Branched propylene polymer

Abstract

To provide a branched propylene-based polymer having excellent malleability in melting, while keeping melt tension necessary for mold processing.SOLUTION: A branched propylene-based polymer of the invention has following characteristics (1), (2), and (3). Characteristic (1): the multi branching index (MBI) is 0.45 or more and 1.00 or less. Characteristic (2): the rate of strain hardening (SHI@1 s-1) at the strain rate (dε / dt) of 1.0 / sec is 0.70 or more and 3.00 or less. Characteristic (3): the maximum drawing speed (MaxDraw) and the melt flow rate (MFR) at 230°C satisfy the relation represented by following expression (1-1). (MaxDraw)>112×log(MFR)+30 Expression (1-1)SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to branched propylene polymers. [Background technology]

[0002] In recent years, there has been much research into introducing a branched structure to polypropylene to improve its suitability for sheet molding, blow molding, thermoforming, foam molding, and other processes that require materials with relatively high melt tension. Recently, macromer copolymerization, primarily using metallocene catalysts, has been proposed as a method for introducing branched structures into polypropylene. Branched polypropylene produced by macromer copolymerization has advantages over polypropylene in which branched structures are introduced by irradiation with electron beams, such as less gel formation due to crosslinking reactions.

[0003] One proposed macromer copolymerization method involves, for example, producing a propylene macromer with a vinyl structure at its ends in the first polymerization step (macromer synthesis step) using a specific catalyst and specific polymerization conditions, and then copolymerizing propylene with the propylene macromer in the second polymerization step (macromer copolymerization step) using a specific catalyst and specific polymerization conditions. The resulting branched polypropylene has been shown to have high melt strength and melt tension (see, for example, Patent Documents 1 and 2). Furthermore, a single-stage polymerization method has been proposed that uses a specific metallocene catalyst to simultaneously perform the macromer synthesis and macromer copolymerization steps, and it has been shown that the resulting branched polypropylene exhibits improved melt strength (see, for example, Patent Document 3). Furthermore, a multi-stage polymerization method has been proposed using a catalyst containing two specific metallocene compounds, specifically a catalyst combining metallocene compounds such as rac-SiMe2[2-Me-4-Ph-lnd]2ZrC12 and rac-SiMe2[2-Me-4-Ph-lnd]2HfC12 with silica supported with methylaluminoxane (MAO). It has been reported that the resulting branched polypropylene exhibits relatively high melt tension (see Patent Document 4). Furthermore, a method has been devised using a catalyst containing a specific metallocene compound and an ion-exchangeable layered silicate, and it has been reported that the resulting branched polypropylene has a broad molecular weight distribution, a high branching rate, and good melt tension (see Patent Document 5).

[0004] Furthermore, a method has been devised to produce a propylene polymer with a strain hardening degree (λmax) of 2.0 or higher in melt tension measurements using a catalyst containing several specific metallocene compounds, and it has been reported that the resulting branched polypropylene has good melt tension (see Patent Document 6).

[0005] Furthermore, Patent Document 7 discloses that branched polypropylene with a better balance between mechanical properties and manufacturing properties can be obtained by polymerizing propylene using a catalyst in which a single metallocene catalyst is supported on silica with very low porosity, thereby introducing short-chain branching of a specific degree and a relatively large amount of amorphous regions. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2001-525460 [Patent Document 2] Japanese Patent Application Publication No. 10-338717 [Patent Document 3] Special Publication No. 2002-523575 [Patent Document 4] Japanese Patent Publication No. 2001-64314 [Patent Document 5] Japanese Patent Publication No. 2007-154121 [Patent Document 6] Japanese Patent Publication No. 2009-57542 [Patent Document 7] Special Publication No. 2009-542872 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, while branched polypropylene obtained by the macromer copolymerization method disclosed in the above-mentioned Patent Documents 1 to 6 has high melt tension and is suitable for sheet molding, blow molding, thermoforming, foam molding, etc., it has the problem of poor ductility of the molten material. Furthermore, the branched polypropylene obtained by the method disclosed in Patent Document 7 has improved mechanical properties when the content of amorphous regions is increased, but the degree of strain hardening at a fast strain rate (SHI@1 second) -1 Because the coefficient of action was not very high, it was not able to fully satisfy the moldability requirements for various molding processes.

[0008] The object of the present invention is to provide a branched propylene polymer that maintains the melt tension necessary for molding while exhibiting excellent extensibility during melting. [Means for solving the problem]

[0009] The branched propylene polymer provided by the present invention is characterized by having the following properties (1), (2), and (3). Characteristic (1): The branching index (MBI) is between 0.45 and 1.00. Characteristics (2): Strain hardening degree (SHI@1s) at strain rate (dε / dt) of 1.0 / sec -1 The value is between 0.70 and 3.00. Characteristic (3): The relationship between the maximum winding speed (MaxDraw) and the melt flow rate (MFR) at 230°C is given by the following equation (1-1). (MaxDraw)>112×log(MFR)+30 ···Equation (1-1) Here, the multi-branching index (MBI) is the slope when the degree of strain hardening (SHI) for strain rates (dε / dt) from 0.01 / sec to 1.0 / sec is plotted on the x-axis with the logarithm of the strain rate (log(dε / dt)) and the degree of strain hardening (SHI) for strain rates from 0.01 / sec to 1.0 / sec is plotted on the y-axis. Furthermore, the degree of strain hardening (SHI) is the slope when plotting the logarithm of Henkey strain (ε) on the x-axis and the logarithm of extensional viscosity (ηE) (log(ηE)) on the y-axis, in the interval between Henkey strain (ε) 1 and 3, when measuring extensional viscosity at a temperature of 180°C and a predetermined strain rate (dε / dt). The maximum draw speed at 230°C (MaxDraw) is defined as the following conditions: resin temperature: 230°C, capillary: diameter 2.0 mm, length 40 mm, cylinder diameter: 9.55 mm, cylinder extrusion speed: 20 mm / min. The resin is extruded in a string-like form and wound onto the roller while the acceleration is 1.8 cm / s². 2 This is the winding speed (in m / min) just before the string-like material breaks when the winding speed is increased from 4.0 m / min to 200.0 m / min. Melt flow rate (MFR) is the melt flow rate measured at a temperature of 230°C and a load of 2.16 kg (unit: g / 10 min). [Effects of the Invention]

[0010] According to the present invention, a branched propylene polymer is provided that maintains the melt tension necessary for molding while exhibiting excellent extensibility during melting. [Brief explanation of the drawing]

[0011] [Figure 1A] Figure 1A is a schematic diagram illustrating that when a branched propylene polymer has many branches with short chain lengths in the high molecular weight region of its molecular weight distribution, the number of entanglement points of the molecular chains is not very large. [Figure 1B] Figure 1B is a schematic diagram illustrating that when a branched propylene polymer has many branches with long branching chain lengths in the high molecular weight region of its molecular weight distribution, numerous entanglement points of the molecular chains appear. [Figure 2] Figure 2 is an example of a plot diagram used to determine the degree of strain hardening (SHI). [Figure 3] Figure 3 is an example of a plot diagram used to calculate the multi-branching index (MBI). [Figure 4]Figure 4 illustrates the baseline and interval of the chromatogram in GPC. [Figure 5] Figure 5 is a graph plotting the data for branched propylene polymers obtained in each example and comparative example, with the logarithmic log(MFR) of MFR (MFR 230°C, 2.16 kg load) on the horizontal axis and the maximum winding speed (MaxDraw) at 230°C on the vertical axis. [Figure 6] Figure 6 is a graph plotting the data for branched propylene polymers obtained in each example and comparative example, with the logarithmic scale (log(MT)) of the melt tension (MT) at 230°C on the horizontal axis and the maximum winding speed (MaxDraw) at 230°C on the vertical axis. [Figure 7] Figure 7 is a graph plotting the data for branched propylene polymers obtained in each example and comparative example, with MFR (MFR 230°C, 2.16 kg load) on the horizontal axis and the branching index (MBI) on the vertical axis. [Modes for carrying out the invention]

[0012] The inventors of the present invention have found a design concept that, in order to improve the malleability of branched propylene polymers, it is preferable to include a component in the high molecular weight region of the molecular weight distribution of the branched propylene polymer that has a long relaxation time, but not an extremely long one. Based on this design concept, they synthesized a branched propylene polymer containing a highly branched molecule having a molecular structure in which many branched chains with shorter branched chain lengths per molecule are introduced compared to the branched chain lengths of conventional branched propylene polymers. As a result, they succeeded in obtaining a branched propylene polymer with improved malleability. As shown in Figure 1A, when a branched propylene polymer contains highly branched molecules with many short branching chains in the high molecular weight region of its molecular weight distribution, when strain occurs in the branched propylene polymer, a moderate number of entanglement points of the molecular chains appear. This results in a relaxation time distribution where many components have relatively short relaxation times and few components have extremely long relaxation times. Therefore, localized oriented crystallization starting from the entanglement points of the molecular chains is less likely to occur, and the non-uniformity of oriented crystallization can be suppressed, which is thought to improve ductility. In contrast, as shown in Figure 1B, when a branched propylene polymer contains a highly branched molecule with many branches having excessively long branching chain lengths in the high molecular weight region, numerous entanglement points of the molecular chains appear when strain occurs in the branched propylene polymer. As a result, many components that do not relax or have long relaxation times exist, and localized oriented crystallization progresses at numerous locations in the polymer, starting from the entanglement points of the molecular chains. This leads to non-uniform oriented crystallization and poor ductility. In other words, the branched propylene polymer of the present invention is presumed to have a molecular structure that follows a design concept of introducing a large number of relatively short, long-chain branches in the high molecular weight region of the molecular weight distribution, and on the other hand, it has the characteristic values ​​described below, and exhibits excellent ductility during melting while maintaining the melt tension necessary for molding. The present invention will be described in detail below. In this specification, the "~" indicating a numerical range is used to mean that the numbers written before and after it are included as the lower and upper limits, respectively. In this invention, logarithms are expressed as common logarithms, i.e., with base 10. In this invention, "ductility" refers to the property of a resin to be able to be stretched broadly, thinly, and uniformly, or thinly, long, and uniformly, while in a molten state.

[0013] I. Branched propylene polymer of the present invention The branched propylene polymer of the present invention has the following properties (1), (2), and (3), and preferably further has one or more of the following properties (4) to (12). The branching index (MBI) can be used as an indicator to determine the degree of ductility of the molten resin, and the degree of strain hardening (SHI) can be used as an indicator to determine the degree of melt tension of the molten resin. The relationship between MaxDraw and MFR can be used as an indicator of ductility relative to fluidity. In the present invention, by specifying the branching index (MBI) defined in characteristic (1) and the degree of strain hardening (SHI) defined in characteristic (2) to be within a certain range, and by ensuring that MaxDraw and MFR satisfy equation (1-1) defined in characteristic (3), a branched propylene polymer is provided that maintains the melt tension necessary for molding while exhibiting excellent ductility during melting.

[0014] Characteristics (1): The branched propylene polymer of the present invention has a branching index (MBI) of 0.45 or higher and 1.00 or lower. Here, the multi-branching index (MBI) is the slope when the degree of strain hardening (SHI) of a polymer is calculated for strain rates (dε / dt) from 0.01 / sec to 1.0 / sec, and the logarithm of the strain rate (log(dε / dt)) is plotted on the x-axis, and the degree of strain hardening (SHI) for strain rates from 0.01 / sec to 1.0 / sec is plotted on the y-axis. The degree of strain hardening of a polymer changes with the strain rate (dε / dt). The branching index (MBI) indicates the dependence of the degree of strain hardening (SHI) on the strain rate (dε / dt). A larger MBI value means that the degree of strain hardening (SHI) increases more rapidly with increasing strain rate (dε / dt).

[0015] Furthermore, the degree of strain hardening (SHI) is the slope when plotting the logarithm of Henkey strain (ε) (log(ε)) on the x-axis and the logarithm of extensional viscosity (ηE) (log(ηE)) on the y-axis, in the interval between Henkey strain (ε) 1 and 3, when the extensional viscosity of a polymer is measured at a temperature of 180°C and a predetermined strain rate (dε / dt). The degree of strain hardening (SHI) indicates the strain hardening properties of a polymer when it is subjected to a predetermined strain rate (dε / dt). A polymer with a high degree of strain hardening (SHI) at a predetermined strain rate (dε / dt) will not relax when subjected to that predetermined strain rate (dε / dt), and its extensional viscosity will increase as the amount of strain increases.

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

[0017] Figure 2 shows an example of a plot for determining the degree of strain hardening (SHI). Using the measurement method described above, time-varying data of extensional viscosity (ηE) is obtained at a predetermined constant strain rate (dε / dt). The measurement data is plotted on a graph with the logarithm of Henkey strain (ε) (log(ε)) on the x-axis and the logarithm of extensional viscosity (ηE) (log(ηE)) on the y-axis. The slope of the line through which the Henkey strain (ε) passes through the two points 1 and 3 is defined as the degree of strain hardening (SHI) at the strain rate (dε / dt) under the measurement conditions. Figure 3 shows an example of a plot for determining the Multi-Branching Index (MBI). Using the measurement method described above, the degree of strain hardening (SHI) is measured at multiple strain rates (dε / dt) ranging from 0.01 / sec to 1.0 / sec. The degree of strain hardening (SHI) at each strain rate is plotted on a graph with the logarithm of the strain rate (log(dε / dt)) on the x-axis and the degree of strain hardening (SHI) on the y-axis. The slope of the approximate straight line of the plots in the strain rate range of 0.01 / sec to 1.0 / sec is defined as the Multi-Branching Index (MBI). In the example in Figure 3, SHI@0.01s -1 SHI@0.1s -1 SHI@1.0s -1 The slope of the line approximating the three plotted points using the least squares method was defined as the multi-branching index (MBI).

[0018] Generally, the more components with long relaxation times present in a polymer, the greater the strain-hardening properties the polymer exhibits, even at slower strain rates. The relaxation time of a polymer depends on the structure of the polymer molecule, including its molecular weight, the presence or absence of branching, the amount of branching, and the length of the branched chains. In particular, in the case of branched propylene polymers, the longer the branched chain length, the longer the relaxation time. When the branched chain length of a branched propylene polymer is very long, the relaxation time of the branched propylene polymer is very long, resulting in high strain hardening properties even at slow strain rates. On the other hand, when the branched chain length is short, the relaxation time of the branched propylene polymer is short, so at fast strain rates the branched propylene polymer does not relax and exhibits high strain hardening properties, but at slow strain rates the branched propylene polymer relaxes and its strain hardening properties decrease. Therefore, the dependence of the degree of strain hardening on the strain rate, i.e., the branching index (MBI), of branched propylene polymers as polymer aggregates varies depending on the combination of components with long and short relaxation times, and the proportion of each component present. When a branched propylene polymer contains many components that do not relax or components with long relaxation times, localized oriented crystallization proceeds at numerous locations within the polymer, starting from entanglement points of molecular chains. This results in non-uniform oriented crystallization, which is thought to lead to poor ductility. In contrast, when a branched propylene polymer contains many highly branched molecules, each having numerous short branches in the high molecular weight region of its molecular weight distribution, it exhibits a relaxation time distribution with many components having relatively short relaxation times and few components having extremely long relaxation times. This makes localized oriented crystallization starting from entanglement points of molecular chains less likely to occur, suppressing heterogeneity in oriented crystallization and thus improving malleability.

