KR102471861B1 - Polyamic acid solution and transparent polyimide film using the same - Google Patents

Abstract

The present invention relates to (a) a diamine mixture comprising diamine represented by Formula 1 and diamine represented by Formula 2; (b) a dianhydride mixture comprising dianhydride represented by Formula 3 and dianhydride represented by Formula 4; (c) a basic catalyst having a boiling point in the range of 140 to 200°C; and (d) a polyamic acid solution containing an organic solvent.
A transparent polyimide resin film and a transparent substrate prepared by imidizing such a polyamic acid solution have excellent optical and mechanical properties and can be applied to flexible displays.

Description

Polyamic acid solution and transparent polyimide resin film using the same {POLYAMIC ACID SOLUTION AND TRANSPARENT POLYIMIDE FILM USING THE SAME}

The present invention relates to a polyamic acid solution applicable to a flexible display and a transparent polyimide resin film manufactured using the same.

Polyimide (PI) resin is an insoluble, insoluble, ultra-high heat-resistant resin that has excellent electrical, chemical, thermal, and mechanical properties, and is used in heat-resistant high-tech materials such as automobile materials, aviation and spacecraft materials; It is widely used in electronic materials such as insulating coatings, insulating films, semiconductors, and LCD electrode protective films.

As a method of synthesizing such a polyimide resin, a polyamic acid solution is prepared by polymerizing dianhydride and diamine in an organic solvent, and then cured by heat treatment to form a film or chemically imidized. (Imidazation), followed by immersion, washing, drying, re-dissolving, etc., to produce a film is common.

First, a method of preparing a polyimide resin film by curing a polyamic acid solution by heat treatment includes heating at a high temperature of 250 to 400 ° C. for several hours. Since the resin is colored in the process, transmittance and yellowness in the visible ray region are reduced, making it difficult to use it as an optical material requiring transparency. On the other hand, when heating at a low temperature, there is a problem in that the strength of the polyimide resin film is reduced because the time required for manufacturing the polyimide resin film is increased and the molecular weight of the polyamic acid is reduced.

Next, a method for preparing a polyimide resin film by chemically imidizing the polyamic acid solution is a process of imidizing the polyamic acid solution by the Dean Stark Method by adding xylene or toluene to the polyamic acid solution, or using a catalyst such as pyridine in the polyamic acid solution and a process of imidization at low temperature by adding a dehydrating agent such as acetic anhydride. However, the chemical imidization method requires a separate Dean Stark facility or undergoes various processes such as immersion, washing, drying, and re-dissolution after imidization, so the process is complicated and a large amount of contaminated wastewater is generated. There is a problem.

Therefore, there is a need to develop a polyamic acid solution for producing a transparent polyimide resin film having excellent thermal and mechanical properties while exhibiting high transparency by a relatively simple process.

The present invention adopts a dianhydride monomer and a diamine monomer of a specific structure and adjusts their content to a specific range and at the same time cures it at a constant temperature using a catalyst with a specific boiling point range, resulting in low YI (Yellow Index) and high light intensity. An object of the present invention is to prepare a transparent polyamic acid solution and a transparent polyimide film capable of implementing transmittance and adjusting mechanical properties.

In addition, polyamic acid compositions and transparent polyis applicable to plastic transparent substrates for flexible displays of LCD and OLED, TFT substrates, flexible printed circuit boards, flexible OLED surface lighting substrates, substrate materials for electronic paper, etc. It aims at providing a mid film.

In order to achieve the above object, the present invention provides (a) a diamine mixture comprising diamine represented by Formula 1 and diamine represented by Formula 2; (b) a dianhydride mixture comprising a dianhydride represented by the following Chemical Formula 3 and a dianhydride represented by the following Chemical Formula 4; (c) a basic catalyst having a boiling point in the range of 140 to 200°C; and (d) a polyamic acid solution containing an organic solvent.

(In Formula 1 above,

A is selected from the group consisting of a single bond, C(=O), C(=O)NH, and C ₆ ~ C ₂₀ arylene groups;

X ₁ and X ₂ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, a C ₁ to C ₆ alkyl group, and a C ₁ to C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms,

However, when A is a single bond, at least one of X ₁ and X ₂ is a halogen or a C ₁ to C ₆ alkyl group substituted with a halogen atom,

The C ₆ ~ C ₂₀ arylene group may be substituted with a halogen or a C ₁ ~ C ₆ alkyl group substituted with a halogen atom, and m is an integer of 0 to 2)

(In Formula 2 above,

B is selected from the group consisting of C ₁ ~ C ₆ alkyl groups, C ₁ ~ C ₆ alkyl groups in which one or more hydrogen atoms are substituted with halogen atoms, O, OBO, S, SO ₂ , and C ₆ ~ C ₂₀ arylene groups;

X ₃ and X ₄ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, C ₁ ~ C ₆ alkyl groups, and C ₁ ~ C ₆ alkyl groups in which one or more hydrogen atoms are substituted with halogen atoms,

The C ₆ ~C ₂₀ arylene group may be substituted with a halogen, a C ₁ ~C ₆ alkyl group, or a C ₁ ~C ₆ alkyl group substituted with a halogen atom)

(In Formula 3,

C is selected from the group consisting of a C ₆ ~ C ₂₀ arylene group, a C ₆ ~ C ₂₀ arylene group connected by a linking group, and a C ₄ to C ₄₀ alicyclic group;

The C ₆ ~ C ₂₀ arylene group may be substituted with a C ₁ ~ C ₆ alkyl group,

The linking group may be one or more selected from the group consisting of -C(=O)-, -C(=O)NH- and -S(=O) ₂ )

(In Chemical Formula 4,

D is selected from the group consisting of a C ₁ ~ C ₆ alkyl group, a C ₁ ~ C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms, O, S and SO ₂ ;

X ₅ and X ₆ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, a C ₁ to C ₆ alkyl group, and a C ₁ to C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms;

n is an integer from 1 to 3).

In addition, the present invention provides a transparent polyimide resin film prepared by imidizing the polyamic acid solution.

In addition, the present invention provides a transparent commercial product including the transparent polyimide resin film.

