A method for preparing high-purity cycloolefin polymer and its product

Abstract

The invention relates to the technical field of C08F32 / 00, and in particular to a method for preparing a high-purity cycloolefin polymer and a product thereof. The method comprises at least the following steps: (1) adding a catalyst solvent and stirring uniformly, adding a catalyst modifier, and finally adding a co-catalyst for activation for 20-40 minutes to obtain a catalyst solution; (2) adding the prepared catalyst solution to a reaction container containing a cycloolefin monomer solution for reaction to obtain a polymer slurry; and (3) after the reaction is completed, adding a post-treatment adsorbent to the reaction system for treatment, performing three-stage filtration, and taking a supernatant, performing a hydrogenation catalytic reaction between the collected supernatant and a hydrogenation catalyst in a hydrogenation device, filtering out the hydrogenation catalyst, and then devolatilizing and deashing the filtrate obtained by filtration to obtain the polymer, thereby effectively solving the problems of difficult operability and high cost of a traditional post-treatment process for preparing a high-purity cycloolefin polymer.

Description

Technical Field

[0001] The invention relates to the technical field of C08F32 / 00, in particular to a preparation method of a high-purity cycloolefin polymer and a product thereof. Background Art

[0002] Cyclic olefin polymer (COP) material is a kind of amorphous transparent polyolefin material, and is currently gradually applied to the field of optical materials due to its outstanding material specificity. However, the trace metal ions present in COP polymers will accelerate the aging process of polymers, seriously threatening the high temperature resistance of COP, and when COP is used for optical materials, the polymers obtained by the catalyst or co-catalyst containing a small amount of Al metal components have poor hue, low transparency, and white spots when forming thin films. The COP material prepared by the ring-opening metathesis polymerization (ROMP) method in the prior art has double bonds, which are easily oxidized to cause poor anti-aging properties, so after the polymerization is completed, a hydrogenation step under high temperature and high pressure conditions is required, and the traditional ZN catalyst is used. It is inevitable to use a catalyst or co-catalyst containing Cl, because the Cl ion radius is small and the penetration ability is strong, so it can be preferentially selected to be adsorbed on the passivation film and oxygen atoms are squeezed out, and then combined with the cations in the passivation film into soluble chlorides, thereby causing corrosion to the equipment.

[0003] At present, there are many methods for removing impurity ions of COP, including acetone precipitation method, chelating agent adsorption method, silica gel adsorption method, non-solvent reverse precipitation method, and diatomaceous earth post-treatment method. For example, Chinese invention authorization CN1307216C discloses a method for preparing cycloolefin polymers with high bulk density and cycloolefin polymers prepared by the method; Chinese invention authorization CN1315878C discloses a deashing method for polymers and a method for manufacturing polymers; Chinese patent application CN114345300A discloses an adsorbent and a preparation method thereof, and a method for purifying cycloolefin polymers; Chinese invention authorization CN1151866C discloses microparticles prepared from cycloolefin copolymers and their use for controlling the release of active substances; Chinese invention authorization CN1042546C discloses a cycloolefin polymer molding composition with improved chemical degradation stability. These methods have good impurity removal effects and can successfully reduce the impurity ions in the polymer content of several hundred ppm to within a few ppm. However, these methods are not highly operable and require a large amount of precipitants or adsorbents, which increases production costs, cannot effectively improve product production efficiency, and are not conducive to large-scale industrial production. Summary of the invention

[0004] In order to solve the problems of difficult operability and high cost of traditional post-treatment processes for preparing high-purity cycloolefin polymers, the present invention provides a method for preparing high-purity cycloolefin polymers, which can prepare a polymerization system with low viscosity and easy separation and recovery. The method is simple to operate and low in cost, and at the same time, effective polymer post-treatment adsorption purification is achieved, and has high practical application value.

[0005] In one aspect, the present invention provides a method for preparing a high-purity cycloolefin polymer, comprising at least the following preparation steps:

[0006] (1) After the catalyst is mixed with a solvent and stirred evenly, a catalyst modifier is added, and finally a co-catalyst is added to activate for 20-40 minutes to obtain a catalyst solution;

[0007] (2) adding the prepared catalyst solution into a reaction vessel containing a cycloolefin monomer solution to react and obtain a polymer slurry;

[0008] (3) After the reaction is completed, a post-treatment adsorbent is added to the reaction system for treatment, and then the supernatant is taken after three-stage filtration. The collected supernatant is subjected to a hydrogenation catalytic reaction with a hydrogenation catalyst in a hydrogenation device, and then the hydrogenation catalyst is filtered out. The filtrate obtained by filtration is devolatilized, deashed, and granulated to obtain the product.

