KR20160037847A - Resin composition for display substrate, thin resin film for display substrate, and process for producing thin resin film for display substrate - Google Patents

Abstract

The present invention provides a highly heat resistant resin composition for a display substrate having a sufficient transparency and an appropriate linear expansion coefficient without depending on a curing condition as a substrate for a flexible display. The present invention relates to a compound represented by any one of formulas (1-1) and (1-4): wherein Ar ¹ and Ar ² are each different and independently represent a tetravalent group having an aromatic group having a substituent substituted with fluorine, Ar ³ Represents a divalent group represented by the formula (4) (wherein q represents 1 or 2 and 1 represents 1 or 2), and n ¹ and n ⁴ represent the number of each repeating unit) ≪ / RTI > And a resin composition for a display substrate containing an organic solvent.

Description

Technical Field The present invention relates to a resin thin film for a display substrate, a resin thin film for a display substrate, and a resin thin film for a display substrate. BACKGROUND ART [0002]

The present invention relates to a resin composition for a display substrate, a resin thin film for a display substrate, and a method for producing a resin thin film for a display substrate.

In recent years, along with the rapid progress of displays such as liquid crystal, organic EL, and electronic paper, and electronics such as solar cells and touch panels, there has been a demand for thinning and lightening of devices and also in flexibility. In these devices, various electronic elements such as a thin film transistor and a transparent electrode are formed on a glass substrate. By changing the glass material into a film material, the panel itself can be made thinner, lighter, and more flexible.

However, in addition to transparency, a film material to be replaced with glass is required to have a high heat resistance in that a high-temperature process is required when a fine electronic device made of an inorganic material is formed on a film, Since the difference in coefficient of linear thermal expansion between the material and the film may lead to warpage of the film or destruction of the electronic element after formation of the electronic element, a low linear thermal expansion property as that of the inorganic material is required.

On the other hand, polyimide resins have been applied to electronic component materials such as FPCs because they have high heat resistance and high insulation performance. In these applications, metal, such as silicon or copper, is frequently laminated, and attempts have been made to reduce the linear thermal expansion coefficient of a polyimide resin to the same level as that of silicon or metal.

 However, such a polyimide resin for electronic component materials has high heat resistance and low linear expansion, but generally has low transparency and can not be used as an optical film to replace glass.

Therefore, several proposals have been made as polyimide materials capable of avoiding this problem. Patent Document 1 discloses a polyimide film for a display substrate using a tetracarboxylic acid dianhydride containing an alicyclic structure and a polyimide obtained from various diamines. Patent Document 2 discloses a polyimide film for a display substrate using an alicyclic tetracarboxylic acid dianhydride having a cyclohexane skeleton and a polyimide obtained from an aromatic diamine containing a sulfone group.

Japanese Patent Application Laid-Open No. 2008-231327 Japanese Patent Publication No. 2008-297360

As described above, a material for improving heat resistance has been proposed as a material for a transparent flexible display substrate. However, since the tetracarboxylic acid dianhydride used in Patent Document 1 contains an aromatic group, it contains an aromatic group There is a problem that the transparency of the film obtained by intramolecular conjugation or charge transfer interaction of the polyimide chain is lowered as compared with the tetracarboxylic acid dianhydride consisting only of the alicyclic group. In addition, since the acid dianhydride used in Patent Document 2 has a special structure of cyclohexane skeleton of cis structure, the general versatility is insufficient, the production cost of polyimide becomes relatively high, and further, the obtained product becomes expensive there is a problem.

Further, the alicyclic tetracarboxylic acid dianhydride has a problem that a high-molecular-weight substance sufficient to exhibit sufficient film toughness in terms of polymerization reactivity may not be obtained. Of these, 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride (hereinafter referred to as CBDA), which is most widely known among tetracarboxylic dianhydrides, exhibits relatively high polymerization reactivity with diamines , Imidization reaction of the polyimide precursor from the steric structure is difficult to occur and higher temperature is required for completing the imidization reaction. This causes the coloring of the polyimide film and the use of CBDA for the display substrate is not advantageous (Patent Document 1 and Patent Document 2).

