Preparation method of ultra-low refractive index and highly transparent cycloolefin copolymer

Abstract

The invention discloses a kind of preparation method of ultra-low refractive index, high transparency cycloolefin copolymer, belong to the field of polymer preparation technology, the method comprises the following steps:Under the conditions of Grubbs catalyst and organic solvent, cycloolefin monomer and fluorine-containing cycloolefin monomer are used to pass through ring-opening metathesis polymerization, unsaturated fluorine-containing cycloolefin copolymer is prepared;The unsaturated fluorine-containing cycloolefin copolymer and hydrogen source are hydrogenated to obtain the fluorine-containing cycloolefin copolymer.The fluorine-containing cycloolefin copolymer prepared by the inventive method has the excellent properties such as ultra-low refractive index, high transparency, high thermal stability, excellent mechanical properties, amorphous amorphous type, and refractive index is adjustable within the range of 1.37 1.47;Ultra-low refractive index is much lower than current typical organic low refractive index commercial material PMMA (refractive index 1.49).Therefore, the fluorine-containing cycloolefin copolymer prepared by the present invention can be widely used in optical field, such as low refractive index optical lens (AR, VR glasses), anti-reflection coating etc.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer preparation, and in particular relates to a method for preparing an ultra-low refractive index and highly transparent cycloolefin copolymer. Background Art

[0002] Cycloolefin polymers, a class of high-value-added thermoplastic engineering plastics made from the polymerization of cycloolefin monomers, possess excellent comprehensive properties, such as high transparency, low birefringence, low dielectric constant, and good dimensional stability. Therefore, cycloolefin polymers hold broad application prospects in areas such as mobile phone lenses and VR lenses. However, the rapid development of multimedia technology has led to higher demands for high-quality image acquisition and recording. Therefore, reducing light reflection from the display surface of image-receiving devices can effectively improve image quality. Currently, to reduce reflection from display surfaces, anti-reflection treatment is often required. Common anti-reflection techniques include: 1. coating the plastic surface with inorganic materials such as silica and magnesium fluoride; 2. constructing micro-nanostructures on the surface; and 3. coating with low-refractive-index polymers. Inorganic materials have poor compatibility with the substrate, leading to a high risk of particle delamination. Micro-nanostructure construction typically requires high equipment requirements, cumbersome production, and poor material stability. Low-refractive-index polymers, on the other hand, offer advantages due to their low cost in large-scale production, lightweight design, and tunable molecular structure, making them suitable for matching the refractive index of different substrates. Anti-reflective polymer films (AR films) are usually composed of alternating high-refractive index polymer layers and low-refractive index polymer layers. In recent years, its application in the fields of displays, lens materials, etc. is becoming increasingly important. In AR films used in the optical field, in addition to requiring a low refractive index, a high Abbe number, and a low reflectivity (1.5% or lower), the film is also required to have strong compatibility with the base material to ensure the adhesion strength of the coating. In addition, in addition to the requirements of low refractive index and high Abbe number, the amorphous structure of the polymer is also crucial for anti-reflective materials. Since crystalline polymers have a large shrinkage rate of the crystallized part during molding, there are amorphous parts and crystalline parts coexisting in the molded products, resulting in irregular reflections. Therefore, even if the crystalline polymer has a lower refractive index (such as poly-4-methyl-1-pentene, refractive index 1.46), it is not suitable for applications in the fields of anti-reflection films and optical lenses.

[0003] For example, it is recorded in the literature (Macromolecules, 1991, 24 (25): 6660-6663) that fluorine-containing materials often have a low refractive index. Therefore, fluorine-containing polymers with a specific structure can be used in the low refractive index layer of AR films. Patent No. CN116574208A discloses the use of metallocene catalysts to synthesize a series of cycloolefin copolymers of ethylene and fluorine-containing cycloolefin monomers. Although the material has a high fluorine content, its crystallization behavior is not conducive to the application of the material in the field of anti-reflection films. It is well known that an increase in fluorine content will reduce the low refractive index of the material, but it also leads to a decrease in its surface energy, resulting in a decrease in the interfacial adhesion with the adjacent high refractive index layer. At the same time, high fluorine-containing polymers are generally poorly soluble in cheap solvents that do not contain fluorine atoms, and often require special fluorine-containing solvents such as perfluorobenzene for dissolution, which directly leads to an increase in the production cost of the material.