[0019] In order to achieve excellent ductility during melting, the branched propylene polymer of the present invention has a lower limit of branching index (MBI) of 0.45 or higher, preferably 0.46 or higher, more preferably 0.47 or higher, and even more preferably 0.48 or higher. Furthermore, in order to obtain stability of melt tension by suppressing the strain rate dependence of strain hardening, the branched propylene polymer of the present invention has an upper limit of branching index (MBI) of 1.00 or lower, preferably 0.80 or lower, and even more preferably 0.60 or lower. On the other hand, in the branched propylene polymer of the present invention, which has a large melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg, molding is possible even if the melt tension is relatively small, so even if the branching index (MBI) is large, it is easy to achieve a good balance between ductility and melt tension during molding. For example, the branched propylene polymer of the present invention, having an MFR of 4.5 g / 10 min or more, preferably has a branching index (MBI) greater than 0.60 and 1.00 or less, and more preferably greater than 0.60 and 0.90 or less, in order to exhibit excellent spreadability relative to fluidity and spreadability relative to melt tension. On the other hand, the branched propylene polymer of the present invention, having an MFR of less than 4.5 g / 10 min, preferably has a branching index (MBI) of 0.45 or more and 0.60 or less, in order to exhibit excellent spreadability relative to fluidity and spreadability relative to melt tension. By setting the multi-branching index (MBI) of the branched propylene-based polymer to 0.45 or more and 1.00 or less, at a high strain rate (1.0 / sec), it does not relax and the strain hardening degree (SHI@1.0 / sec) is large, but at a low strain rate (0.01 / sec), it relaxes and the strain hardening degree (SHI@0.01 / sec) is small. Therefore, the branched propylene-based polymer of the present invention has a relaxation time distribution in which there are many components having a relaxation time of a certain degree of shortness and few components having an extremely long relaxation time, and thus has excellent ductility. Even if the branched propylene-based polymer has a strain hardening degree (SHI@1s within the specific range defined in the following characteristic (2) -1 ) if the multi-branching index (MBI) is too small, the strain rate dependence of the strain hardening degree (SHI) is too small. Therefore, even at a low strain rate such as 0.01 second or 0.1 second, the strain hardening degree (SHI@1s at a strain rate of 1 second -1 ) shows a large strain hardening degree with little difference. Therefore, in this case, the branched propylene-based polymer contains many components with a long relaxation time, has poor ductility, and in particular, the ductility corresponding to fluidity or melt tension is likely to deteriorate. On the other hand, even if the branched propylene-based polymer has a strain hardening degree (SHI@1s within the specific range defined in the following characteristic (2) -1 ) if the multi-branching index (MBI) exceeds 1.0, the strain rate dependence of the strain hardening degree (SHI) is too large. Therefore, the strain hardening degree changes with only a slight change in the strain rate, and the melt tension is likely to become unstable. Therefore, in this case, when molding the branched propylene-based polymer, there are problems such as molding defects occurring and difficulty in controlling the conditions of the molding process.

[0020] The strain hardening degree and the multi-branching index (MBI) indicated by the strain rate dependence of the strain hardening degree can be adjusted by controlling the amount and length of the branched chains in the branched propylene-based polymer. For example, the magnitude of the molecular weight of the macromer in the macromer synthesis step correlates with the magnitude of the length of the branched chain. Therefore, in a combination of a metallocene complex that mainly contributes to the synthesis of macromers and a metallocene complex that mainly contributes to the copolymerization of propylene and macromers, the molecular weight of the macromer can be adjusted by selecting the metallocene complex that contributes to the synthesis of macromers. Specifically, the molecular weight of the macromer can be adjusted by introducing appropriate substituents at the 2nd and 4th positions of the indene skeleton of the metallocene. In addition, macromers are formed via β-hydrogen elimination from the end of the growth chain, but by increasing the polymerization temperature, the β-hydrogen elimination reaction can be accelerated relative to the propylene insertion growth reaction, thereby lowering the molecular weight of the macromer. Furthermore, regarding the amount of branching, the ratio of propylene to macromer in the copolymerization process between propylene and macromer correlates with the amount of branched chains. Specifically, the amount of macromer incorporated can be adjusted by selecting the activity of the metallocene complex that contributes to macromer synthesis and the activity of the metallocene complex that mainly contributes to the copolymerization between propylene and macromer. Another method involves adjusting the amount of macromer incorporated by selecting the amount of metallocene complex used that contributes to macromer synthesis and the amount of metallocene complex used that primarily contributes to copolymerization between propylene and the macromer.

[0021] Characteristics (2): The branched propylene polymer of the present invention exhibits a degree of strain hardening (SHI@1s) at a strain rate (dε / dt) of 1.0 / second. -1 The value is between 0.70 and 3.00. Here, the degree of strain hardening at 1.0 / second (SHI@1s -1 The logarithm of extensional viscosity (ηE) is plotted on the x-axis with the logarithm of extensional viscosity (ηE) on the y-axis, in the interval between Henkey strain (ε) 1 and 3, when measuring extensional viscosity at a temperature of 180°C and a strain rate (dε / dt) of 1.0 / second. From the viewpoint of increasing melt tension to improve moldability and also improving ductility, the branched propylene polymer of the present invention has a strain hardening degree (SHI@1s) in the measurement of extensional viscosity.-1 The lower limit of ) is preferably 1.00 or higher, more preferably 1.30 or higher, and even more preferably 1.60 or higher, while the strain hardening degree (SHI@1s -1 The upper limit of ) is preferably 2.50 or less, more preferably 2.00 or less, and even more preferably 1.80 or less. Branched propylene polymers exhibit a rapid strain hardening rate (SHI@1s). -1 When the MFR is relatively large, the presence of components in the polymer that do not relax at a fast strain rate tends to increase the extensional viscosity. Therefore, linear polymers that do not exhibit strain hardening at a fast strain rate, or polymers with a similar MFR and strain hardening degree (SHI@1s -1 Compared to polymers with a low strain hardening degree (SHI@1s), the extensional viscosity is higher, resulting in increased melt tension and improved moldability. From this viewpoint, the branched propylene polymer of the present invention has a strain hardening degree (SHI@1s) -1 The value should be 0.70 or higher. On the other hand, branched propylene polymers exhibit a rapid strain hardening rate (SHI@1s). -1 If the strain hardening degree (SHI@1s) is too large, there are many components that do not relax or have long relaxation times, which causes oriented crystallization to proceed locally starting from the entanglement points of the molecular chains, resulting in a problem of deteriorated ductility. From this viewpoint, the branched propylene polymer of the present invention has a strain hardening degree (SHI@1s) -1 ) shall be 3.00 or less.

[0022] Characteristics (3): The branched propylene polymer of the present invention preferably satisfies the relationship between the maximum draw speed (MaxDraw) and the melt flow rate (MFR) at 230°C as shown in formula (1-1), and further satisfies the relationship shown in formula (1-2). It may also satisfy the relationship shown in formula (1-3), and may also satisfy the relationship shown in formula (1-4). (MaxDraw)>112×log(MFR)+30 ...Equation (1-1) (MaxDraw)>112×log(MFR)+51 ...Equation (1-2) (MaxDraw) < 112 × log(MFR) + 150 ... Equation (1-3) (MaxDraw) < 112 × log(MFR) + 120 ... Equation (1-4) Here, the maximum winding speed (MaxDraw) at 230°C refers to the process where, at a resin temperature of 230°C, the resin is extruded into a string-like form under the following conditions and wound onto a roller while accelerating to 1.8 cm / s². 2 This is the winding speed (in m / min) just before the string-like material breaks when the winding speed is gradually increased from 4.0 m / min to 200.0 m / min. • Capillary: 2.0mm diameter, 40mm length Cylinder diameter: 9.55mm Cylinder extrusion speed: 20 mm / min The maximum winding speed (MaxDraw) can be measured using a melt tension tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name: Capillograph 1B). MFR is the melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg (unit: g / 10 min). In this invention, the melt flow rate (MFR) is the value measured in accordance with JIS K6921-2 "Plastics - Polypropylene (PP) molding and extrusion materials - Part 2: Preparation of test specimens and determination of properties" under test conditions of 230°C and a load of 2.16 kgf. The melt flow rate (MFR) can be easily adjusted by changing the polymerization temperature and pressure, or, more commonly, by adding chain transfer agents such as hydrogen during polymerization.

[0023] Generally, increasing fluidity improves ductility, but it has the problem of decreasing melt tension. Therefore, a propylene polymer that achieves both the melt tension necessary for molding and excellent ductility is desirable. Satisfying formula (1-1) or (1-2) above indicates that the branched propylene polymer of the present invention has superior ductility relative to fluidity compared to conventional propylene polymers. In other words, in order to distinguish the branched propylene polymer of the present invention from conventional polymers, the maximum winding speed (MaxDraw) is considered to be a function positively correlated with an increase in fluidity (MFR), and the parameters of this function are set to show that the maximum winding speed (MaxDraw) of the branched propylene polymer of the present invention is greater in proportion to the fluidity than the maximum winding speed (MaxDraw) of conventional propylene polymers defined by this function. Specifically, based on the data of the examples and comparative examples, values ​​for maximum winding speed (MaxDraw) and fluidity (MFR) that distinguish the examples from the comparative examples of the prior art are assumed, and the parameters of the relationship between the maximum winding speed (MaxDraw) and fluidity (MFR) are determined by the least squares method. The branched propylene polymer of the present invention exhibits excellent ductility relative to its fluidity, thus maintaining the melt tension necessary for molding and showing excellent ductility even with relatively low fluidity. Furthermore, those that satisfy the above formulas (1-3) or (1-4) are preferred from the viewpoint of ease of manufacture.

[0024] Characteristics (4): The branched propylene polymer of the present invention preferably satisfies the relationship between the maximum winding speed (MaxDraw) and melt tension (MT) at 230°C shown in formula (2-1), and more preferably satisfies the relationship shown in formula (2-2). It may also satisfy the relationship shown in formula (2-3), and may also satisfy the relationship shown in formula (2-4). (MaxDraw)>-119×log(MT)+200...Equation (2-1) (MaxDraw)>-119×log(MT)+220...Equation (2-2) (MaxDraw)<-119×log(MT)+280...Equation (2-3) (MaxDraw)<-119×log(MT)+260...Equation (2-4) Here, the maximum winding speed (MaxDraw) at 230°C is as described in characteristic (3) above. Melt tension (MT) is the tension (in grams) detected when winding resin onto a roller at a winding speed of 4.0 m / min during measurement of the maximum winding speed (MaxDraw) at 230°C. Specifically, the tension detected on the pulley when the resin is extruded into a string-like form and wound onto a roller using a melt tension tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name: Capillograph 1B) at a resin temperature of 230°C under the following conditions is defined as the melt tension (MT) at 230°C. • Capillary: 2.0mm diameter, 40mm length Cylinder diameter: 9.55mm Cylinder extrusion speed: 20 mm / min · Winding speed: 4.0m / min Furthermore, if a break occurs at a winding speed of 4.0 m / min, it should be stated that "the fusion tension cannot be evaluated." Satisfying either formula (2-1) or (2-2) above indicates that the branched propylene polymer of the present invention has higher ductility at melt relative to its melt tension compared to conventional propylene polymers. In other words, in order to distinguish the branched propylene polymer of the present invention from conventional polymers, the maximum winding speed (MaxDraw) is considered to be a function that has a negative correlation with the increase in melt tension (MT), and the parameters of this function are set to show that the maximum winding speed (MaxDraw) of the branched propylene polymer of the present invention is greater than the maximum winding speed (MaxDraw) of conventional propylene polymers defined by this function in proportion to the melt tension. Specifically, based on the data of the examples and comparative examples, values ​​of maximum winding speed (MaxDraw) and melt tension (MT) that distinguish the examples from the comparative examples of the prior art are assumed, and the parameters of the relational expression that holds between the maximum winding speed (MaxDraw) and melt tension (MT) are determined by the least squares method. Furthermore, those that satisfy the above formulas (2-3) or (2-4) are preferred from the viewpoint of ease of manufacture.

[0025] Characteristics (5): The branched propylene polymer of the present invention preferably has a component soluble in p-xylene at 25°C (CXS) of less than 0.5% by mass. CXS is used as an indicator of the proportion of low-order and low-molecular-weight components in branched propylene polymers. If CXS is too high, the proportion of low-molecular-weight and low-steric-order components increases, affecting various physical properties. The amount of CXS is more preferably 0.4% by mass or less, and even more preferably 0.3% by mass or less. There is no lower limit for CXS, but from the viewpoint of the tactile feel of the molded product, it is preferably 0.1% by mass or more, and more preferably 0.2% by mass or more.

[0026] In this invention, the method for measuring CXS is as follows: 2 g of the sample is dissolved in 300 ml of p-xylene (containing 0.5 mg / ml of BHT) at 130°C to form a solution, which is then allowed to stand at 25°C for 48 hours. After that, the precipitate and filtrate are separated by filtration. The p-xylene is evaporated from the filtrate, and the solution is further dried under reduced pressure at 100°C for 12 hours to recover the components that were dissolved in the p-xylene at 25°C. The CXS is defined as the percentage of the mass of the recovered components relative to the mass of the sample.

[0027] To control the amount of CXS, it is common to select cross-linked indene or azulene complexes as the metallocene complex catalyst component, which have relatively few low molecular weight components and high stereoregularity. In particular, the amount of CXS can be controlled by adjusting the bulkiness of the substituents at the 2nd or 4th position. Furthermore, when combining two complexes, the overall amount of CXS can be controlled by selecting a highly stereoregular complex and adjusting the ratio of the complexes. Furthermore, increasing the amount of the organoaluminum compound, which is the catalytic component, causes it to coordinate with and alter a portion of the complex, resulting in an increase in low molecular weight components and a decrease in stereoregularity. Therefore, the amount of CXS can be controlled by optimizing the amount of the organoaluminum compound.

[0028] Characteristics (6): In the branched propylene polymer of the present invention, it is preferable that the number-average molecular weight (Mn) of the branched side chains of the branched propylene polymer is 11,000 or more and 30,000 or less. Reference: Macromolecules, Vol. 31, p. 1335 (1998) states that the entanglement molecular weight of isotactic polypropylene is 6900 g / mol. Furthermore, the reference Macromolecules, Vol. 35, p. 10062 (2002) states that the effect on viscoelasticity is minimal when the branching length of propylene polymers is 7000 g / mol or less. In light of these studies, the emergence of viscoelastic behavior such as strain hardening requires that the branched chain length be 6900-7000 g / mol or more in terms of the entangled molecular weight of polypropylene. This corresponds to approximately 400 or more carbon atoms in the skeleton. Here, skeleton carbon refers to all carbon atoms other than methyl carbon in the case of propylene alone or copolymerization of propylene and ethylene. Furthermore, when butene is used in addition to the above monomers, it refers to all carbon atoms other than methyl carbon and ethyl carbon. Therefore, in order to obtain the melt tension necessary for molding, which requires a high degree of strain hardening at a fast strain rate, the length of the branched chains of the branched propylene polymer of the present invention is preferably 500 or more (equivalent to 11,000 or more polypropylene molecular weight), more preferably 600 or more (equivalent to 13,000 or more polypropylene molecular weight), and even more preferably 700 or more (equivalent to 15,000 or more polypropylene molecular weight), as the number of carbon atoms in the skeleton. Furthermore, regarding the branching length of the branched propylene polymer of the present invention, at a fast strain rate, the degree of strain hardening is large and the melt tension necessary for molding is obtained, but at a slow strain rate, the strain is sufficiently relaxed and the strain hardening properties are reduced. Therefore, the number of carbon atoms in the skeleton is preferably 1450 or less (equivalent to polypropylene molecular weight: 30,000 or less), more preferably 1350 or less (equivalent to polypropylene molecular weight: 28,000 or less), and even more preferably 1300 or less (equivalent to polypropylene molecular weight: 27,000 or less).

[0029] The polypropylene molecular weight equivalent value used here is not strictly the same as the molecular weight measured by GPC, but it approximates the number-average molecular weight (Mn) measured by GPC. Furthermore, although the length of the branches on a branched propylene polymer cannot be directly measured, by polymerizing propylene under the same conditions as those used to produce the branched propylene polymer of the present invention, a macromer corresponding to the branched portion can be synthesized, and the number-average molecular weight (Mn) of this macromer, measured by GPC using the method shown in the examples, can be estimated to represent the length of the branches. Therefore, the lower limit of the branched chain length of the branched propylene polymer of the present invention is preferably 11,000 or more, more preferably 13,000 or more, and even more preferably 15,000 or more, as measured by GPC with a number-average molecular weight (Mn). On the other hand, the upper limit of the branched chain length of the branched propylene polymer of the present invention is preferably 30,000 or less, more preferably 28,000 or less, and even more preferably 27,000 or less, as measured by GPC with a number-average molecular weight (Mn).

