Cycloolefin polymer and preparation method thereof

Abstract

According to the cycloolefin polymer and the preparation method thereof, N, O and S aromatic heterocyclic structures with high polarizability are introduced into polymer molecules, so that the polymer material has low birefringence of 4-27 and high light transmittance of more than 90% while achieving a high refractive index of 1.60-1.72, and shows very excellent optical performance. Compared with commercially available cycloolefin polymers, the cycloolefin polymer has multiple advantages of optical and physical properties, and has an extremely wide application prospect in high-end optical equipment and elements such as AR / VR, security lenses and the like.

Description

Technical Field

[0001] This invention relates to the field of polyolefins, and more specifically to a high-refractive-index, low-birefractive-index cyclic olefin polymer and its preparation method. Background Technology

[0002] Cyclic olefin polymers (COPs) are widely used in optical lenses, thin films, and light guides due to their high transparency, low moisture absorption, and good heat resistance. However, with the increasing demands for "thinness, high image quality, and low aberration" in emerging applications such as AR / VR, automotive HUDs, and ultra-high-definition mobile phone lenses, two major drawbacks of traditional COP materials are becoming increasingly prominent: ① Refractive index bottleneck: The refractive index is generally only 1.50–1.54, which is insufficient to provide enough refractive power in short focal length and ultra-thin structures. To shorten the focal length and reduce the overall length of the lens, the industry has to increase the number of lenses or adopt glass / wafer-level hybrid packaging, resulting in a simultaneous increase in module thickness, weight, and cost; ② Uncontrolled birefringence: After introducing fused rings or polar groups to increase the refractive index, the molecular chain orientation stress increases, and the birefringence (Δn) often exceeds 10 × 10⁻ 4 This leads to image distortion and chromatic aberration, which is particularly intolerable in high-pixel, wide-angle lenses.

[0003] Existing technologies primarily employ three routes for improvement. First, introducing condensed aromatic ring structures such as naphthalene and fluorene into the main chain or side chains can increase the refractive index to 1.58–1.62, but the rigid aromatic rings have poor symmetry and tend to orient along the flow direction during melt processing, causing a sharp increase in Δn. Second, physically blending high-refractive-index nanoparticles such as TiO2 and ZrO2 can increase the refractive index n at low filling amounts, but this leads to problems such as particle agglomeration, decreased transparency, and difficulty in secondary dispersion. Third, first synthesizing COP containing reactive side groups, and then introducing polar groups through click chemistry or esterification followed by functionalization, is a cumbersome process, and the grafting uniformity is limited by polymer solubility and reaction kinetics, making scale-up difficult.

[0004] In summary, existing cyclic olefin copolymers inevitably suffer a decline in other properties when increasing refractive index or birefringence, failing to meet the demand for excellent overall performance. Therefore, developing cyclic olefin polymers with low refractive index and birefringence, and with easy-to-operate preparation processes, along with their preparation methods, has become a key technology urgently needing breakthroughs in the field of optical resins. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a high-refractive-index, low-birefractive-index cyclic olefin polymer and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a cyclic olefin polymer having the structure shown in Formula I:

[0008] Formula I

[0009] In Formula I, m and n are the degree of polymerization, 50≤m≤750, 50≤n≤850; i and j are the number of rings, i is an integer from 0 to 2, preferably i is 0, j is an integer from 0 to 2, preferably j is 0; X represents one or more of C, N, O, S atoms or -SO2, -C=O, -N-CH3 groups; R1 is independently selected from one or more of H, alkyl, cycloalkyl, and phenyl; R2 and R3 are independently selected from one or more of H, alkyl, cycloalkyl, alkenyl, alkynyl, and phenyl, respectively; R2 and R3 are bonded to each other to form a ring or are not bonded.

[0010] Preferably, R2 and R3 are bonded together to form a five-membered ring or a six-membered ring.

[0011] Preferably, R1 is H, R2 is H, methyl, ethyl, cyclopentyl, cyclohexyl, or phenyl, and R3 is H, methyl, ethyl, cyclopentyl, cyclohexyl, or phenyl.

[0012] The cyclic olefins in this application can be block copolymers or non-block copolymers, such as random copolymers.

[0013] The present invention also provides a method for preparing the cyclic olefin polymer, comprising the following steps:

[0014] (1) Polymerization: In the presence of a polymerization catalyst, an organic solvent and a chain transfer agent, a ring-opening metathesis polymerization reaction is carried out using the cyclic olefin monomers shown in Formula II and Formula III to prepare unsaturated cyclic olefin polymers.