[0009] As a preferred technical solution, the catalyst is selected from one or more of tantalum, molybdenum, tungsten, ruthenium and their chlorides or oxychlorides. Preferably, the catalyst is molybdenum chloride or tungsten chloride.

[0010] As a preferred technical solution, the solvent is selected from one or more of n-hexane, cyclohexane, n-heptane, n-octane, benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene, dichloromethane, chloroform, and carbon tetrachloride. Preferably, the solvent is toluene or cyclohexane.

[0011] As a preferred technical solution, the catalyst modifier is one or more of an alcohol compound, a phenolic compound, an ether compound, an acid compound, an acyl compound, an ester compound, and a heterocyclic compound. Preferably, the catalyst modifier is at least one of ethanol, isopropanol, n-butanol, phenol, cresol, 4-methoxyphenol, ethylphenol, propylphenol, p-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, biphenol, biphenyldiphenol, pyrogallol, 1,5-naphthalene diol, 2,3-naphthalene diol, binaphthol, ether, propyl ether, diphenyl ether, acetic acid, propionic acid, ethyl acetate, tetrabutyl titanate, pentaerythritol tetraphenylpropionate, pyrrole, imidazole, and furan. Preferably, the catalyst modifier is one of p-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,3-naphthalene diol, and 4-methoxyphenol.

[0012] Preferably, the molar ratio of the catalyst modifier to the catalyst is (0.1-100): 1, preferably (1-10): 1. Based on the system of the present invention, the catalyst is modified by a catalyst modifier, especially 4-methoxyphenol is used as the modifier, and the molar ratio of the catalyst modifier to the catalyst is controlled to be (1-10): 1, so that the prepared high-purity cycloolefin polymer has a relatively high conversion rate, the viscosity of the polymer slurry obtained after the reaction is relatively low, the polymer slurry has good filterability, and the residual amount of impurity ions in the product is effectively reduced.

[0013] As a preferred technical solution, the co-catalyst is a haloalkylaluminum, preferably one or more of trimethylaluminum, triethylaluminum, diethylaluminum monochloride, monoethylaluminum dichloride, tri-n-butylaluminum, triisobutylaluminum, and tri-n-octylaluminum; more preferably, the co-catalyst is triisobutylaluminum.

[0014] Preferably, the molar ratio of the co-catalyst to the catalyst is (10-1000):1; preferably (50-200):1.

[0015] Based on the system of the present invention, by introducing triisobutylaluminum as a co-catalyst, especially controlling the molar ratio of triisobutylaluminum to the catalyst to (50-200):1, the activity of the catalyst modified by the catalyst modifier is effectively improved, and at the same time, trace water in the reaction system can be removed to ensure the smooth progress of the polymerization reaction.

[0016] As a preferred technical solution, the concentration of the cycloolefin monomer in the cycloolefin monomer solution is 0.5-0.8 mol / L.

[0017] As a preferred technical solution, the cycloolefin monomer is at least one of monocyclic monoolefin, monocyclic polyolefin, polycyclic olefin, and bridged cyclic olefin. Preferably, the cycloolefin monomer is selected from one or more of cyclopentene, cyclopentadiene, dicyclopentadiene, tricyclopentadiene, cyclopentadiene polymer, norbornene, methyl norbornene, vinyl norbornene, tetracyclododecene, methyl tetracyclododecene, and tricyclodecene; more preferably, the cycloolefin monomer is a combination of tricyclodecene and tetracyclododecene; the molar ratio of tricyclodecene to tetracyclododecene is 1:(0.5-2).

[0018] Preferably, the solvent in the cycloolefin monomer solution is toluene.

[0019] As a preferred technical solution, the reaction in step (2) is specifically as follows: react at 0-5°C for 20-40 minutes, and then continue to react at 65-75°C for 1.5-2.5 hours.

[0020] Based on the system of the present invention, by using tricyclodecene and tetracyclododecene as cycloolefin monomers, under the above reaction conditions, the polymer slurry obtained after the polymerization reaction has good filterability, is easy to dissipate heat and carry out subsequent post-treatment adsorbent treatment, has high catalytic reaction efficiency with hydrogenation catalyst, is easy to separate and recover, and the residual impurity ion (Al, Cl) content in the product is less than 100ppm. The inventor analyzed that the reason may be: tricyclodecene and tetracyclododecene have good steric hindrance matching, and under the high catalytic efficiency of catalyst-catalyst modifier-cocatalyst, a polymer slurry with low viscosity can be obtained, and subsequent effective treatment is achieved to prepare high-purity cycloolefin polymers.

