Method for drying and storing particles containing polyolefins

Abstract

To stably discharge all amount of particles containing polyolefin to the outside of a drying container.SOLUTION: A drying method of particles containing a polyolefin includes a drying step for supplying particles containing the polyolefin to a drying container to dry the particles containing the polyolefin in the drying container, and in the drying step, a value obtained by the following formula (a) is -0.20 or more and 1.05 or less. Formula (a): 0.00304×diameter of device[m]+0.00261×height of bed[m]+0.0179×residence time[hr]+0.00213×particle temperature in drying container[K]-0.0109×inclination angle[°]+0.0212×CXS component amount[mass%].SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for drying and storing particles containing polyolefin.

Background Art

[0002] In a method for producing particles containing polyolefin, typified by particles containing a propylene-based polymer, usually, a step of drying (degassing) the particles containing polyolefin and further a step of storing them are included. Specifically, for example, a method for producing a polyolefin-based polymer is known which includes a step of degassing polyolefin particles by bringing them into contact with nitrogen gas in a degassing vessel (drying vessel) (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=3P4]] However, depending on the conventional drying (degassing) process, even if the dried particles containing polyolefin are discharged from the drying vessel, the particles may inadvertently remain in the drying vessel, and it may not be possible to take out the entire amount of the dried particles outside the drying vessel. Similarly, in the storage process, even if the particles are discharged from the storage vessel, it may not be possible to take out the entire amount of the particles outside the storage vessel.

Means for Solving the Problems

[0005] The inventors of the present invention diligently conducted research to solve the above problems and found that the above problems can be solved by carrying out a drying process that satisfies predetermined requirements when drying particles containing polyolefin, and by carrying out a storage process that satisfies predetermined requirements when storing particles containing polyolefin, thus completing the present invention.

[0006] In other words, the present invention provides the following [1] to

[24] . [1] A drying step comprising supplying particles containing polyolefin to a drying container and drying the particles containing polyolefin in the drying container, A method for drying particles containing polyolefin, wherein the value obtained by the following formula (a) in the drying step is between -0.20 and 1.05. Formula (a): 0.00304 × apparatus diameter [m] + 0.00261 × bed height [m] + 0.0179 × residence time [hours] + 0.00213 × particle temperature in drying container [K] - 0.0109 × tilt angle [degrees] + 0.0212 × CXS component amount [mass %] (In formula (a), The device diameter refers to the maximum diameter of the body of the drying container. Bed height refers to the maximum height from the height of the discharge port for discharging polyolefin-containing particles to the height at which the polyolefin-containing particles remaining in the drying container are located. Residence time refers to the time that particles containing polyolefin remain in the drying container. The particle temperature in the drying container refers to the temperature of the polyolefin-containing particles in the drying container. The inclination angle refers to the outer angle between the inclined surface of the drying container and the mounting surface, where the outer angle means the angle on the outside of the container. The CXS component amount refers to the amount of CXS component contained in particles containing polyolefin. [2] A method for drying particles containing a polyolefin according to [1], wherein the polyolefin contains a propylene polymer. [3] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less. The drying method according to [2], wherein the content of the CXS component in the particles containing the polyolefin is 5% by mass or more. [4] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less, The drying method according to [3], wherein the content of the CXS component in the particles containing the polyolefin is 15% by mass or more. [5] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less, The drying method according to [2], wherein the content of the CXS component in the particles containing the polyolefin is 5% by mass or more. [6] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less, The drying method according to [5], wherein the content of the CXS component in the particles containing the polyolefin is 15% by mass or more. [7] The drying method according to any one of [1] to [6], wherein the temperature of the polyolefin-containing particles in the drying container is 0°C or higher and 160°C or lower. [8] The drying method according to any one of [1] to [7], wherein the residence time of the particles containing the polyolefin in the drying container is 1 hour or more and 48 hours or less. [9] The drying method according to any one of [1] to [8], wherein the inclination angle in the drying container is 30° or more.

[10] The drying method according to any one of [1] to [9], wherein the median diameter of the particles containing the polyolefin is 500 μm or more and 10,000 μm or less. A method for producing polyolefin-containing particles, comprising the step of drying the polyolefin-containing particles by the drying method described in any one of [1] to

[10] . A method for producing a polyolefin resin composition, comprising the step of drying the particles containing the polyolefin by the drying method described in any one of [1] to

[10] .

[13] A storage step comprising supplying particles containing polyolefin to a storage container and storing the particles containing polyolefin in the storage container, A method for storing particles containing polyolefins, wherein the value obtained by the following formula (b) in the storage step is between -0.20 and 1.05. Formula (b): 0.00304 × device diameter [m] + 0.00261 × bed height [m] + 0.0179 × residence time [hours] + 0.00213 × particle temperature in storage container [K] - 0.0109 × tilt angle [degrees] + 0.0212 × CXS component amount [mass %] (In formula (b), The device diameter refers to the maximum diameter of the body of the storage container. Bed height refers to the maximum height from the height of the discharge port for discharging polyolefin-containing particles to the height at which the polyolefin-containing particles remaining in the storage container are located. Residence time refers to the time that particles containing polyolefin remain in the storage container. The particle temperature in the storage container refers to the temperature of the polyolefin-containing particles in the storage container. The inclination angle refers to the outer angle between the inclined surface of the storage container and the installation surface, where the outer angle means the angle on the outside of the container. The CXS component amount refers to the amount of CXS component contained in particles containing polyolefin.

[14] A method for storing particles containing a polyolefin according to

[13] , wherein the polyolefin is a propylene polymer.

[15] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less, The storage method according to

[14] , wherein the CXS component content of the particles containing the polyolefin is 5% by mass or more.

[16] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less, The storage method according to

[15] , wherein the content of the CXS component in the particles containing the polyolefin is 15% by mass or more.

[17] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less, The storage method according to

[14] , wherein the CXS component content of the particles containing the polyolefin is 5% by mass or more.

[18] The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less, The storage method according to

[17] , wherein the content of the CXS component in the particles containing the polyolefin is 15% by mass or more.

[19] The storage method according to any one of

[13] to

[18] , wherein the temperature of the particles containing the polyolefin in the storage container is 0°C or higher and 160°C or lower.

[20] The storage method according to any one of

[13] to

[19] , wherein the residence time of the particles containing the polyolefin in the storage container is 1 hour or longer and 48 hours or shorter.

[21] The storage method according to any one of

[13] to

[20] , wherein the inclination angle in the storage container is 30° or higher.

[22] The storage method according to any one of

[13] to

[21] , wherein the median diameter of the particles containing the polyolefin is 500 μm or larger and 10,000 μm or smaller.

[23] A method for producing particles containing a polyolefin, comprising a step of storing the particles containing the polyolefin by the storage method according to any one of

[13] to

[22] .

[24] A method for producing a polyolefin-based resin composition, comprising a step of storing the particles containing the polyolefin by the storage method according to any one of

[13] to

[22] . [Effect of the Invention]

[0007] According to the method for drying particles containing a polyolefin of the present invention, it is possible to effectively suppress the occurrence of blockage by particles in a pipe for discharging the dried particles from the drying container or at the discharge port on the drying container side and in the vicinity thereof, and it is possible to stably discharge the entire amount of the particles outside the drying container. Similarly, in the storage method, it is possible to stably discharge the entire amount of the particles outside the storage container. [Brief Description of the Drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram for explaining a configuration example of a first drying container. [Figure 2] FIG. 2 is a schematic diagram for explaining a configuration example of a second drying container. [Figure 3] FIG. 3 is a schematic diagram for explaining a configuration example of a third drying container.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that each drawing only schematically shows the shape, size, and arrangement of the components to the extent that the invention can be understood. The present invention is not limited by the following description, and each component can be modified without departing from the gist of the present invention. In the following drawings, the same reference numerals used for the same components may be omitted from redundant explanations.

[0010] In the present specification, "α-olefin" means an aliphatic unsaturated hydrocarbon having a carbon-carbon unsaturated double bond at the α-position.

[0011] In the present specification, "heterophasic propylene polymerization material" means a mixture having a structure in which a propylene copolymer containing monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is dispersed in a matrix of a propylene-based polymer containing 80% by mass or more of monomer units (structural units) derived from propylene (where the total mass of the propylene-based polymer is 100% by mass).

[0012] In the present specification, "AA~BB" means AA or more and BB or less. Here, AA and BB each represent a numerical value, and AA < BB. The unit of AA is the same as the unit described immediately after BB, unless otherwise specified.

[0013] In the present specification, the term "monomer unit" means a structural unit having a structure obtained by polymerizing the monomer.

[0014] In the present specification, the "intrinsic viscosity (unit: dL / g)" is a value measured at a temperature of 135 °C using tetralin as a solvent by the following method. Using an Ubbelohde viscometer, the reduced viscosity is measured at multiple concentrations, the reduced viscosity is plotted against the concentration, and the intrinsic viscosity is determined by the "extrapolation method," which involves extrapolating the concentration to zero. More specifically, using the method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (Kyoritsu Shuppan Co., Ltd., 1982), the reduced viscosity is measured at three points with concentrations of 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL, the reduced viscosity is plotted against the concentration, and the intrinsic viscosity is determined by extrapolating the concentration to zero.

[0015] In this specification, "Melt Flow Rate (MFR)" is the value measured in accordance with JIS K7210-1:2014 and K7210-2:2014 under conditions of 230°C and a load of 2.16 kgf.

[0016] 1. Method for drying particles containing polyolefins The drying method for polyolefin-containing particles according to this embodiment includes a drying step of supplying polyolefin-containing particles to a drying container and drying the polyolefin-containing particles in the drying container, wherein the value obtained by the following formula (a) in the drying step is between -0.20 and 1.05. Formula (a): 0.00304 × apparatus diameter [m] + 0.00261 × bed height [m] + 0.0179 × residence time [hours] + 0.00213 × particle temperature in drying container [K] - 0.0109 × tilt angle + 0.0212 × CXS component content [mass %] (In formula (a), the device diameter represents the maximum diameter of the body of the drying container, the bed height represents the maximum height from the height of the outlet for discharging polyolefin-containing particles to the height where the polyolefin-containing particles remaining in the drying container are located, the residence time represents the time the polyolefin-containing particles remain in the drying container, the temperature represents the temperature of the polyolefin-containing particles in the drying container, and the inclination angle represents the outer angle between the inclined surface of the drying container and the mounting surface. Here, the outer angle refers to the angle on the outside of the drying container, not the inside of the drying container where the particles are located. Furthermore, regarding the "device diameter," if the shape of the body is cylindrical, the "maximum diameter" corresponds to the inner diameter (diameter) when the cylinder is cut in a direction perpendicular to the direction of extension, and if the shape of the body is other than cylindrical, it corresponds to the "equivalent circular diameter" that applies to the shape defined by the inner wall when the cylinder is cut in a direction perpendicular to the direction of extension.)

[0017] Here, "particles containing polyolefin" means particles containing 50% by mass or more of polyolefin, with particles containing 80% by mass or more of polyolefin being preferred, and particles containing 95% by mass or more of polyolefin being more preferred. The following describes polyolefins that can constitute "particles containing polyolefins."

[0018] Polyolefins Polyolefins are polymers that contain structural units (olefin units) having a structure obtained by polymerizing olefins.

[0019] The polyolefin may be a polymer containing only one type of olefin unit, or a copolymer containing two or more types of olefin units.

[0020] Polyolefins may contain structural units other than olefin units. The content of olefin units that may be contained in a polyolefin is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, with the total mass of all structural units contained in the polyolefin being 100% by mass, and is usually 100% by mass or less, and may be 100% by mass.

[0021] The olefins that can constitute a polyolefin may be linear or branched. The olefin may also be a cyclic olefin, for example, an α-olefin having a cyclic structure such as vinylcyclopropane or vinylcyclobutane.

[0022] Specific examples of olefins that can constitute polyolefins include α-olefins (e.g., ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene).

[0023] The olefins that can constitute the polyolefin are preferably α-olefins, more preferably ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, and even more preferably ethylene, propylene, 1-butene, 1-hexene, and 1-octene.

[0024] Polyolefins can be produced, for example, using the olefins exemplified above as raw materials by any suitable conventional method known to date.

[0025] In this embodiment, the polyolefin is preferably a propylene polymer containing propylene units. In this embodiment, the properties of the "particles containing polyolefin" are not particularly limited. The "particles containing polyolefin" may be in the form of a powder or pellets.

[0026] First, let's explain propylene polymers, which are polyolefins that can constitute "particles containing polyolefins."

[0027] In this embodiment, the polyolefin is preferably a polymer in which the mass percentage of structural units derived from ethylene and at least one olefin selected from the group consisting of olefins having 4 to 12 carbon atoms is 30% by mass or more, more preferably 50% by mass or more, more preferably 80% by mass or less, and more preferably 95% by mass or less.