[0015] (2) Hydrogenation: The unsaturated cyclic olefin polymer obtained in step (1) is subjected to a hydrogenation reaction with a hydrogen source to obtain the cyclic olefin polymer described in this invention.

[0016] The structure of the cyclic olefin monomer shown in Formula II is as follows:

[0017] Formula II

[0018] In Equation II, the selection of i, X, and R1 is the same as in Equation I.

[0019] The structure of the cyclic olefin monomer shown in Formula III is as follows:

[0020] Formula III;

[0021] In Equation III, the selection of j, R2, and R3 is the same as in Equation I, and R2 and R3 are bonded to each other to form a ring or are not bonded.

[0022] In a preferred embodiment of the present invention, the compound represented by Formula II is selected from at least one of the H1H7 structures:

[0023]

[0024] In a preferred embodiment of the present invention, the compound represented by Formula III is selected from at least one of the M1M9 structures:

[0025]

[0026] The present invention does not impose any special restrictions on the source of the cyclic olefin monomers with the structures shown in Formula II and Formula III, which can be obtained by preparation methods well known to those skilled in the art or through commercial channels.

[0027] Preferably, the molar ratio of the cyclic olefin monomers of Formula II to those of Formula III is 1:17 to 13:1, more preferably 1:5 to 5:1.

[0028] In this invention, cyclic olefin monomers and polymerization catalysts are dissolved in solvents, and then a subsequent ring-opening metathesis polymerization reaction is carried out. The resulting cyclic olefin polymer solution is then hydrogenated with a hydrogenation catalyst.

[0029] In this invention, the number average molecular weight of the cyclic olefin polymer is 5,000 to 100,000, for example, 5,000, 10,000, 20,000, 30,000, 40,000, 50,000, or 100,000.

[0030] In this invention, the molar content of double bonds in the cyclic olefin polymer is ≤50%, for example 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 1%, preferably ≤1%.

[0031] An exemplary method for preparing a cyclic olefin polymer, using the structural unit shown in Formula II as an example, is illustrated by the following reaction route:

[0032]

[0033] The polymerization catalyst is selected from any one or at least a combination of two of tungsten-based catalysts, Grubbs series catalysts, and Schrock series catalysts. This invention does not impose any special restrictions on the source of the polymerization catalyst; catalysts of the aforementioned types well known to those skilled in the art can be used and are commercially available.

[0034] Preferably, the amount of the polymerization catalyst added is 0.1 to 100 ppm of the total mass of the monomer, more preferably 0.5 to 50 ppm.

[0035] The organic solvent includes one or more combinations of dichloromethane, chloroform, tetrachloroethane, chlorobenzene, o-dichlorobenzene, trichlorobenzene, cyclohexane, methylcyclohexane, toluene, or xylene. This invention does not impose any special restrictions on the source of the solvent; solvents of the above-mentioned types, well-known to those skilled in the art, and commercially available, can be used.

[0036] The chain transfer agent is selected from at least one of 1-pentene, 1-hexene, 1-heptene, 1-octene, styrene, vinyl ether, etc. The present invention does not impose any special restrictions on the source of the chain transfer agent; solvents of the aforementioned types well known to those skilled in the art can be used, and these solvents can be purchased commercially.

[0037] Preferably, the amount of chain transfer agent added is 0.1% to 10% of the total mass of the monomer, more preferably 0.2% to 2%.

[0038] The ring-opening metathesis polymerization reaction is carried out at a temperature of 10℃-120℃, for example, 0℃, 10℃, 30℃, 50℃, 80℃, 100℃, 120℃; and for a time of 2-200min, for example, 2min, 10min, 20min, 30min, 40min, 50min, 100min, 200min.

[0039] Preferably, the hydrogenation reaction is carried out in the presence of a hydrogenation catalyst, which can be a homogeneous or heterogeneous catalyst. The heterogeneous catalyst may be a solid catalyst containing a noble metal supported on a support, such as ruthenium, platinum, nickel, rhodium, or ruthenium, and the support may be carbon, silica, alumina, or titanium dioxide. Suitable examples of homogeneous catalysts include nickel naphthenate, nickel acetylacetonate, cobalt octanoate, titanium dichlorodichlorocerocene, rhodium acetate, rhodium chloride tris(triphenylphosphine)rhodium, ruthenium dichlorotris(triphenylphosphine)ruthenium chloride, ruthenium carbonyl chloride tris(triphenylphosphine)ruthenium chloride, and ruthenium dichlorocarbonyl tris(triphenylphosphine)ruthenium. The present invention does not impose any particular limitation on the source of the hydrogenation catalyst; solvents of the types described above, well-known to those skilled in the art, can be used and are commercially available. The hydrogenation catalyst may also contain a co-catalyst, such as n-butyllithium, alkylaluminum, or haloalkylaluminum. In some preferred embodiments of the present invention, when the noble metal of the hydrogenation catalyst is nickel, cobalt, or titanium, a co-catalyst needs to be added.

