JP2020523427A - Highly transparent polyimide precursor resin composition having excellent optical characteristics and phase delay characteristics, a method for producing a polyimide resin film using the same, and a polyimide resin film produced thereby - Google Patents

Abstract

The present invention has a low coefficient of thermal expansion, does not cause clouding phenomenon during solution casting, polyimide precursor resin composition excellent in optical characteristics and phase delay characteristics while having excellent high transparency, The present invention relates to a method for producing a polyimide resin film used and a polyimide resin film produced thereby. INDUSTRIAL APPLICABILITY The present invention can be effectively used for flexible display substrate materials and semiconductor materials. [Selection diagram] None

Description

The present invention has a low coefficient of thermal expansion, does not occur clouding phenomenon during solution casting, polyimide precursor resin composition excellent in optical characteristics and phase retardation characteristics while having excellent high transparency, The present invention relates to a method for producing a polyimide resin film used and a polyimide resin film produced by the method, and can be effectively used for a flexible display substrate material and a semiconductor material.

The substrate material of the flexible display, which has been attracting attention as a next-generation display device, must be light, non-tearable, flexible, and easy to process without any restrictions on its shape.
Not only is it lighter than the glass substrate currently used as a display substrate material, it is not fragile and easy to manufacture, and the polymer material that can produce a thin film is the most suitable for realizing a flexible display. Has attracted attention as a material.

Currently, flexible devices generally use organic light emitting diode (OLED) displays, and TFT processes at high process temperatures (300-500° C.) are used. Polymer materials that can withstand such high process temperatures are very limited. Therefore, recently, there has been an increasing interest in polyimide (PI) resins, which are excellent in heat resistance and dimensional stability, as candidates for plastic substrates for transparent flexible displays.

In order to apply a flexible display substrate, in addition to excellent heat resistance and dimensional stability, excellent transparency, a low refractive index, and a phase delay property for ensuring a display viewing angle are essential. However, a normal polyimide has a brown or yellow color, which is mainly due to an electron transfer complex (Charge Transfer Complex, CTC) due to intra-molecular and inter-molecular interactions of the polyimide. It is a cause. This lowers the light transmittance of the polyimide thin film, increases the birefringence, and causes a problem of narrow viewing angle. As a related prior art, Korean Patent Publication No. 2015-0046463 discloses polyamic acid (polyamide acid) using various acid dianhydrides and diamine compounds so as to have colorless and transparent birefringence and retardation properties. The present invention provides a method for producing a polyimide film by producing a polyamic acid) solution.
On the other hand, an organic light emitting diode (OLED) display is manufactured by a method in which a glass substrate is coated with a resin, then thermally cured to form a film, and peeled from the glass substrate after several steps. When a glass substrate is coated with resin during such a manufacturing process, resin stability at room temperature is important. If the stability of the resin is not ensured, a uniform film may not be formed after curing due to hardening of the resin, a white turbidity phenomenon due to moisture, and the like, which may eventually lead to product defects.

Therefore, for application as a display material, the combination of the optimal monomer and organic solvent has resin stability at room temperature, no hue is expressed, and the birefringence is lowered to provide excellent phase delay characteristics. It is necessary to develop colorless and transparent polyimide resin.

Therefore, the present inventors, in order to solve the above problems, in the production of a highly transparent polyimide film excellent in optical characteristics and phase retardation characteristics, the composition of the aromatic diamine compound containing a novel diamine compound, and white turbidity By finding a composition of an organic solvent in which a phenomenon does not occur, a polyimide precursor resin composition having high transparency, excellent optical characteristics and phase delay characteristics as compared with conventional polyimide films was discovered, and the present invention was completed. It was

Therefore, an object of the present invention is to provide a polyimide precursor resin composition that can be used as a highly transparent flexible display substrate material having excellent optical characteristics and phase delay characteristics.
Another object of the present invention is to provide a method for producing a polyimide resin film using the composition.
In addition, the present invention is based on a thickness of 10 to 15 μm of the film produced by the above production method, birefringence of 0.01 or less, in-plane retardation (Ro) of 1 nm or less, and thickness-direction retardation ( To provide a polyimide resin film having an Rth of 100 nm or less, a turbidity (Haze) of 1.0 or less, a transmittance (Transmittance) of 88% or more, and a yellowness (Yellow Index, YI) of 7 or less. Has that purpose.

