JP2021055104A - Transparent polyimide resin film using polyimide forming composition - Google Patents

Abstract

To provide a transparent polyimide resin film and a transparent substrate that have excellent optical and mechanical properties, so that they can be applied to a flexible display.SOLUTION: Provided is a polyamic acid solution comprising: (a) a diamine mixture including diamine represented by chemical formula 1 and diamine represented by chemical formula 2; (b) a dianhydride mixture including dianhydride represented by chemical formula 3 and dianhydride represented by chemical formula 4; (c) a basic catalyst having the boiling point in the range of 140 to 200°C; and (d) an organic solvent.SELECTED DRAWING: None

Description

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

Polyimide (PI) resin is an insoluble and infusible ultra-high heat resistant resin, and has the advantages of excellent electrical, chemical, thermal, and mechanical properties. It is widely used as a heat-resistant advanced material such as a spacecraft material, and as an electronic material such as an insulating coating agent, an insulating film, a semiconductor, and an LCD electrode protective film.

As a method for synthesizing such a polyimide resin, generally, a method of polymerizing dianhydride and diamine in an organic solvent to produce a polyamic acid solution, and then curing the solution by heat treatment to produce a film. Alternatively, a method is carried out in which a film is produced as a film through processes such as immersion, washing, and redissolution after chemically imidization.

First, a method for producing a polyimide resin film by curing a polyamic acid solution by heat treatment includes a process of heating at a high temperature of 250 to 400 ° C. for several hours. Since the resin is colored in the process, the transmittance and yellowness in the visible light region are lowered, and it is difficult to use it as an optical material that requires transparency. On the other hand, when the polyimide resin film is heated at a low temperature, the time required for producing the polyimide resin film becomes long and the molecular weight of the polyamic acid is reduced, so that there is a problem that the strength of the produced polyimide resin film is lowered.

The method for producing a polyimide resin film by chemically imidizing a polyamic acid solution is a process of adding xylene or toluene to the polyamic acid solution and imidizing by the Dean Stark Method, or polyamic. The process of adding a catalyst such as pyridine and a dehydrating agent such as acetic anhydride to the acid solution and imidizing at a low temperature is included. However, in the method of chemically imidizing, the process is complicated because another Dean-Stark apparatus needs to be provided or a process such as dipping, washing, drying, and redissolving is required after imidization. Therefore, there is a problem that a large amount of wastewater is generated.

Therefore, it is required to develop a polyamic acid solution for producing a transparent polyimide resin film which exhibits high transparency and is excellent in thermal properties and mechanical properties by a relatively simple process.

The present invention employs a dianhydride monomer and a diamine monomer having a specific structure, adjusts the content of these to a specific range, and uses a catalyst having a boiling point within the specific range at a constant temperature. It is an object of the present invention to produce a transparent polyamic acid solution and a transparent polyimide film which can realize low YI (Yello Index) and high light transmittance by curing and can adjust mechanical properties.

Further, the present invention is a polyamic acid composition and a transparent polyimide film applicable to plastic transparent substrates for LCD and OLED flexible display devices, TFT substrates, flexible printed circuit boards, flexible OLED surface lighting substrates, substrate materials for electronic paper, and the like. Is intended to provide.

In order to achieve the above object, the present invention has a diamine mixture containing (a) a diamine represented by the following chemical formula (1) and a diamine represented by the following chemical formula (2); (b) the following chemical formula (3).
A dianhydride mixture containing the dianhydride represented by (c) and the 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; is provided.

（前記化学式（１）中、
Ａは、単結合、−Ｃ（＝Ｏ）−、−Ｃ（＝Ｏ）ＮＨ−、及びＣ_６〜Ｃ_２０のアリーレン基
からなる群から選択され、
Ｘ_１及びＸ_２は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ
_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル
基からなる群から選択され、
但し、Ａが単結合である場合、Ｘ_１及びＸ_２のうちの少なくとも１つ以上は、ハロゲン、
またはハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基であり、
前記Ｃ_６〜Ｃ_２０のアリーレン基は、ハロゲン、またはハロゲン原子で置換されたＣ_１〜
Ｃ_６のアルキル基で置換されることがあり、
ｍは、０〜２の整数である。）

(In the chemical formula (1),
A represents a single bond, -C (= O) -, - C (= O) NH-, and is selected from the group consisting of arylene group _C 6 _{-C 20,}
X ₁ and X ₂ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
However, when A is a single bond, at least one or more of _{X 1} and X _{2 is a halogen.}
Alternatively, it is an alkyl group of _{C 1 to C 6} substituted with a halogen atom.
The arylene groups of C _{6 to} C _{20 are halogen or C 1} to C 20 substituted with a halogen atom.
It may be substituted with an alkyl group of C _6,
m is an integer from 0 to 2. )

（前記化学式（２）中、
Ｂは、単結合、Ｃ_１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換された
Ｃ_１〜Ｃ_６のアルキレン基、−Ｏ−、−Ｏ−Ｂ−Ｏ−、−Ｓ−、−Ｓ（＝Ｏ）_２−、−Ｃ
（＝Ｏ）ＮＨ−、及びＣ_６〜Ｃ_２０のアリーレン基からなる群から選択され、
Ｘ_３及びＸ_４は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ
_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル
基からなる群から選択され、
前記Ｃ_６〜Ｃ_２０のアリーレン基は、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、またはハロゲ
ン原子で置換されたＣ_１〜Ｃ_６のアルキル基で置換されることがある。）

(In the chemical formula (2),
B represents a single _bond, an alkylene group of C 1 -C _6, 1 or more hydrogen is alkylene _C 1 -C ₆ substituted by a halogen atom, -O -, - O-B -O -, - S -, -S (= O) _2- , -C
(= O) Selected from the group consisting of allylene groups of _{NH- and C 6 to} C _20.
X ₃ and X ₄ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
The arylene group _C 6 _{-C 20} is selected from _halogen, C 1 -C alkyl group having ₆ or it may be substituted with an alkyl group of _C 1 -C ₆ substituted by a halogen atom. )

（前記化学式（３）中、
Ｃは、４価のＣ_６〜Ｃ_２０の芳香族環基、及び４価のＣ_４〜Ｃ_４０の脂肪族環基からなる
群から選択され、
前記４価のＣ_６〜Ｃ_２０の芳香族環基は、それぞれ独立に、Ｃ_１〜Ｃ_６のアルキル基で置
換されることがあり、
前記Ｃは、複数個の環であることができ、複数個の環は、互いに同一または異なり、複数
個の環同士が、−Ｃ（＝Ｏ）−、−Ｃ（＝Ｏ）ＮＨ−、−Ｃ（＝Ｏ）−Ｏ−、及び−Ｓ（
＝Ｏ）_２−からなる群から選択される１種以上の連結基を介して連結されている。）

(In the chemical formula (3),
C is selected from the group consisting of _{tetravalent C 6 to} C ₂₀ aromatic ring groups and tetravalent C _{4 to} C _{40 aliphatic ring groups.}
The tetravalent C _{6 to} C ₂₀ aromatic ring groups may be independently substituted with _{C 1 to} C _{6 alkyl groups, respectively.}
The C can be a plurality of rings, the plurality of rings are the same or different from each other, and the plurality of rings are -C (= O)-, -C (= O) NH-,-. C (= O) -O- and -S (
= O) It is linked via one or more linking groups selected from the group consisting of _{2 −.} )

（前記化学式（４）中、
Ｄは、Ｃ_１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ
_６のアルキレン基、−Ｏ−、−Ｓ−、−Ｃ（＝Ｏ）−、及び−Ｓ（＝Ｏ）_２−からなる群
から選択され、
Ｘ_５及びＸ_６は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ
_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル
基からなる群から選択され、
ｎは、１〜３の整数である。）

(In the chemical formula (4),
D _is, C 1 -C ₆ alkylene group, one or more _C 1 hydrogens are replaced by halogen atoms as -C
Selected from the group consisting of ₆ alkylene groups, −O−, −S−, −C (= O) −, and −S (= O) _2−.
X ₅ and X ₆ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
n is an integer of 1 to 3. )

The present invention also provides a transparent polyimide resin film produced by imidizing the polyamic acid solution.

Furthermore, the present invention provides a transparent substrate containing the transparent polyimide resin film.

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

Further, according to the present invention, a flexible display device exhibiting excellent physical properties and product reliability by applying the transparent polyimide composition having excellent optical properties, mechanical properties, thermal properties, etc. to a substrate. A transparent substrate for use can be provided.

Hereinafter, the present invention will be described in detail. However, the examples described below are merely examples, and the present invention is not limited by these examples, and the scope of the present invention is indicated by the scope of claims described later.

<Polyamic acid solution>
The polyamic acid solution according to the present invention is for producing a polyimide resin film having improved mechanical properties and thermal properties while maintaining high transparency and excellent optical properties, and (a) the following chemical formula. A diamine mixture containing a diamine represented by (1) and a diamine represented by the following chemical formula (2); (b) containing a dianehydride represented by the following chemical formula (3) and a dianhydride represented by the following chemical formula (4). Diamine hydride mixture; (c) 140-20
It contains a basic catalyst having a boiling point in the range of 0 ° C.; and (d) an organic solvent;

(A) Diamine Mixture The polyamic acid solution according to the present invention contains a diamine represented by the following chemical formula (1) and a diamine represented by the following chemical formula (2) as a diamine component.

前記化学式（１）中、
Ａは、単結合、−Ｃ（＝Ｏ）−、−Ｃ（＝Ｏ）ＮＨ−、及びＣ_６〜Ｃ_２０のアリーレン基
からなる群から選択され、
Ｘ_１及びＸ_２は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ
_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル
基からなる群から選択され、
但し、Ａが単結合である場合、Ｘ_１及びＸ_２のうちの少なくとも１つ以上は、ハロゲン、
またはハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基であり、
前記Ｃ_６〜Ｃ_２０のアリーレン基は、ハロゲン、またはハロゲン原子で置換されたＣ_１〜
Ｃ_６のアルキル基で置換されることがあり、
ｍは、０〜２の整数である。

In the chemical formula (1),
A represents a single bond, -C (= O) -, - C (= O) NH-, and is selected from the group consisting of arylene group _C 6 _{-C 20,}
X ₁ and X ₂ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
However, when A is a single bond, at least one or more of _{X 1} and X _{2 is a halogen.}
Alternatively, it is an alkyl group of _{C 1 to C 6} substituted with a halogen atom.
The arylene groups of C _{6 to} C _{20 are halogen or C 1} to C 20 substituted with a halogen atom.
It may be substituted with an alkyl group of C _6,
m is an integer from 0 to 2.

前記化学式（２）中、
Ｂは、単結合、Ｃ_１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換された
Ｃ_１〜Ｃ_６のアルキレン基、−Ｏ−、−Ｏ−Ｂ−Ｏ−、−Ｓ−、−Ｓ（＝Ｏ）_２−、−Ｃ
（＝Ｏ）ＮＨ−、及びＣ_６〜Ｃ_２０のアリーレン基からなる群から選択され、
Ｘ_３及びＸ_４は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ
_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル
基からなる群から選択され、
前記Ｃ_６〜Ｃ_２０のアリーレン基は、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、またはハロゲ
ン原子で置換されたＣ_１〜Ｃ_６のアルキル基で置換されることがある。

In the chemical formula (2),
B represents a single _bond, an alkylene group of C 1 -C _6, 1 or more hydrogen is alkylene _C 1 -C ₆ substituted by a halogen atom, -O -, - O-B -O -, - S -, -S (= O) _2- , -C
(= O) Selected from the group consisting of allylene groups of _{NH- and C 6 to} C _20.
X ₃ and X ₄ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
The arylene group _C 6 _{-C 20} is selected from _halogen, C 1 -C alkyl group having ₆ or it may be substituted with an alkyl group of _C 1 -C ₆ substituted by a halogen atom.

According to a preferred example of the present invention, the X ₁ and X ₄ are a well-known electron-withdrawing groups in the art (E
It can be lectron Withdrawing Group, EWG), preferably _{fluorine (F) or CF 3 independently of each other.}

Further, the A _{can be an arylene group of C 6 to} C ₂₀ well known in the art, and specific examples thereof include phenylene, biphenylene, and triphenylene. in particular,
The A is preferably selected from the substituent group represented by the following chemical formula (5).

前記化学式（５）中、＊は、前記化学式（１）における連結部位である。また、Ｒ_１〜Ｒ
_３は、互いに同一または異なり、それぞれ独立に、水素、Ｆ、及びＣＦ_３からなる群から
選択される。

In the chemical formula (5), * is a connecting site in the chemical formula (1). Also, R _{1 to} R
₃ is the same as or different from each other and is 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 in the} above-mentioned chemical formula (1), an intermolecular and intramolecular charge transfer complex (Chan) is introduced.
By controlling the formation of ge Transfer Complex (CTC), the transparency of the polyimide resin can be improved.