[0030] (Method for measuring molecular weight) Molecular weight is obtained by gel permeation chromatography (GPC) as number-average molecular weight (Mn), weight-average molecular weight (Mw), and Q-value (Mw / Mn). Details of the measurement method and measuring equipment are as follows. • Equipment: Waters GPC (ALC / GPC, 150C) • Detector: FOXBORO MIRAN, 1A, IR detector (measurement wavelength: 3.42 μm) • Columns: Showa Denko AD806M / S (3 pieces) Mobile phase solvent: o-dichlorobenzene (ODCB) ·Measurement temperature: 140℃ ·Flow rate: 1.0mL / min ·Injection volume: 0.2mL Sample preparation is performed by mixing the sample with ODCB (containing 0.5 mg / mL of dibutylhydroxytoluene (BHT)) at a sample concentration of 1 mg / mL and dissolving it at 140°C for approximately 1 hour. The baseline and interval of the obtained chromatogram are defined as shown in Figure 4. Furthermore, the conversion from the retention capacity obtained by GPC measurement to molecular weight is performed using a calibration curve prepared in advance using standard polystyrene. The standard polystyrene used is the following brand manufactured by Tosoh Corporation. Brands: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000 Calibration curves are created by injecting 0.2 mL of a solution prepared by dissolving each standard in ODCB (containing 0.5 mg / mL BHT) so that each standard has a concentration of 0.5 mg / mL. The calibration curves are approximated using a cubic equation obtained by the least squares method. Viscosity formula used for conversion 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

[0031] Characteristics (7): The branched propylene polymer of the present invention preferably has a melt flow rate (MFR) of 1.0 g / 10 min or more and 10.0 g / 10 min or less, measured at a temperature of 230°C and a load of 2.16 kg. MFR is an indicator of fluidity during melting. As the molecular weight of a polymer increases, the MFR decreases. If the MFR is too low, the fluidity during melting deteriorates, making heat molding difficult. On the other hand, as the molecular weight of a polymer decreases, the MFR increases. If the MFR is too high, it causes a decrease in melt tension. Also, while a high MFR improves fluidity during melting, it can sometimes reduce impact strength. From the viewpoint of heat moldability, the MFR of the branched propylene polymer of the present invention is preferably 1.0 g / 10 min or more, and more preferably 2.0 g / 10 min or more. On the other hand, from the viewpoint of melt tension and impact strength, the MFR of the branched propylene polymer of the present invention is preferably 10.0 g / 10 min or less, more preferably 8.0 g / 10 min or less, and even more preferably 6.0 g / 10 min or less. Among these, the particularly preferred range of MFR is 1.0 g / 10 min or more and 6.0 g / 10 min or less. On the other hand, the branched propylene polymer of the present invention has preferred applications depending on whether the MFR is relatively small or relatively large. For example, when molding the branched propylene polymer of the present invention into a sheet, a smaller MFR makes it easier to mold it thicker, while a larger MFR makes it easier to mold it thinner. Therefore, it is preferable to adjust the MFR of the branched propylene polymer of the present invention within the range of 1.0 g / 10 min to 10.0 g / 10 min, depending on the application. For example, the branched propylene polymer of the present invention with an MFR of 1.0 g / 10 min or more and less than 4.5 g / 10 min is preferred when molding it to be relatively thick (e.g., sheet molding, blow molding, thermoforming, foam molding, etc.). The branched propylene polymer of the present invention with an MFR of 4.5 g / 10 min or more and 10.0 g / 10 min or less is preferred when molding it to be relatively thin (e.g., film molding, lamination, etc.). The branched propylene polymer of the present invention exhibits excellent spreadability relative to flow in any of the above-mentioned MFRs. The method for measuring MFR is as described in characteristic (3) above.

[0032] Characteristics (8): Regarding the branching amount of the branched propylene polymer of the present invention, 13 It can be measured as the average value of the entire polymer using 1C-NMR, and the absolute molecular weight (M) can be measured using 3D-GPC. abs The relationship between () and the branching index (g') allows us to roughly determine the relative degree of branching at each absolute molecular weight as an indicator. In the branched propylene polymer of the present invention, the ratio of components with a molecular weight M of 1 million or more (W1,000,000) to the total amount of polymer in the molecular weight distribution curve measured by GPC is preferably 0.070 or more and 0.100 or less, more preferably 0.070 or more and 0.095 or less, and even more preferably 0.080 or more and 0.095 or less. W1,000,000 is an index indicating the ratio of high molecular weight components contained in the polymer. W1,000,000 is defined as the value obtained by subtracting from 1 the integral value up to a molecular weight M of 1 million (Log(M)=6.0) or less in the integral molecular weight distribution curve measured by GPC (total amount normalized to 1 on a mass basis). Furthermore, the branched propylene polymer of the present invention has an absolute molecular weight M measured by 3D-GPC. abs It is preferable that the branching index g'(1 million) at 1 million is 0.80 or greater and 0.90 or less.

[0033] The branching index g' is the intrinsic viscosity [η] of polymers having a long-chain branched structure. br The intrinsic viscosity [η] of a linear polymer having the same molecular weight. lin The ratio ([η] br / [η] lin It is given by ) and takes a value less than 1.0 if a long-chain branching structure exists. The definition is described, for example, in "Developments in Polymer Charactarization-4" (JV Dawkins ed. Applied Science Publishers, 1983), and is a well-known indicator to those skilled in the art. The branching index g' can be determined, for example, by using a 3D-GPC equipped with a light scattering meter and a viscometer as detectors, as shown below, to determine the absolute molecular weight M abs It can be obtained as a function of . In this invention, 3D-GPC refers to a GPC device in which three detectors are connected. These three detectors are a differential refractometer (RI), a viscometer, and a multi-angle laser light scattering detector (MALLS). The GPC system used is a Waters Alliance GPCV2000 equipped with a differential refractometer (RI) and a viscometer. Additionally, a multi-angle laser light scattering detector (MALLS) DAWN-E from Wyatt Technology is used as the light scattering detector. The detectors are connected in the following order: MALLS, RI, and Viscometer. The mobile phase solvent is 1,2,4-trichlorobenzene (with BASF Japan's antioxidant Irganox 1076 added at a concentration of 0.5 mg / mL). The flow rate is 1 mL / min, and two Tosoh Corporation GMHHR-H(S)HT columns are connected in series. The temperature of the column, sample injection section, and each detector is 140°C. The sample concentration was 1 mg / mL, and the injection volume (sample loop volume) was 0.2175 mL. Absolute molecular weight (M) obtained from MALLS abs To determine the mean square radius of inertia (Rg) and the intrinsic viscosity ([η]) obtained from the Viscometer, the data processing software ASTRA (version 4.73.04) included with MALLS is used, and the calculations are performed 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]) obtained by measuring the sample with the Viscometer described above. br ) and the intrinsic viscosity ([η] obtained by separately measuring the linear polymer. lin ) ratio ([η] br / [η] lin It is calculated as follows:

[0034] When a long-chain branched structure is introduced into a polymer molecule, its radius of inertia decreases compared to a linear polymer molecule of the same molecular weight. A smaller radius of inertia leads to a smaller intrinsic viscosity, and therefore, as the introduction of a long-chain branched structure increases, the intrinsic viscosity ([η]) of a linear polymer of the same molecular weight decreases. lin The intrinsic viscosity ([η]) of branched polymers relative to ) br ) ratio ([η] br / [η] lin ) becomes smaller. Therefore, polymers with a long-chain branched structure have a branching index g'([η] br / [η] lin When the value becomes less than 1.0, the linear polymer, by definition, has a branching index g' of 1.0. Here, commercially available homopolypropylene (Novatec PP® grade name: FY6, manufactured by Nippon Polypropylene Co., Ltd.) is used as the linear polymer [η] lin Obtain the linear polymer [η] lin The logarithm of has a linear relationship with the logarithm of molecular weight, as is well known from the Mark-Houwink-Sakurada equation, therefore [η] lin The values ​​can be obtained by appropriately extrapolating to the low molecular weight or high molecular weight side. To make the branching index g' less than 1.0, this can be achieved by introducing many long-chain branches, or, for the same number of branches, by increasing the branching chain length. This can be achieved by controlling the selection, combination, and ratio of catalysts, as well as the pre-polymerization conditions during polymerization. To bring each branching index g' within the specific range described above, it is possible to adjust the amount of hydrogen during polymerization as appropriate, in addition to selecting catalysts, their combinations, and their ratios, as described later.

[0035] Characteristics (9): Branched propylene polymers are preferably characterized by a melting point (Tm) measured by differential scanning calorimetry (DSC) of 150°C or higher and 157°C or lower. The heat resistance and rigidity of branched propylene polymers improve as the Tm increases. Therefore, Tm is preferably 150°C or higher, and more preferably 151°C or higher. On the other hand, if the Tm of a branched propylene polymer is too high, it may become too rigid, resulting in poor tactile properties such as a poor feel to the touch. Therefore, the Tm is preferably 157°C or lower, and more preferably 155°C or lower. In the case of polypropylene, Tm decreases due to the insertion of ethylene units and positional regularity defects. The branched propylene polymer of the present invention allows for control of Tm by selecting an optimal complex for positional regularity defects as a polymerization catalyst, selecting a combination of multiple complexes, and further controlling the polymerization temperature and polymerization pressure. The melting point (Tm) of branched propylene polymers can be measured by the following method: Using a Seiko Instruments DSC6200, a sheet of sample is placed in a 5 mg aluminum pan, heated from room temperature to 200°C at a rate of 100°C / min, held for 5 minutes, then cooled to 20°C at a rate of 10°C / min to determine the crystallization temperature (Tc) as the maximum peak temperature (°C) at which crystallization occurs, and then the melting point (Tm) is determined as the maximum peak temperature (°C) at which melting occurs when the temperature is heated to 200°C at a rate of 10°C / min. The sheet-like sample can be obtained by sandwiching 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.

[0036] Characteristics (10): The branched propylene polymer of the present invention may have a long-chain branched (LCB) structural moiety represented by the following structural formula (A).

[0037] [ka]

[0038] [However, in structural formula (A), P1, P2, and P3 are residues formed at the ends of a branched propylene polymer, each having one or more propylene units, Cbr represents the methine carbon at the base of a branched chain with 7 or more carbon atoms, and Ca, Cb, and Cc represent methylene carbons adjacent to the methine carbon (Cbr).] In structural formula (A), the main chain of the branched propylene polymer is P 1 -Cbr-P 2 The line, P 1 -Cbr-P 3 line or P 2 -Cbr-P 3 There are three possible lines. Therefore, corresponding to each, Cbr-P 3 The line, Cbr-P 2 The line or Cbr-P 1 The line can become the branching chain described above. P 1 , P 2 , P 3 It may also contain branched carbon atoms (Cbr) within itself that are different from the Cbr shown in structural formula (A). Here, the LCB structure is assigned to branched propylene polymers. 13 1C-NMR revealed three methylene carbons (Ca, Cb, Cc) at 44.0–44.1 ppm, 44.7–44.8 ppm, and 44.8–44.9 ppm, and a methine carbon (Cbr) at 31.6–31.8 ppm. A distinctive feature is that the three methylene carbons adjacent to the Cbr are observed as three separate, non-equivalent diastereotopic molecules. Also, the LCB number is, 13 This is the number of branched chains with 7 or more carbon atoms per 1000 monomer units (1000P) calculated by 13C-NMR, and also the number of methine carbons at the base of branched chains with 7 or more carbon atoms. Branched chains with seven or more carbon atoms and branched chains with fewer than seven carbon atoms can be distinguished by the difference in the peak position of the methine carbon at the base of the branch (Macromolecules, Vol. 35, No. 10, 2002). In the present invention, the LCB number of the branched propylene polymer is not particularly limited, but it is preferably 1.0 or less per 1000P. Furthermore, by polymerizing propylene under the same conditions as those used to produce the branched propylene polymer of the present invention, a macromer corresponding to the branched portion can be synthesized, and the number of LCBs measured for this macromer using the method described above can be estimated to be the number of LCBs in the branched portion. The lower limit of the number of LCBs in the branched chain of the branched propylene polymer of the present invention measured in this way is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more per 1000P. The upper limit of the number of LCBs in the branched chain is not particularly limited, and is usually 1.0 or less.

[0039] 13 The details of the measurement method for long-chain branching (LCB) structures calculated by 13C-NMR are as follows. [Sample preparation] Approximately 200 mg of the sample is placed in a 10 mm diameter NMR sample tube along with 2.4 ml of o-dichlorobenzene / deuterated bromide benzene (C6D5Br) = 2 / 1 (volume ratio) and hexamethyldisiloxane, which is the reference substance for chemical shifts. After purging with nitrogen, the tube is sealed and heated to dissolve the sample and obtain a homogeneous solution. [Equipment and Measurement Methods] NMR measurements were performed using a Bruker BioSpin AVANCE400 NMR spectrometer equipped with a 10 mmφ cryoprobe. Using a proton broadband decoupling method with a probe temperature of 120°C, a pulse angle of 45°, a pulse interval of 4.2 seconds, and more than 20,000 integration cycles. 13 Perform 1C-NMR measurement. The chemical shift is hexamethyldisiloxane. 13 Set the C signal to 1.98 ppm, and the other 13 The chemical shift of the signal due to C was based on this. [Method for calculating the number of long chain branches (LCBs)] When the methylene carbon intensity of a propylene main chain at 44.4–49.0 ppm is normalized to 1000, the average of the methylene carbon intensity at 44.0–44.1 ppm and the methine carbon (Cbr) intensity at 31.6–31.8 ppm is taken as the number of long-chain branches per 1000 propylene monomer units.

[0040] Characteristics (11): The branched propylene polymer of the present invention, in order to obtain a propylene polymer with excellent ductility while maintaining the melt tension necessary for molding, has a lower limit of melt tension (MT230℃) of preferably 3.5g or more, more preferably 4.0g or more, even more preferably 5.0g or more, even more preferably 6.0g or more, and particularly preferably 8.0g or more, and an upper limit of MT230℃ is preferably 19.0g or less, even more preferably 18.0g or less, and particularly preferably 17.0g or less. The branched propylene polymer of the present invention can be easily molded by adjusting the processing conditions as long as the melt tension (MT230℃) is within the above range. The method for measuring the melt tension (MT230℃) is as described in the above characteristic (4).

[0041] Characteristics (12): The branched propylene polymer of the present invention has a controlled branching structure (branching amount, branching length, branching distribution), and therefore possesses high melt tension while exhibiting excellent melt ductility. Melt-ductility can be evaluated using the maximum draw speed (MaxDraw) as an indicator. A larger MaxDraw value indicates better ductility. In the branched propylene polymer of the present invention, the maximum draw speed (MaxDraw) at 230°C is preferably 90 m / min or more, more preferably 100 m / min or more, and even more preferably 110 m / min or more. The method for measuring the maximum draw speed (MaxDraw) is as described in characteristic (3) above.

[0042] II. Method for producing branched propylene polymers The method for producing the branched propylene polymer of the present invention is not particularly limited, as long as it is a method that can produce a branched propylene polymer that satisfies the above-mentioned physical properties which are characteristic of the present invention. For example, a method using a metallocene catalyst for macromer copolymerization is one such method. As a method for producing the branched propylene polymer of the present invention using a metallocene catalyst and macromer copolymerization, examples include a first method in which a macromer synthesis step and a copolymerization step of propylene and macromer are carried out simultaneously using a catalyst containing a plurality of metallocene compounds that yield a long-chain branched propylene polymer, and a second method in which the macromer synthesis step and the copolymerization step of propylene and macromer are carried out in two separate steps.

[0043] II-1. First manufacturing method Among the above-mentioned first manufacturing methods, a preferred method is to obtain the branched propylene polymer of the present invention by homopolymerizing propylene using an olefin polymerization catalyst containing the following catalyst components (A), (B), and (C), or by copolymerizing propylene with at least one comonomer selected from α-olefins having 2 to 20 carbon atoms other than propylene. (A): Two or more transition metal compounds from Group 4 of the periodic table, selected from at least one catalyst component [A-1] which is a compound represented by the following general formula (a1), and at least one catalyst component [A-2] which is a compound represented by the following general formula (a2). Catalyst component [A-1]: Compound represented by general formula (a1) Catalyst component [A-2]: Compound represented by general formula (a2) (B): A compound that reacts with the catalyst component (A) to form an ion pair, or an ion-exchangeable layered silicate. (C): Organoaluminum compounds

[0044] The catalyst components (A), (B), and (C) will be described in detail below. 1. Catalyst component (A) 1-1. Catalyst component [A-1]: Compound represented by general formula (a1) As the catalyst component [A-1], a metallocene compound represented by the following general formula (a1) is preferably used because it has a number-average molecular weight Mn of 30,000 or less and produces a macromer with a high terminal vinyl content.

[0045] [ka]

[0046] [In general formula (a1), R 11 and R 12 Each of these independently represents a thienyl group that is either unsubstituted or has a substituent at the 5-position. 13 and R 14 Each of these independently represents an unsubstituted or substituted aryl group having 6 to 30 carbon atoms, which may contain a halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or multiple heteroatoms selected from these. 11 This 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. 11 X represents zirconium or hafnium. 11 and Y 11 Each of these independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl 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.

