JP2021109908A - Resin composition, polyimide, and method for producing polyimide film - Google Patents

Abstract

To provide a resin composition forming a polyimide film that excels in both of optical properties and other properties required for a display.SOLUTION: A resin composition contains a polyimide precursor having a structure represented by the following formula (1) {in formula (1), P1 is a divalent organic group, P2 is a tetravalent organic group}, and a solvent. In the formula (1), P1 contains a diamino benzamide-derived structure, and a polyimide, which is an imidized product of the polyimide precursor, satisfies both conditions of: (A) a yellowness (YI) is 10 or less as a film of 10 μm in thickness and (B) a retardation (Rth) in thickness direction is 300 nm or less as a film of 10 μm in thickness.SELECTED DRAWING: None

Description

The present invention relates to a resin composition containing a polyimide precursor, a polyimide, and a method for producing a polyimide film, and further provides a method for producing a polyimide film with an element, a laminate with an element, and a method for producing a flexible device.

The polyimide resin is an insoluble and insoluble superheat resistant resin, and has excellent properties such as heat oxidation resistance, heat resistance, radiation resistance, low temperature resistance, and chemical resistance. For this reason, polyimide resins are used in a wide range of fields including electronic materials. Examples of applications of the polyimide resin in the field of electronic materials include an insulating coating material, an insulating film, a semiconductor, an electrode protective film of a thin film transistor liquid crystal display (TFT-LCD), and the like. Recently, taking advantage of the lightness and flexibility of the polyimide film, its adoption as a flexible substrate is being considered in place of the glass substrate conventionally used in the field of display materials.

Patent Document 1 describes a gas-separated composite membrane in which a polyimide membrane obtained by using 3,5-diaminobenzamide (DAB-H) as a part of a monomer is formed on a porous membrane. It is explained that this gas separation composite membrane is excellent in solvent resistance and gas separation performance.
Patent Document 2 and Non-Patent Document 1 describe a polyimide film obtained by curing a polyimide precursor using DAB-H, 2,2'-bis (trifluoromethyl) benzidine (TFMB), or the like as a monomer, respectively. Is described, and it is explained that this polyimide film is useful as an interlayer insulating film because it can suppress thermal expansion in the Z direction while maintaining low thermal expansion in the XY direction.

International Publication No. 2015/129554 JP-A-2019-127503

Reactive and Fundamental Polymers, 139 (2019), pp181-188

The uses of the polyimide films described in Patent Documents 1 and 2 and Non-Patent Document 1 are limited to gas separation membrane applications and interlayer insulation film applications, and the use of polyimide films as optical materials has been completely investigated. It has not been.

The present inventors have produced a polyimide film using DAB-H (3,5-diaminobenzamide) as a monomer in accordance with the above description in the prior art document, and examined its applicability to optical applications.
As a result, although the polyimide film described in the above-mentioned prior art document is excellent in optical characteristics, other characteristics required for display applications, for example, heat resistance of a laminate having an inorganic film formed on the film, etc. are not good. Found to be sufficient.
The present invention has been made in view of the above circumstances, and provides a polyimide film excellent in both optical properties and other properties required for display applications, and a resin composition for forming the polyimide film. The purpose.

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ、
前記ポリイミド前駆体のイミド化物であるポリイミドが、以下の要件（Ａ）及び（Ｂ）：
（Ａ）膜厚１０μｍのフィルムとしたときの黄色度（ＹＩ）が１０以下であること、及び
（Ｂ）膜厚１０μｍのフィルムとしたときの厚さ方向のリターデーション（Ｒｔｈ）が３００ｎｍ以下であること
の双方を満たす、
樹脂組成物。
《態様２》下記式（１）：

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ、
前記ポリイミド前駆体のイミド化物であるポリイミドが、以下の要件（Ｂ）及び（Ｃ）：
（Ｂ）膜厚１０μｍのフィルムとしたときの厚さ方向のリターデーション（Ｒｔｈ）が３００ｎｍ以下であること、及び
（Ｃ）膜厚１０μｍのフィルムとしたときの全光線透過率が８０％以上であること
の双方を満たす、
樹脂組成物。
《態様３》下記式（１）：

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、
前記樹脂組成物中のフッ素原子の含有割合が、前記ポリイミド前駆体の質量を基準として、５質量％未満であり、かつ、
前記ポリイミド前駆体のイミド化物であるポリイミドが、以下の要件（Ａ）及び（Ｄ）：
（Ａ）膜厚１０μｍのフィルムとしたときの黄色度（ＹＩ）が１０以下であること、及び
（Ｄ）ガラス転移温度（Ｔｇ）が３００℃以上であること
のうちの少なくとも一方を満たす、
樹脂組成物。
《態様４》下記式（１）：
前記式（１）中のＰ_１及びＰ_２が、それぞれ、フッ素原子を含まない、態様３に記載の樹脂組成物。
《態様５》下記式（１）：

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ
前記式（１）中のＰ_２が、ビフェニルテトラカルボン酸二無水物、９，９−ビス（３，４−ジカルボキシフェニル）フルオレン二無水物、ノルボルナン−２−スピロ−α−シクロペンタン−α’−スピロ−２”−ノルボルナン−５，５”，６、６”−テトラカルボン酸二無水物、ｐ−フェニレンビス（トリメリテート無水物）、３，３’，４，４’−ジフェニルスルホンテトラカルボン酸二無水物、及び１，２，４，５−シクロヘキサンテトラカルボン酸二無水物から成る特定テトラカルボン酸二無水物から選択される１種又は２種以上に由来する４価の基を含む、
樹脂組成物。
《態様６》下記式（１）：

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ、
前記式（１）中のＰ_１が、４−アミノフェニル４−アミノベンゾエート、１，４−シクロヘキサンジアミン、及び４，４’−ビス（ジアミノフェニル）スルホンから成る特定ジアミンから選択される１種又は２種以上に由来する２価の基を更に含む、
樹脂組成物。
《態様７》下記式（１）：

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ、
前記樹脂組成物が、フレキシブルディスプレイを製造するために用いられる、
樹脂組成物。
《態様８》前記式（Ａ１）で表される構造が、下記式（Ａ１−１）：

｛式（Ａ１−１）中、Ｌ_１、ｎ１、及び「＊」は、それぞれ、前記式（Ａ１）におけるＬ_１、ｎ１、及び「＊」と同じ意味である。｝で表される構造である、態様１〜７のいずれか一項に記載の樹脂組成物。
《態様９》前記ポリイミド前駆体のイミド化物であるポリイミドのガラス転移温度（Ｔｇ）が３００℃以上である、態様１〜８のいずれか一項に記載の樹脂組成物。
《態様１０》前記ポリイミド前駆体のイミド化物であるポリイミドのヤング率が３．５ＧＰａ以上である、態様１〜９のいずれか一項に記載の樹脂組成物。
《態様１１》前記ポリイミド前駆体のイミド化物であるポリイミドの残留応力が２５ＭＰａ以下である、態様１〜１０のいずれか一項に記載の樹脂組成物。
《態様１２》下記式（１）：

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ、
前記ポリイミド前駆体が、下記式（２）：

｛式（２）中、Ｒは、それぞれ独立に、炭素数１〜５の１価の脂肪族炭化水素基又は炭素数６〜１０の１価の芳香族基であり、ｍは、１〜２００の整数である。｝で表される構造を更に含む、
樹脂組成物。
《態様１３》前記式（２）で表される構造が、下記式（Ｓ１）：

｛式（Ｓ１）中、
Ｒ_１は、それぞれ独立に、単結合又は炭素数１〜１０の２価の有機基であり、
Ｒ_２及びＲ_３は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_２及びＲ_３のうちの少なくとも１つは、炭素数１〜５の１価の脂肪族炭化水素基であり、
Ｒ_４及びＲ_５は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_４及びＲ_５のうちの少なくとも１つは、炭素数６〜１０の１価の芳香族基であり、
Ｒ_６及びＲ_７は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_６及びＲ_７のうちの少なくとも１つは、炭素数２〜１０の不飽和脂肪族炭化水素基を含む有機基であり、
Ｌ_３は、それぞれ独立に、酸無水物構造を含む１価の有機基、アミノ基、イソシアネート基、カルボキシル基、アルコキシカルボニル基、ハロゲン化カルボニル基、ヒドロキシ基、エポキシ基、又はメルカプト基であり、
ｉ及びｊは、それぞれ独立に、１〜２００の整数であり、
ｋは、０〜２００の整数であり、そして、
０．０５≦ｊ／（ｉ＋ｊ＋ｋ）≦０．５０の関係を満たす。｝で表されるシランモノマーに由来する構造であり、
前記樹脂組成物が、下記式（Ｓ２）：

｛式（Ｓ２）中、Ｒ_１０は、メチル基又はフェニル基であり、ａは２〜８の整数である。｝で表される低分子シラン化合物を含み、
前記ポリイミド前駆体が、テトラカルボン酸二無水物と、ジアミンと、前記シランモノマーとを含むモノマー組成物から得られる共重縮合物であり、そして、
前記樹脂組成物中の前記低分子シラン化合物の含有割合が、前記前記ポリイミド前駆体の共重縮合に用いた前記シランモノマーの質量を基準として、０ｐｐｍ超２８０ｐｐｍ以下である、
態様１２に記載の樹脂組成物。
《態様１４》前記ポリイミド前駆体が、テトラカルボン酸二無水物と、ジアミンと、下記式（Ｓ１）：

｛式（Ｓ１）中、
Ｒ_１は、それぞれ独立に、単結合又は炭素数１〜１０の２価の有機基であり、
Ｒ_２及びＲ_３は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_２及びＲ_３のうちの少なくとも１つは、炭素数１〜５の１価の脂肪族炭化水素基であり、
Ｒ_４及びＲ_５は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_４及びＲ_５のうちの少なくとも１つは、炭素数６〜１０の１価の芳香族基であり、
Ｒ_６及びＲ_７は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_６及びＲ_７のうちの少なくとも１つは、炭素数２〜１０の不飽和脂肪族炭化水素基を含む有機基であり、
Ｌ_３は、それぞれ独立に、酸無水物構造を含む１価の有機基、アミノ基、イソシアネート基、カルボキシル基、アルコキシカルボニル基、ハロゲン化カルボニル基、ヒドロキシ基、エポキシ基、又はメルカプト基であり、
ｉは、１〜２００の整数であり、
ｊ及びｋは、それぞれ独立に、０〜２００の整数であり、そして、
０．０５≦ｊ／（ｉ＋ｊ＋ｋ）≦０．５０の関係を満たす。｝で表されるシランモノマーと、下記式（Ｓ３）：

｛式（Ｓ３）中、ｂは２以上の整数である。｝で表される化合物とを含むモノマー組成物から得られる共重縮合物であり、かつ、
前記モノマー組成物に含まれる、前記式（Ｓ３）においてｂ＝５である化合物の含有割合が、前記式（Ｓ１）で表される化合物及び前記式（Ｓ３）で表される化合物の合計に基づいて、０ｐｐｍ超５００ｐｐｍ以下である、
態様１２に記載の樹脂組成物。
《態様１５》態様１〜１４のいずれか一項に記載の樹脂組成物の硬化物である、ポリイミド。
《態様１６》下記式（４）：

