CN115819656B

CN115819656B - Cyclic olefin copolymer and its preparation method and application

Info

Publication number: CN115819656B
Application number: CN202111086528.1A
Authority: CN
Inventors: 简忠保; 崔磊; 张燚鑫; 穆红亮; 陈辰; 邹海良; 叶海水
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2025-02-25
Anticipated expiration: 2041-09-16
Also published as: CN115819656A

Abstract

The present application relates to the field of polymer synthesis technology, and provides a cycloolefin copolymer and a preparation method and application thereof. The cycloolefin copolymer has a general structural formula as shown in the following formula (1-1) or formula (1-2): In formula (1‑1) or formula (1‑2), the values of x, y, and z satisfy: 0.57≤x/(x+y+z)≤0.67, 0.32≤y/(x+y+z)≤0.39, 0.01≤z/(x+y+z)≤0.04; A is an atom or an atomic group, B is an atom or an atomic group, and A and B are not hydrogen atoms at the same time. The present application introduces MDMON monomer into the cycloolefin copolymer, which can increase the glass transition temperature of the cycloolefin polymer, thereby improving the heat resistance of the cycloolefin copolymer.

Description

Cycloolefin copolymer, preparation method and application thereof

Technical Field

The application belongs to the technical field of high polymer synthesis, and particularly relates to a cycloolefin copolymer and a preparation method and application thereof.

Background

The cycloolefin copolymer is thermoplastic engineering plastic with high added value, which is formed by polymerizing cycloolefin and alpha-olefin, and is a very promising optical material. Cycloolefin copolymers have high transparency, excellent heat resistance, chemical stability, melt flowability, dimensional stability and the like, and have been widely used for manufacturing various optical lens prisms, automobile headlamps, optical films for liquid crystal displays, contact lenses and the like. Cycloolefin copolymers are expected to replace polycarbonates as the best materials for the production of next generation high density DVDs. In addition, cycloolefin copolymer resins have extremely low dielectric constants, and are useful for the production of electronic and electric parts, and are also being used as emerging medical and food packaging materials due to their excellent moisture barrier properties.

Two methods are used for synthesizing cycloolefin copolymers, one is chain polymerization of ethylene and norbornene monomers, and the other is Ring Opening Metathesis Polymerization (ROMP) and hydrogenation of norbornene monomers. Currently, commercialized COCs have been proposed by Mitsui chemical company (Mitsui) in japan and tacona company (Ticona) in the united states under the trade names APEL and TOPAS, respectively.

U.S. patent No. 20200369812A1 discloses a process for preparing a cyclic olefin copolymer based on copolymerization of ethylene and DMON as raw materials by adding a second cyclic olefin monomer (IndNB) for ternary polymerization in order to achieve the effect of increasing the glass transition temperature of the copolymer while maintaining the excellent properties of the cyclic olefin copolymer. The technology is based on the fact that the molar ratio of ethylene to total cycloolefin monomers is basically unchanged, namely the molar ratio of ethylene to total cycloolefin monomers is about 64:36, and the high-temperature resistant cycloolefin copolymer is prepared, wherein the reaction formula is shown in the following formula 1:

The patent provides performance test data for examples and comparative examples, such as table 1 of US20200369812A1 application. As can be seen from the data provided in Table 1, the cycloolefin copolymer obtained by this technique has a glass transition temperature of 143 to 152℃as compared with comparative example II (the ratio of copolymerized ethylene to DMON is 65:35) (the glass transition temperature of the comparative example copolymerized ethylene to DMON copolymer is 150 ℃) and a refractive index of 1.55 to 1.56 (the refractive index of the comparative example copolymerized ethylene to DMON copolymer is 1.54) and an Abbe number of 43 to 49 (the Abbe number of the comparative example copolymerized ethylene to DMON copolymer is 56). It can be seen that the effect of increasing the glass transition temperature of the cycloolefin copolymer by adding the second cycloolefin monomer is not obvious (at a temperature of substantially 150 ℃ or less, at a maximum of 165 ℃) while keeping the insertion rate of the total cycloolefin monomer substantially unchanged, and that the tendency of regulation is disordered (the glass transition temperature of the copolymer does not rise and fall as the third monomer increases, such as P5 and P6), which is related to the selection of the second cycloolefin monomer. Furthermore, there are problems that the optical properties (refractive index is not raised but abbe number is significantly lowered) of the cycloolefin copolymer become poor after the introduction of the second cycloolefin monomer, etc., as compared with the cycloolefin copolymer into which the second cycloolefin monomer is not introduced, because the introduction of the benzene ring has a large influence on the norbornene ring that is singly present and the influence is unavoidable.

Disclosure of Invention

The application aims to provide a cycloolefin copolymer, a preparation method and application thereof, and aims to solve the problems that the cycloolefin copolymer prepared by the existing method is low in glass transition temperature and poor in optical performance.

In order to achieve the purposes of the application, the technical scheme adopted by the application is as follows:

the first aspect of the present application provides a cycloolefin copolymer having a structural general formula shown in the following formula (1-1) or formula (1-2):

in the formula (1-1) or the formula (1-2), x/(x+y+z) is more than or equal to 0.57 and less than or equal to 0.67,0.32 and less than or equal to y/(x+y+z) and less than or equal to 0.39,0.01 and less than or equal to z/(x+y+z) and less than or equal to 0.04, A is an atom or an atomic group, B is an atom or an atomic group, and A, B is not a hydrogen atom at the same time.

The cycloolefin copolymer provided by the application is formed by polymerizing ethylene monomer (first monomer counted from left corresponding to the structure shown in the formula (1-1) or the formula (1-2)), DMON monomer (second monomer counted from left corresponding to the structure shown in the formula (1-1) or the formula (1-2)), MDMON monomer (third monomer counted from left corresponding to the structure shown in the formula (1-1) or the formula (1-2)). Wherein, the polymer formed by the MDMON monomer through self ring-opening metathesis polymerization and hydrogenation has higher glass transition temperature which can reach more than 230 ℃. According to the application, MDMON monomers are introduced into the cycloolefin copolymer to improve the glass transition temperature of the cycloolefin polymer, so that the heat resistance of the cycloolefin copolymer is improved. Since MDMON polymers have high glass transition temperatures, small amounts (0.01 to 0.04% by mole based on the total polymer) of MDMON monomers form cycloolefin copolymers which can significantly increase the glass transition temperatures of cycloolefin polymers. Meanwhile, the cycloolefin copolymer provided by the application can not contain benzene ring substituent groups in MDMON monomers or has a longer distance from the benzene ring substituent groups to the reaction site-norbornene ring, so that the negative influence of the reaction on the optical properties of the cycloolefin copolymer can be reduced, and the cycloolefin copolymer can maintain good optical properties. In addition, the application can achieve the effect of obviously improving the vitrification temperature of the cycloolefin polymer by introducing a small amount of MDMON monomers, so the content of MDMON monomers can be reduced, and the application is beneficial to improving the economic efficiency of preparing the cycloolefin polymer.

As a possible implementation of the cycloolefin copolymers according to the application, A, B are each independently selected from the group consisting of hydrogen, halogen, alkyl, substituted alkyl, heteroalkyl, aryl, substituted aryl, heterocyclyl, alkoxy, hydroxy, ester, cyano, amino and thiol. By introducing MDMON containing A, B into the cycloolefin copolymer, the volume of polymer molecules is increased, and the volume effect of MDMON monomers is beneficial to improving the glass transition temperature of the cycloolefin polymer.

As a possible implementation of the cycloolefin copolymer according to the application, the alkyl group is selected from alkyl groups having a carbon number of less than or equal to 20. In this case, the above alkyl group may increase the volume of MDMON monomer, which is advantageous for increasing the glass transition temperature of the cycloolefin polymer, and simultaneously, since the number of carbon atoms of the alkyl group is in a proper range, the influence of steric hindrance on the reactivity of MDMON monomer may be reduced, which is advantageous for obtaining the cycloolefin copolymer represented by formula (1-1) or formula (1-2).

As one possible implementation manner of the cyclic olefin copolymer of the present application, the number of carbon atoms of the substituted alkyl group is less than or equal to 20, and the substituent in the substituted alkyl group is at least one of a hydroxyl group, a carboxyl group, an ester group, a cyano group, an amino group, a thiol group, and a halogen atom. In this case, the above-mentioned substituted alkyl group can increase the volume of MDMON monomer, promote MDMON monomer to produce volume effect, and is favorable for raising glass transition temperature of cycloolefin polymer, at the same time, because the number of carbon atoms of substituted alkyl group is in proper range, the influence of steric hindrance on reaction activity of MDMON monomer can be reduced. Furthermore, by introducing polar groups such as hydroxyl, carboxyl, ester, cyano, amino, thiol and the like into A, B, the polarity of the cycloolefin copolymer can be increased, so that the compatibility between the cycloolefin copolymer and the polar material is improved, the cycloolefin copolymer can be compatible with other polar materials or materials containing the polar material, and the application range of the cycloolefin copolymer is further widened.