[0047] By using the metallocene compound represented by the above general formula (a1), a heterocycle and a transition metal (M 11 ) The coordination field on the surface and the relative positional relationship with the growing polymer chain tend to be appropriate, making it easier to obtain macromers with a high terminal vinyl content and a small molecular weight. In the metallocene compounds represented by the above general formula (a1), among others, R 11 and R 12 Compared to R 13 and R 14 It is preferable that the base is bulkier.

[0048] The above R11 and R 12 Each of these is independently an unsubstituted or substituted thienyl group at the 5-position. Here, a thienyl group substituted at the 5-position is a thienyl group that has a substituent only at the 5-position. The above R 11 and R 12 The macromer's molecular weight and terminal vinyl content are easily controlled within a favorable range, so it is preferably an unsubstituted or substituted 2-thienyl group at the 5-position, and more preferably a substituted 2-thienyl group at the 5-position. R 11 and R 12 Examples of substituents that the thienyl group may have include C1-C6 alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and t-butyl groups; C6-C12 aryl groups such as phenyl groups; halogen atoms such as fluorine and chlorine atoms; C1-C6 alkoxy groups such as methoxy and ethoxy groups; and silyl groups having C1-C6 hydrocarbon groups such as trimethylsilyl and triethylsilyl groups. Among these, C1-C4 alkyl groups are preferred, C1-C3 alkyl groups are more preferred, and methyl groups are even more preferred. Also, R 11 and R 12 It is preferable that they are identical to each other.

[0049] The above R 13 and R 14 Each of these is an unsubstituted or substituted aryl group having 6 to 30 carbon atoms, which may independently contain a halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroatoms selected from these. Examples of aryl groups include a phenyl group, a biphenylyl group, a naphthyl group, etc., with the phenyl group being preferred. R 13 and R 14 By increasing its bulk appropriately, a macromer with higher stereoregularity, fewer heterogeneous bonds, a higher terminal vinyl content, and a lower molecular weight can be obtained. Therefore, R 13 and R 14is preferably a phenyl group having a substituent in the range of 6 to 16 carbon atoms, an unsubstituted biphenylyl group or a naphthyl group. Among them, R 13 and R 14 are preferably a phenyl group having at least one substituent selected from the group consisting of a hydrocarbon group having 1 to 6 carbon atoms, a silyl group having a hydrocarbon group having 1 to 6 carbon atoms, a halogen-containing hydrocarbon group having 1 to 6 carbon atoms, and a halogen atom in the range of 6 to 16 carbon atoms, an unsubstituted biphenylyl group or a naphthyl group, and more preferably a phenyl group having the above substituents. R 11 or R 12 When the thienyl group has a substituent, R 13 and R 14 are preferably, among others, a phenyl group having at least one substituent selected from the group consisting of a hydrocarbon group having 2 to 6 carbon atoms, a silyl group having a hydrocarbon group having 1 to 6 carbon atoms, a halogen-containing hydrocarbon group having 1 to 6 carbon atoms, and a halogen atom in the range of 6 to 16 carbon atoms, an unsubstituted biphenylyl group or a naphthyl group, and more preferably a phenyl group having the above substituents. Also, when R 11 or R 12 is a thienyl group having a substituent and R 13 or R 14 is an aryl group having a substituent, the substituent of the aryl group of R 13 or R 14 is preferably a bulkier group than the substituent of the thienyl group of R 11 or R 12 Also, among the substituents of the aryl group of R 13 or R 14 the total number of carbon atoms and heteroatoms of the substituent having the smallest total number is preferably larger than the total number of the substituent having the largest total number of carbon atoms and heteroatoms among the substituents of the thienyl group of R 11 or R 12 Preferred R 13 and R 14Specific examples include, for instance, 4-isopropylphenyl group, 4-t-butylphenyl group, 2,3-dimethylphenyl group, 3,5-di-t-butylphenyl group, 4-chlorophenyl group, 4-trimethylsilylphenyl group, 4-biphenylyl group, 1-naphthyl group, and 2-naphthyl group. Among these, phenyl groups having substituents only at the 4-position are more preferred, phenyl groups substituted with C3-C4 alkyl groups are even more preferred, and 4-isopropylphenyl group or 4-t-butylphenyl group are even more preferred. Also, R 13 and R 14 It is preferable that they are identical to each other.

[0050] Also, R 11 , R 12 , R 13 and R 14 A preferred combination is, for example, R 11 and R 12 Compared to the total number of carbon atoms and heteroatoms of substituents on the thienyl group, 13 and R 14 Examples of combinations in which the total number of carbon atoms and heteroatoms of the substituents on the aryl group is 1 to 5 greater, more preferably 2 to 3 greater, include combinations in which the total number of carbon atoms and heteroatoms is 1 to 5 greater. For example, a suitable combination would be R 11 and R 12 However, it is a 5-methyl-2-thienyl group, R 13 and R 14 However, combinations of a 4-isopropylphenyl group, a 4-t-butylphenyl group, or a 4-trimethylsilylphenyl group, and R 11 and R 12 However, it is a 5-isopropyl-2-thienyl group, R 13 and R 14 However, examples include combinations of a 4-t-butylphenyl group or a 4-trimethylsilylphenyl group.

[0051] The above Q 11This 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, that connects two five-membered rings. If two hydrocarbon groups are present on the silylene group or germylene group mentioned above, they may be bonded to each other to form a ring structure. The above Q 11 Specific examples include alkylene groups such as methylene, methylmethylene, dimethylmethylene, and 1,2-ethylene; arylalkylene 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 tetramethyldisylylene; germylene groups; alkylgermylene groups obtained by substituting the silicon in the above-mentioned divalent silylene group having 1 to 20 carbon atoms with germanium; (alkyl)(aryl)germylene groups; and arylgermylene groups. Among these, silylene groups having a hydrocarbon group with 1 to 20 carbon atoms, or germylene groups having a hydrocarbon group with 1 to 20 carbon atoms, are preferred, and alkylsilylene groups and alkylgermylene groups are particularly preferred. Furthermore, the above M 11 This is zirconium or hafnium, preferably hafnium.

[0052] The above X 11 and Y 11 This is an auxiliary ligand that reacts with catalyst component (B) to produce an active metallocene with olefin polymerization ability. Therefore, as long as this objective is achieved, X 11 and Y 11 The type of ligand is not limited, and each represents independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl 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.

[0053] Among the compounds represented by the above general formula (a1), preferred compounds are specifically exemplified below. (1) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-phenyl-indenyl}]hafnium, (2) Dichloro[1,1'-diphenylsilylenebis{2-(5-methyl-2-thienyl)-4-phenyl-indenyl}]hafnium, (3) Dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-thienyl)-4-phenyl-indenyl}]hafnium, (4) Dichloro[1,1'-dimethylsilylenebis{2-(5-trimethylsilyl-2-thienyl)-4-phenyl-indenyl}]hafnium, (5) Dichloro[1,1'-dimethylsilylenebis{2-(5-phenyl-2-thienyl)-4-phenyl-indenyl}]hafnium, (6) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-chlorophenyl)-indenyl}]hafnium, (7) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-isopropylphenyl)-indenyl}]hafnium, (8) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (9) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, (10) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-biphenylyl)-indenyl}]hafnium, (11) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(1-naphthyl)-indenyl}]hafnium, (12) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(2-naphthyl)-indenyl}]hafnium, (13) Dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-thienyl)-4-(1-naphthyl)-indenyl}]hafnium, (14) Dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-thienyl)-4-(2-naphthyl)-indenyl}]hafnium, (15) Dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-thienyl)-4-(4-isopropylphenyl)-indenyl}]hafnium, (16) Dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (17) Dichloro[1,1'-dimethylsilylenebis{2-(5-t-butyl-2-thienyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, (18) Dichloro[1,1'-dimethylsilylenebis{2-(5-isopropyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (19) Dichloro[1,1'-dimethylsilylenebis{2-(5-isopropyl-2-thienyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium,

[0054] Of these, the more preferable is, (7) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-isopropylphenyl)-indenyl}]hafnium, (8) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (9) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, (18) Dichloro[1,1'-dimethylsilylenebis{2-(5-isopropyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (19) Dichloro[1,1'-dimethylsilylenebis{2-(5-isopropyl-2-thienyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, That is the case.

[0055] Furthermore, what is particularly preferable is, (7) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-isopropylphenyl)-indenyl}]hafnium, (8) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium, (9) Dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-trimethylsilylphenyl)-indenyl}]hafnium, That is the case.

[0056] 1-2. Catalyst component [A-2] As the catalyst component [A-2], a metallocene compound represented by the following general formula (a2) is preferably used because it efficiently copolymerizes the macromer and propylene.

[0057] [ka]

[0058] [In general formula (a2), R 21 and R 22 These are each an independent hydrocarbon group having 1 to 6 carbon atoms. 23 and R 24 Each of these independently represents an unsubstituted or substituted aryl group having 6 to 30 carbon atoms, which may contain a halogen, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or multiple heteroatoms selected from these. 21This 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. 21 X represents zirconium or hafnium. 21 and Y 21 Each of these independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl 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.

[0059] The above R 21 and R 22 Each of these is independently a hydrocarbon group having 1 to 6 carbon atoms, preferably an alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms. Specific examples include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, n-pentyl, i-pentyl, n-hexyl, etc., with methyl, ethyl, and n-propyl being preferred.

[0060] Also, the above R 23 and R 24 Each of these is an unsubstituted or substituted aryl group having 6 to 30 carbon atoms, preferably 6 to 24 carbon atoms, which may independently contain halogens, silicon, oxygen, sulfur, nitrogen, boron, phosphorus, or a plurality of heteroatoms selected from these. Such aryl groups may be substituted phenyl, biphenylyl, or naphthyl groups. Preferred examples include phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorophenyl, 4-fluorophenyl, 4-methylphenyl, 4-i-propylphenyl, 4-t-butylphenyl, 4-trimethylsilylphenyl, 4-(2-fluoro-4-biphenylyl), 4-(2-chloro-4-biphenylyl), 1-naphthyl, 2-naphthyl, 4-chloro-2-naphthyl, 3-methyl-4-trimethylsilylphenyl, 3,5-dimethyl-4-t-butylphenyl, 3,5-dimethyl-4-trimethylsilylphenyl, and 3,5-dichloro-4-trimethylsilylphenyl.

[0061] Q 21 This 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, that connects two five-membered rings. If two hydrocarbon groups are present on the silylene group or germylene group described above, they may be bonded to each other to form a ring structure. The above Q 21 A concrete example of this is, for instance, Q in the general formula (a1) above. 11 Similar examples can be given to the above Q. 21 Among these, silylene groups having a hydrocarbon group with 1 to 20 carbon atoms, or germylene groups having a hydrocarbon group with 1 to 20 carbon atoms, are preferred, and alkylsilylene groups and alkylgermylene groups are particularly preferred. Furthermore, the above M 21 This is zirconium or hafnium, preferably hafnium.

[0062] The above X 21 and Y 21 This is an auxiliary ligand that reacts with catalyst component (B) as a co-catalyst to produce an active metallocene with olefin polymerization ability. Therefore, as long as this objective is achieved, X 21 and Y 21 The type of ligand is not limited, and each represents independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silyl 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.

[0063] Non-limiting examples of metallocene compounds represented by the above general formula (a2) include the following: However, to avoid a cumbersome number of examples, only representative example compounds are listed. Furthermore, while 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-hydroazlenyl)}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-hydroazlenyl}]hafnium, (4) Dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-trimethylsilylphenyl)-4-hydroazlenyl}]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-hydroazlenyl}]hafnium, (8) Dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazlenyl}]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-hydroazlenyl}]hafnium, (15) Dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(4-chlorophenyl)-4-hydroazlenyl}]hafnium, (16) Dichloro[1,1'-dimethylsilylenebis{2-n-propyl-4-(3-chloro-4-trimethylsilylphenyl)-4-hydroazlenyl}]hafnium, (17) Dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-chloro-4-t-butylphenyl)-4-hydroazlenyl}]hafnium, (18) Dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazlenyl}]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-hydroazlenyl}]hafnium, etc.

[0064] Among these, preferably, (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-hydroazlenyl}]hafnium, (18) Dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazlenyl}]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-hydroazlenyl}]hafnium, That is the case.

[0065] Furthermore, particularly preferably, (2) Dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium, (18) Dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(3-methyl-4-trimethylsilylphenyl)-4-hydroazlenyl}]hafnium, (22) Dichloro[1,1'-dimethylsilylenebis{2-ethyl-4-(2-fluoro-4-biphenylyl)-4-hydroazulenyl}]hafnium, (24) Dichloro[1,1'-(9-silafluorene-9,9-diyl)bis{2-ethyl-4-(3,5-dichloro-4-trimethylsilylphenyl)-4-hydroazlenyl}]hafnium, That is the case.

[0066] 2. Catalyst component (B) The catalyst component (B) used in the present invention is a compound that reacts with catalyst component (A) to form an ion pair, or an ion-exchangeable layered silicate. The catalyst component (B) may be used alone or in combination of two or more types. Preferably, it is an ion-exchangeable layered silicate.

[0067] 2-1. Compounds that form ion pairs with catalyst component (A) Examples of compounds that react with catalyst component (A) to form ion pairs include aluminum oxy compounds and boron compounds. Specifically, examples of aluminum oxy compounds include those represented by the following general formulas (I) to (III).

[0068] [ka]

[0069] In the above general formulas (I), (II), and (III), R 91 , R 101 and R 111 R represents a hydrogen atom or a hydrocarbon group, preferably a hydrocarbon group having 1 to 10 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 6 carbon atoms. Also, multiple R 91 , R 101 and R 111 These can be the same or different. Also, p represents an integer between 0 and 40, preferably between 2 and 30. The compounds represented by general formulas (I) and (II) are also called aluminoxanes, and among these, methylaluminoxane or methylisobutylaluminoxane is preferred. Multiple types of the above aluminoxanes can be used in combination within and between each group. Furthermore, the above aluminoxanes can be prepared under various known conditions. In general formula (III), R 112This represents a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. The compound represented by general formula (III) is a trialkylaluminum or two or more trialkylaluminums and general formula R 112 It can be obtained by a reaction with an alkylboronic acid represented by B(OH)2 in a molar ratio of 10:1 to 1:1. Examples of boron compounds include complexes of cations such as carbonium cations and ammonium cations with organoboron compounds such as triphenylboron, tris(3,5-difluorophenyl)boron, and tris(pentafluorophenyl)boron, or various organoboron compounds, such as tris(pentafluorophenyl)boron.

[0070] 2-2. Ion-exchange layered silicates In the present invention, the ion-exchangeable layered silicate (hereinafter sometimes simply referred to as silicate) used as a raw material refers to a silicate compound having a crystalline structure in which layers composed of ionic bonds or the like are stacked parallel to each other by bonding forces, having interlayer ions between the layers, and in which the contained interlayer ions are exchangeable. Most silicates occur naturally, mainly as the main component of clay minerals. Purification is typically carried out by dispersing / swelling them in water and analyzing differences in sedimentation rate, etc. However, complete removal of impurities is not required, and they may contain impurities other than ion-exchangeable layered silicates (such as quartz and cristobalite). Depending on the type, amount, particle size, crystallinity, and dispersion state of these impurities, they may be preferable to pure silicates, and such complexes are also included in the ion-exchangeable layered silicate of catalyst component (B). Furthermore, the silicates used in this invention are not limited to naturally occurring ones, but may also be artificially synthesized.

[0071] Specific examples of ion-exchangeable layered silicates include, for example, layered silicates with 1:1 type and 2:1 type structures described in "Clay Mineralogy" by Haruo Shiramizu, Asakura Shoten (1988). A 1:1 type structure refers to a structure based on a stack of one tetrahedral sheet and one octahedral sheet, as described in "Clay Mineralogy" and other texts. A 2:1 type structure refers to a structure based on a stacking arrangement in which two layers of tetrahedron sheets sandwich one layer of octahedron sheets. Specific examples of ion-exchangeable layered silicates with a 1:1 structure include kaolin group silicates such as dickite, nacrite, kaolinite, metahaloysite, and halloysite, and serpentine group silicates such as chrysotile, lizardite, and antigorite. Specific examples of ion-exchangeable layered silicates with a 2:1 structure include smectite group silicates such as montmorillonite, bydelite, nontronite, saponite, hectorite, and stevensite; vermiculite group silicates such as vermiculite; mica group silicates such as mica, illite, sericite, and erythrolith; attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, and chlorite groups. These may form mixed layers. Among these, those in which the main component is an ion-exchangeable layered silicate having a 2:1 structure are preferred. More preferably, the main component is a smectite group silicate, and even more preferably, the main component is montmorillonite. The type of interlayer cation (cation contained between the layers of ion-exchangeable layered silicate) is not particularly limited, but alkali metals of Group 1 of the periodic table such as lithium and sodium, alkaline earth metals of Group 2 of the periodic table such as calcium and magnesium, or transition metals such as iron, cobalt, copper, nickel, zinc, ruthenium, rhodium, palladium, silver, iridium, platinum, and gold are preferred as main components because they are relatively easy to obtain.

