Method for manufacturing propylene-based block copolymers

Abstract

This invention provides a method in which the polymerization activity in the first and second polymerization steps is excellent, easily producing propylene-based block copolymers with high melt flow rates and a high proportion of propylene / α-olefin copolymer components. A method for manufacturing a propylene-based block copolymer includes using an olefin polymerization catalyst, performing a first polymerization step, and then performing a second polymerization step. The olefin polymerization catalyst comprises (A) a solid catalyst component for olefin polymerization and (B) an organoaluminum compound. The (A) solid catalyst component for olefin polymerization contains titanium, magnesium, halogen, and a 1,3-diether compound. The first polymerization step is performed at a temperature of 45-65°C, where olefins containing 95-100% by mass of propylene are polymerized to obtain a propylene-based polymer. The second polymerization step is performed at a temperature of 50-90°C, in the presence of the propylene-based polymer, where olefins containing 5% by mass and less than 95% by mass of propylene and α-olefins other than propylene are copolymerized to obtain a propylene / α-olefin copolymer.

Description

Technical Field

[0001] This invention relates to a method for manufacturing propylene-based block copolymers. Background Technology

[0002] For a long time, operations have been carried out to polymerize olefins such as propylene using catalysts for olefin polymerization. In particular, propylene block copolymers polymerized using catalysts for olefin polymerization have become suitable for use due to their excellent balance of rigidity and impact resistance.

[0003] Among propylene-based block copolymers, especially ethylene-propylene block copolymers, mechanical properties such as rigidity and heat resistance are good, and they can be manufactured relatively inexpensively, so they are used in a wide range of applications.

[0004] The ethylene-propylene block copolymer refers to a copolymer formed by blending a propylene-based polymer that mainly contains propylene with a random copolymer of propylene and ethylene. It is usually manufactured by polymerizing the polymers sequentially under conditions corresponding to the desired polymer and blending the polymers in a reaction vessel.

[0005] For example, as a polymerization reaction to obtain an ethylene-propylene block copolymer, the following reaction is suitably carried out: a homopolymerization reaction of propylene or a random copolymerization reaction of propylene with a small amount of ethylene is carried out in the front stage, and a copolymerization reaction of propylene and ethylene is carried out in the back stage in the presence of the obtained propylene-based polymer. The ethylene-propylene block copolymer obtained by the above method is melted and shaped using various molding machines, stretching machines, etc., and is used not only for molded products such as automotive parts and home appliance parts, but also for various applications such as containers and sheets.

[0006] As catalysts for olefin polymerization used in the manufacture of the aforementioned propylene block copolymers, many catalysts for olefin polymerization have been proposed, which include a solid catalyst component, an organoaluminum compound, and an organosilicon compound as an external electron-donating compound. The solid catalyst component contains internal electron-donating compounds such as magnesium atoms, titanium atoms, halogen atoms, and phthalates as essential components (see, for example, Patent Document 1).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2003-268060 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] The aforementioned ethylene-propylene block copolymers are widely used in injection molding of automobile bumpers, etc. Therefore, in order to improve the productivity of the injection molding process, it is desirable to have excellent melt flow rate (hereinafter also referred to as MFR).

[0012] In addition, to improve the impact resistance of ethylene-propylene block copolymers, it is necessary to keep the proportion of random copolymer components at a constant value or higher. Furthermore, it is also required that most of the ethylene constituting the ethylene-propylene block copolymer is incorporated into the random copolymer, and that the amount of crystalline polyethylene is low. Therefore, it is desirable to have a technology that has high polymerization activity when forming a random copolymer of propylene and ethylene as the rubber part, and that ethylene is efficiently introduced into the random copolymer.

[0013] However, as mentioned above, there is a known method for manufacturing ethylene-propylene block copolymers, wherein in a first polymerization step, a propylene-based polymer component mainly comprising propylene is manufactured, and in a second polymerization step, propylene and ethylene are randomly copolymerized in the presence of the aforementioned propylene-based polymer.

[0014] In the above polymerization reaction, generally speaking, if the polymerization activity in the first polymerization step becomes excessively high, it becomes difficult to increase the polymerization activity in the second polymerization step. As a result, the proportion of propylene / ethylene random copolymer components in the obtained propylene block copolymer becomes easy to decrease.

[0015] In order to solve the above-mentioned technical problems, the inventors conceived of suppressing the polymerization temperature in the first polymerization step to a temperature lower than the normal polymerization temperature, thereby suppressing the polymerization activity in the first polymerization step and improving the polymerization activity in the second polymerization step.

[0016] However, the inventors conducted research and determined that when using the olefin polymerization catalyst containing phthalate as an internal electron-donating compound as described in Patent Document 1, and suppressing the polymerization temperature in the first polymerization step to a temperature lower than the normal polymerization temperature, the yield of the obtained ethylene-propylene block copolymer also decreased.

[0017] Furthermore, the catalyst for olefin polymerization described in Patent Document 1, which contains phthalate as an internal electron-donating compound, is difficult to obtain ethylene-propylene block copolymers with excellent melt flow rate (MFR) when used for olefin polymerization.

[0018] Furthermore, if one wants to improve the polymerization activity in the second polymerization step to obtain an ethylene-propylene block copolymer with a high content of propylene / ethylene random copolymer, the fluidity of the resulting ethylene-propylene block copolymer usually decreases as the content of propylene / ethylene random copolymer increases, making it difficult to obtain an ethylene-propylene block copolymer with sufficient melt flow rate (MFR).

[0019] Under such circumstances, the object of the present invention is to provide a method in which, in the case of manufacturing propylene block copolymers, the polymerization activity in the first polymerization step of homopolymerization of propylene or copolymerization of propylene with a small amount of α-olefins (excluding propylene) is excellent, and in the presence of the propylene polymer obtained in the first polymerization step, the polymerization activity in the second polymerization step of copolymerization of propylene and α-olefins (excluding propylene) is excellent, thereby easily producing propylene block copolymers with a practically high melt flow rate and a high proportion of propylene / α-olefin copolymers.

[0020] Solution for solving the problem

[0021] To solve the aforementioned technical problems, the inventors conducted in-depth research and discovered that by using a catalyst for olefin polymerization to further implement a second polymerization step after the first polymerization step, the aforementioned problems can be solved, thus completing the present invention. The catalyst for olefin polymerization comprises (A) a solid catalyst component for olefin polymerization and (B) an organoaluminum compound. The (A) solid catalyst component for olefin polymerization contains titanium, magnesium, halogen, and a 1,3-diether compound as an internal electron-donating compound. The first polymerization step is carried out at a temperature of 45°C to 65°C to polymerize olefins containing 95 to 100% by mass of propylene to obtain a propylene-based polymer. The second polymerization step is carried out at a temperature of 50°C to 90°C in the presence of the aforementioned propylene-based polymer to copolymerize olefins containing 5% by mass and less than 95% by mass of propylene and α-olefins other than propylene to obtain a propylene / α-olefin copolymer.

[0022] That is, the present invention provides:

[0023] (1) A method for manufacturing a propylene-based block copolymer, characterized in that,

[0024] After the first polymerization step is carried out using a catalyst for olefin polymerization, a second polymerization step is then carried out.

[0025] The catalyst for olefin polymerization comprises (A) a solid catalyst component for olefin polymerization and (B) an organoaluminum compound, wherein (A) the solid catalyst component for olefin polymerization contains titanium, magnesium, halogen, and a 1,3-diether compound as an internal electron-donating compound.

[0026] The first polymerization step involves polymerizing an olefin containing 95-100% by mass of propylene at a temperature of 45°C to 65°C to obtain a propylene-based polymer.

[0027] The second polymerization step copolymerizes olefins containing 5% by mass or more and less than 95% by mass of propylene and α-olefins other than propylene at a temperature of 50°C to 90°C in the presence of the aforementioned propylene-based polymer to obtain a propylene / α-olefin copolymer;

[0028] (2) The method for producing a propylene-based block copolymer according to (1) above, wherein the aforementioned (B) organoaluminum compound is one or more compounds represented by the following general formula (I),

[0029] R 1 p AlQ 3-p (I)

[0030] (In the formula, R 1 is an alkyl group having 1 to 6 carbon atoms, Q is a hydrogen atom or a halogen atom, p is 0 < p ≤ 3, and when there are multiple Rs 1 , each R 1 may be the same or different from each other, and when there are multiple Qs, each Q may be the same or different from each other.) ;

[0031] (3) The method for producing a propylene-based block copolymer according to (1) or (2) above, wherein the aforementioned olefin polymerization catalyst further comprises (C) an external electron-donating compound;

[0032] (4) The method for producing a propylene-based block copolymer according to any one of (1) to (3) above, wherein in the obtained propylene-based block copolymer, the content ratio of the propylene / α-olefin part is 25.0 to 50.0% by mass.

