Composite catalyst and preparation method of cycloolefin copolymer using same

Abstract

The invention provides a composite catalyst and a preparation method of a cycloolefin copolymer using the composite catalyst. The composite catalyst comprises a first metallocene catalyst, a second metallocene catalyst and an aluminum alkyl compound, the first metallocene catalyst has a structure as shown in a formula I, and the second metallocene catalyst has a structure as shown in a formula II. According to the invention, two metallocene catalysts are compounded to form a double-active center, and the double-active center and the alkyl aluminum compound act together, so that the composite catalyst can give full play to the high catalytic activity and excellent stability of the catalyst, and when the composite catalyst is used for catalyzing the copolymerization of cycloolefin, the molecular weight distribution of the prepared cycloolefin copolymer is proper, and the molecular weight distribution of the cycloolefin copolymer is uniform. The processing performance is excellent; moreover, the cycloolefin copolymer has excellent elongation at break and impact property while maintaining excellent strength and modulus.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst and polymer preparation, and particularly relates to a composite catalyst and a method for preparing a cycloolefin copolymer using the composite catalyst. Background Art

[0002] Cyclic Olefin Copolymer (COC) is a type of high value-added thermoplastic material formed by the addition copolymerization of cycloolefin monomers and chain olefins. It has high strength, high rigidity, excellent heat resistance, chemical corrosion resistance, excellent UV-Vis transparency and extremely low hygroscopicity. It has broad application prospects in optical lenses, medical packaging materials, display components, electronic and electrical components and other fields.

[0003] Early cycloolefin copolymerization reactions were carried out under the catalysis of Ziegler-Natta catalysts, but the polymerization activity was low, making it difficult to achieve large-scale preparation of COC. In recent years, metallocene catalysts have been a research hotspot in metal organic chemistry, catalysis, polymer chemistry, and materials science. The characteristics of metallocene catalysts are that the molecular weight distribution and chemical composition distribution of the polymers obtained by their catalysis are uniform, and the molecular structure and molecular weight of the polymers can be controlled by adjusting the catalyst structure. Through metallocene catalysis, the polymerization activity can be improved to obtain olefin copolymers with a high comonomer content, which is very important for the preparation of cycloolefin copolymers.

[0004] At present, the application of metallocene catalysts in the preparation of cycloolefin copolymers has made phased research progress. For example, CN101157742A discloses a catalytic system for preparing cycloolefin copolymers, wherein the main catalyst is The cocatalyst uses an alkyl aluminum compound, and the catalytic system can catalyze the copolymerization of ethylene and norbornene to obtain a cycloolefin copolymer with a relatively high molecular weight and excellent heat resistance. CN102702433A discloses a method for preparing an ethylene-norbornene copolymer, wherein the main catalyst used is a semi-metallocene catalyst, and the molecular structure of the catalyst contains P, O or S, which makes it have good activity. After the cocatalyst acts, it forms a salt ion active center, and then catalyzes the copolymerization of ethylene and norbornene to obtain a cycloolefin copolymer with a relatively high molecular weight. CN115677879A discloses a method for preparing a cycloolefin copolymer using a metallocene catalyst, and the main catalyst used is At least one of R5, R6, R7, and R8 is a silicon-containing substituent, and / or R a , R bCN116925275A discloses a system for preparing polar ethylene-cycloolefin copolymers, wherein the catalyst used comprises at least one metallocene compound, at least one alkylaluminoxane and at least one organoaluminum compound, and such catalyst can catalyze the copolymerization reaction of ethylene and 5-norbornene-2-ol to obtain ethylene-cycloolefin copolymers with polar groups.

[0005] However, the molecular weight distribution of the cycloolefin copolymer obtained by using the existing metallocene catalyst system is relatively narrow, resulting in poor processability of the copolymer. Moreover, the copolymerization activity of the existing metallocene catalyst is still low, resulting in high production cost of COC, which restricts its further market expansion. Therefore, it is an urgent problem to be solved in the art to develop a more economical and effective catalyst system to obtain COC with good processability and excellent mechanical properties. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a composite catalyst and a method for preparing a cycloolefin copolymer using the composite catalyst. Through the design and compounding of two metallocene catalysts and an alkyl aluminum compound, the composite catalyst has high catalytic activity and is used for catalytic preparation of cycloolefin copolymers. The cycloolefin copolymers that can be prepared have suitable molecular weight distribution, good processing performance and excellent mechanical properties.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a composite catalyst, comprising a first metallocene catalyst, a second metallocene catalyst and an alkyl aluminum compound; the first metallocene catalyst has a structure as shown in Formula I, and the second metallocene catalyst has a structure as shown in Formula II:

[0009]

[0010] Among them, R N Any one selected from C3-C10 straight or branched chain alkyl, C3-C20 cycloalkyl.

