Patent Application
20240199780
The present invention relates to a fluorine-based polymer, a fluorine-based polymer composition comprising the same, and a fluorine-based polymer membrane using the same.
Fluorine has a high electron density and the smallest atomic radius after the hydrogen atom, and it also has a strong electronegativity, so it forms a strong carbon-fluorine bond. Due to these fluorine-based characteristics, monomers containing perfluoroalkyl groups are extremely hydrophobic, with critical surface tension of 6-8 dynes/cm, and have very low surface energy, repelling both water and oil. Accordingly, fluorine-based compounds are gradually expanding their use due to their excellent chemical stability, heat resistance, weather resistance, non-adhesiveness, low surface energy, water repellency, and low refractive index, despite their relatively high price.
Currently, fluorine-based functional materials are widely used as core materials for next-generation technologies in the high-tech industries of optical communications, optoelectronics, semiconductors, automobiles, and computers because of their excellent performance in stain resistance, weather resistance, heat resistance, and optical properties that other materials cannot achieve. In particular, research on fluorine-based functional materials is being actively conducted due to the increasing interest in anti-fouling coatings, including anti-fouling coatings such as the front outermost layer of liquid crystal displays or the frame of aesthetic displays, which are rapidly increasing in recent years, as well as various paints and coating agents applied to household appliances, architecture, shipbuilding, and civil engineering fields that require traditional anti-fouling surface properties.
Fluoropolymers are materials having such properties as low surface energy, water repellency, lubricity, and low refractive index along with excellent heat resistance, chemical resistance, and weather resistance, and have been widely used throughout the industry, starting with household products.
However, despite their excellent performance (water repellency, stain resistance, etc.), conventional fluoropolymers have been facing significant manufacturing problems due to the high cost of materials and the difficulty of using general organic solvents.
Furthermore, since the surface energy of the conventional fluoropolymer or antifouling film containing the same is not sufficiently low, there is a need to further improve antifouling properties.
In addition, depending on the type of substrate, there have been problems such as poor adhesion when coating on the substrate. That is, if it is well soluble in general organic solvents while maintaining the performance of a fluoropolymer and has excellent adhesion to a substrate for use as a coating material, its industrial value is expected to be very great.
It is an object of the present invention to provide a fluorine-based polymer having a low surface energy, a fluorine-based polymer composition comprising the same, a fluorine-based polymer membrane containing the same, and a manufacturing method thereof.
To achieve the above object, the present invention provides a fluorine-based polymer represented by the following formula 1:
(In formula 1 above,
The present invention also provides a fluorine-based polymer composition comprising a fluorine-based polymer represented by formula 1 below and an organic solvent :
(In formula 1 above,
In addition, the present invention provides a fluorine-based polymer membrane comprising a fluorine-based polymer represented by the following formula 1:
(In formula 1 above,
The fluorine-based polymer provided in one aspect of the present invention has low surface energy and high light transmittance, so it can be applied to various applications requiring these characteristics. At the same time, there is an effect of exhibiting excellent pencil strength.
In addition, the fluorine-based polymer provided in one aspect of the present invention can be applied as a surface coating and membrane material for various products due to its high solubility in general organic solvents despite having a very low surface energy during coating.
Furthermore, it has excellent adhesion to the substrate surface and can be cured, so it can be applied to various fields such as automotive glass, building exterior materials, condensers in freshwater or power plants, and solar cells.
In one aspect of the present invention, the invention provides a fluorine-based polymer represented by the following formula 1:
(In formula 1 above,
Hereinafter, a fluorine-based polymer according to the present invention is described in detail.
The fluorine-based polymer according to the present invention can be represented by formula 1 above.
In the fluorine-based polymer represented by formula 1 above, Rf is C1-20 fluorinated straight alkyl or C3-20 fluorinated branched alkyl, wherein the number of fluorocarbon is 3 to 5, and more preferably 4.
In addition, as an example, in the fluorine-based polymer represented by formula 1 above, R1, R2, R3, and R4 can be independently hydrogen (H), methyl (CH3), and halogen, respectively. The halogen may be fluorine (F) or chlorine (Cl). Furthermore, in the fluorine-based polymer represented by formula 1 above, R1 is preferably hydrogen, and R2, R3 and R4 are methyl.
In addition, as an example, in the fluorine-based polymer represented by formula 1 above, R5 can be represented by —(CH2)c—CH3.
In this case, c may be an integer in the range of 0-15, an integer in the range of 1-10, an integer in the range of 1-5, but the range of the value of c is not limited thereto.
