Catalysts for olefin polymerization processes, propylene polymers, and methods for producing the same.

Abstract

The present invention belongs to the technical field of propylene polymerization, and more particularly to catalysts for olefin polymerization, and propylene polymers containing ultra-high molecular weight polypropylene components and having adjustable isotactic properties, and methods for producing the same. The method comprises the steps of reacting propylene in the presence of hydrogen and a polymerization catalyst, or reacting propylene with one or more arbitrarily selected comonomers, and a mixture D of a hydrogenation catalyst and an external electron donor. H The invention includes the step of polymerizing at least a portion of the resulting material stream containing polypropylene component I for 0.05 to 3.0 hours in a pipeline located outside the reactor or in a subsequent reactor connected in series thereto, in the presence of a hydrogenation catalyst, thereby obtaining a polypropylene polymer product containing 0.03 to 15.0% by mass of ultra-high molecular weight polypropylene component, wherein the molar ratio of the hydrogenation catalyst to the total amount of hydrogen is 1 / 10000 to 1 / 100. In this invention, a polypropylene product containing a relatively low content of ultra-high molecular weight component can be prepared, and the isotacticity of the ultra-high molecular weight polypropylene component can be flexibly adjusted.

Description

[Technical Field]

[0001] The present invention belongs to the technical field of propylene polymerization, and more particularly to catalysts for olefin polymerization, and propylene polymers containing ultra-high molecular weight polypropylene components and having adjustable isotactic properties, and methods for producing the same. [Background technology]

[0002] Generally speaking, the molecular chain structure of homopolymer polypropylene is linear and semi-crystalline. Typical polypropylene has a relatively low molecular weight (approximately several hundred thousand) and a softening point close to its melting point. After exceeding the melting point, the melt strength decreases rapidly, leading to problems such as uneven wall thickness of containers during thermoforming, edge curling and shrinkage during extrusion coating and calendering, and cell collapse during extrusion foaming. Thus, it is difficult to produce large products and achieve high-speed molding, which limits the applications of polypropylene.

[0003] The properties of polypropylene are directly related to its total molecular weight, molecular weight distribution, stereoregularity of its molecular chains, and the type, content, and distribution of comonomers, as well as to the isotactic distribution and comonomer distribution of high and low molecular weight components. Studies have shown that increasing the total molecular weight of polypropylene improves its stiffness, toughness, and melt strength. Adding a small amount of high molecular weight polypropylene components to general polypropylene can broaden the molecular weight distribution of the polypropylene product and improve its crystallization rate and processability. However, if the proportion of high molecular weight polypropylene components is too high, the processability of the material will rapidly decrease.

[0004] In polypropylene, the distribution of low molecular weight components with high isotacticity and high molecular weight components with low isotacticity is highly beneficial for the biaxial stretching of polypropylene film materials.

[0005] The U.S. Patent Document No. 6875826B1 of BOREALIS discloses a method for producing propylene homopolymers or copolymers in which asymmetric hydrogenation is carried out in two reactors, i.e., in a series-connected loop gas-phase polymerization reactor, a Ziegler-Natta catalyst or metallocene catalyst and an external electron donor (dicyclopentadienyldimethoxysilane or cyclohexylmethyldimethoxysilane) are selected, and by changing the amount of hydrogen in the different reactors, a broadly distributed polypropylene having different molecular weight components, including high molecular weight components and low molecular weight components, is prepared. The inventors realized that while it is possible to produce components with different molecular weights in different reactors by changing the amount of hydrogen in each reactor under hydrogen-using conditions, hydrogen cannot be removed between reactors. Therefore, they found that by producing a high molecular weight component with a melt mass flow rate or melt index (MFR) of less than 0.1 g / 10 min by not adding hydrogen to the first reactor, and then producing a medium-low molecular weight component with an MFR of more than 0.5 g / 10 min by adding an appropriate amount of hydrogen to the second reactor, the resulting polypropylene would have the characteristic of having high melt strength. In this patent, the load ratio of the two reactors is suggested to be 5:95 to 95:5, but due to the difficulty of actual operation, the proportion of the high molecular weight component in the embodiment is 20% or more.

[0006] Patent documents Chinese Patent Application Publication No. 102134291A, Chinese Patent Application Publication No. 102816269A, and Chinese Patent Application Publication No. 105623077A all disclose that a widely distributed propylene homopolymer or propylene-ethylene copolymer with high melt strength can be obtained by direct polymerization in a reactor using a double reactor in series, using conventional Ziegler-Natta catalyst, asymmetric addition of an external electron donor, and asymmetric hydrogen control techniques. Specifically, first, an external electron donor of dicyclopentyl dimethoxysilane (D-donor), which is not sensitive to hydrogen control, is added to the first reactor to prepare a propylene homopolymer or copolymer with high molecular weight and high isotacticity under conditions where hydrogen is absent or low. Next, an external electron donor of tetraethoxysilane (TEOS), which is sensitive to hydrogen control, is added to the second reactor to prepare a propylene homopolymer or copolymer with high hydrogen concentration and low molecular weight. Finally, a propylene homopolymer, random copolymer, or impact copolymer product is obtained having a melt index of 2.0-3.0 g / 10 min and a melt strength of 0.8-2.0 N. In this case, the load ratio of the two reactors is 30:70-70:30.

[0007] In the disclosed method described above, regardless of whether asymmetric hydrogenation is performed or an external electron donor is added, a large amount of hydrogen (sometimes as much as 20,000 ppm) is added to the second reactor to adjust the molecular weight of the product. When the hydrogen returns to the first reactor with the circulating gas, the first reactor can no longer produce polyolefins with high molecular weight. Therefore, it is necessary to separate or remove the hydrogen by conventional separation methods such as venting or pressure swing adsorption, which leads to the loss of a large amount of unreacted monomer, increases the product variety switching time, produces a large amount of intermediate transition material, and raises production costs. The high molecular weight components produced by the first polymerization reactor have a high compositional content, and the adjustable range is small due to the limitations of the reactor's continuous operation load. This narrows the adjustable melt index range of the final product, reducing processability. In addition, a D-donor is used in the first polymerization reactor to produce high molecular weight components, which makes the isotacticity of the high molecular weight components very high, making it difficult to adjust their flexibility. Simultaneously, introducing a large amount of external electron donor and hydrogen into the second reactor to produce low molecular weight components significantly reduces polymerization activity, increasing the difficulty of production control and resulting in an increase in the ash content of the final product.

[0008] U.S. Patent Documents 10934372B2 and 10544237B2 both propose a method suitable for two or more slurry phase polymerization reactors for producing bimodal polyolefins, in which hydrogen is typically added to a first reactor to produce a low molecular weight polyolefin component, and all or part of the hydrogen is removed from all or part of the stream discharged from the first reactor by contact with a hydrogenation catalyst to form a stream with a low hydrogen concentration, which is then fed into a second reactor or returned to the first reactor for polymerization to produce a high molecular weight polyolefin component, thereby producing a polyolefin homopolymer or copolymer having a bimodal molecular weight distribution. Therefore, a flash separation unit is omitted, i.e., there is no step of emptying the material stream discharged from the first reactor to remove hydrogen. In this method, a hydrogenation catalyst is added to the stream discharged from the outlet of the first reactor. After the material containing the hydrogenation catalyst flows into the second reactor or returns to the first reactor, the reaction activity clearly decreases, affecting the quality indicators of the polypropylene product, such as the melt index and isotacticity, and subsequently affecting the normal operation of the device.

[0009] In a dual reactor system, if a hydrogenation catalyst is used on the material obtained from the first polymerization reactor before it enters the second reactor, it becomes difficult to adjust the loads of the two reactors, the proportion of high molecular weight components becomes too high, and it becomes impossible to control the isotactic properties of the high molecular weight components.

