A non-yellowing cyclic olefin monomer composition and use thereof

Abstract

The application discloses a yellowing-resistant cyclic olefin monomer composition and application. The cyclic olefin monomer composition contains the following components in parts by weight: 100 parts of cyclic olefin monomer, 0.01-0.25 parts of antioxidant, 0.001-0.05 parts of organic metal passivator and 0-0.05 parts of polymerization inhibitor. The cyclic olefin monomer composition provided by the application not only has stable long-term storage and resistance to refined yellowing, but also can keep excellent yellowing resistance during storage after refinement, thereby solving the yellowing problem of the cyclic olefin monomer raw material.

Description

Technical Field

[0001] This invention relates to a cyclic olefin monomer, and more particularly to a cyclic olefin monomer composition resistant to yellowing and its application. Background Technology

[0002] Cyclic olefin monomers (such as norbornene, dicyclopentadiene, and tetracyclododecene) are key monomer raw materials for preparing high-end optical resins such as cyclic olefin copolymers (COC) and cyclic olefin polymers (COP). Cyclic olefin monomer molecules contain highly reactive ring-strained double bonds, making them highly susceptible to yellowing during storage, purification, and polymerization. This leads to the formation of peroxides and chromophores with conjugated polyene structures, resulting in significant yellowing and increased color intensity. This not only reduces monomer purity but also severely interferes with the subsequent metallocene-catalyzed polymerization activity, leading to decreased polymerization conversion, and deterioration of resin transmittance and optical properties.

[0003] Currently, most published literature focuses on solving the yellowing problem of cyclic olefin polymers, with no reports on addressing the yellowing issue of cyclic olefin monomers during storage or purification from the raw material end. Furthermore, the chromogenic groups in the raw cyclic olefin monomers inevitably remain in the COC / COP resin matrix after the polymerization reaction, forming permanent optical defects. Even with subsequent polymer modification and decolorization treatments, the yellowing phenomenon can only be superficially and compensatorily improved, failing to fundamentally eliminate the chromogenic precursors inherent in the raw materials. This results in the finished resin consistently exhibiting problems such as high chromaticity, insufficient light transmittance, and susceptibility to secondary yellowing after long-term use, severely limiting the application of high-end optical-grade COC / COP resins in sophisticated fields such as precision optical lenses, automotive optical devices, high-end optoelectronic displays, and aseptic pharmaceutical packaging.

[0004] Therefore, given the shortcomings of existing anti-yellowing technologies for cyclic olefin systems, such as delayed treatment at the treatment end, limited improvement effect, and poor adaptability, it is necessary to propose an anti-yellowing solution that blocks the monomer oxidation and color-generating pathway from the source of raw materials, eliminates color-generating precursors, and is adaptable to the entire production process. Summary of the Invention

[0005] This invention addresses the problem of discoloration of cyclic olefin monomers during refining or storage by proposing a yellowing-resistant cyclic olefin monomer composition. This composition contains both antioxidants and organometallic passivating agents, and studies have shown that it has a typical synergistic effect in improving the yellowing problem during the refining or storage of cyclic olefin monomers, providing a good solution for reducing product color number and improving product storage stability.

[0006] Secondly, this invention also proposes an application method for a yellowing-resistant cyclic olefin monomer composition. Industrial-grade cyclic olefin monomers, limited by their synthesis processes, contain impurities such as water and oxygen. Even trace amounts of these impurities can impair polymerization performance. Therefore, downstream manufacturers typically need to purify industrial-grade cyclic olefin monomers before polymerizing them to prepare optical-grade COC / COP. Undesirable yellowing can occur during the storage process after monomer procurement or purification, as well as during the purification process itself. By configuring industrial-grade cyclic olefin monomers into the cyclic olefin monomer composition described in this invention, not only can the yellowing resistance of the product be improved over a longer storage period, but it also significantly improves the yellowing resistance during purification and post-purification storage.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A yellowing-resistant cyclic olefin monomer composition, comprising the following components in parts by weight:

[0009] 100 parts of cyclic olefin monomers

[0010] Antioxidant 0.01-0.25 parts, preferably 0.01-0.2 parts.

[0011] The organometallic passivating agent is used in amounts of 0.001-0.05 parts, preferably 0.001-0.03 parts.

[0012] The polymerization inhibitor is 0-0.05 parts, preferably 0-0.03 parts.

[0013] As a preferred embodiment of the cyclic olefin monomer composition proposed in this invention, the cyclic olefin monomer is at least one selected from norbornene, vinyl norbornene, ethylene norbornene, norbornediene, tetracyclododecene, cyclopentadiene, cyclopentene, and dicyclopentadiene.

