodic table, such as lithium and sodium; alkaline earth metals of Group 2 of the periodic table, such as calcium and magnesium; and transition metals, such as iron, cobalt, copper, nickel, zinc, ruthenium, rhodium, palladium, silver, iridium, platinum, and gold.

[0109] 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 in the shape as it is produced in nature or in a spherical shape artificially synthesized. Furthermore, naturally occurring layered silicates can be processed into a spherical shape by operations such as pulverization and granulation, and it is particularly preferable to process the layered silicates into a spherical shape by operations such as classification, thereby narrowing the particle size distribution and providing good polymer particle properties.

[0110] 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 layered silicate, reference can be made to the description in paragraphs 0048 to 0066 of JP-A-2018-162391, for example.

[0111] The component [B] preferably used in the present invention is a chemically treated layered silicate. From the viewpoint of the amounts and distribution of the catalyst components [A-1] and [A-2] supported, the atomic ratio of Al / Si 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 aluminum and silicon in the layered silicate are measured by creating a calibration curve using chemical analysis according to the JIS method, with reference to the description in paragraph 0089 of JP 2018-162391, and quantifying the amounts using fluorescent X-rays.

[0112] 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 (4) is used. (AlR n X 3-n ) m ...General formula (IV) [In the above general formula (IV), R represents an alkyl group having 1 to 20 carbon atoms, X represents a halogen, hydrogen, an alkoxy group, or an amino group, n represents an integer of 1 to 3, and m represents an integer of 1 or 2.] The organoaluminum compounds can be used alone or in combination of two or more. Specific examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, tri-normal propylaluminum, tri-normal butylaluminum, triisobutylaluminum, tri-normal hexylaluminum, tri-normal octylaluminum, tri-normal decylaluminum, diethylaluminum chloride, diethylaluminum sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, and diisobutylaluminum chloride. Among these, preferred are trialkylaluminums in which m=1 and n=3 and dialkylaluminum hydrides in which m=2, n=1, and X is hydrogen. More preferred are trialkylaluminums in which R has 1 to 8 carbon atoms.

[0113] II-1-5. Preparation of catalyst The olefin polymerization catalyst preferably used in the present invention contains the above-mentioned components [A-1], [A-2], [B], and [C]. These can be obtained by contacting them in a polymerization vessel or outside the 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 component [A-1] and component [A-2] used is preferably in the range of 0.1 μmol to 1000 μmol, more preferably 0.5 μmol to 500 μmol, per 1 g of 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. By appropriately changing this ratio, the average molecular weight, high molecular weight, very high molecular weight, as well as the number of branches and branching distribution can be changed, and the branched propylene polymer of the present invention can be obtained which maintains the required branched structure while containing few components with extremely long relaxation times. The amount of component [C] used is preferably 0.01 to 5×10 in terms of the molar ratio of aluminum in component [C] to the total transition metals in component [A-1] and component [A-2]. 6 , more preferably 0.1 to 1 × 10 4 The range is.

[0114] The order in which the components [A-1], [A-2], [B] and [C] are contacted is arbitrary. Of these, it is also possible to contact either one of the components [A-1] or [A-2] with the component [B], and then contact them with the component [C], and then contact them with the remaining one of the components [A-1] or [A-2]. Component [A-1] and component [A-2] may be contacted with component [B] separately or simultaneously, and then contacted with component [C]; After component [C] and component [B] are contacted, component [A-1] and component [A-2] may be contacted sequentially or simultaneously. Among these, it is particularly preferred that components [A-1] and [A-2] come into contact with component [C] in the presence of component [B].

[0115] In this contact, a solvent may be used to ensure sufficient contact. Examples of the solvent include saturated aliphatic hydrocarbons, aromatic hydrocarbons, unsaturated aliphatic hydrocarbons, and their halides, as well as prepolymerized monomers. Specific examples of saturated aliphatic hydrocarbons and aromatic hydrocarbons include hexane, heptane, and toluene. Furthermore, propylene can be used as a solvent for the prepolymerized monomer.

[0116] II-1-6. Prepolymerization The olefin polymerization catalyst is preferably subjected to prepolymerization in which a small amount of olefin is polymerized by contacting the catalyst with the olefin. Prepolymerization can improve catalytic activity and reduce the production cost of the propylene polymer. 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, and styrene, with propylene being preferred. The olefin can be fed to the prepolymerization reactor by any method, such as a method of feeding the olefin at a constant rate or at a constant pressure, a combination of these, or a method of 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 is preferably 0.01 to 100, more preferably 0.1 to 50, in terms of the mass ratio of the prepolymerized polymer to the component [B]. Alternatively, component [C] can be added during prepolymerization. It is also possible to use a method in which a polymer such as polyethylene or polypropylene or a solid inorganic oxide such as silica or titania is made to coexist during or after the prepolymerization.