Further, in the fluorine-based polymer represented by formula 1 above, x, y, p, and q are such that, based on a molar ratio of x+y+p+q=100, x is 30 to 70, p is 5 to 20, and y+q is 20 to 60.
More preferably, x is 60, p is 10 to 15, and y+q is 20 to 30. By having a composition in the above range, the polymer can exhibit significantly higher pencil strength with lower surface energy and higher light transmittance.
In addition, as an example, the fluorine-based polymer represented by formula 1 above preferably has a number average molecular weight of 70,000 to 100,000. If the number average molecular weight of the fluorine-based polymer is less than 70,000, the thermal and mechanical strength of the polymer may decrease, and if it exceeds 100,000, the solubility in organic solvents may decrease rapidly.
Unlike conventional fluorine-based polymers, the polymer represented by formula 1 provided in one aspect of the present invention is soluble in generally known organic solvents, and thus has a very advantageous effect in the manufacturing process. Examples of the organic solvent include any general organic solvent, such as at least one selected from the group consisting of tetrahydrofuran (THF), 2-butanol (MEK), methylisobutyl ketone (MIBK), propylene glycol methyl ether (PGMEA), and the like. However, it is preferable to use a solvent capable of dissolving both the monomer before reaction and the polymer after reaction as the organic solvent at this time.
The present invention also provides a fluorine-based polymer composition comprising a fluorine-based polymer represented by formula 1 below and an organic solvent:
(In formula 1 above,
Hereinafter, a fluorine-based polymer composition according to the present invention is described in detail.
The fluorine-based polymer is as described above. The fluorine-based polymer according to the present invention has low surface energy and high light transmittance, so it can be applied to various applications requiring these characteristics. The fluorine-based polymer composition is a composition for such applications, characterized in that it has a high solubility in organic solvents.
The organic solvent can be at least one selected from the group consisting of tetrahydrofuran (THF), 2-butanol (MEK), methylisobutyl ketone (MIBK), propylene glycol methyl ether (PGMEA), and the like, but not always limited thereto. However, it is preferable to use a solvent capable of dissolving both the monomer before reaction and the polymer after reaction.
Preferably, the fluorine-based polymer composition further includes a curing agent comprising an isocyanate group. The synthesized fluorine-based polymer can have stronger chemical and mechanical durability by including a curing agent. However, when the curing agent reacts with the polymer at room temperature, the viscosity changes over time from the moment of mixing, resulting in poor workability and storability. To prevent this, it is desirable to use a curing agent composed of a compound in which reactive groups dissociate at a certain temperature, and in view of this, it is desirable to further include an HDI trimer-based curing agent containing an isocyanate group.
If the fluorine-based polymer composition of the present invention further includes a curing agent comprising an isocyanate group, the curing agent is preferably included in a molar ratio of 1.1 to 1.5 based on the total number of moles of a hydroxyl group in the fluorine-based polymer. If the amount is less than 1.1, the degree of curing is reduced and the mechanical and chemical properties are not sufficient, and if the amount exceeds 1.5, the content ratio of fluorine methacrylate to the total composition is reduced and the surface energy is increased.
The fluorine-based polymer composition provided in one aspect of the present invention exhibits very low surface energy and excellent light transmittance. In addition, it has excellent adhesion to the substrate surface and can be cured, so it can be applied to various fields such as automotive glass, building exterior materials, condensers in freshwater or power plants, and solar cells.
The present invention also provides a fluorine-based polymer membrane comprising a fluorine-based polymer represented by the following formula 1:
(In formula 1 above,
Hereinafter, a fluorine-based polymer membrane according to the present invention is described in detail.
The fluorine-based polymer is as described above. The fluorine-based polymer according to the present invention has low surface energy and high light transmittance, so it can be applied to various applications requiring these characteristics. The fluorine-based polymer composition is a composition for such applications, characterized in that it has a high solubility in organic solvents.
Preferably, the fluorine-based polymer membrane further includes a curing agent comprising an isocyanate group. The synthesized fluorine-based polymer can have stronger chemical and mechanical durability by including a curing agent. However, when the curing agent reacts with the polymer at room temperature, the viscosity changes over time from the moment of mixing, resulting in poor workability and storability. To prevent this, it is desirable to use a curing agent composed of a compound in which reactive groups dissociate at a certain temperature, and in view of this, it is desirable to further include an HDI trimer-based curing agent containing an isocyanate group.