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a resin composition for a display substrate having high heat resistance, which has sufficient transparency and appropriate linear expansion coefficient without depending on a curing condition as a substrate for a flexible display.

Means for Solving the Problems The present inventors have intensively studied in order to achieve the above object, and as a result, have found the following inventions.

Wherein Ar ¹ and Ar ² are each independently a quadrivalent group having an aromatic group having a substituent substituted with fluorine and Ar ³ Represents a divalent group represented by the formula (4) (wherein q represents 1 or 2 and 1 represents 1 or 2), n ¹ and n ⁴ represent the number of each repeating unit, and n ¹ and n ⁴ , wherein n ¹ : n ⁴ is 50:50 to 99: 1); And an organic solvent.

[Chemical Formula 1]

(2): wherein Ar ¹ is represented by the following formula (2): wherein k represents 1 or 2, p represents 1 or 2, and Ar ² is represented by the formula (3) A fluoroalkylene group having 1 to 3 carbon atoms.

(2)

<3> The composition of <1> or <2>, wherein Ar ¹ is represented by formula (2-1).

(3)

&Lt; 4 &gt; The composition according to any one of &lt; 1 &gt; to &lt; 3 &gt;, wherein Ar &lt; ² &gt;

[Chemical Formula 4]

<5> The composition according to any one of <1> to <4>, wherein Ar ³ is any one of formulas (4-1) to (4-6).

[Chemical Formula 5]

(6) The polyamic acid according to any one of (1) to (5), wherein Ar ¹ and Ar ² have the same definitions as above, and Ar ⁴ represents a group represented by formula (5) , 2 or 3), and n ² and n ⁵ represent the number of each repeating unit. The composition according to any one of <1> to <5>, wherein the composition further contains a repeating unit represented by the following formula

[Chemical Formula 6]

The organic solvent may be a solvent represented by the following formula (A) or (B): wherein R ¹ and R ² each independently represent an alkyl group of 1 to 4 carbon atoms, and h represents a natural number &Lt; 1 &gt; to &lt; 6 &gt;.

(7)

&Lt; 8 &gt; A resin thin film for a display substrate produced by using the resin composition for a display substrate according to any one of &lt; 1 &gt; to &lt; 7 &gt;.

&Lt; 9 &gt; An image display device comprising a resin thin film for a display substrate of <8>.

&Lt; 10 &gt; A method for producing a resin thin film for a display substrate using the resin composition for a display substrate according to any one of &lt; 1 &gt; to &lt; 7 &gt;.

&Lt; 11 &gt; A method for manufacturing an image display apparatus using a resin thin film for a display substrate according to &lt; 8 &gt;.

According to the present invention, it is possible to provide a resin composition for a display substrate having a high heat resistance, which has sufficient transparency and an appropriate coefficient of linear expansion without depending on a curing condition, as a substrate for a flexible display.

The resin composition for a display substrate of the present invention can form a useful cured film having required performance as a flexible display substrate, that is, sufficient heat resistance, high transparency, suitable linear expansion coefficient, and appropriate flexibility without being influenced by the curing condition of the film production . Therefore, the cured film can be used for a base film for a flexible display or the like.

Hereinafter, the present invention will be described in detail.

The resin composition for a display substrate of the present invention is a polyamic acid containing repeating units represented by formulas (1-1) and (1-4); And an organic solvent.

In the formulas, Ar ¹ and Ar ² are each different and independently represent a tetravalent group having an aromatic group having a substituent substituted with fluorine;

Ar ³ represents a divalent group represented by the formula (4) (wherein q represents 1 or 2 and 1 represents 1 or 2);

n ¹ and n ⁴ is the number of the recurring units, n ¹ and n ⁴ in the ratio n ^1: n ⁴ is 50: 50 to 99: 1, preferably 70: 30 to 95: 5, and more preferably 70: 30 to 90: 10.

[Chemical Formula 8]

Ar ¹ in the formula (1-1) is represented by the following formula (2) and Ar ² in the formula (1-4) is represented by the following formula (3).

In the formula (2), k represents the number of trifluoromethyl groups substituted with a benzene ring and is 1 or 2, preferably 1, and p is 1 or 2, preferably 2.

In the formula (3), X represents a fluoroalkylene group having 1 to 3 carbon atoms.