｛式（４）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミドであって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ、
前記ポリイミドが、以下の要件（Ａ）及び（Ｅ）：
（Ａ）膜厚１０μｍのフィルムとしたときの黄色度（ＹＩ）が１０以下であること、及び
（Ｅ）前記ポリイミド中のフッ素原子含有割合が、前記ポリイミドの質量に基づいて、５質量％未満であること
の双方を満たす、
ポリイミド。
《態様１７》支持体の表面上に、態様１〜１４のいずれか一項に記載の樹脂組成物を塗布して、前記支持体上に樹脂組成物の塗膜を形成する、塗布工程と、
前記樹脂組成物の塗膜を加熱して、前記支持体上にポリイミド樹脂膜を形成する、ポリイミド樹脂膜形成工程と、
前記ポリイミド樹脂膜を前記支持体から剥離して、ポリイミドフィルムを得る、剥離工程と、
をこの順に含む、ポリイミドフィルムの製造方法。
《態様１８》前記ポリイミド樹脂膜形成工程の後、かつ、前記剥離工程の前に、
前記支持体の、前記ポリイミド樹脂膜が形成された側とは反対側の表面から、レーザーを照射する、レーザー照射工程を更に含む、
態様１７に記載のポリイミドフィルムの製造方法。
《態様１９》支持体の表面上に、態様１〜１４のいずれか一項に記載の樹脂組成物を塗布して、前記支持体上に樹脂組成物の塗膜を形成する、塗布工程と、
前記樹脂組成物の塗膜を加熱して、前記支持体上にポリイミド樹脂膜を形成する、ポリイミド樹脂膜形成工程と、
前記ポリイミド樹脂膜上に素子を形成して、前記支持体上に素子付きポリイミド樹脂膜を形成する、素子形成工程と、
前記素子付きポリイミド樹脂膜を前記支持体から剥離して、素子付きポリイミドフィルムを得る、剥離工程と、
をこの順に含む、素子付きポリイミドフィルムの製造方法。
《態様２０》支持体の表面上に、態様１〜１４のいずれか一項に記載の樹脂組成物を塗布して、前記支持体上に樹脂組成物の塗膜を形成する、塗布工程と、
前記樹脂組成物の塗膜を加熱して、前記支持体上にポリイミド樹脂膜を形成する、ポリイミド樹脂膜形成工程と、
前記ポリイミド樹脂膜上に素子を形成して、前記支持体上に素子付きポリイミド樹脂膜を形成する、素子形成工程と、
をこの順に含む、素子付き積層体の製造方法。
《態様２１》態様１９に記載の素子付きポリイミドフィルムの製造方法、又は態様２０に記載の素子付き積層体の製造方法を含む、フレキシブルディスプレイの製造方法。 Hereinafter, non-limiting examples of embodiments of the present invention will be listed in the following << Aspect 1 >> to << Aspect 21 >>.
<< Aspect 1 >> The following equation (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (A) and (B):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (B) the retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less. Satisfy both sides of being
Resin composition.
<< Aspect 2 >> The following equation (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (B) and (C):
(B) The retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less, and (C) the total light transmittance of a film having a film thickness of 10 μm is 80% or more. Satisfy both sides of being
Resin composition.
<< Aspect 3 >> The following equation (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } Including the structure represented by
The content ratio of fluorine atoms in the resin composition is less than 5% by mass and is less than 5% by mass based on the mass of the polyimide precursor.
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (A) and (D):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (D) the glass transition temperature (Tg) is 300 ° C. or more, whichever is satisfied.
Resin composition.
<< Aspect 4 >> The following equation (1):
The resin composition according to embodiment 3, wherein _{P 1} and P ₂ in the formula (1) do not contain fluorine atoms, respectively.
<< Aspect 5 >> The following equation (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). It includes a structure represented by the} and the formula (1) _{P 2} is in, biphenyltetracarboxylic dianhydride, 9,9-bis (3,4-carboxyphenyl) fluorene dianhydride, norbornane - 2-Spiro-α-Cyclopentane-α'-Spiro-2 "-norbornan-5,5", 6,6 "-tetracarboxylic dianhydride, p-phenylenebis (trimeritate anhydride), 3,3' , 4,4'-Diphenylsulfonetetracarboxylic dianhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride, one or more selected from specific tetracarboxylic dianhydrides. Containing tetravalent groups derived from,
Resin composition.
<< Aspect 6 >> The following equation (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
_{P 1} in the formula (1) is selected from a specific diamine composed of 4-aminophenyl 4-aminobenzoate, 1,4-cyclohexanediamine, and 4,4'-bis (diaminophenyl) sulfone, or one of them. Further containing divalent groups derived from two or more species,
Resin composition.
<< Aspect 7 >> The following equation (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The resin composition is used for producing a flexible display.
Resin composition.
<< Aspect 8 >> The structure represented by the above formula (A1) is the following formula (A1-1):

{Wherein _(A1-1), L 1, n1, and "*", respectively, _L 1 in Formula (A1), n1, and the same meaning as "*". } The resin composition according to any one of aspects 1 to 7, which has a structure represented by.
<< Aspect 9 >> The resin composition according to any one of aspects 1 to 8, wherein the glass transition temperature (Tg) of the polyimide, which is an imide of the polyimide precursor, is 300 ° C. or higher.
<< Aspect 10 >> The resin composition according to any one of aspects 1 to 9, wherein the polyimide, which is an imide of the polyimide precursor, has a Young's modulus of 3.5 GPa or more.
<< Aspect 11 >> The resin composition according to any one of aspects 1 to 10, wherein the polyimide, which is an imide of the polyimide precursor, has a residual stress of 25 MPa or less.
<< Aspect 12 >> The following equation (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide precursor has the following formula (2):

{In formula (2), R is independently a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200. Is an integer of. } Further including the structure represented by
Resin composition.
<< Aspect 13 >> The structure represented by the above formula (2) is the following formula (S1):

{In equation (S1),
R ₁ is independently a single bond or a divalent organic group having 1 to 10 carbon atoms.
R ₂ and R ₃ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 2} and R ₃ is a monovalent aliphatic group having 1 to 5 carbon atoms. It is a hydrocarbon group and
R ₄ and R ₅ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 4} and R ₅ is a monovalent aromatic group having 6 to 10 carbon atoms. Is the basis and
R ₆ and R ₇ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 6} and R ₇ is an unsaturated aliphatic hydrocarbon having 2 to 10 carbon atoms. It is an organic group containing a hydrogen group and
L ₃ is independently a monovalent organic group containing an acid anhydride structure, an amino group, an isocyanate group, a carboxyl group, an alkoxycarbonyl group, a halogenated carbonyl group, a hydroxy group, an epoxy group, or a mercapto group.
i and j are independently integers of 1 to 200, respectively.
k is an integer from 0 to 200, and
The relationship of 0.05 ≦ j / (i + j + k) ≦ 0.50 is satisfied. } Is a structure derived from the silane monomer.
The resin composition has the following formula (S2):

{In formula (S2), R ₁₀ is a methyl group or a phenyl group, and a is an integer of 2 to 8. } Contains a small molecule silane compound
The polyimide precursor is a polycondensate obtained from a monomer composition containing a tetracarboxylic dianhydride, a diamine, and the silane monomer, and
The content ratio of the small molecule silane compound in the resin composition is more than 0 ppm and 280 ppm or less based on the mass of the silane monomer used for the polycondensation of the polyimide precursor.
The resin composition according to aspect 12.
<< Aspect 14 >> The polyimide precursor is a tetracarboxylic dianhydride, a diamine, and the following formula (S1):

{In equation (S1),
R ₁ is independently a single bond or a divalent organic group having 1 to 10 carbon atoms.
R ₂ and R ₃ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 2} and R ₃ is a monovalent aliphatic group having 1 to 5 carbon atoms. It is a hydrocarbon group and
R ₄ and R ₅ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 4} and R ₅ is a monovalent aromatic group having 6 to 10 carbon atoms. Is the basis and
R ₆ and R ₇ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 6} and R ₇ is an unsaturated aliphatic hydrocarbon having 2 to 10 carbon atoms. It is an organic group containing a hydrogen group and
L ₃ is independently a monovalent organic group containing an acid anhydride structure, an amino group, an isocyanate group, a carboxyl group, an alkoxycarbonyl group, a halogenated carbonyl group, a hydroxy group, an epoxy group, or a mercapto group.
i is an integer from 1 to 200,
j and k are each independently an integer from 0 to 200, and
The relationship of 0.05 ≦ j / (i + j + k) ≦ 0.50 is satisfied. } And the following formula (S3):

{In equation (S3), b is an integer of 2 or more. } Is a polycondensate obtained from a monomer composition containing the compound represented by
The content ratio of the compound having b = 5 in the formula (S3) contained in the monomer composition is based on the total of the compound represented by the formula (S1) and the compound represented by the formula (S3). It is more than 0 ppm and less than 500 ppm.
The resin composition according to aspect 12.
<< Aspect 15 >> A polyimide which is a cured product of the resin composition according to any one of Aspects 1 to 14.
<< Aspect 16 >> The following equation (4):

{In formula (4), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, Which is a polyimide having a structure represented by
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide has the following requirements (A) and (E):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (E) the fluorine atom content in the polyimide is less than 5% by mass based on the mass of the polyimide. Satisfy both sides of being
Polyimide.
<< Aspect 17 >> A coating step of applying the resin composition according to any one of aspects 1 to 14 on the surface of a support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of the resin composition to form a polyimide resin film on the support.
A peeling step of peeling the polyimide resin film from the support to obtain a polyimide film.
A method for producing a polyimide film, which comprises the above in this order.
<< Aspect 18 >> After the polyimide resin film forming step and before the peeling step,
A laser irradiation step of irradiating the support from the surface of the support opposite to the side on which the polyimide resin film is formed is further included.
The method for producing a polyimide film according to aspect 17.
<< Aspect 19 >> A coating step of applying the resin composition according to any one of aspects 1 to 14 on the surface of a support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of the resin composition to form a polyimide resin film on the support.
An element forming step of forming an element on the polyimide resin film and forming a polyimide resin film with an element on the support.
A peeling step of peeling the polyimide resin film with an element from the support to obtain a polyimide film with an element.
A method for producing a polyimide film with an element, which comprises the above in this order.
<< Aspect 20 >> A coating step of applying the resin composition according to any one of aspects 1 to 14 on the surface of a support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of the resin composition to form a polyimide resin film on the support.
An element forming step of forming an element on the polyimide resin film and forming a polyimide resin film with an element on the support.
A method for manufacturing a laminate with an element, which includes the above in this order.
21. A method for manufacturing a flexible display, which comprises the method for manufacturing a polyimide film with an element according to the aspect 19 or the method for manufacturing a laminate with an element according to the aspect 20.

According to the present invention, there is provided a polyimide film excellent in both optical properties and other properties required for display applications, and a resin composition for forming the polyimide film.
It should be noted that the above description should not be regarded as disclosing all the embodiments of the present invention and all the advantages relating to the present invention. Further embodiments of the present invention and their advantages will become apparent with reference to the following description.

Hereinafter, an exemplary embodiment of the present invention (hereinafter, abbreviated as “the present embodiment”) will be described in detail. The present invention is not limited to the present embodiment, and can be variously modified and implemented within the scope of the gist thereof. In the specification of the present application, the upper limit value and the lower limit value of each numerical range can be arbitrarily combined.

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミド前駆体と、溶媒と、を含む樹脂組成物であって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含む。 The resin composition of this embodiment is
The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } Includes the structure represented by.