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

The content of the diamine represented by the chemical formula (1) is not particularly limited, but can be 50 to 99.9 mol% with respect to 100 mol% of the diamine mixture, and is preferably 70 to 99. Mol%. When the diamine represented by the chemical formula (1) is contained within the above range, the optical properties can be further improved due to the charge transfer effect between the substituents in the monomer.

In the present invention, the diamine represented by the chemical formula (2) includes 2,2'-dimethylbiphenyl-4,4'-diamine (m-Toliline) and 4,4'-oxydibenzeneamine (4,4'). -ODA), 3,4-oxydibenzeneamine (3,4'-ODA)
, 3,3'-oxydibenzeneamine (3,3'-ODA), 4,4'-oxy (3-(
Trifluoromethyl) benzeneamine) (FODA), 4,4'-(1,4-phenylenebis (oxy)) bis (3- (trifluoromethyl) benzeneamine) (FABP), 4
, 4'-(perfluoropropane-2,2'-diyl) dibenzeneamine, 4,4'-(
2,2'-(1,4-phenylene) bis (1,1,1,3,3,3-hexafluoropropane-2,2-diyl) dibenzeneamine, 4,4'-sulfonyldibenzeneamine (1,4'-sulfonyldibenzeneamine ( 4
, 4'-DDS), 4,4'-(4,4'-(perfluoropropane-2,2-diyl))
Bis (4,51-phenylene)) Bis (oxy) dibenzeneamine, 4,4'-(4,4'
-Sulfonyl bis (4,5-phenylene) bis (oxy) dibenzeneamine, 4,4'
-(1,4-phenylenebis (oxy)) dibenzeneamine, 4,4'-(4,4'-(4,4'-(
Propane-2,2-diyl) bis (4,1-phenylene)) bis (oxy) dibenzeneamine, cyclohexane-1,4-diamine, 4,4'-methylenedicyclohexaneamine, 4,4'-methylenebis (4,4'-methylenebis ( It can be selected from structures derived from 2-methylcyclohexaneamine) and the like, but is not limited thereto. The diamine represented by such a chemical formula (2) _{can be a monomer containing phenyl, biphenyl, a sulfone group (SO 2} ), a silane group and the like. In addition, m-Toldine, 4,4'-ODA, FODA,
FAPB, DABA (4,4'-Diaminobenzanilide), 4,4'-DDS, or 4,4'-
When (perfluoropropane-2,2'-diyl) dibenzeneamine is used, the optical characteristics can be further improved without deteriorating the thermal characteristics of the polyimide resin.

The content of the diamine represented by the chemical formula (2) is not particularly limited, but can be 0.01 to 50 mol% with respect to 100 mol% of the diamine mixture, preferably 0.1. ~ 30 mol%. When the diamine represented by the chemical formula (2) is contained within the above range, the optical characteristics (light transmittance and yellowness) can be further improved.

The (a) diamine according to the present invention takes into consideration the high transparency and low yellowness of the polyimide resin.
As the diamine represented by the chemical formula (1), TFDB is used and the chemical formula (1) is used.
As the diamine represented by 2), m-Toliline, 4,4'-ODA, FODA,
FAPB, DABA, 4,4'-DDS, or 4,4'-(perfluoropropane-2)
, 2'-Diyl) Dibenzeneamine is preferably mixed and used.

(B) Diane Hydride Mixture The polyamic acid solution according to the present invention contains diane hydride represented by the following chemical formula (3) and diane hydride represented by the following chemical formula (4) as diane hydride components.

前記化学式（３）中、
Ｃは、４価のＣ_６〜Ｃ_２０の芳香族環基、及び４価のＣ_４〜Ｃ_４０の脂肪族環基からなる
群から選択され、
前記４価のＣ_６〜Ｃ_２０の芳香族環基は、それぞれ独立に、ハロゲン、Ｃ_１〜Ｃ_６のアル
キル基、またはハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基で置換されることがあ
り、
前記Ｃは、複数個の環であることができ、複数個の環は、互いに同一または異なり、複数
個の環同士が、−Ｃ（＝Ｏ）−、−Ｃ（＝Ｏ）ＮＨ−、−Ｃ（＝Ｏ）−Ｏ−、及び−Ｓ（
＝Ｏ）_２−からなる群から選択される１種以上の連結基（Ｌ）を介して連結されている。

In the chemical formula (3),
C is selected from the group consisting of _{tetravalent C 6 to} C ₂₀ aromatic ring groups and tetravalent C _{4 to} C _{40 aliphatic ring groups.}
Aromatic cyclic group of the tetravalent _C 6 _{-C 20} are each independently substituted _halogen, an alkyl group of C 1 -C ₆ alkyl _C 1 -C ₆ that or substituted with a halogen atom, Sometimes,
The C can be a plurality of rings, the plurality of rings are the same or different from each other, and the plurality of rings are -C (= O)-, -C (= O) NH-,-. C (= O) -O- and -S (
= O) It is linked via one or more linking groups (L) selected from the group consisting of _{2 −.}

前記化学式（４）中、
Ｄは、Ｃ_１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ
_６のアルキレン基、−Ｏ−、−Ｓ−、−Ｃ（＝Ｏ）−、及び−Ｓ（＝Ｏ）_２−からなる群
から選択され、
Ｘ_５及びＸ_６は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ
_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル
基からなる群から選択され、
ｎは、１〜３の整数である。

In the chemical formula (4),
D _is, C 1 -C ₆ alkylene group, one or more _C 1 hydrogens are replaced by halogen atoms as -C
Selected from the group consisting of ₆ alkylene groups, −O−, −S−, −C (= O) −, and −S (= O) _2−.
X ₅ and X ₆ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
n is an integer of 1 to 3.

According to a preferred example of the present invention, C is a tetravalent hydrocarbon ring group well known in the art.
Examples of the hydrocarbon ring group include _{aromatic ring groups of C 6 to} C ₂₀ and aliphatic ring groups of C _{4 to} C ₄₀ . The C is preferably a tetravalent 6-membered aromatic ring group or a tetravalent 6-membered alicyclic ring group. When C is a tetravalent 6-membered aromatic ring group, the chemical formula (3)
) Is an aromatic diane hydride containing a diamine structure.
When C is a tetravalent 6-membered aliphatic ring group, the dianhydride represented by the chemical formula (3) can be a non-aromatic dianhydride containing a diamine structure.

The C can be a plurality of rings, the plurality of rings are the same or different from each other, and the plurality of rings are -C (= O)-, -C (= O) NH-,-. C (= O) -O- and -S
(= O) It is linked via one or more linking groups selected from the group consisting of _2-.

For example, the C if it is a tetravalent six-membered aromatic ring group, one or more well known in the art C ₆
~ C ₄₀ can be in the form of an arylene group, a sulfone group, or an arylene group and a sulfone group linked together. Specific examples thereof include phenylene, biphenylene, triphenylene, and sulfonyldiphenylene. In particular, C is preferably selected from the substituent group represented by the following chemical formula (6).

前記化学式（６）中、＊は、前記化学式（３）における連結部位であり、Ｒ_４〜Ｒ_６は、
互いに同一または異なり、それぞれ独立に、水素、またはＣ_１〜Ｃ_６のアルキル基である
。好ましくは、それぞれ独立に、水素、またはメチル基であることができる。

In Chemical Formula (6), * is the a linking site in the chemical formula _(3), R 4 to R ₆ is
They are the same or different from each other, and are independently hydrogen or alkyl groups of _{C 1 to} C _6. Preferably, each can be independently hydrogen or a methyl group.

The dianhydride represented by the chemical formula (3) is resistant to an external impact without being decomposed by heat or light due to the introduction of an arylene group and / or a sulfone group having a rigid structure between the dianehydrides. Since it is stable, the optical properties, thermal properties, mechanical properties, etc. of the polyimide resin produced by using it are significantly improved. In addition, the chemical formula (3)
The compound represented by is reacted with an oxygen atom in another dianhydride monomer to form a hydrogen bond by introducing an amide group (-C (= O) -NH-) between the dianhydrides. And
By generating a certain binding force in the main chain of the polymer, the mechanical properties and heat resistance properties of the polyimide resin are significantly improved.

Further, when the C is a tetravalent 6-membered aliphatic ring group, since π electrons do not exist in the structure of the compound, the formation of the charge transfer complex (CTC) is controlled to increase the transmittance of the polyimide resin. And will play a major role in achieving low yellowness.

Examples of the dianhydride represented by the chemical formula (3) include 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 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), pyromellitic dianhydride (PMDA), N, N'-(4,4'-sulfonylbis (4,4') It can be selected from structures derived from 1-phenylene)) bis (1,3-dioxo-octahydroisobenzofuran-5-carboxamide) and the like, but is not limited thereto.

The content of dianhydride represented by the chemical formula (3) is not particularly limited, but is not particularly limited.
It can be 10-95 mol%, preferably 50-90 mol%, based on 100 mol% of the dianhydride mixture. When the dianhydride represented by the chemical formula (3) is contained within the above range, the high light transmittance and yellowness of the polyimide resin can be maintained and the coefficient of thermal expansion of the polyimide resin can be lowered.

Further, according to a preferred example of the present invention, the X ₅ and X ₆ can be electron-withdrawing groups (EWGs) well known in the art, each independently of fluorine (F) or CF ₃ . It is preferable to have.

Examples of the dianhydride represented by the chemical formula (4) include 5,5'-(perfluoropropane-2,2-diyl) diisobenzofuran-1,3-dione (6-FDA), 5,5'.
-Oxydiisobenzofuran-1,3-dione (ODPA), 5,5'-sulfonyldiisobenzofuran-1,3-dione (DSDA), benzophenone-3,3', 4,4'-
It can be selected from structures derived from tetracarboxylic dianhydride (BTDA) and the like, but is not limited thereto. When 6FDA is used, the transparency of the polyimide resin can be improved by controlling the formation of the charge transfer complex (CTC) between the molecular chains and within the molecular chain.

The content of dianhydride represented by the chemical formula (4) is not particularly limited, but is not particularly limited.
It can be 5 to 90 mol%, preferably 5 to 90 mol%, relative to 100 mol% of dianhydride.
It is 10 to 50 mol%.

As described above, in the example of the present invention, the diamine represented by the chemical formula (1) and the diamine represented by the chemical formula (2) are used as the diamine component as the diamine component, and the diamine represented by the chemical formula (3). The hydride and the dian hydride represented by the chemical formula (4) are mixed and used. At this time, the (a) diamine mixture and the (b) dian hydride mixture are used.
In order to improve the yellowness and mechanical properties of the polyimide resin, (a): (b) = 1: 0.1-
It can be mixed in a weight ratio of 10.

(C) Basic catalyst The basic catalyst is a basic catalyst having a boiling point of 140 to 200 ° C., for example, 4-tert.
-Butyl pyridine, 4-ethyl pyridine, 2-methyl piperazine, 2,6-dimethyl piperazine, 4-tert-butyl pyridine, 2-propyl pyridine, 4-propyl pyridine, 2,3,5-cholidine, 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 can be mentioned, and these can be used alone or in admixture of two or more.

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

(D) Organic solvent The solvent for synthesizing the polyamic acid solution is not particularly limited as long as it is well known in the art. Examples of the solvent include m-cresol and N-methyl-2-pyrrolidone (NM).
P), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), acetone, diethyl acetate, dimethylphthalate (DM)
Polar solvents such as P), low boiling point solvents such as tetrahydrofuran (THF), chloroform, etc.
Examples thereof include low-absorption solvents such as γ-butyrolactone, which can be used alone or in admixture of two or more.

In the polyamic acid solution according to the present invention as described above, the contents of the diamine mixture, the dianhydride mixture, the catalyst, and the organic solvent are not particularly limited, but are (a) with respect to 100% by weight of the total polyamic acid solution. 1-20% by weight of the diamine mixture, (b) 1 to 20% by weight of the dianhydride mixture, (c) the content of the catalyst known in the art, eg, about 0.01.
~ 20% by weight, specifically about 0.01-15% by weight, more specifically about 0.1-10% by weight
, And (d) the organic solvent can be the balance. Here, if 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, and on the other hand, if it exceeds the above range, the polyamic acid The viscosity of the solution may become too high. Therefore, by adjusting the content of each component in the polyamic acid solution according to the present invention within the above range, the polyamic acid solution can be reduced to about 1,000.
It can have a viscosity in the range of ~ 500,000 cps, preferably about 10,000 to 200,000 cps. If the viscosity of the polyamic acid solution is within the above range,
The thickness is easily adjusted during the coating of the polyamic acid solution so that the surface of the coating film to be coated is uniformly formed.

On the other hand, the polyamic acid solution according to the present invention is, if necessary, a plasticizer, an antioxidant, a flame retardant, a dispersant, a viscosity modifier, and a leveling agent within a range that does not impair the object and effect of the present invention. It can contain a small amount of additives such as.

