JP6935623B2 - A 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 by the same. - Google Patents

Description

The present invention is a polyimide precursor resin composition having a low thermal expansion coefficient, no cloudiness phenomenon during solution casting, excellent high transparency, and excellent optical characteristics and phase delay characteristics. It relates to the method for producing the polyimide resin film used and the polyimide resin film produced by the method, and can be usefully used for a flexible display substrate material and a semiconductor material.

The substrate material of a flexible display, which is attracting attention as a next-generation display device, must be light, unbreakable, flexible, easy to process, and not restricted in form.
A polymer material that is not only lighter than the glass substrate currently used as a display substrate material, is not torn, is easy to manufacture, and can produce a thin film, is optimal for the realization of flexible displays. It is attracting attention as a material.

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

For the application of the flexible display substrate, in addition to excellent heat resistance and dimensional stability, excellent transparency, low refractive index, and phase delay characteristics for ensuring the display viewing angle are indispensable. However, ordinary polyimide has a brown or yellow color, which is mainly an electron transfer complex (Change Transfer Complex, CTC) due to intramolecular and intermolecular interactions of polyimide. Cause. This lowers the light transmittance of the polyimide thin film, increases birefringence, and causes the problem of a narrow viewing angle. As a related prior art, Korean Publication No. 2015-0046463 uses various acid dianhydrides and diamine compounds to make polyamic acids (polyimides and diamine compounds so as to have improved compound refraction and phase difference characteristics while being colorless and transparent. Provided is a method for producing a polyamic acid) solution and using the solution to produce a polyimide film.
On the other hand, an organic light emitting diode (OLED) display is manufactured by applying a resin to a glass substrate, heat-curing it to form a film, and peeling it off from the glass substrate after several steps. When a resin is applied to a glass substrate during such a manufacturing process, resin stability at room temperature is important. If the stability of the resin is not ensured, a uniform film will not be formed after curing due to the lumping of the resin, the white turbidity phenomenon due to moisture, and the like, which may eventually lead to defects in the product.

Therefore, for application as a display material, it has resin stability at room temperature, does not develop hue, lowers the birefringence, and has excellent phase delay characteristics, depending on the optimum combination of monomer and organic solvent. , It is necessary to develop a colorless and transparent polyimide resin.

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

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.
Further, in the present invention, the birefringence is 0.01 or less, the phase difference (Ro) in the plane direction is 1 nm or less, and the phase difference in the thickness direction is based on the thickness of the film produced by the production method of 10 to 15 μm. Provided is a polyimide resin film having a Rth) of 100 nm or less, a turbidity (Haze) of 1.0 or less, a transmittance of 88% or more, and a yellowness (Yellow Index, YI) of 7 or less. Has its purpose.

In the present invention, in a polyimide precursor resin composition containing a diamine component, an acid dianhydride compound, and an organic solvent, the diamine component is a 2,2-bis [4- (4-amino4-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 Chemical Formula 2 below. Ethane (BATPPE), 4,4'-bis (4-amino-2-trifluoromethylphenoxy) phenyl (BATPP) represented by Chemical Formula 3 below, and 4,4'-bis (4-amino-2-trifluoromethylphenoxy) phenyl (BATPP) represented by Chemical Formula 4 below. 4-Amino-2-trifluoromethylphenoxy) A highly transparent polyimide precursor having excellent optical and phase delay characteristics, which comprises one or more aromatic diamines selected from the group consisting of biphenyl (BATBP). A body resin composition is provided.

In the present invention, the aromatic diamine compounds represented by the chemical formulas 1 to 4 can also contain 5 to 30 mol% with respect to the total content of the 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 (mMADA), p-cyclohexanediamine (pCHDA), p-xylylene Amine (pXDA), m-xylylene diamine (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 is 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) and 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 by using the above composition to produce a film.
In the present invention, the polyamic acid solution uses an organic solvent content based on a solid content of 10 to 40% by weight, and a diamine component of 95 to 100 mol% and an acid dianhydride compound of 100 to 105 mol% are mixed. 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 yellowness (Yellow Index, YI.) at a wavelength of 532 nm is based on the thickness of the film produced by the above-mentioned production method of 10 to 15 μm. Provided is a polyimide resin film having 7 or less, a compound refraction of 0.01 or less, and a phase difference (Rth) in the thickness direction of 100 or less.

