KR20220147724A - Polyimide precursor, resin composition, and method for producing resin film - Google Patents

Abstract

{식 중, X₁ 은 탄소수 4 ∼ 32 의 4 가의 기를 나타낸다. R₁, R₂, R₃ 은 각각 독립적으로 탄소수 1 ∼ 20 의 1 가의 유기기를 나타낸다. n 은 0 또는 1 을 나타낸다. 그리고 a 와 b 와 c 는 0 ∼ 4 의 정수이다.} 로 나타내는 구조 단위 L 과,
하기 일반식 (2)：

{식 중, X₂ 는 탄소수 4 ∼ 32 의 4 가의 기를 나타낸다.} 로 나타내는 구조 단위 M 을, 1/99 ≤ (구조 단위 L 의 몰수/구조 단위 M 의 몰수) ≤ 99/1 로 포함하는, 폴리이미드 전구체.(a1) the following general formula (1):

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a, b and c are integers from 0 to 4. a structural unit L represented by };
The following general formula (2):

{wherein, X ₂ represents a tetravalent group having 4 to 32 carbon atoms}, including the structural unit M represented by 1/99 ≤ (number of moles of structural unit L/number of moles of structural unit M) ≤ 99/1; polyimide precursor.

Description

A polyimide precursor, a resin composition, and the manufacturing method of a resin film TECHNICAL FIELD

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to, for example, a polyimide precursor, a resin composition, and a method for producing a resin film, which are used for producing a substrate for a flexible device.

Generally, the film of a polyimide resin is used as a resin film for the use by which high heat resistance is calculated|required. A general polyimide resin is produced by preparing a polyimide precursor by solution polymerization of an aromatic carboxylic acid dianhydride and an aromatic diamine, and then thermal imidizing this at a high temperature or chemical imidization using a catalyst. it is resin

Polyimide resin is an insoluble, infusible, super heat-resistant resin, and has excellent characteristics such as heat oxidation resistance, heat resistance characteristics, radiation resistance, low temperature resistance, chemical resistance, and the like. For this reason, polyimide resin is used in the wide field including an electronic material. As an application example of the polyimide resin in the field of electronic materials, an insulating coating agent, an insulating film, the protective film of a semiconductor, the electrode protective film of TFT-LCD, etc. are mentioned, for example. In recent years, instead of the glass substrate conventionally used in the field|area of a display material, adoption as a colorless transparent flexible substrate using the lightness and flexibility is examined.

When manufacturing the polyimide resin film as a flexible substrate, on a suitable support body, after apply|coating the composition containing a polyimide precursor and forming a coating film, it heat-processes and imidizes and obtains a polyimide resin film. As the support, for example, glass, silicon, silicon nitride, silicon oxide, metal or the like is used. When manufacturing the laminated body which has a polyimide film on such a support body, heat processing in high temperature 250 degreeC or more is required for drying and imidation of a polyimide precursor. By this heat treatment, residual stress is generated in the laminate, and serious problems such as warpage and peeling occur. This is because the linear thermal expansion coefficient of polyimide is large compared with the material which comprises said support body.

As a polyimide material with a small coefficient of thermal expansion, a polyimide formed from 3,3',4,4'-biphenyltetracarboxylic dianhydride and paraphenylenediamine is best known. Although depending on the film thickness and manufacturing conditions, it has been reported that this polyimide film exhibits a very low coefficient of linear thermal expansion (Non-Patent Document 1).

Moreover, since the polyimide which has an ester structure in a molecular chain has moderate linearity and rigidity, it is reported that it shows a low linear thermal expansion coefficient (patent document 1).

However, since general polyimide resins, including the polyimides described in the above documents, are colored brown or yellow due to high aromatic ring density, the light transmittance in the visible light region is low, and therefore transparency is required. It is difficult to use in For example, the polyimide of the said nonpatent literature 1 obtained from 3,3',4,4'-biphenyltetracarboxylic dianhydride and paraphenylenediamine has yellowness (YI) in a film thickness of 10 micrometers. value) is as high as 40 or more, which is insufficient in terms of transparency.

About the yellowness of a film, it is known that the polyimide which used the monomer which has a fluorine atom shows very low yellowness, for example (patent document 2).

Japanese Patent No. 4627297 Specification Japanese Patent Publication No. 2010-538103 Japanese Patent No. 3079867 Specification

Latest Polyimide Japan Polyimide Research Society Edition N.T.S.

By the way, in order to apply a polyimide resin as a colorless transparent flexible substrate, mechanical properties, such as excellent elongation and breaking strength, are calculated|required in addition to transparency. Especially in recent years, with the device type of TFT becoming LTPS (low temperature polysilicon TFT), also in the thermal history more than conventional, the film which exhibits said physical property is desired.

However, the physical properties of known transparent polyimides are not sufficient for use as heat-resistant colorless transparent substrates for displays.

Further, as confirmed by the present inventor, the polyimide resin described in Patent Document 1 showed a low coefficient of linear thermal expansion, but the yellowness (YI value) of the polyimide resin film after peeling was large, and the residual stress was high, It turned out that elongation is low and there exists a subject that breaking strength is low.

As for the yellowness, it can be seen that the polyimide film described in Patent Document 2 shows a low yellowness in a temperature range of about 300°C, but significantly deteriorates the yellowness (YI value) in a high temperature range of 400°C or more. there was.

Moreover, the polyimide which consists of 4,4'- diamino diphenyl ether and 4,4'- diamino diphenyl ester is disclosed as a polyimide which lowered the coefficient of linear expansion (patent document 3).

However, when this inventor confirmed, in order to apply the polyimide resin of patent document 3 as a flexible substrate, the film|membrane was very soft, and there existed room for improvement in the yellowness in high temperature.

The present invention has been made in view of the above-described problems. Accordingly, an object of the present invention is to provide a polyimide resin film having low residual stress, little warpage, small yellowness (YI value), and high elongation, and a method for producing the same.

The present invention is as follows.

[One]

(a1) the following general formula (1):

[Formula 1]

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a, b and c are integers from 0 to 4. a structural unit L represented by };

The following general formula (2):

[Formula 2]

{Wherein, X ₂ represents a tetravalent group having 4 to 32 carbon atoms. Y is at least one member selected from the group consisting of the following general formulas (3), (4) and (5)};

1/99 ≤ (number of moles of structural unit L/number of moles of structural unit M) ≤ 99/1

A polyimide precursor comprising a.

[Formula 3]

[Formula 4]

[Formula 5]

{In the formula, R ₄ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms. d to k are integers from 0 to 4.}

[2]

The polyimide precursor as described in [1] whose n in the said General formula (1) is 0.

[3]

The polyimide precursor as described in [1] or [2] whose Y of the said General formula (2) is General formula (3).

[4]

The polyimide precursor as described in [1] or [2] whose Y of the said General formula (2) is General formula (4).

[5]

The polyimide precursor as described in [1] or [2] whose Y of the said General formula (2) is General formula (5).

[6]

(a2) the following general formula (10):

[Formula 6]

It has a structural unit represented by, and a weight average molecular weight is 30,000 or more and 300,000 or less, The polyimide precursor characterized by the above-mentioned.

{wherein, X ₃ is 4,4'-oxydiphthalic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and 4,4'-biphenylbis(trimellitic acid monoesteric anhydride) ) (TAHQ), represents a tetravalent group derived from at least one selected from the group consisting of. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.}

[7]

The polyimide precursor as described in [6] whose content of the molecule|numerator with a weight average molecular weight less than 1,000 in said (a2) polyimide precursor is less than 5 mass %.

[8]

The polyimide precursor as described in [6] or [7] whose n in General formula (10) is 0.

[9]

wherein X ₁ , X ₂ is pyromellitic dianhydride (PMDA), 4,4′-oxydiphthalic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and 4,4′-ratio The polyimide precursor according to any one of [1] to [5], which is a tetravalent organic group derived from at least one selected from the group consisting of phenylbis(trimellitic acid monoesteric anhydride) (TAHQ).

[10]

A resin composition comprising the polyimide precursor according to any one of [1] to [9] and (b) an organic solvent.

[11]

The resin composition according to [10], further comprising at least one selected from the group consisting of (c) a surfactant and (d) an alkoxysilane compound.

[12]

The following general formula (11):

[Formula 7]

{Wherein, X ₁ and X ₂ represent a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b, and c are integers from 0 to 4. Y is at least 1 type selected from the group which consists of following general formula (3), (4) and (5). l and m each independently represent an integer of 1 or more and satisfy 0.01 ≤ l / (l + m) ≤ 0.99.} A polyimide characterized by having a structural unit represented by:

[Formula 8]

[Formula 9]

[Formula 10]

{In the formula, R ₄ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms. d to k are integers from 0 to 4.}

[13]

The following general formula (12):

[Formula 11]

{wherein, X ₃ is 4,4'-oxydiphthalic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and 4,4'-biphenylbis(trimellitic acid monoesteric anhydride) ) (TAHQ), represents a tetravalent group derived from at least one selected from the group consisting of. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a, b, and c are integers of 0 to 4. A polyimide having a structural unit represented by } and having an elongation of 15% or more.

[14]

A step of forming a coating film by applying the resin composition according to [10] or [11] on the surface of the support;

a step of forming a polyimide resin film by imidizing a polyimide precursor contained in the coating film by heating the support and the coating film;

Step of peeling the polyimide resin film from the support

A method for producing a resin film comprising a.

[15]

The method for producing a resin film according to [14], wherein a step of irradiating a laser from the side of the support is performed prior to the step of peeling the polyimide resin film from the support.

[16]

A step of forming a coating film by applying the resin composition according to [10] or [11] on the surface of the support;

A step of forming a polyimide resin film by imidizing a polyimide precursor contained in the coating film by heating the support and the coating film

A method for producing a laminate, comprising:

[17]

A step of forming a coating film by applying the resin composition according to [10] or [11] on the surface of the support;

a step of forming a polyimide resin film by imidizing a polyimide precursor contained in the coating film by heating the support and the coating film;

forming an element or circuit on the polyimide resin film;

Step of peeling the polyimide resin film on which the element or circuit is formed from the support

A method of manufacturing a display substrate comprising a.

[18]

The following general formula (12):

[Formula 12]

{wherein, X ₃ is 4,4'-oxydiphthalic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and 4,4'-biphenylbis(trimellitic acid monoesteric anhydride) ) (TAHQ), and R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.}

A polyimide film for a display, comprising a polyimide represented by

[19]

The following general formula (13):

[Formula 13]

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a, b, and c are integers of 0 to 4. A laminate comprising a polyimide film layer containing a polyimide represented by } and a low-temperature polysilicon TFT layer.

[20]

A yellowness of 20 or less at a film thickness of 10 microns after heating at 400° C. or higher, an absorbance at 308 nm when a film thickness of 1 micron is 0.6 or more and 2.0 or less, and an elongation of 15% or more. , polyimide film.

[21]

(a) a polyimide precursor represented by the following general formula (1);

(b) an organic solvent;

(c) at least one selected from the group consisting of surfactants and (d) alkoxysilane compounds

A resin composition comprising a.

[Formula 14]

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.}

The polyimide film obtained from the polyimide precursor and resin composition which concerns on this invention has a low residual stress, there is little curvature, a yellowness (YI value) is small, and an elongation is high.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the organic electroluminescent board|substrate manufactured by the Example and the comparative example.

DESCRIPTION OF EMBODIMENTS Hereinafter, exemplary embodiments of the present invention (hereinafter abbreviated as "embodiments") will be described in detail. In addition, this invention is not limited to the following embodiment, It can variously deform and implement within the range of the summary. In addition, unless otherwise noted, the characteristic values described in the present disclosure are intended to be values measured by a method understood by those skilled in the art that is equivalent to the method described in the section of [Examples] or equivalent thereto.

<Resin composition>

The resin composition provided by one aspect of the present invention contains (a) a polyimide precursor and (b) an organic solvent.

Hereinafter, each component is demonstrated in order.