[0033] Effects of the Invention

[0034] According to the present invention, a method can be provided in which the polymerization activity in the first polymerization step of homopolymerizing propylene or copolymerizing propylene with a small amount of (excluding propylene) α-olefin is excellent, and in the presence of the propylene-based polymer obtained in the first polymerization step, the polymerization activity in the second polymerization step of copolymerizing propylene and (excluding propylene) α-olefin is excellent, and it is easy to produce a propylene-based block copolymer having a melt flow rate sufficiently high in practical use and a high content ratio of the propylene / α-olefin copolymer component. Detailed Embodiments

[0035] First, the method for producing a propylene-based block copolymer of the present invention will be described.

[0036] The method for manufacturing propylene-based block copolymers of the present invention is characterized in that, after performing a first polymerization step using an olefin polymerization catalyst, a second polymerization step is further performed. The olefin polymerization catalyst comprises (A) a solid catalyst component for olefin polymerization and (B) an organoaluminum compound. The (A) solid catalyst component for olefin polymerization contains titanium, magnesium, halogen, and a 1,3-diether compound as an internal electron-donating compound. In the first polymerization step, olefins containing 95 to 100% by mass of propylene are polymerized at a temperature of 45°C to 65°C to obtain a propylene-based polymer. In the second polymerization step, olefins containing 5% by mass or more but less than 95% by mass of propylene and α-olefins other than propylene are copolymerized at a temperature of 50°C to 90°C in the presence of the aforementioned propylene-based polymer to obtain a propylene / α-olefin copolymer.

[0037] In the method for manufacturing propylene block copolymers of the present invention, as a solid catalyst component for olefin polymerization (A) comprising titanium, magnesium, halogen and 1,3-diether compound as an internal electron-donating compound, an example is a contact reactant formed by contacting and reacting a raw material component that serves as a supply source of magnesium, titanium and halogen with an internal electron-donating compound comprising 1,3-diether compound in an organic solvent.

[0038] Specifically, as a solid catalyst component for the above-mentioned (A) olefin polymerization, an example is a contact reactant formed by using magnesium compounds and tetravalent titanium halides as raw material components that serve as the supply source of magnesium, titanium, and halogens, and bringing these raw material components into contact with an internally electron-donating compound containing a 1,3-diether compound.

[0039] As the aforementioned magnesium compounds, one or more selected from magnesium dialkoxy, magnesium dihalide, and magnesium alkoxyhalide can be cited.

[0040] Among the aforementioned magnesium compounds, magnesium dialkoxy or magnesium dihalide are preferred. Specifically, examples include magnesium dimethoxy, magnesium diethoxy, magnesium dipropoxy, magnesium dibutoxy, magnesium ethoxymethoxy, magnesium ethoxypropoxy, magnesium butoxyethoxy, magnesium dichloride, magnesium dibromide, and magnesium diiodide, with magnesium dialkoxy and magnesium dichloride being particularly preferred.

[0041] Among the magnesium compounds mentioned above, magnesium dialkoxy can be obtained by reacting metallic magnesium with an alcohol in the presence of halogens or halogen-containing metal compounds.

[0042] The aforementioned magnesium dialkoxy is preferably in granular or powder form, and its shape may be irregular or spherical.

[0043] When using spherical particles as magnesium dialkoxy, polymer powders with better particle shape (further spherical) and narrow particle size distribution can be obtained. The processability of the polymer powder generated during polymerization is improved, and the occurrence of clogging and other problems caused by microparticles contained in the generated polymer powder can be suppressed.

[0044] The aforementioned spherical dieoxymagnesium does not necessarily need to be spherical; it can also be oval or potato-shaped.

[0045] Furthermore, the average particle size (average particle size D50) of the aforementioned magnesium diethoxy group is preferably 1.0 to 200.0 μm, more preferably 5.0 to 150.0 μm. Here, the average particle size D50 refers to the particle size that accounts for 50% of the cumulative particle size in the volumetric cumulative particle size distribution when measured using a laser scattering diffraction particle size analyzer.

[0046] When the magnesium diekoxy is spherical, the average particle size D50 is preferably 1.0 to 100.0 μm, more preferably 5.0 to 80.0 μm, and even more preferably 10.0 to 70.0 μm.

[0047] In addition, for the particle size distribution of magnesium dialkoxy, it is preferred to have less fine powder and coarse powder and a narrow particle size distribution.

[0048] Specifically, for magnesium dialkoxy, when measured using a laser scattering diffraction particle size analyzer, particles with a diameter of 5.0 μm or less preferably account for 20% or less, more preferably 10% or less. On the other hand, when measured using a laser scattering diffraction particle size analyzer, particles with a diameter of 100.0 μm or more preferably account for 20% or less, more preferably 10% or less.

[0049] Furthermore, if the particle size distribution is expressed as ln(D90 / D10), it is preferably 3 or less, more preferably 2 or less. Here, D90 refers to the particle size that accounts for 90% of the cumulative particle size in the volumetric cumulative particle size distribution when measured using a laser scattering diffraction particle size analyzer. Additionally, D10 refers to the particle size that accounts for 10% of the cumulative particle size in the volumetric cumulative particle size distribution when measured using a laser scattering diffraction particle size analyzer.

[0050] The methods for manufacturing the aforementioned spherical dialkoxy magnesium are exemplified in, for example, Japanese Patent Application Publication No. 62-51633, Japanese Patent Application Publication No. 3-74341, Japanese Patent Application Publication No. 4-368391, and Japanese Patent Application Publication No. 8-73388.

[0051] The magnesium compound is preferably in the form of a solution or suspension during the reaction, which allows the reaction to proceed suitably.

[0052] When the aforementioned magnesium compound is a solid, it can be prepared as a solution by dissolving it in a solvent that has the solubility of magnesium compounds, or it can be prepared as a suspension by suspending it in a solvent that does not have the solubility of magnesium compounds.

[0053] It should be noted that when the magnesium compound is in liquid form, it can be used directly as a solution, or it can be further dissolved in a solvent that has the solubility for magnesium compounds to be used as a solution.

[0054] Examples of compounds that can soluble solid magnesium compounds include at least one compound selected from the group consisting of alcohols, ethers, and esters, preferably alcohols such as ethanol, propanol, butanol, and 2-ethylhexanol, with 2-ethylhexanol being particularly preferred.

[0055] On the other hand, as a medium that does not have the ability to dissolve solid magnesium compounds, one or more of the following can be cited as media: saturated hydrocarbon solvents or unsaturated hydrocarbon solvents.

[0056] In the method for manufacturing propylene block copolymers of the present invention, the raw material component, namely a tetravalent titanium halide, which serves as the supply source of titanium and halogen constituting the solid catalyst component for (A) olefin polymerization, is not particularly limited, but is suitably selected from one or more compounds of the group consisting of titanium halide and alkoxy titanium halide as shown in the following general formula (II).

[0057] Ti(OR) 2 ) t X 4-t (II)

[0058] (where R) 2 This indicates an alkyl group with 1 to 4 carbon atoms, where X represents a halogen atom such as chlorine, bromine, or iodine, and t is 0 ≤ s ≤ 3.

[0059] In the above general formula (II), t is 0≤t≤3. Specifically, t can be 0, 1, 2 or 3.

[0060] As the titanium halide represented by the above general formula (II), one or more titanium halide selected from titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, etc. can be cited.

[0061] Furthermore, as the alkoxy titanium halide represented by the above general formula (II), one or more can be selected from titanium trichloride of methoxy, titanium trichloride of ethoxy, titanium trichloride of propoxy, titanium trichloride of n-butoxy, titanium dichloride of dimethoxy, titanium dichloride of diethoxy, titanium dichloride of dipropoxy, titanium dichloride of di-n-butoxy, titanium trimethoxy, titanium triethoxy, titanium tripropoxy, titanium tri-n-butoxy

[0062] As a tetravalent titanium halide, titanium tetrahalide is preferred, and titanium tetrachloride is more preferred.

[0063] These titanium compounds can be used alone or in combination of two or more.

[0064] In the method for manufacturing propylene block copolymers of the present invention, (A) the solid catalyst component for olefin polymerization contains a 1,3-diether compound as an internal electron-donating compound.

[0065] In this application, 1,3-diether compounds refer to the group of compounds having a basic propane skeleton with an ether group bonded at the 1,3 positions (1,3-dialkoxypropane structure) and may also contain desired substituents.

[0066] As a 1,3-diether compound, one or more compounds selected from those shown in general formula (III) below can be cited.