The present invention provides a polyimide precursor resin composition containing a diamine component, an acid dianhydride compound, and an organic solvent, wherein the diamine component is 2,2-bis[4-(4-amino) represented by the following Chemical Formula 1. -2-Trifluoromethylphenoxy)-phenyl]propane (BATP), 1,1-bis[4-4-amino-2-trifluoromethylphenoxy]-phenyl]-1-phenyl- represented by the following chemical formula 2 Ethane (BATPPE), 4,4′-bis(4-amino-2-trifluoromethylphenoxy)phenyl (BATPP) represented by the following chemical formula 3, and 4,4′-bis( represented by the following chemical formula 4 A highly transparent polyimide precursor excellent in optical characteristics and phase delay characteristics, characterized by containing at least one aromatic diamine selected from the group consisting of 4-amino-2-trifluoromethylphenoxy)biphenyl (BATPB). A body resin composition is provided.

In the present invention, the aromatic diamine compound represented by Chemical Formulas 1 to 4 may be included in an amount of 5 to 30 mol% based on the total content of diamine components.
In the present invention, the diamine component is 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB), 4,4-oxydianiline (ODA), 4,4-methylenedianiline. (MDA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), p-cyclohexanediamine (pCHDA), p-xylylenediene. Amine (pXDA), m-xylylenediamine (mXDA), m-cyclohexanediamine (mCHDA), 4,4′-diaminodiphenylsulfone (DDS), 2,2-bis[4-(4-aminophenoxy)phenyl] One or more selected from the group consisting of -1,1,1,3,3,3-hexafluoropropane (BAFP), and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP). Can also be included.
In the present invention, the organic solvent may be a mixture of gamma-butyrolactone (GBL) and N-methyl-2-pyrrolidone (NMP), or gamma-butyrolactone (GBL) and 3-methoxy-N,N-dimethylpropanamide (DMPA). ), or 3-methoxy-N,N-dimethylpropanamide (DMPA) alone.
In the present invention, the amount of the organic solvent used is 30 to 70 mol% of gamma-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) or 3-methoxy-N,N-dimethylpropanamide (DMPA) 70. It can also be -30 mol%.
The present invention also provides a method for producing a transparent polyimide resin film, which comprises heat-treating a polyamic acid solution produced using the composition to produce a film.
In the present invention, the polyamic acid solution uses an organic solvent content based on a solid content content of 10 to 40% by weight, and mixes a diamine component of 95 to 100 mol% and an acid dianhydride compound of 100 to 105 mol%. It can also be manufactured.
In the present invention, it is also effective that the polyamic acid solution has a viscosity of 1,000 to 10,000 cP.
Further, in the present invention, the transmittance at a wavelength of 532 nm is 88% or more, and the yellow index (Yellow Index, Y.I.) at a wavelength of 532 nm is based on a thickness of 10 to 15 μm of the film produced by the above production method. Provided is a polyimide resin film having a birefringence of 7 or less, a birefringence of 0.01 or less, and a retardation (Rth) in the thickness direction of 100 or less.

According to the present invention, as compared with the conventional polyamic acid solution, there is no clouding phenomenon during solution casting, the resin stability at room temperature is excellent, and during the production of a film by thermosetting, excellent mechanical properties and optical properties while being transparent. Since it provides phase delay characteristics and heat resistance characteristics, it can be effectively used for flexible display substrate materials, semiconductor materials and the like.

The polyimide precursor resin composition of the present invention (hereinafter, referred to as “polyamic acid composition”) has an aromatic diamine component containing a novel specific diamine compound for improving optical characteristics and phase retardation characteristics, and has a white turbidity phenomenon. It is characterized in that the composition of the organic solvent that does not generate and the use amount thereof are optimized to provide a polyimide resin film having excellent optical characteristics and phase delay characteristics and having high transparency. The polyimide precursor composition according to the present invention, that is, a “polyamic acid composition” means a composition used for producing a polyamic acid solution used for producing a polyimide resin film.

