Method for producing propylene polymer

Abstract

Provided is a method for producing a propylene-based polymer in which a propylene-based polymer is polymerized by a continuous gas phase polymerization method in the presence of a catalyst, in which a cylindrical horizontal polymerization reactor in which a stirring mechanism that rotates about a horizontal axis is provided is used to remove reaction heat by gasification heat of a liquid containing a liquefied monomer, thereby producing a propylene-based polymer. Wherein: a catalyst is supplied from the upper part of one end of the horizontal polymerization reactor; and discharging the propylene polymer from the lower part of the other end part of the horizontal polymerization reactor. The method for producing a propylene polymer comprises: a temperature measurement step in which the temperature distribution in the circumferential direction of a cylindrical horizontal polymerization reactor is measured such that the interval between adjacent measurement points is [pi] / 10 (rad) or less in terms of the central angle; a calculation step in which a specific temperature distribution parameter (A) is calculated from the temperature distribution obtained in the temperature measurement step; and a monitoring step in which the temperature distribution parameter (A) is monitored such that the temperature distribution parameter (A) does not exceed a predetermined value.

Description

TECHNICAL FIELD

[0001] The present invention relates to a manufacturing method of propylene-based polymers. More specifically, the present invention relates to a polymerization method configured to suppress formation of lumpy polymers and stably produce propylene-based polymers for a long period of time in polymerization of propylene using a cylindrical horizontal polymerization reactor by monitoring a specific temperature distribution parameter calculated from a temperature distribution in a circumferential direction of the reactor. BACKGROUND

[0002] Propylene-based polymers are used in a wide range of industrial applications because they have excellent mechanical properties such as rigidity and heat resistance and good formability; propylene-based polymers can be produced at relatively low cost; and propylene-based polymers have high adaptability to environmental problems.

[0003] Therefore, technical research on the manufacturing process of polypropylene is continuously conducted from the viewpoint of simplifying the steps, reducing production costs, improving productivity, and improving catalyst performance.

[0004] In the manufacturing process of polypropylene, the necessity of removing catalyst residues and random polymers and the like has been reduced as catalyst performance has significantly improved. Currently, a gas phase process is mainstream.

[0005] In the gas phase process, a high-activity catalyst typified by a supported catalyst has been commonly used recently. New catalysts developed in the latest progress of catalyst technology (e.g., high-activity catalysts and metallocene-based catalysts) are applied to this process and, in relation to this application, suppressing formation of lumpy polymers and reducing formation of fine powders are problems that should be solved from the viewpoint of stable operation of the process.

[0006] To prevent formation of aggregated amorphous polymers in gas phase polymerization, removal of polymerization heat in the catalyst supply part of the fluidized bed reactor is considerably difficult, and the temperature inside the fluidized bed is likely to be unstable due to local accumulation of polymerization heat. Therefore, a polypropylene manufacturing method is proposed in which the temperature and pressure inside the gas phase polymerization reactor are adjusted using the gasification heat by the liquid flow rate of liquefied circulating gas returned to the reactor, the flow rate of exhaust gas discharged to the outside of the system, and the flow rate of supplied monomer gas using a fluidized bed reactor (see, for example, Patent Literature 1). However, when the yield increases and the grade drastically changes, there is still room for improvement in the removal of polymerization heat in the fluidized bed reactor in this manufacturing method.

[0007] Further, for the purpose of suppressing formation of lumps of polymer and maintaining a fluid state, a gas phase polymerization method is proposed which is characterized in that the inner wall temperature of a fluidized bed reactor is cooled to below the dew point of the flowing gas at the time of polymerization in the reactor (for example, see Patent Literature 2). However, the inventors of the present application have recognized that there are difficulties in operation control due to changes in local phase.

[0008] For the purpose of enabling stable, long-term gas phase olefin polymerization, Patent Literature 3 discloses a fluidized bed type polymerization apparatus equipped with an infrared type thermometer which measures the temperature distribution of the outer wall surface of the polymerization apparatus from a predetermined measurement distance, and a controller which pre-stores a target temperature distribution value of the outer wall surface of the polymerization apparatus, displays the temperature distribution measured by the infrared type thermometer, performs a comparison operation between the target temperature distribution value and the measured temperature distribution of the outer wall surface, and changes the polymerization conditions to meet the target. However, the inventors of the present application have recognized the following situation: in the case where the temperature distribution of the outer wall surface is measured from a predetermined measurement distance by the infrared type thermometer, the measurement is easily affected by heat dissipation or external temperature; the precision of temperature management is likely to decrease; and the precision of temperature management further decreases when the reactor is covered with an insulating material.

[0009] On the other hand, as a gas phase process, it is known to use a horizontal polymerization reactor including a stirrer rotating around a horizontal axis as an olefin gas phase reactor which removes polymerization heat using the gasification heat of liquefied propylene. The method of removing polymerization heat using the gasification heat of liquefied propylene has an advantage that a large heat removal capacity can be achieved by a small facility.

[0010] In the case of using the gasification heat of liquefied propylene, gas is generally discharged from the reactor; the discharged gas is liquefied by cooling with a heat exchanger; and the liquefied gas is returned to the reactor. Since the liquefaction temperature (dew point) of the gas depends on the pressure and the gas composition, when propylene is mixed with a gas component such as hydrogen or ethylene which has a lower dew point than propylene, the dew point decreases as the amount of the mixed gas component increases. The cooling capacity of the heat exchanger is determined by the facility, and in the case of using the same facility, the lower the dew point of the gas component, the lower the capacity of liquefying the gas, i.e., the heat removal capacity.

[0011] Therefore, in a manufacturing process in which a large amount of hydrogen or ethylene is present in the reactor, such as a manufacturing process of a propylene-based polymer or a random polymer having a high melt flow rate using a new type of catalyst such as a high-activity catalyst or a metallocene catalyst, the catalyst activity is enhanced; however, due to the decrease in the heat removal capacity, formation of lumps of polymer is inevitable.

[0012] To cope with such a problem, a method of suppressing polymer aggregation by separating a titanium-supported catalyst component supply port from a cocatalyst component supply port in a horizontal polymerization reactor is proposed (for example, see Patent Literature 4). A method of suppressing aggregation of amorphous polymer by using a prepolymerization treatment of an α-olefin and a donor addition is also proposed (for example, see Patent Literature 5).

[0013] The inventors of the present application have proposed a method of continuously manufacturing a propylene-based polymer, particularly a low-crystallinity propylene-based polymer, by a gas phase polymerization process, removing reaction heat mainly with gasification heat of liquefied propylene, while achieving both keeping good flowability of the polymer and reducing formation of a massive polymer that hinders stable operation of the process, by limiting the temperature of a recovered gas of gasified propylene supplied to the reactor to a certain temperature (Patent Literature 6).

[0014] In addition, the inventors of the present application have proposed a process of continuously manufacturing a propylene-based polymer by using a horizontal polymerization reactor in which a temperature difference ΔΤ1 (°C) (= Tx - Tz) between a temperature (Tx) of a region including a catalyst supply part and a dew point (Tz) of a mixed gas in the reactor is set to 0°C to 5°C in a temperature condition inside the polymerization reactor, a method of manufacturing a propylene-based polymer excellent in transparency and low-temperature heat sealability, and suppressing formation of a massive polymer and achieving improvement in manufacturing efficiency, industrially and stably (Patent Literature 7).

[0015] Meanwhile, Patent Literature 8 discloses an apparatus for measuring a temperature inside a reactor of a gasification apparatus using an optical pyrometer.

[0016] Prior Art Documents

[0017] Patent Literature

[0018] Patent Literature 1: Japanese Patent Application Laid-Open No. 11-209415

[0019] Patent Literature 2: Japanese Patent No. 3,180,305

[0020] Patent Literature 3: Japanese Patent Application Laid-Open No. 11-189603

[0021] Patent Literature 4: Japanese Patent Application Laid-Open No. 7-94485

[0022] Patent Literature 5: International Publication No. 00 / 42081

[0023] Patent Literature 6: Japanese Patent Application Laid-Open No. 2009-73890

[0024] Patent Literature 7: Japanese Patent Application Laid-Open No. 2011-148980

[0025] Patent Literature 8: Japanese Patent Application Laid-Open No. 2001-521144 SUMMARY

[0026] PROBLEMS TO BE SOLVED BY THE INVENTION

[0027] However, the continuous gas phase polymerization method using the cylindrical horizontal polymerization reactor in which the reaction heat is removed by the gasification heat of the liquid containing the liquidized monomer, even under the conditions of Patent Literature 7, sometimes fails to suppress the formation of the lump-shaped polymer. Therefore, a technical improvement in terms of suppressing the formation of the lump-shaped polymer and achieving improvement in manufacturing efficiency is desired.

[0028] As described above, in the prior art, a technology capable of achieving the purpose such as suppressing the formation of the lump-shaped polymer and stably manufacturing a propylene-based polymer for a long period of time by using the continuous gas phase polymerization method using the cylindrical horizontal polymerization reactor in which the reaction heat is removed by the gasification heat of the liquid containing the liquidized monomer has not been achieved. From such a viewpoint, a further technical improvement is desired.

[0029] In view of the above circumstances, an object of the present application is to provide a manufacturing method of a propylene-based polymer configured to suppress the formation of a lump-shaped polymer and exhibit excellent long-term operability by using a continuous gas phase polymerization method using a cylindrical horizontal polymerization reactor in which the reaction heat is removed by the gasification heat of a liquid containing a liquidized monomer.

[0030] SOLUTION TO THE PROBLEM

[0031] In the continuous gas phase polymerization method using the cylindrical horizontal polymerization reactor in which the reaction heat is removed by the gasification heat of the liquid containing the liquidized monomer, even when the difference between the dew point of the mixed gas in the reactor and the polymerization temperature of the catalyst supply portion is reduced and the continuous polymerization operation is performed in the same manner as in Patent Literature 7, sometimes the lump-shaped polymer is formed. In this regard, the inventors of the present application have studied what happens inside the reactor when the lump-shaped polymer is formed therein.

[0032] Based on the study, the inventors of the present application found that by measuring the temperature distribution in the circumferential direction of the cylindrical horizontal polymerization reactor in real time during the continuous polymerization operation in a manner that the central angle between adjacent measurement points is π / 10 (rad) or less, calculating the temperature distribution as a specific temperature parameter, and monitoring the specific temperature parameter, a manufacturing method of a propylene-based polymer configured to suppress the formation of the lump-shaped polymer and exhibit excellent long-term operability can be achieved. Based on this finding, the inventors of the present application finally achieved the present application.

[0033] That is, the present application encompasses the following embodiments.

[0034] [1] A manufacturing method of a propylene-based polymer,

[0035] wherein a cylindrical horizontal polymerization reactor including a stirring mechanism rotating around a horizontal axis is used inside the reactor, a propylene-based polymer is polymerized from propylene or from propylene and an α-olefin other than propylene in the presence of a catalyst by a continuous gas phase polymerization method in which reaction heat is removed by gasification heat of a liquid containing a liquid monomer; the catalyst is supplied from an upper portion of one end portion of the horizontal polymerization reactor; and the propylene-based polymer is discharged from a lower portion of the other end portion of the horizontal polymerization reactor;

[0036] wherein the method comprises:

[0037] a temperature measurement step in which a temperature distribution of the cylindrical horizontal polymerization reactor in a circumferential direction is measured in a manner that a central angle between adjacent measurement points is π / 10 (rad) or less,

[0038] a calculation step in which a temperature distribution parameter (A) defined by the following formula 1 is calculated from the temperature distribution obtained by the temperature measurement step, and

[0039] a monitoring step in which the temperature distribution parameter (A) is monitored to prevent the parameter from exceeding a predetermined value; and

[0040] wherein the method optionally further comprises at least one selected from the group consisting of:

[0041] a condition adjustment step (1) in which a manufacturing condition is adjusted to prevent the temperature distribution parameter (A) from exceeding a predetermined value, and

[0042] a condition adjustment step (2) in which when the temperature distribution parameter (A) exceeds a predetermined value, the manufacturing condition is adjusted so that the temperature distribution parameter (A) is below the predetermined value:

[0043] A = Th × θw (Formula 1)

[0044] (wherein, Th = Tp - Tave; Ti is a temperature (°C) of the i-th measurement point (where i is an integer of 1 to n, and n is the number (pieces) of measurement points in the circumferential direction); Tp is a temperature (°C) having a maximum value among Ti; Tave is an average temperature (°C) of Ti; and θw is a sum (rad) of central angles of adjacent intervals of each other of measurement points including Tp, Ti, and Tave, in which a difference (Ti - Tave) is 0.5 °C or more.)

[0045] [2] A method for producing a propylene-based polymer,

[0046] wherein a cylindrical horizontal polymerization reactor including a stirring mechanism rotating around a horizontal axis is used inside the reactor, a propylene-based polymer is polymerized from propylene or from propylene and an α-olefin other than propylene in the presence of a catalyst by a continuous gas phase polymerization method in which reaction heat is removed by gasification heat of a liquid containing a liquidized monomer; the catalyst is supplied from an upper portion of one end portion of the horizontal polymerization reactor; and the propylene-based polymer is discharged from a lower portion of the other end portion of the horizontal polymerization reactor;

[0047] wherein the method comprises:

[0048] a temperature measuring step in which a temperature distribution of a portion of the cylindrical horizontal polymerization reactor in the circumferential direction is measured in a manner that an interval between adjacent measurement points is a central angle of π / 10 (rad) or less,

[0049] a calculating step in which a temperature distribution parameter (As) defined by the following formula 2 is calculated from the temperature distribution obtained by the temperature measuring step, and

[0050] a monitoring step in which the temperature distribution parameter (As) is monitored to prevent the parameter from exceeding a predetermined value; and

[0051] wherein the method optionally further comprises at least one selected from the group consisting of:

[0052] a condition adjusting step (1') in which a manufacturing condition is adjusted to prevent the temperature distribution parameter (As) from exceeding the predetermined value, and

[0053] a condition adjusting step (2') in which, when the temperature distribution parameter (As) exceeds the predetermined value, the manufacturing condition is adjusted so that the temperature distribution parameter (As) is the predetermined value or less:

[0054] As = Th s × θw s (Formula 2)

[0055] (wherein Th s = TP - Tref; Ti is a temperature (°C) of the i-th measurement point (wherein i is an integer of 1 to n and n is the number (pieces) of the measurement points in the circumferential direction); Tp is a temperature (°C) having a maximum value among Ti; Tref is a predetermined reference temperature (°C); θw s is a sum (rad) of central angles of adjacent intervals of the measurement points from each other, including the measurement point of Tp, for which a difference (Ti - Tref) between Ti and Tref is a predetermined temperature or more.)

