Transition metal carbene catalyst and preparation method and application thereof

Abstract

The invention relates to the field of new compounds and preparation thereof, and particularly provides a transition metal carbene catalyst and a preparation method and application thereof.The transition metal carbene catalyst with the general formula as follows: # imgabs0 # has good comprehensive performance and good selectivity to polymeric monomers, and a cycloolefin polymerization process using the catalyst is good in product structure controllability and high in product yield. The prepared cycloolefin copolymer has high tensile strength and low tensile strength, and also has high heat resistance, so that the polymeric material has better processability and is more suitable for molding, cutting, heat sealing and other processes.

Description

Technical Field

[0001] The present invention relates to the field of new compounds and their preparation, specifically to the field of polymer chemical synthesis and olefin metathesis reaction catalysts, and particularly to a transition metal carbene catalyst, a preparation method and application thereof. Background Art

[0002] Cyclic olefin copolymers obtained by copolymerization of cyclic olefins have a high glass transition temperature and excellent optical, mechanical, and thermal properties. They 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 closing metathesis), 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 been focused on the efficacy of catalysts with low catalyst loading and fast / stable substrate conversion.

[0004] Existing cycloolefin polymers are mainly prepared by reaction injection molding (RIM), and their catalytic systems are mostly selected from the first-generation catalytic systems such as tungsten, molybdenum, tantalum, or the second-generation catalytic systems of ruthenium metal carbene. The polydicyclopentadiene polymer prepared based on the first-generation catalytic systems such as tungsten, molybdenum, tantalum, etc. is mixed and molded by a two-component liquid containing a catalyst A and a co-catalyst B. Functional fillers, copolymers, auxiliary agents and other components can be added to adjust the product performance, but the preparation process must be filled with nitrogen for storage, and the general formula needs to block moisture and air to ensure the activity and stability of the catalytic system. There are defects such as harsh storage molding conditions, high mold equipment cost, and low product comprehensive performance. In addition, most of the catalytic systems have poor selectivity for monomers, and the polymerization process lacks adjustment of the product structure. There is still no cycloolefin polymer material that can take into account high tensile strength, low yield strength and heat resistance. Summary of the invention

[0005] In order to solve the problems existing in the prior art, such as harsh catalyst preparation, storage and molding conditions, high mold equipment cost, low comprehensive performance of catalyst products, poor selectivity for polymerization monomers, lack of adjustment of product structure in the polymerization process, and inability to take into account high tensile strength, low tensile strength and heat resistance during polymerization, the present invention provides a transition metal carbene catalyst and a preparation method thereof, and uses the same for the polymerization of cycloolefins, which has high tensile strength, low tensile strength and high heat resistance.

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

[0007]

[0008] Wherein X is one of Cl and Br; L is one of imidazolyl, 2-bromoimidazolyl, benzimidazolyl, 1,2,4-triazolyl, 5-bromo-1,2,4-triazolyl, and benzotriazolyl; R 1 and R 2 are hydrogen, methyl (Me), ethyl (Et), tert-butyl (tBu), isobutyl (iBu), CF 3 , phenyl (Ph), benzyl (Bn), isopropyl (i-Pr), and n-propyl (n-Pr).

[0009] More specifically, the above transition metal carbene catalyst includes a compound represented by the following chemical formula:

[0010]

[0011] The above-mentioned catalyst provided by the present invention re-introduces azole ligands on the basis of the catalyst nitrogen tungsten carbene structure, so that its electron cloud density is more uniform and more stable. In addition, due to the presence of azole groups, the monomer arrangement order and spatial structure of the polymer can be adjusted during the chain growth of cycloolefin monomers; specifically, the delocalized π electrons on the azole groups are combined with tungsten ions in the form of a face, making the catalyst more stable as a whole. In addition, when the ring-opening metathesis reaction is carried out with the cycloolefin monomer, the steric hindrance of the azole monomers is present, which has a protective effect on the catalytic active sites, so that the activity difference between the monomers due to the structure is reduced, and the obtained polymer is more irregular, thereby fundamentally optimizing the polymer performance, and the prepared cycloolefin copolymer is a non-crystalline polymer. Compared with ordinary cycloolefin copolymers, the cycloolefin polymer has mechanical performance advantages 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, and the N=W bond and the azole monomer can work together 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 transition metal carbene catalyst, which specifically comprises the following steps:

