A transition metal carbene catalyst, its preparation method and use

Abstract

The application relates to the field of new compounds and preparation thereof, and specifically provides a transition metal carbene catalyst, a preparation method and application thereof, a general formula of the catalyst being as follows: the prepared catalyst has good comprehensive performance, is good in polymer monomer selectivity, and a ring olefin polymerization process using the catalyst is good in product structure controllability; the prepared ring olefin copolymer is high in tensile strength and low in tensile strength, and is also high in heat resistance, so that the polymer material has better processability, and is more suitable for forming, cutting, heat sealing and other processes.

Description

Technical Field

[0001] This invention relates to the field of novel compounds and their preparation, specifically to the field of catalysts for polymer chemical synthesis and olefin metathesis reactions, and particularly to a transition metal carbene catalyst, its preparation method, and its application. Background Technology

[0002] Cyclic olefin copolymers obtained by copolymerization of cyclic olefins have high glass transition temperatures and excellent optical, mechanical, and thermal properties, and have been widely used in materials such as DVD lenses, smartphone imaging lenses, storage disks, and optical fibers.

[0003] The technology of metathesis catalysts has enabled the development of several research platforms, including CM (cross-metathesis), RCM (ring-closed metathesis), and ROMP (ring-opening metathesis polymerization). The incorporation of NHC (N-heterocyclic carbene) ligands has played an important role in the development of metathesis catalysts. In the past, most attention has focused on the efficacy of catalysts with low catalyst loading and fast / stable substrate transformation.

[0004] Existing cyclic olefin polymers are mainly produced using reaction injection molding (RIM), with catalytic systems primarily selected from first-generation catalytic systems such as tungsten, molybdenum, and tantalum, or second-generation catalytic systems using ruthenium carbene. Polydicyclopentadiene polymers prepared based on first-generation catalytic systems such as tungsten, molybdenum, and tantalum are produced by molding a two-component mixture containing catalyst A and co-catalyst B. Functional fillers, copolymers, and additives can be added to adjust product performance. However, the preparation process requires nitrogen storage, and generally necessitates the isolation of moisture and air to ensure the activity and stability of the catalytic system. This results in drawbacks such as stringent storage and molding conditions, high mold and equipment costs, and low overall product performance. Furthermore, most catalytic systems exhibit poor monomer selectivity, and the polymerization process lacks the ability to adjust the product structure. There is still no cyclic olefin polymer material that can simultaneously achieve high tensile strength, low yield strength, and heat resistance. Summary of the Invention

[0005] To address the problems in existing technologies, such as harsh conditions for catalyst preparation, storage, and molding; high cost of mold equipment; low overall performance of catalyst products; poor selectivity for monomers; lack of product structure adjustment in polymerization processes; and inability to simultaneously achieve high tensile strength, low tensile strength, and heat resistance during polymerization, this invention provides a transition metal carbene catalyst and its preparation method. This catalyst is then used in the polymerization of cycloolefins, exhibiting high tensile strength, low tensile strength, and high heat resistance.

[0006] The first aspect of this invention provides a transition metal carbene catalyst, the general structural formula of which is as follows:

[0007]

[0008] Where X is one of Cl and Br; L is one of imidazole, 2-bromoimidazolium, benzimidazole, 1,2,4-triazolium, 5-bromo-1,2,4-triazolium, and benzotriazolium; and R1 and R2 are one of hydrogen, methyl (Me), ethyl (Et), tert-butyl (tBu), isobutyl (iBu), CF3, phenyl (Ph), benzyl (Bn), isopropyl (i-Pr), and n-propyl (n-Pr), respectively.

[0009] More specifically, the aforementioned transition metal carbene catalysts include compounds with the following chemical structural formulas:

[0010]

[0011] The catalyst provided by this invention introduces azole ligands again on the basis of the nitrogen-tungsten carbene structure of the catalyst, making its electron cloud density more uniform and stable. Furthermore, due to the presence of azole groups, the monomer arrangement and spatial structure of the polymer can be adjusted during the chain growth of cyclic olefin monomers. Specifically, the delocalized π electrons on the azole groups combine with tungsten ions in a planar form, making the catalyst more stable overall. In addition, during the ring-opening metathesis reaction with cyclic olefin monomers, the steric hindrance of the azole monomers protects the catalytic active sites, reducing the activity differences between monomers due to structure, resulting in a more random polymer and fundamentally optimizing the polymer performance. Moreover, the prepared cyclic olefin copolymer is an amorphous polymer. Compared with ordinary cyclic olefin copolymers, the cyclic olefin polymer has advantages in mechanical properties such as high tensile strength and low yield strength, is insensitive to stress corrosion, and has good processing and molding performance.

[0012] The W=C bond in the catalyst molecule is a necessary structure for ring-opening metathesis polymerization catalysis. The N=W bond can work together with azole monomers to disperse the electron cloud density around the W atom and improve the stability of the catalyst.