[0117] II-2. Polymerization method for propylene 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 component [A-1], component [A-2], component [B], and component [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.

[0118] For example, the polymerization temperature in the bulk polymerization is preferably 40° C. or higher and 80° C. or lower, more preferably 50° C. or higher and 75° C. or lower. The polymerization pressure in the bulk polymerization is preferably 1.0 MPa or higher and 5.0 MPa or lower, more preferably 1.5 MPa or higher and 4.0 MPa or lower, and even more preferably 2.0 MPa or higher and 3.5 MPa or lower. As for the polymerization method, a method of carrying out continuous polymerization or batch polymerization can be adopted. The number of polymerization stages may be a single stage polymerization or two or more stages.

[0119] The polymerization may be homopolymerization of propylene, or copolymerization of propylene with at least one comonomer selected from an α-olefin comonomer having 2 to 20 carbon atoms other than propylene, such as 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.

[0120] [Use of hydrogen] In order to obtain the branched propylene polymer of the present invention, it is preferable to control the use of hydrogen in the presence of the above catalyst. Regarding the use of hydrogen, for example, when the amount of hydrogen is small, the propylene-based polymer produced from component [A-2] becomes high molecular weight and the molecular weight distribution broadens toward the high molecular weight side, resulting in larger Mz, Mz / Mw, W1 million, and W2 million. Furthermore, in terms of propylene polymerization activity, component [A-1] is activated by hydrogen relatively more than component [A-2], so when the amount of hydrogen is small, activation of component [A-1] becomes insufficient, and the proportion of propylene-based polymer produced from component [A-2] increases relatively, resulting in further larger values ​​of W1 million and W2 million. If the branched structure of the high molecular weight components, represented by Mz, W1 million, and W2 million, increases too much, the amount of components with extremely long relaxation times will increase too much. This will increase SHI@1, reducing the difference in strain hardening rate due to strain rate [SHI@10-SHI@1], and impairing the stability of the molten resin when it flows. On the other hand, when the amount of hydrogen is large, component [A-2] is more susceptible to molecular weight reduction by hydrogen than component [A-1], and the average molecular weight of the propylene-based polymer produced from component [A-2] decreases and approaches the average molecular weight of the propylene-based polymer produced from component [A-1], narrowing the molecular weight distribution and decreasing the values ​​of Mz / Mw, Mw / Mn, and Mz. Furthermore, since component [A-1] is relatively more activated by hydrogen than component [A-2], when there is a large amount of hydrogen, there is less polymer derived from component [A-2], and the values ​​of W1 million and W2 million decrease. If the branched structure components in the high molecular weight range, indicated by Mz, W1 million, and W2 million, are reduced too much, the components with extremely long relaxation times will also be reduced too much. This will result in a decrease in not only SHI@1 but also SHI@10, making it impossible to obtain the required melt tension. The amount of hydrogen referred to here is an amount that can be increased or decreased depending on the ratio of the amount of hydrogen introduced to the amount of propylene introduced, and is an amount that can be measured as a hydrogen concentration using a gas chromatograph.

[0121] Regarding the hydrogen concentration, there are methods for changing the hydrogen concentration over time by introducing hydrogen only at the beginning of polymerization in batch polymerization, so that the hydrogen concentration is high in the early stages and then decreased as hydrogen is consumed in the later stages; methods for continuously introducing hydrogen in batch polymerization, so that the hydrogen concentration is kept constant; and methods for maintaining a constant hydrogen concentration by keeping the ratio of the amount of propylene introduced to the amount of hydrogen introduced per unit time constant in continuous polymerization. Among these, in order to prevent the amount of hydrogen from becoming too large or too small over time while maintaining the melt tension required for molding, it is preferable to homopolymerize propylene or copolymerize propylene and a comonomer at a constant hydrogen concentration so that the amount of hydrogen introduced does not become too large or too small over time. In continuous polymerization in which hydrogen and propylene are continuously introduced into a polymerization reactor, a method for homopolymerizing propylene or copolymerizing propylene and a comonomer at a constant hydrogen concentration is preferred. Whether the hydrogen concentration in the polymerization reactor is constant or not can be confirmed, for example, in bulk polymerization, by measuring the hydrogen concentration in the gas phase at regular intervals. Furthermore, for example, in order to obtain the branched propylene polymer of the present invention by bulk polymerization, it is preferable that the average hydrogen concentration in the gas phase be constant so that the coefficient of variation is 0.02 or less in the range of 200 volppm to 1000 volppm, and more preferably so that the coefficient of variation is 0.02 or less in the range of 400 volppm to 600 volppm.