[0067] R 3 OCH2CR 4 R 5 CH2OR 6 (III)

[0068] (where R) 4 and R 5 Represents a hydrogen atom, a halogen atom, an alkyl or vinyl group having 1 to 12 carbon atoms, an alkenyl group having 3 to 12 carbon atoms, a cycloalkyl or cycloalkenyl group having 3 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 12 carbon atoms or a halogen-substituted aromatic hydrocarbon group, an aromatic hydrocarbon group having 7 to 12 carbon atoms with a substituent, an alkylamino group having 1 to 12 carbon atoms, or a dialkylamino group having 2 to 12 carbon atoms. R 4 and R 5 They can be the same or different. R 4 and R 5 They can bond together to form a ring. R 3 and R 6 R represents alkyl, vinyl, alkenyl, cycloalkyl, aromatic hydrocarbon groups with 1 to 12 carbon atoms, halogenated aromatic hydrocarbon groups with 3 to 12 carbon atoms, aromatic hydrocarbon groups with 3 to 6 carbon atoms, aromatic hydrocarbon groups with 6 to 12 carbon atoms, or aromatic hydrocarbon groups with 7 to 12 carbon atoms and substituents. 3 and R 6 They can be the same or different.

[0069] Specifically, the 1,3-diether compound mentioned above can be selected from one or more of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)1,3-dimethoxypropane, and 9,9-bis(methoxymethyl)fluorene, wherein it is preferred to select one or more of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, and 9,9-bis(methoxymethyl)fluorene.

[0070] In the method for manufacturing the propylene block copolymer of the present invention, by including a 1,3-diether compound as an internal electron-donating compound in the solid catalyst component for (A) olefin polymerization, the polymerization activity can be easily maintained even when the polymerization reaction is carried out at a lower temperature of about 45°C to 65°C in the first polymerization step described later, and the high polymerization activity can be easily exerted in the second polymerization step.

[0071] Furthermore, in the method for manufacturing the propylene block copolymer of the present invention, by including a 1,3-diether compound as an internal electron-donating compound in the solid catalyst component for (A) olefin polymerization, the resulting propylene block copolymer can maintain a high melt flow rate (MFR) even when the content ratio of propylene / α-olefin random copolymer is as high as about 25.0 to 50.0% by mass.

[0072] In the method for manufacturing propylene-based block copolymers of the present invention, (A) the solid catalyst component for olefin polymerization may contain, in addition to 1,3-diether compounds, one or more of the following as internal electron-donating compounds selected from benzoate esters, diesters (malonate diester, maleate diester, succinate diester, glutarate ester), glycol diesters, carbonate ethers, carbonate diesters, diester ethers, heteroatom-containing compounds, etc.

[0073] In the method for manufacturing propylene block copolymers of the present invention, (A) the solid catalyst component for olefin polymerization may or may not contain phthalates as internal electron-donating compounds, and preferably does not contain phthalates.

[0074] In the method for manufacturing the propylene block copolymer of the present invention, (A) the solid catalyst component for olefin polymerization preferably contains 60 to 100% by weight of the above-mentioned 1,3-diether compound relative to the total content of the internal electron-donating compound, more preferably 70 to 100% by weight of the above-mentioned 1,3-diether compound, and even more preferably 80 to 100% by weight of the above-mentioned 1,3-diether compound.

[0075] In the method for manufacturing the propylene block copolymer of the present invention, by including a 1,3-diether compound in the solid catalyst component for (A) olefin polymerization at the above-mentioned proportion relative to the total content of the internal electron-donating compounds, the olefin polymerization catalyst containing the above-mentioned solid catalyst component for (A) olefin polymerization can easily maintain polymerization activity even when the polymerization reaction is carried out at a lower temperature of about 45°C to 65°C in the first polymerization step described later, and can easily exhibit high polymerization activity in the second polymerization step.

[0076] Furthermore, in the method for manufacturing the propylene block copolymer of the present invention, by including a 1,3-diether compound as an internal electron-donating compound in the solid catalyst component for olefin polymerization in the above proportion, the resulting propylene block copolymer can easily achieve a sufficiently high melt flow rate (MFR) even if the content ratio of propylene / α-olefin random copolymer increases to about 25.0 to 50.0% by mass.

[0077] In the method for manufacturing propylene-based block copolymers of the present invention, (A) the solid catalyst component for olefin polymerization may further include polysiloxane.

[0078] Polysiloxanes are polymers with siloxane bonds (-Si-O- bonds) in their main chain, also collectively known as silicone oils, with a viscosity of 0.02~100 cm⁻¹ at 25°C. 2 / s (2~10000 centiliters), more preferably 0.03~5cm 2 Chains, partially hydrogenated, cyclic or modified polysiloxanes in the form of liquid or viscous substances at room temperature, with a concentration of 3~500 centiliters per second.

[0079] In the method for manufacturing propylene block copolymers of the present invention, by further including polysiloxane in the solid catalyst component for (A) olefin polymerization, it is possible to easily generate olefin polymers with excellent structural regularity or crystallinity during olefin polymerization, thereby easily reducing the amount of micropowder in the generated olefin polymer.

[0080] In the method for manufacturing propylene-based block copolymers of the present invention, (A) the solid catalyst component for olefin polymerization can be prepared, for example, by contacting magnesium dialkoxy, tetravalent titanium halide, internal electron-donating compound, and polysiloxane as needed in an inactive organic solvent.

[0081] As the aforementioned inactive organic solvent, a solvent that is liquid at room temperature (20°C) and has a boiling point of 50 to 150°C is preferred, and a saturated hydrocarbon compound or an aromatic hydrocarbon compound that is liquid at room temperature and has a boiling point of 50 to 150°C is even more preferred.

[0082] Specifically, one or more of the following can be selected as non-reactive organic solvents: straight-chain aliphatic hydrocarbons such as hexaane, heptane, and decane; branched-chain aliphatic hydrocarbons such as methylheptane; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and ethylcyclohexane; and aromatic hydrocarbons such as toluene, xylene, and ethylbenzene.

[0083] Among the aforementioned inactive organic solvents, aromatic hydrocarbon compounds that are liquid at room temperature and have a boiling point of 50-150°C can easily improve the activity of the obtained solid catalyst components and can easily improve the stereoregularity of the obtained polymer, and are therefore suitable.

[0084] In the method for manufacturing propylene-based block copolymers of the present invention, when the components are brought into contact with each other in order to prepare (A) a solid catalyst component for olefin polymerization, the process can be carried out under an inactive gas atmosphere.

[0085] Specifically, under an inactive gas atmosphere and after removing moisture, the components are stirred and brought into contact in a container equipped with a stirrer, and then reacted at a specified temperature to obtain (A) a solid catalyst component for olefin polymerization.

[0086] Regarding the temperature at which the components come into contact, it can be a lower temperature range near room temperature, whether it is simply a matter of stirring and mixing them in contact, or a matter of dispersing or suspending them for modification.

[0087] When the components react after contact to obtain a product, a temperature range of 40 to 130°C is preferred. In this case, it is preferable to keep the components at the same temperature after contact and allow them to react.

[0088] When the temperature at which the above product is obtained is below 40°C, the reaction cannot proceed sufficiently, resulting in the solid catalyst component failing to exert its full performance. Furthermore, when the temperature exceeds 130°C, the evaporation of the solvent becomes significant, making reaction control difficult.

[0089] The reaction time for obtaining the above product is preferably 1 minute or more, more preferably 10 minutes or more, and even more preferably 30 minutes or more.

[0090] The proportions of each component used in the preparation of the solid catalyst for (A) olefin polymerization vary depending on the preparation method, so they can be determined appropriately.

[0091] In preparing (A) a solid catalyst composition for olefin polymerization, it is preferable to contact 0.50 to 100.00 moles of tetravalent titanium halide relative to 1.00 moles of dialkoxy magnesium compound, more preferably contact 0.50 to 10.00 moles of tetravalent titanium halide, and even more preferably contact 1.00 to 5.00 moles of tetravalent titanium halide.

[0092] In addition, when preparing the solid catalyst composition for (A) olefin polymerization, it is preferable to contact 0.01 to 10.00 moles of an internally electron-donating compound relative to 1.00 moles of dialkoxymagnesium, more preferably to contact 0.01 to 1.00 moles of an internally electron-donating compound, and even more preferably to contact 0.02 to 0.6 moles of an internally electron-donating compound.

[0093] Furthermore, when preparing the solid catalyst component for (A) olefin polymerization, if polysiloxane is used, it is preferable to contact 0.01 to 100.00 g of polysiloxane relative to 1.00 moles of magnesium diekoxy, more preferably to contact 0.05 to 80.00 g of polysiloxane, and even more preferably to contact 1.00 to 50.00 g of polysiloxane.

[0094] In addition, when preparing the solid catalyst component for (A) olefin polymerization, the amount of inactive organic solvent is preferably 0.001 to 500.000 mol, more preferably 0.001 to 70.000 mol, and even more preferably 0.005 to 50.000 mol, relative to 1.000 mol of magnesium diekoxy.

