CN115677879B - Catalyst for preparing cycloolefin copolymer, preparation method of cycloolefin copolymer, cycloolefin copolymer and application of cycloolefin copolymer - Google Patents

Abstract

The present invention provides a catalyst for preparing a cycloolefin copolymer, comprising a main catalyst represented by formula (1-a): D is a bridging group, Q is a metal center; R ₅ , R ₆ , R ₇ , and R ₈ independently include hydrogen atoms, hydrocarbon groups, or silicon-containing substituents, and the silicon-containing substituents are connected to the carbon atoms at the corresponding substitution positions through silicon atoms; _Ra and R _b are carbon-containing groups, silicon-containing groups, germanium-containing groups, or tin-containing groups; at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing substituent, and/or at least one of _Ra and R _b is a silicon-containing group; R ₉ , R ₁₃ , R ₁₄ , and R ₁₈ independently include hydrogen atoms, hydrocarbon groups, or hydrocarbonoxy groups. The catalyst can be used to prepare a low molecular weight cycloolefin copolymer without additionally introducing a molecular weight regulator such as hydrogen or propylene, and the cycloolefin copolymer has a moderate glass transition temperature.

Description

Catalyst for preparing cycloolefin copolymer, method for preparing cycloolefin copolymer, cycloolefin copolymer and application thereof

Technical Field

The embodiments of the present application relate to the technical field of engineering plastic preparation, and in particular to a catalyst for preparing a cycloolefin copolymer, a method for preparing a cycloolefin copolymer, a cycloolefin copolymer and applications thereof.

Background technique

Cyclic olefin polymers are a type of thermoplastic engineering plastics with high added value. Due to their excellent optical transparency, heat resistance, chemical stability, melt fluidity, moisture barrier, dimensional stability and low dielectric constant, they have been widely used in various electronic products, car headlights, glasses, pharmaceutical and food packaging materials and other fields.

There are two main ways to synthesize cycloolefin polymers: one method is the chain addition copolymerization of ethylene or α-olefin (referring to a monoolefin with a double bond at the end of the molecular chain) and a norbornene-type cycloolefin monomer (as shown in chemical reaction formula (1), m and n represent the degree of polymerization), and the polymer prepared by this method is also called cycloolefin copolymer (Cyclic Olefin Copolymer, COC); the other method is the ring-opening metathesis polymerization (ROMP) of cycloolefin monomers such as norbornene and subsequent hydrogenation (as shown in chemical reaction formula (2), n represents the degree of polymerization), and the polymer obtained by this method is also called cycloolefin homopolymer (Cyclic Olefin Polymer, COP).

During the synthesis, processing and practical application of cycloolefin polymers, their molecular weight and glass transition temperature ( _Tg ) are two key performance indicators. Molecular weight significantly affects the mechanical properties and processing properties of cycloolefin polymers. When the molecular weight of cycloolefin polymers is high (for example, the weight average molecular weight is greater than 100,000), the melt flow rate (MFR) is very low and processing is difficult. When the _Tg of cycloolefin polymers is too high, it will cause the cycloolefin polymers to be difficult to process or difficult to injection mold; when _Tg is too low, it will limit the use environment and conditions of cycloolefin polymers. Therefore, for the practical application of COC, it is necessary to seek effective methods to prepare cycloolefin copolymers with both low molecular weight (weight average molecular weight less than or equal to 150,000) and moderate _Tg (110℃-180℃).

Summary of the invention

In view of this, an embodiment of the present application provides a catalyst for preparing a cycloolefin copolymer. The catalyst can be used to prepare a low molecular weight (weight average molecular weight less than or equal to 150,000) cycloolefin copolymer without introducing additional molecular weight regulators such as hydrogen or propylene, while ensuring that the cycloolefin copolymer has a moderate glass transition temperature (110°C-180°C).

In a first aspect, an embodiment of the present application provides a catalyst for preparing a cycloolefin copolymer, wherein the catalyst comprises a main catalyst having a structural formula as shown in formula (1-a):

In formula (1-a), D is a bridging group and Q is a metal center;

R ₅ , R ₆ , R ₇ , and R ₈ independently include a hydrogen atom, a hydrocarbon group, or a silicon-containing substituent, wherein the silicon-containing substituent is connected to the carbon atom at the corresponding substitution position through a silicon atom;

_Ra and _Rb are carbon-containing groups, silicon-containing groups, germanium-containing groups or tin-containing groups;

At least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing substituent, and/or at least one of _Ra and R _b is a silicon-containing group;

R ₉ , R ₁₃ , R ₁₄ and R ₁₈ independently include a hydrogen atom, a hydrocarbon group or a hydrocarbonoxy group.

The cycloolefin copolymer preparation catalyst provided by the present application embodiment, including the main catalyst shown in formula (1-a), the main catalyst is a transition metal catalyst of cyclopentadiene fluorene bridged, the cyclopentadienyl or fluorenyl of the main catalyst is introduced with a silicon-containing heteroatom group, in the process of copolymerization of ethylene, alpha-olefin and cycloolefin monomer, the metal center of the main catalyst and the silicon atom introduced on the cyclopentadienyl or fluorenyl produce synergistic effect, the chain transfer of the polymerization process can be promoted, the insertion rate of cycloolefin monomer is improved, so that the cycloolefin copolymer with low molecular weight (weight average molecular weight is less than or equal to 150,000) and moderate glass transition temperature can be obtained by chain addition copolymerization mode without additionally introducing molecular weight regulators such as hydrogen or propylene. The obtained cycloolefin copolymer has a low melt flow index due to having a relatively low molecular weight, and has good processing performance, and due to having a moderate glass transition temperature, it is possible to avoid the problem that the glass transition temperature is too high and is difficult to process and is difficult to injection molding, and the moderate glass transition temperature can have better heat resistance, so that the cycloolefin copolymer is suitable for various application scenarios.

In the embodiment of the present application, the metal center Q is represented by ^-M1 ( _R1R2 )-, ^M1 represents scandium, titanium, vanadium, zirconium, hafnium, niobium or tantalum, and _R1 and _R2 independently include hydrogen atoms, halogen atoms, _alkyl groups, alkoxy groups, alkenyl groups, aryl groups, aryloxy groups, aralkyl groups, alkaryl groups or aralkenyl groups.

In the embodiment of the present application, the bridging group D is represented by -X(R ₃ R ₄ )-, wherein X represents carbon or silicon, and R ₃ and R ₄ independently include a hydrogen atom or a hydrocarbon group.

In the embodiment of the present application, the _Ra is represented by ^-M2 ( _R10R11R12 ), the _Rb is represented by ^-M3 ( _R15R16R17 ), ^M2 and ^M3 independently represent _carbon , silicon, germanium or tin, and _R10 , _{R11 , R12 , R15} , _R16 and _R17 independently include alkyl, alkoxy, alkenyl, aryl _, aryloxy, aralkyl, alkaryl or aralkenyl.

In one embodiment of the present application, the specific structural formula of the main catalyst shown in formula (1-a) is shown in formula (1-b):

In some embodiments of the present application, at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing substituent, _Ra and R _b are not silicon-containing groups, _Ra and R _b are carbon-containing groups, germanium-containing groups, or tin-containing groups, that is, M ² and M ³ independently include carbon, germanium, or tin. In other embodiments of the present application, at least one of _Ra and R _b is a silicon-containing group, that is, one or both of M ² and M ³ are silicon, R ₅ , R ₆ , R ₇ , and R ₈ are not silicon-containing substituents, and R ₅ , R ₆ , R ₇ , and R ₈ are hydrogen atoms or hydrocarbon groups. In other embodiments of the present application, at least one of _Ra and R _b is a silicon-containing group, that is, one or both of M ² and M ³ are silicon, and at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing substituent.

In some embodiments of the present application, at least one of R ₆ and R ₇ is a silicon-containing substituent, and/or at least one of _Ra and R _b is a silicon-containing group. The silicon-containing substituent is located at the 3rd and 4th positions of cyclopentadiene, which are farther from the metal center M ¹ than the 2nd and 5th positions. The introduction of silicon-containing substituents at the 3rd and 4th positions of cyclopentadiene can not only form weak coordination with the metal center M ¹ to promote chain transfer and reduce the molecular weight of the polymer, but also avoid affecting the polymerization activity of the catalyst due to the strong coordination effect.

In the embodiment of the present application, the carbon number of the hydrocarbon group and the silicon-containing substituent in R ₅ , R ₆ , R ₇ and R ₈ is less than or equal to 6.

In the embodiment of the present application, the carbon number of R ₁₀ , R ₁₁ , R ₁₂ , R ₁₅ , R ₁₆ , and R ₁₇ is less than or equal to 10.

In the embodiment of the present application, the catalyst for preparing the cycloolefin copolymer further comprises a co-catalyst, and the co-catalyst includes but is not limited to one or more of methylaluminoxane, modified methylaluminoxane, and an organic boron compound. In the embodiment of the present application, the organic boron compound includes one or more of tris(pentafluorophenyl)boron, triphenylcarbonium tetrakis(pentafluorophenyl)borate, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate. Using methylaluminoxane, modified methylaluminoxane, and an organic boron compound as a co-catalyst is conducive to ensuring the copolymerization activity of the cycloolefin copolymer preparation.

In an embodiment of the present application, the molar ratio of the main catalyst represented by the formula (1-a) to the co-catalyst is 1:(10-10000).

In the embodiment of the present application, the catalytic reaction activity of the catalyst is higher than 10 ⁶ g·mol ^-1 ·h ^-1 . The main catalyst represented by formula (1-a) of the present application has a high catalytic reaction activity for preparing cycloolefin copolymers.

In the embodiment of the present application, the main catalyst and the co-catalyst may be supported on a carrier, such as silicon oxide, aluminum oxide, titanium oxide, etc.

In a second aspect, an embodiment of the present application provides a method for preparing a cycloolefin copolymer, comprising:

In the presence of the catalyst for preparing the cycloolefin copolymer described in the first aspect, the cycloolefin monomer is copolymerized with ethylene or α-olefin to obtain the cycloolefin copolymer.

In the embodiment of the present application, the copolymerization reaction system includes an inert solvent, and the inert solvent includes one or more of straight-chain alkane compounds, cyclic hydrocarbon compounds and aromatic hydrocarbon compounds.

In the embodiment of the present application, the amount of the main catalyst represented by formula (1-a) in the copolymerization reaction system is 0.001 mmol/L-10 mmol/L.

In the embodiment of the present application, the amount of the cycloolefin monomer in the copolymerization reaction system is 0.01 mol/L-10 mol/L.

In the embodiment of the present application, the molar ratio of the cycloolefin monomer to the main catalyst in the copolymerization reaction system is 500-500000. The main catalyst of the present application can adapt to a wide range of cycloolefin monomer usage and has high catalytic activity.

In the embodiment of the present application, the copolymerization reaction temperature is 50°C-120°C; the copolymerization reaction time is 2min-10min. The preparation method of the cycloolefin copolymer of the present application has low copolymerization reaction temperature requirement, short reaction time and high efficiency.

In the embodiment of the present application, the structural formula of the cycloolefin monomer is as shown in formula (2):

In formula (2), R ₁₉ is a hydrocarbon group or a hydrocarbon silicon group; R ₂₀ and R ₂₁ are independently hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, hydroxyl groups, ester groups, carbonate groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups;

R ₂₂ and R ₂₃ are independently selected from hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, hydroxyl groups, ester groups, carbonate groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups, or R ₂₂ and R ₂₃ are connected to form a group having a cyclic structure;

z is a positive integer.

In the embodiment of the present application, the α-olefin can be propylene, 1-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene or 2-ethyl-1-butene.