As one possible implementation manner of the cycloolefin copolymer according to the present application, the number of carbon atoms in the heteroalkyl group is 20 or less, and the heteroatom in the heteroalkyl group is at least one of an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom. In this case, the above heteroalkyl group can increase the volume of MDMON monomer, promote MDMON monomer to generate volume effect, and is beneficial to increasing the glass transition temperature of cycloolefin polymer, and simultaneously, the carbon number of the heteroalkyl group is in a proper range, and the influence of steric hindrance on the reactivity of MDMON monomer can be reduced. Furthermore, the backbone structure of the cycloolefin copolymer has excellent affinity, and after oxygen atoms, nitrogen atoms, sulfur atoms and phosphorus atoms are introduced into A, B, the polarity of the cycloolefin copolymer can be increased, so that the compatibility between the cycloolefin copolymer and the polar material is improved, the cycloolefin copolymer can be compatible with other polar materials or materials containing the polar material, and the application range of the cycloolefin copolymer is further widened.

As a possible implementation of the cycloolefin copolymers according to the application, the aryl radicals are selected from phenyl, tolyl, naphthyl, benzyl or phenethyl. By introducing aryl into MDMON monomer structure of cycloolefin polymer, volume of MDMON monomer can be increased, volume effect of MDMON monomer can be promoted, glass transition temperature of cycloolefin polymer can be improved, and introduction of benzene ring can be beneficial to improving refractive index of cycloolefin polymer, and optical performance of cycloolefin polymer can be improved.

The aryl in the substituted aryl is selected from phenyl, tolyl, naphthyl, benzyl or phenethyl, and the substituent in the substituted aryl is at least one of alkyl, hydroxyl, carboxyl, ester, cyano, amino, thiol and halogen atoms. The aryl in the aryl is replaced, so that the glass transition temperature and refractive index of the cycloolefin polymer are improved, and polar groups such as hydroxyl, carboxyl, ester group, cyano, amino and thiol group are beneficial to regulating the polarity of the cycloolefin polymer, so that the compatibility between the cycloolefin polymer and other polar materials is improved, and the cycloolefin polymer has wider application prospect.

The heterocyclic group is selected from furan, pyran, pyridine or thiophene. The groups have certain aromaticity, are favorable for improving the glass transition temperature and refractive index of the cycloolefin polymer, and the oxygen atoms, the nitrogen atoms and the sulfur atoms are favorable for regulating the polarity of the cycloolefin polymer, so that the compatibility between the cycloolefin polymer and other polar materials is improved, and the cycloolefin polymer has wider application prospect.

As a possible implementation of the cycloolefin copolymer according to the application, A, B is each independently selected from the group consisting of hydrogen atom, halogen atom, alkoxy group, hydroxyl group, ester group, cyano group, amino group, thiol group 、-OC_nH_m、-OCOC_nH_m、-C_nH_m、-C₆H₅、-C₆H₄CH₃、-C₁₀H₇、-CH₂C₆H₅、-CH₂CH₂C₆H₅、-C_nH_mC₆H₅;, where n is a positive integer less than or equal to 10 and m.ltoreq.2n+1. Since A, B is not hydrogen atom at the same time, introducing at least one above substituted alkyl group in the formula (1-1) or the formula (1-2) can increase the volume of MDMON monomer, promote MDMON monomer to generate volume effect, be beneficial to increasing the glass transition temperature of cycloolefin polymer, introduce aryl group, be beneficial to increasing the glass transition temperature and refractive index of cycloolefin polymer, and introduce polar group or polar atom can increase the polarity of cycloolefin copolymer, thereby improving the compatibility between cycloolefin copolymer and polar material, enabling cycloolefin copolymer to be compatible with other polar materials or materials containing polar materials, and further widening the application range of cycloolefin copolymer.

As a possible implementation of the cycloolefin copolymers according to the application, the A, B is linked in a ring. A. B is connected into a ring, the volume of MDMON monomers is increased, the volume effect is increased, and the glass transition temperature of the cycloolefin polymer is improved.

As a possible implementation of the cycloolefin copolymer according to the application, the ring is an aromatic ring, a cycloalkane or a ring structure containing both an aromatic ring and a cycloalkane. In this case, the cycloolefin polymer has a relatively high glass transition temperature. When the ring is an aromatic ring or a ring structure containing both an aromatic ring and a cycloalkane, the refractive index of the cycloolefin copolymer can be increased without lowering the Abbe number of the cycloolefin copolymer, and the optical properties of the cycloolefin polymer can be improved to some extent.

As a possible implementation of the cycloolefin copolymer according to the application, the ring is one of the following ring structures:

When A, B are connected into the ring structure, the glass transition temperature of the cycloolefin polymer can be improved, and the refractive index of the cycloolefin copolymer can be improved on the premise of not reducing the Abbe number, so that the overall optical performance of the cycloolefin copolymer is improved.

As a possible implementation of the cycloolefin copolymer according to the present application, the cycloolefin copolymer is a copolymer represented by the following structure:

the cycloolefin copolymer has a good glass transition temperature, so that the glass transition temperature is endowed with good high temperature resistance. In addition, the refractive index of the cycloolefin copolymer can be improved on the premise of not reducing the Abbe number because the cycloolefin copolymer contains a benzene ring structure, so that the overall optical performance of the cycloolefin copolymer is improved.

As one possible implementation of the cycloolefin copolymer according to the application, the cycloolefin copolymer has a number average molecular weight of less than or equal to 8 ten thousand and a weight average low molecular weight of less than or equal to 15 ten thousand. In this case, the cycloolefin copolymer has a low viscosity and good fluidity at low temperatures, thereby contributing to improvement of processability of the polymer.

In a second aspect, the present application provides a process for preparing a cycloolefin copolymer, comprising the steps of:

Heating a solution system containing DMON, MDMON, ethylene, a catalyst and a cocatalyst for reaction to prepare the cycloolefin copolymer;

wherein the structural general formula of the cycloolefin copolymer is shown as the following formula (1-1) or formula (1-2):

In the formula (1-1) or the formula (1-2), the values of x, y and z are satisfied that x/(x+y+z) is more than or equal to 0.57 and less than or equal to 0.67,0.32 and y/(x+y+z) is more than or equal to 0.39,0.01 and less than or equal to 0.04, R ₁ is an atom or an atomic group, R ₂ is an atom or an atomic group, and R ₁、R₂ is not a hydrogen atom at the same time;

The catalyst is a metallocene catalyst.

According to the preparation method of the cycloolefin copolymer, DMON and quaternary cyclic cycloolefin monomer MDMON are selected as cycloolefin monomers, wherein a polymer formed by ring-opening metathesis polymerization and hydrogenation of MDMON monomers has a high glass transition temperature which can reach more than 230 ℃. Therefore, the application takes ethylene, DMON and MDMON monomers as raw materials for polymerization reaction, and can improve the glass transition temperature of the ternary cycloolefin polymer, thereby improving the heat resistance of the cycloolefin copolymer. Since MDMON polymers have high glass transition temperatures, the glass transition temperature of cycloolefin polymers can be significantly increased by adding a small amount of MDMON monomer (0.01 to 0.04 of the total molar amount of the binder polymer) to the bonding reaction. Meanwhile, according to the preparation method of the cycloolefin copolymer, since MDMON monomers do not contain benzene ring substituent groups or the distance between the benzene ring substituent groups and the reaction site-norbornene ring is far, the negative influence of the reaction on the optical properties of the cycloolefin copolymer can be reduced, and the cycloolefin copolymer can maintain good optical properties. In addition, the application can achieve the effect of obviously improving the glass transition temperature of the cycloolefin polymer by introducing a small amount of MDMON monomers, thus being capable of reducing the addition amount of MDMON monomers and being beneficial to improving the economic efficiency of preparing the cycloolefin polymer.

The structural general formula of the catalyst is shown as the following formula (2):

In formula (2), M ¹ is selected from scandium, titanium, vanadium, zirconium, hafnium, niobium or tantalum, and M ²、M³ is each independently selected from carbon, silicon, germanium or tin;

x represents carbon or silicon;

r ₁ and R ₂ are each independently selected from 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;

R ₃ and R ₄ are each independently selected from a hydrogen atom or a hydrocarbon group;

r ₅、R₆、R₇、R₈ is each independently selected from a hydrogen atom, a hydrocarbyl group, or a silicon-containing group, the silicon-containing group being attached to a carbon atom at the corresponding substitution position by a silicon atom;

R ₁₀、R₁₁、R₁₂、R₁₅、R₁₆、R₁₇ is each independently selected from alkyl, alkoxy, alkenyl, aryl, aryloxy, aralkyl, alkaryl, or aralkenyl;

R ₉、R₁₃、R₁₄、R₁₈ is each independently selected from a hydrogen atom, a hydrocarbyl group, or a hydrocarbyloxy group;

Wherein at least one of the R ₅、R₆、R₇、R₈ is a silicon-containing group and/or at least one of the M ²、M³ is silicon.

The catalyst represented by the formula (2) is advantageous in promoting polymerization of three kinds of polymerization monomers to form the cycloolefin polymer represented by the formula (1-1) or the formula (1-2).

As a possible implementation of the preparation method of the cyclic olefin copolymer of the present application, at least one of the R ₆、R₇ is the silicon-containing group, or at least one of the M ²、M³ is silicon.

In this case, the catalyst represented by the formula (2) is advantageous in promoting polymerization activity of polymerization of three polymerization monomers, and the substituent in the heteroatom-containing substituted alkyl group contains a silicon group, so that it is advantageous in controlling selectivity of the reaction monomers, and further controlling ratios of the three reaction monomers, to finally obtain a cycloolefin polymer having a structure of the formula (1-1) or the formula (1-2) in which each monomer ratio is controlled.