[0122] [How to use the catalyst] When the branched propylene polymer of the present invention is continuously polymerized, it is preferable to continuously introduce the catalyst when at least hydrogen and propylene are continuously introduced into the polymerization reactor.

[0123] [Polymer slurry concentration] When the branched propylene polymer of the present invention is produced by, for example, 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 amounts of the produced polymer and unreacted propylene recovered. At this time, the ratio of the amount of polymer to the mass of propylene 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 propylene liquid, which will result in different hydrogen consumption rates depending on the position, resulting in broader molecular weights and branching distributions. 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 even more 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.

[0124] 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 may be blended with various additives such as antioxidants, ultraviolet absorbers, antistatic agents, nucleating agents, lubricants, flame retardants, antiblocking agents, colorants, inorganic fillers, and organic fillers, as well as various resins such as various synthetic resins and natural resins. The branched propylene polymer of the present invention can be molded by various polypropylene molding methods, such as injection molding, extrusion molding, foam molding, and blow molding, to produce various molded articles such as industrial injection-molded parts, containers, unstretched films, uniaxially oriented films, biaxially oriented films, sheets, pipes, and fibers. Furthermore, the branched propylene polymer of the present invention has a required melt tension and contains few components with extremely long relaxation times. Therefore, in extrusion lamination molding, the polymer can be molded at high speed without generating draw resonance, and the neck-in phenomenon is reduced, so that the polymer can be suitably used to increase productivity. The branched propylene polymer of the present invention can also be used by blending with other resins. [Example]

[0125] Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0126] The following (1) to (11) were measured and calculated by the methods described in the present specification. (1) Melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg (2) Mn, Mw, Mz, Mw / Mn, and Mz / Mw obtained by GPC (3) W1 million and W2 million in the integrated molecular weight distribution curve obtained by GPC (4) Absolute molecular weight M obtained by 3D-GPC abs Weight average molecular weight (Mw abs), branching index g'(million), branching index g'(Mw abs ), and [g'(Mw abs )-g'(1 million)] (5) η in dynamic viscoelasticity measurement * (0.01), η * (100), and [η * (0.01) / η * (100)] (6) 13 Mesotriad fraction (mm), heterogeneous bond content (2,1 bond), and heterogeneous bond content (1,3 bond) measured by C-NMR (7) The amount of components eluting at temperatures below 40°C in the elution curve obtained by temperature rising elution fractionation (TREF) measurement using o-dichlorobenzene (TREF 40°C) (8) Melting point (Tm) measured by differential scanning calorimetry (DSC) (9) 13 Number of long chain branches (LCB number) measured by C-NMR (10) SHI@10 / s, SHI@1.0 / s, [SHI@10 / s-SHI@1.0 / s] obtained from extensional viscosity measurement (11) Melt tension at 190°C (MT190)

[0127] (Synthesis Example 1: Preparation of Component [A-1] (Complex 1)) (1) Synthesis of Complex 1 As component [A-1] (complex 1), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium was synthesized according to the method described in Synthesis Example 1 of JP 2012-149160 A.