A polyamic acid can be obtained by performing a solution polymerization reaction of the polyamic acid solution according to the present invention as described above. Specifically, the diamine represented by the chemical formula (1) and the diamine represented by the chemical formula (2) are added to an organic solvent to dissolve them, and then the dianhydride represented by the chemical formula (3) and the chemical formula (4) are here. ) Is added and then a solution polymerization reaction is carried out to obtain a polyamic acid. At this time, the reaction conditions are not particularly limited, but are -20 to 8
The reaction can be carried out at 0 ° C. for 1 to 12 hours (preferably 1 to 3 hours).

<Transparent polyimide resin film>
Furthermore, the present invention provides a transparent polyimide resin film produced by imidizing the above-mentioned polyamic acid solution.

The polyimide resin can be in the form of a random copolymer or a block copolymer.

Since the transparent polyimide resin film according to the present invention is produced by using the polyamic acid solution, it has improved mechanical properties (elastic modulus, strength) as well as optical properties (transparency and yellowness).
Excellent thermal characteristics (coefficient of thermal expansion and glass transition temperature) can be expected. 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 and yellowness (Yellow Index, YI) at a wavelength of 550 nm.
) Is 5.0 or less, Haze is 1.0 or less, and the elastic modulus (Modulu)
s) is 3 to 6 GPa, and the mechanical strength (Strength) is 120 to 200 MPa.

Further, since the transparent polyimide resin film according to the present invention contains an imide group, it is excellent in heat resistance, chemical resistance, abrasion resistance, and electrical characteristics.

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 can be produced by carrying out an imidization reaction for ~ 12 hours.

As the coating method, a method well known in the art can be used without limitation.
For example, spin coating method, dip coating method (Dip c)
Oating), solvent casting, slot die coating, spray coating
Ting) and the like.

The thickness of the transparent polyimide resin film is not particularly limited, but is several hundred nm to several tens of μm.
The above-mentioned polyamic acid composition can be coated one or more times to prepare the above-mentioned polyamic acid composition.

Such a transparent polyimide resin film can be used in various fields, and in particular, a display for an organic EL element (OLED), a display for a liquid crystal element, a TFT substrate, and a flexible printing circuit, which are required to have high transparency and heat resistance. Substrate, flexible OLED surface illumination substrate,
It can be used as a substrate for a flexible display device such as a substrate material for electronic paper and a protective film.

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

[Example 1]
1-1. Preparation of polyamic acid solution In a 1500 ml 3-neck round bottom flask, N, N-dimethylacetamide (DMAc) 64
After adding 0.016 g, the temperature of the flask was raised to 50 ° C. Then in the flask, 2
, 2'-bis (trifluoromethyl) biphenyl-4,4'-diamine (TFDB) 85
.. Add 0 g, and after 60 minutes, 2,2'-dimethylbiphenyl-4,4'-diamine (m)
-Tol) 1.743 g was added. This was stirred for 1 hour to completely dissolve TFDB and m-Tol. Next, on the fresco, 45.615 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), and 5,5'-(perfluoropropane-2,2-diyl) diisobenzofuran-1 , 3-Dione (6FDA) 18.235 g were added in sequence and dissolved. At this time, the solid content was 15%, and then the reaction was carried out with stirring for 5.5 hours. After confirming the completion of the inter-monomeric reaction by checking whether the viscosity increased, 37 g of 4-tert-butylpyridine was gradually added, and the mixture was stirred for 4.5 hours. Next, it was naturally cooled to obtain a polyamic acid solution (solution viscosity at 25 ° C.: 85,000 CPs).

1-2. Production of Transparent Polyimide Resin Film 1-1. The polyamic acid solution obtained in 1) was coated on a glass plate for LCD using a bar coater, and then in a convection oven under a nitrogen atmosphere at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, and 200 ° C. 1 hour at 280 ° C
For 1 hour, the mixture was dried while gradually raising the temperature stepwise, and an imidization reaction was carried out. resulting in,
A transparent polyimide resin film having a film thickness of 52 μm (imidization rate: 85% or more) was obtained. Next, the film was separated from the glass plate to obtain a transparent polyimide resin film.

[Example 2]
2-1. Production of Polyamic Acid Solution 1-1. Polyamic acid solution (solution viscosity at 25 ° C: 85) in the same manner as above.
000 CPs) was obtained.

2-2. Manufacture of transparent polyimide resin film In a nitrogen atmosphere, dry in a convection oven at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 320 ° C. for 1 hour while gradually increasing the temperature. , 1-2. Of Example 1, except that the imidization reaction is carried out. Manufactured in the same manner as above.

[Example 3]
3-1. Production of Polyamic Acid Solution 1-1. Polyamic acid solution (solution viscosity at 25 ° C: 85) in the same manner as above.
000 CPs) was obtained.

3-2. Manufacture of transparent polyimide resin film In a nitrogen atmosphere, dry in a convection oven at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 350 ° C. for 1 hour while gradually increasing the temperature. , 1-2. Of Example 1, except that the imidization reaction is carried out. Manufactured in the same manner as above.

[Example 4]
4-1. Preparation of Polyamic Acid Solution 1-1. Of Example 1 above, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. Polyamic acid solution (25) in the same manner as
Solution viscosity at ° C .: 79000 CPs) was obtained.

4-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Manufactured in the same manner as above.

[Example 5]
5-1. Preparation of Polyamic Acid Solution Except for the use of 4-ethylpyridine instead of 4-tert-butylpyridine
1-1. Of Example 1 Polyamic acid solution (solution viscosity at 25 ° C: 820) in the same manner as above.
00 CPs) was obtained.

5-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 5, 5-1.
Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 6]
6-1. Preparation of Polyamic Acid Solution 1-1. Of Example 1 above, except that 2-methylpiperazine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C: 81) in the same manner as above.
000 CPs) was obtained.

6-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 6, 6-1.
Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 7]
7-1. Preparation of Polyamic Acid Solution 1-1. Of Example 1 above, except that TFDB: 4,4'-ODA: CBDA: 6FDA is used in a molar ratio of 9: 1: 9: 1. A polyamic acid solution (solution viscosity at 25 ° C.: 122000 CPs) was obtained in the same manner as above.

7-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 7, 7-1.
Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 8]
8-1. Preparation of Polyamic Acid Solution 7-1. Of Example 7 above, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. Polyamic acid solution (25) in the same manner as
Solution viscosity at ° C .: 118,000 CPs) was obtained.

8-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 8, 8-1.
Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 9]
9-1. Preparation of Polyamic Acid Solution 7-1. Of Example 7 above, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C: 11) in the same manner as above.
9000 CPs) was obtained.

9-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 9, 9-1.
Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 10]
10-1. Preparation of polyamic acid solution TFDB: FODA: CHDA: 6FDA was used in a molar ratio of 9: 1: 8: 2, 4-t.
1-1. Of Example 1 above, except that 4-methoxypyridine is used instead of ert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C: 47,000 C) in the same manner as above.
Ps) was obtained.

10-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 10-10-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 11]
11-1. Production of Polyamic Acid Solution 10-1 of Example 10. Polyamic acid solution (solution viscosity at 25 ° C: 47) in the same manner as above.
000 CPs) was obtained.

11-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 11-11-
1. 1. In a convection oven under a nitrogen atmosphere using the polyamic acid solution produced in the above, gradually gradually at 80 ° C. for 30 minutes, at 150 ° C. for 30 minutes, at 200 ° C. for 1 hour, and at 320 ° C. for 1 hour. Except for drying while raising the temperature and performing an imidization reaction, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 12]
12-1. Production of Polyamic Acid Solution 10-1 of Example 10. Polyamic acid solution (solution viscosity at 25 ° C: 47) in the same manner as above.
000 CPs) was obtained.

12-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 12, 12-
1. 1. In a convection oven under a nitrogen atmosphere using the polyamic acid solution produced in the above, gradually gradually at 80 ° C. for 30 minutes, at 150 ° C. for 30 minutes, at 200 ° C. for 1 hour, and at 350 ° C. for 1 hour. Except for drying while raising the temperature and performing an imidization reaction, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 13]
13-1. Preparation of polyamic acid solution TFDB: FODA: s-BPDA: 6FDA was used in a molar ratio of 9: 1: 9: 1 and 4
1-1. Of Example 1 above, except that 4-methoxypyridine is used instead of -tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C.: 1120) in the same manner as
00 CPs) was obtained.

13-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 13, 13-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 14]
14-1. Preparation of Polyamic Acid Solution 13-1. Of Example 13 above, except that 4-tert-butylpyridine is used instead of 4-methoxypyridine. Polyamic acid solution (solution viscosity at 25 ° C.:
113000 CPs) was obtained.

14-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 14, 14-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 15]
15-1. Preparation of Polyamic Acid Solution Example 13 above, except that 3-picoline is used instead of 4-methoxypyridine.
13-1. Polyamic acid solution (solution viscosity at 25 ° C: 110,000 CP
s) was obtained.

15-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 15, 15-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 16]
16-1. Preparation of Polyamic Acid Solution 13-1 of Example 13 above, except that 2,3-lutidine is used instead of 4-methoxypyridine. Polyamic acid solution (solution viscosity at 25 ° C: 112000
CPs) were obtained.

16-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 16-16-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 17]
17-1. Preparation of Polyamic Acid Solution 13-1 of Example 13 above, except that 2,3,5-cholidine is used instead of 4-methoxypyridine. Polyamic acid solution (solution viscosity at 25 ° C.: 1190)
00 CPs) was obtained.

17-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 17- of Example 17 instead of the polyamic acid solution used in
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 18]
18-1. Preparation of polyamic acid solution TFDB: FABP: a-BPDA: ODPA was used in a molar ratio of 9: 1: 7: 3 and 4
1-1. Of Example 1 above, except that 4-diazabicyclo [2.2.2] octane is used instead of -tert-butylpyridine. A polyamic acid solution (solution viscosity at 25 ° C.: 52000 CPs) was obtained in the same manner as above.

18-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 18- of Example 18 instead of the polyamic acid solution used in
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 19]
19-1. Production of Polyamic Acid Solution 18-1 of Example 18. Polyamic acid solution (solution viscosity at 25 ° C: 52) in the same manner as above.
000 CPs) was obtained.

19-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 19- of Example 19 instead of the polyamic acid solution used in
1. 1. In a convection oven under a nitrogen atmosphere using the polyamic acid solution produced in the above, gradually gradually at 80 ° C. for 30 minutes, at 150 ° C. for 30 minutes, at 200 ° C. for 1 hour, and at 320 ° C. for 1 hour. Except for drying while raising the temperature and performing an imidization reaction, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 20]
20-1. Production of Polyamic Acid Solution 18-1 of Example 18. Polyamic acid solution (solution viscosity at 25 ° C: 52) in the same manner as above.
000 CPs) was obtained.

20-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 20- of Example 20 instead of the polyamic acid solution used in
1. 1. In a convection oven under a nitrogen atmosphere using the polyamic acid solution produced in the above, gradually gradually at 80 ° C. for 30 minutes, at 150 ° C. for 30 minutes, at 200 ° C. for 1 hour, and at 350 ° C. for 1 hour. Except for drying while raising the temperature and performing an imidization reaction, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 21]
21-1. Production of Polyamic Acid Solution 1-1. Of Example 1 above, except that TFDB: DABA: CBDA: DSDA is used in a molar ratio of 8: 2: 8: 2. Polyamic acid solution (solution viscosity at 25 ° C.:
83000 CPs) was obtained.

21-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 21- of Example 21 instead of the polyamic acid solution used in
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 22]
22-1. Preparation of Polyamic Acid Solution 21-1. Of Example 21 above, except that 2,3,5-cholidine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C.:
81000 CPs) was obtained.

22-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 22-22-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 23]
23-1. Preparation of Polyamic Acid Solution 21-1. Of Example 21 above, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C.:
82000 CPs) was obtained.

23-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 23-23-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 24]
24-1. Preparation of Polyamic Acid Solution TFDB: 4,4'-DDS: s-BPDA: 6FDA was used in a molar ratio of 9: 1: 7: 3 and 4-diazabicyclo [2.2] instead of 4-tert-butylpyridine. .2] 1-1. Of Example 1 above, except that octane is used. Polyamic acid solution (similar to
Solution viscosity at 25 ° C.: 61000 CPs) was obtained.

24-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 24, 24-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 25]
25-1. Production of Polyamic Acid Solution 24-1 of Example 24. Polyamic acid solution (solution viscosity at 25 ° C: 61) in the same manner as above.
000 CPs) was obtained.

