Cycloolefin copolymer and preparation method thereof

Abstract

The invention discloses a cycloolefin copolymer and a preparation method thereof. The cycloolefin copolymer has a structure as shown in # imgabs0 #, ethylene units of x structures account for 50-75% of the total mole number of all structural units, cycloolefin units of y structures account for 20-45% of the total mole number of all structural units, conjugated diene units of z structures account for 1-15% of the total mole number of all structural units, R3 is C1-C10 alkyl, and R4 is C1-C10 alkyl. And R4 is hydrogen, phenyl, substituted or unsubstituted C1-C20 alkyl or alkyl phenyl. The polymer is transparent resin with an amorphous structure at normal temperature, and the glass transition temperature can be adjusted according to the ratio of x to y to z, and the adjusting range is 80-200 DEG C. Compared with the traditional ethylene and cycloolefin binary copolymer, the ethylene and cycloolefin binary copolymer has better toughness. Compared with a method of directly adding an elastomer into a finished product or preparing a segmented copolymer, the method is simple and easy to implement, and more cost is saved.

Description

Technical Field

[0001] The present invention belongs to the field of copolymers, and particularly relates to a polycyclic olefin copolymer and a preparation method thereof. Background Art

[0002] Ethylene-cycloolefin copolymer (COC) is usually an amorphous polymer obtained by copolymerizing ethylene and cycloolefin monomers through solution polymerization using a metallocene catalyst, and is a non-crystalline thermoplastic transparent resin. Due to its good transparency, high glass transition temperature, low water absorption, low birefringence, as well as excellent thermal stability, barrier property and biocompatibility, cycloolefin copolymer is widely used in the fields of optical lenses, medical treatment, packaging, electronics, etc. With the rapid development of the cycloolefin copolymer market and the continuous expansion of downstream applications, the differentiated requirements for some properties in different usage scenarios have gradually become a popular research direction for cycloolefin copolymers. Among them, the poor toughness of cycloolefin copolymers restricts the expansion and popularization of their downstream applications.

[0003] Patent CN1229417A discloses a method for preparing a cycloolefin (co)polymer. This method is based on cycloolefins and α-olefins having two or more carbon atoms, and a monomer optionally being a conjugated or non-conjugated diene is added for terpolymerization to prepare a cycloolefin copolymer for optical data storage. It is characterized in that the catalyst used is a metallocene compound or π complex with a special structure. However, this patent does not mention the influence of adding conjugated or non-conjugated diene monomers on the mechanical properties of cycloolefin copolymers.

[0004] Patent CN116162193A discloses a method for preparing a cycloolefin copolymer. This method is copolymerized from α-olefins, polar monomer A and cyclic olefin B, and by introducing a benzene ring group and a heteroatom, the cycloolefin copolymer has the characteristics of high refractive index, low Abbe number and high toughness. However, the polar monomer and heteroatom-containing cyclic olefin of this patent are too complex and difficult to obtain, and the introduction of polar groups and heteroatoms may lead to unknown factors such as oxidation and crosslinking during the polymer processing.

[0005]

[0006] In addition to the methods provided by the above patents, the current adjustment methods mostly introduce plasticizers or elastomers and other additives through physical methods such as blending. This method will not only affect the mechanical properties of the material, but is more likely to cause some safety problems in aspects such as the environment and biology due to the release of additives, thus restricting its application. Summary of the Invention

[0007] In view of the above, the present invention provides a tercycloolefin copolymer and a preparation method thereof. Compared with the traditional binary copolymer of ethylene and cycloolefin, the tercycloolefin copolymer has better toughness and rigidity. Compared with directly adding a plasticizer or an elastomer to the finished product, this method is simple and feasible, the mechanical properties of the polymer are better, and the manufacturing cost is more saved. When a special monomer with a phenyl group is selected, the polymer has a higher refractive index and a lower birefringence, making the polymer have better optical properties.

[0008] The present invention provides a cycloolefin copolymer, and its structure has the structure shown in formula (I):

[0009]

[0010] Among them, the molar number x of ethylene units accounts for 50-75% of the total molar number (x + y + z) of all structural units, the molar number y of cycloolefin units accounts for 20-45% of the total molar number of all structural units, and the molar number z of conjugated diene units accounts for 1-15% of the total molar number of all structural units;

[0011] In formula (I), R1 and R2 are the same or different atoms or atomic groups, such as hydrogen, phenyl, carboxyl, substituted or unsubstituted alkyl, etc.; R3 is an alkyl group with 1-10 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, etc.; R4 is hydrogen, phenyl, substituted or unsubstituted alkyl or alkylphenyl with 1-20 carbon atoms; n is 0-5, preferably 0-2.

