Olefin polymerization catalyst component and process for its preparation, olefin polymerization catalyst and use thereof

Abstract

The present application relates to an olefin polymerization catalyst component and a preparation method thereof, an olefin polymerization catalyst and application thereof. The olefin polymerization catalyst component comprises magnesium, titanium, halogen and an internal electron donor, wherein the internal electron donor has a structure shown in general formula (I): wherein R1 and R2 are the same or different from each other, and are selected from C1-C 20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl groups, optionally containing heteroatoms; groups R3 to R8 are the same or different from each other, and are hydrogen or C1-C 20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl groups, optionally containing heteroatoms, and two or more groups of R3-R8 are bonded to each other to form one or several fused ring structures. The hydrazine carbamate compound with a special nitrogen-containing heterocyclic structure is used as the internal electron donor, so that the comprehensive performance of the catalyst is excellent.

Description

Technical Field

[0001] This invention relates to the field of catalysts, specifically to an olefin polymerization catalyst component and its preparation method, an olefin polymerization catalyst and its application. Background Technology

[0002] As is well known, olefin polymerization catalysts are solid titanium catalyst components with magnesium, titanium, halogens, and electron donors as basic components. They can be used in the CH2=CHR olefin polymerization reaction, especially in the polymerization of α-olefins with three or more carbon atoms, where high yields and high stereoregularity of polymers can be obtained. Among them, electron donors are an essential component of the catalyst components, and the development of electron donor compounds has led to the continuous upgrading of Ziegler-Natta catalysts.

[0003] Previously, numerous electron-donating compounds were reported in the literature, such as polycarboxylic acids, mono- or polycarboxylic esters, acid anhydrides, ketones, mono- or poly-ethers, alcohols, amines, and their derivatives. Among these, diaromatic carboxylic esters were commonly used, such as di-n-butyl phthalate or diisobutyl phthalate (CN85100997A). Recent studies have found that phthalate esters pose health risks, and the United States, the European Union, and other regions have begun to restrict their use in plastics. Therefore, finding a novel internal electron-donating agent to replace phthalate esters is urgently needed.

[0004] Researchers have attempted to use other compounds as electron donors in olefin polymerization catalysts. US4971937, US2004014597, and EP728769 (see also CN1042547A, CN1143651A, US2003027715, and WO03076480) employ special 1,3-diether compounds as electron donors, such as 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, and 9,9-di(methoxymethyl)fluorene. These catalysts exhibit high activity, but the synthesis of 1,3-diether compounds is difficult and costly, hindering their widespread application.

[0005] The catalyst component disclosed in CN1054139A for olefin polymerization uses special 1,3-dione compounds as electron donors, such as 2,2,6,6-tetramethyl-3,5-heptadecane and 2,2,4,6,6-pentamethyl-3,5-heptadecane, etc. The catalyst has low activity and low isotacticity of polypropylene.

[0006] In recent years, a special class of dialiphatic carboxylic acid esters and glycol esters, such as succinates, malonates, glutarates, ethylene glycol esters, propylene glycol esters, butylene glycol esters, pentylene glycol esters, and hexanediol esters, have been disclosed as internal electron donors in olefin polymerization catalysts (see CN201010199059.X, CN201010199066.X, CN1313869A, CN1236373A, CN1236374A, CN1552741A, CN1213080C, CN1542024A, CN1552742A, and CN1552740A). The use of these electron-donating compounds not only improves the catalyst activity but also significantly broadens the molecular weight distribution of the resulting polypropylene. However, without external electron-donating components, the isotacticity of the resulting polymer remains low.

[0007] US6818583 and WO2004024785 disclose substituted succinates as internal electron donors, which significantly broaden the molecular weight distribution of the resulting polypropylene. However, the activity of the catalyst is still not ideal, and the synthesis of substituted succinate compounds is difficult and costly.

[0008] Patent EP45977 discloses the use of unsubstituted maleic esters as internal electron donor compounds in the polymerization of olefins, but the results are poor in both activity and stereoregulation. Patent US5436213 involves unsubstituted and 2-methyl-unsubstituted maleic esters, but the catalyst performance, particularly activity, is poor. Japanese Patent JP58-138708 discloses an ester formed by an internal electron donor—a straight-chain alcohol and a substituted or unsubstituted maleic acid—but the catalyst performance is still unsatisfactory in terms of activity and stereoregulation.