[0011] R1, R2, R3, and R4 are each independently selected from any one of a C1-C10 straight chain or branched alkyl group, a C6-C20 aryl group, and a C7-C20 aryl alkyl group.

[0012] R5 is selected from any one of hydrogen and C1-C10 straight or branched chain alkyl.

[0013] M1 and M2 are each independently selected from any one of Group IVB metals.

[0014] X1, X2, X3, and X4 are each independently selected from any one of halogen, C1-C10 straight or branched alkyl, C6-C20 aryl, C7-C20 arylalkyl, C1-C20 alkylamino, and C6-C30 arylamino.

[0015] In the present invention, the first metallocene catalyst of the structure shown in formula I is a CGC type metallocene compound, and the second metallocene catalyst of the structure shown in formula II is C s The symmetrical metallocene compound is compounded to form a dual active center, and acts together with the alkyl aluminum compound, so that the composite catalyst can give full play to the high catalytic activity and excellent stability of the catalyst. It is used to catalyze the copolymerization reaction of cycloolefins, so that the prepared cycloolefin copolymer has a higher molecular weight, a suitable molecular weight distribution, a lower processing temperature and excellent processing performance; moreover, the cycloolefin copolymer has a better balance of strength and toughness while maintaining high strength and high modulus, and obtains excellent elongation at break and impact performance.

[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0017] In the present invention, the halogen includes fluorine, chlorine, bromine and iodine.

[0018] In the present invention, the C3-C10 straight chain or branched alkyl group can be a straight chain or branched alkyl group of C3, C4, C5, C6, C7, C8, C9, or C10, illustratively including but not limited to: n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, 2-ethylhexyl, n-octyl, n-heptyl, n-nonyl, n-decyl, etc., preferably a C4-C10 straight chain or branched alkyl group.

[0019] In the present invention, the C1-C10 straight chain or branched alkyl group can be a straight chain or branched alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, illustratively including but not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, 2-ethylhexyl, n-octyl, n-heptyl, n-nonyl, n-decyl, etc.

[0020] In the present invention, the C3-C20 cycloalkyl group can be a cycloalkyl group of C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C20, including a monocyclic alkyl group, a polycyclic alkyl group and a bridged cycloalkyl group, preferably a C3-C12 cycloalkyl group, illustratively including but not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl and the like.

[0021] In the present invention, the C6-C20 aromatic groups can be aromatic groups of C6, C9, C10, C12, C14, C16, C18, C20, etc., including monocyclic aromatic groups and condensed-ring aromatic groups, illustratively including but not limited to: phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, indenyl, etc.

[0022] In the present invention, the C7-C20 aryl alkyl group can be an aryl alkyl group of C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, etc., and a specific example is a monovalent group formed by connecting the above aryl groups to a straight-chain or branched alkyl group, and a typical example is benzyl (phenylmethyl).

[0023] In the present invention, the C1-C20 alkylamino group can be an alkylamino group of C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, etc., which is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above-mentioned straight-chain or branched alkyl group.

[0024] In the present invention, the C6-C30 arylamino group can be an arylamino group of C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, which is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above aryl group.

[0025] Preferably, in Formula I, the R N Any one selected from C4-C6 straight or branched alkyl, C3-C12 cycloalkyl, more preferably any one selected from n-butyl, tert-butyl, isobutyl, cyclopentyl, cyclohexyl, adamantyl, further preferably tert-butyl, cyclohexyl or adamantyl.

[0026] Preferably, in Formula I, R1 and R2 are each independently selected from any one of C1-C6 straight chain or branched alkyl, C6-C12 aryl, and benzyl, more preferably any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, phenyl, biphenyl, naphthyl, and benzyl, and further preferably methyl, ethyl, phenyl or benzyl.

[0027] Preferably, in Formula I, X1 and X2 are each independently selected from any one of halogen, C1-C6 straight or branched alkyl, benzyl, C2-C10 alkylamino, and more preferably any one of chlorine, methyl, tert-butyl, benzyl, and dimethylamino.

[0028] Preferably, in Formula I, the M1 is selected from any one of titanium, zirconium and hafnium, and titanium is more preferably selected.

[0029] Preferably, R5 is selected from any one of hydrogen, C1-C6 straight chain or branched alkyl, more preferably any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, further preferably hydrogen, ethyl, isopropyl or tert-butyl.

[0030] Preferably, R3 and R4 are each independently selected from any one of C1-C6 straight chain or branched alkyl, C6-C12 aryl, and benzyl, more preferably any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, phenyl, biphenyl, naphthyl, and benzyl, and further preferably methyl, ethyl, phenyl or benzyl.

[0031] Preferably, X3 and X4 are each independently selected from any one of halogen, C1-C6 straight or branched alkyl, benzyl, and C2-C10 alkylamino, and more preferably any one of chlorine, methyl, tert-butyl, benzyl, and dimethylamino.

[0032] Preferably, the M2 is selected from any one of titanium, zirconium and hafnium, and zirconium is more preferred.