[Polyimide precursor]

A polyimide precursor as a first aspect of the present embodiment,

(a1) the following general formula (1):

[Formula 15]

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a, b and c are integers from 0 to 4. a structural unit L represented by };

The following general formula (2):

[Formula 16]

{Wherein, X ₂ represents a tetravalent group having 4 to 32 carbon atoms. Y is at least one member selected from the group consisting of the following general formulas (3), (4) and (5)}

1/99 ≤ (number of moles of structural unit L/number of moles of structural unit M) ≤ 99/1, it is a polyimide precursor.

[Formula 17]

[Formula 18]

[Formula 19]

{In the formula, R ₄ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms. d to k are integers from 0 to 4.}

When the polyimide precursor of the 1st aspect of this implementation is set as a polyimide film, residual stress is low, there is little curvature, yellowness (YI value) is small, and elongation is high. Moreover, when the polyimide precursor of the 1st aspect of this embodiment is set as a polyimide film, the yellowness (YI value) in a high temperature area|region is small.

Here, R< ₁ >-R< ₃ > will not be limited if it is a C1-C20 monovalent organic group each independently. Examples of such an organic group include an alkyl group such as a methyl group, an ethyl group, and a propyl group, a halogen-containing group such as a trifluoromethyl group, and an alkoxy group such as a methoxy group and an ethoxy group. Among them, from the viewpoint of YI in the high temperature region, a methyl group is preferable.

Here, a, b, c, and d will not be limited if it is an integer of 0-4. Among these, the integer of 0-2 is preferable from a viewpoint of YI and residual stress, and 0 is especially preferable from a viewpoint of YI in a high temperature range.

Here, n is 0 or 1. Among them, 0 is preferable from the viewpoint of YI in the high temperature region.

The lower limit of the molar ratio of the structural unit L to the structural unit M (the number of moles of the structural unit L/the number of moles of the structural unit M) may be 5/95, 10/90, 20/80, or 30/70. and 40/60 may be sufficient. The upper limit of the molar ratio of the structural unit L to the structural unit M (the number of moles of the structural unit L/the number of moles of the structural unit M) may be 95/5, 90/10, 80/20, 70/30, It may be 60/40.

X ₁ and X ₂ are each independently a tetravalent group having 4 to 32 carbon atoms, and may be the same or different. The tetravalent organic group derived from the following tetracarboxylic dianhydride is illustrated.

Specifically, as said tetracarboxylic dianhydride, C8-C36 aromatic tetracarboxylic dianhydride, C6-C36 aliphatic tetracarboxylic dianhydride, and C6-C36 alicyclic ring The compound selected from the formula tetracarboxylic dianhydride can be illustrated. Among these, the C8-C36 aromatic tetracarboxylic dianhydride from a viewpoint of the yellowness in a high temperature range is preferable. The number of carbons contained in a carboxyl group is also included in carbon number here.

More specifically, as an aromatic tetracarboxylic dianhydride having 8 to 36 carbon atoms, for example, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (hereinafter also referred to as 6FDA), 5- (2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2 dicarboxylic acid anhydride, pyromellitic dianhydride (hereinafter also referred to as PMDA), 1,2, 3,4-benzenetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (hereinafter also referred to as BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2 ',3,3'-biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylidene-4,4'-diphthalic dianhydride, 2,2-propyl Liden-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetra Methylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride (hereinafter also referred to as ODPA), p- phenylenebis(trimellitate anhydride) (hereinafter also referred to as TAHQ) thio-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis(3, 4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1, 3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, Bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3) ,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethyl Silane dianhydride, 1,3-bis(3,4 -dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid Dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic acid 2 Anhydride, 1,2,7,8-phenanthrene tetracarboxylic dianhydride, etc. can be illustrated.

Examples of the aliphatic tetracarboxylic dianhydride having 6 to 50 carbon atoms include ethylene tetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride;

Examples of the alicyclic tetracarboxylic dianhydride having 6 to 36 carbon atoms include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1, 2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride (hereinafter referred to as CHDA), 3,3',4,4'-ratio Cyclohexyltetracarboxylic dianhydride, carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis(cyclohexane-1,2- Dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethylidene-4,4'-bis( Cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4' -bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'- Bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, rel-[ 1S,5R,6R]-3-oxabicyclo[3,2,1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4- (2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, ethylene glycol-bis-(3,4-dicarboxylic Acid anhydride phenyl) ether etc. are mentioned, respectively.

From a viewpoint of the balance of CTE, chemical resistance, Tg, and yellowness in a high temperature area|region, PMDA, BPDA, TAHQ, and ODPA are preferable, and BPDA and TAHQ are more preferable.

The polyimide precursor in an embodiment is good also as a polyamideimide precursor by using dicarboxylic acid in addition to the above-mentioned tetracarboxylic dianhydride in the range which does not impair the performance. By using such a precursor, the film obtained WHEREIN: Various performance, such as the improvement of mechanical elongation, the improvement of a glass transition temperature, and reduction of yellowness, can be adjusted. Examples of such dicarboxylic acids include dicarboxylic acids and alicyclic dicarboxylic acids having an aromatic ring. It is especially preferable that it is at least 1 compound selected from the group which consists of C8-C36 aromatic dicarboxylic acid and C6-C34 alicyclic dicarboxylic acid. The number of carbons contained in a carboxyl group is also included in carbon number here.

Among these, the dicarboxylic acid which has an aromatic ring is preferable.

Specifically, for example, isophthalic acid, terephthalic acid, 4,4'-biphenyldicarboxylic acid, 3,4'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 1, 4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-sulfonylbisbenzoic acid, 3, 4'-sulfonylbisbenzoic acid, 3,3'-sulfonylbisbenzoic acid, 4,4'-oxybisbenzoic acid, 3,4'-oxybisbenzoic acid, 3,3'-oxybisbenzoic acid, 2,2-bis (4-carboxyphenyl)propane, 2,2-bis(3-carboxyphenyl)propane, 2,2'-dimethyl-4,4'-biphenyldicarboxylic acid, 3,3'-dimethyl-4,4 '-biphenyldicarboxylic acid, 2,2'-dimethyl-3,3'-biphenyldicarboxylic acid, 9,9-bis(4-(4-carboxyphenoxy)phenyl)fluorene, 9, 9-bis(4-(3-carboxyphenoxy)phenyl)fluorene, 4,4'-bis(4-carboxyphenoxy)biphenyl, 4,4'-bis(3-carboxyphenoxy)biphenyl, 3,4'-bis(4-carboxyphenoxy)biphenyl, 3,4'-bis(3-carboxyphenoxy)biphenyl, 3,3'-bis(4-carboxyphenoxy)biphenyl, 3, 3'-bis(3-carboxyphenoxy)biphenyl, 4,4'-bis(4-carboxyphenoxy)-p-terphenyl, 4,4'-bis(4-carboxyphenoxy)-m-ter Phenyl, 3,4'-bis(4-carboxyphenoxy)-p-terphenyl, 3,3'-bis(4-carboxyphenoxy)-p-terphenyl, 3,4'-bis(4-carboxy Phenoxy)-m-terphenyl, 3,3'-bis(4-carboxyphenoxy)-m-terphenyl, 4,4'-bis(3-carboxyphenoxy)-p-terphenyl, 4,4 '-bis(3-carboxyphenoxy)-m-terphenyl, 3,4'-bis(3-carboxyphenoxy)-p-terphenyl, 3,3'-bis(3-carboxyphenoxy)-p -terphenyl, 3,4'-bis(3-carboxyphenoxy)-m-terphenyl, 3,3'-bis(3-carboxyphenoxy)-m-terphenyl, 1,1-cyclobutanedicar Acid, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4,4'-benzophenonedicarboxylic acid, 1,3-phenylene diacetic acid, 1,4- phenylene diacetic acid, etc.; and

The 5-aminoisophthalic acid derivative of the international publication 2005/068535 pamphlet, etc. are mentioned. When actually copolymerizing these dicarboxylic acids with a polymer, you may use in the form of an acid chloride body derived from thionyl chloride etc., an active ester body, etc.

10,000-300,000 are preferable and, as for the weight average molecular weight (Mw) of the polyimide precursor in this embodiment, 30,000-200,000 are especially preferable. When the weight average molecular weight is larger than 10,000, mechanical properties such as elongation and breaking strength are excellent, residual stress is low, and YI is low. When the weight average molecular weight is smaller than 300,000, it becomes easy to control the weight average molecular weight at the time of synthesis of the polyamic acid, a resin composition having an appropriate viscosity can be obtained, and the applicability of the resin composition is improved. In this indication, a weight average molecular weight is a value calculated|required as a standard polystyrene conversion value using gel permeation chromatography (henceforth GPC).

It is preferable that it is less than 5 mass % with respect to the whole quantity of a polyimide precursor, and, as for content of the molecule|numerator of molecular weight less than 1,000, as for the polyimide precursor in this embodiment, it is more preferable that it is less than 1 mass %. The polyimide film formed from the resin composition obtained using such a polyimide precursor becomes a thing with a low residual stress, and it is preferable from a viewpoint that the Haze of the inorganic film formed on the polyimide film becomes low.

Content of the molecule|numerator with molecular weight less than 1,000 with respect to the whole quantity of a polyimide precursor is computable from the peak area obtained by performing GPC measurement using the solution which melt|dissolved the polyimide precursor.

As diamine used for the structural unit represented by General formula (1) in this embodiment, the diamine represented by following General formula (6) can be illustrated.

[Formula 20]

(Wherein, R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.)

Examples of R ₁ and R ₂ include an alkyl group such as a methyl group, an ethyl group, and a propyl group, a halogen-containing group such as a trifluoromethyl group, and an alkoxy group such as a methoxy group and an ethoxy group. Among them, from the viewpoint of YI in the high temperature region, a methyl group is preferable.

Here, if a and b are integers of 0-4, it will not be limited. Among these, the integer of 0-2 is preferable from a viewpoint of YI and residual stress, and 0 is especially preferable from a viewpoint of YI in a high temperature range.

More specifically, when n is 0, 4-aminophenyl-4-aminobenzoate (APAB), 2-methyl-4-aminophenyl-4-aminobenzoate (ATAB), 4-aminophenyl-3 -aminobenzoate (4,3-APAB) and the like can be exemplified.

When n is 1, [4-(4-aminobenzoyl)oxyphenyl]4-aminobenzoate etc. can be illustrated.

As diamine used for the structural unit represented by General formula (3) in this embodiment, the diamine represented by following General formula (7) can be illustrated.

[Formula 21]

(Wherein, R ₄ and R ₅ each independently represent a monovalent organic group having 1 to 20 carbon atoms. d and e are integers from 0 to 4.)

Here, R ₄ and R ₅ are not limited as long as each independently represents a monovalent organic group having 1 to 20 carbon atoms. Examples of such an organic group include an alkyl group such as a methyl group, an ethyl group, and a propyl group, a halogen-containing group such as a trifluoromethyl group, and an alkoxy group such as a methoxy group and an ethoxy group. Among them, from the viewpoint of YI in the high temperature region, a methyl group is preferable.

Here, if c and d are integers of 0-4, it will not be limited. Among these, the integer of 0-2 is preferable from a viewpoint of YI and residual stress, and 0 is especially preferable from a viewpoint of YI in a high temperature region.

More specifically, 4,4'-diaminodiphenylsulfone and 3,3'-diaminodiphenylsulfone can be illustrated.

As diamine used for the structural unit represented by General formula (4) in this embodiment, the diamine represented by following General formula (8) can be illustrated.

[Formula 22]

Here, R ₆ and R ₇ are not limited as long as each independently represents a monovalent organic group having 1 to 20 carbon atoms. As such an organic group, For example, alkyl groups, such as a methyl group, an ethyl group, and a propyl group; Halogen-containing groups, such as a trifluoromethyl group; Alkoxy groups, such as a methoxy group and an ethoxy group; etc. are mentioned. Among them, from the viewpoint of YI in the high temperature region, a methyl group is preferable.

