JP2022159241A - Polyimide block copolymerization based polymer, polyimide block copolymerization based film, polyamic acid-imide copolymer, and resin composition - Google Patents

Abstract

To provide a polyimide block copolymerization based film excellent in all of transparency, heat resistance and bending resistance.SOLUTION: A polyimide film comprises a polyimide block copolymerization based polymer, and has a degree of crystallinity greater than 0.11 in wide angle X-ray diffraction measurement. The polyimide block copolymerization based polymer comprises a structural unit represented by general formula (1), where X2 has a structure represented by general formula (A-1).SELECTED DRAWING: Figure 1

Description

The present invention relates to a polyamic acid-imide, a resin composition containing the same, a polyimide resin film, a resin film, and a method for producing the same, which are used, for example, in the production of substrates for flexible devices.

In general, polyimide resin films are used as resin films for applications that require high heat resistance. A general polyimide resin is produced by solution polymerization of an aromatic carboxylic dianhydride and an aromatic diamine to produce a polyimide precursor, which is then thermally imidized at a high temperature, or chemically imidized using a catalyst. It is a highly heat-resistant resin manufactured by

A polyimide resin is an insoluble and infusible super heat-resistant resin, and has excellent properties such as thermal oxidation resistance, heat resistance, radiation resistance, low temperature resistance, and chemical resistance. Therefore, polyimide resins are used in a wide range of fields including electronic materials. Examples of applications of polyimide resins in the field of electronic materials include insulating coating materials, insulating films, semiconductors, electrode protection films for thin film transistor liquid crystal displays (TFT-LCDs), and the like. Recently, in the field of display materials, it is being considered to use it as a flexible substrate, taking advantage of its lightness and flexibility, in place of the glass substrate that has been conventionally used.

When a polyimide resin is used as a flexible substrate, a varnish containing a polyimide resin or a precursor thereof and other components is applied to a suitable support such as a glass substrate, dried to form a film, and the film is obtained. A process of peeling the film from the glass substrate after forming elements, circuits, etc. on the glass substrate is widely used. However, when producing a laminate having a polyimide resin, a heat treatment at a high temperature of 250° C. or higher is required for drying and imidizing the polyimide precursor. Due to this heat treatment, residual stress is generated in the laminate, causing serious problems such as warping and peeling. This is because the coefficient of linear expansion of polyimide is larger than that of the material forming the support.

In order to reduce the residual stress in the laminate, the use of a polyimide resin whose coefficient of thermal expansion is as small as that of glass has been studied. Polyimides formed from '-biphenyltetracarboxylic dianhydride (hereinafter also referred to as BPDA) and paraphenylenediamine are the most well known. It has been reported that this polyimide exhibits a very low coefficient of linear thermal expansion, although it depends on the film thickness and production conditions (Non-Patent Document 1).

However, general polyimide resins, including the polyimides described in the above literature, are colored brown or yellow due to high electron density, and therefore have low light transmittance in the visible light region, and therefore fields where transparency is required. It has been difficult to achieve a low enough yellowness index (YI value) for use in In addition, it is known that polyimide, which has a low coefficient of linear expansion, generally has high molecular orientation, so that turbidity and cloudiness are likely to occur in the laminate, which causes deterioration in transmittance (Patent Document 2). .

Generally, regarding the yellowness (YI value), for example, a solvent-soluble polyimide using a diamine having a trifluoromethyl group or a polyimide using an alicyclic tetracarboxylic dianhydride or diamine has an extremely low yellowness. (YI value) and residual stress (Patent Documents 3 and 4).

WO2005/113647 Japanese Patent No. 6443579 WO2019/211972 WO2020/138360 Japanese Patent No. 4303623

"Latest Polyimides -Basics and Applications-", edited by Japan Polyimide Study Group

As described above, in order to apply a polyimide resin as a colorless and transparent flexible substrate, it is required to have both excellent thermal properties and transparency, which contradict each other. In recent years, in addition to these properties, there has been a demand for the development of polyimide resins that have sufficient bending resistance to be used as substrates for flexible devices.