[0095] The following preparation methods are particularly preferred as components of solid catalysts for olefin polymerization.

[0096] First, magnesium diekoxy is suspended in an inert organic solvent containing an alicyclic hydrocarbon compound with a boiling point of 50–150 °C to obtain a suspension. Next, the resulting suspension is contacted with a tetravalent titanium halide to carry out a reaction.

[0097] Before or after contacting the tetravalent titanium halide with the above suspension, the internal electron-donating compound is contacted at -20 to 130°C. Further reaction treatment is performed by contacting the polysiloxane as needed.

[0098] In the above preparation method, it is desirable to carry out the ripening reaction at a low temperature before or after contacting the internal electron-donating compound.

[0099] (A) The solid catalyst for olefin polymerization preferably contains 1.0% to 10.0% by mass, more preferably 1.5% to 8.0% by mass, and even more preferably 1.5% to 5.0% by mass of titanium atoms.

[0100] (A) The solid catalyst for olefin polymerization preferably contains 10.0% to 70.0% by mass, more preferably 10.0% to 50.0% by mass, even more preferably 15.0% to 40.0% by mass, and even more preferably 15.0% to 25.0% by mass of magnesium atoms.

[0101] (A) The solid catalyst for olefin polymerization preferably contains 20.0% to 90.0% by mass, more preferably 30.0% to 85.0% by mass, even more preferably 40.0% to 80.0% by mass, and even more preferably 45.0% to 80.0% by mass of halogen atoms.

[0102] (A) The solid catalyst for olefin polymerization preferably contains a total of 0.5% to 30.0% by mass, more preferably a total of 1.0% to 25.0% by mass, and even more preferably a total of 2.0% to 20.0% by mass of an internal electron-donating compound.

[0103] In this application, the content of titanium atoms in the solid catalyst for olefin polymerization refers to the value measured according to the method (redox titration) described in JIS 8311-1997 "Method for quantitative determination of titanium in titanium ore".

[0104] In addition, in this application, the magnesium content in the solid catalyst component for olefin polymerization refers to the value measured by EDTA titration, which involves dissolving the solid catalyst component for olefin polymerization in hydrochloric acid solution and titrating it with EDTA solution.

[0105] In this application, the proportion of halogen atoms contained in the solid catalyst component for olefin polymerization refers to the value obtained by silver nitrate titration, which is performed by treating the solid catalyst component with a mixed solution of sulfuric acid and pure water to prepare an aqueous solution, separating and recovering a specified amount, and titrating the halogen atoms with a standard silver nitrate solution.

[0106] In addition, in this application, the content of internal electron-donating compounds refers to the value obtained by hydrolyzing the solid catalyst, extracting the internal electron donor with an aromatic solvent, and measuring the solution by gas chromatography-FID (Flame Ionization Detector).

[0107] In the method for manufacturing propylene-based block copolymers of the present invention, the catalyst for olefin polymerization includes (B) an organoaluminum compound.

[0108] In the method for producing an acrylic block copolymer of the present invention, as the (B) organoaluminum compound constituting the catalyst for olefin polymerization, one or more compounds represented by the following general formula (I) are preferred.

[0109] R 1 p AlQ 3-p (I)

[0110] (In the formula, R 1 is an alkyl group having 1 to 6 carbon atoms, Q is a hydrogen atom or a halogen atom, p is 0 < p ≤ 3, and when there are multiple Rs 1 each R 1 is optionally the same as or different from each other, and when there are multiple Qs, each Q is optionally the same as or different from each other.).

[0111] In the organoaluminum compound represented by the general formula (I), R 1 is an alkyl group having 1 to 6 carbon atoms. Specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, etc. can be cited.

[0112] In the organoaluminum compound represented by the above general formula (I), Q represents a hydrogen atom or a halogen atom. When Q is a halogen atom, fluorine atom, chlorine atom, bromine atom, iodine atom can be cited.

[0113] In addition, in the organoaluminum compound represented by the above general formula (I), p is 0 < p ≤ 3, preferably 2 to 3, more preferably 2, 2.5 or 3.

[0114] As the organoaluminum compound represented by the above general formula (I), specifically, one or more selected from triethylaluminum, diethylaluminum chloride, triisobutylaluminum, diethylaluminum bromide, diethylaluminum hydride can be cited, and triethylaluminum and triisobutylaluminum are preferred.

[0115] In the method for producing an acrylic block copolymer of the present invention, it is considered that by making the catalyst for olefin polymerization contain the specific organoaluminum compound represented by the above general formula (I), the action of the organoaluminum compound on the internal electron donor compound constituting the solid catalyst component for olefin polymerization can be improved, and the solid catalyst component for olefin polymerization can be optimally activated. Moreover, it is considered that excellent catalytic activity is exhibited during the polymerization treatment, and an olefin polymer having excellent stereoregularity can be produced.

[0116] In the method for producing an acrylic block copolymer of the present invention, the catalyst for olefin polymerization preferably further contains (C) an external electron donor compound together with the (A) solid catalyst component for olefin polymerization and the (B) organoaluminum compound.

[0117] In the method for manufacturing the propylene block copolymer of the present invention, the external electron-donating compound (C) can be, for example, a silicon compound represented by the following general formula (IV).

[0118] R 7 r Si(NR) 8 R 9 ) s (OR) 10 ) 4-（r+s） (IV)

[0119] (In the formula, r is 0 or 1~2, s is 0 or 1~2, r+s is 0 or 1~4, R) 7 R 8 Or R 9 R is a hydrogen atom or any one of the following groups selected from straight-chain or branched alkyl groups having 1 to 12 carbon atoms, substituted or unsubstituted cycloalkyl groups, phenyl groups, allyl groups, and aralkyl groups, and optionally contains heteroatoms, which may be the same or different from each other. 8 With R 9 They can be bonded to form a ring shape, R 7 R 8 and R 9 Choose either the same or different. Additionally, R... 10 It is any group selected from alkyl, cycloalkyl, phenyl, vinyl, allyl, and aralkyl groups having 1 to 4 carbon atoms, and optionally contains a heteroatom.

[0120] In the silicon compounds represented by the above general formula (IV), R 7 It is a hydrogen atom or any one of the following groups selected from straight-chain or branched alkyl groups having 1 to 12 carbon atoms, substituted or unsubstituted cycloalkyl groups, phenyl groups, allyl groups, and aralkyl groups, and optionally contains heteroatoms.

[0121] As R 7 Preferably, it is a straight-chain or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms, and particularly preferably a straight-chain or branched alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms.

[0122] In the silicon compounds represented by the above general formula (IV), R 8 Or R 9 It is a hydrogen atom or any one of the following groups selected from straight-chain or branched alkyl groups having 1 to 12 carbon atoms, substituted or unsubstituted cycloalkyl groups, phenyl groups, allyl groups, and aralkyl groups, and optionally contains heteroatoms.

[0123] As R 8 Or R 9Preferably, it is a straight-chain or branched alkyl group with 1 to 10 carbon atoms, or a cycloalkyl group with 5 to 8 carbon atoms, and particularly preferably a straight-chain or branched alkyl group with 1 to 8 carbon atoms, or a cycloalkyl group with 5 to 8 carbon atoms.

[0124] Additionally, R 8 With R 9 They can be bonded to form a ring shape, in which case the ring shape is formed (NR) 8 R 9 The preferred forms are perhydroquinoline or perhydroisoquinoline.

[0125] In the silicon compounds represented by the above general formula (IV), R 7 R 8 and R 9 They can be the same or different.

[0126] In the silicon compounds represented by the above general formula (IV), R 10 It is any group selected from alkyl, cycloalkyl, phenyl, allyl and aralkyl with 1 to 4 carbon atoms, and optionally contains heteroatoms.

[0127] As R 10 Preferably, it is a straight-chain or branched alkyl group having 1 to 4 carbon atoms.

[0128] In the silicon compounds represented by the above general formula (IV), r is 0 or 1 to 2. Specifically, r can be 0, 1 or 2.

[0129] In the silicon compounds represented by the above general formula (IV), s is 0 or 1 to 2. Specifically, 0, 1 or 2 can be cited as s.

[0130] In the silicon compounds represented by the above general formula (IV), r+s is 0 or 1 to 4. Specifically, r+s can be 0, 1, 2, 3 or 4.

[0131] Specifically, examples of such silicon compounds as those represented by the general formula (IV) above include one or more organosilicon compounds selected from phenylalkoxysilane, alkylalkoxysilane, phenylalkylalkoxysilane, cycloalkylalkoxysilane, cycloalkylalkylalkoxysilane, (alkylamino)alkoxysilane, alkyl(alkylamino)alkoxysilane, alkyl(alkylamino)silane, alkylaminosilane, alkylaminosilane, etc.