25-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 25, 25-
1. 1. In a convection oven under a nitrogen atmosphere using the polyamic acid solution produced in the above, gradually gradually at 80 ° C. for 30 minutes, at 150 ° C. for 30 minutes, at 200 ° C. for 1 hour, and at 350 ° C. for 1 hour. Except for drying while raising the temperature and performing an imidization reaction, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 26]
26-1. Preparation of polyamic acid solution TFDB: 4,4- (perfluoropropane-2,2'-diyl) dibenzeneamine:
1-1. Of Example 1 above, except that CBDA: 6FDA is used in a molar ratio of 9: 1: 7: 3 and 4-methoxypyridine is used instead of 4-tert-butylpyridine. A polyamic acid solution (solution viscosity at 25 ° C.: 47,000 CPs) was obtained in the same manner as above.

26-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 26- of Example 26 instead of the polyamic acid solution used in
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 27]
27-1. Preparation of Polyamic Acid Solution 1-1. Of Example 1 above, except that TFDB: FODA: s-BPDA: DSDA is used in a molar ratio of 9: 1: 9: 1. A polyamic acid solution (solution viscosity at 25 ° C.: 107,000 CPs) was obtained in the same manner as above.

27-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 27-27-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 28]
28-1. Preparation of Polyamic Acid Solution 1-1. Of Example 1 above, except that TFDB: FODA: s-BPDA: BTDA is used in a molar ratio of 9: 1: 9: 1. A polyamic acid solution (solution viscosity at 25 ° C.: 89000 CPs) was obtained in the same manner as above.

28-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 28, 28-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 29]
29-1. Preparation of Polyamic Acid Solution 28-1 of Example 28, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C.:
85,000 CPs) was obtained.

29-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 29-29-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 30]
30-1. Preparation of Polyamic Acid Solution 28-1. Of Example 28, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. Polyamic acid solution (similar to
Solution viscosity at 25 ° C.: 87,000 CPs) was obtained.

30-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 30, 30-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 31]
31-1. Preparation of Polyamic Acid Solution TFDB: 4,4'-DDS: s-BPDA: 6FDA was used in a molar ratio of 8: 2: 7: 3 and 4-diazabicyclo [2.2] instead of 4-tert-butylpyridine. .2] 1-1. Of Example 1 above, except that octane is used. Polyamic acid solution (similar to
Solution viscosity at 25 ° C.: 46000 CPs) was obtained.

31-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 31- of Example 31 instead of the polyamic acid solution used in
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 32]
32-1. Preparation of polyamic acid solution TFDB: 4,4'-DDS: Bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride: 6FDA in moles of 8: 2: 7: 3. Except for the ratio, 1-1. Polyamic acid solution (solution viscosity at 25 ° C: 3700) in the same manner as
0 CPs) was obtained.

32-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 32, 32-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 33]
33-1. Preparation of Polyamic Acid Solution 32-1. Of Example 32, except that 2,3,5-cholidine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C.:
35,000 CPs) was obtained.

33-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 33, 33-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 34]
34-1. Preparation of Polyamic Acid Solution 32-1. Of Example 32, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C.:
35,000 CPs) was obtained.

34-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 34- of Example 34 instead of the polyamic acid solution used in
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 35]
35-1. Preparation of Polyamic Acid Solution TFDB: FODA: Bicyclo [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride: 6FDA in molar ratio of 9: 1: 7: 3. 1-1. Of the above-mentioned Example 1 except that it is used in 1. Polyamic acid solution (solution viscosity at 25 ° C: 4100) in the same manner as above.
0 CPs) was obtained.

35-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 35, 35-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 36]
36-1. Preparation of Polyamic Acid Solution 35-1. Of Example 35, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. Polyamic acid solution (similar to
Solution viscosity at 25 ° C.: 41000 CPs) was obtained.

36-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Example 36, 36-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 37]
37-1. Preparation of Polyamic Acid Solution 35-1. Of Example 35, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. Polyamic acid solution (solution viscosity at 25 ° C.:
40,000 CPs) was obtained.

37-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyamic acid solution used in Example 37, 37-
1. 1. Except for using the polyamic acid solution prepared in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Comparative Example 1]
1-1. Preparation of Polyamic Acid Solution 1-1. Of Example 1 above, except that 19.987 g of pyridine is used instead of 4-tert-butyl pyridine. Polyamic acid solution (solution viscosity at 25 ° C: 8) in the same manner as above.
2000 CPs) was obtained.

1-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Comparative Example 1, 1-1.
Except for using the polyamic acid solution prepared in Example 1, 1-2. After manufacturing in the same manner as in the above, an attempt was made to separate the film from the glass plate, but the formed film cracked and the film could not be obtained.

[Comparative Example 2]
2-1. Production of Polyamic Acid Solution 1-1. Of Comparative Example 1 except that isoquinoline is used instead of pyridine. A polyamic acid solution (solution viscosity at 25 ° C.: 80,000 CPs) was obtained in the same manner as above.

2-2. Production of Transparent Polyimide Resin Film 1-2 of Comparative Example 1. In place of the polyamic acid solution used in Comparative Example 2, 2-1.
In Comparative Example 1 1-2, except that the polyamic acid solution prepared in 1 was used. However, a normal film could not be obtained because the remaining amount of isoquinoline was too large.

[Comparative Example 3]
3-1. Production of Polyamic Acid Solution 1-1. Of Comparative Example 1 except that TFDB: BTDA: 6FDA is used in a molar ratio of 10: 7: 3. Polyamic acid solution (solution viscosity at 25 ° C: 73000 CP) in the same manner as above.
s) was obtained.

3-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyamic acid solution used in Comparative Example 3, 3-1.
In Comparative Example 1 1-2, except that the polyamic acid solution prepared in 1 was used. After manufacturing in the same manner as in the above, an attempt was made to separate the film from the glass plate, but the formed film cracked and the film could not be obtained.

[Comparative Example 4]
4-1. Production of Polyamic Acid Solution 35-1 of Example 35. Polyamic acid solution (solution viscosity at 25 ° C: 73) in the same manner as above.
000 CPs) was obtained.

4-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 4-1 of Comparative Example 4 instead of the polyamic acid solution used in
.. In a convection oven under a nitrogen atmosphere, using the polyamic acid solution produced in the above, 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 350 ° C. for 1 hour,
1 of Example 1 except that the imidization reaction is carried out by drying while gradually raising the temperature stepwise.
-2. Manufactured in the same manner as above. Next, the polyimide film was separated from the glass plate and obtained.

The compositions of the diamine mixture, the dianhydride mixture, and the catalyst used in Examples 1 to 37 and Comparative Examples 1 to 4 described above are shown in Table 1 below.

[Experimental Example 1] Evaluation of Physical Properties of Transparent Polyimide Resin Film The physical characteristics of the transparent polyimide resin film obtained in Examples 1 to 37 and Comparative Examples 1 to 4 described above are evaluated by the following methods, and the results are shown in the table. Shown in 2.

(1) Measurement of light transmittance (T%) UV-Vis NIR Spectrophotomete at a wavelength of 550 nm
Using r (manufactured by Shimadzu Corporation, model name: UV-3150), measurements were performed with a C light source according to the standards of ASTM E313-73 and a viewing angle of 2 °.

(2) Measurement of yellowness (Yellow Index, YI) Wavelength 55 using a spectrophotometer (manufactured by Konica Minolta, model name: CM-3700d)
The yellowness at 0 nm was measured according to the ASTM E313 standard.

(3) Measurement of mechanical properties Using UTM (manufactured by Instron, model name: 5942), tensile strength (Strength, MPa) and elastic modulus (Modulus, GPa) according to the ISO 527-3 standard.
) Was measured.

From Tables 1 and 2 above, changes in characteristics depending on the composition of the obtained transparent polyimide resin film can be seen.

First, from the results of Examples 1 to 37, when the same composition and the same catalyst are used, but different curing temperatures are applied, the higher the curing temperature, the more the optical characteristics deteriorate, and the mechanical characteristics differ greatly. It turns out that there is no. That is, it can be seen that a transparent polyimide resin film having excellent properties can be obtained in the imidization step in which the curing temperature is 280 ° C.

Further, from the results of Examples 1 and 4 to 6, it can be seen that when catalysts having different boiling points are used at the same curing temperature (280 ° C.), a transparent polyimide resin having similar characteristics can be obtained. However, in Example 5, it is confirmed that the obtained film is partially damaged.

Furthermore, from the results of Examples 7 to 37, when various basic catalysts having a boiling point of 140 to 200 ° C. are used, transparency having excellent properties even in an imidization step in which the curing temperature is relatively low at 300 or less. It can be seen that a polyimide resin film can be obtained. That is, it is confirmed that the high temperature process can be improved at the time of production.

From the above results, it is confirmed that the optical properties and the mechanical properties can be adjusted by combining the composition, the curing temperature, and the type of catalyst.

On the other hand, from the results of Comparative Examples 1 and 2, when pyridine having the same composition and a low boiling point of 115 ° C. was used as a catalyst, no film was obtained (Comparative Example 1), and isoquinoline having a boiling point of 240 ° C. When is used as a catalyst, a film is obtained, but it is confirmed that the remaining amount of the catalyst is too large. Needless to say, such a problem may cause a big trouble when applied to a device after mass production.

Further, from the results of Comparative Examples 3 to 4, when a catalyst having a boiling point of 115 ° C. is used, 280.
It is confirmed that a film is not obtained at a low curing temperature of ° C. (Comparative Example 3), and a film is obtained at a curing temperature of 350 ° C., but partial damage occurs (Comparative Example 4). ..

As a result of analyzing the above results, the transparent polyimide resin films of Examples 1 to 37 according to the present invention have excellent optical properties and also excellent mechanical properties such as an increase in tensile strength and elastic modulus. It turned out to be a thing.

Specifically, the transparent polyimide resin films obtained in Examples 1 to 37 have a transparency of 88% or more, a yellowness of 5.0 or less, an elasticity of 3 to 6 GPa, and a strength of 120 to 60 MPa, and are comparative examples 1 to 1. Compared with the transparent polyimide resin film obtained in No. 4, the light transmittance is high, the yellowness is low, and the mechanical properties are excellent, so that the conditions applicable as a material for a flexible display device are satisfied. I understood.

As described above, the transparent polyimide resin film produced by using the polyamic acid solution according to the present invention has an improved high-temperature process at the time of production, has high light transmittance, low yellowness, and is mechanical. It has been confirmed that it can be applied as a material for a flexible display device, a substrate, or a protective film because of its excellent characteristics.

The present invention relates to a transparent polyimide resin film produced by using a polyimide-forming composition applicable to a flexible display device.

Polyimide (PI) resin is an insoluble and infusible ultra-high heat resistant resin, and has the advantages of excellent electrical, chemical, thermal, and mechanical properties. It is widely used as a heat-resistant advanced material such as a spacecraft material, and as an electronic material such as an insulating coating agent, an insulating film, a semiconductor, and an LCD electrode protective film.

As a method for synthesizing such a polyimide resin, generally, a method of polymerizing dianhydride and diamine in an organic solvent to produce a polyamic acid solution, and then curing the solution by heat treatment to produce a film. Alternatively, a method is carried out in which a film is produced as a film through processes such as immersion, washing, and redissolution after chemically imidization.

First, a method for producing a polyimide resin film by curing a polyamic acid solution by heat treatment includes a process of heating at a high temperature of 250 to 400 ° C. for several hours. Since the resin is colored in the process, the transmittance and yellowness in the visible light region are lowered, and it is difficult to use it as an optical material that requires transparency. On the other hand, when the polyimide resin film is heated at a low temperature, the time required for producing the polyimide resin film becomes long and the molecular weight of the polyamic acid is reduced, so that there is a problem that the strength of the produced polyimide resin film is lowered.

The method for producing a polyimide resin film by chemically imidizing a polyamic acid solution is a process of adding xylene or toluene to the polyamic acid solution and imidizing it by the Dean Stark Method, or polyamic acid. The process of adding a catalyst such as pyridine and a dehydrating agent such as acetic anhydride to the acid solution and imidizing at a low temperature is included. However, in the method of chemically imidizing, the process is complicated because another Dean-Stark apparatus needs to be provided or a process such as dipping, washing, drying, and redissolving is required after imidization. Therefore, there is a problem that a large amount of wastewater is generated.

Therefore, it is required to develop a polyamic acid solution for producing a transparent polyimide resin film which exhibits high transparency and is excellent in thermal properties and mechanical properties by a relatively simple process.

The present invention employs a dianhydride monomer and a diamine monomer having a specific structure, adjusts the content of these to a specific range, and uses a catalyst having a boiling point within the specific range at a constant temperature. It is an object of the present invention to produce a transparent polyimide film which can realize low YI (Yello Index) and high light transmittance by curing and can adjust mechanical properties.

The present invention also provides a transparent polyimide film applicable to LCD and OLED flexible display device plastic transparent substrates, TFT substrates, flexible printed circuit boards, flexible OLED surface lighting substrates, electronic paper substrate materials, and the like. I am aiming.