[0040] Preferably, the amount of hydrogenation catalyst added is 10-10000 ppm of the total mass of the monomer, more preferably 20-5000 ppm.

[0041] Preferably, the hydrogen source is hydrogen gas.

[0042] The hydrogenation reaction is carried out at a temperature of 25℃-250℃, for example, 25℃, 50℃, 75℃, 100℃, 150℃, 200℃, and 250℃; for a time of 1-12h, for example, 1h, 2h, 3h, 4h, 5h, 10h, and 12h; and for a hydrogen pressure of 1-10MPa, for example, 1, 2, 3, 4, 5, and 10MPa.

[0043] Compared with the prior art, the present invention has the following advantages and technical effects:

[0044] This invention revolutionizes the molecular design paradigm of high-refractive-index cyclic olefin polymers with a "one-step side-chain heteroatom aromatic cyclization" strategy. Traditional routes either embed fused aromatic rings in the main chain or rely on secondary grafting or inorganic nanocomposites, often resulting in a vicious cycle of "uncontrolled birefringence with increasing refractive index, a sharp narrowing of the processing window, and a surge in water absorption." In contrast, this invention precisely suspends highly polarizable aromatic rings containing heteroatoms such as O, S, and N on the side chains of strained cyclic olefins, and uses a Grubbs or SchrockMo / W catalytic system highly tolerant to polar functional groups for ring-opening metathesis polymerization, followed by hydrogenation end-capping, directly yielding polymers with n≥1.60 and Δn≤5×10⁻⁻⁻⁶. 4 This homogeneous resin, with a Tg > 140℃, can be used to mold 0.2mm ultrathin lenses in a single step using a conventional injection molding machine without the need for fractional purification. The heteroatoms are far from the main chain backbone, maintaining the inherent low polarity of the cycloolefin backbone while simultaneously relaxing orientation stress through the synergistic effect of side chain dipole moments and flexible spacers, reducing the saturated water absorption rate to below 0.01%. Furthermore, the entire process eliminates multiple functionalization, solvent recovery, and nano-dispersion steps, allowing for the removal of catalyst residues at the ppm level through simple adsorption. Production costs are reduced by 20–30% compared to existing post-modified high-refractive-index COP, achieving a true breakthrough in both high refractive index and low birefringence, as well as ease of processing and low cost. This fills the gap in ultrathin, lightweight, and high-quality resin materials for high-end mobile terminals, automotive HUDs, AR / VR, and other optical systems. Detailed Implementation

[0045] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0047] It is readily understood that the above embodiments are merely illustrative examples for clear explanation and do not imply that the invention is limited thereto. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

[0048] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0049] All raw materials used in the examples are conventional raw materials in the art, and the purity specifications used are analytical grade or chemically pure:

[0050] High-purity hydrogen: 99.999%, Dalian Guangming Special Gases Co., Ltd.;

[0051] Argon: 99.99%, Dalian Guangming Special Gases Co., Ltd.;

[0052] Dicyclopentadiene: 98% (GC), Sigma-Aldrich;

[0053] Norbornene: 98%, TCI;

[0054] Tetracyclododecene: 98%, TCI;

[0055] 2,5-Norbornene: 97%, Alfa;

[0056] Tricyclopentadiene: ≥95%, TRC2-phenyl-5-norbornene: 98%, Adamas

[0057] 2-Cyclohexane-5-norbornene: 95%, Bydex

[0058] Cyclopentene: 98%, Adamas

[0059] Cyclooctene: 95%, Adamas

[0060] 2-Bromodithionthane: 97%, Adamas;

[0061] 2-Bromodibenzo-p-dioxin: 97%, Adamas;

[0062] 2-Bromophenazine: 98%, Leyan;

[0063] 2-Bromoanthraquinone: 98%, Alfa;

[0064] 2-Bromoanthracene: 97%, Alfa;

[0065] 1-Hexene: 99%, Sigma-Aldrich;

[0066] Styrene: 99%, Bailingwei Technology;