Specifically, the polyamic acid composition according to the present invention is a polyimide precursor resin composition containing a diamine component, an acid dianhydride compound, and an organic solvent, wherein the diamine component is 2,2-bis[4-( 4-Amino-2-trifluoromethylphenoxy)-phenyl]propane (BATP), 1,1-bis[4-4-amino-2-trifluoromethylphenoxy]-phenyl]-1-phenyl-ethane (BATPPE) , 4,4′-bis(4-amino-2-trifluoromethylphenoxy)phenyl (BATPP) and 4,4′-bis(4-amino-2-trifluoromethylphenoxy)biphenyl (BATPB) below. By containing at least one aromatic diamine selected from the group, it has excellent light transmittance and phase delay characteristics. Each component is specifically described as follows.

(A) Diamine component The diamine component in the present invention is 2,2-bis[4-(4-amino-2-trifluoromethylphenoxy)-phenyl]propane (BATP) represented by the following chemical formula 5 and the following chemical formula 6 1,1-bis[4-4-amino-2-trifluoromethylphenoxy]-phenyl]-1-phenyl-ethane (BATPPE) represented by, and 4,4′-bis( represented by Chemical Formula 7 below. From the group consisting of 4-amino-2-trifluoromethylphenoxy)phenyl (BATPP) and 4,4′-bis(4-amino-2-trifluoromethylphenoxy)biphenyl (BATPB) represented by the following chemical formula 8. It contains one or more aromatic diamines selected.

Here, the aromatic diamine compound represented by Chemical Formulas 5 to 8 preferably contains 5 to 30 mol% of the total content of the diamine components. If the aromatic diamine compound represented by Chemical Formulas 5 to 8 is less than 5 mol %, there is a limit to the improvement of birefringence and retardation properties, and if it exceeds 30 mol %, there is a limit due to the deterioration of thermal properties. Therefore, it is preferable to include the above range.

The diamine component may include a non-fluorinated aromatic diamine monomer as well as a fluorinated aromatic diamine monomer such as TFMB. Specifically, the aromatic diamine component is 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 4,4-oxydianiline (ODA), 4,4-methylenedi Aniline (MDA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), p-cyclohexanediamine (pCHDA), p-xylyl. Diamine (pXDA), m-xylylenediamine (mXDA), m-cyclohexanediamine (mCHDA), 4,4′-diaminodiphenylsulfone (DDS), 2,2-bis[4-(4-aminophenoxy)phenyl ]-1,1,1,3,3,3-hexafluoropropane (BAFP), and one selected from the group consisting of 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) The above can be included.

(B) Acid dianhydride compound The aromatic acid dianhydride compound of the present invention includes a fluorinated aromatic dianhydride, a non-fluorinated aromatic dianhydride, or a mixture thereof.
When the fluorinated aromatic dianhydride and the non-fluorinated aromatic dianhydride are mixed and used, the optical properties and heat resistance of the polyimide film can be simultaneously improved. By the fluorine substituent of the fluorinated aromatic dianhydride, a polyimide film having excellent optical properties can be produced, and a polyimide film having excellent heat resistance due to the rigid molecular structure of the non-fluorinated aromatic dianhydride can be produced. It can be manufactured.

Specifically, the fluorinated aromatic dianhydride is an aromatic dianhydride in which a fluorine substituent is introduced, and is, for example, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (4 4′-(Hexafluoroisopropylidene) diphthalic anhydride, 6FDA)), and 4,4′-(4,4′-hexafluoroisopropylidenediphenoxy)bis-(phthalic anhydride) (4,4′-(4,4) One or more kinds selected from the group consisting of'-Hexafluoroisopropylidene diphenoxy)bis-(phthalic anhydride, 6-FDPDA) can be used.

Next, the non-fluorinated aromatic dianhydride is an aromatic dianhydride in which no fluorine substituent is introduced, and is pyromellitic dianhydride (PMDA), 3, 3′, 4, 4'-biphenyltetracarboxylic dianhydride (3,3'4,4'-biphenyltetraccarboxylic acid dianhydride, BPDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (3,3', 4,4'-benzophenonetetracarboxy dianhydride, BTDA), 4,4' oxydiphthalic anhydride (4,4'-oxydiphthalic anhydride, ODPA), 2,2-bis[4-3,4-dicarboxyphenoxy]phenyl]propane Anhydrous (2,2-Bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, BPADA), 3,3′,4,4′-diphenylsulfone tetracarboxylic acid anhydride (3,3′,4 , 4'-Diphenyl sufone tetracarboxy dianhydride (DSDA), and ethylene glycol bis(4-trimellitate anhydrous) (the group 1 or more selected from TMEG) can be selected from the group consisting of TM1). ..