[0072] The ion-exchangeable layered silicate may be used in a dry state or in a liquid slurry state. Furthermore, there are no particular restrictions on the shape of the ion-exchangeable layered silicate; it may be in its naturally occurring form, its form at the time of artificial synthesis, or it may be an ion-exchangeable layered silicate whose shape has been processed by operations such as crushing, granulation, or classification. Of these, using granulated ion-exchangeable layered silicate is particularly preferable because, when the ion-exchangeable layered silicate is used as a catalyst component, it provides good polymer particle properties. Ion-exchangeable layered silicates can be used as is without any special treatment, but chemical treatment is preferable. For methods of chemical treatment of ion-exchangeable layered silicates, refer to paragraphs 0042 to 0071 of Japanese Patent Application Publication No. 2009-299046.

[0073] The catalyst component (B) preferably used in the present invention is a chemically treated ion-exchangeable layered silicate, with an Al / Si atomic ratio of 0.01 to 0.25, preferably 0.03 to 0.24, and more preferably in the range of 0.05 to 0.23. The Al / Si atomic ratio is considered to be an indicator of the acid treatment strength of the clay portion. The aluminum and silicon in ion-exchange layered silicates are measured by creating a calibration curve using chemical analysis according to JIS standards and then quantifying them using fluorescent X-rays.

[0074] 3. Catalyst component (C) The catalyst component (C) used in the present invention is an organoaluminum compound, and preferably an organoaluminum compound represented by the following general formula (IV) is used. (AlR n X 3-n ) m ...General formula (IV) [In the above general formula (IV), R represents an alkyl group having 1 to 20 carbon atoms, X represents a halogen, hydrogen, alkoxy group, or amino group, n represents an integer from 1 to 3, and m represents an integer from 1 to 2.] If X is a halogen, chlorine is preferred; if it is an alkoxy group, an alkoxy group having 1 to 8 carbon atoms is preferred; and if it is an amino group, an amino group having 1 to 8 carbon atoms is preferred. Organoaluminum compounds can be used individually or in combination. Specific examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, trin-n-propylaluminum, trin-n-butylaluminum, triisobutylaluminum, trin-n-hexylaluminum, trin-n-octylaluminum, trin-n-decylaluminum, diethylaluminum chloride, diethylaluminum sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, and diisobutylaluminum chloride. Of these, trialkylaluminum and alkylaluminum hydrides with m=1 and n=3 are preferred. More preferably, trialkylaluminum is used in which R has 1 to 8 carbon atoms.

[0075] 4. Preparation of the catalyst The olefin polymerization catalyst used in the present invention contains the above-mentioned catalyst components. These can be obtained by contacting them inside or outside the polymerization tank. The olefin polymerization catalyst may also be prepolymerized in the presence of olefin. The contact of each catalyst component is usually carried out in an aliphatic hydrocarbon or aromatic hydrocarbon solvent. The contact temperature is not particularly limited, but it is preferably between -20°C and 150°C. Any purposeful combination of contact sequences is possible, but particularly preferred sequences for each catalyst component are as follows. When using catalyst component (C), it is possible to contact catalyst component (C) with catalyst component (A), or catalyst component (B), or both catalyst component (A) and catalyst component (B) before contacting catalyst component (A) and catalyst component (B), or to contact catalyst component (C) simultaneously with contacting catalyst component (A) and catalyst component (B), or to contact catalyst component (C) after contacting catalyst component (A) and catalyst component (B). However, it is preferable to contact catalyst component (C) with either catalyst component (A) or catalyst component (B) before contacting them. Furthermore, after contacting each catalyst component, it is possible to wash them with an aliphatic hydrocarbon or aromatic hydrocarbon solvent.

[0076] The amounts of catalyst components (A), (B), and (C) used in this invention are arbitrary. For example, the amount of catalyst component (A) used relative to catalyst component (B) is preferably in the range of 0.1 μmol to 1000 μmol, more preferably 0.5 μmol to 500 μmol, per 1 g of catalyst component (B). Furthermore, the amount of catalyst component (C) used relative to catalyst component (A) is preferably 0.01 to 5 × 10⁻¹⁶, expressed as the molar ratio of aluminum in catalyst component (C) to the transition metal in catalyst component (A). 6 , more comfortable 0.1~1×10 4 It is within the range of [the specified range].

[0077] The branched propylene polymer of the present invention can be produced by using a catalyst component having the ability to generate macromers and a catalyst component having the ability to copolymerize the macromers with propylene. It is also possible to produce it using a single catalyst component that simultaneously has the ability to generate macromers and copolymerize the macromers with propylene, but in order to efficiently produce the branched propylene polymer of the present invention, it is possible to choose a method that uses separate catalyst components having each of these abilities. That is, by using a catalyst component [A-1] having the ability to generate macromers and a catalyst component [A-2] having the ability to copolymerize the macromers with propylene, the production of a branched propylene polymer that meets the requirements of the present invention becomes easier. Therefore, the ratio of catalyst component [A-1] and catalyst component [A-2] used is arbitrary within the range that satisfies the characteristics of the branched propylene polymer of the present invention, but the molar ratio of the transition metal of catalyst component [A-1] to the total amount of each catalyst component [A-1] and [A-2] is preferably 0.30 or more and 0.99 or less. By changing this ratio, it is possible to adjust the balance between melt properties and catalytic activity. Specifically, catalyst component [A-1] generates low molecular weight terminal vinyl macromers, and catalyst component [A-2] generates high molecular weight polymers by copolymerizing some of the macromers. Therefore, by changing the ratio of catalyst component [A-1], it is possible to control the average molecular weight, molecular weight distribution, bias of the molecular weight distribution towards the low molecular weight side, very high molecular weight components, and branching (amount, length, distribution) of the resulting polymer, thereby controlling melt properties such as strain hardening degree and melt tension. The molar ratio of the transition metal in catalyst component [A-1] to the total amount of catalyst component [A-1] and catalyst component [A-2] is preferably 0.30 or higher, more preferably 0.40 or higher, and even more preferably 0.50 or higher. Regarding the upper limit, it is preferably 0.99 or lower, even more preferably 0.90 or lower, and to efficiently obtain the polymer in the present invention with high catalytic activity, it is preferably in the range of 0.80 or lower, and even more preferably 0.70 or lower. Furthermore, by using catalyst component [A-1] within the above range, the balance between average molecular weight and catalytic activity can be adjusted.

[0078] 5. Prepolymerization It is preferable that the catalyst for olefin polymerization be subjected to prepolymerization, which involves contacting the olefin and polymerizing a small amount of it. By performing prepolymerization, gel formation can be prevented during the main polymerization. This is thought to be because the long-chain branching can be uniformly distributed among the polymer particles during the main polymerization. The olefin used during prepolymerization is not particularly limited, but examples 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 feeding method for olefins can be any method, such as a feeding method that maintains the olefins in the prepolymerization tank at a constant rate or constant pressure, a combination of these methods, or a stepwise change. The prepolymerization temperature and prepolymerization time are not particularly limited, but are preferably in the range of -20°C to 100°C and 5 minutes to 24 hours, respectively. The amount of prepolymerization is such that the mass ratio of the prepolymerized polymer to the catalyst component (B) is preferably 0.01 to 100, and more preferably 0.1 to 50. Furthermore, catalyst component (C) can be added during prepolymerization, and washing is possible at the end of prepolymerization. Furthermore, methods such as introducing solid polymers like polyethylene and polypropylene, or inorganic oxides like silica and titania, into the contact of each of the catalyst components mentioned above, either during or after contact, are also possible. After prepolymerization, the catalyst may be dried. There are no particular restrictions on the drying method, but examples include drying under reduced pressure, heating, and drying by circulating a drying gas. These methods may be used individually or in combination of two or more methods. The catalyst may be stirred, vibrated, or fluidized during the drying process.

[0079] 6. Propylene polymerization Any polymerization mode can be employed, as long as the olefin polymerization catalyst and the monomer come into efficient contact. Specifically, methods such as slurry polymerization using an inert solvent, bulk polymerization using propylene as the solvent without substantially using an inert solvent, solution polymerization, or gas-phase polymerization that keeps each monomer in a gaseous state without substantially using a liquid solvent can be employed. Furthermore, methods involving continuous polymerization and batch polymerization can also be applied. Furthermore, multi-stage polymerization of two or more stages is possible, but single-stage polymerization is preferable. In particular, bulk polymerization is preferred, in which case the polymerization temperature can be set from 50°C to below the critical temperature of propylene.

[0080] Furthermore, in order to produce the branched propylene polymer of the present invention, it is preferable to set the polymerization temperature to 65°C or higher. In the polymerization reaction mediated by the catalyst component [A-1] described above, a β-methyl elimination reaction occurs as a termination reaction, forming vinyl groups at the terminals and generating a macromer copolymerizable with propylene. The rate of the β-methyl elimination reaction is affected by the polymerization temperature; generally, a higher polymerization temperature results in a higher β-methyl elimination rate, which in turn increases the ratio to the growth reaction rate, leading to a decrease in the molecular weight of the macromer. Therefore, in the method for producing the branched propylene polymer of the present invention, it is preferable to set the polymerization temperature to 65°C or higher. By setting the polymerization temperature to 65°C or higher, the average molecular weight of the macromer falls within the range preferred in this invention, making it possible to introduce branches with short branching chain lengths into the branched propylene polymer. For the reasons stated above, the polymerization temperature is preferably 65°C or higher, and more preferably 70°C or higher. On the other hand, the upper limit must be below the critical temperature of propylene in order to carry out bulk polymerization, and is preferably 90°C or lower, and more preferably 85°C or lower. Furthermore, the polymerization pressure is more preferably 1.5 MPa or higher, even more preferably 2.5 MPa or higher, and even more preferably 3.5 MPa or higher. The upper limit is preferably 4.4 MPa or lower, and even more preferably 4.0 MPa or lower. Furthermore, polymerization may be carried out by homopolymerization of propylene, or by copolymerization using one or more α-olefin comonomers having 2 to 20 carbon atoms other than propylene, such as ethylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc., as comonomers in addition to propylene monomer. The amount of comonomer is preferably 10 mol% or less, more preferably 5 mol% or less, as a copolymerization ratio in the branched propylene polymer, and is preferably 15 mol% or less, more preferably 7.5 mol% or less, as the amount added during polymerization.

[0081] Furthermore, hydrogen is used as a molecular weight modifier to produce the branched propylene polymer of the present invention. The range of hydrogen introduced is 1.0 × 10⁻⁶ in molar ratio to propylene. -5 The above is preferable, 1.0 × 10 -4 The above is even more preferable, 0.5 × 10 -3 The above is even more preferable. Regarding the upper limit, 1.0 × 10 -2 The following is preferable: 0.5 × 10 -2 The following is even more preferable: 0.2 × 10 -2 The following are even more preferable. The polymer produced by catalyst component [A-1] has very slow hydrogen-mediated chain transfer, while the polymer produced by catalyst component [A-2] has relatively fast hydrogen-mediated chain transfer. Therefore, when hydrogen is scarce, high molecular weight polymers can be produced. When the amount of hydrogen used is small, the polymer produced by catalyst component [A-2] (i.e., a copolymer of polypropylene and terminal vinyl macromer, corresponding to a branched propylene polymer) is on the higher molecular weight side than the polymer produced by catalyst component [A-1] (i.e., a terminal vinyl macromer, a polymer that forms a branched chain). Therefore, by using catalyst components [A-1] and [A-2] in combination and polymerizing propylene under conditions of low hydrogen usage, the molecular weight distribution of the branched propylene polymer can be broadened towards the high molecular weight side, and the branched chain length can be shortened.

[0082] Furthermore, catalyst component [A-1] generates terminal vinyl macromers, and catalyst component [A-1] itself, having generated the macromers, mediates the copolymerization of propylene and macromers to produce branched macromers with terminal vinyl groups. On the other hand, catalyst component [A-2] does not generate macromers on its own, and only when the macromer generated by catalyst component [A-1] approaches catalyst component [A-2] does it mediate the copolymerization of propylene and macromers to produce branched polymers.

[0083] As described above, when producing a branched propylene polymer by macromer copolymerization using catalyst component [A-1] and catalyst component [A-2], (1) by setting the polymerization temperature to 65°C or higher, branches with short branching chain lengths can be introduced; (2) by reducing the amount of hydrogen used as a molecular weight adjuster, the molecular weight distribution of the branched propylene polymer can be broadened to the high molecular weight side; and (3) due to the difference in contact efficiency between catalyst component [A-1] and catalyst component [A-2] and the terminal vinyl macromer, macromers with many branched structures generated by catalyst component [A-1], which has a high contact efficiency with the macromer, are introduced into the high molecular weight branched polymer generated by catalyst component [A-2]. Therefore, through the combined effects of (1), (2), and (3) above, a large number of branches with short branching chain lengths can be introduced into the high molecular weight region of the molecular weight distribution of the branched propylene polymer. Specifically, in the molecular weight distribution, components with a molecular weight M of 1 million or more, and absolute molecular weight M abs The branching exponent g' at 1 million can be set to the preferred range described above. Therefore, the resulting branched propylene polymer can have a relaxation time distribution in which there are many components with relatively short relaxation times and few components with extremely long relaxation times.

[0084] II-2. Second manufacturing method A second method for producing the branched propylene polymer of the present invention is a method that divides the macromer synthesis step and the copolymerization step of propylene and macromer into two steps. In the second method described above, in the macromer synthesis step, it is preferable to use a method to produce a terminal vinyl group-containing propylene polymer by homopolymerizing propylene using an olefin polymerization catalyst containing the following catalyst components [A-1], (B) and (C), or by copolymerizing propylene with a comonomer selected from α-olefins having 2 to 20 carbon atoms other than propylene. [A-1]: Compound represented by the general formula (a1) above (B): A compound or ion-exchange layered silicate that reacts with the catalyst component [A-1] to form an ion pair. (C): Organoaluminum compounds

[0085] In the macromer synthesis step described above, the catalyst components [A-1], (B) and (C) are the same as the catalyst components [A-1], (B) and (C) used in the first manufacturing method described above. The olefin polymerization catalyst used in the macromer synthesis step described above can be prepared by using only catalyst component [A-1] as catalyst component (A) in "4. Preparation of Catalyst" of the first manufacturing method described above. The olefin polymerization catalyst used in the macromer synthesis step described above may be prepolymerized by the same method as in "5. Prepolymerization" of the first manufacturing method described above. The homopolymerization of propylene, or copolymerization of propylene and comonomer, carried out in the macromer synthesis step described above can be performed by the same method as in "6. Propylene Polymerization" of the first manufacturing method described above.

[0086] The macromer obtained in the above macromer synthesis step is preferably a propylene polymer containing terminal vinyl groups having the following physical properties (1) to (3). When the macromer has the following physical properties (1) to (3), the melt tension and melt spreadability of the branched propylene polymer of the present invention obtained by copolymerization of the macromer with propylene are more likely to be improved.

[0087] Physical properties (1): Number average molecular weight (Mn) The terminal vinyl group-containing propylene polymer obtained in the macromer synthesis step has a number-average molecular weight (Mn) measured by GPC, preferably 30,000 or less, more preferably 28,000 or less, and even more preferably 27,000 or less. The lower limit is not particularly limited, but preferably 11,000 or more, more preferably 13,000 or more, and even more preferably 15,000 or more. When the number-average molecular weight (Mn) of the macromer is within the above range, the molecular weight of the branched chains of the branched propylene polymer of the present invention can be made sufficiently small, thereby improving the melt tension and melt spreadability. The number-average molecular weight (Mn) is measured using the same method as the measurement of the number-average molecular weight (Mn) by GPC described in characteristic (6) above.