[0067] Anhydrous ethanol: 99.7%, Alfa;

[0068] Tetrahydrofuran: 99%, Alfa;

[0069] N,N-Dimethylformamide: 98%, Alfa;

[0070] Triethylamine: 99%+, Alfa;

[0071] Hydrogen peroxide: 33%, Adamas;

[0072] Glacial acetic acid: 99.5%, Adamas;

[0073] Hydrochloric acid: 17.98%, Adamas;

[0074] Toluene: 99.8%, Adamas;

[0075] Sodium chloride: 99%, Adamas;

[0076] Anhydrous sodium sulfate: 99.5%, Sigma-Aldrich;

[0077] Grubbs third-generation catalyst: 99.95%, Shanghai Aladdin;

[0078] Nickel acetylacetone: 95%, Shanghai Aladdin;

[0079] Triisobutylaluminum: 1.0M n-hexane solution, Shanghai Aladdin;

[0080] n-Butyllithium: 2.5M n-hexane solution, TCI;

[0081] Dichlorotriphenylphosphine palladium: 99%, Adamas;

[0082] Sodium dithionite: 85%, Alfa;

[0083] ZEONEXK26R:ZEONEX Co., Ltd.

[0084] ZEONEX360R: ZEONEX Co., Ltd.;

[0085] The structures of the compounds and polymers synthesized in this invention were determined by a Bruker ARX400 nuclear magnetic resonance spectrometer, using deuterated chloroform (CDCl3), deuterated benzene (C6D6), and deuterated 1,1,2,2 tetrachloroethane (C2D2Cl4) as solvents, at room temperature or 90°C.

[0086] The molecular weight and molecular weight distribution of the polymer synthesized in this invention were obtained by testing with a PLGPC220 at 150°C using three PLgel 10μm MIXEDB separation columns in series, with 1,2,4-trichlorobenzene as the solvent.

[0087] The refractive index (nd) and Abbe number (vd) of the polymer were measured using an Atago DRM4 refractometer according to ASTM D542 standard; the birefringence (CR) of the polymer was measured using a PlaWPA200.

[0088] Example 1

[0089] Synthesis of cyclic olefin monomer H1 (ring number 0)

[0090] H1

[0091] 4.06 mmol of 2-bromodithionane, 16.3 mmol of freshly distilled norbornene, and 0.16 mmol of dichlorotriphenylphosphine palladium were dissolved in 1.8 mL of a mixed solvent of triethylamine and 1.9 mL of N,N-dimethylformamide, and degassed by bubbling with argon for 15 minutes. The resulting mixture was stirred at 80°C for 6 hours and then cooled to room temperature. 10 mL of toluene and 10 mL of 10% hydrochloric acid aqueous solution were added, and the organic layer was separated. The aqueous layer was extracted with toluene. The combined organic phases were washed successively with water and saturated brine, dried over anhydrous Na₂SO₄, filtered, and concentrated by rotary evaporation. Finally, the desired monomer H1 was obtained by silica gel column chromatography (cyclohexane).

[0092] 1HNMR(400MHz, CDCl3):7.50-7.46(m,2H),7.41-7.40(m,1H),7.39(d,J=8.1Hz,1H ),7.25-7.21(m,2H),7.15(ddd,J=8.1,2.0,0.7Hz,1H),6.24(dd,J=5.7,3.1Hz,1H ),6.17(dd,J=5.7,2.9Hz,1H),2.98-2.95(m,1H),2.89-2.86(m,1H),2.69-2.65(m ,1H),1.71-1.66(m,1H),1.65-1.60(m,1H),1.54-1.51(m,1H),1.45-1.42(m,1H).

[0093] Example 2

[0094] Synthesis of cyclic olefin monomer H2 (ring number 0)

[0095] H2

[0096] The preparation of monomer H2 is the same as that of H1, except that 2-bromodibenzo-p-dioxin is used instead of 2-bromothiazide.

[0097] Example 3

[0098] Synthesis of cyclic olefin monomer H3 (ring number 0)

[0099] H3

[0100] The preparation method of monomer H3 is the same as that of H1, except that 2-bromoanthracene is used instead of 2-bromothiaanthracene.

[0101] Example 4

[0102] Synthesis of cycloolefin monomer H4 (ring number 0)

[0103] H4

[0104] The preparation method of monomer H4 is the same as that of H1, except that 2-bromophenazine is used instead of 2-bromothiazine.