[0014] 1) Add phenyl isocyanate to WOCl 4 Mix with a toluene suspension, heat to 100-150°C, reflux and stir for 12-36h to obtain a dark green suspension;

[0015] 2) centrifuging the suspension obtained in step 1), and filtering and collecting a crude product in the form of dark green microcrystals after centrifugation;

[0016] 3) dissolving the crude product obtained in step 2) in ether to obtain a green solution, filtering the green solution and vacuum drying to obtain green microcrystals;

[0017] 4) preparing a mixed solvent by mixing ether and n-hexane in a volume ratio of 1:3, completely dissolving the green microcrystals obtained in step 3) in the mixed solvent at 40° C., cooling to -5° C. for recrystallization to obtain dark green prism crystals, collecting the dark green prism crystals by filtration and vacuum drying to obtain crystals (1), whose chemical structure is shown in formula (1):

[0018]

[0019] 5) dissolving the crystals (1) obtained in step 4) in a solvent, wherein the solvent is pentane or toluene, adding triisobutylaluminum and an azole compound in sequence, and stirring at 30-80° C. 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 formula respectively.

[0021] Preferably, in step 1), phenyl isocyanate and WOCl 4 The molar ratio of WOCl is 1:1. 4 The concentration in toluene is 0.3-0.5 mol / L, for example, 14.4 mmol of isocyanate and 40 mL of 14.4 mmol of WOCl 4 A toluene suspension of the reaction mixture.

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

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

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

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

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

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

[0028] The cycloolefin monomer is any substituted or unsubstituted, monounsaturated, diunsaturated or polyunsaturated C5 to C24 compound containing or not containing heteroatoms. The cycloolefin monomer can be a monocyclic, bicyclic or polycyclic cycloolefin 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 tetramer and cyclopentadiene pentamer.

[0030] Preferably, the ring-opening metathesis polymerization reaction is carried out in a solvent, and the solvent is a solvent known to those skilled in the art that can dissolve or disperse cycloolefin monomers and catalysts. In the present 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 cycloolefin 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, decalin and norbornane; the aromatic hydrocarbon solvents include but are not limited to one or more of benzene, toluene, xylene, ethylbenzene and isopropylbenzene; the halogenated aromatic hydrocarbon solvents include but are not limited to one or more of butyl chloride, hexyl bromide, 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; the ether solvents include but are not limited to one or more of dibutyl ether, tetrahydrofuran and dimethoxyethane.

[0032] In the process of ring-opening metathesis polymerization, the polymerization conditions can be appropriately adjusted so that the obtained cycloolefin copolymer has a desired molecular weight according to the purpose; in addition, a molecular weight regulator can be added to the ring-opening metathesis polymerization; the molecular weight regulator is preferably a chain olefin, and more preferably the molecular weight regulator includes but is not limited to ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and other α-olefins and styrene, etc. One or more, among which 1-butene or 1-octene or 1-hexene is 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 cycloolefin monomer is preferably (0.0001-1):1, and more preferably (0.0005-0.01):1.

[0033] The temperature of the ring-opening metathesis polymerization reaction is preferably 50°C-180°C, more preferably 50°C-120°C, further preferably 50°C-100°C, further preferably 60°C-80°C, and most preferably 70°C; the time of the ring-opening metathesis polymerization reaction is preferably 0.1-10h, more preferably 0.1-5h, further preferably 0.1-3h.

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

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

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

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

[0038] The present invention also provides a method for preparing the cycloolefin copolymer hydrogenate, wherein the cycloolefin copolymer is subjected to a hydrogenation reaction with hydrogen in the presence of a hydrogenation catalyst to obtain the cycloolefin copolymer hydrogenate.

[0039] The amount of hydrogenation catalyst added can be adjusted according to actual conditions and has no obvious correlation with the invention of the present invention, so it is not limited.

[0040] The hydrogenation catalyst is any catalyst known to those skilled in the art that can be used as a hydrogenation catalyst for cycloolefin copolymers, and is not particularly limited. In the present invention, it includes Raney nickel, nickel diatomaceous earth, nickel acetate, palladium acetate, PdCl 2 、RhCl(PPh) 3 and palladium on carbon.

[0041] The hydrogenation reaction is preferably carried out in an inactive organic solvent; the inactive 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 inactive organic solvent in the hydrogenation reaction to the cycloolefin copolymer is (20-50) mL:1 g.