[0033] Preferably, the first metallocene catalyst comprises any one of the following compounds:

[0034]

[0035] In the present invention, the first metallocene catalyst can be purchased from the market, or can be prepared by referring to a synthesis method known in the art. For example, reference can be made to the prior art “Heteroatom-Substituted Con-strained Geometry Complexes. Dramatic Substituent Effect on Catalyst Efficiency and Polymer Molecular Weight”, Organometallics 2001, 20, 2663-2665.

[0036] And / or, preferably, the second metallocene catalyst comprises any one of the following compounds:

[0037]

[0038] In the present invention, the second metallocene catalyst can be purchased from the market, for example, from Jiangsu Sinoco Catalyst Co., Ltd.

[0039] Preferably, the molar ratio of the first metallocene catalyst to the second metallocene catalyst is 1:(0.1-10), for example, it can be 1:0.2, 1:0.4, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, etc., and more preferably 1:(0.5-6).

[0040] As a preferred technical solution of the present invention, the molar ratio of the first metallocene catalyst to the second metallocene catalyst is 1:(0.1-10), and by adjusting the CGC metallocene compound shown in formula I and the C s The ratio of the symmetrical metallocene compounds can be used to adjust the number and ratio of the two active centers to obtain polymerization products with different properties.

[0041] Preferably, the alkyl aluminum compound includes any one of trimethyl aluminum (TMA), triethyl aluminum (TEA), triisobutyl aluminum (TIBA), tri-n-hexylaluminum, or a combination of at least two thereof, and triisobutyl aluminum is more preferred.

[0042] Preferably, the total molar amount of the first metallocene catalyst and the second metallocene catalyst is n1, the molar amount of the alkyl aluminum compound is n2, and n1:n2 is 1:(40-1200), for example, it can be 1:50, 1:80, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:550, 1:600, 1:650, 1:700, 1:750, 1:800, 1:850, 1:900, 1:950, 1:1000 or 1:1100, etc., and 1:(50-1000) is further preferred.

[0043] Preferably, the composite catalyst also includes an organic boron compound.

[0044] Preferably, the organic boron compound includes any one of triphenylborane, tri(pentafluorophenyl)borane, triperfluorobiphenylborane, triphenylmethyltetrakis(pentafluorophenyl)borate, and N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, or a combination of at least two thereof.

[0045] Preferably, the total molar amount of the first metallocene catalyst and the second metallocene catalyst is n1, the molar amount of the organic boron compound is n3, and n1:n3 is 1:(0.8-15), for example, it can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13 or 1:14, etc., and 1:(1-10) is further preferred.

[0046] In a second aspect, the present invention provides a use of the composite catalyst as described in the first aspect in olefin polymerization.

[0047] Preferably, the olefin includes any one of ethylene, α-olefin, cycloolefin, or a combination of at least two thereof.

[0048] Preferably, the polymerization comprises homopolymerization or copolymerization.

[0049] Further preferably, the olefin polymerization is copolymerization of a cycloolefin and a second olefin monomer, and the second olefin monomer includes any one of ethylene and α-olefin or a combination of at least two of them.

[0050] In a third aspect, the present invention provides a method for preparing a cycloolefin copolymer, the method comprising: polymerizing a cycloolefin and a second olefin monomer in the presence of the composite catalyst as described in the first aspect to obtain the cycloolefin copolymer.

[0051] Preferably, the cyclic olefin includes any one of norbornene, vinyl norbornene, 5-ethylidene-2-norbornene (ethylidene norbornene), dicyclopentadiene, and tetracyclododecene, or a combination of at least two thereof.

[0052] Preferably, the second olefin monomer includes any one of ethylene and α-olefin or a combination of at least two of them, and ethylene is more preferred.

[0053] Preferably, the α-olefin includes C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C11, C12, C14, C15, C16, C18, etc.) α-olefins, illustratively including but not limited to: any one of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene, or a combination of at least two thereof.

[0054] Preferably, the molar ratio of the cycloolefin to the second olefin monomer is (1-40):1, for example, 2:1, 5:1, 8:1, 10:1, 12:1, 15:1, 18:1, 20:1, 22:1, 25:1, 28:1, 30:1, 32:1, 35:1, 38:1, etc., and more preferably (1.5-30):1.

[0055] Preferably, the polymerization reaction device comprises a single polymerization reactor device, and a continuous or intermittent polymerization method can be adopted.

[0056] Preferably, the polymerization reaction is carried out in the presence of a solvent, that is, the polymerization reaction adopts a solution polymerization method.

[0057] Preferably, the solvent includes any one of aliphatic hydrocarbon solvents, halogenated aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, aromatic hydrocarbon solvents, and halogenated aromatic hydrocarbon solvents, or a combination of at least two thereof.