According to the present invention, as compared with a conventional polyamic acid solution, there is no clouding phenomenon during solution casting, resin stability at room temperature is excellent, and when a film is produced by thermosetting, it is transparent but has excellent mechanical and optical properties. Since it provides phase delay characteristics and heat resistance characteristics, it can be usefully 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 light characteristics and phase delay characteristics, and a cloudiness phenomenon. It is characterized in that it provides a polyimide resin film having excellent optical characteristics and phase delay characteristics and high transparency by optimizing the composition of organic solvents that are not generated and the amount of them used. The polyimide precursor composition according to the present invention, that is, "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) Consists of 4,4'-bis (4-amino-2-trifluoromethylphenoxy) phenyl (BATPP) and 4,4'-bis (4-amino-2-trifluoromethylphenoxy) biphenyl (BATBP) below. By containing one or more aromatic diamines selected from the group, it has excellent light transmission and phase delay characteristics. A specific description of each component is 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 (4,4'-bis) represented by the following chemical formula 7. From the group consisting of 4-amino-2-trifluoromethylphenoxy) phenyl (BATPP) and 4,4'-bis (4-amino-2-trifluoromethylphenoxy) biphenyl (BATBP) represented by the following chemical formula 8. Contains one or more aromatic diamines of choice.

Here, the aromatic diamine compound represented by the chemical formulas 5 to 8 preferably contains 5 to 30 mol% with respect to the total content of the diamine components. If the amount of the aromatic diamine compound represented by the chemical formulas 5 to 8 is less than 5 mol%, there is a limit to the improvement of birefringence and retardation characteristics, and if it exceeds 30 mol%, there is a limit due to a decrease in thermal characteristics. Therefore, it is preferable to include it in the above range.

The diamine component can include not only a fluorinated aromatic diamine monomer such as TFMB but also a non-fluorinated aromatic diamine monomer. Specifically, the aromatic diamine components are 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 (mMADA), p-cyclohexanediamine (pCHDA), p-xylyl Range amine (pXDA), m-xylylene diamine (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 above can be included.

(B) Acid dianhydride compound The aromatic acid dianhydride compound of the present invention contains a fluorinated aromatic acid dianhydride, a non-fluorinated aromatic acid dianhydride, or a mixture thereof.
When a fluorinated aromatic acid dianhydride and a non-fluorinated aromatic acid dianhydride are mixed and used, the optical properties and heat resistance properties of the polyimide film can be improved at the same time. A polyimide film having excellent optical properties can be produced by the fluorine substituent of the fluorinated aromatic acid dianhydride, and a polyimide film having excellent heat resistance properties can be produced by the tough molecular structure of the non-fluorinated aromatic acid dianhydride. Can be manufactured.

Specifically, the fluorinated aromatic acid dianhydride is an aromatic acid dianhydride having a fluorine substituent introduced therein, and is, for example, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (4,). 4'-(Hexafluoroisopropylide) diphthalic anhydride, 6FDA), and 4,4'-(4,4'-hexafluoroisopropylideneoxy) bis- (phthalic anhydride) (4,4'-(4,4) One or more selected from the group consisting of'-Hexafluoroisotropic lidenediphenoxy) bis- (physical anhydride, 6-FDPDA) can be used.

Next, the non-fluorinated aromatic acid dianhydride is an aromatic acid dianhydride in which a fluorine substituent is not introduced, and is pyromellitic dianhydride (PMDA), 3, 3', 4, 4'-biphenyltetracarboxylic acid dianhydride (3,3'4,4'-biphenyltetracarboxicid dianhydride, BPDA), 3,3', 4,4'-benzophenone tetracarboxylic dianhydride (3,3', 4,4'-benzophenonetracarboxylic dianhydride, BTDA), 4,4'-oxydiphthalic anhydride (ODPA), 2,2-bis [4-3,4-dicarboxyphenoxy] phenyl] propane Anhydride (2,2-Bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, BPADA), 3,3', 4,4'-diphenylsulfone tetracarboxylic acid anhydride (3,3', 4) , 4'-Diphenyl sulfone terracarboxylic dianhydride, DSDA), and ethylene glycol bis (4-trimeritate anhydride), TMEG (which can be selected from one species or more), TMEG). ..