[0013] In a second aspect, the present invention provides a method for preparing the above-mentioned transition metal carbene catalyst, specifically comprising the following steps:

[0014] 1) Add phenyl isocyanate to a toluene suspension of WOCl4 and mix. Heat to 100-150℃ and reflux for 12-36 hours to obtain a dark green suspension.

[0015] 2) Centrifuge the suspension obtained in step 1), and filter and collect the crude product that is dark green microcrystals after centrifugation;

[0016] 3) Dissolve the crude product obtained in step 2) in diethyl ether to obtain a green solution. Filter the green solution and vacuum dry it to obtain green microcrystals.

[0017] 4) Prepare a mixed solvent by mixing diethyl ether and n-hexane in a volume ratio of 1:3. Dissolve the green microcrystals obtained in step 3) completely in the mixed solvent at 40°C. Cool to -5°C and recrystallize to obtain dark green prism crystals. Filter and collect the dark green prism crystals and vacuum dry to obtain crystal (1), whose chemical structure is shown in formula (1):

[0018]

[0019] 5) Dissolve the crystal (1) obtained in step 4) in a solvent, wherein the solvent is pentane or toluene, and add triisobutylaluminum and azole compounds in sequence, and stir at 30-80℃ for 20-60 min to obtain a solution of the target catalyst.

[0020] Preferably, the azole compound is one of imidazole, 2-bromoimidazole, benzimidazole, 1,2,4-triazole, 5-bromo-1,2,4-triazole, and benzotriazole, and the prepared transition metal carbene catalyst corresponds to (A)-(F) in the above chemical formulas.

[0021] Preferably, in step 1), the molar ratio of phenyl isocyanate to WOCl4 is 1:1, and the concentration of WOCl4 in toluene is 0.3-0.5 mol / L. For example, a reaction combination of 14.4 mmol isocyanate and 40 mL of toluene suspension containing 14.4 mmol WOCl4 can be used.

[0022] Preferably, the centrifugation speed in step 2) is 2000-6000 r / min and the time is 20-60 min;

[0023] Preferably, the ratio of diethyl ether to crude product in step 3) is (1-150) mL:1 g, more preferably (1-10) mL:1 g.

[0024] Preferably, the vacuum drying pressure in steps 3) and 4) is -0.1 to -0.08 MPa, the temperature is 20 to 80°C, and the time is 2 to 6 hours.

[0025] Preferably, the ratio of the mixed solvent to the green microcrystals in step 4) is (1-10) mL:1g, more preferably (5-10) mL:1g.

[0026] Preferably, in step 5), the molar ratio of crystal (1) to triisobutylaluminum is (0.8-1.2):1, the molar ratio of crystal (1) to azole compound is (0.8-1.2):1, and the molar volume ratio of crystal (1) to solvent is 1 mmol: (3-10) mL. For example, crystal (1), triisobutylaluminum and azole compound can all be 11.1 mmol, and toluene solvent can be 50 mL.

[0027] The third aspect of the present invention provides the application of the above-mentioned transition metal carbene catalyst in the copolymerization of cyclic olefins, wherein cyclic olefin monomers are subjected to ring-opening metathesis polymerization in the presence of the transition metal carbene catalyst to obtain cyclic olefin copolymers; wherein the molar ratio of the transition metal carbene catalyst to all cyclic olefin monomers is 1:(1000-10000).

[0028] The cyclic olefin monomer is any substituted or unsubstituted, heteroatom-containing or heteroatom-free monounsaturated, diunsaturated or polyunsaturated C5 to C24 compound, and the cyclic olefin monomer may be a monocyclic, bicyclic or polycyclic cyclic olefin compound.

[0029] Preferably, the cycloolefin monomer is selected from one or more of dicyclopentadiene (DCPD), norbornene (NB), tetracyclododecene (TCD), methyltetrahydrofluorene, and higher oligomers of cyclopentadiene; the higher oligomers of cyclopentadiene include one or more of cyclopentadiene tetramers and cyclopentadiene pentamers.

[0030] Preferably, the ring-opening metathesis polymerization reaction is carried out in a solvent, which can be any solvent known to those skilled in the art capable of dissolving or dispersing the cyclic olefin monomer and the catalyst. In this invention, the solvent includes, but is not limited to, one or more of aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, aromatic hydrocarbon solvents, halogenated aromatic hydrocarbon solvents, carboxylic acid ester solvents, and ether solvents; the mass of the solvent is preferably 60%-95% of the total mass of the solvent and the cyclic olefin monomer.

[0031] The aliphatic hydrocarbon solvents include, but are not limited to, one or more of pentane, hexane, heptane, octane, nonane, and decane; the alicyclic hydrocarbon solvents include, but are not limited to, one or more of cyclohexane, cycloheptane, cyclooctane, naphthane, and norbornene; the aromatic hydrocarbon solvents include, but are not limited to, one or more of benzene, toluene, xylene, ethylbenzene, and cumene; the halogenated aromatic hydrocarbon solvents include, but are not limited to, one or more of chlorobutane, bromohexane, dichloromethane, dichloroethane, 1,6-dibromohexane, chlorobenzene, chloroform, and tetrachloroethylene; the carboxylic acid ester solvents include, but are not limited to, one or more of ethyl acetate, n-butyl acetate, isobutyl acetate, and methyl propionate; and the ether solvents include, but are not limited to, one or more of dibutyl ether, tetrahydrofuran, and dimethoxyethane.