R ₈ and R ₉ are not limited as long as each independently represents a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, or a halogen atom. As said organic group, For example, alkyl groups, such as a methyl group, an ethyl group, and a propyl group; Halogen-containing groups, such as a trifluoromethyl group; Alkoxy groups, such as a methoxy group and an ethoxy group; etc. are mentioned. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example.

f, g, h, and i are not limited as long as they are each independently an integer of 0-4. Among these, the integer of 0-2 is preferable from a viewpoint of YI and residual stress, and 0 is especially preferable from a viewpoint of YI in a high temperature region.

Z can be exemplified by a single bond, a methylene group, an ethylene group, an ether, a ketone, and the like. Among them, from the viewpoint of YI in the high temperature region, a single bond is more preferable.

More specifically, 9,9-bis(aminophenyl)fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 9,9-bis(4-amino-3-fluorophenyl) fluorene, 9,9-bis(4-hydroxy-3-aminophenyl)fluorene, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, and the like, among these It is preferable to use 1 or more types selected.

As diamine used for the structural unit represented by general formula (5) in this embodiment, the diamine represented by the following general formula (9) can be illustrated.

[Formula 23]

Here, R ₁₀ and R ₁₁ are not limited as long as each independently represents a monovalent organic group having 1 to 20 carbon atoms. As such an organic group, For example, alkyl groups, such as a methyl group, an ethyl group, and a propyl group; Halogen-containing groups, such as a trifluoromethyl group; Alkoxy groups, such as a methoxy group and an ethoxy group; etc. are mentioned. Among them, from the viewpoint of YI in the high temperature region, a methyl group is preferable.

Moreover, if j and k are each independently the integer of 0-4, it will not be limited. Among these, the integer of 0-2 is preferable from a viewpoint of YI and residual stress, and 0 is especially preferable from a viewpoint of YI in a high temperature range.

More specifically, 2,2'-bis(trifluoromethyl)benzidine etc. can be illustrated.

The polyimide film formed from the polyimide precursor of the 1st aspect of this embodiment has a low residual stress, there is little curvature, the yellowness (YI value) in a high temperature area|region is small, and elongation is high.

As a second aspect of this embodiment,

(a2) the following general formula (10):

[Formula 24]

A polyimide precursor having a structural unit represented by and having a weight average molecular weight of 30,000 or more and 300,000 or less can be provided.

{wherein, X ₃ is 4,4'-oxydiphthalic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and 4,4'-biphenylbis(trimellitic acid monoesteric anhydride) ) (TAHQ), represents a tetravalent group derived from at least one selected from R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.}

Here, although it will not be limited if X< ₃ > is a tetravalent organic group derived from at least 1 type selected from ODPA, BPDA, and TAHQ, From a viewpoint of CTE and Tg, BPDA and TAHQ are preferable.

Here, R< ₁ >-R< ₃ > will not be limited if it is a C1-C20 monovalent organic group each independently. Examples of such an organic group include an alkyl group such as a methyl group, an ethyl group, and a propyl group, a halogen-containing group such as a trifluoromethyl group, and an alkoxy group such as a methoxy group and an ethoxy group. Among them, from the viewpoint of YI in the high temperature region, a methyl group is preferable.

Here, a, b, c, and d will not be limited if it is an integer of 0-4. Among these, the integer of 0-2 is preferable from a viewpoint of YI and residual stress, and 0 is especially preferable from a viewpoint of YI in a high temperature region.

Here, n is 0 or 1. Among them, 0 is preferable from the viewpoint of YI in the high temperature region.

As diamine for the structure represented by the above-mentioned general formula (10), the diamine used by the above-mentioned general formula (6) can be used.

The weight average molecular weights (Mw) of the polyimide precursor in a 2nd aspect are 30,000-300,000. When the weight average molecular weight is larger than 30,000, mechanical properties such as elongation and breaking strength are excellent, residual stress is low, and YI is low. When the weight average molecular weight is smaller than 300,000, it becomes easy to control the weight average molecular weight at the time of synthesis of the polyamic acid, a resin composition having an appropriate viscosity can be obtained, and the applicability of the resin composition is improved. Among these, 35000 or more and 250000 or less are more preferable, and, as for a weight average molecular weight (Mw), 40000 or more and 230000 or less are especially preferable.

It is preferable that it is less than 5 mass % with respect to the total amount of a polyimide precursor, and, as for content of the molecule|numerator of molecular weight less than 1,000, it is more preferable that it is less than 1 mass % of the polyimide precursor in 2nd aspect of this implementation. The polyimide film formed from the resin composition obtained using such a polyimide precursor becomes a thing with a low residual stress, and it is preferable from a viewpoint that the Haze of the inorganic film formed on the polyimide film becomes low.

Content of the molecule|numerator with molecular weight less than 1,000 with respect to the whole quantity of a polyimide precursor is computable from the peak area obtained by performing GPC measurement using the solution which melt|dissolved the polyimide precursor.

The polyimide precursor of the second aspect of the present embodiment is excellent in storage stability and excellent in coatability. Moreover, the polyimide film formed from the polyimide precursor of the 2nd aspect of this Example has a low residual stress, there is little curvature, a yellowness (YI value) is small, elongation is high, and breaking strength is high.

In the polyimide precursor in a 1st aspect and a 2nd aspect, in the range which does not impair elongation, intensity|strength, stress, yellowness, etc. other than the diamine represented by the general formula (6)-(9) mentioned above, other Diamines may be used.

Examples of other diamines include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide, and 3,3' -diaminodiphenyl sulfide, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobenzophenone, 3, 4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane , 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4-(4- Aminophenoxy)phenyl]sulfone, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl ]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis( 4-aminophenyl)anthracene, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy) )phenyl)propane, 2,2-bis[4-(4-aminophenoxy)phenyl)hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, and the like, and select from these It is preferable to use one or more of these.

20 mol% or less is preferable and, as for content of the said other diamine in all the diamines, 10 mol% or less is especially preferable.

[Preparation of polyimide precursor]

The polyimide precursor (polyamic acid) of the present invention is a tetracarboxylic dianhydride, a diamine (eg APAB) used for a structural unit represented by the above-mentioned general formula (1), and the above-mentioned general formula (2) It can synthesize|combine the diamine (for example, 4,4'-DAS) used for the structural unit represented by ) by carrying out a polycondensation reaction. It is preferable to carry out this reaction in a suitable solvent. Specifically, for example, after dissolving a predetermined amount of APAB and 4,4'-DAS in a solvent, a predetermined amount of tetracarboxylic dianhydride is added to the obtained diamine solution, and a method of stirring is mentioned. .

Among the diamine components, the molar ratio of the diamine used for the structural unit represented by the general formula (1) to the diamine used for the structural unit represented by the general formula (2) is not limited as long as it is 99/1 to 1/99. Among the diamine components, when the diamine used for the structural unit represented by the general formula (2) is 1 mol% or more, the yellowness tends to be good, and the diamine used for the structural unit represented by the general formula (1) is 1 mol% or more There exists a tendency for the curvature after forming an inorganic film on the polyimide film obtained on this back to be favorable. The molar ratio of the diamine used for the structural unit represented by the general formula (1) to the diamine used for the structural unit represented by the general formula (2) is preferably 95/5 to 50/50, and 90/10 to 50/50 more preferably. The molar ratio of the diamine used for the structural unit represented by General formula (1) and the diamine used for the structural unit represented by General formula (2) may be 80/20-50/50, and 70/30-50/50 may be sufficient as it. do. It is preferable to make the molar ratio of the diamine used for the structural unit represented by General formula (1) into more than the molar ratio of the diamine used for the structural unit represented by General formula (2).

Moreover, the polyimide precursor of the 2nd aspect of this embodiment is tetracarboxylic dianhydride (for example, TAHQ), and the diamine used for the structural unit represented by the above-mentioned general formula (6) (for example, APAB) , it can be synthesized by a polycondensation reaction. It is preferable to carry out this reaction in a suitable solvent. For example, after dissolving a predetermined amount of APAB in a solvent specifically, the method of adding and stirring a predetermined amount of TAHQ to the obtained diamine solution is mentioned.

The ratio (molar ratio) of the tetracarboxylic dianhydride component and the diamine component at the time of synthesizing the said polyimide precursor is the coefficient of thermal linear expansion, residual stress, elongation, and yellowness (hereinafter also referred to as YI) of the obtained resin film. ) is preferably in the range of tetracarboxylic dianhydride:diamine = 100:90 to 100:110 (0.90 to 1.10 mole parts of diamine with respect to 1 mole part of tetracarboxylic dianhydride) , 100:95 to 100:105 (0.95 to 1.05 mol parts of diamine with respect to 1 mol part of acid dianhydride) is more preferable.

In this embodiment, when synthesize|combining the polyamic acid which is a preferable polyimide precursor, the molecular weight is adjusted by adjustment of the ratio of a tetracarboxylic dianhydride component and a diamine component, and addition of a terminal blocker It is possible to control The molecular weight of polyamic acid can be enlarged, so that ratio of an acid dianhydride component and a diamine component is close to 1:1, and there is little usage-amount of a terminal blocker.

As the tetracarboxylic dianhydride component and the diamine component, it is recommended to use a high-purity product. The purity is preferably 98 mass% or more, more preferably 99 mass% or more, and still more preferably 99.5 mass% or more. In the case of using a plurality of types of acid dianhydride components or diamine components together, it is sufficient if the acid dianhydride component or diamine component has the above purity as a whole. It is desirable to have a purity of

As a solvent for reaction, a tetracarboxylic dianhydride component and a diamine component, and a polyamic acid which generate|occur|produced can be melt|dissolved, and if it is a solvent from which a high molecular weight polymer is obtained, a restriction|limiting in particular will not be carried out. Specific examples of such a solvent include, for example, an aprotic solvent, a phenolic solvent, an ether, and a glycol-based solvent. Specific examples thereof include:

As the aprotic solvent, for example, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), N-methylcapro Lactam, 1,3-dimethylimidazolidinone, tetramethylurea, the following general formula (13):

[Formula 25]

In the formula, R ₁₂ = Ecamide M100 represented by a methyl group (trade name: manufactured by Idemitsu Kogsan Co., Ltd.), and R ₁₂ = Ecamide B100 represented by an n-butyl group (trade name: manufactured by Idemitsu Kogsan Co., Ltd.) amide solvents;

lactone-based solvents such as γ-butyrolactone and γ-valerolactone;

phosphorus-containing amide solvents such as hexamethylphosphoric amide and hexamethylphosphine triamide;

sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane;

Ketone solvents, such as cyclohexanone and methylcyclohexanone;

tertiary amine solvents such as picoline and pyridine;

Ester solvents such as acetic acid (2-methoxy-1-methylethyl)

My back:

As the phenolic solvent, for example, phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2, 6-xylenol, 3,4-xylenol, 3,5-xylenol, etc.:

As the ether and glycol solvent, for example, 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-( 2-methoxyethoxy) ethyl] ether, tetrahydrofuran, 1,4-dioxane, etc.;

each can be

60-300 degreeC is preferable, as for the boiling point in normal pressure of the solvent used for the synthesis|combination of a polyamic acid, 140-280 degreeC is more preferable, 170-270 degreeC is especially preferable. When the boiling point of a solvent is higher than 300 degreeC, a drying process becomes necessary for a long time. On the other hand, when the boiling point of the solvent is lower than 60°C, roughness occurs on the surface of the resin film, mixing of air bubbles into the resin film, etc. occur during the drying step, and a uniform film may not be obtained.

Thus, it is preferable from a viewpoint of solubility and an edge repelling at the time of coating that it is preferable to use the solvent whose boiling point is 170-270 degreeC preferably, More preferably, the vapor pressure in 20 degreeC is 250 Pa or less. More specifically, it is preferable to use at least one member selected from the group consisting of N-methyl-2-pyrrolidone, γ-butyrolactone, and a compound represented by the general formula (11).

As for the water content in a solvent, 3000 mass ppm or less is preferable.

You may use these solvents individually or in mixture of 2 or more types.

