KR102103552B1 - Chalcogenide diamine compound, polyamic acid prepared therefrom, polyimide prepared therefrom, and polyimide film including polyimde - Google Patents

Abstract

상기 화학식 1에서, X₁은 셀레늄(Se) 이산화셀레늄(SeO₂), 텔루늄(Te), 이산화텔루늄(TeO₂) 또는 그 조합물이고, Ar₁ 및 Ar₂는 각각 독립적으로 하기 화학식 1-1 내지 1-3로 이루어지는 그룹으로부터 선택되고,
[화학식 1-1] [화학식 1-2] [화학식 1-3]

화학식 1-1 내지 1-3 중, *는 결합위치를 나타내고, R₁ 내지 R₄는 각각 독립적으로 수소, 불소, 탄소수 1 내지 30의 알킬기 및 탄소수 1 내지 30의 퍼플루오로알킬기로 이루어지는 그룹으로부터 선택된다.The present invention provides a polyamic acid that is a polymerization reaction product of a chalcogen-based diamine represented by the following Chemical Formula 1 and an acid dianhydride, a polyimide obtained from the polyimide film, and a chalcogen-based diamine.
[Formula 1]

In Chemical Formula 1, X ₁ is selenium (Se) selenium dioxide (SeO ₂ ), tellurium (Te), tellurium dioxide (TeO ₂ ), or a combination thereof, Ar ₁ and Ar ₂ are each independently represented by the following Chemical Formula 1 Is selected from the group consisting of -1 to 1-3,
[Formula 1-1] [Formula 1-2] [Formula 1-3]

In formulas 1-1 to 1-3, * represents a bonding position, and R ₁ to R ₄ are each independently from a group consisting of hydrogen, fluorine, an alkyl group having 1 to 30 carbon atoms and a perfluoroalkyl group having 1 to 30 carbon atoms. Is selected.

Description

Chalcogenide diamine, polyamic acid and polyimide formed therefrom, polyimide film including the polyimide {Chalcogenide diamine compound, polyamic acid prepared therefrom, polyimide prepared therefrom, and polyimide film including polyimde}

The present invention relates to a chalcogen-based diamine, a polyamic acid and polyimide formed therefrom, and a polyimide film containing the polyimide.

Recently, transparent inorganic materials in the near-infrared region, for example, chalcogenide glass and germanium semiconductors, have attracted attention in the near-infrared imaging device. Chalcogenide glass has the characteristics of high transmittance and high refractive index (n≥2.0) in the near-infrared region, and has been used in the near-infrared imaging field. However, chalcogenides not only require very high temperatures for synthesis and manufacturing, but also have the disadvantage of being highly toxic and expensive.

On the other hand, polymer composite materials using inorganic nanoparticles have recently been developed, and they exhibit a dielectric constant of 2 or less, but the polymer composite material has low chemical stability, high light loss rate, and complicated manufacturing process. Accordingly, the prior art is a situation that does not provide a polyimide film excellent enough to be applied to an advanced integrated device, and improves the dielectric constant, light transmittance, etc. while exhibiting mechanical durability, heat resistance, and ease in the manufacturing process over the conventional polyimide film. Development of a polyimide film that can be used for semiconductor substrate materials and the like is urgently required.

According to one aspect, it is to provide a novel chalcogen-based diamine.

According to another aspect, it is to provide a polyamic acid formed from the above-described chalcogen-based diamine and a polyimide obtained from the polyamic acid.

According to another aspect, it is intended to provide a polyimide film having the above-described polyimide and having light transmittance, excellent heat resistance, and high refractive index.

According to one aspect, a polyamic acid that is a polymerization reaction product of a chalcogen-based diamine represented by the following Chemical Formula 1 and an acid dianhydride is provided.

[Formula 1]

In Chemical Formula 1, X ₁ is selenium (Se) selenium dioxide (SeO ₂ ), tellurium (Te), tellurium dioxide (TeO ₂ ), or a combination thereof,

Ar ₁ and Ar ₂ are each independently selected from the group consisting of the following formulas 1-1 to 1-3,

[Formula 1-1] [Formula 1-2] [Formula 1-3]

In formulas 1-1 to 1-3, * represents a bonding position, and R ₁ to R ₄ are each independently from a group consisting of hydrogen, fluorine, an alkyl group having 1 to 30 carbon atoms and a perfluoroalkyl group having 1 to 30 carbon atoms. Is selected.