As a possible implementation of the preparation method of the cycloolefin copolymer according to the present application, the R ₅、R₆、R₇、R₈ is independently selected from a hydrocarbon group having 6 or less carbon atoms or a silicon-containing group. In this case, the silicon-containing group can control the selectivity of the reaction monomer and thus the ratio of the three reaction monomers by steric hindrance, and furthermore, R ₅、R₆、R₇、R₈ is the catalyst represented by the formula (2) of the silicon-containing group, and when catalyzing the polymerization reaction of the three reaction monomers, a cycloolefin copolymer having a low molecular weight (such as 8 ten thousand or less and 15 ten thousand or less in weight average) can be obtained without adding an additive such as a chain transfer agent.

As a possible implementation of the process for preparing cycloolefin copolymers according to the application, R ₁₀、R₁₁、R₁₂、R₁₅、R₁₆、R₁₇ has a carbon number of 10 or less. In this case, the catalyst has a suitable space size, which is advantageous in improving its catalytic activity.

As a possible implementation of the preparation method of the cycloolefin copolymer according to the present application, the cocatalyst is at least one of methylaluminoxane, modified methylaluminoxane, and organoboron compound. The methylaluminoxane, the modified methylaluminoxane and the organoboron compound can activate the catalyst with the structure shown in the formula (2) and improve the activity of the catalyst. When R ₅、R₆、R₇、R₈ in the catalyst is a silicon-containing group, the selectivity of the catalyst to the reaction monomer can be improved, so that the ratio of the reaction monomer in the polymerization reaction can be controlled.

As a possible implementation of the process for preparing cycloolefin copolymers according to the application, the heating reaction is carried out at a temperature of from 50 to 90℃for a period of from 2 to 60 minutes. In this case, the catalyst has a good catalytic activity, which is advantageous for improving the polymerization efficiency.

The third aspect of the present application provides an application of a cycloolefin copolymer as a camera lens material, where the cycloolefin copolymer is the cycloolefin copolymer according to the first aspect or the cycloolefin copolymer prepared by the method according to the second aspect.

The cycloolefin copolymer provided by the application has higher glass transition temperature, thus having better high temperature resistance and keeping better optical performance, and can be used as a camera lens material to endow a camera lens with good high temperature resistance and optical performance.

As one possible implementation manner of the application of the cycloolefin copolymer, the camera lens material is a vehicle-mounted camera lens material or a security camera lens material. Compared with the currently commercial cycloolefin copolymer material, the cycloolefin copolymer provided by the application is used as a vehicle-mounted camera lens material and a security camera lens material, and has better heat resistance on the basis of not affecting the optical performance of the camera lens.

Drawings

FIG. 1 is a ¹ H-NMR nuclear magnetic spectrum of cycloolefin monomer MDMON prepared in example 1 according to the present application;

FIG. 2 is a ¹³ C-NMR nuclear magnetic spectrum of novel cycloolefin monomer MDMON prepared in example 1 according to the present application;

FIG. 3 is a DSC graph of the cycloolefin copolymer P1 according to example 2 of the present application;

FIG. 4 is a nuclear magnetic resonance spectrum of ¹³ C-NMR of the cycloolefin copolymer P1 according to example 2 of the present application;

FIG. 5 is a DSC graph of the cycloolefin copolymer P2 according to example 3 of the present application;

FIG. 6 is a nuclear magnetic resonance spectrum of ¹³ C-NMR of the cycloolefin copolymer P2 according to example 3 of the present application;

FIG. 7 is a DSC graph of cycloolefin copolymer P3 according to example 4 of the present application;

FIG. 8 is a nuclear magnetic resonance spectrum of ¹³ C-NMR of the cycloolefin copolymer P3 according to example 4 of the present application;

FIG. 9 is a DSC graph of cycloolefin copolymer P4 according to example 5 of the present application;

FIG. 10 is a ¹³ C-NMR nuclear magnetic spectrum of cycloolefin copolymer P5 obtained in comparative example 1;

FIG. 11 is a DSC graph of cycloolefin copolymer P5 obtained in comparative example 1.

In the DSC graph, the abscissa "Temperature" represents Temperature, and the ordinate "Heat Flow" represents "Heat Flow".

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

In the present application, the term "and/or" describes an association relationship of an association object, which means that three relationships may exist, for example, a and/or B may mean that a exists alone, a and B exist together, and B exists alone. Wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship.

In the present application, "at least one" means one or more, and "a plurality" means two or more. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (a), b, or c)", or "at least one (a, b, and c)", may each represent a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.

It should be understood that, in various embodiments of the present application, the sequence number of each process described above does not mean that the execution sequence of some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The weights of the relevant components mentioned in the description of the embodiments of the present application may refer not only to the specific contents of the components, but also to the proportional relationship between the weights of the components, so long as the contents of the relevant components in the description of the embodiments of the present application are scaled up or down within the scope of the disclosure of the embodiments of the present application. Specifically, the mass described in the specification of the embodiment of the application can be a mass unit which is known in the chemical industry field such as mu g, mg, g, kg.

The terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated for distinguishing between objects such as substances from each other. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

The term "COC" is an abbreviation for "Cyclic Olefin Copolymer" and means cyclic olefin copolymers;

The term "DVD" is abbreviated as "Digital Video Disc" and denotes a high-density digital video disc;

The term "ROMP" is an abbreviation for "Ring-Opening Metathesis Polymerization" and represents Ring-opening metathesis polymerization;

The term "DMON" is an abbreviation for "1,2,3, 4a,5, 8a-octahydro-1,4:5,8-dimethanonaphthalene r" and means dimethylbridge octahydronaphthalene;

The term "MDMON" is an abbreviation for "Modified DMON" and represents a substituted dimethylbridged octahydronaphthalene, which is the third monomer introduced in the examples of the present application;

The term "IndNB" is an abbreviation for "1, 4a,9 a-tetrahydroo-1, 4-methano-fluor r" and represents indeno norbornene;

The term "IndDMON" is an abbreviation for "5,5a,6, 9a,10 a,11-octahydro-4bH-5,10,6,9-dimethano-benzob fluorener" representing indeno dimethbridge octahydronaphthalene;

the term "MAO" is an abbreviation for "Methylaluminoxane" and represents methylaluminoxane.

COC is widely applied due to excellent performances such as high transparency, excellent heat resistance, chemical stability, melt fluidity and dimensional stability, and a large amount of COC materials are consumed annually in China for manufacturing various commodities, but the Tg of the COC materials is lower than 140 ℃ at present, the requirements of application scenes with higher long-term use temperature are not met, and therefore, the development of optical resin materials with better heat resistance is very important.

In view of this, the embodiment of the present application provides a cycloolefin copolymer, which is a random copolymer formed of an ethylene monomer and two cycloolefin monomers, having the structural general formula (1-1) or (1-2) as follows:

The structure of formula (1-1) or formula (1-2) shows the molar content of the three monomers in the cycloolefin copolymer, but does not indicate the arrangement order of the three monomers in the cycloolefin copolymer. In the structures of the formula (1-1) or the formula (1-2) in the embodiment of the application, three monomers are randomly arranged in a molecular chain to form a random copolymer.

In the embodiment of the application, two olefin monomers are a DMON monomer and a MDMON monomer respectively, and the structures of an ethylene monomer (a first monomer from the left corresponding to the structure shown in the formula (1-1) or the formula (1-2)) and a DMON monomer (a second monomer from the left corresponding to the structure shown in the formula (1-1) or the formula (1-2)) are shown in the following formulas (1-1) and (1-2) respectively:

MDMON the monomer according to the structural difference of the formula (1-1) or the formula (1-2) includes two cases, the structures of which correspond to the third monomer of the structures shown in the formula (1-1) and the formula (1-2) from left to right, and the monomer structures of the two cases are shown in the following formulas (1-3-1) and (1-3-2), respectively:

wherein, the structure (MDMON monomer) shown in the formula (1-3-1) and the formula (1-3-2) has higher glass transition temperature which can reach more than 230 ℃ after self-ring-opening metathesis polymerization and hydrogenation. Therefore, according to the embodiment of the application, the MDMON monomer is introduced into the cycloolefin copolymer to improve the glass transition temperature of the cycloolefin polymer, so that the heat resistance of the cycloolefin copolymer is improved.

Furthermore, the reaction site-norbornene ring in the structures of the formula (1-3-1) and the formula (1-3-2) can be not connected with benzene rings, even if the benzene ring structure or substituent containing the benzene ring structure is introduced into the structures of the formula (1-3-1) and the formula (1-3-2), the distance between the benzene ring and the norbornene ring is far, so that the structure of the formula (1-3) can reduce the negative influence of the polymerization reaction on the optical property of the cycloolefin copolymer, and the cycloolefin copolymer provided by the embodiment of the application can keep good optical property. The good optical properties include at least that the Abbe number of the cycloolefin copolymer is not reduced.

In the embodiment of the application, because the glass transition temperature of MDMON polymer is high, in the formula (1-1) or the formula (1-2), the values of x, y and z are 0.57-or-minus x/(x+y+z) -0.67,0.32-or-minus y/(x+y+z) -0.39,0.01-or-minus z/(x+y+z) -0.04. The small amount of MDMON monomers forms cycloolefin copolymers which can significantly increase the glass transition temperature of cycloolefin polymers. In addition, the embodiment of the application can achieve the effect of obviously improving the glass transition temperature of the cycloolefin polymer by introducing a small amount of MDMON monomers, so that the content of MDMON monomers can be reduced, and the economic efficiency of preparing the cycloolefin polymer is improved.