[0014] As a preferred embodiment of the cyclic olefin monomer composition proposed in this invention, the antioxidant includes a hindered phenolic primary antioxidant and optionally a phosphite secondary antioxidant;

[0015] Preferably, the hindered phenolic primary antioxidant is at least one of 2,6-di-tert-butyl-p-cresol (BHT), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (1010), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (1330), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1076), and triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (245), preferably at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1076) and triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (245);

[0016] Preferably, the phosphite-based auxiliary antioxidant is at least one of tris(2,4-di-tert-butylphenyl) phosphite (168), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (626), pentaerythritol distearate diphosphite (618), and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (PEP36), and more preferably at least one of tris(2,4-di-tert-butylphenyl) phosphite (168), pentaerythritol distearate diphosphite (618), and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (PEP36).

[0017] As a preferred embodiment of the cyclic olefin monomer composition proposed in this invention, the organometallic passivating agent is an acylhydrazine passivating agent;

[0018] Preferably, the acylhydrazine passivating agent is selected from at least one of N,N,-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propionylhydrazine, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionylhydrazine, N,N,-disalicylic acid hydrazine, dioxalylhydrazine, and formylhydrazine.

[0019] To meet the application requirements for the polymerization preparation of optical-grade COC / COP resin, the organometallic passivating agent described in this invention is preferably an acylhydrazine-based passivating agent. It has been verified that when an acylhydrazine-based passivating agent is used, the cyclic olefin monomer composition has no adverse effect on the polymerization activity during the polymerization reaction of optical-grade COC / COP.

[0020] As a preferred embodiment of the cyclic olefin monomer composition proposed in this invention, the polymerization inhibitor is at least one selected from 4-methoxyphenol, o-methyl-p-benzoquinone, 2,6-di-tert-butylphenol, and 2,5-di-tert-butylhydroquinone, preferably at least one selected from 2,6-di-tert-butylphenol and 2,5-di-tert-butylhydroquinone. If the purpose is only to extend the product's shelf life, the polymerization inhibitor may be omitted. However, if the cyclic olefin monomer composition needs to be refined, it is preferable to add a certain amount of polymerization inhibitor to suppress uncontrolled polymerization reactions.

[0021] In a preferred embodiment of the cyclic olefin monomer composition proposed in this invention, the total amount of the antioxidant, organometallic passivator, and polymerization inhibitor does not exceed 0.25 parts. When the total amount of additives does not exceed 0.25 parts, it is beneficial to reduce the impact on the polymerization reactivity of optical-grade COC / COP resin.

[0022] The present invention also proposes a method for purifying cyclic olefin monomers, characterized in that the cyclic olefin monomers are formed into the aforementioned yellowing-resistant cyclic olefin monomer composition, and water and oxygen are removed under a nitrogen atmosphere to obtain the purified cyclic olefin monomers.

[0023] Preferably, an antioxidant, an organometallic passivator, and optionally a polymerization inhibitor are dissolved in an anhydrous alkane solvent to form a homogeneous mother liquor, which is then stirred and mixed with a cyclic olefin monomer. The mother liquor is then dehydrated and deoxygenated under a nitrogen atmosphere, and the solvent is removed by vacuum distillation to obtain a purified cyclic olefin monomer.

[0024] Deoxygenation and dehydration are routine operations in this field. This invention does not have specific requirements for the methods used, as long as the water and oxygen content in the cyclic olefin monomer can be controlled within the required range.

[0025] As a preferred embodiment of the purification method proposed in this invention, the water removal control condition is that the water content in the system does not exceed 10 ppm;

[0026] Preferably, the water removal method is molecular sieve adsorption water removal.

[0027] Furthermore, the molecular sieve is preferably an alkali metal aluminosilicate molecular sieve, and more preferably one or more of 4A molecular sieve, 5A molecular sieve, and 13X molecular sieve.

[0028] As a preferred embodiment of the purification method proposed in this invention, the oxygen removal control condition is that the oxygen content in the system does not exceed 10 ppm;

[0029] Preferably, the deoxygenation method is nitrogen bubbling deoxygenation or deoxygenation by adsorption of deoxygenating agent.

[0030] Furthermore, the deoxidizer is preferably an inorganic compound such as copper oxide or manganese oxide.