[0010] In addition, the aforementioned methods for producing polypropylene products containing high molecular weight polyolefin components have similar problems, regardless of whether a hydrogenation catalyst is used to remove hydrogen, or whether asymmetric hydrogen control or asymmetric control of an external electron donor is used. Specifically, when an external electron donor is used in a fixed manner, asymmetric hydrogenation in two reactors results in an excessive amount of hydrogen being used, limiting the molecular weight adjustment range of the polypropylene product, making reactor operation difficult and increasing operational risk, resulting in an insufficiently broad molecular weight distribution of the resulting polypropylene, making it impossible to control the isotacticity of the high molecular weight component, and reducing the processability of the high molecular weight component. When different types of external electron donors are added to two reactors and asymmetric hydrogenation is performed simultaneously, several problems arise, such as the large amount of external electron donor used, difficulty in adjusting the load of the two reactors, a high proportion of the high molecular weight component (equal to or greater than 30% by mass), reduced processability of the product, and a high ash content in the product.

[0011] The above methods share a common drawback: the resulting propylene polymer products tend to have a relatively high content of high molecular weight components, generally equal to or greater than 15%. Excessively high content of high molecular weight components affects the processability of the material and makes it difficult to control the isotactic properties of these components. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] U.S. Specification No. 6875826B1 [Patent Document 2] Chinese Patent Application Publication No. 102134291A Specification [Patent Document 3] Chinese Patent Application Publication No. 102816269A Specification [Patent Document 4] Chinese Patent Application Publication No. 105623077A Specification [Patent Document 5] U.S. Patent No. 10934372B2 [Patent Document 6] U.S. Specification No. 10544237B2 [Patent Document 7] Chinese Patent Application Publication No. 101054424A Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] Therefore, the ability to control the isotacticity of high molecular weight components in propylene polymers is beneficial for improving the properties of the product. How to control the proportion of high molecular weight components and flexibly adjust their isotacticity during the polymerization process is a research area worth investigating.

[0014] The present invention aims to address problems in the preparation of polypropylene in the prior art, and to provide a catalyst for olefin polymerization, a propylene polymer containing ultra-high molecular weight polypropylene components and having adjustable isotactic properties, and a method for producing the same. By installing a pipeline or the like as an additional polymerization reaction site outside the reactor at the end of the polymerization reaction, and adding a mixture of a hydrogenation catalyst and an external electron donor thereto to continue the polymerization reaction, a polypropylene product with a low content of ultra-high molecular weight polypropylene components can be prepared, and the isotactic properties of the ultra-high molecular weight polypropylene components can be flexibly adjusted. As a result, the properties of the polypropylene product (including melt strength, tensile strength, impact strength, and flexural strength, etc.) are significantly improved while maintaining good processability. [Means for solving the problem]

[0015] To achieve the above objectives, the present invention provides the following technical solutions.

[0016] In a first aspect, there is provided a catalyst for an olefin polymerization process, which is a mixture of a Group IVB transition metal metallocene compound, an alkylaluminum compound, and an external electron donor D1, and the Group IVB transition metal metallocene compound is at least mixed with a part of the alkylaluminum compound before contacting with the external electron donor D1.

[0017] According to the catalyst provided by the present invention, in some embodiments, the catalyst is a mixture of a hydrogenation catalyst and an external electron donor D1, and the hydrogenation catalyst is a mixture of a Group IVB transition metal metallocene compound and an alkylaluminum compound.

[0018] According to the catalyst provided by the present invention, in some embodiments, the external electron donor D1 is an alkoxy-substituted silane compound, for example, dicyclopentyldimethoxysilane (D-donor), methylcyclohexyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, tetraethoxysilane (TEOS), diethylaminotriethoxysilane, preferably, it can be selected from dimethoxysilane compounds.

[0019] In some embodiments, the general formula of the Group IVB transition metal metallocene compound is R(R’)-M-X(X’), wherein, R and R’ are each independently cyclopentadienyl, indenyl, or fluorenyl which has no substituent or has a substituent, and the substituent is preferably selected from methyl, ethyl, propyl, butyl, and cycloalkyl; R and R’ may be bridged by a substituent containing C or Si, M is one or more selected from transition metal elements, preferably Ti, Zr, and Hf, X and X’ are each independently a halogen atom, an alkyl, or an alkoxy; More preferably, the Group IVB transition metal metallocene compound is Cp2TiCl2.

[0020] According to the catalyst provided by the present invention, in some embodiments, the molar ratio of the alkylaluminum compound to the external electron donor D1 in the catalyst is 0.1:1 to 50:1 (e.g., 0.2:1, 0.5:1, 0.8:1, 1:1, 2:1, 5:1, 8:1, 10:1, 15:1, 20:1, 25:1, 35:1, 40:1 and 45:1), preferably 0.1:1 to 30:1, and the molar ratio of aluminum to the transition metal group IVB metallocene compound in the alkylaluminum compound is 5.5 to 100.0:1 (e.g., 6:1, 7:1, 8:1, 9:1, 10:1, 25:1, 50:1, 80:1 and 90:1), preferably 5.5 to 10.0:1, more preferably 5.5 to 8.0:1.

[0021] In a second embodiment, a propylene polymer containing an ultra-high molecular weight polypropylene component and having adjustable isotactic properties is provided, wherein the melt mass flow rate (MFR, tested under 230°C and a 2.16 kg load) of the propylene polymer is equal to or greater than 0.01 g / 10 min and equal to or less than 10,000 g / 10 min, for example. The available doses are 0.05g / 10 min, 0.1g / 10 min, 0.2g / 10 min, 0.5g / 10 min, 1.0g / 10 min, 2.0g / 10 min, 5.0g / 10 min, 10.0g / 10 min, 20.0g / 10 min, 50.0g / 10 min, 100g / 10 min, 200g / 10 min, 500g / 10 min, 1000g / 10 min, 2000g / 10 min, 5000g / 10 min, and 8000g / 10 min; The propylene polymer contains ultra-high molecular weight components, the molecular weight MW of the ultra-high molecular weight components being equal to or greater than 10,000,000; the content of the ultra-high molecular weight components in the propylene polymer is 0.03 to 15.0% by mass (e.g., 0.035% by mass, 0.04% by mass, 0.05% by mass, 0.06% by mass, 0.08% by mass, 0.1% by mass, 0.2% by mass, 0.4% by mass, 0.5% by mass, 0.8% by mass, 1.0% by mass, 5.0% by mass, and 10.0% by mass), and A propylene polymer is provided in which the ratio of the number-average molecular weight Mn of the ultra-high molecular weight component to the peak molecular weight Mp of the propylene polymer, Mn (MW is equal to or greater than 10,000,000) / Mp, is equal to or greater than 80, for example, 85, 90, 100, 110, 120, 130, 140, and 150.

[0022] According to the propylene polymer provided by the present invention, in some embodiments, the content of ultra-high molecular weight components in the propylene polymer is 0.03 to 5.0% by mass.

[0023] In some embodiments, the ratio of the number-average molecular weight Mn of the ultra-high molecular weight component to the peak molecular weight Mp of the propylene polymer, Mn(MW is equal to or greater than 10,000,000) / Mp, is equal to or greater than 100, preferably Mn(MW is equal to or greater than 10,000,000) / Mp, is equal to or greater than 120.

[0024] In some embodiments, the melt mass flow rate (MFR) of the propylene polymer is equal to or greater than 0.01 g / 10 min and equal to or less than 300 g / 10 min, preferably equal to or greater than 0.1 g / 10 min and equal to or less than 200 g / 10 min.

[0025] In some embodiments, the melt strength of the propylene polymer is equal to or greater than 2.0 cN, for example, 2.5 cN, 3.0 cN, 3.5 cN, 4.0 cN, 4.5 cN, 5.0 cN, and 6.0 cN.