[0004] Therefore, it is of great significance to develop an amorphous, ultra-low refractive index, highly transparent and highly fluorinated cyclic olefin copolymer. Summary of the Invention

[0005] In response to the above technical problems, the present invention proposes a method for preparing an ultra-low refractive index and highly transparent cycloolefin copolymer.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention:

[0008] A fluorinated cyclic olefin copolymer, the general structural formula of which is shown in Formula I:

[0009]

[0010] Among them, A is selected from Any of;

[0011] 0.5≤y∶x≤19;

[0012] 0≤m≤1;

[0013] 1≤n≤4;

[0014] R1 is selected from any one of m1-m3, and the structures of m1-m3 are as follows:

[0015]

[0016] R2 and R3 are independently selected from any one of hydrogen, halogen, and C1-C10 perfluoroalkyl;

[0017] R4 and R5 are independently selected from any one of hydrogen, fluorine atom, and perfluoromethyl;

[0018] Among them, at least one group among R2, R3, R4 and R5 contains a fluorine atom.

[0019] Beneficial effects: The fluorinated cyclic olefin copolymer disclosed in the present invention has a high fluorine content (wt%). The high fluorine content and random structure give the fluorinated cyclic olefin copolymer excellent physical properties such as a low refractive index, a high Abbe number, high transparency, and amorphousness.

[0020] Preferably, the C1-C10 perfluoroalkyl group includes any one of a perfluoromethyl group, a perfluoroethyl group, a perfluoro-n-butyl group, a perfluoro-isopropyl group, a perfluoro-n-hexyl group, a perfluoro-n-octyl group, and a perfluoro-n-decyl group.

[0021] Preferably, the structural formula of the fluorinated cyclic olefin copolymer includes:

[0022]

[0023] Preferably, the weight average molecular weight of the fluorinated cyclic olefin copolymer is (2-10)×10 4 g / mol; molecular weight distribution is 1.3~2.2.

[0024] The second technical solution of the present invention:

[0025] The preparation method of the fluorinated cyclic olefin copolymer comprises the following steps:

[0026] Under the conditions of Grubbs catalyst and organic solvent, a cycloolefin monomer and a fluorinated cycloolefin monomer undergo a ring-opening metathesis polymerization reaction to prepare an unsaturated fluorinated cycloolefin copolymer;

[0027] The unsaturated fluorinated cyclic olefin copolymer and a hydrogen source are subjected to a hydrogenation reaction to obtain the fluorinated cyclic olefin copolymer.

[0028] Preferably, the cycloolefin monomer comprises any one of the following structures of Formula II,

[0029]

[0030] Preferably, the fluorinated cycloolefin monomer comprises any one of the following structures:

[0031]

[0032] Preferably, the organic solvent includes any one of dichloromethane, chloroform, tetrachloroethane, chlorobenzene, o-dichlorobenzene, trichlorobenzene, cyclohexane, methylcyclohexane, toluene, and xylene; more preferably, it is one or more of dichloromethane, chloroform, tetrachloroethane, methylcyclohexane, and chlorobenzene.

[0033] Preferably, the hydrogen source includes hydrazine compounds and high-purity hydrogen; more preferably, p-toluenesulfonyl hydrazide or high-purity hydrogen.

[0034] Preferably, the Grubbs catalyst is Cat.1 (Grubbs II, dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](3-methyl-2-butenylidene)(tricyclohexylphosphine)ruthenium(II)) and / or Cat.2 (Grubbs III, dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](benzylidene)bis(3-bromopyridine)ruthenium(II)).

[0035] Beneficial Effects: When the Grubbs II / III generation catalyst is used in ring-opening metathesis polymerization, the catalyst exhibits excellent tolerance to polar groups, exhibiting excellent homopolymerization and copolymerization capabilities and high reactivity with fluorinated cycloolefin monomers. Furthermore, with ring tension as the driving force for polymerization, the ring-opening metathesis copolymers obtained from compounds having the structures of Formula II and Formula III all have an amorphous structure. This is crucial for applications in optical fields such as antireflective films.

[0036] Preferably, the conditions for the ring-opening metathesis polymerization reaction are:

[0037] React at 25°C for 120 min.

[0038] Preferably, the conditions of the hydrogenation reaction are:

[0039] Heat the reaction at 120-150°C for 6-16 hours.

[0040] The third technical solution of the present invention:

[0041] The fluorinated cyclic olefin copolymer is used in the preparation of low-refractive-index optical lenses and anti-reflection coatings.

[0042] Compared with the prior art, the present invention has the following advantages and technical effects:

[0043] 1. Compared with the prior art, the present invention uses a highly tolerant Grubbs catalyst to design and synthesize a fluorinated cyclic olefin copolymer with an amorphous structure, high fluorine content, ultra-low refractive index (refractive index adjustable between 1.37 and 1.47), high transparency, and good solubility in conventional solvents.

[0044] 2. The fact that both the polymer and the monomer are cyclic structures, the driving force for polymerization is the release of ring tension, and the random copolymerization properties of the catalyst synergistically achieve the synthesis of amorphous polymers.