[0031] Preferably, the anhydrous alkane solvent is selected from one or more of n-hexane, n-heptane, cyclohexane, methylcyclohexane, cyclopentane, decahydronaphthalene, and tetrahydronaphthalene;

[0032] Preferably, the conditions for vacuum distillation are: temperature 30-120℃, pressure (absolute pressure) ≤50kPa;

[0033] This invention also proposes a method for storing cyclic olefin monomers, comprising at least the following two scenarios:

[0034] 1. Form the cyclic olefin monomers into the yellowing-resistant cyclic olefin monomer composition described above, and store it under nitrogen.

[0035] or,

[0036] 2. The purified cyclic olefin monomers obtained by the purification method described above are then nitrogen-sealed for storage.

[0037] According to the storage method provided by this invention, after nitrogen sealing at 60°C for 30 days, the color number of the cyclic olefin monomer changes by no more than 10 Hazen.

[0038] The present invention also provides the application of purified cycloolefin monomers obtained by the purification method described above in the polymerization preparation of optical grade COC / COP resin.

[0039] The cyclic olefin monomer composition provided by this invention not only has stable long-term storage properties and resistance to yellowing after refining, but also maintains excellent resistance to yellowing during long-term storage after refining, thereby fundamentally solving the yellowing problem at the source of cyclic olefin monomer raw materials. Detailed Implementation

[0040] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0041] Unless otherwise specified, the raw materials and reagents used in the following embodiments of the present invention can be obtained through commercial channels.

[0042] In the following examples, the colorimetric analysis uses the platinum-cobalt colorimetric method (APHA / Hazen).

[0043]

Example 1

[0044] A yellowing-resistant cyclic olefin monomer composition, comprising the following components in parts by weight:

[0045] 100 parts of cyclic olefin monomer (norbornene),

[0046] 0.08 parts of hindered phenolic primary antioxidant (BHT),

[0047] 0.01 parts of organometallic passivating agent (N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine),

[0048] 0.02 parts of polymerization inhibitor (2,6-di-tert-butylphenol).

[0049]

Example 2

[0050] A yellowing-resistant cyclic olefin monomer composition, comprising the following components in parts by weight:

[0051] 100 parts of cyclic olefin monomer (dicyclopentadiene),

[0052] 0.06 parts of hindered phenolic primary antioxidant (1076),

[0053] Phosphite co-antioxidant (168) 0.05 parts,

[0054] 0.005 parts of organometallic passivating agent (N,N,-disalicylhydrazine),

[0055] 0.035 parts of polymerization inhibitor (2,6-di-tert-butylphenol).

[0056]

Example 3

[0057] A yellowing-resistant cyclic olefin monomer composition, comprising the following components in parts by weight:

[0058] 100 parts of cyclic olefin monomer (tetracyclododecene),

[0059] 0.15 parts of hindered phenolic primary antioxidant (1010),

[0060] Phosphite co-antioxidant (618) 0.05 parts,

[0061] 0.05 parts of organometallic passivating agent (N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine),

[0062] 0.03 parts of polymerization inhibitor (2,6-di-tert-butylphenol).

[0063]

Example 4

[0064] A yellowing-resistant cyclic olefin monomer composition, comprising the following components in parts by weight:

[0065] 100 parts of cyclic olefin monomer (tetracyclododecene),

[0066] 0.15 parts of hindered phenolic primary antioxidant (245),

[0067] 0.1 parts of phosphite co-antioxidant (PEP36),

[0068] 0.03 parts of organometallic passivating agent (N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine),

[0069] 0.05 parts of polymerization inhibitor (2,6-di-tert-butylphenol).

[0070]

Example 5

[0071] A yellowing-resistant cyclic olefin monomer composition, comprising the following components in parts by weight:

[0072] 100 parts of cyclic olefin monomer (tetracyclododecene),

[0073] 0.005 parts of hindered phenolic primary antioxidant (245),

[0074] 0.005 parts of phosphite co-antioxidant (PEP36),

[0075] Organometallic passivating agent (N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine) 0.001 parts,

[0076] 0.02 parts of polymerization inhibitor (2,6-di-tert-butylphenol).

[0077] Comparative Example 1

[0078] A cyclic olefin monomer composition, which, compared with Example 1, does not contain the organometallic passivator (N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine).

[0079] Comparative Example 2

[0080] A cyclic olefin monomer composition, which, compared with Example 1, does not contain hindered phenolic primary antioxidant (BHT).

[0081] Comparative Example 3

[0082] A cyclic olefin monomer composition, compared with Example 1, is free of organometallic passivator (N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine) and hindered phenolic primary antioxidant (BHT).