[0128] (2) Evaluation of terminal vinyl ratio (Rv) and weight average molecular weight (2-1) Preparation of catalyst (2-a) Chemical treatment of layered silicates Into a 1 L three-necked flask equipped with a stirring blade and a reflux device, 645.1 g of distilled water and 82.6 g of 98% sulfuric acid were added, and the temperature was raised to 95°C. To this was added 100 g of commercially available montmorillonite (Benclay KK manufactured by Mizusawa Industrial Chemicals, Al=9.78 mass%, Si=31.79 mass%, Mg=3.18 mass%, Al / Si (atomic ratio)=0.320, average particle size 14 μm), and the mixture was reacted at 95° C. for 320 minutes. After 320 minutes, 0.5 L of distilled water was added to stop the reaction, and the mixture was filtered to obtain 255 g of a cake-like solid. 1545 g of distilled water was added to this cake-like solid to form a slurry, and the temperature was raised to 40°C. 5.734 g of lithium hydroxide hydrate was added as a solid to the slurry, and the reaction was carried out at 40°C for 1 hour. After 1 hour, the reaction slurry was filtered and washed three times with 1 L of distilled water to obtain another cake-like solid. The collected cake-like solid was dried to obtain 80 g of chemically treated montmorillonite, which had a chemical composition of Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, Al / Si (atomic ratio) = 0.222, and Li = 0.53 mass%. (2-b) Prepolymerization 20 g of the obtained chemically treated montmorillonite was placed in a 1 L three-neck flask and 131 mL of heptane was added to form a slurry, to which 50 mmol of triisobutylaluminum (69 mL of a heptane solution with a concentration of 143.4 mg / mL) was added and stirred at room temperature for 1 hour. After 1 hour, the mixture was washed with heptane until the volume was 1 / 100, and the total volume was brought to 100 mL. The temperature of the slurry solution containing the chemically treated montmorillonite was raised to 50° C. 4.2 mmol of tri-normal octylaluminum (10.6 mL of a heptane solution with a concentration of 145.0 mg / mL) was added thereto, and the mixture was stirred at 50° C. for 20 minutes. To this was added 0.3 mmol of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium (complex 1) (slurried in 50 mL of toluene), and the mixture was stirred for 20 minutes while maintaining the temperature at 50°C. Thereafter, heptane was added so that the total volume became 500 mL, and the resulting slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was raised to 40°C, propylene was introduced at a rate of 10 g / hour and prepolymerization was carried out for 4 hours while maintaining the temperature at 40°C. Thereafter, the introduction of propylene was stopped and residual polymerization was carried out for 1 hour while maintaining the temperature at 40°C. The supernatant of the resulting catalyst slurry was removed by decantation, and then heptane was added again and decanted to wash the prepolymerized catalyst. To the portion remaining after the decantation, 12 mmol of triisobutylaluminum (16.6 mL of a heptane solution with a concentration of 143.4 mg / mL) was added and stirred for 10 minutes. The catalyst slurry was dried under reduced pressure at 40°C for 2 hours to obtain 54.0 g of prepolymerized catalyst. The prepolymerization ratio (the value (mass ratio) obtained by dividing the amount of prepolymerized polymer by the amount of chemically treated montmorillonite) was 1.70.

[0129] (2-2) Polymerization A 3L autoclave was thoroughly dried by passing nitrogen through it under heating, then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86 mL of a heptane solution of triisobutylaluminum (143.4 mg / mL), 240 mL of hydrogen, and 750 g of liquefied propylene were introduced, and the temperature was raised to 70°C. Subsequently, 100 mg of the prepolymerized catalyst (excluding the prepolymerized polymer) was pumped into the polymerization vessel using high-pressure argon to initiate polymerization. After maintaining the temperature at 70°C for 1 hour, the unreacted propylene was quickly purged to terminate the polymerization. Approximately 128 g of propylene homopolymer with an MFR of 38 was obtained.

[0130] (2-3) Terminal vinyl ratio, terminal vinylidene ratio, weight average molecular weight The resulting propylene homopolymer was evaluated for terminal vinyl ratio, terminal vinylidene ratio, and weight-average molecular weight, and the results were terminal vinyl ratio (Rv) = 0.79, terminal vinylidene ratio (Rvd) = 0.13, and weight-average molecular weight (Mw) = 184209. The heterogeneous bond amounts were 2,1 bond amount=0.05 mol % and 1,3 bond amount=0.13 mol %, respectively.

[0131] (Synthesis Example 2: Preparation of Component [A-2] (Complex 2)) (1) Synthesis of Complex 2 As component [A-2] (complex 2), rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium was synthesized according to the method described in Example 7 of JP-A-11-240909.

[0132] (2) Evaluation of terminal vinyl ratio (Rv) and weight average molecular weight (2-1) Preparation of catalyst (2-b) Prepolymerization 20 g of the chemically treated montmorillonite obtained in (2-a) Evaluation of the Terminal Vinyl Ratio (Rv) of Component [A-1] (Complex 1) was placed in a 1 L three-neck flask, and 131 mL of heptane was added to form a slurry. 50 mmol of triisobutylaluminum (69 mL of a heptane solution with a concentration of 143.4 mg / mL) was added and stirred at room temperature for 1 hour. After 1 hour, the mixture was washed with heptane until the total volume reached 100 mL. The temperature of the slurry solution containing the chemically treated montmorillonite was raised to 50° C. 4.2 mmol of tri-normal octylaluminum (10.6 mL of a heptane solution with a concentration of 145.0 mg / mL) was added thereto, and the mixture was stirred at 50° C. for 20 minutes. To this was added 0.3 mmol of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (complex 2) (slurried in 50 mL of toluene), and the mixture was stirred for 20 minutes while maintaining the temperature at 50°C. Thereafter, heptane was added so that the total volume became 500 mL, and the resulting slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was raised to 40°C, propylene was introduced at a rate of 10 g / hour and prepolymerization was carried out for 4 hours while maintaining the temperature at 40°C. Thereafter, the introduction of propylene was stopped and residual polymerization was carried out for 1 hour while maintaining the temperature at 40°C. The supernatant of the resulting catalyst slurry was removed by decantation, and then heptane was added again and decanted to wash the prepolymerized catalyst. To the portion remaining after the decantation, 12 mmol of triisobutylaluminum (16.6 mL of a heptane solution with a concentration of 143.4 mg / mL) was added and stirred for 10 minutes. The catalyst slurry was dried under reduced pressure at 40°C for 2 hours to obtain 62.2 g of prepolymerized catalyst. The prepolymerization ratio (the amount of prepolymerized polymer divided by the amount of chemically treated montmorillonite) was 2.11.