[0132] As for the silicon compound with s=0 in the above general formula (IV), particularly preferred are one or more organosilicon compounds selected from the following: di-n-propyl dimethoxysilane, diisopropyl dimethoxysilane, di-n-butyl dimethoxysilane, diisobutyl dimethoxysilane, di-tert-butyl dimethoxysilane, tert-butylmethyl dimethoxysilane, tert-butylethyl dimethoxysilane, di-n-butyl diethoxysilane, tert-butyltrimethoxysilane, tert-butyltriethoxysilane, dicyclohexyl dimethoxysilane, dicyclohexyl diethoxysilane, dicyclohexyldiethoxysilane, dicyclohexyldimeth ... Cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, cyclohexylethyldimethoxysilane, cyclohexylethyldiethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylmethyldiethoxysilane, cyclopentylethyldiethoxysilane, cyclohexylcyclopentyldimethoxysilane, cyclohexylcyclopentyldiethoxysilane, 3-methylcyclohexylcyclopentyldimethoxysilane, 4-methylcyclohexylcyclopentyldimethoxysilane, 3,5-dimethylcyclohexylcyclopentyldimethoxysilane.

[0133] Examples of organosilicon compounds in which s is 1 or 2 in the above general formula (IV) include one or more organosilicon compounds selected from bis(alkylamino)dialkoxysilane, (alkylamino)(cycloalkylamino)dialkoxysilane, (alkylamino)(alkyl)dialkoxysilane, bis(cycloalkylamino)dialkoxysilane, vinyl(alkylamino)dialkoxysilane, allyl(alkylamino)dialkoxysilane, (alkoxyamino)trialkoxysilane, (alkylamino)trialkoxysilane, and (cycloalkylamino)trialkoxysilane. Ethyl(tert-)silane is particularly preferred. The organosilicon compounds include butylamino)dimethoxysilane, cyclohexyl(cyclohexylamino)dimethoxysilane, ethyl(tert-butylamino)dimethoxysilane, bis(cyclohexylamino)dimethoxysilane, bis(perhydroisoquinolinyl)dimethoxysilane, bis(perhydroquinolinyl)dimethoxysilane, ethyl(isoquinolinyl)dimethoxysilane, diethylaminotrimethoxysilane, and diethylaminotriethoxysilane, with a particular preference for one or more organosilicon compounds selected from bis(perhydroisoquinolinyl)dimethoxysilane, diethylaminotrimethoxysilane, or diethylaminotriethoxysilane.

[0134] It should be noted that two or more silicon compounds represented by the above general formula (IV) can be used in combination.

[0135] In the method for manufacturing propylene-based block copolymers of the present invention, the catalyst for olefin polymerization comprises (A) a solid catalyst component for olefin polymerization, (B) an organoaluminum compound and (C) an externally electron-donating compound as needed, i.e., their contact material.

[0136] The catalyst for olefin polymerization described above can be prepared by contacting (A) a solid catalyst component for olefin polymerization, (B) an organoaluminum compound and (C) an externally electron-donating compound as needed in the absence of olefins, or it can be prepared by contacting in the presence of olefins (within the polymerization system) as described below.

[0137] In the method for manufacturing the propylene-based block copolymer of the present invention, the content ratio of each component constituting the catalyst for olefin polymerization is arbitrary and not particularly limited, as long as it does not affect the effect of the present invention. Generally, relative to 1 mole of titanium atoms in the solid catalyst component for olefin polymerization (A) above, it is preferable to include 1 to 2000 moles of the organoaluminum compound (B) above, and more preferably 50 to 1000 moles of the organoaluminum compound (B) above. In addition, relative to 1 mole of the organoaluminum compound (B) above, the catalyst for olefin polymerization preferably includes 0.002 to 10.000 moles of the externally electron-donating compound (C) above, more preferably 0.010 to 2.000 moles of the externally electron-donating compound (C) above, and even more preferably 0.010 to 0.500 moles of the externally electron-donating compound (C) above.

[0138] The catalyst for olefin polymerization described above can be manufactured by contacting the above (A) solid catalyst component for olefin polymerization, (B) organoaluminum compound, and (C) external electron-donating compound as needed.

[0139] That is, it can be manufactured by bringing the above-mentioned (A) solid catalyst component for olefin polymerization and (B) organoaluminum compound into contact with each other in the presence of (C) external electron-donating compound, or in the absence of external electron-donating compound.

[0140] When manufacturing the catalyst for olefin polymerization described above, in the absence of an external electron-donating compound (C), it is preferable to contact the solid catalyst component for olefin polymerization (A) with the organoaluminum compound (B), and then further contact the resulting contact-treated product with the external electron-donating compound (C).

[0141] When manufacturing the above-mentioned catalyst for olefin polymerization, the contact amount of the above-mentioned (A) solid catalyst component for olefin polymerization and (B) organoaluminum compound, and the contact amount of (C) external electron-donating compound used as needed, can be appropriately determined according to the desired composition of the catalyst for olefin polymerization.

[0142] The concentration of inactive gas in the atmosphere during the preparation of the above-mentioned catalyst for olefin polymerization is preferably 0.0~1.0 mol / L, more preferably 0.0~0.5 mol / L, and even more preferably 0.0~0.1 mol / L.

[0143] Examples of inactive gases include one or more selected from nitrogen, helium, neon, and argon.

[0144] The catalysts for olefin polymerization described above can be manufactured in the presence of olefins that are the target of polymerization, or in the absence of olefins that are the target of polymerization.

[0145] When manufacturing the catalyst for olefin polymerization, the temperature at which the components come into contact is preferably below 40°C, more preferably 0°C to 40°C, even more preferably 10°C to 40°C, and particularly preferably 10°C to 20°C.

[0146] When manufacturing the catalyst for olefin polymerization, the contact treatment time for each component is preferably 10 seconds to 60 minutes, more preferably 30 seconds to 30 minutes, further preferably 1 minute to 30 minutes, and particularly preferably 1 minute to 10 minutes.

[0147] When manufacturing the above-mentioned catalyst for olefin polymerization, when (A) the solid catalyst component for olefin polymerization and (B) the organoaluminum compound, and then (C) the external electron-donating compound as needed, the reaction begins instantaneously, and the target catalyst for olefin polymerization can be formed.

[0148] In the method for manufacturing propylene block copolymers of the present invention, by using a catalyst for olefin polymerization having specific (A) solid catalyst components for olefin polymerization and (B) organoaluminum compounds, sufficiently high polymerization activity can be easily achieved even when the polymerization reaction is carried out at a low temperature in the first polymerization step described later, and high polymerization activity can also be easily achieved in the second polymerization step. This allows for the easy manufacture of propylene block copolymers with practically high melt flow rates and high propylene / α-olefin copolymer content ratios.

[0149] In the method for manufacturing propylene-based block copolymers of the present invention, after performing a first polymerization step using the above-mentioned catalyst for olefin polymerization, a second polymerization step is further performed. In the first polymerization step, olefins containing 95 to 100% by mass of propylene are polymerized at a temperature of 45°C to 65°C to obtain a propylene-based polymer. In the second polymerization step, olefins containing 5% by mass or more but less than 95% by mass of propylene and α-olefins other than propylene are copolymerized at a temperature of 50°C to 90°C in the presence of the aforementioned propylene-based polymer to obtain a propylene / α-olefin copolymer.

[0150] In the method for manufacturing the propylene-based block copolymer of the present invention, in the first polymerization step, an olefin containing 95 to 100% by mass of propylene is used, preferably an olefin containing 97 to 100% by mass of propylene, and more preferably an olefin containing 99 to 100% by mass of propylene.

[0151] In the method for manufacturing the propylene block copolymer of the present invention, the first polymerization step is carried out at a temperature of 45°C to 65°C, preferably at a temperature of 50°C to 65°C, and more preferably at a temperature of 55°C to 60°C.

[0152] In the method for manufacturing propylene block copolymers of the present invention, by carrying out the first polymerization step under the above-mentioned temperature conditions, excessive polymerization reaction in the first polymerization step is suppressed, and by using the above-mentioned specific olefin polymerization catalyst, high polymerization activity can be easily achieved and propylene polymers as intermediate products can be obtained.

[0153] In the method for manufacturing propylene block copolymers of the present invention, as a second polymerization step, in the presence of a propylene polymer obtained as an intermediate product, propylene comprising 5% by mass and less than 95% by mass of propylene and an olefin other than propylene are copolymerized to obtain a propylene / α-olefin copolymer.