[0105] Example 5

[0106] Synthesis of cyclic olefin monomer H5 (ring number 0)

[0107] H5

[0108] The preparation of monomer H5 is the same as that of H1, except that 2-bromoanthraquinone is used instead of 2-bromothiaanthracene.

[0109] Example 6

[0110] Synthesis of cycloolefin monomer H6 (ring number 0)

[0111] H6

[0112] 18.8 mmol of 4-bromo-1,2-benzoquinone and 18.8 mmol of 1,2-phenylenediamine were dissolved in 180 mL of ethanol. A catalytic amount of hydrochloric acid was added to the deep red solution, and the mixture was refluxed for 6 hours. The solvent was removed by vacuum distillation, and the residue was separated by silica gel column chromatography (PE:DCM = 2:1). The intermediate product was then recrystallized from ethanol.

[0113] The subsequent preparation steps are the same as those for H1, except that the intermediate product from the previous step is used instead of 2-bromothiathracene.

[0114] Example 7

[0115] Synthesis of cycloolefin monomer H7 (ring number 0)

[0116] H7

[0117] 20 mmol of H1, 8 ml of 33% hydrogen peroxide, and 50 ml of glacial acetic acid were mixed and reacted at 110 °C for 3 h. After the reaction was completed, ice water was added to quench the reaction, and the mixture was separated by filtration and recrystallized from chloroform to obtain the intermediate product.

[0118] The subsequent preparation steps are the same as those for H1, except that 2-bromothiathracene is replaced with a reaction intermediate.

[0119] Example 8

[0120] The structural formula of the cyclic olefin copolymer is:

[0121]

[0122] Where m=520, n=480, the synthesis steps are as follows:

[0123] In a glove box, at room temperature, 0.52 mol of H1 and 0.48 mol of M8 were weighed and added to 150 mL of toluene, followed by 2 mmol of 1-hexene. Stirring and heating were then initiated. When the temperature reached 40 °C, 0.01 mmol of Grubbs third-generation catalyst was added to the flask to begin polymerization. After 30 min of polymerization, 0.1 g of ethanol was added to terminate the active site, yielding 150 mL of polymerization solution.

[0124] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize it to 4 MPa with hydrogen. Start stirring and heat to 80 °C. After reacting for 4 hours, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, flocculate and wash three times, then wash the precipitated polymer three times with deionized water and dry it in a vacuum oven to obtain the hydrogenated polymer HD1.

[0125] Example 9

[0126] The structural formula of the cyclic olefin copolymer is:

[0127]

[0128] Where m=350, n=650, the synthesis steps are as follows:

[0129] In a glove box at room temperature, weigh 0.35 mol of H2 and 0.65 mol of M8 and add them to 150 mL of toluene, followed by 2 mmol of 1-hexene. Stirring and heating are then initiated. When the temperature reaches 40 °C, 0.01 mmol of Grubbs third-generation catalyst is added to the flask to begin polymerization. After 30 min of polymerization, 0.1 g of ethanol is added to terminate the active site, yielding 150 mL of polymerization solution.

[0130] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize it to 4 MPa with hydrogen. Start stirring and heat to 80 °C. After reacting for 4 hours, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, wash three times for flocculation, wash the precipitated polymer three times with deionized water, and dry it in a vacuum oven to obtain the hydrogenated polymer HD2.

[0131] Example 10

[0132] The structural formula of the cyclic olefin copolymer is:

[0133]

[0134] Where m=750, n=250, the synthesis steps are as follows:

[0135] In a glove box, at room temperature, weigh 0.75 mol of H3 and 0.25 mol of M8 and add them to 150 mL of toluene. Then add 2 mmol of 1-hexene and start stirring and heating. When the temperature reaches 40 °C, add 0.01 mmol of Grubbs third-generation catalyst to the flask to start polymerization. After polymerization for 30 min, add 0.1 g of ethanol to terminate the active site, yielding 150 mL of polymerization solution.

[0136] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize it to 4 MPa with hydrogen. Start stirring and heat to 80 °C. After reacting for 4 hours, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, wash three times for flocculation, wash the precipitated polymer three times with deionized water, and dry it in a vacuum oven to obtain the hydrogenated polymer HD3.

[0137] Example 11

[0138] The structural formula of the cyclic olefin copolymer is:

[0139]

[0140] Where m=150, n=850, the synthesis steps are as follows:

[0141] In a glove box, at room temperature, weigh 0.15 mol of H4 and 0.85 mol of M8 and add them to 150 mL of toluene. Then add 2 mmol of 1-hexene and start stirring and heating. When the temperature reaches 40 °C, add 0.01 mmol of Grubbs third-generation catalyst to the flask to start polymerization. After polymerization for 30 min, add 0.1 g of ethanol to terminate the active site, yielding 150 mL of polymerization solution.