[0056] [3] The propylene-based polymer production method according to the above-mentioned [1] or [2], wherein, in the temperature measuring step, a temperature distribution is measured at least in the circumferential direction of the catalyst supply portion of the horizontal polymerization reactor.

[0057] [4] The method for producing a propylene-based polymer according to any one of [1] to [3] above, wherein in the temperature measurement step, the temperature distribution of the outer surface of the horizontal polymerization reactor is measured.

[0058] [5] The method for producing a propylene-based polymer according to any one of [1] to [4] above, wherein in the temperature measurement step, the temperature distribution is measured so that the distance between adjacent measurement points is within a range of 10 mm to 1000 mm.

[0059] [6] The method for producing a propylene-based polymer according to any one of [1] to [5] above, wherein in the temperature measurement step, the temperature measured at each measurement point in the circumferential direction is plotted to create a temperature curve, with the radial coordinate r being the temperature and the angular coordinate θ being the position of each measurement point in the circumferential direction in circular coordinates.

[0060] [7] The method for producing a propylene-based polymer according to any one of [1] to [6] above, wherein the predetermined value is set within a range of 0π to 30π.

[0061] [8] The method for producing a propylene-based polymer according to any one of [1] to [7] above, wherein the rotation frequency of the stirring mechanism is 5 rpm to 50 rpm.

[0062] [9] The method for producing a propylene-based polymer according to any one of [1] to [8] above, wherein the temperature difference ΔT1 (°C) (=Tx-Tz) between the temperature (Tx) of the region including the catalyst supply section of the horizontal polymerization reactor and the dew point (Tz) of the mixed gas in the reactor is 0°C to 3.0°C.

[0063]

[10] The method for producing a propylene-based polymer according to any one of [1] to [9] above, wherein the catalyst is a Ziegler polymerization catalyst or a metallocene polymerization catalyst.

[0064]

[11] The method for producing a propylene-based polymer according to any one of [1] to

[10] above, wherein the melt flow rate (MFR) of the produced propylene-based polymer measured at a temperature of 230° C. and a load of 2.16 kg is 0.3 g / 10 min to 150 g / 10 min.

[0065] The present invention can be expressed as follows.

[0066] <1> A method for producing a propylene polymer,

[0067] wherein a cylindrical horizontal polymerization reactor including a stirring mechanism rotating around a horizontal axis is used inside the reactor, a propylene-based polymer is polymerized from propylene or from propylene and an α-olefin other than propylene in the presence of a catalyst by a continuous gas phase polymerization method in which reaction heat is removed by gasification heat of a liquid containing a liquid monomer; the catalyst is supplied from an upper portion of one end portion of the horizontal polymerization reactor; and the propylene-based polymer is discharged from a lower portion of the other end portion of the horizontal polymerization reactor;

[0068] wherein the method comprises the following step group (I) or (II).

[0069] [Step group (I)]

[0070] Step group (I) includes the following steps (I-1), (I-2), and (I-3). It can further include at least one selected from the group consisting of the following steps (I-4) and (I-5).

[0071] Step (I-1): Temperature measurement step in which a temperature distribution of the cylindrical horizontal polymerization reactor in the circumferential direction is measured in a manner that the interval between adjacent measurement points is a central angle of π / 10 (rad) or less.

[0072] Step (I-2): Calculation step in which a temperature distribution parameter (A) defined by the following formula 1 is calculated from the temperature distribution obtained by the temperature measurement step.

[0073] A = Th × θw (Formula 1)

[0074] (wherein, Th = Tp - Tave; Ti is the temperature (°C) of the i-th measurement point (where i is an integer of 1 to n, and n is the number (pieces) of the measurement points in the circumferential direction); Tp is the temperature (°C) having a maximum value among Ti; Tave is the average temperature (°C) of Ti; and θw is the sum (rad) of the central angles of the adjacent intervals of the measurement points each other including Tp, the measurement points in which the difference (Ti - Tave) is 0.5°C or more.)

[0075] Step (I-3): Monitoring step in which the temperature distribution parameter (A) is monitored to prevent the parameter from exceeding a predetermined value.

[0076] Step (I-4): Condition adjustment step (1) in which the manufacturing conditions are adjusted to prevent the temperature distribution parameter (A) from exceeding a predetermined value.

[0077] Step (I-5): Condition adjustment step (2) in which the manufacturing conditions are adjusted to make the temperature distribution parameter (A) be a predetermined value or less when the temperature distribution parameter (A) exceeds a predetermined value.

[0078] [Step group (II)]

[0079] The step group (II) includes the following steps (II-1), (II-2), and (II-3). It can further include at least one selected from the group consisting of the following steps (II-4) and (II-5).

[0080] Step (II-1): a temperature measurement step in which a part of the temperature distribution in the circumferential direction of the cylindrical horizontal polymerization reactor is measured in a manner that the interval between adjacent measurement points is a central angle of π / 10 (rad) or less.

[0081] Step (II-2): a calculation step in which a temperature distribution parameter (As) defined by the following formula 2 is calculated from the temperature distribution obtained by the temperature measurement step.

[0082] As = Th s × θw s (Formula 2)

[0083] (wherein Th s = TP - Tref; Ti is the temperature (°C) of the i-th measurement point (wherein i is an integer of 1 to n, and n is the number (pieces) of the measurement points in the circumferential direction); TP is the temperature (°C) having a maximum value among Ti; Tref is a predetermined reference temperature (°C); θw s is the sum (rad) of the central angles of the adjacent intervals of the measurement points from each other, including the measurement point of TP, for which the difference (Ti - Tref) between Ti and Tref is above a predetermined temperature.)

[0084] Step (II-3): a monitoring step in which the temperature distribution parameter (As) is monitored so as not to exceed a predetermined value.

[0085] Step (II-4): a condition adjustment step (1'), in which the manufacturing conditions are adjusted so as not to exceed the predetermined value of the temperature distribution parameter (As).

[0086] Step (II-5): a condition adjustment step (2'), in which the manufacturing conditions are adjusted so as to make the temperature distribution parameter (As) be below the predetermined value when the temperature distribution parameter (As) exceeds the predetermined value.

[0087] <2> The method for producing a propylene-based polymer according to <1> described above, in which, in the temperature measurement step, the temperature distribution is measured at least in the circumferential direction of the catalyst supply part of the horizontal polymerization reactor.

[0088] <3> The method for producing a propylene-based polymer according to <1> or <2> described above, in which, in the temperature measurement step, the temperature distribution is measured on the outer surface of the horizontal polymerization reactor.

[0089] <4> According to the above <1> to <3> The method for producing a propylene-based polymer according to any one of the preceding claims, wherein in the temperature measurement step, the temperature distribution is measured so that the intervals between adjacent measurement points are within a range of 10 mm to 1000 mm.

[0090] <5> According to the above <1> to <4> The method for producing a propylene-based polymer according to any one of the preceding claims, wherein in the temperature measurement step, the temperatures measured at the measurement points in the circumferential direction are plotted to create a temperature curve, with the radial coordinate r representing the temperature and the angular coordinate θ representing the position of each measurement point in the circumferential direction in circular coordinates.

[0091] <6> According to the above <1> to <5> The method for producing a propylene-based polymer according to any one of the preceding claims, wherein the predetermined value is set within a range of 0π to 30π.

[0092] <7> According to the above <1> to <6> The method for producing a propylene-based polymer according to any one of the preceding claims, wherein the rotation frequency of the stirring mechanism is 5 rpm to 50 rpm.

[0093] <8> According to the above <1> to <7> The method for producing a propylene-based polymer according to any one of the preceding claims, wherein the temperature difference ΔT1 (°C) (=Tx-Tz) between the temperature (Tx) of the region including the catalyst supply portion of the horizontal polymerization reactor and the dew point (Tz) of the mixed gas in the reactor is 0°C to 3.0°C.

[0094] <9> According to the above <1> to <8> The method for producing a propylene-based polymer according to any one of the preceding claims, wherein the catalyst is a Ziegler polymerization catalyst or a metallocene polymerization catalyst.

[0095] <10> According to the above <1> to <9> The method for producing a propylene-based polymer according to any one of the preceding claims, wherein the produced propylene-based polymer has a melt flow rate (MFR) of 0.3 to 150 g / 10 min as measured at a temperature of 230° C. and a load of 2.16 kg.

[0096] Effects of the Invention

[0097] According to the production method of the present invention, in a continuous gas-phase polymerization method using a cylindrical horizontal polymerization reactor in which the heat of reaction is removed by the heat of vaporization of a liquid containing liquefied monomers, the formation of block polymers can be suppressed; excellent long-term operability can be achieved; improvement in production efficiency can be achieved; and propylene-based polymers can be stably produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] [ Figure 1 ] Figure 1This is a schematic explanatory diagram showing an example of the configuration of equipment used in the production method using a horizontal polymerization reactor of the present invention.

[0099] [ Figure 2 ] Figure 2 This is a schematic explanatory diagram showing another example of the configuration of the equipment used in the production method using the horizontal polymerization reactor of the present invention.

[0100] [ Figure 3 ] Figure 3 Schematic diagram showing temperature measurement points in the circumferential direction of a horizontal polymerization reactor.

[0101] [ Figure 4 ] Figure 4 This is a diagram showing a temperature curve (T) created by plotting the temperatures measured at the measurement points in the circumferential direction, with the radial coordinate r representing the temperature and the angular coordinate θ representing the position of each measurement point in the circumferential direction in circular coordinates.

[0102] [ Figure 5 ] Figure 5 This diagram shows a method for obtaining θw on a temperature curve (T) created by plotting the temperatures measured at the measurement points in the circumferential direction, with the radial coordinate r representing the temperature and the angular coordinate θ representing the position of each measurement point in the circumferential direction in circular coordinates. DETAILED DESCRIPTION

[0103] Hereinafter, the present invention will be described in detail. In this specification, "to (~)" showing a numerical range is used to describe that the numerical values ​​described before and after "to (~)" represent a range of lower and upper limits.

[0104] In addition, in this specification, the combination of the upper limit and the lower limit of the numerical range may be any combination. In addition, the preferred range of each property described in this specification may be any combination.

[0105] A first embodiment of the method for producing a propylene-based polymer of the present invention is a method for producing a propylene-based polymer as follows:

[0106] The method comprises a cylindrical horizontal polymerization reactor including a stirring mechanism rotating about a horizontal axis, wherein propylene or propylene and an α-olefin other than propylene are polymerized into a propylene-based polymer in the presence of a catalyst by a continuous gas phase polymerization process in which the heat of reaction is removed by utilizing the heat of vaporization of a liquid containing liquefied monomers. The catalyst is supplied from the upper portion of one end of the horizontal polymerization reactor, and the propylene-based polymer is discharged from the lower portion of the other end of the horizontal polymerization reactor.

[0107] The method comprises:

[0108] a temperature measuring step in which a temperature distribution in a circumferential direction of a cylindrical horizontal polymerization reactor is measured in a manner that an interval between adjacent measurement points is a central angle of π / 10 (rad) or less,

[0109] a calculating step in which a temperature distribution parameter (A) defined by the following formula 1 is calculated from the temperature distribution obtained by the temperature measuring step, and

[0110] a monitoring step in which the temperature distribution parameter (A) is monitored to prevent the parameter from exceeding a predetermined value; and

[0111] wherein the method optionally further comprises at least one selected from the group consisting of:

[0112] a condition adjusting step (1) in which a manufacturing condition is adjusted to prevent the temperature distribution parameter (A) from exceeding a predetermined value, and

[0113] a condition adjusting step (2) in which, when the temperature distribution parameter (A) exceeds a predetermined value, the manufacturing condition is adjusted to make the temperature distribution parameter (A) be a predetermined value or less:

[0114] A = Th x θw (Formula 1)

[0115] (wherein Th = Tp - Tave; Ti is a temperature (°C) of the i-th measurement point (wherein i is an integer of 1 to n, n is the number (pieces) of the measurement points in the circumferential direction); Tp is a temperature (°C) having a maximum value among Ti; Tave is an average temperature (°C) of Ti; θw is a sum (rad) of central angles of adjacent intervals of the measurement points each other including Tp, the measurement points whose difference (Ti - Tave) is 0.5°C or more.)

[0116] A second embodiment of the method for producing a propylene-based polymer of the present application is a method for producing a propylene-based polymer,

[0117] wherein a propylene-based polymer is polymerized from propylene or from propylene and an α-olefin other than propylene in the presence of a catalyst by a continuous gas phase polymerization method in which a reaction heat is removed by a gasification heat of a liquid containing a monomer to be liquefied, using a cylindrical horizontal polymerization reactor including a stirring mechanism rotating around a horizontal axis inside the reactor; the catalyst is supplied from an upper portion of one end portion of the horizontal polymerization reactor; and the propylene-based polymer is discharged from a lower portion of the other end portion of the horizontal polymerization reactor;

[0118] wherein the method comprises:

[0119] a temperature measuring step in which a part of a temperature distribution in a circumferential direction of a cylindrical horizontal polymerization reactor is measured in a manner that an interval between adjacent measurement points is a central angle of π / 10 (rad) or less,

[0120] a calculating step in which a temperature distribution parameter (As) defined by the following equation 2 is calculated from the temperature distribution obtained by the temperature measuring step, and

[0121] a monitoring step in which the temperature distribution parameter (As) is monitored to prevent the parameter from exceeding a predetermined value; and

[0122] wherein the method optionally further comprises at least one selected from the group consisting of:

[0123] a condition adjusting step (1'), in which manufacturing conditions are adjusted to prevent the temperature distribution parameter (As) from exceeding a predetermined value, and

[0124] a condition adjusting step (2'), in which manufacturing conditions are adjusted to make the temperature distribution parameter (As) be below a predetermined value when the temperature distribution parameter (As) exceeds the predetermined value:

[0125] As = Th s x θw s (Equation 2)

[0126] (wherein Th s = Tp - Tref; Ti is a temperature (°C) of the i-th measurement point (where i is an integer of 1 to n, and n is the number (pcs) of measurement points in the circumferential direction); Tp is a temperature (°C) having a maximum value among Ti; Tref is a predetermined reference temperature (°C); θw s is a sum (rad) of central angles of adjacent intervals of each other of measurement points including Tp, and having a difference (Ti - Tref) of Ti and Tref being above a predetermined temperature.)

