Method for efficiently purifying cycloolefin polymer

Abstract

The invention discloses a method for efficiently purifying a cycloolefin polymer, and belongs to the technical field of cycloolefin polymer purification. The method comprises the following steps: mixing silicon dioxide particles with 3-aminopropyltriethoxysilane and aminoethylpiperazine, stirring the mixture in a water environment, and after stirring, performing suction filtration and drying to obtain the scavenger, the method comprises the following steps: adding a scavenger into a to-be-purified cycloolefin polymer product, mixing, sealing, oscillating, filtering the mixed solution, and washing with a solvent of the cycloolefin polymer; and precipitating the washed polymer by using a non-solvent of the cycloolefin polymer, and filtering and collecting the cycloolefin polymer. The modified silicon dioxide particles are used for removing impurities such as a catalyst from the polymer to be purified, the content of the impurities such as the residual catalyst in the polymer is effectively reduced, and the oxidation stability of the polymer is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of cyclic olefin polymer purification technology, and specifically to a method for efficiently purifying cyclic olefin polymers. Background Technology

[0002] Cyclic olefin polymers (COPs) are a class of amorphous, highly transparent linear thermoplastic polymers obtained from norbornene derivatives through ring-opening metathesis polymerization (ROMP). Due to their excellent optical properties, low water absorption, and high glass transition temperature, COPs are widely used in optical lenses, optical disc substrates, and electronic packaging materials.

[0003] In the production of cycloolefin polymers, the presence of impurities (such as unreacted monomers and catalyst residues) can affect the stability and lifespan of cycloolefin polymers, thus hindering their further expansion in some high-end application fields. Therefore, developing efficient impurity removal processes and optimizing production processes to reduce impurity content are key technological breakthroughs for improving the performance of cycloolefin polymers and promoting their widespread application in high-end fields such as optical devices and medical consumables.

[0004] Currently, the main purification method for cyclic olefin polymers is precipitation. In traditional preparation processes, multiple precipitation steps are typically used to purify the polymer. Specifically, the polymerization product is poured into a precipitant, and the polymer precipitates out due to differences in solubility. The polymer is then collected through filtration and drying. However, studies have found that the polymer product obtained by this purification method still contains high levels of impurities (especially residual catalyst). Even with multiple precipitation processes, the impurity level in the final polymer product remains high. For many applications requiring extremely high purity, such as high-end optical lenses and advanced electronic packaging materials, this impurity level is far from meeting the requirements, becoming a bottleneck restricting the wider application of cyclic olefin polymers.

[0005] In summary, there is an urgent need to develop a method that can effectively reduce the impurity content in cyclic olefin polymers in order to overcome the limitations of existing technologies, improve the quality of cyclic olefin polymers, and meet the demand for high-performance cyclic olefin polymer materials in various fields. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a method for efficiently purifying cyclic olefin polymers, so as to solve the problem that the high impurity content of cyclic olefin polymers in the prior art affects the polymer performance.

[0007] The technical solution of this invention is as follows: A method for efficiently purifying cyclic olefin polymers includes the following steps: Preparation of the cleaning agent: Silica particles are mixed with 3-aminopropyltriethoxysilane and aminoethylpiperazine. The mixture is stirred in an aqueous environment. After stirring, the mixture is filtered and dried to obtain the cleaning agent. Add a scavenging agent to the cyclic olefin polymer product to be purified, mix, seal and shake, then filter the mixture and wash with the solvent of the cyclic olefin polymer; precipitate the washed polymer with a non-solvent of the cyclic olefin polymer, and collect the cyclic olefin polymer by filtration. The cyclic olefin polymer product to be purified contains a ruthenium-based catalyst.

[0008] Preferably, the mass ratio of the silica particles to 3-aminopropyltriethoxysilane and aminoethylpiperazine is 1:30~50:20~35.

[0009] Preferably, the mass ratio of the silica particles to 3-aminopropyltriethoxysilane, aminoethylpiperazine, and water is 1:30~50:20~35:20.