According to another aspect, an imidization reaction product of the polyamic acid described above is provided.

According to another aspect, the above-described polyimide film is provided.

According to another aspect, a chalcogen-based diamine represented by Chemical Formula 1 is provided.

[Formula 1]

In Chemical Formula 1, X ₁ is independently selenium (Se) selenium dioxide (SeO ₂ ), tellurium (Te), tellurium dioxide (TeO ₂ ), or a combination thereof,

Ar ₁ and Ar ₂ are each independently selected from the group consisting of the following formulas 1-1 to 1-3,

[Formula 1-1] [Formula 1-2] [Formula 1-3]

In Formulas 1-1 to 1-3, * represents a bonding position, and R ₁ to R ₄ are each independently from a group consisting of hydrogen, fluorine, an alkyl group having 1 to 30 carbon atoms, and a perfluoroalkyl group having 1 to 30 carbon atoms. Is selected.

The polyamic acid obtained from the chalcogen-based diamine according to an embodiment of the present invention and the polyimide film obtained therefrom are excellent in transparency and heat resistance, but also have high refractive index characteristics.

1A and 1B are graphs showing the results of measurement of nuclear magnetic resonance (NMR) of a compound of Formula 1f prepared according to Example 1, respectively.
2A and 2B are graphs showing the results of measurement of nuclear magnetic resonance (NMR) of a compound of Formula 1e prepared according to Example 1, respectively.
3 is a graph showing the results of differential scanning calorimetry (DSC) measurement of polymer films prepared according to Examples 5 and 6.
4 is a graph showing the measurement results of thermogravimetric analysis of polymer films prepared according to Examples 5 and 6.
5 is a graph showing the results of measuring the refractive index (refractive index) of the polymer films prepared according to Examples 5 and 6.
6 is a graph showing the results of ultraviolet-visible spectroscopy (UV-Vis) measurements of polymer films prepared according to Examples 5 and 6.
7 is a graph showing the results of measuring the refractive index of the nanocomposite films prepared according to Examples 6 to 9.
8 is a graph showing the results of ultraviolet-visible light spectrophotometer measurements of the nanocomposite films prepared according to Examples 6 to 9.

Hereinafter, a chalcogen-based diamine according to one embodiment, a polyamic acid formed therefrom, a polyimide obtained from a polyamic acid, and a polyimide film containing the polyimide will be described in more detail.

A chalcogen-based diamine represented by the following Chemical Formula 1 is provided.

 [Formula 1]

In Chemical Formula 1, X ₁ is selenium (Se) selenium dioxide (SeO ₂ ), tellurium (Te), tellurium dioxide (TeO ₂ ), or a combination thereof,

Ar ₁ and Ar ₂ are each independently selected from the group consisting of the following formulas 1-1 to 1-3,

[Formula 1-1] [Formula 1-2] [Formula 1-3]

In formulas 1-1 to 1-3, * represents a bonding position, and R ₁ to R ₄ are each independently from a group consisting of hydrogen, fluorine, an alkyl group having 1 to 30 carbon atoms and a perfluoroalkyl group having 1 to 30 carbon atoms. Is selected.

In the present specification, "chalcogen-based diamine" means a diamine compound containing a phenyl group connected by one chalcogen element.

In general, the more the benzene ring present in the main chain of the compound is included, the easier the transfer of electrons of the benzene ring can occur. This may result in absorbing light in the visible light region, which may cause browning, which changes the color of the compound, and may decrease light transmittance. The kalko gengye diamine is selenium (Se) and selenium dioxide (SeO _2), Tel runyum (Te), dioxide Tel runyum (TeO ₂₎ comprises a high polarizability element, such as a number, and kalko gengye of the diamine compound in the benzene ring The element has an atom having a large molecular radius, and thus has an effect of minimizing the interaction between the polymer main chains, thereby reducing the high aromatic ring density. Polymers and polyimide films prepared using this as a monomer may exhibit high refractive index and excellent light transmittance. In addition, the diamine compound according to an embodiment of the present invention has a structure in which an aromatic is connected to a flexible chalcogen element in a molecule, thereby reducing the crystallinity and anisotropy in the molecule of polymers and polyimide films produced using the same. As this decreases, the glass transition temperature may be high and the birefringence may also be kept low.