[0032] During the ring-opening metathesis polymerization reaction, the polymerization conditions can be appropriately adjusted to obtain a cyclic olefin copolymer with the desired molecular weight for the intended application. Furthermore, a molecular weight regulator can be added to the ring-opening metathesis polymerization reaction. The molecular weight regulator is preferably an olefin, and more preferably includes, but is not limited to, one or more of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene, as well as styrene, with 1-butene, 1-octene, or 1-hexene being more preferred. These compounds can be used alone or in combination of two or more as molecular weight regulators. The molar ratio of the molecular weight regulator to the cyclic olefin monomer is preferably (0.0001-1):1, more preferably (0.0005-0.01):1.

[0033] The preferred temperature for the ring-opening metasomatic polymerization reaction is 50℃-180℃, more preferably 50℃-120℃, even more preferably 50℃-100℃, even more preferably 60℃-80℃, and most preferably 70℃; the preferred time for the ring-opening metasomatic polymerization reaction is 0.1-10h, more preferably 0.1-5h, and even more preferably 0.1-3h.

[0034] Preferably, after the ring-opening metathesis polymerization reaction is completed, the mixture is cooled to room temperature, the reaction is terminated with a terminator, and the reaction product is precipitated, washed, filtered and dried to obtain the cyclic olefin copolymer.

[0035] The terminator may be one or more of ethanol, ethylene glycol, isopropanol, and 1,3-butanediol.

[0036] The weight-average molecular weight of the finally obtained cyclic olefin copolymer is 20,000-200,000, more preferably 50,000-100,000.

[0037] In a fourth aspect, the present invention provides a cyclic olefin copolymer hydrogenated by hydrogenation of the above-mentioned cyclic olefin copolymer, wherein the weight-average molecular weight of the obtained cyclic olefin copolymer hydrogenated product is 10,000-150,000, the number-average molecular weight is 5,000-100,000, more preferably, the weight-average molecular weight is 100,000-150,000, the number-average molecular weight is 50,000-80,000, the glass transition temperature is 110-230°C, more preferably 130-180°C, and the hydrogenation rate is 90-100%.

[0038] The present invention also provides a method for preparing the above-mentioned cyclic olefin copolymer hydride, wherein the cyclic olefin copolymer is subjected to a hydrogenation reaction with hydrogen in the presence of a hydrogenation catalyst to obtain the cyclic olefin copolymer hydride.

[0039] The amount of hydrogenation catalyst added can be adjusted according to the actual situation, and it is not significantly related to the inventive point of this invention, so it is not limited thereto.

[0040] The hydrogenation catalyst can be any hydrogenation catalyst known to those skilled in the art that can be used as a hydrogenation catalyst for cyclic olefin copolymers, and there are no special limitations. In this invention, it includes one or more of Raney nickel, nickel diatomaceous earth, nickel acetate, palladium acetate, PdCl2, RhCl(PPh)3 and palladium on carbon.

[0041] The hydrogenation reaction is preferably carried out in a non-reactive organic solvent; the non-reactive organic solvent includes, but is not limited to, one or more of alicyclic hydrocarbons, aromatic hydrocarbons, halogenated aliphatic hydrocarbons, halogenated aromatic hydrocarbons and ether solvents; the ratio of the non-reactive organic solvent to the cyclic olefin copolymer in the hydrogenation reaction is (20-50) mL: 1 g.

[0042] The alicyclic hydrocarbons mentioned therein include, but are not limited to, one or more of cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, tricyclodecane, hexahydroindenecyclohexane, and cyclooctane; aromatic hydrocarbons include one or more of benzene, toluene, and xylene; halogenated aliphatic hydrocarbons include one or more of dichloromethane, chloroform, and 1,2-dichloroethane; halogenated aromatic hydrocarbons include chlorobenzene and / or dichlorobenzene; and ether solvents include one or more of diethyl ether, tetrahydrofuran, anisole, and phenethyl ether.

[0043] In the hydrogenation reaction, the suitable conditions vary depending on the hydrogenation catalyst system used. The preferred reaction temperature is -20℃ to 250℃, more preferably -10℃ to 220℃, and even more preferably 0℃ to 200℃. When the hydrogenation temperature is too low, the reaction rate may become too slow; when it is too high, side reactions may occur.

[0044] In the case of hydrogenation reaction with a catalyst, the hydrogen pressure is typically 0.01-20 MPa, preferably 0.05-15 MPa, and more preferably 0.1-10 MPa. When the hydrogen pressure is too low, the hydrogenation rate may become too slow; when it is too high, it creates a limitation on equipment requiring high-pressure-resistant reaction equipment. The reaction time is not particularly limited as long as the desired hydrogenation rate is achieved, and is typically 0.1-10 hours. After the hydrogenation reaction, the cyclic olefin copolymer hydrogenate can be recovered using conventional methods. During the recovery of the cyclic olefin copolymer hydrogenate, catalyst residue can be removed by methods such as filtration to obtain the hydrogenation reaction solution.