Preferably, in the present invention, when the compound represented by Chemical Formulas 5 to 8 is included as the diamine component, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) is included as the acid dianhydride component. 4,4'-(4,4'-hexafluoroisopropylidenephenoxy)bis-(phthalic anhydride) (6-FDPDA), cyclobutanetetracarboxylic dianhydride (CBDA), 3,3',4' ,4-biphenyltetracarboxylic dianhydride (s-BPDA), bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTDA), 4- (2,5-Dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA), pyromellitic dianhydride (PMDA), benzophenone tetracarboxylic One or more selected from the group consisting of acid dianhydride (BTDA) and oxydiphthalic dianhydride (ODPA) can be used.

(C) Organic solvent The organic solvent in the present invention is m-cresol, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), diethyl. A polar solvent such as acetate (DEA), 3-methoxy-N,N-dimethylpropanamide (DMPA), a low boiling solvent such as tetrahydrofuran (THF), chloroform or a low solvent such as gamma-butyrolactone (GBL). A water absorbing solvent can be used.

Specifically, the organic solvent used in the present invention plays an important role in improving the white turbidity, but in order to improve the white turbidity during solution casting at room temperature, gamma-butyrolactone (GBL) and N-methyl-2 are used. -Pyrrolidone (NMP) mixture, or gamma-butyrolactone (GBL) and 3-methoxy-N,N-dimethylpropanamide (DMPA) mixture, or 3-methoxy-N,N-dimethylpropanamide (DMPA) alone Is preferably used.

At this time, the amount of the organic solvent used is N-methyl-2-pyrrolidone (NMP) or 3-methoxy-N,N-dimethylpropanamide (DMPA) 70 with respect to 30 to 70 mol% of gamma-butyrolactone (GBL). It is preferable to use ˜30 mol %. More preferably, 30 to 50 mol% of N-methyl-2-pyrrolidone (NMP) or 3-methoxy-N,N-dimethylpropanamide (DMPA) is used with respect to 50 to 70 mol% of gamma-butyrolactone (GBL). be able to. Alternatively, 100 mol% of gamma-butyrolactone (GBL) alone can be used.

(D) Reaction catalyst The present invention may further include a reaction catalyst in addition to the above components. The reaction catalyst of the present invention may further include at least one selected from the group consisting of trimethylamine, Xylene, pyridine, and quinoline depending on the reactivity, but is not necessarily limited thereto. Not done. In addition, the polyamic acid composition may be added with a plasticizer, an antioxidant, a flame retardant, a dispersant, a viscosity modifier, a leveling agent, etc., if necessary, within a range that does not significantly impair the objects and effects of the present invention. Agents can be included in small amounts.

Incidentally, the polyamic acid composition according to the present invention, a diamine component, an acid dianhydride compound, an organic solvent, and a polyamic acid solution obtained by polymerization using a reaction catalyst are relative to the total weight of the polyamic acid solution. The solid content is 10 to 40% by weight, preferably 10 to 25% by weight. When the solid content is less than 10% by weight, there is a limit in increasing the thickness of the film during the film production, and when the solid content exceeds 40% by weight, there is a limit in adjusting the viscosity of the polyamic acid resin. Therefore, it is formed within the above range.

Specifically, the polyamic acid solution uses an organic solvent content based on a solid content content of 10 to 40% by weight, and mixes a diamine component of 95 to 100 mol% and an acid dianhydride compound of 100 to 105 mol%. It is preferable that the reaction is performed for 12 to 48 hours under the temperature condition of 10 to 70°C. At this time, the reaction temperature can be changed depending on the monomers used.
Here, it is preferable that the acid dianhydride compound is added in an amount of 5 mol% less to 5 mol% greater than the aromatic diamine component to reach the target viscosity. This is to ensure stability.

The polyamic acid solution produced by such a reaction preferably has a viscosity in the range of 1,000 to 10,000 cP. When the viscosity is less than 1,000 cP, there is a problem in obtaining an appropriate level of film thickness, and when it exceeds 10,000 cP, there is a problem in uniform coating and effective solvent removal. Is preferred.