[0127] Hereinafter, the present application will be described in detail. First, a method for producing a propylene-based polymer by a continuous gas phase polymerization method in which reaction heat is removed by gasification heat of a liquid containing a liquid monomer, using a cylindrical horizontal polymerization reactor including a stirring mechanism rotating around a horizontal axis inside the reactor, which is common to the first embodiment and the second embodiment, will be described. Next, a production management method including a monitoring step based on a specific temperature distribution parameter characteristic of the present application will be described.

[0128] 1. A monomer used for producing the propylene-based polymer of the present application.

[0129] The "α-olefin" polymerized with propylene in the present application is not particularly limited. It is preferable to use an olefin having 2 to 12 carbon atoms other than propylene, and it is particularly preferable to use an α-olefin having 2 to 12 carbon atoms.

[0130] Examples of the α-olefin other than propylene include, but are not limited to, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and 3-methyl-1-pentene. Among them, ethylene, 1-butene, or 4-methyl-1-pentene is more preferably used. These α-olefins can be used singly or in combination of two or more. The α-olefin other than propylene to be polymerized in the present application is also described as "other α-olefin" in the present specification.

[0131] 2. Catalyst

[0132] As the catalyst for olefin polymerization used in the present application, examples include (I) a polymerization catalyst composed of (1) a solid catalyst component containing titanium, magnesium, halogen, and an electron-donating compound as an internal donor as essential components, (2) an organoaluminum compound, and (3) an electron-donating compound as an external donor as needed, i.e., a Ziegler system polymerization catalyst.

[0133] A metallocene system polymerization catalyst composed of (1) a metallocene complex containing a transition metal compound, (2) a catalyst component containing a cocatalyst capable of activating the complex as an essential component, and (3) an organoaluminum compound as needed, i.e., (II) can also be used. The phrase "containing... as an essential component" means the following: elements other than the component can be contained; these elements can exist individually as any desired compound; and these elements can exist as one in which they are combined with each other.

[0134] As the catalyst for olefin polymerization used in the present application, a catalyst for olefin polymerization conventionally known can be used. For example, a catalyst for olefin polymerization described in Japanese Patent Application Publication No. 2011-148980, Japanese Patent Application Publication No. 2012-92275, Japanese Patent Application Publication No. 2011-153287, and Japanese Patent Application Publication No. 2017-95606 can be appropriately selected and used.

[0135] The catalyst for olefin polymerization usable in the present application is preferably the above-described Ziegler system catalyst or metallocene system catalyst. However, they are not limited thereto.

[0136] 3. Polymerization mode and polymerization reactor

[0137] In the present application, the production of a propylene-based polymer obtained by polymerizing propylene or propylene and other α-olefins is performed by a continuous gas phase polymerization method in which the reaction heat is removed by the gasification heat of a liquid containing a monomer to be liquefied, using a cylindrical horizontal polymerization reactor including a stirring mechanism rotating around a horizontal axis inside the reactor.

[0138] In the present invention, a gas-phase polymerization process does not necessarily mean the complete absence of any liquid. It is sufficient that the polymerization phase is essentially a gas phase, and liquid may be present unless it deviates from the main purpose of the present invention. Examples of liquids include, but are not limited to, liquefied propylene for heat removal and inactive hydrocarbon components such as hexane.

[0139] The polymerization reactor used in the present invention (hereinafter, it may sometimes be referred to as "reactor") depends on the raw materials used, reaction conditions, reaction mode, product, etc., and can be selected from any existing reactor and used without being restricted by size, material, etc., as long as it is suitable for the reaction. The shape is a cylindrical horizontal polymerization reactor with a cylindrical portion. Since the heat of gasification (latent heat of evaporation) of liquefied propylene is utilized for heat removal, the reactor is preferably equipped with a recycling device, which discharges a gas containing propylene from the reactor, cools the discharged gas to liquefy at least a portion thereof, and supplies at least a portion of the liquefied component to the reactor. In order to minimize the influence of heat dissipation or external temperature, the reactor is preferably heat-insulated. For example, the reactor can be heat-insulated by steam heating or by covering the reactor with a heat-insulating material. The heat-insulating material for the reactor can be selected from known heat-insulating materials. As such a material, examples include, but are not limited to, glass wool.

[0140] The size of the reactor can be appropriately selected according to the reaction mode. The volume is usually 0.1m 3 More than 150m 3 From the viewpoint of industrial productivity and economic efficiency, the volume is preferably 20m 3 From the viewpoint of industrial productivity and economic efficiency, the aspect ratio is preferably 2.0 or more and may be 5.0 or less.

[0141] In the polymerization method of the present invention, the catalyst is supplied from the upper portion of one end of the horizontal polymerization reactor, and the propylene-based polymer is discharged from the lower portion of the other end of the horizontal polymerization reactor.

[0142] The polymer particles polymerized in a horizontal polymerization reactor are formed in a stirred reactor and, as the polymerization proceeds, are transferred by stirring and moved along the reactor. Therefore, the polymerization reactor used in the present invention is a plug flow type, a feature not found in other polymerization reactors, and is a flow type in which multiple continuous stirred tanks are arranged in series. The horizontal polymerization reactor is economically advantageous because, in terms of aspect ratio, it can easily achieve a solid mixing degree equal to that of two, three or more reactors. In addition, since the polymerization reactor is horizontal, it is advantageous compared to a vertical reactor because the polymerization heat can be efficiently removed during the heat removal period.

[0143] Meanwhile, in the case of polymerization by a gas phase process using a horizontal polymerization reactor including a stirrer rotating around a horizontal axis inside the reactor, the amount of the block polymer increases due to abnormal reaction influenced by local heat generation and the like in the reactor; therefore, the amount of the fine powder tends to increase due to physical contact of the block polymer with the stirrer.

[0144] The production method of the propylene-based polymer of the present application has the following feature: by appropriately monitoring a temperature parameter and adjusting production conditions as described below, formation of the block polymer, and as a result, formation of the fine powder, can be suppressed, and therefore, stability of operation and productivity and the like can be improved.

[0145] As for the configuration of the reactor, any method can be used as long as the gist of the present application is not hindered. The number of reactors can be one or more. In the case of using two or more reactors, they can be connected in series, or they can be connected in parallel.

[0146] A preferred example is a reaction apparatus in which two to four reactors are connected in series. Particularly in the case of producing a block copolymer of propylene and another α-olefin, a configuration including at least two reactors connected in series is preferred. The method of configuring two or more reactors is not particularly limited. In the case of using a plurality of horizontal polymerization reactors including a stirrer rotating around a horizontal axis, the rotation axis of the stirrer of the upstream reactor is preferably configured at the same level or a higher level than the rotation axis of the stirrer of the downstream reactor, more preferably at a certain level higher than the rotation axis of the stirrer of the downstream reactor.

[0147] From the viewpoint of dispersibility of the catalyst and contact efficiency between the powder and the liquid containing the liquefied monomer, the rotation frequency of the stirring mechanism is preferably 5 rpm to 50 rpm, more preferably 10 rpm to 30 rpm.

[0148] By a method of providing a weir for limiting transfer of the powder inside the reactor, the residence time distribution of the powder can be narrowed without increasing the number of reactors. The weir can be in the form of a fixed weir fixed to the reactor, or in the form of a rotating weir fixed to the rotation axis. Depending on the production amount, the residence time can be changed as needed.

[0149] As a heat removal method using the gasification heat of the liquid containing the liquefied monomer, any method can be used.

[0150] For heat removal using the gasification heat of the liquid containing the liquefied monomer, it is sufficient to supply a liquid containing the liquefied monomer (including liquefied propylene) and other components and being in a substantially liquid state to the reactor. Although fresh liquefied monomer can be supplied to the reactor, it is generally desirable to use a recycled monomer. A commonly used procedure using a recycled monomer is exemplified below.

[0151] Unreacted gas containing propylene is discharged from the reactor; the discharged unreacted gas is cooled to liquefy at least a part thereof; and at least a part of the liquefied component is supplied to the reactor. At this time, propylene should be contained in the component to be liquefied. However, it can contain a comonomer component represented by ethylene and an inactive hydrocarbon component such as isobutane and hexane.

[0152] In the present application, removal of reaction heat by using the gasification heat of the liquid containing the liquefied monomer does not mean that the heat removal is performed by using only the gasification heat of the liquid containing the liquefied monomer. Other heat removal methods can be used in combination, unless the gist of the present application is departed from. As the method, examples include, but are not limited to, a heat removal method using a reactor equipped with a jacket, a heat removal method in which a part of the gas is discharged from the reactor, the discharged gas is cooled by a heat exchanger, and the cooled gas is returned to the reactor again. However, in the present application, it is required that the heat removal is mainly achieved by using the gasification heat of the liquid containing the liquefied monomer. More specifically, it can be a heat removal in which at least half of the amount of heat to be removed is removed by using the gasification heat of the liquid containing the liquefied monomer in at least one reactor.

[0153] Figure 1 is a schematic explanatory view showing one example of the configuration of an apparatus used in the production method of the present application using a horizontal polymerization reactor. The horizontal polymerization reactor 10 is an elongated reactor, and includes partition walls 10a and 10b. As shown in Figure 1 , the reactor is generally disposed in a horizontal position. The polymerization reaction is performed in a space formed between the partition walls 10a and 10b in the horizontal polymerization reactor 10. In Figure 1 , the partition wall 10a as the upstream-side partition wall is the upstream-side end 12 of the reactor, and the partition wall 10b as the downstream-side partition wall is the downstream-side end 14 of the reactor. Although not shown in the drawing, in the case where the partition walls are in a curved form, the top of the curved upstream-side partition wall and the top of the curved downstream-side partition wall are the upstream-side end and the downstream-side end of the reactor, respectively.

[0154] The horizontal shaft 20a of the stirrer 20 extends into the downstream-side end 14 of the reactor of the horizontal polymerization reactor 10, and a plurality of stirring blades 20b for stirring are fitted in the horizontal polymerization reactor 10. In the horizontal polymerization reactor 10, the stirring blades 20b mix the polymer particles with other substances introduced into the reactor.

[0155] The catalyst components are supplied from the catalyst component supply pipes 1 and 2 of the horizontal polymerization reactor 10, and the supplied catalyst components start polymerization while being mixed with the polymer particles by the stirring blade 20b. The catalyst component supply pipes 1 and 2 can be provided at any position as long as the catalyst is supplied from the upper portion of the end portion of the horizontal polymerization reactor so that the temperature of the region section including the catalyst supply portion can be measured in the positional relationship between the thermometer and the quenching nozzle, and the catalyst supplied into the reactor can be mixed with the liquid containing the liquidized monomer. This is because once the catalyst components are added to the upstream portion of the reactor, they can move to the downstream portion of the reactor while growing into polymer particles by polymerization.

[0156] The polymerization catalyst and other optional components of the present application can be supplied into the horizontal polymerization reactor using known methods. The polymerization catalyst can be supplied into the reactor as it is in powder form, or can be supplied after being diluted with a non-active solvent such as a liquid saturated hydrocarbon or mineral oil.

[0157] In addition, other components constituting the polymerization catalyst such as an organic aluminum compound can be supplied as a component contained in the catalyst after being brought into contact with the Ziegler system solid catalyst component or the metallocene complex component, or it can be supplied separately from these components.

[0158] The catalyst component supply pipe 1 can be a pipe for supplying a main component of the catalyst, for example, a solid catalyst component including the Ziegler system solid catalyst component or the metallocene complex, and other polymerization catalyst components. When the distance between the partitions 10a and 10b is represented as L, and the position of the partition 10a and the position of the partition 10b are represented as 0(L) and 1L, respectively, in the direction from the partition 10a to the partition 10b, the catalyst component supply pipe 1 is preferably provided in a range of 1 / 9L or more and 2 / 9L or less from the partition 10a. When the catalyst component supply pipe 1 is located at a position of 1 / 9L or more from the partition 10a, the catalyst is less likely to adhere to the inner wall of the reactor; the formation of aggregates or bulk polymers can be suppressed; and enhanced operation stability can be obtained. When the catalyst component supply pipe 1 is located at a position of 2 / 9L or less from the partition 10a, the residence time of the catalyst in the reactor is not too short, and a decrease in activity can be suppressed, and thus this case is economically advantageous.

[0159] Therefore, in the present application, when the distance between the partitions 10a and 10b is represented as L, and the position of the partition 10a and the position of the partition 10b are represented as 0(L) and 1L, respectively, in the direction from the partition 10a to the partition 10b, the catalyst supply portion for supplying the catalyst from the upper portion of the end portion of the horizontal polymerization reactor can be configured in a range of 1 / 9L or more and 2 / 9L or less from the partition 10a.

[0160] The catalyst component supply pipe 2 can be a pipe for supplying a cocatalyst, an organic aluminum compound, and other polymerization catalyst components. When the distance between the partitions 10a and 10b is represented as L, the catalyst component supply pipe 2 can be disposed in a range of 0 (L) or more and 2 / 9 L or less from the partition 10a. The catalyst component supply pipe 2 is preferably disposed at the same distance from the partition 10a as the catalyst component supply pipe 1 or on the upstream side thereof.

[0161] As needed, each of the catalyst component supply pipes 1 and 2 can be a single line, or a plurality of pipes in the above range can be used as each of the catalyst component supply pipes 1 and 2. The catalyst component supply pipe 1 can also serve as the catalyst component supply pipe 2.