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

[0043] In the hydrogenation reaction, the suitable condition range varies depending on the hydrogenation catalyst system used, and the reaction temperature is preferably -20°C to 250°C, more preferably -10°C to 220°C, and even more preferably 0°C to 200°C. When the hydrogenation temperature is too low, the reaction rate may become too slow, and when it is too high, side reactions may occur.

[0044] In the case of the hydrogenation reaction of the catalyst, the hydrogen pressure is generally 0.01-20MPa, preferably 0.05-15MPa, and more preferably 0.1-10MPa. When the hydrogen pressure is too low, the hydrogenation rate may become too slow, and when it is too high, the restriction on the device is generated in terms of the need for a high pressure-resistant reaction device. The reaction time is not particularly limited as long as the desired hydrogenation rate can be achieved, and is generally 0.1-10 hours. After the hydrogenation reaction, the cycloolefin copolymer hydrogenation product is recovered according to a conventional method. When the cycloolefin copolymer hydrogenation product is recovered, the catalyst residue can be removed by filtering and the like to obtain a hydrogenation reaction solution.

[0045] The hydrogenation reaction solution was poured into a large amount of methanol and stirred continuously to completely precipitate the cycloolefin copolymer hydrogenate, which was filtered out and dried at 40° C. for 24 hours to obtain the cycloolefin copolymer hydrogenate.

[0046] Methanol is a poor solvent for cycloolefin copolymer hydrogenation. The solubility of cycloolefin copolymer hydrogenation in methanol decreases and precipitates. Preferably, the ratio of the mass of cycloolefin copolymer in the raw material to the mass of methanol used is 1:(2-5).

[0047] The hydrogenation rate (ratio of hydrogenated main chain double bonds) of the hydrogenation reaction of the cycloolefin 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 finally obtained cycloolefin copolymer hydrogenate.

[0048] A fifth aspect of the present invention provides a molding material, which includes the cycloolefin copolymer hydrogenated product.

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

[0050] In summary, the present invention provides a transition metal carbene catalyst and a preparation method thereof. The transition metal carbene catalyst is used for the preparation of a cycloolefin copolymer, which has the advantages of mild conditions and low cost. The prepared catalyst has good comprehensive performance and good selectivity for polymerization monomers. The cycloolefin polymerization process using the catalyst has good controllability of the product structure. The prepared cycloolefin copolymer has high tensile strength and low tensile strength as well as high heat resistance, so that the polymer material has better processability and is more suitable for processes such as molding, cutting, and heat sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is the hydrogen nuclear magnetic resonance spectrum of the transition metal carbene catalyst prepared in Example 1;

[0052] Figure 2 is the hydrogen nuclear magnetic resonance spectrum of the transition metal carbene catalyst prepared in Example 2;

[0053] Figure 3 is the hydrogen nuclear magnetic resonance spectrum of the transition metal carbene catalyst prepared in Example 3;

[0054] Figure 4 is the hydrogen nuclear magnetic resonance spectrum of the transition metal carbene catalyst prepared in Example 4;

[0055] Figure 5 is the hydrogen nuclear magnetic resonance spectrum of the transition metal carbene catalyst prepared in Example 5;

[0056] Figure 6 This is the hydrogen nuclear magnetic resonance spectrum of the transition metal carbene catalyst prepared in Example 6. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is further described below in conjunction with 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 protection scope of the present invention.

[0058] The reagents and substances used in the following examples, unless otherwise specified, are generally commercially available products.

[0059] The following method for detecting the weight average molecular weight of the cycloolefin polymer involved: using a high temperature gel permeation chromatograph (model: Agilent PL gel MIXED-BLS, manufacturer: Agilent, USA), the mobile phase is tetrahydrofuran, the column temperature is 40°C, the flow rate is 1 mL / min, the injection volume is 200 μL, and the standard is narrow distribution polystyrene.

[0060] The hydrogenation rate of the cycloolefin polymer described below was measured by FTIR infrared spectroscopy.

[0061] The following test method for the permeability of cycloolefin copolymer hydride refers to GB / T 7962.12-2010.

[0062] The detection method of the refractive index of the cycloolefin copolymer hydride mentioned below refers to 20232037-T-607.

[0063] The following methods for testing the tensile strength and tensile strength of cycloolefin copolymers refer to GB 13022-91.

[0064] The following glass transition temperature Tg test method involves: using a DSC differential scanning calorimeter (model: DSC200F3, manufacturer: NETZSCH, Germany), weighing a sample of 10 mg, and testing a temperature range of 30°C to 300°C.