[0058] Preferably, the aliphatic hydrocarbon solvent includes any one of n-hexane, n-heptane, and isoparaffins, or a combination of at least two of them.

[0059] Preferably, the alicyclic hydrocarbon solvent includes any one of cyclohexane, cyclooctane, and decalin, or a combination of at least two of them.

[0060] Preferably, the aromatic hydrocarbon solvent includes toluene and / or xylene.

[0061] Preferably, the polymerization reaction is carried out optionally in the presence of a chain transfer agent.

[0062] Preferably, the chain transfer agent comprises hydrogen.

[0063] As a preferred technical solution of the present invention, the preparation method comprises: adding a solvent, a cycloolefin, a second olefin monomer, and optionally a chain transfer agent into a reaction device, adding a first metallocene catalyst, a second metallocene catalyst and an alkyl aluminum compound, and finally adding an organic boron compound to carry out a solution polymerization reaction to obtain the cycloolefin copolymer.

[0064] Preferably, the polymerization reaction temperature is 90-170°C, for example, it can be 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C or 165°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the range, and 100-160°C is further preferred.

[0065] Preferably, the polymerization reaction pressure is 0.1-3.0 MPa, for example, it can be 0.2 MPa, 0.3 MPa, 0.5 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.8 MPa, 2.0 MPa, 2.2 MPa, 2.5 MPa or 2.8 MPa, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the range, and 0.2-2.0 MPa is further preferred.

[0066] Preferably, the polymerization reaction time is 1-30 min, for example, it can be 2 min, 5 min, 8 min, 10 min, 12 min, 15 min, 16 min, 18 min, 20 min, 22 min, 25 min or 28 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0067] Preferably, after the polymerization reaction is completed, a post-treatment step is further included, and the post-treatment includes precipitation, filtration, washing and drying.

[0068] As a preferred technical solution of the present invention, the composite catalyst is used for catalytic preparation of cycloolefin copolymers, and has good thermal stability and high catalytic activity, with an activity of ≥1.0×10 8 g / (mol Cat·h), preferably ≥1.4×10 8 g / (mol Cat·h), can reach 1.4×10 8 -3×10 8 g / (mol Cat·h). The cycloolefin copolymer prepared by its catalysis has a large molecular weight, suitable molecular weight distribution, low processing temperature and excellent processability; and the cycloolefin copolymer not only maintains excellent strength and modulus, but also has excellent elongation at break and impact performance, achieving an excellent balance between high strength and high toughness.

[0069] Preferably, the weight average molecular weight (M w )≥4×10 4 g / mol, for example, 4.5×10 4 g / mol, 5×10 4 g / mol, 5.5×10 4 g / mol, 6×10 4 g / mol, 6.5×10 4 g / mol, 6.8×10 4 g / mol, 7×10 4g / mol, 7.5×10 4 g / mol, 8×10 4 g / mol or 9×10 4 g / mol, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range. It is further preferred that ≥4.5×10 4 g / mol.

[0070] Preferably, the molecular weight distribution (PDI, M w / M n ) is 3-8, for example, it can be 3.5, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5 or 7.8, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the said range, and 4-7 is further preferred.

[0071] Preferably, the molar insertion rate of cycloolefin in the cycloolefin copolymer is ≥30%, for example, it can be 45%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78% or 80%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0072] Preferably, the glass transition temperature (T g )≥105°C, for example, it can be 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C or 170°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0073] Preferably, the processing temperature of the cycloolefin copolymer is ≤220°C, for example, it can be 205°C, 208°C, 210°C, 212°C, 215°C or 218°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0074] Preferably, the tensile strength of the cycloolefin copolymer is ≥48 MPa, for example, it may be 49 MPa, 50 MPa, 51 MPa, 52 MPa, 53 MPa, 54 MPa or 55 MPa, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0075] Preferably, the flexural modulus of the cycloolefin copolymer is ≥3350 MPa, for example, it may be 3400 MPa, 3420 MPa, 3450 MPa, 3480 MPa, 3500 MPa, 3520 MPa, 3550 MPa, 3580 MPa, 3600 MPa, 3620 MPa, 3650 MPa or 3700 MPa, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0076] Preferably, the elongation at break of the cycloolefin copolymer is ≥5%, for example, it may be 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5% or 14%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0077] Compared with the prior art, the present invention has the following beneficial effects:

[0078] In the composite catalyst provided by the present invention, the first metallocene catalyst of CGC type and C s The second metallocene catalyst with a symmetrical structure is compounded to form a double active center, and acts together with the alkyl aluminum compound, so that the composite catalyst can give full play to the high catalytic activity and excellent stability of the catalyst. It is used to catalyze the copolymerization reaction of cycloolefins, so that the prepared cycloolefin copolymer has a higher molecular weight, a suitable molecular weight distribution, a lower processing temperature and excellent processing performance; moreover, the cycloolefin copolymer obtains excellent elongation at break and impact performance while maintaining excellent strength and modulus, and has a more excellent balance of strength and toughness. DETAILED DESCRIPTION

[0079] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0080] In the specific implementation of the present invention, the raw materials used are all commercially available chemicals, or can be prepared by preparation methods known in the art, as follows:

[0081]

[0082] In a specific embodiment, the first metallocene catalyst Cat A1 is synthesized with reference to the aforementioned literature, and the specific method is as follows. The molecular structures of all products are characterized and confirmed by hydrogen nuclear magnetic spectrum.