A, B in the MDMON monomer which is the structure of the formula (1-3-1) and the formula (1-3-2) is A, B in the cycloolefin shown in the formula (1-1) or the formula (1-2). Wherein A is an atom or an atomic group, B is an atom or an atomic group, and A, B is not simultaneously a hydrogen atom. The introduction of atoms or atomic groups which are not hydrogen at the same time in the formulas (1-3-1) and (1-3-2) can increase the volume of MDMON monomers, promote MDMON monomers to generate volume effect, and are beneficial to increasing the glass transition temperature of the cycloolefin copolymer. In addition, the skeleton structure of the cycloolefin copolymer provided by the embodiment of the application has excellent affinity and hydrophobicity, and has better compatibility with nonpolar or weakly polar materials. According to the embodiment of the application, the polarity of the cycloolefin copolymer can be regulated by introducing the polar group or the polar atom into A, B, so that the polarity requirement of the cycloolefin copolymer in different application scenes can be met.

As one possible implementation, A, B is each independently selected from a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, a heteroalkyl group, an aryl group, a substituted aryl group, a heteroaryl group, an alkoxy group, a hydroxyl group, an ester group, a cyano group, an amino group, a thiol group. When A, B is not hydrogen atom at the same time, MDMON containing A, B is introduced into the cycloolefin copolymer, the molecular volume of the polymer is increased, and the volume effect of MDMON increases the glass transition temperature of the cycloolefin polymer.

As a possible implementation, the alkyl group is selected from alkyl groups having a carbon number of less than or equal to 20. In this case, the above alkyl group may increase the volume effect of MDMON monomers, which is advantageous in increasing the glass transition temperature of the cycloolefin polymer, and simultaneously, since the number of carbon atoms of the alkyl group is in a proper range, the influence of steric hindrance on the reactivity of MDMON monomers may be reduced, which is advantageous in obtaining the cycloolefin copolymer represented by formula (1-1) or formula (1-2). In some embodiments, the alkyl group has a carbon number of less than or equal to 10. The alkyl group may be exemplified by the following groups having an isomeric structure ：-CH₃、-C₂H₅、-C₃H₇、-C₄H₉、-C₅H₁₁、-C₆H₁₃、-C₇H₁₅、-C₈H₁₇、-C₉H₁₉、-C₁₀H₂₁.

As one possible implementation manner, the number of carbon atoms of the substituted alkyl group is less than or equal to 20, and the substituent in the substituted alkyl group is at least one of a hydroxyl group, a carboxyl group, an ester group, a cyano group, an amino group, a thiol group, and a halogen atom. In this case, the above-mentioned substituted alkyl group can increase the volume of MDMON monomer, promote MDMON monomer to produce volume effect, and is favorable for raising glass transition temperature of cycloolefin polymer, at the same time, because the number of carbon atoms of substituted alkyl group is in proper range, the influence of steric hindrance on reaction activity of MDMON monomer can be reduced. Furthermore, by introducing polar groups such as hydroxyl, carboxyl, ester, cyano, amino, thiol and the like into A, B, the polarity of the cycloolefin copolymer can be increased, so that the compatibility between the cycloolefin copolymer and the polar material is improved, the cycloolefin copolymer can be compatible with other polar materials or materials containing the polar material, and the application range of the cycloolefin copolymer is further widened. In some embodiments, the substituted alkyl group has 10 or less carbon atoms. Exemplary, substituted alkyl groups may be -CH₂OH、-C₂H₄OH、-C₃H₆OH、-C₄H₈OH、-C₅H₁₀OH、-C₆H₁₂OH、-C₇H₁₄OH、-C₈H₁₆OH、-C₉H₁₈OH、-C₁₀H₂₀OH、-CH₂COOH、-C₂H₄COOH、-C₃H₆COOH、-C₄H₈COOH、-C₅H₁₀COOH、-C₆H₁₂COOH、-C₇H₁₄COOH、-C₈H₁₆COOH、-C₉H₁₈COOH、-OCOCH₃、-COOCH₃、-COOC₂H₅、-OCOC₂H₅、-CH₂COOCH₃、-CH₂OCOCH₃、-COOC₃H₇、-OCOC₃H₇、-CH₂COOC₂H₅、-CH₂OCOC₂H₅、-C₂H₄COOCH₃、-C₂H₄OCOCH₃、-COOC₄H₉、-OCOC₄H₉、-CH₂COOC₃H₇、-CH₂OCOC₃H₇、-C₂H₄COOC₂H₅、-C₂H₄OCOCC₂H₅、-C₃H₆COOCH₃、-C₃H₆OCOCCH₃、-COOC₅H₁₁、-OCOC₅H₁₁、-CH₂COOC₄H₉、-CH₂OCOC₄H₉、-C₂H₄COOC₃H₇、-C₂H₄OCOCC₃H₇、-C₃H₆COOC₂H₅、-C₃H₆OCOCC₂H₅、-C₄H₇COOCH₃、-C₄H₇OCOCCH₃、-COOC₆H₁₃、-OCOC₆H₁₃、-CH₂COOC₅H₁₁、-CH₂OCOC₅H₁₁、-C₂H₄COOC₄H₉、-C₂H₄OCOCC₄H₉、-C₃H₆COOC₃H₇、-C₃H₆OCOCC₃H₇、-C₄H₈COOC₂H₅、-C₄H₈OCOCC₂H₅、-C₅H₁₀COOCH₃、-C₅H₁₀OCOCCH₃、-COOC₇H₁₅、-OCOC₇H₁₅、-CH₂COOC₆H₁₃、-CH₂OCOC₆H₁₃、-C₂H₄COOC₅H₁₁、-C₂H₄OCOCC₅H₁₁、-C₃H₆COOC₄H₉、-C₃H₆OCOCC₄H₉、-C₄H₈COOC₃H₇、-C₄H₈OCOCC₃H₇、-C₅H₁₀COOC₂H₅、-C₅H₁₀OCOCC₂H₅、-C₆H₁₂COOCH₃、-C₆H₁₂OCOCH₃、-COOC₈H₁₇、-OCOC₈H₁₇、-CH₂COOC₇H₁₅、-CH₂OCOC₇H₁₅、-C₂H₄COOC₆H₁₃、-C₂H₄OCOCC₆H₁₃、-C₃H₆COOC₅H₁₁、-C₃H₆OCOCC₅H₁₁、-C₄H₈COOC₄H₉、-C₄H₈OCOCC₄H₉、-C₅H₁₀COOC₃H₇、-C₅H₁₀OCOCC₃H₇、-C₆H₁₂COOC₂H₅、-C₆H₁₂OCOC₂H₅、-C₇H₁₄COOCH₃、-C₇H₁₄OCOCH₃、-CH₂CN、-C₂H₄CN、-C₃H₆CN、-C₄H₈CN、-C₅H₁₀CN、-C₆H₁₂CN、-C₇H₁₄CN、-C₈H₁₆CN、-C₉H₁₈CN、-C₁₀H₂₀CN、-CH₂NH₂、-C₂H₄NH₂、-C₃H₆NH₂、-C₄H₈NH₂、-C₅H₁₀NH₂、-C₆H₁₂NH₂、-C₇H₁₄NH₂、-C₈H₁₆NH₂、-C₉H₁₈NH₂、-C₁₀H₂₀NH₂、-CH₂SH、-C₂H₄SH、-C₃H₆SH、-C₄H₈SH、-C₅H₁₀SH、-C₆H₁₂SH、-C₇H₁₄SH、-C₈H₁₆SH、-C₉H₁₈SH、-C₁₀H₂₀SH.

As one possible implementation, the number of carbon atoms in the heteroalkyl is less than or equal to 20, and the heteroatom in the heteroalkyl is at least one of an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom. In this case, the above heteroalkyl group can increase the volume of MDMON monomer, promote MDMON monomer to generate volume effect, and is beneficial to increasing the glass transition temperature of cycloolefin polymer, and simultaneously, the carbon number of the heteroalkyl group is in a proper range, and the influence of steric hindrance on the reactivity of MDMON monomer can be reduced. Furthermore, the skeleton structure of the cycloolefin copolymer has excellent affinity, and the polarity of the cycloolefin copolymer can be increased after the oxygen atom, the nitrogen atom, the sulfur atom and the phosphorus atom are introduced into A, B, so that the compatibility between the cycloolefin copolymer and the polar material is improved, the cycloolefin copolymer can be compatible with other polar materials or materials containing the polar material, and the application range of the cycloolefin copolymer is further widened. In some embodiments, the number of carbon atoms in the heteroalkyl group is 10 or less.

As a possible implementation, the aryl group is selected from aryl groups having a carbon number of less than or equal to 30. Aryl groups include aryl and aralkyl groups. Illustratively, the aryl group is selected from the group consisting of aryl or aralkyl groups such as phenyl, tolyl, naphthyl, benzyl, and phenethyl. By introducing aryl into MDMON monomer structure of cycloolefin polymer, volume of MDMON monomer can be increased, volume effect of MDMON monomer can be promoted, glass transition temperature of cycloolefin polymer can be improved, and introduction of benzene ring can be beneficial to improving refractive index of cycloolefin polymer, and optical performance of cycloolefin polymer can be improved.

As one possible implementation, the number of carbon atoms in the substituted aryl group is less than or equal to 30. The aryl group in the substituted aryl group is exemplified by an aryl or aralkyl group such as phenyl, tolyl, naphthyl, benzyl, and phenethyl. The substituent in the substituted aryl is at least one of alkyl, hydroxyl, carboxyl, ester, cyano, amino, thiol and halogen atoms. The aryl in the aryl is replaced, so that the glass transition temperature and refractive index of the cycloolefin polymer are improved, and polar groups such as hydroxyl, carboxyl, ester group, cyano, amino and thiol group are beneficial to regulating the polarity of the cycloolefin polymer, so that the compatibility between the cycloolefin polymer and other polar materials is improved, and the cycloolefin polymer has wider application prospect.