[0065] The number average molecular weight Mn, weight average molecular weight Mw and molecular weight distribution PDI of the cycloolefin copolymers involved below and the molecular weight distribution PDI test method: use a high temperature gel permeation chromatograph (model: Agilent PL gelMIXED-BLS, manufacturer: Agilent Corporation, USA), the mobile phase is 1,2,4-trichlorobenzene, the column temperature is 150°C, the flow rate is 1mL / min, the injection volume is 200μL, and the standard is narrow distribution polystyrene.

[0066] Example 1

[0067] 1.1 Preparation of transition metal carbene catalysts

[0068] The transition metal carbene catalyst was prepared by the following method.

[0069] (1) Add freshly purified phenyl isocyanate (1.71 g, 14.4 mmol) to WOCl 4 (4.91 g, 14.4 mmol) was suspended in toluene (40 mL). The mixture was heated to 110°C and refluxed at 110°C while stirring for 18 hours to obtain a dark green suspension.

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

[0071] (3) The crude product obtained in step 2) was dissolved in 30 ml of ether to obtain a green solution, and the green solution was filtered and placed 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 of ether and n-hexane in a volume ratio of 1:3, completely dissolve the green microcrystals obtained in step (3) with 30 ml of the mixed solvent at 40° C., cool to -5° C., recrystallize the obtained dark green prism crystals, collect the dark green prism crystals by filtration and place them in a vacuum drying oven at -0.01 MPa, 40° C. for 2 h, and obtain 5.46 g of crystals (1). 1 HNMR detection showed that the obtained crystal (1) was the compound represented by formula (1), with a substance mass of 11.1 mmol and a yield of 77%;

[0073]

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

[0075]

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

[0077] 1.2 Cycloolefin copolymerization

[0078] The polymerization reactor was first evacuated four times with high-purity nitrogen to exhaust the air in the reactor, and then 120g of anhydrous toluene, 16.0g (0.1mol) of tetracyclododecene TCD, 13.2g (0.1mol) of dicyclopentadiene DCPD, and 11.2mg (0.1mmol) of 1-octene were added under nitrogen protection and stirring was started; the catalyst A solution (the catalyst A was calculated according to the concentration of the catalyst A solution, and the catalyst A was 0.02mmol) in total) was placed in a transfer tank; the transfer tank was connected to the reactor through a feed pump; the catalyst was transferred to the reactor through a feed pump, and then the reactor was heated to 70°C for 3h, and the heating was stopped and cooled to 25°C. After the polymerization reaction was completed, 5mL of ethanol was used to terminate the reaction, and then 300mL of ethanol was used to wash, and the precipitated white powder solid was filtered at 20°C to obtain a cycloolefin copolymer, which was vacuum dried at 70°C for 8h. The obtained cycloolefin copolymer had a weight average molecular weight of 75621.

[0079] 1.3 Preparation of cycloolefin copolymers

[0080] Use a stirrer to add 15 g of the above-mentioned cycloolefin copolymer and 0.5 g of palladium carbon with a loading amount of 10 wt% into a glass reactor, and then add 500 mL of p-xylene. At room temperature, 0.5 mol of hydrogen is introduced into the reactor to make the hydrogen pressure 4 MPa, and the hydrogenation reaction is carried out at 125°C for 5 hours to obtain a hydrogenation reaction solution.

[0081] The hydrogenation reaction solution was poured into 45 g of methanol and stirred continuously to completely precipitate the cycloolefin copolymer hydrogenate, which was filtered out and dried at 40° C. for 24 h to obtain the cycloolefin copolymer hydrogenate.

[0082] The obtained cycloolefin copolymer hydrogenated product has a hydrogenation rate of more than 99%, a glass transition temperature Tg of 132° C., a number average molecular weight of 57038, and a weight average molecular weight of 129012.

[0083] Example 2

[0084] 2.1 Preparation of transition metal carbene catalysts

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

[0086]

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

[0088] 2.2 Cycloolefin copolymerization

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

[0090] 2.3 Preparation of cycloolefin copolymers

[0091] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydride, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in 2.2 of this Example. The hydrogenation rate of the obtained cycloolefin copolymer hydride was above 99%, the glass transition temperature Tg was 133°C, 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 in the same manner as described in 1.1 of Example 1, except that in step (5), imidazole was not added but 11.1 mmol of benzimidazole was added. 1 By HNMR detection, a 0.16 mmol / ml toluene solution of catalyst C was obtained with a yield of 91.2%. The structural formula of C is as follows.