[0012] The weight-average molecular weight of the cycloolefin copolymer is between 10,000 and 1,000,000, preferably between 30,000 and 600,000.

[0013] The molecular weight distribution of the cycloolefin copolymer is between 1 and 10, preferably between 1 and 5.

[0014] The glass transition temperature of the cycloolefin copolymer is between 80 and 200 °C, preferably between 100 and 190 °C.

[0015] The present invention also provides a preparation method of a cycloolefin copolymer, including the following steps: in the presence of a catalyst system and a solvent, ethylene, a cycloolefin, and a conjugated diene compound are subjected to a polymerization reaction.

[0016] The cycloolefin monomer is as shown in formula (II), wherein R1 and R2 are the same or different atoms or atomic groups, and n is 0-5, preferably 0-2.

[0017]

[0018] The conjugated diene compound is represented by the formula (Ⅲ), wherein R3 is an alkyl group having 1 to 10 carbon atoms, and R4 is hydrogen, phenyl, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or an alkylphenyl group.

[0019]

[0020] When the conjugated diene compound is introduced as a monomer into the polymer main chain, a 1,4 addition reaction similar to that of isoprene occurs. At the same degree of polymerization, the main chain of the cycloolefin copolymer is longer and the mechanical properties are better.

[0021] When the R3 group is a methyl group, the conjugated diene monomer is similar to a substituted isoprene, and the structure introduced into the polymer main chain is similar to that of polyisoprene. Its structure and properties are similar to those of natural rubber, having good elasticity and strength, and providing good tensile strength and flexural strength to the cycloolefin copolymer as the polymer main chain.

[0022] When the R4 group is an alkylphenyl group, the phenyl group at its end can effectively increase the refractive index of the polymer and reduce the birefringence. Moreover, as the number of phenyl groups increases, the refractive index becomes higher and the birefringence becomes lower, making the polymer have more excellent optical properties.

[0023] The polymerization reaction temperature is 50 to 200 °C, preferably 90 to 160 °C.

[0024] The polymerization reaction time is 0.5 to 120 min, preferably 1 to 30 min.

[0025] As a preferred embodiment, after the polymerization reaction is completed, at room temperature and normal pressure, a hydrochloric acid / ethanol solution is injected into the reaction solution, and the polymer is obtained by stirring, precipitation, filtration, and drying.

[0026] The method for preparing the terpolymer is characterized in that the catalyst system for the polymerization reaction comprises: a transition metal complex, an organoboron compound, and an organoaluminum compound.

[0027] The transition metal complex has the following structure of formula (Ⅳ):

[0028]

[0029] In formula (Ⅳ), R5 and R6 are each independently selected from an unsubstituted cyclopentadienyl group and its derivatives, an indenyl group and its derivatives, or a fluorenyl group and its derivatives;

[0030] R7 and R8 are each independently selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, 2,6-dimethylphenyl, 4-methylphenyl, mesityl, 2,6-diisopropylphenyl, 2,4,6-triisopropylphenyl, or 2,6-di-tert-butylphenyl;

[0031] X1 and X2 are monoanionic ligands, and X1 and X2 are independently selected from hydrogen, straight-chain or branched aliphatic groups or alicyclic groups containing 1 to 20 carbon atoms, phenyl, phenyl substituted by straight-chain or branched alkyl or cycloaliphatic groups or aromatic groups containing 1 to 20 carbon atoms, straight-chain or branched alkoxy groups containing 1 to 20 carbon atoms, straight-chain or branched alkanamino groups containing 1 to 20 carbon atoms, straight-chain or branched arylamino groups containing 1 to 20 carbon atoms, straight-chain or branched silyl groups containing 1 to 20 carbon atoms, borohydride groups, allyl groups and allyl derivatives or halogens;

[0032] M is selected from transition metal atoms such as titanium, zirconium, vanadium, chromium, hafnium, etc.;

[0033] E is C, Si or Ge;

[0034] m = 1 or 2;

[0035] The organic boron compound is an ionic compound formed by an organic boron anion and a cation;

[0036] The organic boron anion is selected from tetraphenylborate, tetrakis(monofluorophenyl)borate, tetrakis(difluorophenyl)borate, tetrakis(trifluorophenyl)borate, tetrakis(tetrafluorophenyl)borate, tetrakis(pentafluorophenyl)borate, tetrakis(tetrafluoromethylphenyl)borate, tetrakis(tolyl)borate, tetrakis(xylenyl)borate, (triphenyl,pentafluorophenyl)borate, [tris(pentafluorophenyl),phenyl]borate or undecahydro-7,8-dicarbaundecaborate;

[0037] The cation is selected from carbocation, oxonium cation, ammonium cation, phosphonium cation, cycloheptatrienyl cation or ferrocenium cation containing a transition metal;