It is preferable that content of the molecule|numerator of molecular weight less than 1,000 is less than 5 mass % of (a) polyimide precursor in this embodiment.

(a) It is thought that the reason that this molecular weight less than 1,000 molecules exists in a polyimide precursor is because the water content of the solvent used at the time of synthesis|combining is involved. That is, it is thought that it is because the acid anhydride group of a part of acid dianhydride monomers hydrolyzes with water|moisture content, becomes a carboxyl group, and remains in the state of a low molecular weight without becoming high molecular weight. Therefore, the amount of water in the solvent used for the polymerization reaction is preferably as small as possible. It is preferable to set it as 3,000 mass ppm or less, and, as for the moisture content of this solvent, it is more preferable to set it as 1,000 mass ppm or less.

The water content of the solvent is determined by the grade of the solvent used (dehydration grade, general-purpose grade, etc.), solvent container (bottle, 18 liter can, canister can, etc.), storage condition of the solvent (whether or not sealed with noble gas, etc.), from opening to use. Time (use immediately after opening, use after time has elapsed after opening, etc.) is considered to be involved. Moreover, it is thought that the rare gas substitution of the reactor before synthesis|combination, the presence or absence of rare gas flow|circulation during synthesis|combination, etc. are also involved. Therefore, (a) when synthesizing the polyimide precursor, it is recommended to use a high-purity product as a raw material, use a solvent with a low water content, and take measures to prevent moisture from the environment from entering the system before and during the reaction. it is recommended

When dissolving each monomer component in a solvent, you may heat as needed.

(a) It is preferable that the reaction temperature at the time of polyimide precursor synthesis|combination shall be 0 degreeC - 120 degreeC, More preferably, it is 40 degreeC - 100 degreeC, More preferably, it is 60-100 degreeC. By performing a polymerization reaction at this temperature, a polyimide precursor with a high polymerization degree is obtained. It is preferable to set it as 1 to 100 hours, and, as for polymerization time, it is more preferable to set it as 2 to 10 hours. By making polymerization time into 1 hour or more, it becomes a polyimide precursor of a uniform polymerization degree, and by setting it as 100 hours or less, a polyimide precursor with a high polymerization degree can be obtained.

A preferable aspect of this embodiment WHEREIN: (a1) polyimide precursor and (a2) polyimide precursor have the following characteristics.

(a) A solution obtained by dissolving a polyimide precursor in a solvent (for example, N-methyl-2-pyrrolidone) is applied to the surface of the support, and then the solution is subjected to a nitrogen atmosphere (for example, 2,000 ppm oxygen concentration) In the resin obtained by imidating the polyimide precursor by heating (for example, 1 hour) at 300 to 550°C (for example, 430°C) in nitrogen below), the yellowness in a 10 µm film thickness is 30 or less.

(a) A solution obtained by dissolving a polyimide precursor in a solvent (for example, N-methyl-2-pyrrolidone) is applied to the surface of the support, and then the solution is subjected to a nitrogen atmosphere (for example, 2,000 ppm oxygen concentration) Resin obtained by imidating the polyimide precursor by heating (for example, 1 hour) at 300-550 degreeC (for example, 430 degreeC) in the following nitrogen WHEREIN: A residual stress is 25 Mpa or less.

The polyimide precursor which concerns on this embodiment is a range which does not impair the desired performance of this invention as needed, following General formula (14):

[Formula 26]

{In general formula (14), two or more R ₁₃ are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or a monovalent aromatic group;

X ₄ is a tetravalent organic group having 4 to 32 carbon atoms,

Y is a C4-C32 divalent organic group. only,

The structural unit corresponding to the said General formula (1) and the said General formula (6) is excluded.} You may further contain the polyimide precursor which has a structure represented by.

In the general formula (14), R ₁₃ is preferably a hydrogen atom. Moreover, from a viewpoint of heat resistance, reduction of YI value, and total light transmittance, X ₃ is preferably a tetravalent aromatic group. Moreover, Y is preferably a divalent aromatic group or an alicyclic group from a viewpoint of heat resistance, reduction of YI value, and total light transmittance.

It is preferable that the mass ratio of the polyimide precursor which has a structural unit represented by General formula (14) in the (a) polyimide precursor which concerns on this embodiment is 80 mass % or less with respect to all (a) polyimide precursors. And it is more preferable that it is 70 mass % or less from a viewpoint of the fall of the oxygen dependence of YI value and a total light transmittance.

A preferable aspect of this embodiment WHEREIN: As for (a1) polyimide precursor and (a2) polyimide precursor, the part may be imidated. It is preferable to set it as 80 % or less, and, as for the imidation ratio in this case, it is more preferable to set it as 50 % or less. This partial imidation is obtained by heating said (a) polyimide precursor, and carrying out dehydration closing ring. This heating becomes like this. Preferably it is 120-200 degreeC, More preferably, it is a temperature of 150-180 degreeC. WHEREIN: Preferably it is 15 minutes - 20 hours, More preferably, it can perform 30 minutes - 10 hours.

Moreover, N,N- dimethylformamide dimethyl acetal or N,N- dimethylformamide diethyl acetal is added to the polyamic acid obtained by the reaction mentioned above, and it heats, and esterifies part or all of carboxylic acid. Then, by using as (a) polyimide precursor in this embodiment, the resin composition with which the viscosity stability at the time of room temperature storage improved can also be obtained. In addition, these ester-modified polyamic acids react sequentially with the above-mentioned acid dianhydride component with 1 equivalent of monohydric alcohol with respect to the acid anhydride group, and a dehydration-condensing agent such as thionyl chloride and dicyclohexylcarbodiimide. After making it, it can obtain also by the method of making a diamine component and a condensation reaction.

The ratio of the (a) polyimide precursor (preferably polyamic acid) in the resin composition of the present embodiment is preferably from 3 to 50 mass%, more preferably from 5 to 40 mass%, from the viewpoint of coating film formability, , 10-30 mass % is especially preferable.

<Resin composition>

Another aspect of this invention provides the resin composition containing the above-mentioned (a) polyimide precursor and (b) an organic solvent. This resin composition is typically a varnish.

[(b) organic solvent]

There will be no restriction|limiting in particular, if the (b) organic solvent in this embodiment can melt|dissolve the above-mentioned (a) polyimide precursor and the other component used arbitrarily. As such (b) organic solvent, the thing mentioned above as a solvent which can be used at the time of the synthesis|combination of (a) polyimide precursor can be used. A preferable organic solvent is also the same as the above. The (b) organic solvent in the resin composition of this embodiment may be the same as or different from the solvent used for the synthesis|combination of (a) polyimide precursor.

(b) It is preferable to make organic solvent into the quantity used as 3-50 mass % of solid content concentration of a resin composition. Moreover, it is preferable to add after adjusting the structure and quantity of (b) organic solvent so that the viscosity (25 degreeC) of a resin composition may become 500 mPa*s - 100,000 mPa*s.

[Other Ingredients]

The resin composition of this embodiment may contain (c) surfactant, (d) an alkoxysilane compound, etc. other than the said (a) and (b) component further.

The resin composition which concerns on this embodiment contains at least 1 sort(s) chosen from the group which consists of (a) polyimide precursor, (b) organic solvent, (c) surfactant, and (d) alkoxysilane compound.

The skeleton of the polyimide precursor is not limited to the skeleton described above in the first aspect and the second aspect. That is, there will be no limitation in particular if it is frame|skeleton represented by the following general formula (1) as for frame|skeleton of a polyimide precursor.

[Formula 27]

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.}

((c) surfactant)

By adding surfactant to the resin composition of this embodiment, the applicability|paintability of the resin composition can be improved. Specifically, generation|occurrence|production of the stripe in a coating film can be prevented.

Examples of such surfactants include silicone-based surfactants, fluorine-based surfactants, and nonionic surfactants other than these surfactants. These examples include:

As the silicone surfactant, for example, organosiloxane polymers KF-640, 642, 643, KP341, X-70-092, X-70-093, (above, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428, DC-57, DC-190 (above, trade names, manufactured by Toray Dow Corning Silicon Corporation), SILWET L-77, L-7001, FZ-2105 , FZ-2120, FZ-2154, FZ-2164, FZ-2166, L-7604 (above, trade names, manufactured by Nippon Unika), DBE-814, DBE-224, DBE-621, CMS-626, CMS-222 , KF-352A, KF-354L, KF-355A, KF-6020, DBE-821, DBE-712 (Gelest), BYK-307, BYK-310, BYK-378, BYK-333 (above, brand name, Big Chemie)・Japan), granol (trade name, manufactured by Kyoeisha Chemical Co., Ltd.), etc.;

As the fluorine-based surfactant, for example, Megapac F171, F173, R-08 (manufactured by Dainippon Ink Chemical Industry Co., Ltd., trade name), Fluorad FC4430, FC4432 (Sumitomo 3M Co., Ltd., trade name), etc.;

As nonionic surfactants other than these, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether etc. are mentioned, respectively, for example.

Among these surfactants, silicone-based surfactants and fluorine-based surfactants are preferable from the viewpoint of coatability (streak suppression) of the resin composition, and from the viewpoint of the influence on the YI value and total light transmittance by the oxygen concentration during the curing process, silicone-based surfactants Surfactants are preferred.

(c) When using surfactant, 0.001-5 mass parts is preferable with respect to 100 mass parts of (a) polyimide precursors in a resin composition, and, as for the compounding quantity, 0.01-3 mass parts is more preferable.

(d) alkoxysilane compounds

In order for the resin film obtained from the resin composition which concerns on this embodiment to show sufficient adhesiveness between support bodies in manufacturing processes, such as a flexible device, the resin composition is (a) with respect to 100 mass % of polyimide precursors. and 0.01-20 mass % of an alkoxysilane compound can be contained. When content of the alkoxysilane compound with respect to 100 mass % of polyimide precursors is 0.01 mass % or more, favorable adhesiveness between support bodies can be acquired. Moreover, it is preferable from a viewpoint of storage stability of a resin composition that content of an alkoxysilane compound is 20 mass % or less. It is more preferable that content of an alkoxysilane compound is 0.02-15 mass % with respect to 100 mass parts of polyimide precursors, It is still more preferable that it is 0.05-10 mass %, It is especially preferable that it is 0.1-8 mass %.

By using an alkoxysilane compound as an additive of the resin composition which concerns on this embodiment, while improving the coatability (streak nonuniformity suppression) of a resin composition in addition to said adhesive improvement, cure oxygen of YI value of the cured film obtained concentration dependence can be reduced.

Examples of the alkoxysilane compound include 3-ureidepropyltriethoxysilane, bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, γ -Aminopropyltrimethoxysilane, γ-aminopropyltripropoxysilane, γ-aminopropyltributoxysilane, γ-aminoethyltriethoxysilane, γ-aminoethyltripropoxysilane, γ-aminoethyltribu Toxysilane, γ-aminobutyltriethoxysilane, γ-aminobutyltrimethoxysilane, γ-aminobutyltripropoxysilane, γ-aminobutyltributoxysilane, phenylsilane triol, trimethoxyphenylsilane, Trimethoxy(p-tolyl)silane, diphenylsilanediol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, triphenylsilanol and an alkoxysilane compound represented by each of the following structures etc. are mentioned, It is preferable to use 1 or more types selected from these.

[Formula 28]

The manufacturing method of the resin composition in this embodiment is not specifically limited. For example, it can follow the following method.

(a) When the solvent used when synthesize|combining a polyimide precursor and (b) organic solvent are the same, the synthesize|combined polyimide precursor solution can be used as a resin composition as it is. Moreover, after adding and stirring and mixing 1 or more types of (b) an organic solvent and other components to a polyimide precursor in the temperature range of room temperature (25 degreeC) - 80 degreeC as needed, it is used as a resin composition also be For this stirring and mixing, an appropriate device such as a three-one motor (manufactured by Shinto Chemical Co., Ltd.) equipped with stirring blades and an autorotation revolving mixer can be used. Moreover, you may apply the heat|fever of 40-100 degreeC as needed.