The polyimide resin described in Patent Document 1, which is a general polyimide, exhibits a low coefficient of linear thermal expansion, but does not have sufficient transparency for use in an LTPS process at 400° C. or higher. In addition, it is reported that the polyimide described in Patent Document 2 is excellent in linear expansion coefficient (hereinafter also referred to as "CTE") and transparency by using a specific tetracarboxylic dianhydride and diamine. When heated to 400° C. or higher, the laminate becomes turbid and cloudy, and the haze (hereinafter also referred to as “haze value”) is not sufficient for use as a transparent substrate.

Furthermore, as a known technical idea, in order to achieve transparency, as described in Patent Document 3, an alicyclic acid dianhydride or diamine having no aromatic ring is used, or Intramolecular CT transition is suppressed by using a diamine (for example, 2,2'-bis(trifluoromethyl)benzidine, hereinafter also referred to as TFMB) having a bulky functional group that induces intramolecular twisting in the molecule. method is known. However, these highly transparent polyimides have insufficient heat resistance and thermal properties in the state of polyamic acid, and in order to obtain high transparency, it is necessary to use solvent-soluble polyimide resins that have completed imidization during solution polymerization. These polyimides have a large coefficient of linear expansion when made into a film, have poor thermal stability in a high temperature range of 430° C. or higher, and cannot be said to have sufficient solubility in solvents.

In order to achieve both thermal properties and transparency, which are contradictory performances, a mixture of polyimide and polyamic acid or a polyimide copolymer film obtained from a copolymer has been studied, but these resins are simply Even if mixed, it is known that phase separation occurs during film forming processing, and it was not suitable as a transparent substrate (Patent Document 5). This is because the heat-resistant polyimide has a highly planar and rigid skeleton, and thus is difficult to be compatible with the soluble polyimide having a bending group when formed into a film, resulting in phase separation. Furthermore, when a bending test is performed on these polyimides having a rigid skeleton, the orientation progresses, causing turbidity on the film surface.

The aforementioned Patent Document 4 discloses that storage stability and moldability can be improved by partially coexisting an imide structure and an amide structure in the molecule. However, as a result of confirmation by the present inventors, the polyamic acid-imide resin composition described in Patent Document 4 has poor heat resistance, and in the heat history of 430 ° C. or higher in the LTPS process, yellowness (YI value) and haze (Haze value) was remarkably deteriorated. The main reason for this is that polyimide and polyamic acid have a common monomer skeleton. It was difficult to reconcile the conflicting properties of properties, mechanical properties (bending resistance) and transparency.

Therefore, in view of such circumstances, an object of the present invention is to provide a polyimide block copolymer film having excellent transparency, heat resistance and bending resistance.

｛式中、Ｘ_１及びＸ_３は、それぞれ独立に、４価の有機基を表し、Ｘ_２及びＸ_４は、それぞれ独立に、２価の有機基を表し、そしてｎ及びｍは、それぞれ独立に、正の整数であり、
下記構成１，２を除く：
構成１．Ｘ_３が９，９－ビス（３，４－ジカルボキシフェニル）フルオレン二酸無水物（ＢＰＡＦ）に由来する基である場合は、Ｘ_４が、４，４’－ジアミノジフェニルスルホン、及び／又は２，２’―ビス（トリフルオロメチル）ベンジジンに由来する基である；
構成２．Ｘ_３がノルボルナン―２―スピロ―α―シクロペンタノン―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に由来する基である｝
で示される構造単位を含み、かつ
前記Ｘ_２として、下記一般式（Ａ－１）：

｛式中、Ｒ_１及びＲ_２は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ａ及びｂは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示す｝
で表される構造を有する、
ポリイミドフィルム。
＜２＞
小角Ｘ線散乱測定において、結晶長周期ｄ（ｎｍ）が１２．０ｎｍ以上である、項目１に記載のポリイミドフィルム。
＜３＞
前記小角Ｘ線散乱測定において、散乱強度Ｉ＝Ａ×ｑ^－Ｂ式により算出される乗数Ｂが、０．０４＜ｑ＜０．０５の範囲において、３．６以下である、項目１または項目２に記載のポリイミドフィルム。
＜４＞
曇り度（Ｈａｚｅ値）が１．０％以下である、項目１～３のいずれか１項に記載のポリイミドフィルム。
＜５＞
前記結晶化度が０．２１よりも小さい、項目１～４のいずれか１項に記載のポリイミドフィルム。
＜６＞
前記一般式（１）中、前記Ｘ_３が、下記一般式（Ａ－３）：