Preferably, when the present invention contains the compound represented by the chemical formulas 5 to 8 as the diamine component, the acid dianhydride component is 4,4'-(hexafluoroisopropylidene) diphthalic acid anhydride (6FDA). 4,4'-(4,4'-hexafluoroisopropyridenediphenoxy) bis- (phthalic acid anhydride) (6-FDPDA), cyclobutanetetracarboxylic acid dianhydride (CBDA), 3,3', 4' , 4-Biphenyltetracarboxylic acid dianhydride (s-BPDA), Bicyclo [2.2.2] Oct-7-en-2,3,5,6-tetracarboxylic acid dianhydride (BTDA), 4- (2,5-Dioxotetratetra-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid dianhydride (TDA), pyromelitoic acid dianhydride (PMDA), benzophenone tetracarboxylic One or more selected from the group consisting of acid dianhydride (BTDA) and oxydiphthalic acid 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. Polar solvents such as acetate (DEA), 3-methoxy-N, N-dimethylpropanamide (DMPA), low boiling solvents such as tetrahydrofuran (THF), chloroform, etc. or low such as gamma-butyrolactone (GBL). A water-absorbent solvent can be used.

Specifically, the organic solvent used in the present invention plays an important role in improving the cloudiness phenomenon, but gamma-butyrolactone (GBL) and N-methyl-2 are used to improve the cloudiness phenomenon during solution casting at room temperature. A mixture of -pyrrolidone (NMP), or a mixture of gamma-butyrolactone (GBL) and 3-methoxy-N, N-dimethylpropanamide (DMPA), or a mixture of 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, and is not necessarily limited to, one or more selected from the group consisting of trimethylamine, xylene, pyridine and quinoline, depending on the reactivity. Not done. Further, the polyamic acid composition is added with a plasticizer, an antioxidant, a flame retardant, a dispersant, a viscosity modifier, a leveling agent and the like, if necessary, within a range that does not significantly impair the object and effect of the present invention. It can contain a small amount of agent.

The polyamic acid solution obtained by polymerizing the polyamic acid composition according to the present invention using a diamine component, an acid dianhydride compound, an organic solvent, and a reaction catalyst is based on the total weight of the polyamic acid solution. The solid content is 10 to 40% by weight, preferably 10 to 25% by weight. If the solid content is less than 10% by weight, there is a limit to increasing the thickness of the film during film production, and if the solid content exceeds 40% by weight, there is a limit to 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 of 10 to 40% by weight, and a diamine component of 95 to 100 mol% and an acid dianhydride compound of 100 to 105 mol% are mixed. The reaction is preferably carried out at a temperature of 10 to 70 ° C. for 12 to 48 hours. At this time, the reaction temperature can be changed depending on the monomer used.
Here, the acid dianhydride compound is preferably added in an amount 5 mol% less to 5 mol% more than the aromatic diamine component to reach the target viscosity, which is suitable for viscosity adjustment and storage. 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. If the viscosity is less than 1,000 cP, there is a problem in obtaining an appropriate level of film thickness, and if it exceeds 10,000 cP, there is a problem in uniform coating and effective solvent removal. Is preferable.

In the present invention, the transparent polyimide film and the method for producing the same are as follows. The present invention provides a transparent polyimide film produced by thermally imidizing a polyamic acid solution produced using the above-mentioned polyamic acid composition. The polyamic acid solution according to the present invention has a viscosity and is heat-treated after being coated on a glass substrate by an appropriate method at the time of film production. As the coating method, a well-known ordinary method can be used without limitation, for example, spin coating (Spin coating), dip coating (Dip coating), solvent casting (Solvent casting), slot die coating (Slot die coating), spraying. There is, but is not limited to, coating (Spray coating) and the like.

The polyamic acid composition of the present invention can be produced as a polyimide film by heat treatment in a high-temperature convection oven. At this time, the heat treatment conditions are carried out in a nitrogen atmosphere at 100 to 450 ° C. for 30 to 120 minutes. More preferably, the film is obtained under the temperature and time conditions of 100 ° C./30 minutes, 220 ° C./30 minutes, and 350 ° C./30 minutes. This is due to imidization, which allows for proper solvent removal and maximization of properties.