In the embodiment of the present application, the copolymerization reaction system does not contain a molecular weight regulator. The molecular weight regulator is, for example, hydrogen, propylene, etc. The addition of a molecular weight regulator not only makes the preparation process more complicated, but also affects the polymerization reaction itself. For example, the introduction of hydrogen will reduce the activity of the catalyst system, and the introduction of propylene will introduce propylene molecules into the polymer, affecting the structure of the cycloolefin copolymer.

The preparation method of the cycloolefin copolymer provided in the embodiment of the present application adopts the catalyst provided in the first aspect of the embodiment of the present application, and does not need to introduce additional molecular weight regulators such as hydrogen or propylene, so as to prepare a cycloolefin copolymer with a low molecular weight and a moderate glass transition temperature, so as to meet the processing performance, heat resistance and other requirements of various optical products such as optical lenses, display materials and packaging materials. This preparation method not only greatly simplifies the preparation method of the cycloolefin copolymer material, but also significantly improves the polymerization activity and energy economic benefits, and opens up a new path for the large-scale production of cycloolefin copolymer materials.

In a third aspect, an embodiment of the present application provides a cycloolefin copolymer, which is prepared according to the preparation method described in the second aspect, and the structural formula of the cycloolefin copolymer is shown in formula (3):

In formula (3), R ₁₉ is a hydrocarbon group or a hydrocarbon silicon group; R ₂₀ and R ₂₁ are independently hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, hydroxyl groups, ester groups, carbonate groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups;

R ₂₂ , R ₂₃ , R ₂₄ , and R ₂₅ are independently selected from hydrogen, halogen, alkyl, alkoxy, aryl, aryloxy, hydroxy, ester, carbonate, cyano, amino, thiol, and atoms or atomic groups that can replace the above groups, or R ₂₂ and R ₂₃ are connected to form a group having a cyclic structure, and R ₂₄ and R ₂₅ are connected to form a group having a cyclic structure;

x and y represent the degree of polymerization, both x and y are positive numbers, 1＜x∶y＜3, and z is a positive integer.

In the embodiment of the present application, the weight average molecular weight of the cycloolefin copolymer is in the range of 5000 to 150000 (g/mol); and the molecular weight distribution index is in the range of 1.5 to 3.0.

In the embodiment of the present application, the insertion rate of the cycloolefin monomer of the cycloolefin copolymer is in the range of 20%-60%; and the glass transition temperature of the cycloolefin copolymer is in the range of 110°C to 180°C.

In the embodiment of the present application, the visible light transmittance of the molded body of the cycloolefin copolymer is greater than 90%.

In a fourth aspect, the embodiments of the present application provide a composition, including the cycloolefin copolymer described in the third aspect of the embodiments of the present application, or including the cycloolefin copolymer prepared by the preparation method described in the second aspect.

In an embodiment of the present application, the composition further comprises additives, and the additives include one or more of fillers, dyes, antioxidants, light stabilizers, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, and release agents.

In a fifth aspect, an embodiment of the present application provides an optical product, wherein the optical product comprises the cycloolefin copolymer described in the third aspect of the embodiment of the present application, or comprises the cycloolefin copolymer prepared by the preparation method described in the second aspect.

In the embodiment of the present application, the optical product includes an optical lens, an optical film, an optical disc, a light guide plate or a display panel. The optical lens includes a glasses lens, a camera lens, a sensor lens, a lighting lens, and an imaging lens.

The embodiment of the present application also provides a device, including the optical product described in the fifth aspect of the embodiment of the present application.

An embodiment of the present application also provides an electronic device, including an electronic device body and a camera module mounted on the electronic device body, the camera module including a lens, and the lens is prepared using the cycloolefin copolymer described in the third aspect or the composition described in the fourth aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a device 100 provided in an embodiment of the present application;

FIG2 is a nuclear magnetic resonance hydrogen spectrum ( ¹ H Nuclear Magnetic Resonance Spectroscopy, ¹ H NMR) of catalyst A in Example 1 of the present application;

FIG3 is a carbon nuclear magnetic resonance spectrum ( ¹³ C Nuclear Magnetic Resonance Spectroscopy, ¹³ C NMR) of catalyst A in Example 1 of the present application;

FIG4 is a hydrogen nuclear magnetic resonance spectrum of the cycloolefin monomer in Example 1 of the present application;

FIG5 is a carbon NMR spectrum of the cycloolefin monomer of Example 1 of the present application;

FIG6 is a hydrogen nuclear magnetic resonance spectrum of the cycloolefin copolymer in Example 1 of the present application;

FIG7 is a carbon NMR spectrum of the cycloolefin copolymer of Example 1 of the present application;

FIG8 is a DSC (Differential Scanning Calorimetry) curve of the cycloolefin copolymer of Example 1 of the present application;

FIG9 is a visible light transmittance test curve of the cyclic olefin copolymer of Example 1 of the present application;

FIG10 is a DSC curve of the cyclic olefin copolymer of Example 2 of the present application;

FIG11 is a DSC curve of the cyclic olefin copolymer of Example 3 of the present application;

FIG12 is a DSC curve of the cyclic olefin copolymer of Example 4 of the present application;

FIG. 13 is a DSC curve of the cyclic olefin copolymer of Example 5 of the present application.

Detailed ways

The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

The molecular weight and glass transition temperature of cycloolefin copolymer COC are two key performance indicators. The molecular weight affects the processing performance, and the glass transition temperature affects the processing performance and the use environment and conditions. At present, the preparation of cycloolefin copolymers usually uses metallocene catalysts. However, the molecular weight of cycloolefin copolymers directly prepared using existing metallocene catalysts is usually 200,000 or more, the melt flow index is low, the processing is difficult, and the commercial value is low. In order to obtain cycloolefin copolymers with low molecular weight, the existing traditional method is to introduce additional molecular weight regulators such as hydrogen and propylene during the preparation process, and the additional introduction of molecular weight regulators may reduce the catalytic activity of the catalyst, and may also introduce molecular weight regulators into the cycloolefin copolymers, affecting the structure of the cycloolefin copolymers, and the additional introduction of molecular weight regulators will also make the preparation process complicated. In addition, in the process of copolymerizing ethylene or α-olefins with cycloolefin monomers, the glass transition temperature of the cycloolefin copolymer COC can be adjusted by adjusting the insertion rate of the cycloolefin monomers in the copolymer.

In order to obtain a cycloolefin copolymer COC having a relatively low molecular weight and a suitable glass transition temperature, the present invention provides a catalyst for preparing a cycloolefin copolymer. The catalyst can be used to directly prepare a cycloolefin copolymer having a low molecular weight and a moderate glass transition temperature without additionally introducing a molecular weight regulator such as hydrogen or propylene. The catalyst includes a main catalyst having a structural formula as shown in formula (1-a):

In formula (1-a), D is a bridging group and Q is a metal center;

R ₅ , R ₆ , R ₇ , and R ₈ independently include a hydrogen atom, a hydrocarbon group, or a silicon-containing substituent, wherein the silicon-containing substituent is connected to the carbon atom at the corresponding substitution position through a silicon atom;

_Ra and _Rb are carbon-containing groups, silicon-containing groups, germanium-containing groups or tin-containing groups;

At least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing substituent, and/or at least one of _Ra and R _b is a silicon-containing group;

R ₉ , R ₁₃ , R ₁₄ and R ₁₈ independently include a hydrogen atom, a hydrocarbon group or a hydrocarbonoxy group.

The catalyst for preparing cycloolefin copolymers provided in the embodiments of the present application, the main catalyst shown in formula (1-a) is a cyclopentadienylfluorene-bridged transition metal catalyst, a silicon-containing heteroatom group is introduced at the 2-position or 7-position of the cyclopentadienyl or fluorenyl group in the cyclopentadienylfluorene-bridged transition metal catalyst, and in the process of copolymerization of ethylene or α-olefin and cycloolefin monomer, the metal center ^M1 of the main catalyst and the silicon atom introduced on the cyclopentadienyl or fluorenyl group produce a synergistic effect, which can promote the chain transfer of the polymerization process and improve the insertion rate of the cycloolefin monomer, so that a cycloolefin copolymer with a low molecular weight and a moderate glass transition temperature can be obtained without the additional introduction of molecular weight regulators such as hydrogen or propylene. Specifically, the silicon atom introduced on the cyclopentadienyl or fluorenyl group produces a weak coordination effect with the empty orbital of the metal center ^M1 , and competes with the coordination between the olefin-metal center ^M1 , thereby promoting chain transfer, reducing the polymer molecular weight so that the cycloolefin copolymer has a low molecular weight; At the same time, through this competitive effect, the difficulty of ethylene or alpha-olefin coordination with the metal center ^M1 is increased, and the insertion rate of the cycloolefin monomer is improved, so as to play the role of regulating the glass transition temperature, so that the cycloolefin copolymer has a moderate glass transition temperature, and is suitable for various application scenarios. The cycloolefin copolymer preparation catalyst of the present application embodiment can make the preparation of low-molecular-weight cycloolefin copolymers more simple and efficient, greatly simplify the polymerization process and polymerization equipment, and is conducive to the large-scale production of low-molecular-weight cycloolefin copolymers. At the same time, other properties of the cycloolefin polymer such as optical properties, thermal properties and mechanical properties can reach the level of low-molecular-weight COC materials prepared by traditional methods, so as to be able to adapt to the application scenarios of COC materials prepared by traditional methods.

In the embodiment of the present application, the metal center Q is represented by ^-M1 ( _R1R2 )-, ^M1 represents scandium, titanium, vanadium, zirconium, hafnium, niobium or tantalum, and _R1 and _R2 independently include hydrogen atoms, halogen atoms, _alkyl groups, alkoxy groups, alkenyl groups, aryl groups, aryloxy groups, aralkyl groups, alkaryl groups or aralkenyl groups.

In the embodiment of the present application, the bridging group D is represented by -X(R ₃ R ₄ )-, wherein X represents carbon or silicon, and R ₃ and R ₄ independently include a hydrogen atom or a hydrocarbon group.

In the embodiment of the present application, the _Ra is represented by ^-M2 ( _R10R11R12 ), the _Rb is represented by ^-M3 ( _R15R16R17 ), ^M2 and ^M3 independently represent carbon _{, silicon} , germanium or tin, and _R10 , _{R11 , R12} , _R15 , _R16 and _R17 independently include alkyl, alkoxy, alkenyl, aryl, aryloxy, aralkyl, alkaryl or _aralkenyl . Ra is connected to the carbon atom _at the corresponding position on the fluorene ring through ^M2 , and _Rb is connected to the carbon atom at the corresponding position on the fluorene ring through ^M3 .

In one embodiment of the present application, the specific structural formula of the main catalyst shown in formula (1-a) is shown in formula (1-b):

In the embodiment of the present application, the main catalyst shown in formula (1-b) is a type of bridged diocene transition metal compound, ^M1 is a metal center, representing a pre-transition metal such as scandium, titanium, vanadium, zirconium, hafnium, niobium or tantalum, _R1 and _R2 are connected to the metal center ^M1 , and _R1 and _R2 independently include hydrogen atoms, halogen atoms, alkyl, alkoxy, alkenyl, aryl, aryloxy, aralkyl, alkaryl or _aralkenyl . Cyclopentadiene and fluorene are connected by a bridging group -X ( _R3R4 )-, and cyclopentadiene and fluorene are coordinated with the metal center ^M1 . X represents carbon or silicon, _R3 and _R4 independently include hydrogen atoms or hydrocarbon groups, and the hydrocarbon group can be an alkyl, alkenyl, aryl, aralkyl, alkaryl or aralkenyl. Specifically, the hydrocarbon group can be an alkyl, alkenyl, aryl, aralkyl, alkaryl or aralkenyl group having a carbon number less than or equal to 10 (i.e., a carbon number of 1-10). In some embodiments of the present application, R ₃ and R ₄ may also be connected to form a ring structure.