In the present invention, by adopting a diamine monomer and a dianhydride monomer of a specific structure, adjusting their content to a specific range, and using a catalyst with a specific boiling point range, transparency having excellent optical properties, mechanical properties, thermal properties, etc. at the same time A polyamic acid solution and a polyimide resin film may be provided.

In addition, in the present invention, by applying the composition for transparent polyimide having excellent optical properties, mechanical properties, thermal properties, etc. to a substrate, it is possible to provide a transparent substrate for a flexible display exhibiting excellent physical properties and product reliability.

Hereinafter, the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

<Polyamic acid solution>

The polyamic acid solution according to the present invention is for preparing a polyimide resin film having improved mechanical and thermal properties while maintaining high transparency and excellent optical properties, and is composed of (a) diamine represented by Formula 1 and Formula 2 below. diamine mixtures containing the indicated diamines; (b) a dianhydride mixture comprising a dianhydride represented by the following Chemical Formula 3 and a dianhydride represented by the following Chemical Formula 4; (c) a basic catalyst having a boiling point in the range of 140 to 200°C; and (d) an organic solvent.

(a) diamine mixture

The polyamic acid solution according to the present invention includes diamine represented by Formula 1 and diamine represented by Formula 2 as diamine components.

[Formula 1]

In Formula 1,

A is selected from the group consisting of a single bond, C(=O), C(=O)NH, and C ₆ ~ C ₂₀ arylene groups;

X ₁ and X ₂ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, a C ₁ to C ₆ alkyl group, and a C ₁ to C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms,

However, when A is a single bond, at least one of X ₁ and X ₂ is a halogen or a C ₁ to C ₆ alkyl group substituted with a halogen atom,

The C ₆ ~C ₂₀ arylene group may be substituted with a halogen or a C ₁ ~C ₆ alkyl group substituted with a halogen atom, and m is an integer of 0 to 2.

[Formula 2]

(In Formula 2 above,

B is selected from the group consisting of C ₁ ~ C ₆ alkyl groups, C ₁ ~ C ₆ alkyl groups in which one or more hydrogen atoms are substituted with halogen atoms, O, OBO, S, SO ₂ , and C ₆ ~ C ₂₀ arylene groups;

X ₃ and X ₄ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, C ₁ ~ C ₆ alkyl groups, and C ₁ ~ C ₆ alkyl groups in which one or more hydrogen atoms are substituted with halogen atoms,

The C ₆ ~C ₂₀ arylene group may be substituted with a halogen, a C ₁ ~C ₆ alkyl group, or a C ₁ ~C ₆ alkyl group substituted with a halogen atom.

According to a preferred example of the present invention, the X ₁ and X ₄ may be a conventional electron withdrawing group known in the art (electron withdrawing group, EWG), and each independently fluorine (F) or CF ₃ It is preferable.

In addition, A may be a conventional C ₆ ~ C ₂₀ arylene group known in the art, and specific examples thereof include phenylene, biphenylene, triphenylenyl, and the like. In particular, the A is preferably selected from a group of substituents represented by the following formula.

In the above substituents, * means a site connected to Formula 1 above. In addition, R ₁ to R ₃ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, F and CF ₃ .

By introducing at least one electron-withdrawing group (EWG) such as fluorine (F) or CF ₃ into the above-described formula 1, controlling the formation of charge transfer complexes (Change transfer complexes, CTC) between and within molecular chains. Transparency of polyimide resin can be improved.

In the present invention, the diamine represented by Formula 1 is 2,2'-bis(trifluoromethyl)biphenyl-4,4'-diamine, 2,2'-dimethylbiphenyl-4,4'-diamine, It may be selected from structures derived from 4-amino-N-(4-aminophenyl)benzamine, bis(4-aminophenyl)methanone, etc., but is not limited thereto. However, diamine containing a fluorinated biphenyl structure can improve thermal properties by realizing a high glass transition temperature and low thermal expansion while controlling reactivity with dianhydride. For example, when 2,2'-TFDB is used, the thermal expansion coefficient can be lowered while increasing the transmittance and glass transition temperature of the polyimide resin.

The content of the diamine represented by Formula 1 is not particularly limited, but may be 50 to 99.9 mol%, preferably 70 to 99 mol%, based on 100 mol% of the diamine mixture. When the diamine represented by Formula 1 is included within the above range, optical properties may be further improved due to a charge transfer effect between substituents in the monomer.

In the present invention, the diamine represented by Formula 2 is 4,4'-oxydibenzeneamine (4,4'-ODA), 3,4-oxydibenzeneamine (3,4'-ODA), 3,3 '-oxydibenzenamine (3,3'-ODA), 4,4'-oxybis(3-(trifluoromethyl)benzenamine) (FODA), 4,4'-(1,4-phenylene Bis(oxy))bis(3-(trifluoromethyl)benzenamine)(FAPB), 4,4'-(perfluoropropane-2,2'-diyl)dibenzene amine, 4,4'-( 2,2'-(1,4-phenylene)bis(1,1,1,3,3,3-hexafluoropropane-2,2-diyl) dibenzenamine, 4,4'-sulfonyldibenzene Amine (4,4'-DDS), 4,4'-(4,4'-(perfluoropropane-2,2-diyl)bis(4,1-phenylene))bis(oxy)dibenzeneamine , 4,4'-(4,4'-sulfonylbis(4,1-phenylene) bis(oxy))dibenzenamine, 4,4'-(1,4-phenylenebis(oxy))di Benzeneamine, 4,4'-(4,4'-(propane-2,2-diyl)bis(4,1-phenylene))bis(oxy)dibenzenamine, cyclohexane-1,4-diamine, It may be selected from structures derived from 4,4'-methylenedicyclohexanamine, 4,4'-methylenebis(2-methylcyclohexanamine), etc., but is not limited thereto. It may be a monomer containing a biphenyl, a sulfone group (SO ₂ ), a silane group, etc. In this case, m-Tolidine, 4,4'-ODA, FODA, FAPB, DABA, 4,4-DDS or 4,4' In the case of using -(perfluoropropane-2,2'-diyl)dibenzeneamine, the thermal properties of the polyimide resin are not deteriorated and the optical properties can be further improved.