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 phase difference (Ro) in the plane direction of 1.0 nm or less, and a phase difference (Rth) in the thickness direction of 100 nm based on a film thickness of 10 to 15 μm. Hereinafter, the turbidity (Haze) is 1.0 or less, the transmittance (Transmitance) is 85% or more, preferably 88% or more, and the yellowness (Yellow Index, YI) is 7 or less, preferably 5 or less. ..

The polyimide film of the present invention can be used in various fields, and in particular, an OLED display, a liquid crystal element display, a TFT substrate, a flexible printing circuit substrate, and a flexible (Flexible) display, which require high transparency and phase delay characteristics. It can be provided as a substrate for a flexible display such as an OLED surface illumination substrate and 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 for exemplifying the present invention and do not limit the scope of the present invention.
In Table 1, the units of the numbers of acid dianhydride and diamine are molar parts, which 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. rice field. Then, after adding 45.333 g (0.102 mole) of 6FDA which is a dianhydride monomer, the mixture was stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30 ° C., at this time, the solid content was a reaction solvent. It is maintained so as to be 15% by weight based on the total weight of.). As a result of measurement with a viscosity measuring device (Blockfield DV2T, SC4-27), the viscosity was 4,500 cP.

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

Example 2
As the compositions shown in Table 2 below, 28.215 g (0.088 mole) of TFMB and 5.400 g (0.010 mole) of BATP, which are diamine-based monomers, were added to 440.08 g of DMPA, which is an organic solvent, to create a nitrogen atmosphere. , Was dissolved at room temperature for 30 minutes to 1 hour. Then, after adding 44.047 g (0.099 mole) of 6FDA which is a dianhydride monomer, the mixture was stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30 ° C., at this time, the solid content was a reaction solvent. It is maintained so as to be 15% by weight based on the total weight of.). As a result of measurement with a viscosity measuring device (Blockfield 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 and 15.292 g (0.028 mol) of BATP, which are diamine-based monomers, were added to 440.08 g of DMPA, which is an organic solvent. It was dissolved at room temperature for 30 minutes to 1 hour. Then, after adding 41.657 g (0.094 mole) of 6FDA which is a dianhydride monomer, the mixture was stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30 ° C., at this time, the solid content was a reaction solvent. It is maintained so as to be 15% by weight based on the total weight of.). As a result of measurement with a viscosity measuring device (Blockfield DV2T, SC4-27), the viscosity was 4,600 cP.

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

Example 5
As the compositions shown in Table 2 below, TFMB 28.009 g (0.087 mole) and BATPPE 5.970 g (0.010 mol), which are diamine-based monomers, were added to the organic solvent DMPA 440.08 g, and the atmosphere was nitrogen and the temperature was normal. It was dissolved in 30 minutes to 1 hour. Then, after adding 6FDA 44.483 g (0.100 mole) which is a dianhydride monomer, the mixture was stirred for 24 hours to prepare a polyamic acid solution (reaction temperature: 30 ° C., at this time, the solid content was a reaction solvent. It is maintained so as to be 15% by weight based on the total weight of.). As a result of measurement with a viscosity measuring device (Blockfield DV2T, SC4-27), the viscosity was 4,600 cP.

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

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

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

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

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

Experimental example: Measurement of physical properties (1) Evaluation of normal temperature cloudiness phenomenon Drop the polyamic acid solution prepared in Examples 1 to 10 and Comparative Example 1 onto a glass plate and use a spin coater to obtain a constant thickness (based on solid content of 15%). When the thickness of the solution was 100 μm, the temperature was adjusted to 15 μm after the heat treatment, and the solution was left to stand in an atmosphere of temperature 25 ° C. and humidity> 90% for 30 minutes, and then a cloudiness phenomenon was observed. The white turbidity phenomenon occurrence level was quantified as 0 to 5 and evaluated (0: no occurrence, 5: large occurrence).

(2) Film production and evaluation of physical properties The 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 conditions were carried out in a nitrogen atmosphere, and the final film was obtained under the temperature and time conditions of 100 ° C./30 minutes, 220 ° C./30 minutes, and 350 ° C./30 minutes. The physical properties of the film thus obtained were measured by the following methods, and the results are shown in Table 1 below.