[0088] Physical properties (2): End vinyl content The terminal vinyl group-containing propylene polymers obtained in the above macromer synthesis process have a terminal vinyl ratio that is preferably 0.70 or higher, more preferably 0.80 or higher, even more preferably 0.85 or higher, and even more preferably 0.90 or higher, ideally 1.0 (where one end of all polymers consists entirely of vinyl groups). Furthermore, increasing the terminal vinyl ratio can also improve the stereoregularity of the macromer. The vinyl content at the end is measured by the method described in Japanese Patent Publication No. 2009-299046. in particular, 13 The vinyl (propenyl) terminal concentration [Vi] obtained from 1C-NMR is calculated as a percentage of the total polymer chain number obtained from the number-average molecular weight (Mn) determined from GPC, using the following formula. (End vinyl content) = (Mn / 42) × 2 × [Vi] / 1000 (However, Mn is the number-average molecular weight determined by GPC, and [Vi] is 13 This is the number of terminal vinyl groups per 1000 carbon atoms forming the entire skeleton, calculated from 1C-NMR. Here, 13 The details of the method for measuring vinyl (propenyl) terminal concentration [Vi] by 13C-NMR are as follows. 390 mg of the sample was completely dissolved in 2.6 ml of deuterated 1,1,2,2-tetrachloroethane in an NMR sample tube (10φ), and then measured by proton complete decoupling at 125°C. The chemical shift was set to 74.2 ppm, with the middle peak of the three peaks of deuterated 1,1,2,2-tetrachloroethane being used as the reference point for the chemical shifts of the other carbon peaks. Flip angle: 90 degrees Pulse interval: 10 seconds Resonance frequency: 100MHz or more Total number of times: 10,000 or more Observation range: -20 ppm to 179 ppm [Vi] is calculated as follows, based on the fact that carbon 1 and carbon 2 of structural formula (B) are detected at 115.5 ppm and 137.6 ppm, respectively, and represents the number of carbon atoms relative to 1000 total skeleton-forming carbon atoms. Here, total skeleton-forming carbon refers to all carbon atoms except methyl carbon. [Vi] = [Peak intensity of carbon 1] / [Sum of peak intensities of all skeleton-forming carbons] × 1000

[0089] [ka]

[0090] Physical properties (3): LCB number The terminal vinyl group-containing propylene polymer obtained in the above macromer synthesis step has a long-chain branched (LCB) structure portion represented by the above structural formula (A), and the lower limit of the number of LCBs is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more per 1000P. The upper limit of the number of LCBs of the above terminal vinyl group-containing propylene polymer is not particularly limited, but is preferably 1.0 or less per 1000P. When the above terminal vinyl group-containing propylene polymer used as a macromer contains a long-chain branched (LCB) structure portion in an amount within the above range, when copolymerization of propylene and macromer is carried out later, the crystallinity decreases, making it easier for propylene and macromer to move through the polymerization medium and approach copolymerization active sites, thereby increasing the amount of macromer copolymerization, and thus increasing the number of branching points in the resulting branched propylene polymer. The LCB structure is measured using the same method as the measurement of characteristic (10) described above.

[0091] The propylene polymer containing terminal vinyl groups obtained in the above macromer synthesis process can be used not only as a macromer, but also as a raw material for paints, primers, surface modifiers, and coatings. Furthermore, the propylene polymer containing terminal vinyl groups obtained in the above macromer synthesis process can be used as pellets after being mixed with various additives and resins as needed, heated and melt-kneaded using a melt-kneader, and then cut into granular form.

[0092] In the second method described above, in the copolymerization step of propylene and macromer, it is preferable to use a method in which the macromer obtained in the macromer synthesis step is copolymerized with propylene, or a mixture of propylene and α-olefins having 2 to 20 carbon atoms excluding propylene, using an olefin polymerization catalyst containing the following catalyst components [A-2], (B) and (C). [A-2]: Compound represented by the general formula (a2) above (B): A compound that reacts with the catalyst component [A-2] to form an ion pair, or an ion-exchange layered silicate. (C): Organoaluminum compounds

[0093] In the copolymerization step described above, catalyst components [A-2], (B) and (C) are the same as those used in the first manufacturing method described above. The olefin polymerization catalyst used in the copolymerization process described above can be prepared by using only catalyst component [A-2] as catalyst component (A) in "4. Preparation of Catalyst" of the first manufacturing method described above. The olefin polymerization catalyst used in the copolymerization step described above may be prepolymerized by the same method as in "5. Prepolymerization" of the first manufacturing method described above. The polymerization carried out in the copolymerization step described above can be performed in the same manner as in "6. Propylene Polymerization" of the first manufacturing method described above. Specifically, a slurry polymerization method can be employed in which the macromer is dissolved in an inert solvent.

[0094] III. Applications of branched propylene polymers The branched propylene polymer of the present invention can be used as a molding material as pellets after being heated, melt-kneaded, and then cut into granular form using a melt-kneading machine. Furthermore, the branched propylene polymer of the present invention can be compounded with various additives as needed, such as known antioxidants, ultraviolet absorbers, antistatic agents, nucleating agents, lubricants, flame retardants, antiblocking agents, colorants, inorganic or organic fillers, as well as various synthetic resins and natural resins. These pelletized molding materials can be molded using various known polypropylene molding methods, such as injection molding, extrusion molding, foam molding, and hollow molding, to produce various molded products such as industrial injection molded parts, containers, unstretched films, uniaxially oriented films, biaxially oriented films, sheets, pipes, and fibers. Furthermore, since the branched propylene polymer of the present invention has an excellent balance between melt fluidity and melt tension, it can be suitably used in fields where uniformity of wall thickness is required in sheet molding and blow molding, uniformity of foam cell diameter is required in foam molding, and fineness of fiber diameter is required in melt spinning. The branched propylene-based polymer of the present invention can also be used by blending with other resins.

Examples

[0095] Next, the present invention will be described more specifically by way of examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[0096] (1) Synthesis of catalyst component (A) (1-1) Synthesis example of catalyst component [A-1] (Complex 1) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)indenyl}]hafnium: (1-a) Synthesis of dimethylbis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)indenyl}silane: In a 1000 ml glass reaction vessel, 2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)indene (8.4 g, 24.4 mmol) and THF (150 ml) were added, and the mixture was cooled to -70°C. To this, an n-butyllithium-hexane solution (15.5 ml, 24.3 mmol, 1.57 mol / L) was added dropwise. After the dropwise addition, the mixture was stirred for 2 hours while gradually returning to room temperature. It was cooled again to -70°C, 1-methylimidazole (0.02 ml) was added, and dimethyldichlorosilane (1.47 ml, 12.1 mmol) was added dropwise. After the dropwise addition, the mixture was stirred for 1 hour while gradually returning to room temperature. Distilled water was added to the reaction solution, and the mixture was transferred to a separatory funnel and washed with brine until it became neutral. Sodium sulfate was added thereto to dry the reaction solution. Sodium sulfate was filtered off, and the solvent was distilled off under reduced pressure to obtain a pale yellow solid (9 g) of dimethylbis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)indenyl}silane. (1-b) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)indenyl}]hafnium: In a 500 ml glass reaction vessel, 9 g (12.2 mmol) of dimethylbis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)indenyl}silane, 30 ml of diethyl ether, and 90 ml of toluene were added. 15.5 ml (24.3 mmol, 1.57 mol / L) of n-butyllithium-hexane solution was then added dropwise over an ice bath. After addition, the mixture was allowed to cool to room temperature and stirred for 1 hour. Subsequently, 110 ml of toluene was added, and the mixture was cooled to -70°C in a dry ice-methanol bath. 3.9 g (12.2 mmol) of hafnium tetrachloride was then added. The mixture was then stirred overnight while gradually returning to room temperature. The solvent was removed by vacuum distillation, followed by extraction with toluene, and then washing with a toluene-hexane mixture to obtain 1 g (8% yield) of a racemic mixture of dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)indenyl}]hafnium (purity 99% or higher) as yellow-orange crystals. Proton nuclear magnetic resonance spectroscopy on the obtained racemic mixture ( 1 The identification values ​​obtained by 1H-NMR are listed below. 1 H-NMR (CDCl3) Identification Results Racemic: δ1.07(s,6H), δ1.31(s,18H), δ2.48(s,6H), δ6.62(s,2H), δ6.7-7.1(m,4H), δ7.2-7.6(m,10H), δ7.41(d,2H), δ7.55(d,2H)

[0097] (Complex 2) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium: rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium was synthesized according to the method of Synthesis Example 1 in Japanese Patent Application Publication No. 2012-149160.

[0098] (1-2) Synthesis example of catalyst component [A-2] (Complex 3) Synthesis of rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium: rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazlenyl}]hafnium was synthesized according to the method of Example 7 in Japanese Patent Publication No. 11-240909.

[0099] (2) Example of synthesis of catalyst component (B): Chemical treatment of ion-exchangeable layered silicate 645.1 g of distilled water and 82.6 g of 98% sulfuric acid were added to a 1 L three-necked flask equipped with a stirring blade and reflux device, and the mixture was heated to 95°C. 100g of commercially available montmorillonite (Benclay KK, manufactured by Mizusawa Chemical Industries, Ltd., Al=9.78% by mass, Si=31.79% by mass, Mg=3.18% by mass, Al / Si (molar ratio)=0.320, average particle size 14μm) was added, and the reaction was carried out at 95°C for 320 minutes. After 320 minutes, 0.5L of distilled water was added to stop the reaction, and 255g of a cake-like solid was obtained by filtration. Each gram of this cake contained 0.31 grams of chemically treated montmorillonite (intermediate). The chemical composition of the chemically treated montmorillonite (intermediate) was Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, and Al / Si (molar ratio) = 0.222. 1545g of distilled water was added to the above cake to form a slurry, and the temperature was raised to 40°C. 5.734g of lithium hydroxide hydrate was added in solid form, and the mixture was reacted at 40°C for 1 hour. After 1 hour, the reaction slurry was filtered, washed three times with 1L of distilled water, and a cake-like solid was obtained again. The recovered cake was dried to obtain 80 g of chemically treated montmorillonite. The chemical composition of this chemically treated montmorillonite was Al = 7.68 mass%, Si = 36.05 mass%, Mg = 2.13 mass%, Al / Si (molar ratio) = 0.222, and Li = 0.53 mass%.

[0100] (3) Preparation of catalyst (3-1) Preparation of Catalyst 1 In a three-necked flask (volume 1 L), 10 g of the chemically treated montmorillonite obtained in (2) above was placed, and heptane (66 mL) was added to form a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution with a concentration of 143 mg / mL) was added to this slurry and stirred for 1 hour. The mixture was then washed with heptane until the residual liquid volume was reduced to 1 / 100, and the total volume was adjusted to 50 mL. In addition, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium (complex 1) (126 μmol), prepared in the synthesis example of catalyst component [A-1], was dissolved in toluene (21 mL) to prepare solution 1-1. Furthermore, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (complex 3) (54 μmol), prepared in the synthesis example of catalyst component [A-2], was dissolved in toluene (9 mL) to prepare solutions 1-2. To a 1 L flask containing the aforementioned chemically treated montmorillonite, triisobutylaluminum (0.22 mmol: 0.3 mL of a 143 mg / mL heptane solution) was added, followed by the addition of the above solutions 1-2 (9 mL), and the mixture was stirred at room temperature for 20 minutes. Subsequently, tri-n-octylaluminum (1.76 mmol: 4.5 mL of a heptane solution with a concentration of 144 mg / mL) was added, followed by the addition of solution 1-1, and the mixture was stirred at room temperature for 1 hour. Subsequently, 215 mL of heptane was added, and the resulting slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was set to 40°C, propylene was fed at a rate of 10 g / hour, and prepolymerization was carried out for 2 hours while maintaining the temperature at 40°C. Then, the propylene feed was stopped, and residual polymerization was carried out for 2.5 hours. After removing the supernatant of the resulting catalyst slurry by decantation, triisobutylaluminum (6 mmol: 8.5 mL of a heptane solution with a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes. By drying this solid under reduced pressure for 1 hour, 29.6 g of dried prepolymerization catalyst was obtained. The prepolymerization ratio (the amount of prepolymerized polymer divided by the amount of solid catalyst) was 1.96. This prepolymerization catalyst was designated as catalyst 1.

[0101] (3-2) Preparation of Catalyst 2 In a three-necked flask (volume 1 L), 10 g of the chemically treated montmorillonite obtained in (2) above was placed, and heptane (66 mL) was added to form a slurry. Triisobutylaluminum (25 mmol: 34.0 mL of a heptane solution with a concentration of 143 mg / mL) was added to this slurry and stirred for 1 hour. The mixture was then washed with heptane until the residual liquid volume was reduced to 1 / 100, and the total volume was adjusted to 50 mL. In addition, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 2) (126 μmol), prepared in the synthesis example of catalyst component [A-1], was dissolved in toluene (21 mL) to prepare solution 2-1. Furthermore, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4-hydroazulenyl}]hafnium (complex 3) (54 μmol), prepared in the synthesis example of catalyst component [A-2], was dissolved in toluene (9 mL) to prepare solution 2-2. To a 1 L flask containing the aforementioned chemically treated montmorillonite, triisobutylaluminum (0.22 mmol: 0.3 mL of a 143 mg / mL heptane solution) was added, followed by the addition of the above solution 2-2 (9 mL), and the mixture was stirred at 50°C for 60 minutes. Subsequently, tri-n-octylaluminum (1.76 mmol: 4.5 mL of a heptane solution with a concentration of 144 mg / mL) was added, followed by the addition of solution 2-1, and the mixture was stirred at room temperature for 1 hour. Subsequently, 170 mL of heptane was added, and the resulting slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was set to 40°C, propylene was fed at a rate of 5 g / hour, and prepolymerization was carried out for 4 hours while maintaining the temperature at 40°C. Then, the propylene feed was stopped, and residual polymerization was carried out for 1 hour. After removing the supernatant of the resulting catalyst slurry by decantation, triisobutylaluminum (6 mmol: 8.5 mL of a heptane solution with a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes. This solid was dried under reduced pressure for 1 hour to obtain a dried prepolymerization catalyst 30.9. The prepolymerization ratio (the amount of prepolymerized polymer divided by the amount of solid catalyst) was 2.09. This prepolymerization catalyst was designated as catalyst 2.

[0102] (4) Examples [Example 1] (polymerization) A 3L autoclave was heated and thoroughly dried by circulating nitrogen, then the contents were replaced with propylene and cooled to room temperature. 2.8 mL of heptane solution of triisobutylaluminum (143 mg / mL) was added, followed by the introduction of 70 N mL of hydrogen. Next, 750 g of liquid propylene was introduced, and the temperature was raised to 70°C. Then, 70 mg of catalyst 1 (after removing the pre-polymerized polymer) was pumped into the polymerization vessel with high-pressure argon to start polymerization. After holding at 70°C for 1 hour, polymerization was stopped by injecting 5 ml of ethanol. As a result, 189 g of branched propylene polymer was obtained. (granulation) Per 100 parts by mass of the obtained branched propylene polymer, 0.125 parts by mass of the phenolic antioxidant IRGANOX1010 (trade name, manufactured by BASF Japan, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane) and the phosphite antioxidant IRGAFOS168 (trade name, manufactured by BASF Japan) were added. Manufactured by a Japanese company, 0.125 parts by mass of tris(2,4-di-t-butylphenyl) phosphite was blended, and using a high-speed stirring type mixer, a Henschel mixer (trade name, manufactured by Nippon Coke & Engineering Co., Ltd.), it was mixed at room temperature for 3 minutes. Then, using a twin-screw extruder KZW-15 (manufactured by Techno-Bel), the screw rotation speed was 400 rpm, and the kneading temperature was 80, 120, 230 °C from below the hopper (the same temperature until the die outlet hereafter), and melt kneading was performed. The molten resin extruded from the strand die was taken out while being cooled and fixed in a cooling water tank, and the strand was cut using a strand cutter and pelletized. The MFR (MFR pellet ) of the obtained pellets was 1.2 g / 10 min. Also, the catalyst activity was 2700 g / ghr. Note that the catalyst activity is the value per unit time obtained by dividing the yield (g) of the polymer by the amount of catalyst introduced (value excluding the prepolymerized polymer) (g).

[0103] [Example 2] In the polymerization of Example 1, the same polymerization was carried out except that 40 mg of Catalyst 1 was introduced in terms of mass excluding the prepolymerized polymer and 120 Nml of hydrogen was introduced. As a result, 172 g of a branched propylene-based polymer was obtained. When granulation was carried out in the same manner as in Example 1, the MFR (MFR pellet ) of the obtained pellets was 2.6 g / 10 min. Also, the catalyst activity was 4300 g / ghr.

[0104] [Example 3] In the polymerization of Example 1, the same polymerization was carried out except that 40 mg of Catalyst 1 was introduced in terms of mass excluding the prepolymerized polymer and 180 Nml of hydrogen was introduced. As a result, 196 g of a branched propylene-based polymer was obtained. When granulation was carried out in the same manner as in Example 1, the MFR (MFRpellet) of the obtained pellets was 4.8 g / 10 min. Also, the catalyst activity was 4900 g / ghr.