[0133] (2-2) Polymerization A 3L autoclave was thoroughly dried by passing nitrogen through it under heating, then the inside of the autoclave was replaced with propylene and cooled to room temperature. 2.86mL of a heptane solution of triisobutylaluminum (143.4mg / mL), 240mL of hydrogen, and 750g of liquefied propylene were introduced, and the temperature was raised to 70°C. Then, 30mg of the prepolymerized catalyst (excluding the prepolymerized polymer) was pumped into the polymerization vessel using high-pressure argon to initiate polymerization. After maintaining the temperature at 70°C for 1 hour, the unreacted propylene was quickly purged to terminate the polymerization. Approximately 157g of propylene homopolymer with an MFR of 1.0 was obtained. (2-3) Terminal vinyl ratio, terminal vinylidene ratio, weight average molecular weight The resulting propylene homopolymer was evaluated for terminal vinyl ratio, terminal vinylidene ratio, and weight-average molecular weight, and the results were terminal vinyl ratio (Rv) = 0, terminal vinylidene ratio (Rvd) = 0.60, and weight-average molecular weight (Mw) = 511,559. The heterologous bond amounts were 2,1 bond amount=0.55 mol % and 1,3 bond amount=0.37 mol, respectively.

[0134] From the above, it was demonstrated 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 carried out using component [A-1] at 70°C, and complex 2 of Synthesis Example 2 can be used as a metallocene compound that gives a propylene homopolymer a-2 having a weight-average molecular weight larger than that of propylene homopolymer a-1 and a terminal vinyl ratio (Rv) of less than 0.5 when propylene homopolymerization is carried out using component [A-2] at 70°C.

[0135] (Preparation Example 1: Preparation of propylene polymerization catalyst) Internal volume 1m 3 150 kg of chemically treated montmorillonite obtained as in Synthesis Example 1 (2-a) was placed in a reactor, and 2832 L of hexane was added to form a slurry. 74.4 kg (375 mol) of triisobutylaluminum was added over 85 minutes and stirred for 60 minutes. The resulting slurry was then washed with hexane until it reached 1 / 32 of its original volume, bringing the total volume to 900 L. The slurry solution containing this chemically treated montmorillonite was kept at 50°C, and 0.65 kg of triisobutylaluminum (4.257 kg of a hexane solution with a concentration of 15.3% by mass, 3.28 mol) was added thereto. The resulting slurry was stirred for 5 minutes, after which 0.657 kg (0.81 mol) of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium and 96 L of toluene were added, and stirring was continued for 60 minutes. Then, 9.758 kg (26.61 mol) of tri-normal octylaluminum was added to the obtained slurry and stirred for 6 minutes. Then, in another vessel equipped with a stirrer, 0.064 kg of triisobutylaluminum (9.88 kg, 0.32 mol of a toluene solution with a concentration of 0.648 mass%) was added to 240 L of toluene, and 1.768 kg (1.89 mol) of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-i-propylphenyl)indenyl}]hafnium was added to prepare a solution. The solution was then poured into the slurry, and 100 L of toluene was added, followed by further stirring for 20 minutes. Thereafter, 2387 L of hexane was added, the internal temperature of the reactor was raised to 40°C, and then 328.1 kg of propylene was fed over 240 minutes to carry out prepolymerization while maintaining the temperature at 40°C. Thereafter, the propylene feed was stopped, and the residual polymerization was carried out at 40°C for 80 minutes. After the completion of the residual polymerization, stirring was stopped and the contents were allowed to settle. The supernatant was removed so that the solution volume was 1500 L. Then, 12.7 kg of triisobutylaluminum was added, and 3974 L of hexane was added again. After stirring, the contents were allowed to settle and settle. The supernatant was removed so that the solution volume was 1500 L. To this solution, 8.9 kg of triisobutylaluminum (42.9 kg of a hexane solution with a concentration of 20.8% by mass) and 205 L of hexane were added. The reaction solution was then transferred to a dryer and dried at 40°C for 9 hours to obtain 465 kg of a prepolymerized catalyst (prepolymerized catalyst 1). The prepolymerization ratio (the value (mass ratio) obtained by dividing the amount of prepolymerized polymer by the amount of chemically treated montmorillonite) was 2.10.