[0083] (1) Synthesis of 1-(1H-indol-3-yl)pyrrolidine

[0084] 1-Indole ketone (0.189 mol) and 50 mL of pyrrolidine dried over 3A molecular sieves were added into a 500 mL three-necked flask, and 200 mL of dry benzene was added. The solution was heated to reflux and reacted for 30 h. After the reaction, the solvent was removed in vacuo, and the obtained product was distilled to obtain 1-(1H-indol-3-yl)pyrrolidine.

[0085] (2) Synthesis of 1-(1-pyrrolidinyl)-1H-indolyl lithium

[0086] In a drying oven, 1-(1H-indol-3-yl)pyrrolidine (18.9 mmol) was mixed with 100 mL of hexane, and 9.5 mL (18.9 mmol) of n-butyl lithium solution (2.0 M) was added dropwise thereto. After the addition was complete, the reaction solution was stirred overnight to ensure that the reaction was complete. After the reaction was completed, the precipitate was collected by filtration, washed with hexane, and dried under reduced pressure to obtain 1-(1-pyrrolidinyl)-1H-indolyl lithium.

[0087] (3) Synthesis of N-(1,1-dimethylethyl)-1,1-dimethyl-1-(3-(1-pyrrolidinyl)-1H-indol-1-yl)silanamine

[0088] 1-(1-pyrrolidinyl)-1H-indolyl lithium (17.25mmol) was added to 40mL tetrahydrofuran (THF) to prepare a solution, and the solution was added to a THF solution (100mL) of N-(tert-butyl)-N-(1-chloro-1,1-dimethylsilyl)amine (17.25mmol) within 30min. After the addition was completed, the mixture was reacted overnight under stirring conditions to ensure that the reaction was complete. After the reaction was completed, the solvent was removed under reduced pressure, extracted with hexane, and filtered to obtain a red liquid, which was N-(1,1-dimethylethyl)-1,1-dimethyl-1-(3-(1-pyrrolidinyl)-1H-indol-1-yl)silanamine.

[0089] (4) Synthesis of 1-((1,1-dimethylethyl)amino)dimethylsilyl)-3-(1-pyrrolidinyl)-1H-indolyl lithium salt

[0090] In a drying oven, N-(1,1-dimethylethyl)-1,1-dimethyl-1-(3-(1-pyrrolidinyl)-1H-indol-1-yl)silanamine (16.3mmol)) was mixed with 80mL of hexane to obtain a solution, 16.3mL (32.6mmol) of n-butyllithium solution (2.0M) was added dropwise to the solution, and stirred overnight after the addition was completed to ensure that the reaction was complete. After the reaction was completed, a yellow precipitate was obtained, which was collected and washed with hexane, and dried under reduced pressure to obtain 1-((1,1-dimethylethyl)amino)dimethylsilyl)-3-(1-pyrrolidinyl)-1H-indolyl lithium salt.

[0091] (5) Synthesis of the first metallocene catalyst Cat A1

[0092] TiCl3(THF)3 (16.32 mmol) was dispersed in 30 mL of tetrahydrofuran, 1-((1,1-dimethylethyl)amino)dimethylsilyl)-3-(1-pyrrolidinyl)-1H-indolyl lithium salt (16.32 mmol) was added thereto, and the reaction was stirred for 1 hour, and then PbCl2 (8.16 mmol) was added, and the reaction was continued to be stirred for 1 hour, and then the solvent was removed under reduced pressure, the product was extracted with toluene, filtered, and the toluene was removed under reduced pressure. The product was washed with hexane and dried under reduced pressure to obtain the target product Cat A1.

[0093] In the following specific embodiments of the present invention, the main testing methods for cycloolefin copolymers are as follows:

[0094] (1) Molecular weight (weight average molecular weight M w , number average molecular weight M n ), molecular weight distribution index (PDI, M w / M n ) was obtained by high temperature gel permeation chromatography (GPC) test, the instrument was Polymer Char GPC-IR, the chromatographic column was Agilent PL1110-6400, 1,2,4-trichlorobenzene was used as the eluent, the elution was carried out at 160°C with a flow rate of 1.00mL / min, and the instrument calibration standard was narrow distribution polystyrene.