[0105] [Example 4] In the polymerization of Example 1, the polymerization was carried out in the same manner as in Example 1, except that 40 mg of catalyst 1 (excluding the mass of the prepolymerized polymer) and 245 N ml of hydrogen were introduced. As a result, 212 g of branched propylene polymer was obtained. When granulation was performed in the same manner as in Example 1, the MFR (MFRpellet) of the obtained pellets was 8.1 g / 10 min. The catalytic activity was 5300 g / ghr.

[0106] [Reference Example 1]: Example of a method for homopolymerization of side chains (Preparation of catalyst 3) In a three-necked flask (volume 1 L), 10 g of the chemically treated montmorillonite obtained in (2) above was placed, and heptane (65 mL) was added to form a slurry. Triisobutylaluminum (25 mmol: 35 mL of a heptane solution with a concentration of 143 mg / mL) was added to this slurry and stirred for 1 hour. The mixture was then washed with heptane until the residual liquid volume was reduced to 1 / 100, and the total volume was adjusted to 50 mL. In addition, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-thienyl)-4-(4-t-butylphenyl)-indenyl}]hafnium (complex 1) (0.15 mmol), prepared in the synthesis example of catalyst component [A-1], was dissolved in toluene (30 mL) to prepare solution 3-1. To a 1 L flask containing the aforementioned chemically treated montmorillonite, tri-n-octylaluminum (2.1 mmol: 5.3 mL of a 144 mg / mL heptane solution) was added, followed by the addition of solution 3-1 and the mixture was stirred at room temperature for 1 hour. Subsequently, 215 mL of heptane was added, and the resulting slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was set to 40°C, propylene was fed at a rate of 10 g / hour, and prepolymerization was carried out for 2 hours while maintaining the temperature at 40°C. Then, the propylene feed was stopped, and residual polymerization was carried out for 1.5 hours. After removing the supernatant of the resulting catalyst slurry by decantation, triisobutylaluminum (10 mmol: 8.3 mL of a heptane solution with a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes. By drying this solid under reduced pressure for 40 minutes, 13.6 g of dried prepolymerization catalyst was obtained. The prepolymerization ratio (the amount of prepolymerized polymer divided by the amount of solid catalyst) was 0.33. This prepolymerization catalyst was designated as catalyst 3. (polymerization) A 3L autoclave was thoroughly dried beforehand by heating and circulating nitrogen, then the contents of the chamber were replaced with propylene and cooled to room temperature. 2.8 mL of heptane solution of triisobutylaluminum (143 mg / mL) was added, followed by the introduction of 70 N mL of hydrogen. Next, 750 g of liquid propylene was introduced, and the temperature was raised to 70°C. Then, 300 mg of catalyst 3 (after removing the pre-polymerized polymer) was pumped into the polymerization vessel with high-pressure argon to start polymerization. After holding at 70°C for 1 hour, the unreacted propylene was quickly purged, and polymerization was stopped. As a result, approximately 270 g of propylene-based polymer was obtained. The obtained propylene polymer had an MFR of 1050 g / 10 min. The manganese content calculated by GPC was 26,500, which can be estimated to be 1,262 carbon atoms in the skeleton. The catalytic activity was 900 g / ghr.

[0107] [Reference Example 2]: Example of a method for homopolymerization of side chains In the polymerization described in Reference Example 1, the polymerization was carried out in the same manner as in Reference Example 1, except that 200 mg of catalyst 3 (excluding the mass of the prepolymerized polymer) and 120 N ml of hydrogen were introduced. As a result, 240 g of propylene-based polymer was obtained. The obtained propylene polymer had an MFR of 1600 g / 10 min. The manganese content calculated by GPC was 26,000, which can be estimated to be 1238 carbon atoms in the skeleton. The catalytic activity was 1200 g / ghr.

[0108] [Reference example 3] In the polymerization described in Reference Example 1, the temperature was raised to 75°C, 300 mg of catalyst 3 was introduced (excluding the pre-polymerized polymer), and polymerization was carried out at 75°C for 1 hour without introducing hydrogen. The polymerization was carried out in the same manner as described above. As a result, 30 g of propylene polymer was obtained. The obtained propylene polymer had an MFR of 1700 g / 10 min. The manganese content calculated by GPC was 21500, which can be estimated to be 1024 carbon atoms in the skeleton. The catalytic activity was 100 g / ghr.

[0109] [Reference example 4] In the polymerization described in Reference Example 1, the temperature was raised to 80°C, 500 mg of catalyst 3 was introduced (excluding the mass of the prepolymerized polymer), and polymerization was carried out at 80°C for 1 hour without introducing hydrogen. The polymerization was carried out in the same manner as described above. As a result, 75 g of propylene polymer was obtained. The obtained propylene polymer had an MFR of 5200 g / 10 min. The manganese content calculated by GPC was 16500, which can be estimated to be 786 carbon atoms in the skeleton. The catalytic activity was 150 g / ghr.

[0110] [Comparative Example 1] A 3L autoclave was heated and thoroughly dried by circulating nitrogen, then the contents of the chamber were replaced with propylene and cooled to room temperature. 2.8 mL of heptane solution of triisobutylaluminum (143 mg / mL) was added, followed by the introduction of 210 N mL of hydrogen. Next, 750 g of liquid propylene was introduced, and the temperature was raised to 70°C. Then, 60 mg of catalyst 2 (after removing the prepolymerized polymer) was pumped into the polymerization vessel with high-pressure argon to start polymerization. After holding at 70°C for 1 hour, polymerization was stopped by injecting 5 ml of ethanol. As a result, 225 g of branched propylene polymer was obtained. When granulation was performed in the same manner as in Example 1, the resulting pellets had a MFR (MFR pellet The concentration was 1.4 g / 10 min. The catalytic activity was 3750 g / ghr.

[0111] [Comparative Example 2] In the polymerization of Comparative Example 1, the same polymerization procedure was carried out except that 45 mg of catalyst 2 (excluding the mass of the prepolymerized polymer) and 230 N ml of hydrogen were introduced. As a result, 240 g of branched propylene polymer was obtained. When granulation was performed in the same manner as in Example 1, the resulting pellets had a MFR (MFR pellet The concentration was 2.8 g / 10 min. The catalytic activity was 5333 g / ghr.

[0112] [Reference Example 5]: Example of a method for homopolymerizing side chains (Preparation of catalyst 4) In a three-necked flask (volume 1 L), 10 g of the chemically treated montmorillonite obtained in (2) above was placed, and heptane (65 mL) was added to form a slurry. Triisobutylaluminum (25 mmol: 35 mL of a heptane solution with a concentration of 143 mg / mL) was added to this slurry and stirred for 1 hour. The mixture was then washed with heptane until the residual liquid volume was reduced to 1 / 100, and the total volume was adjusted to 50 mL. In addition, in a separate flask (volume 200 mL), rac-dichloro[1,1'-dimethylsilylenebis{2-(5-methyl-2-furyl)-4-(4-isopropylphenyl)indenyl}]hafnium (complex 2) (0.15 mmol), prepared in the synthesis example of catalyst component [A-1], was dissolved in toluene (30 mL) to prepare solution 4-1. To a 1 L flask containing the aforementioned chemically treated montmorillonite, tri-n-octylaluminum (2.1 mmol: 5.4 mL of a 143 mg / mL heptane solution) was added, followed by the addition of solution 4-1, and the mixture was stirred at room temperature for 60 minutes. Subsequently, 215 mL of heptane was added, and the resulting slurry was introduced into a 1 L autoclave. After the internal temperature of the autoclave was set to 40°C, propylene was fed at a rate of 10 g / hour, and prepolymerization was carried out for 2 hours while maintaining the temperature at 40°C. Then, the propylene feed was stopped, and residual polymerization was carried out for 1.5 hours. After removing the supernatant of the resulting catalyst slurry by decantation, triisobutylaluminum (10 mmol: 8.3 mL of a heptane solution with a concentration of 143 mg / mL) was added to the remaining portion and stirred for 5 minutes. This solid was dried under reduced pressure for 40 minutes to obtain 29.5 g of dried prepolymerization catalyst. The prepolymerization ratio (amount of prepolymerized polymer divided by amount of solid catalyst) was 1.95. This prepolymerization catalyst was designated as catalyst 4. (polymerization) A 3L autoclave was thoroughly dried beforehand by heating and circulating nitrogen, then the contents of the chamber were replaced with propylene and cooled to room temperature. 2.8 mL of heptane solution of triisobutylaluminum (143 mg / mL) was added, followed by the introduction of 210 N mL of hydrogen. Next, 750 g of liquid propylene was introduced, and the temperature was raised to 70°C. Then, 150 mg of catalyst 4 (after removing the pre-polymerized polymer) was pumped into the polymerization vessel with high-pressure argon to start polymerization. After holding at 70°C for 1 hour, the unreacted propylene was quickly purged, and polymerization was stopped. As a result, approximately 225 g of propylene-based polymer was obtained. The obtained propylene polymer had an MFR of 38 g / 10 min. The manganese content calculated by GPC was 63,000, which can be estimated to be 3,000 carbon atoms in the skeleton. Furthermore, the catalytic activity was 1500 g / ghr.

[0113] [Reference Example 6]: Example of a method for homopolymerizing side chains In the polymerization described in Reference Example 5, the polymerization was carried out in the same manner as in Reference Example 5, except that 130 mg of catalyst 4 (excluding the mass of the prepolymerized polymer) and 245 N ml of hydrogen were introduced. As a result, 230 g of propylene polymer was obtained. The obtained propylene polymer had an MFR of 53 g / 10 min. The manganese content calculated by GPC was 62,000, which can be estimated to be 2,952 carbon atoms in the skeleton. Furthermore, the catalytic activity was 1769 g / ghr.

[0114] [Reference Example 7]: Example of a method for homopolymerization of side chains In the polymerization described in Reference Example 1, the polymerization was carried out in the same manner as in Reference Example 1, except that 150 mg of catalyst 3 (excluding the mass of the prepolymerized polymer) and 180 N ml of hydrogen were introduced. As a result, 270 g of propylene-based polymer was obtained. The obtained propylene polymer had an MFR of 1650 g / 10 min. The manganese content calculated by GPC was 25,000, which can be estimated to be 1,190 carbon atoms in the skeleton. The catalytic activity was 1800 g / ghr.

[0115] [Reference Example 8]: Example of a method for homopolymerizing side chains In the polymerization described in Reference Example 1, the polymerization was carried out in the same manner as in Reference Example 1, except that 100 mg of catalyst 3 (excluding the mass of the prepolymerized polymer) and 245 N ml of hydrogen were introduced. As a result, 300 g of propylene polymer was obtained. The obtained propylene polymer had an MFR of 1700 g / 10 min. The manganese content calculated by GPC was 21500, which can be estimated to be 1024 carbon atoms in the skeleton. The catalytic activity was 3000 g / ghr.

[0116] (5) Measurement and evaluation methods The branched propylene polymers obtained in Examples 1-4 and Comparative Examples 1-3 were measured or evaluated by the following methods. (5-1) Extensional viscosity (ηE), strain hardening degree (SHI), and branching index (MBI) In the descriptions of characteristics (1) and (2), the extensional viscosity was measured at each strain rate (1.0 / sec, 0.1 / sec, 0.01 / sec) using the method described above, and the degree of strain hardening (SHI) at each strain rate (dε / dt) was calculated using the obtained extensional viscosity values. Furthermore, the multi-branching index (MBI) was calculated using the calculated values ​​of the degree of strain hardening (SHI) at each strain rate (dε / dt). The apparatus and conditions used for measuring extensional viscosity are as follows: <Measurement equipment and conditions> • Device: Ares, manufactured by Rheometorics Corporation. • Fixture: Extensional Viscosity Fixture manufactured by TA Instruments Corporation ·Measurement temperature: 180℃ ·Strain rate: 1.0 / sec, 0.1 / sec, 0.01 / sec • Preparation of test specimens: Press-form a sheet measuring 18mm x 10mm and 0.7mm thick.

[0117] (5-2) Melt flow rate (MFR) at a temperature of 230°C and a load of 2.16 kg. The MFR of branched propylene polymers in pellet form was measured. The MFR of macromers obtained in Reference Examples 1-6 was also measured. As described above in the explanation of characteristic (3), the MFR was measured in accordance with JIS K6921-2 "Plastics - Polypropylene (PP) molding and extrusion materials - Part 2: Preparation of test specimens and determination of properties" under test conditions of 230°C and a load of 2.16 kgf. Also, the measured MFR pellet Using the values, we calculated the value obtained by the right-hand side of equation (1-1) (112 × log(MFR) + 30) and the value obtained by the right-hand side of equation (1-2) (112 × log(MFR) + 51).

[0118] (5-3) Percentage of components soluble in p-xylene at 25°C (CXS) In the description of characteristic (5), the proportion of p-xylene-soluble content (CXS) in the branched propylene polymer was measured using the method described above.

[0119] (5-4) Molecular weight of branched side chains The catalysts used in the examples and comparative examples (catalysts 1 and 2) were a combination of complex 1 or complex 2, which is catalyst component [A-1] having macromer synthesis ability, and complex 3, which is catalyst component [A-2] having copolymerization ability between propylene and macromers. Reference Examples 1 to 6 were carried out using only complex 1 (catalyst 3) or complex 2 (catalyst 4), which has macromer synthesis ability, in order to measure or estimate the molecular weight of the branched side chains, and the number-average molecular weight (Mn) of the obtained macromers was measured. The number-average molecular weight (Mn) of the macromers was measured by gel permeation chromatography (GPC) using the method described above in the description of characteristic (6). The apparatus and conditions used for measuring the macromer number-average molecular weight (Mn) are as follows: <Measurement equipment and conditions> • Equipment: Waters GPC (ALC / GPC, 150C) • Detector: FOXBORO MIRAN, 1A, IR detector (measurement wavelength: 3.42 μm) • Columns: Showa Denko AD806M / S (3 pieces) Mobile phase solvent: o-dichlorobenzene (ODCB) ·Measurement temperature: 140℃ ·Flow rate: 1.0mL / min ·Injection volume: 0.2mL

[0120] (5-5) Components with a molecular weight M of 1 million or more (W1 million), and absolute molecular weight M abs The branching exponent g'(1,000,000) is 1 million. In the description of characteristic (8), the method described above yields a branched propylene polymer with a molecular weight M of 1 million or more (W1 million), and an absolute molecular weight M abs The branching exponent g'(1,000,000) was measured for 1 million.

[0121] (5-6) Melting point (Tm) The melting point (Tm) of the branched propylene polymer was measured using the method described above in the explanation of characteristic (9).

[0122] (5-7) Number of long chain branches (LCBs) In the description of characteristic (10), the number of long-chain branches (LCBs) with 7 or more carbon atoms per 1000 monomer units was measured for the branched propylene polymers and the macromers obtained in Reference Examples 1 to 6 using the method described above.

[0123] (5-8) Melt tension In the description of characteristic (4), the melt tension MT (unit: g) of the branched propylene polymer at 230°C was measured using the method described above, with a Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd. Furthermore, using the measured MT value, the values ​​calculated by the right-hand side of equation (2-1) (-119 × log(MT) + 200) and the right-hand side of equation (2-2) (-119 × log(MT) + 220) were determined.

[0124] (5-9) Spreadability In the description of characteristic (3), the maximum winding speed MaxDraw (unit: m / min) of the branched propylene polymer at 230°C was measured using the method described above.

[0125] (5-10) End vinyl ratio In the explanation of the physical properties of propylene polymers containing terminal vinyl groups (2), the terminal vinyl content was measured for the propylene polymers obtained in Reference Examples 1 to 6 using the method described above.