[Chemical Formula 9]

A preferable example of the group represented by the formula (2) is a group represented by the following formula (2-1), but is not limited thereto.

[Chemical formula 10]

Examples of the group represented by X in the formula (3) include difluoromethylene group (-CF ₂ -), trifluoromethylfluoromethylene group (-CF (CF ₃ ) -), 1,1,2,2 (-CF ₂ CF ₂ -), 1,1,1,3,3,3-hexafluoropropane-2,2-diyl group (-C (CF ₃ ) ₂ -), , 1,2,2,3,3-hexafluorotrimethylene group (-CF ₂ CF ₂ CF ₂ -), and the like, but 1,1,1,3,3,3-hexafluoropropane-2 , And 2-diyl group are preferable.

A preferable example of the group represented by the formula (3) is a group represented by the formula (3-1), but is not limited thereto.

(11)

Preferable examples of Ar ³ represented by the formula (4) include groups represented by the formulas (4-1) to (4-6), but the present invention is not limited thereto. The Ar ³ represented by the formula (4) is preferably (4-1), (4-2), (4-3) or (4-5), and from the viewpoint of availability, Is more preferable.

[Chemical Formula 12]

The above-mentioned polyamic acid preferably contains a repeating unit represented by formulas (1-2) and (1-5).

Wherein Ar ¹ and Ar ² have the same definitions as above,

Ar ⁴ represents a divalent group represented by the formula (5) (wherein r represents 1, 2 or 3).

n ² and n ⁵ represent the number of each repeating unit, and n ² : n ^{5, which} is the ratio of n ² and n ⁵ , is preferably 50:50 to 99: 1, more preferably 70:30 to 95: More preferably from 70:30 to 90:10.

The sum (n ¹ + n ⁴ ) of the number n ¹ of repeating units represented by the formula (1-1) and the number n ⁴ of repeating units represented by the formula (1-4) (N ¹ + n ⁴ ), which is the ratio of the number n ² of repeating units represented by the following formula (1-2) : n ² is preferably 50:50 to 99: 1, more preferably 70:30 to 95: 5, and even more preferably 75:25 to 90:10.

[Chemical Formula 13]

In the formula (5), r is 1, 2 or 3, preferably 1 or 2, more preferably 1.

Preferable examples of the group represented by formula (5) include groups represented by formulas (5-1) to (5-3), but are not limited thereto.

[Chemical Formula 14]

It is preferable that the polyamic acid described above further contains a repeating unit represented by formulas (1-3) and (1-6).

Wherein Ar ¹ and Ar ² have the same definitions as above,

Ar ⁵ represents a divalent group represented by the formula (6) (wherein Y is -O- or -S-, preferably -O-, and s is 1 or 2, preferably 2) .

n ³ and n ⁶ represent the number of each repeating unit, and n ³ : n ^{6, which} is the ratio of n ³ and n ⁶ , is preferably 50:50 to 99: 1, more preferably 70:30 to 95: More preferably from 70:30 to 90:10.

(N ¹ + n ⁴ ) of the number n ¹ of repeating units represented by the formula (1-1) and the number n ⁴ of repeating units represented by the formula (1-4) ratio representing the number of repeating units ^{n 3 (n 1 + n 4} ): n 3 is preferably from 60: 40 to 99: 1, more preferably from 70:30 to 99: 1, still more preferably 80: 20 to 99: 1.

[Chemical Formula 15]

Preferable examples of the group represented by the formula (6) include groups represented by the formulas (6-1) to (6-5), but are not limited thereto.

[Chemical Formula 16]

The polyamic acid containing the repeating units represented by the above formulas (1-1) and (1-4) is obtained by repeating the repeating units represented by the formulas (1-1) and (1-4) May contain other constituent units).

The polyamic acid further containing the repeating units represented by the above formulas (1-2) and (1-5), that is, the polyamic acid represented by the above formulas (1-1), (1-2), (1-4) (1), (1-2), (1-4) and (1-5) in a random order (these And other constituent units may be contained between the units).