[0021] As a preferred technical solution, the post-treatment adsorbent is an alkaline compound. Preferably, the alkaline compound is a normal salt and / or a basic salt; preferably, the alkaline compound is Ca(OH) 2 、Ba(OH) 2 , activated alumina, CaO, calcium chloride. Preferably, the molar ratio of the post-treatment adsorbent to the co-catalyst is (1-1.5): 1. Preferably, the post-treatment adsorbent treatment time is 1.5-3h.

[0022] Preferably, the three-stage filtration specifically includes a first-stage 300-mesh filter cloth filtration, a second-stage 10 μm pore size nylon filter membrane filtration, and a third-stage 0.45 μm filter press filtration.

[0023] Based on the preparation method provided by the present invention, the polymer solution with qualified filterability obtained by the polymerization reaction in step (2) is subjected to simple adsorption purification treatment using alkaline compounds, especially using Ca(OH) 2 The polymer slurry is chemically reacted to effectively remove residual impurity ions without affecting the conversion rate. The filterability of the polymer solution is determined by filtering through a secondary 10μm pore size nylon filter membrane. Finally, the solid base compound after the reaction is removed through a filter press with a pore size of 0.45μm to obtain a clear and transparent polymer solution.

[0024] As a preferred technical solution, the hydrogenation catalyst is a palladium / carbon hydrogenation catalyst; the amount of the palladium / carbon hydrogenation catalyst added is 1-10wt% of the polymer solution. Preferably, the hydrogenation catalytic reaction is specifically: reacting at a temperature of 170-190 and a 4-6MPa hydrogen atmosphere for 4-6h.

[0025] Another aspect of the present invention provides a product prepared by a method for preparing a high-purity cycloolefin polymer, wherein the product has a weight average molecular weight of 8000-80000, a molecular weight distribution of 1.5-2.5, and a glass transition temperature of 100-170°C.

[0026] Beneficial Effects

[0027] 1. The present invention provides a method for preparing a high-purity cycloolefin polymer, which can prepare a polymerization system with low viscosity and easy separation and recovery. The method is simple to operate and low in cost, and can achieve effective polymer post-treatment adsorption purification. The catalytic efficiency is greater than 3000 g COP / g cat / h, the hydrogenation rate is more than 99%, the production efficiency is high, and it is conducive to large-scale industrial production.

[0028] 2. Based on the system of the present invention, a catalyst modifier is used to modify the catalyst, especially 4-methoxyphenol is used as the modifier, and the molar ratio of the catalyst modifier to the catalyst is controlled to be (1-10):1, so that the prepared high-purity cycloolefin polymer has a relatively high conversion rate, and the viscosity of the polymer slurry obtained after the reaction is relatively low, the polymer slurry has good filterability, and the residual amount of impurity ions in the product is effectively reduced.

[0029] 3. Based on the system of the present invention, by introducing triisobutylaluminum as a co-catalyst, especially controlling the molar ratio of triisobutylaluminum to the catalyst to (50-200):1, the activity of the catalyst modified by the catalyst modifier is effectively improved, and at the same time, trace water in the reaction system can be removed to ensure the smooth progress of the polymerization reaction.

[0030] 4. Based on the system of the present invention, by using tricyclodecene and tetracyclododecene as cycloolefin monomers, under the above reaction conditions, the polymer slurry obtained after the polymerization reaction has good filterability, is easy to dissipate heat and carry out subsequent post-treatment adsorbent treatment, has high catalytic reaction efficiency with the hydrogenation catalyst, is easy to separate and recover, and the residual impurity ion (Al, Cl) content in the product is less than 100ppm.