As one possible implementation, the number of carbon atoms in the heterocyclic group is less than or equal to 30. Illustratively, the heteroaryl is selected from furan, pyran, pyridine or thiophene. The groups have certain aromaticity, are favorable for improving the glass transition temperature and refractive index of the cycloolefin polymer, and the oxygen atoms, the nitrogen atoms, the sulfur atoms and the phosphorus atoms are favorable for regulating the polarity of the cycloolefin polymer, so that the compatibility between the cycloolefin polymer and other polar materials is improved, and the cycloolefin polymer has wider application prospect.

As one possible implementation, A, B is each independently selected from a hydrogen atom, a halogen atom, an alkoxy group, a hydroxyl group, an ester group, a cyano group, an amino group, a thiol group 、-OC_nH_m、-OCOC_nH_m、-C_nH_m、-C₆H₅、-C₆H₄CH₃、-C₁₀H₇、-CH₂C₆H₅、-CH₂CH₂C₆H₅、-C_nH_mC₆H₅;, wherein n is a positive integer less than or equal to 10, m is less than or equal to 2n+1, i.e., m is a positive integer less than or equal to 21. Since A, B is not hydrogen atom at the same time, introducing at least one above substituted alkyl group in the formula (1-1) or the formula (1-2) can increase the volume of MDMON monomer, promote MDMON monomer to generate volume effect, be beneficial to increasing the glass transition temperature of cycloolefin polymer, introduce aryl group, be beneficial to increasing the glass transition temperature and refractive index of cycloolefin polymer, and introduce polar group or polar atom can increase the polarity of cycloolefin copolymer, thereby improving the compatibility between cycloolefin copolymer and polar material, enabling cycloolefin copolymer to be compatible with other polar materials or materials containing polar materials, and further widening the application range of cycloolefin copolymer.

As one possible implementation A, B are connected in a ring. The term "A, B attached in a ring" in embodiments of the present application means A, B bonded such that A, B is in a ring structure. A. After B is connected into a ring, the volume of MDMON monomers is increased, the volume effect is increased, and the glass transition temperature of the cycloolefin polymer is improved.

As one possible implementation, the ring is an aromatic ring, a cycloalkane, or a ring structure containing both an aromatic ring and a cycloalkane. In this case, the cycloolefin polymer has a relatively high glass transition temperature. When the ring is an aromatic ring or a ring structure containing both an aromatic ring and a cycloalkane, the refractive index of the cycloolefin copolymer can be increased without lowering the Abbe number of the cycloolefin copolymer, and the optical properties of the cycloolefin polymer can be improved to some extent.

As one possible implementation, the ring is one of the following ring structures:

Illustratively, MDMON monomers may be INDDMON or StDMON, but are not limited thereto.

As one possible implementation, the cyclic olefin copolymer is a polymer of the structure:

The cycloolefin copolymer has a good glass transition temperature, so that the glass transition temperature is endowed with good high temperature resistance. In addition, when the cycloolefin copolymer contains a benzene ring structure, the refractive index of the cycloolefin copolymer can be improved without reducing the Abbe number, so that the overall optical performance of the cycloolefin copolymer can be improved.

According to the embodiment of the application, the cycloolefin copolymer with different molecular weights can be obtained according to the application scene of the cycloolefin copolymer. As one possible implementation, the cycloolefin copolymer has a number average molecular weight of less than or equal to 8 ten thousand and a weight average low molecular weight of less than or equal to 15 ten thousand. In this case, the cycloolefin copolymer has a low viscosity and good fluidity at low temperatures, thereby contributing to improvement of processability of the polymer.

The cycloolefin copolymer provided by the embodiment of the application can be prepared by the following method.

Correspondingly, the embodiment of the application provides a preparation method of the cycloolefin copolymer, which comprises the following steps:

The solution system containing DMON, MDMON, ethylene, catalyst and cocatalyst is heated to react to prepare the cycloolefin copolymer.

In the embodiment of the application, two cycloolefin monomers DMON and MDMON (such as INDDMON or StDMON) and ethylene are used as polymerization monomers, and the three monomers are subjected to random copolymerization under the action of a catalyst and a cocatalyst to prepare the cycloolefin copolymer shown in the structure of the formula (1-1) or the formula (1-2).

Among them, cycloolefin monomer IndDMON, which is originally a by-product generated in the IndNB synthesis process, is rarely produced and hardly used. The structure of cycloolefin monomer IndDMON is described in example 1 and example 2. In one possible implementation, the yield of cycloolefin monomer IndDMON is increased by varying the ratio of the two starting materials for synthesis IndNB. By this method, indNB and IndDMON are mainly synthesized, and both are important cycloolefin monomers, which can be more effectively used.

The embodiment of the application can achieve the effect of greatly improving the glass transition temperature of the cycloolefin copolymer by introducing a very small amount of cycloolefin monomer MDMON, and maintain the excellent optical property of the prepared cycloolefin copolymer and the high heat-resistant cycloolefin copolymer on the basis.

In the embodiment of the application, when three reaction monomers are subjected to random polymerization, the activity of MDMON is slightly reduced, so that the feeding content of the reaction monomers is properly adjusted according to the molar ratio of the three monomers in the expected obtained copolymer. In one possible implementation, the cycloolefin polymer is prepared with a molar ratio of ethylene, DMON and MDMON of (0.57 to 0.67): 0.32 to 0.39): 0.01 to 0.04. In this case, the three can participate in the reaction in a proper ratio to prepare the cycloolefin copolymer represented by the structure of the formula (1-1) or the formula (1-2).

In the embodiment of the application, when DMON, MDMON and ethylene are added into the reaction device, the DMON and MDMON can be added into the reaction device first, and then ethylene is connected into the reaction device through a pipeline. The method can control the content of ethylene monomer and regulate the reaction efficiency by controlling the ethylene pressure during pumping.

In the embodiment of the application, a metallocene catalyst is used for catalyzing DMON, MDMON and ethylene to carry out random polymerization to form the cycloolefin copolymer with the structure shown in the formula (1-1) or the formula (1-2). In one possible implementation, the structural general formula of the catalyst is as follows (2):

x represents carbon or silicon;

The catalyst shown in the formula (2) is a cyclopentadienyl fluorene bridged transition metal catalyst, a silicon-containing heteroatom group is introduced on a cyclopentadienyl or fluorenyl group of the catalyst, and in the ternary polymerization process, a metal center M ¹ of the catalyst and a silicon atom introduced on the cyclopentadienyl or fluorenyl group generate a synergistic effect, so that chain transfer in the polymerization process can be promoted, and the insertion rate of a cycloolefin monomer is improved, thereby obtaining the cycloolefin copolymer with low molecular weight (weight average molecular weight is less than or equal to 15 ten thousand) and moderate glass transition temperature through a chain addition copolymerization mode under the condition of not additionally introducing molecular weight regulators such as hydrogen, propylene and the like. The obtained cycloolefin copolymer has low melt flow index due to low molecular weight and good processability, so that the cycloolefin copolymer is suitable for various application scenes. In addition, the silicon-containing group can control the selectivity of the reaction monomers through steric effect, so as to control the proportion of the three reaction monomers.

As one possible implementation, at least one of R ₅、R₆、R₇、R₈ is a silicon-containing group, and M ²、M³ is independently selected from carbon, germanium, or tin. In other embodiments of the application, R ₅、R₆、R₇、R₈ is independently selected from a hydrogen atom or a hydrocarbyl group, and at least one of M ²、M³ is silicon. In other embodiments of the application, at least one of R ₅、R₆、R₇、R₈ is a silicon-containing group, while at least one of M ²、M³ is silicon. The silicon-containing group is beneficial to controlling the selectivity of the reaction monomers, and further controlling the proportion of the three reaction monomers, so as to finally obtain the cycloolefin polymer with the proportion of each monomer in the structure of the formula (1-1) or the formula (1-2).

In some embodiments of the application, R ₅、R₆、R₇、R₈ is independently selected from hydrocarbyl groups having less than or equal to 6 carbon atoms or silicon-containing groups. Illustratively, the silicon-containing groups may be selected from trimethylsilyl, triethylsilyl, triphenylsilyl, but are not limited thereto.

In some embodiments of the application, at least one of R ₆、R₇ is a silicon-containing group, or at least one of M ²、M³ is silicon. The silicon-containing groups are located at the 2 position and the 5 position of the cyclopentadiene 3 position and the 4 position which are farther away from the metal center M ¹, and the introduction of the silicon-containing groups at the 3 position and the 4 position of the cyclopentadiene not only can realize the formation of weak coordination with the metal center M ¹ to promote chain transfer and reduce the molecular weight of a polymer, but also can avoid influencing the polymerization activity of the catalyst due to stronger coordination.

In some embodiments of the application, the number of carbon atoms of R ₁₀、R₁₁、R₁₂、R₁₅、R₁₆、R₁₇ is less than or equal to 10. In this case, the catalyst has a suitable space size, which is advantageous in improving its catalytic activity.