[0026] In a third aspect, a method for producing a propylene polymer is provided, the method employing two or more polymerization steps arranged in succession, the method comprising the following steps: (1) A step of preparing a material stream containing polypropylene component I by reacting propylene in a polymerization reactor in the presence of hydrogen and a polymerization catalyst, or by reacting propylene with one or more arbitrarily selected comonomers, to carry out a first-stage (co)polymerization reaction for 0.1 to 10 hours (for example, 0.2 hours, 0.4 hours, 0.5 hours, 1.0 hour, 1.5 hours, 2.0 hours, 3.0 hours, 5 hours, and 8 hours), (2) After the first step of the (co)polymerization reaction, a mixture D of the hydrogenation catalyst and the external electron donor H A step of polymerizing at least a portion of a material stream containing polypropylene component I for 0.05 to 3.0 hours (for example, 0.06 hours, 0.08 hours, 0.1 hours, 0.2 hours, 0.4 hours, 0.5 hours, 0.8 hours, 1.0 hours, 1.5 hours, 2.0 hours, and 2.5 hours) in the presence of, in a pipeline located outside the polymerization reactor of step (1), or in second and subsequent reactors connected in series with the polymerization reactor of step (1), thereby obtaining an ultra-high molecular weight polypropylene (UHMWPP) component, A step to stop the reaction and obtain a propylene polymer product containing ultra-high molecular weight polypropylene (UHMWPP) components; Here, the molar ratio of the hydrogenation catalyst to the total amount of hydrogen present in the reactor is 1 / 10000 to 1 / 100 (for example, 1 / 8000, 1 / 5000, 1 / 4000, 1 / 2000, 1 / 1000, 1 / 800, 1 / 500, 1 / 400, and 1 / 200), preferably 1 / 10000 to 1 / 1000.

[0027] The material stream containing polypropylene component I obtained in step (1) contains at least unreacted propylene, unreacted hydrogen, polypropylene component I, and possibly a small amount of hydrogen, and a polymerization catalyst, etc.

[0028] According to the manufacturing method provided by the present invention, in some embodiments, in step (1), the polymerization catalyst comprises (a) an active solid catalyst component, preferably a solid catalyst active component containing titanium; (b) an organoaluminum compound as a cocatalyst component; and optionally (3) an external electron donor D2; the polymerization catalyst is preferably a mixture D formed by the active solid catalyst component, the organoaluminum compound, and the external electron donor D2.

[0029] In some embodiments, mixture D H The catalytic effect strength of is higher than that of mixture D.

[0030] Mixture D H The external electron donor D1 in the mixture and the external electron donor D2 in the mixture D may be the same or different. Depending on the isotactic requirements of the ultra-high molecular weight polypropylene component, different external electron donors or two or more different external electron donor compositions may be flexibly selected. When different external electron donors are used, the mixture D H It is preferable to select a compound that has a stronger effect than the external electron donor D2 in mixture D as the external electron donor D1.

[0031] In this specification, "stronger effect" means that, under the same polymerization reaction conditions, the isotacticity or molecular weight of the polymerization product obtained by using an external electron donor that has a stronger effect in the polymerization system is higher than that obtained by using an external electron donor that has a relatively weaker effect. For example, a D-donor is stronger than a C-donor and TEOS, and a P-donor is stronger than a B-donor.

[0032] In the present invention, catalysts used in propylene (co)polymerization include, but are not limited to, Ziegler-Natta catalysts, and such catalysts generally include (a) an active solid catalyst component, preferably a solid catalyst active component containing titanium, (b) an organoaluminum compound as a cocatalyst component, and optionally (3) an external electron donor D2.

[0033] The active solid catalyst component may be a Ziegler-Natta catalyst or a molecular catalyst containing metallocene. The active main catalyst component may be a commercially available SUG catalyst, SAL catalyst, or other catalysts containing both titanium chloride and magnesium chloride.

[0034] As a co-catalyst component in the catalyst, the organoaluminum compound is preferably selected from alkylaluminum compounds, more preferably from trialkylaluminum (triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, etc.), methylaluminoxane (MAO), modified methylaluminoxane (MMAO), etc., and the ratio of the active solid catalyst component to the organoaluminum compound is 1:5 to 1:400, preferably 1:25 to 1:200, based on the Ti / Al molar ratio. The amount of external electron-donating component used in the polymerization catalyst may be a conventional choice in the art and is not described herein.

[0035] In some embodiments, the external electron donors D1 and D2 are the same or different, and each is independently an alkoxy-substituted silane compound or a mixture of multiple alkoxy-substituted silane compounds.

[0036] External electron donors D1 or D2 are of the general formula SiR n (OR') 4-n This may be a variety of electron-donating compounds, including alkoxy-substituted silane compounds having, where, 0 ≤ n ≤ 2, R and R' are either the same or different, and each is independently an alkyl, cycloalkyl, aryl, haloalkyl, etc. R may also be a halogen or a hydrogen atom.

[0037] In some embodiments, the external electron donor may be, specifically, tetramethoxysilane, tetraethoxysilane (TEOS), dimethyldimethoxysilane, dimethyldiethoxysilane, methyltert-butyldimethoxysilane, methylisopropyldimethoxysilane, diphenoxydimethoxysilane, vinyltrimethoxysilane, methylcyclohexyldimethoxysilane, ethylcyclohexyldimethoxysilane, di-n-propyldimethoxysilane, diisopropyldimethoxysilane, di-n-butyldimethoxysilane, diisobutyldimethoxysilane, ditert-butyldimethoxysilane, dicyclopentyldimethoxysilane (D-donor), cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxy These may include, but are not limited to, dicyclopentyl dimethoxysilane (D-donor), methylcyclohexyl dimethoxysilane, diisopropyl dimethoxysilane, bis(pyrrolidino)dimethoxysilane, bis(perhydroisoquinolino)dimethoxysilane, 2-ethylpiperidinyl-2-tert-butyldimethoxysilane, (1,1,1-trifluoro-2-propyl)-2-ethylpiperidinyldimethoxysilane, and (1,1,1-trifluoro-2-propyl)-methyldimethoxysilane. Preferably, they are selected from dicyclopentyl dimethoxysilane (D-donor), methylcyclohexyl dimethoxysilane, diisopropyl dimethoxysilane, diisobutyl dimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, tetraethoxysilane (TEOS), and diethylaminotriethoxysilane.

[0038] In some embodiments, the hydrogenation catalyst is a mixture of organometallic compounds and alkylaluminum compounds.

[0039] In some embodiments, the general formula of the organometallic compound is R(R')-MX(X'), where, R and R' are each independently unsubstituted or substituted cyclopentadienyl, indenyl, or fluorenyl, wherein the substituent is preferably selected from methyl, ethyl, propyl, butyl, and cycloalkyl; R and R' may also be crosslinked by substituents containing C or Si. M is one or more transition metal elements, preferably selected from Ti, Zr, and Hf; X and X' are each independently a halogen atom, an alkyl group, or an alkoxy group.

[0040] In some embodiments, the organometallic compounds are specifically di(cyclopentadienyl)titanium dichloride (titanocene), di(cyclopentadienyl)titanium dibromide, bis(cyclopentadienyl)methoxytitanium chloride, bis(cyclopentadienyl)ethoxytitanium chloride, bis(cyclopentadienyl)phenoxytitanium chloride, di(cyclopentadienyl)dimethyltitanium, di(cyclopentadienyl)diethyltitanium, di-indenyltitanium dichloride, di-indenyl One or more of tanebromide, di-indenyldimethyltitanium, di-indenyldiethyltitanium, di(cyclopentadienyl)zirconium dichloride, di(cyclopentadienyl)zirconium dibromide, di(cyclopentadienyl)dimethylzirconium, and di(cyclopentadienyl)diethylzirconium can be selected, preferably di(cyclopentadienyl)titanium dichloride and / or di(cyclopentadienyl)diethyltitanium.

[0041] In some embodiments, the alkylaluminum compound can be selected from one or more of trimethylaluminum, triethylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, monochlorodimethylaluminum, monochlorodiethylaluminum, monochlorodibutylaluminum, monochlorodiisobutylaluminum, methylaluminoxane (MAO), and modified methylaluminoxane (MMAO), preferably selected from triethylaluminum and / or methylaluminoxane.