[0095] (2) Molar insertion rate of cycloolefins: measured by carbon nuclear magnetic resonance spectroscopy 13 C NMR test was performed using a Bruker Ascend III 400 MHz instrument. 100 mg of sample was weighed into the NMR tube, 0.6 mL of deuterated o-dichlorobenzene was added, and the sample was fully dissolved in a heating mantle at 140 °C. The solution was tested after it became clear and transparent, and the test temperature was 120 °C.

[0096] (3) Glass transition temperature (T g): The temperature range of the scanning was 30-230°C, and the heating and cooling rates were both 15 K / min, T g The second heating stage shall prevail.

[0097] (4) Catalytic activity: Calculated by the formula: Catalytic activity = mass of cycloolefin copolymer / (total molar amount of two metallocene catalysts × polymerization time).

[0098] (5) Tensile strength and elongation at break: tested in accordance with GB / T 1040.1-2018.

[0099] (6) Flexural modulus: tested according to GB / T 9341-2008.

[0100] (7) Processing temperature: The injection molding temperature of the polymer sample using a Haake MiniJet II injection molding machine.

[0101] The composite catalyst of the present invention and its application in the catalytic preparation of cycloolefin copolymers will be described in detail below with multiple embodiments, but the composite catalyst of the present invention and its application in the catalytic preparation of cycloolefin copolymers are not limited to these embodiments.

[0102] Example 1

[0103] A composite catalyst comprises a first metallocene catalyst Cat A1, a second metallocene catalyst Cat B1, an alkyl aluminum compound TIBA and triphenylmethyltetrakis(pentafluorophenyl)borate (abbreviated as C1).

[0104] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this embodiment, specifically comprises:

[0105] In a 2L autoclave reactor, 0.5mol of refined norbornene, 1L of refined toluene and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 100°C and stirring at 500rpm, 3.3μmol of Cat A1, 1.7μmol of Cat B1, 250μmol of TIBA and 5μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.2MPa by adding ethylene in a supplementary metered manner.

[0106] After reacting for 1 min, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 13.4 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0107] Example 2

[0108] A composite catalyst comprises a first metallocene catalyst Cat A1, a second metallocene catalyst Cat B1, an alkyl aluminum compound TIBA and triphenylmethyltetrakis(pentafluorophenyl)borate.

[0109] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this embodiment, specifically comprises:

[0110] In a 2L autoclave reactor, 1.5 mol of refined norbornene, 1L of refined toluene and 0.016 g of hydrogen were added in sequence. The solution temperature was 160°C. Under stirring at 500 rpm, 0.8 μmol of Cat A1, 4.2 μmol of Cat B1, 5.0 mmol of TIBA and 50 μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene was added by supplementary metering to control the ethylene partial pressure to 2.0 MPa.

[0111] After reacting for 5 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 120.8 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0112] Example 3

[0113] A composite catalyst comprises a first metallocene catalyst Cat A1, a second metallocene catalyst Cat B1, an alkyl aluminum compound TIBA and triphenylmethyltetrakis(pentafluorophenyl)borate.

[0114] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this embodiment, specifically comprises:

[0115] In a 2L autoclave reactor, 2.8mol of refined norbornene, 1L of refined toluene and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 2.5μmol of Cat A1, 2.5μmol of Cat B1, 1.0mmol of TIBA and 40μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.8MPa by adding ethylene in a supplementary metered manner.

[0116] After reacting for 15 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 256.1 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0117] Example 4

[0118] A composite catalyst comprises a first metallocene catalyst Cat A1, a second metallocene catalyst Cat B1, an alkyl aluminum compound TIBA and triphenylmethyltetrakis(pentafluorophenyl)borate.

[0119] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this embodiment, specifically comprises:

[0120] In a 2L autoclave reactor, 2.8mol of refined norbornene, 1L of refined cyclohexane and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 2.5μmol of Cat A1, 2.5μmol of Cat B1, 1.0mmol of TIBA and 20μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.8MPa by adding ethylene in a supplementary metered manner.

[0121] After reacting for 15 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 221.7 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0122] Example 5

[0123] A composite catalyst comprises a first metallocene catalyst Cat A1, a second metallocene catalyst Cat B1, an alkyl aluminum compound TIBA and triphenylmethyltetrakis(pentafluorophenyl)borate (abbreviated as C1).

[0124] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this embodiment, specifically comprises:

[0125] In a 2L autoclave reactor, 3.5mol of refined norbornene, 1L of refined cyclohexane and 0.04g of hydrogen were added in sequence. Under the conditions of solution temperature of 120°C and stirring at 500rpm, 2μmol of Cat A1, 3μmol of Cat B1, 0.5mmol of TIBA and 15μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.8MPa by adding ethylene in a supplementary metered manner.

[0126] After reacting for 30 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 367.9 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0127] Example 6

[0128] A composite catalyst comprises a first metallocene catalyst Cat A1, a second metallocene catalyst Cat B1, an alkyl aluminum compound TIBA and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate (abbreviated as C2).