｛式（２）中、Ｒは、それぞれ独立に、炭素数１〜５の１価の脂肪族炭化水素基又は炭素数６〜１０の１価の芳香族基であり、ｍは、１〜２００の整数である。｝で表される構造を更に含んでいてもよい。 The polyimide precursor contained in the resin composition of the present embodiment has the following formula (2):

{In formula (2), R is independently a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200. Is an integer of. } May further include the structure represented by.

In the resin composition of the present embodiment, instead of the polyimide precursor as described above, or together with the polyimide precursor, a polymer in which a part or all of the amidic acid structure of the polyimide precursor is imidized may be used. good.

<< Characteristics of resin composition >>
The resin composition of the present invention further comprises
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (A) to (D):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less.
(B) The retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less.
(C) The total light transmittance of a film having a film thickness of 10 μm is 80% or more, and
(D) It is preferable to satisfy at least one of the glass transition temperature (Tg) of 300 ° C. or higher.

More preferably, it is any of the following cases.
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (A) and (B):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (B) the retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less. Satisfy both of the things;
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (B) and (C):
(B) The polyimide (Rth) in the thickness direction when a film with a film thickness of 10 μm is 300 nm or less, and (C) the total light transmittance when a film with a film thickness of 10 μm is 80% or more. Both of the above are met; or the polyimide, which is an imidized version of the polyimide precursor, has the following requirements (A) and (D):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (D) the glass transition temperature (Tg) is 300 ° C. or more, whichever is satisfied.

Regarding requirement (A), for a film having a YI value of 10 or less in terms of film thickness of 10 μm, it is easy to adjust the color reproduction in the display process using a color filter, but when the YI is more than 10, the color reproduction is easy. Is difficult or impossible to adjust. From this point of view, the yellowness (YI) when the polyimide is made into a film having a film thickness of 10 μm is preferably 10 or less, more preferably 5 or less, still more preferably 3 or less.

Regarding requirement (B), for a film having an Rth of 300 nm or less in terms of film thickness of 10 μm, the phase difference in the display process can be easily adjusted by using the C plate, or the use of the C plate itself is unnecessary. , Easy to apply to display materials. On the other hand, in a film having an Rth of more than 300 nm, the phase difference cannot be adjusted even if a C plate is used, the contrast becomes insufficient, and it is difficult to apply the film to a display material. From this viewpoint, the retardation (Rth) in the thickness direction when the polyimide is made into a film having a film thickness of 10 μm is preferably 300 nm or less, more preferably 200 nm or less, and particularly preferably 100 nm or less.

Regarding requirement (C), if a film having a total light transmittance of 80% or more in terms of a film thickness of 10 μm is used, it is easy to increase the brightness of the display, and if the transmittance is particularly high, the polyimide should be thickened. It is also possible and useful as a display material. On the other hand, a film having a transmittance of less than 80% needs to improve the brightness of a light emitting body (backlight of a liquid crystal panel, an organic EL element, etc.) in order to increase the brightness of a display, and is applicable as a display material. Have difficulty. From this point of view, the total light transmittance when the polyimide is made into a film having a film thickness of 10 μm is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more.

Regarding the requirement (D), if a film made of a resin having a glass transition temperature of 300 ° C. or higher is used, the display process can be performed without causing wrinkles, swelling, etc. in the film. When a film is used as a TFT substrate in a display process, particularly a flexible display process, there is a step of exposing the film to a high temperature of 300 ° C. or higher, particularly 400 ° C. or higher, when manufacturing the display. For example, an annealing step when forming an inorganic film on a film. In such a step, if a film made of a resin having a glass transition temperature of less than 300 ° C. is used, wrinkles, swelling, etc. often occur in the film. From this viewpoint, the glass transition temperature (Tg) of polyimide is preferably 300 ° C. or higher, more preferably 350 ° C. or higher, and even more preferably 400 ° C. or higher.

The content ratio of fluorine atoms in the resin composition of the present embodiment is preferably less than 5% by mass based on the mass of the polyimide precursor. When the content ratio of the fluorine atoms is less than 5% by mass, wrinkles, swelling and the like are suppressed in the polyimide film in the annealing step after forming the inorganic film on the polyimide film.
The reason is not clear, but it is considered to be related to the structure of the polyimide precursor represented by the formula (A1) included in the above formula (1).
That is, it is considered that the fluorine atom in the polyimide film is contained as a CF bond in the polymer side chain, for example. In a polyimide film containing a significant amount of CF bond, in the annealing step of the inorganic film, the amine (or ammonia) generated by decomposing the amide group in the structure represented by the formula (A1) causes the CF bond. It is presumed that the cutting of the film is related to the occurrence of wrinkles, swelling, etc. of the film.
From the viewpoint of avoiding this, the content ratio of fluorine atoms in the resin composition of the present embodiment is preferably less than 5% by mass, more preferably 3% by mass or less, based on the mass of the polyimide precursor, and more preferably fluorine. It is particularly preferable that it contains no atoms.
In the polyimide precursor contained in the resin composition of the present embodiment, it is particularly preferable that neither _{P 1} nor P _{2 in the formula (1) contains a fluorine atom.}

A film made of a resin having a Young's modulus of 3.0 GPa or more is unlikely to be torn even when it is repeatedly wound and rewound, and therefore can be applied to a flexible display, for example. On the other hand, a film having a Young's modulus of less than 3.0 GPa is repeatedly wound and rewound, torn, and the like, and a reinforcing material or the like is required when it is applied to a flexible display. From this point of view, the Young's modulus of polyimide, which is an imide of the polyimide precursor contained in the resin composition of the present embodiment, is preferably 3.0 GPa or more, more preferably 3.5 GPa or more, and 4.0 GPa or more. More preferred.

Even when a film made of a resin having a residual stress of 25 MPa or less is formed on a large-sized substrate such as G8 (8th generation, 2,160 mm × 2,460 mm), the resin film / substrate laminate “ The occurrence of "warpage" tends to be suppressed, and it is easy to carry out the display process. On the other hand, a film made of a resin having a residual stress of more than 25 MPa tends to cause "warp" in the resin film / substrate laminate, which makes it difficult to apply as a display material. If "warp" occurs in the grease film / substrate laminate, there is a risk of collision with other laminates, structures in the apparatus, etc. in the display manufacturing apparatus.
From such a viewpoint, the residual stress of polyimide, which is an imide of the polyimide precursor contained in the resin composition of the present embodiment, is preferably 25 MPa or less, more preferably 20 MPa or less, and even more preferably 15 MPa or less.
The substrate in the resin film / substrate laminate may be, for example, a glass substrate or the like.

The resin composition of the present embodiment having the above-mentioned characteristics is preferably used for producing, for example, a flexible display. The resin composition of the present embodiment is particularly suitable as a constituent material for a substrate of a flexible display, a cover window, and the like.

｛式（１）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有し、
式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含むものである。 《Polyimide precursor》
The polyimide precursor contained in the resin composition of the present embodiment is as described above.
The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. } Has a structure represented by
_{P 1} is represented by the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } Includes the structure represented by.

｛式（Ａ１−１）中、Ｌ_１、ｎ１、及び「＊」は、それぞれ、前記式（Ａ１）におけるＬ_１、ｎ１、及び「＊」と同じ意味である。｝で表される構造であってもよい。 The structure represented by the above formula (A1) is, for example, the following formula (A1-1):

{Wherein _(A1-1), L 1, n1, and "*", respectively, _L 1 in Formula (A1), n1, and the same meaning as "*". } May be the structure represented by.

_{The alkyl group of L 1 in} the above formulas (A1) and (A1-1) may be an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, and a methyl group or ethyl. It may be a base. As the halogen atom other than the fluorine atom, a chlorine atom or an iodine atom is preferable, and a chlorine atom is more preferable.

｛式（２）中、Ｒは、それぞれ独立に、炭素数１〜５の１価の脂肪族炭化水素基又は炭素数６〜１０の１価の芳香族基であり、ｍは、１〜２００の整数である。｝で表される構造を更に含んでいてもよい。 The polyimide precursor in this embodiment has the following formula (2):

{In formula (2), R is independently a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200. Is an integer of. } May further include the structure represented by.

In the resin composition of the present embodiment, instead of the polyimide precursor as described above, or together with the polyimide precursor, a polymer in which a part or all of the amidic acid structure of the polyimide precursor is imidized may be used. good. The method for imidizing the polyimide precursor will be described later.

The polyimide precursor having the structure represented by the above formula (1) may be, for example, a polycondensate obtained from a monomer composition containing a tetracarboxylic dianhydride and a diamine.
The polyimide precursor having the structure represented by the above formula (1) and the structure represented by the above formula (2) is represented by, for example, tetracarboxylic dianhydride, diamine, and formula (2). It may be a copolycondensate obtained from a monomer composition containing a silane monomer containing a structure.

<Tetracarboxylic dianhydride>
In the polyimide precursor in the present embodiment, the tetravalent organic group represented by P ₂ in the above formula (1) is derived from the tetracarboxylic dianhydride used for synthesis of the polyimide precursor. Therefore, the tetracarboxylic dianhydride used for synthesis of the polyimide precursor in the present embodiment, the desired tetravalent group P ₂ in formula (1), a compound obtained by adding two acid anhydride structures It's okay.
The tetracarboxylic dianhydride used for the synthesis of the polyimide precursor in the present embodiment is divided into a tetracarboxylic dianhydride containing no fluorine atom and a tetracarboxylic dianhydride containing a fluorine atom.

Examples of the tetracarboxylic dianhydride containing no fluorine atom include aromatic tetracarboxylic dianhydride containing no fluorine atom, alicyclic tetracarboxylic dianhydride containing no fluorine atom, and the like.
Examples of the aromatic tetracarboxylic acid dianhydride containing no fluorine atom include pyromellitic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3, 3'-Biphenyltetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro-3-franyl) -3-methyl-cyclohexene-1,2 dicarboxylic acid anhydride, 1,2,3,4-benzene Tetracarboxylic acid dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride, 2,2', 3,3'-benzophenone tetracarboxylic acid dianhydride, 3,3', 4, 4'-Diphenylsulfone tetracarboxylic acid dianhydride, methylene-4,4'-diphthalic acid dianhydride, 1,1-ethylidene-4,4'-diphthalic acid dianhydride, 2,2-propylidene-4, 4'-Diphthalic Acid Dianhydride, 1,2-ethylene-4,4'-Diphthalic Acid Dianhydride, 1,3-Trimethylene-4,4'-Diphthalic Acid Dianhydride, 1,4-Tetramethylene- 4,4'-Diphthalic hydride, 1,5-pentamethylene-4,4'-diphthalic hydride, 4,4'-oxydiphthalic hydride, p-phenylenebis (trimeritate anhydride), Thio-4,4'-diphthalic hydride, sulfonyl-4,4'-diphthalic hydride, 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) dimethylsilane 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-naphthalente Tracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 9,9-bis [4- (3,3) 1-dicarboxyphenoxy) phenyl] fluorene dianhydride, 9,9-bis [4- (3,2-dicarboxyphenoxy) phenyl] fluorene dianhydride, 9,9-bis [4- (3,3-3,3-) Dicarboxyphenoxy) phenyl] fluorene dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) phenyl] fluorene dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride And so on.