[0028] In this embodiment, the polyolefin is preferably a polymer in which the mass percentage of structural units derived from ethylene and at least one olefin selected from the group consisting of 4 to 12 carbon atoms is 30% by mass or more, more preferably 50% by mass or more, more preferably 80% by mass or less, and more preferably 95% by mass or less.

[0029] In this embodiment, the polyolefin may be an ethylene-based polymer containing ethylene units. Here, an ethylene-based polymer is a polymer containing more than 50% by mass of ethylene units relative to the total structural units of the polyolefin. The amount of ethylene units in an ethylene-based polymer is usually 100% by mass or less. Examples of ethylene-based polymers include ethylene homopolymers (polyethylene) and copolymers of ethylene with other monomers that can copolymerize with it, with ethylene homopolymers being preferred. The copolymer may be a random copolymer (propylene-ethylene random polymer (RC)) or a block copolymer.

[0030] Specific examples of polyolefins include propylene polymers, ethylene polymers, and butene polymers. A preferred example of a polyolefin is a propylene polymer. Furthermore, the particles containing polyolefins may contain only one type of polyolefin or two or more types of polyolefins.

[0031] Furthermore, in this embodiment, the polyolefin preferably contains a propylene polymer containing propylene units, and the content of the propylene polymer in the polyolefin is preferably 30% by mass or more, preferably 60% by mass or more, and more preferably 90% by mass or more.

[0032] (Propylene polymer) A propylene polymer is a polymer that contains 50% by mass or more of propylene units relative to the total structural units of the polymer, and preferably a polymer that contains more than 50% by mass of propylene units. In this embodiment, the propylene unit content in the propylene polymer is usually 100% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 80% by mass or less, preferably 55% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0033] Examples of propylene-based polymers include propylene homopolymers and copolymers of propylene with other monomers that can copolymerize with it. The copolymers may be random copolymers or block copolymers.

[0034] The propylene polymer may contain only one type of propylene polymer, or it may contain two or more types of propylene polymers in any combination.

[0035] Examples of propylene-based polymers consisting of only one type include propylene homopolymers and copolymers of propylene with other monomers capable of copolymerization (also called propylene copolymers). The aforementioned copolymers may be random copolymers or block copolymers. A random copolymer is a polymer in which monomer units derived from ethylene and at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms are randomly bonded to monomer units derived from propylene. A block copolymer is a polymer that includes blocks in which monomer units derived from ethylene and at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms are continuously bonded, and blocks in which monomer units derived from propylene are continuously bonded.

[0036] In this embodiment, the propylene polymer is preferably a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and olefins having 4 to 12 carbon atoms is 20% by mass or more.

[0037] In this embodiment, the propylene polymer is preferably a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 20% by mass or more.

[0038] In this embodiment, it is preferable that at least one of the propylene polymers is a heterophagic propylene polymerization material. Here, a heterophagic propylene polymerization material means a material that includes two or more propylene polymers, in which the two or more propylene polymers are immiscible and form separate phases from each other. The heterophagic propylene polymerization material of this embodiment will now be described in detail.

[0039] (Heterophagic propylene polymerization material) The heterophagic propylene polymerization material of this embodiment is a heterophagic propylene polymerization material comprising a propylene polymer a and a propylene copolymer b, wherein the propylene polymer a preferably contains 80% by mass or more monomer units derived from propylene, and the propylene copolymer b preferably contains 20 to 70% by mass of monomer units derived from ethylene and at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms, and monomer units derived from propylene.

[0040] The propylene polymer a may be, for example, a propylene homopolymer, or it may contain monomer units derived from monomers other than propylene. If the propylene polymer a contains monomer units derived from monomers other than propylene, the amount may be, for example, 0.01% by mass or more and less than 20% by mass, based on the total mass of the propylene polymer a.

[0041] Examples of monomers other than propylene include ethylene and α-olefins having 4 to 12 carbon atoms. Among these, at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms is preferred, at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, and 1-octene is more preferred, and at least one selected from the group consisting of ethylene and 1-butene is even more preferred.

[0042] Examples of propylene-based polymers containing monomer units derived from monomers other than propylene include propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, and propylene-ethylene-1-octene copolymer.

[0043] The propylene-based polymer a is preferably a propylene homopolymer, a propylene-ethylene copolymer, a propylene-1-butene copolymer, or a propylene-ethylene-1-butene copolymer, with a propylene homopolymer being more preferred.

[0044] The heterophagic propylene polymerization material of this embodiment may contain only one type of propylene polymer a, or it may contain two or more types.

[0045] In propylene copolymer b, the content of monomer units derived from ethylene and at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms may be 20 to 70% by mass, 30 to 60% by mass, or 35 to 55% by mass.

[0046] In propylene copolymer b, the at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, 1-octene and 1-decene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0047] Examples of propylene copolymer b include propylene-ethylene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer, propylene-ethylene-1-decene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, and propylene-1-decene copolymer. Among these, propylene-ethylene copolymer, propylene-1-butene copolymer, or propylene-ethylene-1-butene copolymer are preferred as propylene copolymer b, and propylene-ethylene copolymer is more preferred.

[0048] The heterophagic propylene polymerization material of this embodiment may contain only one type of propylene copolymer b, or it may contain two or more types.

[0049] Examples of heterophagic propylene polymerization materials in this embodiment include (propylene)-(propylene-ethylene) polymerization materials, (propylene)-(propylene-ethylene-1-butene) polymerization materials, (propylene)-(propylene-ethylene-1-hexene) polymerization materials, (propylene)-(propylene-ethylene-1-octene) polymerization materials, (propylene)-(propylene-1-butene) polymerization materials, (propylene)-(propylene-1-hexene) polymerization materials, (propylene)-(propylene-1-octene) polymerization materials, and (propylene)-(propylene-ethylene-1-octene) polymerization materials. (Pyrene-1-decene) polymerization material, (propylene-ethylene)-(propylene-ethylene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-butene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-hexene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-octene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-decene) polymerization material, (propylene-ethylene)-(propylene-1-butene) polymerization material, (propylene-ethylene)-(propylene-1 -Hexene) polymerization material, (propylene-ethylene)-(propylene-1-octene) polymerization material, (propylene-ethylene)-(propylene-1-decene) polymerization material, (propylene-1-butene)-(propylene-ethylene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-butene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-hexene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-octene) polymerization material, (propylene-1-butene)-(propylene-ethylene (-1-decene) polymerization material, (propylene-1-butene)-(propylene-1-butene) polymerization material, (propylene-1-butene)-(propylene-1-hexene) polymerization material, (propylene-1-butene)-(propylene-1-octene) polymerization material, (propylene-1-butene)-(propylene-1-decene) polymerization material, (propylene-1-hexene)-(propylene-1-hexene) polymerization material, (propylene-1-hexene)-(propylene-1-octene) polymerization material, (propylene-1-hexene)-(propylene-1-decene) polymerization material,Examples include (propylene-1-octene)-(propylene-1-octene) polymerization materials and (propylene-1-octene)-(propylene-1-decene) polymerization materials. Among these, (propylene)-(propylene-ethylene) polymerization materials, (propylene)-(propylene-ethylene-1-butene) polymerization materials, (propylene-ethylene)-(propylene-ethylene) polymerization materials, (propylene-ethylene)-(propylene-ethylene-1-butene) polymerization materials, or (propylene-1-butene)-(propylene-1-butene) polymerization materials are preferred, and (propylene)-(propylene-ethylene) polymerization materials are more preferred.

[0050] Here, the above description represents "(type of propylene polymer containing 80% by mass or more monomer units derived from propylene)-(type of propylene copolymer b)". In other words, the description "(propylene)-(propylene-ethylene) polymerization material" represents "a heterophagous propylene polymerization material in which propylene polymer a is a propylene homopolymer and propylene copolymer b is a propylene-ethylene copolymer". The same applies to other similar expressions below.

[0051] (Method for producing heterophagic propylene polymerization material) A method for producing a propylene polymer containing 80% by mass or more monomer units derived from propylene that may be included in a heterophagic propylene polymerization material preferably includes the following step 1, i.e., steps 1-a and 1-b. Furthermore, a method for producing a heterophagic propylene polymerization material preferably includes the following steps 1 and 2.

[0052] (Step 1-a) In step 1-a, for example, a monomer containing propylene is polymerized in the presence of a polymerization catalyst and hydrogen using a liquid-phase polymerization reactor. The composition of the monomers used for polymerization may be appropriately adjusted based on the type and content of monomer units constituting the propylene polymer a. The propylene content in the monomer may be, for example, 80% by mass or more, 90% by mass or more, or 100% by mass, relative to the total mass of the monomer.

[0053] Examples of liquid-phase polymerization reactors include loop-type liquid-phase reactors and vessel-type liquid-phase reactors.

[0054] Examples of polymerization catalysts include Ziegler-Natta type catalysts and metallocene-based catalysts, with Ziegler-Natta type catalysts being preferred. Examples of Ziegler-Natta type catalysts include Ti-Mg-based catalysts such as solid catalyst components obtained by contacting a magnesium compound with a titanium compound; and catalysts containing a solid catalyst component obtained by contacting a magnesium compound with a titanium compound, an organoaluminum compound, and optionally a third component such as an electron-donating compound. Preferably, the catalyst contains a solid catalyst component obtained by contacting a magnesium compound with a titanium compound, an organoaluminum compound, and optionally a third component such as an electron-donating compound. More preferably, the catalyst contains a solid catalyst component obtained by contacting a magnesium compound with a titanium halide compound, an organoaluminum compound, and an electron-donating compound. A catalyst pre-activated by contacting it with a small amount of olefin can also be used as a polymerization catalyst.

[0055] As a polymerization catalyst, a prepolymerization catalyst component obtained by prepolymerizing an olefin in the presence of the above-mentioned solid catalyst component, n-hexane, triethylaluminum, tert-butyl-n-propyldimethoxysilane, etc., can also be used. The olefin used for prepolymerization is preferably one of the olefins that constitute the heterophagic propylene polymerization material.

[0056] The polymerization temperature can be, for example, 0 to 120°C. The polymerization pressure can be, for example, atmospheric pressure to 10 MPaG.

[0057] (Step 1-b) In step 1-b, for example, a monomer containing propylene is polymerized in the presence of a polymerization catalyst and hydrogen using a gas-phase polymerization reactor. The composition of the monomers used for polymerization can be appropriately adjusted based on the type and content of monomer units constituting the propylene polymer a. The propylene content in the monomer may be, for example, 80% by mass or more, 90% by mass or more, or 100% by mass, relative to the total mass of the monomer.

[0058] Examples of gas-phase polymerization reactors include fluidized bed reactors and jet bed reactors.

[0059] The gas-phase polymerization reactor may be a multi-stage gas-phase polymerization reactor having multiple reaction regions connected in series. The multi-stage gas-phase polymerization reactor may be a multi-stage gas-phase polymerization reactor having multiple polymerization tanks connected in series.

[0060] A multi-stage gas-phase polymerization reactor can include, for example, a cylindrical section that extends vertically during use, a conical reduced-diameter section integrally formed with the cylindrical section, the inner diameter of which decreases as it goes vertically downward and has a gas introduction opening at its lower end, a jet-bed type olefin polymerization reaction region surrounded by the inner surface of the reduced-diameter section and the inner surface of the cylindrical section above the reduced-diameter section, with a jet layer formed inside, and a fluid-bed type olefin polymerization reaction region.

[0061] A multi-stage gas-phase polymerization reactor preferably has multiple reaction regions in the vertical direction. From the viewpoint of optimizing the intrinsic viscosity of the propylene polymer a, a multi-stage gas-phase polymerization reactor preferably has multiple reaction regions in the vertical direction, where the uppermost stage is a fluidized bed type olefin polymerization reaction region and the remaining stages are multiple jet-bed type olefin polymerization reaction regions. In such a reactor, for example, a solid component such as a catalyst is supplied from the upper side of the reactor, and a gaseous component is supplied from the lower side of the reactor to form a fluidized bed or jet bed in the reaction region. The gaseous component may include monomers containing propylene and hydrogen, as well as an inert gas such as nitrogen gas. In the reactor, it is preferable that the number of jet-bed type olefin polymerization reaction regions be three or more.

[0062] In a multi-stage gas-phase polymerization reactor, when multiple reaction regions are arranged vertically, the lower reaction region may be positioned diagonally below the upper reaction region. In such a reactor, for example, the solid component obtained in the upper reaction region is discharged diagonally downward, and the discharged solid component is supplied to the lower reaction region from diagonally above. In this case, the gaseous component is supplied, for example, from the lower part of the upper reaction region by the gaseous component discharged from the upper part of the lower reaction region.