In the embodiment of the present application, in formula (1-b), when _R1 and _R2 are halogen atoms, the halogen atoms may be fluorine, chlorine, bromine or iodine. In the embodiment of the present application, the alkyl group may be a straight chain, branched chain or alkyl group having a cyclic structure. The alkyl group may be an unsubstituted alkyl group or a substituted alkyl group. The alkenyl group may be a straight chain or branched chain alkenyl group. The alkenyl group may be an unsubstituted alkenyl group or a substituted alkenyl group. The alkoxy group may be a straight chain, branched chain or alkoxy group having a cyclic structure. In the embodiment of the present application, the number of carbon atoms of the alkyl group, alkoxy group and alkenyl group may be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. Specifically, the alkyl group may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group or the like. In the embodiment of the present application, the aryl group may be an unsubstituted aryl group or a substituted aryl group. The number of carbon atoms of the aryl group, the aryloxy group, the arylalkyl group, the alkaryl group and the arylalkenyl group may be 6, 7, 8, 9 or 10. In some embodiments of the present application, the bridging group -X(R ₃ R ₄ )- can be, for example but not limited to, methylene, ethylene, isopropylene (-C(CH ₃ ) ₂ -), benzhydryl (-C(C ₆ H ₅ ) ₂ -), bistrimethylsilylmethylene (-C(Si(CH ₃ ) ₃ ) ₂ -), and the like.

In the embodiment of the present application, in formula (1-b), R ₅ , R ₆ , R ₇ , and R ₈ may independently include hydrogen atoms, hydrocarbon groups, or silicon-containing substituents. Specifically, the hydrocarbon group may be an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkaryl group, or an aralkenyl group having a carbon number less than or equal to 10 (i.e., a carbon number of 1-10). The alkyl group may be a straight chain, a branched chain, or an alkyl group having a cyclic structure. The alkyl group may be an unsubstituted alkyl group or a substituted alkyl group. The alkenyl group may be a straight chain or a branched chain alkenyl group. The alkenyl group may be an unsubstituted alkenyl group or a substituted alkenyl group. The carbon number of the alkyl group and the alkenyl group may be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Specifically, the alkyl group may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, or the like. In the embodiment of the present application, the aryl group may be an unsubstituted aryl group or a substituted aryl group. The carbon number of the aryl group, the aralkyl group, the alkaryl group, and the alkenyl group may be 6, 7, 8, 9, or 10. R ₅ , R ₆ , R ₇ , and R ₈ correspond to the carbon atoms at positions 2, 3, 4, and 5 of cyclopentadiene, respectively. In the embodiment of the present application, when R ₅ , R ₆ , R ₇ or R ₈ is a silicon-containing substituent, the silicon-containing substituent forms a carbon-silicon bond with the carbon atom at positions 2, 3, 4, or 5 of cyclopentadiene. In the embodiment of the present application, one of R ₅ , R ₆ , R ₇ and R ₈ may be a silicon-containing substituent, or two, three, or four of R ₅ , R ₆ , R ₇ and R ₈ may be silicon-containing substituents. When some of R ₅ , R ₆ , R ₇ and R ₈ are silicon-containing substituents, the group that is not a silicon-containing substituent may be a hydrogen atom or a hydrocarbon group. When multiple of R ₅ , R ₆ , R ₇ and R ₈ are silicon-containing substituents, they may be the same silicon-containing substituent or different silicon-containing substituents. When more than one of R ₅ , R ₆ , R ₇ and R ₈ is a hydrocarbon group, they may be the same hydrocarbon group or different hydrocarbon groups. The silicon-containing substituent is connected to the carbon atom at the corresponding substitution position through a silicon atom, that is, the silicon-containing substituent is connected to the carbon atom on the cyclopentadiene ring at the corresponding position through a silicon atom. The silicon-containing substituent can be represented by -Si(R'R"R"'), R', R", R"' can be an alkyl group or an aryl group, that is, the silicon-containing substituent can be an alkylsilanyl group or an arylsilanyl group. Specifically, the alkylsilanyl group can be, for example, a trimethylsilanyl group (that is, R', R", R"' are methyl groups), a triethylsilanyl group (that is, R', R", R"' are ethyl groups), etc., and specifically, the arylsilanyl group can be, for example, a triphenylsilanyl group (that is, R', R", R"' are phenyl groups). In some embodiments of the present application, the silicon-containing substituent can be an alkylsilanyl group having a total carbon atom count of 1-10. In some embodiments, _R5 , _R6 , _R7 , and _R8 independently include hydrocarbon groups or silicon-containing substituents having carbon atoms less than or equal to 6 (i.e., _C1 - _C6 ). Hydrocarbon groups or silicon-containing substituents having smaller carbon atoms can reduce the steric hindrance around the metal center ^M1 , which is beneficial for maintaining the catalytic activity of the catalyst at a higher level.

The silicon-containing substituent introduced on the carbon position of cyclopentadiene can produce a synergistic effect with the metal center ^M1 , promote chain transfer in the polymerization process, increase the insertion rate of cycloolefin monomers, and make the cycloolefin copolymer have a low molecular weight and a moderate glass transition temperature. In some embodiments of the present application, at least one of _R6 or _R7 is a silicon-containing substituent. The substituents at positions 3 and 4 of cyclopentadiene are farther from the metal center ^M1 than the substituents at positions 2 and 5. The introduction of silicon-containing substituents at positions 3 and 4 of cyclopentadiene can not only achieve weak coordination with the metal center ^M1 to promote chain transfer and reduce the molecular weight of the polymer, but also avoid affecting the polymerization activity of the catalyst due to strong coordination. For example, in one embodiment, _R6 is a silicon-containing substituent, and _R5 , _R7 and _R8 are hydrogen or a hydrocarbon group. In another embodiment, _R7 is a silicon-containing substituent, and _R5 , _R6 and _R8 are hydrogen or a hydrocarbon group. In some embodiments, _R6 and _R7 are silicon-containing substituents, and _R5 and _R8 are hydrogen or hydrocarbon groups.

In the embodiment of the present application, in formula (1-b), ^M2 represents carbon, silicon, germanium or tin, and ^M3 represents carbon, silicon, germanium or tin. ^M2 and ^M3 can be the same atom or different atoms. ^M2 or ^M3 can produce a synergistic effect with the metal center ^M1 , promote chain transfer in the polymerization process, increase the insertion rate of the cycloolefin monomer, play a role in regulating the molecular weight and adjusting the glass transition temperature, so that the cycloolefin copolymer has a low molecular weight and a moderate glass transition temperature.

In order to enable the main catalyst shown in formula (1-b) to achieve the functions of regulating molecular weight and glass transition temperature in the preparation process of cycloolefin copolymer, and finally obtain cycloolefin copolymer with low molecular weight and moderate glass transition temperature, in the embodiment of the present application, at least one of the substituents R ₅ , R ₆ , R ₇ , and R ₈ on the cyclopentadiene ring is a silicon-containing substituent, or at least one of the substituents at the 2nd or 7th position of the fluorene ring is a silicon-containing group, that is, at least one of M ² and M ³ is silicon. The distance between the 2nd and 7th positions of the fluorene ring and the metal center M ¹ is moderate, and the synergistic coordination between the silicon-containing groups at the 2nd and 7th positions and the metal center M ¹ is neither too strong nor too weak, which is conducive to promoting chain transfer through weak coordination synergy, reducing the molecular weight of the polymer, and avoiding affecting the polymerization activity of the catalyst due to strong coordination. When one or both of M ² and M ³ are silicon, R ₅ , R ₆ , R ₇ , and R ₈ are all hydrogen atoms or hydrocarbon groups, which is beneficial to ensure that the polymerization activity is maintained at a higher level, better balance the low molecular weight of the polymer and the polymerization activity, and reduce the difficulty of catalyst preparation. When one or both of M ² and M ³ are silicon, at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing group, which can be beneficial to prepare a polymer with a lower molecular weight through the coordination effect of silicon and the metal center M ¹ .

In some embodiments of the present application, at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing substituent, and M ² and M ³ independently include carbon, germanium, or tin. In other embodiments of the present application, R ₅ , R ₆ , R ₇ , and R ₈ independently include hydrogen atoms or hydrocarbon groups, and at least one of M ² and M ³ is silicon. In other embodiments of the present application, at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a silicon-containing substituent, and at least one of M ² and M ³ is silicon. In one embodiment, R ₅ , R ₆ , R ₇ , and R ₈ independently include hydrogen atoms or hydrocarbon groups, M ² and M ³ are silicon, and R ₉ , R ₁₃ , R ₁₄ , and R ₁₈ are hydrogen atoms, that is, positions 2 and 7 on the fluorene ring are silicon-containing groups, and the remaining substitution positions are hydrogen atoms. The main catalyst of this embodiment can not only adjust the molecular weight and glass transition temperature of the copolymer through synergistic effects, but also has a simple structure and is easy to prepare.

In the embodiments of the present application, R ₁₀ , R ₁₁ , R ₁₂ , R ₁₅ , R ₁₆ , and R ₁₇ may independently include an alkyl group, an alkoxy group, an alkenyl group, an aryl group, an aryloxy group, an aralkyl group, an alkaryl group, or an aralkenyl group. Specifically, R ₁₀ , R ₁₁ , R ₁₂ , R ₁₅ , R ₁₆ , and R ₁₇ may independently include an alkyl group, an alkoxy group, an alkenyl group, an aryl group, an aryloxy group, an aralkyl group, an alkaryl group, or an aralkenyl group having a carbon number less than or equal to 10. In the embodiments of the present application, the alkyl group may be a straight chain, a branched chain, or an alkyl group having a cyclic structure. The alkyl group may be an unsubstituted alkyl group or a substituted alkyl group. The alkenyl group may be a straight chain or a branched chain alkenyl group. The alkenyl group may be an unsubstituted alkenyl group or a substituted alkenyl group. The alkoxy group may be a straight chain, a branched chain, or an alkoxy group having a cyclic structure. In the embodiments of the present application, the carbon number of the alkyl, alkoxy, and alkenyl groups may be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Specifically, the alkyl group may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, or the like. In the embodiments of the present application, the aryl group may be an unsubstituted aryl group or a substituted aryl group. The carbon number of the aryl group, the aryloxy group, the aralkyl group, the alkaryl group, and the aralkenyl group may be 6, 7, 8, 9, or 10.

In the embodiment of the present application, in formula (1-b), R ₉ , R ₁₃ , R ₁₄ , and R ₁₈ independently include hydrogen atoms, hydrocarbon groups, or hydrocarbonoxy groups. Specifically, the hydrocarbon group may be an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkaryl group, or an aralkenyl group having a carbon number of less than or equal to 10 (i.e., a carbon number of 1-10). The hydrocarbonoxy group may be an alkoxy group or an aryloxy group having a carbon number of less than or equal to 10 (i.e., a carbon number of 1-10). The alkyl group may be a straight chain, a branched chain, or an alkyl group having a cyclic structure. The alkyl group may be an unsubstituted alkyl group or a substituted alkyl group. The alkenyl group may be a straight chain or a branched chain alkenyl group. The alkenyl group may be an unsubstituted alkenyl group or a substituted alkenyl group. The alkoxy group may be a straight chain, a branched chain, or an alkoxy group having a cyclic structure. In the embodiment of the present application, the carbon number of the alkyl group, the alkoxy group, and the alkenyl group may be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Specifically, the alkyl group may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, or the like. In the embodiments of the present application, the aryl group may be an unsubstituted aryl group or a substituted aryl group. The carbon number of the aryl group, aryloxy group, arylalkyl group, alkylaryl group, and arylalkenyl group may be 6, 7, 8, 9, or 10. In some embodiments of the present application, R ₉ , R ₁₃ , R ₁₄ , and R ₁₈ are all hydrogen atoms, that is, only the carbon atoms at positions 2 and 7 on the fluorenyl group have substituents, which can make the substitution structure on the fluorenyl group simpler and simplify the preparation process of the catalyst.