[0038] The carbocation includes trisubstituted carbocations such as triphenylcarbocation and tris(substituted phenyl)carbocations, and tris(substituted phenyl)carbocations such as tris(tolyl)carbocation;

[0039] The ammonium cation includes trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation and tributylammonium cation;

[0040] The phosphonium cation includes triarylphosphonium cations such as triphenylphosphonium cation, tris(tolyl)phosphonium cation or tris(xylenyl)phosphonium cation;

[0041] The organoaluminum compound is selected from hydrocarbyl-substituted aluminum compounds, including but not limited to diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, benzylisopropylaluminum hydride, ethyldialuminum hydride, butyldialuminum hydride, isobutyldialuminum hydride, octyldialuminum hydride, pentyldialuminum hydride, diethylaluminum ethoxide, dipropylaluminum ethoxide, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldiphenylaluminum, ethyldi-p-tolylaluminum, ethyldibenzylaluminum, diethylphenylaluminum, diethyl-p-tolylaluminum, and diethylbenzylaluminum; preferably, the organoaluminum compound is one or more of diisobutylaluminum hydride, diethylaluminum hydride, trioctylaluminum, triisobutylaluminum, and trimethylaluminum.

[0042] The pressure of ethylene in the polymerization reaction system is 1 to 12 atm, preferably 1 to 10 atm.

[0043] The concentration of the transition metal complex in the polymerization solution system is 0.1 to 5 μmol / ml, preferably 0.2 to 2 μmol / ml.

[0044] The organoboron compound and the organoaluminum compound are used as cocatalysts, and the molar ratios thereof to the transition metal complex are (1 to 10000):1, preferably (1 to 100):1.

[0045] The solvent for the polymerization reaction is selected from one or several of aliphatic saturated hydrocarbons, aromatic hydrocarbons, aryl halides, and cycloalkanes; preferably, it is at least one of pentane, hexane, toluene, xylene, heptane, cyclohexane, cycloheptane, dichloromethane, chlorobenzene, o-dichlorobenzene, and dichloroethane, and more preferably at least one of toluene, hexane, and cyclohexane.

[0046] Compared with the prior art, the present invention provides a tercycloolefin copolymer and a preparation method thereof. The tercycloolefin copolymer provided by the present invention can regulate the glass transition temperature of the polymer through the combination of cycloolefin monomers, and the regulation range is 80°C to 200°C. Compared with the traditional ethylene-cycloolefin binary copolymer, it has better toughness, and the method is simple and easy to implement, saving the manufacturing cost. Therefore, this material has very great application prospects in the fields of packaging, medical treatment, etc. Detailed Embodiments

[0047] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention. Test methods:

[0048] 1. The monomer composition of the cycloolefin copolymer was determined by the methods of nuclear magnetic resonance hydrogen spectrum and nuclear magnetic resonance carbon spectrum of Varian Inova-400 (FT, 400 MHz, 1H; 100 MHz, 13C).

[0049] 2. The weight-average molecular weight (Mw) and molecular weight distribution (PDI) were measured by high-temperature gel permeation chromatography. 1,2,4-Trichlorobenzene was used as the mobile phase, and narrow-distribution polystyrene was used as the standard sample at a temperature of 150 °C.

[0050] 3. The glass transition temperature (Tg) was measured by DSC at a heating rate of 10 °C / min and a temperature range of 25 - 300 °C.

[0051] 4. Mechanical property test: The tensile strength of the cycloolefin copolymer was tested according to GB / T 1040.2-2006, where the tensile rate was 50 mm / min; the flexural modulus of the cycloolefin copolymer was tested according to GB / T 9341-2008, where the flexural rate was 2 mm / min and the span was 64 mm; the Izod notched impact strength of the cycloolefin copolymer was tested according to GB / T 1843-2008, and the notch type was A-type notch.

[0052] 5. Optical property test: The refractive index and birefringence of the cycloolefin copolymer material were tested according to ASTM D542.

[0053] Example 1

[0054] Catalyst preparation: In the glove box, weigh the transition complex (10 μmol) of the main catalyst (R5 is fluorenyl, R6 is cyclopentadienyl, R7 and R8 are hydrogen, E is carbon, m = 1, X1 and X2 are methyl, M is zirconium), Al i Bu3 (20 μmol) and triphenylcarbenium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol) were dissolved in 5 mL of toluene to obtain a catalyst solution.