In the present invention, the transparent polyimide film and its manufacturing method are as follows. The present invention provides a transparent polyimide film produced by thermal imidization of a polyamic acid solution produced using the polyamic acid composition described above. The polyamic acid solution according to the present invention has a viscosity and is heat-treated after coating a glass substrate by a suitable method during film production. As the coating method, a known conventional method can be used without limitation, for example, spin coating, dip coating, solvent casting, slot die coating, spraying. Examples include, but are not limited to, coating (Spray coating).

The polyamic acid composition of the present invention can be heat-treated in a high temperature convection oven to produce a polyimide film. At this time, the heat treatment is performed in a nitrogen atmosphere at 100 to 450° C. for 30 to 120 minutes. More preferably, it is preferable to obtain a film under temperature and time conditions of 100° C./30 minutes, 220° C./30 minutes, 350° C./30 minutes. This is because of the imidization that can appropriately remove the solvent and maximize the characteristics.

Since the transparent polyimide film of the present invention is produced using the polyamic acid composition, it exhibits high transparency and at the same time has a low coefficient of thermal expansion.
The polyimide film of the present invention has a birefringence of 0.01 or less, a plane direction retardation (Ro) of 1.0 nm or less, and a thickness direction retardation (Rth) of 100 nm based on a film thickness of 10 to 15 μm. Hereinafter, the turbidity (Haze) is 1.0 or less, the transmittance (Transmittance) is 85% or more, preferably 88% or more, and the yellowness (Yellow Index, YI) is 7 or less, preferably 5 or less. ..

INDUSTRIAL APPLICABILITY The polyimide film of the present invention can be used in various fields, and in particular, OLED displays, liquid crystal element displays, TFT substrates, flexible printed circuit boards, and flexible (Flexible) that require high transparency and phase delay characteristics. It can be provided as an OLED surface illumination substrate, a flexible display substrate such as a substrate material for electronic paper, and a protective film.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are intended to illustrate the invention and not to limit the scope of the invention.
In Table 1, the units of the numbers of acid dianhydride and diamine are molar parts and are approximate values.

Comparative Example 1
As the composition shown in Table 2 below, 32.329 g (0.101 mole) of TFMB, which is a diamine-based monomer, was added to 440.08 g of DMPA, which is an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. It was After that, 45.333 g (0.102 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at which time the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,500 cP.

Example 1
As compositions shown in Table 2 below, TFMB 30.257 g (0.094 mole), which is a diamine-based monomer, and BATP 2.743 g (0.005 mole) were added to DMPA 440.08 g, which is an organic solvent, and a nitrogen atmosphere was added. The solution was dissolved at room temperature for 30 minutes to 1 hour. Then, 44.661 g (0.100 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at this time, the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,800 cP.

Example 2
As compositions shown in Table 2 below, 28.215 g (0.088 mole) of TFMB, which is a diamine-based monomer, and 5.400 g (0.010 mole) of BATP, were placed in 440.08 g of DMPA as an organic solvent, and a nitrogen atmosphere was added. The solution was dissolved at room temperature for 30 minutes to 1 hour. Then, 44.047 g (0.099 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at which time the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,500 cP.

Example 3
As the composition shown in Table 2 below, 20.713 g (0.065 mole) of TFMB which is a diamine-based monomer and 15.292 g (0.028 mole) of BATP were put in DMPA440.08 g which is an organic solvent, and a nitrogen atmosphere, It was dissolved at room temperature for 30 minutes to 1 hour. Then, 41.657 g (0.094 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at which time the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,600 cP.

Example 4
As the composition shown in Table 2 below, 30.136 g (0.094 mole) of TFMB, which is a diamine-based monomer, and 3.043 g (0.005 mole) of BATPPE were placed in 440.08 g of an organic solvent DMPA, a nitrogen atmosphere, and room temperature. It was dissolved for 30 minutes to 1 hour. Then, 44.483 g (0.100 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at this time, the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,700 cP.

Example 5
As the composition shown in Table 2 below, 28.09 g (0.087 mole) of TFMB, which is a diamine-based monomer, and 5.970 g (0.010 mole) of BATPPE were placed in an organic solvent DMPA 440.08 g, and the mixture was placed in a nitrogen atmosphere at room temperature. It was dissolved for 30 minutes to 1 hour. Then, 44.483 g (0.100 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at this time, the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,600 cP.