[0042] In some embodiments, the molar ratio of aluminum to organometallic compound in the alkylaluminum compound in the hydrogenation catalyst is 5.5 to 100.0:1 (for example, 6.0:1, 7.0:1, 8.0:1, 9.0:1, 10:1, 25:1, 50:1, 80:1, and 90:1), preferably 5.5 to 10.0:1, and more preferably 5.5 to 8.0:1.

[0043] In some embodiments, the hydrogenation catalyst is a mixture of Cp2TiCl2 and an alkylaluminum compound, where the molar ratio of aluminum in the alkylaluminum compound to Cp2TiCl2 is 5.5 to 100.0:1 (e.g., 6.0:1, 7.0:1, 8.0:1, 9.0:1, 10:1, 25:1, and 50:1), preferably 5.5 to 10.0:1, and more preferably 5.5 to 8.0:1.

[0044] In some embodiments, a mixture D formed by a hydrogenation catalyst and an external electron donor D1 is used. H In this configuration, the molar ratio of the alkylaluminum compound in the hydrogenation catalyst to the external electron donor D1 is 0.1:1 to 50:1 (for example, 0.2:1, 0.5:1, 0.8:1, 1:1, 2:1, 5:1, 8:1, 10:1, 15:1, 20:1, 25:1, 35:1, 40:1, and 45:1), preferably 0.1:1 to 30:1.

[0045] In this invention, the outlet pipeline may be located outside a single reactor or at the outer end of multiple series (parallel) reactors.

[0046] In this invention, the mixture of the hydrogenation catalyst and the external electron donor can be added by either continuous addition or pulsed addition.

[0047] In this invention, there is no step of circulating the material containing the hydrogenation catalyst to the polymerization reactor, and this does not affect the normal operation and indicator control of the polymerization reactor. Furthermore, the location of adding the mixture of the hydrogenation catalyst and the external electron donor is flexible and may be at any location on the pipeline set up for the process of transporting the polypropylene powder to the container, or at the front end of the inlet of a second or subsequent reactor connected in series with the first polymerization reactor.

[0048] In some embodiments, the length of the pipeline located outside the polymerization reactor in step (1) is 0.1 to 50 meters, for example, 0.5 meters, 1 meter, 2 meters, 5 meters, 10 meters, 20 meters, and 40 meters.

[0049] The pipeline may include a pipeline as a polymerization reaction site outside a single reactor or multiple reactors in series for propylene polymerization, and connecting pipelines connected to subsequent separation devices. The pipeline material may be any material conventionally used in the art.

[0050] In some embodiments, the polymerization time in step (i) is 0.2 to 5 hours, preferably 0.3 to 3 hours.

[0051] In some embodiments, the polymerization temperature in step (i) is 40 to 250°C (for example, 50°C, 60°C, 70°C, 80°C, 100°C, 150°C, and 220°C), preferably 50 to 200°C.

[0052] In some embodiments, the polymerization time in step (ii) is 0.08 to 2.0 hours, preferably 0.1 to 1.5 hours.

[0053] The polymerization temperature in step (ii) is 0 to 250°C (for example, 20°C, 50°C, 60°C, 70°C, 80°C, 100°C, 150°C, and 220°C), preferably 20 to 200°C.

[0054] The polymerization temperature in step (ii) may be the same as or lower than the polymerization temperature in step (i).

[0055] According to the method provided by the present invention, a propylene monomer can be polymerized in a polymerization reaction, or a propylene monomer can be copolymerized with one or more comonomers. In some embodiments, the comonomers may be ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-nonene, 1-decene, etc., or a mixture of any two or more comonomers.

[0056] According to the manufacturing method provided by the present invention, in some embodiments, the isotacticity of the prepared propylene polymer is modified (adjustable), and the mixture D formed by the hydrogenation catalyst and external electron donor D1 is modified. H The difference in xylene solubility content (XS%) of the prepared propylene polymer compared to a polymer obtained without using the hydrogenation catalyst or a polymer obtained using only the hydrogenation catalyst is within the range of 0.02 to 5%, preferably 0.1 to 2%.

[0057] According to the manufacturing method of the present invention, in some embodiments, the melt mass flow rate (MFR) of the prepared propylene polymer is equal to or greater than 0.01 g / 10 min and equal to or less than 10,000 g / 10 min, for example, 0.05 g / 10 min, 0.1 g / 10 min, 0.2 g / 10 min, 0.5 g / 10 min, 1.0 g / 10 min, 2.0 g / 10 min, 5.0 g / 10 min, 10.0 g / 10 min, 20.0 g / 10 min, 50.0 g / 10 min, 100 g / 10 min, 200 g / 10 min, 500 g / 10 min, 1000 g / 10 min, 2000 g / 10 min, 5000 g / 10 min, and 8000 g / 10 min.

[0058] According to the manufacturing method of the present invention, in some embodiments, the prepared propylene polymer contains an ultra-high molecular weight component, and the molecular weight MW of the ultra-high molecular weight component is equal to or greater than 10,000,000, for example, the molecular weight MW is equal to or greater than 10,000,000, and equal to or less than 1,000,000,000, and the content of the ultra-high molecular weight component in the propylene polymer is 0.03 to 15.0 mass% (for example, 0.035 mass%, 0.04 mass%, 0.05 mass%, 0.06 mass%, 0.08 mass%, 0.1 mass%, 0.2 mass%, 0.4 mass%, 0.5 mass%, 0.8 mass%, 1.0 mass%, 5.0 mass%, and 10.0 mass%).

[0059] According to the manufacturing method of the present invention, in some embodiments, the ratio of the number-average molecular weight Mn of the prepared ultra-high molecular weight component to the peak molecular weight Mp of the propylene polymer, Mn (MW is equal to or greater than 10,000,000) / Mp, is equal to or greater than 80, for example, 85, 90, 100, 110, 120, 130, 140, and 150.

[0060] The outlet material of a propylene polymerization reactor contains polypropylene powder, a catalyst, optionally an electron donor, propylene, comonomer, hydrogen, a small amount of propane, a small amount of nitrogen, etc. Typically, such materials are still within the conditions necessary for polymerization, the catalyst still has polymerization activity, and a certain concentration of polymerization monomer and hydrogen is present in the environment, allowing the polymerization reaction to continue. According to the present invention, a material outlet pipeline located at the outer end of the reactor is used as an additional polymerization reaction site, or any location on a second and subsequent reactor connected in series with the first polymerization reactor or on a transport pipeline connecting the powder and container is used as an additional polymerization reaction site. As a result, the product material stream discharged from a single reactor or reactors connected in series (parallel) with the first polymerization stage is brought into contact with a mixture of hydrogenation catalyst and external electron donor D1, and then can be fed into a gas / solid separator through a connecting pipeline of 0.1 to 50 meters in length. Subsequently, after catalyst deactivation and degassing, a final product containing ultra-high molecular weight components is obtained.

[0061] In the second polymerization step, by adding a hydrogenation catalyst and a certain amount of external electron donor D1, the Al-Si ratio of the system can be effectively adjusted, further adjusting the isotacticity of the product and improving the molecular weight of the product. In a mixture of the hydrogenation catalyst and the external electron donor, the hydrogenation catalyst is used to remove residual hydrogen (chain transfer agent) from the product material stream (powder) discharged from the reactor in the first polymerization step. As a result, propylene can continue to polymerize under conditions with almost no hydrogen content, producing ultra-high molecular weight polypropylene component (UHWMPP). The external electron donor is used to adjust the isotacticity of the ultra-high molecular weight polypropylene component (UHWMPP) produced by the continuous reaction of propylene and further improving the molecular weight of the product. The present invention unexpectedly discovered that the introduction of external electron donor D1 did not show any indication of changing the hydrogenation efficiency of the hydrogenation catalyst.