In some embodiments of the present application, the catalyst for preparing cycloolefin copolymer includes the main catalyst shown in formula (1-a), and also includes a co-catalyst, and the co-catalyst may be one or more of methylaluminoxane (MAO), modified methylaluminoxane (MMAO), and an organic boron compound. Among them, the organic boron compound may be one or more of tris(pentafluorophenyl)boron, triphenylcarbonium tetrakis(pentafluorophenyl)borate, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate. The co-catalyst is beneficial to improving the activity of the main catalyst. Compared with methylaluminoxane (MAO), the use of modified methylaluminoxane (MMAO) as a co-catalyst can help reduce the amount of cycloolefin monomers. Using methylaluminoxane, modified methylaluminoxane, and an organic boron compound as a co-catalyst is beneficial to ensuring the copolymerization activity of the cycloolefin copolymer.

In the embodiment of the present application, the catalyst for preparing the cycloolefin copolymer includes a main catalyst and a co-catalyst as shown in formula (1-a). The more the co-catalyst is used, the lower the molecular weight of the cycloolefin polymer is and the higher the glass transition temperature is. Considering the molecular weight and glass transition temperature of the cycloolefin polymer, in the present application, the molar ratio of the main catalyst to the co-catalyst can be 1: (10-10000). In some embodiments, the molar ratio of the main catalyst to the co-catalyst can be 1: (100-5000). In some embodiments, the molar ratio of the main catalyst to the co-catalyst can be 1: (500-4000).

In the embodiment of the present application, the catalyst for preparing cycloolefin copolymer is used to prepare cycloolefin copolymer, and has a high catalytic reaction activity. Specifically, the catalytic reaction activity is higher than 1×10 ⁶ g·mol ^-1 ·h ^-1 . In some embodiments, the catalytic reaction activity is higher than 1×10 ⁷ g·mol ^-1 ·h ^-1 . The main catalyst represented by formula (1-a) of the present application is used to prepare cycloolefin copolymer and has a high catalytic reaction activity, which is beneficial to improve the reaction rate and conversion rate of the copolymerization reaction.

In the embodiment of the present application, the main catalyst and the co-catalyst may be supported on a carrier, such as silicon oxide, aluminum oxide, titanium oxide, etc.

The compound represented by the above formula (1-b) in the embodiment of the present application can be prepared by the following method:

The -X(R ₃ R ₄ )-bridged cyclopentadienylfluorene ligand is prepared by using a lithiation agent to lithiate the cyclopentadienylfluorene ligand, and then reacting with the M ¹ metal salt to obtain a compound shown in formula (1-b). The reaction process is shown in reaction formula (A).

The lithiation agent may be, but is not limited to, n-butyl lithium. The ^M1 metal salt may be a scandium salt, a titanium salt, a vanadium salt, a zirconium salt, a hafnium salt, a niobium salt or a tantalum salt. The lithiation process may be carried out under anhydrous and oxygen-free conditions with an ice bath. After the cyclopentadienylfluorene ligand is lithiated, suction filtration is performed, and the obtained product is transferred into a glove box, an organic solvent and the ^M1 metal salt are added, and the coordination reaction is carried out by stirring overnight. The organic solvent may be a solvent such as toluene, hexane, etc. that can dissolve the above product. The product obtained after the coordination reaction may be washed, extracted, and recrystallized to obtain the final product.

Taking catalyst A as an example, the specific preparation process of catalyst A may include the following steps:

(1) Preparation of cyclopentadienylfluorene ligand:

Under anhydrous and oxygen-free conditions, at a reaction temperature of -78°C, 2,7-dibromofluorene and anhydrous tetrahydrofuran are added to a reaction vessel, and then a hexane solution containing n-butyl lithium is added dropwise, followed by a tetrahydrofuran solution containing trimethylsilyl chloride (Me ₃ SiCl) and the reaction is continued overnight. Then, a hexane solution containing n-butyl lithium and a tetrahydrofuran solution containing triphenylsilyl chloride (Ph ₃ SiCl) are added dropwise again, and the reaction is continued overnight. Subsequently, an aqueous sodium hydroxide solution is added at room temperature for hydrolysis, and the separation is separated by extraction with diethyl ether. The organic phase is dried over anhydrous magnesium sulfate to obtain 2,7-bis(triphenylsilyl)fluorene;

Under anhydrous and oxygen-free conditions, the prepared 2,7-bis(triphenylsilyl)fluorene and anhydrous tetrahydrofuran are added to a reaction container, an equimolar amount of methyl lithium ether solution is added dropwise at room temperature, the reaction is carried out overnight at room temperature, and then an anhydrous tetrahydrofuran solution containing 6,6-dimethylfulvene is added dropwise, the reaction is carried out overnight, an aqueous solution of tetrabutylammonium chloride is added, the mixture is stirred, and the liquid is separated by extraction, the aqueous phase is washed three times with ether, the organic phase is dried over anhydrous magnesium sulfate, and then dried and recrystallized to obtain a cyclopentadienylfluorene ligand precursor.

Under anhydrous and oxygen-free conditions, the above-prepared cyclopentadienylfluorene ligand precursor and anhydrous tetrahydrofuran were added to a reaction container, an equimolar amount of n-butyl lithium hexane solution was added at -78°C, and then trimethylsilyl chloride ( _Me3SiCl ) was added dropwise, stirred overnight, the solvent was drained, and washed with hexane to obtain a cyclopentadienylfluorene ligand (i.e., catalyst A precursor).

The reaction process of the above steps can be seen in reaction formula (1-1).

(2) Preparation of Catalyst A:

Under anhydrous and oxygen-free conditions, add cyclopentadienylfluorene ligand (catalyst A precursor) to a reaction vessel, add n-butyl lithium under ice bath, remove the ice bath, react for 2-12 hours, drain the solvent, move into a glove box, add hexane, add zirconium tetrachloride under full stirring, and stir overnight. After overnight reaction, filter, wash the filter cake with hexane and dissolve it in excess toluene, filter out the earthy yellow insoluble matter, then concentrate the toluene solution, and recrystallize to obtain a pink solid catalyst A. The reaction process of this step can be seen in reaction formula (1-2).

In the embodiments of the present application, the preparation of catalysts of other structures represented by formula (1-b) can refer to the preparation of catalyst A, and will not be described one by one here.

The present application also provides a method for preparing a cycloolefin copolymer, using the catalyst for preparing the cycloolefin copolymer described in the present application. The method comprises:

In the presence of the above-mentioned catalyst for preparing the cycloolefin copolymer, the cycloolefin monomer is copolymerized with ethylene or α-olefin to obtain the cycloolefin copolymer.

In the embodiment of the present application, the copolymerization reaction system includes an inert solvent, and the inert solvent includes one or more of a straight-chain alkane compound, a cyclic hydrocarbon compound and an aromatic hydrocarbon compound. The straight-chain alkane compound can specifically be a straight-chain alkane with a carbon number of 5-16, such as pentane, hexane, heptane, octane, etc. The cyclic hydrocarbon compound can specifically be a cyclic hydrocarbon with a carbon number of 5-11, such as cyclopentane, cyclohexane, etc. The aromatic hydrocarbon compound can specifically be a liquid aromatic hydrocarbon with a carbon number of 6-20, such as toluene.

In the embodiment of the present application, the amount of the main catalyst shown in formula (1-a) in the copolymerization reaction system is 0.001mmol/L-10mmol/L. In some embodiments, the amount of the main catalyst shown in formula (1-a) in the copolymerization reaction system is 0.01mmol/L-1mmol/L. In some embodiments, the amount of the main catalyst shown in formula (1-a) in the copolymerization reaction system is 0.01mmol/L-0.1mmol/L.

In the embodiment of the present application, the molar ratio of the main catalyst to the co-catalyst shown in formula (1-a) in the copolymerization reaction system can be 1: (10-10000). In some embodiments, the molar ratio of the main catalyst to the co-catalyst can be 1: (100-5000). In some embodiments, the molar ratio of the main catalyst to the co-catalyst can be 1: (500-4000).

In the embodiment of the present application, the amount of cycloolefin monomer in the copolymerization reaction system can be 0.01mol/L-10mol/L. In some embodiments, the amount of cycloolefin monomer in the copolymerization reaction system can be 0.01mol/L-5mol/L. In some embodiments, the amount of cycloolefin monomer in the copolymerization reaction system can be 0.01mol/L-1mol/L.

In the embodiment of the present application, the molar ratio of the cycloolefin monomer to the main catalyst in the copolymerization reaction system is 500-500000. In some embodiments, the molar ratio of the cycloolefin monomer to the main catalyst in the copolymerization reaction system is 1000-100000. In some embodiments, the molar ratio of the cycloolefin monomer to the main catalyst in the copolymerization reaction system is 5000-100000. The main catalyst of the present application can adapt to a larger range of cycloolefin monomer usage, and has high catalytic activity.

In the embodiment of the present application, the temperature of the copolymerization reaction may be 50°C-120°C; the time of the copolymerization reaction may be 2min-10min. The present application adopts the above-mentioned catalyst for copolymerization, and the reaction temperature is relatively mild and the time is short, so the polymerization process can be optimized. In some embodiments, the temperature of the copolymerization reaction may be 60°C-110°C. In some embodiments, the temperature of the copolymerization reaction may be 80°C-100°C. In some embodiments, the time of the copolymerization reaction may be 3min-6min.

In the embodiment of the present application, the structural formula of the cycloolefin monomer may be as shown in formula (2):

In formula (2), R ₁₉ is a hydrocarbon group or a hydrocarbon silicon group; R ₂₀ and R ₂₁ are independently hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, hydroxyl groups, ester groups, carbonate groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups;

R ₂₂ and R ₂₃ are independently selected from hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, hydroxyl groups, ester groups, carbonate groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups, or R ₂₂ and R ₂₃ are connected to form a group having a cyclic structure;

z is a positive integer.

In the embodiment of the present application, R ₁₉ is a hydrocarbon group or a hydrocarbon silyl group, and the hydrocarbon group can be an alkylene group, an alkenylene group, an arylene group, an aralkylene group, an alkarylene group or an aralkenylene group. The carbon number of the hydrocarbon group can be less than or equal to 10 (i.e., the carbon number is 1-10). Specifically, the carbon number of the alkylene group and the alkenylene group can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. The carbon number of the arylene group, the aralkylene group, the alkarylene group and the aralkenylene group can be 6, 7, 8, 9, 10. The hydrocarbon silyl group can be an alkylsilylene group and an arylsilylene group. The carbon number of the hydrocarbon silyl group can be less than or equal to 10 (i.e., the carbon number is 1-10). In some embodiments, the hydrocarbon silicon group may be specifically dimethylsilylene (—Si(CH ₃ ) ₂ -), diethylsilylene (—Si(C ₂ H ₅ ) ₂ -), diphenylsilylene (—Si(C ₆ H ₅ ) ₂ -), or the like.