[0063] Specific examples of polymerization catalysts that can be used in multi-stage gas-phase polymerization reactors are the same as those described above.

[0064] The polymerization temperature may be, for example, 0 to 120°C, 20 to 100°C, or 40 to 100°C. The polymerization pressure may be, for example, atmospheric pressure to 10 MPaG, or 1 to 5 MPaG.

[0065] (Process 2) Step 2 can be carried out in either the gas phase or the liquid phase. It is preferable to carry out Step 2 in the gas phase. When Step 2 is carried out in the gas phase, for example, a gas-phase reactor such as a fluidized bed reactor or a jet-bed reactor can be used. When Step 2 is carried out in the liquid phase, for example, a liquid-phase reactor such as a loop-type or vessel-type reactor can be used.

[0066] In step 2, for example, a polymerization catalyst similar to that already described can be used to polymerize a monomer containing at least one α-olefin selected from the group consisting of α-olefins having 4 to 12 carbon atoms and propylene in the presence of hydrogen. The composition of the monomer used for polymerization can be appropriately adjusted based on the type and content of monomer units constituting propylene copolymer b. The content of at least one α-olefin selected from the group consisting of α-olefins having 4 to 12 carbon atoms in the monomer used for polymerization may be, for example, 20 to 70% by mass, or 30 to 60% by mass, based on the total mass of the monomer.

[0067] When polymerization occurs in the liquid phase, the polymerization temperature is, for example, 40 to 100°C, and the polymerization pressure is, for example, atmospheric pressure to 5 MPaG. When polymerization occurs in the gas phase, the polymerization temperature is, for example, 40 to 100°C, and the polymerization pressure is, for example, 0.5 to 5 MPaG.

[0068] Propylene polymer a and propylene copolymer b may be prepared in separate steps, and after deactivating the polymerization catalyst, they may be mixed in a solution, molten state, or the like. Alternatively, the polymer may be polymerized continuously by supplying the resulting polymer to the next step without deactivating the polymerization catalyst. When polymerization is carried out continuously without deactivating the polymerization catalyst, the polymerization catalyst from the previous step can usually function as the polymerization catalyst in the subsequent step.

[0069] The order in which steps 1 and 2 are carried out is not particularly limited. Step 1 preferably includes steps 1-a and 1-b as described above. Steps 1 and 2 are not particularly limited to being carried out in the presence of hydrogen and can also be carried out under hydrogen-free conditions.

[0070] The method for producing the heterophagic propylene polymerization material according to this embodiment preferably includes steps 1-a, 1-b, and 2 in this order.

[0071] (Solid-gas separation process and catalyst deactivation process) The propylene polymer (heterophasic propylene polymerization material) obtained by the above process is subjected to a solid-gas separation process and a catalyst deactivation process. Specifically, the reaction mixture containing the propylene polymer is transferred from the polymerization reactor to a conventionally known and suitable solid-gas separation vessel, and a catalyst deactivation process can be performed in conjunction with the solid-gas separation process by supplying, for example, water vapor (steam) and nitrogen gas from the bottom of the solid-gas separation vessel, thereby deactivating the solid catalyst component.

[0072] Particles containing polyolefins In this embodiment, the polyolefin-containing particles may, in addition to the one or more polyolefins already described, further contain, as necessary, conventionally known and suitable additives such as heat stabilizers, ultraviolet stabilizers, antioxidants, nucleating agents, lubricants, colorants, antiblocking agents, antistatic agents, antifogging agents, flame retardants, petroleum resins, foaming agents, foaming aids, organic fillers, and inorganic fillers. In other words, the polyolefin-containing particles according to this embodiment may also be particles of a polyolefin-based resin composition.

[0073] The amount of additive added is preferably 0.01% by mass or more, and preferably 30% by mass or less, relative to the total amount (100% by mass) of particles containing polyolefin (particles containing propylene polymer). The additive may be used alone or in combination of two or more types.

[0074] In this embodiment, the CXS component content of the polyolefin-containing particles (particles containing a propylene polymer) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 80% by mass or less, more preferably 60% by mass or less, preferably 5% by mass or more and 80% by mass or less, and more preferably 10% by mass or more and 60% by mass or less.

[0075] Here, the CXS (cold xylene water part) component refers to the xylene-soluble component.

[0076] More specifically, the CXS component refers to the remaining component after the CXIS component has been separated from the substance being measured. The CXIS (cold xylene insoluble part) component refers to the xylene-insoluble component, and more specifically, it refers to the component insoluble in p-xylene among the components contained in the substance being measured (polyolefin, particles containing polyolefin), which can be obtained, for example, by the separation method described below.

[0077] (Separation method) Approximately 2 g of the sample to be measured (polyolefin, or particles containing polyolefin) is dissolved in boiling p-xylene for 2 hours to obtain a solution. The obtained solution is then cooled to 20°C, and the solid precipitated in the cooled solution is considered the CXIS component.

[0078] Method for drying particles containing polyolefins The drying method for polyolefin-containing particles (hereinafter sometimes simply referred to as "particles") according to this embodiment includes a drying step of supplying the polyolefin-containing particles to a drying container and supplying a drying gas to the drying container to dry the polyolefin-containing particles in the drying container. A specific example of the configuration of the drying container will be described later.

[0079] (granulation process) The granulation process in this embodiment can be carried out using any suitable conventionally known granulation apparatus.

[0080] The particles of this embodiment can be produced, for example, by melt-kneading, using the polyolefin and additives already described as raw materials. The temperature during melt-kneading may be 180°C or higher, 180 to 300°C, or 180 to 250°C.

[0081] Examples of granulation apparatus suitably used in this embodiment include, for example, a Banbury mixer, a single-screw extruder, a twin-screw coaxial extruder, and a twin-screw anomalous-direction extruder.

[0082] (drying process) After the granulation process, the granulated particles are dried using a drying container. The specific configuration of the drying container will be described later.

[0083] In the following description, an example configuration in which the body of the drying container is cylindrical will be described, but the present invention is not limited to this. The shape of the drying container, particularly the shape of the body, can be any suitable shape according to the design, for example, by making the outer shape a rectangular parallelepiped, provided that the effects of the present invention are not impaired.

[0084] In the drying process of this embodiment, the temperature of the particles supplied into the drying container (the temperature of the particles when they are placed into the drying container) is preferably 25°C or higher and 160°C or lower. More preferably, the temperature of the particles supplied into the drying container is 50°C or higher and 100°C or lower.

[0085] In this embodiment, any conventionally known and suitable gas can be used as the drying gas supplied to the drying container. Preferably, an inert gas such as nitrogen gas is used as the drying gas.

[0086] In this embodiment, the "empty tower velocity (m / s)" of the drying gas is defined as the total flow rate (m / s) of the drying gas supplied to the drying container. 3 The area (m²) of the cross-section (circular in the case of a cylindrical part) extending in a direction perpendicular to the direction of extension (vertical direction) of the body (cylindrical part) of the drying container in the direction of flow of the drying gas. 2 This refers to the speed that can be calculated by dividing by (m²). Note that if the cross-section extending in a direction perpendicular to the extension direction (vertical direction) of the body of the drying container in the flow direction of the drying gas changes with the height in the extension direction of the body, the area of ​​the said cross-section (m²) 2 ) is the value obtained by dividing the volume of the drying container by the height of the drying container in the direction of its extension.

[0087] In the drying process of this embodiment, the value obtained by the following formula (a) is between -0.20 and 1.05, with a lower limit of -0.15 or higher, and more preferably 0 or higher. The upper limit of the value is preferably 0.95 or lower, and more preferably 0.85 or lower. Formula (a): 0.00304 × apparatus diameter [m] + 0.00261 × bed height [m] + 0.0179 × residence time [hours] + 0.00213 × particle temperature in drying container [K] - 0.0109 × tilt angle [degrees] + 0.0212 × CXS component content [mass %]

[0088] If the value obtained by formula (a) is between -0.20 and 1.05, then rat holes and other issues will not occur in the container, preventing residual particles from remaining in the container, and allowing the entire amount of dried particles to be stably discharged outside the drying container. If there is a downstream process, when the particles are transferred in the transfer piping, blockage of the transfer piping by the particles will not occur, and the particles can be stably transferred to the downstream process. Ultimately, this enables the stable production of polyolefin resin compositions.

[0089] Here, "rat hole" refers to a cylindrical pore formed by particles remaining inside the drying container when particles inside the container are discharged, as only the particles located directly above the discharge opening are discharged.

[0090] In formula (a), the apparatus diameter, more specifically, represents the maximum inner diameter when the cylindrical body of the drying container, which contains the particles, is cut by a plane perpendicular to the direction of extension.

[0091] In this embodiment, the diameter of the device is preferably, for example, 0.1m to 10.0m, and more preferably 0.6m to 7.0m.

[0092] In equation (a), the bed height is, more specifically, the maximum height at which polyolefin-containing particles remaining in the drying container are located, and represents the distance from the lowest end of the drying container, i.e., the height of the outlet for normally discharging particles, to the substantially flat surface on which the polyolefin-containing particles remaining in the drying container are located (specific embodiments will be described later with reference to the drawings).

[0093] In this embodiment, the bed height is preferably, for example, 0.10m to 40.00m, and more preferably 0.72m to 25.00m.

[0094] In formula (a), residence time represents the time that the particles containing polyolefin remain in the drying container during the drying process.

[0095] Specifically, if the drying process is a batch drying process, residence time refers to the total time from when the particles are supplied into the drying container and the drying gas is supplied into the drying container, until the dried particles are discharged from the drying container. If the drying process is a continuous drying process, residence time refers to the value calculated by dividing the average amount of particles held in the drying container during the continuous drying process [kg] by the average discharge rate of particles discharged from the drying container during the continuous drying process [kg / hour]. Note that "during the continuous drying process" refers to the period from the start point when a predetermined amount of particles are present in the drying container, the drying gas is supplied into the drying container, particles are supplied into the drying container, and dried particles are discharged from the drying container, to the end point when the supply of particles into the drying container and the discharge of particles from the drying container are stopped.

[0096] In this embodiment, the residence time is preferably 1 hour or more and 48 hours or less, the lower limit of the value is more preferably 2 hours or more, and even more preferably 4 hours or more. The upper limit of the value is preferably 23 hours or less, and even more preferably 19 hours or less.

[0097] In formula (a), the particle temperature in the container refers to the temperature of the particles in the drying container. In this embodiment, the temperature of the particles in the drying container during the drying process is preferably, for example, between 273K (0°C) and 433K (160°C), with the lower limit of the value being more preferably 298K (25°C) or higher, and even more preferably 333K (60°C) or higher. The upper limit of the value is more preferably 413K (140°C) or lower, and even more preferably 373K (110°C) or lower.

[0098] Here, regarding the particle temperature inside the container, if the drying process is a batch drying process, the particle temperature inside the container refers to the average particle temperature inside the drying container from the time the particles are supplied into the drying container until the particles are discharged from the drying container. If the drying process is a continuous drying process, the particle temperature inside the drying container refers to the average temperature of the particles present inside the drying container during the continuous drying period in which particles are continuously supplied into and discharged from the drying container. The particle temperature can be measured by measuring the temperature of the particle filling section inside the drying container, and if temperatures are measured at multiple locations, the average value can be used as the particle temperature.

[0099] In equation (a), the inclination angle represents the external angle between the inclined surface of the drying container and the horizontal surface on which it is installed, when the drying container is installed in the operating state, i.e., when the direction of extension of the cylindrical part of the drying container coincides with the vertical direction. Note that the external angle refers to the angle on the outside of the drying container, not the angle on the inside of the drying container where the particles are present.

[0100] In this embodiment, the inclination angle is typically greater than 0° and less than 180°. Preferably, the inclination angle is 30° or greater, more preferably 45° or greater, and even more preferably 55° or greater. It is preferably 120° or less, and more preferably 90° or less.

[0101] In this embodiment, a particle discharge device may be installed downstream of the drying container. The discharge device is not particularly limited. Examples of discharge devices include ball valves, rotary valves, and circle feeders.

[0102] Medium diameter of a particle The median diameter of the particles in this embodiment is preferably 500 μm or more and 10000 μm or less, more preferably 1500 μm or more and 7500 μm or less, and even more preferably 3000 μm or more and 5000 μm or less.

[0103] In this embodiment, the median diameter of the particles can be measured by laser diffraction particle size distribution analysis or sieve vibration particle size distribution analysis. These methods will be described below.

[0104] (Laser diffraction particle size distribution measurement method) In this embodiment, the median diameter of the particles can be measured, for example, using a laser diffraction particle size distribution analyzer (e.g., HELOS / KF, sample disperser: GRADIS+VIBRI, manufactured by Sympatec).