[0045] The hydrogenation reaction solution was poured into a large amount of methanol and stirred continuously to completely precipitate the cyclic olefin copolymer hydrogenate. After filtration, it was dried at 40°C for 24 hours to obtain the cyclic olefin copolymer hydrogenate.

[0046] Methanol is a poor solvent for cyclic olefin copolymers. The solubility of cyclic olefin copolymers decreases and they precipitate when they come into contact with methanol. Preferably, the mass ratio of the cyclic olefin copolymer in the raw material to the mass of methanol used is 1:(2-5).

[0047] The hydrogenation rate (the proportion of hydrogenated main chain double bonds) of the hydrogenation reaction of the cyclic olefin copolymer is not particularly limited, but is preferably 98% or more, more preferably 99% or more, and most preferably 99.5% or more. The higher the hydrogenation rate, the better the heat resistance of the final cyclic olefin copolymer hydrogenate.

[0048] A fifth aspect of the present invention provides a molding material comprising the cyclic olefin copolymer hydride.

[0049] In this invention, the molding material is preferably a medical packaging material and / or an optical material.

[0050] In summary, this invention provides a transition metal carbene catalyst and its preparation method. Using this transition metal carbene catalyst in the preparation of cyclic olefin copolymers offers advantages such as mild conditions and low cost. The prepared catalyst exhibits good overall performance, good selectivity for monomers, and the cyclic olefin polymerization process using this catalyst provides good controllability over the product structure. The prepared cyclic olefin copolymers possess high tensile strength and low tensile strength, as well as high heat resistance, resulting in better processability and making them more suitable for molding, cutting, heat sealing, and other processes. Attached Figure Description

[0051] Figure 1 The 1H NMR spectrum of the transition metal carbene catalyst prepared in Example 1;

[0052] Figure 2 The 1H NMR spectrum of the transition metal carbene catalyst prepared in Example 2;

[0053] Figure 3 The 1H NMR spectrum of the transition metal carbene catalyst prepared in Example 3;

[0054] Figure 4 The 1H NMR spectrum of the transition metal carbene catalyst prepared in Example 4;

[0055] Figure 5 The 1H NMR spectrum of the transition metal carbene catalyst prepared in Example 5;

[0056] Figure 6 The image shows the 1H NMR spectrum of the transition metal carbene catalyst prepared in Example 6. Detailed Implementation

[0057] The technical solution of the present invention will be further described below with reference to specific embodiments. These embodiments are only used to illustrate the technical solution of the present invention in more detail and should not be construed as limiting the scope of protection of the present invention.

[0058] Unless otherwise specified, all reagents and substances used in the following examples are commercially available products.

[0059] The following method for determining the weight-average molecular weight of cyclic olefin polymers was used: a high-temperature gel permeation chromatography system (model: Agilent PL gel MIXED-BLS, manufacturer: Agilent Technologies, USA) was used, with tetrahydrofuran as the mobile phase, a column temperature of 40℃, a flow rate of 1 mL / min, an injection volume of 200 μL, and narrow-distribution polystyrene as the standard.

[0060] The hydrogenation rate of the cyclic olefin polymers mentioned below was detected by FTIR infrared spectroscopy.

[0061] The test method for the transmittance of cyclic olefin copolymer hydrides mentioned below refers to GB / T 7962.12-2010.

[0062] The method for determining the refractive index of cyclic olefin copolymers mentioned below is referenced in 20232037-T-607.

[0063] The test methods for tensile and tensile strength of cyclic olefin copolymers mentioned below refer to GB 13022-91.

[0064] The glass transition temperature (Tg) test method described below is as follows: using a DSC differential scanning calorimeter (model: DSC200F3, manufacturer: Netzsch GmbH, Germany), weighing 10 mg of sample, and testing in the temperature range of 30℃ to 300℃.

[0065] The number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (PDI) of the cyclic olefin copolymers mentioned below, as well as the PDI test method, were as follows: a high-temperature gel permeation chromatography system (model: Agilent PL gelMIXED-BLS, manufacturer: Agilent Technologies, USA) was used, with 1,2,4-trichlorobenzene as the mobile phase, a column temperature of 150℃, a flow rate of 1 mL / min, an injection volume of 200 μL, and narrow-distribution polystyrene as the standard.

[0066] Example 1

[0067] 1.1 Preparation of transition metal carbene catalysts

[0068] Transition metal carbene catalysts were prepared using the following method.

[0069] (1) Freshly purified phenyl isocyanate (1.71 g, 14.4 mmol) was added to a suspension of WOCl4 (4.91 g, 14.4 mmol) and toluene (40 mL). The mixture was heated to 110 °C and refluxed at 110 °C with stirring for 18 hours to obtain a dark green suspension.

