A metallocene catalyst composition and its use in the synthesis of cyclic olefin copolymers

Abstract

The application provides a metallocene catalyst composition and application thereof in synthesis of cyclic olefin copolymer, and belongs to the technical field of olefin catalytic polymerization. The metallocene catalyst composition is combined with an active component, the activity of the catalyst is significantly improved when the cyclic olefin copolymer is synthesized, the copolymerization performance is enhanced, and the molecular weight of the synthesized cyclic olefin copolymer is increased.

Description

Technical Field

[0001] This invention relates to the field of cyclic olefin copolymer synthesis technology, and more specifically to a metallocene catalyst composition and its application in the synthesis of cyclic olefin copolymers. Background Technology

[0002] In recent decades, metallocene compounds for olefin polymerization have been a research hotspot in organometallic chemistry, catalysis, polymer chemistry, and materials science. Since their introduction in the 1990s, metallocene compounds have been used as catalysts to synthesize and produce many high-performance polyolefin materials, including metallocene polyethylene (mPE), metallocene polypropylene (mPP), polyolefin elastomers (POE), and cyclic olefin copolymers (COC).

[0003] Cyclic olefin copolymers (COCs) are copolymers of ethylene and cyclic vinyl monomers. They possess excellent heat and chemical resistance, along with superior transparency and high refractive index and Abbe number. Therefore, COCs have wide applications in optical devices and medical instruments.

[0004] The structure of a metallocene catalyst determines its catalytic performance. When designing metallocene catalysts, efforts should be made to maximize the catalyst's polymerization activity and copolymerization performance, as well as the molecular weight of the polymer, thereby broadening the flexibility of production. Summary of the Invention

[0005] This invention addresses the current shortcomings in the activity, copolymerization properties, and polymer molecular weight of metallocenes by proposing a novel metallocene compound as a catalyst for olefin polymerization, used to synthesize cyclic olefin copolymers.

[0006] This invention protects a metallocene catalyst composition comprising a metallocene compound of formula (1) and an activating component as a co-catalyst.

[0007] Equation (1).

[0008] The activating component can be an alkylaluminoxane having the structure shown in formula (2) or formula (3);

[0009] Equation (2),

[0010] Equation (3),

[0011] Among them, R 1 It is an alkyl group, preferably an alkyl group containing 1 to 15 carbon atoms, and more preferably a methyl group;

[0012] n is an integer from 4 to 30, preferably an integer from 10 to 30.

[0013] The molar ratio of the metallocene compound to the alkylaluminoxane shown in formula (1) is 1:(100~50000), preferably 1:(500~10000), and more preferably 1:(500~2000).

[0014] The activating component can also be a combination of organoaluminum and organoboron:

[0015] The structure of organoaluminum is R. 2 R 3 R 4 Al, R 2 R 3 R 4 It is an alkyl or halogen atom containing 1 to 12 carbon atoms, and at least one alkyl group, preferably one or a mixture of two or more of diethylaluminum chloride, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum, more preferably triisobutylaluminum; the molar ratio of the metallocene compound shown in formula (1) to the organoaluminum is 1:(10 to 5000), preferably 1:(50 to 1000), more preferably 1:(50 to 500).

[0016] The organoboron compound is [B(C6F5)4]. - Q + Q + It has the structure shown in equation (4) or equation (5):

[0017] Equation (4),

[0018] Equation (5),

[0019] The molar ratio of the metallocene compound to organoboron shown in formula (1) is 1:(1~20), preferably 1:(1~5), and more preferably 1:(1~2).

[0020] The concentration of the metallocene compound shown in equation (1) is 1 × 10⁻⁶. -9 ~1x10 -2 mol / L, preferably 1x10 -8 ~1x10 -4 mol / L. X in the metallocene compound shown in formula (1) 1 X 2 They are, respectively, one of the following: halogen (one of fluorine, chlorine, bromine, or iodine atoms), alkyl (containing 1 to 18 carbon atoms), alkoxy (containing 1 to 18 carbon atoms), aryloxy (containing 6 to 18 carbon atoms), amino (containing 6 to 18 carbon atoms), and silanoxy (containing 3 to 18 carbon atoms). X 1 X 2 They can be the same or different.