[0062] Compared to conventional technologies, the technical solution of the present invention has the following beneficial effects. By adjusting the addition position of the mixture of the hydrogenation catalyst and the external electron donor, the residence time of the material at additional polymerization reaction sites such as discharge pipelines can be flexibly adjusted, thereby flexibly controlling the amount of ultra-high molecular weight polypropylene component produced. As a result, the proportion of ultra-high molecular weight component in the final polypropylene product can be adjusted and controlled, avoiding the adverse effects on processability caused by excessively high molecular weight component content. By adjusting the molar ratio of alkylaluminum in the hydrogenation catalyst to the external electron donor, the ratio of aluminum to silicon in the system can be flexibly changed, further flexibly adjusting the isotacticity of the ultra-high molecular weight polypropylene component. By adjusting the amount of hydrogenation catalyst, the molecular weight of the ultra-high molecular weight polypropylene component can be adjusted so that its molecular weight MW reaches a value of 10,000,000 or greater. Therefore, a series of polypropylene products with ultra-high molecular weight and different compositions can be prepared. By controlling the amount of hydrogenation catalyst and the amount of alkylaluminum within it to a suitable range, the influence of alkylaluminum as a chain transfer agent on the molecular weight of ultra-high molecular weight components can be reduced, and catalyst residue in the product can be reduced. High-temperature gel permeation chromatography (GPC) test results indicate that the final product contains a certain amount of UHWMPP component, and that the molecular weight distribution of the product is slightly broadened. The low content of UHWMPP component allows for the maintenance of good processing rheological properties, and comprehensively improves properties such as melt strength, tensile strength, and impact strength of the polypropylene product. The polypropylene product prepared by this method can meet the requirements of more advanced application scenarios and can be used in fields such as extrusion foaming, coating, blow molding, and thermoforming. [Modes for carrying out the invention]

[0063] Description of Exemplary Embodiments To gain a more detailed understanding of the technical features and content of the present invention, preferred embodiments of the present invention will be described in more detail below. While preferred embodiments of the present invention are described in the examples, it should be understood that the present invention can be realized in various forms and is not limited to the embodiments described herein. Where specific conditions are not specified in the examples, they shall be carried out according to conventional conditions or conditions suggested by the manufacturer.

[0064] <Raw material source> In each example and comparative example, catalyst A was prepared according to Example 5 described in the patent application, Chinese Patent Application Publication No. 101054424A, and the Ti content in the catalyst was 3.0% by mass. Catalyst B was prepared according to Example 3 described in the patent application, Chinese Patent Application Publication No. 101054424A, and the Ti content in the catalyst was 2.4% by mass.

[0065] In each example and comparative example, the procedure for preparing the titanocene hydrogenation catalyst was as follows: Under a nitrogen atmosphere, titanocene dichloride and triethylaluminum (triethylaluminum was supplied as a 1.0 mol / L n-hexane solution) were mixed at different molar ratios (e.g., 1:5.5 to 1:10) at room temperature for at least 24 hours to prepare multiple mixed solutions, i.e., titanocene hydrogenation catalysts. Next, 1.0 ml of each mixed solution was taken and diluted with 33 ml of n-hexane for later use.

[0066] Preparation of external electron donor solutions: Different types of external electron donors were collected, and 0.50 M hexane solutions were prepared for later use.

[0067] The hydrogenation catalyst and the external electron donor can be injected into the polymerization reactor separately and mixed online, or they can be mixed in equal proportions before being injected into the polymerization reactor.

[0068] In each example and comparative example, the properties of the polymer were evaluated by the following test methods. (1) Meltmass flow rate (MFR): Detected in accordance with ASTM D1238. (2) Xylene soluble content XS: Detected by Polymer Char's automated xylene solubility analyzer (CRYSTEX QC). (3) Molecular weight and its distribution: Detected by Polymer Char's high-temperature gel permeation chromatography (GPC-IR6). (4) Melt strength: Detected using a Malvern Instruments RH7-2 capillary rheometer + balance. (5) Tensile strength: Tested in accordance with GB / T1040.2-2006. (6) Bending strength: Tested in accordance with GB / T9341-2008. (7) Impact test: Tested in accordance with GB / T1843-2008.

[0069] In each of the following examples and comparative examples, the reaction environment and material concentrations in the reactor after the reaction in step (i) were essentially the same as those in the pipeline outside the reactor, or in the second and subsequent polymerization reactors connected in series with the first polymerization reactor. Therefore, the experimental process simulated the polymerization reaction in industrial production by using a single reactor and dividing it into two stages, adding a hydrogenation catalyst and an external electron donor to the first polymerization reactor and the discharge pipeline outside the first polymerization reactor, or to the second and subsequent polymerization reactors connected in series with the first polymerization reactor. In other words, the polymerization reaction in the first stage of the single reactor corresponded to the normal polymerization reaction in the first reactor in industrial production. The second stage polymerization reaction in a single reactor corresponds to the polymerization reaction after adding the hydrogenation catalyst and external electron donor to the discharge pipeline outside the industrial production device, or to the second and subsequent polymerization reactors connected in series with the first polymerization reactor. By using a mixture of hydrogenation catalyst and external electron donor in the second stage polymerization of a single reactor, the situation of introducing the mixture of hydrogenation catalyst and external electron donor to the discharge pipeline outside the industrial production device, or to the second and subsequent polymerization reactors connected in series, was simulated.

Example

[0070] Polymerization was carried out in a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (the water was less than 1 ppm and the oxygen was less than 1 ppm), and then 2.2 L of liquid propylene and 0.125 mol of hydrogen were sequentially added at room temperature and heated to 70°C. Before the temperature of the reactor reached 70°C, 2.0 ml of a 0.50 M heptane solution of triethylaluminum, 0.4 ml of a 0.50 M hexane solution of a D-donor, and 8.1 mg of catalyst A were mixed for 5 minutes to form a mixture. When the reactor reached 70°C, the mixture was injected into the reactor through the catalyst supply pipe, the timing of the reaction was started, and the first-stage polymerization reaction was carried out to prepare a material stream containing polypropylene component I. (2) After the reaction continued for 60 minutes, 25.5 ml of a titanocene hydrogenation catalyst (the concentration was 4.9×10 -6 mol / ml) and 1.5 ml of a 0.50 M D-donor, which is an external electron donor, were re-added from the catalyst supply pipe (in the mixed solution, the molar ratio of the alkylaluminum contained in the hydrogenation catalyst to the external electron donor was 1:1, and the molar ratio of the alkylaluminum to titanocene in the hydrogenation catalyst was 6). The temperature was maintained at 70°C and the timing of the reaction was started. It was simulated that the material stream containing polypropylene component I continued to react for 5 minutes in the outlet pipeline outside the reactor or in the second and subsequent reactors connected in series to the polymerization reactor in step (1) (that is, the situation where the material stream containing polypropylene component I remained in the pipeline outside the polymerization reactor in step (1) or in the second and subsequent polymerization reactors connected in series to the polymerization reactor in step (1) for 5 minutes was simulated). The unreacted materials were vented (discharged), the temperature was lowered, and the reaction was stopped to obtain a propylene polymer product containing an ultra-high molecular weight polypropylene (UHMWPP) component. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 1. [Examples]

[0071] The method for producing the propylene polymer was described in Example 1. The difference was that the polymerization time was changed to 30 minutes in the presence of a mixed solution of the hydrogenation catalyst and the D-donor, which is an external electron donor, in step (2).

[0072] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 1. [Examples]

[0073] The method for producing the propylene polymer was the same as in Example 1. The differences were that the amount of hydrogenation catalyst in step (2) was changed to 2.55 ml (i.e., the amount was 1 / 10,000th of the amount of hydrogen), and the amount of the external electron donor, the D-donor, was changed to 0.15 ml (the molar ratio of alkylaluminum in the hydrogenation catalyst to the external electron donor in the mixed solution was 1:1), and the polymerization time remained 5 minutes.

[0074] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 1.