[0055] Synthesis of cycloolefin copolymer:

[0056] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After that, the reaction kettle was cooled to room temperature. Add 20 mmol (0.5 mol / L) to a 150 ml reaction kettle The toluene solution of this monomer, 20 mmol of tetracyclododecene (TCD, n = 1, R1, R2 are hydrogen), and 20 mL of toluene were thoroughly purged with nitrogen. Subsequently, the temperature of the reaction kettle was raised to 140 °C, stirring was started, and 1.0 atm of ethylene was introduced into it under vigorous stirring to saturate it in the toluene solution. After the pressure stabilized, the catalyst solution was injected through the feed hopper of the reaction kettle, and then 8.0 atm of ethylene was introduced for reaction. After reacting for 15 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it, and then a large amount of ethanol solution was added for precipitation. The polymer precipitated in ethanol. After the polymer was taken out of ethanol, it was placed in a vacuum dryer and treated to constant weight to obtain the cycloolefin copolymer. By testing, its Mw was 14.48×10 4 g / mol, the PDI was 3.4, the Tg was 172 °C, the tensile strength was 53.8 MPa, the flexural strength was 2822 MPa, the refractive index was 1.568, and the birefringence was 2.1×10 -4 .

[0057] Example 2

[0058] Catalyst preparation: In a glove box, 10 μmol of a transition complex of the main catalyst (R5 is a fluorenyl group, R6 is a cyclopentadienyl group, R7, R8 are methyl groups, E is carbon, m = 1, X1, X2 are methyl groups, M is zirconium), 20 μmol of AlEt3, and 10 μmol of triphenylcarbonium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] were dissolved in 5 mL of toluene to obtain the catalyst solution.

[0059] Synthesis of cycloolefin copolymer:

[0060] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After completion, the reaction kettle was cooled to room temperature. 20 mmol (0.5 mol / L) of the toluene solution of this monomer, 20 mmol of tetracyclododecene (TCD, n = 1, R1, R2 are hydrogen), and 20 mL of toluene were thoroughly purged with nitrogen. Subsequently, the temperature of the reaction kettle was raised to 130 °C, stirring was started, and 1.0 atm of ethylene was introduced into it under vigorous stirring to saturate it in the toluene solution. After the pressure stabilized, the catalyst solution was injected through the feed hopper of the reaction kettle, and then 8.0 atm of ethylene was introduced for reaction. After reacting for 12 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it, and then a large amount of ethanol solution was added for precipitation. The polymer precipitated in ethanol. After the polymer was taken out of ethanol, it was placed in a vacuum dryer and treated to constant weight to obtain the cycloolefin copolymer. By testing, its Mw was 8.31×10 4g / mol, the PDI is 3.3, the Tg is 168 °C, the tensile strength is 49.2 MPa, the flexural strength is 2683 MPa, the refractive index is 1.572, and the birefringence is 2.1×10 -4 .

[0061] Example 3

[0062] Catalyst preparation: In a glove box, weigh out a transition complex of the main catalyst (where R5 is a fluorenyl group, R6 is a cyclopentadienyl group, R7 and R8 are phenyl groups, E is carbon, m = 1, X1 and X2 are methyl groups, and M is zirconium) (10 μmol), AlMe3 (20 μmol), and triphenylcarbenium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol), and dissolve them in 5 mL of toluene to obtain a catalyst solution.

[0063] Synthesis of cycloolefin copolymer:

[0064] Before the experiment, preheat the reaction kettle to 100 °C, repeat the operation of evacuating and filling with nitrogen 3 times, and then cool the reaction kettle to room temperature. Add 20 mmol (0.5 mol / L) a toluene solution of this monomer, 20 mmol of norbornene (n = 0, R1 and R2 are hydrogen), and 20 mL of toluene, and purge thoroughly with nitrogen. Then raise the temperature of the reaction kettle to 120 °C, start stirring, and introduce 1.0 atm of ethylene under vigorous stirring to saturate it in the toluene solution. After the pressure stabilizes, inject the catalyst solution through the charging bin of the reaction kettle, and then introduce 9.0 atm of ethylene for reaction. After reacting for 10 minutes, turn off the heating, release the pressure and open the kettle, inject an ethanol solution into the reaction solution to terminate the reaction and inactivate it, and then add a large amount of ethanol solution for precipitation. The polymer precipitates in ethanol. After taking out the polymer from ethanol, place it in a vacuum dryer and process it to constant weight to obtain a cycloolefin copolymer. By testing, its Mw is 5.33×10 4 g / mol, the PDI is 2.8, the Tg is 151 °C, the tensile strength is 48.7 MPa, the flexural strength is 2614 MPa, the refractive index is 1.545, and the birefringence is 9.9×10 -4 .

[0065] Example 4

[0066] Catalyst preparation: In a glove box, weigh out a transition complex of the main catalyst (where R5 is a fluorenyl group, R6 is a cyclopentadienyl group, R7 and R8 are methyl groups, E is silicon, m = 1, X1 and X2 are methyl groups, and M is zirconium) (10 μmol), Al i Bu3 (20 μmol) and triphenylcarbenium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol), and dissolve them in 5 mL of toluene to obtain a catalyst solution.