[0129] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this embodiment, specifically comprises:

[0130] In a 2L autoclave reactor, 3.2mol of refined norbornene, 1L of refined cyclohexane and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 1μmol of Cat A1, 4μmol of Cat B1, 2.0mmol of TIBA and 20μmol of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 1.2MPa by adding ethylene in a supplementary metered manner.

[0131] After reacting for 10 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 192.4 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0132] Comparative Example 1

[0133] A composite catalyst comprises a first metallocene catalyst Cat A1, an alkyl aluminum compound TIBA and triphenylmethyltetrakis(pentafluorophenyl)borate.

[0134] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this comparative example, specifically comprises:

[0135] In a 2L autoclave reactor, 2.8mol of refined norbornene, 1L of refined cyclohexane and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 3.0mmol of TIBA, 15μmol of Cat A1 and 60μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. Ethylene was added by supplementary metering during the polymerization process, and the ethylene partial pressure was 0.8MPa.

[0136] After reacting for 15 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 48.6 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0137] Comparative Example 2

[0138] A composite catalyst comprises a second metallocene catalyst Cat B1, an alkyl aluminum compound TIBA and triphenylmethyltetrakis(pentafluorophenyl)borate.

[0139] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this comparative example, specifically comprises:

[0140] In a 2L autoclave reactor, 2.8mol of refined norbornene, 1L of refined cyclohexane and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 3.0mmol of TIBA, 15μmol of Cat B1 and 60μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. Ethylene was added by supplementary metering during the polymerization process, and the ethylene partial pressure was 0.8MPa.

[0141] After reacting for 15 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 73.7 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0142] Comparative Example 3

[0143] A composite catalyst comprises a first metallocene catalyst Cat A1, a second metallocene catalyst Cat B1 and an alkoxy aluminum compound MAO.

[0144] A method for preparing a cycloolefin copolymer, using the composite catalyst provided in this comparative example, specifically comprises:

[0145] In a 2L autoclave reactor, 2.8 mol of refined norbornene, 1L of refined cyclohexane and 0.016 g of hydrogen were added in sequence. At a solution temperature of 130°C and stirring at 500 rpm, 2.5 μmol of Cat A1, 2.5 μmol of Cat B1 and 5000 μmol of MAO were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.8 MPa by adding ethylene in a supplementary metered manner.

[0146] After reacting for 5 minutes, the reaction was stopped, the reaction solution was poured into acid alcohol for precipitation and then filtered, the filter cake was washed with ethanol, and dried at 80° C. to constant weight to obtain 19.4 g of cycloolefin copolymer, the physical properties of which are shown in Tables 2 and 3.

[0147] The preparation process parameters of the composite catalyst components and cycloolefin copolymers of Examples 1-6 and Comparative Examples 1-3 are summarized in Table 1. In Table 1, the total molar amount of the first metallocene catalyst Cat A1 and the second metallocene catalyst Cat B1 is n1, the molar amount of the alkyl aluminum compound TIBA is n2, and the molar amount of the organic boron compound is n3.

[0148] Table 1

[0149]

[0150]

[0151] Table 2

[0152]

[0153] Table 3

[0154]

[0155]

[0156] Combining the data in Table 2 and Table 3, it can be seen that the present invention combines the CGC type first metallocene catalyst shown in Formula I with the C s The symmetrical second metallocene catalyst is compounded to form a double active center, and together with the alkyl aluminum compound, it forms the main catalyst of the composite catalyst, which can give full play to the high catalytic activity and excellent stability of the catalyst. Its catalytic activity is ≥1.47×10 8 g / (mol Cat·h), so that the prepared cycloolefin copolymer has a higher molecular weight and a wider molecular weight distribution. Its PDI (M w / M n ) is 4.9-6.2, so that the processing temperature of the copolymer is 210°C, which is more conducive to processing. At the same time, the tensile strength of the cycloolefin copolymer is 48-53MPa, the bending modulus is 3400-3620MPa, and the elongation at break is 7.5-13%. While maintaining high strength and high modulus, an excellent elongation at break is obtained, which better takes into account the balance effect of strength and toughness.

[0157] Comparative Examples 1-2 contain only one metallocene catalyst, and Comparative Example 3 does not contain an alkyl aluminum compound; since the catalytic activity of a single-component metallocene catalyst is insufficient, in order to obtain an appropriate amount of polymer for subsequent characterization tests, the amount of the metallocene catalyst used in Comparative Examples 1-2 is increased. Compared with the embodiments, Comparative Examples 1-3 not only have significantly insufficient activity of the catalytic system, but also have a narrow molecular weight distribution of the prepared cycloolefin copolymer, a high processing temperature, poor processing performance, low bending modulus and elongation at break of the cycloolefin copolymer, and poor toughness of the material.