On the other hand, when (a) the solvent used when synthesizing the polyimide precursor and (b) the organic solvent differ, the solvent in the synthesized polyimide precursor solution is appropriately subjected to methods such as reprecipitation and solvent distillation. After removing and isolating (a) a polyimide precursor, you may prepare a resin composition by adding (b) an organic solvent and other components as needed and stirring and mixing in the temperature range of room temperature - 80 degreeC.

After preparing the resin composition as mentioned above, by heating the composition solution at 130-200 degreeC for 5 minutes - 2 hours, for example, a part of polyimide precursor is dehydrated already so that a polymer does not raise|generate precipitation. You can make it Here, the imidation rate can be controlled by controlling the heating temperature and the heating time. By partially imidating a polyimide precursor, the viscosity stability at the time of room temperature storage of a resin composition can be improved. As a range of the imidation ratio, it is preferable to set it as 5 % - 70 % from a viewpoint of balancing the solubility of the polyimide precursor with respect to a resin composition solution, and the storage stability of a solution.

It is preferable that the water content of the resin composition which concerns on this embodiment is 3,000 mass ppm or less.

From a viewpoint of viscosity stability at the time of storing the resin composition, it is more preferable that it is 1,000 mass ppm or less, and, as for the moisture content of a resin composition, it is more preferable that it is 500 mass ppm or less.

In 25 degreeC, as for the solution viscosity of the resin composition which concerns on this embodiment, 500-200,000 mPa*s is preferable, 2,000-100,000 mPa*s is more preferable, 3,000-30,000 mPa*s is especially preferable. This solution viscosity can be measured using the E-type viscometer (The Toki Sangyo Co., Ltd. make, VISCONICEHD). When the solution viscosity is lower than 300 mPa·s, coating at the time of film formation is difficult, and when it is higher than 200,000 mPa·s, there is a fear that a problem arises that stirring at the time of synthesis becomes difficult.

(a) When synthesize|combining a polyimide precursor, even if a solution becomes high viscosity, it is possible to obtain the resin composition of the viscosity with good handleability by adding and stirring a solvent after completion|finish of reaction.

The resin composition of this embodiment has the following characteristics in a preferable aspect.

After the resin composition is applied to the surface of the support to form a coating film, the coating film is included in the coating film by heating in a nitrogen atmosphere (for example, in nitrogen with an oxygen concentration of 2,000 ppm or less) at 300°C to 550°C. The resin film obtained by imidating the polyimide precursor used has yellowness YI in 10 micrometers film thickness of 30 or less.

After the resin composition is applied to the surface of the support to form a coating film, the coating film is included in the coating film by heating in a nitrogen atmosphere (for example, in nitrogen with an oxygen concentration of 2,000 ppm or less) at 300°C to 550°C. Residual stress of the resin film obtained by imidating the polyimide precursor used is 25 Mpa or less.

The resin composition according to the present embodiment can be suitably used, for example, to form a transparent substrate of a display device such as a liquid crystal display, an organic electroluminescence display, a field emission display, or electronic paper. Specifically, it can be used in order to form the board|substrate of a thin film transistor (TFT), the board|substrate of a color filter, the board|substrate of a transparent conductive film (ITO, IndiumThinOxide), etc.

Since the resin precursor of this embodiment can form the polyimide film whose residual stress is 25 MPa or less, it is easy to apply to the display manufacturing process provided with the TFT element device on the colorless transparent polyimide substrate.

<resin film>

Another aspect of the present invention provides a resin film formed from the above-mentioned resin precursor.

Moreover, another aspect of this invention provides the method of manufacturing a resin film from the above-mentioned resin composition.

The resin film in this embodiment,

A step of forming a coating film by applying the resin composition described above on the surface of the support (application step);

a step of imidizing a polyimide precursor contained in the coating film by heating the support and the coating film to form a polyimide resin film (heating process);

Step of peeling the polyimide resin film from the support (peeling step)

It is characterized in that it includes.

Here, a support body will not be specifically limited, if it has heat resistance in the heating temperature of a subsequent process and peelability is favorable. For example, a glass (eg, alkali-free glass) substrate;

silicon wafer;

PET (polyethylene terephthalate), OPP (stretched polypropylene), polyethylene glycol terephthalate, polyethylene glycol naphthalate, polycarbonate, polyimide, polyamideimide, polyetherimide, polyetheretherketone, polyethersulfone, polyphenylene resin substrates such as sulfone and polyphenylene sulfide;

Metal substrates such as stainless steel, alumina, copper, nickel, etc.

etc are used.

When forming a film-like polyimide molded body, for example, a glass substrate, a silicon wafer, etc. are preferable, and when forming a film-form or sheet-like polyimide molded body, for example, PET (polyethylene terephthalate), OPP (stretched polypropylene) or the like is preferable.

Examples of the coating method include a doctor blade knife coater, an air knife coater, a roll coater, a rotary coater, a flow coater, a die coater, a bar coater, etc. coating methods, spin coating, spray coating, dip coating, etc.; Printing techniques, such as screen printing and gravure printing, can be applied.

The coating thickness should be appropriately adjusted depending on the desired thickness of the resin film and the content of the polyimide precursor in the resin composition, but is preferably about 1 to 1,000 µm. Although implementation in room temperature is sufficient for an application|coating process, in order to lower|hang a viscosity and make workability|operativity favorable, you may heat and implement a resin composition in the range of 40-80 degreeC.

A drying process may be implemented following an application|coating process, a drying process may be abbreviate|omitted, and you may proceed directly to the next heating process. This drying process is implemented for the purpose of organic solvent removal. When performing a drying process, suitable apparatuses, such as a hot plate, a box-type dryer, and a conveyor-type dryer, can be used, for example. It is preferable to implement at 80-200 degreeC, and, as for a drying process, it is more preferable to implement at 100-150 degreeC. It is preferable to set it as 1 minute - 10 hours, and, as for the implementation time of a drying process, it is more preferable to set it as 3 minutes - 1 hour.

As mentioned above, the coating film containing a polyimide precursor is formed on a support body.

Then, a heating process is implemented. A heating process is a process of advancing the imidation reaction of the polyimide precursor in a coating film while removing the organic solvent which remained in the coating film in said drying process, and obtaining the film|membrane which consists of a polyimide.

This heating process can be implemented using apparatuses, such as an inert gas oven, a hot plate, a box-type dryer, and a conveyor-type dryer, for example. This process may be performed simultaneously with the said drying process, and you may implement both processes sequentially.

Although you may implement a heating process in air atmosphere, it is recommended to implement in an inert gas atmosphere from a viewpoint of safety|security, transparency of the polyimide film obtained, and a YI value. As an inert gas, nitrogen, argon, etc. are mentioned, for example.

Although heating temperature may be set suitably according to the kind of (b) organic solvent, 250 degreeC - 550 degreeC are preferable, and 300-450 degreeC is more preferable. If it is 250 degreeC or more, imidation will become enough, and if it is 550 degrees C or less, there will be no problems, such as a fall of transparency of the polyimide film obtained, and deterioration of heat resistance. The heating time is preferably about 0.5 to 3 hours.

In this embodiment, 2,000 mass ppm or less is preferable from a viewpoint of transparency of the polyimide film obtained, and a YI value, as for the oxygen concentration of the ambient atmosphere in said heating process, 100 mass ppm or less is more preferable, 10 mass ppm or less is more preferable. The YI value of the polyimide film obtained can be made into 30 or less by heating in the atmosphere whose oxygen concentration is 2,000 mass ppm or less.

The peeling process of peeling a resin film from a support body is needed after the said heating process depending on the use use/purpose of a polyimide resin film. It is preferable to perform this peeling process, after cooling the resin film on a support body to room temperature - about 50 degreeC.

As this peeling process, the aspect of following (1)-(4) is mentioned, for example.

(1) After producing a structure including a polyimide resin film/support by the above method, laser is irradiated from the support side of the structure, and the interface between the support and the polyimide resin film is ablated by ablation processing, thereby polyimide resin How to peel. As a kind of laser, a solid-state (YAG) laser, a gas (UV excimer) laser, etc. are mentioned. It is preferable to use a spectrum with a wavelength of 308 nm or the like (refer to Japanese Patent Application Laid-Open No. 2007-512568, Japanese Patent Application Laid-Open No. 2012-511173, etc.).

(2) Before coating the resin composition on the support, a release layer is formed on the support, and then a polyimide resin film/release layer/support-containing structure is obtained, and the polyimide resin film is peeled off. Examples of the release layer include a method using parylene (registered trademark, manufactured by Nippon Parylene Co., Ltd.) and tungsten oxide; a method using a release agent such as vegetable oil, silicone, fluorine, or alkyd. (Refer to Unexamined-Japanese-Patent No. 2010-67957, Unexamined-Japanese-Patent No. 2013-179306, etc.).

You may use this method (2) and the laser irradiation of said (1) together.

(3) A method of obtaining a polyimide resin film by using an etchable metal substrate as a support to obtain a structure including a polyimide resin film/support and then etching the metal with an etchant. As a metal, copper (As a specific example, the electrolytic copper foil "DFF" manufactured by Mitsui Metals Mining Co., Ltd.), aluminum, etc. can be used, for example. As the etchant, ferric chloride or the like for copper and dilute hydrochloric acid or the like can be used for aluminum.

(4) After obtaining a structure containing a polyimide resin film/support body by the said method, an adhesive film is affixed on the polyimide resin film surface, and an adhesive film/polyimide resin film is separated from the support body, and the A method of separating a polyimide resin film from a post-adhesive film.

Among these peeling methods, from the viewpoint of the refractive index difference, YI value, and elongation of the front and back of the polyimide resin film obtained, method (1) or (2) is suitable, and the viewpoint of the difference in refractive index between the front and back of the polyimide resin film obtained. In method (1), it is more appropriate.

Moreover, in the method (3), when copper is used as a support body, the YI value of the polyimide resin film obtained becomes large, and the tendency for elongation to become small is seen. This is thought to be the influence of a copper ion.

Although the thickness of the resin film obtained by the said method is not specifically limited, It is preferable that it is the range of 1-200 micrometers, More preferably, it is 5-100 micrometers.

The resin film according to the present embodiment may have a yellowness YI of 30 or less at a thickness of 10 µm. In addition, the residual stress may be 25 MPa or less. In particular, the yellowness YI in the 10 μm film thickness may be 30 or less, and the residual stress may be 25 MPa or less. Such characteristics are, for example, the resin precursor of the present disclosure in a nitrogen atmosphere (for example, in nitrogen with an oxygen concentration of 2,000 ppm or less), preferably 300 ° C. to 550 ° C., more preferably 350 ° C. to 450 ° C. It is realized favorably by imidating at °C.

The resin film according to the present embodiment may further have a tensile elongation of 15% or more. The tensile elongation of the resin film may also be 20% or more, and particularly may be 30% or more. This tensile elongation degree can be measured using a commercially available tensile tester using a resin film with a film thickness of 10 micrometers as a sample.

The resin film which concerns on this embodiment is a film which consists of the polyimide by which the (a1) polyimide precursor contained in the above-mentioned resin composition was thermally imidated. Therefore, the following general formula (11):

[Formula 29]

{Wherein, X ₁ and X ₂ represent a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b, and c are integers from 0 to 4. Y is at least 1 sort(s) selected from the group which consists of said General formula (3), (4) and (5). l and m each independently represent an integer of 1 or more and satisfy 0.01 ≤ l / (l + m) ≤ 0.99.}

The lower limit of l/(l+m) may be 0.05, 0.10, 0.20, 0.30, or 0.40.

The upper limit of l/(l+m) may be 0.95, 0.90, 0.80, 0.70, or 0.60 may be sufficient as it.

As described above, preferably, the residual stress is 25 MPa or less, YI is 30 or less, the glass transition temperature is 400°C or more, the elongation is 15% or more, and the breaking strength is 250 MPa or more.