[0021] If X 1 X 2 If the atoms are halogens, then chlorine atoms are preferred.

[0022] If X 1 X 2 The alkyl groups are alkyl groups containing 1 to 18 carbon atoms. The alkyl groups can be straight-chain or branched, and are preferably methyl, ethyl, or isobutyl.

[0023] If X 1 X 2 Each alkoxy group contains 1 to 18 carbon atoms, and the alkyl group attached to the oxygen atom can be straight-chain or branched, with methoxy, ethoxy, and isopropoxy being preferred.

[0024] If X 1 X 2 The aryloxy groups containing 6 to 18 carbon atoms are preferably phenoxy, 2,6-dimethylphenoxy, 2,6-diisopropylphenoxy, 2,6-di-tert-butylphenoxy, 2,4,6-tri-tert-butylphenoxy, or 2,6-di-tert-butyl-4-methylphenoxy.

[0025] If X 1 X 2 The amino groups containing 2 to 18 carbon atoms are preferred, such as N,N-dimethylamino, N,N-diethylamino, and N,N-diisopropylamino.

[0026] If X 1 X 2 The silanoxy groups containing 3 to 18 carbon atoms are preferred, with trimethylsiloxy, dimethyltert-butylsiloxy, and triethylsiloxy being the most suitable.

[0027] The present invention also protects the application of the above-mentioned metallocene catalyst composition in the synthesis of cyclic olefin copolymers, wherein the cyclic olefin is one or more of cyclopentene, cyclohexene, cycloheptene, cyclooctene, norbornene, and tetracyclo[6.2.1.13,6.02,7]dodecyl-4-ene, preferably norbornene and tetracyclo[6.2.1.13,6.02,7]dodecyl-4-ene.

[0028] The solvent used in the polymerization is one or more of alkanes, aromatic hydrocarbons, and halogenated hydrocarbons, preferably a mixture of one or more of decahydronaphthalene, toluene, cyclohexane, cyclopentane, and hexane. The partial pressure of ethylene in the polymerization system is 0.01 to 6.0 MPa, preferably 0.1 MPa to 3.0 MPa; the polymerization temperature is 0 to 200°C, preferably 25°C to 150°C.

[0029] This invention provides a metallocene catalyst composition that combines a metallocene catalyst with an active component. In the synthesis of cyclic olefin copolymers, the activity of the catalyst is significantly improved, the copolymerization performance is enhanced, and the molecular weight of the synthesized cyclic olefin copolymer is increased. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical applications of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

[0031] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0032] Example 1

[0033] Preparation of metallocene catalyst cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia dichloride:

[0034] 1. Synthesis of 6,6-tetramethylene-richene

[0035] A nitrogen atmosphere was established in a 1000 mL three-necked flask, and 500 mL of anhydrous methanol, 84 g of cyclopentanone, and 8.6 mL of tetrahydropyrrole were added. Then, 132 g of cyclopentadiene was slowly added. After reacting for 24 hours under stirring, 15 mL of hydrochloric acid (1 M concentration) was added to the reaction system, and stirring was continued for 30 minutes.

[0036] Hexane was then added for extraction, the organic phases were combined, dried with anhydrous sodium sulfate, and hexane was removed to obtain 116.2 g of brownish-yellow oil, with a yield of 88%.

[0037] 1 H-NMR (CDCl3): 6.34-6.48ppm (4H), 2.69-2.90ppm (4H), 1.73-1.89ppm (4H).

[0038] 2. Synthesis of 1-(1'-cyclopentan-2',4'-dienyl)-1-(9'-fluorenyl)-cyclopentane

[0039] A nitrogen atmosphere was established in a 250 mL three-necked flask, 5.0 g of fluorene was added, followed by 100 mL of anhydrous diethyl ether. The mixture was stirred and dissolved at 15 °C. 13.4 mL of a hexane solution of n-butyllithium (concentration 2.5 mol / L) was slowly added. After the addition was complete, the temperature was raised to 0 °C and stirred continuously for 1 hour.