[0158] The applicant declares that the present invention illustrates the composite catalyst of the present invention and the preparation method of the cycloolefin copolymer using the composite catalyst through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of each raw material of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A composite catalyst, characterized in that: The composite catalyst comprises a first metallocene catalyst, a second metallocene catalyst and an alkyl aluminum compound; The first metallocene catalyst has a structure as shown in Formula I, and the second metallocene catalyst has a structure as shown in Formula II: Among them, R N Any one selected from C3-C10 straight or branched alkyl, C3-C20 cycloalkyl; R1, R2, R3, and R4 are each independently selected from any one of a C1-C10 straight or branched alkyl group, a C6-C20 aryl group, and a C7-C20 arylalkyl group; R5 is selected from any one of hydrogen, C1-C10 straight chain or branched alkyl; M1 and M2 are each independently selected from any one of the Group IVB metals; X1, X2, X3, and X4 are each independently selected from any one of halogen, C1-C10 straight or branched alkyl, C6-C20 aryl, C7-C20 arylalkyl, C1-C20 alkylamino, and C6-C30 arylamino.

2. The composite catalyst according to claim 1, characterized in that The R N Any one selected from C4-C6 straight or branched alkyl, C3-C12 cycloalkyl, preferably tert-butyl, cyclohexyl or adamantyl; Preferably, R1 and R2 are each independently selected from any one of C1-C6 straight chain or branched alkyl, C6-C12 aryl, and benzyl, and more preferably methyl, ethyl, phenyl, or benzyl; Preferably, X1 and X2 are each independently selected from any one of halogen, C1-C6 straight or branched alkyl, benzyl, C2-C10 alkylamino, and more preferably any one of chlorine, methyl, tert-butyl, benzyl, and dimethylamino; Preferably, the M1 is selected from any one of titanium, zirconium and hafnium, and titanium is more preferred.

3. The composite catalyst according to claim 1, characterized in that R5 is selected from any one of hydrogen, C1-C6 straight chain or branched alkyl, preferably hydrogen, ethyl, isopropyl or tert-butyl; Preferably, R3 and R4 are each independently selected from any one of C1-C6 straight chain or branched alkyl, C6-C12 aryl, and benzyl, and more preferably methyl, ethyl, phenyl, or benzyl; Preferably, X3 and X4 are each independently selected from any one of halogen, C1-C6 straight or branched alkyl, benzyl, and C2-C10 alkylamino, and more preferably any one of chlorine, methyl, tert-butyl, benzyl, and dimethylamino; Preferably, the M2 is selected from any one of titanium, zirconium and hafnium, and zirconium is more preferred.

4. The composite catalyst according to claim 1, characterized in that The first metallocene catalyst comprises any one of the following compounds: And / or, the second metallocene catalyst comprises any one of the following compounds:

5. The composite catalyst according to claim 1, characterized in that The molar ratio of the first metallocene catalyst to the second metallocene catalyst is 1:(0.1-10), preferably 1:(0.5-6).

6. The composite catalyst according to claim 1, characterized in that The alkyl aluminum compound includes any one of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, or a combination of at least two thereof, preferably triisobutyl aluminum; Preferably, the total molar amount of the first metallocene catalyst and the second metallocene catalyst is n1, the molar amount of the alkyl aluminum compound is n2, and n1:n2 is 1:(40-1200), and more preferably 1:(50-1000).

7. The composite catalyst according to claim 1, characterized in that The composite catalyst also includes an organic boron compound; Preferably, the organic boron compound includes any one of triphenylborane, tri(pentafluorophenyl)borane, triperfluorobiphenylborane, triphenylmethyltetrakis(pentafluorophenyl)borate, and N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, or a combination of at least two thereof; Preferably, the total molar amount of the first metallocene catalyst and the second metallocene catalyst is n1, the molar amount of the organic boron compound is n3, and n1:n3 is 1:(0.8-15), and more preferably 1:(1-10).

8. Use of the composite catalyst according to any one of claims 1 to 7 in olefin polymerization; Preferably, the olefin includes any one of ethylene, α-olefin, cycloolefin, or a combination of at least two thereof.

9. A method for preparing a cycloolefin copolymer, characterized in that: The preparation method comprises: carrying out polymerization reaction between a cycloolefin and a second olefin monomer in the presence of the composite catalyst as claimed in any one of claims 1 to 7 to obtain the cycloolefin copolymer.

10. The preparation method according to claim 9, characterized in that: The cyclic olefin includes any one or a combination of at least two of norbornene, vinyl norbornene, 5-ethylidene-2-norbornene, dicyclopentadiene, and tetracyclododecene; Preferably, the second olefin monomer comprises any one of ethylene and α-olefin or a combination of at least two thereof; Preferably, the polymerization reaction is carried out in the presence of a solvent; Preferably, the polymerization reaction temperature is 90-170°C; Preferably, the polymerization reaction pressure is 0.1-3.0 MPa; Preferably, the polymerization reaction time is 1-30 min.

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