[0136] (Example 1: Production of propylene polymer) Internal volume 100m 3Liquefied propylene, triisobutylaluminum, hydrogen, and prepolymerization catalyst 1 were continuously introduced into a stirred high-pressure reactor (length L / inner diameter D = 1.2 mm) at flow rates of 20 T / hr, 80 kg / hr, 0.180 kg / hr, and 0.87 kg / hr (mass excluding prepolymerized polymer) of prepolymerization catalyst 1. The temperature was maintained at 70 ± 0.1 °C, and continuous polymerization was carried out so that the polymer slurry concentration in the polymerization reactor was maintained at 40 mass%. The production rate of propylene polymer (powder) was 8.0 T / hr. The average hydrogen-to-propylene ratio was 9.0 mass ppm, with a standard deviation of 0.050 mass ppm or less and a coefficient of variation of 0.010 or less. The hydrogen concentration in the gas phase of the polymerization reactor was 450 ± 5 ppm. The resulting propylene polymer (powder) was thoroughly dried and then subjected to measurements of MFR, GPC, 3D-GPC, NMR, and TREF. The powder was also pressed to prepare a sample piece, which was then subjected to DSC measurements. The powder was granulated under the following granulation conditions to obtain pellets of a propylene polymer. The granulated pellets were used to measure melt tension, dynamic viscoelasticity, extensional viscosity, etc. The evaluation results are shown in Table 1.

[0137] (granulation) 0.125 parts by mass of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane (trade name: IRGANOX 1010, manufactured by BASF Japan Ltd.), a phenol-based antioxidant, and 0.125 parts by mass of tris(2,4-di-t-butylphenyl)phosphite (trade name: IRGAFOS 168, manufactured by BASF Japan Ltd.), a phosphite-based antioxidant, were blended with 100 parts by mass of the propylene polymer powder. The mixture was mixed at room temperature for 3 minutes using a high-speed stirring mixer (trade name: Henschel mixer), and then melt-kneaded in a twin-screw extruder to obtain pellets of the propylene polymer. The twin-screw extruder used was a KZW-25 manufactured by Technobel Co., Ltd., with a screw rotation speed of 400 RPM and kneading temperatures set at 80°C, 160°C, 210°C, and 230°C from the bottom of the hopper (the same temperature was maintained from then until the die exit).

[0138] (Example 2: Production of propylene polymer) In the polymerization of a propylene polymer in Example 1, the amount of hydrogen introduced was changed from 0.180 kg / hr to 0.230 kg / hr, the amount of catalyst was changed from 0.87 kg / hr to 0.73 kg / hr, and the polymer slurry concentration in the polymerization reactor was maintained at 40 mass% and the amount of propylene polymer (powder) withdrawn was maintained at 8.0 T / hr. At this time, the average ratio of the amount of hydrogen introduced continuously to the amount of propylene introduced continuously was 11.5 mass ppm, with a standard deviation of 0.050 mass ppm or less and a coefficient of variation of 0.005 or less, and the hydrogen concentration in the gas phase in the polymerization reactor was 600±5 ppm. The resulting propylene polymer (powder) was thoroughly dried and then subjected to measurements of MFR, GPC, 3D-GPC, NMR, and TREF. The powder was also pressed to prepare a sample piece, which was then subjected to DSC measurements. The powder was granulated under the same granulation conditions as in Example 1 to obtain pellets of a propylene polymer. The granulated pellets were used to measure melt tension, dynamic viscoelasticity, extensional viscosity, and the like. The evaluation results are shown in Table 1.