[0162] The polymerization heat generated during polymerization is removed by the gasification heat of the liquidized monomer-containing liquid including the raw material liquidized propylene supplied from the liquidized monomer-containing liquid supply pipe 19.

[0163] The liquidized monomer-containing liquid introduced from the liquidized monomer-containing liquid supply pipe 19 into the horizontal polymerization reactor 10 is polymerized while being mixed with the catalyst components and the polymer particles by the stirring blade 20b.

[0164] As a method of supplying the liquidized monomer-containing liquid used at the time of heat removal, any method can be used as long as it is a method of supplying the liquidized monomer-containing liquid in a substantially liquid state into the reactor. Since the catalyst supply portion is present in the upper portion of the reactor, it is preferable to supply the liquidized monomer-containing liquid from the upper portion of the reactor to the gas phase portion inside the reactor. When both the catalyst supply portion and the liquidized monomer supply pipe are present in the upper portion of the reactor, the liquidized monomer is well dispersed. Furthermore, since the powder does not come into direct contact with the pipe, it is possible to suppress the adhesion of the polymer to the catalyst supply portion and the liquidized monomer supply pipe.

[0165] In particular, in the region section including the catalyst supply portion, the liquidized monomer-containing liquid is preferably supplied at least at one site, and when the distance between the partitions 10a and 10b is L, the position of the site is preferably in a range of 0 (L) or more and 2 / 9 L or less from the partition 10a.

[0166] In addition, in the region section including the catalyst supply portion, the site of supply of the liquidized monomer-containing liquid is particularly preferably disposed at the same distance from the partition 10a as the catalyst component supply pipe 1 or on the upstream side thereof.

[0167] In addition, in the region section including the catalyst supply portion, the liquidized monomer-containing liquid can be supplied at a plurality of sites.

[0168] The unreacted gas is discharged from the unreacted gas discharge pipe 13 to the outside of the reaction system, a part of which is condensed at the condenser 15, and separated into a liquid phase and a gas phase in the recirculation drum 11. The liquid phase portion is reintroduced into the liquid monomer containing liquid supply pipe 19 to perform polymerization heat removal. The gas phase portion is mixed with hydrogen for molecular weight adjustment supplied from the pipe 4, and other α-olefins, etc., pressurized by the compressor 16, and supplied again through the raw material mixed gas supply pipe 18 located at the bottom of the horizontal polymerization reactor 10.

[0169] At this time, the flow rate of the liquid monomer containing liquid from the liquid monomer containing liquid supply pipes 19-1, 19-2, 19-3, 19-4, and 19-5 arranged at specific intervals in the upper portion, and the flow rate of the temperature controlled mixed gas from the raw material mixed gas supply pipes 18-1, 18-2, 18-3, 18-4, and 18-5 arranged at specific intervals in the lower portion can be controlled separately. These flow rates are controlled by the operation valves provided at the liquid monomer containing liquid supply pipes and the raw material mixed gas supply pipes.

[0170] The polymer particles, as the reaction and mixing proceed, are transferred from the upstream portion to the downstream portion in the polymerization tank, and then they are discharged to the outside of the reaction system through the polymer discharge pipe 21. From the discharged powder, each gas is separated by the gas recovery machine 22, and the polymer particles are recovered by the powder recovery machine 23.

[0171] For the horizontal polymerization reactor of the present application, a plurality of zone sections having different temperatures in the horizontal axis direction can be provided inside thereof. When a plurality of zone sections having different temperatures in the horizontal axis direction are provided inside the reactor, among these zone sections, the zone section including the catalyst supply portion is the zone section including the catalyst component supply pipe. When a plurality of catalyst component supply pipes are present, the zone section including the catalyst supply portion is the zone section including the catalyst component supply pipe for supplying the main component of the catalyst, i.e., the zone section including the catalyst component supply pipe 1 as shown in Figure 1 The polymerization temperature of each zone section is obtained by measuring the temperature of the polymer particles stirred by the stirrer using the thermometer provided inside the reactor in each zone section. That is, the polymerization temperature of each zone section is the temperature of the polymer particles in that zone section. It is considered that the temperature of the polymer particles stirred by the stirrer rotating around the horizontal axis is the average value in the zone section around the horizontal axis.

[0172] Next, the method for measuring the temperature (Tx) of the polymer particles in the zone section including the catalyst supply portion of the horizontal polymerization reactor will be described in detail with reference to Figure 2 Figure 2 ​As shown, the temperature (Tx) of the polymer particles in the region section (Z1) including the catalyst supply part is detected by the thermometers 34-1 and 34-2 disposed in the region section (Z1) including the catalyst supply part. The thermometers can also be the thermometers for measuring the temperature distribution described below, or they can be thermometers disposed separately from the thermometers for measuring the temperature distribution. The thermometers 34-1 and 34-2 disposed in the region section (Z1) including the catalyst supply part are suitably disposed in the vicinity of the catalyst component supply pipe 31 in a manner capable of measuring the temperature of the polymer particles in the vicinity of the catalyst component supply pipe 31 for supplying the main component of the catalyst. When x0, x1, x2, and L are the intersection of the perpendicular line from the catalyst component supply pipe 31 to the horizontal axis 35 and the horizontal axis 35, the intersection of the perpendicular line from the thermometer 34-1 to the horizontal axis 35 and the horizontal axis 35, the intersection of the perpendicular line from the thermometer 34-2 to the horizontal axis 35 and the horizontal axis 35, and the distance between the upstream side partition wall 32 and the downstream side partition wall 33, respectively, the distance between the intersections x0 and x1 and the distance between the intersections x0 and x2 are each preferably in the range of 0 to 1 / 9 L, more preferably in the range of 0 to 1 / 12 L, and still more preferably in the range of 0 to 1 / 15 L. Once the thermometers are disposed in the above range, the polymerization temperature of the catalyst supply part is represented by the polymer being stirred. Therefore, the number of the thermometers for measuring the temperature (Tx) of the polymer particles in the region section including the catalyst supply part can be one. With the thermometers 34-1 and 34-2 shown, at least one thermometer is preferably disposed on both the upstream side and the downstream side of the catalyst component supply pipe 31, like the thermometers disposed in the region section including the catalyst supply part. When the temperatures of the thermometers 34-1 and 34-2 disposed on the upstream side and the downstream side of the catalyst component supply pipe 31 are equal, it is considered that at least the region section sandwiched between the thermometers 34-1 and 34-2 is the region section including the catalyst supply part, and it is considered that the temperature of the thermometers 34-1 and 34-2 represents the temperature (Tx) of the polymer particles in the region section including the catalyst supply part. Figure 2 With the thermometers 34-1 and 34-2 shown, at least one thermometer is preferably disposed on both the upstream side and the downstream side of the catalyst component supply pipe 31, like the thermometers disposed in the region section including the catalyst supply part. When the temperatures of the thermometers 34-1 and 34-2 disposed on the upstream side and the downstream side of the catalyst component supply pipe 31 are equal, it is considered that at least the region section sandwiched between the thermometers 34-1 and 34-2 is the region section including the catalyst supply part, and it is considered that the temperature of the thermometers 34-1 and 34-2 represents the temperature (Tx) of the polymer particles in the region section including the catalyst supply part.

[0173] In the case where two or more thermometers are used to measure the temperature (Tx) of the polymer particles in the region section including the catalyst supply part, when the distance between the partition walls 32 and 33 is represented as L, and the positions of the partition walls 32 and 33 on the horizontal axis 35 in the direction from the partition wall 32 to the partition wall 33 are represented as 0(L) and 1L, respectively, at least one thermometer 34-1 is preferably disposed between the position of 0(L) and the position of x0, and more preferably between the position of 1 / 9 L and the position of x0. Further, at least one thermometer 34-2 is preferably disposed between the position of x0 and the position of 1 / 3 L, and more preferably between the position of x0 and the position of 2 / 9 L.

[0174] When the thermometers 34-1 and 34-2 are disposed within the above range, the polymerization temperature of the catalyst supply section is more accurately represented by the stirred polymer.

[0175] When a plurality of region sections having different temperatures in the horizontal axis direction are not disposed inside the reactor and the temperature inside the reactor is constant, the thermometers 34-1 and 34-2 can be disposed at any position.

[0176] In the steady state operation, a polymer bed is formed in the entire horizontal polymerization reactor, and the polymerization reaction is performed in all regions.

[0177] The polymerization conditions such as pressure, residence time and temperature can be set as needed, unless they deviate from the gist of the present application.

[0178] More specifically, the polymerization pressure is preferably 1,200 kPaG or more, more preferably 1,400 kPaG or more, and particularly preferably 1,600 kPaG or more. On the other hand, it is preferably 4,200 kPaG or less, more preferably 3,500 kPaG or less, and particularly preferably 3,000 kPaG or less. Since the gas phase is usually circulated in the horizontal polymerization reactor, the polymerization pressure in the same reactor is kept constant. Further, the physical separation can be performed by the weir-shaped article disposed in the reactor.

[0179] The residence time can be adjusted as needed depending on the configuration of the reactor and the target polymer. Generally, the residence time is set in the range of 30 minutes to 5 hours.

[0180] The polymerization temperature is preferably 0°C or more, more preferably 30°C or more, and particularly preferably 40°C or more. On the other hand, it is preferably 100°C or less, more preferably 90°C or less, and particularly preferably 80°C or less.

[0181] In the present application, from the viewpoint of suppressing the formation of massive polymer, achieving improvement in manufacturing efficiency and stably manufacturing propylene-based polymers, the temperature (Tx) of the region section including the catalyst supply section is preferably set to 50°C or more and 65°C or less, and more preferably set to 55°C or more and 65°C or less.

[0182] Inside the horizontal polymerization reactor used in the present application, a plurality of region sections having different temperatures in the horizontal axis direction can be set. In the present application, the region section does not indicate a physical region section using a weir. It indicates a region section in which temperature control is performed.

[0183] Reference Signs List Figure 2An example of temperature control performed in a horizontal polymerization reactor is described in detail. The horizontal polymerization reactor 30 is an exemplary horizontal polymerization reactor that includes partition walls 32 and 33 and divides the region into i number of sections of Z1 to Zi. The partition wall 32, which is an upstream-side end of the reactor, is a partition wall on the upstream side, and the partition wall 33, which is a downstream-side end of the reactor, is a partition wall on the downstream side. In Figure 2 , the section Z1 is a region section including the upstream-side end, and the section Zi is a region section including the downstream-side end. In Figure 2 , the catalyst component is supplied from the catalyst component supply pipe 31 of the reactor. The region section including the catalyst supply part is the section Z1. In Figure 2 , the stirrer is omitted.

[0184] The reaction heat generated during polymerization is removed by the gasification heat of the liquid containing the liquefied monomer supplied from the liquid containing the liquefied monomer supply pipe. The polymerization temperature of each region section is detected by the thermometers 34-1, 34-2, 34-3, 34-4,..., and 34-i provided in each region section.

[0185] In the present application, with respect to the polymerization temperature inside the reactor, the reactor temperature Ti of each region section (Zi) can be individually controlled at different temperatures by the thermometer provided inside the reactor.

[0186] The polymerization temperature of each region section can be individually controlled by the combination of the flow rate of the liquid containing the liquefied monomer from the liquid containing the liquefied monomer supply pipe arranged at a specific interval in the upper portion and the flow rate of the temperature-controlled mixed gas from the raw material mixed gas supply pipe arranged at a specific interval in the lower portion.

[0187] The same reaction conditions are generally used in a single polymerization reactor. However, in the present application, it is preferable to divide the reactor from the upstream to the downstream direction into i (i is a desired integer of 2 or more) number of region sections in a manner that the reaction temperature Tn of the n-th (n is an integer of 1 or more and (i-1) or less) region section (n) from the upstream end to the downstream end of the horizontal polymerization reactor of the present application and the reaction temperature Tn+1 of the region section (n+1) adjacent to the downstream side thereof satisfy Tn≤Tn+1. Therefore, the polymerization temperature can be controlled in accordance with the polymerization performance of the catalyst, and it is effective for the suppression of the formation of a massive polymer due to insufficient heat removal caused by local heat generation or the like.

[0188] In this case, thermometers can be provided as needed depending on the reactor volume and the reaction mode. However, they are preferably at least controlled for the upstream, middle, and downstream portions (corresponding to i = 3) of the inside of the reactor. When the distance between the partitions 32 and 33 is represented as L, and the positions of the partitions 32 and 33 on the horizontal axis 35 in the direction from the partition 32 to the partition 33 are represented as 0(L) and 1L, respectively, at least one thermometer is preferably provided at each position between 0(L) and 1 / 3L, between 1 / 3L and 2 / 3L, and between 2 / 3L and 3 / 3L, i.e., preferably more than three thermometers are provided. That is, the number of the zone sections i is preferably three or more. The thermometers for measuring the temperature of the polymer particles in each zone section can also serve as the thermometers for measuring the temperature distribution in the circumferential direction of the reactor described below, or they can be thermometers provided separately from the thermometers for measuring the temperature distribution.

[0189] In the present application, from the viewpoint of obtaining the effect of improving productivity accompanying the temperature rise in the downstream portion of the reactor, the temperature difference ΔT2 (°C) (= Tω - Tα) between the temperature (Tα) of the zone section including the upstream end and the temperature (Tω) of the zone section including the downstream end in the reactor is preferably 0.1°C or more and 20°C or less. When ΔT2 exceeds 20°C, a large temperature change occurs in a single reactor, and it is possible that a change in the polymer composition will be caused.

[0190] In the present application, the temperature (Tα) of the zone section including the upstream end and the temperature (Tω) of the zone section including the downstream end in the reactor are the temperature of the most upstream zone section and the temperature of the most downstream zone section thereof, respectively. They are the temperatures of the polymer particles in each zone section.

[0191] Each thermometer is preferably provided at a position in the range of 1 / 9L to 2 / 9L from the upstream end of each zone section of the horizontal axis 35.