[0031] 5. Based on the preparation method provided by the present invention, the polymer solution with qualified filterability obtained by the polymerization reaction in step (2) is subjected to simple adsorption purification treatment using alkaline compounds, especially using Ca(OH) 2 The polymer slurry is chemically reacted to effectively remove the residual impurity ions without affecting the conversion rate. Finally, the solid base compound after the reaction is removed through a filter press with a pore size of 0.45 μm to obtain a clear and transparent polymer solution. DETAILED DESCRIPTION

[0032] Example 1

[0033] Embodiment 1 of the present invention provides a method for preparing a high-purity cycloolefin polymer, comprising the following preparation steps:

[0034] (1) First, take 5*10 -4mol of tungsten hexachloride was placed in a dehydrated Schlenk bottle, dissolved in 50 ml of toluene, stirred evenly with a magnetic stirrer, and then 10*10 -4 mol of 4-methoxyphenol, and finally add triisobutylaluminum 5*10 -2 mol was activated for 30 min to obtain a catalyst solution;

[0035] (2) Add the prepared catalyst solution to a dried 5 L reaction vessel containing 0.5 mol tetracyclododecene, 0.5 mol tricyclodecene and 1.5 L toluene. After reacting at 0° C. for 30 min, transfer the reaction to 70° C. and continue the reaction for 2 hours;

[0036] (3) After the reaction is completed, add 5*10 -2 mol of Ca(OH) 2 After 2 hours of treatment, filter through a 300-mesh filter cloth, a 10 μm nylon filter membrane, and a 0.45 μm filter press. After discarding the waste residue, transfer the collected supernatant to a hydrogenation device of the same scale and add 5*10 -3 mol palladium / carbon hydrogenation catalyst, and then adjust the reaction temperature to 180°C, and react for 5 hours under a 5MPa hydrogen atmosphere. Finally, the generated polymer solution is filtered to remove the hydrogenation catalyst, and a colorless clear filtrate is obtained again, which is devolatilized, deashed, and granulated to obtain the obtained product.

[0037] On the other hand, Example 1 of the present invention provides a product obtained by a method for preparing a high-purity cycloolefin polymer. The product (highly transparent colorless polymer) has a weight average molecular weight of 39658, a molecular weight distribution of 2.51, and a glass transition temperature of 134°C.

[0038] Example 2

[0039] Example 2 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that the Ca(OH) 2 Replaced by Ba(OH) 2 The product (highly transparent colorless polymer) had a weight average molecular weight of 38609, a molecular weight distribution of 2.53, and a glass transition temperature of 133°C.

[0040] Example 3

[0041] Example 3 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that the Ca(OH) 2The product (highly transparent colorless polymer) had a weight average molecular weight of 40778, a molecular weight distribution of 2.50, and a glass transition temperature of 134°C.

[0042] Example 4

[0043] Example 4 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that the Ca(OH) 2 The product (highly transparent colorless polymer) has a weight average molecular weight of 36778, a molecular weight distribution of 2.51, and a glass transition temperature of 132°C.

[0044] Example 5

[0045] Example 5 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that the Ca(OH) 2 The product (highly transparent colorless polymer) had a weight average molecular weight of 41220, a molecular weight distribution of 2.49, and a glass transition temperature of 133°C.

[0046] Example 6

[0047] Example 6 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, wherein the specific implementation manner is the same as that of Example 1, except that the 4-methoxyphenol is replaced by an equimolar amount of p-tert-butylphenol. The weight average molecular weight of the product (highly transparent colorless polymer) is 29179, the molecular weight distribution is 2.12, and the glass transition temperature is 136°C.

[0048] Example 7

[0049] Example 7 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that the 4-methoxyphenol is replaced by an equimolar amount of 2,3-naphthalenediol. The weight average molecular weight of the product (highly transparent colorless polymer) is 31198, the molecular weight distribution is 2.66, and the glass transition temperature is 133°C.

[0050] Example 8

[0051] Example 8 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that the 4-methoxyphenol is replaced by an equimolar amount of 2,6-di-tert-butyl-p-cresol. The weight average molecular weight of the product (highly transparent colorless polymer) is 36987, the molecular weight distribution is 3.32, and the glass transition temperature is 130°C.

[0052] Example 9

[0053] Embodiment 9 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Embodiment 1, except that the tricyclodecene is replaced by an equimolar amount of dicyclopentadiene. The weight average molecular weight of the product (highly transparent colorless polymer) is 34509, the molecular weight distribution is 2.50, and the glass transition temperature is 116°C.

[0054] Example 10

[0055] Embodiment 10 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and the specific implementation manner is the same as that of Embodiment 1, except that the tricyclodecene is replaced by an equimolar amount of norbornene. The weight average molecular weight of the product (highly transparent colorless polymer) is 40034, the molecular weight distribution is 2.70, and the glass transition temperature is 105°C.