[0040] A solution of 4.0 g of 6,6-tetramethylene-rich ether (30 mL) was slowly added, and the mixture was stirred at 0 °C for 2 hours. While maintaining the reaction system at 0 °C, 50 mL of saturated ammonium chloride aqueous solution was slowly added dropwise, followed by 100 mL of water. The solution was extracted with n-hexane (200 mL × 2), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and after solvent removal, 8.3 g of a pale yellow solid was obtained, with a yield of 92%.

[0041] 1 H-NMR (CDCl3): 7.05-7.61ppm (8H), 5.98-6.17ppm (4H), 3.98-4.12ppm (1H), 2.64-2.73ppm (1H), 1.33-2.34ppm (8H).

[0042] 3. Synthesis of cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia dichloride

[0043] A nitrogen atmosphere was established in a 100 mL three-necked flask. 502 mg of 1-(1'-cyclopent-2',4'-dienyl)-1-(9'-fluorenyl)-cyclopentane was dissolved in 16 mL of anhydrous diethyl ether. The reaction system was cooled to -70 °C with stirring. 1.8 mL of a hexane solution of n-butyllithium (concentration 2.5 mol / L) was slowly added. The mixture was allowed to rise naturally to room temperature and reacted for 24 hours with stirring.

[0044] After removing the solvent under vacuum, 16 mL of toluene was added, and the mixture was stirred at -70°C for 30 minutes. 389 mg of zirconium tetrachloride solid was slowly added to the reaction system, and after the system naturally warmed to room temperature, the reaction was stirred continuously for 36 hours. The reaction mixture was filtered to obtain a red solution, which was concentrated to 7 mL. 2 mL of n-hexane was added, and the mixture was placed in a refrigerator at -20°C for crystallization. After 24 hours, a red solid was obtained. After two crystallizations, a total of 470 mg of product was obtained, with a yield of 61%.

[0045] 1H-NMR (CDCl3): 7.99-8.12ppm (2H), 7.61-7.72ppm (2H), 7.45-7.55ppm (2H), 7.14-7.27ppm (2H), 6.19-6.30ppm (2H), 5.59-5.72ppm (2H), 3.04-3.25ppm(2H), 2.60-2.77ppm(2H), 1.91-2.10ppm(4H).

[0046] Example 2

[0047] Ethylene copolymerization with norbornene:

[0048] Heat a 1L stainless steel reactor to 120°C and continuously evacuate it for 1 hour. After turning off the heating system, fill the reactor with ethylene to a pressure of 0.1MPa and maintain the pressure.

[0049] Add 500 mL of a toluene solution containing 200 g of norbornene, start the stirring device, set the stirring speed to 300 rpm, and start the heating program. When the temperature inside the vessel reaches 80°C, add 10 mL of a toluene solution containing 0.5 mmol of triisobutylaluminum. Continue stirring and heating. When the temperature reaches 100°C, add 5 mL of a toluene solution containing 1 μmol of cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia. Continue stirring and heating until the temperature reaches 110°C, then add 5 mL of a toluene solution containing 2 μmol of triphenylmethyltetra(pentafluorophenyl)borate.

[0050] In this embodiment, the organoaluminum is triisobutylaluminum, and the organoboron compound is triphenylmethyltetra(pentafluorophenyl)borate; the molar ratio of the metallocene compound to the organoaluminum is 1:500, and the molar ratio of the metallocene compound to the organoboron is 1:2.

[0051] The ethylene pressure was rapidly increased to 1.2 MPa, and the reaction was continued for 30 minutes with stirring at 300 rpm. Then the temperature was lowered and the ethylene pressure was released. The reaction mixture was poured into a mixture of anhydrous ethanol and concentrated hydrochloric acid (volume ratio of 500 mL: 20 mL), stirred thoroughly for 8 hours, filtered, and the filter cake was thoroughly washed with anhydrous ethanol. The obtained polymer was placed in a vacuum oven and dried at 60 °C under vacuum (-0.099 MPa) for 48 hours to obtain 80.1 g of polymer.