[0139] (Comparative Example 1: Production of Propylene-Based Polymer) A 20 L autoclave was thoroughly dried by passing nitrogen through it under heating, then the inside of the autoclave was replaced with propylene and cooled to room temperature. 18.7 mL of a heptane solution of triisobutylaluminum (140 mg / mL) and 0.083 g of hydrogen were introduced, followed by 5,000 g of liquefied propylene, and the temperature was raised to 63 °C. Subsequently, 200 mg of the above prepolymerized catalyst 1 (excluding the prepolymerized polymer) was pumped into the polymerization vessel using high-pressure argon to initiate polymerization, and the temperature was quickly raised to 70 °C. The temperature was maintained at 70 °C, and after 1 hour from the start of polymerization, the reacted propylene was quickly purged to terminate the polymerization. Approximately 2,039 g of propylene homopolymer was obtained. The resulting propylene polymer (powder) was thoroughly dried and then subjected to measurements of MFR, GPC, 3D-GPC, NMR, and TREF. The powder was also pressed to prepare a sample piece, which was then subjected to DSC measurements. The powder was granulated under the same granulation conditions as in Example 1 to obtain pellets of a propylene polymer. The granulated pellets were used to measure melt tension, dynamic viscoelasticity, extensional viscosity, and the like. The evaluation results are shown in Table 1.

[0140] (Comparative Example 2: Production of Propylene-Based Polymer) Polymerization was carried out in the same manner as in Comparative Example 1, except that 0.099 g of hydrogen was introduced. As a result, about 2058 g of a propylene homopolymer was obtained. The resulting propylene polymer (powder) was thoroughly dried and then subjected to measurements of MFR, GPC, 3D-GPC, NMR, and TREF. The powder was also pressed to prepare a sample piece, which was then subjected to DSC measurements. The powder was granulated under the same granulation conditions as in Example 1 to obtain pellets of a propylene polymer. The granulated pellets were used to measure melt tension, dynamic viscoelasticity, extensional viscosity, and the like. The evaluation results are shown in Table 1.

[0141] (Comparative Example 3: Production of Propylene-Based Polymer) Polymerization was carried out in the same manner as in Comparative Example 1, except that the amount of hydrogen introduced was changed to 0.106 g. As a result, about 2278 g of a propylene homopolymer was obtained. The resulting propylene polymer (powder) was thoroughly dried and then subjected to measurements of MFR, GPC, 3D-GPC, NMR, and TREF. The powder was also pressed to prepare a sample piece, which was then subjected to DSC measurements. The powder was granulated under the same granulation conditions as in Example 1 to obtain pellets of a propylene polymer. The granulated pellets were used to measure melt tension, dynamic viscoelasticity, extensional viscosity, and the like. The evaluation results are shown in Table 1.

[0142] (Comparative Example 4: Production of Propylene-Based Polymer) Polymerization was carried out in the same manner as in Comparative Example 1, except that 0.084 g of hydrogen and 320 g of ethylene were introduced and the amount of the prepolymerization catalyst 1 was changed to 70 mg (mass excluding the prepolymerized polymer). As a result, about 2260 g of propylene homopolymer was obtained. The resulting propylene polymer (powder) was thoroughly dried and then subjected to measurements of MFR, GPC, 3D-GPC, NMR, and TREF. The powder was pressed to prepare a sample, and the ethylene content was measured using IR based on a previously prepared calibration curve, which was found to be 3.6 wt%. The same pressed sample was also used to perform DSC measurements. The powder was granulated under the same granulation conditions as in Example 1 to obtain pellets of a propylene polymer. The granulated pellets were used to measure melt tension, dynamic viscoelasticity, extensional viscosity, and the like. The evaluation results are shown in Table 1.

[0143] (Comparative Example 5: Production of Propylene-Based Polymer) Polymerization was carried out in the same manner as in Comparative Example 1, except that 0.091 g of hydrogen and 107 g of ethylene were introduced and the amount of the prepolymerization catalyst 1 was changed to 120 mg (mass excluding the prepolymerized polymer). As a result, about 2413 g of a propylene homopolymer was obtained. The resulting propylene-based polymer (powder) was thoroughly dried and then subjected to measurements of MFR, GPC, 3D-GPC, NMR, and TREF. The powder was pressed to prepare a sample, and the ethylene content was measured using IR based on a previously prepared calibration curve, which was found to be 1.0 wt%. The same pressed sample was also used to perform DSC measurements. The powder was granulated under the same granulation conditions as in Example 1 to obtain pellets of a propylene polymer. The granulated pellets were used to measure melt tension, dynamic viscoelasticity, extensional viscosity, and the like. The evaluation results are shown in Table 1.

[0144] [Table 1]

[0145] Also, the complex viscosity η * Figure 3 shows the relationship between the angular frequency ω dependence of (ω) and MFR. From Examples 1 and 2 and Comparative Examples 1 to 5, it can be seen that the branched propylene polymer of the present invention has a branched propylene structure, particularly a molecular weight distribution and a branching distribution, that is different from conventional structures, and the complex viscosity η * It was shown that when the angular frequency ω dependence of (ω) and the MFR satisfy a specific equation, the components with extremely long relaxation times are reduced, strain hardening in the low deformation rate region is reduced while maintaining the melt tension necessary for forming, and the difference between strain hardening in the low deformation rate region and strain hardening in the high deformation rate region is increased.