[0105] Specifically, a sample of approximately 1-10g of particles is placed in a particle size distribution analyzer to measure the particle size distribution, and then analyzed using analysis software (e.g., WINDOX ver5.3.1.0) to determine the median diameter (D) based on volume. 50 The average of the measurements can be calculated. Alternatively, the above sample may be measured 3 to 5 more times, and the average of these measurements may be used as the average median diameter.

[0106] (Sieve vibration type particle size distribution measurement method) In this embodiment, when measuring the average median diameter of particles, the average median diameter may be calculated by vibrating a sieve and using gravity to separate particles based on their particle size from the mesh stretched at the bottom of the sieve, thereby measuring the particle size distribution by sieving.

[0107] Specifically, it is as follows: First, using sieves with different mesh sizes, stack them in several layers, from the largest mesh to the smallest mesh, starting from the largest. Next, the sample is placed into the top sieve, and then all sieves are vibrated four times for 5 minutes each, with a shaking amplitude of 1.0 mm, to perform sieving.

[0108] For example, sieves with mesh sizes of 5600 μm, 4750 μm, 4000 μm, 3350 μm, 2360 μm, 2000 μm, 1700 μm, 1400 μm, 1180 μm, 1000 μm, 850 μm, 710 μm, 500 μm, 300 μm, and 150 μm (JIS Z 8801, manufactured by Manabe Kogyo Co., Ltd.) can be used.

[0109] The sample size should be, for example, 100g or more. A Retsch AS200 electromagnetic sieve vibrator can be used as the sieve vibrator.

[0110] The measurement can be performed by weighing the sample remaining on each sieve. Specifically, it is as follows: The amount of sample remaining on each sieve after shaking is weighed. The amounts of sample remaining on each sieve are added together, starting with the sieve with the largest mesh size. Sieve b is designated as the sieve whose combined amount exceeds 50% of the total amount of sample put into the sieve. Sieve a is designated as the sieve immediately above sieve b. Based on the above measurements, the average median diameter (D) can be calculated using the following formula. 50 It is possible to calculate ). D 50 =Da-[(Da-Db)×{(xb-50) / (xb-xa)}]

[0111] If more than 50% of the total sample volume is not found in any of the sieves, the sieve with the largest amount of remaining sample is designated as sieve b, and the sieve immediately above sieve b is designated as sieve a.

[0112] In the above formula, Da represents the mesh size [μm] of sieve a, Db represents the mesh size [μm] of sieve b, xa represents the sum of the percentage [%] of the amount of sample remaining on sieve a relative to the total sample amount, and the cumulative percentage [%] of the sieve above sieve a, and xb represents the sum of the percentage [%] of the amount of sample remaining on sieve b relative to the total sample amount, and the cumulative percentage [%] of the sieve above sieve b.

[0113] 2. Method for storing particles containing polyolefins The storage method for polyolefin-containing particles according to this embodiment includes a storage step of supplying polyolefin-containing particles to a storage container and storing the polyolefin-containing particles in the storage container, This is a method for storing particles containing polyolefins, wherein the value obtained by the following formula (b) during the storage process is between -0.20 and 1.05. Formula (b): 0.00304 × device diameter [m] + 0.00261 × bed height [m] + 0.0179 × residence time [hours] + 0.00213 × particle temperature in storage container [K] - 0.0109 × tilt angle [degrees] + 0.0212 × CXS component amount [mass %]

[0114] In formula (b), The device diameter refers to the maximum diameter of the body of the storage container. Bed height refers to the maximum height from the outlet for discharging polyolefin-containing particles to the height at which polyolefin-containing particles are located within the storage container. Residence time refers to the time that polyolefin-containing particles remain in the storage container. The particle temperature inside the storage container refers to the temperature of the polyolefin-containing particles inside the storage container. The inclination angle refers to the external angle between the inclined surface of the storage container and the mounting surface, where the external angle refers to the angle on the outside of the container. The CXS component amount refers to the amount of CXS component contained in polyolefin-containing particles. Here, the outer angle refers to the angle on the outside of the storage container, not the inside of the storage container where the particles are located. Furthermore, regarding the "device diameter," if the shape of the body is cylindrical, the "maximum diameter" corresponds to the inner diameter (diameter) when the cylinder is cut in a direction perpendicular to the direction of extension. If the shape of the body is other than cylindrical, it corresponds to the "equivalent circular diameter" that applies to the shape defined by the inner wall when the cylinder is cut in a direction perpendicular to the direction of extension.

[0115] In the storage method for polyolefin-containing particles of this embodiment, the "polyolefin-containing particles" are the same as the "polyolefin-containing particles" in the "drying method for polyolefin-containing particles" described above.

[0116] The method for storing polyolefin-containing particles according to this embodiment includes a storage step of supplying polyolefin-containing particles to a storage container and storing the polyolefin-containing particles in the storage container. The configuration of the storage container is the same as that of the drying container in the drying step described above.

[0117] The granulation process in the storage method of this embodiment can be carried out using any suitable conventionally known granulation apparatus. The granulation process (granulation conditions) and the granulation apparatus used in the granulation process are the same as those for the drying method of polyolefin-containing particles described above.

[0118] After the granulation process, the granulated particles are stored in a storage container. The configuration of the storage container is the same as that of the drying container described later.

[0119] In the storage process of this embodiment, the value obtained by the following formula (b) is between -0.20 and 1.05, with a lower limit of -0.15 or higher, and more preferably 0 or higher. The upper limit of the value is between 0.95 or lower, and more preferably 0.85 or lower. Formula (b): 0.00304 × Device diameter [m] + 0.00261 × Bed height [m] + 0.0179 × Residence time [hours] + 0.00213 × Particle temperature in storage container [K] - 0.0109 × Inclination angle [degrees] + 0.0212 × CXS component content [mass %]

[0120] Furthermore, the storage process in this embodiment is carried out using a so-called "batch method." That is, the storage process in this embodiment can be carried out in the same manner as the batch drying process in the drying method described earlier. Here, in the storage process of this embodiment, the particles do not necessarily have to be dried. In other words, in the storage process, volatile components and the like contained in the particles may or may not be removed.

[0121] If the value obtained by formula (b) is between -0.20 and 1.05, then rat holes and other issues will not occur in the container, preventing particles from remaining in the container, and allowing the entire amount of stored particles to be stably discharged outside the storage container. If there is a downstream process, when the particles are transferred in the transfer piping, blockage of the transfer piping by the particles will not occur, and the particles can be stably transferred to the downstream process. Ultimately, this enables the stable production of polyolefin resin compositions.

[0122] In this embodiment, the drying method and storage method described above can be combined. That is, in this embodiment, for example, the storage method described above may be carried out after the drying method described above has been carried out. In this embodiment, the finished product can be made from polyolefin-containing particles produced by carrying out only the drying method described above, or from polyolefin-containing particles produced by carrying out only the storage method (provided that volatile components contained in the particles are removed) without carrying out the drying method. [Examples]

[0123] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples.

[0124] The measurement and evaluation methods in the examples and comparative examples are shown below.

[0125] [Ethylene content (unit: mass%)] The ethylene unit content in the polymer was determined using the IR spectral method, which conforms to the IR spectral measurement described on page 619 of the Polymer Handbook (published by Kinokuniya Shoten in 1995). Here, "ethylene unit" refers to a structural unit derived from ethylene.

[0126] The ethylene unit content in the propylene-ethylene copolymer was determined by dividing the content of structural units derived from ethylene in the heterophagic propylene polymerization material (referred to as the ethylene unit content) by the mass percentage [mass%] of the propylene-ethylene copolymer in the heterophagic propylene polymerization material, and then multiplying by 100.

[0127] [Amount of xylene soluble at 20°C (unit: mass%)] The amount of xylene-soluble portion (CXS component, unit: mass%) of polyolefin-containing particles at 20°C was determined by adding 200 mL of xylene to 1 g of polyolefin-containing particles, boiling to completely dissolve the polyolefin, then cooling and conditioned at 20°C for at least 1 hour. The soluble and insoluble portions were then separated using filter paper. For the soluble portion, the solvent was removed from the filtrate, and the sample was dried. The amount of CXS component was determined by weighing the sample.

[0128] [Mooney viscosity (unit: ML(1+4)125℃)] Mooney viscosity was measured at a temperature of 125°C in accordance with JIS K 6300. [Diene content (unit: mass%)] The diene content was measured by FT-IR. [Propylene content (unit: mass%)] In Table 1, the propylene content of EPDM is the value obtained by subtracting the ethylene content and diene content from 100% by mass, while the propylene content of HP1, HP2, and RC is the value obtained by subtracting the ethylene content from 100% by mass. The meaning of the abbreviations will be explained later.

[0129] [Example 1] (Production of Particle A) The raw material components shown in Table 1 below were mixed in the proportions shown in Table 2 below, and a granulation process was carried out using an extruder (TEX 90α) manufactured by Japan Steel Works, Ltd. under the conditions shown in Table 3 below to obtain particles A containing a propylene-based polymer, which is a polyolefin. The physical properties of particles A are shown in Table 4 below.

[0130] [Table 1]

[0131] [Table 2]

[0132] [Table 3]

[0133] <Drying process for particle A> Using the first drying container 11 shown in Figure 1, a drying process was carried out in which particles A were dried in a batch manner under the conditions shown in Table 4 below by supplying heated air from the bottom of the first drying container.

[0134] Here, with reference to Figure 1, an example of the configuration of the first drying container 11 will be described. Figure 1 is a schematic diagram illustrating an example of the configuration of the first drying container.

[0135] As shown in Figure 1, the first drying container 11, in this configuration example, includes a hollow drying container 100 which is composed of a cylindrical body 100A, a frustoconical portion 100B integrally connected to the body 100A and having an inclined surface 100Ba, and a circle feeder 100C connected to the frustoconical portion 100B (the protruding motor portion 100D is also included in the circle feeder). The drying container 100 can be made of any suitable material that is conventionally known.

[0136] When in use, the drying container 100 is positioned such that the smaller of the two frustoconical sections 100B, the apex 100Bb, is the lower end in the vertical direction, and the end of the body section 100A on the side opposite to where the frustoconical section 100B is connected becomes the upper end 100Aa. More specifically, the drying container 100 is installed such that the central axis C passing through the apex 100Bb of the frustoconical section 100B and the center of the upper end 100Aa of the body section 100A is perpendicular to the horizontal installation surface 1.

[0137] A supply line 101 is connected to the upper end portion 100Aa of the body portion 100A of the drying container 100. The supply line 101 is configured to introduce the material to be dried, such as particles containing a propylene polymer, which is a polyolefin, into the drying container 100.

[0138] A cylindrical circle feeder 100C is provided on the top surface 100Bb of the frustoconical portion 100B of the drying container 100, such that the upper surface 100Ca of the circle feeder 100C is connected to the top surface 100Bb of the frustoconical portion 100B.

[0139] Here, the angle θ between the inclined surface 100Ba of the frustum-shaped portion 100B, which is a part of the side wall of the drying container 100, and the upper surface 100Ca of the circle feeder 100C, that is, the angle θ (referred to as the inclination angle) between the inclined surface 100Ba of the frustum-shaped portion 100B and the horizontal installation surface 1, is 70° in Example 1.

[0140] A motor unit 100D protrudes from the lower surface 100Cb of the circle feeder 100C. A discharge line 102 is connected to the area of ​​the lower surface 100Cb of the circle feeder 100C that is away from the central axis C and the motor unit 100D. The discharge line 102 is connected to a discharge port and is configured to discharge the dried material outside the circle feeder 100C, i.e., outside the drying container 100.

[0141] In the first drying container 11, the lowest point used as the basis for calculating the "bed height" is the top surface 100Bb, which is the lower end of the frustoconical portion 100B. Furthermore, if a discharge device such as a circle feeder 100C is provided, the diameter of the discharge port corresponds to the diameter of the opening on the first drying container 11 side to which the discharge device is connected.

[0142] The supply line 101 and the discharge line 102 can be any suitable configuration that is conventionally known, including piping, valves, etc. Furthermore, the supply line 101 and the discharge line 102 can be configured in any suitable arrangement, shape, and size according to the desired configuration. The circle feeder 100C (and motor unit 100D) can also be any suitable configuration that is conventionally known.

[0143] After the drying process was completed, the Circle Feeder 100C (manufactured by Yoshikawa Co., Ltd.) was started and particles A were discharged from the first drying container 11, and the entire amount of particles A was discharged stably.

[0144] [Examples 2 and 3 and Comparative Examples 1 and 2] Examples 2 and 3, and Comparative Examples 1 and 2 were carried out in the same manner as in Example 1, except that the drying process conditions were as shown in Table 4 below. The results are shown in Table 4 below.