[0154] In the method for manufacturing the propylene-based block copolymer of the present invention, the α-olefin used as the second polymerization step, other than propylene, is not particularly limited as long as it is selected from one or more α-olefins other than propylene. Examples include one or more selected from ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, vinylcyclohexane, etc., with ethylene or 1-butene being suitable.

[0155] In the method for manufacturing the propylene-based block copolymer of the present invention, in the second polymerization step, an olefin comprising 5% by mass and more but less than 95% by mass of propylene and α-olefins other than propylene is used. Preferably, an olefin comprising 10% by mass to 90% by mass of propylene and 10% by mass to 90% by mass of α-olefins other than propylene is used. More preferably, an olefin comprising 20% ​​by mass to 80% by mass of propylene and 20% by mass to 80% by mass of α-olefins other than propylene is used.

[0156] In the method for manufacturing the propylene block copolymer of the present invention, the second polymerization step is carried out at a temperature of 50°C to 90°C, preferably at a temperature of 55°C to 90°C, more preferably at a temperature of 65°C to 90°C, even more preferably at a temperature of 70°C to 85°C, and particularly preferably at a temperature of 70°C to 80°C.

[0157] In the method for manufacturing propylene block copolymers of the present invention, by using the specific olefin polymerization catalyst described above, the polymerization reaction is carried out at the temperature conditions described above in the second polymerization step, thereby enabling the easy exertion of excellent polymerization activity in the second polymerization step and easily manufacturing propylene block copolymers with a high propylene / α-olefin copolymer content.

[0158] In the method for manufacturing propylene-based block copolymers of the present invention, olefin monomers such as propylene can be used in any state, either gaseous or liquid. The processes in the first polymerization step and the second polymerization step can be carried out in the presence of an organic solvent or in the absence of an organic solvent.

[0159] Specifically, in the first polymerization step, by adjusting the polymerization temperature and polymerization time, the monomers are polymerized in an amount equivalent to 50 to 70% by mass of the total amount of the desired propylene block copolymer. Then, in the second polymerization step, propylene and other α-olefins (such as ethylene) are introduced, and the rubber components such as ethylene-propylene rubber (EPR) and ethylene-propylene-1-butene terpolymer are polymerized while adjusting the reaction conditions so that the proportion of the rubber components is 25.0 to 50.0% by mass of the total amount of the desired propylene block copolymer.

[0160] The polymerization reaction in the second polymerization step described above is usually preferably carried out by gas-phase polymerization to suppress the leaching of rubber components such as EPR from polypropylene particles.

[0161] Furthermore, the polymerization reactions in the first and second polymerization steps described above can be carried out by either continuous polymerization or batch polymerization.

[0162] Furthermore, the polymerization reaction can be a single stage or multiple stages in either the first polymerization step or the second polymerization step. In the case of implementing each step in multiple stages, they can be carried out under the same conditions or different conditions.

[0163] In the method for manufacturing propylene-based block copolymers of the present invention, the polymerization of olefins in the first polymerization step and the second polymerization step can be carried out by heating and pressurizing in a reactor (polymerization tank) such as an autoclave in the presence of a catalyst for olefin polymerization.

[0164] For example, the target propylene block copolymer can be manufactured by performing a first polymerization step in a first polymerization tank to obtain a propylene-based polymer by polymerizing a monomer mainly containing propylene as an olefin, and then performing a second polymerization step in a second polymerization tank or a multi-stage (multi-level polymerization tank) in the presence of the obtained propylene-based polymer to copolymerize propylene with α-olefins other than propylene (such as ethylene) to obtain a propylene / α-olefin random copolymer.

[0165] The polymerization pressure in the first polymerization step and the second polymerization step described above is preferably 10 MPa or less, and more preferably 5 MPa or less.

[0166] Furthermore, regarding the polymerization time (residence time of the reactants), the total polymerization time in the first and second polymerization steps described above is appropriately 1 minute to 5 hours.

[0167] It should be noted that in the method for manufacturing propylene block copolymers of the present invention, when olefins are polymerized using a catalyst for olefin polymerization (also known as formal polymerization), in order to further improve catalytic activity, stereoregularity and particulate properties of the resulting polymer, it is preferable to perform prepolymerization before formal polymerization. During prepolymerization, the same olefins or monomers such as styrene as those used in formal polymerization can be used.

[0168] During prepolymerization, the contact order of the components constituting the catalyst for olefin polymerization and the monomers (olefins) is arbitrary, but it is preferred that, in a prepolymerization system set to an inactive gas atmosphere or an olefin gas atmosphere, the organoaluminum compound is first loaded, followed by the solid catalyst components for olefin polymerization, and after they are brought into contact, olefins such as propylene are brought into contact alone, or propylene and α-olefins other than propylene are mixed and brought into contact.

[0169] In the aforementioned prepolymerization, when (C) an external electron-donating compound is further introduced into the prepolymerization system, it is preferable that (B) an organoaluminum compound is introduced first, followed by (C) an external electron-donating compound, in a prepolymerization system set to an inactive gas atmosphere or an olefin gas atmosphere, so that they come into contact, thereby bringing the aforementioned (A) olefin polymerization solid catalyst component into contact, and then contacting olefins such as propylene alone, or mixing propylene and α-olefins other than propylene and bringing them into contact.

[0170] Examples of propylene-based block copolymers obtained by the manufacturing method of the present invention include the propylene-based block copolymers of the present invention described later.

[0171] Next, the propylene block copolymer obtained by the manufacturing method of the present invention will be described.

[0172] As for the propylene block copolymer obtained by the manufacturing method of the present invention, it is preferred that the melt flow rate (MFR) is 10 to 200 g / 10 min, more preferably 15 to 150 g / 10 min, and even more preferably 20 to 100 g / 10 min.

[0173] It should be noted that in this application, the melt flow rate (MFR), which represents the melt flowability of the polymer, refers to the value measured according to ASTM D 1238 and JIS K 7210.

[0174] In the method for manufacturing the propylene block copolymer of the present invention, the propylene block copolymer obtained preferably contains 25.0 to 50.0% by mass of propylene / α-olefin copolymer, more preferably 30.0 to 45.0% by mass, and even more preferably 35.0 to 40.0% by mass.

[0175] It should be noted that, in this application, the content ratio of propylene / α-olefin copolymer in propylene block copolymer refers to the value obtained as follows: 5.0 g of propylene block copolymer and 250 ml of p-xylene are placed in a flask equipped with a stirring device. The polymer is dissolved for 2 hours while maintaining the temperature of p-xylene inside the flask below its boiling point (137~138°C) by keeping the external temperature above the boiling point of xylene (about 150°C). Then, the liquid temperature is cooled to 23°C for 1 hour. The undissolved and dissolved components are filtered and classified. The solution of the dissolved components is collected, and the p-xylene is removed by distillation through heating and vacuum drying. The weight of the residue is calculated, and the relative proportion (mass%) of the residue to the generated polymer (propylene block copolymer) is calculated.

[0176] Furthermore, in the method for manufacturing the propylene block copolymer of the present invention, the content of the propylene polymer in the obtained propylene block copolymer is preferably 50.0 to 75.0% by mass, more preferably 55.0 to 70.0% by mass, and even more preferably 60.0 to 65.0% by mass.

[0177] It should be noted that, in this application document, the content ratio of propylene polymer in propylene block copolymer refers to the value obtained by subtracting the content of propylene / α-olefin copolymer (mass%) and the content of ethylene in xylene-insoluble components (mass%) from the total weight (mass%) of the generated polymer (propylene block copolymer) as 100 (mass%).

[0178] It should be noted that the ethylene content in the xylene-insoluble component refers to the value calculated as follows: a small sample of the xylene-insoluble component obtained when determining the content of the above-mentioned propylene / α-olefin copolymer was taken, and after being hot-pressed into a film, the value was calculated based on the absorbance measured using a Fourier transform infrared spectrometer (FT-IR, Thermonicolet, AvaTar) and the thickness of the film, based on a standard curve made from multiple samples with known contents.

[0179] Measurement wavelength: 720cm -1 and 1150cm -1

[0180] Film thickness: 0.1-0.2mm

[0181] According to the present invention, a method can be provided in which the polymerization activity in the first polymerization step of homopolymerization of propylene or copolymerization of propylene with a small amount of α-olefin (excluding propylene) is excellent, and in the presence of the propylene-based polymer obtained in the first polymerization step, the polymerization activity in the second polymerization step of copolymerization of propylene and α-olefin (excluding propylene) is excellent, making it easy to manufacture propylene-based block copolymers with a practically high melt flow rate and a high proportion of propylene / α-olefin copolymer components.

[0182] Example

[0183] The invention will now be described in more detail by way of examples and comparative examples, but the invention is not limited to any of the examples below.