In an embodiment of the present application, the catalyst for preparing a cycloolefin copolymer further includes a cocatalyst including, but not limited to, at least one of methylaluminoxane, modified methylaluminoxane, and an organoboron compound. In some embodiments of the application, the organoboron compound comprises one or more of tris (pentafluorophenyl) boron, triphenylcarbonium tetrakis (pentafluorophenyl) borate, N-dimethylanilinium tetrakis (pentafluorophenyl) borate. The methyl aluminoxane, the modified methyl aluminoxane and the organoboron compound are used as cocatalysts, which is beneficial to ensuring the copolymerization activity of the preparation of the cycloolefin copolymer.

As a possible implementation, the molar ratio of the catalyst and the cocatalyst represented by the formula (2) is 1 (10-10000). The molar amounts of the two are in the range, which is favorable for the activation performance of the catalyst by the cocatalyst. Illustratively, the molar ratio of the catalyst and the cocatalyst represented by the formula (1-1) or the formula (1-2) is 1:100、1:200、1:300、1:400、1:500、1:600、1:700、1:800、1:900、1:1000、1:1200、1:1500、1:1800、1:2000、1:2200、1:2500、1:2800、1:3000、1:3200、1:3500、1:3800、1:4000, etc. specific molar ratio.

In the embodiment of the application, the solvent used for dispersing the raw materials and the catalyst in the solution system containing DMON, MDMON, ethylene, the catalyst and the cocatalyst is an inert solvent. In one possible implementation, the solvent is a nonpolar solvent, has better dispersibility to DMON, MDMON and ethylene, has reaction inertia and does not influence the reaction effect of the polymerization reaction. In some embodiments, the solvent is a linear alkane, a cyclic hydrocarbon, or an aromatic hydrocarbon. Illustratively, the solvent is toluene, but is not limited thereto.

In embodiments of the present application, the polymerization reaction is conducted in an inert environment. The inert environment can be nitrogen atmosphere or inert atmosphere. In some embodiments, the gaseous environment in the reaction environment is replaced with an inert environment prior to the reaction. Illustratively, the reaction ambient gas is replaced with nitrogen.

In the examples of the present application, the polymerization reaction is carried out under heating. As a possible implementation, the heating reaction is carried out at a temperature of 50-90 ℃ for a time of 2-60min. In this case, the catalyst has a good catalytic activity, which is advantageous for improving the polymerization efficiency. The temperature of the heating reaction is, for example, a specific temperature of 50 ℃, 55 ℃,60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃,100 ℃ or the like, and the heating time can be a specific time of 2min, 5min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min or the like. Generally, the higher the heating temperature, the shorter the heating time. In some embodiments, the temperature of the heating reaction is 2-20 minutes.

In one possible implementation, the reaction is carried out under heating of a solution system containing DMON, MDMON, ethylene, catalyst and cocatalyst, at a pressure of 1 to 3 atmospheres. By properly pressurizing, the progress of the reaction can be promoted. However, when the pressure is too high, the requirement on the safety performance of the equipment is higher, which is unfavorable for improving the safety performance.

After the polymerization reaction, an aqueous solution of an inorganic acid is added to the resulting solution system to remove the catalyst and the cocatalyst in the solution system, particularly for removing the cocatalyst present in a large amount in the solution system. Specifically, the catalyst and the cocatalyst are dissolved in an aqueous solution of inorganic acid, and after the aqueous solution of inorganic acid and the prepared cycloolefin polymer are layered, the catalyst and the cocatalyst dissolved in the aqueous solution of inorganic acid are removed by collecting an organic phase. In some embodiments, the inorganic acid aqueous solution contains 2-10% by mass of inorganic acid. The inorganic acid is preferably hydrochloric acid which is inexpensive and does not cause side reactions, for example. The oxidizing nature of nitric acid and the reactivity of sulfuric acid may cause other miscellaneous side reactions.

After the organic phase is collected, the organic phase is washed with water to further remove residual water-soluble impurities. The organic phase is purified with acetone and/or ethanol, and after drying, the white cycloolefin copolymer is collected. When the organic phase is purified using acetone and ethanol, the acetone and ethanol may be mixed in any ratio to form a mixed solution. The organic phase is purified by adopting acetone and/or ethanol, so that unreacted monomers in the organic phase can be removed, and the purity of the cycloolefin polymer is improved.

In some embodiments, the method for purifying the organic phase by using acetone comprises the steps of fully stirring the obtained organic layer by using acetone and/or ethanol, standing for sedimentation, filtering, adding acetone and/or ethanol into the solution collected by filtration, refluxing, filtering, and washing again. In some embodiments, the drying process is vacuum drying.

In the embodiment of the application, the structural general formula of the prepared cycloolefin copolymer is shown as the following formula (1-1) or formula (1-2):

In the formula (1-1) or the formula (1-2), the values of x, y and z are satisfied that x/(x+y+z) is more than or equal to 0.57 and less than or equal to 0.67,0.32 and y/(x+y+z) is more than or equal to 0.39,0.01 and less than or equal to 0.04, R ₁ is an atom or an atomic group, R ₂ is an atom or an atomic group, and R ₁、R₂ is not a hydrogen atom at the same time. In the case of the cycloolefin polymer having the structure represented by the formula (1-1) or the formula (1-2), as described above, the structure of the cycloolefin polymer will not be described here again for the sake of economy.

According to the preparation method of the cycloolefin copolymer provided by the embodiment of the application, DMON and quaternary cyclic cycloolefin monomer MDMON are selected as cycloolefin monomers, wherein a polymer formed by ring-opening metathesis polymerization and hydrogenation of MDMON monomers has a higher glass transition temperature which can reach more than 230 ℃. Therefore, in the embodiment of the application, ethylene, DMON and MDMON monomers are used as raw materials for polymerization reaction, so that the glass transition temperature of the ternary cycloolefin polymer can be increased, and the heat resistance of the cycloolefin copolymer can be improved. Since MDMON polymers have high glass transition temperatures, the glass transition temperature of cycloolefin polymers can be significantly increased by adding a small amount of MDMON monomer (0.01 to 0.04 of the total molar amount of the binder polymer) to the bonding reaction. Meanwhile, according to the preparation method of the cycloolefin copolymer, since MDMON monomers do not contain benzene ring substituent groups or the distance between the benzene ring substituent groups and the reaction site-norbornene ring is far, the negative influence of the reaction on the optical properties of the cycloolefin copolymer can be reduced, and good optical properties can be maintained. In addition, the embodiment of the application can achieve the effect of obviously improving the glass transition temperature of the cycloolefin polymer by introducing a small amount of MDMON monomers, thereby being beneficial to improving the economic efficiency of preparing the cycloolefin polymer.

In a third aspect, the present embodiment provides an application of a cycloolefin copolymer as a lens material for a camera, where the cycloolefin copolymer is the cycloolefin copolymer according to the first aspect or the cycloolefin copolymer prepared by the method according to the second aspect.

The cycloolefin copolymer provided by the embodiment of the application has higher glass transition temperature, thus having better high temperature resistance, keeping better optical performance, being capable of being used as a camera lens material and endowing the camera lens with good high temperature resistance and optical performance.

As a possible implementation manner of the application of the cycloolefin copolymer, the camera lens material is a vehicle-mounted camera lens material or a security camera lens material. Compared with the currently commercial cycloolefin copolymer material, the cycloolefin copolymer provided by the application is used as a vehicle-mounted camera lens material and a security camera lens material, and has better heat resistance on the basis of not affecting the optical performance of the camera lens.

The following description is made with reference to specific embodiments.

Example 1

A process for preparing a cyclic olefin monomer IndDMON comprising:

58g of cyclopentadiene, 33g of indene and 0.5g of butynedioic acid were introduced into a stainless steel autoclave and reacted at 190℃for 15 hours. Reduced pressure distillation was performed after cooling to obtain crude products of 22g IndNB and 10g IndDMON. The crude product was dissolved in hexane and recrystallized in a refrigerator, and after filtration 8g of white solid was obtained.

The 1H-NMR spectrum of the cycloolefin monomer IndDMON obtained in example 1 is shown in FIG. 1, and the 13C-NMR spectrum of the cycloolefin monomer IndDMON obtained is shown in FIG. 2.

Example 2

A method for preparing a cyclic olefin copolymer, comprising:

A glass reaction vessel containing 2.5g of a cycloolefin monomer DMON,0.25g of a cycloolefin monomer IndDMON,2.5mL of MAO (1.5 mol/L) and 45mL of toluene was connected to an ethylene pipe, the gas in the ethylene pipe was replaced with nitrogen, the ethylene gas was vented after three times of replacement, and the toluene solution in the glass vessel was saturated with ethylene by stirring. The polymerization temperature was adjusted to 90℃and 2.0mg of a 2mL toluene solution of catalyst A having the structure below was added under ethylene-introducing conditions, the ethylene pressure was adjusted to one atmosphere and maintained, and the polymerization was carried out for 5 minutes. After the polymerization is completed, the obtained reaction liquid is poured into 10% hydrochloric acid aqueous solution by mass percent, the solution is separated after full stirring, an organic layer is collected and washed twice with water, the obtained organic layer is settled under full stirring with acetone, a proper amount of acetone is added after filtration and reflux is carried out for 2 hours, the collected polymer is filtered and washed three times with acetone, and the product is placed in a vacuum drying box and dried for 18 hours at 130 ℃ to obtain the white cycloolefin copolymer P1.

The glass transition temperature of the cycloolefin copolymer obtained in example 2 was measured by the Differential Scanning Calorimetry (DSC), and the result is shown in FIG. 3. The results in FIG. 3 show that the cycloolefin copolymer prepared in example 2 has a glass transition temperature of 142.81 ℃.