[0142] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize it to 4 MPa with hydrogen. Start stirring and heat to 80 °C. After reacting for 4 hours, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, wash three times for flocculation, wash the precipitated polymer three times with deionized water, and dry it in a vacuum oven to obtain the hydrogenated polymer HD4.

[0143] Example 12

[0144] The structural formula of the cyclic olefin copolymer is:

[0145]

[0146] Where m=400, n=600, the synthesis steps are as follows:

[0147] In a glove box, at room temperature, weigh 0.40 mol of H5 and 0.60 mol of M8 and add them to 150 mL of toluene, followed by 2 mmol of 1-hexene. Stirring and heating are then initiated. When the temperature reaches 40 °C, 0.01 mmol of Grubbs third-generation catalyst is added to the flask to begin polymerization. After 30 min of polymerization, 0.1 g of ethanol is added to terminate the active site, yielding 150 mL of polymerization solution.

[0148] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize with hydrogen to 4 MPa. Start stirring and heat to 80 °C. After 4 hours of reaction, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, wash three times for flocculation, wash the precipitated polymer three times with deionized water, and dry in a vacuum oven to obtain the hydrogenated polymer HD5.

[0149] Example 13

[0150] The structural formula of the cyclic olefin copolymer is:

[0151]

[0152] Where m=650, n=350, the synthesis steps are as follows:

[0153] In a glove box, at room temperature, 0.65 mol of H6 and 0.35 mol of M8 were weighed and added to 150 mL of toluene, followed by 2 mmol of 1-hexene. Stirring and heating were then initiated. When the temperature reached 40 °C, 0.01 mmol of Grubbs third-generation catalyst was added to the flask to begin polymerization. After 30 min of polymerization, 0.1 g of ethanol was added to terminate the active site, yielding 150 mL of polymerization solution.

[0154] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize with hydrogen to 4 MPa. Start stirring and heat to 80 °C. After 4 hours of reaction, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, flocculate and wash three times, then wash the precipitated polymer three times with deionized water and dry in a vacuum oven to obtain the hydrogenated polymer HD6.

[0155] Example 14

[0156] The structural formula of the cyclic olefin copolymer is:

[0157]

[0158] Where m=550, n=450, the synthesis steps are as follows:

[0159] In a glove box, at room temperature, weigh 0.55 mol of H7 and 0.45 mol of M8 and add them to 150 mL of toluene. Then add 2 mmol of 1-hexene and start stirring and heating. When the temperature reaches 40 °C, add 0.01 mmol of Grubbs third-generation catalyst to the flask to start polymerization. After polymerization for 30 min, add 0.1 g of ethanol to terminate the active site, yielding 150 mL of polymerization solution.

[0160] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize with hydrogen to 4 MPa. Start stirring and heat to 80 °C. After reacting for 4 hours, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, flocculate and wash three times, then wash the precipitated polymer three times with deionized water and dry in a vacuum oven to obtain the hydrogenated polymer HD7.

[0161] Example 15

[0162] The structural formula of the cyclic olefin copolymer is:

[0163]

[0164] The polymer HD8 is identical to the HD3, except that M2 replaces M8.

[0165] Example 16

[0166] The structural formula of the cyclic olefin copolymer is:

[0167]

[0168] The polymer HD9 is identical to the HD3, except that M8 is replaced by M5.

[0169] Example 17

[0170] The structural formula of the cyclic olefin copolymer is:

[0171]

[0172] The polymer HD10 is identical to the HD5, except that the M8 is replaced by the M5.

[0173] Example 18

[0174] The structural formula of the cyclic olefin copolymer is:

[0175]

[0176] The polymer HD11 is identical to the HD1, except that M8 is replaced by M3.

[0177] Comparative Example 1

[0178] The structural formula of the cyclic olefin copolymer is:

[0179]

[0180] Where m=750, n=250, the synthesis steps are as follows:

[0181] In a glove box, at room temperature, weigh 0.75 mol of M4 and 0.25 mol of M8 and add them to 150 mL of toluene. Then add 2 mmol of 1-hexene and start stirring and heating. When the temperature reaches 40 °C, add 0.01 mmol of Grubbs third-generation catalyst to the flask to start polymerization. After polymerization for 30 min, add 0.1 g of ethanol to terminate the active site, yielding 150 mL of polymerization solution.