[0145] Now, with reference to Figure 2, an example of the configuration of the second drying container 12 will be described. Figure 2 is a schematic diagram illustrating an example of the configuration of the second drying container.

[0146] As shown in Figure 2, the second drying container 12 includes a hollow drying container 100 composed of a cylindrical section 100A and a circle feeder 100C connected to the cylindrical section 100A (the protruding motor section 100D is also included in the circle feeder). The drying container 100 can be made of any suitable material that is conventionally known.

[0147] When the drying container 100 is in use, the central axis C passing through the center of the upper end 100Aa and lower end 100Ab of the cylindrical portion 100A, and the center of the upper surface 100Ca and lower surface 100Cb of the circle feeder 100C, is installed perpendicular to the horizontal installation surface 1. The upper end 100Aa and lower end 100Ab of the cylindrical portion 100A, and the upper surface 100Ca and lower surface 100Cb of the circle feeder 100C are all positioned parallel to the installation surface 1.

[0148] A supply line 101 is connected to the upper end 100Aa of the cylindrical portion 100A of the drying container 100. The supply line 101 is configured to introduce the material to be dried, such as particles containing a propylene polymer, which is a polyolefin, into the drying container 100.

[0149] A cylindrical circle feeder 100C is provided at the lower end 100Ab of the cylindrical portion 100A of the drying container 100, such that the upper surface 100Ca of the circle feeder 100C is connected to the lower end 100Ab.

[0150] Here, the angle θ between the side wall 100Ac of the cylindrical portion 100A (drying container 100) and the upper surface 100Ca of the circle feeder 100C, that is, the angle θ between the side wall 100Ac and the horizontal installation surface 1, is 90° in Examples 2 and 3 and Comparative Examples 1 and 2. Even when the angle is 90° as in this embodiment, "θ" is referred to as the "angle of inclination" in this specification. Therefore, in the second drying container 12, the angle of inclination θ is 90°.

[0151] A motor unit 100D, which is part of the circle feeder 100C, protrudes from the lower surface 100Cb of the circle feeder 100C. A discharge line 102 is connected to a discharge port located in the area of ​​the lower surface 100Cb of the circle feeder 100C that is away from the central axis C and the motor unit 100D. The discharge line 102 is configured to discharge the dried material outside the circle feeder 100C, i.e., outside the drying container 100.

[0152] In the second drying container 12, the lowest point used as the basis for calculating the "bed height" is the lower end 100Ab of the cylindrical section 100A. Thus, when a discharge device such as a circle feeder 100C is provided, the connection point between the discharge device and the drying container becomes the lowest point. Also, when a discharge device such as a circle feeder 100C is provided, the diameter of the discharge port corresponds to the diameter of the opening on the second drying container 12 side to which the discharge device is connected.

[0153] The supply line 101 and the discharge line 102 can be any suitable configuration known conventionally, including piping, valves, etc. Furthermore, the supply line 101 and the discharge line 102 can be configured in any suitable arrangement, shape, and size according to the desired configuration. The circle feeder 100C can also be any suitable configuration known conventionally.

[0154] [Example 4] (Production of Particle B) <Manufacturing of Solid Catalyst Components> After replacing the atmosphere inside a 100 mL flask equipped with a stirrer, dropping funnel, and thermometer with nitrogen gas, 36.0 mL of toluene and 22.5 mL of titanium tetrachloride were added to the flask and stirred to obtain a titanium tetrachloride solution.

[0155] Next, the atmosphere temperature inside the flask was set to 0°C, and then 1.88 g of magnesium diethoxide was added four times at 30-minute intervals at 0°C, followed by stirring at 0°C for 1.5 hours.

[0156] Next, 0.60 mL of ethyl 2-ethoxymethyl-3,3-dimethylbutanoate was added to the flask, and then the temperature inside the flask was raised to 10°C.

[0157] The mixture was then stirred at 10°C for 2 hours, and 9.8 mL of toluene was added. Next, the temperature in the flask was raised, and when it reached 60°C, 3.15 mL of ethyl 2-ethoxymethyl-3,3-dimethylbutanoate was added to the flask, and the temperature was raised to 110°C. The mixture in the flask was then stirred at 110°C for 3 hours.

[0158] The mixture obtained by stirring as described above was separated into solid and liquid to obtain a solid. The obtained solid was washed three times with 56.3 mL of toluene at 100°C.

[0159] To the washed solid, 38.3 mL of toluene was added to form a slurry. To the obtained slurry, 15.0 mL of titanium tetrachloride and 0.75 mL of ethyl 2-ethoxymethyl-3,3-dimethylbutanoate were added to form a mixture, and the mixture was stirred at 110°C for 1 hour. The resulting mixture was separated into solid and liquid components, and the obtained solid was washed three times with 56.3 mL of toluene at 60°C, and then three times with 56.3 mL of hexane at room temperature. The washed solid was dried under reduced pressure to obtain a solid catalyst component.

[0160] The obtained solid catalyst component had a titanium atom content of 2.53 mass%, an ethoxy group content of 0.44 mass%, and an internal electron donor content of 13.7 mass%.

[0161] The median particle size of the obtained solid catalyst components, determined by laser diffraction and scattering, was 59.5 μm, and the cumulative percentage of components with a particle size of 10 μm or less in the volume-based particle size distribution was 5.3%.

[0162] XPS analysis of the obtained solid catalyst components revealed that 85.0% of the peak components originating from the oxygen atom 1s orbital had peak positions in the bond energy range of 532–534 eV, while 15.0% had peak positions in the bond energy range of 529–532 eV.

[0163] The total pore volume of the obtained solid catalyst component obtained by mercury intrusion was 1.43 mL / g, the total volume of pores in the pore radius range of 5-30 nm was 0.160 mL / g, the total volume of pores in the pore radius range of 30-700 nm was 0.317 mL / g, and the specific surface area was 107.44 m². 2 It was / g.

[0164] (Manufacturing of heterophagic propylene polymerization materials) <Prepolymerization Process> A stainless steel (SUS) autoclave with a stirrer and an internal volume of 3 L contained 1.7 L of thoroughly dehydrated and degassed n-hexane, 34 mmol of triethylaluminum (TEA), and 3.4 mmol of tert-butyl-n-propyldimethoxysilane.

[0165] After adding 12g of the solid catalyst component prepared as described above into the autoclave, a preliminary polymerization process was carried out in which 12g of propylene was continuously supplied over approximately 30 minutes while maintaining the temperature inside the autoclave at approximately 10°C.

[0166] Subsequently, the slurry obtained from the preliminary polymerization process was transferred to a SUS316L autoclave with a stirrer and an internal volume of 260L, and 180L of liquid butane was added to form the slurry.

[0167] <Main polymerization process> In this polymerization process, an apparatus was used in which a slurry polymerization reactor, a multi-stage gas-phase polymerization reactor, and two gas-phase polymerization reactors were arranged and connected in series.

[0168] This polymerization process was carried out in polymerization steps 1-a, 1-b, 2-a, and 2-b. Specifically, a propylene homopolymer, propylene polymer a, was produced in polymerization steps 1-a and 1-b. The generated propylene polymer a and solid catalyst components were transferred to the next polymerization reactor without deactivation, and the polymerization was carried out in polymerization steps 2-a and 2-b by polymerizing propylene copolymer b, which is a propylene-ethylene copolymer. Polymerization steps 1-a, 1-b, 2-a, and 2-b will be described in detail below.

[0169] (Polymerization process 1-a) (Homopolymerization of propylene using a slurry polymerization reactor) Propylene homopolymerization was performed using a SUS304 vessel-type slurry polymerization reactor equipped with a stirrer.

[0170] Specifically, the slurry of propylene, hydrogen, TEA, tert-butyl-n-propyldimethoxysilane, and the aforementioned prepolymerization catalyst components obtained in the prepolymerization step was continuously supplied to a slurry polymerization reactor to carry out the polymerization reaction. The reaction conditions were as follows. Polymerization temperature: 50℃ Stirring speed: 150rpm Liquid level in slurry polymerization reactor: 18L Propylene supply: 20 kg / hour Hydrogen supply: 28.6 NL / hour TEA supply: 39.0 mmol / hour Supply rate of tert-butyl-n-propyldimethoxysilane: 7.60 mmol / hour Slurry supply rate (calculated as solid catalyst component): 0.45 g / hour Polymerization pressure: 3.77 MPa (gauge pressure)

[0171] The intrinsic viscosity [η]L1 of the product (propylene homopolymer) sampled from the outlet of the slurry polymerization reactor was 1.23 dL / g.

[0172] (Polymerization process 1-b) (Homopolymerization of propylene using a multi-stage gas-phase polymerization reactor (gas-phase polymerization)) Propylene homopolymerization was carried out using a multi-stage gas-phase polymerization reactor with six reaction zones in the vertical direction, the uppermost of which was a fluidized bed, and the remaining five zones were jet beds.

[0173] Specifically, the slurry containing particulate propylene homopolymer and liquid propylene produced in polymerization step 1-a was transferred from the slurry polymerization reactor to the fluidized bed, which is the uppermost stage of the multi-stage gas-phase polymerization reactor, without deactivation and continuously supplied.

[0174] Interstage transfer of propylene homopolymer within the multistage gas-phase polymerization reactor was performed using a double-valve system. In this system, the upper and lower reaction regions were connected by a 1-inch diameter pipe, and two on-off valves were installed in the pipe. The downstream valve was closed while the upstream valve was opened, temporarily accumulating powder between the valves from the upper reaction region. Then, the particulate propylene homopolymer was transferred to the lower reaction region by closing the upstream valve and opening the downstream valve.

[0175] Propylene and hydrogen were continuously supplied from the bottom of the multi-stage gas-phase polymerization reactor having the above configuration. This formed a fluidized bed or jet bed in each reaction region of the multi-stage reactor, and the supply amounts of propylene and hydrogen were controlled to maintain a constant gas composition and pressure, while further homopolymerization of propylene was carried out while purging excess gas. The reaction conditions were as follows. Polymerization temperature: 60℃ Polymerization pressure: 1.80 MPa (gauge pressure) Gas concentration ratio (hydrogen / (hydrogen + propylene)): 6.0 mol%

[0176] The intrinsic viscosity [η]G1 of the product (propylene homopolymer) sampled from the outlet of the multi-stage gas-phase polymerization reactor was 1.24 dL / g. [η]L1 and [η]G1 were approximately the same value. Therefore, the propylene homopolymer produced by carrying out polymerization step 1-b is propylene-based polymer a, and [η]G1 is the intrinsic viscosity of propylene-based polymer a.

[0177] <Polymerization Process 2-a> (Propylene-ethylene copolymerization (gas-phase polymerization) using a gas-phase polymerization reactor (first gas-phase polymerization reactor)) The propylene polymer a discharged from the multi-stage gas-phase polymerization reactor used in polymerization step 1-b was continuously supplied to the subsequent first gas-phase polymerization reactor. The first gas-phase polymerization reactor used in polymerization step 2-a was a reactor equipped with a gas dispersion plate, and the transfer of propylene polymer a from the multi-stage gas-phase polymerization reactor to the first gas-phase polymerization reactor was carried out using the double valve system already described.

[0178] Propylene, ethylene, and hydrogen were continuously supplied to the first gas-phase polymerization reactor with the above configuration. The gas supply rate was adjusted to maintain a constant gas composition and pressure, and excess gas was purged. Propylene copolymerization of propylene and ethylene was carried out in the presence of propylene polymer a particles. The reaction conditions were as follows. Polymerization temperature: 70℃ Polymerization pressure: 1.50 MPa (gauge pressure) Gas concentration ratio (ethylene / (propylene + ethylene)): 45.6 mol% (Hydrogen / (Hydrogen + Propylene + Ethylene)): 3.3 mol%

[0179] <Polymerization Process 2-b> (Propylene-ethylene copolymerization (gas-phase polymerization) using a gas-phase polymerization reactor (second gas-phase polymerization reactor)) The particles discharged from the first gas-phase polymerization reactor used in polymerization step 2-a were continuously supplied to the subsequent second gas-phase polymerization reactor. The second gas-phase polymerization reactor used in polymerization step 2-b was a reactor equipped with a gas dispersion plate, and the transfer of particles from the first gas-phase polymerization reactor to the second gas-phase polymerization reactor was carried out using the double valve system already described.

[0180] Propylene, ethylene, and hydrogen were continuously supplied to the second gas-phase polymerization reactor with the above configuration. By adjusting the gas supply rate to maintain a constant gas composition and pressure, and purging excess gas, copolymerization of propylene and ethylene was carried out to produce a propylene-ethylene copolymer, which is propylene copolymer b, and a heterophagous propylene polymerization material, which is a mixture of propylene polymer a and propylene copolymer b, was obtained.