The chalcogen-based diamine represented by Chemical Formula 1 may be at least one selected from compounds represented by Chemical Formulas 1a to 1f.

[Formula 1a]

[Formula 1b]

[Formula 1c]

[Formula 1d]

[Formula 1e]

[Formula 1f]

According to another aspect, a polyamic acid that is a polymerization reaction product of the above-described diamine compound and acid dianhydride is provided.

The acid dianhydride is not particularly limited, and any acid dianhydride commonly used in the art can be used. Acid sap is for example

It can be represented by the following formula 2a.

[Formula 2a]

In Formula 2a, R ₅ is selected from the group consisting of a tetravalent aromatic cyclic organic group and a tetravalent aliphatic cyclic organic group.

For example, R ₅ in Formula 2a is selected from the group represented by Formulas 2-4 to 2-14 below.

[Formula 2-4] [Formula 2-5] [Formula 2-6]

[Formula 2-7] [Formula 2-8] [Formula 2-9]

[Formula 2-10] [Formula 2-11] [Formula 2-12]

[Formula 2-13] [Formula 2-14]

In Formulas 2-4 to 2-14, * represents a bonding position.

In an exemplary embodiment, the polyamic acid may be represented by Formula 2 below.

[Formula 2]

In Formula 2, X ₁ is selenium (Se) selenium dioxide (SeO ₂ ), tellurium (Te), tellurium dioxide (TeO ₂ ), or a combination thereof,

n is an integer from 10 to 1,000,

Ar ₃ and Ar ₄ are each independently selected from the group consisting of the following formulas 2-1 to 2-3,

[Formula 2-1] [Formula 2-2] [Formula 2-3]

In Formulas 2-1 to 2-3, R ₁ to R ₄ are each independently selected from the group consisting of hydrogen, fluorine, an alkyl group having 1 to 30 carbon atoms and a perfluoroalkyl group having 1 to 30 carbon atoms, and R ₁ To R ₄ may be the same or different, respectively. In addition, in Chemical Formula 2, R ₅ is selected from the group consisting of a tetravalent aromatic cyclic organic group and a tetravalent aliphatic cyclic organic group,

Is selected from the group represented by the following formula 2-4 to 2-14,

[Formula 2-4] [Formula 2-5] [Formula 2-6]

[Formula 2-7] [Formula 2-8] [Formula 2-9]

[Formula 2-10] [Formula 2-11] [Formula 2-12]

[Formula 2-13] [Formula 2-14]

In Formulas 2-4 to 2-14, * represents a bonding position.

The polyamic acid according to one embodiment is one selected from polymers represented by the following Chemical Formulas 2a or 2b.

[Formula 2a]

[Formula 2b]

The polyamic acid according to an embodiment has a number average molecular weight of 10,000 to 500,000 g / mol. When having such a number average molecular weight, the polyamic acid has excellent dielectric constant and optical properties.

According to another aspect, a polyimide obtained by imidizing the aforementioned polyamic acid is provided. In one embodiment, a polyimide prepared by imidizing the polyamic acid is provided.

The polyimide may be represented by Formula 3 below.

[Formula 3]

In Chemical Formula 3, X ₁ is selenium (Se) selenium dioxide (SeO ₂ ), tellurium (Te), tellurium dioxide (TeO ₂ ), or a combination thereof, Ar ₃ and Ar ₄ are each independently Formula 3 Is selected from the group consisting of -1 to 3-3,

[Formula 3-1] [Formula 3-2] [Formula 3-3]

In Chemical Formulas 3-1 to 3-3, R ₁ to R ₄ are each independently selected from the group consisting of hydrogen, fluorine, an alkyl group having 1 to 30 carbon atoms, and a perfluoroalkyl group having 1 to 30 carbon atoms, and R ₁ To R ₄ may be the same or different, respectively. In addition, in Chemical Formula 3, R ₅ is selected from the group consisting of a tetravalent aromatic cyclic organic group and a tetravalent aliphatic cyclic organic group.

R ₅ is selected from the group represented by the following Chemical Formulas 2-4 to 2-14.

[Formula 2-4] [Formula 2-5] [Formula 2-6]

[Formula 2-7] [Formula 2-8] [Formula 2-9]

[Formula 2-10] [Formula 2-11] [Formula 2-12]

[Formula 2-13] [Formula 2-14]

In Formulas 2-4 to 2-14, * represents a bonding position.