[0045] 3. The introduction of non-fluorinated cycloolefin monomers into the polymer structure not only increases the solubility of the material in non-fluorinated solvents, but also effectively increases its compatibility with commercial cycloolefin copolymers (COC) and cycloolefin copolymers (COP), which are pure cycloalkane structures, thereby improving the interfacial adhesion between the anti-reflective coating and the substrate material. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0047] Figure 1 (a) is the H NMR spectrum obtained in Example 1 of the present invention; (b) is the H NMR spectrum obtained in Example 2 of the present invention;

[0048] Figure 2 (a), (b), (c), and (d) are the light transmittances of the fluorinated copolymers obtained in Example 3, Example 4, Example 5, and Example 10 of the present invention, respectively;

[0049] Figure 3 Where (a), (b), (c), and (d) are the refractive indices of the fluorinated copolymers obtained in Example 3, Example 11, Example 7, and Example 19 of the present invention, respectively;

[0050] Figure 4 (a), (b), and (c) are differential scanning calorimetry (DSC) curves of the fluorinated copolymers obtained in Example 4, Example 10, and Example 20, respectively;

[0051] Figure 5 (a), (b), and (c) are the tensile curves of the fluorinated copolymers obtained in Example 4, Example 5, and Example 8, respectively. DETAILED DESCRIPTION

[0052] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0053] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0054] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0055] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0056] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0057] The present invention discloses a fluorinated cyclic olefin copolymer having a structure of formula I:

[0058]

[0059] In formula I (I1, I2), x and y are the degree of polymerization, 0.5≤y:x≤19, 0≤m≤1,

[0060] R2 and R3 are independently selected from one or more of hydrogen, halogen, and C1-C10 perfluoroalkyl.

[0061] R4 and R5 are independently selected from any one of hydrogen, fluorine atom, and perfluoromethyl;

[0062] wherein at least one of R2, R3, R4, and R5 contains a fluorine atom;

[0063] In formula I1, 1≤n≤4, the structure on the left side of formula I1 is a non-cyclic straight-chain alkane structure;

[0064] In formula I2, the structure on the left side of formula I2 is a cyclic structure, wherein R1 is selected from any one of m1-m3, and the structures of m1-m3 are as follows:

[0065]

[0066] The carbon atom marked with * in m1-m3 is directly connected to the carbon atom corresponding to the carbon atom marked with * in the cycloolefin monomer via a carbon-carbon single bond.

[0067] In some preferred embodiments, the C1-C10 perfluoroalkyl group includes C1, C2, C4, C6, C8, and C10 perfluoroalkyl groups, and further, preferably any one of a perfluoromethyl group, a perfluoroethyl group, a perfluoro-n-butyl group, a perfluoroisopropyl group, a perfluoro-n-hexyl group, a perfluoro-n-octyl group, and a perfluoro-n-decyl group.

[0068] In some preferred embodiments, the weight average molecular weight of the fluorinated copolymer is 2×10 4 g / mol-10×10 4 g / mol, more preferably 2×10 4 g / mol-8×10 4 g / mol.

[0069] In some preferred embodiments, the insertion rate of the above-mentioned fluorinated cycloolefin monomer can be adjusted between 5% and 95%, that is, 0.052≤y:x≤19; more preferably, it is 50%-95%, that is, 1≤y:x≤19, and further preferably, it is 60%-90%, that is, 1.5≤y:x≤9.

[0070] In some preferred embodiments, the fluorine content in the fluorine-containing copolymer of formula I is 20 wt%-64 wt%; more preferably 25 wt%-64 wt%, further preferably 30 wt%-64 wt%.

[0071] In addition, the present invention also provides a preparation process of a fluorinated cycloolefin copolymer, wherein cycloolefin monomers having structures represented by formula II and formula III and a fluorinated cycloolefin monomer are subjected to ring-opening metathesis polymerization in the presence of a Grubbs catalyst, and then hydrogenated with a hydrogen source to obtain a fluorinated cycloolefin copolymer having a structure represented by formula I;

[0072]

[0073] The process for preparing the above-mentioned fluorinated cycloolefin copolymer is as follows:

[0074] (1) Under the action of a Grubbs catalyst, a compound having a structure represented by Formula II and a compound having a structure represented by Formula III are subjected to a ring-opening metathesis polymerization reaction in a solvent to obtain an unsaturated fluorinated cycloolefin copolymer;

[0075] (2) hydrogenating the polymerization product and a hydrogen source to obtain a fluorinated cycloolefin copolymer having a structure as shown in Formula I;