The content of the diamine represented by Formula 2 is not particularly limited, but may be 0.01 to 50 mol%, preferably 0.1 to 30 mol%, based on 100 mol% of the diamine mixture. When the diamine represented by Formula 2 is included within the above range, optical properties (light transmittance and yellowness) may be further improved.

(a) diamine according to the present invention uses 2,2'-TFDB as the diamine represented by the formula (1) in consideration of high transparency and low yellowness of the polyimide resin, and m-Tolidine as the diamine represented by the formula (2) , 4,4'-ODA, FODA, FAPB, DABA, 4,4-DDS or 4,4'-(perfluoropropane-2,2'-diyl) dibenzenamine is preferably used in combination.

(b) dianhydride mixture

The polyamic acid solution according to the present invention includes a dianhydride represented by the following Chemical Formula 3 and a dianhydride represented by the following Chemical Formula 4 as a dianhydride component.

[Formula 3]

In Formula 3,

C is selected from the group consisting of a C ₆ ~ C ₂₀ arylene group, a C ₆ ~ C ₂₀ arylene group connected by a linking group, and a C ₄ to C ₄₀ alicyclic group;

The C ₆ ~C ₂₀ arylene group may be substituted with a halogen, a C ₁ ~C ₆ alkyl group, or a C ₁ ~C ₆ alkyl group substituted with a halogen atom,

The linking group may be one or more selected from the group consisting of -C(=O)-, -C(=O)NH-, and -S(=O) ₂ .

[Formula 4]

In Formula 4,

D is selected from the group consisting of a C ₁ ~ C ₆ alkyl group, a C ₁ ~ C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms, O, S and SO ₂ ;

X ₅ and X ₆ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, a C ₁ to C ₆ alkyl group, and a C ₁ to C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms;

n is an integer from 1 to 3;

According to a preferred example of the present invention, the C is a conventional C ₆ ~ C ₂₀ aromatic ring or C ₄ ~ C ₄₀ alicyclic ring known in the art, which is a 6-membered aromatic ring or a 6-membered alicyclic ring. desirable. In this case, when C is a 6-membered aromatic ring, it may be an aromatic dianhydride containing a diamine structure, and when C is a 6-membered alicyclic ring, it may be a non-aromatic dianhydride containing a diamine structure.

When C is a 6-membered aromatic ring, it may be in the form of one or more common C ₆ ~ C ₄₀ arylene groups, sulfone groups, or arylene groups and sulfone groups connected to each other known in the art. Specific examples thereof include phenylene, biphenylene, triphenylene, and sulfonyl diphenylene. In particular, the C is preferably selected from a group of substituents represented by the following formula.

In the substituent, * means a site linked to Formula 3, R ₄ to R ₆ are the same as or different from each other, and each independently represents hydrogen or a C ₁ -C ₆ alkyl group, preferably each independently It can be hydrogen or methyl.

The dianhydride represented by Formula 3 is not decomposed by heat or light and is more stable against external impact as an arylene group and/or a sulfone group having a rigid structure are introduced between the dianhydrides, so it is prepared using this The optical properties, thermal properties and mechanical properties of the polyimide resin can be significantly improved. In addition, the compound represented by Chemical Formula 3 reacts with an oxygen atom in another dianhydride monomer as a diamine group is introduced between dianhydride monomers to form a hydrogen bond, thereby generating a certain binding force in the main chain of the polymer. The mechanical properties and heat resistance properties of the resin can be significantly improved.

In addition, when C is a 6-membered alicyclic ring, since π electrons do not exist in the compound structure, the formation of a change transfer complex (CTC) is controlled to realize high transmittance and low yellowness of the polyimide resin. plays a big role in

The dianhydride represented by Formula 3 is 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 1,2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA) ), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPBA), bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride (S-BPDA) , 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA), pyromellitric dianhydride (PMDA), N, N'-(4,4'-sulfonylbis( 4,1-phenylene)) may be selected from structures derived from bis(1,3-dioxo-octahydroisobenzofuran-5-carboxamide), etc., but is not limited thereto.

The content of the dianhydride represented by Formula 3 is not particularly limited, but may be 10 to 95 mol%, preferably 50 to 90 mol%, based on 100 mol% of the dianhydride mixture. When the dianhydride represented by Chemical Formula 3 is included within the above range, the thermal expansion coefficient of the polyimide resin may be further lowered while maintaining high light transmittance and low yellowness of the polyimide resin.

In addition, according to a preferred example of the present invention, the X ₅ and X ₆ may be a conventional electron withdrawing group (electron withdrawing group, EWG) known in the art, and each independently fluorine (F) or CF ₃ It is preferable that .

The dianhydride represented by Formula 4 is 5,5'-(perfluoropropane-2,2-diyl)diisobenzofuran-1,3-dione (6-FDA), 5,5'-oxydi Isobenzofuran-1,3-dione (ODPA), 5,5'-sulfonyldiisobenzofuran-1,3-dione (DSDA), benzophenone-3,3',4,4''-tetracarboxylic It may be selected from structures derived from dianhydride (BTDA) and the like, but is not limited thereto. At this time, when 6FDA is used, the transparency of the polyimide resin can be improved by controlling the formation of charge transfer complexes (Change transfer complexes, CTCs) between and within molecular chains.

The content of the dianhydride represented by Chemical Formula 4 is not particularly limited, but may be 5 to 90 mol%, preferably 10 to 50 mol%, based on 100 mol% of the dianhydride.

As described above, in one example of the present invention, diamine represented by Chemical Formula 1 and diamine represented by Chemical Formula 2 are used as the diamine component, and dianhydride represented by Chemical Formula 3 and dianhydride represented by Chemical Formula 4 are used as dianhydride components. Hydrides are mixed and used, where (a) diamine mixture and (b) dianhydride mixture are (a): (b) = 1: 0.1 to 10 to improve the yellowness and mechanical properties of the polyimide resin. They can be mixed in weight ratio.