[0010] Preferably, the stirring temperature is 70~90℃.

[0011] Preferably, the molar ratio of the ruthenium-based catalyst to the scavenger is 1:40~50.

[0012] Preferably, the solvent for the cyclic olefin polymer includes dichloromethane.

[0013] Preferably, the non-solvent for the cyclic olefin polymer includes methanol.

[0014] Preferably, the sealing vibration time is 24 hours.

[0015] Preferably, when using solvents containing cyclic olefin polymers for washing, the washing ratio is typically 1g:5~10mL. Of course, the amount of solvent can be appropriately increased or decreased depending on the actual washing effect.

[0016] Preferably, when precipitating polymers with non-solvents, non-solvents are typically added at a ratio of 1g:5~10mL for precipitation.

[0017] A scavenging agent for purifying cyclic olefin polymers, the scavenging agent comprising silica particles and 3-aminopropyltriethoxysilane and aminoethylpiperazine. The mass ratio of the silica particles to 3-aminopropyltriethoxysilane and aminoethylpiperazine is 1:30~50:20~35.

[0018] Compared with the prior art, the beneficial results of the present invention are as follows: This invention significantly reduces the content of impurities (residual catalyst) in cyclic olefin polymers by using modified silica particles as a scavenging agent. It can reduce residual Ru levels to below 5 ppm, effectively solving the problem of high residual catalyst content in traditional methods.

[0019] Differential scanning calorimetry (DSC) testing showed that the oxidation-induced temperature of the purified cyclic olefin polymer increased by more than 25°C, making the polymer more stable in practical applications and broadening its application range. Detailed Implementation

[0020] To better understand the technical content of this invention, the invention will be further described below with reference to specific embodiments.

[0021] Example 1: A method for efficient purification of cyclic olefin polymers (1) A ruthenium-based catalyst (e.g., a Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0022] (2) Mix silica particles with 3-aminopropyltriethoxysilane, aminoethylpiperazine and water at a mass ratio of 1:50:20:20. Stir at 70-90℃ for 24 hours. After stirring, filter and dry to obtain modified silica particles (i.e. cleaning agent) for later use.

[0023] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:50 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0024] The purified polymer was analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine the Ru content. The results showed that the Ru content was 2 ppm, and the cyclic olefin polymer yield was 95% (actual polymer mass / theoretical mass × 100%). Differential scanning calorimetry (DSC) analysis showed that the oxidation-induced temperature of the purified cyclic olefin polymer (compared to Comparative Example 1) increased by 30°C.

[0025] Example 2 This example, based on Example 1, increases the number of methanol precipitation cycles. The specific operation is as follows: (1) Ruthenium-based catalyst (Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0026] (2) Mix silica particles with 3-aminopropyltriethoxysilane, aminoethylpiperazine and water at a mass ratio of 1:50:20:20. Stir at 70-90℃ for 24 hours. After stirring, filter and dry to obtain modified silica particles (i.e. cleaning agent) for later use.

[0027] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:50 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated twice in methanol, collected by vacuum filtration, and dried under vacuum.

[0028] The results of this embodiment show that after treatment by this method, the Ru content is 2 ppm, and the yield and oxidation induction temperature are not significantly different from those of Example 1, indicating that the number of methanol precipitation cycles has no significant impact on the product yield. In actual operation, 1-2 methanol precipitation cycles can be performed.

[0029] This invention further explored the applicable range of each technical parameter, determining that the mass ratio of the silica particles to 3-aminopropyltriethoxysilane, aminoethylpiperazine, and water was 1:30~50:20~35:20, the mixing and stirring time was 12~24h, and the molar ratio of the ruthenium-based catalyst to the scavenger was 1:40~50. Related Examples 3~6 are shown in the following examples. Examples 3~6 all achieved the following effects: Ru content of 4~7 ppm, yield above 95%, and the oxidation induction temperature of the purified cyclic olefin polymer (compared to Comparative Example 1) increased by 22~25°C.