[0076] In some preferred embodiments, the Grubbs catalyst is selected from Cat.1 (Grubbs II, dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](3-methyl-2-butenylidene)(tricyclohexylphosphine)ruthenium(II)) and / or Cat.2 (Grubbs III, dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](benzylidene)bis(3-bromopyridine)ruthenium(II));

[0077] The specific structure of Grubbs catalyst is as follows:

[0078]

[0079] In some preferred embodiments, the polymerization reaction solvent is a halogenated hydrocarbon compound, a halogenated aromatic hydrocarbon compound, a cycloalkane compound, or an aromatic hydrocarbon compound; more preferably, it is any one of dichloromethane, chloroform, tetrachloroethane, chlorobenzene, o-dichlorobenzene, trichlorobenzene, cyclohexane, methylcyclohexane, toluene, and xylene; further preferably, it is any one of dichloromethane, chloroform, tetrachloroethane, methylcyclohexane, and chlorobenzene.

[0080] In some preferred embodiments, the fluorinated cycloolefin monomers (III-1 to III-12) of the structure shown in Formula III include but are not limited to the following structures:

[0081]

[0082] The compounds having the structure shown in Formula II and the structure shown in Formula III used in the embodiments of the present invention can be prepared by existing literature or methods (e.g., Macromolecular Chemistry and Physics, 2016, 217(24): 2708-2716; or CN103965402A).

[0083] In the present invention, the compound having the structure shown in Formula III is prepared according to the following reaction scheme:

[0084]

[0085] Among them, the preferred range of R2-R5 is the same as above and will not be repeated here.

[0086] In some preferred embodiments, the molar ratio of cyclopentadiene to the substituted monoolefin is 1:(2-4); more preferably 1:(2.5-4);

[0087] The present invention has no particular limitation on the amount of the polymerization reaction solvent, and the amount of the solvent used in the polymerization reaction well known to those skilled in the art can be used.

[0088] In some preferred embodiments, in a 100 mL reactor, the volume of the polymerization solvent is selected to be 35-60 mL, more preferably 40-50 mL, and the mass concentration of the total monomer feed is controlled at 1 wt% to 4 wt%.

[0089] In some preferred embodiments, after the polymerization reaction in step (1) is completed, the following steps are further included:

[0090] The polymerization reaction is terminated by using a small amount of vinyl ethyl ether to obtain a polymerization reaction solution; the polymerization reaction solution is mixed with ethanol to obtain a precipitated product; the precipitated product is filtered, washed, and dried to obtain a polymerization reaction product.

[0091] In some preferred embodiments, the hydrogenation reaction is carried out under protective gas conditions; preferably nitrogen;

[0092] The hydrogen source includes hydrazine compounds and high-purity hydrogen gas; more preferably, it is p-toluenesulfonyl hydrazide or high-purity hydrogen gas.

[0093] In some preferred embodiments, after the hydrogenation reaction in step (2) is completed, the following steps are further included:

[0094] The obtained hydrogenation reaction product is mixed with a large amount of ethanol, and the obtained mixed product is filtered, washed, and dried to obtain a hydrogenated fluorinated cycloolefin copolymer.

[0095] The structure and properties of the fluorinated cyclic olefin copolymer obtained by the above preparation method were characterized as follows:

[0096] The structure of the obtained fluorinated cycloolefin copolymer is characterized by nuclear magnetic hydrogen spectrum. The insertion rate of the fluorinated cycloolefin monomer is consistent with the monomer feed ratio. The fluorine content of the cycloolefin copolymer can be controlled at 30wt%-64wt%.

[0097] The present invention characterized the crystallization behavior of the obtained fluorinated cycloolefin copolymers by differential scanning calorimetry (DSC), and found that no melting peaks appeared in the fluorinated cycloolefin copolymers, indicating that the obtained fluorinated cycloolefin copolymers were amorphous and did not exhibit crystallization behavior.

[0098] The refractive index of the material is characterized by an ellipsometer (SE-VE-L), and the refractive index of the prepared fluorinated cycloolefin copolymer can be adjusted between 1.37 and 1.47.

[0099] The mechanical properties of the fluorinated cycloolefin copolymer polymer material tested on an INSTRON 5969 instrument are tested in accordance with the standard of GB / T1040-1992 "Test Method for Tensile Properties of Plastics".

[0100] The molecular weight of the fluorinated cycloolefin copolymer was characterized by GPC. The results showed that the weight average molecular weight of the prepared fluorinated copolymer was controlled within 2×10 4 g / mol~8×10 4 g / mol, with a molecular weight distribution of 1.3 to 2.2. The lower molecular weight effectively ensures good solubility of the material in conventional solvents.