[0192] Further, in the present application, the temperature difference ΔT1 (°C) (= Tx - Tz) between the temperature (Tx) of the zone including the catalyst supply portion and the dew point (Tz) of the mixed gas in the reactor is preferably in the range of 0°C to 5.0°C, more preferably in the range of 0°C to 3.0°C.

[0193] The lower limit value of ΔΤ1 is more preferably 0.5°C or higher, still more preferably 1.0°C or higher, and even more preferably 1.5°C or higher. The upper limit value is more preferably 4.0°C or lower, and still more preferably 3.0°C or lower. When the temperature difference ΔΤ1 is lower than the lower limit value, since the polymerization temperature and the dew point of the mixed gas in the reactor are too close, there is a possibility that the polymerization gas condenses in the reactor, so that the target reaction pressure cannot be maintained. When the temperature difference ΔΤ1 exceeds the upper limit value, after the liquid containing the liquefied monomer is vaporized, the heat removal amount increases by sensible heat, and the heat removal amount per unit volume of the liquid containing the liquefied monomer increases. Therefore, the amount of the liquid containing the liquefied monomer decreases, and the formation of a lump polymer can occur due to the melting of the polymer formed by local heating due to insufficient heat removal, and the like. In addition, particularly when the temperature difference ΔΤ exceeds the upper limit value by making the polymerization temperature too high, in addition to the above reasons, the amount of entrainment increases because the powder form deteriorates due to the rapid reaction and the powder is likely to be pulverized by the stirring and the gas fluidization, and particularly because the formation of fine powder increases due to the pulverization of the powder during the stirring.

[0194] The dew point (Tz) of the mixed gas in the reactor can be calculated using the analysis result value of the mixed gas by gas chromatography according to the method described in the Chemical Engineering Handbook (Kagaku Kogaku Binran), revised 5th edition (published by Maruzen Co., Ltd.; page 485).

[0195] In the present application, the amount of entrainment means the amount of particles that are transported to the outside of the reactor together with the gas through the unreacted gas discharge piping provided on the upper tank wall (may also be the side or the bottom) of the reactor. For example, the amount of entrainment (g / kg) can be specifically measured by weighing the amount of fine powder removed by a fine particle removal device (such as a cyclone or a bag filter) provided in front of the condenser and dividing the amount by the production amount.

[0196] The amount of entrainment is preferably 0.10 g / kg or lower at the time of production of the propylene-based polymer.

[0197] When the value is high, there is a possibility that the load and adhesion to the gas discharge piping system increase due to the increase in the amount of entrainment, or the gas condensation capacity decreases due to the inflow of fine powder into the condenser.

[0198] 4. Monitoring method of temperature distribution parameter

[0199] 4-1. First embodiment [step group (I)]

[0200] In the first embodiment of the production method of the propylene-based polymer of the present application, the method includes:

[0201] a temperature measuring step of measuring the temperature distribution in the circumferential direction of the cylindrical horizontal polymerization reactor in such a manner that the interval between adjacent measurement points is π / 10 (rad) or less at the central angle,

[0202] a calculating step of calculating a temperature distribution parameter (A) defined by the following formula 1 from the temperature distribution obtained by the temperature measuring step, and

[0203] A monitoring step, wherein the temperature distribution parameter (A) is monitored to prevent the parameter from exceeding a predetermined value:

[0204] A = Th × θw (Equation 1)

[0205] (Where Th = Tp - Tave; Ti is the temperature (°C) at the i-th measurement point (where i is an integer from 1 to n, and n is the number of measurement points in the circumferential direction); Tp is the temperature (°C) with the maximum value among Ti; Tave is the average temperature (°C) of Ti; θw is the sum (rad) of the central angles between adjacent measurement points including the measurement point Tp and the measurement points where the difference between Ti and Tave (Ti - Tave) is 0.5°C or greater.)

[0206] The method optionally further comprises at least one selected from the group consisting of:

[0207] a condition adjustment step (1), wherein the manufacturing conditions are adjusted to prevent the temperature distribution parameter (A) from exceeding a predetermined value, and

[0208] Condition adjustment step (2), wherein when the temperature distribution parameter (A) exceeds a predetermined value, the manufacturing conditions are adjusted so that the temperature distribution parameter (A) is below the predetermined value.

[0209] 4-1-1. Temperature measurement procedure (step (I-1))

[0210] In the temperature measuring step, the temperature distribution in the circumferential direction of the cylindrical horizontal polymerization reactor is measured in such a manner that the interval between adjacent measurement points is a central angle of π / 10 (rad) or less.

[0211] As described above, by arranging a plurality of thermometers in the circumferential direction for measuring the temperature (Tx) of polymer particles within the reactor, the temperature distribution in the circumferential direction of a horizontal polymerization reactor can be measured. From the perspective of reducing installation costs compared to installing new thermometers inside an existing reactor, it is preferable to measure the temperature distribution on the outer surface of the horizontal polymerization reactor.

[0212] As a means for measuring the temperature distribution, for example, a contact temperature sensor (e.g., a thermocouple thermometer, an optical fiber thermometer) or a non-contact temperature sensor (e.g., a thermal imager) can be used. Contact sensors are preferred because they can monitor the temperature distribution with high precision. An optical fiber thermometer is more preferably used to measure the temperature distribution in contact with the outer surface of the reactor because it can monitor the temperature distribution over a wide area with high precision.

[0213] Examples of the structure of the optical fiber thermometer include, but are not limited to, a structure including a light emitter and a mechanism for converting light into temperature. The temperature detection portion of the optical fiber thermometer is preferably arranged to contact the outer surface of the reactor.

[0214] The temperature distribution measurement means should be arranged such that the temperature detection portions are arranged at specific intervals around the reactor where the temperature measurement is performed. When using fiber optic thermometers as the temperature distribution measurement means, the fiber optic thermometers should be arranged such that the temperature detection portions are arranged at specific intervals around the reactor where the temperature measurement is performed. For example, when the intervals between the temperature detection portions of the fiber optic thermometers are larger than the temperature distribution measurement interval in the circumferential direction of the reactor, the fiber optic thermometers may be arranged in a zigzag pattern such that the temperature detection portions are arranged at specific measurement intervals around the reactor.

[0215] Figure 3 Schematic diagram showing temperature measurement points in the circumferential direction of a horizontal polymerization reactor. Figure 3 Corresponding to Figure 1 The cross section of the horizontal polymerization reactor 10 is shown, which is formed when the reactor 10 is cut perpendicularly to the horizontal axis 20a of the stirrer 20 at a position where the temperature distribution in the circumferential direction needs to be measured.

[0216] like Figure 3 As shown, each of the temperature distribution measurement intervals in the circumferential direction of the horizontal polymerization reactor can be represented by a central angle θ equivalent to the length of the arc between the measurement points (e.g., P1 and P2). In order to accurately detect the correlation between the specific temperature parameter described below and the formation of bulk polymers, the temperature distribution is measured in such a way that the interval between adjacent measurement points is a central angle of π / 10 (rad) or less. The interval between adjacent measurement points can be a central angle of π / 18 (rad) or less; it can be a central angle of π / 24 (rad) or less; or it can be a central angle of π / 32 (rad) or less. The lower limit value of the interval between adjacent measurement points is not particularly limited and can be a central angle of π / 150 (rad) or more.

[0217] In order to accurately detect the correlation between the specific temperature parameters described below and the formation of bulk polymers, the distance between the temperature detection parts as the temperature distribution measurement interval in the circumferential direction of the horizontal polymerization reactor can be in the range of 10 mm to 1000 mm, in the range of 10 mm to 500 mm, or in the range of 10 mm to 150 mm.

[0218] The temperature measuring step may be performed in the catalyst supply portion or in a desired portion downstream of the catalyst supply portion.

[0219] In the temperature measuring step, it is preferred to measure the temperature distribution at least in the circumferential direction of the catalyst supply portion of the horizontal polymerization reactor because the effect of suppressing the formation of bulk polymers is improved and the effect of improving long-term operability is high.

[0220] As mentioned above, when Figure 1 The distance between the partition walls 10a and 10b shown is represented as L, and in the direction from the partition wall 10a to the partition wall 10b, the position of the partition wall 10a and the position of the partition wall 10b are represented as 0 (L) and 1L respectively, the catalyst supply part for temperature distribution measurement refers to the part within the range of more than 1 / 9L and less than 2 / 9L away from the partition wall 10a.

[0221] A preferred temperature distribution measurement position of the catalyst supply section is located downstream of the position where the catalyst component supply pipe 1 is installed, and is within a range of 2 / 9 L or less from the position where the catalyst component supply pipe 1 is installed.

[0222] In the temperature measurement step, in order to calculate and monitor the specific temperature distribution parameters described below, it is preferred to Figure 4 As shown, in circular coordinates, the radial coordinate r is the temperature and the angular coordinate θ is the position of each measurement point in the circumferential direction. The temperatures measured at the measurement points in the circumferential direction are plotted to create a temperature curve (T). For example, Figure 4 The results of temperature measurement along the periphery of the horizontal polymerization reactor are shown, starting from the apex 0 (0π) of the reactor to 2π in the direction of rotation (Dr) of the stirrer.

[0223] By creating such a temperature curve as a result of temperature distribution measurement, the extent and location of abnormal temperatures can be visualized in real time. This makes it easy to monitor and appropriately adjust manufacturing operating conditions based on the extent and location of abnormal temperatures. By setting a predetermined temperature distribution parameter value to be monitored, it is sufficient to change operating conditions to keep the temperature distribution parameter below that value, allowing for efficient changes in operating conditions.

[0224] 4-1-2. Calculation steps (step (I-2))

[0225] In the calculation step, from the temperature distribution obtained by the temperature measurement step, a temperature distribution parameter (A) defined by the following formula 1 is calculated:

[0226] A = Th x Qw (Formula 1)

[0227] (where Th = Tp - Tave; Ti is the temperature (°C) of the i-th measurement point (where i is an integer from 1 to n, and n is the number (pieces) of measurement points in the circumferential direction); Tp is the temperature (°C) having a maximum value among Ti; Tave is the average temperature (°C) of Ti; Qw is the sum (rad) of the central angles of the adjacent intervals of each other of the measurement points including Tp, for which the difference (Ti - Tave) is 0.5°C or more.)

[0228] As shown in FIG. 1, when there is one peak in the temperature distribution of the measurement points obtained by the temperature measurement step, Tp corresponds to the highest temperature among Ti. Figure 4

[0229] The average temperature (°C) of Ti is calculated as Tave, and the difference between Tp and Tave is calculated as Th.

[0230] Figure 5 is a diagram showing a method of obtaining Qw on a temperature curve (T) in which the temperatures measured at the measurement points in the circumferential direction are plotted with the radial coordinate r as the temperature and the angular coordinate Q as the position of each measurement point in the circumferential direction. As shown in FIG. 2, the sum Qw (rad) of the central angles of the adjacent intervals of each other of the measurement points for which the difference (Ti - Tave) is 0.5°C or more can be obtained as the sum of the central angles of the adjacent intervals of each other of the measurement points including Tp, which are in the range of Tave + 0.5°C or more. Figure 5

[0231] Using the obtained Th and Qw, the temperature distribution parameter (A) is calculated by the formula A = Th x Qw.

[0232] For example, there can be a case where there are two peaks (not shown) in the temperature distribution of the measurement points obtained by the temperature measurement step, i.e., there is another temperature having a maximum value Tp2 of the measurement points not included in the sum (Qw1) of the central angles of the adjacent measurement points in the range of Tave + 0.5°C or more and including Tp1 (the highest temperature among Ti). In this case, the difference between Tp2 and Tave is calculated as Th2 of the other temperature having a maximum value Tp2. Then, Qw2 is obtained as the sum of the central angles of the adjacent measurement points in the range of Tave + 0.5°C or more and including the measurement point having Tp2. ​​

[0233] For the peak of Tp1, using the obtained Th1 and θw1, the temperature distribution parameter Al is calculated by the formula A = Th x θw. For the peak of Tp2, using the obtained Th2 and θw2, the temperature distribution parameter A2 is calculated in the same manner as described above.

[0234] Even in the case where three or more peaks are present in the temperature distribution of the measurement points obtained by the temperature measurement step, the temperature distribution parameters Al, A2 and A3, etc. of the three or more peaks can be calculated in the same manner as described above.

[0235] The calculation step can be performed by computer processing.

[0236] The computer processing is not particularly limited, and a conventionally known processing method can be appropriately selected and used.

[0237] In the present application, in particular, by monitoring the temperature distribution parameter A determined by the formula 1 (A = Th x θw) as an index, the correlation with the formation of the lump polymer is easily obtained compared to the case where the temperature distribution is simply monitored; the operating conditions can be changed toward the safe (toward the suppression of the formation of the lump polymer) direction without depending on the feeling or experience of the operator in charge of the production; and the formation of the lump polymer can be effectively suppressed.

[0238] 4-1-3. Monitoring step (step (I-3))

[0239] In the monitoring step, the temperature distribution parameter (A) is monitored to prevent the parameter from exceeding a predetermined value.

[0240] In this step, the predetermined value is an upper limit value acceptable for suppressing the formation of the lump polymer. The predetermined value can be set in advance, or can be set according to the production variety of the propylene polymer.

[0241] The production variety means the category of the propylene polymer having predetermined properties specified by the kind of catalyst, performance (e.g., MFR) and the formulation of additives.

[0242] The problem occurring inside the reactor during the production, such as the formation of a large amount of the lump polymer, can be suppressed by monitoring the temperature distribution parameter (A) to prevent the parameter from exceeding a predetermined value.

[0243] The predetermined value for monitoring the temperature distribution parameter (A) can be appropriately determined from the viewpoint of the correlation between the temperature distribution parameter (A) and the occurrence state of the adverse situation, the viewpoint of whether the production can be continued, and the viewpoint of the value of the product, etc. in the production of each propylene polymer production variety.

[0244] For example, the predetermined value of the temperature distribution parameter (A) can be set to 20π at an MFR of 70 (g / 10 min), or it can be set to 10π at an MFR of 0.7 (g / 10 min).