The polyamic acid further containing the repeating units represented by the above formulas (1-3) and (1-6), that is, the polyamic acid containing the repeating units represented by the above formulas (1-1) to (1-6) The acid is preferably bound to the repeating units represented by the formulas (1-1) to (1-6) in an arbitrary order (which may contain another constituent unit between these units).

The bond "hand" of each repeating unit in the formulas (1-1) to (1-6) does not penetrate the parentheses in order to explain the above. In short, the polyamic acid used in the present invention is a copolymer having the above structural unit, and the copolymer may be any of a block copolymer, an alternating copolymer, and a random copolymer.

The weight average molecular weight of the polyamic acid used in the present invention is 5000 or more, preferably 10000 or more. On the other hand, although the upper limit of the weight average molecular weight of the polyamic acid used in the present invention is usually 200,000 or less, it is preferable to suppress the excessively high viscosity of the resin composition (varnish), to obtain a resin thin film with high flexibility with good reproducibility It is preferably not more than 150,000, more preferably not more than 100,000.

The weight average molecular weight in the present invention is measured by gel permeation chromatography (GPC) in terms of polystyrene.

The polyamic acid used in the present invention may contain other structural units (repeating units) in addition to the structural units (repeating units) represented by the above formulas (1-1) to (1-6) Is preferably less than 40 mol%, preferably less than 30 mol%, more preferably less than 20 mol%, still more preferably less than 10 mol% in the entire unit.

Polyamic used in the present invention, the acid formula (7) to (8), an acid dianhydride and a diamine represented by the formula (9) to (11) represented by, after taking into account the structure derived from these, the above-mentioned n ¹ ~ n can be obtained by reacting a molar ratio satisfying the ratio of ^6. In the formulas, Ar ¹ to Ar ⁵ have the same definitions as above.

[Chemical Formula 17]

The acid dianhydrides represented by the formulas (7) to (8) and the diamines represented by the formulas (9) to (11) may be either commercially available products or synthesized by known methods.

As the acid dianhydride represented by the above formula (7), N, N '- [2,2'-bis (trifluoromethyl) biphenyl-4,4'- , 3-dihydroisobenzofuran-5-carboamide), and the like, but the present invention is not limited thereto.

As the acid dianhydride represented by the above formula (8), 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride and the like can be exemplified, but the present invention is not limited thereto.

As the diamine represented by the above formula (9), there can be mentioned 2,2'-bis (trifluoromethyl) benzidine, 3,3'-bis (trifluoromethyl) benzidine, 5- Diamine, 5-trifluoromethylbenzene-1,2-diamine, 3,5-bis (trifluoromethyl) benzene-1,2-diamine, and the like.

Examples of the diamine represented by the above formula (10) include 1,4-benzenediamine (p-phenylenediamine), 1,3-benzenediamine (m-phenylenediamine), 1,2- ), But the present invention is not limited thereto.

Examples of the diamine represented by the formula (11) include 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, (Aminophenoxy) benzene, 1,3'-bis (4-aminophenoxy) benzene and 1,4-bis (3-aminophenoxy) benzene.

In the above reaction, the acid dianhydrides represented by the formulas (7) to (8) and the diamines represented by the formulas (9) to (11) (molar ratio) are suitably set in consideration of the molecular weight of the polyamic acid However, with respect to the amine component 1, the acid anhydride component can usually be set to about 0.9 to 1.1, and preferably about 0.95 to 1.02.

The above reaction is preferably carried out in a solvent. When a solvent is used, various solvents may be used as long as they do not adversely affect the reaction.

Specific examples include m-cresol, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N- Amide, N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropylamide, 3-ethoxy- Butoxy-N, N-dimethylpropylamide, 3-tert-butoxy-N, N-dimethylacetamide, N-dimethylformamide, and? -Butyrolactone. However, the present invention is not limited thereto. These may be used alone or in combination of two or more.

The reaction temperature may be appropriately set within a range from the melting point to the boiling point of the solvent to be used, and is usually about 0 to 100 ° C, preferably about 0 to 70 ° C, more preferably about 0 to 60 ° C, Is preferably about 0 to 50 ° C.

The reaction time depends on the reaction temperature and the reactivity of the raw material, and therefore can not be uniformly defined, but is usually about 1 to 100 hours.