[0052] Example 3

[0053] Copolymerization of ethylene and norbornene: The polymerization conditions and process were the same as in Example 2, except that all toluene was replaced with decahydronaphthalene, yielding 69.9 g of polymer.

[0054] Example 4

[0055] Copolymerization of ethylene and norbornene:

[0056] Heat a 1L stainless steel reactor to 120°C and continuously evacuate it for 1 hour. After turning off the heating system, fill the reactor with ethylene to a pressure of 0.1MPa and maintain the pressure.

[0057] Add 500 mL of a toluene solution containing 200 g of norbornene, start the stirring device, set the stirring speed to 300 rpm, and start the heating program. When the temperature inside the vessel reaches 80°C, add 10 mL of a toluene solution containing 0.5 mmol of triisobutylaluminum. Continue stirring and heating. When the temperature reaches 100°C, add 5 mL of a toluene solution containing 1 μmol of cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia. Continue stirring and heating until the temperature reaches 110°C, then add 5 mL of a toluene solution containing 2 μmol of N,N-dimethylaniline tetra(pentafluorobenzene)borate.

[0058] In this embodiment, the organoaluminum is triisobutylaluminum, and the organoboron compound is N,N-dimethylaniline tetra(pentafluorobenzene)borate; the molar ratio of the metallocene compound to the organoaluminum is 1:500, and the molar ratio of the metallocene compound to the organoboron is 1:2.

[0059] The ethylene pressure was rapidly increased to 1.2 MPa, and the reaction was continued for 30 minutes with a stirring speed of 300 rpm. Then the temperature was lowered and the ethylene pressure was released. The reaction mixture was poured into a mixture of anhydrous ethanol and concentrated hydrochloric acid (volume ratio of 500 mL: 20 mL), stirred thoroughly for 8 hours, filtered, and the filter cake was thoroughly washed with anhydrous ethanol. The obtained polymer was placed in a vacuum oven and dried at 60 °C under vacuum (-0.099 MPa) for 48 hours to obtain 75.7 g of polymer.

[0060] Example 5

[0061] Copolymerization of ethylene and norbornene:

[0062] Heat a 1L stainless steel reactor to 120°C and continuously evacuate it for 1 hour. After turning off the heating system, fill the reactor with ethylene to a pressure of 0.1MPa and maintain the pressure.

[0063] Add 500 mL of a toluene solution containing 200 g of norbornene, start the stirring device, set the stirring speed to 300 rpm, and start the heating program. When the temperature inside the vessel reaches 80°C, add 10 mL of a toluene solution containing 5 mmol of methylaluminoxane, continue stirring and heating, and when the temperature reaches 110°C, add 5 mL of a toluene solution containing 1 μmol of cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia.

[0064] In this embodiment, the activating component is methylaluminoxane, and the molar ratio of metallocene compound to alkylaluminoxane is 1:5000.

[0065] The ethylene pressure was rapidly increased to 1.2 MPa, and the reaction was continued for 30 minutes with a stirring speed of 300 rpm. Then the temperature was lowered and the ethylene pressure was released. The reaction mixture was poured into a mixture of anhydrous ethanol and concentrated hydrochloric acid (volume ratio of 500 mL: 20 mL), stirred thoroughly for 8 hours, filtered, and the filter cake was thoroughly washed with anhydrous ethanol. The obtained polymer was placed in a vacuum oven and dried at 60 °C under vacuum (-0.099 MPa) for 48 hours to obtain 70.5 g of polymer.

[0066] Example 6

[0067] Copolymerization of ethylene and norbornene:

[0068] Heat a 1L stainless steel reactor to 120°C and continuously evacuate it for 1 hour. After turning off the heating system, fill the reactor with ethylene to a pressure of 0.1MPa and maintain the pressure.