[0245] The predetermined value of the temperature distribution parameter (A) is not particularly limited. The predetermined value is preferably set within a range of 0π to 30π regardless of the manufactured product. The lower limit value of the predetermined value can be 5π or more, or it can be 10π or more. On the other hand, the upper limit value can be 25π or less, or it can be 20π or less.

[0246] In the same manufactured product, depending on the operating conditions of the previous manufactured product, the season, the weather, the length of the continuous manufacturing time, the batch, and the like, there can be a case where the temperature distribution parameter (A) does not change much during the continuous operation and does not exceed the predetermined value. In such a case, it is sufficient to monitor the temperature distribution parameter (A) so as not to exceed the predetermined value during the continuous operation of the polymerization.

[0247] The monitoring method can be, for example, checking the calculated value of the temperature distribution parameter (A) so as not to exceed the predetermined value set in advance, and drawing a temperature profile (T) by measuring the temperatures at the measurement points in the circumferential direction as shown in Figure 4

[0248] When there are two or more peaks in the temperature distribution of the measurement points obtained by the temperature measurement step, for example, in the case where there are three peaks in the temperature distribution, the predetermined values set for the temperature distribution parameters Al, A2, and A3 of the three peaks can be the same or different.

[0249] The timing of the monitoring can be any timing, for example, every 30 minutes, every 1 hour, and every 4 hours.

[0250] For example, when the manufactured product is changed, the length of the monitoring interval immediately after the change is preferably short. The length of the monitoring interval can be long in a period in which relatively stable continuous operation can be performed.

[0251] For the monitoring, a distributed control system (DCS) equipped with a panel configured to show the temperature profile (T) and the calculated value of the temperature distribution parameter (A) can be used as the monitoring device.

[0252] The panel is not particularly limited, and a conventionally known panel can be appropriately selected and used.

[0253] According to the result of the monitoring step, the manufacturing method of the present application optionally further includes at least one selected from the group consisting of:

[0254] a condition adjustment step (1) in which the manufacturing conditions are adjusted so as to prevent the temperature distribution parameter (A) from exceeding the predetermined value, and ​

[0255] the temperature distribution parameter (A) is below the predetermined value.

[0256] That is, according to the result of the monitoring step, the manufacturing method can include the condition adjustment step (1), the condition adjustment step (2), or the condition adjustment steps (1) and (2).

[0257] In the present application, according to the result of the monitoring step, when the temperature distribution parameter (A) exceeds the predetermined value, the condition adjustment step (2) in which the manufacturing conditions are adjusted so that the temperature distribution parameter (A) is below the predetermined value is required to be performed.

[0258] 4-1-4. Condition adjustment step (1) (Step (I-4))

[0259] In the monitoring step, when the temperature distribution parameter (A) almost exceeds the predetermined value, the manufacturing conditions can be adjusted to reduce the temperature distribution parameter (A) to prevent the temperature distribution parameter (A) from exceeding the predetermined value.

[0260] One example of the case where the temperature distribution parameter (A) almost exceeds the predetermined value is that the value of the temperature distribution parameter (A) calculated from the temperature distribution curve measured in real time approaches the predetermined value over time.

[0261] When the temperature distribution parameter (A) approaches the predetermined value, for example, when the difference between the temperature distribution parameter (A) and the predetermined value reaches a value of -5π, the manufacturing conditions can be adjusted to prevent the temperature distribution parameter (A) from exceeding the predetermined value or to reduce the temperature distribution parameter (A). It is preferable that, when the difference between the temperature distribution parameter (A) and the predetermined value reaches a value of 0, the manufacturing conditions are adjusted to prevent the temperature distribution parameter (A) from exceeding the predetermined value or to reduce the temperature distribution parameter (A).

[0262] As a method of adjusting the manufacturing conditions to prevent the temperature distribution parameter (A) from exceeding the predetermined value or to reduce the temperature distribution parameter (A), examples include, but are not limited to, reducing the peak height (i.e., reducing the temperature having a maximum value) or narrowing the peak width (i.e., narrowing the range having a high temperature), and the like.

[0263] In order to adjust the manufacturing conditions, for example, it is possible to use as an index that the preset temperature of the reactor (i.e., the polymer temperature in the reactor) approaches the gas dew point temperature of the gas phase. More specifically, the temperature difference ΔT1 (°C) (= Tx - Tz) between the temperature (Tx) of the region including the catalyst supply part and the dew point (Tz) of the mixed gas in the reactor can be set to 0°C to 3.0°C.

[0264] In order to adjust the manufacturing conditions, for example, it is also possible to use as an index that the rotation frequency of the stirring mechanism is increased.

[0265] 4-1-5. Condition adjustment step (2) (Step (I-5))

[0266] In the monitoring step, it is preferable to prevent the temperature distribution parameter (A) from exceeding the predetermined value. When the temperature distribution parameter (A) exceeds the predetermined value, an adverse situation can be eliminated by quickly adjusting the manufacturing conditions so that the temperature distribution parameter (A) is below the predetermined value.

[0267] Even when the temperature distribution parameter (A) exceeds the predetermined value, in a case where the temperature distribution parameter (A) does not greatly exceed the predetermined value or does not exceed the predetermined value for a long time, or in a case where Th and 0w in Equation 1 are not large, an adverse situation can be eliminated by quickly adjusting the manufacturing conditions so that the temperature distribution parameter (A) is below the predetermined value.

[0268] For example, a case where the temperature distribution parameter (A) does not greatly exceed the predetermined value can be a case where the temperature distribution parameter (A) is equal to or less than a value obtained by multiplying the predetermined value by 1.25 (predetermined value x 1.25).

[0269] A case where the temperature distribution parameter (A) does not exceed the predetermined value for a long time can be a case where a time during which the temperature distribution parameter (A) exceeds the predetermined value is 8 hours or less.

[0270] A case where Th in Equation 1 is not large can be a case where Th is less than 20 (°C). A case where 0w in Equation 1 is not large can be a case where 0w is less than π / 3.6 (rad).

[0271] A target value for reducing the temperature distribution parameter (A) can be equal to or less than a value obtained by multiplying the predetermined value of the temperature distribution parameter (A) by 0.75 (predetermined value x 0.75), or it can be equal to or less than a value obtained by multiplying the predetermined value by 0.5 (predetermined value x 0.5).

[0272] A method for adjusting the manufacturing conditions so that the temperature distribution parameter (A) is reduced below the predetermined value can be the same as that of the condition adjustment step (1). In order to make the temperature distribution parameter (A) below the predetermined value, examples include, but are not limited to, reducing the peak height (i.e., reducing the temperature having a maximum value) or narrowing the peak width (i.e., narrowing the range having a high temperature).

[0273] In order to adjust the manufacturing conditions, for example, it is possible to use as an index that a preset temperature of the reactor approaches a gas dew point temperature of the gas phase. More specifically, a temperature difference ΔT1 (°C) (= Tx - Tz) between the temperature (Tx) of a region including the catalyst supply part and the dew point (Tz) of the mixed gas in the reactor can be set to 0°C to 3.0°C.

[0274] 4-2. Second embodiment [Step group (II)]

[0275] In a second embodiment of the method for producing a propylene-based polymer of the present invention, the method includes:

[0276] a temperature measuring step of measuring a portion of the temperature distribution in the circumferential direction of the cylindrical horizontal polymerization reactor in such a manner that the interval between adjacent measurement points is π / 10 (rad) or less at a central angle,

[0277] a calculating step of calculating a temperature distribution parameter (As) defined by the following formula 2 from the temperature distribution obtained by the temperature measuring step, and

[0278] A monitoring step wherein a temperature profile parameter (As) is monitored to prevent the parameter from exceeding a predetermined value:

[0279] As=Th s × θw s (Formula 2)

[0280] (Th s = Tp-Tref; Ti is the temperature (°C) of the i-th measurement point (where i is an integer from 1 to n, and n is the number of measurement points in the circumferential direction); Tp is the temperature (°C) with the maximum value among Ti; Tref is a predetermined reference temperature (°C); θw s It is the sum (rad) of the central angles of adjacent intervals between measurement points including the measurement point of Tp and the measurement points where the difference between Ti and Tref (Ti-Tref) is at or above a predetermined temperature.

[0281] The method optionally further comprises at least one selected from the group consisting of:

[0282] a condition adjustment step (1') in which the manufacturing conditions are adjusted to prevent the temperature distribution parameter (As) from exceeding a predetermined value, and

[0283] A condition adjustment step (2'), wherein when the temperature distribution parameter (As) exceeds a predetermined value, the manufacturing conditions are adjusted so that the temperature distribution parameter (As) is below the predetermined value.

[0284] 4-2-1. Temperature measurement procedure (step (II-1))

[0285] In the temperature measuring step, a temperature distribution of a portion of the cylindrical horizontal polymerization reactor in the circumferential direction is measured in such a manner that the interval between adjacent measurement points becomes a central angle of π / 10 (rad) or less.

[0286] For example, when the portion to be managed in the temperature distribution in the circumferential direction of a cylindrical horizontal polymerization reactor is clearly defined according to the manufacturing variety of the propylene-based polymer, the temperature distribution of a portion in the circumferential direction of the cylindrical horizontal polymerization reactor can be measured in the same manner as in the second embodiment.

[0287] The means for measuring the temperature distribution used in this step can be the same as in the first embodiment.

[0288] In the measurement of a part of the temperature distribution in the circumferential direction, the interval between adjacent measurement points can be the same as in the first embodiment.

[0289] The temperature measurement step can be performed in the catalyst supply part or in any part downstream of the catalyst supply part.

[0290] In the temperature measurement step, it is preferable to measure the temperature distribution at least in the circumferential direction of the catalyst supply part of the horizontal polymerization reactor, because the effect of suppressing the formation of bulk polymers and the effect of improving the long-term operability are high.

[0291] The temperature distribution measurement position can be the same as in the first embodiment.

[0292] As a measurement of a part of the cylindrical horizontal polymerization reactor in the circumferential direction in the temperature measurement step, examples include, but are not limited to, measurement of only Figure 4 the range of 3π / 2 to 2π (0) shown in the figure, measurement of only Figure 4 the range of 3π / 2 to 11π / 6 shown in the figure, and these ranges include Tp.

[0293] Even in the case where only a part of the temperature distribution in the circumferential direction is measured, in order to calculate and monitor the specific temperature distribution parameters described below in the temperature measurement step, it is preferable to plot the temperatures measured at the measurement points in the circumferential direction as a temperature profile (T) with the radial coordinate r as the temperature and the angular coordinate Θ as the position of each measurement point in the circumferential direction, as shown in Figure 4

[0294] By making such a temperature profile as a result of temperature distribution measurement, it is possible to easily monitor the degree and the occurrence site of abnormal temperature in real time, and it is possible to appropriately adjust the manufacturing conditions according to the degree and the occurrence site of abnormal temperature.

[0295] 4-2-2. Calculation step (step (II-2))

[0296] In the calculation step, from the temperature distribution obtained by the temperature measurement step, a temperature distribution parameter (As) defined by the following formula 2 is calculated:

[0297] As = Th s × Θw s (Formula 2)

[0298] (where Th s ​= Tp-Tref; Ti is the temperature (°C) of the i-th measurement point (where i is an integer from 1 to n, and n is the number of measurement points in the circumferential direction); Tp is the temperature (°C) with the maximum value among Ti; Tref is a predetermined reference temperature (°C); θw s It is the sum (rad) of the central angles of adjacent intervals between measurement points including the measurement point of Tp and the measurement points where the difference between Ti and Tref (Ti-Tref) is at or above a predetermined temperature.

[0299] like Figure 4 As shown in FIG. 1 , when there is one peak in the temperature distribution of the measurement points obtained in the temperature measurement step, Tp corresponds to the highest temperature in Ti.

[0300] Tref is a predetermined reference temperature (° C.) Depending on the product type, a reference temperature equivalent to Tave in the first embodiment may be set in advance as Tref.

[0301] For example, when measuring only Figure 4 In the case where the range of 3π / 2 to 2π(0) is a portion of the cylindrical horizontal polymerization reactor in the circumferential direction, Tref may be an average value of the temperatures in the range of 3π / 2 to 2π(0), or it may be an average value of the temperatures in the range of 11π / 6 to 2π(0). Figure 4 In the case where the range of π to 2π(0) is a portion of the cylindrical horizontal polymerization reactor in the circumferential direction, Tref may be an average value of temperatures in the range of π to 3π / 2.

[0302] Then, the difference between Tp and Tref is calculated as Th s .

[0303] Depending on the product type, the predetermined temperature of the difference between Ti and Tref (Ti-Tref) may be set to a predetermined temperature equivalent to 0.5°C in the first embodiment. The predetermined temperature of the difference between Ti and Tref (Ti-Tref) may be 0.5°C as in the first embodiment.

[0304] The difference between Ti and Tref (Ti-Tref) is equal to or greater than the sum of the central angles θw of adjacent measurement points at a predetermined temperature. s It can be obtained in the same manner as θw in the first embodiment.

[0305] From the obtained Th s and θw s , calculate the temperature distribution parameter (As) by the following formula: As=Th s × θw s .

[0306] For example, even in the case where there are two or more peaks in the temperature distribution of the measurement points obtained by the temperature measurement step, the temperature distribution parameters Asl, As2, and As3, etc. of the two or more peaks can be calculated in the same manner as in the first embodiment.

[0307] The calculation step can be performed in the same manner as in the first embodiment.

[0308] In the present application, a part of the temperature distribution in the circumferential direction of the cylindrical horizontal polymerization reactor is measured, and the temperature distribution parameter As (Ax= Th s × θw s determined by Equation 2 is monitored as an index. Thus, in addition to the advantages of the first embodiment, the following advantages are obtained: effective temperature management, such as detailed management of the temperature distribution of the portion where a peak is likely to occur, for example, can be performed while labor saving is achieved, without overall temperature distribution management.

[0309] 4-2-3. Monitoring step (step (II-3))

[0310] The monitoring step of the second embodiment can be the same as that of the first embodiment.