｛式中、Ｒ_４～Ｒ_７は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｄ～ｇは、それぞれ独立に、０～４の整数であり、Ｚ_１は、結合基を示し、そして＊は、結合部を示す｝
で表される構造、及び４，４’－オキシジフタル酸二無水物（ＯＤＰＡ）由来の構造から成る群から選択される少なくとも１種である、項目１～５のいずれか１項に記載のポリイミドフィルム。
＜７＞
前記一般式（１）中、前記Ｘ_３が、下記一般式（Ａ－３）：

｛式中、Ｒ_４～Ｒ_７は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｄ～ｇは、それぞれ独立に、０～４の整数であり、Ｚ_１は、結合基を示し、そして＊は、結合部を示す｝
で表される構造である、項目１～６のいずれか１項に記載のポリイミドフィルム。
＜８＞
上記一般式（１）中のＸ_４が、下記一般式（Ａ－４）：

｛式中、Ｒ_８～Ｒ_１１は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｈ～ｋは、それぞれ独立に、０～４の整数であり、Ｚ_２は、結合基を示し、そして＊は、結合部を示す｝
で表される構造、及び下記一般式（Ａ－５）：

｛式中、Ｒ_１２及びＲ_１３は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｌ及びｍは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示し、但し前記Ｘ_３が９，９－ビス（３，４－ジカルボキシフェニル）フルオレン二酸無水物（ＢＰＡＦ）に由来する基である場合は、一般式（Ａ－５）は、４，４’－ジアミノジフェニルスルホンに由来する基を除く｝
で表される構造から成る群から選択される少なくとも１種である、項目１～７のいずれか１項に記載のポリイミドフィルム。
＜９＞
上記一般式（１）中のＸ_１が、ビフェニルテトラカルボン酸二無水物（ＢＰＤＡ）由来の構造を含む、項目１～８のいずれか１項に記載のポリイミドフィルム。
＜１０＞
上記一般式（１）中に含まれるＸ_１とＸ_２のモル比（Ｘ_２／Ｘ_１）が、０．８４～１．００であり、かつ、上記一般式（２）に含まれるＸ_３とＸ_４（Ｘ_４／Ｘ_３）のモル比が、１．０１～２．００である、項目１～９のいずれか１項に記載のポリイミドフィルム。
＜１１＞
上記一般式（１）中のＸ_１及びＸ_２から構成されるポリイミドの構成単位とＸ_３及びＸ_４から構成されるポリイミドの構成単位のモル比（構成単位Ｎのモル数：構成単位Ｍのモル数）が、６０：４０～９５：５の範囲である、項目１～１０のいずれか１項に記載のポリイミドフィルム。
＜１２＞
ポリアミド酸－イミド共重合体であって、下記一般式（２）：

｛式中、Ｘ_１およびＸ_３は、４価の有機基を表し、Ｘ_２およびＸ_４は、２価の有機基を表し、ｎ、ｍ、及びｌは、正の整数であり、Ｘ_１及びＸ_２から構成される構造単位を構造単位Ｎと呼び、そしてＸ_１及びＸ_２から構成される構造単位を構造単位Ｍと呼び、
下記構成１，２を除く：
構成１．Ｘ_３が９，９－ビス（３，４－ジカルボキシフェニル）フルオレン二酸無水物（ＢＰＡＦ）に由来する基である場合は、Ｘ_４が４，４’－ジアミノジフェニルスルホン、及び／又は２，２’―ビス（トリフルオロメチル）ベンジジンに由来する基である；
構成２．Ｘ_３がノルボルナン―２―スピロ―α―シクロペンタノン―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に由来する基である｝
で示される構造単位Ｌを含み、
前記ポリアミド酸－イミド共重合体はキュアされると小角Ｘ線散乱測定において、結晶長周期ｄ（ｎｍ）が１２．０ｎｍ以上であり、かつ広角Ｘ線回折測定において、結晶化度が０．１１よりも大きいことを特徴とし、
上記一般式（２）中のＸ_２が、下記一般式（Ａ－１）：