[0067] Synthesis of cycloolefin copolymer:

[0068] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After that, the reaction kettle was cooled to room temperature. Add 20 mmol (0.5 mol / L) The toluene solution of this monomer, 20 mmol of 2-norbornene (n = 0, R1 and R2 are hydrogen), and 20 mL of toluene were fully purged with nitrogen. Subsequently, the temperature of the reaction kettle was raised to 140 °C, the stirring was started, and ethylene at 1.0 atm was charged into it under vigorous stirring to make it reach a saturated state in the toluene solution. After the pressure was stabilized, the catalyst solution was injected through the feeding bin of the reaction kettle, and then ethylene at 9.0 atm was introduced for reaction. After reacting for 30 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it, and then a large amount of ethanol solution was added for precipitation of the colloid, and the polymer was precipitated in ethanol. After taking out the polymer from ethanol, it was placed in a vacuum dryer and treated to constant weight to obtain the cycloolefin copolymer. By testing, its Mw was 16.73×10 4 g / mol, the PDI was 2.9, the Tg was 176 °C, the tensile strength was 54.3 MPa, the flexural strength was 2901 MPa, the refractive index was 1.565, and the birefringence was 8.2×10 -4 .

[0069] Example 5

[0070] Catalyst preparation: In the glove box, weigh the transition complex (10 μmol) of the main catalyst (R5 is indenyl, R6 is cyclopentadienyl, R7 and R8 are methyl, E is silicon, m = 1, X1 and X2 are methyl, M is zirconium), AlMe3 (20 μmol), and triphenylcarbonium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol) and dissolve them in 5 mL of toluene to obtain the catalyst solution.

[0071] Synthesis of cycloolefin copolymer:

[0072] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After that, the reaction kettle was cooled to room temperature. Add 20 mmol (0.5 mol / L) The toluene solution of this monomer and 20 mmol of the monomer And 20 mL of toluene. After thoroughly purging with nitrogen, the temperature of the reaction kettle was then raised to 160 °C, and stirring was started. Under vigorous stirring, 1.0 atm of ethylene was introduced into it to reach a saturated state in the toluene solution. After the pressure stabilized, the catalyst solution was injected through the feed hopper of the reaction kettle, and then 9.0 atm of ethylene was introduced for reaction. After reacting for 12 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it, and then a large amount of ethanol solution was added for precipitation of the gel, and the polymer precipitated out in ethanol. After taking out the polymer from ethanol, it was placed in a vacuum dryer and processed to constant weight to obtain the cycloolefin copolymer. By testing, its Mw was 9.07×10 4 g / mol, the PDI was 2.7, the Tg was 167 °C, the tensile strength was 50.9 MPa, the flexural strength was 2738 MPa, the refractive index was 1.586, and the birefringence was 1.5×10 -4 .

[0073] Example 6

[0074] Catalyst preparation: In a glove box, a transition complex (10 μmol) of the main catalyst (R5 is fluorenyl, R6 is indenyl, R7 and R8 are methyl, E is carbon, m = 1, X1 and X2 are methyl, M is titanium), Al i Bu3 (20 μmol) and triphenylcarbenium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol) were dissolved in 5 mL of toluene to obtain the catalyst solution.

[0075] Synthesis of cycloolefin copolymer:

[0076] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After that, the reaction kettle was cooled to room temperature. 20 mmol (0.5 mol / L) of the monomer toluene solution and 20 mmol of the monomer and 20 mL of toluene were added to a 150 ml reaction kettle. After thoroughly purging with nitrogen, the temperature of the reaction kettle was then raised to 140 °C, and stirring was started. Under vigorous stirring, 1.0 atm of ethylene was introduced into it to reach a saturated state in the toluene solution. After the pressure stabilized, the catalyst solution was injected through the feed hopper of the reaction kettle, and then 6.0 atm of ethylene was introduced for reaction. After reacting for 10 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it, and then a large amount of ethanol solution was added for precipitation of the gel, and the polymer precipitated out in ethanol. After taking out the polymer from ethanol, it was placed in a vacuum dryer and processed to constant weight to obtain the cycloolefin copolymer. By testing, its Mw was 14.53×10 4g / mol, the PDI is 2.9, the Tg is 190 °C, the tensile strength is 55.4 MPa, the flexural strength is 2990 MPa, the refractive index is 1.608, and the birefringence is 1.2×10 -4 .