In order to achieve the above object, the present invention has (a) a diamine represented by the following chemical formula (1), a diamine represented by the following chemical formula (2), a diamine represented by the following chemical formula (2A), and 2,2. A diamine mixture containing one or more diamines selected from the group consisting of'-dimethylbiphenyl-4,4'-diamine ; (b) dianhydride represented by the following chemical formula (3) and the following chemical formula (4). A diamine hydride mixture containing the indicated diamine hydride; (c) one or more basic catalysts selected from the group consisting of 2-methylpiperazin, 4-tert-butylpyridine, and 2,3,5-colysine; Provided is a transparent polyimide resin film produced by imidizing a polyimide-forming composition containing (d) an organic solvent; and excluding a dehydrating agent, and satisfying the following physical properties of (i) to (v).
When the film thickness is 10 μm or less
(I) The light transmittance at a wavelength of 550 nm is 88% or more.
(Ii) The yellowness according to the ASTM E313 standard is 5.0 or less.
(Iii) Haze is 1.0 or less,
(Iv) The elastic modulus is in the range of 3 to 6 GPa.
(V) The tensile strength is in the range of 120 to 200 MPa.

（前記化学式（１）中、
Ａは、単結合、−Ｃ（＝Ｏ）−、及び−Ｃ（＝Ｏ）ＮＨ−、並びにハロゲン、又はハロゲン原子で置換されたＣ _１ 〜Ｃ _６ のアルキル基で置換されたＣ_６〜Ｃ_２０のアリーレン基からなる群から選択され、
Ｘ_１及びＸ_２は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基からなる群から選択され、
但し、Ａが単結合である場合、Ｘ_１及びＸ_２のうちの少なくとも１つ以上は、ハロゲン、またはハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基であり、
ｍは、０〜２の整数である。）

(In the chemical formula (1),
A represents a single bond, -C (= O) -, and -C (= O) NH-, and halogen, or C ₆ substituted with an alkyl group of _C 1 -C ₆ substituted by a halogen atom -C Selected from a group of _{20 Halogen groups,}
X ₁ and _{X 2,} equal to or different from each other, each independently, hydrogen, _halogen, an alkyl group, and one or more hydrogen an alkyl group of _C 1 -C ₆ substituted by a halogen atom C 1 -C ₆ Selected from the group consisting of
However, when A is a single bond, at least one or more of _{X 1} and X ₂ is a halogen or an alkyl group of _{C 1 to} C ₆ substituted with a halogen atom.
m is an integer from 0 to 2. )

（前記化学式（２）中、
Ｂ _１ は、Ｃ _１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキレン基、−Ｏ−、−Ｓ−、−Ｓ（＝Ｏ）_２−、−Ｃ（＝Ｏ）ＮＨ−、及びＣ _１ 〜Ｃ _６ のアルキル基で置換または非置換されたＣ_６〜Ｃ_２０のアリーレン基からなる群から選択され、
Ｘ_３及びＸ_４は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基からなる群から選択される。）

（前記化学式（２Ａ）中、
Ｂ _２ は、単結合、Ｃ _１ 〜Ｃ _６ のアルキレン基、１つ以上の水素がハロゲン原子で置換されたＣ _１ 〜Ｃ _６ のアルキレン基、及びＣ _１ 〜Ｃ _６ のアルキル基で置換または非置換されたＣ _６ 〜Ｃ _２０ のアリーレン基からなる群から選択され、
Ｘ _３ 及びＸ _４ は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ _１ 〜Ｃ _６ のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ _１ 〜Ｃ _６ のアルキル基からなる群から選択される。）

（前記化学式（３）中、
Ｃは、４価のＣ_６〜Ｃ_２０の芳香族環基、及び４価のＣ_４〜Ｃ_２０の脂肪族環基からなる群から選択され、
前記４価のＣ_６〜Ｃ_２０の芳香族環基は、Ｃ_１〜Ｃ_６のアルキル基で置換されることがあり、
前記Ｃは、複数個の環であることができ、複数個の環は、互いに同一または異なり、複数個の環同士が、−Ｃ（＝Ｏ）ＮＨ−、及び−Ｃ（＝Ｏ）−Ｏ−からなる群から選択される１種以上の連結基を介して連結されている。）

（前記化学式（４）中、
Ｄは、Ｃ_１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキレン基、−Ｏ−、−Ｓ−、−Ｃ（＝Ｏ）−、及び−Ｓ（＝Ｏ）_２−からなる群から選択され、
Ｘ_５及びＸ_６は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基からなる群から選択され、
ｎは、１〜３の整数である。）

(In the chemical formula (2),
B ₁ represents an alkylene group of _C 1 -C _6, 1 or more hydrogen is alkylene _C 1 -C ₆ substituted by a halogen atom, -O -, - S -, - S (= O) 2 - , -C (= O) NH-, and is selected from the group consisting of arylene group substituted or unsubstituted C ₆ -C ₂₀ alkyl group C ₁ -C _6,
X ₃ and _{X 4,} equal to or different from each other, each independently, hydrogen, _halogen, an alkyl group, and one or more hydrogen an alkyl group of _C 1 -C ₆ substituted by a halogen atom C 1 -C ₆ Ru is selected from the group consisting of. )

(In the chemical formula (2A),
B ₂ represents a single _bond, C 1 -C ₆ alkylene group, one or more hydrogens alkylene group _C 1 -C ₆ substituted by a halogen atom, and unsubstituted or alkyl group of _C 1 -C ₆ Selected from the group consisting of substituted C _{6 to} C _{20 allylene groups,}
X ₃ and _{X 4,} equal to or different from each other, each independently, hydrogen, _halogen, an alkyl group, and one or more hydrogen an alkyl group of _C 1 -C ₆ substituted by a halogen atom C 1 -C ₆ Selected from the group consisting of. )

(In the chemical formula (3),
C is selected from the group consisting of _{tetravalent C 6 to} C ₂₀ aromatic ring groups and tetravalent C _{4 to} C _{20 aliphatic ring groups.}
The tetravalent C _{6 to} C ₂₀ aromatic ring groups may be substituted with _{C 1 to} C _{6 alkyl groups.}
The C can be a plurality of rings, the plurality of rings are the same or different from each other, and the plurality of rings are −C (= O) NH− and −C (= O) −O. - are connected via one or more linking groups selected either from Ranaru group. )

(In the chemical formula (4),
D is _an alkylene group of C 1 -C _6, 1 or more hydrogen is alkylene _C 1 -C ₆ substituted by a halogen atom, -O -, - S -, - C (= O) -, and Selected from the group consisting of −S (= O) ₂₋
X ₅ and _{X 6,} equal to or different from each other, each independently, hydrogen, _halogen, an alkyl group, and one or more hydrogen an alkyl group of _C 1 -C ₆ substituted by a halogen atom C 1 -C ₆ Selected from the group consisting of
n is an integer of 1 to 3. )

Furthermore, the present invention provides a transparent substrate containing the transparent polyimide resin film.

According to the present invention, by adopting a diamine monomer having a specific structure and a dianhydride monomer, adjusting the content of these to a specific range and using a catalyst having a boiling point within the specific range. , it is possible to provide a transparent polyimide resin film that Yusuke excellent optical properties, mechanical properties, thermal properties at the same time.

Further, according to the present invention, for a flexible display device that exhibits excellent physical properties and product reliability by applying the transparent polyimide resin film having excellent optical properties, mechanical properties, thermal properties, etc. to a substrate. A transparent substrate can be provided.

Hereinafter, the present invention will be described in detail. However, the examples described below are merely examples, and the present invention is not limited by these examples, and the scope of the present invention is indicated by the scope of claims described later.

< Transparent polyimide resin film >
Diamine transparent polyimide resin film according to the present invention, improved der those with excellent mechanical properties and thermal properties while maintaining the optical properties with high transparency it is, represented by (a) the following chemical formula (1) And one or more diamines selected from the group consisting of the diamine represented by the following chemical formula (2), the diamine represented by the following chemical formula (2A), and 2,2'-dimethylbiphenyl-4,4'-diamine. Diamine mixture containing (b) a diamine hydride mixture represented by the following chemical formula (3) and a diamine hydride represented by the following chemical formula (4); (c) 2-methylpiperazin, 4-tert-butyl Imidized a polyimide-forming composition containing pyridine and one or more basic catalysts selected from the group consisting of 2,3,5-colysine ; and (d) an organic solvent; and excluding the dehydrating agent. Manufactured and satisfies the following physical property conditions (i) to (v).
When the film thickness is 10 μm or less
(I) The light transmittance at a wavelength of 550 nm is 88% or more.
(Ii) The yellowness according to the ASTM E313 standard is 5.0 or less.
(Iii) Haze is 1.0 or less,
(Iv) The elastic modulus is in the range of 3 to 6 GPa.
(V) The tensile strength is in the range of 120 to 200 MPa.

(A) Diamine mixture
The polyimide-forming composition contains a diamine represented by the following chemical formula (1) and a diamine represented by the following chemical formula (2) as a diamine component.

（前記化学式（１）中、
Ａは、単結合、−Ｃ（＝Ｏ）−、及び−Ｃ（＝Ｏ）ＮＨ−、並びにハロゲン、又はハロゲン原子で置換されたＣ _１ 〜Ｃ _６ のアルキル基で置換されたＣ_６〜Ｃ_２０のアリーレン基からなる群から選択され、
Ｘ_１及びＸ_２は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基からなる群から選択され、
但し、Ａが単結合である場合、Ｘ_１及びＸ_２のうちの少なくとも１つ以上は、ハロゲン、またはハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基であり、
ｍは、０〜２の整数である。）

(In the chemical formula (1),
A represents a single bond, -C (= O) -, and -C (= O) NH-, and halogen, or C ₆ substituted with an alkyl group of _C 1 -C ₆ substituted by a halogen atom -C Selected from a group of _{20 Halogen groups,}
X ₁ and _{X 2,} equal to or different from each other, each independently, hydrogen, _halogen, an alkyl group, and one or more hydrogen an alkyl group of _C 1 -C ₆ substituted by a halogen atom C 1 -C ₆ Selected from the group consisting of
However, when A is a single bond, at least one or more of _{X 1} and X ₂ is a halogen or an alkyl group of _{C 1 to} C ₆ substituted with a halogen atom.
m is an integer from 0 to 2. )

（前記化学式（２）中、
Ｂ _１ は、Ｃ _１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキレン基、−Ｏ−、−Ｓ−、−Ｓ（＝Ｏ）_２−、−Ｃ（＝Ｏ）ＮＨ−、及びＣ _１ 〜Ｃ _６ のアルキル基で置換または非置換されたＣ_６〜Ｃ_２０のアリーレン基からなる群から選択され、
Ｘ_３及びＸ_４は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基からなる群から選択される。）

(In the chemical formula (2),
B ₁ represents an alkylene group of _C 1 -C _6, 1 or more hydrogen is alkylene _C 1 -C ₆ substituted by a halogen atom, -O -, - S -, - S (= O) 2 - , -C (= O) NH-, and is selected from the group consisting of arylene group substituted or unsubstituted C ₆ -C ₂₀ alkyl group C ₁ -C _6,
X ₃ and _{X 4,} equal to or different from each other, each independently, hydrogen, _halogen, an alkyl group, and one or more hydrogen an alkyl group of _C 1 -C ₆ substituted by a halogen atom C 1 -C ₆ Ru is selected from the group consisting of. )

(In the chemical formula (2A),
B ₂ Is a single bond, C ₁ ~ C ₆ Alkylene group of C with one or more hydrogens substituted with halogen atoms ₁ ~ C ₆ Alkylene group, and C ₁ ~ C ₆ C substituted or unsubstituted with an alkyl group of ₆ ~ C ₂₀ Selected from the group consisting of Alleren groups of
X ₃ And X ₄ Are the same or different from each other, and independently, hydrogen, halogen, and C. ₁ ~ C ₆ Alkyl group of C, and one or more hydrogens substituted with halogen atoms ₁ ~ C ₆ Selected from the group consisting of alkyl groups of. )

According to a preferred example of the present invention, the X ₁ and X ₄ can be electron withdrawing groups (EWG) well known in the art, respectively, independently of fluorine (F) or CF. It is preferably _3.

Further, the A _{can be an arylene group of C 6 to} C ₂₀ well known in the art, and specific examples thereof include phenylene, biphenylene, and triphenylene. In particular, it is preferable that A is selected from the substituent group represented by the following chemical formula (5).

前記化学式（５）中、＊は、前記化学式（１）における連結部位である。また、Ｒ_１〜Ｒ_３は、互いに同一または異なり、それぞれ独立に、Ｆ、及びＣＦ_３からなる群から選択される。

In the chemical formula (5), * is a connecting site in the chemical formula (1). Further, R _{1 to} R ₃ are the same as or different from each other, and are independently selected from the group consisting of F and CF _3.

_{By introducing at least one electron-withdrawing group (EWG) such as fluorine (F) or CF 3 in the} above-mentioned chemical formula (1), an intermolecular and intramolecular charge transfer complex (Change Transfer Complex, CTC) is introduced. ) Can be controlled to improve the transparency of the polyimide resin.