[0101] The light transmittance and anti-reflection properties of the fluorinated cyclic olefin copolymer were tested using a Shimadzu UV-3600 ultraviolet-visible-near-infrared spectrophotometer. The prepared cyclic olefin copolymer had a light transmittance of >92% in the visible light region (with a test film thickness of 30 μm-50 μm) and a reflectivity of less than 1.5%.

[0102] Unless otherwise specified, the "room temperature" in the present invention refers to 20-30°C.

[0103] The "parts" described in the present invention, unless otherwise specified, refer to parts by mass.

[0104] The raw materials used in the present invention are all purchased from the market.

[0105] The technical solution of the present invention is further illustrated by the following examples.

[0106] Example 1

[0107] The preparation process of fluorinated cycloolefin monomer III (III-4) is shown in the following formula:

[0108]

[0109] To a 500 mL stainless steel autoclave, 19 g of cyclopentadiene and 180 g of III-1 fluorinated cycloolefin monomer were added in sequence. The autoclave was evacuated and replaced with nitrogen three times, followed by filling with 1.5 MPa of nitrogen. The autoclave was deheated to 180°C and the contents were allowed to react with stirring for 30 h. After cooling the autoclave to room temperature, the excess III-1 monomer was collected by vacuum distillation at 40°C. The residual liquid monomer was then vacuum distilled at 90°C, and the fractions were collected to obtain 50 g of the target product in a yield of 45.9%.

[0110] The product obtained above was subjected to nuclear magnetic resonance hydrogen spectrum detection. Figure 1 As can be seen from (a), the product obtained in Example 1 of the present invention is a compound having a structure represented by Formula III (III-4).

[0111] Example 2

[0112] The preparation process of fluorinated cycloolefin monomer III (III-5) is shown in the following formula:

[0113]

[0114] To a 500 mL stainless steel autoclave were added 19 g of cyclopentadiene and 292 g of III-2 fluorinated cycloolefin monomer. The autoclave was evacuated and replaced with nitrogen three times, followed by filling with nitrogen at 1.5 MPa. The autoclave was deheated to 180° C., and the contents were reacted with stirring for 30 h. After cooling the autoclave to room temperature, the excess III-2 monomer was collected by vacuum distillation at 57° C. The residual liquid monomer was then distilled under reduced pressure at 105° C., and the fractions were collected to obtain 68 g of the target product with a yield of 49.3%. The product was a white solid at room temperature.

[0115] The product obtained above was subjected to nuclear magnetic resonance hydrogen spectrum detection. Figure 1 As can be seen from (b), the target product obtained in Example 2 of the present invention is a compound having a structure shown in Formula III (III-5).

[0116] Example 3

[0117] A preparation process of a fluorinated cyclic olefin copolymer:

[0118] 1. Add 1.28 mmol (0.2058 g) of the compound represented by Formula II (M4) and 1.93 mmol (0.7942 g) of the compound represented by Formula III (III-2) to a dry polymerization reaction bottle at 25°C. Add 45 mL of chloroform and stir for 5 minutes to fully dissolve. Then, under vigorous stirring, dissolve 23.7 mg of the catalyst, Cat.2, in 5 mL of chloroform and add it to the polymerization reaction bottle. Polymerize at 25°C for 120 minutes.

[0119] 2. After the polymerization reaction, 0.5 mL of vinyl ethyl ether was added to the polymerization reaction bottle under stirring to quench the polymerization reaction. The polymerization reaction solution was then poured into anhydrous ethanol to obtain a precipitate. The precipitate was filtered and washed three times with ethanol. It was then dried in a vacuum oven at 40°C for 12 h to obtain 0.99 g of a polymerization product.

[0120] 3. In a dry, pressure-resistant reaction flask, 0.9 g of the above polymerization product, 2.69 g (5 eqv of the number of unsaturated double bonds in the polymer) of p-toluenesulfonylhydrazide, 2.28 g (5.5 eqv of the number of unsaturated double bonds in the polymer) of tri-n-propylamine, 0.1 g of 2,6-di-tert-butyl-4-methylphenol (BHT), and 30 mL of chloroform were added in sequence. The mixture was heated at 120°C for 16 h to obtain a hydrogenation product. The hydrogenation product solution was added dropwise to 300 mL of anhydrous ethanol for precipitation. The precipitate was then redissolved in 20 mL of chloroform at room temperature and washed twice. The resulting polymer was dried in a vacuum oven at 60°C for 12 h to obtain 0.85 g of a saturated fluorinated cyclic olefin copolymer.

[0121] The weight average molecular weight of the fluorinated cycloolefin copolymer prepared in this example is 3.7×10 4 g / mol, molecular weight distribution 1.53. Fluorine content is 47.6wt%. Figure 2 (a) It can be seen that the transmittance of the fluorinated cyclic olefin copolymer obtained in Example 3 of the present invention is greater than 92% in the visible light region; Figure 3 (a) It can be seen that the fluorinated cyclic olefin copolymer obtained in Example 3 of the present invention has a refractive index of 1.42 (wavelength 589 nm); the reflectivity of the material is 0.9%; the polymer has an amorphous structure and no crystallization behavior is found.