Moreover, as a 2nd aspect, it is a film which consists of the polyimide by which the (a2) polyimide precursor contained in the above-mentioned resin composition was thermally imidated. Therefore, the following general formula (12):

[Formula 30]

{wherein, X ₃ is 4,4'-oxydiphthalic dianhydride (ODPA), biphenyltetracarboxylic dianhydride (BPDA), and 4,4'-biphenylbis(trimellitic acid monoesteric anhydride) ) (TAHQ), represents a tetravalent group derived from at least one selected from R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a, b, and c are integers from 0 to 4.} It is a resin film having a structural unit represented by } and having an elongation of 15% or more, preferably a residual stress of 25 MPa or less, and YI of 30 or less, The glass transition temperature is 400° C. or higher, and the breaking strength is 250 MPa or higher.

<Laminate>

Another aspect of the present invention provides a laminate comprising a support and a polyimide resin film formed from the resin composition described above on the surface of the support.

Moreover, another aspect of this invention provides the manufacturing method of the said laminated body.

The laminate in this embodiment,

The process of forming a coating film by apply|coating the above-mentioned resin composition on the surface of a support body (application process);

It can obtain with the manufacturing method of a laminated body including the process (heating process) of imidating the polyimide precursor contained in the coating film by heating the said support body and the said coating film, and forming a polyimide resin film.

The manufacturing method of said laminated body can carry out similarly to the manufacturing method of the above-mentioned resin film, for example, except not implementing a peeling process, and can be implemented.

This laminated body can be used suitably for manufacture of a flexible device, for example.

In more detail, it is as follows.

When forming a flexible display, a glass substrate is used as a support body, a flexible board|substrate is formed on it, and TFT etc. are formed on it. The process of forming TFT etc. on a flexible substrate is typically performed at the temperature of the wide range of 150-650 degreeC. However, in order to realistically realize the desired performance, at a high temperature around 250 ° C. to 450 ° C., using an inorganic material, TFT-IGZO (InGaZnO) oxide semiconductor or TFT (a-Si-TFT, poly-Si-TFT) ) is required to form

On the other hand, by these thermal histories, various physical properties (especially yellowness and elongation) of a polyimide film tend to fall, and when it exceeds 400 degreeC, especially yellowness and elongation fall. By the way, the polyimide film obtained from the polyimide precursor which concerns on this invention has very little fall of yellowness and elongation also in the high temperature area|region of 400 degreeC or more, and can be used favorably in the said area|region.

Moreover, in this embodiment, the laminated body containing the polyimide film layer containing the polyimide represented by following General formula (13), and a LTPS (low-temperature polysilicon TFT) layer can be provided.

[Formula 31]

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.}

As a manufacturing method of the said laminated body, after manufacturing the laminated body containing the above-mentioned support body and the polyimide resin film formed from the above-mentioned resin composition on the surface of the support body, an amorphous Si layer is formed, and 400-450. After performing dehydrogenation annealing at about 0.5 to 3 hours at 占폚, the LTPS layer can be formed by crystallization with an excimer laser or the like. Then, the said laminated body can be obtained by peeling glass and a polyimide film by laser peeling etc.

The laminate containing the polyimide film layer containing the polyimide represented by the general formula (13) and the LTPS (low temperature polysilicon TFT) layer has little peeling or swelling after the heat cycle test, and there is little substrate warpage.

In addition, when the residual stress generated in the flexible substrate and the polyimide resin film is high, when the laminate formed of both expands in a high-temperature TFT process and then contracts at room temperature cooling, the glass substrate warps and breaks, and the flexible substrate Problems, such as peeling from a glass substrate, may arise. Generally, since the thermal expansion coefficient of a glass substrate is small compared with resin, residual stress generate|occur|produces between the glass substrate and a flexible substrate. Since the resin film which concerns on this embodiment can make the residual stress which generate|occur|produces between a glass substrate 25 Mpa or less as above-mentioned, it can be used suitably for formation of a flexible display.

Moreover, the polyimide film which concerns on this embodiment can make yellowness YI in 10 micrometers film thickness into 30 or less, and can make tensile elongation into 15 % or more. Thereby, the resin film which concerns on this embodiment is excellent in the breaking strength at the time of handling a flexible substrate, Therefore, the yield at the time of manufacturing a flexible display can be improved.

Further, as another aspect, the yellowness at a film thickness of 10 microns after heating at 400°C or higher is 20 or less, the absorbance at 308 nm when the film thickness is 0.1 microns is 0.6 or more and 2.0 or less, and the elongation is 15 % or more, a polyimide film can be provided.

By setting YI to 20 or less, a flexible board|substrate can be manufactured, without degrading the image quality at the time of setting it as a display.

More preferably, it is 18 or less, and it is especially preferable that it is 16 or less.

When the absorbance at 308 nm when the film thickness is 0.1 microns is 0.6 or more and 2.0 or less and the elongation is 15% or more, the polyimide film can be easily removed from the glass substrate with a laser, for example. From the viewpoint of suppressing ash after laser exfoliation, 0.6 or more and 1.5 or less and 20% or more of elongation are preferable, for example, from the viewpoint of not degrading the performance of the organic EL device, 0.6 or more and 1.0 or less, and 20% or more of elongation Especially preferred.

Although there is no upper limit in particular of elongation, 80 % or less may be sufficient, 70 % or less may be sufficient, 60 % or less may be sufficient, 50 % or less may be sufficient, and 40 % or less may be sufficient.

In addition, the polyimide film may be burned by laser light at the time of laser peeling, and what remains after the burning is ash.

Accordingly, another aspect of the present invention provides a display substrate.

Another aspect of the present invention provides a method for manufacturing the display substrate.

The manufacturing method of the display board|substrate in this embodiment,

A step of forming a coating film by applying the resin composition described above on the surface of the support (application step);

a step of imidizing a polyimide precursor contained in the coating film by heating the support and the coating film to form a polyimide resin film (heating process);

forming an element or circuit on the polyimide resin film (element/circuit formation process);

Step of peeling the polyimide resin film on which the element or circuit is formed from the support (peeling step)

It is characterized in that it includes.

The said method WHEREIN: An application|coating process, a heating process, and a peeling process can each carry out similarly to the manufacturing method of the above-mentioned resin film, and can implement it.

The device/circuit forming step can be performed by a method known to those skilled in the art.

The resin film according to the present embodiment that satisfies the above physical properties is suitably used for applications where use is restricted due to the yellow color of the existing polyimide films, in particular, a colorless transparent substrate for flexible displays, a protective film for color filters, and the like. Furthermore, for example, the light-diffusing sheet and coating film in a protective film, TFT-LCD, etc. (For example, the interlayer of TFT-LCD, a gate insulating film, a liquid crystal aligning film, etc.), ITO board|substrate for touch panels, cover glass replacement for smartphones It can be used also in the field|area in which colorless transparency and low birefringence are requested|required, such as a resin substrate. When the polyimide which concerns on this embodiment is applied as a liquid crystal aligning film, an aperture ratio will be high and manufacture of TFT-LCD with high contrast ratio will become possible.

The polyimide precursor which concerns on this embodiment, the resin film manufactured using the resin precursor, and a laminated body are applicable as a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, etc., for example, and manufacture of a flexible device In particular, it can be suitably used as a board|substrate. Here, as a flexible device to which the resin film and laminated body which concern on this embodiment are applicable, a flexible display, a flexible solar cell, a flexible touch panel electrode board|substrate, a flexible lighting, a flexible battery etc. are mentioned, for example.

Example

Hereinafter, the present invention will be described in more detail based on examples, which are described for the purpose of explanation, and the scope of the present invention is not limited to the following examples.

Various evaluations in Examples and Comparative Examples were performed as follows.

<Measurement of weight average molecular weight>

The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) under the following conditions.

As a solvent, N,N-dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd., for high performance liquid chromatography, 24.8 mmol/L lithium bromide monohydrate (manufactured by Wako Pure Chemical Industries, Ltd., purity 99.5%) just before measurement) and 63.2 m mol/L phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., for high-performance liquid chromatography) was added and dissolved) was used. The analytical curve for calculating a weight average molecular weight was created using standard polystyrene (made by Tosoh Corporation).

Column: Shodex KD-806M (manufactured by Showa Denko Co., Ltd.)

Flow rate: 1.0 ml/min

Column temperature: 40°C

Pump: PU-2080Plus (manufactured by JASCO)

Detector: RI-2031Plus (RI: Differential Refractometer, manufactured by JASCO) and UV-2075Plus (UV-VIS: Ultraviolet-Visible Absorber, manufactured by JASCO)

<Evaluation of content of molecules having a molecular weight of less than 1,000 (low molecular weight content)>

The content of molecules having a molecular weight of less than 1,000 in the resin was calculated as the ratio (percentage) of the peak area occupied by the component having a molecular weight of less than 1,000 to the peak area of the entire molecular weight distribution using the measurement result of GPC obtained above.

<Evaluation of moisture content>

The moisture content of the synthetic solvent and the resin composition (varnish) was measured using a Karl Fischer moisture measuring apparatus (a trace moisture measuring apparatus AQ-300, the Hiranuma Industrial Co., Ltd. make).

<Evaluation of viscosity stability of resin composition>

About the resin composition prepared in each of an Example and a comparative example,

After preparation, the sample left still at room temperature for 3 days is used as the sample after preparation, and the viscosity in 23 degreeC is measured;

Then, the sample left still at room temperature for 2 weeks was made into the sample 2 weeks later, and the viscosity measurement in 23 degreeC was performed again. These viscosity measurements were performed using a viscometer with a temperature controller (TV-22 manufactured by Toki Sangyo Co., Ltd.).

Using the measured value, the rate of change in viscosity for 2 weeks at room temperature was calculated by the following formula.

Rate of change in viscosity for 2 weeks at room temperature (%) = [(viscosity of sample after 2 weeks)-(viscosity of sample after preparation)] / (viscosity of sample after preparation) x 100

The rate of change of the viscosity for 2 weeks at room temperature was evaluated on the basis of the following criteria.

◎: Viscosity change rate of 5% or less (storage stability "excellent")

○: Viscosity change rate of more than 5 and 10% or less (storage stability "good")

x: Viscosity change rate exceeds 10% (storage stability "poor")

<Evaluation of varnish applicability>

The resin composition prepared in each of Examples and Comparative Examples was coated on an alkali-free glass substrate (size 37 × 47 mm, thickness 0.7 mm) using a bar coater to a film thickness of 15 µm after curing, and then at 140°C. It was pre-baked for 60 minutes.

The applicability of the varnish was evaluated by measuring the level difference on the surface of the coating film using a step meter (manufactured by Tencor, model name P-15).

◎: Surface level difference of 0.1 μm or less (applicability “excellent”)

○: Surface level difference greater than 0.1 and less than or equal to 0.5 μm (applicability “good”)

×: The step difference of the surface exceeds 0.5 μm (applicability “poor”)

<Evaluation of residual stress>

Each resin composition was apply|coated with the spin coater on the 6-inch silicon wafer of 625 micrometers +/-25 micrometers in which "deflection amount" was measured beforehand, and it prebaked in 100 degreeC for 7 minutes. Then, using a vertical curing furnace (manufactured by Koyo Lindbergh, model name VF-2000B), the oxygen concentration in the warehouse is adjusted to be 10 mass ppm or less, and heating at 430°C for 1 hour A hardening process (cure process) was performed, and the silicon wafer with a 10-micrometer-thick polyimide resin film was manufactured after hardening.

The amount of warpage of this wafer was measured using a residual stress measuring apparatus (manufactured by Tencor Corporation, model name: FLX-2320), and the residual stress generated between the silicon wafer and the resin film was evaluated.