[0069] After cooling to below 80°C, add 500 mL of a cyclohexane solution of norbornene (containing 200 g of norbornene), start the stirring device, set the stirring speed to 300 rpm, and start the heating program. When the temperature inside the vessel reaches 60°C, add 10 mL of a cyclohexane solution of triisobutylaluminum (containing 0.5 mmol of triisobutylaluminum), continue stirring for 5 minutes, then add 5 mL of a cyclohexane solution of cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia (containing 1 μmol of cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia), continue stirring and heating until the temperature reaches 80°C, then add 5 mL of a cyclohexane solution of triphenylmethyltetra(pentafluorophenyl)borate (containing 2 μmol of triphenylmethyltetra(pentafluorophenyl)borate).

[0070] In this embodiment, the solvent used for polymerization is replaced with cyclohexane instead of toluene, the organoaluminum compound is triisobutylaluminum, and the organoboron compound is triphenylmethyltetra(pentafluorophenyl)borate; the molar ratio of metallocene compound to organoaluminum is 1:500, and the molar ratio of metallocene compound to organoboron is 1:2.

[0071] The ethylene pressure was rapidly increased to 1.2 MPa, and the reaction was continued for 30 minutes with a stirring speed of 300 rpm. Then the temperature was lowered and the ethylene pressure was released. The reaction mixture was poured into a mixture of anhydrous ethanol and concentrated hydrochloric acid (volume ratio of 500 mL: 20 mL), stirred thoroughly for 8 hours, filtered, and the filter cake was thoroughly washed with anhydrous ethanol. The obtained polymer was placed in a vacuum oven and dried at 60 °C under vacuum (-0.099 MPa) for 48 hours to obtain 57.8 g of polymer.

[0072] Example 7

[0073] Ethylene copolymerization with tetracyclo[6.2.1.13,6.02,7]dodecyl-4-ene: The polymerization conditions and process were the same as in Example 2, except that 150 g of tetracyclo[6.2.1.13,6.02,7]dodecyl-4-ene was used to replace norbornene, resulting in 60.1 g of polymer.

[0074] Example 8

[0075] Ethylene copolymerization with tetracyclo[6.2.1.13,6.02,7]dodecyl-4-ene: The polymerization conditions and process were the same as in Example 4, except that 150 g of tetracyclo[6.2.1.13,6.02,7]dodecyl-4-ene was used to replace norbornene, resulting in 52.6 g of polymer.

[0076] Comparative Example 1

[0077] Copolymerization of ethylene and norbornene: The polymerization conditions and process were the same as in Example 2, except that cyclopentyl-(cyclopentadienyl)(fluorenyl)zirconia was replaced with zirconium dichlorocerocene to obtain 29.7 g of polymer.

[0078] Examples 2-8 and Comparative Example 1 were tested for activity, number-average molecular weight, weight-average molecular weight, molecular weight distribution, glass transition temperature, comonomer insertion rate, etc. The test results are recorded in Table 1, where the activity unit is ton-polymer / molar catalyst / hour.

[0079] The molecular weight of the polymer was determined by gel permeation chromatography (GPC) at 150 °C on a Waters Alliance GPCV2000 with 1,2,4-trichlorobenzene as solvent.

[0080] The content of comonomers in polymers is determined by solution. 13 C nuclear magnetic resonance (C 13 C-NMR experiments were conducted on a Bruker AVANCE III-400MHz spectrometer equipped with a 10mm PASEX sensor. 13 C- 1 H / D Z-GRD probe. Spectrometer 13The C resolution is 0.09 Hz. A sample solution was prepared by dissolving 200 mg of polymer material in 2.5 mL of o-dichlorobenzene (ODCB-d4) in a 10 mm test tube at 130 °C. 13 The C-NMR measurements were performed at 125 °C, a spin rate of 20 Hz, a pulse angle of 90°, continuous Waltz-16 decoupling, a spectral width of 120 ppm, an acquisition time of 5 s, and a relaxation delay of 10 s. The repeating backbone methylene peak was set to 30.0000 ppm as a chemical shift reference.