[0122] Example 4

[0123] A preparation process of a fluorinated cyclic olefin copolymer:

[0124] 1. Add 1.37 mmol (0.2202 g) of the compound represented by Formula II (M4) and 2.06 mmol (0.7798 g) of the compound represented by Formula III (III-4) to a dry polymerization reaction flask at 25°C. Add 45 mL of dichloromethane and stir for 5 minutes to fully dissolve. Then, under vigorous stirring, dissolve 19.5 mg of the catalyst (Cat. 1) in 5 mL of dichloromethane and add it to the polymerization flask. Polymerize at 25°C for 120 minutes.

[0125] 2. After the polymerization reaction, 0.5 mL of vinyl ethyl ether was added to the polymerization reaction bottle under stirring to quench the polymerization reaction. The polymerization reaction solution was then poured into anhydrous ethanol to obtain a precipitate. The precipitate was filtered and washed three times with ethanol. It was then dried in a vacuum oven at 40°C for 12 h to obtain 0.98 g of a polymerization product.

[0126] 3. The autoclave was vacuum dried at 110°C for 6 h and then cooled to room temperature; 0.9 g of the polymer was completely dissolved in ultra-dry tetrachloroethane, and then 10 wt% Pd / C (0.033 g) catalyst was mixed with the polymer solution under a nitrogen atmosphere. The mixed polymer solution was immediately introduced into an autoclave, and high-purity hydrogen was introduced at 5 MPa. The reaction was carried out at 150°C for 6 h to obtain a hydrogenation product; the hydrogenation product solution was added dropwise to 300 mL of anhydrous ethanol for precipitation, and the precipitate was then redissolved in 20 mL of chloroform at room temperature. The above operation was repeated twice for washing; the resulting polymer was placed in a vacuum oven and dried at 60°C for 12 h to obtain 0.86 g of a saturated fluorinated cyclic olefin copolymer.

[0127] The weight average molecular weight of the fluorinated cycloolefin copolymer prepared in this example is 4.4×10 4 g / mol, molecular weight distribution 1.65. Fluorine content is 35.2wt%. Figure 2 As shown in (b), the transmittance of the fluorinated cyclic olefin copolymer obtained in Example 4 of the present invention is >92% in the visible light region; the refractive index of the material is 1.46 (wavelength 589nm), and the reflectivity is 1.3%; Figure 4 From (a), it can be seen that the glass transition temperature of the fluorinated cyclic olefin copolymer obtained in Example 4 is 149°C, and the polymer is amorphous and no crystallization behavior is found; Figure 5 From (a), it can be seen that the tensile strength of the fluorinated cycloolefin copolymer obtained in Example 4 is 59.5 MPa and the elongation at break is 10.1%.

[0128] Example 5

[0129] A preparation process of a fluorinated cyclic olefin copolymer:

[0130] 1. Add 1.27 mmol (0.2043 g) of the compound represented by Formula II (M4) and 1.91 mmol (0.7957 g) of the compound represented by Formula III (III-8) to a dry polymerization reaction flask at 25°C. Add 45 mL of chloroform and stir for 5 minutes to fully dissolve. Then, under vigorous stirring, dissolve 20.1 mg of the catalyst, Cat.2, in 5 mL of chloroform and add it to the polymerization flask. Polymerize at 25°C for 120 minutes.

[0131] 2. After the polymerization reaction, 0.5 mL of vinyl ethyl ether was added to the polymerization reaction bottle under stirring to quench the polymerization reaction. The polymerization reaction solution was then poured into anhydrous ethanol to obtain a precipitate. The precipitate was filtered and washed three times with ethanol. It was then dried in a vacuum oven at 40°C for 12 h to obtain 0.98 g of a polymerization product.

[0132] 3. In a dry pressure-resistant reaction bottle, 0.9 g of the above-mentioned polymerization reaction product, 2.88 g (5 eqv in the molar number of unsaturated double bonds in the polymer) of p-toluenesulfonyl hydrazide, 2.44 g (5.5 eqv in the molar number of unsaturated double bonds in the polymer) of tri-n-propylamine, 0.1 g of 2,6-di-tert-butyl-4-methylphenol (BHT) and 30 mL of chloroform were added in sequence, and heated at 120°C for 16 h to obtain a hydrogenation reaction product; the hydrogenation product solution was added dropwise to 300 mL of anhydrous ethanol for precipitation, and the precipitate was then redissolved in 20 mL of chloroform at room temperature, and the above operation was repeated for washing twice; the obtained polymer was placed in a vacuum oven and dried at 60°C for 12 h to obtain 0.86 g of a saturated fluorinated cyclic olefin copolymer.