The cycloolefin copolymer obtained in example 2 was subjected to high-temperature nuclear magnetic resonance spectroscopy, and the results are shown in FIG. 4. The results of fig. 4 show that the insertion rates of the cycloolefin monomers DMON and IndDMON of the cycloolefin copolymer prepared in example 2 are 32% and 1%, respectively.

The cycloolefin copolymer obtained in example 2 was weighed to have a mass of 3.42g and an activity of 2.05X10 ⁷g mol^-1h^-1, and the number average molecular weight of the cycloolefin copolymer obtained in example 2 was measured to be 47kg/mol by high temperature gel chromatography and a molecular weight distribution index was 1.73.

The cycloolefin copolymer prepared in example 2 was prepared into a cycloolefin copolymer film by a solution film plating method, and the cycloolefin copolymer film was tested by an optical instrument, and it was found that the refractive index of the cycloolefin copolymer P1 was 1.54, the Abbe number was 55.1, and the transmittance was 90.7%.

Example 3

A method for preparing a cyclic olefin copolymer, comprising:

A glass reaction vessel containing 2.5g of a cycloolefin monomer DMON,0.5g of a cycloolefin monomer IndDMON,2.5mL of MAO (1.5 mol/L) and 45mL of toluene was connected to an ethylene pipe, the gas in the ethylene pipe was replaced with nitrogen, the ethylene gas was vented after three times of replacement, and the toluene solution in the glass vessel was saturated with ethylene by stirring. The polymerization temperature was adjusted to 90℃and 2.0mg of a 2mL toluene solution of catalyst A (same as in example 1) was added under the condition of introducing ethylene, and the ethylene pressure was adjusted and maintained at one atmosphere to carry out polymerization for 5 minutes. After the polymerization is completed, the obtained reaction liquid is poured into 10% hydrochloric acid aqueous solution by mass percent, the solution is separated after full stirring, an organic layer is collected and washed twice with water, the obtained organic layer is settled under full stirring with acetone, a proper amount of acetone is added for refluxing for 2 hours after filtration, the collected polymer is filtered and washed three times with acetone, and the product is placed in a vacuum drying oven and dried for 18 hours at 130 ℃ to obtain the white cycloolefin copolymer P2.

The glass transition temperature of the cycloolefin copolymer obtained in example 3 was measured by the Differential Scanning Calorimetry (DSC), and the result is shown in FIG. 5. The results in FIG. 5 show that the cycloolefin copolymer prepared in example 3 has a glass transition temperature of 150.58 ℃.

The high-temperature nuclear magnetic resonance spectrum of the cycloolefin copolymer obtained in example 3 was examined, and the results are shown in FIG. 6. The results of fig. 6 show that the insertion rates of the cycloolefin monomers DMON and IndDMON of the cycloolefin copolymer prepared in example 3 are 35.4% and 1.6%, respectively.

The cycloolefin copolymer obtained in example 3 was weighed to have a mass of 2.82g and an activity of 1.69X 10 ⁷g mol^-1h^-1, and the number average molecular weight of the cycloolefin copolymer obtained in example 3 was examined by high temperature gel chromatography to be 37kg/mol and a molecular weight distribution index was 1.78.

The cycloolefin copolymer prepared in example 3 was prepared into a cycloolefin copolymer film by a solution film plating method, and the cycloolefin copolymer film was tested by an optical instrument, and it was found that the refractive index of the cycloolefin copolymer P2 was 1.54, the Abbe number was 53.2, and the transmittance was 90.6%.

Example 4

A method for preparing a cyclic olefin copolymer, comprising:

A glass reaction vessel containing 2.5g of a cycloolefin monomer DMON,1g of a cycloolefin monomer IndDMON,2.5mL of MAO (1.5 mol/L) and 45mL of toluene was connected to an ethylene pipe, the gas in the ethylene pipe was replaced with nitrogen, the ethylene gas was purged three times, and the toluene solution in the glass vessel was saturated with ethylene by stirring. The polymerization temperature was adjusted to 90℃and 1.5mg of a 2mL toluene solution of catalyst B having the structure below was added under ethylene-introducing conditions, the ethylene pressure was adjusted to one atmosphere and maintained, and the polymerization was carried out for 5 minutes. After the polymerization is completed, the obtained reaction liquid is poured into 10% hydrochloric acid aqueous solution by mass percent, the solution is separated after full stirring, an organic layer is collected and washed twice with water, the obtained organic layer is settled under full stirring with acetone, a proper amount of acetone is added after filtration and reflux is carried out for 2 hours, the collected polymer is filtered and washed three times with acetone, and the product is placed in a vacuum drying box and dried for 18 hours at 130 ℃ to obtain the white cycloolefin copolymer P3.

The glass transition temperature of the cycloolefin copolymer obtained in example 4 was measured by the Differential Scanning Calorimetry (DSC), and the result is shown in FIG. 7. The results in FIG. 7 show that the cycloolefin copolymer prepared in example 4 has a glass transition temperature of 164.89 ℃.

The high temperature nuclear magnetic resonance spectrum of the cycloolefin copolymer obtained in example 4 was examined, and the result is shown in FIG. 8. The results of fig. 8 show that the insertion rates of the cycloolefin monomers DMON and IndDMON of the cycloolefin copolymer prepared in example 4 are 39% and 4%, respectively.

The cycloolefin copolymer obtained in example 4 was weighed to have a mass of 1.78g and an activity of 1.07X 10 ⁷g mol^-1h^-1, and the cycloolefin copolymer obtained in example 4 was examined by high-temperature gel chromatography to have a number average molecular weight of 38kg/mol and a molecular weight distribution index of 1.77.

The cycloolefin copolymer prepared in example 4 was prepared into a cycloolefin copolymer film by a solution film plating method, and the cycloolefin copolymer film was tested by an optical instrument, and it was found that the refractive index of the cycloolefin copolymer P3 was 1.55, the Abbe number was 53.5, and the transmittance was 91.4%.

Example 5

A method for preparing a cyclic olefin copolymer, comprising:

a glass reaction vessel containing 2.5g of a cycloolefin monomer DMON,0.5g of a cycloolefin monomer StDMON,2.5mL of MAO (1.5 mol/L) and 45mL of toluene was connected to an ethylene pipe, the gas in the ethylene pipe was replaced with nitrogen, the ethylene gas was vented after three times of replacement, and the toluene solution in the glass vessel was saturated with ethylene by stirring. The polymerization temperature was adjusted to 90℃and 1.5mg of a 2mL toluene solution of the structural catalyst B (same as in example 4) was added under the condition of introducing ethylene, and the pressure of ethylene was adjusted and maintained at one atmosphere to carry out the polymerization for 5 minutes. After the polymerization is completed, the obtained reaction liquid is poured into 10% hydrochloric acid aqueous solution by mass percent, the solution is separated after full stirring, an organic layer is collected and washed twice with water, the obtained organic layer is settled under full stirring with acetone, a proper amount of acetone is added after filtration and reflux is carried out for 2 hours, the collected polymer is filtered and washed three times with acetone, and the product is placed in a vacuum drying box and dried for 18 hours at 130 ℃ to obtain the white cycloolefin copolymer P4.

The glass transition temperature of the cycloolefin copolymer obtained in example 2 was measured by the Differential Scanning Calorimetry (DSC), and the result is shown in FIG. 9. The results in FIG. 9 show that the cycloolefin copolymer prepared in example 5 has a glass transition temperature of 157 ℃.

The cycloolefin copolymer obtained in example 5 was examined by high-temperature nuclear magnetic resonance spectroscopy, and the insertion rates of the cycloolefin monomers DMON and StDMON of the cycloolefin copolymer were 35.8% and 2%, respectively.

The cycloolefin copolymer obtained in example 5 was weighed to have a mass of 2.66g and an activity of 1.60X 10 ⁷g mol^-1h^-1, and the number average molecular weight of the cycloolefin copolymer obtained in example 5 was measured to be 36kg/mol by high temperature gel chromatography and a molecular weight distribution index was 1.78.

The cycloolefin copolymer prepared in example 5 was prepared into a cycloolefin copolymer film by a solution film plating method, and the cycloolefin copolymer film was tested by an optical instrument, and it was found that the refractive index of the cycloolefin copolymer P4 was 1.55, the Abbe number was 53.2, and the transmittance was 90.1%.

Comparative example 1

A method for preparing a cyclic olefin copolymer, comprising:

A glass reaction kettle containing 2.5g of cycloolefin monomer DMON,2.5mL of MAO (1.5 mol/L) and 45mL of toluene is connected into an ethylene pipeline, the gas in the ethylene pipeline is replaced by nitrogen, the ethylene gas is opened after three times of replacement, and the toluene solution in the glass kettle is saturated with ethylene by stirring treatment. The polymerization temperature was adjusted to 90℃and a solution of 1.2mg of metallocene catalyst B (same as in example 4) in 2mL of toluene was added under the condition of introducing ethylene, and the pressure of ethylene was adjusted and maintained at one atmosphere to carry out polymerization for 5 minutes. After the polymerization is completed, the obtained reaction liquid is poured into 10% hydrochloric acid aqueous solution by mass percent, the solution is separated after full stirring, an organic layer is collected and washed twice with water, the obtained organic layer is settled under full stirring with acetone, a proper amount of acetone is added after filtration and reflux is carried out for 2 hours, the collected polymer is filtered and washed three times with acetone, and the product is placed in a vacuum drying box and dried for 18 hours at 130 ℃ to obtain the white cycloolefin copolymer P5.