In the embodiments of the present application, the atoms or atomic groups that can replace the above-mentioned groups refer to atoms or atomic groups that can replace hydrogen atoms, halogen atoms, alkyl groups, aryl groups, alkoxy groups, hydroxyl groups, ester groups, carbonate groups, cyano groups, amino groups, and thiol groups. Specifically, for example, they can be isotope atoms of hydrogen atoms (deuterium, etc.), boranes, metal ligands, etc.

In the embodiments of the present application, in R ₂₀ , R ₂₁ , R ₂₂ and R ₂₃ , the halogen atom may be fluorine, chlorine, bromine or iodine. The alkyl group may be an alkyl group having 1 to 20 carbon atoms. In some embodiments, the alkyl group has 2 to 10 carbon atoms; in other embodiments, the alkyl group has 8 to 20 carbon atoms; in other embodiments, the alkyl group has 8 to 15 carbon atoms. The alkyl group may be a linear, branched or cyclic alkyl group. Specifically, the alkyl group may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, etc. The alkyl group may be an unsubstituted alkyl group or a substituted alkyl group. In the embodiments of the present application, the aromatic group may be an aromatic group having 6 to 20 carbon atoms, and further, the aromatic group may have 6 to 10 carbon atoms; further, the aromatic group may have 7 to 8 carbon atoms. The aromatic group may be an unsubstituted aromatic group or a substituted aromatic group. In the embodiments of the present application, the alkoxy group may have 1 to 20 carbon atoms. In some embodiments, the number of carbon atoms in the alkoxy group is 2 to 10; in other embodiments, the number of carbon atoms in the alkoxy group is 8 to 20; in other embodiments, the number of carbon atoms in the alkoxy group is 8 to 15. The alkoxy group may be a linear, branched, or cyclic alkoxy group.

In the embodiment of the present application, the cyclic structure formed by connecting R ₂₂ and R ₂₃ can be a saturated or unsaturated carbon ring, a saturated or unsaturated heterocyclic ring, and the heteroatom in the heterocyclic ring can be nitrogen, sulfur, oxygen, boron, silicon, etc. For example, the group connected to the cyclic structure formed by connecting R ₂₂ and R ₂₃ can include hydrogen atoms, halogen atoms, alkyl groups, aromatic groups, alkoxy groups, hydroxyl groups, ester groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups.

In the implementation manner of the present application, z is a positive integer, and specifically can be 1, 2, 3, 4, etc.

In the embodiment of the present application, α-olefin refers to a monoolefin with a double bond at the end of the molecular chain, and the number of carbon atoms of the α-olefin may be 2 to 20. Specifically, the α-olefin may be propylene, 1-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene or 2-ethyl-1-butene.

In the embodiment of the present application, the copolymerization reaction system does not contain a molecular weight regulator. The method for preparing a cycloolefin copolymer in the embodiment of the present application can achieve the effect of regulating the molecular weight by only using the catalyst for preparing cycloolefins provided in the embodiment of the present application to obtain a low molecular weight cycloolefin copolymer.

In the embodiment of the present application, taking the copolymerization reaction of cycloolefin monomer and ethylene as an example, the reaction process for preparing cycloolefin copolymer can be shown as reaction formula (1-3):

The preparation method of the cycloolefin copolymer provided in the embodiment of the present application, by using the catalyst provided in the embodiment of the present application, does not need to introduce additional molecular weight regulators such as hydrogen or propylene, and can prepare a cycloolefin copolymer with a low molecular weight and a moderate glass transition temperature, so as to meet the processing performance, heat resistance and other requirements of various optical products such as optical lenses, display materials and packaging materials, and at the same time, other properties of the cycloolefin copolymer such as optical properties, thermal properties and mechanical properties are kept at the same level as traditional low molecular weight cycloolefin copolymer materials, so the low molecular weight cycloolefin copolymer material produced by this method can be applied to traditional cycloolefin copolymer material application scenarios. This preparation method not only greatly simplifies the preparation route of cycloolefin copolymer materials, but also significantly improves the polymerization activity and energy economic benefits, opening up a new path for the large-scale production of cycloolefin copolymer materials. The polymerization reaction of cycloolefin monomers and α-olefins in the embodiment of the present application has high activity. The experimental results show that the cycloolefin copolymer prepared by the above method of the embodiment of the present application has a moderate T _g (110-180 ° C) and a low molecular weight (≤150,000), the insertion rate of cycloolefin monomers is between 20%-60%, and the molecular weight distribution index is between 1.5-3.0.

The present application also provides a cycloolefin copolymer prepared by the above method, the structural formula of which is shown in formula (3):

In formula (3), R ₁₉ is a hydrocarbon group or a hydrocarbon silicon group; R ₂₀ and R ₂₁ are independently hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, hydroxyl groups, ester groups, carbonate groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups;

R ₂₂ , R ₂₃ , R ₂₄ , and R ₂₅ are independently selected from hydrogen, halogen, alkyl, alkoxy, aryl, aryloxy, hydroxy, ester, carbonate, cyano, amino, thiol, and atoms or atomic groups that can replace the above groups, or R ₂₂ and R ₂₃ are connected to form a group having a cyclic structure, and R ₂₄ and R ₂₅ are connected to form a group having a cyclic structure;

x and y represent the degree of polymerization, both x and y are positive numbers, 1＜x∶y＜3, and z is a positive integer.

It can be understood that in the cycloolefin polymer of formula (3) of the present application, R ₁₉ , R ₂₀ , R ₂₁ , R ₂₂ , and R ₂₃ are selected in the same manner as R ₁₉ , R ₂₀ , R ₂₁ , R ₂₂ , and R ₂₃ in the cycloolefin monomer of formula (2), and will not be described in detail herein.

In the embodiments of the present application, in R ₂₄ and R ₂₅ , the halogen atom may be fluorine, chlorine, bromine or iodine. The alkyl group may be an alkyl group having 1 to 20 carbon atoms. In some embodiments, the alkyl group has 2 to 10 carbon atoms; in other embodiments, the alkyl group has 8 to 20 carbon atoms; in other embodiments, the alkyl group has 8 to 15 carbon atoms. The alkyl group may be a linear, branched or cyclic alkyl group. Specifically, the alkyl group may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, etc. The alkyl group may be an unsubstituted alkyl group or a substituted alkyl group. In the embodiments of the present application, the aryl group may be an aromatic group having 6 to 20 carbon atoms, and further, the aryl group may have 6 to 10 carbon atoms; further, the aryl group may have 7 to 8 carbon atoms. The aryl group may be an unsubstituted aromatic group or a substituted aromatic group. In the embodiments of the present application, the alkoxy group may have 1 to 20 carbon atoms. In some embodiments, the number of carbon atoms in the alkoxy group is 2 to 10; in other embodiments, the number of carbon atoms in the alkoxy group is 8 to 20; in other embodiments, the number of carbon atoms in the alkoxy group is 8 to 15. The alkoxy group may be a linear, branched, or cyclic alkoxy group.

In the embodiment of the present application, the cyclic structure formed by connecting R ₂₄ and R ₂₅ can be a saturated or unsaturated carbon ring, a saturated or unsaturated heterocyclic ring, and the heteroatom in the heterocyclic ring can be nitrogen, sulfur, oxygen, boron, silicon, etc. For example, the group connected to the cyclic structure formed by connecting R ₂₄ and R ₂₅ can include hydrogen atoms, halogen atoms, alkyl groups, aromatic groups, alkoxy groups, hydroxyl groups, ester groups, cyano groups, amino groups, thiol groups, and atoms or atomic groups that can replace the above groups.

In the implementation manner of the present application, z is a positive integer, and specifically can be 1, 2, 3, 4, etc. The ratio of x to y can be 1.5<x:y<2.5.

In the embodiment of the present application, the weight average molecular weight of the cycloolefin copolymer is less than or equal to 150,000; the molecular weight distribution index is in the range of 1.5 to 3.0. In some embodiments, the weight average molecular weight of the cycloolefin copolymer is in the range of 5,000 to 150,000; in some embodiments, the weight average molecular weight of the cycloolefin copolymer is in the range of 10,000 to 120,000. In some embodiments, the weight average molecular weight of the cycloolefin copolymer is in the range of 20,000 to 100,000. Cyclic olefin copolymers have relatively low weight average molecular weights and better processing properties, which are conducive to improving commercial value. In some embodiments, the molecular weight distribution index is in the range of 1.7-2.4.

In some embodiments of the present application, the insertion rate of cycloolefin monomers is between 20% and 60%; in some embodiments, the insertion rate of cycloolefin monomers is between 20% and 50%; in some embodiments, the insertion rate of cycloolefin monomers is between 30% and 40%. Suitable insertion rates of cycloolefin monomers can make cycloolefin polymers have suitable glass transition temperatures. In some embodiments of the present application, the glass transition temperature of cycloolefin copolymers is in the range of 110°C to 180°C. In some embodiments, the glass transition temperature of cycloolefin copolymers is in the range of 120°C to 160°C. In some embodiments, the glass transition temperature of cycloolefin copolymers is in the range of 130°C to 150°C. The glass transition temperature in the range of 120°C to 160°C can not only obtain excellent processing and molding properties, but also ensure that the copolymer products are used under higher ambient temperature conditions, thereby better balancing processing performance and use conditions.

In the embodiment of the present application, the visible light transmittance of the cycloolefin copolymer molded body is greater than 90%. The molded body can be a sheet-shaped molded body formed by hot pressing or a film-shaped molded body formed by coating. The thickness of the molded body can be in the range of 0.1 mm to 1 mm.

In the present application, "-" indicates a range, including two endpoint values. For example, the amount of the main catalyst in the copolymerization reaction system is 0.001mmol/L-10mmol/L, which means that the amount of the main catalyst is any value in the range of 0.001mmol/L to 10mmol/L, including the endpoint values 0.001mmol/L and 10mmol/L.

The present application also provides a composition, including the cycloolefin copolymer described in the present application. The composition can be used as an optical material.

In the embodiment of the present application, the composition also includes additives, which may be one or more of fillers, dyes, antioxidants, light stabilizers, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, and release agents. The composition may also include other polymers, which may be other cycloolefin polymers different from the embodiments of the present application, or non-cycloolefin polymers, which may be added in appropriate amounts as needed. In the composition, the mass content of the cycloolefin polymers described above in the embodiments of the present application may be greater than or equal to 60%. In some embodiments, the mass content of the cycloolefin polymers described above in the embodiments of the present application may be 60%, 70%, 80%, 90%, 95%, or 98%.

The embodiment of the present application also provides an optical product, which includes the cycloolefin copolymer described above in the embodiment of the present application. The cycloolefin copolymer or composition described above can be processed into an optical product by various known molding methods. The optical product can be partially processed using the cycloolefin copolymer or composition described above, or the entire optical product can be processed using the cycloolefin polymer or optical material described above.

In the embodiments of the present application, the optical product may specifically include an optical lens, an optical film, an optical disc, a light guide plate or a display panel.

In the implementation manner of the present application, the optical lens may specifically include a glasses lens, a camera lens, a sensor lens, a lighting lens, an imaging lens, etc. The camera lens may specifically be a mobile phone camera lens, a laptop camera lens, a desktop camera lens, a car camera lens, etc. Among them, the glasses lens may include a myopia glasses lens, a reading glasses lens, a sunglass lens, a contact lens correction lens, a goggles lens, etc. Among them, the sensor lens may be a motion detector lens, a proximity sensor lens, a posture control lens, an infrared sensor lens, etc. Among them, the lighting lens may be an indoor lighting lens, an outdoor lighting lens, a vehicle headlight lens, a vehicle fog light lens, a vehicle rear light lens, a vehicle running light lens, a vehicle fog light lens, a vehicle interior lens, a light emitting diode (LED) lens or an organic light emitting diode (OLED) lens, etc. Among them, the imaging lens may be a scanner lens, a projector lens, a telescope lens, a microscope lens, a magnifying glass lens, etc.