Example 6
As compositions shown in Table 2 below, TFMB 20.270 g (0.063 mole), which is a diamine-based monomer, and BATPPE 16.665 g (0.027 mole) were placed in an organic solvent DMPA 440.08 g, and the mixture was placed in a nitrogen atmosphere at room temperature. It was dissolved for 30 minutes to 1 hour. After that, 40.727 g (0.092 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at this time, the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,600 cP.

Example 7
As the composition shown in Table 2 below, 30.446 g (0.095 mole) of TFMB, which is a diamine-based monomer, and 2.165 g (0.005 mole) of BATPP were placed in 440.08 g of an organic solvent, DMPA, and placed in a nitrogen atmosphere at room temperature. It was dissolved for 30 minutes to 1 hour. Then, 45.051 g (0.101 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at which time the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,800 cP.

Example 8
As compositions shown in Table 2 below, 21.626 g (0.068 mole) of TFMB, which is a diamine-based monomer, and 12.520 g (0.029 mole) of BATPP, were placed in 440.08 g of organic solvent DMPA, and the mixture was placed in a nitrogen atmosphere at room temperature. It was dissolved for 30 minutes to 1 hour. Then, 43.515 g (0.098 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at which time the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measuring with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,300 cP.

Example 9
As the composition shown in Table 2 below, 30.330 g (0.095 mole) of TFMB, which is a diamine-based monomer, and 2.539 g (0.005 mole) of BATPB were put in 440.08 g of DMPA as an organic solvent, and the mixture was placed in a nitrogen atmosphere at room temperature. It was dissolved for 30 minutes to 1 hour. Then, 44.792 g (0.101 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at this time, the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,700 cP.

Example 10
As the composition shown in Table 2 below, 21.069 g (0.066 mole) of TFMB, which is a diamine-based monomer, and 14.364 g (0.028 mole) of BATPB were placed in 440.08 g of an organic solvent, DMPA, and placed in a nitrogen atmosphere at room temperature. It was dissolved for 30 minutes to 1 hour. Then, 42.228 g (0.095 mole) of 6FDA, which is a dianhydride monomer, was added and stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30° C., at this time, the solid content was the reaction solvent). 15% by weight, based on the total weight of. As a result of measurement with a viscosity measuring device (Brookfield DV2T, SC4-27), the viscosity was 4,800 cP.

Experimental Example: Measurement of physical properties (1) Evaluation of room temperature clouding phenomenon The polyamic acid solutions prepared in Examples 1 to 10 and Comparative Example 1 were dropped on a glass plate and a spin coater was used to obtain a constant thickness (15% solid content standard). When the thickness of the solution was 100 μm, the temperature was changed to 15 μm after the heat treatment, and the solution was allowed to stand for 30 minutes in an atmosphere having a temperature of 25° C. and a humidity of >90%, and then a white turbid phenomenon was observed. The white turbidity occurrence level was numerically evaluated as 0 to 5 (0: no occurrence, 5: large occurrence).

(2) Film Production and Evaluation of Physical Properties A polyamic acid solution was coated on a glass plate using a spin coater, and then heat-treated in a high temperature convection oven. The heat treatment was carried out in a nitrogen atmosphere to obtain a final film under the temperature and time conditions of 100° C./30 minutes, 220° C./30 minutes, 350° C./30 minutes. Physical properties of the film thus obtained were measured by the following methods, and the results are shown in Table 1 below.

(A) Transmittance
The transmittance was measured at 532 nm using a UV-Vis NIR Spectrophotometer (Shimadsu, UV-1800).
(B) Birefringence and Retardation
Using a refractive index measuring device (Metricon, Prism Coupler 2010M), TE (Transverse Electric) mode and TM (Transverse Magnetic) mode were measured at 532 nm, and the value of (TE value)-(TM value) was used as a birefringence value. The phase difference (Ro) and the phase difference (Rth) in the thickness direction of 532 nm were measured and calculated using a phase difference measuring device (RETs-100, Otsuka Co.).
(C) Yellowness index (Yellowness Index, YI)
It measured using the color difference meter (LabScan XE).
(D) Turbidity (haze)
It measured using the haze meter (TOYOSEIKI company, Haze-GARD).