[0182] Weigh 0.1 mmol of nickel acetylacetonate in a glove box and disperse it in 6 ml of toluene. Add 0.5 mmol of triisobutylaluminum to the nickel acetylacetonate mixture and react for 5 min to obtain a hydrogenation catalyst. Add the catalyst to the resulting polymerization solution and pressurize it to 4 MPa with hydrogen. Start stirring and heat to 80 °C. After reacting for 4 hours, the hydrogenation reaction endpoint is reached when the double bond content in the product decreases to 1%, yielding the corresponding hydrogenated polymer solution. After cooling, pour the reaction solution into acidified ethanol, wash three times for flocculation, wash the precipitated polymer three times with deionized water, and dry it in a vacuum oven to obtain the hydrogenated polymer HM1.

[0183] Comparative Example 2

[0184] The structural formula of the cyclic olefin copolymer is:

[0185]

[0186] The preparation method of polymer HM2 is the same as that of HM1, except that M4 is replaced by M2.

[0187] Comparative Example 3

[0188] The structural formula of the cyclic olefin copolymer is:

[0189]

[0190] The preparation method of polymer HM3 is the same as that of HM1, except that M5 is used instead of M4.

[0191] Table 1 shows the amounts of catalyst and monomer used in the preparation of cyclic olefin polymers.

[0192] Monomer 1 Monomer 2 1-Hexene Polymerization catalyst Example 8 0.52 mol (H1) 0.48 mol (M8) 2mmol 0.01mmol Example 9 0.35 mol (H2) 0.65 mol (M8) 2mmol 0.01mmol Example 10 0.75 mol (H3) 0.25 mol (M8) 2mmol 0.01mmol Example 11 0.15 mol (H4) 0.85 mol (M8) 2mmol 0.01mmol Example 12 0.40 mol (H5) 0.60 mol (M8) 2mmol 0.01mmol Example 13 0.65 mol (H6) 0.35 mol (M8) 2mmol 0.01mmol Example 14 0.55 mol (H7) 0.45 mol (M8) 2mmol 0.01mmol Example 15 0.75 mol (H1) 0.25 mol (M2) 2mmol 0.01mmol Example 16 0.75 mol (H1) 0.25 mol (M9) 2mmol 0.01mmol Example 17 0.40 mol (H5) 0.60 mol (M5) 2mmol 0.01mmol Example 18 0.52 mol (H1) 0.48 mol (m3) 2mmol 0.01mmol Comparative Example 1 0.75 mol (M4) 0.25 mol (M8) 2mmol 0.01mmol Comparative Example 2 0.75 mol (M2) 0.25 mol (M8) 2mmol 0.01mmol Comparative Example 3 0.75 mol (M5) 0.25 mol (M8) 2mmol 0.01mmol

[0193] Table 2. Properties of polymers prepared in the embodiments and comparative examples of the present invention and properties of commercially available cyclic olefin polymers.

[0194] Refractive index Birefringence (nm) Example 8 (HD1) 1.69 6.4 Example 9 (HD2) 1.68 8.9 Example 10 (HD3) 1.62 16.3 Example 11 (HD4) 1.66 11.2 Example 12 (HD5) 1.67 9.8 Example 13 (HD6) 1.68 10.5 Example 14 (HD7) 1.72 4.1 Example 15 (HD8) 1.62 17.2 Example 16 (HD9) 1.62 17.6 Example 17 (HD10) 1.67 8.7 Example 18 (HD11) 1.69 6.2 Comparative Example 1 1.53 24.3 Comparative Example 2 1.53 27.2 Comparative Example 3 1.53 22.9 ZEONEXK26R 1.54 14.1 ZEONEX360R 1.54 4.6

[0195] Compared to mainstream commercially available cyclic olefin polymers, the refractive index is significantly increased while maintaining extremely low birefringence, resulting in high transparency. According to the present invention, it can be advantageously used as an optical material for VR / AR applications.