[0009] Patents CN1714105A, EP2002010049 and WO2003022894 disclose a series of monosubstituted and disubstituted maleic esters. The catalysts described have good activity and stereodirection, but the compounds are difficult to synthesize and costly.

[0010] There is not much research on internal electron-donating compounds containing heteroatoms. Among them, Dow Global Technologies introduced heteroatoms into the main chain of diester compounds to synthesize a class of compounds containing silyl esters (see CN 102282181), but the catalysts prepared when used as electron donors have low activity.

[0011] The catalyst disclosed in patent CN201710144264.8 uses two different types of internal electron donors. One electron donor is a 2-substituted amino-phenyl ester compound, and the other electron donor is 9,9-di(methoxymethyl)fluorene, diol ester, or diester. This increases the cost and makes the synthesis of the electron donors more difficult, making it unsuitable for widespread application.

[0012] Patents CN201680026686.9 and US20180142044A1 disclose a series of catalysts containing alcohol ester-carbamate internal electron donors. These catalysts exhibit good activity and stereoregulation. However, due to the asymmetric chemical structure of these internal electron donor compounds, the activity, stereoregulation, and reproducibility of the resulting catalysts are poor. Furthermore, the synthesis methods for these internal electron donor compounds are complex, difficult, and costly.

[0013] Patent CN201780066463.X discloses a series of carbonate-urethane and aminobenzoate compounds as internal electron donors, but the resulting catalysts have very low activity.

[0014] Chinese patent CN101423571A discloses an internal electron donor for olefin polymerization catalysts, wherein the internal electron donor is a maleic ester containing a 5-norbornene structure. The resulting catalyst exhibits high activity and stereospecificity, but the molecular weight distribution of the resulting polymer is relatively narrow. Summary of the Invention

[0015] The purpose of this invention is to provide an olefin polymerization catalyst component to solve the problems of low catalyst activity and low isotacticity of the prepared polymer in the prior art.

[0016] Another objective of this invention is to provide a method for preparing olefin polymerization catalyst components.

[0017] Another objective of this invention is to provide an olefin polymerization catalyst.

[0018] Another objective of this invention is to provide an application of an olefin polymerization catalyst.

[0019] To achieve the above objectives, the present invention provides an olefin polymerization catalyst component comprising magnesium, titanium, halogen, and an internal electron donor, wherein the internal electron donor has the structure shown in general formula (I):

[0020]

[0021] Where R1 and R2 are the same or different from each other, they are selected from C1-C 20 The linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl groups, optionally containing heteroatoms; groups R3 to R8 may be the same or different from each other, and are hydrogen or C1-C2. 20 The linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl groups, optionally containing heteroatoms, and two or more groups in R3-R8 can bond together to form one or more fused ring structures.

[0022] The olefin polymerization catalyst component of the present invention comprises 10-30% magnesium, 1-10% titanium, 40-60% halogen and 1-30% internal electron donor.

[0023] The olefin polymerization catalyst component of the present invention, wherein R1 and R2 are each independently C1 to C2. 10 The alkyl, cycloalkyl, or arylalkyl group is preferred, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or neopentyl.

[0024] In the olefin polymerization catalyst component of the present invention, at least one group of R3 and R4, R5 and R6, and R7 and R8 is hydrogen, more preferably, all of R3 to R8 are hydrogen.

[0025] The olefin polymerization catalyst component of the present invention, wherein the internal electron donor is diethyl 2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, dimethyl 1,4-dimethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, diisopropyl 1,4,5-trimethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, di-tert-butyl 1,4,5,6,-tetramethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, or diethyl 1,4,5,6,7-pentamethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate.

[0026] The above-mentioned general formula compounds can be synthesized using known methods, namely the Diels-Alder reaction. Relevant literature includes: Gassman PG; Mansfield KTOrg. Synth. 1973, Coll. Vol. 5, 96; Org. Syn. IV, 242; DCTabor, FH White, LW Collier, SAEvans J. Org. Chem. 1983, 48(10), 1638; Y. Chen, R. Kiattansakul, B. Ma, JK Snyder J. Org. Chem. 2001, 66(21), 6932.

[0027] The olefin polymerization catalyst component of the present invention contains magnesium with a particle size distribution of 20-250 μm and the general formula Mg(OR'). m X (2-m) The pROH is provided by magnesium halide alkoxides, where R' is C1 to C2. 20an alkyl group, an aralkyl group or an aryl group; X is a halogen; m is an integer of 0 ≦ m < 2; p is a decimal or an integer of 0 < p < 6; R is a C1-C 20 alkyl group or aralkyl group.