[0030] Comparing the purification effects of Examples 3-6 with Example 1, the results showed that Example 1 had the best effect. The oxidation induction temperature of the purified cyclic olefin polymer was about 5°C higher than that of the other examples. This indicates that strictly controlling the mixing ratio of silica particles with 3-aminopropyltriethoxysilane, aminoethylpiperazine, and water to 1:50:20:20 during the purification process, and stirring at 70-90°C for 24 hours to prepare the scavenging agent, while using the scavenging agent in the cyclic olefin polymer at a molar ratio of 1:50, ensures the best purification effect. The above factors synergistically optimized the number of active sites, activity, and adsorption efficiency of the scavenging agent: under optimal conditions, the scavenging agent surface was grafted with a sufficient number of active sites, which could efficiently capture catalyst impurities and was easily and completely removed itself, ultimately reducing the residual impurities in the polymer and significantly improving the purity of the product.

[0031] Example 3 (1) A ruthenium-based catalyst (e.g., a Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0032] (2) Mix silica particles with 3-aminopropyltriethoxysilane, aminoethylpiperazine and water at a mass ratio of 1:50:20:20. Stir at 70-90℃ for 12 hours. After stirring, filter and dry to obtain modified silica particles (i.e. cleaning agent) for later use.

[0033] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:50 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0034] Example 4 (1) A ruthenium-based catalyst (e.g., a Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0035] (2) Mix silica particles with 3-aminopropyltriethoxysilane, aminoethylpiperazine and water in a mass ratio of 1:30:20:20. Stir at 70-90℃ for 24 hours. After stirring, filter and dry to obtain modified silica particles (i.e. cleaning agent) for later use.

[0036] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:50 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0037] Example 5 (1) A ruthenium-based catalyst (e.g., a Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0038] (2) Mix silica particles with 3-aminopropyltriethoxysilane, aminoethylpiperazine and water at a mass ratio of 1:50:35:20 and stir at 70-90℃ for 24 hours. After stirring, filter and dry to obtain modified silica particles (i.e. cleaning agent) for later use.

[0039] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:50 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0040] Example 6 (1) A ruthenium-based catalyst (e.g., a Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0041] (2) Mix silica particles with 3-aminopropyltriethoxysilane, aminoethylpiperazine and water at a mass ratio of 1:50:20:20. Stir at 70-90℃ for 24 hours. After stirring, filter and dry to obtain modified silica particles (i.e. cleaning agent) for later use.

[0042] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:40 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0043] Comparative Example 1 In this example, no cleaning agent was used; the product after the polymerization reaction was simply filtered through diatomaceous earth and precipitated with methanol. The specific procedures were as follows: (1) The ruthenium-based catalyst (Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0044] (2) The product after quenching polymerization in step (1) was filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0045] The results showed that the Ru content was 130 ppm and the cyclic olefin polymer yield was 96%. This indicates that without purification treatment using a scavenger, there was a certain amount of catalyst residue in the cyclic olefin polymer, resulting in a high impurity content.

[0046] Comparative Example 2 In this example, Siliabond® DMT is used instead of the silica particles in Example 1 as a cleaning agent.

[0047] The specific steps are as follows: (1) Ruthenium-based catalyst (Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0048] (2) The scavenging agent was added to the product after quenching polymerization in step (1) according to a molar ratio of ruthenium-based catalyst to scavenging agent Siliabond® DMT of 1:50. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0049] The results showed that the Ru content in the purified polymer was 37 ppm, and the yield of the cyclic olefin polymer was 90%. The oxidation induction temperature of the purified cyclic olefin polymer (compared to Comparative Example 1) increased by 5°C.

[0050] Comparative Example 3 This example modifies the preparation method of the scavenger in Example 1, i.e., 3-aminopropyltriethoxysilane is not used. The specific steps are as follows: (1) A ruthenium-based catalyst (e.g., a Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0051] (2) Mix silica particles with aminoethylpiperazine and water at a mass ratio of 1:20:20, stir at 70-90℃ for 24 hours, filter and dry after stirring to obtain modified silica particles (i.e. cleaning agent) for later use.