[0070] (2) 6.93 g of crude product containing dark green microcrystals was collected from the suspension by centrifugation at 2400 r / min for 20 min;

[0071] (3) Dissolve the crude product obtained in step 2) in 30 ml of diethyl ether to obtain a green solution. Filter the green solution and place it in a vacuum drying oven at -0.01 MPa and 40°C for 2 h to obtain 5.82 g of green microcrystals.

[0072] (4) Prepare a mixed solvent by mixing diethyl ether and n-hexane at a volume ratio of 1:3. Dissolve the green microcrystals obtained in step (3) completely in 30 ml of the mixed solvent at 40 °C. Cool to -5 °C and recrystallize to obtain dark green prism crystals. Filter and collect the dark green prism crystals and place them in a vacuum drying oven at -0.01 MPa and 40 °C for 2 h to obtain 5.46 g of crystals (1). 1 The crystal (1) obtained by HNMR detection is the compound shown in formula (1), with a content of 11.1 mmol and a yield of 77%.

[0073]

[0074] (5) Dissolve the crystal (1) obtained in step (4) in 50 ml of toluene, and add triisobutylaluminum (2.19 g, 11.1 mmol) and imidazole (7.54 g, 11.1 mmol) in sequence. Stir at 40 °C for 30 min to obtain a toluene solution of the target catalyst A. 1 HNMR analysis showed that the concentration of the catalyst solution was 0.18 mmol / ml. In this example, the catalyst yield was 98%. The structural formula of catalyst A is shown below:

[0075]

[0076] Figure 1 The results of the proton nuclear magnetic resonance spectrum of the prepared catalyst (A) are shown, indicating that the transition metal carbene catalyst of the compound shown in formula (A) was successfully prepared by the above method.

[0077] 1.2 Cycloolefin copolymerization

[0078] The polymerization reactor was first purged four times with high-purity nitrogen to remove air. Then, under nitrogen protection, 120 g of anhydrous toluene, 16.0 g (0.1 mol) of tetracyclododecene (TCD), 13.2 g (0.1 mol) of dicyclopentadiene (DCPD), and 11.2 mg (0.1 mmol) of 1-octene were added, and stirring was started. Catalyst A solution (0.02 mmol of catalyst A based on the concentration of catalyst A solution) was placed in a transfer tank connected to the reactor via a feed pump. The catalyst was transferred to the reactor using the feed pump, and the reactor was heated to 70 °C for 3 hours. Heating was then stopped and the reactor cooled to 25 °C. After polymerization, 5 mL of ethanol was used to terminate the reaction, followed by washing with 300 mL of ethanol. A white powdery solid precipitated was collected and filtered at 20 °C to obtain the cyclic olefin copolymer, which was then vacuum dried at 70 °C for 8 hours. The obtained cyclic olefin copolymer had a weight-average molecular weight of 75621.

[0079] 1.3 Preparation of Cyclic Olefin Cohydropolymers

[0080] Add 15g of the above-mentioned cyclic olefin copolymer and 0.5g of palladium on carbon with a loading of 10wt% to a glass reactor using a stirrer, then add 500mL of p-xylene, and introduce 0.5mol of hydrogen gas into the reactor at room temperature to make the hydrogen pressure 4MPa, and carry out the hydrogenation reaction at 125℃ for 5h to obtain the hydrogenation reaction solution.

[0081] The hydrogenation reaction solution was poured into 45g of methanol and stirred continuously to completely precipitate the cyclic olefin copolymer hydrogenate. After filtration, it was dried at 40°C for 24h to obtain the cyclic olefin copolymer hydrogenate.

[0082] The hydrogenation rate of the obtained cyclic olefin copolymer hydrogenates is above 99%, the glass transition temperature (Tg) is 132℃, the number-average molecular weight is 57038, and the weight-average molecular weight is 129012.

[0083] Example 2

[0084] 2.1 Preparation of transition metal carbene catalysts

[0085] The carbene metal catalyst was prepared using the same method as described in 1.1 of Example 1, except that imidazole was not added in step (5), but instead 11.1 mmol of 2-bromoimidazole was added. 1 HNMR analysis revealed that a toluene solution of catalyst B with a concentration of 0.12 mmol / ml was obtained in 88.3% yield. The structural formula of B is as follows.

[0086]

[0087] Figure 2The results of the proton nuclear magnetic resonance spectrum of the prepared catalyst (B) are shown, indicating that the transition metal carbene catalyst of the compound shown in formula (B) was successfully prepared by the above method.

[0088] 2.2 Cycloolefin copolymerization

[0089] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the catalyst B solution in this example was used instead of the catalyst A solution in Example 1, to obtain a cyclic olefin copolymer with a weight-average molecular weight of 87651.

[0090] 2.3 Preparation of Cycloolefin Cohydropolymers

[0091] The same method described in 1.3 of Example 1 was used to prepare the cyclic olefin copolymer hydrogenate by hydrogenation, except that the cyclic olefin copolymer in the raw material was the cyclic olefin copolymer prepared in Example 2.2. The hydrogenation rate of the obtained cyclic olefin copolymer hydrogenate was above 99%, the glass transition temperature Tg was 133℃, the number average molecular weight was 58672, and the weight average molecular weight was 119246.