[0028] For the olefin polymerization catalyst component described in the present invention, among them, the magnesium halide in the magnesium halide alcoholate is selected from one or more of magnesium dichloride, magnesium dibromide, chloromethoxy magnesium or chloroethoxy magnesium, preferably magnesium dichloride; the alcohol in the magnesium halide alcoholate is selected from one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol, preferably ethanol.

[0029] The magnesium halide alcoholate is obtained by a method in which magnesium halide and alcohol are co-heated and dissolved, then ejected under high pressure or stirred at high speed, and solidified into microsphere particles in a cooling medium. For the specific method, see the relevant description in US4399054.

[0030] For the olefin polymerization catalyst component described in the present invention, among them, titanium in the catalyst is provided by a compound with the general formula TiX q (OR 1 ) 4-q [[ID=十七]]In the formula, R 1 is a C1-C 20 hydrocarbon group; X is a halogen; q is 1 ≤ q ≤ 4.

[0031] For the olefin polymerization catalyst component described in the present invention, it is characterized in that titanium is provided by one or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxy titanium, tetraethoxy titanium, monochloro triethoxy titanium, dichloro diethoxy titanium and trichloro monoethoxy titanium, preferably titanium tetrachloride.

[0032] To achieve the above object, the present invention also provides a preparation method of the above catalyst component, which includes:

[0033] (1) Add the spherical magnesium halide alcoholate to the titanium compound at -40 to 10 °C, react for 1 to 4 hours, and the molar ratio of magnesium to titanium is 1:5 to 1:50;

[0034] (2) Raise the temperature to 30 to <80> °C, add an internal electron donor compound, and the molar ratio of magnesium to the internal electron donor compound is 2:1 to 15:1;

[0035] (3) Raise the temperature to 100 to 150 °C and react for 1 to 4 hours;

[0036] (4) After filtration, add the same amount of titanium compound as in step (1), react at 110 to 130 °C for 1 to 4 hours, and then obtain it after filtration, washing and drying.

[0037] To achieve the above objectives, the present invention also provides an olefin polymerization catalyst, comprising the catalyst components described above and an alkylaluminum compound.

[0038] The olefin polymerization catalyst of the present invention, wherein the alkylaluminum compound is one or more selected from trialkylaluminum compounds, alkylaluminum halides, alkylaluminum hydrides, and alkylaluminoxanes.

[0039] The olefin polymerization catalyst of the present invention, wherein the trialkylaluminum compound is one or more of triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.

[0040] The olefin polymerization catalyst of the present invention further includes an external electron donor.

[0041] External electron donor components can be selectively added as needed. For olefin polymers requiring high stereoregularity (e.g., isoregularity greater than 99%), the addition of external electron donor compounds is recommended.

[0042] The olefin polymerization catalyst of the present invention, wherein the external electron donor has the general formula R 2 k Si(0R 3 ) 4-k In the formula, k is an integer 1 ≤ k ≤ 3, and R 2 and R 3 Each is independently alkyl, cycloalkyl, or aryl, optionally containing a heteroatom; R 2 It can also be a halogen or a hydrogen atom.

[0043] The olefin polymerization catalyst of the present invention, wherein the external electron donor is one or more of trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, cyclohexylmethyldimethoxysilane, methyltert-butyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, di-n-butyldimethoxysilane, dicyclopentyldimethoxysilane, and di(cyclobutylmethyl)dimethoxysilane, preferably cyclohexylmethyldimethoxysilane.

[0044] The olefin polymerization catalyst of the present invention is wherein the molar ratio between titanium, aluminum and external electron donor compound is 1:5 to 1000:0 to 500, preferably 1:25 to 100:25 to 300.

[0045] To achieve the above objectives, the present invention also provides the application of the above-mentioned catalyst in the homopolymerization of propylene or the copolymerization of propylene with other olefins.

[0046] At the same time, it is not excluded that it is suitable for the production of copolymerization of polyethylene and ethylene with α-olefins such as propylene, 1-butene, l-pentene, 4-methyl-l-pentene, 1-hexene or l-octene.