[0052] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:50 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0053] The results showed that the Ru content in the purified polymer was 23 ppm, and the yield of the cyclic olefin polymer was 94%. The oxidation induction temperature of the purified cyclic olefin polymer (compared to Comparative Example 1) increased by 9°C.

[0054] Comparative Example 4 This example modifies the preparation method of the scavenger in Example 1, i.e., it does not use aminoethylpiperazine. The specific steps are as follows: (1) A ruthenium-based catalyst (e.g., a Grubbs third-generation catalyst) and 5-carboxymethyl-2-norbornene were dissolved in dichloromethane to obtain a catalyst solution of 5.5 mg / mL and a 5-carboxymethyl-2-norbornene solution of 0.5 g / mL. Under stirring, the catalyst solution was rapidly injected into the 5-carboxymethyl-2-norbornene solution at a volume ratio of 1:10. After 30 minutes, excess ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for 15 minutes.

[0055] (2) Mix silica particles with 3-aminopropyltriethoxysilane and water at a mass ratio of 1:50:20 and stir at 70-90℃ for 24 hours. After stirring, filter and dry to obtain modified silica particles (i.e. cleaning agent) for later use.

[0056] The scavenging agent was added to the product after quenching polymerization in step (1) at a molar ratio of 1:50 for ruthenium-based catalyst and scavenging agent. After mixing, the mixture was sealed and shaken for 24 hours. The mixture was then filtered through diatomaceous earth and washed with dichloromethane. The washed polymer was precipitated once in methanol, collected by vacuum filtration, and dried under vacuum.

[0057] The results showed that the Ru content in the purified polymer was 94 ppm, and the yield of the cyclic olefin polymer was 94%. The oxidation induction temperature of the purified cyclic olefin polymer (compared to Comparative Example 1) was not significantly increased.

[0058] The above description is only a part of the embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for efficiently purifying cyclic olefin polymers, characterized in that, Includes the following steps: Preparation of the cleaning agent: Silica particles are mixed with 3-aminopropyltriethoxysilane and aminoethylpiperazine. The mixture is stirred in an aqueous environment. After stirring, the mixture is filtered and dried to obtain the cleaning agent. Add a scavenging agent to the cyclic olefin polymer product to be purified, mix, seal and shake, then filter the mixture and wash with the solvent of the cyclic olefin polymer; precipitate the washed polymer with a non-solvent of the cyclic olefin polymer, and collect the cyclic olefin polymer by filtration. The cyclic olefin polymer product to be purified contains a ruthenium-based catalyst.

2. The method according to claim 1, characterized in that, The mass ratio of the silica particles to 3-aminopropyltriethoxysilane and aminoethylpiperazine is 1:30~50:20~35.

3. The method according to claim 1, characterized in that, The mass ratio of the silica particles to 3-aminopropyltriethoxysilane, aminoethylpiperazine, and water is 1:30~50:20~35:

20.

4. The method according to claim 1, characterized in that, The stirring temperature is 70~90℃.

5. The method according to claim 1, characterized in that, The molar ratio of the ruthenium-based catalyst to the scavenger is 1:40~50.

6. The method according to claim 1, characterized in that, The solvent for the cyclic olefin polymer includes dichloromethane.

7. The method according to claim 1, characterized in that, The non-solvents for the cyclic olefin polymers include methanol.

8. The method according to claim 1, characterized in that, The mixing time of the mixture is 12~24h, and the sealing and vibration time is 24h.

9. A scavenger for purifying cyclic olefin polymers, characterized in that, The cleaning agent contains silica particles, 3-aminopropyltriethoxysilane, and aminoethylpiperazine.

10. The cleaning agent according to claim 9, characterized in that, The mass ratio of the silica particles to 3-aminopropyltriethoxysilane and aminoethylpiperazine is 1:30~50:20~35.