[0092] Example 3

[0093] 3.1 Preparation of transition metal carbene catalysts

[0094] The carbene metal catalyst was prepared using the same method as described in 1.1 of Example 1, except that in step (5), instead of imidazole, 11.1 mmol of benzimidazole was added. 1 HNMR analysis revealed that a toluene solution of catalyst C with a concentration of 0.16 mmol / ml was obtained with a yield of 91.2%. The structural formula of C is as follows.

[0095]

[0096] Figure 3 The results of the proton nuclear magnetic resonance spectrum of the prepared catalyst (C) are shown, indicating that the transition metal carbene catalyst of the compound shown in formula (C) was successfully prepared by the above method.

[0097] 3.2 Cycloolefin copolymerization

[0098] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the catalyst C solution in this example was used instead of the catalyst A solution in Example 1, to obtain a cyclic olefin copolymer with a weight-average molecular weight of 83542.

[0099] 3.3 Preparation of Cycloolefin Cohydropolymers

[0100] The same method described in 1.3 of Example 1 was used to prepare the cyclic olefin copolymer hydrogenate by hydrogenation, except that the cyclic olefin copolymer in the raw material was the cyclic olefin copolymer prepared in 3.2 of this Example. The hydrogenation rate of the obtained cyclic olefin copolymer hydrogenate was above 99%, the glass transition temperature Tg was 128°C, the number average molecular weight was 61038, and the weight average molecular weight was 134525.

[0101] Example 4

[0102] 4.1 Preparation of transition metal carbene catalysts

[0103] The carbene metal catalyst was prepared using the same method as described in 1.1 of Example 1, except that imidazole was not added in step (5), but instead 11.1 mmol of 1,2,4-triazole was added. 1 HNMR analysis yielded a toluene solution of catalyst D at a concentration of 0.15 mmol / ml, with a yield of 94%. The structural formula of D is as follows.

[0104]

[0105] Figure 4 The results of the proton nuclear magnetic resonance spectrum of the prepared catalyst (D) are shown, indicating that the transition metal carbene catalyst of the compound shown in formula (D) was successfully prepared by the above method.

[0106] 4.2 Cycloolefin copolymerization

[0107] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the catalyst D solution in this example was used instead of the catalyst A solution in Example 1, to obtain a cyclic olefin copolymer with a weight-average molecular weight of 85621.

[0108] 4.3 Preparation of Cycloolefin Cohydrogenates

[0109] The same method described in Example 1, section 1.3 was used to prepare the cyclic olefin copolymer hydride by hydrogenation, except that the cyclic olefin copolymer in the raw material was the same as that prepared in Example 4.2. The hydrogenation rate of the obtained cyclic olefin tool hydride was above 99%, the glass transition temperature Tg was 125°C, the number average molecular weight was 63515, and the weight average molecular weight was 130735.

[0110] Example 5

[0111] 5.1 Preparation of transition metal carbene catalysts

[0112] The carbene metal catalyst was prepared using the same method as described in 1.1 of Example 1, except that imidazole was not added in step (5), but instead 11.1 mmol of 5-bromo-1,2,4-triazole was added. 1HNMR analysis revealed that a toluene solution of catalyst E with a concentration of 0.09 mmol / ml was obtained with a yield of 72%. The structural formula of E is as follows.

[0113]

[0114] Figure 5 The results of the 1H NMR spectrum of the prepared catalyst (E) are shown, indicating that the transition metal carbene catalyst of the compound shown in formula (E) was successfully prepared by the above method.

[0115] 5.2 Cycloolefin copolymerization

[0116] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the catalyst E solution in this example was used instead of the catalyst A solution in Example 1, to obtain the cyclic olefin copolymer with a weight-average molecular weight of 73681.

[0117] 5.3 Preparation of Cycloolefin Cohydrogenates

[0118] The same method described in 1.3 of Example 1 was used to prepare the cyclic olefin copolymer hydrogenate by hydrogenation, except that the cyclic olefin copolymer in the raw material was the cyclic olefin copolymer prepared in Example 5.2. The hydrogenation rate of the obtained cyclic olefin copolymer hydrogenate was above 99%, the glass transition temperature Tg was 137°C, the number average molecular weight was 58462, and the weight average molecular weight was 125647.

[0119] Example 6

[0120] 6.1 Preparation of transition metal carbene catalysts

[0121] The carbene metal catalyst was prepared using the same method as described in 1.1 of Example 1, except that imidazole was not added in step (5), but instead 11.1 mmol of benzotriazole was added. 1 HNMR analysis yielded a toluene solution of catalyst F at a concentration of 0.10 mmol / ml, with a yield of 78%. The structural formula of F is as follows.