[0047] In the application described in this invention, propylene polymerization is carried out in the gas phase or liquid phase, the polymerization temperature is 0 to 150°C, preferably 40 to 90°C, and the polymerization pressure is 0.01 to 10 MPa.

[0048] Hydrogen or other compounds that can act as chain transfer agents can be used to control the molecular weight of polymers.

[0049] The beneficial effects of this invention are:

[0050] This invention employs a hydrazine carbamate compound with a special nitrogen-containing heterocyclic structure as an internal electron donor. On the one hand, the presence of two hydrazine amino groups increases the carbonyl electron cloud that interacts with magnesium and titanium. Simultaneously, the relationship between the connection position and structure of the norbornene structure in the electron donor and the hydrazine carbamate optimizes the steric hindrance and electron cloud effect, resulting in high catalyst activity. On the other hand, this compound retains the advantages of diester-type internal electron donors. These characteristics enable the catalyst disclosed in this invention to exhibit good sensitivity to hydrogen regulation when used for propylene (co)polymerization. This not only improves the catalyst activity and polymer isotacticity but also results in a wide molecular weight distribution when the obtained polymer has comparable isotacticity. Furthermore, the synthesis method of this compound is simple and easy to implement, facilitating its widespread application.

[0051] This invention uses hydrazine carbamate compounds with special nitrogen-containing heterocyclic structures as internal electron donors, resulting in excellent overall performance of the catalyst and facilitating the development of different polymer grades. Detailed Implementation

[0052] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0053] The synthetic route for the hydrazine carbamate compounds of this invention is shown below:

[0054]

[0055] Test method:

[0056] 1. Polymer molecular weight and molecular weight distribution (MWD = M w / M n): The determination was performed using gel permeation chromatography with o-dichlorobenzene as solvent at 135℃ using an Alliance-GPCV2000.

[0057] 2. Polymer isotacticity: The isotacticity is determined by the heptane extraction method (boiling heptane extraction for 8 hours). That is, 1 gram of dry polymer sample is placed in an extractor and extracted with boiling heptane for 8 hours. After drying the residue to constant weight, the ratio of the polymer weight (g) obtained to 1 is the isotacticity.

[0058] 3. Determination of polymer melt index (MI): Measured according to μPXRZ-400C.

[0059] 4. Determination of titanium percentage: determined by spectrophotometry.

[0060] 5. Determination of the percentage of internal electron donors: determined using a PE Autosystem XL gas chromatograph.

[0061] Preparation of MgCl2·2.8CH3CH2OH spherical support:

[0062] All operations for preparing the spherical support were performed under nitrogen protection.

[0063] Add 50g of anhydrous MgCl2, 80g of anhydrous ethanol and 1.2L of white oil to a 2L stainless steel reactor, heat to 120℃ with stirring (3000r / min), and continue stirring at high speed at 120℃ for 2 hours to obtain the ethanol complex of MgCl2.

[0064] Under nitrogen pressure, the ethanol complex of MgCl2 was slowly transferred through a stainless steel tube insulated at 120°C and with an inner diameter of 1 mm to a 5L stainless steel reactor that had been pre-filled with 2.5L of dry n-hexane and cooled to -40°C. After the transfer was completed, the temperature was raised to 0°C.

[0065] The sample was filtered, washed with n-hexane, and dried under vacuum to obtain 104 g of MgCl2·2.8C2H5OH spherical support.

[0066] Example 1

[0067] (1) Synthesis of internal electron donor 2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid diethyl ester

[0068] 174 g (1.0 mol) of diethyl azodicarbonate (CAS No.: 1972-28-7) and 150 mL of diethyl ether were added to a reactor. 70 g (1.06 mol) of freshly distilled cyclopentadiene (CAS No.: 542-92-7) was added dropwise with stirring, which took approximately 1 hour. The reactor was cooled in an ice-water bath, and the reaction was controlled to a gentle boil. After the addition was complete, the mixture was allowed to stand for at least 4 hours until the yellow diethyl azodicarbonate had completely disappeared. The ether and unreacted cyclopentadiene were distilled off in a water bath, followed by vacuum distillation. The fraction collected at 119–120 °C / 0.4 mmHg yielded 228 g of a pale yellow liquid product, with a yield of 95%. 1 1H NMR (TMS, CDCl3, 400MHz) analysis results: δ5.65 (q, 2H, olefin H); δ4.37 (q, 2H, CH); δ2.50 (q, 1H, CH2); δ2.25 (q, 1H, CH2); δ4.11 (q, 4H, CH2CH3); δ1.27 (t, 6H, CH3).