Examples of the alicyclic tetracarboxylic dianhydride containing no fluorine atom include cyclobutanetetracarboxylic dianhydride (for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3). , 4-Tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, etc.), Cyclohexanetetracarboxylic dianhydride (eg, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, etc.) ), Norbornan-2-spiro-α-cyclopentanone-α'-spiro-2 "-norbornan-5,5", 6,6 "-tetracarboxylic dianhydride and the like.

Examples of the tetracarboxylic dianhydride containing a fluorine atom include 4,4'-(hexafluoroisopropyridene) diphthalic anhydride and 3,6-bis (trifluoromethyl) -1,2,4,5-. Benzenetetracarboxylic acid 1,2: 4,5-2 anhydride, 9,9-bis (trifluoromethyl) -9H-xanthene 2,3,6,7-tetracarboxylic acid 2,3: 6,7-2 Anhydrous and the like can be mentioned.

Among these, the tetracarboxylic dianhydride used for the synthesis of the polyimide precursor in the present embodiment includes biphenyltetracarboxylic dianhydride and 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride. , Norbornan-2-spiro-α-cyclopentane-α'-spiro-2 "-norbornan-5,5", 6,6 "-tetracarboxylic dianhydride, p-phenylenebis (trimeritate anhydride), One selected from a specific tetracarboxylic dianhydride consisting of 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride. Alternatively, it is preferable to use two or more types.
The proportion of these specific tetracarboxylic dianhydrides used is preferably 10 mol% or more, more preferably 30 mol% or more, based on the total amount of the tetracarboxylic dianhydrides used in the synthesis of the polyimide precursor. It is more preferably 50 mol% or more, and may be 100 mol%.

Further, from the viewpoint of heat resistance after forming an inorganic film on the obtained polyimide film as described above, the resin composition of the present embodiment preferably contains a small amount of fluorine atoms. From this viewpoint, the proportion of the tetracarboxylic dianhydride containing a fluorine atom contained in the tetracarboxylic dianhydride used for the synthesis of the polyimide precursor in the present embodiment is preferably small. Specifically, the ratio of the tetracarboxylic dianhydride containing a fluorine atom to the total amount of the tetracarboxylic dianhydride used for the synthesis of the polyimide precursor is preferably 10 mol% or less, preferably 5 mol% or less. Is more preferable, 3 mol% or less is further preferable, 1 mol% or less is particularly preferable, and it is most preferable not to use a tetracarboxylic dianhydride containing a fluorine atom.

When an imidized polymer in which a part or all of the amidic acid structure of the polyimide precursor is imidized is used in the resin composition of the present embodiment, the imidized polymer is synthesized from the viewpoint of polymer solubility. The tetralacarboxylic acid dianhydride used in this case preferably contains an alicyclic tetracarboxylic acid dianhydride (for example, an alicyclic tetracarboxylic acid dianhydride containing no fluorine atom).

In the tetracarboxylic dianhydride used for the synthesis of the polyimide precursor, the content ratios of pyromellitic dianhydride and m-phenylenebis (trimeritate anhydride) are higher than the total amount of tetracarboxylic dianhydride, respectively. , 50 mol% or less is preferable from the viewpoint of the permeability, YI, and residual stress of the obtained polyimide.

<Diamine>
In the polyimide precursor in the present embodiment, the divalent organic group represented by P ₁ in the formula (1) is derived from a diamine used in the synthesis of the polyimide precursor. Thus, a diamine used for synthesis of the polyimide precursor in the present embodiment, the desired divalent group P ₁ in the formula (1) may be a compound obtained by adding two amino groups.
The diamine used for the synthesis of the polyimide precursor in the present embodiment is divided into a diamine containing "structure A1" represented by the above formula (A1), a diamine not containing a fluorine atom, and a diamine containing a fluorine atom.

｛式（Ａ１−１）中、Ｌ_１、ｎ１、及び「＊」は、それぞれ、前記式（Ａ１）におけるＬ_１、ｎ１、及び「＊」と同じ意味である。｝で表される構造を含むことになる。特に、３，５−ジアミノベンズアミドを用いると、Ｐ_１で表される２価の有機基は、下記式（A１−２）：

｛式（Ａ１−２）中、「＊」は、前記式（Ａ１）における「＊」と同じ意味である。｝
で表される構造を含むことになる。このようなポリイミド前駆体を含有する樹脂組成物から得られるポリイミドは、Ｒｔｈが低く、ヤング率が高いとの利点があり、好ましい。 Examples of the diamine containing the structure A1 include 2,3-diaminobenzamide, 2,4-diaminobenzamide, 2,5-diaminobenzamide, 2,6-diaminobenzamide, 3,4-diaminobenzamide, and 3,5-diamino. Benzamide, 2-methyl-3,5-diaminobenzamide, 2,6-dimethyl-3,5-diaminobenzamide, 2,4,6-trimethyl-3,5-diaminobenzamide, 2-ethyl-3,5-diamino Benzamide, 2-chloro-3,5-diaminobenzamide and the like can be mentioned. Of these, when a 3,5-diamino compound is used, the divalent organic group represented by _{P 1 is represented by the following formula (A1-1):}

{Wherein _(A1-1), L 1, n1, and "*", respectively, _L 1 in Formula (A1), n1, and the same meaning as "*". } Will be included. In particular, when 3,5-diaminobenzamide is used, the _{divalent organic group represented by P 1} is represented by the following formula (A1-2):

{In the formula (A1-2), "*" has the same meaning as "*" in the formula (A1). }
Will include the structure represented by. A polyimide obtained from a resin composition containing such a polyimide precursor has advantages of low Rth and high Young's modulus, and is preferable.

The proportion of the diamine containing the structure A1 is preferably 10 mol% or more, more preferably 30 mol% or more, still more preferably 50 mol% or more, based on the total amount of the diamine used in the synthesis of the polyimide precursor. The proportion of the diamine containing the structure A1 may be 100 mol% with respect to the total amount of the diamine used in the synthesis of the polyimide precursor.

Examples of the diamine containing no fluorine atom include diaminodiphenylsulfone (for example, 4,4'-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, etc.), p-phenylenediamine, m-phenylenediamine, 4,4'. -Diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, m-tridin , 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-amino) Phenoxy) 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- (4-aminophenoxy) phenyl) propane, cyclohexanediamine (eg, 1,4-cyclohexanediamine, 1,2-cyclohexanediamine, etc.), 4,4 ′ -Diaminodicyclohexylmethane, 1,4-bis (3-aminopropyldimethylsilyl) benzene and the like can be mentioned.

Examples of the diamine containing a fluorine atom include 2,2'-bis (trifluoromethyl) benzidine, 2,2-bis (4-aminophenyl) hexafluoropropane, and 2,2-bis [4- (4-amino). Phenoxy) Phenyl) Hexafluoropropane, 6-fluoro-1,3,5-triazine-2,4-diamine, 4-fluoro-1,3-phenylenediamine, 5-tolufluoromethyl-1,3-phenylenediamine, Examples thereof include 2,4,5,6-tetrafluoro-1,3-phenylenediamine, 5-torfluoromethyl-1,3-benzenediamine and the like.

Of these, the diamine used in the synthesis of the polyimide precursor in the present embodiment is specified to consist of 4-aminophenyl4-aminobenzoate, 1,4-cyclohexanediamine, and 4,4'-bis (diaminophenyl) sulfone. It preferably contains one or more selected from diamines.
The proportion of these specific diamines used is preferably 10 mol% or more, more preferably 30 mol% or more, further preferably 50 mol% or more, and even more preferably 100 mol%, based on the total amount of diamines used in the synthesis of the polyimide precursor. It may be.

Further, from the viewpoint of heat resistance after forming an inorganic film on the obtained polyimide film as described above, the resin composition of the present embodiment preferably contains a small amount of fluorine atoms. From this point of view, the proportion of the diamine containing a fluorine atom contained in the diamine used for the synthesis of the polyimide precursor in the present embodiment is preferably small. Specifically, the ratio of diamine containing a fluorine atom is preferably 10 mol% or less, more preferably 5 mol% or less, and further preferably 3 mol% or less, based on the total amount of diamine used in the synthesis of the polyimide precursor. Preferably, 1 mol% or less is particularly preferable, and it is most preferable not to use a diamine containing a fluorine atom.

<Silane monomer>
The polyimide precursor in the present embodiment may have a structure represented by the above formula (1) as well as a structure represented by the above formula (2). The content ratio of the structure represented by the formula (2) in the polyimide precursor is preferably 5% by mass or more and 40% by mass or less based on the mass of the polyimide precursor. When the polyimide precursor contains the structure represented by the formula (2) in this range, it is possible to achieve both low residual stress and high transparency and heat resistance in the obtained polyimide film, which is preferable. The content ratio of the structure represented by the formula (2) may be 6% by mass or more, 7% by mass or more, and 30% by mass or less, or 25% by mass or less, based on the mass of the polyimide precursor. There may be.

The structure represented by the formula (2) in the polyimide precursor is derived from the silane monomer used for the synthesis of the polyimide precursor. Therefore, the silane monomer used in the synthesis of the polyimide precursor in the present embodiment has a structure represented by the formula (2) and a reactive group capable of cocondensing with at least one of tetracarboxylic dianhydride and diamine. It may be a compound having and.

｛式（Ｓ１）中、
Ｒ_１は、それぞれ独立に、単結合又は炭素数１〜１０の２価の有機基であり、
Ｒ_２及びＲ_３は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_２及びＲ_３のうちの少なくとも１つは、炭素数１〜５の１価の脂肪族炭化水素基であり、
Ｒ_４及びＲ_５は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_４及びＲ_５のうちの少なくとも１つは、炭素数６〜１０の１価の芳香族基であり、
Ｒ_６及びＲ_７は、それぞれ独立に、炭素数１〜１０の１価の有機基であって、Ｒ_６及びＲ_７のうちの少なくとも１つは、炭素数２〜１０の不飽和脂肪族炭化水素基を含む有機基であり、
Ｌ_３は、それぞれ独立に、酸無水物構造を含む１価の有機基、アミノ基、イソシアネート基、カルボキシル基、アルコキシカルボニル基、ハロゲン化カルボニル基、ヒドロキシ基、エポキシ基、又はメルカプト基であり、
ｉは、１〜２００の整数であり、
ｊ及びｋは、それぞれ独立に、０〜２００の整数であり、そして、
０．０５≦ｊ／（ｉ＋ｊ＋ｋ）≦０．５０の関係を満たす。｝で表される化合物が挙げられる。
ｊは、１〜２００の整数であってもよい。 Such a silane monomer is, for example, the following formula (S1):

{In equation (S1),
R ₁ is independently a single bond or a divalent organic group having 1 to 10 carbon atoms.
R ₂ and R ₃ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 2} and R ₃ is a monovalent aliphatic group having 1 to 5 carbon atoms. It is a hydrocarbon group and
R ₄ and R ₅ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 4} and R ₅ is a monovalent aromatic group having 6 to 10 carbon atoms. Is the basis and
R ₆ and R ₇ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 6} and R ₇ is an unsaturated aliphatic hydrocarbon having 2 to 10 carbon atoms. It is an organic group containing a hydrogen group and
L ₃ is independently a monovalent organic group containing an acid anhydride structure, an amino group, an isocyanate group, a carboxyl group, an alkoxycarbonyl group, a halogenated carbonyl group, a hydroxy group, an epoxy group, or a mercapto group.
i is an integer from 1 to 200,
j and k are each independently an integer from 0 to 200, and
The relationship of 0.05 ≦ j / (i + j + k) ≦ 0.50 is satisfied. } Can be mentioned.
j may be an integer of 1 to 200.