If the fluorine-based polymer membrane of the present invention further includes a curing agent comprising an isocyanate group, the curing agent is preferably included in a molar ratio of 1.1 to 1.5 based on the total number of moles of a hydroxyl group in the fluorine-based polymer. If the amount is less than 1.1, the degree of curing is reduced and the mechanical and chemical properties are not sufficient, and if the amount exceeds 1.5, the content ratio of fluorine methacrylate to the total composition is reduced and the surface energy is increased.
The fluorine-based polymer membrane provided in one aspect of the present invention exhibits very low surface energy and excellent light transmittance. In addition, it has excellent adhesion to the substrate surface and can be cured, so it can be applied to various fields such as automotive glass, building exterior materials, condensers in freshwater or power plants, and solar cells.
In another aspect of the present invention, method of producing a fluorine-based polymer membrane comprising the following steps is provided:
Hereinafter, a method of producing a fluorine-based polymer membrane according to the present invention is described in detail.
First, in the method of producing a fluorine-based polymer membrane according to the present invention, step 1 is to prepare a polymer solution by dissolving the fluorine-based polymer presented in the present invention in an organic solvent.
The fluorine-based polymer according to the present invention has excellent solubility in organic solvents, so that a polymer solution can be easily prepared by dissolving it in an organic solvent.
For example, at least one selected from the group consisting of tetrahydrofuran (THF), 2-butanol (MEK), methylisobutyl ketone (MIBK), and propylene glycol methyl ether (PGMEA) can be used as the organic solvent in step 1, but not always limited thereto.
Next, in the method of producing a fluorine-based polymer membrane according to the present invention, step 2 is to apply the polymer solution of step 1 on a substrate and dry it to form a polymer membrane.
As a specific example, the application of step 2 can be performed by a method such as spin coating, dip coating, roll coating, or spray coating.
Meanwhile, the method of producing a fluorine-based polymer membrane preferably further includes a step of mixing a curing agent comprising an isocyanate group with the polymer solution prepared in step 1.
If a curing agent is further included in the process of producing a fluorine-based polymer membrane, it may have stronger chemical and mechanical durability. However, when the curing agent reacts with the polymer at room temperature, the viscosity changes over time from the moment of mixing, resulting in poor workability and storability. To prevent this, it is desirable to use a curing agent composed of a compound in which reactive groups dissociate at a certain temperature, and in view of this, it is desirable to further include an HDI trimer-based curing agent containing an isocyanate group.
If the method of producing a fluorine-based polymer membrane of the present invention further includes a step of mixing a curing agent comprising an isocyanate group, the curing agent is preferably included in a molar ratio of 1.1 to 1.5 based on the total number of moles of a hydroxyl group in the fluorine-based polymer. If the amount is less than 1.1, the degree of curing is reduced and the mechanical and chemical properties are not sufficient, and if the amount exceeds 1.5, the content ratio of fluorine methacrylate to the total composition is reduced and the surface energy is increased.
In another aspect of the present invention, a method of forming an antifouling coating film comprising the following steps is provided:
Hereinafter, a method of producing an antifouling coating film according to the present invention is described in detail.
First, in the method of producing an antifouling coating film according to the present invention, step 1 is to prepare a polymer solution by dissolving the fluorine-based polymer presented in the present invention in an organic solvent.
The fluorine-based polymer according to the present invention has excellent solubility in organic solvents, so that a polymer solution can be easily prepared by dissolving it in an organic solvent.
For example, at least one selected from the group consisting of tetrahydrofuran (THF), 2-butanol (MEK), methylisobutyl ketone (MIBK), and propylene glycol (PGMEA) can be used as the organic methyl ether solvent in step 1, but not always limited thereto.
Next, in the method of producing an antifouling coating film according to the present invention, step 2 is to apply the polymer solution of step 1 on a substrate and dry it to form a polymer membrane.
As a specific example, the application of step 2 can be performed by a method such as spin coating, dip coating, roll coating, or spray coating.
Meanwhile, the method of producing an antifouling coating film preferably further includes a step of mixing a curing agent comprising an isocyanate group with the polymer solution prepared in step 1.
If a curing agent is further included in the process of producing an antifouling coating film, it may have stronger chemical and mechanical durability. However, when the curing agent reacts with the polymer at room temperature, the viscosity changes over time from the of moment mixing, resulting in poor workability and storability. To prevent this, it is desirable to use a curing agent composed of a compound in which reactive groups dissociate at a certain temperature, and in view of this, it is desirable to further include an HDI trimer-based curing agent containing an isocyanate group.