[0126] (6) Evaluation results The results for each example, comparative example, and reference example are shown in Tables 1 to 4. Table 1 shows the polymerization conditions for each example and comparative example in which branched propylene polymers were synthesized, and for the obtained branched propylene polymers, the MFR, the proportion of xylene-soluble components, the molecular weight M of components with a molecular weight M of 1 million or more (W1 million), and the absolute molecular weight M. abs This document summarizes the branching index g'(1 million) at 1 million units, the number of long-chain branches (LCBs) with 7 or more carbon atoms per 1000 monomer units, the melting point (Tm), and macromers that correspond to the branched chains of branched propylene polymers as reference examples. Table 2 summarizes the polymerization conditions for the macromers corresponding to the branched chains of the branched propylene polymers obtained in each example and comparative example, as well as the MFR, number-average molecular weight (Mn), number of carbon atoms in the backbone, the number of long-chain branches (LCBs) with 7 or more carbon atoms per 1000 monomer units, and the terminal vinyl content for the obtained macromers. Table 3 summarizes the extensional viscosity ηE when the Henkey strain (ε) is 1 at each strain rate (0.01 / sec, 0.1 / sec, 1.0 / sec), the degree of strain hardening (SHI) at each strain rate (0.01 / sec, 0.1 / sec, 1.0 / sec), and the branching index (MBI) calculated from the degree of strain hardening (SHI) at strain rates from 0.01 / sec to 1.0 / sec for each branched propylene polymer obtained in each example and comparative example. Table 4 summarizes the MFR, melt tension (MT) at 230°C, maximum winding speed (MaxDraw) at 230°C, the value calculated by the right-hand side of equation (1-1) (112 × log(MFR) + 30), whether or not equation (1-1) is satisfied, the value calculated by the right-hand side of equation (1-2) (112 × log(MFR) + 51), whether or not equation (1-2) is satisfied, the value calculated by the right-hand side of equation (2-1) (-119 × log(MT) + 200), whether or not equation (2-1) is satisfied, the value calculated by the right-hand side of equation (2-2) (-119 × log(MT) + 220), and whether or not equation (2-2) is satisfied. In Table 4, a circle (○) is indicated if the above formulas (1-1), (1-1), (2-1), or (2-2) are satisfied, and a cross (×) is indicated if they are not satisfied. The graph in Figure 5 plots the data for branched propylene polymers obtained in each example and comparative example, with the horizontal axis representing the logarithmic log(MFR) of MFR (MFR 230°C, 2.16 kg load) and the vertical axis representing the maximum winding speed (MaxDraw) at 230°C. The graph in Figure 6 plots the data for branched propylene polymers obtained in each example and comparative example, with the horizontal axis representing the logarithmic scale of the melt tension (MT) at 230°C (log(MT)) and the vertical axis representing the maximum winding speed (MaxDraw) at 230°C. The graph in Figure 7 plots the branched propylene polymer data obtained in each example and comparative example, with MFR (MFR 230°C, 2.16 kg load) on the horizontal axis and the branching index (MBI) on the vertical axis.

[0127] [Table 1]

[0128] [Table 2]

[0129] [Table 3]

[0130] [Table 4]

[0131] As shown in Table 3, the branched propylene polymers of Examples 1 and 2 have a branching index (MBI) of 0.48 to 0.58, which falls within the range of characteristic (1), and a strain hardening degree (SHI@1.0s) -1 The degree of strain hardening (SHI@1.0s) was 1.73, which was within the range of characteristic (2). The branched propylene polymers of Examples 3-4 had a branching index (MBI) of 0.64-0.80, which was within the range of characteristic (1), and the degree of strain hardening (SHI@1.0s) was 1.73. -1The value of ) was between 1.67 and 1.75, which fell within the range of characteristic (2). Furthermore, as shown in Table 4 and Figure 5, the branched propylene polymers of Examples 1 to 4 satisfied the relationship between the maximum winding speed (MaxDraw) and MFR at 230°C as shown in equation (1-1), and also satisfied the relationship shown in equation (1-2). The dotted line shown in Figure 5 is a straight line represented by the equation (MaxDraw) = 112 × log(MFR) + 30, which corresponds to equation (1-1). In addition, as shown in Table 4 and Figure 6, the branched propylene polymers of Examples 1 to 4 satisfied the relationship between the maximum winding speed (MaxDraw) and melt tension (MT) at 230°C as shown in equation (2-1), and also satisfied the relationship shown in equation (2-2). The dotted line shown in Figure 6 is a straight line represented by the equation (MaxDraw) = -119 × log(MT) + 200, which corresponds to equation (2-1). As shown in Table 4, the branched propylene polymers of Examples 1 and 2 had a melt tension (MT) of 8.6 to 11.2 g at 230°C, maintaining the melt tension necessary for molding, while also exhibiting excellent ductility during melting, with a maximum draw speed (MaxDraw) of 114 to 117 m / min at 230°C. The branched propylene polymers of Examples 1 and 2 had a relatively low MFR of 1.2 to 2.6 g / 10 min, and possessed a well-balanced melt tension and ductility for a propylene polymer with a relatively low MFR, exhibiting excellent ductility relative to fluidity and ductility relative to melt tension. The branched propylene polymers of Examples 3 and 4 had a melt tension (MT) of 3.9 to 5.8 g at 230°C, a maximum draw speed (MaxDraw) of 167 to 176 m / min at 230°C, and a relatively large MFR of 4.8 to 8.1 g / 10 min. As a propylene polymer with a relatively large MFR, it possessed a well-balanced melt tension and ductility, exhibiting excellent ductility relative to its fluidity and ductility relative to its melt tension. In contrast, as shown in Table 3, the branched propylene polymers of Comparative Examples 1 and 2 exhibited a strain hardening degree (SHI@1.0s). -1The strain hardening degree (SHI@1.0s) was 1.75 to 1.88, which fell within the range of characteristic (2), but the branching index (MBI) was 0.05 to 0.08, which was smaller than the lower limit of the range of characteristic (1). The branched propylene polymer of Comparative Example 3 also showed a strain hardening degree (SHI@1.0s) -1 The value of ) was 1.50, which was within the range of characteristic (2), but the branching index (MBI) was 0.11, which was lower than the lower limit of the range of characteristic (1). Furthermore, as shown in Table 4 and Figure 5, the branched propylene polymers of Comparative Examples 1 to 3 did not satisfy the relationship shown by formula (1-1) above between the maximum winding speed (MaxDraw) and MFR at 230°C, nor did they satisfy the relationship shown by formula (1-2) above. Moreover, as shown in Table 4 and Figure 6, the branched propylene polymers of Comparative Examples 1 to 3 did not satisfy the relationship shown by formula (2-1) above between the maximum winding speed (MaxDraw) and melt tension (MT) at 230°C, nor did they satisfy the relationship shown by formula (2-2) above. As shown in Table 4, the branched propylene polymers of Comparative Examples 1 and 2 had a melt tension (MT) of 8.6 to 16.6 g at 230°C, which was sufficient for molding. However, their maximum draw speed (MaxDraw) at 230°C was 31 to 53 m / min, indicating poor ductility during melting. The branched propylene polymers of Comparative Examples 1 and 2 had relatively low MFRs of 1.4 to 2.8 g / 10 min. As propylene polymers with relatively low MFRs, their ductility during melting was insufficient, and they were inferior in terms of ductility relative to fluidity and ductility relative to melt tension. The branched propylene polymer of Comparative Example 3 had a melt tension (MT) of 5.1 g at 230°C and a maximum draw speed (MaxDraw) at 230°C of 114 m / min. The branched propylene polymer of Comparative Example 3 had the same MaxDraw value as Example 1, but its MFR was relatively large at 7.9 g / 10 min. As a propylene polymer with a relatively large MFR, its spreadability at melt was insufficient, and it was inferior in both spreadability relative to fluidity and spreadability relative to melt tension. Furthermore, as shown in Figure 7, when a graph was created plotting the branching index (MBI) on the horizontal axis and the branching index (MBI) on the vertical axis for the branched propylene polymers obtained in each example and comparative example, it was confirmed that the branched propylene polymers in the example group had a larger MBI than the branched propylene polymers in the comparative example group.

[0132] As shown in Table 1, the ratio of components with a molecular weight M of 1 million or more (W1 million) in the molecular weight distribution curve was 0.080 to 0.092 for the branched propylene polymers of Examples 1 and 2, and 0.071 to 0.077 for the branched propylene polymers of Examples 3 and 4. In contrast, the branched propylene polymers of Comparative Examples 1 and 2 were 0.067 to 0.068, and the branched propylene polymer of Comparative Example 3 was 0.036. Therefore, the branched propylene polymers of Examples 1-4 contain more components in the high molecular weight range compared to the branched propylene polymer of the comparative example.

[0133] Furthermore, as shown in Table 1, the branched propylene polymers of Examples 1 and 2 have an absolute molecular weight M abs The branching index g'(1,000,000) at 1,000,000 was 0.89 for the branched propylene polymer of Example 3, and the branching index g'(1,000,000) for the branched propylene polymer of Example 4 was 0.85. The branching index g'(1,000,000) for the branched propylene polymers of Comparative Examples 1 and 2 was 0.89, and the branching index g'(1,000,000) for the branched propylene polymer of Comparative Example 3 was 0.83. The branched propylene polymers of Examples 1 and 2 are equivalent to those of Comparative Examples 1 and 2 when comparing only the branching index g'(1 million). However, as mentioned above, the proportion of components in the high molecular weight region, represented by the ratio of components with a molecular weight M of 1 million or more (W1 million), is greater than that of Comparative Examples 1 and 2. Therefore, the amount of branched chains introduced into the high molecular weight region is greater than that of Comparative Examples 1 and 2. Similarly, the branched propylene polymers of Examples 1 and 2 have the same branching index g'(1 million) as Comparative Example 3, but because W1 million is larger, the amount of branched chains introduced into the high molecular weight region is greater. The branched propylene polymers of Examples 3 and 4 are also equivalent to those of Comparative Examples 1 and 3 when comparing only the branching index g'(1 million). However, because W1 million is larger, the amount of branched chains introduced into the high molecular weight region is greater than that of Comparative Examples 1 and 3.

[0134] Furthermore, as shown in Tables 1 and 2, the length of the side chains introduced into the branched propylene polymers of Examples 1 and 2 is estimated to have a number average molecular weight Mn of 26,000 (equivalent to 1,238 carbon atoms in the skeleton) to 26,500 (equivalent to 1,262 carbon atoms in the skeleton) based on the results of Reference Examples 1 and 2. The length of the side chains introduced into the branched propylene polymers of Examples 3 and 4 is estimated to have a number average molecular weight Mn of 21,500 (equivalent to 1,024 carbon atoms in the skeleton) to 25,000 (equivalent to 1,190 carbon atoms in the skeleton) based on the results of Reference Examples 7 and 8. In contrast, the length of the side chains introduced into the branched propylene polymers of Comparative Examples 1 and 2 is estimated to have a number average molecular weight Mn of 62,000 to 63,000 based on the results of Reference Examples 5 and 6. The length of the side chains introduced into the branched propylene polymer of Comparative Example 3 is also estimated to have a number average molecular weight Mn of 62,000 based on the results of Reference Example 6. Therefore, the branched propylene polymers of Examples 1-4 have shorter side chain lengths compared to the branched propylene polymers of the comparative examples.

[0135] Furthermore, as shown in Table 1, the branched propylene polymers of Examples 1 and 2 exhibit long-chain branching as shown in structural formula (A), but the number of long-chain branches (LCBs) with 7 or more carbon atoms per 1000 monomer units is less than 0.1, indicating a small number of long-chain branches. The branched propylene polymers of Examples 3 and 4 also exhibit long-chain branching as shown in structural formula (A), but the number of long-chain branches (LCBs) with 7 or more carbon atoms per 1000 monomer units is less than 0.1, indicating a small number of long-chain branches. The branched propylene polymers of Comparative Examples 1 and 3 also had a number of long-chain branches (LCBs) of less than 0.1. Based on the results of Reference Examples 1-2, the number of long-chain branches (LCBs) with 7 or more carbon atoms per 1000 monomer units introduced into the branched propylene polymers of Examples 1-2 is estimated to be 0.3. Based on the results of Reference Examples 7-8, the number of long-chain branches (LCBs) with 7 or more carbon atoms per 1000 monomer units introduced into the branched propylene polymers of Examples 3-4 is estimated to be 0.3. Based on the results of Reference Examples 7-8, the number of long-chain branches (LCBs) introduced into the branched propylene polymers of Comparative Examples 1-3 is estimated to be 0.2. Based on the results of Reference Examples 5-6, the number of long-chain branches (LCBs) introduced into the branched propylene polymers of Comparative Examples 1-3 is estimated to be 0.2.

[0136] From the molecular structure analysis described above, it was confirmed that the branched propylene polymers obtained in Examples 1 to 4 contain many highly branched molecules in the high molecular weight region, each having numerous branches with short branching chain lengths. They also have a molecular structure with a distribution of relaxation times, where many components have relatively short relaxation times, and few components have extremely long relaxation times.

Claims

1. A branched propylene polymer having the following characteristics (1), (2), and (3). Characteristic (1): The branching index (MBI) is between 0.45 and 1.

00. Characteristics (2): Strain hardening degree (SHI@1s) at strain rate (dε / dt) of 1.0 / sec －１ The value is between 0.70 and 3.

00. Characteristic (3): The relationship between the maximum winding speed (MaxDraw) and the melt flow rate (MFR) at 230°C is given by the following equation (1-1). (MaxDraw) > 112 × log(MFR) + 30 ... Equation (1-1) Here, the multi-branching index (MBI) is the slope when the degree of strain hardening (SHI) for strain rates (dε / dt) from 0.01 / sec to 1.0 / sec is plotted on the horizontal axis with the logarithm of the strain rate (log(dε / dt)) and the degree of strain hardening (SHI) for strain rates from 0.01 / sec to 1.0 / sec is plotted on the vertical axis. Furthermore, the degree of strain hardening (SHI) is the slope when the logarithm of Henkey strain (ε) (log(ε)) is plotted on the x-axis and the logarithm of extensional viscosity (ηE) (log(ηE)) is plotted on the y-axis, in the interval between Henkey strain (ε) 1 and 3, when measuring extensional viscosity at a temperature of 180°C and a predetermined strain rate (dε / dt). The maximum winding speed (MaxDraw) at 230°C is defined as follows: resin temperature: 230°C, capillary: diameter 2.0 mm, length 40 mm, cylinder diameter: 9.55 mm, cylinder extrusion speed: 20 mm / min. The resin is extruded in a string-like form and wound onto the roller while the acceleration is 1.8 cm / s². ２ This is the winding speed (in m / min) just before the string-like material breaks when the winding speed is increased from 4.0 m / min to 200.0 m / min. Melt flow rate (MFR) is the melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg (unit: g / 10 min).

2. Furthermore, the branched propylene polymer according to claim 1 satisfies the following characteristic (4). Characteristic (4): It is preferable that the relationship between the maximum winding speed (MaxDraw) and the melt tension (MT) at 230°C is shown by the following formula (2-1). (MaxDraw)>-119×log(MT)+200 ...Formula (2-1) Here, the maximum winding speed (MaxDraw) at 230°C is the same as that given in equation (1-1), and the melt tension (MT) is the tension (in g) detected when winding the resin onto the roller at a winding speed of 4.0 m / min during the measurement of the maximum winding speed (MaxDraw) at 230°C.

3. Furthermore, the branched propylene polymer according to claim 1 or 2 satisfies the following characteristic (5). Characteristic (5): The proportion of components soluble in p-xylene at 25°C (CXS) is less than 0.5% by mass.

4. Furthermore, the branched propylene polymer according to claim 1 or 2 satisfies the following characteristic (6). Characteristic (6): The number-average molecular weight (Mn) of the branched side chains is between 11,000 and 30,000.

5. Furthermore, the branched propylene polymer according to claim 1 or 2 satisfies the following characteristic (7). Characteristic (7): The melt flow rate (MFR), measured at a temperature of 230°C and a load of 2.16 kg, is 1 g / 10 min or more and 10 g / 10 min or less.

6. Furthermore, the branched propylene polymer according to claim 1 or 2 satisfies the following characteristic (8-1). Characteristics (8-1): In the molecular weight distribution curve measured by GPC, the ratio of components with a molecular weight M of 1 million or more (W1 million) is between 0.070 and 0.

100.

7. Furthermore, the branched propylene polymer according to claim 6 satisfies the following characteristic (8-2). Characteristics (8-2): Absolute molecular weight M measured by 3D-GPC ａｂｓ The break-even point g'(1 million) at 1 million is between 0.80 and 0.

90.

8. Furthermore, the branched propylene polymer according to claim 1 or 2 satisfies the following characteristic (9). Characteristic (9): The melting point (Tm) measured by differential scanning calorimetry (DSC) is between 150°C and 157°C.

9. Furthermore, the branched propylene polymer according to claim 1 or 2 satisfies the following characteristic (10). Characteristics (10): The branched propylene polymer has a long-chain branched structure portion represented by the following structural formula (A). 【Chemistry 1】 [However, in structural formula (A), P １ , P ２ , P ３ Cbr is a residue formed at the end of a branched propylene polymer, each having one or more propylene units. Cbr represents the methine carbon at the base of a branched chain with seven or more carbon atoms, while Ca, Cb, and Cc represent methylene carbons adjacent to the methine carbon (Cbr).

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