[0122]

[0123] Figure 6 The results of the proton nuclear magnetic resonance spectrum of the prepared catalyst (F) are shown, indicating that the transition metal carbene catalyst of the compound shown in formula (F) was successfully prepared by the above method.

[0124] 6.2 Cycloolefin copolymerization

[0125] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the catalyst F solution in this example was used instead of the catalyst A solution in Example 1, to obtain the cyclic olefin copolymer with a weight-average molecular weight of 85803.

[0126] 6.3 Preparation of Cycloolefin Cohydropolymers

[0127] The same method described in 1.3 of Example 1 was used to prepare the cyclic olefin copolymer hydrogenate by hydrogenation, except that the cyclic olefin copolymer in the raw material was the cyclic olefin copolymer prepared in 6.2 of this Example. The hydrogenation rate of the obtained cyclic olefin copolymer hydrogenate was above 99%, the glass transition temperature Tg was 129°C, the number average molecular weight was 58742, and the weight average molecular weight was 139415.

[0128] Comparative Example 1

[0129] 7.1 Catalyst Preparation

[0130] The commercially available Grubbs I catalyst (2 mmol) was dissolved in 5 ml of toluene solution to obtain a Grubbs I catalyst solution.

[0131] 7.2 Cycloolefin copolymerization

[0132] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the Grubbs I catalyst solution in this comparative example was used instead of the catalyst A solution in Example 1, to obtain a cyclic olefin copolymer with a weight average molecular weight of 88629.

[0133] 7.3 Preparation of Cycloolefin Cohydropolymers

[0134] The same method described in 1.3 of Example 1 was used to prepare cyclic olefin copolymer hydrogenates by hydrogenation, except that the cyclic olefin copolymer in the raw material was the cyclic olefin copolymer prepared in this comparative example. The hydrogenation rate of the obtained cyclic olefin copolymer hydrogenates was above 99%, the glass transition temperature Tg was 93°C, the number average molecular weight was 49374, and the weight average molecular weight was 104717.

[0135] Comparative Example 2

[0136] 8.1 Catalyst Preparation

[0137] The commercially available Grubbs II catalyst (2 mmol) was dissolved in 5 ml of toluene solution to obtain the Grubbs II catalyst solution.

[0138] 8.2 Cycloolefin copolymerization

[0139] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the Grubbs II catalyst solution in this comparative example was used instead of the catalyst A solution in Example 1, to obtain a cyclic olefin copolymer with a number average molecular weight of 78612.

[0140] 8.3 Preparation of Cyclic Olefin Cohydropolymers

[0141] The same method described in 1.3 of Example 1 was used to prepare cyclic olefin copolymer hydrides by hydrogenation, except that the cyclic olefin copolymer in the raw material was the same as that prepared in this comparative example. The hydrogenation rate of the obtained cyclic olefin tool hydride was above 99%, the glass transition temperature Tg was 92°C, the number average molecular weight was 50237, and the weight average molecular weight was 105613.

[0142] Comparative Example 3

[0143] 9.1 Catalyst Preparation

[0144] A commercially available Grubbs III catalyst (2 mmol) was dissolved in 5 ml of toluene solution to obtain a Grubbs II catalyst solution.

[0145] 9.2 Cycloolefin copolymerization

[0146] The same method as in Example 1 was used to carry out the cyclic olefin copolymerization reaction, except that the Grubbs II catalyst solution in this comparative example was used instead of the catalyst A solution in Example 1, to obtain a cyclic olefin copolymer with a weight-average molecular weight of 96573.

[0147] 9.3 Preparation of Cycloolefin Cohydropolymers

[0148] The same method described in 1.3 of Example 1 was used to prepare the cyclic olefin copolymer hydrogenate by hydrogenation, except that the cyclic olefin copolymer in the raw material was the cyclic olefin copolymer prepared in this comparative example. The hydrogenation rate of the obtained cyclic olefin copolymer hydrogenate was above 99%, the glass transition temperature Tg was 94°C, the number average molecular weight was 49374, and the weight average molecular weight was 94717.

[0149] The properties of the cyclic olefin copolymers obtained in Examples 1-6 and Comparative Examples 1-3 were tested, and the test results are shown in Table 1.

[0150] Table 1 Performance test results of cyclic olefin copolymers

[0151]

[0152] As can be seen from Table 1, the molecular weight of the cyclic olefin copolymer prepared by the catalyst of the present invention is significantly increased compared with that of the comparative example using other catalysts. The glass transition temperature and tensile strength are also significantly increased, while the tensile strength is decreased. This makes the polymer material more processable and more suitable for molding, cutting, heat sealing and other processes. Moreover, the degree of branching is significantly higher than that of the comparative example 2, indicating that the catalyst of the present invention has good monomer selectivity and controllability of product structure.

[0153] The above embodiments are merely exemplary implementations used to illustrate the principles of the invention. However, the invention is not limited thereto. Those skilled in the art can make various improvements and modifications without departing from the essence of the invention, and these improvements and modifications also fall within the protection scope of the invention.