[0069] (2) Preparation of catalyst components

[0070] Under anhydrous and oxygen-free conditions, in a reactor fully purged with high-purity nitrogen, 100 mL of TiCl4 and 60 mL of toluene were added, and the temperature was lowered to -20 °C. 10.0 g of MgCl2·2.8CH3CH2OH spherical support was added. The temperature was raised to 0 °C within 1 hour, then to 20 °C within 2 hours, and finally to 40 °C within 1 hour. 7.4 mmol of diethyl 2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid was added, and the temperature was raised to 100 °C within 1 hour and maintained for 2 hours. The filtrate was then discarded. 100 mL of TiCl4 was added, and the temperature was raised to 120 °C within 1 hour and maintained for 2 hours. The filtrate was then discarded. 60 mL of anhydrous hexane was added, and the mixture was washed 5 times at boiling point. Then, 60 mL of anhydrous hexane was added, and the mixture was washed 3 times at room temperature. Finally, the obtained catalytic fraction was dried under vacuum.

[0071] Example 2

[0072] (1) Synthesis of dimethyl 1,4-dimethyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, an internal electron donor.

[0073] It was prepared using dimethyl azodicarbonate (CAS No.: 2446-84-6) and 1,4-dimethylcyclopentadiene (CAS No.: 5602-47-1) as raw materials, and the yield was 92%. 11H NMR (TMS, CDCl3, 400MHz) analysis results: δ5.62 (d, 2H, olefin H); δ2.37 (d, 1H, CH2); δ2.14 (d, 1H, CH2); δ1.51 (s, 6H, CH3); δ3.57 (s, 6H, CH3).

[0074] (2) Preparation of catalyst components

[0075] Under anhydrous and oxygen-free conditions, in a reactor fully purged with high-purity nitrogen, 100 mL of TiCl4 and 60 mL of toluene were added, and the temperature was lowered to -20 °C. 10.0 g of MgCl2·2.8CH3CH2OH spherical support was added. The temperature was raised to 0 °C within 1 hour, then to 20 °C within 2 hours, and finally to 40 °C within 1 hour. 7.4 mmol of dimethyl 1,4-dimethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate was added, and the temperature was raised to 100 °C within 1 hour and maintained for 2 hours. The filtrate was then discarded. 60 mL of anhydrous hexane was added, and the mixture was washed 5 times at boiling point. Then, 60 mL of anhydrous hexane was added, and the mixture was washed 3 times at room temperature. Finally, the obtained catalytic fraction was dried under vacuum.

[0076] Example 3

[0077] (1) Synthesis of the internal electron donor 1,4,5-trimethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid diisopropyl ester

[0078] It was prepared using diisopropyl azodicarbonate (CAS No.: 2446-83-5) and 1,2,4-trimethylcyclopentadiene (CAS No.: 4784-94-5) as raw materials, and the yield was 90%. 1 1H NMR (TMS, CDCl3, 400MHz) analysis results: δ5.40 (s, 1H, olefin H); δ1.67 (s, 3H, CH3); δ2.40 (d, 1H, CH2); δ2.21 (d, 1H, CH2); δ1.55 (s, 6H, CH3); δ4.32 (q, 2H, CH); δ1.33 (d, 12H, CH3).

[0079] (2) Preparation of catalyst components

[0080] Under anhydrous and oxygen-free conditions, in a reactor fully purged with high-purity nitrogen, 100 mL of TiCl4 and 60 mL of toluene were added, and the temperature was lowered to -20 °C. 10.0 g of MgCl2·2.8CH3CH2OH spherical support was added. The temperature was raised to 0 °C within 1 hour, then to 20 °C within 2 hours, and then to 40 °C within 1 hour. 5.6 mmol of 1,4,5-trimethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid diisopropyl ester was added, and the temperature was raised to 100 °C within 1 hour and maintained for 2 hours. The filtrate was then discarded. 100 mL of TiCl4 was added, and the temperature was raised to 120 °C within 1 hour and maintained for 2 hours. The filtrate was then discarded. 60 mL of anhydrous hexane was added, and the mixture was washed 5 times in a boiling state. Then, 60 mL of anhydrous hexane was added, and the mixture was washed 3 times at room temperature. Finally, the obtained catalytic fraction was dried under vacuum.