The polyimide is, for example, one polymer selected from polymers represented by the following Chemical Formulas 3a or 3b.

[Formula 3a]

In Formula 3a, n is an integer of 10 to 1,000,

[Formula 3b]

In Formula 3b, n is an integer of 10 to 1,000.

The polyimide of Chemical Formula 3a or 3b has less birefringence compared to polyimide which is oxygen (O) instead of sulfur (S) in the region of acid anhydride and oxygen (O) instead of Te and Se of the region obtained in diamine, and is useful as an optical material Do.

Let us look at the polyamic acid of the present invention and a method for producing polyimide using the same.

The polyamic acid is prepared by mixing a chalcogen-based diamine of Formula 1 and an acid dianhydride with a solvent, and then performing a polymerization reaction under an inert gas atmosphere to produce a polyamic acid. As the solvent, for example, N-methylpyrrolidone, tetrahydrofuran, or the like is used.

The inert gas atmosphere is formed using argon, nitrogen, or the like.

In the polymerization reaction described above, reaction conditions such as temperature may be changed according to the type of diamine compound and acid anhydride used. For example, the polymerization reaction can be carried out, for example, in the range of 25 ° C to 150 ° C.

The desired polyimide can be obtained by performing the imidization reaction of the polyamic acid.

The imidization reaction includes a method of dehydrocycling by heating, a method of performing dehydrocyclization using a dehydrating agent, and the like.

The method of performing dehydration by heating is carried out, for example, at a high temperature of 200 to 300 ° C to imidize.

The method of performing dehydration using a dehydrating agent is performed at a temperature of 200 ° C. or lower to imidize. It is also possible to use a catalyst such as an acid or a base together with a dehydrating agent. For example, an organic acid such as p-hydroxyphenylacetic acid is used as the acid catalyst, and isoquinoline, triethylamine, pyridine, 1,4-diazabicyclo [2.2.2] octane, etc. are used as the base catalyst. .

The inherent viscosity of the polyimide according to one embodiment is 0.3927 to 0.4904 dL / g.

In one embodiment, a polyimide film may be prepared using the polyimide.

Diamine compound is selenium (Se) and selenium dioxide (SeO _2), Tel runyum (Te), dioxide Tel runyum (TeO ₂₎ comprises a high polarizability element, such as a number, and the diamine compound in a benzene ring in accordance with one embodiment The chalcogen-based element of has an atom having a large molecular radius, and thus has the effect of minimizing the interaction between the polymer main chains, thereby lowering the high aromatic ring density. Polyimide and polyimide films produced using this as a monomer may exhibit high refractive index and excellent light transmittance. Since the diamine compound contains chalcogen, the structure may not be located on the same plane, and thus may have low birefringence.

In one embodiment, the polyimide film prepared using the chalcogen-based diamine may exhibit a refractive index (wavelength: about 637 nm) between 1.75 and 1.78. The refractive index can be, for example, 1.7618 to 1.7783.

In one embodiment, the polyimide film prepared using the chalcogen-based diamine may exhibit birefringence (wavelength: about 637 nm) between 0.005 and 0.0159. The birefringence is, for example, 0.0068 to 0.0159.

The transmittance (at 550 nm) of the polyimide film is 80 to 89.95%, for example, 80.60 to 89.69%.

The polyimide film according to one embodiment is very useful as an optical film when it has the above-described refractive index, transmittance, birefringence and dielectric constant characteristics.

The polyimide film according to one embodiment has a 10% weight reduction temperature of 510 ° C to 560 ° C. As used herein, the term "10% weight loss temperature" refers to the temperature when the total weight of the film or compound decreases to 90% of the total weight of the film or compound at room temperature. That is, it means the temperature when the weight is reduced by 10% compared to the total weight at room temperature.

In addition, the polymer as a curing reaction product of the chalcogen-based diamine and the curable monomer according to the present invention can be applied to a glass fiber composite film, a spectacle lens, a light diffusion film, a sealing material, an infrared camera, and the like.

The polyimide film according to one embodiment can be used for an optical film, and such an optical film is useful as a film and coating material when manufacturing a micro lens, a functional optical coating, and a high-brightness LED (Light Emitting Diode).

The polyimide film is useful as an LED encapsulant or substrate.

According to another embodiment, a nanocomposite film is provided.