(double-circle): Residual stress -15 MPa or less for -5 seconds (evaluation of residual stress "excellent")

○: Residual stress greater than 15 and less than or equal to 25 MPa (evaluation of residual stress “good”)

x: residual stress exceeds 25 MPa (residual stress evaluation "bad")

<Evaluation of warpage of polyimide resin film in which inorganic film was formed>

The resin composition prepared in each of Examples and Comparative Examples was spin-coated on a 6-inch silicon wafer substrate having an aluminum vapor deposition layer formed on its surface so that the film thickness after curing was 10 µm, and pre-baked at 100°C for 7 minutes. Thereafter, using a vertical curing furnace (manufactured by Koyo Lindbergh, model name: VF-2000B), the oxygen concentration in the warehouse was adjusted to be 10 mass ppm or less, and heat-hardening treatment was performed at 430°C for 1 hour, A wafer with a mid resin film formed thereon was manufactured. Using this wafer, a silicon nitride (SiNx) film, which is an inorganic film, is formed to a thickness of 100 nm at 350° C. by a CVD method on a polyimide resin film, and an inorganic film/polyimide resin is formed on the laminate wafer. got it

The laminate wafer obtained above was immersed in a dilute hydrochloric acid aqueous solution, and the sample of the polyimide film in which the inorganic film was formed on the surface was obtained by peeling from the wafer by integrating two layers of an inorganic film and a polyimide film. Using this sample, warpage of the polyimide resin film was evaluated.

◎: No warpage (bending “good”)

○: There is only a little warpage (bending “good”)

×: Film is rounded due to warping (warpage “defective”)

<Evaluation of yellowness (YI value)>

It carried out similarly to the said <warpage evaluation of the polyimide resin film in which the inorganic film was formed>, and manufactured the wafer (the thing in which the inorganic film is not formed). The wafer was immersed in a dilute hydrochloric acid aqueous solution, and the polyimide resin film was peeled, and the resin film was obtained.

About the obtained polyimide resin film, the YI value (10 micrometers of film thickness conversion) was measured by the Nippon Denshoku Industries Co., Ltd. product (Spectrophotometer: SE600) using the D65 light source.

<Evaluation of elongation and breaking strength>

It carried out similarly to the said <warpage evaluation of the polyimide resin film in which the inorganic film was formed>, and manufactured the wafer (the thing in which the inorganic film is not formed). Using a dicing saw (DAD 3350 manufactured by Disco Co., Ltd.), cuts of 3 mm in width were placed in the polyimide resin film of the wafer, and then soaked in an aqueous dilute hydrochloric acid solution overnight to peel the resin film piece and dried. This was cut to 50 mm in length, and it was set as the sample.

For the above samples, using TENSILON (UTM-II-20 manufactured by Orientec), elongation and breaking strength were measured at a test speed of 40 mm/min and an initial weight of 0.5 fs.

<Measurement of absorbance at 308 nm of polyimide resin film>

Each of the said varnishes was spin-coated on the quartz glass substrate, and the polyimide resin film with a film thickness of 0.1 micrometer was obtained by heating at 430 degreeC in nitrogen atmosphere for 1 hour, respectively. About these polyimide films, the absorbance in 308 nm was measured using UV-1600 (made by Shimadzu Corporation).

[Example 1]

In a 500 ml separable flask purged with nitrogen, 96 g of N-methyl-2-pyrrolidone (NMP) was placed, and 17.71 g (77.6 mmol) and 4 of 4-aminophenyl-4-aminobenzoate (APAB) were added. , 4.82 g (19.4 mmol) of 4'-diaminodiphenylsulfone (DAS) was added and stirred to dissolve APAB and DAS. Then, 29.42 g (100 mmol) of biphenyl-3,3',4,4'-tetracarboxylic dianhydride (BPDA) was added, and the polymerization reaction was carried out under nitrogen flow at 80°C under stirring for 3 hours. carried out. Then, the NMP solution (henceforth a varnish) P-1 of polyamic acid was obtained by cooling to room temperature, adding said NMP, and adjusting so that a solution viscosity might be set to 51,000 mPa*s. The weight average molecular weight (Mw) of the obtained polyamic acid was 65,000.

[Examples 2 to 21 and Comparative Examples 1 to 5]

In Example 1, except that the input amount (molar ratio) of the raw material, the type of solvent used, the polymerization temperature, and the polymerization time were respectively changed as described in Table 1, in the same manner as in Example 1, varnish P- 2-P-26 was obtained.

Table 1 shows the weight average molecular weight (Mw) of the polyamic acid contained in each varnish.

The abbreviation of each component in Table 1 has the following meaning, respectively.

BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride

PMDA: pyromellitic dianhydride

TAHQ: p-phenylenebis (trimellitate anhydride)

APAB: 4-aminophenyl-4-aminobenzoate

ATAB: 2-methyl-4-aminophenyl-4-aminobenzoate

BABB: [4-(4-aminobenzoyl)oxyphenyl]4-aminobenzoate

BAFL: 9,9-bis(aminophenyl)fluorene

BFAF: 9,9-bis(4-amino-3-fluorophenyl)fluorene

TFMB: 2,2'-bis(trifluoromethyl)benzidine

DAS: 4,4'-diaminodiphenylsulfone

NMP: N-methyl-2-pyrrolidone

DMF: N,N-dimethylformamide

DMAc: N,N-dimethylacetamide

The varnishes P-1 to P-26 obtained by the said Example and the comparative example were used as it was as a resin composition, and it evaluated according to the method mentioned above. The evaluation results are shown in Table 2.

As is clear from Tables 1 and 2, the polyimide films obtained in Comparative Examples 1 and 2 containing only the structural unit represented by the general formula (1) were brittle and were not able to evaluate physical properties such as elongation. In addition, the result was also high in residual stress. Moreover, the polyimide film obtained by the comparative example 3 containing only the structural unit represented by General formula (2) had high residual stress, and curvature generate|occur|produced after forming an inorganic film, and also had low elongation.

On the other hand, the polyimide film obtained from Examples 1-21 which contains the structural unit represented by General formula (1), and the structural unit represented by General formula (2) at a molar ratio 99/1-1/99 is yellowness was as low as 20 or less, the residual stress was also as low as 25 MPa or less, and the elongation was as high as 20% or more. Moreover, the curvature after formation of an inorganic film also did not generate|occur|produce, or even if it generate|occur|produced, it was very insignificant.

From the result of said Table 2, it was confirmed that the polyimide resin film obtained from the resin composition which concerns on this invention is a resin film excellent in mechanical properties with a small yellowness degree and low residual stress.

Specifically, in the present invention, a resin film having a residual stress of 25 MPa or less, a yellowness YI of 30 or less, and an elongation of 15% or more is obtained.

[Example 22]

In a 500 ml separable flask purged with nitrogen, N-methyl-2-pyrrolidone (NMP) (water content 250 mass ppm) immediately after opening an 18 L can was placed in an amount corresponding to 17 wt% solid content, 4- 5.71 g (25.0 mmol) of aminophenyl-4-aminobenzoate (APAB, purity 99.5%, Nippon Pharmaceutical Co., Ltd. make) was put, it stirred, and APAB was dissolved. Thereafter, 7.36 g (25.0 mmol) of biphenyl-3,3',4,4'-tetracarboxylic dianhydride (BPDA, purity 99.5%, manufactured by Manak Corporation) was added, and 80°C under a nitrogen flow The polymerization reaction was carried out under stirring for 3 hours. Then, the NMP solution (henceforth a varnish) P-27 of polyamic acid was obtained by cooling to room temperature, adding the said NMP and adjusting so that a solution viscosity might be set to 51,000 mPa*s. The weight average molecular weight (Mw) of the obtained polyamic acid was 128,000, and content of the molecule|numerator of molecular weight less than 1,000 was 0.01 mass %.

[Examples 23 to 33 and Comparative Examples 6 to 11]

In Example 22, the same as in Synthesis Example 1, except that the type of raw material, the input amount of the raw material, the type of solvent used, the polymerization temperature, and the polymerization time were changed as described in Table 3, respectively, varnish P -28 to P-44 were obtained.

Table 3 also shows the weight average molecular weight (Mw) of the polyamic acid contained in each varnish.

The abbreviation of each component in Table 3 has the following meaning, respectively.

BPDA: Biphenyltetracarboxylic dianhydride, purity 99.5%, manufactured by Mitsubishi Chemical Corporation

TAHQ: p-phenylenebis (trimellitate acid anhydride), purity 99.5%, manufactured by Manarch Corporation

PMDA: pyromellitic dianhydride

APAB: 4-aminophenyl-4-aminobenzoate, purity 99.5%

4,3-APAB: 4-aminophenyl-3-aminobenzoate, purity 99.5%

ATAB: 2-methyl-4-aminophenyl-4-aminobenzoate

BABB: [4-(4-aminobenzoyl)oxyphenyl]4-aminobenzoate

NMP 1:18 ℓ Immediately after opening the can, moisture content 250 ppm

NMP 2: 500 ㎖ bottles left for 1 month after opening, moisture content 3,070 ppm

DMF: 500 ml bottled, unopened, moisture content 3510 ppm

DMAc: 500 ml bottled, unopened, moisture content 3430 ppm

[Examples 22 to 33 and Comparative Examples 6 to 11]

The varnishes P-27-P-44 obtained by the said Example and the comparative example were used as it was as a resin composition, and it evaluated according to the method mentioned above. The evaluation results are shown in Table 4.

As is clear from Tables 3 and 4, the weight average molecular weight of the polyimide precursor (varnish) is 30,000 or less, Comparative Example 6 (P-39), Comparative Example 7 (P-40), Comparative Example 8 (P-41) ), Comparative Example 10 (P-43) and Comparative Example 11 (P-44) had a large residual stress and large warpage. Moreover, the yellowness was large, and the elongation and breaking strength were also small. In particular, in Comparative Examples 10 and 11 with a large amount of moisture, the film was very soft.

On the other hand, in Comparative Example 9 (P-42) in which the weight average molecular weight of the polyimide precursor was 30000 or more, residual stress and warpage were small, yellowness was also low, and elongation and breaking strength were also large, but applicability deteriorated. .

In contrast, in Examples 22 to 33 using polyimide precursors P-27 to P-38 having a weight average molecular weight of 30,000 or more and 300,000 or less, residual stress is low, warpage is small, yellowness is low, elongation and The result which was excellent also in any characteristic with a large breaking strength was obtained.

From the result of said Table 4, it was confirmed that the polyimide resin film obtained from the resin composition which concerns on this invention is a resin film excellent in mechanical properties with a small yellowness and low residual stress.

Specifically, in the present invention, a resin film having a residual stress of 25 MPa or less, a yellowness YI of 20 or less, a glass transition temperature of 400° C. or more, an elongation of 15% or more, and a breaking strength of 250 MPa or more. this is obtained

In Examples 34 to 45 shown below, an experiment was conducted on the effect when at least one selected from the group consisting of a surfactant and an alkoxysilane compound was added to the resin composition.

[Example 34]

First, the varnish P-27 obtained in the said Example 22 was used as it is as a resin composition, and the following procedure evaluated coating stripes.

<Evaluation of coating stripes (coatability)>

The said resin composition was coated on the alkali-free-glass board|substrate (size 37x47mm, thickness 0.7mm) using the bar coater so that it might become the film thickness after a cure of 15 micrometers. After coating and leaving it to stand for 10 minutes in room temperature, it was visually confirmed whether coating streaks had not generate|occur|produced in the obtained coating film. Coating was performed three times using the same resin composition, the number of coating stripes was investigated about each coating film, and the following reference|standard evaluated using the average value.

◎: 0 continuous coating stripes with a width of 1 mm or more and a length of 1 mm or more (evaluation of coating stripes “excellent”)

○: 1 or 2 above coating stripes (Evaluation of coating stripes “good”)

△: 3 to 5 of the coating stripes (Evaluation of coating stripes “good”)

The evaluation results are shown in Table 5.

[Examples 35 to 45]

A resin composition was prepared by adding a surfactant or an alkoxysilane compound in the type and amount shown in Table 5 as additional additives to the varnish P-27 obtained in Example 22, respectively, and then filtering with a 0.1 µm filter.

Using the said resin composition, it carried out similarly to Example 34, and evaluated the coating stripe. The results are shown in Table 5.