The glass transition temperature of the cycloolefin copolymer obtained in comparative example 1 was examined by the Differential Scanning Calorimetry (DSC), and the results are shown in FIG. 10. The results in FIG. 10 show that the cycloolefin copolymer prepared in comparative example 1 has a glass transition temperature of 128 ℃.

The cycloolefin copolymer obtained in comparative example 1 was subjected to high-temperature nuclear magnetic resonance spectroscopy, and the results are shown in FIG. 11. The results of fig. 11 show that the insertion rate of the cycloolefin monomer DMON of the cycloolefin copolymer prepared in the comparative example is 30%.

The cycloolefin copolymer obtained in comparative example 1 was weighed to have a mass of 3.72g and an activity of 2.23X10 ⁷g mol^-1h^-1, and the cycloolefin copolymer obtained in comparative example 1 was examined by high-temperature gel chromatography to have a relative number average molecular weight of 54kg/mol and a molecular weight distribution index of 1.62.

The cycloolefin copolymer prepared in comparative example 1 was prepared into a cycloolefin copolymer film by a solution film plating method, and the cycloolefin copolymer film was tested by an optical instrument, and it was found that the refractive index of the cycloolefin copolymer P5 was 1.54, the Abbe number was 59.1, and the transmittance was 91.0%.

Comparative example 2

The cycloolefin copolymer P6 prepared in Table3 sample 5 of the patent U.S. Pat. No. 3, 20200369812A1 has a glass transition temperature of 154℃and the cycloolefin copolymers prepared in comparative Example 2 have an insertion rate of the cycloolefin monomers DMON and IndNB of 21.3% and 15.4%, respectively, and refractive indices and Abbe numbers of 1.56 and 47, respectively.

In the preparation methods of examples 2 to 4 and comparative examples 1 to 2, the cycloolefin monomers DMON and IndNB were selected and used in the amounts thereof, the reactivity was obtained, and the numbers of cycloolefin copolymers, the insertion amounts of the ethylene monomers, the cycloolefin monomers DMON and IndNB, mn, the glass transition temperature, abbe numbers and the results of transmittance were statistically shown in Table 1 below.

TABLE 1

As can be seen from Table 1, compared with comparative example 1, the Abbe number and transmittance of the cycloolefin monomers IndDMON and StDMON were not significantly reduced in the examples of the present application, but the glass transition temperature was increased, and it can be seen that the heat resistance of the cycloolefin copolymer prepared in the examples of the present application was improved on the basis of maintaining the good optical properties.

Compared with comparative example 2, the cycloolefin copolymer prepared by the embodiment of the application has a very small amount of IndDMON, stDMON as cycloolefin monomer, the Abbe number is improved, the better refractive index can be maintained, and the vitrification temperature is 143-165 ℃, so that the cycloolefin copolymer prepared by the embodiment of the application has better optical performance and heat resistance, namely the cycloolefin copolymer provided by the embodiment of the application does not sacrifice the optical performance to improve the vitrification temperature. In particular, the cycloolefin copolymer obtained in example 4 has an insertion amount of the cycloolefin monomer IndDMON of only about one fourth of that of comparative example 2, but since the cycloolefin monomer IndDMON has a multi-ring structure and a benzene ring structure affecting an Abbe number is far away from a polymerization site, the Abbe number of the cycloolefin copolymer obtained in example 4 is higher than that of the cycloolefin copolymer provided in comparative example 2, and a glass transition temperature is higher than that of the cycloolefin copolymer provided in comparative example 2.

The test method of the embodiment and the comparative case of the application is as follows:

refractive index test method refers to ASTM D542;

Transmittance test method refers to ASTM D1003;

The insertion rate refers to the molar ratio of the cycloolefin monomer in the polymer, and is calculated by high-temperature nuclear magnetism, wherein the insertion rate is =a/(a+b+c) ·100%, wherein a is the molar amount of the cycloolefin monomer in the polymer, b is the molar amount of other cycloolefin monomers in the polymer, and c is the molar amount of polyethylene in the polymer;

mn refers to the number average molecular weight of the polymer, the number of which is directly measured by high temperature GPC.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims

1. A cycloolefin copolymer characterized in that the structural general formula of the cycloolefin copolymer is represented by the following formula (1-1) or the formula (1-2):

formula (1-1) formula (1-2)

In the formula (1-1) or the formula (1-2), the values of x, y and z are 0.57-0.67,0.32 y/(x+y+z) -0.39,0.01-0.04, A is an atom or an atomic group, B is an atom or an atomic group, A and B are not hydrogen atoms at the same time, A and B can be connected into a ring or not, and the vitrification temperature of the cycloolefin copolymer is 143-165 ℃.

2. The cycloolefin copolymer according to claim 1, wherein a and B are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, a heteroalkyl group, an aryl group, a substituted aryl group, a heterocyclic group, an alkoxy group, a hydroxyl group, an ester group, a cyano group, an amino group, and a thiol group.

3. The cycloolefin copolymer according to claim 2, wherein the alkyl group is selected from alkyl groups having 20 or less carbon atoms;

the carbon number of the substituted alkyl is less than or equal to 20, and the substituent in the substituted alkyl is at least one of hydroxyl, carboxyl, ester, cyano, amino, thiol and halogen atoms;

The number of carbon atoms in the heteroalkyl is less than or equal to 20, and the heteroatom in the heteroalkyl is at least one of an oxygen atom, a nitrogen atom, a sulfur atom and a phosphorus atom.

4. The cyclic olefin copolymer according to claim 2, wherein the aryl group is selected from phenyl, tolyl, naphthyl, benzyl or phenethyl;

The aryl in the substituted aryl is selected from phenyl, tolyl, naphthyl, benzyl or phenethyl, and the substituent in the substituted aryl is at least one of alkyl, hydroxyl, carboxyl, ester, cyano, amino, thiol and halogen atoms;

the heterocyclic group is selected from furan, pyran, pyridine or thiophene.

5. The cycloolefin copolymer according to any one of claims 1 to 4, wherein A and B are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkoxy group, a hydroxyl group, an ester group, a cyano group, an amino group, a thiol group, an alkyl group, and a substituted alkyl group 、-C₆H₅、-C₆H₄CH₃、-C₁₀H₇、-CH₂C₆H₅、-CH₂CH₂C₆H₅.

6. The cycloolefin copolymer according to claim 1, wherein the A and the B are linked to form a ring.

7. The cycloolefin copolymer as claimed in claim 6, wherein the ring is an aromatic ring, a cycloalkane or a ring structure containing both an aromatic ring and a cycloalkane.

8. The cyclic olefin copolymer according to claim 7, wherein the ring is one of the following ring structures:

。

9. The cycloolefin copolymer according to any one of claims 1, 6 to 8, characterized in that the cycloolefin copolymer is a copolymer having the structure:

。

10. the cycloolefin copolymer according to claim 1,2 or 4, characterized in that the cycloolefin copolymer is a copolymer having the structure:

。

11. The cyclic olefin copolymer of claim 1, wherein the cyclic olefin copolymer has a number average molecular weight of less than or equal to 8 ten thousand and a weight average molecular weight of less than or equal to 15 ten thousand.

12. A process for the preparation of a cyclic olefin copolymer, comprising the steps of:

Heating a solution system containing DMON, MDMON, ethylene, a catalyst and a cocatalyst for reaction to prepare the cycloolefin copolymer, wherein the structural formula of the DMON is The MDMON has the structural formula ofOr alternatively;

formula (1-1) formula (1-2)

In the formula (1-1) or the formula (1-2), the values of x, y and z are 0.57-0.67,0.32 y/(x+y+z) -0.39,0.01-0.04, A is an atom or an atomic group, B is an atom or an atomic group, A, B is not a hydrogen atom, A and B can be connected into a ring or not, and the vitrification temperature of the cycloolefin copolymer is 143-165 ℃;

The catalyst is a metallocene catalyst.

13. The method for preparing a cycloolefin copolymer according to claim 12, characterized in that the structural general formula of the catalyst is represented by the following formula (2):

(2)

x represents carbon or silicon;

14. The method for producing a cycloolefin copolymer according to claim 13, characterized in that at least one of the R ₆、R₇ is the silicon-containing group or at least one of the M ²、M³ is silicon.

15. The process for preparing cycloolefin copolymers according to claim 13 or 14, characterized in that R ₅、R₆、R₇、R₈ is independently selected from hydrocarbon groups having a carbon number of 6 or less or silicon-containing groups.

16. The method for producing a cycloolefin copolymer according to claim 13, characterized in that the number of carbon atoms of R ₁₀、R₁₁、R₁₂、R₁₅、R₁₆、R₁₇ is 10 or less.

17. The method for preparing a cycloolefin copolymer according to claim 12, wherein the cocatalyst is at least one of methylaluminoxane, modified methylaluminoxane, and an organoboron compound.

18. The process for preparing cycloolefin copolymers according to claim 12, characterized in that the heating reaction is carried out at a temperature of from 50 to 90℃for a period of from 2 to 60 min.

19. Use of a cyclic olefin copolymer as a camera lens material, characterized in that the cyclic olefin copolymer is a cyclic olefin copolymer according to any one of claims 1 to 11 or a cyclic olefin copolymer prepared by a method according to any one of claims 12 to 18.

20. The use of claim 19, wherein the camera lens material is a vehicle camera lens material, a security camera lens material.