_{R 1} in the formula (S1) is independently a single bond or a divalent organic group having 1 to 10 carbon atoms. The divalent organic group having 1 to 10 carbon atoms may be linear, cyclic, or branched, and may be saturated or unsaturated. Examples of the divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms include a methylene group, an ethylene group, an n-propylene group, an i-propylene group, an n-butylene group, an s-butylene group and a t-butylene group. Linear or branched alkylene groups such as n-pentylene group, neopentylene group, n-hexylene group, n-heptylene group, n-octylene group, n-nonylene group, n-decylene group; cyclopropylene group, cyclobutylene group, Cycloalkylene groups such as a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, and a cyclooctylene group can be mentioned. The divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms is preferably at least one selected from the group consisting of an ethylene group, an n-propylene group, and an i-propylene group.

_{R 2} and R ₃ in the formula (S1) are independently monovalent organic groups having 1 to 10 carbon atoms, and at least one is a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms.
The monovalent organic group having 1 to 10 carbon atoms may be linear, cyclic or branched, and may be saturated or unsaturated. For example, the monovalent organic group having 1 to 10 carbon atoms includes a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an s-butyl group, a t-butyl group, and an n-pentyl group. , Neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group and other linear or branched alkyl groups; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group , Cycloalkyl group such as cycloheptyl group, cyclooctyl group; aromatic group such as phenyl group, tolyl group, xsilyl group, α-naphthyl group, β-naphthyl group and the like.
The monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms may be linear, cyclic or branched, and may be saturated or unsaturated. For example, the monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms includes a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an s-butyl group, a t-butyl group, and the like. Linear or branched alkyl groups such as n-pentyl group and neopentyl group; cycloalkyl groups such as cyclopropyl group, cyclobutyl group and cyclopentyl group can be mentioned. The monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms is preferably at least one selected from the group consisting of a methyl group, an ethyl group, and an n-propyl group.

_{R 4} and R ₅ in the formula (S1) are independently monovalent organic groups having 1 to 10 carbon atoms, and at least one is a monovalent aromatic group having 6 to 10 carbon atoms. The monovalent organic group having 1 to 10 carbon atoms may be linear, cyclic or branched, and may be saturated or unsaturated. For example, monovalent organic groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, s-butyl group, t-butyl group and n-pentyl. Linear or branched alkyl groups such as groups, neopentyl groups, n-hexyl groups, n-heptyl groups, n-octyl groups, n-nonyl groups, n-decyl groups; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl. Cycloalkyl groups such as groups, cycloheptyl groups and cyclooctyl groups; aromatic groups such as phenyl group, trill group, xsilyl group, α-naphthyl group and β-naphthyl group can be mentioned. Examples of the monovalent aromatic group having 6 to 10 carbon atoms include a phenyl group, a tolyl group, a xsilyl group, an α-naphthyl group, a β-naphthyl group and the like, and may be a phenyl group, a tolyl group, or a xsilyl group. It is preferable to have.

_{R 6} and R ₇ in the formula (S1) are independently monovalent organic groups having 1 to 10 carbon atoms, and at least one is an organic group having an unsaturated aliphatic hydrocarbon group. The monovalent organic group having 1 to 10 carbon atoms may be linear, cyclic or branched. Examples of the monovalent organic group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an s-butyl group, a t-butyl group and an n-pentyl group. Linear or branched alkyl groups such as groups, neopentyl groups, n-hexyl groups, n-heptyl groups, n-octyl groups, n-nonyl groups, n-decyl groups; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl. Cycloalkyl groups such as groups, cycloheptyl groups and cyclooctyl groups; aromatic groups such as phenyl group, trill group, xsilyl group, α-naphthyl group and β-naphthyl group can be mentioned. The monovalent organic group having 1 to 10 carbon atoms is preferably at least one selected from the group consisting of a methyl group, an ethyl group, and a group phenyl.
The organic group having an unsaturated aliphatic hydrocarbon group may be an unsaturated aliphatic hydrocarbon group having 3 to 10 carbon atoms, and may be linear, cyclic or branched. Examples of the unsaturated aliphatic hydrocarbon group having 3 to 10 carbon atoms include a vinyl group, an allyl group, a 1-propenyl group, a 3-butenyl group, a 2-butenyl group, a pentenyl group, a cyclopentenyl group, a hexenyl group and a cyclo. Examples thereof include a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, an ethynyl group, a propynyl group, a butynyl group, a pentynyl group and a hexynyl group. The unsaturated aliphatic hydrocarbon group having 3 to 10 carbon atoms is preferably at least one selected from the group consisting of a vinyl group, an allyl group, and a 3-butenyl group.

_{A part or all of the hydrogen atoms of R 1 to} R ₇ in the formula (S1) may be substituted with a substituent such as a halogen atom such as F, Cl or Br, or may be unsubstituted.
It is preferably at least one selected.

｛上記式中、「＊」は、結合手を表す。｝で表される、２，５−ジオキソテトラヒドロフラン−３−イル基が挙げられる。
アルコキシカルボニル基におけるアルコキシル基は、炭素数１〜６のアルコキシル基であってよく、例えば、メトキシル基、エトキシル基、ｎ−プロポキシル基、ｉ−プロポキシル基、ｎ−ブトキシル基、ｉ−ブトキシル基、ｔ−ブトキシル基等であってよい。
ハロゲン化カルボニル基におけるハロゲン原子は、フッ素原子以外のハロゲン原子が好ましく、より好ましくは、塩素原子又はヨウ素原子である。 _{L 3} in the formula (S1) is independently a monovalent organic group containing an acid anhydride structure, an amino group, an isocyanate group, a carboxyl group, an alkoxycarbonyl group, a halogenated carbonyl group, a hydroxy group, an epoxy group, and the like. Or it is a mercapto group.
Examples of the monovalent organic group containing an acid anhydride structure include the following formula:

{In the above formula, "*" represents a bond. }, Examples thereof include a 2,5-dioxotetrahydrofuran-3-yl group.
The alkoxyl group in the alkoxycarbonyl group may be an alkoxyl group having 1 to 6 carbon atoms, for example, a methoxyl group, an ethoxyl group, an n-propoxyl group, an i-propoxyl group, an n-butoxyl group, or an i-butoxyl group. , T-butoxyl group and the like.
The halogen atom in the halogenated carbonyl group is preferably a halogen atom other than a fluorine atom, and more preferably a chlorine atom or an iodine atom.

I in the formula (S1) is an integer of 1 to 200, preferably an integer of 2 to 100, more preferably an integer of 4 to 80, and even more preferably an integer of 8 to 40. j and k are independently integers of 0 to 200, preferably an integer of 0 to 50, more preferably an integer of 0 to 20, and even more preferably an integer of 0 to 50.

｛式（Ｓ２）中のＲ_１０は、メチル基又はフェニル基であり、ａは２〜８の整数であり；
式（Ｓ３）中のｂは、２以上の整数である｝のそれぞれで表される化合物が挙げられる。式（Ｓ３）中のｂは、例えば、２〜８の整数であってよい。 Silane monomers often contain impurities that are by-produced in the process of synthesis in a certain ratio.
In the prior art, the silane monomer has been purified before use to remove these impurities as much as possible before use.
However, in the present embodiment, it has been found that when the resin composition contains a cyclic low molecular weight silane compound in a predetermined ratio, the transparency of the obtained polyimide film is improved. Examples of such a small molecule silane compound include the following formulas (S2) and (S3):

_{{R 10} in formula (S2) is a methyl group or a phenyl group, and a is an integer of 2-8;
B in the formula (S3) is an integer of 2 or more}. B in the formula (S3) may be, for example, an integer of 2 to 8.

The resin composition of the present embodiment preferably contains a small molecule silane compound represented by the above formula (S2) in a proportion of more than 0 ppm and 280 ppm or less based on the mass of the silane monomer. Further, in the resin composition of the present embodiment, among the small molecule silane compounds represented by the above formula (S3), decamethylcyclopentasiloxane having b of 5 is represented by the above formula (S1). Based on the total of the compound and the compound represented by the above formula (S3), it is preferably contained in a ratio of more than 0 ppm and not more than 500 ppm.
The amount of the small molecule silane compound in the silane monomer may be adjusted by purifying the silane monomer by an appropriate method and reducing it to a predetermined range.

<Weight average molecular weight of polyimide precursor>
The weight average molecular weight of the polyimide precursor in the present embodiment is preferably 50,000 or more, more preferably 60,000 or more, from the viewpoint of reducing the YI value of the obtained polyimide film. Further, from the viewpoint of reducing the haze of the polyimide film, the weight average molecular weight of the polyimide precursor is preferably 150,000 or less, more preferably 120,000 or less. The desired weight average molecular weight of the polyimide precursor may vary depending on the desired application, the type of the polyimide precursor, the solid content of the resin composition, the type of solvent that the resin composition can contain, and the like.
The weight average molecular weight of the polyimide precursor is a polystyrene-equivalent value measured by gel permeation chromatography.

<Synthesis of polyimide precursor>
The polyimide precursor of the present embodiment can be synthesized by polycondensation of a monomer composition containing a tetracarboxylic dianhydride and a diamine, and if necessary, a silicon-containing compound and a solvent.
The molar ratio of tetracarboxylic dianhydride to diamine in synthesizing the polyimide precursor is determined from the viewpoint of increasing the molecular weight of the polyimide precursor resin and improving the slit coating characteristics of the resin composition. The number of moles of diamine with respect to 1 mole of the anhydride is preferably in the range of 0.99 to 1.10 moles, and more preferably in the range of 0.95 to 1.05 moles.

In the present embodiment, the solvent used in the synthesis of the polyimide precursor may be used as it is as the solvent contained in the resin composition. In this case, as the synthetic solvent for the polyimide precursor, it is preferable to use a mixture of an amide-based solvent and a non-amide-based solvent having a boiling point of 160 ° C. or higher.

Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, tetramethylurea and the like.
Examples of non-amide solvents having a boiling point of 160 ° C. or higher include γ-butyrolactone, ethyl acetoacetate, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide, sulfolane, diisobutyl ketone, 3-methoxy-3-methyl. Examples thereof include butyl acetate, butyl cellosolve, butyl cellosolve acetate, ethylene glycol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol, dipropylene glycol dimethyl ether, and dipropylene glycol methyl ether acetate.

From another aspect, a solvent capable of dissolving the tetracarboxylic dianhydride and the diamine, the optionally used silane monomer, and the resulting polyimide precursor can be used to obtain a high molecular weight polymer. Examples of such a solvent include an aprotic solvent, a phenol-based solvent, an ether, a glycol-based solvent and the like.
As the aprotic solvent, the above-mentioned amide solvent can be used, and
Phosphorus-containing amide solvents such as hexamethylphosphoric amide and hexamethylphosphine triamide;
Lactone-based solvents such as γ-butyrolactone and γ-valerolactone;
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 solvent such as acetic acid (2-methoxy-1-methyl ethyl);
And so on.

Examples of the phenolic solvent include 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 and the like can be mentioned.
Examples of the ether and glycol-based solvent include 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, and bis [2- (2-methoxyethoxy) ethyl. ] Ether, tetrahydrofuran, 1,4-dioxane and the like can be mentioned.