The nanocomposite film may be prepared by mixing a polyamic acid and a filler titanium oxide to obtain a composition for forming a nanocomposite film, and then casting and heat-treating it. The nanocomposite film prepared according to this process contains polyimide and titanium oxide.

The conditions for casting and heat-treating the composition for forming the nanocomposite film are, for example, 30 minutes, 30 minutes at 150 ° C, 30 minutes at 200 ° C, and 30 minutes at 250 ° C.

The content of titanium oxide in the composition for forming a nanocomposite film is 0.1 to 10 parts by weight, for example, 0.5 to 3 parts by weight based on 100 parts by weight of the composition for forming a nanocomposite film.

The nanocomposite film is useful, for example, as a film and coating material when manufacturing microlenses, functional optical coatings, and high-brightness LEDs (Light Emitting Diodes).

Hereinafter, the present invention will be described with reference to the following examples, but the present invention is not limited to the following examples.

Example  1: chalcogenide Diamine  Produce

With reference to Reaction Scheme 1, 250 ml round bottom flask 100ml DMSO, 4- iodo-aniline are placed 5.0g, Tel runyum 2.91g, potassium hydroxide 2.58g was refluxed for 1 days at 155 ℃ ^o compound of the formula 1e 4.5 g was obtained.

[Scheme 1]

[Formula 1e]

Example  2: chalcogenide Diamine  Produce

With reference to Reaction Scheme 2, 100 ml round bottom flask 30ml DMSO, 4- iodo-aniline 3.2g, Tel runyum 0.705g, potassium carbonate 2.07g was placed one days under reflux at 155 ℃ ^o compound of the formula 1f 2.1g Was obtained.

[Scheme 2]

[Formula 1f]

Example  3: Formula 2a Polyamic  Produce

0.57 g of a compound of Formula 1e prepared according to Example 1 in a 10 ml round flask, 4,4 ′-[p-thiobis (phenylenesulfanyl)] diphthalic anhydride (3SDEA) represented by Formula 7 After adding 1.0g and 3.66g of N-methyl-2-pyrrolidone, the polyamic acid having a solid content of 30wt% containing a polyamic acid represented by Chemical Formula 2a is reacted for 24 hours at room temperature (25 ° C) under a nitrogen atmosphere. The solution was prepared. The intrinsic viscosity of the polyamic acid obtained by solidifying the polyamic acid solution was 0.393. (Measurement conditions: 30 ° C, N-methyl-2-pyrrolidone solution).

[Formula 7]

[Formula 2a]

In Formula 2a, n is 70 as a polymerization degree.

Example  4: Formula 2b Polyamic  Produce

0.435 g of a compound of formula 1f prepared according to Example 2 in a 10 ml round flask, 4,4 ′-[p-thiobis (phenylenesulfanyl)] diphthalic anhydride (3SDEA) represented by formula (7) After adding 1.0 and 5.936 g of N-methyl-2-pyrrolidone, a polyamic acid solution having a solid content of 30 wt% containing a polyamic acid represented by Formula 2b by reacting at room temperature (25 ° C.) for 24 hours under a nitrogen atmosphere. Was prepared. The intrinsic viscosity of the polyamic acid obtained by solidifying the polyamic acid solution was 0.406 (measurement condition: 30 ° C, N-methyl-2-pyrrolidone solution).

[Formula 2b]

In Formula 2b, n is 70 as a polymerization degree.

Example  5: Preparation of polyimide film represented by Chemical Formula 3a

After casting the polyamic acid solution according to Example 3 on the silicon substrate, respectively, the mixture was heated at 120 ° C for 30 minutes, 150 ° C for 30 minutes, 200 ° C for 30 minutes, and 250 ° C for 30 minutes to have a thickness of about 10 μm. A polyimide film containing a polyimide represented by the following Chemical Formula 3a was prepared.

[Formula 3a]

In Formula 3a, n is 70 as a polymerization degree.

Example  6: Preparation of polyimide film represented by Chemical Formula 3b

After casting the polyamic acid solution according to Example 4 on the silicon substrate, respectively, the mixture was heated at 120 ° C for 30 minutes, 150 ° C for 30 minutes, 200 ° C for 30 minutes, and 250 ° C for 30 minutes. A polyimide film containing a polyimide represented by Chemical Formula 3b was prepared.

[Formula 3b]

In Formula 3b, n is 70 as a polymerization degree.