In the embodiment of the present application, the optical film may include a light guide film, a reflective film, an anti-reflection film, a diffusion film, a filter film, a polarizing film, a spectroscopic film, a phase film, etc. The optical film can be used in the display field, the lighting field, etc., for example, it can be used as a film for a liquid crystal substrate.

Referring to FIG. 1 , the present application embodiment also provides a device 100, including the optical product described above in the present application embodiment. The device 100 may be an electronic device, specifically including a mobile terminal, glasses, a camera, a vehicle (e.g., a car, a motorcycle, a train, etc.), a lighting device (e.g., a table lamp, a ceiling lamp, a street lamp, etc.), an imaging device (e.g., an endoscope, a microscope, a telescope, a projector, a scanner, etc.), a security device, etc. Among them, the mobile terminal may specifically include various handheld devices with wireless communication functions (e.g., various mobile phones, tablet computers, mobile notebooks, netbooks), wearable devices (e.g., smart watches), or other processing devices connected to a wireless modem, as well as various forms of user equipment (UE), mobile stations (MS), terminal devices, etc. The device 100 includes a camera module 2, the camera module 2 includes a camera lens, and the camera lens is prepared using the cyclic olefin copolymer described above in the present application embodiment. The device 100 also includes a camera protection cover 103 provided on the camera lens.

In a specific embodiment of the present application, the device 100 is a mobile terminal, the mobile terminal includes a camera module, the camera module includes a camera lens, and the camera lens is prepared using the above-mentioned cycloolefin copolymer in the embodiment of the present application.

In a specific embodiment of the present application, the device 100 is an endoscope, which includes a camera module, which includes a camera lens, and the camera lens is prepared using the cycloolefin copolymer described above in the embodiment of the present application.

In a specific embodiment of the present application, the device 100 is a vehicle, the vehicle includes a camera module, the camera module includes a camera lens, and the camera lens is prepared using the above-mentioned cycloolefin copolymer in the embodiment of the present application.

In a specific embodiment of the present application, the device 100 is a security device, which includes a camera module. The camera module includes a camera lens, and the camera lens is prepared using the above-mentioned cycloolefin copolymer in the embodiment of the present application.

The embodiments of the present application are further described below with reference to a plurality of embodiments.

Example 1

Catalyst preparation:

(1a) Under anhydrous and oxygen-free conditions, in a 100 mL reaction container, at a reaction temperature of -78°C, 5 mmol of 2,7-dibromofluorene and 50 mL of anhydrous tetrahydrofuran were added, and a hexane solution containing 10 mmol of n-butyl lithium was added dropwise, followed by a tetrahydrofuran solution containing 10 mmol of trimethylsilyl chloride (Me ₃ SiCl) and a tetrahydrofuran solution containing 10 mmol of n-butyl lithium. The mixture was reacted overnight. Then, a hexane solution containing 10 mmol of n-butyl lithium and a tetrahydrofuran solution containing 10 mmol of triphenylsilyl chloride (Ph ₃ SiCl) were added dropwise again, and the mixture was reacted overnight. Subsequently, 50 mL of a 0.5 mol/L sodium hydroxide aqueous solution was added at room temperature for hydrolysis, and the mixture was separated by extraction with diethyl ether. The organic phase was dried over anhydrous magnesium sulfate to obtain 2,7-bis(triphenylsilyl)fluorene.

(1b) Under anhydrous and oxygen-free conditions, 5 mmol of the prepared 2,7-bis(triphenylsilyl)fluorene and 50 mL of anhydrous tetrahydrofuran were added to a 100 mL reaction container, and an equimolar amount of methyl lithium ether solution (1.4 mol/L) was added dropwise at room temperature. The mixture was reacted overnight at room temperature. Then, 20 mL of anhydrous tetrahydrofuran solution containing 5 mmol of 6,6-dimethylfulvene was added dropwise. The mixture was reacted overnight. 100 mL of tetrabutylammonium chloride aqueous solution was added, the mixture was stirred for 10 min, and the mixture was extracted and separated. The aqueous phase was washed three times with 50 mL of ether. The organic phase was dried over anhydrous magnesium sulfate, dried and recrystallized to obtain a cyclopentadienylfluorene ligand precursor.

(1c) Under anhydrous and oxygen-free conditions, 5 mmol of the cyclopentadienylfluorene ligand precursor prepared above and 50 mL of anhydrous tetrahydrofuran were added to a 100 mL reaction container, an equimolar amount of n-butyl lithium hexane solution was added at -78°C, and then 5 mL of trimethylsilyl chloride ( _Me3SiCl ) was added dropwise. The mixture was stirred overnight, the solvent was drained, and the mixture was washed with hexane for 1-3 times to obtain a catalyst A precursor.

(1d) Under anhydrous and oxygen-free conditions, 1 g of catalyst A precursor was added to a 100 mL reaction container, 3.4 mL of n-butyl lithium was added at a reaction temperature of 0°C, the temperature was slowly raised to room temperature, the reaction was continued for 2-12 hours, the solvent was drained, hexane was added to a glove box, 0.6 g of zirconium tetrachloride was added under full stirring, and the mixture was stirred overnight. After overnight reaction, the mixture was filtered, the filter cake was washed with hexane and dissolved in excess toluene, the earthy yellow insoluble matter was filtered out, and then the toluene solution was concentrated and recrystallized to obtain a pink solid catalyst A. The pink solid catalyst A0.3 g obtained in this embodiment has a yield of 19.7% and a purity of 93.5%. FIG2 is the nuclear magnetic resonance hydrogen spectrum of catalyst A. FIG3 is the nuclear magnetic resonance carbon spectrum of catalyst A. The nuclear magnetic resonance hydrogen spectrum of FIG2 and the nuclear magnetic resonance carbon spectrum of FIG3 indicate that catalyst A was successfully prepared.

Preparation of cycloolefin monomer: In a 220mL autoclave, 78g of dicyclopentadiene, 110g of norbornene and a small amount of 2,6-dimethoxyphenol (BHT) were added in sequence, and the reaction was heated at 220°C for 24 hours under a nitrogen atmosphere. After the reaction was completed, the temperature of the reaction system was lowered to room temperature, and the distillation was directly performed under reduced pressure. The previous fraction was unreacted dicyclopentadiene, and the subsequent fraction was the target product of cycloolefin monomer. The reaction process is shown in reaction formula (1-4). The cycloolefin monomer obtained in this embodiment is 128g of colorless liquid with a yield of 67%. Figure 4 is the nuclear magnetic resonance hydrogen spectrum of the cycloolefin monomer in this embodiment; Figure 5 is the nuclear magnetic resonance carbon spectrum of the cycloolefin monomer of Example 1 of this application. The nuclear magnetic resonance hydrogen spectrum of Figure 4 and the nuclear magnetic resonance carbon spectrum of Figure 5 indicate that the cycloolefin monomer was successfully prepared.

Preparation of cycloolefin copolymer: A glass reactor containing 2.5g of the above cycloolefin monomer, 2.5mL of MAO solution (1.5mol/L, dissolved in toluene) and 45mL of toluene was connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature was adjusted to 90°C, and 2mL toluene solution of 2.0mg of the catalyst A prepared in this embodiment was added. The pressure of ethylene was adjusted and maintained to be one atmosphere, and the polymerization reaction was carried out for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% hydrochloric acid aqueous solution, and the liquid was separated after sufficient stirring. The organic layer was washed twice with water; the obtained organic layer was fully stirred with acetone and settled, and an appropriate amount of acetone was added after filtering and refluxed for 2 hours. Finally, the polymer was filtered and washed with acetone three times. The product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer material. The process of the polymerization reaction is shown in reaction formula (1-5). FIG6 is a hydrogen nuclear magnetic resonance spectrum of the cycloolefin copolymer of Example 1 of the present application; FIG7 is a carbon nuclear magnetic resonance spectrum of the cycloolefin copolymer of Example 1 of the present application. FIG7 a) is an enlarged view of the dotted line area. The hydrogen nuclear magnetic resonance spectrum of FIG6 and the carbon nuclear magnetic resonance spectrum of FIG7 indicate that the cycloolefin polymer was successfully prepared.

The mass of the cycloolefin copolymer material prepared in this embodiment is 2.4g, and the polymerization activity of the catalyst is 1.4*10 ⁷ gmol ^-1 h ^-1 . The relative number average molecular weight of the cycloolefin copolymer material detected by high temperature gel chromatography is 26kg/mol (weight average molecular weight is 62.4kg/mol), and the molecular weight distribution index is 2.4 (molecular weight distribution index is equal to weight average molecular weight divided by number average molecular weight). The obtained cycloolefin copolymer is detected by high temperature nuclear magnetic carbon spectrum, and the results show that the insertion rate of the cycloolefin monomer of the COC material prepared in this embodiment is 33%, and the insertion rate = (y/(x+y))*100%. The glass transition temperature of the obtained cycloolefin copolymer was detected by differential scanning calorimetry (DSC). FIG8 is the DSC curve of the cycloolefin copolymer of Example 1 of the present application. The results show that the glass transition temperature of the cycloolefin copolymer prepared in this embodiment is 141.02°C. It can also be seen from FIG8 that there is no crystallization peak in the DSC curve. This is because the main catalyst of the embodiment of the present application improves the insertion rate of the cycloolefin monomer of the COC material, which is conducive to avoiding the formation of crystalline polyethylene segments. The cycloolefin copolymer of the embodiment of the present application is formed into a film or sheet sample with a thickness of 0.1mm-1mm. After testing, the visible light transmittance of the cycloolefin copolymer film or sheet sample prepared in this embodiment is greater than 90%. FIG9 is a visible light transmittance test curve of the cycloolefin copolymer of Example 1 of the present application.

Compared with the prior art, the embodiments of the present application do not require an external molecular weight regulator, and the catalyst A can be used to directly prepare the low molecular weight cycloolefin copolymer material, while ensuring that the other properties of the cycloolefin copolymer material are excellent.

Example 2

The synthesis steps of the catalyst and the cycloolefin monomer are the same as those in Example 1.

Preparation of cycloolefin copolymer: A glass reactor containing 3.5g of cycloolefin monomer, 2.5mL of MAO (1.5mol/L, dissolved in toluene) and 45mL of toluene was connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, the ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature was adjusted to 90°C, 2.0mg of catalyst A in 2mL of toluene solution was added, and the pressure of ethylene was adjusted and maintained to be one atmosphere, and the polymerization reaction was carried out for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% hydrochloric acid aqueous solution, and the liquid was separated after sufficient stirring. The organic layer was washed twice with water; the obtained organic layer was fully stirred with acetone and settled, and an appropriate amount of acetone was added after filtering and refluxed for 2 hours. Finally, the polymer was filtered and washed with acetone three times, and the product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer material.

The mass of the cycloolefin copolymer obtained in this embodiment is 3.28g, and the polymerization activity of the catalyst is 1.9*10 ⁷ gmol ^-1 h ^-1 . The relative number average molecular weight of the cycloolefin copolymer detected by high temperature gel chromatography is 58kg/mol (weight average molecular weight is 98.6kg/mol), and the molecular weight distribution index is 1.7. The obtained cycloolefin copolymer is detected by high temperature nuclear magnetic carbon spectrum, and the results show that the insertion rate of the cycloolefin monomer of the cycloolefin copolymer material prepared in this embodiment is 38%. The glass transition temperature of the obtained cycloolefin copolymer is detected by differential scanning calorimetry (DSC), and Figure 10 is the DSC curve of the cycloolefin copolymer of Example 2 of the present application, and the results show that the glass transition temperature of the cycloolefin copolymer is 141.43°C. After testing, the visible light transmittance of the cycloolefin copolymer obtained in this embodiment is greater than 90%.