(c) basic catalyst

Basic catalysts are 4-ethylpyridine, 2-methylpiperazine, 2,6-dimethylpiperazine, 4-tert-butylpyridine, 2-propylpyridine, 4-propylpyridine, 2,3 at a boiling point between 140 and 200°C. ,5-Collidine, 2,5-lutidine, 2,6-lutidine, 2,3-lutidine, 4-diazabicyclo[2.2.2]octane, 3-ethylpyridine, 3-picoline, 2 ,3-dimethylpyrazine, 2,5-dimethylpyrazine, and the like, which may be used alone or in combination of two or more.

If the boiling point of the basic catalyst is less than 140 ° C., it is difficult to form a film. On the other hand, if the boiling point is 200 ℃ or more, it is difficult to remove the catalyst at the curing temperature of the present invention, and when the curing temperature is increased to remove the catalyst, the optical properties are impaired.

(d) organic solvents

A solvent for synthesizing the polyamic acid solution is not particularly limited as long as it is known in the art. The organic solvent includes m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), acetone, diethyl acetate, dimethyl polar solvents such as phthalate (DMP); low boiling point solutions such as tetrahydrofuran (THF) and chloroform; It may be a low water absorption solvent such as γ-butyrolactone, and these may be used alone or in combination of two or more.

In the polyamic acid solution according to the present invention described above, the contents of the diamine mixture, the dianhydride mixture, the catalyst and the organic solvent are not particularly limited, but based on the total weight of 100 polyamic acid solution (a) the diamine mixture is 1 to 20 % by weight and (b) 1 to 20% by weight of the dianhydride mixture, (c) catalyst and (d) organic solvent may be the balance. At this time, when the content of each component in the polyamic acid solution is less than the above range, the viscosity of the polyamic acid solution may be too low, whereas when it exceeds the above range, the viscosity of the polyamic acid solution may be excessively high. Therefore, when the content of each component in the polyamic acid solution according to the present invention is adjusted within the above range, the polyamic acid solution may have a viscosity ranging from about 1,000 to 500,000 cps, preferably from about 10,000 to 200,000 cps. In addition, when the viscosity of the polyamic acid solution is within the above range, it is easy to control the thickness during coating of the polyamic acid solution, and the surface of the coated film can be formed uniformly.

On the other hand, the polyamic acid solution according to the present invention may contain a small amount of additives such as plasticizers, antioxidants, flame retardants, dispersants, viscosity modifiers, leveling agents, etc. within a range that does not significantly impair the objects and effects of the present invention, if necessary. have.

Polyamic acid can be obtained by solution polymerization of the polyamic acid solution according to the present invention as described above. Specifically, the diamine represented by Chemical Formula 1 and the diamine represented by Chemical Formula 2 were put into an organic solvent to dissolve them, and then dianhydride represented by Chemical Formula 3 and dianhydride represented by Chemical Formula 4 were added to the solution. When polymerized, polyamic acid can be produced. At this time, the reaction conditions are not particularly limited, and may be reacted at -20 to 80 ° C for 1 to 12 hours (preferably, 1 to 3 hours).

<Transparent polyimide resin film >

The present invention provides a transparent polyimide resin film prepared by imidizing the polyamic acid solution described above.

In this case, the polyimide resin may be in the form of a random copolymer or a block copolymer.

Since the transparent polyimide resin film according to the present invention is prepared using the polyamic acid solution, it has excellent thermal properties (coefficient of thermal expansion and glass transition temperature). Specifically, the transparent polyimide resin film according to the present invention has a light transmittance of 88% or more at a wavelength of 550 nm, a yellow index (YI) of 5.0 or less, and a haze of 1.0 at a wavelength of 550 nm. or less, the elastic modulus (Modulus) is 3 to 6 GPa, and the mechanical strength (Strength) is 120 to 200 MPa.

In addition, since the transparent polyimide resin film according to the present invention contains an imide group, it has excellent heat resistance, chemical resistance, abrasion resistance and electrical properties.

The method for producing such a transparent polyimide resin film is not particularly limited, but, for example, after coating (casting) the transparent polyamic acid composition on a glass substrate, a metal substrate, or a heat-resistant polymer substrate, the temperature is gradually raised in the range of 80 to 300 °C. A polyimide resin film may be prepared by performing an imidation reaction (Imidazation) for 1 to 12 hours while doing so.

As the coating method, conventional methods known in the art may be used without limitation, and examples thereof include spin coating, dip coating, solvent casting, and slot die coating. and spray coating.

The thickness of the transparent polyimide resin film is not particularly limited, but may be adjusted by coating the above-described polyamic acid composition one or more times to have a thickness of several hundred nm to several tens of μm.

Such a transparent polyimide resin film can be used in various fields, in particular, displays for organic EL devices (OLED), displays for liquid crystal devices, TFT substrates, flexible printed circuit boards, and flexible substrates requiring high transparency and heat resistance. It can be used as a substrate and protective film for flexible displays such as OLED surface lighting substrates and substrate materials for electronic paper.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited by the following Examples and Comparative Examples.

[Example 1]

1-1. polyamic acid preparation of solution

After filling 640.016 g of N,N-dimethylacetamide (DMAc) into a 1500 ml three-necked round bottom flask, the temperature of the flask was raised to 50°C. Thereafter, 85.0 g of 2,2'-bis(trifluoromethyl)biphenyl-4,4'-diamine (TFMB) was added to the flask, and after 60 minutes, 2,2'-dimethylbiphenyl-4,4' - Added 1.743 g of diamine (m-Tol). It was stirred for 1 hour to completely dissolve TFMB and m-Tol. Then, 45.615 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 5,5'-(perfluoropropane-2,2-diyl)diisobenzofuran-1 were added to the flask. 18.235 g of ,3-dione (6FDA) was sequentially added to dissolve each. At this time, the solid content was 15%, and then reacted by stirring for 5.5 hours. After confirming that the reaction between the monomers was completed by increasing the viscosity, 37 g of 4-tert-butylpyridine was gradually added and stirred for 4.5 hours. Then, it was naturally cooled to obtain a polyamic acid solution (solution viscosity at 25° C.: 85000 CPs).

1-2. Manufacturing of transparent polyimide resin film

The polyamic acid solution prepared in 1-1 of Example 1 was coated on a glass plate for LCD using a bar coater, and then in a nitrogen atmosphere convection oven at 80 ° C for 30 minutes, at 150 ° C for 30 minutes, at 200 ° C 1 hour at 280 ° C. for 1 hour, while gradually increasing the temperature in stages, drying and imidation were performed. As a result, a transparent polyimide resin film (imidation rate: 85% or more) having a film thickness of 52 μm was produced. Then, the film was separated from the glass plate to obtain a transparent polyimide resin film.