As shown in Table 1, as compared with Comparative Example 1, in the case of Examples 1 to 10, when a predetermined amount of the novel diamine monomer BATPP, BATPPE, BATP, BATPB is contained, a high transmittance is shown. It can be confirmed that the phase delay characteristics are excellent. In addition, it can be seen that the transmittance, turbidity, yellowness, etc. required by the polyimide film were satisfied, and the white turbidity phenomenon did not occur.

Accordingly, the polyamic acid precursor resin solution produced according to the present invention has a transmittance of 88% or more at a wavelength of 532 nm and a yellowness index (Yellow Index, Y.I.) based on a film thickness of 10 to 15 μm. It is possible to provide a transparent polyimide film having a birefringence of 7 or less, a birefringence of 0.01 or less, and a retardation (Rth) in the thickness direction of 100 or less.

Therefore, the polyimide film manufactured according to the present invention satisfies the excellent light transmittance and phase delay characteristics, and has a display for OLED, a display for liquid crystal device, a TFT substrate, a flexible printed circuit board, a flexible OLED surface lighting substrate, The present invention can be widely applied to flexible display substrates such as electronic paper substrate materials and protective films.

Claims (9)

A diamine component, an acid dianhydride compound, and a polyimide precursor resin composition containing an organic solvent,
The diamine component is 2,2-bis[4-(4-amino-2-trifluoromethylphenoxy)-phenyl]propane (BATP) represented by the following chemical formula 1, and 1,1 represented by the following chemical formula 2. -Bis[4-4-amino-2-trifluoromethylphenoxy]-phenyl]-1-phenyl-ethane (BATPPE), 4,4'-bis(4-amino-2-tri) represented by the following chemical formula 3 One or more aromas selected from the group consisting of fluoromethylphenoxy)phenyl (BATPP) and 4,4′-bis(4-amino-2-trifluoromethylphenoxy)biphenyl (BATPB) represented by the following chemical formula 4. A highly transparent polyimide precursor resin composition excellent in optical characteristics and phase retardation characteristics, which comprises a group diamine.

The polyimide precursor resin composition according to claim 1, wherein the aromatic diamine compound represented by Chemical Formulas 1 to 4 contains 5 to 30 mol% of the total content of diamine components. The diamine component is 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 4,4-oxydianiline (ODA), 4,4-methylenedianiline (MDA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), p-cyclohexanediamine (pCHDA), p-xylylenediamine (pXDA) , M-xylylenediamine (mXDA), m-cyclohexanediamine (mCHDA), 4,4′-diaminodiphenylsulfone (DDS), 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1. , 1,3,3,3-hexafluoropropane (BAFP), and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP). The polyimide precursor resin composition according to claim 1, which is characterized. The organic solvent is a mixture of gamma-butyrolactone (GBL) and N-methyl-2-pyrrolidone (NMP), or a mixture of gamma-butyrolactone (GBL) and 3-methoxy-N,N-dimethylpropanamide (DMPA), Or it is 3-methoxy-N,N- dimethylpropanamide (DMPA) single substance, The polyimide precursor resin composition of Claim 1 characterized by the above-mentioned. The amount of the organic solvent used is 30-70 mol% of gamma-butyrolactone (GBL) N-methyl-2-pyrrolidone (NMP) or 3-methoxy-N,N-dimethylpropanamide (DMPA) 70-30. It is mol%, The polyimide precursor resin composition of Claim 1 characterized by the above-mentioned. A method for producing a polyimide resin film, which comprises subjecting a polyamic acid solution produced by using the composition according to claim 1 to heat treatment to produce a film. The polyamic acid solution is prepared by mixing 95 to 100 mol% of the diamine component and 100 to 105 mol% of the acid dianhydride compound using the organic solvent content based on the solid content of 10 to 40% by weight. The method for producing a polyimide resin film according to claim 6, which is characterized in that. The method for producing a polyimide resin film according to claim 6, wherein the polyamic acid solution has a viscosity of 1,000 to 10,000 cP. The transmittance at a wavelength of 532 nm is 88% or more, and the yellow index (Yellow Index, YI) at a wavelength of 532 nm is 7 or less, based on the thickness of the film manufactured by the method of claim 6 of 10 to 15 μm, and is 7 or less. A polyimide resin film having a refraction of 0.01 or less and a retardation (Rth) in the thickness direction of 100 or less.