[0083] The initial color (in Hazen) of the cyclic olefin monomer compositions in each example and comparative example was analyzed, and a storage stability test for resistance to yellowing was performed (1*ROMAN1). The results are shown in Table 1. Furthermore, the cyclic olefin monomer compositions in each example and comparative example were purified by mixing with anhydrous alkane solvent, and a purification stability test (2*ROMANII) and a post-purification storage stability test (3*ROMANIII) were performed. The specific test methods are as follows:

[0084] (1) Storage stability test I: The prepared cyclic olefin monomer composition was nitrogen-sealed and stored at 60°C for 30 days. The color was tested and recorded.

[0085] (2) Purification Stability Test II: The cyclic olefin monomer composition was mixed with anhydrous cyclohexane, with the amount of anhydrous cyclohexane being 3 times the mass of the cyclic olefin monomer in the composition. Under a high-purity nitrogen atmosphere, nitrogen bubbling was used to remove oxygen, and molecular sieve (4A) adsorption was used to remove water, controlling the oxygen content in the system to be below 10 ppm and the water content to be below 10 ppm. Then, vacuum distillation was carried out at 60℃ and 35 kPa absolute pressure to remove the solvent, obtaining the polymerization-grade cyclic olefin monomer, and the color was tested and recorded.

[0086] (3) Storage stability test after purification = 3\*ROMANIII: The purified polymer grade cycloolefin monomer was nitrogen-sealed and stored at 60°C for 30 days. The color was tested and recorded.

[0087] Table 1. Colorimetric Analysis Results

[0088] initial chromaticity Test I chromaticity Test II Colorimetry Test III Chromaticity Example 1 10 16 10 13 Example 2 9 18 11 15 Example 3 14 20 14 17 Example 4 14 21 15 18 Example 5 14 23 14 16 Comparative Example 1 10 78 28 56 Comparative Example 2 10 61 25 47 Comparative Example 3 10 142 45 138

[0089] Polymerization activity test:

[0090] The cyclic olefin monomer compositions prepared in each embodiment were mixed with anhydrous cyclohexane, deoxygenated, dehydrated, and purified by vacuum distillation to obtain polymer-grade cyclic olefin monomers (refer to the specific method in Purification Stability Test II). Cyclic olefin monomers from the same batch that did not form a composition were used as blank controls.

[0091] The obtained polymerization-grade cyclic olefin monomers and the blank control cyclic olefin monomers were subjected to polymerization reactions according to the following methods, and the polymerization activity and the retention rate of polymerization activity were calculated:

[0092] (1) The batch polymerization reactor was purged with nitrogen three times and ethylene three times at a high temperature of 150℃. Under an ethylene atmosphere, 60 mmol of cycloolefin monomer was dissolved in 30 mL of purified cyclohexane to prepare a cycloolefin / cyclohexane solution. The above cycloolefin / cyclohexane solution and 0.8 mmol of triisobutylaluminum were added sequentially to the batch polymerization reactor. The reaction temperature was adjusted to 110℃. After the ethylene was dissolved to saturation in cyclohexane, 4 μmol of [unspecified substance] was added sequentially. i Pr(Cp)(Flu)ZrMe2 and 8 μmol of [Me(C 18 H 37 The polymerization reaction was initiated by adding ethylene to control the pressure at 5.0 bar. The reaction was carried out for 2 minutes, and then 10 mL of ethanol was added to terminate the reaction, resulting in a polymer solution.

[0093] (2) Pour the polymer solution obtained in step (1) into a mixture of 100 mL hydrochloric acid and 900 mL ethanol to precipitate and then filter. Wash the filter cake three times with ethanol (300 mL) and vacuum dry it to constant weight at 80 °C. Weigh the sample to obtain the polymer sample weight and calculate the polymerization activity.

[0094] The polymerization activity retention rate (%) refers to the percentage of polymerization activity of the obtained polymerization-grade cyclic olefin monomers relative to the polymerization activity of the blank control cyclic olefin monomers; the analytical results are shown in Table 2.

[0095] Table 2. Results of Polymerization Activity Test

[0096] Polymer activity retention rate (%) Example 1 99.7 Example 2 99.1 Example 3 99.5 Example 4 99.3 Example 5 99.8

[0097] The test results above show that cyclic olefin monomers are susceptible to light, temperature and humidity fluctuations, and oxygen permeation during storage. The refining process also involves high temperature and aerobic conditions, and the combined effect of these multiple factors accelerates the oxidative yellowing process of the monomers. This invention proposes a solution that enables cyclic olefin monomers to exhibit excellent resistance to yellowing during refining or storage. This helps reduce the color of cyclic olefin monomers from the raw material stage, avoids the accumulation and buildup of color-developing factors during polymerization, and reduces the difficulty of removing color-developing factors after polymerization, thus possessing broad applicability.