[0077] Example 7

[0078] Catalyst preparation: In a glove box, weigh out the transition complex of the main catalyst (R5 is fluorenyl, R6 is cyclopentadienyl, R7 and R8 are methyl, E is silicon, m = 1, X1 and X2 are methyl, M is titanium) (10 μmol), AlEt3 (20 μmol), and triphenylcarbenium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol), and dissolve them in 5 mL of toluene to obtain a catalyst solution.

[0079] Synthesis of cycloolefin copolymer:

[0080] Before the experiment, preheat the reaction kettle to 100 °C, repeat the operation of evacuating and filling with nitrogen 3 times, and then cool the reaction kettle to room temperature. Add 20 mmol (0.5 mol / L) the toluene solution of this monomer and 20 mmol of monomer and 20 mL of toluene, and purge with nitrogen thoroughly. Then raise the temperature of the reaction kettle to 100 °C, start stirring, and introduce 1.0 atm of ethylene under vigorous stirring to make it reach a saturated state in the toluene solution. After the pressure stabilizes, inject the catalyst solution through the feed hopper of the reaction kettle, and then introduce 8.0 atm of ethylene for reaction. After reacting for 15 minutes, turn off the heating, release the pressure and open the kettle, inject an ethanol solution into the reaction solution to terminate the reaction and inactivate it, and then add a large amount of ethanol solution for precipitation. The polymer precipitates in ethanol. After taking out the polymer from ethanol, place it in a vacuum dryer and process it to constant weight to obtain the cycloolefin copolymer. By testing, its Mw is 12.94×10 4 g / mol, the PDI is 2.7, the Tg is 183 °C, the tensile strength is 54.7 MPa, the flexural strength is 2851 MPa, the refractive index is 1.639, and the birefringence is 1.2×10 -4 .

[0081] Example 8

[0082] Catalyst preparation: In a glove box, weigh out the transition complex of the main catalyst (R5 is indenyl, R6 is cyclopentadienyl, R7 and R8 are methyl, E is silicon, m = 1, X1 and X2 are methyl, M is titanium) (10 μmol), AlMe3 (20 μmol), and triphenylcarbenium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol), and dissolve them in 5 mL of toluene to obtain a catalyst solution.

[0083] Synthesis of cycloolefin copolymer:

[0084] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After that, the reaction kettle was cooled to room temperature. Add 20 mmol (0.5 mol / L) toluene solution of this monomer and 20 mmol of monomer and 20 mL of toluene, and purge it thoroughly with nitrogen. Subsequently, the temperature of the reaction kettle was raised to 120 °C, the stirring was started, and 1.0 atm of ethylene was charged into it under vigorous stirring to make it reach a saturated state in the toluene solution. After the pressure was stabilized, the catalyst solution was injected through the feeding bin of the reaction kettle, and then 10.0 atm of ethylene was introduced for reaction. After reacting for 10 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it. Then, a large amount of ethanol solution was added for precipitation of the colloid, and the polymer precipitated in ethanol. After taking out the polymer from ethanol, it was placed in a vacuum dryer and treated to constant weight to obtain the cycloolefin copolymer. By testing, its Mw was 6.87×10 4 g / mol, PDI was 2.8, Tg was 149 °C, tensile strength was 48.9 MPa, flexural strength was 2690 MPa, refractive index was 1.644, and birefringence was 1.3×10 -4 .

[0085] Comparative Example 1

[0086] Catalyst preparation: Weigh the transition complex (10 μmol) of the main catalyst (R5 is fluorenyl, R6 is cyclopentadienyl, R7 and R8 are hydrogen, E is carbon, m = 1, X1 and X2 are methyl, M is zirconium), Al i Bu3 (20 μmol) and triphenylcarbonium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol) were dissolved in 5 mL of toluene to obtain the catalyst solution.

[0087] Synthesis of cycloolefin copolymer without conjugated diene structure:

[0088] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After that, the reaction kettle was cooled to room temperature. 40 mmol of tetracyclododecene (n = 1, R1 and R2 are hydrogen) and 20 mL of toluene were added to a 150 mL reaction kettle. After purging thoroughly with nitrogen. Subsequently, the temperature of the reaction kettle was raised to 140 °C, stirring was started, and ethylene at 1.0 atm was introduced into it under vigorous stirring to make it reach a saturated state in the toluene solution. After the pressure was stabilized, the catalyst solution was injected through the feed hopper of the reaction kettle, and then ethylene at 8.0 atm was introduced for reaction. After reacting for 15 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it, and then a large amount of ethanol solution was added for gel precipitation, and the polymer precipitated in ethanol. After the polymer was taken out of ethanol, it was placed in a vacuum dryer and treated to constant weight to obtain a cycloolefin copolymer. By testing, its Mw was 11.29×10 4 g / mol, the PDI was 3.3, the Tg was 136 °C, the tensile strength was 42.9 MPa, the flexural strength was 2214 MPa, the refractive index was 1.545, and the birefringence was 2.3×10 -4 .