Compared with Example 1, Example 2 increases the amount of cycloolefin monomers. It can be seen from Examples 1 and 2 that the main catalyst of the embodiments of the present application can achieve the preparation of low molecular weight COC suitable for glass transition temperature within a wider monomer concentration range.

Example 3

The synthesis steps of the catalyst and the cycloolefin monomer are the same as those in Example 1.

Preparation of cycloolefin copolymer: A glass reactor containing 2.5g cycloolefin monomer, 2.6mL MMAO solution (8%wt, dissolved in heptane) and 45mL toluene was connected to an ethylene pipeline, and the ethylene pipeline was replaced with nitrogen three times, and then ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene, and the polymerization temperature was adjusted to 90°C, and 2mL toluene solution of 2.0mg catalyst A was added, and the pressure of ethylene was adjusted and maintained to be one atmosphere, and the polymerization reaction was carried out for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% hydrochloric acid aqueous solution, and the liquid was separated after sufficient stirring, and the organic layer was washed twice with water; the obtained organic layer was fully stirred with acetone and settled, and an appropriate amount of acetone was added after filtering and refluxed for 2 hours, and finally the polymer was filtered and washed with acetone three times, and the product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer.

The mass of the cycloolefin copolymer obtained in this embodiment is 2.97g, and the polymerization activity of the catalyst is 1.8*10 ⁷ gmol ^-1 h ^-1 . The relative number average molecular weight of the cycloolefin copolymer material obtained in this embodiment is detected by high temperature gel chromatography, which is 35kg/mol (weight average molecular weight is 84kg/mol), and the molecular weight distribution index is 2.4. The obtained cycloolefin copolymer is detected by high temperature nuclear magnetic carbon spectrum, and the results show that the insertion rate of the cycloolefin monomer of the cycloolefin copolymer material prepared in this embodiment is 30%. The glass transition temperature of the obtained cycloolefin copolymer is detected by differential scanning calorimetry (DSC), and Figure 11 is the DSC curve of the cycloolefin copolymer of Example 3 of the present application. The results show that the glass transition temperature of the cycloolefin copolymer prepared in this embodiment is 129.81°C. After testing, the visible light transmittance of the cycloolefin copolymer obtained in this embodiment is greater than 90%.

Compared with Example 1, Example 3 changes the co-catalyst. It can be seen from Examples 1 and 3 that when Catalyst A of the present application is used as the main catalyst, the preparation of COC with low molecular weight and suitable glass transition temperature can be achieved when different co-catalysts are used.

Example 4

The synthesis steps of the catalyst and the cycloolefin monomer are the same as those in Example 1.

Preparation of cycloolefin copolymer: A glass reactor containing 3.5g of cycloolefin monomer, 2.6mL of MMAO (8%wt heptane) and 45mL of toluene is connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, ethylene gas is opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature is adjusted to 90°C, 2mL toluene solution of 1.2mg of the catalyst prepared by the present invention is added, and the pressure of ethylene is adjusted and maintained to be one atmosphere. The polymerization reaction takes 5 minutes. After the polymerization is completed, the obtained reaction solution is poured into a 10% hydrochloric acid aqueous solution, and the liquid is separated after sufficient stirring. The organic layer is washed twice with water; the obtained organic layer is precipitated under sufficient stirring with acetone, filtered, and then an appropriate amount of acetone is added to reflux for 2 hours. Finally, the polymer is filtered and washed with acetone three times. The product is placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer material.

The mass of the cycloolefin copolymer obtained in this embodiment is 1.96g, and the polymerization activity of the catalyst is 1.2*10 ⁷ gmol ^-1 h ^-1 . The relative number average molecular weight of the cycloolefin copolymer material obtained in this embodiment is 26kg/mol (weight average molecular weight is 62.4kg/mol) detected by high temperature gel chromatography, and the molecular weight distribution index is 2.4. The insertion rate of the cycloolefin monomer obtained by high temperature nuclear magnetic carbon spectrum detection of the cycloolefin copolymer obtained is 39%. The glass transition temperature of the obtained cycloolefin copolymer is detected by differential scanning calorimetry (DSC), and Figure 12 is the DSC curve of the cycloolefin copolymer of Example 4 of the present application. The results show that the glass transition temperature of the cycloolefin copolymer material prepared in this embodiment is 145.67°C. After testing, the visible light transmittance of the cycloolefin copolymer obtained in this embodiment is greater than 90%.

Compared with Example 1, Example 4 changes the amount of co-catalyst and cycloolefin monomer. The results show that by using the main catalyst of the example of the present application and changing the amount of co-catalyst and cycloolefin monomer, the preparation of low molecular weight COC suitable for glass transition temperature can be achieved. The main catalyst provided by the example of the present application has a wide range of application and good effect.

Example 5

Catalyst preparation:

(1a) Under anhydrous and oxygen-free conditions, in a 100 mL reaction container, at a reaction temperature of -78°C, 5 mmol of 2,7-dibromofluorene and 50 mL of anhydrous tetrahydrofuran were added, and a hexane solution containing 10 mmol of n-butyl lithium was added dropwise, followed by a tetrahydrofuran solution containing 10 mmol of trimethylsilyl chloride (Me ₃ SiCl) and a tetrahydrofuran solution containing 10 mmol of n-butyl lithium and a tetrahydrofuran solution containing 10 mmol of trimethylsilyl chloride (Me ₃ SiCl) were added dropwise again, and the reaction was allowed to proceed overnight. Subsequently, 50 mL of a 0.5 mol/L sodium hydroxide aqueous solution was added at room temperature for hydrolysis, and the liquid was separated by extraction with diethyl ether. The organic phase was dried over anhydrous magnesium sulfate to obtain 2,7-bis(trimethylsilyl)fluorene.

(1b) to (1d) are the same as in Example 1.

The synthesis steps of the cycloolefin monomer are the same as those in Example 1.

Preparation of cycloolefin copolymer: A glass reactor containing 2.5g of cycloolefin monomer, 2.5mL of MAO (1.5mol/L toluene solution) and 45mL of toluene was connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, the ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature was adjusted to 90°C, 1.3mg of catalyst B in 2mL toluene solution was added, and the ethylene pressure was adjusted and maintained at one atmosphere. The polymerization reaction lasted for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% hydrochloric acid aqueous solution, stirred thoroughly and separated, and the organic layer was washed twice with water; the obtained organic layer was stirred thoroughly with acetone and settled, filtered, and then an appropriate amount of acetone was added and refluxed for 2 hours. Finally, the polymer was filtered and washed with acetone three times, and the product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer material.

The mass of the cycloolefin copolymer obtained in this embodiment is 1.99g, and the polymerization activity of the catalyst is 1.2*10 ⁷ gmol ^-1 h ^-1 . The relative number average molecular weight of the cycloolefin copolymer material obtained in this embodiment is 35kg/mol (weight average molecular weight is 70kg/mol) detected by high temperature gel chromatography, and the molecular weight distribution index is 2.0. The insertion rate of the cycloolefin monomer obtained by high temperature nuclear magnetic carbon spectrum detection of the cycloolefin copolymer obtained is 31%. The glass transition temperature of the obtained cycloolefin copolymer is detected by differential scanning calorimetry (DSC), and Figure 13 is the DSC curve of the cycloolefin copolymer of Example 5 of the present application. The results show that the glass transition temperature of the cycloolefin copolymer material prepared in this embodiment is 131.51°C. After testing, the visible light transmittance of the cycloolefin copolymer obtained in this embodiment is greater than 90%.

Example 6

Catalyst preparation:

(1a) Under anhydrous and oxygen-free conditions, in a 100 mL reaction container, at a reaction temperature of -78°C, 5 mmol of 2,7-dibromofluorene and 50 mL of anhydrous tetrahydrofuran were added, and a hexane solution containing 10 mmol of n-butyl lithium was added dropwise, followed by a tetrahydrofuran solution containing 10 mmol of trimethylsilyl chloride (Me ₃ SiCl) and a tetrahydrofuran solution containing 10 mmol of n-butyl lithium and a tetrahydrofuran solution containing 10 mmol of triethylsilyl chloride (Et ₃ SiCl) were added dropwise again, and the reaction was continued overnight. Subsequently, 50 mL of a 0.5 mol/L sodium hydroxide aqueous solution was added at room temperature for hydrolysis, and the liquid was separated by extraction with diethyl ether. The organic phase was dried over anhydrous magnesium sulfate to obtain 2,7-bis(triethylsilyl)fluorene.

(1b) to (1d) are the same as in Example 1.

The synthesis steps of the cycloolefin monomer are the same as those in Example 1.

Preparation of cycloolefin copolymer: A glass reactor containing 2.5g of cycloolefin monomer, 2.5mL of MAO (1.5mol/L toluene solution) and 45mL of toluene was connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, the ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature was adjusted to 90°C, 1.5mg of catalyst C in 2mL toluene solution was added, and the ethylene pressure was adjusted and maintained at one atmosphere. The polymerization reaction lasted for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% hydrochloric acid aqueous solution, stirred thoroughly and separated, and the organic layer was washed twice with water; the obtained organic layer was stirred thoroughly with acetone and settled, filtered, and then an appropriate amount of acetone was added and refluxed for 2 hours. Finally, the polymer was filtered and washed with acetone three times, and the product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer material.

The mass of the cycloolefin copolymer obtained in this embodiment is 0.62g, and the polymerization activity of the catalyst is 3.7*10 ⁶ gmol ^-1 h ^-1 . The relative number average molecular weight of the cycloolefin copolymer material obtained in this embodiment is 44kg/mol (weight average molecular weight is 70.4kg/mol) detected by high temperature gel chromatography, and the molecular weight distribution index is 1.6. The insertion rate of the cycloolefin monomer obtained by high temperature nuclear magnetic carbon spectrum detection of the cycloolefin copolymer obtained is 37%. The glass transition temperature of the cycloolefin copolymer obtained is detected by differential scanning calorimetry (DSC), and the results show that the glass transition temperature of the cycloolefin copolymer material prepared in this embodiment is 145.7℃. After testing, the visible light transmittance of the cycloolefin copolymer obtained in this embodiment is greater than 90%.

Example 7

Catalyst preparation:

The only difference from Example 1 is that step (1c) is not required, and the cyclopentadienylfluorene ligand precursor obtained in step (1b) is directly used as the catalyst D precursor to carry out step (1d).

The synthesis steps of the cycloolefin monomer are the same as those in Example 1.

Preparation of cycloolefin copolymer: A glass reactor containing 2.5g of cycloolefin monomer, 2.5mL of MAO (1.5mol/L toluene solution) and 45mL of toluene was connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, the ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature was adjusted to 90°C, 2mL toluene solution of 1.9mg of catalyst D was added, and the pressure of ethylene was adjusted and maintained at one atmosphere. The polymerization reaction lasted for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% hydrochloric acid aqueous solution, stirred thoroughly and separated, and the organic layer was washed twice with water; the obtained organic layer was stirred thoroughly with acetone and settled, filtered, and then an appropriate amount of acetone was added and refluxed for 2 hours. Finally, the polymer was filtered and washed three times with acetone. The product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white COC material.