｛式中、Ｒ_１及びＲ_２は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ａ及びｂは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示す｝
で表される構造を有し、
上記一般式（２）中のＸ_２を構成するジアミン成分とＸ_４を構成するジアミン成分とが、ジアミン組成、又はジアミン種のいずれかが異なる、
ポリアミド酸－イミド共重合体。
＜１３＞
上記一般式（２）中のＸ_３が、下記一般式（Ａ－３）：

｛式中、Ｒ_４～Ｒ_７は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｄ～ｇは、それぞれ独立に、０～４の整数であり、Ｚ_１は、結合基を示し、そして＊は、結合部を示す｝
で表される構造、及び４，４’－オキシジフタル酸二無水物（ＯＤＰＡ）由来の構造から成る群から選択される少なくとも１種である、項目１２に記載のポリアミド酸－イミド共重合体。
＜１４＞
上記一般式（２）中のＸ_３が、上記一般式（Ａ－３）で表される構造である、項目１３に記載のポリアミド酸－イミド共重合体。
＜１５＞
上記一般式（２）中のＸ_４が、下記一般式（Ａ－４）：

｛式中、Ｒ_８～Ｒ_１１は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｈ～ｋは、それぞれ独立に、０～４の整数であり、Ｚ_２は、結合基を示し、そして＊は、結合部を示す｝
で表される構造、及び下記一般式（Ａ－５）：

｛式中、Ｒ_１２及びＲ_１３は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｌ及びｍは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示し、但し前記Ｘ_３が９，９－ビス（３，４－ジカルボキシフェニル）フルオレン二酸無水物（ＢＰＡＦ）に由来する基である場合は、一般式（Ａ－５）は、４，４’－ジアミノジフェニルスルホンに由来する基を除く｝
で表される構造から成る群から選択される少なくとも１種である、項目１２～１４のいずれか１項に記載のポリアミド酸－イミド共重合体。
＜１６＞
上記一般式（２）中のＸ_１が、ビフェニルテトラカルボン酸二無水物（ＢＰＤＡ）由来の構造を含む、項目１２～１５のいずれか１項に記載のポリアミド酸－イミド共重合体。
＜１７＞
上記一般式（２）中に含まれるＸ_１とＸ_２のモル比（Ｘ_２／Ｘ_１）が、０．８４～１．００であり、かつ上記一般式（２）に含まれるＸ_３とＸ_４（Ｘ_４／Ｘ_３）のモル比が、１．０１～２．００である、項目１２～１６のいずれか１項に記載のポリアミド酸－イミド共重合体。
＜１８＞
上記一般式（２）中のＸ_１及びＸ_２から構成されるポリアミド酸の構成単位とＸ_３及びＸ_４から構成されるポリイミドの構成単位のモル比（構成単位Ｎのモル数：構成単位Ｍのモル数）が、６０：４０～９５：５の範囲である、項目１２～１７のいずれか１項に記載のポリアミド酸－イミド共重合体。
＜１９＞
項目１２～１８のいずれか１項に記載のポリアミド酸－イミド共重合体と、（ｄ）有機溶剤とを含有する、樹脂組成物。
＜２０＞
前記樹脂組成物に含まれる全ポリマーのうち、Ｘ_１とＸ_２から構成されるポリアミド酸の構造単位Ｍの比率が、６０～９５モル％である、項目１９に記載の樹脂組成物。
＜２１＞
更に、（ｅ）イミド化触媒を含む、項目１９又は２０に記載の樹脂組成物。
＜２２＞
前記（ｅ）イミド化触媒が、１－メチルイミダゾールもしくは、Ｎ－Ｂｏｃ－イミダゾールを含む、項目２１に記載の樹脂組成物。
＜２３＞
ポリイミドブロック共重合系高分子の製造方法であって、
ポリアミド酸－イミド共重合体を原料として使用し、
前記ポリアミド酸－イミド共重合体は、下記一般式（２）：