[0089] Comparative Example 2

[0090] Catalyst preparation: In a glove box, a transition complex (10 μmol) of the main catalyst (R5 is indenyl, R6 is cyclopentadienyl, R7 and R8 are methyl, E is silicon, m = 1, X1 and X2 are methyl, M is titanium), AlMe3 (20 μmol) and triphenylcarbonium tetrakis(pentafluorophenyl)borate [Ph3C][B(C6F5)4] (10 μmol) were dissolved in 5 mL of toluene to obtain a catalyst solution.

[0091] Synthesis of cycloolefin copolymer without conjugated diene structure:

[0092] Before the experiment, the reaction kettle was preheated to 100 °C, and the operation of evacuating and filling with nitrogen was repeated 3 times. After that, the reaction kettle was cooled to room temperature. 40 mmol of 2-norbornene (n = 0, R1 and R2 are hydrogen) and 20 mL of toluene were added to a 150 mL reaction kettle. After purging thoroughly with nitrogen. Subsequently, the temperature of the reaction kettle was raised to 120 °C, stirring was started, and ethylene at 1.0 atm was introduced into it under vigorous stirring to make it reach a saturated state in the toluene solution. After the pressure was stabilized, the catalyst solution was injected through the feed hopper of the reaction kettle, and then ethylene at 9.0 atm was introduced for reaction. After reacting for 10 minutes, the heating was turned off, the pressure was released, and the kettle was opened. An ethanol solution was injected into the reaction solution to terminate the reaction and inactivate it, and then a large amount of ethanol solution was added for gel precipitation, and the polymer precipitated in ethanol. After the polymer was taken out of ethanol, it was placed in a vacuum dryer and treated to constant weight to obtain a cycloolefin copolymer. By testing, its Mw was 4.26×10 4g / mol, PDI is 2.7, Tg is 133 °C, tensile strength is 40.3 MPa, flexural strength is 2159 MPa, refractive index is 1.531, birefringence is 10.5×10 -4 。

[0093] Table 1 Detection results of copolymers prepared in the examples and comparative examples of the present invention

[0094]

[0095] From the data analysis of the comparative examples and examples, it can be seen that the insertion of diene monomers can effectively improve the tensile strength and flexural modulus of cycloolefin copolymers. The tensile strength of the cycloolefin copolymer without diene structural units is 42.9 MPa and the flexural modulus is 2214 MPa. After introducing diene structural units, the tensile strength is increased to 55.4 MPa and the flexural modulus is increased to 2990 MPa. And from the analysis of Examples 1-8, it can be seen that the higher the insertion rate of diene monomers, the more obvious the improvement of tensile strength and flexural modulus, indicating that the cycloolefin copolymer preparation method described in the present invention provides polymers with good toughness and high rigidity.

[0096] From the data analysis, it can be seen that when the conjugated diene monomer has a phenyl group, it can effectively increase the refractive index of the polymer and decrease the birefringence of the polymer. For example, the refractive index of the copolymer without phenyl-conjugated diene monomer in Comparative Example 1 is 1.545 and the birefringence is 2.3×10 -4 ,while the refractive index of the polymer in Example 5 with one phenyl group in the conjugated diene monomer is 1.586 and the birefringence is 1.5×10 -4 ,and the refractive index of the polymer in Example 6 with two phenyl groups in the conjugated diene monomer is 1.608 and the birefringence is 1.2×10 -4 。This indicates that as the number of phenyl groups in the polymer increases, the refractive index of the polymer gradually increases and the birefringence gradually decreases, indicating that the polymers provided by the cycloolefin preparation method described in the present invention have better optical properties.

Claims

1. A cycloolefin copolymer having a structure shown by formula (I): wherein the mole number x of ethylene units accounts for 50 - 75% of the total mole number x + y + z of all structural units, the mole number y of cycloolefin units accounts for 20 - 45% of the total mole number of all structural units, and the mole number z of conjugated diene units accounts for 1 - 15% of the total mole number of all structural units; In formula (I), R1 and R2 are the same or different atoms or atomic groups, preferably hydrogen, phenyl, carboxyl, substituted or unsubstituted alkyl groups; R3 is an alkyl group having 1 - 10 carbon atoms, preferably methyl, ethyl, n - propyl, or isopropyl; R4 is hydrogen, phenyl, substituted or unsubstituted alkyl group having 1 - 20 carbon atoms or alkylphenyl; n is 0 - 5, preferably 0 - 2.

2. The cycloolefin copolymer according to claim 1, wherein The weight-average molecular weight of the cycloolefin copolymer is between 10,000 and 1,000,000, preferably between 30,000 and 600,000.