[Example 2]

2-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 85000 CPs) was prepared in the same manner as in 1-1 of Example 1.

2-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 320 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1.

[Example 3]

3-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 85000 CPs) was prepared in the same manner as in 1-1 of Example 1.

1-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 350 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1.

[Example 4]

4-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 79000 CPs) in the same manner as in 1-1 of Example 1, except that 4-diazabicyclo [2.2.2] octane was used instead of 4-tert-butylpyridine. ) was prepared.

4-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 5]

5-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 82000 CPs) was prepared in the same manner as in 1-1 of Example 1, except that 4-ethylpyridine was used instead of 4-tert-butylpyridine.

5-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 6]

6-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 81000 CPs) was prepared in the same manner as in 1-1 of Example 1, except that 2-methylpiperazine was used instead of 4-tert-butylpyridine.

6-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 7]

7-1. polyamic acid preparation of solution

Polyamic acid solution (solution at 25 ° C. Viscosity: 122000 CPs).

7-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 8]

8-1. polyamic acid preparation of solution

Except for using 4-diazabicyclo[2.2.2]octane instead of 4-tert-butylpyridine, a polyamic acid solution (solution viscosity at 25° C.: 118000 CPs) was prepared in the same manner as 7-1 of Example 7. ) was prepared.

8-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 9]

9-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 119000 CPs) was prepared in the same manner as 7-1 of Example 7, except that 4-methoxypyridine was used instead of 4-tert-butylpyridine.

9-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 7-2 of Example 7.

[Example 10]

10-1. polyamic acid preparation of solution

TFMB: FODA: CHDA: 6FDA was used in a molar ratio of 9: 1: 8: 2, except that 4-methoxypyridine was used instead of 4-tert-butylpyridine, 1-1 of Example 1 and A polyamic acid solution (solution viscosity at 25°C: 47000 CPs) was prepared in the same manner.

10-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 11]

11-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 47000 CPs) was prepared in the same manner as in Example 1 1-1.

11-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 320 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1.

[Example 12]

12-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 47000 CPs) was prepared in the same manner as in Example 1 1-1.

12-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 350 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1.

[Example 13]

13-1. polyamic acid preparation of solution

TFMB: FODA: s-BPDA: 6FDA was used in a molar ratio of 9: 1: 9: 1, and 4-methoxypyridine was used instead of 4-tert-butylpyridine, 1- A polyamic acid solution (solution viscosity at 25°C: 112000 CPs) was prepared in the same manner as in 1.

13-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 14]

14-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 113000 CPs) was prepared in the same manner as 13-1 of Example 13, except that 4-tert-butylpyridine was used instead of 4-methoxypyridine.

14-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 15]

15-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 110000 CPs) was prepared in the same manner as in 13-1 of Example 13, except that 3-picoline was used instead of 4-methoxypyridine.

15-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 16]

16-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 112000 CPs) was prepared in the same manner as in 13-1 of Example 13, except that 2,3-lutidine was used instead of 4-methoxypyridine.

16-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 17]

17-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25 ° C: 119000 CPs) was prepared in the same manner as in 13-1 of Example 13, except that 2,3,5-collidine was used instead of 4-methoxypyridine. .

17-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 18]

18-1. polyamic acid preparation of solution

Except that TFMB:FAPB:a-BPDA:ODPA was used in a molar ratio of 9:1:7:3 and 4-diazabicyclo[2.2.2]octane was used instead of 4-tert-butylpyridine, the above A polyamic acid solution (solution viscosity at 25° C.: 52000 CPs) was prepared in the same manner as in Example 1 1-1.

18-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 19]

19-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 52000 CPs) was prepared in the same manner as in 18-1 of Example 18.

19-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 320 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1.

[Example 20]

20-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 52000 CPs) was prepared in the same manner as in 18-1 of Example 18.

20-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 350 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1.

[Example 21]

21-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25 ° C: 83000 CPs) in the same manner as 1-1 of Example 1, except that TFMB: DABA: CBDA: DSDA was used in a molar ratio of 8: 2: 8: 2 ) was prepared.

21-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 22]

22-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 81000 CPs) was prepared in the same manner as 21-1 of Example 21, except that 2,3,5-collidine was used instead of 4-tert-butylpyridine. did

22-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 23]

23-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 82000 CPs) was prepared in the same manner as 21-1 of Example 21, except that 4-methoxypyridine was used instead of 4-tert-butylpyridine.

23-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 24]

24-1. polyamic acid preparation of solution

Except that TFMB:4,4-DDS:s-BPDA:6FDA was used in a molar ratio of 9:1:7:3 and 4-diazabicyclo[2.2.2]octane was used instead of 4-tert-butylpyridine. Then, a polyamic acid solution (solution viscosity at 25° C.: 61000 CPs) was prepared in the same manner as in 1-1 of Example 1.

24-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 25]

25-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 61000 CPs) was prepared in the same manner as in 24-1 of Example 24.

25-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 350 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1.

[Example 26]

26-1. polyamic acid preparation of solution

TFMB:4,4'-(perfluoropropane-2,2'-diyl)dibenzenamine:CBDA:6FDA was used in a molar ratio of 9:1:7:3, and 4-tert-butylpyridine was replaced by 4 -Except for using methoxypyridine, a polyamic acid solution (solution viscosity at 25°C: 47000 CPs) was prepared in the same manner as in Example 1 1-1.

26-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 27]

27-1. polyamic acid preparation of solution

Polyamic acid solution (solution viscosity at 25 ° C.: 107000 CPs) were prepared.

27-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 28]

28-1. polyamic acid preparation of solution

Polyamic acid solution (solution viscosity at 25 ° C.: 89000 CPs) were prepared.

28-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 29]

29-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 85000 CPs) was prepared in the same manner as 28-1 of Example 28, except that 4-methoxypyridine was used instead of 4-tert-butylpyridine.