[0311] 4-2-4. Condition adjustment step (1’) (step (II-4)) and condition adjustment step (2’) (step (II-5))

[0312] According to the result of the monitoring step, the manufacturing method optionally further includes at least one selected from the group consisting of:

[0313] the condition adjustment step (1’) in which the manufacturing conditions are adjusted to prevent the temperature distribution parameter (As) from exceeding a predetermined value, and

[0314] the condition adjustment step (2’) in which, when the temperature distribution parameter (As) exceeds a predetermined value, the manufacturing conditions are adjusted so that the temperature distribution parameter (As) is below the predetermined value.

[0315] That is, according to the result of the monitoring step, the manufacturing method of the present application can include the condition adjustment step (1’), the condition adjustment step (2’), or both the condition adjustment steps (1’) and (2’).

[0316] In the present application, according to the result of the monitoring step, when the temperature distribution parameter (As) exceeds a predetermined value, the condition adjustment step (2’) in which the manufacturing conditions are adjusted so that the temperature distribution parameter (As) is below the predetermined value is required to be performed.

[0317] The condition adjustment step (1’) and the condition adjustment step (2’) of the second embodiment can be the same as the condition adjustment step (1) and the condition adjustment step (2) of the first embodiment, respectively.

[0318] As described above, in the case where the polymerization is performed in a horizontal polymerization reactor, the particles of the propylene-based polymer move along the axial direction of the reactor while gradually growing under the action of both the formation of the propylene-based polymer by the polymerization reaction and the mechanical stirring, and thus the flow pattern becomes a plug flow pattern. Therefore, the propylene-based polymer can experience different temperature histories in the reactor from the catalyst supply port to the powder discharge port.

[0319] With the technique according to the present application, regardless of the Ziegler catalyst and the metallocene catalyst, it becomes an effective method of suppressing the disorderly polymerization reaction caused by the local heating in the catalyst supply part, and in particular, suppressing the formation of the lump-shaped polymer due to the rapid polymerization rate that easily occurs in the random copolymerization of propylene and ethylene or an a-olefin.

[0320] Further, by employing the technique according to the present application, the formation of the lump-shaped polymer in the reactor is suppressed, and it also becomes possible to further improve the manufacturing continuity and the operation stability. Further, the catalyst activity is maintained high, and the manufacturing cost can be suppressed, and thus the technique is economical.

[0321] 5. The propylene-based polymer manufactured in the present application

[0322] The propylene-based polymer manufactured in the present application encompasses [i] a propylene homopolymer, [ii] a random copolymer containing propylene and at least one other a-olefin, [iii] a block copolymer containing propylene and at least one other a-olefin, and [iv] an olefin polymer component supported in an olefin polymerization catalyst obtained by a prepolymerization step of contacting a small amount of an olefin with the olefin polymerization catalyst, and a propylene-based polymer of the above [i], [ii], or [iii] polymerized using the prepolymerization catalyst as a main component of a catalyst for propylene production. Hereinafter, the term "propylene-based polymer" is used in this meaning.

[0323] In the present application, the melt flow rate (MFR) of the manufactured propylene-based polymer can be 0.3 g / 10 min to 150 g / 10 min, measured at a temperature of 230°C and a load of 2.16 kg.

[0324] In the present application, the melt flow rate is a value measured according to JIS K7210 ("Plastics - Determination of the mass and volume flow rates of the melt (MFR and MVR) of thermoplastics") under test conditions of a temperature of 230°C and a load of 2.16 kgf.

[0325] The propylene polymer produced in the present invention may have a melting peak temperature (Tm) (hereinafter referred to as the melting point) of 105° C. or higher and 167° C. or lower. If the melting point is significantly lower than the above range, part of the polymer itself may melt at an industrially acceptable polymerization temperature, making it difficult to maintain stable operation.

[0326] However, the production method of the present invention does not exclude the production of a propylene-based polymer having a melting point other than this melting point.

[0327] The propylene-based polymer having such a low melting point is preferably produced by using a catalyst in which a metallocene compound is supported on a carrier.

[0328] The characteristics of metallocene-based catalysts, namely narrow crystallinity and molecular weight distribution and a small amount of low-crystalline / low-molecular-weight components, can be maximized, and it becomes possible to produce polymers with excellent low-temperature heat sealing properties, which are difficult to produce with conventional Ziegler-Natta catalysts.

[0329] When the polymer produced is a propylene-ethylene random copolymer, the ethylene content in the copolymer can be adjusted so that the melting point of the copolymer falls within the range of 105°C to 140°C. The ethylene content in the copolymer varies depending on the catalyst used. In the case of a metallocene catalyst, the ethylene content is generally in the range of 1% to 10% by mass.

[0330] In the present invention, the melting peak temperature (Tm) is a value measured by differential scanning calorimetry (DSC). More specifically, for example, the melting peak temperature (Tm) is a peak temperature when a sample is heated from room temperature to 230°C at 80°C / min, maintained at this temperature for 10 minutes, then cooled to 50°C at a rate of -10°C / min, maintained at this temperature for 3 minutes, and then melted under heating conditions of 10°C / min using a DSC7 differential scanning calorimeter manufactured by Perkin-Elmer.

[0331] At this time, it is sufficient to adjust the gas concentration molar ratio of ethylene to propylene (ethylene / propylene) in the reactor to a value that gives the above-mentioned melting point. This value is preferably within the range of 0.01 to 0.5, more preferably 0.01 to 0.3, and even more preferably 0.02 to 0.2.

[0332] The propylene polymer may be produced using a multi-stage polymerization method depending on the purpose. In this case, the propylene polymer produced in the first stage is preferably a propylene polymer having the above-mentioned properties, and the composition of the polymers produced in the second stage and thereafter is not particularly limited.

[0333] The ethylene content in the propylene polymer is determined by NMR. In the case of using a multi-stage polymerization method, the propylene polymer polymerized in the first stage is targeted. The specific method is shown below.

[0334] i) Measurement of ethylene content by NMR

[0335] The ethylene content of the obtained propylene polymer is determined by analyzing the C-NMR spectrum measured under the following conditions using the proton complete decoupling method. 13 C-NMR spectrum.

[0336] Model: GSX-400 manufactured by JEOL or equivalent equipment (carbon nuclear magnetic resonance frequency of 100 MHz or more)

[0337] Solvent: o-dichlorobenzene: deuterated benzene = 4: 1 (volume ratio)

[0338] Concentration: 100 mg / ml

[0339] Temperature: 130°C

[0340] Pulse angle: 90°

[0341] Pulse interval: 15 seconds

[0342] Cumulative number: 5,000 times or more

[0343] ii) Spectrum

[0344] For example, the assignment of the spectrum can be performed with reference to Macromolecules, 17, 1950 (1984). The assignment of the spectrum measured under the above conditions is shown below. As the symbols such as Sαα are according to the labeling method of Carman et al. (Macromolecules, 10, 536 (1977)), P, S, and T represent methyl carbon, methylene carbon, and methine carbon, respectively.

[0345] [Table 1]

[0346]

[0347] iii) Calculation of ethylene content

[0348] Hereinafter, when "P" is a propylene unit in the copolymer chain and "E" is an ethylene unit, 6 kinds of triads of PPP, PPE, EPE, PEP, PEE, and EEE can exist in the chain. As described in Macromolecules, 15, 1150 (1982) or the like, the concentrations of these triads and the peak intensities of the spectrum are connected by the following relational expressions (1) to (6).

[0349] [PPP] = k x I(Tββ) (1)

[0350] [PPE] = k × I(Tβδ)(2)

[0351] [EPE] = k × I(Tδδ)(3)

[0352] [PEP] = k × I(Sββ)(4)

[0353] [PEE] = k × I(Sβδ)(5)

[0354] [EEE] = k × {I(Sδδ) / 2 + I(Sγδ) / 4}(6)

[0355] Here, [ ] represents the score of each triple. For example, [PPP] is the score of PPP triples among all triples. Therefore,

[0356] [PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1(7)

[0357] In addition, k is a constant, and I represents the spectrum intensity. For example, I(Tββ) means the intensity of the peak at 28.7 ppm attributed to Tββ.

[0358] By using the above-mentioned relations (1) to (7), the fraction of each triad is determined. In addition, the ethylene content is determined by the following formula.

[0359] Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100

[0360] To accurately determine the ethylene content, it is necessary to consider the peaks derived from a small amount of propylene irregular bonds (2,1-bonds and / or 1,3-bonds) and include them in the calculation. However, since it is difficult to completely separate or identify the peaks derived from irregular bonds, and since the amount of irregular bonds is small, the ethylene content is determined using the above-mentioned relationships (1) to (7) assuming that no irregular bonds are present.

[0361] The ethylene content in mol% was converted to the ethylene content in mass% using the following formula.

[0362] Ethylene content (mass %)=(28×X / 100) / {28×X / 100+42×(1-X / 100)}×100 (wherein X is the ethylene content in mol %).

[0363] Example

[0364] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to these Examples.

[0365] <Methods and Equipment for Measuring Physical Properties>

[0366] (1) Melt flow rate (MFR)

[0367] The melt index value of the polypropylene-based polymer is measured at a temperature of 230° C. and a load of 2.16 kg in accordance with JIS-K-7210.

[0368] (2) Amount of bulk polymer

[0369] The polymer product was sieved through a sieve having square openings with a side length of 1200 μm, and the percentage (weight %) of powder that did not pass through the sieve was taken as the amount of bulk polymer.

[0370] <Reference Example 1>

[0371] During the production of a propylene polymer having an MFR of 70 (g / 10 min), the temperature distribution parameter (A) and the amount of aggregates sampled at that time were obtained over time (every 8 hours). The correlation between the temperature distribution parameter (A) and the amount of aggregates at that time was obtained from the operating data for the previous 96 hours.

[0372] (1) Preparation of prepolymerized catalyst

[0373] The prepolymerized catalyst was produced in the same manner as in Example 1 in JP-A-2011-116979.

[0374] (2) Aggregation

[0375] Reference Figure 1 The schematic diagram shown in FIG. 1 illustrates the polymerization. A horizontal polymerization reactor is used to carry out gas phase polymerization of propylene. The horizontal polymerization reactor 10 has a length to inner diameter ratio of 5.1 (L / D=5.1) and an internal volume of 0.1 m 3 , a continuous horizontal polymerization reactor equipped with a stirrer.

[0376] Here, Figure 1 The position of the mark 12 (partition wall 10a) shown is the upstream end of the reactor. The rotation frequency of the stirring mechanism is 28 rpm.

[0377] After the inside of the horizontal polymerization reactor 10 was replaced with nitrogen, 29 kg of seed powder was introduced thereto, and the nitrogen was flowed for 3 hours. Then, while introducing propylene and hydrogen, the reactor temperature was increased. When the polymerization conditions were ready, the above-obtained prepolymerization catalyst was continuously supplied as a solid component from the catalyst component supply pipe 1 located at a position 255 mm from the end of the upstream side of the reactor at a rate of 0.125 g / hour, and a 7% by weight solution of triethylaluminum in n-hexane was continuously supplied from the catalyst component supply pipe 2 located at a position 160 mm from the end of the upstream side of the reactor at a rate of 27 mmol / hour. Further, the propylene was supplied in such a manner that the ratio of the hydrogen concentration to the propylene concentration in the reactor 10 was maintained at 0.017; the thermometers for measuring the inside of the reactor were disposed at distances of 160 mm, 330 mm, 690 mm, 855 mm, and 1200 mm from the end of the upstream side, and the zone sections were controlled and maintained at 59°C, 59°C, 62°C, 64°C, and 65°C, respectively; and the polymerization pressure in the horizontal polymerization reactor 10 was maintained at 2.2 MPaG. In addition, hydrogen was continuously supplied from the raw material supply pipe 4. As shown in FIG. 3, the thermometers 34-1 and 34-2 disposed in the zone section (Z1) including the catalyst supply part were disposed at positions 1 / 9.62 L and 1 / 4.67 L of the reactor length L from the end of the upstream side of the reactor, respectively. At this time, the dew point (Tz) of the mixed gas in the reactor was 57.2°C, and the temperature difference ΔT1 between the temperature (Tx) of the polymer particles in the zone section including the catalyst supply part and the dew point (Tz) of the mixed gas in the reactor was 1.8°C. The temperature (Tx) of the polymer particles in the zone section including the catalyst supply part was obtained from the thermometers 34-1 and 34-2. Figure 2

[0378] Meanwhile, on the outer surface of the cylindrical horizontal polymerization reactor, the temperature distribution of the catalyst supply part in the circumferential direction (whole circle) was measured by using an optical fiber thermometer. The temperature distribution measurement in the circumferential direction (whole circle) was performed in such a manner that the interval between adjacent measurement points was a central angle of π / 32 (rad). In the temperature distribution measurement in the circumferential direction (whole circle), the interval between adjacent measurement points was about 20 mm.

[0379] The unreacted gas discharged from the horizontal polymerization reactor 10 was discharged to the outside of the reactor through the unreacted gas discharge pipe 13, cooled and condensed in the recirculation drum 11, and then recirculated into the horizontal polymerization reactor 10 through the liquid supply pipe 19 containing the liquefied monomer and the raw material mixed gas supply pipe 18.

[0380] ​The reaction heat is removed by the gasification heat of the liquid monomer-containing liquid supplied from the liquid monomer-containing liquid supply pipe 19. The liquid monomer-containing liquid is supplied from the liquid monomer-containing liquid supply pipe 19 at a rate of 54.4 kg / hour to the zone section including the catalyst supply section.

[0381] The polymer powder is continuously discharged from the horizontal polymerization reactor 10 through the polymer discharge pipe 21 in such a manner that 35 kg of the formed propylene-based polymer is held in the horizontal polymerization reactor 10. Each gas is separated from the discharged powder by the gas recovery machine 22, and the powder portion is discharged to the powder recovery machine 23.

[0382] (3) Correlation between the temperature distribution parameter (A) and the amount of the bulk polymer at that time

[0383] The temperature distribution parameter (A) calculated from the temperature distribution measurement and the amount of the bulk polymer contained in the polymer discharged from the horizontal polymerization reactor 10 during the temperature distribution measurement are obtained. Then, the correlation between the temperature distribution parameter (A) and the amount of the bulk polymer at that time is obtained from the operation data for the past 96 hours.