The mass of the cycloolefin copolymer obtained in this embodiment is 1.3g, and the polymerization activity of the catalyst is 7.8*10 ⁶ g mol ^-1 h ^-1 . The relative number average molecular weight of the cycloolefin copolymer material obtained in this embodiment is detected by high temperature gel chromatography, which is 11.3kg/mol (weight average molecular weight is 21.5kg/mol), and the molecular weight distribution index is 1.9. The insertion rate of the cycloolefin monomer obtained by high temperature nuclear magnetic carbon spectrum detection of the cycloolefin copolymer obtained is 35%. The glass transition temperature of the obtained cycloolefin copolymer is detected by differential scanning calorimetry (DSC), and the results show that the glass transition temperature of the cycloolefin copolymer material prepared in this embodiment is 142°C. After testing, the visible light transmittance of the cycloolefin copolymer obtained in this embodiment is greater than 90%.

Comparative Example 1

The cycloolefin copolymer was prepared using the existing catalyst I (isopropylidene-bridged cyclopentadienylfluorene zirconium dichloride).

Preparation of cycloolefin copolymer: A glass reactor containing 4.5 g of cycloolefin monomer, 3.4 mL of MAO (1.5 mol/L toluene solution) and 45 mL of toluene was connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature was adjusted to 50°C. Under the condition of passing ethylene, 2 mL toluene solution of 0.9 mg of catalyst I was added. The pressure of ethylene was adjusted and maintained to be one atmosphere, and the polymerization reaction was carried out for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% aqueous hydrochloric acid solution, and the liquid was separated after sufficient stirring. The organic layer was washed twice with water; the obtained organic layer was fully stirred with acetone and settled, and an appropriate amount of acetone was added after filtering and refluxed for two hours. Finally, the polymer was filtered and washed three times with acetone. The product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer.

The mass of the cycloolefin copolymer prepared in this comparative example is 1.78 g, and the polymerization activity of the catalyst is 1.1*10 ⁷ gmol ^-1 h ^-1 . The number average molecular weight of the cycloolefin copolymer measured by the same method as the above example is 124 kg/mol (weight average molecular weight is 248 kg/mol), and the molecular weight distribution index is 2.0. The insertion rate of the cycloolefin monomer is 33%. The glass transition temperature of the cycloolefin copolymer is 136.98°C.

Comparative Example 2

Preparation of cycloolefin copolymer: A glass reactor containing 4.5g of cycloolefin monomer, 1.7mL of MAO (1.5M toluene solution) and 45mL toluene was connected to an ethylene pipeline. After replacing the ethylene pipeline with nitrogen three times, ethylene gas was opened and stirred to make the toluene solution in the glass reactor saturated with ethylene. The polymerization temperature was adjusted to 90°C. Under the condition of passing ethylene, 2mL toluene solution of 0.9mg of catalyst I was added. The pressure of ethylene was adjusted and maintained to be one atmosphere, and the polymerization reaction was carried out for 5 minutes. After the polymerization was completed, the obtained reaction solution was poured into a 10% aqueous hydrochloric acid solution, and the liquid was separated after sufficient stirring. The organic layer was washed twice with water; the obtained organic layer was fully stirred with acetone and settled, and an appropriate amount of acetone was added after filtering and refluxed for two hours. Finally, the polymer was filtered and washed three times with acetone. The product was placed in a vacuum drying oven and dried at 130°C for 18 hours to obtain a white cycloolefin copolymer.

The mass of the cycloolefin copolymer prepared in this comparative example is 1.15 g, and the polymerization activity of the catalyst is 0.7*10 ⁷ gmol ^-1 h ^-1 . The number average molecular weight of the cycloolefin copolymer measured by the same method as the above example is 117 kg/mol (weight average molecular weight is 199 kg/mol), and the molecular weight distribution index is 1.7. The insertion rate of the cycloolefin monomer is 35%. The glass transition temperature of the cycloolefin copolymer is 141.24°C.

As shown in Comparative Examples 1 and 2, the catalyst 1 of Comparative Example 1 is used to prepare cycloolefin copolymer, and under different co-catalyst usage amounts and polymerization reaction temperature, the weight-average molecular weight of the obtained cycloolefin copolymer is much greater than 150kg/mol (i.e. 150,000), and the molecular weight is relatively large. And embodiments 1-7, by using the catalyst provided by the present application embodiment, can obtain a cycloolefin copolymer with a relatively small molecular weight of less than 150,000 weight-average molecular weight, mainly due to the silicon-containing group on the primary catalyst cyclopentadienyl or fluorenyl group can produce a weak coordination effect with the metal center empty orbital, and compete with the coordination between olefin/metal center, thereby promoting chain transfer, reducing polymer molecular weight; Meanwhile, by this competitive effect, the difficulty of olefin and metal center coordination is increased, the insertion rate of cycloolefin monomer is improved, thereby being conducive to regulating the glass transition temperature of cycloolefin copolymer.

Claims (27)

1. Use of a catalyst for cycloolefin preparation in the preparation of a cycloolefin copolymer, characterized in that the catalyst comprises a procatalyst having the structural formula (1-a):

in the formula (1-a), D is a bridging group, and Q is a metal center;

R ₅、R₈ is a hydrogen atom, R ₆、R₇ independently comprises a hydrogen atom or a silicon-containing substituent attached to a carbon atom at the corresponding substitution position through a silicon atom; the silicon-containing substituents are represented by-Si (R 'R "R'"), R ', R ", R'" are independently alkyl or aryl;

R _a is represented by-M ²(R₁₀R₁₁ R₁₂),M² being silicon, R ₁₀、R₁₁、R₁₂ being independently alkyl or aryl; r _b is represented by-M ³(R₁₅R₁₆R₁₇),M³ being silicon, R ₁₅、R₁₆、R₁₇ being independently alkyl or aryl;

r ₉、R₁₃、R₁₄、R₁₈ independently includes a hydrogen atom, a hydrocarbyl group, or a hydrocarbyloxy group.

2. The use according to claim 1, wherein at least one of said R ₆、R₇ is a silicon-containing substituent.

3. The use according to claim 1 or 2, wherein the number of carbon atoms of the silicon-containing substituent in R ₆、R₇ is less than or equal to 6.

4. Use according to claim 1, wherein the metal centre Q is denoted-M ¹(R₁R₂) -, the M ¹ is scandium, titanium, vanadium, zirconium, hafnium, niobium or tantalum, and the R ₁ and R ₂ independently comprise a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkenyl group, an aryl group, an aryloxy group, an aralkyl group, an alkylaryl group or an aralkenyl group.

5. Use according to claim 1, wherein the bridging group D is represented by-X (R ₃R₄) -, wherein X represents carbon or silicon, and wherein R ₃ and R ₄ independently comprise a hydrogen atom or a hydrocarbon group.

6. The use according to claim 1, wherein the number of carbon atoms of R ₁₀、R₁₁、R₁₂、R₁₅、R₁₆、R₁₇ is less than or equal to 10.

7. The use of claim 1, wherein the catalyst further comprises a cocatalyst comprising one or more of methylaluminoxane, modified methylaluminoxane, organoboron compound.

8. The use according to claim 7, wherein the organoboron compound comprises one or more of tris (pentafluorophenyl) boron, triphenylcarbonium tetrakis (pentafluorophenyl) borate, N-dimethylanilinium tetrakis (pentafluorophenyl) borate.

9. The use according to claim 7 or 8, characterized in that the molar ratio of the procatalyst to the cocatalyst is 1: (10-10000).

10. The use according to claim 1, wherein the catalytic activity of the catalyst is higher than 10 ⁶g·mol^-1·h^-1.

11. A process for preparing a cyclic olefin copolymer, comprising:

Copolymerizing a cycloolefin monomer with ethylene or an alpha-olefin in the presence of the catalyst for producing a cycloolefin copolymer according to any one of claims 1 to 10 to obtain a cycloolefin copolymer.

12. The method according to claim 11, wherein the reaction system for copolymerization comprises an inert solvent, and the inert solvent comprises one or more of a linear alkane compound, a cyclic hydrocarbon compound and an aromatic hydrocarbon compound.

13. The process according to claim 11 or 12, wherein the amount of the main catalyst used in the copolymerization reaction system is 0.001mmol/L to 10mmol/L.

14. The process according to claim 11, wherein the cycloolefin monomer is used in an amount of 0.01mol/L to 10mol/L in the copolymerization reaction system.

15. The process according to claim 11, wherein the molar ratio of the cycloolefin monomer to the procatalyst in the copolymerization reaction system is 500 to 500000.

16. The process according to claim 11, wherein the temperature of the copolymerization reaction is 50 ℃ to 120 ℃; the copolymerization reaction time is 2min-10min.

17. The method according to claim 11, wherein the cycloolefin monomer has a structural formula shown in formula (2):

In the formula (2), R ₁₉ is alkyl or alkyl silicon base; r ₂₀ and R ₂₁ each independently include a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a hydroxyl group, an ester group, a carbonate group, a cyano group, an amino group, a thiol group, an atom or an atomic group which may be substituted for the above groups;

R ₂₂ and R ₂₃ each independently include a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a hydroxyl group, an ester group, a carbonate group, a cyano group, an amino group, a thiol group, an atom or an atomic group which may be substituted for the above groups, or R ₂₂ and R ₂₃ are connected to form a group having a cyclic structure;

z is a positive integer.

18. The process according to claim 11, wherein the copolymerization system does not contain a molecular weight regulator.

19. Cycloolefin copolymer, characterized in that it is produced according to the production process according to any one of claims 11 to 18, the structural formula of which is shown in formula (3):

In the formula (3), R ₁₉ is alkyl or alkyl silicon base; r ₂₀ and R ₂₁ each independently include a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a hydroxyl group, an ester group, a carbonate group, a cyano group, an amino group, a thiol group, an atom or an atomic group which may be substituted for the above groups;

R ₂₂、R₂₃、R₂₄、R₂₅ each independently includes a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a hydroxyl group, an ester group, a carbonate group, a cyano group, an amino group, a thiol group, an atom or a group which may be substituted for the above groups, or R ₂₂ and R ₂₃ are connected to form a group having a cyclic structure, and R ₂₄ and R ₂₅ are connected to form a group having a cyclic structure;

x and y represent polymerization degree, x and y are positive numbers, x is more than 1 and y is less than 3, and z is a positive integer;

The weight average molecular weight of the cycloolefin copolymer is in the range of 5000 to 150000; the glass transition temperature of the cycloolefin copolymer is in the range of 110 ℃ to 180 ℃; the visible light transmittance of the molded article of the cycloolefin copolymer is more than 90%.

20. The cyclic olefin copolymer according to claim 19, characterized in that the molecular weight distribution index of the cyclic olefin copolymer is in the range of 1.5 to 3.0.

21. The cyclic olefin copolymer according to claim 19 or 20, characterized in that the cyclic olefin monomer insertion rate of the cyclic olefin copolymer is in the range of 20% -60%.

22. A composition comprising the cycloolefin copolymer according to any of claims 19 to 21 or the cycloolefin copolymer obtainable by the preparation process according to any of claims 11 to 18.

23. The composition of claim 22, further comprising an additive comprising one or more of a filler, a dye, an antioxidant, a light stabilizer, an ultraviolet absorber, a plasticizer, a flame retardant, an antistatic agent, and a mold release agent.

24. An optical article comprising the cycloolefin copolymer according to any one of claims 19 to 21 or the cycloolefin copolymer produced by the production method according to any one of claims 11 to 18.

25. The optical article of claim 24, wherein the optical article comprises an optical lens, an optical film, an optical disc, a light guide plate, or a display panel.

26. An electronic device comprising an electronic device body and a camera module mounted on the electronic device body, the camera module comprising a lens made from the cyclic olefin copolymer of any one of claims 19-21 or the composition of claim 24 or 25.

27. An apparatus comprising the optical article of claim 24 or 25.