[0095]

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

[0097] 3.2 Cycloolefin copolymerization

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

[0099] 3.3 Preparation of cycloolefin copolymers

[0100] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydride, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in 3.2 of this Example. The hydrogenation rate of the obtained cycloolefin copolymer hydride 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 in the same manner as described in 1.1 of Example 1, except that in step (5), imidazole was not added but 11.1 mmol of 1,2,4-triazole was added. 1 By HNMR detection, a 0.15 mmol / ml toluene solution of catalyst D was obtained with a yield of 94%. The structural formula of D is as follows.

[0104]

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

[0106] 4.2 Cycloolefin copolymerization

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

[0108] 4.3 Preparation of Cycloolefin Copolymer Hydrogenates

[0109] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydrogenates, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in 4.2 of this Example. The hydrogenation rate of the obtained cycloolefin tool hydrogenate 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 in the same manner as described in 1.1 of Example 1, except that in step (5), imidazole was not added but 11.1 mmol of 5-bromo-1,2,4-triazole was added. 1By HNMR detection, a toluene solution of catalyst E with a yield of 72% was obtained at 0.09 mmol / ml. The structural formula of E is as follows.

[0113]

[0114] Figure 5 The results of hydrogen nuclear magnetic resonance spectrum detection of the prepared catalyst (E) are shown, indicating that the transition metal carbene catalyst of the compound represented by formula (E) was successfully prepared by the above method.

[0115] 5.2 Cycloolefin Copolymerization

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

[0117] 5.3 Preparation of Cycloolefin Copolymer Hydrogenates

[0118] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydride, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in 5.2 of this Example. The hydrogenation rate of the obtained cycloolefin copolymer hydride 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 in the same manner as described in 1.1 of Example 1, except that in step (5), imidazole was not added but 11.1 mmol of benzotriazole was added. 1 By HNMR detection, a 0.10 mmol / ml toluene solution of catalyst F was obtained with a yield of 78%. The structural formula of F is as follows.

[0122]

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

[0124] 6.2 Cycloolefin Copolymerization

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

[0126] 6.3 Preparation of Cycloolefin Copolymer Hydrogenates

[0127] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydride, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in 6.2 of this Example. The hydrogenation rate of the obtained cycloolefin copolymer hydride 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 Preparation of Catalyst

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

[0131] 7.2 Cycloolefin Copolymerization

[0132] The cycloolefin copolymerization reaction was carried out in the same manner as in Example 1, except that the Grubbs I generation catalyst solution in this comparative example was used instead of the catalyst A solution in Example 1 to obtain a cycloolefin copolymer having a weight average molecular weight of 88629.

[0133] 7.3 Preparation of Cycloolefin Copolymer Hydrogenates

[0134] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydride, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in this comparative example. The hydrogenation rate of the obtained cycloolefin copolymer hydride 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 Preparation of Catalyst

[0137] Commercially available Grubbs II generation catalyst (2 mmol) was dissolved in 5 ml of toluene solution to obtain a Grubbs II generation catalyst solution.

[0138] 8.2 Cycloolefin Copolymerization

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

[0140] 8.3 Preparation of Cycloolefin Copolymer Hydrogenates

[0141] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydrogenates, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in this comparative example. The hydrogenation rate of the obtained cycloolefin tool hydrogenate 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 Preparation of Catalyst

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

[0145] 9.2 Cycloolefin Copolymerization

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

[0147] 9.3 Preparation of Cycloolefin Copolymer Hydrogenates

[0148] The same method as described in 1.3 of Example 1 was used for hydrogenation to prepare cycloolefin copolymer hydride, except that the cycloolefin copolymer in the raw material was the cycloolefin copolymer prepared in this comparative example. The hydrogenation rate of the obtained cycloolefin copolymer hydride 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 cycloolefin copolymer hydrogenated products obtained in Examples 1-6 and Comparative Examples 1-3 were tested. The test results are shown in Table 1.

[0150] Table 1 Performance test results of cycloolefin copolymer hydrogenated products

[0151]

[0152] As can be seen from Table 1, the molecular weight of the cycloolefin copolymer prepared by the catalyst of the present invention is significantly improved compared with the comparative example using other catalysts, and the glass transition temperature and tensile strength are significantly improved, and the tensile strength is reduced, so that the polymer material has better processability and is more suitable for processes such as molding, cutting, and heat sealing. The degree of branching is significantly higher than that of comparative example 2, indicating that the catalyst of the present invention has good polymerization monomer selectivity and controllability of product structure.