[0384] From the correlation between the temperature distribution parameter (A) and the amount of the bulk polymer at that time, the predetermined value of the temperature distribution parameter (A) of the propylene-based polymer product variety is set to 20 π.

[0385] <Reference Example 2>

[0386] In the production of the propylene-based polymer having an MFR of 0.7 (g / 10 min), the temperature distribution parameter (A) and the amount of the aggregate sampled at that time are obtained over time (every 8 hours). The correlation between the temperature distribution parameter (A) and the amount of the aggregate at that time is obtained from the operation data for the past 96 hours.

[0387] (1) Production of the prepolymerization catalyst

[0388] The production of the prepolymerization catalyst is performed in the same manner as in Example 1 of Japanese Patent Application Publication No. 2011-116979.

[0389] (2) Polymerization

[0390] The polymerization is performed in the same manner as in Reference Example 1 except that the MFR condition is changed from 70 (g / 10 min) to 0.7 (g / 10 min).

[0391] (3) Correlation between the temperature distribution parameter (A) and the amount of the bulk polymer at that time

[0392] The temperature distribution parameter (A) calculated from the temperature distribution measurement and the amount of lumped polymer contained in the polymer discharged from the horizontal polymerization reactor 10 during the temperature distribution measurement were obtained. Then, from the operation data for the past 96 hours, the correlation between the temperature distribution parameter (A) and the amount of lumped polymer at that time was obtained.

[0393] From the correlation between the temperature distribution parameter (A) and the amount of lumped polymer at that time, the predetermined value of the temperature distribution parameter (A) for the propylene-based polymer product variety was set to 10 π.

[0394] <Comparative Example 1>

[0395] The production of the propylene-based polymer was performed in the same manner as in Reference Example 1.

[0396] After 8 hours from the start of the operation, the temperature distribution parameter (A) for the propylene-based polymer product variety exceeded the predetermined value: 20 π. However, the production was continued for 24 hours without any change. The dew point (Tz) of the mixed gas in the reactor at that time was 60.0°C, and the temperature (Tx) of the polymer particles in the region section including the catalyst supply part was 63°C.

[0397] The aggregation amount of the propylene-based polymer finally obtained (after 32 hours) was 0.54% by weight.

[0398] <Example 1>

[0399] The production of the propylene-based polymer was performed in the same manner as in Reference Example 1. The temperature distribution measurement and the calculation of the temperature distribution parameter (A) were performed over time (every 8 hours).

[0400] After 24 hours from the start of the operation, the temperature distribution parameter (A) for the propylene-based polymer product variety approached the predetermined value: 20 π. Since the dew point (Tz) of the mixed gas in the reactor at that time was 62.0°C, and the temperature (Tx) of the polymer particles in the region section including the catalyst supply part was 63°C, Tx was adjusted to 62.3°C. As a result, the temperature distribution parameter (A) decreased to 3.3 π. The production was further continued until 24 hours.

[0401] The aggregation amount of the propylene-based polymer finally obtained was 0% by weight.

[0402] <Example 2>

[0403] The production of the propylene-based polymer was performed in the same manner as in Reference Example 1. The temperature distribution measurement and the calculation of the temperature distribution parameter (A) were performed over time (every 8 hours).

[0404] After 8 hours from the start of the operation, the temperature distribution parameter (A) of the propylene polymer production variety exceeded the predetermined value: 20π. Since the dew point (Tz) of the mixed gas in the reactor at that time was 60.1°C, and the temperature (Tx) of the polymer particles in the region section including the catalyst supply part was 63°C, Tx was adjusted to 60.5°C. As a result, the temperature distribution parameter (A) decreased to 5.4π. The production was further continued until 24 hours.

[0405] The agglomerated amount of the finally obtained propylene polymer was 0 wt%.

[0406] <Comparative Example 2>

[0407] The production of the propylene polymer was performed in the same manner as in Reference Example 2.

[0408] After 8 hours from the start of the operation, the temperature distribution parameter (A) of the propylene polymer production variety exceeded the predetermined value: 10π. However, the production was continued for 24 hours without any change. The dew point (Tz) of the mixed gas in the reactor at that time was 61.3°C, and the temperature (Tx) of the polymer particles in the region section including the catalyst supply part was 63°C.

[0409] The agglomerated amount of the finally obtained propylene polymer was 0.63 wt%.

[0410] <Example 3>

[0411] The production of the propylene polymer was performed in the same manner as in Reference Example 2. The temperature distribution measurement and the calculation of the temperature distribution parameter (A) were performed over time (every 8 hours).

[0412] After 8 hours from the start of the operation, the temperature distribution parameter (A) of the propylene polymer production variety exceeded the predetermined value: 10π. Since the dew point (Tz) of the mixed gas in the reactor at that time was 62.0°C, and the temperature (Tx) of the polymer particles in the region section including the catalyst supply part was 63°C, Tx was adjusted to 62.4°C. As a result, the temperature distribution parameter (A) decreased to 2.63π. The production was further continued until 24 hours.

[0413] The agglomerated amount of the finally obtained propylene polymer was 0.3 wt%.

[0414] <Example 3>

[0415] First, the production of the propylene polymer was performed in the same manner as in Example 1. The temperature distribution measurement and the calculation of the temperature distribution parameter (A) were performed over time (every 8 hours).

[0416] The temperature distribution parameter (A) was monitored to prevent it from exceeding the predetermined value of the temperature distribution parameter (A) of the propylene-based polymer production variety of Example 1. When the temperature distribution parameter (A) approached the predetermined value, the production conditions were adjusted to prevent the temperature distribution parameter (A) from exceeding the predetermined value. When the temperature distribution parameter (A) exceeded the predetermined value, the production conditions were adjusted to bring the temperature distribution parameter (A) to be below the predetermined value. The production was continued until one week (168 hours). Then, while maintaining continuous operation, the polymerization conditions were changed to switch to production of another propylene-based polymer production variety that was different in index, the temperature distribution parameter (A) was monitored to prevent the temperature distribution parameter (A) of the propylene-based polymer production variety from exceeding the predetermined value. As in Example 1, when the temperature distribution parameter (A) approached the predetermined value thereof, the production conditions were adjusted to prevent the temperature distribution parameter (A) from exceeding the predetermined value, and when the temperature distribution parameter (A) exceeded the predetermined value, the production conditions were adjusted to bring the temperature distribution parameter (A) to be below the predetermined value. The production was continued until 3 days (72 hours). Then, while maintaining continuous operation, the switching to production of another propylene-based polymer production variety was performed in the same manner as described above. The production was continued by monitoring the temperature distribution parameter (A) to prevent the temperature distribution parameter (A) of the propylene-based polymer production variety from exceeding the predetermined value, and adjusting the production conditions as necessary to prevent the temperature distribution parameter (A) from exceeding the predetermined value or being below the predetermined value. As just described, by changing the production variety of the propylene-based polymer to another variety while maintaining continuous operation, and continuously monitoring the temperature distribution parameter (A) using the predetermined value according to the production variety, long-term continuous operation of 1300 hours or more was achieved without forming a large amount of lumpy polymer.

[0417] BRIEF DESCRIPTION OF DRAWINGS

[0418] 1. Catalyst component supply piping

[0419] 2. Catalyst component supply piping

[0420] 3. Raw material monomer supply piping

[0421] 4. Raw material supply piping (e.g., hydrogen)

[0422] 5, 6. Piping

[0423] 10. Horizontal polymerization reactor

[0424] 10a, 10b. Partition

[0425] 11. Recovery drum

[0426] 12. Reactor upstream side end

[0427] 13. Unreacted gas discharge piping

[0428] 14. Reactor downstream side end

[0429] 15. Condenser

[0430] 16. Compressor

[0431] 18, 18-1, 18-2, 18-3, 18-4, 18-5. Raw material mixed gas supply pipe

[0432] 19, 19-1, 19-2, 19-3, 19-4, 19-5. Liquid containing liquefied monomer supply pipe

[0433] 20. Agitator

[0434] 20a. Horizontal shaft

[0435] 20b. Agitator blade

[0436] 21. Polymer discharge pipe

[0437] 22. Gas recovery machine

[0438] 23. Polymer recovery machine

[0439] 30. Horizontal polymerization reactor

[0440] 31. Catalyst component supply pipe

[0441] 32. Partition

[0442] 33. Partition

[0443] 34-1, 34-2, 34-3, 34-3…34-i. Thermometer

[0444] 35. Horizontal shaft

Claims

1. A method for producing a propylene-based polymer, A cylindrical horizontal polymerization reactor including a stirring mechanism rotating about a horizontal axis is used, wherein propylene or propylene and an α-olefin other than propylene are polymerized into a propylene-based polymer in the presence of a catalyst by a continuous gas-phase polymerization process in which the heat of reaction is removed by utilizing the heat of vaporization of a liquid containing liquefied monomers; the catalyst is supplied from the upper portion of one end of the horizontal polymerization reactor; and the propylene-based polymer is discharged from the lower portion of the other end of the horizontal polymerization reactor. The method comprises: a temperature measuring step of measuring the temperature distribution of the cylindrical horizontal polymerization reactor in the circumferential direction in such a manner that the interval between adjacent measurement points is π / 10 (rad) or less at the central angle, a calculation step of calculating a temperature distribution parameter (A) defined by the following formula 1 from the temperature distribution obtained by the temperature measurement step, and a monitoring step, wherein the temperature distribution parameter (A) is monitored to prevent the parameter from exceeding a predetermined value; and wherein the method optionally further comprises at least one selected from the group consisting of: a condition adjustment step (1), wherein the manufacturing conditions are adjusted to prevent the temperature distribution parameter (A) from exceeding a predetermined value, and Condition adjustment step (2), wherein when the temperature distribution parameter (A) exceeds a predetermined value, the manufacturing conditions are adjusted so that the temperature distribution parameter (A) is below the predetermined value: A = Th × θw (Equation 1) Where, Th = Tp – Tave; Ti is the temperature of the i-th measurement point (°C), where i is an integer from 1 to n and n is the number of measurement points in the circumferential direction; Tp is the temperature with a maximum value in Ti (°C); Tave is the average temperature of Ti (°C); θw is the sum (rad) of the central angles of adjacent intervals between the measurement points including the measurement point of Tp and the measurement points where the difference between Ti and Tave, Ti - Tave, is 0.5°C or more.

2. A method for producing a propylene polymer, A cylindrical horizontal polymerization reactor including a stirring mechanism rotating about a horizontal axis is used, wherein propylene or propylene and an α-olefin other than propylene are polymerized into a propylene-based polymer in the presence of a catalyst by a continuous gas-phase polymerization process in which the heat of reaction is removed by utilizing the heat of vaporization of a liquid containing liquefied monomers; the catalyst is supplied from the upper portion of one end of the horizontal polymerization reactor; and the propylene-based polymer is discharged from the lower portion of the other end of the horizontal polymerization reactor. The method comprises: a temperature measuring step of measuring a portion of the temperature distribution in the circumferential direction of the cylindrical horizontal polymerization reactor in such a manner that the interval between adjacent measurement points is a central angle of π / 10 (rad) or less, a calculation step of calculating a temperature distribution parameter (As) defined by the following formula 2 from the temperature distribution obtained by the temperature measurement step, and a monitoring step, wherein the temperature distribution parameter (As) is monitored to prevent the parameter from exceeding a predetermined value; and wherein the method optionally further comprises at least one selected from the group consisting of: a condition adjustment step (1'), wherein the manufacturing conditions are adjusted to prevent the temperature distribution parameter (As) from exceeding a predetermined value, and Condition adjustment step (2'), wherein when the temperature distribution parameter (As) exceeds a predetermined value, the manufacturing conditions are adjusted so that the temperature distribution parameter (As) is below the predetermined value: As=Th s × θw s (Formula 2) Among them Th s =TP-Tref; Ti is the temperature of the i-th measurement point (°C), where i is an integer from 1 to n and n is the number of measurement points in the circumferential direction; Tp is the temperature with the maximum value in Ti (°C); Tref is the predetermined reference temperature (°C); θw s It is the sum (rad) of the central angles of adjacent intervals between measurement points including the measurement point of Tp and the measurement points where the difference Ti-Tref between Ti and Tref is a predetermined temperature or higher.

3. The method for producing a propylene-based polymer according to claim 1 or 2, wherein In the temperature measuring step, temperature distribution is measured at least in a circumferential direction of a catalyst supply portion of the horizontal polymerization reactor.

4. The method for producing a propylene-based polymer according to any one of claims 1 to 3, wherein In the temperature measuring step, the temperature distribution is measured on the outer surface of the horizontal polymerization reactor.

5. The method for producing a propylene-based polymer according to any one of claims 1 to 4, wherein In the temperature measuring step, the temperature distribution is measured in such a manner that an interval between adjacent measurement points is within a range of 10 mm to 1000 mm.

6. The method for producing a propylene-based polymer according to any one of claims 1 to 5, wherein In the temperature measurement step, the temperatures measured at the measurement points in the circumferential direction are plotted to create a temperature curve, with the radial coordinate r representing the temperature and the angular coordinate θ representing the position of each measurement point in the circumferential direction.

7. The method for producing a propylene-based polymer according to any one of claims 1 to 6, wherein The predetermined value is set within the range of 0π to 30π.

8. The method for producing a propylene-based polymer according to any one of claims 1 to 7, wherein The rotation frequency of the stirring mechanism is 5 rpm to 50 rpm.

9. The method for producing a propylene-based polymer according to any one of claims 1 to 8, wherein A temperature difference ΔT1 (°C) (=Tx-Tz) between a temperature (Tx) of a region including a catalyst supply portion of the horizontal polymerization reactor and a dew point (Tz) of a mixed gas in the reactor is 0 to 3.0°C.

10. The method for producing a propylene-based polymer according to any one of claims 1 to 9, wherein The catalyst is a Ziegler polymerization catalyst or a metallocene polymerization catalyst.

11. The method for producing a propylene-based polymer according to any one of claims 1 to 10, wherein The produced propylene-based polymer has a melt flow rate (MFR) measured at a temperature of 230° C. and a load of 2.16 kg of 0.3 g / 10 min to 150 g / 10 min.

Images