By the above-mentioned method, a reaction solution containing the desired polyamic acid can be obtained.

In the present invention, it is usually preferable to filter the reaction solution and then use the filtrate as it is or diluted or concentrated to be used as a resin composition (varnish) for a display substrate. By doing so, it is possible not only to reduce the incorporation of impurities which may cause deterioration of the heat resistance, flexibility or linear expansion coefficient characteristics of the resulting resin thin film, but also to obtain a composition efficiently.

The resin composition for a display substrate of the present invention contains an organic solvent. The organic solvent is not particularly limited, and examples thereof include the same ones as specific examples of the reaction solvent for the above reaction. More specifically, there may be mentioned N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, Pyrrolidone,? -Butyrolactone, and the like. The organic solvent may be used singly or in combination of two or more kinds.

Among them, in consideration of obtaining a resin thin film having high flatness with good reproducibility, it is preferable that R ¹ and R ² each independently represent an alkyl group having 1 to 4 carbon atoms , and h represents a natural number).

[Chemical Formula 18]

In the present invention, a varnish obtained by post-treating the reaction solution according to a conventional method to isolate the polyamic acid and dissolving or dispersing the isolated polyamic acid in a solvent may be used as the resin composition for a display substrate. In this case, it is preferable that the polyamic acid is dissolved in a solvent in consideration of obtaining a highly flat thin film with good reproducibility. The solvent used for dissolving or dispersing is not particularly limited and, for example, the same solvents as the specific examples of the reaction solvent for the above reaction may be used, and these solvents may be used alone or in combination of two or more.

The concentration of the polyamic acid with respect to the total weight of the varnish is appropriately set in consideration of the thickness of the thin film to be produced, the varnish viscosity, and the like, but is usually about 0.5 to 30 mass%, preferably about 5 to 25 mass%.

The viscosity of the varnish is suitably set in consideration of the thickness of the thin film to be produced. In particular, when it is intended to obtain a resin thin film having a thickness of about 5 to 50 탆 with good reproducibility, To about 50,000 mPa · s, and preferably about 1,000 to 20,000 mPa · s.

The resin composition for a display substrate of the present invention may contain a crosslinking agent (hereinafter also referred to as a crosslinking compound). The content of the crosslinking agent is usually about 20 parts by mass or less based on 100 parts by mass of the polyamic acid.

Specific examples of the crosslinkable compound are shown below, but the invention is not limited thereto.

As a compound containing two or more epoxy groups, Epolide GT-401, Epolide GT-403, Epolide GT-301, Polyol GT-302, Cellokside 2021 and Celloxide 3000 An epoxy compound having a cyclohexene structure such as N-vinylpyrrolidone (manufactured by Kagaku Kogyo K.K.); Bisphenol A type epoxy compounds such as Epicoat 1001, Epicoat 1002, Epicoat 1003, Epicoat 1004, Epicoat 1007, Epicoat 1009, Epicoat 1010 and Epicoat 828 (manufactured by Japan Epoxy Resins Co., Ltd.); Bisphenol F type epoxy compounds such as Epikote 807 (manufactured by Japan Epoxy Resin Co., Ltd.); Phenolic novolak-type epoxy compounds such as Epikote 152, Epikote 154 (manufactured by Japan Epoxy Resin Co., Ltd.), EPPN201 and EPPN202 (manufactured by Nippon Kayaku Co., Ltd.); Cresol novolak resin such as ECON-102, ECON-103S, ECON-104S, ECON-1020, ECON-1025 and ECON-1027 (manufactured by NIPPON KAYAKU CO., LTD.) And EPIKOTE 180S75 (manufactured by Japan Epoxy Resin Co., A volatile epoxy compound; Naphthalene type epoxy compounds such as V8000-C7 (manufactured by DIC Corporation); Araldite CY-192, Araldite CY-184 (manufactured by BASF Corporation), Epi Cole EX-252 (manufactured by Nagase ChemteX Corporation), CY175, CY177, CY179, Araldite CY- (Manufactured by Japan Epoxy Resin Co., Ltd.), ED-5661, ED-5662 (manufactured by DIC Corporation), Epikote 871, Epikote 872 )), And the like; Denacol EX-421, Denacol EX-421, Denacol EX-411, Denacol EX-512, Denacol EX-522, Denacol EX-421, Denacol EX- But are not limited to, aliphatic polyglycidyl ether compounds such as EX-313, Denacol EX-314, Denacol EX-312 (manufactured by Nagase ChemteX Corporation).