Comparative example  1: Preparation of polyimide film

A polyimide film was prepared in the same manner as in Example 5, except that 4,4-oxydianiline (ODA) was used instead of the compound of Formula 1e.

Comparative example  2: Preparation of polyimide film

A polyimide film containing polyimide was prepared in the same manner as in Example 5, except that 4,4-thiodianiline (TDA) was used instead of the compound of Formula 1e.

Example  7: Preparation of nanocomposite films

After mixing 0.5 parts by weight of titanium oxide (the content of titanium oxide of 0.5 wt%) with 99.5 parts by weight of the compound of Formula 3b obtained in Example 4 to obtain a composition for forming a nanocomposite and casting it, 30 minutes at 120 ° C. , 30 minutes at 150 ° C, 30 minutes at 200 ° C, and 30 minutes at 250 ° C, to prepare a nanocomposite film containing polyimide and titanium oxide represented by the following formula 4b having a thickness of about 10 μm.

[Formula 4b]

Example  8: Preparation of nanocomposite film

A nanocomposite film containing the polyimide represented by Chemical Formula 4b and titanium oxide was prepared in the same manner as in Example 7, except that the content of titanium oxide was changed to 1.0 part by weight.

Example  9: Preparation of nanocomposite films

A nanocomposite film containing the polyimide represented by Chemical Formula 4b and titanium oxide was prepared in the same manner as in Example 7, except that the content of titanium oxide was changed to 3.0 parts by weight.

Evaluation example  1: Nuclear magnetic resonance analysis (NMR)

The NMR of the compound of Formula 1f prepared according to Example 1 was observed and is shown in FIGS. 1A and 1B. NMR analysis was performed using 600 MHz NMR spectrometer manufacturers (Agilent Technologies, Inc. and Bruker BioSpin Corp.).

Looking at the hydrogen NMR of Figure 1a, the chemical shift ( δ ) 7.49, the hydrogen peak of the aromatic ring represented by a, b, respectively in 6.57, 3.68 ppm at c, the hydrogen peak of the amine group appears, the compound of formula 1f The structure was confirmed.

Looking at the carbon NMR of Figure 1b, the chemical shift ( δ ) 146.20, 139.35, 116.46, 101.43 ppm peaks a, b, c, d appeared to confirm the structure of the compound of formula 1f.

NMR of the compound of Formula 1e prepared according to Example 1 was observed and is shown in FIGS. 2A and 2B. NMR analysis was performed using 600 MHz NMR spectrometer manufacturers (Agilent Technologies, Inc. and Bruker BioSpin Corp.).

Looking at the hydrogen NMR of Figure 2a, the chemical shift ( δ ) of 7.07, 6.46, respectively, the hydrogen peak of the aromatic ring represented by a, b, 3.67 ppm c shows the hydrogen peak of the amine group represented by the compound of formula 1e The structure was confirmed.

Looking at the carbon NMR of Figure 2b, the chemical shift ( δ ) peaks at a 145.85, 134.54, 119.51, 115.97 ppm a, b, c, d appeared to confirm the structure of the compound of formula 1e.

Evaluation example  2: Differential scanning calorimetry: DSC ) And Heat weight  analysis ( Thermogravimetric  analyzer: TGA ) analysis

The glass transition temperature of the polyimide was confirmed through differential scanning calorimetry (DSC) analysis of the polyimide films prepared according to Example 5, Example 6, and Comparative Example 1 and Comparative Example 2. And the heat resistance was measured through a thermogravimetric analyzer (TGA) of the polymer film, and the results are shown in Tables 1 and 3 and 4 below. Figure 3 shows the DSC analysis results of the polyimide, Figure 4 is a graph showing the TGA results of the polyimide

DSC analysis was performed using TA Instruments' Q20, which was measured at a heating rate of 5 per minute under a nitrogen atmosphere and confirmed by heating from room temperature to 300 ^° C. And TGA analysis was performed using TA Instruments' Q50 and was measured at a heating rate of 10 per minute under a nitrogen atmosphere, and confirmed by heating from room temperature to 800 ^° C.

division T _g (℃) T _5% (℃) T _10% (℃) Polyimide film of Example 5 183 407 422 Polyimide film of Example 6 185 394 402 Polyimide film of Comparative Example 1 210 439 452 Polyimide film of Comparative Example 2 212 438 452

In Table 1, T _g represents the glass transition temperature, and T _5% And T _10% represents a 5% weight reduction temperature and a 10% weight reduction temperature, respectively, and refers to a temperature when the total weight of the film decreases to 95% or 90% of the total weight of the film or compound at room temperature. That is, it means the temperature when the weight is reduced by 5% or 10% compared to the total weight at room temperature.