The reaction temperature when synthesizing the polyimide precursor may be preferably 0 ° C. to 120 ° C., 40 ° C. to 100 ° C., or 60 to 100 ° C., and the polymerization time is preferably 1 to 100 hours or more. It may be 2 to 10 hours. A polyimide precursor having a uniform degree of polymerization can be obtained by setting the polymerization time to 1 hour or more, and a polyimide precursor having a high degree of polymerization can be obtained by setting the polymerization time to 100 hours or less.

<Imidization of polyimide precursor>
In the resin composition of the present embodiment, instead of the polyimide precursor as described above, or together with the polyimide precursor, a polymer in which a part or all of the amidic acid structure of the polyimide precursor is imidized may be used. good. The imidization of the polyimide precursor can be carried out by thermal imidization by heating, chemical imidization by a dehydrating agent, or both of these. The dehydrating agent used for chemical imidization may be a known one, and for example, a dehydrating agent composed of a combination of a carboxylic acid anhydride (for example, acetic anhydride) and a tertiary amine (for example, pyridine, triethylamine, etc.) may be used. Can be mentioned.

<solvent>
The resin composition of the present embodiment contains a solvent. As the solvent, a solvent having good solubility of the polyimide precursor and capable of appropriately controlling the solution viscosity of the resin composition is preferable. As the solvent in this embodiment, for example, a reaction solvent for synthesizing a polyimide precursor can be used, or a silane monomer represented by the above formula (S1) may be used as the solvent.
As the solvent in the resin composition of the present embodiment, a reaction solvent for synthesizing the polyimide precursor is preferable, and in particular, N-methyl-2-pyrrolidone is used alone, or N-methyl-2-pyrrolidone and γ are used. -A mixed solvent containing butyrolactone is suitable.

The amount of the solvent used may be appropriately set from the viewpoint of ensuring the coatability of the resin composition.
When the resin composition is applied by the slit coating method, the solution viscosity of the resin composition is preferably 500 to 100,000 mPa · s from the viewpoint of suppressing liquid leakage from the slit nozzle and clogging of the slit nozzle. It is more preferably 1,000 to 50,000 mPa · s, and even more preferably 3,000 to 20,000 mPa · s.
Therefore, in this case, it is preferable to adjust the amount of the solvent so that the solution viscosity of the resin composition is within the above range.

The resin composition of the present embodiment may contain other components, if necessary, in addition to the polyimide precursor and the solvent. Examples of other components include surfactants, alkoxysilane compounds and the like.

<< Manufacturing method of polyimide film >>
From another point of view of this embodiment
A coating step of applying the resin composition of the present embodiment on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of a resin composition to form a polyimide resin film on a support,
The peeling process of peeling the polyimide resin film from the support to obtain the polyimide film,
Is provided in this order, a method for producing a polyimide film.
After the polyimide resin film forming step and before the peeling step,
A laser irradiation step of irradiating the laser from the surface of the support surface opposite to the side on which the polyimide resin film is formed may be further included.

<Applying process>
In the coating step, the resin composition of the present embodiment is coated on the surface of the support.
The support is not particularly limited as long as it has heat resistance to the heating temperature in the subsequent polyimide resin film forming step accompanied by heating and the peelability in the peeling step is good. Examples of the support include a glass substrate (for example, a non-alkali glass substrate); a silicon wafer; PET (polyethylene terephthalate), OPP (stretched polypropylene), polyethylene glycol terephthalate, polyethylene glycol naphthalate, polycarbonate, polyimide, polyamideimide, and polyether. Resin substrates such as imide, polyetheretherketone, polyethersulfone, polyphenylene sulfide, and polyphenylene sulfide; and metal substrates such as stainless steel, alumina, copper, and nickel can be mentioned.

Application methods include doctor blade knife coat, air knife coat, roll coat, rotary coat, flow coat, die coat, bar coat, spin coat, spray coat, dip coat, etc .; typified by screen printing and gravure printing. Printing technology and the like can be mentioned. The resin composition of the present embodiment is preferably coated with a slit coat. The coating thickness should be appropriately adjusted according to the desired thickness of the polyimide film and the content of the polyimide precursor in the resin composition, but is preferably about 1 to 1,000 μm. The temperature in the coating step may be room temperature, and the resin composition may be heated to, for example, 40 to 80 ° C. in order to reduce the viscosity and improve the workability.
The coating film after coating may be dried, or the drying step may be omitted and the process may proceed directly to the next polyimide resin film forming step. Drying can be performed by, for example, placing the coating film of the resin composition under a reduced pressure of 100 Pa or less in order to remove the organic solvent in the resin composition. When drying the coating film, for example, an appropriate device such as a hot plate, a box-type dryer, or a conveyor-type dryer can be used. The drying temperature is preferably 80 to 200 ° C, more preferably 100 to 150 ° C. The drying time is preferably 1 minute to 10 hours, more preferably 3 minutes to 5 hours.
In this way, a coating film containing the polyimide precursor is formed on the support.

<Polyimide resin film forming process>
In the polyimide resin film forming step, the coating film of the resin composition formed on the support is heated to form the polyimide resin film on the support.
This step is a step of removing the solvent contained in the coating film of the resin composition and advancing the imidization reaction of the polyimide precursor in the coating film to obtain a polyimide resin film.
Heating is performed by, for example, using an apparatus such as an inert gas oven, a hot plate, a box-type dryer, and a conveyor-type dryer, and placing a support having a coating film of the resin composition under a reduced pressure of, for example, 100 Pa or less. ,It can be carried out. This step may be carried out at the same time as the above-mentioned drying step, or both steps may be carried out sequentially.

The polyimide resin film forming step may be performed in an air atmosphere, but it is not suitable from the viewpoint of safety, good transparency of the obtained polyimide film, low thickness direction retardation (Rth), and low YI value. It is preferable to carry out in an active gas atmosphere. Examples of the inert gas include nitrogen, argon and the like.
The heating temperature may be appropriately set according to the type of the polyimide precursor and the type of the solvent in the resin composition. The heating temperature is preferably 250 ° C. to 550 ° C., more preferably 300 to 450 ° C. If the temperature is 250 ° C. or higher, imidization proceeds satisfactorily, and if the temperature is 550 ° C. or lower, inconveniences such as deterioration of transparency and heat resistance of the obtained polyimide film can be avoided.
The heating time is preferably about 0.1 to 10 hours.

<Laser irradiation process>
In the optional laser irradiation step, the laser is irradiated from the surface of the support surface opposite to the side on which the polyimide resin film is formed. By this operation, the interface between the support and the polyimide resin film is ablated, and the polyimide resin film can be easily peeled off from the support.
The type of laser may be, for example, a YAG laser, a UV excimer laser, or the like. As the laser, for example, a laser beam including a bright line having a wavelength of 308 nm can be exemplified.

<Peeling process>
Then, in the peeling step, the polyimide film can be obtained by peeling the polyimide resin film from the support.
The thickness of the polyimide film is arbitrary, but can be, for example, 1 μm or more and 200 μm or less, preferably 5 μm or more and 100 μm or less.

<< Manufacturing method of laminate with element and polyimide film with element >>
From yet another point of view of this embodiment,
A coating step of applying the resin composition of the present embodiment on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of a resin composition to form a polyimide resin film on a support,
An element forming step of forming an element on a polyimide resin film and forming a polyimide resin film with an element on a support.
Is provided in this order, and a method for manufacturing a laminate with an element is provided.

From yet another point of view of this embodiment,
A coating step of applying the resin composition of the present embodiment on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of a resin composition to form a polyimide resin film on a support,
An element forming step of forming an element on a polyimide resin film and forming a polyimide resin film with an element on a support.
A peeling step of peeling a polyimide resin film with an element from a support to obtain a polyimide film with an element.
A method for producing a polyimide film with an element including this order is provided.
In the method of manufacturing a polyimide film with an element
After the polyimide resin film forming process and
Before the peeling process,
A laser irradiation step of irradiating the laser from the surface of the support surface opposite to the side on which the polyimide resin film is formed may be further included.

The coating step, the polyimide resin film forming step, the laser irradiation step, and the peeling step in the method for manufacturing the laminate with the element and the method for manufacturing the polyimide film with the element can be performed in the same manner as the method for manufacturing the polyimide film. ..
The element forming step in the method for manufacturing a laminate with an element and the method for producing a polyimide film with an element will be described below.

<Element formation process>
In the element forming step, for example, a thin film transistor (TFT) is formed on the polyimide resin film formed on the support. The TFT can be formed by a known method using, for example, an appropriate material selected from amorphous silicon, metal oxide semiconductor, low temperature polysilicon, and the like.
Since the polyimide resin film obtained from the resin composition of the present embodiment can withstand heating at at least 350 ° C., preferably 400 ° C., more preferably 500 ° C., and even more preferably about 650 ° C., a known material is used. The device can be formed on the polyimide resin film by the above method.

<< Manufacturing method of flexible display >>
From still another aspect of the present embodiment, there is provided a method for manufacturing a flexible display, including a method for manufacturing a polyimide film with an element of the present embodiment, or a method for manufacturing a laminate with a device.
The flexible display manufactured by the method of the present embodiment may be, for example, a flexible organic EL display, a flexible liquid crystal display, or the like.

The manufacturing method of the flexible organic EL display is
A coating step of applying the resin composition of the present embodiment on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of a resin composition to form a polyimide resin film on a support,
An element forming step of forming an organic EL element on a polyimide resin film and forming a polyimide resin film with an organic EL element on a support.
A peeling step of peeling a polyimide resin film with an organic EL element from a support to obtain a flexible organic EL display.
Included in this order.
The organic EL element has, for example, a lower electrode, a hole transport layer, a light emitting layer, and an upper electrode in this order, and these are sandwiched between the interlayer insulating film in which the driving TFT is embedded and the sealing substrate. It may have been done. A multi-barrier layer may be further formed on the lower side (polyimide resin film side) of the lower electrode.
The formation of each of these elements can be performed by a known method using a known material.

The manufacturing method of the flexible liquid crystal display is
A coating step of applying the resin composition of the present embodiment on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of a resin composition to form a polyimide resin film on a support,
An element forming step of forming a liquid crystal element on a polyimide resin film and forming a polyimide resin film with a liquid crystal element on a support.
A peeling process in which a polyimide resin film with a liquid crystal element is peeled from a support to obtain a flexible liquid crystal display.
Included in this order.
The liquid crystal element may have, for example, a TFT, a color filter, a liquid crystal, and a sealing material in this order.
The formation of each of these elements can be performed by a known method using a known material.

｛式（４）中、Ｐ_１は２価の有機基であり、Ｐ_２は４価の有機基である。｝で表される構造を有するポリイミドであって、
前記式（１）中のＰ_１が下記式（Ａ１）：

｛式（Ａ１）中、Ｌ_１は、アルキル基、フッ素原子以外のハロゲン原子で置換されているアルキル基、又はフッ素原子以外のハロゲン原子であり、ｎ１は、０〜３の整数であり、「＊」は、式（１）中の窒素原子と結合している結合手を示す。｝で表される構造を含み、かつ、
前記ポリイミドが、以下の要件（Ａ）及び（Ｅ）：
（Ａ）膜厚１０μｍのフィルムとしたときの黄色度（ＹＩ）が１０以下であること、及び
（Ｅ）前記ポリイミド中のフッ素原子含有割合が、前記ポリイミドの質量に基づいて、５質量％未満であること
の双方を満たす、
ポリイミドであってよい。 《Polyimide》
From yet another aspect of the present embodiment, polyimide, which is a cured product of the resin composition of the present embodiment, is provided.
This polyimide is, for example,
The following formula (4):

{In formula (4), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, Which is a polyimide having a structure represented by
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide has the following requirements (A) and (E):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (E) the fluorine atom content in the polyimide is less than 5% by mass based on the mass of the polyimide. Satisfy both sides of being
It may be polyimide.