[0081] Example 4

[0082] (1) Synthesis of the internal electron donor 1,4,5,6,-tetramethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid ditert-butyl ester

[0083] It was prepared using di-tert-butyl azodicarbonate (CAS No.: 870-50-8) and 1,2,3,4-tetramethylcyclopentadiene (CAS No.: 4249-10-9) as raw materials, and the yield was 88%. 1 1H NMR (TMS, CDCl3, 400MHz) analysis results: δ1.71 (s, 6H, CH3); δ2.39 (d, 1H, CH2); δ2.18 (d, 1H, CH2); δ1.53 (s, 6H, CH3); δ1.38 (s, 18H, CH3).

[0084] (2) Preparation of catalyst components

[0085] Under anhydrous and oxygen-free conditions, in a reactor fully purged with high-purity nitrogen, 100 mL of TiCl4 and 60 mL of toluene were added, and the temperature was lowered to -20 °C. 10.0 g of MgCl2·2.8CH3CH2OH spherical support was added. The temperature was raised to 0 °C within 1 hour, then to 20 °C within 2 hours, and finally to 40 °C within 1 hour. 5.6 mmol of di-tert-butyl 1,4,5,6,-tetramethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate was added, and the temperature was raised to 100 °C within 1 hour and maintained for 2 hours. The filtrate was then discarded. 60 mL of anhydrous hexane was added, and the mixture was washed 5 times at boiling point. Then, 60 mL of anhydrous hexane was added again, and the mixture was washed 3 times at room temperature. Finally, the obtained catalytic fraction was dried under vacuum.

[0086] Example 5

[0087] (1) Synthesis of the internal electron donor 1,4,5,6,7-pentamethyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid diethyl ester

[0088] It was prepared using diethyl azodicarbonate (CAS No.: 1972-28-7) and 1,2,3,4,5-pentamethylcyclopentadiene (CAS No.: 4045-44-7) as raw materials, by the method described in Example 1, with a yield of 85%. 1 H NMR (TMS, CDCl3, 400MHz) analysis results: δ1.69(s,6H,CH3); δ1.09(d,3H,CH3); δ3.24(q,1H, CH); δ1.51(s,6H,CH3); δ4.13(q,4H,CH2CH3); δ1.28(t,6H,CH3).

[0089] (2) Preparation of catalyst components

[0090] Under anhydrous and oxygen-free conditions, in a reactor fully purged with high-purity nitrogen, 100 mL of TiCl4 and 60 mL of toluene were added, and the temperature was lowered to -20 °C. 10.0 g of MgCl2·2.8CH3CH2OH spherical support was added. The temperature was raised to 0 °C within 1 hour, then to 20 °C within 2 hours, and finally to 40 °C within 1 hour. 7.4 mmol of diethyl 1,4,5,6,7-pentamethyl-2,3-diaza-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid was added, and the temperature was raised to 100 °C within 1 hour and maintained for 1 hour. The filtrate was then discarded. 100 mL of TiCl4 was added, and the temperature was raised to 120 °C within 1 hour and maintained for 1 hour. The filtrate was then discarded. 60 mL of anhydrous hexane was added, and the mixture was washed 5 times in a boiling state. Then, 60 mL of anhydrous hexane was added, and the mixture was washed 3 times at room temperature. Finally, the obtained catalytic fraction was dried under vacuum.

[0091] Comparative Examples 1-2

[0092] The catalyst components were prepared according to the method described in Example 1, except that the internal electron donors were replaced with diethyl bicyclo[2.2.1]hept-5-en-2,3-dicarboxylate and 4((ethoxycarbonyl)(methyl)(amino)pent-2-yl-4-propylbenzoate), respectively. The propylene polymerization conditions were the same as in Example 1, and the results are shown in Table 1.

[0093] Propylene polymerization experiment

[0094] The catalytic components of Examples 1-5 and Comparative Examples 1-2 were used to catalyze the polymerization of propylene.

[0095] The polymerization process was as follows: A 10L stainless steel high-pressure reactor was fully purged with high-purity nitrogen. Then, 35.0 mmol of AlEt, 0.2 mmol of external electron donor, 20 mg of the catalyst components from Examples 1-5 and Comparative Examples 1-2, and 1.2L of hydrogen were added. 2.5L of liquid propylene was introduced, and the temperature was raised to 70°C and maintained for 1 hour. The reactor was then cooled and depressurized to 1 atm to obtain polypropylene. The polymerization results are listed in Table 1.