Claims

1. A transition metal carbene catalyst, characterized in that, It includes compounds represented by the following formulas (A) to (F): 。 2. The method for preparing the transition metal carbene catalyst according to claim 1, comprising the following steps: 1) Add phenyl isocyanate to a toluene suspension of WOCl4 and mix. Heat to 100-150℃ and reflux for 12-36 hours to obtain a dark green suspension. 2) Centrifuge the suspension obtained in step 1), and then filter and collect the crude product, which is dark green microcrystals. 3) Dissolve the crude product obtained in step 2) in diethyl ether to obtain a green solution. Filter the green solution and vacuum dry it to obtain green microcrystals. 4) The green microcrystals obtained in step 3) are completely dissolved in a mixed solvent at 40℃, and then recrystallized at -5℃ to obtain dark green prism crystals. The dark green prism crystals are collected by filtration and vacuum dried to obtain crystal (1), whose chemical structure is shown in formula (1): ； 5) Dissolve the crystal (1) obtained in step 4) in a solvent, wherein the solvent is pentane or toluene, and add triisobutylaluminum and azole compounds in sequence, and stir at 30-80℃ for 20-60 min to obtain a solution of the target catalyst.

3. The preparation method according to claim 2, characterized in that, The azole compounds are one of imidazole, 2-bromoimidazole, benzimidazole, 1,2,4-triazole, 5-bromo-1,2,4-triazole, and benzotriazole, and the prepared transition metal carbene catalysts correspond to the compounds shown in formulas (A) to (F).

4. The preparation method according to claim 2, characterized in that, In step 1), the molar ratio of phenyl isocyanate to WOCl4 is 1:1, and the concentration of WOCl4 in toluene is 0.3-0.5 mol / L; The centrifugation speed mentioned in step 2) is 2000-6000 r / min, and the time is 20-60 min; The ratio of diethyl ether to crude product in step 3) is (1-150) mL:1 g; The vacuum drying pressure described in steps 3) and 4) is -0.1 to -0.08 MPa, the temperature is 20 to 80°C, and the time is 2 to 6 hours. The mixed solvent mentioned in step 4) is a mixture of diethyl ether and n-hexane, wherein the volume ratio of diethyl ether to n-hexane is 1:3; the ratio of the mixed solvent to the green microcrystals is (1-10) mL:1 g; In step 5), the molar ratio of crystal (1) to triisobutylaluminum is (0.8-1.2):1, the molar ratio of crystal (1) to azole compound is (0.8-1.2):1, and the molar volume ratio of crystal (1) to solvent is 1 mmol:(3-10) mL.

5. A method for copolymerizing cyclic olefins using the transition metal carbene catalyst of claim 1, characterized in that, The cyclic olefin monomers were subjected to ring-opening metathesis polymerization in the presence of the transition metal carbene catalyst to obtain cyclic olefin copolymers; the molar ratio of the transition metal carbene catalyst to all cyclic olefin monomers was 1:(1000-10000).

6. The method for copolymerizing cycloolefins according to claim 5, characterized in that, The cyclic olefin monomer is any substituted or unsubstituted, heteroatom-containing or heteroatom-free monounsaturated, diunsaturated or polyunsaturated C5 to C24 compound, and the cyclic olefin monomer is a monocyclic, bicyclic or polycyclic cyclic olefin compound.

7. The method for copolymerizing cycloolefins according to claim 5, characterized in that, The cyclic olefin monomers include one or more of dicyclopentadiene, norbornene, tetracyclododecene, methyltetrahydrofluorene, cyclopentadiene tetramer, and cyclopentadiene pentamer; the ring-opening metathesis polymerization reaction is carried out in a solvent, the mass of which is 60%-95% of the total mass of the solvent and the cyclic olefin monomers; the temperature of the ring-opening metathesis polymerization reaction is 50℃-180℃; the time of the ring-opening metathesis polymerization reaction is 0.1-10 h; and the weight-average molecular weight of the finally obtained cyclic olefin copolymer is 20,000-200,000.

8. A cyclic olefin copolymer hydrogenated compound, obtained by hydrogenation of a cyclic olefin copolymer, wherein the cyclic olefin copolymer is obtained by the method of cyclic olefin copolymerization according to any one of claims 5-7, characterized in that, The weight-average molecular weight of the cyclic olefin copolymer hydrogenated product is 10,000-150,000, the number-average molecular weight is 5,000-100,000, the glass transition temperature is 110-230℃, and the hydrogenation rate is 90-100%.

9. The method for preparing the cyclic olefin copolymer hydride according to claim 8, characterized in that, The cyclic olefin copolymer is hydrogenated with hydrogen in the presence of a hydrogenation catalyst to obtain a cyclic olefin copolymer hydrogenate; the hydrogenation catalyst includes one or more of Raney nickel, nickel diatomaceous earth, nickel acetate, palladium acetate, PdCl2, RhCl(PPh)3, and palladium on carbon; in the hydrogenation reaction, the reaction temperature is -20℃ to 250℃; the hydrogen pressure is 0.01-20 MPa; and the reaction time is 0.1-10 hours.

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