Hereinafter, embodiments of the present invention will be specifically described with reference to Experimental Examples, but the present invention is not limited to these Experimental Examples.

<Evaluation of yellowness (YI) and total light transmittance>
A 6-inch silicon wafer substrate having an aluminum-deposited layer on its surface is used as a support, and the resin composition prepared in each experimental example is placed on the surface of the aluminum-deposited layer to have a film thickness of 10 μm after imidization. As described above, a coating film was formed by spin coating. After prebaking this coating film at 100 ° C. for 6 minutes, a vertical curing furnace (manufactured by Koyo Thermo System Co., Ltd., model name "VF-2000B") in which the oxygen concentration in the refrigerator was adjusted to 10 mass ppm or less was used. Using, the film was heated at 400 ° C. for 1 hour to imidize the coating film to form a polyimide film on the wafer. The obtained wafer with a polyimide film was immersed in a dilute aqueous hydrochloric acid solution overnight to peel off the polyimide film pieces and dried. Using a spectral color difference meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., model name "SE600"), the yellowness (YI) value and total light transmittance are measured using the D65 light source as the light source and the dried polyimide film piece as a sample. It was measured. The obtained results are shown in Table 1 as a value converted to a film thickness of 10 μm.

<Evaluation of retardation (Rth) in the thickness direction>
A glass substrate is used as a support, and a polyimide film is formed on the glass substrate on one side thereof in the same manner as in "<Evaluation of yellowness (YI) and transmittance>", peeled and dried, and the polyimide is formed. A film piece sample was obtained. Rth was measured using a phase difference birefringence measuring device (manufactured by Oji Measuring Instruments Co., Ltd., model name "KOBRA-WR") with a measurement wavelength of 589 nm. rice field. The obtained results are shown in Table 1 as a value converted to a film thickness of 10 μm.

<Evaluation of Young's modulus>
A polyimide film was formed on the aluminum-deposited layer surface of a 6-inch silicon wafer substrate having an aluminum-deposited layer on the surface in the same manner as in "<Evaluation of yellowness (YI) and transmittance>". After making a 3 mm wide cut in the obtained polyimide film using a dicing saw (manufactured by Disco Co., Ltd., product name "DAD 3350"), the wafer with the polyimide film is immersed in a dilute hydrochloric acid aqueous solution overnight to form the polyimide film. The pieces were peeled off and dried to obtain a polyimide piece having a width of 3 mm. This was cut to a length of 50 mm to obtain a polyimide measurement sample having a width of 3 mm and a length of 50 mm. Using TENSILON (manufactured by Orientec Co., Ltd., model name "UTM-II-20"), the Young's modulus of the polyimide measurement sample was measured at a test speed of 40 mm / min and an initial load of 0.5 fs. The results obtained are shown in Table 1.

<Evaluation of residual stress>
The resin composition prepared in each experimental example was spun on one side of a 6-inch silicon wafer having a thickness of 625 μm ± 25 μm for which the “warp amount” was measured in advance so that the film thickness after imidization was 10 μm. It was coated to form a coating film. After prebaking this coating film at 100 ° C. for 7 minutes, a vertical curing furnace (manufactured by Koyo Thermo System Co., Ltd., model name "VF-2000B") in which the oxygen concentration in the refrigerator was adjusted to 10 mass ppm or less was used. Using, the film was heated at 400 ° C. for 1 hour to imidize the coating film to form a polyimide film on the wafer. Using a residual stress measuring device (manufactured by KLA Tencor Co., Ltd., model name FLX-2320), the amount of warpage of the obtained wafer with a polyimide film was measured, and the residual stress generated between the silicon wafer and the polyimide film was measured. Was evaluated. The results are shown in Table 1.

<Evaluation of glass transition temperature Tg>
In the same manner as in "<Evaluation of Young's modulus>", a polyimide measurement sample having a width of 3 mm and a length of 50 mm was obtained. Using a thermomechanical analyzer (manufactured by Shimadzu Corporation, model name "TMA-50"), under the conditions of a load of 5 g and a temperature rise rate of 10 ° C./min, under a nitrogen stream (flow rate 20 ml / min), polyimide The breaking elongation of the measurement sample was measured in the temperature range of 50 to 500 ° C. From the measurement results, the temperature dependence of the elongation at break was charted, and the inflection point of the graph was evaluated as the glass transition temperature. The results are shown in Table 1. When no inflection point was observed in the range of 50 to 500 ° C., it was assumed that the glass transition point was in the temperature range exceeding 500 ° C., and "500 <" was described in the table.

<Evaluation of fluorine atom content>
(1) Calculated value The total mass of fluorine atoms contained in the monomers (tetracarboxylic dianhydride, diamine, and silane monomer) used for the synthesis of the polyimide precursor in each experimental example is the mass of the obtained polyimide (monomer). It was divided by the total mass minus the mass of water removed by imidization), and the value expressed as a percentage was evaluated as the fluorine atom content of the polyimide. At this time, the fluorine atom contained in the additive (for example, alkoxysilane, surfactant, etc.) other than the polyimide precursor contained in the resin composition did not enter the calculation. The obtained calculation results are shown in the "F atom content calculated value" column of Table 1.

(2) Measured values The fluorine atom content of the polyimide film obtained in each experimental example was determined by combustion ion chromatography analysis.
In the same manner as in "<Evaluation of Young's modulus>", a polyimide piece having a width of 3 mm was obtained, and about 20 mg thereof was used as a measurement sample. The measured sample whose mass has been precisely weighed is heated and burned by an automatic sample combustion device for ion chromatograph pretreatment (manufactured by Mitsubishi Chemical Analytics Co., Ltd., model name "AQF-100"), and the obtained combustion gas is absorbed. After absorption into the sample, the amount of fluorine ions in the absorption liquid is quantified by a combustion ion chromatograph (manufactured by Thermo Fisher Scientific Co., Ltd., model name "ICS-1600"), and the fluorine atom content is calculated from the sample mass. Was calculated. The results are shown in Table 1. The measurement was performed three times, and the average value was adopted as the fluorine atom content. When the obtained result was less than 10 ppm, it was described as "ND" in Table 1 as below the detection limit.

<Evaluation of the amount of small molecule silane compound (small molecule SiO) and the amount of compound (decamethylcyclopentasiloxane, DMCPSiO) of b = 5 in the formula (S3)>
The content of the low molecular weight silane compound in the silane monomer was determined by dissolving the silane monomer in acetone containing n-tetradecane as an internal standard substance, and the obtained solution was analyzed by gas chromatography (GC). From the peak area of each of the obtained compounds, the concentration of each compound was determined based on the peak area of n-tetradecane according to the method described later.
The GC was measured using the following devices under the following conditions.
Measuring device: Model name "7890A" (manufactured by Agilent Technologies)
Column: J & W Scientific Durabond DB-5MS (manufactured by MEGABORE, inner diameter 0.53 mm, length 30 m, liquid phase thickness 1.0 μm)
Column temperature: 50 ° C, temperature rise at 10 ° C / min, hold at 280 ° C for 17 minutes, total 40 minutes Injection inlet temperature: 270 ° C
Carrier gas: He
Injection method: Split method (split ratio 1/10)
Detector: FID (300 ° C)

The peak area of each compound obtained by GC analysis is calculated by the following formula:
By multiplying the GC area coefficient calculated according to GC area coefficient = molecular weight ÷ carbon number, the peak area was converted into a mass unit ratio to calculate the content of the low molecular weight silane compound in the silane monomer.
The retention time of each compound was as follows.
Compound with b = 3 in formula (S3) (hexamethylcyclotrisiloxane): 3.8 minutes Compound with b = 4 in formula (S3) (octamethylcyclotetrasiloxane): 6.1 minutes b in formula (S3) = 5 compound (decamethylcyclopentasiloxane): 8.4 compound (S3) b = 6 compound (dodecamethylcyclohexasiloxane): 10.7 compound (S3) b = 7 compound (tetra) Decamethylcycloheptasiloxane): Compound of b = 8 in the 12.8 fraction (S3) (Hexadecamethylcyclooctasiloxane): 14.6 In the formula (S2), R ₁₀ is a phenyl group and a In the compound of 3: 16.4 fraction (S2), R ₁₀ is a phenyl group, and in the compound of a of 4: 17.4 fraction (S2), R ₁₀ is a phenyl group and a is 5. Compound: 18.6 minutes Tetradecane: 12.2 minutes

<Evaluation of heat resistance after forming an inorganic film>
A 6-inch silicon wafer substrate was used as the support, and a polyimide film having a thickness of 10 μm was formed on one side of the wafer in the same manner as in “<Evaluation of residual stress>”. A silicon nitride (SiNx) film (inorganic film) having a thickness of 100 nm was formed on the obtained polyimide film by a CVD method, and a wafer, a polyimide film, and a silicon nitride film were laminated in this order to obtain a laminate.
The obtained laminate was used at 400 ° C. and 30 using a vertical curing furnace (manufactured by Koyo Thermo System Co., Ltd., model name "VF-2000B") in which the oxygen concentration in the refrigerator was adjusted to 10 mass ppm or less. After a minute of heat treatment, the surface of the silicon nitride film was observed with the naked eye and an optical microscope, and evaluated according to the following criteria.
AA: No wrinkles or swelling were observed (heat resistance "excellent")
A: No wrinkles were observed, but swelling with a maximum diameter of less than 10 mmΦ was observed (heat resistance "good").
B: No wrinkles were observed, but swelling with a maximum diameter of 10 mmΦ or more was observed (heat resistance "poor").
C: Wrinkles were observed (heat resistance "extremely poor")

<< Experimental Examples 1-1-1-19 and 2-1-2-7 >>
N-methyl-2-pyrrolidone (NMP) as a solvent was placed in a separable flask having a capacity of 3 L equipped with a stirring rod under nitrogen gas flow, and then under stirring, the types and amounts shown in Table 1 were used. Diamine, tetracarboxylic acid dianhydride, and silane monomer were added to prepare a monomer composition. The amount of solvent NMP at this time was adjusted so that the total content of the monomers in the monomer composition was 15% by mass. The obtained monomer composition was stirred at room temperature (23 ° C.) for 48 hours to obtain an NMP solution (varnish) of a colorless and transparent polyamic acid.
The obtained varnish was stored in a freezer having an internal temperature of −20 ° C., and was taken out from the freezer for each evaluation and used.

The evaluation results in each experimental example are shown in Tables 1 and 2 below.