A melamine derivative, a benzoguanamine derivative or a glycoluril having a hydrogen atom of an amino group having a methylol group, an alkoxymethyl group or both of them, MX-750 in which an average of 3.7 methoxymethyl groups per one triazine ring is substituted, triazine MW-30 (manufactured by Sanwa Chemical Co., Ltd.) in which an average of 5.8 substituents of methoxymethyl groups per ring was substituted; Methoxymethylated melamines such as Cymel 300, Cymel 301, Cymel 303, Cymel 350, Cymel 370, Cymel 771, Cymel 325, Cymel 327, Cymel 703, Cymel 712; Methoxymethylated butoxymethylated melamines such as Cymel 235, Cymel 236, Cymel 238, Cymel 212, Cymel 253, Cymel 254, and the like; Butoxymethylated melamines such as Cymel 506 and Cymel 508; Methoxymethylated isobutoxymethylated melamine containing carboxyl groups such as Cymel 1141; Methoxymethylated ethoxymethylated benzoguanamine, such as Cymel 1123; Methoxymethylated butoxymethylated benzoguanamine, such as Cymel 1123-10; Butoxymethylated benzoguanamine, such as Cymel 1128; Carboxyl-containing methoxymethylated ethoxymethylated benzoguanamine, such as Cymel 1125-80; Butoxymethylated glycoluril such as Cymel 1170; And methylol glycoluril such as Cymel 1172 (manufactured by Mitsui Cyanamid Co., Ltd.), but the present invention is not limited thereto.

By applying the above-described resin composition for a display substrate of the present invention to a base body and then heating it, a resin thin film made of polyimide having high heat resistance, suitable flexibility, and appropriate linear expansion coefficient can be obtained.

As the substrate (substrate), for example, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetylcellulose, ABS, AS, norbornene resin, etc.) , Glass, slate, and the like, but a glass gas is optimal in that the resulting resin thin film shows good releasability.

The coating method is not particularly limited. For example, a method such as cast coating, spin coating, blade coating, dip coating, roll coating, bar coating, die coating, Concave plate, flat plate, screen printing, etc.).

The heating temperature is preferably 450 占 폚 or lower from the viewpoints of the strength and / or toughness of the resulting resin thin film.

In consideration of heat resistance and linear expansion coefficient characteristics of the obtained resin thin film, the applied resin composition is heated at 50 to 100 DEG C for 5 minutes to 2 hours, and then is heated stepwise as it is, It is preferable to heat at 450 占 폚 for 30 minutes to 4 hours.

Particularly, the coated resin composition is heated at 50 ° C to 100 ° C for 5 minutes to 2 hours, then heated at 100 ° C to 200 ° C for 5 minutes to 2 hours, then at 200 ° C to 375 ° C for 5 minutes to 2 hours, Finally, it is preferable to heat at 375 DEG C to 450 DEG C for 30 minutes to 4 hours.

Examples of the apparatus used for heating include a hot plate, an oven, and the like. The heating atmosphere may be air or inert gas, or may be normal pressure or reduced pressure.

The thickness of the resin thin film is usually about 1 to 60 mu m, preferably about 5 to 50 mu m when the substrate is used as a substrate for a flexible display, and a resin thin film having a desired thickness is formed by adjusting the thickness of the coating film before heating.

The above-described resin thin film is optimum for use as a base film of a flexible display substrate in that it meets all the necessary conditions as a base film of a flexible display substrate.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[1] A drug used in Examples

<Anhydrous>

N, N '- [2,2'-bis (trifluoromethyl) biphenyl-4,4'-diyl] bis (1,3-dioxo-1,3-dihydroiso Benzofuran-5-carboamide).

6FDA: 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride (AZ Electronic Material Co.).

CBDA: 1,2,3,4-Cyclobutane tetracarboxylic acid dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.).

<Amine>

PDA: p-phenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.).