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

The content of the diamine represented by the chemical formula (1) is not particularly limited, but can be 50 to 99.9 mol% with respect to 100 mol% of the diamine mixture, and is preferably 70 to 99. Mol%. When the diamine represented by the chemical formula (1) is contained within the above range, the optical properties can be further improved due to the charge transfer effect between the substituents in the monomer.

In the present invention, the diamine represented by the chemical formula (2) or the chemical formula (2A) includes 4,4'-oxydibenzeneamine (4,4'-ODA) and 3,4-oxydibenzeneamine (3). , 4'-ODA), 3,3'-oxydibenzeneamine (3,3'-ODA), 4,4'-oxy (3- (trifluoromethyl) benzeneamine) (FODA), 4,4' -(1,4-Penilinebis (oxy)) bis (3- (trifluoromethyl) benzeneamine) (FABP), 4,4'-(perfluoropropane-2,2'-diyl) dibenzeneamine, 4 , 4'-(2,2'-(1,4-phenylene) bis (1,1,1,3,3,3-hexafluoropropane-2,2-diyl) dibenzeneamine, 4,4'- Sulfonyldibenzeneamine (4,4'-DDS), 4,4'-(4,4'-(perfluoropropane-2,2-diyl) bis (4,1-phenylene)) bis (oxy) dibenzene Amin, 4,4'-(4,4'-sulfonylbis (4,1-phenylene) bis (oxy)) dibenzeneamine, 4,4'-(1,4-phenylenebis (oxy)) dibenzeneamine , 4,4 can be selected from among the '- - (4,4' (propane-2,2-diyl) bis (4,1-phenylene)) bis (oxy) Jibenzen'ami emissions, etc. so derived structures However, the diamine represented by the chemical formula (2) _{can be a monomer containing phenyl, biphenyl, a sulfone group (SO 2} ), a silane group, and the like. When using'-ODA, FODA, FAPB, DABA (4,4'-Diaminobenzanilide), 4,4'-DDS, or 4,4'-(perfluoropropane-2,2'-diyl) dibenzeneamine Can further improve the optical properties without deteriorating the thermal properties of the polyimide resin.

The total content of the diamine represented by the chemical formula (2) , the diamine represented by the chemical formula (2A) , and 2,2'-dimethylbiphenyl-4,4'-diamine (m-Tolidine) is not particularly limited. , 0.01 to 50 mol%, preferably 0.1 to 30 mol%, based on 100 mol% of the diamine mixture. One or more selected from the group consisting of the diamine represented by the chemical formula (2), the diamine represented by the chemical formula (2A), and 2,2'-dimethylbiphenyl-4,4'-diamine (m-Tolidine). When the diamine is contained within the above range, the optical characteristics (light transmittance and yellowness) can be further improved.

In consideration of the high transparency and low yellowness of the polyimide resin, the diamine (a) according to the present invention uses TFDB as the diamine represented by the chemical formula (1) and is represented by the chemical formula (2). As one or more diamines selected from the group consisting of diamines, diamines represented by the chemical formula (2A), and 2,2'-dimethylbiphenyl-4,4'-diamines (m-polyimide) , m-polyimide, 4 , 4'-ODA, FODA, FAPB, DABA, 4,4'-DDS, or 4,4'-(perfluoropropane-2,2'-diyl) dibenzeneamine is preferably mixed and used.

(B) Diane Hydride Mixture The polyimide-forming composition according to the present invention contains diane hydride represented by the following chemical formula (3) and diane hydride represented by the following chemical formula (4) as diane hydride components.

（前記化学式（３）中、
Ｃは、４価のＣ_６〜Ｃ_２０の芳香族環基、及び４価のＣ_４〜Ｃ_２０の脂肪族環基からなる群から選択され、
前記４価のＣ_６〜Ｃ_２０の芳香族環基は、Ｃ_１〜Ｃ_６のアルキル基で置換されることがあり、
前記Ｃは、複数個の環であることができ、複数個の環は、互いに同一または異なり、複数個の環同士が、−Ｃ（＝Ｏ）ＮＨ−、及び−Ｃ（＝Ｏ）−Ｏ−からなる群から選択される１種以上の連結基を介して連結されている。）

(In the chemical formula (3),
C is selected from the group consisting of _{tetravalent C 6 to} C ₂₀ aromatic ring groups and tetravalent C _{4 to} C _{20 aliphatic ring groups.}
The tetravalent C _{6 to} C ₂₀ aromatic ring groups may be substituted with _{C 1 to} C _{6 alkyl groups.}
The C can be a plurality of rings, the plurality of rings are the same or different from each other, and the plurality of rings are −C (= O) NH− and −C (= O) −O. - are connected via one or more linking groups selected either from Ranaru group. )

（前記化学式（４）中、
Ｄは、Ｃ_１〜Ｃ_６のアルキレン基、１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキレン基、−Ｏ−、−Ｓ−、−Ｃ（＝Ｏ）−、及び−Ｓ（＝Ｏ）_２−からなる群から選択され、
Ｘ_５及びＸ_６は、互いに同一または異なり、それぞれ独立に、水素、ハロゲン、Ｃ_１〜Ｃ_６のアルキル基、及び１つ以上の水素がハロゲン原子で置換されたＣ_１〜Ｃ_６のアルキル基からなる群から選択され、
ｎは、１〜３の整数である。）

(In the chemical formula (4),
D is _an alkylene group of C 1 -C _6, 1 or more hydrogen is alkylene _C 1 -C ₆ substituted by a halogen atom, -O -, - S -, - C (= O) -, and Selected from the group consisting of −S (= O) ₂₋
X ₅ and _{X 6,} equal to or different from each other, each independently, hydrogen, _halogen, an alkyl group, and one or more hydrogen an alkyl group of _C 1 -C ₆ substituted by a halogen atom C 1 -C ₆ Selected from the group consisting of
n is an integer of 1 to 3. )

According to a preferred example of the present invention, C is a tetravalent hydrocarbon ring group well known in the art, and examples of the hydrocarbon ring group include aromatic ring groups _{C 6 to} C _20. Alternatively, C _{4 to C 40} aliphatic ring groups and the like can be mentioned. The C is preferably a tetravalent 6-membered aromatic ring group or a tetravalent 6-membered alicyclic ring group. When C is a tetravalent 6-membered aromatic ring group, the dianhydride represented by the chemical formula (3) is an aromatic dianhydride containing a diamine structure, and C is a tetravalent 6-membered aliphatic ring. When it is a group, the dianhydride represented by the chemical formula (3) can be a non-aromatic dianhydride containing a diamine structure.

The C can be a plurality of rings, the plurality of rings are the same or different from each other, and the plurality of rings are -C (= O)-, -C (= O) NH-,-. They are linked via one or more linking groups selected from the group consisting of C (= O) -O- and -S (= O) _2-.

For example, when the C is a tetravalent 6-membered aromatic ring group, one or more C _{6 to} C ₄₀ arylene groups, sulfone groups, or arylene groups and sulfone groups known in the art are linked. Can be in the form of Specific examples thereof include phenylene, biphenylene, triphenylene, and sulfonyldiphenylene. In particular, C is preferably selected from the substituent group represented by the following chemical formula (6).

前記化学式（６）中、＊は、前記化学式（３）における連結部位であり、Ｒ_４〜Ｒ_６は、互いに同一または異なり、それぞれ独立に、水素、またはＣ_１〜Ｃ_６のアルキル基である。好ましくは、それぞれ独立に、水素、またはメチル基であることができる。

In Chemical Formula (6), * is the a linking site in the chemical formula _(3), R 4 to R _6, equal to or different from each other, each independently, is hydrogen or an alkyl group of _C 1 -C _6, .. Preferably, each can be independently hydrogen or a methyl group.

The dianhydride represented by the chemical formula (3) is resistant to an external impact without being decomposed by heat or light due to the introduction of an arylene group and / or a sulfone group having a rigid structure between the dianehydrides. Since it is stable, the optical properties, thermal properties, mechanical properties, etc. of the polyimide resin produced by using it are significantly improved. Further, the compound represented by the chemical formula (3) reacts with an oxygen atom in another dianehydride monomer by introducing an amide group (-C (= O) -NH-) between the dianehydrides. As a result, hydrogen bonds are formed and a certain bonding force is generated in the main chain of the polymer, so that the mechanical properties and heat resistance properties of the polyimide resin are significantly improved.

Further, when the C is a tetravalent 6-membered aliphatic ring group, since π electrons do not exist in the structure of the compound, the formation of the charge transfer complex (CTC) is controlled to increase the transmittance of the polyimide resin. And will play a major role in achieving low yellowness.

Examples of the dianhydride represented by the chemical formula (3) include 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 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), pyromellitic dianhydride (PMDA), N, N'-(4,4'-sulfonylbis (4,1-phenylene) )) It can be selected from structures derived from bis (1,3-dioxo-octahydroisobenzofuran-5-carboxamide) and the like, but is not limited thereto.

The content of the dianhydride represented by the chemical formula (3) is not particularly limited, but can be 10 to 95 mol%, preferably 50 to 90 mol%, based on 100 mol% of the dianhydride mixture. %. When the dianhydride represented by the chemical formula (3) is contained within the above range, the high light transmittance and yellowness of the polyimide resin can be maintained and the coefficient of thermal expansion of the polyimide resin can be lowered.

Further, according to a preferred example of the present invention, the X ₅ and X ₆ can be electron-withdrawing groups (EWGs) well known in the art, each independently of fluorine (F) or CF ₃ . It is preferable to have.

Examples of the dianhydride represented by the chemical formula (4) include 5,5'-(perfluoropropane-2,2-diyl) diisobenzofuran-1,3-dione (6-FDA) and 5,5'-oxy. Diisobenzofuran-1,3-dione (ODPA), 5,5'-sulfonyldiisobenzofuran-1,3-dione (DSDA), benzophenone-3,3', 4,4'-tetracarboxylic dianhydride It can be selected from structures derived from (BTDA) and the like, but is not limited thereto. When 6FDA is used, the transparency of the polyimide resin can be improved by controlling the formation of the charge transfer complex (CTC) between the molecular chains and within the molecular chain.

The content of the dianhydride represented by the chemical formula (4) is not particularly limited, but can be 5 to 90 mol%, preferably 10 to 50 mol%, based on 100 mol% of the dianhydride. Is.

As described above, in the example of the present invention, the diamine represented by the chemical formula (1) and the diamine represented by the chemical formula (2) are used as the diamine component as the diamine hydride component, and the diamine represented by the chemical formula (3) is used. The hydride and the dian hydride represented by the chemical formula (4) are mixed and used. At this time, the (a) diamine mixture and the (b) dian hydride mixture improve the yellowness and mechanical properties of the polyimide resin. Therefore, the mixture can be mixed at a weight ratio of (a): (b) = 1: 0.1 to 10.

(C) Basic catalyst The basic catalyst is a basic catalyst having a boiling point of 140 to 200 ° C., for example, 4-tert-butylpyridine, 4-ethylpyridine, 2-methylpiperazine, 2,6-dimethyl. Piperazine, 4-tert-butylpyridine, 2-propylpyridine, 4-propylpyridine, 2,3,5-cholidine, 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, etc., which can be used alone or in admixture of two or more. it can.

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

(D) Organic solvent The solvent for synthesizing the polyimide-forming composition is not particularly limited as long as it is well known in the art. Examples of the solvent include m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), acetone, diethylacetate, and dimethylphthalate (DMP). Examples thereof include a polar solvent, a low boiling solvent such as tetrahydrofuran (THF) and chloroform, and a low absorption solvent such as γ-butyrolactone, which can be used alone or in combination of two or more.

In the polyimide-forming composition according to the present invention as described above, the contents of the diamine mixture, the dianhydride mixture, the catalyst, and the organic solvent are not particularly limited, but are based on 100% by weight of the total polyimide-forming composition. , (A) 1 to 20% by weight of the diamine mixture, (b) 1 to 20% by weight of the dianhydride mixture, (c) the content of the catalyst known in the art, eg, about 0.01 to 20% by weight, specifically. It can be about 0.01 to 15% by weight, more specifically about 0.1 to 10% by weight, and (d) the organic solvent as the balance. Here, if the content of each component in the polyimide-forming composition is less than the above range, the viscosity of the polyimide-forming composition may be too low, but on the other hand, if it exceeds the above range. May cause the viscosity of the polyimide-forming composition to be too high. Therefore, by adjusting the content of each component in the polyimide-forming composition according to the present invention within the above range, the polyimide-forming composition can be adjusted to about 1,000 to 500,000 cps, preferably about 10, It can have viscosities in the range of 000 to 200,000 cps. Further, when the viscosity of the polyimide-forming composition is within the above range , the thickness can be easily adjusted at the time of coating the polyimide-forming composition, and the surface of the coating film to be coated is uniformly formed. Become so.