[0096] Table 1 Results of catalytic propylene polymerization

[0097]

[0098] ED: External electron donor; C: Methylcyclohexyldimethoxysilane; D: Dicyclopentyldimethoxysilane.

[0099] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A catalyst component for olefin polymerization, comprising magnesium, titanium, halogen, and an internal electron donor, characterized in that, The internal electron donor is diethyl 2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, dimethyl 1,4-dimethyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, diisopropyl 1,4,5-trimethyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, di-tert-butyl 1,4,5,6,-tetramethyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate, or diethyl 1,4,5,6,7-pentamethyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate.

2. The olefin polymerization catalyst component according to claim 1, characterized in that, It includes 10–30% magnesium, 1–10% titanium, 40–60% halogens and 1–30% internal electron donors.

3. The olefin polymerization catalyst component according to claim 1, characterized in that, In the catalyst component, magnesium is provided by a magnesium halide alcoholate with a particle size distribution of 20 to 250 μm and a general formula of Mg(OR’) m X (2-m) ·pROH, where R’ is an alkyl group, aralkyl group or aryl group having C1 to C 20 ; X is a halogen; m is an integer where 0 ≦ m < 2; p is a decimal or integer where 0 < p < 6; and R is an alkyl group or aralkyl group having C1 - C 20 .

4. The olefin polymerization catalyst component according to claim 3, characterized in that, The magnesium halide in the magnesium halide alcohol is selected from one or more of magnesium dichloride, magnesium dibromide, magnesium chloromethoxy, or magnesium chloroethoxy; the alcohol in the magnesium halide alcohol is selected from one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol.

5. The olefin polymerization catalyst component according to claim 3, characterized in that, The magnesium halide in the magnesium halide alcohol is magnesium dichloride; the alcohol in the magnesium halide alcohol is ethanol.

6. The olefin polymerization catalyst component according to claim 1, characterized in that, The titanium in the catalyst is of the general formula TiX q (OR 1 ) 4-q The compound provides, where R 1 For C1-C 20 The hydrocarbon group; X is a halogen; q is 1≤q≤4.

7. A method for preparing the catalyst component according to any one of claims 1-6, characterized in that, include: (1) Add spherical magnesium halide alkoxides to titanium compounds at -40 to 10°C and react for 1 to 4 hours. The molar ratio of magnesium to titanium is 1:5 to 1:

50. (2) Heat to 30-80℃ and add an internal electron donor compound. The molar ratio of magnesium to the internal electron donor compound is 2:1 to 15:

1. (3) Reheat to 100-150℃ and react for 1-4 hours; (4) After filtration, add the same amount of titanium compound as in step (1), react at 110-130℃ for 1-4 hours, and then filter, wash and dry to obtain the final product.

8. An olefin polymerization catalyst, characterized in that, It includes the catalyst component and alkyl aluminum compound as described in any one of claims 1-6.

9. The olefin polymerization catalyst according to claim 8, characterized in that, The alkylaluminum compound is one or more of trialkylaluminum compounds, alkylaluminum halides, alkylaluminum hydrides, and alkylaluminoxanes.

10. The olefin polymerization catalyst according to claim 8, characterized in that, It also includes external electron donors.

11. The olefin polymerization catalyst according to claim 10, characterized in that, The general formula for the external electron donor is R. 2 k Si(0R 3 ) 4-k In the formula, k is an integer 1 ≤ k ≤ 3, and R 2 and R 3 Each is independently alkyl, cycloalkyl, or aryl, optionally containing a heteroatom; R 2 It can also be a halogen or a hydrogen atom.

12. The olefin polymerization catalyst according to claim 10, characterized in that, The molar ratio between titanium, aluminum, and external electron donor compounds is 1:5 to 1000:0 to 5000.

13. The olefin polymerization catalyst according to claim 10, characterized in that, The molar ratio between titanium, aluminum, and external electron donor compounds is 1:25–100:25–300.

14. The use of the catalyst according to any one of claims 10-13 in the homopolymerization of propylene or the copolymerization of propylene with other olefins.

15. The application according to claim 14, characterized in that, Propylene polymerization is carried out in the gas or liquid phase at a temperature of 0–150°C and a pressure of 0.01–10 MPa.

16. The application according to claim 15, characterized in that, The polymerization temperature is 40–90℃.

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