29-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 30]

30-1. polyamic acid preparation of solution

Except for using 4-diazabicyclo[2.2.2]octane instead of 4-tert-butylpyridine, a polyamic acid solution (solution viscosity at 25° C.: 87000 CPs) in the same manner as in 28-1 of Example 28. ) was prepared.

30-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 31]

31-1. polyamic acid preparation of solution

TFMB: 4,4-DDS: s-BPDA: 6FDA was used in a molar ratio of 8:2:7:3, except that 4-diazabicyclo[2.2.2]octane was used instead of 4-tert-butylpyridine. Then, a polyamic acid solution (solution viscosity at 25° C.: 46000 CPs) was prepared in the same manner as in 1-1 of Example 1.

31-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 32]

32-1. polyamic acid preparation of solution

TFMB: 4,4-DDS: bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride: 6FDA except for using a molar ratio of 8:2:7:3 A polyamic acid solution (solution viscosity at 25° C.: 37000 CPs) was prepared in the same manner as in Example 1 1-1.

32-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 33]

33-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 35000 CPs) was prepared in the same manner as 32-1 of Example 32, except that 2,3,5-collidine was used instead of 4-tert-butylpyridine. did

33-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 34]

34-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 35000 CPs) was prepared in the same manner as 32-1 of Example 32, except that 4-methoxypyridine was used instead of 4-tert-butylpyridine.

34-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 35]

35-1. polyamic acid preparation of solution

TFMB:FODA:Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride:Except for using 6FDA in a molar ratio of 8:2:7:3 A polyamic acid solution (solution viscosity at 25° C.: 41000 CPs) was prepared in the same manner as in Example 1 1-1.

35-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 36]

36-1. polyamic acid preparation of solution

Except for using 4-diazabicyclo[2.2.2]octane instead of 4-tert-butylpyridine, a polyamic acid solution (solution viscosity at 25° C.: 41000 CPs) in the same manner as 35-1 of Example 35. ) was prepared.

36-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Example 37]

37-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 40000 CPs) was prepared in the same manner as in 35-1 of Example 35, except that 4-methoxypyridine was used instead of 4-tert-butylpyridine.

37-2. Manufacturing of transparent polyimide resin film

It proceeded in the same way as 1-2 of Example 1.

[Comparative Example 1]

1-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 82000 CPs) was prepared in the same manner as in 1-1 of Example 1, except that 19.987 g of pyridine was used instead of 4-tert-butylpyridine.

1-2. Manufacturing of transparent polyimide resin film

In the same manner as in 1-2 of Example 1, the separation of the film from the glass plate was attempted, but the film was not obtained because the entire formed film was fragmented.

[Comparative Example 2]

2-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 80000 CPs) was prepared in the same manner as in 1-1 of Comparative Example 1, except that isoquinoline was used instead of pyridine.

2-2. Manufacturing of transparent polyimide resin film

It was carried out in the same way as 1-2 of Comparative Example 1, but the remaining amount of isoquinoline was too large, so the correct film could not be obtained.

[Comparative Example 3]

3-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25 ° C: 73000 CPs) was prepared in the same manner as 1-1 of Comparative Example 1, except that TFMB: BTDA: 6FDA was used in a molar ratio of 10: 7: 3. .

3-2. Manufacturing of transparent polyimide resin film

In the same manner as in 1-2 of Example 1, the separation of the film from the glass plate was attempted, but the film was not obtained because the entire formed film was fragmented.

[Comparative Example 4]

4-1. polyamic acid preparation of solution

A polyamic acid solution (solution viscosity at 25° C.: 73000 CPs) was prepared in the same manner as in 35-1 of Example 35.

4-2. Manufacturing of transparent polyimide resin film

Example, except that the imidation reaction was carried out while gradually increasing the temperature step by step at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 350 ° C. for 1 hour in a convection oven under a nitrogen atmosphere. It proceeded in the same way as 1-2 of 1. Then, the polyimide film was separated from the glass plate and taken.

Compositions of the diamine mixture, the dianhydride mixture, and the catalyst used in Examples 1 to 37 and Comparative Examples 1 to 3 are shown in Table 1 below.

composition (molar ratio) Hardening
temperature
℃ diamine dianhydride catalyst Example 1 TFDB
-9- m-Tol
-One- CBDA
-7- 6FDA
-3- 4-tert-butylpyridine 280 Example 2 320 Example 3 350 Example 4 4-diazabicyclo
[2.2.2] Octane 280 Example 5 ^* 4-Ethylpyridine Example 6 2-Methylpiperazine Example 7 TFDB
-9- 4,4-ODA
-One- CBDA
-9- 6FDA
-One- 4-tert-butylpyridine 280 Example 8 4-diazabicyclo
[2.2.2] Octane Example 9 4-methoxypyridine Example 10 TFDB
-9- FODA
-One- CHDA
-8- 6FDA
-2- 4-methoxypyridine 280 Example 11 320 Example 12 350 Example 13 TFDB
-9- FODA
-One- S-BPDA
-9- 6FDA
-One- 280 Example 14 4-tert-butylpyridine 280 Example 15 ^* 3-picoline Example 16 ^* 2,3-lutidine Example 17 2,3,5-Collidine Example 18 TFDB
-9- FAPB
-One- a-BPDA
-7- ODPA
-3- 4-diazabicyclo
[2.2.2] Octane 280 Example 19 320 Example 20 ^* 350 Example 21 TFDB
-8- DABA
-2- CBDA
-8- DSDA
-2- 4-tert-butylpyridine 280 Example 22 2,3,5-Collidine Example 23 4-methoxypyridine Example 24 TFDB
-9- 4,4-DDS
-One- S-BPDA
-7- 6FDA
-3- 4-diazabicyclo
[2.2.2] Octane 280 Example 25 ^* 350 Example 26 TFDB
-9- 4,4'-(perfluoropropane-2,2'-diyl)dibenzenamine
-One- CBDA
-7- 6FDA
-3- 4-methoxypyridine 280 Example 27 TFDB
-9- FODA
-One- S-BPDA
-9- DSDA
-One- 4-tert-butylpyridine Example 28 TFDB
-9- FODA
-One- S-BPDA
-9- BTDA
-One- Example 29 4-methoxypyridine Example 30 ^* 4-diazabicyclo
[2.2.2] Octane Example 31 TFDB
-8- 4,4-DDS
-2- S-BPDA
-7- 6FDA
-3- 4-diazabicyclo
[2.2.2] Octane 280 Example 32 TFDB
-8- 4,4-DDS
-2- Bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride
-7- 6FDA
-3- 4-tert-butylpyridine Example 33 2,3,5-Collidine Example 34 4-methoxypyridine Example 35 TFDB
-9- FODA
-One- Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride
-7- 6FDA
-3- 4-tert-butylpyridine 280 Example 36 4-diazabicyclo
[2.2.2] Octane Example 37 4-methoxypyridine Comparative Example 1 TFDB
-9- m-Tol
-One- CBDA
-7- 6FDA
-3- pyridine 280 Comparative Example 2 isoquinoline Comparative Example 3 TFDB
-10- - BTDA
-7- 6FDA
-3- pyridine 280 Comparative Example 4 ^* 350