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

Claims

1. A transition metal carbene catalyst, characterized in that The general formula is as follows: Wherein X is one of Cl and Br; L is one of imidazolyl, 2-bromoimidazolyl, benzimidazolyl, 1,2,4-triazolyl, 5-bromo-1,2,4-triazolyl, and benzotriazolyl; and R1 and R2 are each one of hydrogen, methyl, ethyl, tert-butyl, isobutyl, CF3, phenyl, benzyl, isopropyl, and n-propyl.

2. The transition metal carbene catalyst according to claim 1, characterized in that The transition metal carbene catalyst includes compounds represented by the following formula (A) to formula (F):

3. 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, mix, heat to 100-150°C, reflux and stir for 12-36 hours to obtain a dark green suspension; 2) centrifuging the suspension obtained in step 1), and filtering to collect a crude product in the form of dark green microcrystals; 3) dissolving the crude product obtained in step 2) in ether to obtain a green solution, filtering the green solution and vacuum drying to obtain green microcrystals; 4) The green microcrystals obtained in step 3) are completely dissolved in a mixed solvent at 40° C., cooled to −5° C. for recrystallization to obtain dark green prism crystals, and the dark green prism crystals are collected by filtration and vacuum dried to obtain crystals (1), whose chemical structure is shown in formula (1): 5) dissolving the crystals (1) obtained in step 4) in a solvent, wherein the solvent is pentane or toluene, adding triisobutylaluminum and an azole compound in sequence, and stirring at 30-80° C. for 20-60 min to obtain a solution of the target catalyst.

4. The preparation method according to claim 3, characterized in that: 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 the compounds shown in formula (A) to formula (F) respectively.

5. The preparation method according to claim 3, 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 centrifugal speed in step 2) is 2000-6000 r / min, and the time is 20-60 min; In step 3), the ratio of ether to crude product is (1-150) mL:1 g; The vacuum drying in step 3) and step 4) is carried out under a pressure of -0.1 to -0.08 MPa, at a temperature of 20 to 80°C, and for a time of 2 to 6 hours; The mixed solvent in step 4) is a mixed solvent 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 the crystal (1) to triisobutylaluminum is (0.8-1.2):1, the molar ratio of the crystal (1) to the azole compound is (0.8-1.2):1, and the molar volume ratio between the crystal (1) and the solvent is 1 mmol:(3-10) mL.

6. A method for copolymerizing cycloolefins using the transition metal carbene catalyst according to claim 1, characterized in that: The cycloolefin monomers are subjected to a ring-opening metathesis polymerization reaction in the presence of the transition metal carbene catalyst to obtain a cycloolefin copolymer; the molar ratio of the transition metal carbene catalyst to all cycloolefin monomers is 1:(1000-10000).

7. The method for cycloolefin copolymerization according to claim 6, characterized in that: The cycloolefin monomer is any substituted or unsubstituted, monounsaturated, diunsaturated or polyunsaturated C5 to C24 compound containing or not containing heteroatoms. The cycloolefin monomer is a monocyclic, bicyclic or polycyclic cycloolefin compound.

8. The method for cycloolefin copolymerization according to claim 6, characterized in that: The cycloolefin monomers include one or more of dicyclopentadiene, norbornene, tetracyclododecene, methyltetrahydrofluorene and higher oligomers of cyclopentadiene; the higher oligomers of cyclopentadiene include one or more of cyclopentadiene tetramer and cyclopentadiene pentamer; the ring-opening metathesis polymerization reaction is carried out in a solvent, the mass of the solvent is 60%-95% of the total mass of the solvent and the cycloolefin monomers; the temperature of the ring-opening metathesis polymerization reaction is 50°C-180°C; the time of the ring-opening metathesis polymerization reaction is 0.1-10h; the weight average molecular weight of the finally obtained cycloolefin copolymer is 20000-200000.

9. A cycloolefin copolymer hydrogenate obtained by hydrogenating the cycloolefin copolymer according to any one of claims 6 to 8, characterized in that: The cycloolefin copolymer hydrogenated product has a weight average molecular weight of 10,000-150,000, a number average molecular weight of 5,000-100,000, a glass transition temperature of 110-230° C., and a hydrogenation rate of 90-100%.

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

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