The abbreviation of each component in Table 5 has the following meaning, respectively. The usage-amount of these components in Table 5 is a compounding quantity (usage amount) with respect to 100 mass parts of polyimide precursors respectively contained in a varnish. In Examples 39 and 45, the surfactant 1 and the alkoxysilane compound 1 were used together.

Surfactant 1: DBE-821, product name, silicone surfactant, Gelest manufacturing

Surfactant 2: Megapac F171, product name, fluorine-based surfactant, manufactured by DIC

Alkoxysilane compound 1: a compound represented by the following general formula (AS-1)

Alkoxysilane compound 2: a compound represented by the following general formula (AS-2)

[Formula 32]

As is clear from Table 5, in Examples 35 to 39 and Examples 41 to 45 containing a surfactant or an alkoxysilane compound, the generation of coating streaks was suppressed compared to Examples 34 and 40 not containing it, It turned out that the polyimide resin film excellent in surface smoothness was obtained.

[Example 46]

After apply|coating varnish P-27 so that it might become a film thickness of 10 micrometers after curing using a bar coater on an alkali free glass substrate (size 37x47mm, thickness 0.7mm), it prebaked at 140 degreeC for 60 minutes. Then, using a vertical curing furnace (manufactured by Koyo Lindbergh, model name: VF-2000B), the oxygen concentration in the warehouse is adjusted to be 10 mass ppm or less, and heat curing treatment is performed at 430° C. for 1 hour, polyimide A glass substrate with a resin film was prepared. An amorphous silicon layer was formed on this polyimide film, the LTPS layer was formed by performing dehydrogenation annealing at 430 degreeC for 1 hour, and then irradiating an excimer laser. The glass substrate was peeled off with an excimer laser (wavelength 308 nm, repetition frequency 300 Hz), and the laminated body containing a polyimide film and a LTPS layer was obtained.

This laminate had no warpage and had a yellowness of 20 or less.

[Example 47]

A laminate was obtained in the same manner as in Example 46 except for using the varnish P-1. This laminate had no warpage and had a yellowness of 20 or less.

[Comparative Example 12]

A laminate was obtained in the same manner as in Example 46 except for using the varnish P-24. This laminate had large warpage, and cracks entered a part of the polyimide film.

[Synthesis Example]

In a separable flask equipped with a Dean-Stark apparatus and a reflux device, 2.24 g (9.8 mmol) of APAB, 16.14 g of NMP, and 50 g of toluene were put in a nitrogen atmosphere, and APAB was dissolved under stirring. After adding 2.24 g (10.0 mmol) of H-PMDA there and refluxing in 180 degreeC for 2 hours, the toluene which is an azeotropic solvent was removed over 3 hours. The contents of the flask were cooled to 40°C, and it was confirmed from IR that absorption (C=O) in the vicinity of 1,650 cm ^-1 derived from the amide bond had disappeared. Then, by adding 4.44 g (10.0 mmol) of 6.54 g (30.0 mmol) and 6FDA for 8.95 g (39.2 mmol), NMP, and PMDA for 8.95 g (39.2 mmol) and NMP, and stirring at 80 degreeC for 4 hours, polyimide -A varnish of polyamic acid polymer was obtained (P-45). The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymer was 82,000.

[Examples 48 to 53, Comparative Example 13]

An organic EL substrate as shown in Fig. 1 was prepared.

A polyimide precursor varnish (P-1, P-11, P-20, P-22, P-27, P-33, P-45) was applied on a mother glass substrate (thickness 0.7 mm) using a bar coater, After apply|coating so that it might become a film thickness of 10 micrometers after curing, it prebaked in 140 degreeC for 60 minutes. Then, using a vertical curing furnace (manufactured by Koyo Lindbergh, model name: VF-2000B), the oxygen concentration in the warehouse is adjusted to be 10 mass ppm or less, and heat curing treatment is performed at 430° C. for 1 hour, polyimide A glass substrate with a resin film was prepared.

Then, the SiN layer was formed into a film to a thickness of 100 nm by CVD (Chemical Vapor Deposition) method.

Then, titanium was formed into a film by the sputtering method, and thereafter, it patterned by the photolithographic method, and the scanning signal line was formed.

Next, a SiN layer was formed to a thickness of 100 nm by the CVD method on the entire glass substrate on which the scanning signal lines were formed. (Let this be the lower substrate 2a)

Subsequently, the amorphous silicon layer 256 was formed on the lower substrate 2a, dehydrogenation annealing was performed at 430 degreeC for 1 hour, and the LTPS layer was formed by continuing excimer laser irradiation.

After that, the entire surface of the lower substrate 2a is coated with a photosensitive acrylic resin by spin coating, and exposed and developed by photolithography to form an interlayer insulating film 258 having a plurality of contact holes 257. formed. A part of each LTPS 256 was exposed by this contact hole 257 .

Next, an ITO film is formed on the entire surface of the lower substrate 2a on which the interlayer insulating film 258 is formed by a sputtering method, exposure and development are performed by a photolithography method, patterning is performed by an etching method, and each LTPS and A lower electrode 259 was formed to form a pair.

Further, in each contact hole 257 , the lower electrode 252 passing through the interlayer insulating film 258 and the LTPS 256 were electrically connected.

Next, after forming the partition wall 251, the hole transport layer 253 and the light emitting layer 254 were formed in each space partitioned by the partition wall 251. Moreover, the upper electrode 255 was formed so that the light emitting layer 254 and the partition 251 might be covered. The organic EL substrate 25 was produced by the above process.

Next, an ultraviolet curable resin is coated around the glass substrate, the polyimide film of this embodiment, and the sealing substrate 2b in which the SiN layer is formed in this order, and the sealing substrate 2b and the organic EL substrate are heated in an argon gas atmosphere. By bonding, the organic EL element was sealed. Thereby, the hollow part 261 was formed between each organic electroluminescent element and the sealing substrate 2b.

Excimer laser (wavelength 308 nm, repetition frequency 300 Hz) is irradiated from the lower substrate 2a side and the sealing substrate 2b side of the laminate formed in this way, and peels with the minimum energy required to peel the entire surface. was carried out.

About this laminated body, the board|substrate curvature after peeling, the lighting test, cloudiness evaluation of the laminated body, and the presence or absence evaluation were performed. Moreover, it implemented also about the heat cycle test. A result is shown in Table 6.

<Board warpage>

◎: No warpage

○: There is only a little warp

△: Rounded by bending

<lighting test>

○: lighted

×: Not lit

<Laminate cloudiness evaluation>

After forming the laminated body, the transparent thing of the whole device was made into (circle), the thing which is slightly cloudy was made into (triangle|delta), and the thing which was cloudy was made into x.

<Heat cycle test>

Appearance observation after testing -5 degreeC and 60 degreeC for 1000 cycles in 30 minutes (bath movement time 1 minute), respectively using the SPEC product heat cycle tester was implemented.

A thing in which peeling or swelling was not observed was made into (circle), a thing in which peeling or swelling was observed very partially after a test was made into (triangle|delta), and what peeling or swelling was observed entirely after a test was made into x.

[Examples 54 to 58, Comparative Example 14]

Polyimide precursor varnish (P-1, P-11, P-20, P-22, P-27, P-33, P-45) was used and LTPS was IGZO at the time of manufacturing the above laminate In addition, the laminate was manufactured and the said test was implemented. A result is shown in Table 7.

[Examples 59 to 63, Comparative Example 15]

Polyimide precursor varnishes (P-1, P-11, P-20, P having YI of 20 or less and a film thickness of 0.1 microns, absorbance at 308 nm of 0.6 or more and 2.0 or less, and giving 15% or more of elongation) -27, P-33, and P-45), the minimum energy required for laser peeling at the time of laser peeling, and the ash (ash content) when irradiated with energy obtained by adding 10 mJ/cm 2 to the minimum energy )) was evaluated. What ash did not generate|occur|produce at all was made into (circle), what a little ash was observed at the edge was made into (triangle|delta), and what ash was observed entirely was made into *. A result is shown in Table 8.

This invention is not limited to the said embodiment, It is possible to carry out various changes in the range which does not deviate from the meaning of invention.

The resin film formed from the polyimide precursor of the present invention can be applied to, for example, a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, and the like, and in the production of a flexible display, a substrate for a touch panel ITO electrode, etc., particularly It can be used suitably as a board|substrate.

Claims (13)

(a1) the following general formula (1):

(Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a and b and c are integers of 0 to 4), including a polyimide precursor having a structural unit represented by
Further, (c) a surfactant, and (d) at least one selected from the group consisting of an alkoxysilane compound,
A resin composition used for a flexible display. The method of claim 1,
A resin composition having a weight average molecular weight of 30,000 or more and 300,000 or less of the polyimide precursor. A method for producing a resin composition, comprising:
tetracarboxylic dianhydride;
The following general formula (6):

(Wherein, R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.) Including the polycondensation reaction of the diamine represented by
The said resin composition is the manufacturing method of the resin composition used for a flexible display. A method for producing a resin composition, comprising:
tetracarboxylic dianhydride;
The following general formula (6):

(Wherein, R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b and c are integers from 0 to 4.) a step of carrying out a polycondensation reaction of the diamine represented by
The manufacturing method of the resin composition including the process of adding at least 1 sort(s) chosen from the group which consists of (c) surfactant and (d) an alkoxysilane compound to the varnish obtained by the said process. The following general formula (11):

{Wherein, X ₁ and X ₂ represent a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b, and c are integers from 0 to 4. Y is a C4-C32 divalent organic group. l and m each independently represent an integer of 1 or more and satisfy 0.01 ≤ l / (l + m) ≤ 0.99.};
(c) A polyimide film comprising at least one selected from the group consisting of a surfactant and (d) an alkoxysilane compound. The following general formula (11):

{Wherein, X ₁ and X ₂ represent a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b, and c are integers from 0 to 4. Y is a C4-C32 divalent organic group. l and m each independently represent an integer of 1 or more and satisfy 0.01 ≤ l / (l + m) ≤ 0.99.} A polyimide film comprising a polyimide having a structural unit represented by
A polyimide film having a residual stress of 25 MPa or less. The following general formula (11):

{Wherein, X ₁ and X ₂ represent a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. And a, b, and c are integers from 0 to 4. Y is a C4-C32 divalent organic group. l and m each independently represent an integer of 1 or more and satisfy 0.01 ≤ l / (l + m) ≤ 0.99.} A polyimide film comprising a polyimide having a structural unit represented by
The polyimide film whose absorbance at 308 nm at the time of a film thickness of 0.1 micron is 0.6 or more and 2.0 or less. 8. The method according to any one of claims 5 to 7,
The polyimide film whose said Y is at least 1 sort(s) selected from the group which consists of following general formula (3), (4) and (5).

{In the formula, R ₄ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms. Each Z independently represents a single bond, a methylene group, an ethylene group, an ether or a ketone. d to k are integers from 0 to 4.} A flexible display comprising the polyimide film according to any one of claims 5 to 7. The following general formula (13):

{Wherein, X ₁ represents a tetravalent group having 4 to 32 carbon atoms. R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. and a, b, and c are integers of 0 to 4. A polyimide represented by };
(c) a surfactant, and (d) a flexible display comprising a polyimide film containing at least one selected from the group consisting of an alkoxysilane compound. 11. The method of claim 10,
A flexible display comprising at least one selected from a low temperature polysilicon TFT layer and an IGZO (InGaZnO) TFT layer. A method for producing a laminate comprising a polyimide and a support, comprising:
Imidizing a polyimide precursor to obtain a polyimide;
heating the laminate including the polyimide and the support to 400° C. or higher,
The manufacturing method of the laminated body whose weight average molecular weights of the said polyimide precursor are 30,000 or more and 300,000 or less. A method for manufacturing a flexible display, comprising:
Imidizing a polyimide precursor to obtain a polyimide;
forming a low-temperature polysilicon TFT layer on the polyimide;
A method of manufacturing a flexible display having a weight average molecular weight of the polyimide precursor of 30,000 or more and 300,000 or less.

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