3. The cycloolefin copolymer according to claim 1, wherein The molecular weight distribution of the cycloolefin copolymer is between 1 and 10, preferably between 1 and 5; the glass transition temperature of the cycloolefin copolymer is between 80 and 200 °C, preferably between 100 and 190 °C.

4. A method for preparing the cycloolefin copolymer according to any one of claims 1 - 3, comprising the following steps: in the presence of a catalyst system and a solvent, ethylene, a cycloolefin, and a conjugated diene compound are subjected to a polymerization reaction; the cycloolefin monomer is shown by formula (II), wherein R1 and R2 are the same or different atoms or atomic groups, and n is 0 - 5, preferably 0 - 2; The conjugated diene compound is shown by formula (III), wherein R3 is an alkyl group having 1 - 10 carbon atoms, and R4 is hydrogen, phenyl, substituted or unsubstituted alkyl group having 1 - 20 carbon atoms or alkylphenyl.

5. The method according to claim 4, wherein The catalyst system for the polymerization reaction includes: a transition metal complex, an organoboron compound, and an organoaluminum compound.

6. The method according to claim 4 or 5, wherein The transition metal complex has the following structure of formula (IV): In formula (IV), R5 and R6 are each independently selected from unsubstituted cyclopentadienyl and its derivatives, indenyl and its derivatives, or fluorenyl and its derivatives; R7 and R8 are each independently selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, 2,6-dimethylphenyl, 4-methylphenyl, mesityl, 2,6-diisopropylphenyl, 2,4,6-triisopropylphenyl, or 2,6-di-tert-butylphenyl; X1 and X2 are monoanionic ligands, and X1 and X2 are independently selected from hydrogen, a linear or branched aliphatic group or alicyclic group containing 1 to 20 carbon atoms, phenyl, a phenyl group substituted with a linear or branched alkyl or cyclic aliphatic group or aromatic group containing 1 to 20 carbon atoms, a linear or branched alkoxy group containing 1 to 20 carbon atoms, a linear or branched alkylamine group containing 1 to 20 carbon atoms, a linear or branched arylamine group containing 1 to 20 carbon atoms, a linear or branched silyl group containing 1 to 20 carbon atoms, borohydride, allyl and allyl derivatives, or halogen; M is selected from transition metal atoms such as titanium, zirconium, vanadium, chromium, hafnium, etc.; E is C, Si, or Ge; m = 1 or 2.

7. The method according to any one of claims 4 - 6, wherein The organoboron compound is an ionic compound formed by an organoboron anion and a cation; The organoboron anion is selected from tetraphenylborate, tetrakis(monofluorophenyl)borate, tetrakis(difluorophenyl)borate, tetrakis(trifluorophenyl)borate, tetrakis(tetrafluorophenyl)borate, tetrakis(pentafluorophenyl)borate, tetrakis(tetrafluoromethylphenyl)borate, tetrakis(tolyl)borate, tetrakis(xylenyl)borate, (triphenyl, pentafluorophenyl)borate, [tris(pentafluorophenyl), phenyl]borate, or undecahydro-7,8-dicarbaundecaborate; The cation is selected from a carbonium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienylium cation, or a ferrocenium cation containing a transition metal; The carbonium cation is selected from a triphenylcarbonium cation, a tris(tolyl)carbonium cation; The ammonium cation is selected from a trimethylammonium cation, a triethylammonium cation, a tripropylammonium cation, a tributylammonium cation; The phosphonium cation is selected from a triphenylphosphonium cation, a tris(tolyl)phosphonium cation, a tris(xylenyl)phosphonium cation.

8. The method according to any one of claims 4 to 7, characterized in that, The organoaluminum compound is selected from one or more of diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum, phenyl-n-propylaluminum, p-tolylethylaluminum, p-tolyl-n-propylaluminum, p-tolylisopropylaluminum, benzylethylaluminum, benzyl-n-propylaluminum, benzylisopropylaluminum, ethyldialuminum hydride, butyldialuminum hydride, isobutyldialuminum hydride, octyldialuminum hydride, pentyldialuminum hydride, diethylaluminum ethoxide, dipropylaluminum ethoxide, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldiphenylaluminum, ethyldi-p-tolylaluminum, ethyldibenzylaluminum, diethylphenylaluminum, diethyl-p-tolylaluminum and diethylbenzylaluminum.

9. The method according to any one of claims 4 to 8, characterized in that, The pressure of ethylene in the polymerization reaction system is 1 to 12 atm, preferably 1 to 10 atm.

10. The method according to any one of claims 4 to 9, characterized in that, The polymerization reaction temperature is 50 to 200 °C, preferably 90 to 160 °C.

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