On the other hand, the polyimide-forming composition according to the present invention contains, if necessary, a plasticizer, an antioxidant, a flame retardant, a dispersant, a viscosity modifier, within a range that does not impair the object and effect of the present invention. It can contain a small amount of additives such as leveling agents.

A polyamic acid can be obtained by carrying out the solution polymerization reaction of the polyimide-forming composition according to the present invention as described above. Specifically, the diamine represented by the chemical formula (1) and the diamine represented by the chemical formula (2) are added to an organic solvent to dissolve them, and then the dianhydride represented by the chemical formula (3) and the chemical formula (4) are here. ) Is added and then a solution polymerization reaction is carried out to obtain a polyamic acid. At this time, the reaction conditions are not particularly limited, but the reaction can be carried out at -20 to 80 ° C. for 1 to 12 hours (preferably 1 to 3 hours).

The polyimide resin can be in the form of a random copolymer or a block copolymer.

Since the transparent polyimide resin film according to the present invention is produced by using the polyimide-forming composition, it has improved mechanical properties (elastic modulus, strength) as well as optical properties (transparency and yellowness). Excellent thermal properties (coefficient of thermal expansion and glass transition temperature) can be expected. 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 yellowness (Yellow Index, YI) of 5.0 or less at a wavelength of 550 nm, and a haze (Haze). Haze) is 1.0 or less, the elastic modulus (Modulus) is 3 to 6 GPa, and the mechanical strength (Strength) is 120 to 200 MPa.

Further, since the transparent polyimide resin film according to the present invention contains an imide group, it is excellent in heat resistance, chemical resistance, abrasion resistance, and electrical characteristics.

The method for producing such a transparent polyimide resin film is not particularly limited, but for example, after coating (casting) the polyimide-forming composition on a glass substrate, a metal substrate, or a heat-resistant polymer substrate, the temperature is 80 to 300 ° C. A polyimide resin film can be produced by carrying out an imidization reaction (Imidization) for 1 to 12 hours while gradually raising the temperature in the above range.

As the coating method, a method well known in the art can be used without limitation, and for example, a spin coating method, a dip coating method, a solvent casting method, and a slot die coating method can be used. (Slot die coating), spray coating method (Spray coating) and the like can be mentioned.

The thickness of the transparent polyimide resin film is not particularly limited, but can be adjusted by coating the above-mentioned polyimide-forming composition one or more times so as 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, and in particular, a display for an organic EL element (OLED), a display for a liquid crystal element, a TFT substrate, and a flexible printing circuit, which are required to have high transparency and heat resistance. It can be used as a substrate for a flexible display device such as a substrate, a flexible OLED surface illumination substrate, a substrate material for electronic paper, and a protective film.

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

[Example 1]
1-1. Production of Polyimide Forming Composition After putting 640.016 g of N, N-dimethylacetamide (DMAc) in a 1500 ml three-necked round-bottom flask, the temperature of the flask was raised to 50 ° C. Next, 85.0 g of 2,2'-bis (trifluoromethyl) biphenyl-4,4'-diamine (TFDB) was added to the flask, and after 60 minutes, 2,2'-dimethylbiphenyl-4,4 1.743 g of'-diamine (m-Tol) was added. This was stirred for 1 hour to completely dissolve TFDB and m-Tol. Next, on the fresco, 45.615 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), and 5,5'-(perfluoropropane-2,2-diyl) diisobenzofuran-1 , 3-Dione (6FDA) 18.235 g were added in sequence and dissolved. At this time, the solid content was 15%, and then the reaction was carried out with stirring for 5.5 hours. After confirming the completion of the inter-monomeric reaction by checking whether the viscosity increased, 37 g of 4-tert-butylpyridine was gradually added, and the mixture was stirred for 4.5 hours. Next, it was naturally cooled to obtain a polyimide-forming composition (solution viscosity at 25 ° C.: 85,000 CPs).

1-2. Production of Transparent Polyimide Resin Film 1-1. The polyimide-forming composition obtained in 1) was coated on a glass plate for LCD using a bar coater, and then in a convection oven under a nitrogen atmosphere at 80 ° C. for 30 minutes and at 150 ° C. for 30 minutes. The imidization reaction was carried out by drying at 200 ° C. for 1 hour and 280 ° C. for 1 hour while gradually increasing the temperature. As a result, a transparent polyimide resin film having a film thickness of 52 μm (imidization rate: 85% or more) was obtained. Next, the film was separated from the glass plate to obtain a transparent polyimide resin film.

[Example 2]
2-1. Production of Polyimide Forming Composition 1-1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 85,000 CPs) was obtained.

2-2. Manufacture of transparent polyimide resin film In a nitrogen atmosphere, dry in a convection oven at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 320 ° C. for 1 hour while gradually increasing the temperature. , 1-2. Of Example 1, except that the imidization reaction is carried out. Manufactured in the same manner as above.

[Example 3]
3-1. Production of Polyimide Forming Composition 1-1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 85,000 CPs) was obtained.

3-2. Manufacture of transparent polyimide resin film In a nitrogen atmosphere, dry in a convection oven at 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 350 ° C. for 1 hour while gradually increasing the temperature. , 1-2. Of Example 1, except that the imidization reaction is carried out. Manufactured in the same manner as above.

[Example 4]
4-1 Production of Polyimide Forming Composition 1-1. Of Example 1 above, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 79000 CPs) was obtained.

4-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Manufactured in the same manner as above.

[Example 5]
5-1. Preparation of Polyimide Forming Composition 1-1. Of Example 1 above, except that 4-ethylpyridine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 82000 CPs) was obtained.

5-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 5, 5-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 6]
6-1. Preparation of Polyimide Forming Composition 1-1. Of Example 1 above, except that 2-methylpiperazine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 81000 CPs) was obtained.

6-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 6, 6-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 7]
7-1. Production of Polyimide Forming Composition 1-1. Of Example 1 above, except that TFDB: 4,4'-ODA: CBDA: 6FDA is used in a molar ratio of 9: 1: 9: 1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 122000 CPs) was obtained.

7-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 7, 7-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 8]
8-1. Production of Composition for Polyimide Formation 7-1. Of Example 7 above, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 118,000 CPs) was obtained.

8-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 8, 8-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 9]
9-1. Production of Composition for Polyimide Formation 7-1. Of Example 7 above, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 119000 CPs) was obtained.

9-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 9, 9-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 10]
10-1. Production of Polyimide Forming Composition The above, except that TFDB: FODA: CHDA: 6FDA is used in a molar ratio of 9: 1: 8: 2 and 4-methoxypyridine is used instead of 4-tert-butylpyridine. 1-1 of Example 1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 47,000 CPs) was obtained.

10-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 10, 10-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 11]
11-1. Production of Polyimide Forming Composition 10-1 of Example 10. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 47,000 CPs) was obtained.

11-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 11, 11-1. In a convection oven under a nitrogen atmosphere, using the polyimide-forming composition produced in the above stepwise, 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 320 ° C. for 1 hour, stepwise. Except that the imidization reaction is carried out by drying while gradually raising the temperature, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 12]
12-1. Production of Polyimide Forming Composition 10-1 of Example 10. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 47,000 CPs) was obtained.

12-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 12, 12-1. In a convection oven under a nitrogen atmosphere, using the polyimide-forming composition produced in the above stepwise, 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 350 ° C. for 1 hour, stepwise. Except that the imidization reaction is carried out by drying while gradually raising the temperature, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 13]
13-1. Production of Polyimide Forming Compositions Except for the use of TFDB: FODA: s-BPDA: 6FDA in a molar ratio of 9: 1: 9: 1 and 4-methoxypyridine instead of 4-tert-butylpyridine. 1-1. Of the first embodiment. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 112000 CPs) was obtained.

13-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 13, 13-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 14]
14-1. Production of Composition for Polyimide Formation 13-1 of Example 13 above, except that 4-tert-butylpyridine is used instead of 4-methoxypyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 113000 CPs) was obtained.

14-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 14, 14-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 15]
15-1. Preparation of Polyimide Forming Composition 13-1. Of Example 13 above, except that 3-picoline is used instead of 4-methoxypyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 110,000 CPs) was obtained.

15-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 15, 15-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 16]
16-1. Production of Composition for Polyimide Formation 13-1 of Example 13 above, except that 2,3-lutidine is used instead of 4-methoxypyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 112000 CPs) was obtained.

16-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. 16-1 of Example 16 instead of the polyimide-forming composition used in. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 17]
17-1. Production of Composition for Polyimide Formation 13-1 of Example 13 above, except that 2,3,5-cholidine is used instead of 4-methoxypyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 119000 CPs) was obtained.

17-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 17, 17-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 18]
18-1. Production of Polyimide Forming Compositions TFDB: FABP: a-BPDA: ODPA were used in a molar ratio of 9: 1: 7: 3 and 4-diazabicyclo [2.2.2] instead of 4-tert-butylpyridine. Except for the use of octane, 1-1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 52000 CPs) was obtained.

18-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 18, 18-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 19]
19-1. Production of Polyimide Forming Composition 18-1 of Example 18. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 52000 CPs) was obtained.

19-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 19, 19-1. In a convection oven under a nitrogen atmosphere, using the polyimide-forming composition produced in the above stepwise, 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 320 ° C. for 1 hour, stepwise. Except that the imidization reaction is carried out by drying while gradually raising the temperature, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 20]
20-1. Production of Polyimide Forming Composition 18-1 of Example 18. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 52000 CPs) was obtained.

20-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 20, 20-1. In a convection oven under a nitrogen atmosphere, using the polyimide-forming composition produced in the above stepwise, 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 350 ° C. for 1 hour, stepwise. Except that the imidization reaction is carried out by drying while gradually raising the temperature, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 21]
21-1. Production of Polyimide Forming Composition 1-1. Of Example 1 above, except that TFDB: DABA: CBDA: DSDA is used in a molar ratio of 8: 2: 8: 2. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 83000 CPs) was obtained.

21-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 21, 21-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 22]
22-1. Production of Composition for Polyimide Formation 21-1 of Example 21 above, except that 2,3,5-cholidine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 81000 CPs) was obtained.

22-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 22, 22-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 23]
23-1. Production of Composition for Polyimide Formation 21-1 of Example 21 above, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 82000 CPs) was obtained.

23-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. Instead of the polyimide-forming composition used in Example 23, 23-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 24]
24-1. Production of Polyimide Forming Composition TFDB: 4,4'-DDS: s-BPDA: 6FDA was used in a molar ratio of 9: 1: 7: 3 and 4-diazabicyclo [2] instead of 4-tert-butylpyridine. .2.2] Except for the use of octane, 1-1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 61000 CPs) was obtained.

24-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 24, 24-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 25]
25-1. Production of Polyimide Forming Composition 24-1 of Example 24. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 61000 CPs) was obtained.

25-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 25, 25-1. In a convection oven under a nitrogen atmosphere, using the polyimide-forming composition produced in the above stepwise, 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 350 ° C. for 1 hour, stepwise. Except that the imidization reaction is carried out by drying while gradually raising the temperature, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 26]
26-1. Production of Polyimide Forming Composition TFDB: 4,4- (perfluoropropane-2,2'-diyl) dibenzeneamine: CBDA: 6FDA was used in a molar ratio of 9: 1: 7: 3 and 4-tert. 1-1. Of Example 1 above, except that 4-methoxypyridine is used instead of −butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 47,000 CPs) was obtained.

26-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 26, 26-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 27]
27-1. Production of Polyimide Forming Composition 1-1. Of Example 1 above, except that TFDB: FODA: s-BPDA: DSDA is used in a molar ratio of 9: 1: 9: 1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 107,000 CPs) was obtained.

27-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 27, 27-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 28]
28-1. Production of Polyimide Forming Composition 1-1. Of Example 1 above, except that TFDB: FODA: s-BPDA: BTDA is used in a molar ratio of 9: 1: 9: 1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 89000 CPs) was obtained.

28-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 28, 28-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 29]
29-1. Production of Composition for Polyimide Formation 28-1 of Example 28, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 85,000 CPs) was obtained.

29-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 29, 29-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 30]
30-1. Production of Composition for Polyimide Formation 28-1. Of Example 28, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 87,000 CPs) was obtained.

30-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 30, 30-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 31]
31-1 Production of Polyimide Forming Composition TFDB: 4,4'-DDS: s-BPDA: 6FDA was used in a molar ratio of 8: 2: 7: 3 and 4-tert-butylpyridine was used instead of 4-tert-butylpyridine. Except for the use of diazabicyclo [2.2.2] octane, 1-1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 46000 CPs) was obtained.

31-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 31, 31-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 32]
32-1. Production of Polyimide Forming Composition TFDB: 4,4'-DDS: Bicyclo [2.2.1] Heptane-2,3,5,6-tetracarboxylic dianhydride: 6FDA 8: 2: 7: 3 1-1. Of the above-mentioned Example 1 except that it is used in the molar ratio of. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 37,000 CPs) was obtained.