[0075] [Comparative Example 1] Polymerization was carried out using a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (water content was less than 1 ppm and oxygen content was less than 1 ppm), and then 2.2 L of liquid propylene and 0.12 mol of hydrogen were sequentially added at room temperature and heated to 70°C. Before the reactor temperature reached 70°C, 2.0 ml of a pre-prepared 0.50 M heptane solution of triethylaluminum, 0.4 ml of a 0.50 M hexane solution of the D-donor, and 8.1 mg of catalyst A were mixed for 5 minutes to form a mixture. Once the reactor reached 70°C, the mixture was injected into the reactor through the catalyst supply pipe, and the reaction time was started. (2) After the reaction continued for 65 minutes, the unreacted material was vented, the reaction was cooled, and it was stopped. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 1.

[0076] [Comparative Example 2] The method for producing the propylene polymer was the same as in Comparative Example 1, the only difference being that time was measured according to steps (1) and (2), the reaction was continued for 90 minutes, the unreacted material was vented, the reaction was cooled and stopped. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 1.

[0077] [Comparative Example 3] Polymerization was carried out using a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (water content was less than 1 ppm and oxygen content was less than 1 ppm), then 2.2 L of liquid propylene was added at room temperature without hydrogen, and the resulting system was heated to 70°C. Before the reactor temperature reached 70°C, 2.0 ml of a pre-prepared 0.50 M heptane solution of triethylaluminum, 0.4 ml of a 0.50 M hexane solution of the D-donor, and 8.1 mg of catalyst A were mixed for 5 minutes to form a mixture. Once the reactor reached 70°C, the mixture was injected into the reactor through the catalyst supply pipe, and the reaction time was started. (2) After the reaction continued for 60 minutes, the unreacted material was vented, the reaction was cooled, and it was stopped. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 1. [Examples]

[0078] Polymerization was carried out using a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (water content was less than 1 ppm and oxygen content was less than 1 ppm), and then 2.2 L of liquid propylene and 0.125 mol of hydrogen were sequentially added at room temperature, and the system was heated to 70°C. Before the reactor temperature reached 70°C, 2.0 ml of a pre-prepared 0.50 M heptane solution of triethylaluminum, 0.4 ml of a 0.50 M hexane solution of the D-donor, and 8.1 mg of catalyst A were mixed for 5 minutes to form a mixture. Once the reactor reached 70°C, the mixture was injected into the reactor through the catalyst supply pipe, the reaction time was started, and the first stage polymerization reaction was carried out to prepare a material stream containing polypropylene component I. (2) After continuing the reaction for 60 minutes, add 25.5 ml of titanocene hydrogenation catalyst (concentration of 4.9 × 10) -6 A mixed solution of polypropylene component I (which was mol / ml) and 15 ml of a 0.50 M external electron donor, D-donor, was added from the catalyst supply pipe (the molar ratio of alkylaluminum in the hydrogenation catalyst to the external electron donor in the mixed solution was 0.1:1), the temperature was maintained at 70°C, and the reaction time was started to simulate the material stream containing polypropylene component I continuing to react for 5 minutes in the outlet pipeline outside the reactor, or in the second and subsequent reactors connected in series with the polymerization reactor of step (1) (i.e., the material stream containing polypropylene component I was simulated to remain for 5 minutes in the pipeline outside the polymerization reactor of step (1), or in the second and subsequent polymerization reactors connected in series with the polymerization reactor of step (1)). The unreacted material was vented, the reactants were cooled and stopped to obtain a propylene polymer product containing ultra-high molecular weight polypropylene (UHMWPP) components. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 1. [Examples]

[0079] The method for producing the propylene polymer was described in Example 4, but the difference was that in step (2), the molar ratio of alkylaluminum contained in the hydrogenation catalyst to the external electron donor was changed to 10:1. Specifically, a mixed solution of 25.5 ml of titanocene hydrogenation catalyst and 0.15 ml of a 0.50 M D-donor was used, and the reaction was continued for 5 minutes. After that, the unreacted material was vented, the reaction was cooled, and the reaction was stopped.

[0080] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 2. [Examples]

[0081] The method for producing the propylene polymer was described in Example 4, but the difference was that in step (2), the molar ratio of the alkylaluminum contained in the hydrogenation catalyst to the external electron donor was changed to 50:1. That is, a mixed solution of 25.5 ml of titanocene hydrogenation catalyst and 0.03 ml of a 0.50 M D-donor, which is an external electron donor, was used.

[0082] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 2.

[0083] [Comparative Example 4] The method for producing the propylene polymer was the same as in Example 1, but the difference was that in step (2), only the hydrogenation catalyst was added and no external electron donor was added; that is, only 25.5 ml of titanocene hydrogenation catalyst solution was added, the temperature was maintained at 70°C, and the reaction time measurement was started. The material stream containing polypropylene component I was simulated to continue reacting for 5 minutes in the outlet pipeline outside the reactor, or in the second and subsequent reactors connected in series with the polymerization reactor of step (1).

[0084] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 1.

[0085] [Table 1A]

[0086] [Table 1B]

[0087] From the data in Table 1, it can be seen that, compared to Comparative Examples 1-3 where a mixture of hydrogenation catalyst and external electron donor was not used, in Comparative Example 4, by using the hydrogenation catalyst alone without adding an external electron donor, the mechanical properties of the product were improved and the melt strength was increased to 2.4 cN. In Examples 1-3, after using a mixture of hydrogenation catalyst and external electron donor, polymerization activity improved, the xylene soluble content in the product decreased (reflecting the increase in isotacticity of the ultra-high molecular weight component), the mechanical properties were further improved, and the melt strength increased to 4.3-5.5 cN.

[0088] [Table 2A]

[0089] [Table 2B]

[0090] The data in Table 2 shows that the smaller the molar ratio of alkylaluminum in the hydrogenation catalyst to the external electron donor, i.e., the larger the amount of external electron donor, the lower the xylene-soluble content of the product. Compared to Comparative Example 4, which used only the hydrogenation catalyst and no external electron donor, the performance of the product was clearly improved when the molar ratio of alkylaluminum contained in the hydrogenation catalyst to the external electron donor was in the range of 0.1 to 50. [Examples]

[0091] Propylene and ethylene were polymerized using a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (water content was less than 1 ppm and oxygen content was less than 1 ppm), and then 2.2 L of liquid propylene and 0.20 mol of hydrogen were sequentially added at room temperature, and the resulting system was heated to 60°C. Before the reactor temperature reached 60°C, ethylene was injected into the reactor at a flow rate of 20 g / hour. Simultaneously, 2.0 ml of a pre-prepared 0.50 M heptane solution of triethylaluminum, 0.4 ml of a 0.50 M hexane solution of the D-donor, and 8.1 mg of catalyst A were mixed for 5 minutes to form a mixture. Once the reactor reached 60°C, the mixture was injected into the reactor through a catalyst supply pipe, and the reaction time was started to carry out the first stage polymerization reaction to prepare a material stream containing polypropylene component I. (2) After continuing the reaction for 60 minutes, add 4.0 ml of titanocene hydrogenation catalyst (concentration of 4.9 × 10) -6A mixed solution of polypropylene component I (which was mol / ml) and 0.24 ml of a 0.50 M external electron donor, D-donor, was added from the catalyst supply pipe (in the mixed solution, the molar ratio of alkylaluminum in the hydrogenation catalyst to the external electron donor was 1:1, and the molar ratio of alkylaluminum to titanocene in the hydrogenation catalyst was 6), the temperature was maintained at 60°C, and the reaction time was started to simulate the material stream containing polypropylene component I continuing to react for 10 minutes in the outlet pipeline outside the reactor, or in the second and subsequent reactors connected in series with the polymerization reactor of step (1) (i.e., the material stream containing polypropylene component I was simulated to remain for 10 minutes in the pipeline outside the polymerization reactor of step (1), or in the second and subsequent polymerization reactors connected in series with the polymerization reactor of step (1)). The unreacted material was vented, the reaction was cooled and stopped to obtain a propylene polymer product containing ultra-high molecular weight polypropylene (UHMWPP) components. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 3. [Examples]

[0092] The method for producing the propylene polymer was described in Example 7, but the difference was that the time for continuing the reaction in the presence of the mixed solution of the hydrogenation catalyst and the D-donor, which is an external electron donor, in step (2) was changed to 30 minutes.