If the method of producing an antifouling coating film of the present invention further includes a step of mixing a curing agent comprising an isocyanate group, the curing agent is preferably included in a molar ratio of 1.1 to 1.5 based on the total number of moles of a hydroxyl group in the fluorine-based polymer. If the amount is less than 1.1, the degree of curing is reduced and the mechanical and chemical properties are not sufficient, and if the amount exceeds 1.5, the content ratio of fluorine methacrylate to the total composition is reduced and the surface energy is increased.
Hereinafter, the present invention will be described in detail by the following examples and experimental examples.
However, the following examples and experimental examples are only for illustrating the present invention, and the contents of the present invention are not limited thereto.
Copolymerization was performed by adding 60 mol % of NFHA (nonafluorohexyl acrylate), 10 mol % of SMA (stearyl methacrylate), 25 mol % of HEMA (hydroxyethyl methacrylate), and 5 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THF) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer.
Copolymerization was performed by adding 60 mol % NFHA (nonafluorohexyl acrylate), 10 mol % of SMA (stearyl methacrylate), 20 mol % of HEMA (hydroxyethyl methacrylate), and 10 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THF) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer.
Copolymerization was performed by adding 60 mol % NFHA (nonafluorohexyl acrylate), 10 mol % of SMA 4 (stearyl methacrylate), 15 mol % of HEMA (hydroxyethyl methacrylate), and 15 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THE) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer.
Copolymerization was performed by adding 60 mol % of NFHA (nonafluorohexyl acrylate), 10 mol % of SMA (stearyl methacrylate), 10 mol % of HEMA (hydroxyethyl methacrylate), and 20 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THF) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer.
Copolymerization was performed by adding 60 mol % of NFHA (nonafluorohexyl acrylate), 10 mol % of SMA (stearyl methacrylate), 20 mol % of MMA (methyl methacrylate), and 10 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THF) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer.
Copolymerization was performed by adding 60 mol % of NFHA (nonafluorohexyl acrylate), 10 mol % of SMA (stearyl methacrylate), 20 mol % of HEMA (hydroxyethyl methacrylate), and 10 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THE) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer.
A polymer solution was prepared by dissolving the prepared fluorine-based polymer in a mixed solvent in which EK and PGMEA are mixed in a volume ratio of 9:1, and an HDI-based curing agent was introduced into the polymer solution in an amount such that the ratio of hydroxyl groups in the polymer to functional groups in the curing agent was 100:130 to prepare a polymer composition.
A fluorine-based polymer film was prepared by forming a membrane by spin-coating or bar-coating the polymer composition on a flat substrate, and then curing it by heating in an oven for 5 hours above 145° C., the dissociation temperature of the curing agent .
Copolymerization was performed by adding 60 mol % of NFHA (nonafluorohexyl acrylate), 10 mol % of SMA (stearyl methacrylate), and 30 mol % of HEMA (hydroxyethyl methacrylate) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THF) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer.
Copolymerization was performed by adding 60 mol % of TDFOA (tridecafluoro n-octyl acrylate), 10 mol % of SMA (stearyl methacrylate), 20 mol % of HEMA (hydroxyethyl methacrylate), and 10 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in tetrahydrofuran (THF) and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C. to remove residual radicals, and then the reaction was terminated while cooling to room temperature to is, a prepare a fluorine-based copolymer, that fluorine-based polymer.
Copolymerization was performed by adding 46 mol % of PFPMA (pentafluoropropyl methacrylate), 12 mol % of SMA (stearyl methacrylate), 20 mol % of MMA (methyl methacrylate), 23 of mol % HEMA (hydroxyethyl methacrylate), and 12 mol % of MAA (methacrylic acid) based on the total copolymer. The above monomers were dissolved in a solvent and warmed up to 60° C. under nitrogen atmosphere. Then, an AIBN (azobisisobutyro nitrile) initiator was added and reacted for about 8 hours. Thereafter, reflux was performed by raising the temperature to 80° C.to remove residual radicals, and then the reaction was terminated while cooling to room temperature to prepare a fluorine-based copolymer, that is, a fluorine-based polymer. A polymer solution composition was prepared by dissolving the prepared fluorine-based polymer in a mixed solvent of MEK/PGMEA and adding a curing agent.