[0098] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A cyclic olefin monomer composition resistant to yellowing, characterized in that, It contains the following components in parts by weight: 100 parts of cyclic olefin monomers Antioxidant 0.01-0.25 parts, preferably 0.01-0.2 parts. The organometallic passivating agent is used in amounts of 0.001-0.05 parts, preferably 0.001-0.03 parts. The polymerization inhibitor is 0-0.05 parts, preferably 0-0.03 parts.

2. The yellowing-resistant cyclic olefin monomer composition according to claim 1, characterized in that, The cyclic olefin monomer is at least one of norbornene, vinyl norbornene, ethylene norbornene, norbornediene, tetracyclododecene, cyclopentadiene, cyclopentene, and dicyclopentadiene.

3. The yellowing-resistant cyclic olefin monomer composition according to claim 1, characterized in that, The antioxidants include hindered phenolic primary antioxidants and optionally phosphite secondary antioxidants; Preferably, the hindered phenolic primary antioxidant is at least one of 2,6-di-tert-butyl-p-cresol (BHT), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (1010), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (1330), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1076), and triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (245), preferably at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1076) and triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (245); Preferably, the phosphite-based auxiliary antioxidant is at least one of tris(2,4-di-tert-butylphenyl) phosphite (168), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (626), pentaerythritol distearate diphosphite (618), and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (PEP36), and more preferably at least one of tris(2,4-di-tert-butylphenyl) phosphite (168), pentaerythritol distearate diphosphite (618), and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (PEP36).

4. The yellowing-resistant cyclic olefin monomer composition according to claim 1, characterized in that, The organometallic passivating agent is an acylhydrazine-based passivating agent; Preferably, the acylhydrazine passivating agent is selected from at least one of N,N,-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propionylhydrazine, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionylhydrazine, N,N,-disalicylic acid hydrazine, dioxalylhydrazine, and formylhydrazine.

5. The cyclic olefin monomer composition resistant to yellowing according to any one of claims 1-4, characterized in that, The polymerization inhibitor is at least one of 4-methoxyphenol, o-methyl-p-benzoquinone, 2,6-di-tert-butylphenol, and 2,5-di-tert-butylhydroquinone, preferably at least one of 2,6-di-tert-butylphenol and 2,5-di-tert-butylhydroquinone.

6. The cyclic olefin monomer composition resistant to yellowing according to any one of claims 1-5, characterized in that, The total amount of the antioxidant, organometallic passivator, and polymerization inhibitor shall not exceed 0.25 parts.

7. A method for purifying cyclic olefin monomers, characterized in that, The cyclic olefin monomer is formed into a yellowing-resistant cyclic olefin monomer composition according to any one of claims 1-6, and then water and oxygen are removed under a nitrogen atmosphere to obtain a purified cyclic olefin monomer. Preferably, an antioxidant, an organometallic passivator, and optionally a polymerization inhibitor are dissolved in an anhydrous alkane solvent to form a homogeneous mother liquor, which is then stirred and mixed with a cyclic olefin monomer. The mother liquor is then dehydrated and deoxygenated under a nitrogen atmosphere, and the solvent is removed by vacuum distillation to obtain a purified cyclic olefin monomer.

8. The method for purifying cycloolefin monomers according to claim 7, characterized in that, The water removal control condition is that the water content in the system does not exceed 10 ppm; Preferably, the water removal method is molecular sieve adsorption water removal.

9. The method for purifying cycloolefin monomers according to claim 7, characterized in that, The deoxygenation control condition is that the oxygen content in the system does not exceed 10 ppm; Preferably, the deoxygenation method is nitrogen bubbling deoxygenation or deoxygenation by adsorption of deoxygenating agent.

10. A method for storing cyclic olefin monomers, characterized in that, The cyclic olefin monomers are formed into the yellowing-resistant cyclic olefin monomer composition according to any one of claims 1-6, and then stored under nitrogen. or, The purified cyclic olefin monomers obtained by the purification method according to any one of claims 7-9 are nitrogen-sealed for storage.

11. The method for storing cyclic olefin monomers according to claim 10, characterized in that, After 30 days of nitrogen sealing at 60°C, the color number of the cyclic olefin monomers does not change by more than 10 Hazen.

12. The application of a refined cycloolefin monomer obtained by any one of claims 7-9 in the polymerization preparation of optical grade COC / COP resin.