(A) Transmittance
Transmittance was measured at 532 nm using a UV-Vis NIR Spectrophotometer (Shimadsu, UV-1800).
(B) Birefringence and retardation
Measured in TE (Transverse Eric) mode and TM (Transverse Magic) mode at 532 nm using a refractive index measuring machine (Prism Coupler 2010M, Metallicon), and the value of (TE value)-(TM value) is used as the birefringence value. The calculation was performed, and the phase difference (Ro) in the plane direction and the phase difference (Rth) in the thickness direction at 532 nm were measured using a phase difference measuring device (RTs-100, manufactured by Otsuka).
(C) Yellowness (Yellowness Index, YI)
It was measured using a color difference meter (LabScan XE).
(D) Turbidity (haze)
The measurement was performed using a haze meter (TOYOSEIKI, HAZE-GARD).

As shown in Table 1, in the cases of Examples 1 to 10 as compared with Comparative Example 1, when a predetermined amount of the novel diamine monomers BATPP, BATPPE, BATP, and BATPB is contained, the transmittance is higher and the transmittance is higher. , It can be confirmed that the phase delay characteristic is excellent. It can be seen that the transmittance, turbidity, yellowness, etc. required for the polyimide film were satisfied, and the white turbidity phenomenon did not occur.

As a result, the polyamic acid precursor resin solution produced by the present invention has a transmittance of 88% or more at a wavelength of 532 nm and a yellowness (Yellow Index, YI.) based on a film thickness of 10 to 15 μm. It is possible to provide a transparent polyimide film having a compound refraction of 7 or less, a compound refraction of 0.01 or less, and a phase difference (Rth) in the thickness direction of 100 or less.

Therefore, the polyimide film produced by the present invention satisfies excellent light transmittance and phase delay characteristics, and is an OLED display, a liquid crystal element display, a TFT substrate, a flexible printing circuit substrate, a flexible OLED surface illumination substrate, and the like. It can be widely applied to flexible display substrates and protective films such as electronic paper substrate materials.

Claims (7)

A polyimide precursor resin composition containing a diamine component, an acid dianhydride compound, and 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 aromatics selected from the group consisting of fluoromethylphenoxy) phenyl (BATPP) and 4,4'-bis (4-amino-2-trifluoromethylphenoxy) biphenyl (BATBP) represented by the following chemical formula 4. look including a family diamine, aromatic diamine compounds represented by formula 1-4 includes 5-30 mole% based on the total amount of the diamine component,
The diamine component is 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (TFMB), 4,4-oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylene. Diamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMADA), p-xylylenediamine (pXDA), m-xylylenediamine (mXDA), 4,4'-diaminodiphenylsulfone (mPDA) DDS), 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane (BAFP), and 2,2-bis [4- (4) -Aminophenoxy) Phenyl] A highly transparent polyimide precursor resin composition having excellent optical characteristics and phase delay characteristics, which further contains one or more selected from the group consisting of propane (BAPP).

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). The polyimide precursor resin composition according to claim 1, wherein the polyimide precursor resin composition is a single product of 3-methoxy-N, N-dimethylpropanamide (DMPA). The amount of the organic solvent used is N-methyl-2-pyrrolidone (NMP) or 3-methoxy-N, N-dimethylpropanamide (DMPA) 70 to 30 with respect to 30 to 70 mol% of gamma-butyrolactone (GBL). The polyimide precursor resin composition according to claim 1, wherein the amount is mol%. A method for producing a polyimide resin film, which comprises heat-treating a polyamic acid solution produced by using the composition according to any one of claims 1 to 3 to produce a film. The polyamic acid solution is produced by mixing 95 to 100 mol% of a diamine component and 100 to 105 mol% of an acid dianhydride compound using an organic solvent content based on a solid content of 10 to 40% by weight. The method for producing a polyimide resin film according to claim 4, wherein the polyimide resin film is produced. The method for producing a polyimide resin film according to claim 5 , wherein the polyamic acid solution has a viscosity of 1,000 to 10,000 cP. Based on the thickness of the film produced by the method of claim 4 , the transmittance at a wavelength of 532 nm is 88% or more, and the yellowness (Yellow Index, YI) at a wavelength of 532 nm is 7 or less. A polyimide resin film having a refraction of 0.01 or less and a phase difference (Rth) in the thickness direction of 100 or less.