The abbreviations for the monomers in Tables 1 and 2 have the following meanings, respectively.
<Tetracarboxylic dianhydride>
(Specific tetracarboxylic dianhydride)
BPDA: Biphenyltetracarboxylic dianhydride BPAF: 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride CpODA: Norbornane-2-spiro-α-cyclopentane-α'-spiro-2 " -Norbornane-5,5 ", 6,6" -Tetracarboxylic dianhydride TAHQ: p-phenylenebis (trimeritate anhydride)
DSDA: 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride (other tetracarboxylic dianhydrides)
-Tetracarboxylic dianhydride containing fluorine atom-
6FDA: 4,4'-(hexafluoroisopropyridene) diphthalic anhydride-other tetracarboxylic dianhydrides-
PMDA: Pyromellitic Acid Dianhydride TA-RC: m-Phenylene Bis (Trimeritate Anhydride)

<Diamine>
(Structure A1 containing diamine)
DAB-H: 3,5-diaminobenzamide (specific diamine)
APAB: 4-Aminophenyl 4-aminobenzoate DAS: 4,4'-bis (diaminodiphenyl) sulfone CHDA: 1,4-Cyclohexanediamine BAFL: 9,9-bis (4-aminophenyl) fluorene (other diamines)
-Diamine containing fluorine atom-
TFMB: 2,2'-bis (trifluoromethyl) benzidine-other diamines-
mPD: m-phenylenediamine pPD-4Me: 2,3,5,6-tetramethyl-1,4-phenylenediamine

<Silane monomer>
(1): In a compound having a number average molecular weight of 4,400 represented by the following formula (SiO-1) (where i and j are repeating units, respectively) (R ₁₀ is phenyl in the formula (S2)). It is a group and contains 13 ppm of a compound having a of 3)
(2): A compound having a number average molecular weight of 3,000 represented by the following formula (SiO-2) (i is the number of repeating units) (containing 60 ppm of decamethylcyclopentasiloxane).
(3): A compound having a number average molecular weight of 3,200 represented by the following formula (SiO-3) (i is the number of repeating units) (containing 27 ppm of decamethylcyclopentasiloxane).

Table 1 above shows the superiority of the resin composition of Experimental Examples 1-1 to 1-19 with respect to the resin composition of Experimental Examples 2-1 to 2-7 with respect to the experimental example showing the whole picture of the present embodiment. It is shown in comparison with.
Table 2 shows the superiority of the resin composition of the experimental examples corresponding to the aspects 12 to 14 in comparison with the resin composition of the experimental examples 2-1 to 2-7.

With reference to Table 1, the polyimides obtained from the resin compositions of Experimental Examples 1-1-1-19 are
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (B) the retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less. Meet both of the things;
(B) The retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less, and (C) the total light transmittance of a film having a film thickness of 10 μm is 80% or more. It meets both of the things; and
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (D) the glass transition temperature (Tg) is 300 ° C. or more, whichever is satisfied. Is understood.

Further, referring to Table 2, Experimental Examples 1-2, 1-4, 1-6, wherein the polyimide precursor has a structure represented by the formula (A1) and a structure represented by the formula (2). The polyimide films obtained from the resin compositions 1-8, 1-13, 1-16, and 1-18 are excellent in residual stress, YI, total light transmittance, Rth, Young's modulus, Tg, and inorganic. It was experimentally revealed that it was excellent in all of the heat resistance after film formation, and it was verified that it was suitable for manufacturing a flexible display.

Further, by applying the polyimide film obtained from the resin composition of Experimental Examples 1-1 to 1-19 to the substrate and the cover window of the flexible liquid crystal display and the flexible organic EL display, the flexible display performance is exhibited. I was able to manufacture a display.

Claims (21)

The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (A) and (B):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (B) the retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less. Satisfy both sides of being
Resin composition. The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (B) and (C):
(B) The retardation (Rth) in the thickness direction of a film having a film thickness of 10 μm is 300 nm or less, and (C) the total light transmittance of a film having a film thickness of 10 μm is 80% or more. Satisfy both sides of being
Resin composition. The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } Including the structure represented by
The content ratio of fluorine atoms in the resin composition is less than 5% by mass and is less than 5% by mass based on the mass of the polyimide precursor.
The polyimide, which is an imidized product of the polyimide precursor, has the following requirements (A) and (D):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (D) the glass transition temperature (Tg) is 300 ° C. or more, whichever is satisfied.
Resin composition. The resin composition according to claim 3, _{wherein P 1} and P ₂ in the formula (1) do not contain fluorine atoms, respectively. The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). It includes a structure represented by the} and the formula (1) _{P 2} is in, biphenyltetracarboxylic dianhydride, 9,9-bis (3,4-carboxyphenyl) fluorene dianhydride, norbornane - 2-Spiro-α-Cyclopentane-α'-Spiro-2 "-norbornan-5,5", 6,6 "-tetracarboxylic dianhydride, p-phenylenebis (trimeritate anhydride), 3,3' , 4,4'-Diphenylsulfonetetracarboxylic dianhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride, one or more selected from specific tetracarboxylic dianhydrides. Containing tetravalent groups derived from,
Resin composition. The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
_{P 1} in the formula (1) is selected from a specific diamine composed of 4-aminophenyl 4-aminobenzoate, 1,4-cyclohexanediamine, and 4,4'-bis (diaminophenyl) sulfone, or one of them. Further containing divalent groups derived from two or more species,
Resin composition. The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The resin composition is used for producing a flexible display.
Resin composition. The structure represented by the formula (A1) is the following formula (A1-1):

{Wherein _(A1-1), L 1, n1, and "*", respectively, _L 1 in Formula (A1), n1, and the same meaning as "*". } The resin composition according to any one of claims 1 to 7, which has a structure represented by. The resin composition according to any one of claims 1 to 8, wherein the glass transition temperature (Tg) of polyimide, which is an imide of the polyimide precursor, is 300 ° C. or higher. The resin composition according to any one of claims 1 to 9, wherein the Young's modulus of polyimide, which is an imide of the polyimide precursor, is 3.5 GPa or more. The resin composition according to any one of claims 1 to 10, wherein the residual stress of polyimide, which is an imide of the polyimide precursor, is 25 MPa or less. The following formula (1):

{In formula (1), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, A resin composition containing a polyimide precursor having a structure represented by} and a solvent.
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide precursor has the following formula (2):

{In formula (2), R is independently a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200. Is an integer of. } Further including the structure represented by
Resin composition. The structure represented by the formula (2) is the following formula (S1):

{In equation (S1),
R ₁ is independently a single bond or a divalent organic group having 1 to 10 carbon atoms.
R ₂ and R ₃ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 2} and R ₃ is a monovalent aliphatic group having 1 to 5 carbon atoms. It is a hydrocarbon group and
R ₄ and R ₅ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 4} and R ₅ is a monovalent aromatic group having 6 to 10 carbon atoms. Is the basis and
R ₆ and R ₇ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 6} and R ₇ is an unsaturated aliphatic hydrocarbon having 2 to 10 carbon atoms. It is an organic group containing a hydrogen group and
L ₃ is independently a monovalent organic group containing an acid anhydride structure, an amino group, an isocyanate group, a carboxyl group, an alkoxycarbonyl group, a halogenated carbonyl group, a hydroxy group, an epoxy group, or a mercapto group.
i and j are independently integers of 1 to 200, respectively.
k is an integer from 0 to 200, and
The relationship of 0.05 ≦ j / (i + j + k) ≦ 0.50 is satisfied. } Is a structure derived from the silane monomer.
The resin composition has the following formula (S2):

{In formula (S2), R ₁₀ is a methyl group or a phenyl group, and a is an integer of 2 to 8. } Contains a small molecule silane compound
The polyimide precursor is a polycondensate obtained from a monomer composition containing a tetracarboxylic dianhydride, a diamine, and the silane monomer, and
The content ratio of the small molecule silane compound in the resin composition is more than 0 ppm and 280 ppm or less based on the mass of the silane monomer used for the polycondensation of the polyimide precursor.
The resin composition according to claim 12. The polyimide precursor is a tetracarboxylic dianhydride, a diamine, and the following formula (S1):

{In equation (S1),
R ₁ is independently a single bond or a divalent organic group having 1 to 10 carbon atoms.
R ₂ and R ₃ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 2} and R ₃ is a monovalent aliphatic group having 1 to 5 carbon atoms. It is a hydrocarbon group and
R ₄ and R ₅ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 4} and R ₅ is a monovalent aromatic group having 6 to 10 carbon atoms. Is the basis and
R ₆ and R ₇ are independently monovalent organic groups having 1 to 10 carbon atoms, _{and at least one of R 6} and R ₇ is an unsaturated aliphatic hydrocarbon having 2 to 10 carbon atoms. It is an organic group containing a hydrogen group and
L ₃ is independently a monovalent organic group containing an acid anhydride structure, an amino group, an isocyanate group, a carboxyl group, an alkoxycarbonyl group, a halogenated carbonyl group, a hydroxy group, an epoxy group, or a mercapto group.
i is an integer from 1 to 200,
j and k are each independently an integer from 0 to 200, and
The relationship of 0.05 ≦ j / (i + j + k) ≦ 0.50 is satisfied. } And the following formula (S3):

{In equation (S3), b is an integer of 2 or more. } Is a polycondensate obtained from a monomer composition containing the compound represented by
The content ratio of the compound having b = 5 in the formula (S3) contained in the monomer composition is based on the total of the compound represented by the formula (S1) and the compound represented by the formula (S3). It is more than 0 ppm and less than 500 ppm.
The resin composition according to claim 12. A polyimide which is a cured product of the resin composition according to any one of claims 1 to 14. The following formula (4):

{In formula (4), P ₁ is a divalent organic group and P ₂ is a tetravalent organic group. }, Which is a polyimide having a structure represented by
_{P 1} is the following formula in the formula (1) (A1):

{In formula (A1), L ₁ is an alkyl group, an alkyl group substituted with a halogen atom other than a fluorine atom, or a halogen atom other than a fluorine atom, and n1 is an integer of 0 to 3, and ""*" Indicates a bond that is bonded to the nitrogen atom in the formula (1). } And contains the structure represented by
The polyimide has the following requirements (A) and (E):
(A) The yellowness (YI) of a film having a film thickness of 10 μm is 10 or less, and (E) the fluorine atom content in the polyimide is less than 5% by mass based on the mass of the polyimide. Satisfy both sides of being
Polyimide. A coating step of applying the resin composition according to any one of claims 1 to 14 on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of the resin composition to form a polyimide resin film on the support.
A peeling step of peeling the polyimide resin film from the support to obtain a polyimide film.
A method for producing a polyimide film, which comprises the above in this order. After the polyimide resin film forming step and before the peeling step,
A laser irradiation step of irradiating the support from the surface of the support opposite to the side on which the polyimide resin film is formed is further included.
The method for producing a polyimide film according to claim 17. A coating step of applying the resin composition according to any one of claims 1 to 14 on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of the resin composition to form a polyimide resin film on the support.
An element forming step of forming an element on the polyimide resin film and forming a polyimide resin film with an element on the support.
A peeling step of peeling the polyimide resin film with an element from the support to obtain a polyimide film with an element.
A method for producing a polyimide film with an element, which comprises the above in this order. A coating step of applying the resin composition according to any one of claims 1 to 14 on the surface of the support to form a coating film of the resin composition on the support.
A polyimide resin film forming step of heating a coating film of the resin composition to form a polyimide resin film on the support.
An element forming step of forming an element on the polyimide resin film and forming a polyimide resin film with an element on the support.
A method for manufacturing a laminate with an element, which includes the above in this order. A method for manufacturing a flexible display, which comprises the method for manufacturing a polyimide film with an element according to claim 19, or the method for manufacturing a laminate with an element according to claim 20.