[0133] The weight average molecular weight of the fluorinated cycloolefin copolymer prepared in this example is 4.4×10 4 g / mol, molecular weight distribution 1.43. Fluorine content is 50.9wt%. Figure 2 As shown in (c), the transmittance of the fluorinated cyclic olefin copolymer obtained in Example 5 of the present invention is greater than 92% in the visible light region; the refractive index of the material is 1.40 (wavelength 589nm), and the reflectivity is 0.8%; the polymer has an amorphous structure and no crystallization behavior is found; Figure 5 As shown in (b), the tensile strength of the fluorinated cycloolefin copolymer obtained in Example 5 was 51.3 MPa, and the elongation at break was 14.3%.

[0134] In Examples 6-20, different types of II (M1-M6) monomers were copolymerized with III monomers to prepare fluorinated cycloolefin copolymers.

[0135] Among them, the ROMP reaction and hydrogenation of Examples 6-10 were carried out under the same conditions as in Example 3, and the total feeding amount of the monomers was controlled at 1 g, except that the monomers of Formula II and Formula III were fed at a molar ratio according to the monomer feeding ratio in Table 1, and the amounts of the catalyst Cat.2 in Examples 6-10 were 28.7 mg, 25.2 mg, 29.9 mg, 24.2 mg, and 27.8 mg, respectively; the ROMP reaction and hydrogenation of Examples 11-15 were carried out under the same conditions as in Example 4, and the total feeding amount of the monomers was controlled at 1 g, except that the monomers of Formula II and Formula III were fed at a molar ratio according to the monomer feeding ratio in Table 1. The molar ratio of the monomer feed was used. The amounts of catalyst Cat.1 used in Examples 11-15 were 22.5 mg, 26.3 mg, 28.0 mg, 20.6 mg, and 18.8 mg, respectively. The ROMP reaction and hydrogenation method of Examples 16-20 were carried out under the same conditions as in Example 5, with the total monomer feed amount controlled at 1 g. The difference was that the monomer of Formula II and the monomer of Formula III were carried out according to the molar ratio of the monomer feed in Table 1. The amounts of catalyst Cat.2 used in Examples 16-20 were 25.6 mg, 26.2 mg, 23.8 mg, 19.7 mg, and 18.1 mg, respectively. The properties of the fluoropolymers prepared in Examples 6-20 are shown in Table 1.

[0136] Table 1

[0137]

[0138]

[0139] Note: The refractive index of the fluoropolymer materials in Table 1 is the value at a wavelength of 589nm; M w and PDI are the weight-average molecular weight and molecular weight distribution, respectively, of the polymer, as determined by GPC in 1,2,4-trichlorobenzene at 150°C relative to a polystyrene standard. Transmittance testing uses a film thickness of 30-50 μm. Figure 2 (d) is the light transmittance of the fluorinated copolymer obtained in Example 10 of the present invention. The light transmittance of the fluorinated cycloolefin copolymer obtained in Example 10 is >92% in the visible light region.

[0140] Figure 3 Where (a), (b), (c), and (d) are the refractive indices of the fluorinated copolymers obtained in Examples 3, 11, 7, and 19 of the present invention, respectively; Figure 3 As shown in (b), the refractive index of the fluorinated copolymer obtained in Example 11 is 1.47 (wavelength 589 nm); Figure 3 As shown in (c), the refractive index of the fluorinated copolymer obtained in Example 7 is 1.38 (wavelength 589 nm); Figure 3As shown in (d), the refractive index of the fluorinated copolymer obtained in Example 19 is 1.43 (wavelength: 589 nm).

[0141] Figure 4 (a), (b), and (c) are the differential scanning calorimetry (DSC) curves of the fluorinated copolymers obtained in Example 4, Example 10, and Example 20, respectively; Figure 4 As shown in (b), the glass transition temperature of the fluorinated cyclic olefin copolymer obtained in Example 10 is 161°C, and the polymer is amorphous and no crystallization behavior is found. Figure 4 As shown in (c), the glass transition temperature of the fluorinated cyclic olefin copolymer obtained in Example 20 is 115° C., and the polymer has an amorphous structure and no crystallization behavior is observed.

[0142] Figure 5 (a), (b), and (c) are the tensile curves of the fluorinated copolymers obtained in Example 4, Example 5, and Example 8, respectively. Figure 5 As shown in (c), the tensile strength of the fluorinated cycloolefin copolymer obtained in Example 8 was 58.3 MPa, and the elongation at break was 19.2%.