*: partial damage (brittle)

[Experimental Example 1] Evaluation of physical properties of transparent polyimide resin film

The physical properties of the transparent polyimide resin films prepared in Examples 1 to 37 and Comparative Examples 1 to 4 were evaluated in the following manner, and the results are shown in Table 2.

(1) Measurement of light transmittance (T%)

It was measured using a UV-Vis NIR Spectrophotometer (Shimadzu, model name: UV-3150) at a wavelength of 550 nm at a C light source and a viewing angle of 2°, which is the standard of ASTM E313-73.

(2) Yellow index (YI) measurement

Yellowness at 550 nm was measured according to the ASTM E313 standard using a spectrophotometer (Konica Minolta, model name: CM-3700d).

(3) Measurement of mechanical properties

Tensile strength (Strength, MPa) and elastic modulus (Modulus, GPa) were measured according to ISO 527-3 standard using UTM (Instron, model name: 5942).

characteristic light transmittance
%T yellowness
YI haze modulus of elasticity
GPa The tensile strength
MPa Example 1 89.8 1.7 0.4 5.8 176 Example 2 89.1 2.6 0.5 6.0 184 Example 3 88.2 3.1 0.7 6.0 191 Example 4 88.5 2.1 0.4 5.6 167 Example 5 ^* 88.0 2.5 0.5 5.5 170 Example 6 88.4 2.9 0.7 5.7 166 Example 7 88.1 2.3 0.7 5.0 155 Example 8 86.5 4.8 1.0 5.1 160 Example 9 88.5 2.7 0.6 5.5 163 Example 10 89.1 2.3 0.4 5.2 151 Example 11 88.5 3.6 0.8 5.1 152 Example 12 88.1 4.1 0.9 5.2 161 Example 13 89.3 3.2 0.8 5.4 153 Example 14 89.5 2.1 0.5 5.4 156 Example 15 ^* 88.3 3.9 0.8 4.9 150 Example 16 ^* 88.2 4.6 1.0 5.2 153 Example 17 88.3 3.8 0.8 5.1 149 Example 18 88.7 3.7 1.0 3.7 127 Example 19 86.2 4.5 1.0 3.5 128 Example 20 ^* 88.0 4.9 1.0 3.0 123 Example 21 88.8 2.2 0.6 5.6 171 Example 22 88.4 2.7 0.9 5.1 166 Example 23 88.1 2.4 0.7 5.3 168 Example 24 88.3 2.7 0.9 5.1 156 Example 25 ^* 88.1 4.8 1.0 4.9 167 Example 26 88.5 2.1 0.7 4.5 139 Example 27 88.2 2.3 0.7 4.3 141 Example 28 88.3 2.4 0.7 5.1 146 Example 29 88.1 3.1 0.7 4.3 141 Example 30 ^* 88.2 4.1 0.9 4.3 141 Example 31 88.4 2.6 0.8 3.1 136 Example 32 88.2 2.7 0.9 4.1 139 Example 33 88.1 3.1 0.7 3.9 141 Example 34 88.3 2.6 0.8 4.0 140 Example 35 89.3 1.4 0.4 4.1 139 Example 36 88.3 3.7 0.8 3.9 142 Example 37 88.2 2.7 0.7 4.0 143 Comparative Example 1 damaged Comparative Example 2 Catalyst cannot be removed Comparative Example 3 damaged Comparative Example 4 ^* 83.5 11.0 7 4.5 150

Referring to Table 1 and Table 2, it can be seen that the characteristics of the prepared transparent polyimide resin film according to the composition.

First, looking at the results of Examples 1 to 3, when the same composition and the same catalyst were used while different curing temperatures were applied, the higher the curing temperature, the worse the optical properties and the mechanical properties showed no significant difference. can That is, it can be seen that a transparent polyimide resin film having excellent properties can be obtained in the imidization process at a curing temperature of 280 °C.

In addition, looking at the results of Example 1 and Examples 4 to 6, it can be seen that transparent polyimide resin films having similar properties can be obtained when catalysts of different boiling points are applied at the same curing temperature (280 ° C). . However, in the case of Example 5, it was confirmed that the obtained film was partially damaged.

Next, looking at the results of Examples 7 to 37, in the case of using various basic catalysts having a boiling point between 140 and 200 ° C., the curing temperature is 300 ° C. or less, transparent with excellent properties even in the imidation process. It can be seen that a polyimide resin film can be obtained. That is, it was confirmed that the high-temperature process during manufacturing can be improved.

Through the above results, it was confirmed that optical properties and mechanical properties can be controlled by a combination of composition, curing temperature, and type of catalyst.

On the other hand, looking at the results of Comparative Example 1 and Comparative Example 2, when pyridine having a low boiling point of 115 ° C. was used as a catalyst in the same composition, a film could not be obtained (Comparative Example 1), and an iso having a boiling point of 240 ° C. When quinoline was used as a catalyst, a film could be obtained, but it was confirmed that the residual amount of the catalyst was large. It is obvious that these problems can cause big problems when applied to devices after mass production.