[0181] The reaction conditions for polymerization step 2-b in the second gas-phase polymerization reactor were as follows. Polymerization temperature: 70℃ Polymerization pressure: 1.20 MPa (gauge pressure) Gas concentration ratio (ethylene / (propylene + ethylene)): 45.6 mol% (Hydrogen / (Hydrogen + Propylene + Ethylene)): 3.3 mol%

[0182] Furthermore, since polymerization steps 2-a and 2-b were carried out under the same conditions for polymerization temperature and gas concentration ratio, the propylene-ethylene copolymer produced in polymerization step 2-a and the propylene-ethylene copolymer produced in polymerization step 2-b can be considered to have almost the same structure.

[0183] As described above, by carrying out polymerization steps 2-a and 2-b, a heterophagic propylene polymerization material further containing "propylene copolymer b," which is a propylene-ethylene copolymer, was obtained.

[0184] The proportion (X) of propylene copolymer b in the obtained heterophagic propylene polymerization material was calculated using the following formula, after measuring the heat of fusion of propylene polymer a and the total heat of fusion of the heterophagic propylene polymerization material. Here, the heat of fusion was measured by differential scanning thermal analysis (DSC). X = 1 - (ΔHf)T / (ΔHf)P (ΔHf)T: Total heat of fusion of the heterophagic propylene polymerization material (J / g) (ΔHf)P: Heat of fusion of propylene polymer a (J / g)

[0185] The intrinsic viscosity [η]G2 of the product (heterophasic propylene polymerization material) sampled from the outlet of the second gas-phase polymerization reactor was 1.87 dL / g.

[0186] The product obtained from the outlet of the second gas-phase polymerization reactor is a mixture of propylene polymer a and propylene copolymer b. The intrinsic viscosity [η]C of propylene copolymer b was calculated using the following formula. [η]C=([η]G2-[η]G1×(1-X)) / X

[0187] The obtained heterophagic propylene polymerization material had an intrinsic viscosity ([η]Total) of 1.87 dL / g, with an ethylene content of 19.8% by mass and a propylene content of 80.2% by mass. The polymerization ratio of propylene polymer a and propylene copolymer b was 54 / 46 [mass% / mass%], respectively. The ethylene content in propylene copolymer b was 41% by mass, and the intrinsic viscosity [η]C of propylene copolymer b was 2.6 dL / g.

[0188] <Solid-gas separation process and catalyst deactivation process> The heterophagic propylene polymerization material obtained in polymerization step 2 above was transferred from the gas-phase polymerization reactor to a SUS solid-gas separation vessel, and a catalyst deactivation step was performed in conjunction with the solid-gas separation step by supplying water vapor (steam) and nitrogen gas from the bottom of the solid-gas separation vessel to deactivate the solid catalyst components.

[0189] <Drying process for particle B> Using the third drying container 13 shown in Figure 3, a drying process was carried out in which particles B were dried in a batch manner under the conditions shown in Table 4 by supplying heated nitrogen gas from the bottom of the third drying container.

[0190] Now, with reference to Figure 3, an example of the configuration of the third drying container 13 will be described. Figure 3 is a schematic diagram illustrating an example of the configuration of the third drying container.

[0191] As shown in Figure 3, the third drying container 13 includes a hollow drying container 100 which is composed of a cylindrical portion 100A and a conical portion 100E integrally connected to the cylindrical portion 100A and having an inclined surface 100Ea. The drying container 100 can be made of any suitable material that is conventionally known.

[0192] When in use, the drying container 100 is positioned such that the apex 100Eb of the conical portion 100E is the lower end in the vertical direction, and the end of the cylindrical portion 100A on the side opposite to the side to which the conical portion 100E is connected becomes the upper end 100Aa. More specifically, the drying container 100 is installed such that the central axis C passing through the apex 100Eb of the conical portion 100E and the center of the upper end 100Aa of the cylindrical portion 100A is perpendicular to the horizontal installation surface 1.

[0193] A supply line 101 is connected to the upper end 100Aa of the cylindrical portion 100A of the drying container 100. The supply line 101 is configured to introduce the material to be dried, such as particles containing a propylene polymer, which is a polyolefin, into the drying container 100.

[0194] Here, the angle θ (referred to as the inclination angle) between the inclined surface 100Ea of the cone portion 100E and the horizontal installation surface 1 is 60° in Example 4.

[0195] A discharge line 102 is connected to the discharge port located at the apex 100Eb of the conical portion 100E of the drying container 100. The discharge line 102 is configured to discharge the dried material outside the drying container 100.

[0196] In the third drying container 13, the lowest point used as the basis for calculating the "bed height" is the apex 100Eb, which is the lower end of the conical section 100E.

[0197] In the third drying container 13, a ball valve 103 is provided in the discharge line 102. The ball valve 103 is a functional part that, through its opening and closing operation, either discharges the dried material to the outside of the drying container 100 or retains the material inside the drying container 100.

[0198] As described above, when the ball valve 103 is used, the diameter of the outlet corresponds to the diameter of the opening at the peak of 100Eb.

[0199] The supply line 101 and the discharge line 102 can be any suitable conventional configuration known to include piping, valves, etc. Furthermore, the supply line 101, the discharge line 102, and the ball valve 103 can be configured in any suitable arrangement, shape, and size according to the desired configuration.

[0200] After the drying process was completed, the ball valve 103 of the third drying container 13 was opened, and the particles B were discharged from the third drying container 13, allowing for the stable discharge of the entire amount of particles B.

[0201] [Example 5] Example 5 was carried out in the same manner as Example 4, except that the drying process conditions were as shown in Table 4 below. The results are shown in Table 4 below.

[0202] [Example 6] (Production of Particle D) (Production of propylene homopolymer) <Prepolymerization Process> A stainless steel (SUS) autoclave with a stirrer and an internal volume of 3 L contained 1.9 L of thoroughly dehydrated and degassed n-hexane, 48 mmol of triethylaluminum (TEA), and 4.8 mmol of tert-butyl-n-propyldimethoxysilane.

[0203] After adding 19 g of the solid catalyst component prepared in the same manner as in Example 4 described above to the autoclave, a preliminary polymerization step was performed in which 19 g of propylene was continuously supplied over approximately 30 minutes while maintaining the temperature inside the autoclave at approximately 10°C.

[0204] Subsequently, the slurry obtained from the preliminary polymerization process was transferred to a SUS316L autoclave with a stirrer and an internal volume of 260L, and 180L of liquid butane was added to form the slurry.

[0205] <Main polymerization process> In this polymerization process, an apparatus was used in which a slurry polymerization reactor and a multi-stage gas-phase polymerization reactor were arranged and connected in series.

[0206] In this polymerization process, propylene-based polymer a, which is a propylene homopolymer, was polymerized in polymerization steps 1-a and 1-b described below.

[0207] <Polymerization process 1-a> (Homopolymerization of propylene using a slurry polymerization reactor) Propylene homopolymerization was performed using a SUS304 vessel-type slurry polymerization reactor equipped with a stirrer.

[0208] Specifically, the slurry of propylene, hydrogen, TEA, tert-butyl-n-propyldimethoxysilane, and the aforementioned prepolymerization catalyst components obtained in the prepolymerization step was continuously supplied to a slurry polymerization reactor to carry out the polymerization reaction. The reaction conditions were as follows. Polymerization temperature: 50℃ Stirring speed: 150rpm Liquid level in slurry polymerization reactor: 18L Propylene supply: 18 kg / hour Hydrogen supply: 47.1 NL / hour TEA supply: 33.0 mmol / hour Supply rate of tert-butyl-n-propyldimethoxysilane: 6.46 mmol / hour Slurry supply rate (calculated as solid catalyst component): 0.79 g / hour Polymerization pressure: 4.09 MPa (gauge pressure)

[0209] The intrinsic viscosity [η]L1 of the product (propylene homopolymer) sampled from the outlet of the slurry polymerization reactor was 0.98 dL / g.

[0210] (Polymerization process 1-b) (Homopolymerization of propylene using a multi-stage gas-phase polymerization reactor (gas-phase polymerization)) Propylene homopolymerization was carried out using a multi-stage gas-phase polymerization reactor with six reaction zones in the vertical direction, the uppermost of which was a fluidized bed, and the remaining five zones were jet beds.

[0211] Specifically, the slurry containing particulate propylene homopolymer and liquid propylene produced in polymerization step 1-a was transferred from the slurry polymerization reactor to the fluidized bed, which is the uppermost stage of the multi-stage gas-phase polymerization reactor, without deactivation and continuously supplied.

[0212] Interstage transfer of propylene homopolymer within the multistage gas-phase polymerization reactor was performed using a double-valve system. In this system, the upper and lower reaction regions were connected by a 1-inch diameter pipe, and two on-off valves were installed in the pipe. The downstream valve was closed while the upstream valve was opened, temporarily accumulating powder between the valves from the upper reaction region. Then, the particulate propylene homopolymer was transferred to the lower reaction region by closing the upstream valve and opening the downstream valve.

[0213] Propylene and hydrogen were continuously supplied from the bottom of the multi-stage gas-phase polymerization reactor having the above configuration. This formed a fluidized bed or jet bed in each reaction region of the multi-stage reactor, and the supply amounts of propylene and hydrogen were controlled to maintain a constant gas composition and pressure, while further homopolymerization of propylene was carried out while purging excess gas. The reaction conditions were as follows. Polymerization temperature: 70℃ Polymerization pressure: 1.79 MPa (gauge pressure) Gas concentration ratio (hydrogen / (hydrogen + propylene)): 9.5 mol%

[0214] The intrinsic viscosity [η]G1 of the product (propylene homopolymer) sampled from the outlet of the multi-stage gas-phase polymerization reactor was 0.96 dL / g. [η]L1 and [η]G1 were approximately the same value. Therefore, the propylene homopolymer produced by carrying out polymerization step 1-b is propylene-based polymer a, and [η]G1 is the intrinsic viscosity of propylene-based polymer a.

[0215] <Solid-gas separation process and catalyst deactivation process> The propylene homopolymer obtained in polymerization step 1-b above was transferred from the gas-phase polymerization reactor to a SUS solid-gas separation vessel, and a catalyst deactivation step was performed in conjunction with the solid-gas separation step by supplying water vapor (steam) and nitrogen gas from the bottom of the solid-gas separation vessel to deactivate the solid catalyst components.

[0216] <Drying process for particle D> Using the third drying container 13 shown in Figure 3, a drying process was carried out in which particles D were dried in a batch manner under the conditions shown in Table 4 by supplying heated nitrogen gas from the bottom of the third drying container.

[0217] After the drying process was completed, the ball valve 103 of the third drying container 13 was opened, and the particles D were discharged from the third drying container 13, allowing for the stable discharge of the entire amount of particles D.

[0218] [Example 7] (Production of Particle E) (Manufacturing of heterophagic propylene polymerization materials) <Prepolymerization Process> A stainless steel (SUS) autoclave with a stirrer and an internal volume of 3 L contained 1.7 L of thoroughly dehydrated and degassed n-hexane, 38 mmol of triethylaluminum (TEA), and 7.6 mmol of tert-butyl-n-propyldimethoxysilane.

[0219] After adding 15 g of the solid catalyst component prepared in the same manner as in Example 4 described above to the autoclave, a preliminary polymerization step was performed in which 15 g of propylene was continuously supplied over approximately 30 minutes while maintaining the temperature inside the autoclave at approximately 10°C.

[0220] Subsequently, the slurry obtained from the preliminary polymerization process was transferred to a SUS316L autoclave with a stirrer and an internal volume of 150L, ​​and 100L of liquid butane was added to obtain the slurry.

[0221] <Main polymerization process> In this polymerization process, an apparatus was used in which three slurry polymerization reactors and two gas-phase polymerization reactors were arranged and connected in series.

[0222] This polymerization process was carried out in polymerization steps 1-a1, 1-a2, 1-a3, 1-b, and 2. Specifically, in polymerization steps 1-a1, 1-a2, 1-a3, and 1-b, a propylene homopolymer, propylene polymer a, was produced. The generated propylene polymer a and solid catalyst components were transferred to the next polymerization reactor without deactivation, and the polymerization was carried out in polymerization step 2 by polymerizing propylene copolymer b, which is a propylene-ethylene copolymer. Polymerization steps 1-a1, 1-a2, 1-a3, 1-b, and 2 will be described in detail below.

[0223] <Polymerization process 1-a1> (Homopolymerization of propylene using a slurry polymerization reactor) Propylene homopolymerization was performed using a SUS304 vessel-type slurry polymerization reactor equipped with a stirrer.