[0093] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 3. [Examples]

[0094] The method for producing the propylene polymer was described in Example 7, but the difference was that the time for continuing the reaction in the presence of the mixed solution of the hydrogenation catalyst and the D-donor, which is an external electron donor, in step (2) was changed to 60 minutes.

[0095] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 3.

[0096] [Comparative Example 5] Propylene and ethylene were polymerized using a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (water content was less than 1 ppm and oxygen content was less than 1 ppm), then 2.2 L of liquid propylene and 0.20 mol of hydrogen were sequentially added at room temperature, and the resulting system was heated to 60°C. Before the reactor temperature reached 60°C, ethylene was injected into the reactor at a flow rate of 20 g / hour. Simultaneously, 2.0 ml of a pre-prepared 0.50 M heptane solution of triethylaluminum, 0.4 ml of a 0.50 M hexane solution of the D-donor, and 8.1 mg of catalyst A were mixed for 5 minutes to form a mixture. Once the reactor reached 60°C, the mixture was injected into the reactor through the catalyst supply pipe, and the reaction time was measured. (2) After the reaction was continued for 60 minutes, the unreacted material was vented, the reaction was cooled, and it was stopped. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 3.

[0097] [Table 3]

[0098] From the data in Table 3, it can be seen that when propylene-ethylene random copolymerization was performed and a mixture of hydrogenation catalyst and external electron donor was used in Examples 7-9, the melt index of the product was lower than that of Comparative Example 5, and the molecular weight was higher than that of Comparative Example 5. The content of ultra-high molecular weight polypropylene components increased with the extension of the polymerization time in the second polymerization step. [Examples]

[0099] Polymerization was carried out using a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (water content was less than 1 ppm and oxygen content was less than 1 ppm), and then 2.2 L of liquid propylene and 0.125 mol of hydrogen were sequentially added at room temperature and heated to 70°C. Before the reactor temperature reached 70°C, 2.0 ml of a pre-prepared 0.50 M heptane solution of triethylaluminum, 0.4 ml of a 0.50 M hexane solution of the D-donor, and 8.1 mg of catalyst A were mixed for 5 minutes to form a mixture. Once the reactor reached 70°C, the mixture was injected into the reactor through the catalyst supply pipe, the reaction time was started, and the first stage polymerization reaction was carried out to prepare a material stream containing polypropylene component I. (2) After continuing the reaction for 60 minutes, add 2.55 ml of titanocene hydrogenation catalyst (concentration of 4.9 × 10) -6 A mixed solution of polypropylene component I (which was mol / ml) and 0.15 ml of a 0.50 M external electron donor, D-donor, was added from the catalyst supply pipe (in the mixed solution, the molar ratio of alkylaluminum to titanocene in the hydrogenation catalyst was 8, the molar ratio of alkylaluminum to external electron donor was 1:1, and the molar ratio of hydrogenation catalyst to total hydrogen was 1:10000), the temperature was maintained at 70°C, and the reaction time was started to simulate the material stream containing polypropylene component I continuing to react for 5 minutes in the outlet pipeline outside the reactor, or in the second and subsequent reactors connected in series with the polymerization reactor of step (1) (i.e., the material stream containing polypropylene component I was simulated to remain for 5 minutes in the pipeline outside the polymerization reactor of step (1), or in the second and subsequent polymerization reactors connected in series with the polymerization reactor of step (1)). The unreacted material was vented, the reaction was cooled and stopped to obtain a propylene polymer product containing ultra-high molecular weight polypropylene (UHMWPP) components. (3) After extracting the propylene polymer product, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 4. [Examples]

[0100] The method for producing the propylene polymer was described in Example 10, but the difference was that in step (2), the molar ratio of alkylaluminum to titanocene in the hydrogenation catalyst was set to 10.

[0101] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 4. [Examples]

[0102] The manufacturing method for the propylene polymer was the same as in Example 1, but the difference was that in step (2), the amount of hydrogenation catalyst was adjusted to 5.1 ml and the amount of external electron donor was adjusted to 0.3 ml (i.e., the molar ratio of hydrogenation catalyst to total hydrogen was 1:5000).

[0103] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 4.

[0104] [Comparative Example 6] The method for producing the propylene polymer was described in Example 10, but the difference was that the molar ratio of alkylaluminum to titanocene in the hydrogenation catalyst was set to 1.5.

[0105] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 4.

[0106] [Comparative Example 7] The manufacturing method for the propylene polymer was described in Example 10, but the difference was that the molar ratio of alkylaluminum to titanocene in the hydrogenation catalyst was set to 4.

[0107] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 4.

[0108] [Table 4]

[0109] The data in Table 4 shows that when the molar ratio of alkylaluminum to titanosene in the hydrogenation catalyst was equal to or less than 4, the alkylaluminum could not completely dissolve the titanosene, and at that point, the titanosene could not be effectively hydrogenated. When the molar ratio of alkylaluminum to titanosene was 1.5, a clear precipitate formed, and the catalyst could not be used for polymerization. When the molar ratio of alkylaluminum to titanosene in the hydrogenation catalyst was 8 or 10, there was a slight excess of alkylaluminum, and the melt index of the product increased very slightly, but it could still be used as a hydrogenation catalyst. When the molar ratio (mol / mol) of the hydrogenation catalyst to total hydrogen was 1 / 5000, the hydrogenation effect was better than when it was 1 / 10000, and the melt index of the resulting polymer product was lower. [Examples]

[0110] Polymerization was carried out using a 5L stainless steel polymerization apparatus. (1) First, the reactor was purged with purified nitrogen (water content was less than 1 ppm and oxygen content was less than 1 ppm), then 2.2 L of liquid propylene and 0.048 mol of hydrogen were sequentially added at room temperature, and the resulting system was heated to 70°C. Before the reactor temperature reached 70°C, 2.0 ml of a pre-prepared 0.50 M heptane solution of triethylaluminum, 0.4 ml of a hexane solution of 0.50 M TEOS, and 8.1 mg of catalyst B were mixed for 5 minutes to form a mixture. Once the reactor reached 70°C, the mixture was injected into the reactor through the catalyst supply pipe, and the reaction time was started to carry out the first stage polymerization reaction to prepare a material stream containing polypropylene component I. (2) After the reaction has continued for 60 minutes, add 2.55 ml of titanocene hydrogenation catalyst (concentration of 4.9 × 10) -6A mixed solution of polypropylene component I (which was mol / ml) and 0.15 ml of a 0.50 M external electron donor, D-donor, was added from the catalyst supply pipe (in the mixed solution, the molar ratio of alkylaluminum to titanocene in the hydrogenation catalyst was 6, and the molar ratio of alkylaluminum to external electron donor was 1:1), the temperature was maintained at 70°C, and the reaction time was started to simulate the material stream containing polypropylene component I continuing to react for 60 minutes in the outlet pipeline outside the reactor, or in the second and subsequent reactors connected in series with the polymerization reactor of step (1) (i.e., the material stream containing polypropylene component I was simulated to remain for 60 minutes in the pipeline outside the polymerization reactor of step (1), or in the second and subsequent polymerization reactors connected in series with the polymerization reactor of step (1)). The unreacted material was vented, the reaction was cooled and stopped to obtain a propylene polymer product containing ultra-high molecular weight polypropylene (UHMWPP) components. (3) After the propylene polymer product was extracted, the product was vacuum-dried at 30°C for 2 hours, and then the properties of the dried polypropylene product were evaluated. The test results are shown in Table 5.

[0111] [Comparative Example 8] The manufacturing method for the propylene polymer was described in Example 13, but the difference was that in step (2), only the hydrogenation catalyst was added, and no external electron donor was added.

[0112] The properties of the dried polypropylene product were evaluated. The test results are shown in Table 5.