TFMB: 2,2'-bis (trifluoromethyl) biphenyl-4,4'-diamine (manufactured by Tokyo Chemical Industry Co., Ltd.).

BAPB: bis (4-aminophenoxy) biphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.).

BAPPS: bis (4- (3-aminophenoxy) phenyl) sulfone (manufactured by Tokyo Chemical Industry Co., Ltd.).

BAPS: bis (3-aminophenyl) sulfone (manufactured by Tokyo Chemical Industry Co., Ltd.).

<Solvent>

NMP: N-methyl-2-pyrrolidone.

IPMA: 3-methoxy-N, N-dimethylpropanamide (manufactured by Idemitsu Kosan Co., Ltd.).

[2] Preparation of resin composition (Synthesis of polyamic acid)

Example 1

(0.014 mole) of TFMB, 0.4 g (0.0012 mole) of BAPB and 2.5 g (0.023 mole) of PDA were dissolved in 430 g of IPMA, and 6.3 g (0.014 mole) of 6FDA and 42.8 g (0.064 mole) of CF3- And the mixture was allowed to react at 23 deg. C for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 40,700 and the molecular weight distribution was 2.1. The reaction solution thus obtained was used as it is as the resin composition for a display substrate of Example 1.

The weight average molecular weight (hereinafter abbreviated as Mw) of the polymer and the molecular weight distribution were measured using a GPC apparatus (Shodex column SB803HQ and SB804HQ) manufactured by Tosoh Corporation and dimethylformamide as a dissolution solvent at a flow rate of 0.9 ml / Min, and a column temperature of 40 캜. Mw was a polystyrene-reduced value (hereinafter the same).

Example 2

A reaction solution containing a polymer having Mw of 38,700 and a molecular weight distribution of 2.1 was obtained in the same manner as in Example 1 except that IPMA in Example 1 was replaced with NMP. The reaction solution thus obtained was used as it is for the display substrate of the second embodiment.

&Lt; Comparative Example 1 &

28.1 g (0.063 mol) of BAPPS was dissolved in 160 g of NMP, 12.5 g (0.063 mol) of CBDA was added, and the reaction was allowed to proceed at 23 deg. C for 24 hours under a nitrogen atmosphere. The polymer obtained had Mw of 19,800 and a molecular weight distribution of 2.1. The obtained reaction solution was used as it was as the resin composition of Comparative Example 1. [

&Lt; Comparative Example 2 &

39.1 g (0.16 mol) of BAPS were dissolved in 500 g of NMP, and 30.95 g (0.16 mol) of CBDA was added thereto, followed by reaction at 23 deg. C for 24 hours under a nitrogen atmosphere. The polymer obtained had Mw of 13,600 and a molecular weight distribution of 3.1. The obtained reaction solution was used as the resin composition of Comparative Example 2 as is.

&Lt; Comparative Example 3 &

38.2 g (0.12 mol) of TFMB and 3.2 g (0.029 mol) of PDA were dissolved in 430 g of NMP, 28.6 g (0.15 mol) of CBDA was added and the reaction was allowed to proceed at 23 占 폚 for 24 hours under a nitrogen atmosphere. The polymer obtained had Mw of 30,600 and a molecular weight distribution of 2.1. The obtained reaction solution was used as the resin composition of Comparative Example 3 as is.

&Lt; Examples 3 to 4 and Comparative Examples 4 to 6 &gt;

[3] Production of resin thin film (Production of polyimide film)

Each of the resin compositions of Examples 1 and 2 and Comparative Examples 1 to 3 was coated on a glass substrate with a bar coater and heated at 110 DEG C for 10 minutes, 230 DEG C for 30 minutes, 300 DEG C for 30 minutes, and 350 DEG C And successively heated for 120 minutes to obtain resin thin films (resin thin films of Examples 3 to 4 and Comparative Examples 4 to 6, respectively).

[4] Evaluation of resin thin film

The resulting resin thin film was evaluated by the following method. The results are shown in Table 1. Thin films were also prepared for each evaluation. The film thickness showed the value of the resin thin film used for the flexibility evaluation.

&Lt; Measurement of film thickness &

The film thickness of the resin thin film was measured using a contact type film thickness measuring instrument (Dektak 3ST) manufactured by ULVAC Co., Ltd.