Claims

1. A branched propylene polymer having the following properties (1) to (5): Property (1): The melt flow rate (MFR) measured at a temperature of 230° C. under a load of 2.16 kg is 10 g / 10 min or more and 100 g / 10 min or less. Property (2): The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), obtained by gel permeation chromatography (GPC), is 2.5 or more and less than 3.5, the ratio (Mz / Mw) of the z average molecular weight (Mz) to the weight average molecular weight (Mw) is 3.0 or more and 4.7 or less, and the z average molecular weight (Mz) is 500,000 or more and 940,000 or less. Property (3): In an integrated molecular weight distribution curve obtained by GPC, the proportion of components having a molecular weight of 1 million or more (W1 million) is 1.5% by mass or more and 4.0% by mass or less. Property (4): In the molecular weight distribution curve obtained by 3D-GPC, the absolute molecular weight M ａｂｓ The branching index g' (1 million) is greater than 0.70 and not more than 0.

85. Property (5): Complex viscosity η at angular frequency ω = 0.01 rad / s in dynamic viscoelasticity measurement ＊ (0.01) and the complex viscosity η at angular frequency ω = 100 rad / s ＊ The ratio [η ＊ (0.01) / η ＊ (100)] is 4.0 or more and 20 or less, and η ＊ (0.01) / η ＊ (100) and MFR satisfy the following formulas (1) and (2). or ＊ (0.01) / h ＊ (100)≦ -21×Log(MFR)+45 ・・・expression (1) η ＊ (0.01) / η ＊ (100) ≥ -21 × Log(MFR) + 38 ··· Equation (2)

2. The branched propylene polymer according to claim 1, further having the following property (4'): Characteristic (4'): Weight average molecular weight (Mw) of absolute molecular weight obtained by 3D-GPC ａｂｓ ) is less than 1 million, and in the molecular weight distribution curve obtained by 3D-GPC, the weight average molecular weight Mw ａｂｓ The branching index g' (Mw ａｂｓ ) and the branching index g′ (1 million) satisfy the following formula (3): 0≦g'(Mw ａｂｓ )-g'(1 million)≦0.10 ・・・Equation (3)

3. 3. The branched propylene polymer according to claim 1 or 2, further having the following property (6): Characteristic (6): １３ The mesotriad fraction (mm) measured by C-NMR is 95% or more and less than 99%, the heterogeneous bond amount (2,1 bond) is 0.05 mol% or more and 0.50 mol% or less, and the heterogeneous bond amount (1,3 bond) is 0.05 mol% or more and 0.50 mol% or less.

4. The branched propylene polymer according to any one of claims 1 to 3, further having the following property (7): Property (7): In an elution curve obtained by temperature rising elution fractionation (TREF) measurement using o-dichlorobenzene (ODCB), the content of components eluting at a temperature of 40° C. or less is 0.1% by mass or more and 3.0% by mass or less.

5. The branched propylene polymer according to any one of claims 1 to 4, further having the following property (8): Property (8): The melting point (Tm) measured by differential scanning calorimetry (DSC) is greater than 150.0°C and less than 160.0°C.

6. The branched propylene polymer according to any one of claims 1 to 5, further having the following property (9): Characteristic (9): １３ The number of long chain branches measured by C-NMR is 0.1 or more and 0.5 or less per 1000 monomers.

7. A method for producing the branched propylene polymer according to any one of claims 1 to 6, comprising homopolymerizing propylene or copolymerizing propylene and a comonomer in the presence of a propylene polymerization catalyst comprising the following components [A-1], [A-2], [B], and [C]: Component [A-1]: a metallocene compound that, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-1 having a terminal vinyl ratio (Rv) of 0.5 or more; Component [A-2]: a metallocene compound that, when propylene homopolymerized at 70°C, gives a propylene homopolymer a-2 having a weight average molecular weight greater than that of the propylene homopolymer a-1 and a terminal vinyl ratio (Rv) of 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

8. 8. The method for producing a branched propylene polymer according to claim 7, wherein propylene is homopolymerized or propylene and a comonomer are copolymerized at a constant hydrogen concentration.

9. 9. The method for producing a branched propylene polymer according to claim 7 or 8, wherein hydrogen and propylene are continuously introduced into a polymerization reactor, and the ratio of the amounts of hydrogen and propylene introduced is kept constant, thereby homopolymerizing propylene or copolymerizing propylene and a comonomer while maintaining a constant hydrogen concentration.

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