In addition, looking at the results of Comparative Examples 3 to 4, when using a catalyst having a boiling point of 115 ° C, a film could not be obtained at a low curing temperature of 280 ° C (Comparative Example 3), and a curing temperature of 350 ° C Although it was possible to obtain a film, it was confirmed that it was partially damaged (Comparative Example 4).

As a result of analyzing the above results, it was found that the transparent polyimide resin films of Examples 1 to 37 according to the present invention not only had excellent optical properties, but also had excellent mechanical properties such as increased tensile strength and elastic modulus. .

Specifically, the transparent polyimide resin films of Examples 1 to 37 have a transmittance of 88% or more, a yellowness value of 5.0 or less, an elastic modulus of 3 to 6 GPa, and a strength of 120 to 160 MPa, and the transparent polyimide resins of Comparative Examples 1 to 4 It was found that the light transmittance was higher than that of the film, the yellowness was low, and the mechanical properties were excellent, satisfying the applicable conditions for flexible display materials.

As described above, the transparent polyimide resin film prepared using the polyamic acid solution according to the present invention improves the high-temperature process during manufacturing and at the same time has high light transmittance, low yellowness, and excellent mechanical properties, making it a flexible display material. It was confirmed that it can be applied as a substrate or a protective film.

Claims (12)

(a) a diamine mixture including diamine represented by Formula 1 and diamine represented by Formula 2 below;
(b) a dianhydride mixture comprising a dianhydride represented by the following Chemical Formula 3 and a dianhydride represented by the following Chemical Formula 4;
(c) a basic catalyst having a boiling point in the range of 140 to 200°C; and
(d) organic solvents
including,
The basic catalyst is 4-ethylpyridine, 2-methylpiperazine, 2,6-dimethylpiperazine, 4-tert-butylpyridine, 2-propylpyridine, 4-propylpyridine, 2,3,5-collidine, 2 ,5-lutidine, 2,6-lutidine, 2,3-lutidine, 4-diazabicyclo[2.2.2]octane, 3-ethylpyridine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine At least one selected from the group consisting of, polyamic acid solution:
[Formula 1]

(In Formula 1,
A is selected from the group consisting of a single bond, C(=O), C(=O)NH, and C ₆ ~ C ₂₀ arylene groups;
X ₁ and X ₂ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, a C ₁ to C ₆ alkyl group, and a C ₁ to C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms,
However, when A is a single bond, at least one of X ₁ and X ₂ is a halogen or a C ₁ to C ₆ alkyl group substituted with a halogen atom,
The C ₆ ~ C ₂₀ arylene group may be substituted with a halogen or a C ₁ ~ C ₆ alkyl group substituted with a halogen atom, and m is an integer of 0 to 2)
[Formula 2]

(In Formula 2,
B is selected from the group consisting of C ₁ ~ C ₆ alkyl groups, C ₁ ~ C ₆ alkyl groups in which one or more hydrogen atoms are substituted with halogen atoms, O, OBO, S, SO ₂ , and C ₆ ~ C ₂₀ arylene groups;
X ₃ and X ₄ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, C ₁ ~ C ₆ alkyl groups, and C ₁ ~ C ₆ alkyl groups in which one or more hydrogen atoms are substituted with halogen atoms,
The C ₆ ~C ₂₀ arylene group may be substituted with a halogen, a C ₁ ~C ₆ alkyl group, or a C ₁ ~C ₆ alkyl group substituted with a halogen atom)
[Formula 3]

(In Formula 3,
C is selected from the group consisting of a C ₆ ~ C ₂₀ arylene group, a C ₆ ~ C ₂₀ arylene group connected by a linking group, and a C ₄ to C ₄₀ alicyclic group;
The C ₆ ~ C ₂₀ arylene group may be substituted with a C ₁ ~ C ₆ alkyl group,
The linking group may be one or more selected from the group consisting of -C(=O)-, -C(=O)NH- and -S(=O) ₂ )
[Formula 4]

(In Chemical Formula 4,
D is selected from the group consisting of a C ₁ ~ C ₆ alkyl group, a C ₁ ~ C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms, O, S and SO ₂ ;
X ₅ and X ₆ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, a C ₁ to C ₆ alkyl group, and a C ₁ to C ₆ alkyl group in which one or more hydrogen atoms are substituted with halogen atoms;
n is an integer from 1 to 3). According to claim 1,
The X ₁ to X ₆ are each independently F or CF ₃ Electron withdrawing group (EWG) polyamic acid solution. According to claim 1,
The A is a polyamic acid solution selected from the group of substituents represented by the following formula:

In the substituent,
* means a site linked to Formula 1,
R ₁ to R ₃ are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, F and CF ₃ . According to claim 1,
The C is a polyamic acid solution selected from the group of substituents represented by the following formula:

In the substituent,
* means a site connected to Formula 3,
R ₄ to R ₆ are the same as or different from each other, and are each independently selected from hydrogen or a C ₁ to C ₆ alkyl group. delete According to claim 1,
The content of the diamine represented by Formula 1 is 50 to 99.9 mol% based on 100 mol% of the diamine mixture,
The content of the diamine represented by Formula 2 is 0.1 to 50 mol% based on 100 mol% of the diamine mixture, the polyamic acid solution. According to claim 1,
The content of the dianhydride represented by Formula 3 is 10 to 95 mol% based on 100 mol% of the dianhydride mixture, the polyamic acid solution. According to claim 1,
The content ratio of (a) diamine mixture and (b) dianhydride mixture is (a): (b) = 1: polyamic acid solution in a weight ratio of 0.1 to 10. According to claim 1,
A polyamic acid solution having a viscosity of 1,000 to 500,000 cps at 25 °C. A transparent polyimide resin film produced by imidizing the polyamic acid solution according to any one of claims 1 to 4 and 6 to 9. According to claim 10,
A transparent polyimide resin film satisfying the physical property conditions of the following (i) to (v):
(i) a light transmittance of 88% or more at a wavelength of 550 nm at a film thickness of 100 μm or less;
(ii) Yellowness according to ASTM E313 standard is 5.0 or less,
(iii) has a haze of 1.0 or less;
(iv) an elastic modulus in the range of 3 to 6 GPa;
(v) tensile strength in the range of 120 to 200 MPa; A transparent substrate comprising the transparent polyimide resin film according to claim 10.