[0224] Specifically, a slurry of propylene, hydrogen, TEA, tert-butyl-n-propyldimethoxysilane, and the above-described prepolymerization catalyst component obtained in the prepolymerization step was continuously supplied to a slurry polymerization reactor to conduct a polymerization reaction. The reaction conditions were as follows. Polymerization temperature: 55 °C Stirring speed: 150 rpm Liquid level in the slurry polymerization reactor: 18 L Supply rate of propylene: 20 kg / hour Supply rate of hydrogen: 78.7 NL / hour Supply rate of TEA: 32.3 mmol / hour Supply rate of tert-butyl-n-propyldimethoxysilane: 6.81 mmol / hour Supply rate of the slurry (in terms of solid catalyst component): 0.55 g / hour Polymerization pressure: 4.27 MPa (gauge pressure)

[0225] <Polymerization step 1-a2> (Homopolymerization of propylene using a slurry polymerization reactor) Using a SUS304 vessel-type slurry polymerization reactor equipped with a stirrer, homopolymerization of propylene was carried out. Specifically, the slurry obtained in polymerization step 1-a1 was continuously supplied to the slurry polymerization reactor to conduct a polymerization reaction. The reaction conditions were as follows. Polymerization temperature: 54 °C Stirring speed: 150 rpm Liquid level in the slurry polymerization reactor: 55 L Supply rate of propylene: 15 kg / hour Supply rate of hydrogen: 57.3 NL / hour Polymerization pressure: 3.28 MPa (gauge pressure)

[0226] <Polymerization step 1-a3> (Homopolymerization of propylene using a slurry polymerization reactor) Using a SUS304 vessel-type slurry polymerization reactor equipped with a stirrer, homopolymerization of propylene was carried out.

[0227] Specifically, the slurry obtained in polymerization step 1-a2 was continuously supplied to a slurry polymerization reactor to carry out the polymerization reaction. The reaction conditions were as follows. Polymerization temperature: 50℃ Stirring speed: 150rpm Liquid level in slurry polymerization reactor: 55L Propylene supply: 3 kg / hour Polymerization pressure: 3.06 MPa (gauge pressure) The intrinsic viscosity [η]L1 of the product (propylene homopolymer) sampled from the outlet of the slurry polymerization reactor was 0.94 dL / g.

[0228] <Polymerization Process 1-b> (Homopolymerization of propylene using a gas-phase polymerization reactor (gas-phase polymerization)) The slurry obtained in polymerization step 1-a3 was continuously supplied to the subsequent gas-phase polymerization reactor. The gas-phase polymerization reactor used in polymerization step 1-b is a reactor equipped with a gas dispersion plate.

[0229] Propylene and hydrogen were continuously supplied from the bottom of the gas-phase polymerization reactor. This created fluidized beds in each of the multi-stage reaction zones, and the supply rates of propylene and hydrogen were controlled to maintain a constant gas composition and pressure. Further homopolymerization of propylene was carried out while purging excess gas. The reaction conditions were as follows. Polymerization temperature: 70℃ Polymerization pressure: 1.94 MPa (gauge pressure) Gas concentration ratio (hydrogen / (hydrogen + propylene)): 8.5 mol%

[0230] The intrinsic viscosity [η]G1 of the product (propylene homopolymer) sampled from the outlet of the gas-phase polymerization reactor was 0.95 dL / g. [η]L1 and [η]G1 were approximately the same value. Therefore, the propylene homopolymer produced by carrying out polymerization step 1-b is propylene-based polymer a, and [η]G1 is the intrinsic viscosity of propylene-based polymer a.

[0231] <Polymerization Process 2> (Propylene-ethylene copolymerization using a gas-phase polymerization reactor (gas-phase polymerization)) The propylene polymer a discharged from the gas-phase polymerization reactor used in polymerization step 1-b was continuously supplied to a subsequent gas-phase polymerization reactor. The gas-phase polymerization reactor used in polymerization step 2 is a reactor equipped with a gas dispersion plate.

[0232] Propylene, ethylene, and hydrogen were continuously supplied to the gas-phase polymerization reactor configured as described above. The gas supply rate was adjusted to maintain a constant gas composition and pressure, and excess gas was purged. In the presence of propylene-based polymer a (particles), copolymerization of propylene and ethylene was carried out to produce propylene-ethylene copolymer b, which is propylene copolymer b. A heterophagous propylene polymerization material, a mixture of propylene-based polymer a and propylene copolymer b, was obtained. The reaction conditions were as follows. Polymerization temperature: 70℃ Polymerization pressure: 1.40 MPa (gauge pressure) Gas concentration ratio (ethylene / (propylene + ethylene)): 27.9 mol% (Hydrogen / (Hydrogen + Propylene + Ethylene)): 0.09 mol%

[0233] The proportion (X) of propylene copolymer b in the obtained heterophagic propylene polymerization material was calculated using the following formula, after measuring the heat of fusion of propylene polymer a and the total heat of fusion of the heterophagic propylene polymerization material. Here, the heat of fusion was measured by differential scanning thermal analysis (DSC). X = 1 - (ΔHf)T / (ΔHf)P (ΔHf)T: Total heat of fusion of the heterophagic propylene polymerization material (J / g) (ΔHf)P: Heat of fusion of propylene polymer a (J / g)

[0234] The intrinsic viscosity [η]G2 of the product (heterophasic propylene polymerization material) sampled from the outlet of the gas-phase polymerization reactor was 2.07 dL / g.

[0235] The product obtained from the outlet of the gas-phase polymerization reactor is a mixture of propylene polymer a and propylene copolymer b. The intrinsic viscosity [η]C of propylene copolymer b was calculated using the following formula. [η]C=([η]G2-[η]G1×(1-X)) / X

[0236] The obtained heterophagic propylene polymerization material had an intrinsic viscosity ([η]Total) of 2.07 dL / g, with an ethylene content of 5.1% by mass and a propylene content of 94.9% by mass. The polymerization ratio of propylene polymer a and propylene copolymer b was 86 / 14 [mass% / mass%], respectively. The ethylene content in propylene copolymer b was 36% by mass, and the intrinsic viscosity [η]C of propylene copolymer b was 8.8 dL / g.

[0237] <Solid-gas separation process and catalyst deactivation process> The heterophagic propylene polymerization material obtained in polymerization step 2 above was transferred from the gas-phase polymerization reactor to a SUS solid-gas separation vessel, and a catalyst deactivation step was performed in conjunction with the solid-gas separation step by supplying water vapor (steam) and nitrogen gas from the bottom of the solid-gas separation vessel to deactivate the solid catalyst components.

[0238] <Drying process for particle E> A drying process was carried out in which particles E were dried in a batch manner under the conditions shown in Table 4 by supplying heated nitrogen gas from the bottom of the third drying container 13 using the third drying container 13. The configuration of the third drying container 13 in this example is as already described with reference to Figure 3. The diameter of the third drying container 13 was set to 0.4 m, the inclination angle θ to 67.5°, and the diameter of the outlet to 0.11 m.

[0239] After the drying process was completed, the ball valve 103 of the third drying container 13 was opened, and the particles E were discharged from the third drying container 13, allowing for the stable discharge of the entire amount of particles E.

[0240] [Comparative Example 3] (Production of Particle C) (Manufacturing of heterophagic propylene polymerization materials) <Prepolymerization Step> A stainless steel (SUS) autoclave with a stirrer and an internal volume of 3 L was charged with 1.0 L of n - hexane, 19 mmol of triethylaluminum (TEA), and 1.9 mmol of tert - butyl - n - propyldimethoxysilane, which had been sufficiently dehydrated and degassed.

[0241] After adding 7 g of the solid catalyst component produced in the same manner as in Example 4 described above into the autoclave, a prepolymerization step was carried out in which 7 g of propylene was continuously fed over about 30 minutes while maintaining the temperature inside the autoclave at about 10°C.

[0242] Thereafter, the slurry obtained by the prepolymerization step was transferred to a SUS316L autoclave with a stirrer and an internal volume of 260 L, and further made into a slurry by adding 180 L of liquid butane.

[0243] <Main Polymerization Step> In this main polymerization step, a device in which a slurry polymerization reactor, a multi - stage gas - phase polymerization reactor, and two gas - phase polymerization reactors were arranged and connected in series was used.

[0244] This main polymerization step was carried out through Polymerization Step 1 - a, Polymerization Step 1 - b, Polymerization Step 2 - a, and Polymerization Step 2 - b. Specifically, in Polymerization Step 1 - a and Polymerization Step 1 - b, a propylene - based polymer a, which is a propylene - ethylene copolymer, was produced, and the produced propylene - based polymer a and the solid catalyst component were transferred to the next - stage polymerization reactor without deactivation, and in Polymerization Step 2 - a and Polymerization Step 2 - b, a propylene copolymer b, which is a propylene - ethylene copolymer, was polymerized. Hereinafter, Polymerization Step 1 - a, Polymerization Step 1 - b, Polymerization Step 2 - a, and Polymerization Step 2 - b will be specifically described.

[0245] <Polymerization Step 1 - a> (Propylene - Ethylene Copolymerization Using a Slurry Polymerization Reactor) Propylene - ethylene copolymerization was carried out using a vessel - type slurry polymerization reactor made of SUS304 with a stirrer.

[0246] Specifically, a slurry of propylene, hydrogen, ethylene, TEA, tert-butyl-n-propyldimethoxysilane, and the aforementioned prepolymerization catalyst components obtained in the prepolymerization step was continuously supplied to a slurry polymerization reactor to carry out the polymerization reaction. The reaction conditions were as follows. Polymerization temperature: 50℃ Stirring speed: 150rpm Liquid level in slurry polymerization reactor: 18L Propylene supply: 30 kg / hour Hydrogen supply: 5.4 NL / hour Ethylene supply rate: 0.045 kg / hour TEA supply: 17.9 mmol / hour Supply rate of tert-butyl-n-propyldimethoxysilane: 3.58 mmol / hour Slurry supply rate (calculated as solid catalyst component): 0.35 g / hour Polymerization pressure: 3.04 MPa (gauge pressure)

[0247] The intrinsic viscosity [η]L1 of the product (propylene-ethylene copolymer) sampled from the outlet of the slurry polymerization reactor was 2.13 dL / g.

[0248] The ethylene content (C2'L) of the product (propylene-ethylene copolymer) sampled from the outlet of the slurry polymerization reactor was 1.3% by mass.

[0249] <Polymerization Process 1-b> (Propylene-ethylene copolymerization (gas-phase polymerization) using a multi-stage gas-phase polymerization reactor) Propylene-ethylene copolymerization was carried out using a multi-stage gas-phase polymerization reactor with six reaction zones in the vertical direction, the uppermost of which was a fluidized bed, and the remaining five zones were jet beds.

[0250] Specifically, the slurry containing particulate propylene homopolymer and liquid propylene produced in polymerization step 1-a was transferred from the slurry polymerization reactor to the fluidized bed, which is the uppermost stage of the multi-stage gas-phase polymerization reactor, without deactivation and continuously supplied.

[0251] Interstage transfer of propylene polymers within the multistage gas-phase polymerization reactor was performed using a double-valve system. In this system, the upper and lower reaction regions were connected by a 1-inch diameter pipe, and two on-off valves were installed in the pipe. The downstream valve was closed while the upstream valve was opened, temporarily accumulating powder between the valves from the upper reaction region. Then, after closing the upstream valve, the downstream valve was opened to transfer particulate propylene polymers to the lower reaction region.

[0252] Propylene, ethylene, and hydrogen were continuously supplied from the bottom of the multi-stage gas-phase polymerization reactor having the above configuration. This formed a fluidized bed or jet bed in each of the multi-stage reaction zones, and the supply amounts of propylene, ethylene, and hydrogen were controlled to maintain a constant gas composition and pressure, while further copolymerization of propylene and ethylene was carried out while purging excess gas. The reaction conditions were as follows. Polymerization temperature: 57℃ Polymerization pressure: 1.70 MPa (gauge pressure) Gas concentration ratio (ethylene / (propylene + ethylene)): 4.2 mol% Gas concentration ratio (hydrogen / (hydrogen + propylene + ethylene)): 1.1 mol%

[0253] The intrinsic viscosity [η]G1 of the product (propylene polymer a) sampled from the outlet of the multi-stage gas-phase polymerization reactor was 2.26 dL / g. [η]L1 and [η]G1 were approximately the same value. Therefore, the propylene homopolymer produced by carrying out polymerization step 1-b is propylene polymer a, and [η]G1 is the intrinsic viscosity of propylene polymer a.

[0254] The ethylene content C2'G1 of the product (propylene polymer a) sampled from the outlet of the multi-stage gas-phase polymerization reactor was 5.7% by mass. Here, the propylene homopolymer produced by carrying out polymerization steps 1-b is propylene polymer a, and the ethylene content C2'G1 is the ethylene content of propylene polymer a.