[0184] (Examples 1-3, Comparative Examples 1-2)

[0185] (1) Preparation of solid catalyst components for olefin polymerization

[0186] In a 500 mL flask equipped with a stirrer and purged with nitrogen, 10 g (87.4 mmol) of magnesium diethoxy, 80 mL of toluene, 20 mL of titanium tetrachloride, and 12.0 mmol (2.6 g) of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane were added. The mixture was brought into contact with each other at 100 °C for 120 minutes to allow the reaction to proceed. After the reaction, the reaction product was washed four times with 60 mL of toluene at 100 °C. A titanium tetrachloride toluene solution with a titanium tetrachloride / toluene volume ratio of 0.28 was added again, and the mixture was stirred at 100 °C for 15 minutes to allow the reaction to proceed. After the reaction, the supernatant was collected. This operation was repeated once more, followed by washing six times with 75 mL of n-heptane at 40 °C to obtain the solid catalyst composition for olefin polymerization.

[0187] (2) Formation of catalysts for olefin polymerization

[0188] A catalyst for olefin polymerization was prepared by loading 2.42 mmol of triethylaluminum and 0.0030 mmol of the solid catalyst component for olefin polymerization obtained in (1) above into a 2.0 L autoclave with a stirrer that was completely purged with nitrogen.

[0189] (3) Manufacturing of ethylene-propylene block copolymers

[0190] After forming the olefin polymerization catalyst in (2), 3.5 liters of hydrogen and 1.2 liters of liquefied propylene are loaded into the high-pressure reactor with a stirrer in which the olefin polymerization catalyst is formed. After prepolymerization at 20°C for 5 minutes, the temperature is raised and the homopolymerization reaction of homopolymer (homopolymer segment) is carried out as the first polymerization step at the polymerization temperature and polymerization time shown in Table 1.

[0191] Following the above-mentioned homopolymer polymerization reaction of polypropylene (homopolymer segment), propylene, ethylene, and hydrogen were supplied at a rate of 2.3 L / min, 1.7 L / min, and 0.086 L / min respectively in an autoclave equipped with a stirrer at a pressure of 1.2 MPa. Copolymerization was carried out at the polymerization temperatures and times shown in Table 1 to generate propylene / ethylene copolymers, thereby obtaining various ethylene-propylene block copolymers.

[0192] In the obtained ethylene-propylene block copolymers, the following methods were used to determine the propylene polymerization activity (homopolymer polymerization activity, g / g-catalyst), ethylene-propylene block copolymerization (ICP) activity (g / g-catalyst), total polymerization activity (g / g-catalyst), block ratio of the obtained block copolymer (polymerization ratio of the copolymer, mass %), melt flow rate (MFR) of the obtained block copolymer, ethylene-propylene copolymer (EPR) content ratio in the obtained block copolymer (mass %), and ethylene content ratio in the ethylene-propylene copolymer (EPR) (mass %). The results are shown in Table 1.

[0193] <Propylene Polymerization Activity>

[0194] The polymerization activity of the homopolymer segment in the copolymerization reaction is calculated according to the following formula.

[0195] Homopolymerization activity (g / g-catalyst) = (G(g) - F(g)) / mass of solid catalyst component (g)

[0196] Here, G(g) is the mass of the autoclave (g) after the homopolymer PP polymerization reaction is completed and unreacted monomers are removed, and F(g) is the mass of the autoclave (g).

[0197] <Ethylene-propylene block copolymerization (ICP) activity (g / g-catalyst)>

[0198] The copolymerization activity (ICP) during the formation of ethylene-propylene block copolymers is calculated according to the following formula.

[0199] Copolymerization (ICP) activity (g / g-catalyst) = (I(g) - G(g)) / mass of solid catalyst component in olefin polymerization catalyst (g)

[0200] Here, I(g) is the mass of the autoclave after the copolymerization reaction (g), and G(g) is the mass of the autoclave after the homopolymerization reaction of PP is completed and unreacted monomers are removed (g).

[0201] <Total polymerization activity (g / g-catalyst)>

[0202] The total polymerization activity (g / g-catalyst) during the manufacture of ethylene-propylene block copolymers is calculated according to the following formula.

[0203] Total polymerization activity (g / g-catalyst) = Homopolymerization activity (g / g-catalyst) + Copolymerization (ICP) activity (g / g-catalyst)

[0204] <Segmentation Rate (Quality %)>

[0205] The block ratio of the obtained ethylene-propylene block copolymer is calculated according to the following formula.

[0206] Block ratio (mass%) = {(I(g) - G(g)) / (I(g) - F(g))} × 100

[0207] Here, I represents the mass of the autoclave after the copolymerization reaction (g), G represents the mass of the autoclave after the homopolymerization of polypropylene is completed and unreacted monomers are removed (g), and F represents the mass of the autoclave (g).

[0208] Melt Flow Rate (MFR)

[0209] The melt flow rate (MFR), which indicates the melt flowability of the obtained ethylene-propylene block copolymer, is determined according to ASTM D 1238 and JIS K 7210.

[0210] <Ethylene-propylene copolymer (EPR) content (xylene-soluble component in ICP polymers)>

[0211] 5.0 g of the copolymer (ethylene-propylene block copolymer) and 250 mL of p-xylene were placed in a flask equipped with a stirrer. The mixture was then stirred for 2 hours while maintaining the external temperature at approximately 150°C and the p-xylene (boiling point 137-138°C) under reflux to dissolve the polymer. The solution was then cooled for 1 hour until it reached 23°C, and the xylene-soluble components (EPR) and xylene-insoluble components (XI) were separated by filtration.

[0212] The soluble components were collected together with the solution, and the xylene was removed by heating, vacuum drying and distillation. The weight of the residue was calculated, and the relative proportion (mass %) of the residue to the generated polymer (ethylene-propylene block copolymer) was calculated as the EPR content (amount of xylene-soluble components in the ethylene-propylene block copolymer).

[0213] <Ethylene content in the EPR component>

[0214] A small sample is taken from the xylene-soluble component (EPR) separated from the EPR content of the copolymer mentioned above. After being hot-pressed into a film shape, based on the absorbance measured using a Fourier transform infrared spectrometer (FT-IR) (manufactured by Thermonicolet, Avatar) and the thickness of the film, and based on the standard curve made from multiple samples with known contents, the ethylene content in the xylene-soluble component (XS) of the ICP is calculated.

[0215] Measurement wavelength: 720 cm -1 and 1150 cm -1

[0216] Film thickness: 0.1 - 0.2 mm

[0217] <Ethylene content in the xylene-insoluble component (XI)>

[0218] A small sample is taken from the xylene-insoluble component (XI) separated to determine the EPR content ratio of the copolymer mentioned above. After being hot-pressed into a film shape, the same operation as the ethylene content in the xylene-soluble component (XS) of the above ICP is carried out to calculate the ethylene content in the xylene-insoluble component (XI) of the ICP.

[0219] (Example 4, Comparative Example 3)

[0220] (1) Preparation of the solid catalyst component for olefin polymerization

[0221] 10 g (87.4 mmol) of diethoxymagnesium, 55 mL of toluene, 15 mL of titanium tetrachloride, and 10.0 mmol (2.2 g) of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane are added to a 500 mL flask equipped with a stirring device and purged with nitrogen. They are brought into contact with each other at 100 °C for 180 minutes to react. After the reaction is completed, the contact product is washed 5 times with 55 mL of toluene at 90 °C. A toluene solution of titanium tetrachloride with a volume ratio of titanium tetrachloride to toluene (titanium tetrachloride / toluene volume ratio) of 0.33 is added again, and they are stirred at 100 °C for 15 minutes to react. After the reaction, the supernatant is taken out. After further performing this operation 3 times, it is washed 6 times with 75 mL of n-heptane at 40 °C to obtain the solid catalyst component for olefin polymerization.

[0222] (2) Formation of the catalyst for olefin polymerization

[0223] In a 2.0-liter autoclave equipped with a stirrer and containing 2.42 mmol of triethylaluminum and 0.030 mmol of the solid catalyst component for olefin polymerization obtained in (1) above, which is equivalent to 0.030 mmol of titanium atoms, a catalyst for olefin polymerization (ethylene-propylene copolymerization catalyst) is prepared.

[0224] (3) Manufacturing of ethylene-propylene block copolymers

[0225] After forming the olefin polymerization catalyst in (2), 3.5 liters of hydrogen and 1.2 liters of liquefied propylene are loaded into the high-pressure reactor with a stirrer in which the olefin polymerization catalyst is formed. After prepolymerization at 20°C for 5 minutes, the temperature is raised and the homopolymerization reaction of homopolymer (homopolymer segment) is carried out as the first polymerization step at the polymerization temperature and polymerization time shown in Table 1.