32-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 32, 32-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 33]
33-1. Production of Composition for Polyimide Formation 32-1 of Example 32, except that 2,3,5-cholidine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 35,000 CPs) was obtained.

33-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 33, 33-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 34]
34-1. Production of Composition for Polyimide Formation 32-1 of Example 32, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 35,000 CPs) was obtained.

34-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 34, 34-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 35]
35-1. Production of Polyimide Forming Composition TFDB: FODA: Bicyclo [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride: 6FDA 9: 1: 7: 3 Except for the use in molar ratio, 1-1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 41000 CPs) was obtained.

35-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 35, 35-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 36]
36-1. Production of Composition for Polyimide Formation 35-1. Of Example 35, except that 4-diazabicyclo [2.2.2] octane is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 41000 CPs) was obtained.

36-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 36, 36-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Example 37]
37-1. Production of Composition for Polyimide Formation 35-1. Of Example 35, except that 4-methoxypyridine is used instead of 4-tert-butylpyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 40,000 CPs) was obtained.

37-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Example 37, 37-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. A transparent polyimide resin film was produced in the same manner as in the above.

[Comparative Example 1]
1-1. Preparation of Polyimide Forming Composition 1-1. Of Example 1 above, except that 19.987 g of pyridine is used instead of 4-tert-butyl pyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 82000 CPs) was obtained.

1-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Comparative Example 1, 1-1. Except for using the polyimide-forming composition produced in Example 1, 1-2. After manufacturing in the same manner as in the above, an attempt was made to separate the film from the glass plate, but the formed film cracked and the film could not be obtained.

[Comparative Example 2]
2-1. Production of Composition for Polyimide Formation 1-1. Of Comparative Example 1 except that isoquinoline is used instead of pyridine. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 80,000 CPs) was obtained.

2-2. Production of Transparent Polyimide Resin Film 1-2 of Comparative Example 1. In place of the polyimide-forming composition used in Comparative Example 2, 2-1. In Comparative Example 1 1-2, except that the polyimide-forming composition produced in the above was used. However, a normal film could not be obtained because the remaining amount of isoquinoline was too large.

[Comparative Example 3]
3-1. Production of Polyimide Forming Composition 1-1. Of Comparative Example 1 except that TFDB: BTDA: 6FDA is used in a molar ratio of 10: 7: 3. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 73000 CPs) was obtained.

3-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Comparative Example 3, 3-1. In Comparative Example 1 1-2, except that the polyimide-forming composition produced in the above was used. After manufacturing in the same manner as in the above, an attempt was made to separate the film from the glass plate, but the formed film cracked and the film could not be obtained.

[Comparative Example 4]
4-1. Production of polyimide-forming composition
Except for the use of TFDB: BTDA: 6FDA in a molar ratio of 10: 7: 3, 1-1. In the same manner as above, a polyimide-forming composition (solution viscosity at 25 ° C.: 73000 CPs) was obtained.

4-2. Production of Transparent Polyimide Resin Film 1-2 of Example 1. In place of the polyimide-forming composition used in Comparative Example 4, 4-1. In a convection oven under a nitrogen atmosphere, using the polyimide-forming composition produced in the above stepwise, 80 ° C. for 30 minutes, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 350 ° C. for 1 hour, stepwise. Except that the imidization reaction is carried out by drying while gradually raising the temperature, 1-2. Manufactured in the same manner as above. Next, the polyimide film was separated from the glass plate and obtained.

The compositions of the diamine mixture, the dianhydride mixture, and the catalyst used in Examples 1 to 37 and Comparative Examples 1 to 4 described above are shown in Table 1 below.

[Experimental Example 1] Evaluation of Physical Properties of Transparent Polyimide Resin Film The physical characteristics of the transparent polyimide resin film obtained in Examples 1 to 37 and Comparative Examples 1 to 4 described above are evaluated by the following methods, and the results are shown in the table. Shown in 2.

(1) Measurement of light transmittance (T%) At a wavelength of 550 nm, using a UV-Vis NIR Spectrophotometer (manufactured by Shimadzu Corporation, model name: UV-3150), a C light source and a viewing angle 2 according to the standards of ASTM E313-73. Measurements were made at °.

(2) Measurement of Yellowness (Yellow Index, YI) Using a spectrophotometer (manufactured by Konica Minolta, model name: CM-3700d), the yellowness at a wavelength of 550 nm was measured according to the standards of ASTM E313.

(3) Measurement of mechanical properties Using UTM (manufactured by Instron, model name: 5942), tensile strength (Strength, MPa) and elastic modulus (Modulus, GPa) were measured according to the ISO 527-3 standard.

From Tables 1 and 2 above, changes in characteristics depending on the composition of the obtained transparent polyimide resin film can be seen.

First, from the results of Examples 1 to 37, when the same composition and the same catalyst are used, but different curing temperatures are applied, the higher the curing temperature, the more the optical characteristics deteriorate, and the mechanical characteristics differ greatly. It turns out that there is no. That is, it can be seen that a transparent polyimide resin film having excellent properties can be obtained in the imidization step in which the curing temperature is 280 ° C.

Further, from the results of Examples 1 and 4 to 6, it can be seen that when catalysts having different boiling points are used at the same curing temperature (280 ° C.), a transparent polyimide resin having similar characteristics can be obtained. However, in Example 5, it is confirmed that the obtained film is partially damaged.

Furthermore, from the results of Examples 7 to 37, when various basic catalysts having a boiling point of 140 to 200 ° C. are used, transparency having excellent properties even in an imidization step in which the curing temperature is relatively low at 300 or less. It can be seen that a polyimide resin film can be obtained. That is, it is confirmed that the high temperature process can be improved at the time of production.

From the above results, it is confirmed that the optical properties and the mechanical properties can be adjusted by combining the composition, the curing temperature, and the type of catalyst.

On the other hand, from the results of Comparative Examples 1 and 2, when pyridine having the same composition and a low boiling point of 115 ° C. was used as a catalyst, no film was obtained (Comparative Example 1), and isoquinoline having a boiling point of 240 ° C. When is used as a catalyst, a film is obtained, but it is confirmed that the remaining amount of the catalyst is too large. Needless to say, such a problem may cause a big trouble when applied to a device after mass production.

Further, from the results of Comparative Examples 3 to 4, when a catalyst having a boiling point of 115 ° C. was used, a film was not obtained at a low curing temperature of 280 ° C. (Comparative Example 3), and at a curing temperature of 350 ° C., Although a film has been obtained, it is confirmed that partial damage occurs (Comparative Example 4).

As a result of analyzing the above results, the transparent polyimide resin films of Examples 1 to 37 according to the present invention have excellent optical properties and also excellent mechanical properties such as an increase in tensile strength and elastic modulus. It turned out to be a thing.

Specifically, the transparent polyimide resin films obtained in Examples 1 to 37 have a transparency of 88% or more, a yellowness of 5.0 or less, an elasticity of 3 to 6 GPa, and a strength of 120 to 60 MPa, and are comparative examples 1 to 1. Compared with the transparent polyimide resin film obtained in No. 4, the light transmittance is high, the yellowness is low, and the mechanical properties are excellent, so that the conditions applicable as a material for a flexible display device are satisfied. I understood.

As described above, the transparent polyimide resin film produced by using the polyimide-forming composition according to the present invention has improved high-temperature steps during production, high light transmittance, low yellowness, and It has been confirmed that it can be applied as a material for a flexible display device, a substrate or a protective film because of its excellent mechanical properties.

Claims (12)

(A) A diamine mixture containing a diamine represented by the following chemical formula (1) and a diamine represented by the following chemical formula (2);
(B) A dianhydride mixture containing the dianhydride represented by the following chemical formula (3) and the 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 polyamic acid solution containing.

(In the chemical formula (1),
A represents a single bond, -C (= O) -, - C (= O) NH-, and is selected from the group consisting of arylene group _C 6 _{-C 20,}
X ₁ and X ₂ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
However, when A is a single bond, at least one or more of _{X 1} and X _{2 is a halogen.}
Alternatively, it is an alkyl group of _{C 1 to C 6} substituted with a halogen atom.
The arylene groups of C _{6 to} C _{20 are halogen or C 1} to C 20 substituted with a halogen atom.
It may be substituted with an alkyl group of C _6,
m is an integer from 0 to 2. )

(In the chemical formula (2),
B represents a single _bond, an alkylene group of C 1 -C _6, 1 or more hydrogen is alkylene _C 1 -C ₆ substituted by a halogen atom, -O -, - O-B -O -, - S -, -S (= O) _2- , -C
(= O) Selected from the group consisting of allylene groups of _{NH- and C 6 to} C _20.
X ₃ and X ₄ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
The arylene group _C 6 _{-C 20} is selected from _halogen, C 1 -C alkyl group having ₆ or it may be substituted with an alkyl group of _C 1 -C ₆ substituted by a halogen atom. )

(In the chemical formula (3),
C is selected from the group consisting of _{tetravalent C 6 to} C ₂₀ aromatic ring groups and tetravalent C _{4 to} C _{20 aliphatic ring groups.}
The tetravalent C _{6 to} C ₂₀ aromatic ring groups may be substituted with _{C 1 to} C _{6 alkyl groups.}
The C can be a plurality of rings, the plurality of rings are the same or different from each other, and the plurality of rings are -C (= O)-, -C (= O) NH-,-. C (= O) -O- and -S (
= O) It is linked via one or more linking groups selected from the group consisting of _{2 −.} )

(In the chemical formula (4),
D _is, C 1 -C ₆ alkylene group, one or more _C 1 hydrogens are replaced by halogen atoms as -C
Selected from the group consisting of ₆ alkylene groups, −O−, −S−, −C (= O) −, and −S (= O) _2−.
X ₅ and X ₆ are the same or different from each other, and are independent of hydrogen, halogen, and C ₁ to C.
₆ alkyl group and one or more hydrogen, is selected from the group consisting of alkyl groups of C ₁ -C ₆ substituted by a halogen atom,
n is an integer of 1 to 3. ) The polyamic acid solution according to claim 1, wherein X _{1 to} X ₆ are each independently _{an electron-withdrawing group (EWG) of F or CF 3.} The A is selected from the substituent group represented by the following chemical formula (5), claim 1.
Polyamic acid solution described in:

(In the chemical formula (5),
* Indicates the connection site in the chemical formula (1).
R _{1 to} R ₃ are identical or different from each other and are independently selected from the group consisting of _{hydrogen, F, and CF 3.} ) The C is selected from the substituent group represented by the following chemical formula (6), claim 1.
Polyamic acid solution described in:

(In the chemical formula (6),
* Indicates the connection site in the chemical formula (3).
R _{4 to} R ₆ are the same or different from each other and are independently selected from _{hydrogen or alkyl groups C 1 to} C _6. ) The basic catalysts are 4-ethylpyridine, 2-methylpiperazine, 2,6-dimethylpiperazine, 4-tert-butylpyridine, 2-propylpyridine, 4-propylpyridine, 2,3,5-cholidine, 2, 5-Lutidine, 2,6-Lutidine, 2,3-Lutidine,
4-Diazabicyclo [2,2,2] octane, 3-ethylpyridine, 3-picoline, 2,
The polyamic acid solution according to claim 1, which is one or more selected from the group consisting of 3-dimethylpyrazine and 2,5-dimethylpyrazine. The content of the diamine represented by the chemical formula (1) is 50 to 99.9 mol% with respect to 100 mol% of the diamine mixture.
The polyamic acid solution according to claim 1, wherein the content of the diamine represented by the chemical formula (2) is 0.1 to 50 mol% with respect to 100 mol% of the diamine mixture. The content of dianhydride represented by the chemical formula (3) is the dianhydride mixture 1
The polyamic acid solution according to claim 1, which is 10 to 95 mol% with respect to 00 mol%. The content ratio of the (a) diamine mixture and the (b) dianhydride mixture is (a) :(
b) The polyamic acid solution according to claim 1, wherein the ratio is 1: 0.1 to 10 by weight. The polyamic acid solution according to claim 1, which has a viscosity of 1,000 to 500,000 cps. A transparent polyimide resin film produced by imidizing the polyamic acid solution according to any one of claims 1 to 9. The transparent polyimide resin film according to claim 10, which satisfies the following physical properties of (i) to (v):
(I) When the film thickness is 10 μm or less, the light transmittance at a wavelength of 550 nm is 88% or more.
(Ii) The yellowness according to the ASTM E313 standard is 5.0 or less.
(Iii) Haze is 1.0 or less,
(Iv) The elastic modulus is in the range of 3 to 6 GPa.
(V) The tensile strength is in the range of 120 to 200 MPa. A transparent substrate comprising the transparent polyimide resin film according to claim 10 or 11.