<Flexibility evaluation>

The flexibility of the resin thin film peeled off from the glass substrate was evaluated. The evaluation of the flexibility is carried out by visually checking the ease of breaking (cracking, cracking, fracture, etc.) of the thin film when the peeled resin thin film is bent or pulled by hand, and when it is bent or pulled by hand, And the other cases were determined as defective.

Further, the resin thin film was peeled off by stopping the glass substrate on which the resin thin film was formed, in pure water at 70 캜.

&Lt; Evaluation of heat resistance &

The 5% mass reduction temperature (Td5% (占 폚)) of the resin thin film was measured. The measurement was carried out using TG / DTA2000SA manufactured by Bruker AX Co., Ltd. (temperature rise rate: from 50 占 폚 to 500 占 폚 at 5 占 폚 per minute).

<Measurement of transmittance>

The transmittance of the resin thin film was measured. The measurement was carried out using a magnetic spectrophotometer (UV-3100PC) manufactured by Shimadzu Corporation. The obtained results are shown in Table 1. The transmittance at 450 nm is also described.

&Lt; Measurement of linear expansion coefficient &

A piece of short strip (20 mm x 5 mm) was cut out from the resin thin film and the linear expansion coefficient thereof was measured. The measurement was carried out using a thermomechanical analyzer (TMA-4000SA) manufactured by Bruker AX Co., Ltd. (temperature rise rate: from 50 占 폚 to 300 占 폚 at 5 占 폚 per minute).

Before measurement, each thin film was heated once beforehand (temperature rising rate: from 50 占 폚 to 400 占 폚 at 5 占 폚 per minute).

As shown in Table 1, the resin thin films of Examples 3 and 4 have not only appropriate flexibility and high heat resistance but also excellent transparency and moderate linear expansion coefficient as compared with the resin thin films of Comparative Examples 4 to 6.

From the above, it can be seen that the resin composition of the present invention is suitable for producing a resin thin film (polyimide thin film) having various properties necessary for the substrate use of the display.

Claims (11)

Wherein Ar ¹ and Ar ² are each different and independently represent a tetravalent group having an aromatic group having a substituent substituted with fluorine and Ar ³ is a group represented by the formula (1-1) and (1-4) 4) (wherein q represents 1 or 2 and 1 represents 1 or 2), n ¹ and n ⁴ represent the number of each repeating unit, and the ratio of n ¹ to n ⁴ n ¹ : n ⁴ is 50:50 to 99: 1); And an organic solvent.
[Chemical Formula 1]

The method according to claim 1,
Wherein Ar ¹ is represented by the following formula (2): wherein k is 1 or 2 and p is 1 or 2, and Ar ² is represented by the following formula (3) 3 &lt; / RTI &gt; fluoroalkylene group).
(2)

3. The method according to claim 1 or 2,
Wherein Ar &lt; ¹ &gt; is represented by formula (2-1).
(3)

4. The method according to any one of claims 1 to 3,
Wherein Ar &lt; ² &gt; is represented by formula (3-1).
[Chemical Formula 4]

5. The method according to any one of claims 1 to 4,
Wherein Ar ³ is represented by any one of formulas (4-1) to (4-6).
[Chemical Formula 5]

6. The method according to any one of claims 1 to 5,
Wherein Ar ¹ and Ar ² have the same definitions as above and Ar ⁴ is a group represented by the formula (5): wherein r is 1, 2 or 3; 3, and n ² and n ⁵ represent the number of each repeating unit).
[Chemical Formula 6]

7. The method according to any one of claims 1 to 6,
Wherein the organic solvent is a solvent represented by the following formula (A) or (B): wherein R ¹ and R ² each independently represent an alkyl group of 1 to 4 carbon atoms, and h represents a natural number.
(7)

A resin thin film for a display substrate produced using the resin composition for a display substrate according to any one of claims 1 to 7. An image display apparatus comprising the resin thin film for a display substrate according to claim 8. A method for producing a resin thin film for a display substrate using the resin composition for a display substrate according to any one of claims 1 to 7. A manufacturing method of an image display apparatus using the resin thin film for a display substrate according to claim 8.