[0143] Conclusion: According to the data obtained in the examples of the present invention, it can be concluded that with the increase of fluorine content, the refractive index of the fluorine-containing polymer material tends to decrease, and the introduction of non-fluorinated cycloolefin monomers can improve the solubility of the fluorine-containing polymer.

[0144] Comparative Example 1

[0145] Homopolymerization experiments were conducted using III-8 monomer (63.9 wt%), which has a high fluorine content. To a dry polymerization flask at 25°C, 2.40 mmol (1 g) of the compound represented by Formula III (III-8) was added 45 mL of chloroform and stirred for 5 minutes to fully dissolve the compound. Subsequently, under vigorous stirring, 19.3 mg of the catalyst, Cat.2, dissolved in 5 mL of chloroform, was added to the flask and polymerized at 25°C for 120 minutes. However, precipitation occurred early in the polymerization.

[0146] Effect verification

[0147] The scratch test was conducted to compare the fluorinated cycloolefin polymer obtained in Example 5 containing a non-fluorinated cycloolefin monomer with the fluorinated polymer obtained in Comparative Example 1 which did not contain a non-fluorinated cycloolefin monomer. The coating of the fluorinated cycloolefin polymer obtained in Example 5 containing a non-fluorinated cycloolefin monomer on the surface of a commercial COC / COP sheet showed only minor peeling of the coating at the scratch tip under a critical load of 15 N. The coating of the polymer obtained in Comparative Example 1 on the surface of a commercial COC / COP sheet showed greater curling and peeling of the coating under the same applied force of 15 N.

[0148] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A fluorinated cyclic olefin copolymer, characterized in that: The general structural formula is shown in Formula I: Among them, A is selected from Any of; 0.5≤y∶x≤19; 0≤m≤1； 1≤n≤4； R1 is selected from any one of m1-m3, and the structures of m1-m3 are as follows: R2 and R3 are independently selected from any one of hydrogen, halogen, and C1-C10 perfluoroalkyl; the C1-C10 perfluoroalkyl includes any one of perfluoromethyl, perfluoroethyl, perfluoro-n-butyl, perfluoroisopropyl, perfluoro-n-hexyl, perfluoro-n-octyl, and perfluoro-n-decyl; R4 and R5 are independently selected from any one of hydrogen, fluorine atom, and perfluoromethyl; Among them, at least one group among R2, R3, R4 and R5 contains a fluorine atom.

2. A fluorinated cyclic olefin copolymer according to claim 1, characterized in that: The structural formula of the fluorinated cyclic olefin copolymer includes:

3. A fluorinated cyclic olefin copolymer according to claim 1, characterized in that: The weight average molecular weight of the fluorinated cyclic olefin copolymer is (2-10)×10 4 g / mol; molecular weight distribution is 1.3~2.

2.

4. A method for preparing a fluorinated cyclic olefin copolymer, characterized in that: The following steps are involved: Under the conditions of Grubbs catalyst and organic solvent, a cycloolefin monomer and a fluorinated cycloolefin monomer undergo a ring-opening metathesis polymerization reaction to prepare an unsaturated fluorinated cycloolefin copolymer; The unsaturated fluorinated cyclic olefin copolymer is subjected to a hydrogenation reaction with a hydrogen source to obtain the fluorinated cyclic olefin copolymer according to any one of claims 1 to 3.

5. The method for preparing a fluorinated cyclic olefin copolymer according to claim 4, wherein: The cycloolefin monomer includes any one of the following structures of formula II, The fluorinated cycloolefin monomer includes any one of the following structures:

6. The method for preparing a fluorinated cyclic olefin copolymer according to claim 4, wherein: The Grubbs catalyst is dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](3-methyl-2-butenylidene)(tricyclohexylphosphine)ruthenium(II) and / or dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](benzylidene)bis(3-bromopyridine)ruthenium(II).

7. The method for preparing a fluorinated cyclic olefin copolymer according to claim 4, wherein: The organic solvent includes one or more of dichloromethane, chloroform, tetrachloroethane, chlorobenzene, o-dichlorobenzene, trichlorobenzene, cyclohexane, methylcyclohexane, toluene or xylene; and / or The hydrogen source includes hydrazine compounds or high-purity hydrogen.

8. The method for preparing a fluorinated cyclic olefin copolymer according to claim 4, wherein: The conditions of the ring-opening metathesis polymerization reaction are: reaction at 25° C. for 120 min; and / or The conditions of the hydrogenation reaction are: heating the reaction at 120-150° C. for 6-16 hours.

9. Use of the fluorinated cyclic olefin copolymer according to any one of claims 1 to 3 in the preparation of low refractive index optical lenses and anti-reflective coatings.

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