Molecular weight (Mw) and polydispersity index (PDI) were measured through GPC (Gel Permeation Chromatography) measurement. THF was used for the measurement as a solvent. In the case of the polymer presented in the present invention (Example 2), the molecular weight was 85000 g/mol, and the PDI was 2.24. If the molecular weight of the polymer is too low, mechanical properties or surface properties may be deteriorated, and if the molecular weight is too high, it becomes difficult to dissolve in general-purpose solvents. For utilization as a highly versatile coating material considered in the present invention, the molecular weight is preferably between 70,000 and 100, 000. In addition, the PDI is a criterion representing the width of molecular weight distribution. If it is 2.5 or more in a structure such as the polymer copolymer of the present invention, it may affect the realization of uniform and constant physical properties. Therefore, it is desirable to optimize the synthesis conditions and process to have a PDI of less than that.
Thermogravimetric analysis (TGA) measures the temperature at which pyrolysis occurs while heating a sample. The measurement is performed by raising the temperature of the sample to 100° C., returning it to room temperature, and then heating it to 600° C. at 10° C./min. In the case of the polymer presented in the present invention (Example 2), a mass loss of 1% was observed at 249° C., and a mass loss of 5% was observed at 300° C. The 1% mass loss temperature is a widely used indicator to determine when a material begins to pyrolyze, with higher values indicating that the material can be used in high temperature conditions. The 1% mass loss temperature of the polymer of Example 2 is higher than that of methacrylic copolymers, which are often below 200° C., indicating that it can be utilized at higher temperatures (>200° C.) than conventional methacrylic coating materials.
To confirm the curing process of the method of producing a polymer membrane including a curing agent according to the present invention, the following experiment was performed.
In the process of preparing a polymer membrane in Example 6, a polymer composition including a curing agent was heated to 145° C., and an isocyanate peak (2275 cm−1) of the curing agent was confirmed through FT-IR (JASCO FT-IR 4100) measurement. The results are shown in
In order to confirm the surface energy of the polymer synthesized according to the present invention, the following experiment was performed.
A solution in which the PMMA polymer, the polymer according to Example 2 or Example 6, or the polymer according to Comparative Example 2 of the present invention was diluted to 4 weight % was spin-coated on a silicon wafer at 2000 rpm. The contact angles of water and diiodomethane (DIM) on the surface of the coated film were measured, and the surface energy was calculated by the OWRK method (Owens-Wendt-Rabel-Kaelble Method), and the results are shown in Table 1 below.
According to Table 1, it was confirmed that the polymer according to the present invention had a significantly lower surface energy than PMMA not containing fluorocarbons, and also had a lower surface energy than the polymer of Comparative Example 2 having a higher number of fluorocarbons than the polymer of the present invention. It was also confirmed that the polymer containing a curing agent (Example 6) still showed a low surface energy value. This value was lower than the surface energy of pure poly nonafluorohexyl acrylate (8.5 mN/m) measured by Honda et al. (Macromolecules 2010, 40, 454-460).
In order to confirm the changes in surface energy according to the adjustment of the monomers introduced as repeating units of the copolymer, the following experiment was performed.
A solution in which the polymer synthesized in Examples 1 to 5 or Comparative Example 1 of the present invention was diluted to 4 weights was spin-coated on a silicon wafer at 2000 rpm. The contact angles of water and diiodomethane (DIM) on the surface of the coated film were measured, and the surface energy was calculated by the OWRK method (Owens-Wendt-Rabel-Kaelble Method), and the results are shown in Table 2 below.
According to Table 2 above, the surface energy values of the polymers according to the present invention were all below 11.0 mN/m, and the lowest case was 4.9 mN/m, but in the case of Comparative Example 1, even if the composition was similar, it was confirmed that the surface energy increased rapidly when the composition was outside the scope of the present invention. In addition, as shown in Table 2, since the surface energy of the polymer according to Example 2 is remarkably low among the examples of the present invention, it is expected to show very excellent properties when applied to an antifouling film or the like.
To confirm the mechanical strength of the polymer according to the present invention, the following experiment was performed.
A film was prepared by bar-coding a solution containing 20 weight % of the polymer of Example 6 of the present invention to a height of 0.5 mm, and the hardness at which the film was damaged was measured by increasing pencil hardness from 2H with an applied load of 1 kg. The results are shown in
According to
To confirm the optical properties, that is, light transmittance, of the polymer membrane according to the present invention, the following experiment was performed.
A slide glass (Matsunami FF-011) showing high light transmittance was cleaned, and a coating solution in which the polymer of Example 2 or Comparative Example 3 of the present invention was mixed at 4 weight % based on the total solution was spin-coated on the slide glass at 2000 rpm, respectively, and UV-vis transmittance was measured (Cary 5000). The results are shown in
It is known that fluoropolymers have excellent light transmittance as a unique property. According to
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0046339 | Apr 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/001798 | 2/7/2022 | WO |