[0081] The glass transition temperature of the polymer was determined on a TAQ 100. Approximately 2 mg of the polymer sample was heated from 25°C to 200°C at a heating rate of 10°C per minute under a nitrogen atmosphere. After holding at this temperature for 1 minute, the sample was cooled to 25°C and held at this temperature for another minute. The sample was then heated to 200°C at a heating rate of 10°C per minute, and the data were recorded.

[0082] Table 1

[0083]

[0084] As can be seen from Table 1, when using the metallocene catalyst composition, the activity of the catalyst is significantly improved, the copolymerization performance is enhanced, and the molecular weight of the synthesized cyclic olefin copolymer is increased.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A metallocene catalyst composition, characterized in that, It includes the metallocene compound represented by formula (1), and an activating component as a cocatalyst. Equation (1), The activating component is an alkylaluminoxane, having the structure shown in formula (2) or formula (3); Equation (2), Equation (3), Among them, R 1 The alkyl group is an alkyl group, and n is an integer from 4 to 30. The molar ratio of the metallocene compound shown in formula (1) to the alkylaluminoxane is 1:(100~50000). Alternatively, a combination of organoaluminum and organoboron as the activating components: The structure of organoaluminum is R 2 R 3 R 4 Al, R 2 R 3 R 4 It is an alkyl or halogen atom containing 1 to 12 carbon atoms, and at least one alkyl group. The molar ratio of the metallocene compound shown in formula (1) to the organoaluminum is 1:(10 to 5000). The organoboron compound is [B(C6F5)4]. - Q + Q + It has the structure shown in equation (4) or equation (5): Equation (4), Equation (5), The molar ratio of the metallocene compound to organoboron shown in formula (1) is 1:(1~20).

2. The metallocene catalyst composition according to claim 1, characterized in that, X 1 X 2 If X 1 X 2 They are respectively one of fluorine atom, chlorine atom, bromine atom, iodine atom, or alkyl containing 1 to 18 carbon atoms, or alkoxy containing 1 to 18 carbon atoms, or aryloxy containing 6 to 18 carbon atoms, or amino containing 2 to 18 carbon atoms, or silanoxy containing 3 to 18 carbon atoms.

3. The metallocene catalyst composition according to claim 1, characterized in that, The organoaluminum is preferably one or a mixture of two or more of diethylaluminum chloride, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.

4. The metallocene catalyst composition according to claim 1, characterized in that, The concentration of the metallocene compound shown in equation (1) is 1 × 10⁻⁶. -9 ~1x10 -2 Moles per liter.

5. The metallocene catalyst composition according to claim 1, characterized in that, The concentration of the metallocene compound shown in equation (1) is 1 x 10⁻⁶. -8 ~1x10 -4 Moles per liter.

6. The use of the metallocene catalyst composition according to claims 3-5 in the synthesis of cyclic olefin copolymers.

7. The application of the metallocene catalyst composition according to claim 6 in the synthesis of cyclic olefin copolymers, characterized in that, The cyclic olefin is one or more of cyclopentene, cyclohexene, cycloheptene, cyclooctene, norbornene, and tetracyclo[6.2.1.13,6.02,7]dodecyl-4-ene.

8. The application of the metallocene catalyst composition according to claim 6 in the synthesis of cyclic olefin copolymers, characterized in that, The partial pressure of ethylene in the polymerization system is 0.01~6.0MPa, and the polymerization temperature is 0~200℃.

9. The application of the metallocene catalyst composition according to claim 6 in the synthesis of cyclic olefin copolymers, characterized in that, The solvent used in the polymerization is one or more of alkanes, aromatic hydrocarbons, and halogenated hydrocarbons.

10. The application of the metallocene catalyst composition according to claim 9 in the synthesis of cyclic olefin copolymers, characterized in that, The solvent used in the polymerization is one or a mixture of decahydronaphthalene, toluene, cyclohexane, cyclopentane, and hexane.

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