[0113] [Table 5]

[0114] From the data in Table 5, it can be seen that in Example 13, compared to Comparative Example 8, when TEOS is used in the first polymerization step and a mixture of a hydrogenation catalyst and an external electron donor (D-donor) is used in the second polymerization step, the xylene soluble content of the product can be significantly reduced (i.e., this result reflects an increase in the isotacticity of the product), decreasing from 5.38% to 5.02%, indicating that the isotacticity of the ultra-high molecular weight polypropylene component can be adjusted by using an external electron donor when adding the hydrogenation catalyst in the second polymerization step.

[0115] Therefore, the products of the present invention can significantly improve the performance of polypropylene by containing a small amount of ultra-high molecular weight component, and the isotacticity of the ultra-high molecular weight polypropylene component can be adjusted after using a mixture of a hydrogenation catalyst and an external electron donor. In each example, the average molecular weight Mn (logMW equal to or greater than 7) of the UHMWPP produced was much higher than the peak molecular weight Mp of the obtained product, and the Mn (logMW equal to or greater than 7) / Mp ratio was greater than 10.

[0116] The above is merely a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A catalyst for an olefin polymerization process, wherein the catalyst is a mixture of a transition metal group IVB metallocene compound, an alkylaluminum compound, and an external electron donor D1, and the transition metal group IVB metallocene compound is mixed with at least a portion of the alkylaluminum compound before contact with the external electron donor D1. Preferably, the catalyst is a mixture of a hydrogenation catalyst and an external electron donor D1, and the hydrogenation catalyst is a mixture of a transition metal group IVB metallocene compound and an alkylaluminum compound. Preferably, the external electron donor D1 is an alkoxy-substituted silane compound, preferably a dimethoxysilane compound. Preferably, the general formula of the transition metal group IVB metallocene compound is R(R')-M-X(X') (wherein, R and R' are each independently cyclopentadienyl, indenyl, or fluorenyl, either unsubstituted or substituted, wherein the substituent is preferably selected from methyl, ethyl, propyl, butyl, and cycloalkyl, and R and R' may be crosslinked by substituents containing C or Si. M is one or more transition metal elements, preferably selected from Ti, Zr, and Hf. X and X' are each independently a halogen atom, an alkyl group, or an alkoxy group. More preferably, the transition metal group IVB metallocene compound is Cp ２ TiCl ２ A catalyst.

2. The molar ratio of the alkylaluminum compound to the external electron donor D1 is 0.1:1 to 50:1, preferably 0.1:1 to 30:1, and the molar ratio of aluminum in the alkylaluminum compound to the transition metal group IVB metallocene compound is 5.5 to 100.0:1, preferably 5.5 to 10.0:1, more preferably 5.5 to 8.0:

1. The catalyst according to claim 1.

3. A propylene polymer containing an ultra-high molecular weight polypropylene component and having adjustable isotactic properties, wherein the melt mass flow rate (MFR) of the propylene polymer is equal to or greater than 0.01 g / 10 min and equal to or less than 10,000 g / 10 min. The propylene polymer contains an ultra-high molecular weight component, the molecular weight MW of the ultra-high molecular weight component is equal to or greater than 10,000,000, and the content of the ultra-high molecular weight component in the propylene polymer is 0.03 to 15.0% by mass. The ratio of the number-average molecular weight Mn of the ultra-high molecular weight component to the peak molecular weight Mp of the propylene polymer (Mn (MW is equal to or greater than 10,000,000) / Mp) is equal to or greater than 80. Propylene polymer.

4. The content of ultra-high molecular weight components in the propylene polymer is 0.03 to 5.0% by mass, and / or The ratio of the number-average molecular weight Mn of the ultra-high molecular weight component to the peak molecular weight Mp of the propylene polymer, Mn (MW is equal to or greater than 10,000,000) / Mp, is equal to or greater than 100, preferably Mn (MW is equal to or greater than 10,000,000) / Mp is equal to or greater than 120. The propylene polymer according to claim 3.

5. The melt mass flow rate (MFR) of the propylene polymer is equal to or greater than 0.01 g / 10 min, equal to or less than 300 g / 10 min, preferably equal to or greater than 0.1 g / 10 min, equal to or less than 200 g / 10 min, and / or The melt strength of the propylene polymer is equal to or greater than 2.0 cN. The propylene polymer according to claim 3 or 4.

6. A method for producing propylene polymer, comprising the following steps: (1) A step of preparing a material stream containing polypropylene component I by reacting propylene in a polymerization reactor in the presence of hydrogen and a polymerization catalyst, or by reacting propylene with one or more types of comonomers of arbitrary selection, and carrying out a first-stage (co)polymerization reaction for 0.1 to 10 hours, (2) After the first stage of (co)polymerization reaction, a mixture D of the hydrogenation catalyst and external electron donor Ｈ A step of polymerizing at least a portion of a material stream containing polypropylene component I for 0.05 to 3.0 hours in a pipeline located outside the polymerization reactor of step (1), or in second and subsequent reactors connected in series with the polymerization reactor of step (1), thereby obtaining an ultra-high molecular weight polypropylene (UHMWPP) component, Next, the reaction is stopped to obtain a propylene polymer product containing ultra-high molecular weight polypropylene (UHMWPP) components. Includes, The molar ratio of the hydrogenation catalyst to the total amount of hydrogen present in the reactor is 1 / 10000 to 1 / 100, preferably 1 / 10000 to 1 / 1000. Manufacturing method.

7. In step (1), the polymerization catalyst comprises (a) an active solid catalyst component, preferably a solid catalyst active component containing titanium, (b) an organoaluminum compound as a cocatalyst component, and optionally (3) an external electron donor D2, wherein the polymerization catalyst is preferably a mixture D formed by the active solid catalyst component, the organoaluminum compound, and the external electron donor D2. Preferably, mixture D Ｈ The catalytic effect strength of is greater than that of mixture D. Preferably, the external electron donors D1 and D2 are the same or different, and each is independently an alkoxy-substituted silane compound or a mixture of multiple alkoxy-substituted silane compounds. Preferably, the hydrogenation catalyst is a mixture of an organometallic compound and an alkylaluminum compound, and the general formula of the organometallic compound is R(R')-M-X(X') (In the formula, R and R' are each independently cyclopentadienyl, indenyl, or fluorenyl, either unsubstituted or substituted, wherein the substituent is preferably selected from methyl, ethyl, propyl, butyl, and cycloalkyl, and R and R' may be crosslinked with substituents containing C or Si. M is one or more transition metal elements, preferably selected from Ti, Zr, and Hf. X and X' are each independently a halogen atom, an alkyl group, or an alkoxy group. Preferably, the molar ratio of aluminum to the organometallic compound in the alkylaluminum compound in the hydrogenation catalyst is 3.0 to 100.0:1, preferably 5.5 to 10.0:1, and more preferably 5.5 to 8.0:

1. The manufacturing method according to claim 6.

8. The hydrogenation catalyst is Cp ２ TiCl ２ and a mixture of alkylaluminum compounds, Aluminum and Cp in alkylaluminum compounds ２ TiCl ２ The molar ratio is 5.5 to 100.0:1, preferably 5.5 to 10.0:1, and more preferably 5.5 to 8.0:

1. The manufacturing method according to claim 6 or 7.

9. Mixture D formed by the hydrogenation catalyst and the external electron donor D1 Ｈ wherein the molar ratio of the alkylaluminum compound in the hydrogenation catalyst to the external electron donor D1 is 0.1:1 to 50:1, preferably 0.1:1 to 30:1, The manufacturing method according to any one of claims 6 to 8.

10. The length of the pipeline located outside the polymerization reactor in step (1) is 0.1 to 50 meters, and / or The polymerization time in step (i) is 0.2 to 5 hours, preferably 0.3 to 3 hours, and / or The polymerization temperature in step (i) is 40 to 250°C, preferably 50 to 200°C, and / or The polymerization time in step (ii) is 0.08 to 2.0 hours, preferably 0.1 to 1.5 hours, and / or The polymerization temperature in step (ii) is 0 to 250°C, preferably 20 to 200°C. The manufacturing method according to any one of claims 6 to 9.

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