Claims

1. A cyclic olefin polymer, characterized by, has the following structure shown in formula I: In formula I, m, n are the degree of polymerization, 50≤m≤750, 50≤n≤850; i, j are the number of rings, i is an integer of 0-2, preferably, i is 0, j is an integer of 0-2, preferably, j is 0; X represents one or more of C, N, O, S atoms or -SO2, -C=O, -N-CH3 groups; R1 is independently selected from one or more of H, alkyl, cycloalkyl, phenyl, R2 and R3 are independently selected from one or more of H, alkyl, cycloalkyl, alkenyl, alkynyl, phenyl, R2 and R3 are bonded to each other to form a ring or not bonded; Preferably, R2 and R3 are bonded to each other to form a five-membered ring or a six-membered ring; Preferably, R1 is H, R2 is H, methyl, ethyl, cyclopentyl, cyclohexyl, phenyl, and R3 is H, methyl, ethyl, cyclopentyl, cyclohexyl, phenyl.

2. The method for preparing the cyclic olefin polymer according to claim 1, characterized in that, It comprises the following steps: (1) Polymerization: ring-opening metathesis polymerization of the cycloalkene monomer shown in formula II and the cycloalkene monomer shown in formula III occurs in the presence of a polymerization catalyst, an organic solvent and a chain transfer agent to prepare an unsaturated cycloalkene polymer; (2) Hydrogenation: hydrogenation reaction of the unsaturated cycloalkene polymer prepared in step (1) and a hydrogen source is carried out to obtain a cycloalkene polymer; The structure of the cycloalkene monomer shown in formula II is: In formula II, i, X, R1 are selected in the same way as in formula I. The structure of the cycloalkene monomer shown in formula III is: In formula III, j, R2, R3 are selected in the same way as in formula I, R2 and R3 are bonded to each other to form a ring or not bonded.

3. The production method according to claim 2, characterized by, The compound shown in formula II is selected from at least one of H1-H7 structures: Preferably, the compound shown in formula III is selected from at least one of M1-M9 structures:

4. The production method according to claim 2 or 3, characterized by, The molar ratio of the cycloalkene monomer shown in formula II and the cycloalkene monomer shown in formula III added is 1:17-13:1, preferably 1:5-5:1; Preferably, the number average molecular weight of the cycloalkene polymer is 5000-100000; Preferably, the double bond molar content of the cycloalkene polymer is ≤50%, preferably ≤1%.

5. The method of any one of claims 2-4, wherein, The polymerization catalyst is selected from any one or a combination of at least two of tungsten-based catalysts, Grubbs series catalysts, and Schrock series catalysts; And / or, the addition amount of the polymerization catalyst is 0.1-100 ppm, preferably 0.5-50 ppm, of the total mass of the monomers; And / or, the organic solvent comprises one or more combinations of dichloromethane, chloroform, tetrachloroethane, chlorobenzene, o-dichlorobenzene, trichlorobenzene, cyclohexane, methylcyclohexane, toluene or xylene; And / or, the chain transfer agent is selected from at least one of 1-pentene, 1-hexene, 1-heptene, 1-octene, styrene, vinyl ether, etc. And / or, the addition amount of the chain transfer agent is 0.1-10%, preferably 0.2%-2%, of the total mass of the monomers.

6. The method of any one of claims 2-5, wherein, The temperature of the ring-opening metathesis polymerization reaction is 10-120°C; the time is 2-200 min.

7. The method of any one of claims 2-5, wherein, The hydrogenation reaction is carried out in the presence of a hydrogenation catalyst, which is a homogeneous catalyst or a heterogeneous catalyst.

8. The preparation method according to claim 7, characterized in that, The heterogeneous catalyst is a solid catalyst containing noble metals such as ruthenium, platinum, nickel, rhodium or ruthenium supported on a carrier such as carbon, silicon dioxide, aluminum oxide or titanium dioxide; Preferably, the homogeneous catalyst comprises one or more of nickel naphthenate, nickel acetylacetonate, cobalt octoate, titanium dichloride, rhodium acetate, chloro tris(triphenylphosphine)rhodium, dichloro tris(triphenylphosphine) ruthenium, chloro carbonyl tris(triphenylphosphine) ruthenium and dichloro carbonyl tris(triphenylphosphine) ruthenium; Preferably, the hydrogenation catalyst further comprises a co-catalyst, which is n-butyl lithium, alkyl aluminum or halogenated alkyl aluminum; More preferably, the co-catalyst is required when the noble metal of the hydrogenation catalyst is nickel, cobalt or titanium; Preferably, the hydrogenation catalyst is added in an amount of 10-10000 ppm, preferably 20-5000 ppm, of the total mass of the monomers.

9. The method of any one of claims 2-8, wherein, The hydrogen source is hydrogen gas.

10. The method of any one of claims 2-9, wherein, The hydrogenation reaction is carried out at a temperature of 25-250°C for 1-12 hours under a hydrogen pressure of 1-10 MPa.

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