[0255] <Polymerization Process 2-a> (Propylene-ethylene copolymerization (gas-phase polymerization) using the first gas-phase polymerization reactor) The propylene polymer a discharged from the multi-stage gas-phase polymerization reactor used in polymerization step 1-b was continuously supplied to the subsequent first gas-phase polymerization reactor. The first gas-phase polymerization reactor used in polymerization step 2-a was a reactor equipped with a gas dispersion plate, and the transfer of propylene polymer a from the multi-stage gas-phase polymerization reactor to the first gas-phase polymerization reactor was carried out using the double valve system already described.

[0256] Propylene, ethylene, and hydrogen were continuously supplied to the first gas-phase polymerization reactor with the above configuration. The gas supply rate was adjusted to maintain a constant gas composition and pressure, and excess gas was purged. In the presence of propylene polymer a particles, copolymerization of propylene and ethylene was carried out to produce propylene copolymer b, which is a propylene-ethylene copolymer. A heterophagous propylene polymerization material, a mixture of propylene polymer a and propylene copolymer b, was obtained. The reaction conditions were as follows. Polymerization temperature: 70℃ Polymerization pressure: 1.67 MPa (gauge pressure) Gas concentration ratio (ethylene / (propylene + ethylene)): 21.8 mol% (Hydrogen / (Hydrogen + Propylene + Ethylene)): 1.4 mol%

[0257] <Polymerization Process 2-b> (Propylene-ethylene copolymerization (gas-phase polymerization) using a gas-phase polymerization reactor (second gas-phase polymerization reactor)) The particles discharged from the first gas-phase polymerization reactor used in polymerization step 2-a were continuously supplied to the subsequent second gas-phase polymerization reactor. The second gas-phase polymerization reactor used in polymerization step 2-b was a reactor equipped with a gas dispersion plate, and the transfer of particles from the first gas-phase polymerization reactor to the second gas-phase polymerization reactor was carried out using the double valve system already described.

[0258] Propylene, ethylene, and hydrogen were continuously supplied to the second gas-phase polymerization reactor with the above configuration. By adjusting the gas supply rate to maintain a constant gas composition and pressure, and purging excess gas, copolymerization of propylene and ethylene was carried out to produce a propylene-ethylene copolymer, which is propylene copolymer b, and a heterophagous propylene polymerization material, which is a mixture of propylene polymer a and propylene copolymer b, was obtained. The reaction conditions for polymerization step 2-b in the second gas-phase polymerization reactor were as follows. Polymerization temperature: 70℃ Polymerization pressure: 1.63 MPa (gauge pressure) Gas concentration ratio (ethylene / (propylene + ethylene)): 21.8 mol% (Hydrogen / (Hydrogen + Propylene + Ethylene)): 1.4 mol%

[0259] Furthermore, since polymerization steps 2-a and 2-b were carried out under the same conditions for polymerization temperature and gas concentration ratio, the propylene-ethylene copolymer produced in polymerization step 2-a and the propylene-ethylene copolymer produced in polymerization step 2-b can be considered to have almost the same structure.

[0260] As described above, by carrying out polymerization steps 2-a and 2-b, a heterophagic propylene polymerization material further containing "propylene copolymer b," which is a propylene-ethylene copolymer, was obtained.

[0261] The proportion (X) of propylene copolymer b in the obtained heterophagic propylene polymerization material was calculated using the following formula, after measuring the heat of fusion of propylene polymer a and the total heat of fusion of the heterophagic propylene polymerization material. Here, the heat of fusion was measured by differential scanning thermal analysis (DSC). X = 1 - (ΔHf)T / (ΔHf)P (ΔHf)T: Total heat of fusion of the heterophagic propylene polymerization material (J / g) (ΔHf)P: Heat of fusion of propylene polymer a (J / g)

[0262] The intrinsic viscosity [η]G2 of the product (heterophasic propylene polymerization material) sampled from the outlet of the second gas-phase polymerization reactor was 2.70 dL / g.

[0263] The product obtained from the outlet of the second gas-phase polymerization reactor is a mixture of propylene polymer a and propylene copolymer b. The intrinsic viscosity [η]C of propylene copolymer b was calculated using the following formula. [η]C=([η]G2-[η]G1×(1-X)) / X

[0264] The product obtained from the outlet of the second gas-phase polymerization reactor is a mixture of propylene polymer a and propylene copolymer b. The ethylene content C2'C of propylene copolymer b was calculated using the following formula. C2'C = (C2'G2 - C2'G1 × (1 - X)) / X The obtained heterophagic propylene polymerization material had an intrinsic viscosity ([η]Total) of 2.70 dL / g, with an ethylene content (C2'G2) of 17.6% by mass and a propylene content of 82.4% by mass. The polymerization ratio of propylene polymer a and propylene copolymer b was 34 / 66, respectively. The ethylene content (C2'C) in propylene copolymer b was 24% by mass, and the intrinsic viscosity ([η]C) of propylene copolymer b was 2.9 dL / g.

[0265] <Solid-gas separation process and catalyst deactivation process> The heterophagic propylene polymerization material obtained in polymerization step 2 above was transferred from the gas-phase polymerization reactor to a SUS solid-gas separation vessel, and a catalyst deactivation step was performed in conjunction with the solid-gas separation step by supplying water vapor (steam) and nitrogen gas from the bottom of the solid-gas separation vessel to deactivate the solid catalyst components.

[0266] <Drying process for particle C> Using the third drying container 13 shown in Figure 3, which has already been explained, a drying process was carried out in which particles C were dried in a batch manner under the conditions shown in Table 4 by supplying heated nitrogen gas from the bottom of the third drying container.

[0267] After the drying process was carried out, the ball valve 103 of the third drying container 13 was opened and the particles C were discharged from the third drying container 13, but no particles C could be discharged from the third drying container 13 at all.

[0268] [Table 4]

[0269] As described above, in Examples 1 to 7, where the value obtained by formula (a) is between -0.20 and 1.05 (0.258 to 0.996), the entire amount of dried particles could be stably discharged outside the drying container. On the other hand, in Comparative Examples 1 and 2, a discharge failure occurred in which the entire amount of dried particles could not be discharged outside the drying container, and the particles that remained inside the drying container formed rat holes. Furthermore, in Comparative Example 3, particle C could not be discharged from the drying container at all.

[0270] [Example 8] Example 8 was carried out in the same manner as Example 6, except that the drying process conditions were as shown in Table 5 below. The results are shown in Table 5 below.

[0271] [Comparative Example 4] The tilt angle of the drying container in Example 8 is changed to 89°. If the weight of particles D introduced into the drying container during the drying process is the same as in Example 8, the bed height will be 6.44m.

[0272] As described above, the L / D ratio in Example 8 is 2.5, while in Comparative Example 4 it is 10.7. A large L / D ratio is undesirable because it increases the vertical height of the drying container, which in turn leads to longer piping lengths and increased power requirements.

[0273] [Table 5] [Explanation of symbols]

[0274] 1 Installation surface 11. First drying container 12. Second drying container 13. Third drying container 100 drying containers 100A Body 100Aa upper end 100Ab lower end 100B frustum of a cone 100Ba slope 100Bb top surface 100C Circle Feeder 100Ca top surface 100Cb bottom surface 100D Motor Unit 100E Cone 100Ea sloped surface 100Eb vertex 101 Supply Line 102 Discharge Line 103 Ball Valve C center axis

Claims

1. The process includes supplying particles containing polyolefin to a drying container and drying the particles containing polyolefin in the drying container, A method for drying particles containing polyolefin, wherein the value obtained by the following formula (a) in the drying step is between -0.20 and 1.

05. Formula (a): 0.00304 × apparatus diameter [m] + 0.00261 × bed height [m] + 0.0179 × residence time [hours] + 0.00213 × particle temperature in drying container [K] - 0.0109 × inclination angle [degrees] + 0.0212 × CXS component amount [mass%] (In formula (a), The device diameter refers to the maximum diameter of the body of the drying container. Bed height refers to the maximum height from the height of the discharge port for discharging polyolefin-containing particles to the height at which the polyolefin-containing particles remaining in the drying container are located. Residence time refers to the time that particles containing polyolefin remain in the drying container. The particle temperature in the drying container refers to the temperature of the polyolefin-containing particles in the drying container. The inclination angle refers to the outer angle between the inclined surface of the drying container and the mounting surface, where the outer angle means the angle on the outside of the container. The CXS component amount refers to the amount of CXS component contained in particles containing polyolefin.

2. The method for drying particles containing a polyolefin according to claim 1, wherein the polyolefin contains a propylene polymer.

3. The propylene-based polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less. The drying method according to claim 2, wherein the CXS component content of the particles containing the polyolefin is 5% by mass or more.

4. The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less. The drying method according to claim 3, wherein the CXS component content of the particles containing the polyolefin is 15% by mass or more.

5. The propylene-based polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less. The drying method according to claim 2, wherein the CXS component content of the particles containing the polyolefin is 5% by mass or more.

6. The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less. The drying method according to claim 5, wherein the CXS component content of the particles containing the polyolefin is 15% by mass or more.

7. The drying method according to any one of claims 1 to 6, wherein the temperature of the polyolefin-containing particles in the drying container is 0°C or higher and 160°C or lower.

8. The drying method according to any one of claims 1 to 6, wherein the residence time of the particles containing the polyolefin in the drying container is 1 hour or more and 48 hours or less.

9. The drying method according to any one of claims 1 to 6, wherein the inclination angle in the drying container is 30° or more.

10. The drying method according to any one of claims 1 to 6, wherein the median diameter of the particles containing the polyolefin is 500 μm or more and 10,000 μm or less.

11. A method for producing particles containing a polyolefin, comprising the step of drying the particles containing the polyolefin by the drying method described in any one of claims 1 to 6.

12. A method for producing a polyolefin-based resin composition, comprising the step of drying the particles containing the polyolefin by the drying method described in any one of claims 1 to 6.

13. The storage step includes supplying particles containing polyolefin to a storage container and storing the particles containing polyolefin in the storage container, A method for storing particles containing polyolefins, wherein the value obtained by the following formula (b) in the storage step is between -0.20 and 1.

05. Formula (b): 0.00304 × apparatus diameter [m] + 0.00261 × bed height [m] + 0.0179 × residence time [hours] + 0.00213 × particle temperature in storage container [K] - 0.0109 × tilt angle [degrees] + 0.0212 × CXS component amount [mass%] (In formula (b), The device diameter refers to the maximum diameter of the body of the storage container. Bed height refers to the maximum height from the height of the discharge port for discharging polyolefin-containing particles to the height at which the polyolefin-containing particles remaining in the storage container are located. Residence time refers to the time that particles containing polyolefin remain in the storage container. The particle temperature in the storage container refers to the temperature of the polyolefin-containing particles in the storage container. The inclination angle refers to the outer angle between the inclined surface of the storage container and the installation surface, where the outer angle means the angle on the outside of the container. The CXS component amount refers to the amount of CXS component contained in particles containing polyolefin.

14. The method for storing particles containing a polyolefin according to claim 13, wherein the polyolefin is a propylene polymer.

15. The propylene-based polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less. The storage method according to claim 14, wherein the CXS component content of the particles containing the polyolefin is 5% by mass or more.

16. The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less. The storage method according to claim 15, wherein the CXS component content of the particles containing the polyolefin is 15% by mass or more.

17. The propylene-based polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 95% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 5% by mass or more and 50% by mass or less. The storage method according to claim 14, wherein the CXS component content of the particles containing the polyolefin is 5% by mass or more.

18. The propylene polymer is a polymer in which the mass percentage of structural units derived from propylene is 50% by mass or more and 80% by mass or less, and the mass percentage of structural units derived from at least one olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is 20% by mass or more and 50% by mass or less. The storage method according to claim 17, wherein the CXS component content of the particles containing the polyolefin is 15% by mass or more.

19. The storage method according to any one of claims 13 to 18, wherein the temperature of the polyolefin-containing particles in the storage container is 0°C or higher and 160°C or lower.

20. The storage method according to any one of claims 13 to 18, wherein the residence time of the polyolefin-containing particles in the storage container is 1 hour or more and 48 hours or less.

21. The storage method according to any one of claims 13 to 18, wherein the inclination angle in the storage container is 30° or more.

22. The storage method according to any one of claims 13 to 18, wherein the median diameter of the particles containing the polyolefin is 500 μm or more and 10,000 μm or less.

23. A method for producing particles containing a polyolefin, comprising the step of storing the particles containing the polyolefin by a storage method described in any one of claims 13 to 18.

24. A method for producing a polyolefin resin composition, comprising the step of storing the particles containing the polyolefin by the storage method described in any one of claims 13 to 18.

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