Referring to Table 1, it can be seen that the polyimide films of Examples 5 and 6 and the polyimide films of Comparative Example 1 and Comparative Example 2 both had a weight reduction of 10% at a temperature of 400 ° C. or higher, and glass transition. The temperature appeared to appear at temperatures above 180 ° C.

Evaluation example  3: refractive index of the polyimide film, By wavelength  Transmittance and UV blocking wavelength

Polyimide films prepared according to Examples 5 to 9 and Polyimides prepared according to Comparative Examples 1 and 2 were prepared using the polyamic acid solutions according to Examples 3 and 4 with UV-visible spectrometer. The transmittance and UV blocking wavelength for each wavelength were measured, and the refractive index and birefringence were analyzed with a prism coupler, and the results are shown in Table 2.

division Refractive index
at 637 nm Transmittance at 550nm Birefringence
at 637 nm Example 5 1.7783 81.60 0.0068 Example 6 1.7618 89.69 0.0146 Comparative Example 1 1.7128 88.48 0.0049 Comparative Example 2 1.7384 90.87 0.0106 Example 7 1.7624 81.98 0.0133 Example 8 1.7688 80.60 0.0161 Example 9 1.7738 72.05 0.0159

Referring to Table 2, all of the polyimide films prepared according to Examples 5 and 6 showed a refractive index of 1.75 or more, indicating excellent refractive index, and thus it was confirmed that optical properties were excellent. And the polyimide films prepared using the polyamic acid solutions according to Examples 5 and 6 exhibited excellent birefringence of around 0.010.

The refractive index index characteristics of the polyimide films of Examples 5 and 6 and the polyimide films of Comparative Examples 1 and 2 are shown in FIG. 5. Referring to this, it was found that the polyimide films of Examples 5 and 6 had better refractive index characteristics than the polyimide films of Comparative Examples 1 and 2.

In addition, the refractive index index properties of the titanium oxide nanocomposite films prepared in Examples 7 to 9 are shown in FIG. 7. It was found that the polyimide film of Example 5 had better refractive index properties than the titanium oxide nanocomposite films of Examples 7 to 9.

In particular, in the case of the polyimide film prepared in Example 5, it can be confirmed that it has the highest refractive index of 1.778 at 637 nm, because it contains a large amount of tellurium with a high polarization rate.

In addition, the transmittances of the polyimide films of Examples 5 and 6 and the polyimide films prepared according to Comparative Examples 1 and 2 are shown in FIG. 6 together, and the polyimide films of Example 6 and the nanocomposites of Examples 7 to 9 8 shows the transmittance of the film. Through this, it was found that the polyimide films of Examples 5 and 6 and the titanium oxide nanocomposite films of Examples 7 to 9 all had excellent optical properties.

The embodiments of the present invention described above should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and a person having ordinary knowledge in the technical field of the present invention can improve and modify the technical spirit of the present invention in various forms. Accordingly, such improvements and modifications will fall within the protection scope of the present invention as long as it is apparent to those skilled in the art.

Claims (12)

A polyamic acid that is a polymer represented by the following formula 2a or a polymer represented by the following formula 2b:
[Formula 2a]

In Formula 2a, n is an integer of 10 to 1,000,
[Formula 2b]

In Formula 2b, n is an integer of 10 to 1,000. delete delete delete A polyimide which is a product of the imidation reaction of the polyamic acid of claim 1,
The polyimide is a polymer represented by the following formula 3a or a polymer represented by the following formula 3b.
[Formula 3a]

[Formula 3b]

In Formula 3a and Formula 3b, n is an integer of 10 to 1,000. delete delete A polyimide film comprising the polyimide of claim 5. The method of claim 8,
The polyimide film has a refractive index (wavelength: 637 nm) of 1.75 to 1.78, a birefringence (wavelength: 637 nm) of 0.005 to 0.0159, and a transmittance (at 550 nm) of 80 to 89.95%. The method of claim 8,
The polyimide film is a polyimide film having a 10% weight loss temperature of 400 to 450 ° C.

delete delete

Images