[0226] Following the above-mentioned homopolymer polymerization reaction of polypropylene (homopolymer segment), propylene, ethylene, and hydrogen were supplied at a rate of 2.3 L / min, 1.7 L / min, and 0.086 L / min respectively in an autoclave equipped with a stirrer, under a pressure of 1.2 MPa, and copolymerized at the polymerization temperatures and times shown in Table 1 to generate ethylene-propylene copolymers, thereby obtaining various ethylene-propylene block copolymers.

[0227] In the obtained ethylene-propylene block copolymers, the following measurements were taken using the same method as in Example 1: propylene polymerization activity (homopolymerization activity, g / g-catalyst), ethylene-propylene block copolymerization (ICP) activity (g / g-catalyst), total polymerization activity (g / g-catalyst), block ratio of the obtained block copolymer (polymerization ratio of the copolymer, mass %), melt flow rate (MFR) of the obtained block copolymer, ethylene-propylene copolymer (EPR) content ratio in the obtained block copolymer (mass %), and ethylene content ratio in the ethylene-propylene copolymer (EPR) (mass %). The results are shown in Table 1.

[0228] (Comparative Example 4, Comparative Example 5)

[0229] (1) Preparation of solid catalyst components for olefin polymerization

[0230] In a 500 mL flask equipped with a stirrer and purged with nitrogen, 10 g (87.4 mmol) of magnesium diethoxy, 90 mL of toluene, 30 mL of titanium tetrachloride, and 15.8 mmol (4.4 g) of dibutyl phthalate were added. The mixture was brought into contact with each other at 90 °C for 180 minutes to allow the reaction to proceed. After the reaction, the reaction product was washed four times with 75 mL of toluene at 90 °C. A titanium tetrachloride toluene solution with a titanium tetrachloride / toluene volume ratio of 0.74 was added again, and the mixture was stirred at 110 °C for 60 minutes to allow the reaction to proceed. After the reaction, the supernatant was collected. Then, the mixture was washed six times with 75 mL of n-heptane at 40 °C to obtain the solid catalyst composition for olefin polymerization.

[0231] (2) Formation of catalysts for olefin polymerization

[0232] In a 2.0-liter autoclave equipped with a stirrer and containing triethylaluminum 2.42 mmol, cyclohexylmethyldimethoxysilane 0.24 mmol, and the solid catalyst composition for olefin polymerization obtained in (1) above (equivalent to titanium atoms) were loaded into the autoclave with a volume of 2.0 liters, thereby preparing an olefin polymerization catalyst (ethylene-propylene copolymerization catalyst).

[0233] (3) Manufacturing of ethylene-propylene block copolymers

[0234] After forming the olefin polymerization catalyst in (2), 3.5 liters of hydrogen and 1.2 liters of liquefied propylene are loaded into the high-pressure reactor with a stirrer in which the olefin polymerization catalyst is formed. After prepolymerization at 20°C for 5 minutes, the temperature is raised and the homopolymerization reaction of homopolymer (homopolymer segment) is carried out as the first polymerization step at the polymerization temperature and polymerization time shown in Table 1.

[0235] Following the above-mentioned homopolymer polymerization reaction of polypropylene (homopolymer segment), propylene, ethylene, and hydrogen were supplied at a rate of 2.3 L / min, 1.7 L / min, and 0.086 L / min respectively in an autoclave equipped with a stirrer, under a pressure of 1.2 MPa, and copolymerized at the polymerization temperatures and times shown in Table 1 to generate ethylene-propylene copolymers, thereby obtaining various ethylene-propylene block copolymers.

[0236] In the obtained ethylene-propylene block copolymers, the following measurements were taken using the same method as in Example 1: propylene polymerization activity (homopolymerization activity, g / g-catalyst), ethylene-propylene block copolymerization (ICP) activity (g / g-catalyst), total polymerization activity (g / g-catalyst), block ratio of the obtained block copolymer (polymerization ratio of the copolymer, mass %), melt flow rate (MFR) of the obtained block copolymer, ethylene-propylene copolymer (EPR) content ratio in the obtained block copolymer (mass %), and ethylene content ratio in the ethylene-propylene copolymer (EPR) (mass %). The results are shown in Table 1.

[0237] [Table 1]

[0238]

[0239] As shown in Table 1, in Examples 1 to 3, a catalyst for olefin polymerization with a specific solid catalyst composition for olefin polymerization containing a 1,3-diether compound as an internal electron-donating compound and an organoaluminum compound was used. In the first polymerization step (homopolymerization stage), the polymerization reaction was carried out at a relatively low temperature in the range of 45°C to 65°C. Therefore, high polymerization activity could be easily achieved in the first polymerization step (homopolymerization stage) and the second polymerization step (copolymerization stage), and ethylene-propylene block copolymers with sufficiently high melt flow rate (MFR), high block ratio, and high EPR content could be easily produced.

[0240] On the other hand, as shown in Table 1, in Comparative Examples 1 to 2, the catalyst for olefin polymerization was supplied to the polymerization reaction at a temperature exceeding 65°C in the first polymerization step (homopolymerization stage). As a result, the polymerization activity in the second polymerization step (copolymerization stage) was lower, and only ethylene-propylene block copolymers with low block ratio and EPR content were obtained.

[0241] Furthermore, as shown in Table 1, in Example 4, a catalyst for olefin polymerization with a specific solid catalyst composition for olefin polymerization containing a 1,3-diether compound as an internal electron-donating compound and an organoaluminum compound was also used. In the first polymerization step (homopolymerization stage), the polymerization reaction was carried out at a relatively low temperature in the range of 45°C to 65°C. Therefore, high polymerization activity could be easily achieved in the first polymerization step (homopolymerization stage) and the second polymerization step (copolymerization stage), and ethylene-propylene block copolymers with sufficiently high melt flow rate (MFR), high block ratio, and high EPR content could be easily produced.

[0242] On the other hand, as shown in Table 1, in Comparative Example 3, the catalyst for olefin polymerization was supplied to the polymerization reaction at a temperature exceeding 65°C in the first polymerization step (homopolymerization stage). As a result, the polymerization activity in the second polymerization step (copolymerization stage) was lower, and only ethylene-propylene block copolymers with low block ratio and EPR content were obtained.

[0243] Furthermore, as shown in Table 1, in Comparative Examples 4 to 5, a catalyst for olefin polymerization was used that contained a solid catalyst component for olefin polymerization that did not contain a 1,3-diether compound as an internal electron-donating compound and an organoaluminum compound. Therefore, the polymerization activity in the first polymerization step (homopolymerization stage) and the second polymerization step (copolymerization stage) was poor, and only ethylene-propylene block copolymers with low melt flow rate (MFR) were obtained.

[0244] Industrial availability

[0245] According to the present invention, a method can be provided in which the polymerization activity in the first polymerization step of homopolymerization of propylene or copolymerization of propylene with a small amount of α-olefin (excluding propylene) is excellent, and in the presence of the propylene-based polymer obtained in the first polymerization step, the polymerization activity in the second polymerization step of copolymerization of propylene and α-olefin (excluding propylene) is excellent, making it easy to manufacture propylene-based block copolymers with high melt flow rate and high proportion of propylene / α-olefin copolymer components.

Claims

1. A method for manufacturing a propylene-based block copolymer, characterized in that, After the first polymerization step is carried out using a catalyst for olefin polymerization, a second polymerization step is then carried out. The catalyst for olefin polymerization comprises (A) a solid catalyst component for olefin polymerization and (B) an organoaluminum compound, wherein (A) the solid catalyst component for olefin polymerization contains titanium, magnesium, halogen, and a 1,3-diether compound as an internal electron-donating compound. The first polymerization step involves polymerizing an olefin containing 95-100% by mass of propylene at a temperature of 45°C to 65°C to obtain a propylene-based polymer. The second polymerization step involves copolymerizing propylene containing 5% by mass and less than 95% by mass of propylene and α-olefins other than propylene at a temperature of 50°C to 90°C in the presence of the propylene-based polymer to obtain a propylene / α-olefin copolymer.

2. The method for manufacturing a propylene block copolymer according to claim 1, wherein, The organoaluminum compound (B) is one or more compounds represented by the following general formula (I). R 1 p AlQ 3-p (I) In formula (I), R 1 is an alkyl group having 1 to 6 carbon atoms, Q is a hydrogen atom or a halogen atom, p is 0 < p ≤ 3, and when there are multiple R 1 s, each R 1 is optionally the same as or different from each other, and when there are multiple Qs, each Q is optionally the same as or different from each other.

3. The method for manufacturing a propylene block copolymer according to claim 1, wherein, The catalyst for olefin polymerization also includes (C) an externally electron-donating compound.

4. The method for manufacturing a propylene block copolymer according to any one of claims 1 to 3, wherein, In the obtained propylene-based block copolymers, the propylene / α-olefin moiety contains 25.0 to 50.0% by mass.

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