[0056] Comparative Example 1

[0057] Comparative Example 1 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that it includes the following preparation steps:

[0058] (1) First, take 5*10 -4 mol of tungsten hexachloride was placed in a dehydrated Schlenk bottle, dissolved in 50 ml of toluene, stirred evenly with a magnetic stirrer, and then 10*10 -4 mol of 4-methoxyphenol, and finally add triisobutylaluminum 5*10 -2 mol was activated for 30 min to obtain the catalyst solution

[0059] (2) The prepared catalyst solution was added to a dried 5 L reaction vessel containing 0.5 mol tetracyclododecene, 0.5 mol tricyclodecene and 1.5 L toluene. After reacting at 0° C. for 30 min, the reaction was transferred to 70° C. and continued to react for 2 hours.

[0060] (3) After the reaction is completed, transfer to a hydrogenation device of the same scale and add 5*10 -3 mol palladium / carbon hydrogenation catalyst, and then adjust the reaction temperature to 180°C, and react for 5 hours under a 5MPa hydrogen atmosphere. Finally, the generated polymer solution is filtered to remove the hydrogenation catalyst, and a colorless clear filtrate is obtained again, which is devolatilized, deashed, and granulated to obtain the product. The product has a weight average molecular weight of 30281, a molecular weight distribution of 2.80, and a glass transition temperature of 132°C.

[0061] Comparative Example 2

[0062] Comparative Example 2 of the present invention provides a method for preparing a high-purity cycloolefin polymer and a product thereof, and its specific implementation is the same as that of Example 1, except that the 4-methoxyphenol is replaced by an equal molar amount of ethanol. The product has a weight average molecular weight of 33520, a molecular weight distribution of 2.17, and a glass transition temperature of 130°C.

[0063] Performance Testing Methods

[0064] (1) Conversion rate: The residual amount of cycloolefin monomers in the examples and comparative examples after the reaction was completed was tested in a gas chromatograph (GC) at 190° C. The conversion rate was calculated by the following formula. The results are shown in Table 1.

[0065] Conversion rate = (amount of cycloolefin monomer added - amount of cycloolefin monomer remaining) / amount of cycloolefin monomer added × 100%.

[0066] (2) Filterability: The filterability of the polymer solution through the secondary 10 μm pore nylon filter membrane in the examples and comparative examples was used as the basis. The evaluation criteria were: if the polymer solution in the examples and comparative examples had filtrate flowing out after passing through the secondary 10 μm pore nylon filter membrane, the filterability was recorded as “√”; if the polymer solution in the examples and comparative examples had no filtrate flowing out after passing through the secondary 10 μm pore nylon filter membrane, the filterability was recorded as “×”. The results are shown in Table 1.

[0067] (3) Impurity content: The products prepared in the examples and comparative examples were analyzed by plasma atomic emission spectrometry (ICP) to determine the contents of residual W, Al and Cl in the products. The results are shown in Table 1.

[0068] Table 1

[0069]

[0070]

Claims

1. A method for preparing a high-purity cycloolefin polymer, It is characterized in that The method comprises the following preparation steps: (1) First, take 5*10 -4 mol of tungsten hexachloride was placed in a dehydrated Schlenk bottle, dissolved in 50 ml of toluene, stirred evenly with a magnetic stirrer, and then 10*10 -4 mol of 4-methoxyphenol, and finally add triisobutylaluminum 5*10 -2 mol was activated for 30 min to obtain a catalyst solution; (2) adding the prepared catalyst solution to a dried 5 L reaction vessel containing 0.5 mol tetracyclododecene, 0.5 mol tricyclodecene and 1.5 L toluene; reacting at 0° C. for 30 min, then transferring to 70° C. and continuing the reaction for 2 hours; (3) After the reaction is completed, add 5*10 -2 mol of Ca(OH) 2 After 2 hours of treatment, filter through a 300-mesh filter cloth, a 10 μm nylon filter membrane, and a 0.45 μm filter press in sequence; discard the waste residue and transfer the collected supernatant to a hydrogenation device of the same scale, add 5*10 -3 mol palladium / carbon hydrogenation catalyst, and then adjust the reaction temperature to 180°C, and react for 5 hours under a 5MPa hydrogen atmosphere; finally, filter the generated polymer solution to remove the hydrogenation catalyst, and then obtain a colorless clear filtrate, devolatilize it, deash it, and granulate it to obtain the product; The product is a highly transparent colorless polymer with a weight average molecular weight of 39658, a molecular weight distribution of 2.51, and a glass transition temperature of 134°C.

Images