｛式中、Ｘ_１およびＸ_３は、４価の有機基を表し、Ｘ_２およびＸ_４は、２価の有機基を表し、ｎ、ｍ、及びｌは、正の整数であり、Ｘ_１及びＸ_２から構成される構造単位を構造単位Ｎ、そしてＸ_１及びＸ_２から構成される構造単位を構造単位Ｍと呼び、
下記構成１，２を除く：
構成１．Ｘ_３が９，９－ビス（３，４－ジカルボキシフェニル）フルオレン二酸無水物（ＢＰＡＦ）に由来する基である場合は、Ｘ_４が４，４’－ジアミノジフェニルスルホン、及び／又は２，２’―ビス（トリフルオロメチル）ベンジジンに由来する基である；
構成２．Ｘ_３がノルボルナン―２―スピロ―α―シクロペンタノン―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に由来する基である｝
で示される構造単位Ｌを含み、
前記ポリイミドブロック共重合系高分子は、小角Ｘ線散乱測定において、結晶長周期ｄ（ｎｍ）が１２．０ｎｍ以上であり、かつ広角Ｘ線回折測定において、結晶化度が０．１１よりも大きく、
上記一般式（２）中のＸ_２が、下記一般式（Ａ－１）：

｛式中、Ｒ_１及びＲ_２は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ａ及びｂは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示す｝
で表される構造を有する、
ポリイミドブロック共重合系高分子の製造方法。 In order to solve the above problems, the inventors of the present invention conducted extensive research and repeated experiments. As a result, we found that a polyimide block copolymer film that shows a specific scattering pattern has excellent transparency, haze, heat resistance, linear expansion coefficient, and bending resistance. I came up with the invention. That is, the invention is as follows.
<1>
including a polyimide block copolymer polymer,
In wide-angle X-ray diffraction measurement, the degree of crystallinity is greater than 0.11,
The polyimide block copolymer polymer has the following general formula (1):

{Wherein, X ₁ and X ₃ each independently represent a tetravalent organic group, X ₂ and X ₄ each independently represent a divalent organic group, and n and m each independently , is a positive integer, and
Except configuration 1 and 2 below:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or A group derived from 2,2′-bis(trifluoromethyl)benzidine;
Configuration 2. X ₃ is a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride}
and as X ₂ , the following general formula (A-1):

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
having a structure represented by
polyimide film.
<2>
The polyimide film according to Item 1, having a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement.
<3>
Item 1 or item, wherein in the small-angle X-ray scattering measurement, the multiplier B calculated by the scattering intensity I = A x q - ^B formula is 3.6 or less in the range of 0.04 < q < 0.05 2. The polyimide film according to 2.
<4>
4. The polyimide film according to any one of items 1 to 3, which has a haze value of 1.0% or less.
<5>
5. The polyimide film according to any one of items 1 to 4, wherein the degree of crystallinity is less than 0.21.
<6>
In the general formula (1), the X ₃ is represented by the following general formula (A-3):

{wherein R ₄ to R ₇ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; d to g each independently represent an integer of 0 to 4; ₁ indicates a linking group and * indicates a linking point}
The polyimide film according to any one of items 1 to 5, which is at least one selected from the group consisting of a structure represented by and a structure derived from 4,4'-oxydiphthalic dianhydride (ODPA). .
<7>
In the general formula (1), the X ₃ is represented by the following general formula (A-3):

{wherein R ₄ to R ₇ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; d to g each independently represent an integer of 0 to 4; ₁ indicates a linking group and * indicates a linking point}
The polyimide film according to any one of items 1 to 6, which is a structure represented by.
<8>
X ₄ in the above general formula (1) is represented by the following general formula (A-4):

{Wherein, R ₈ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; ₂ indicates the linking group and * indicates the linking point}
and the following general formula (A-5):

{wherein R ₁₂ and R ₁₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; l and m each independently represent an integer of 0 to 4; * indicates a bond, provided that when X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), general formula (A-5 ) excludes groups derived from 4,4′-diaminodiphenylsulfone}
The polyimide film according to any one of items 1 to 7, which is at least one selected from the group consisting of structures represented by.
<9>
The polyimide film according to any one of items 1 to 8, wherein X ₁ in the general formula (1) contains a structure derived from biphenyltetracarboxylic dianhydride (BPDA).
<10>
The molar ratio (X ₂ /X ₁ ) between X ₁ and X ₂ contained in the general formula (1) is 0.84 to 1.00, and X ₃ contained in the general formula (2) and X ₄ (X ₄ /X ₃ ) in a molar ratio of 1.01 to 2.00, the polyimide film according to any one of items 1 to 9.
<11>
The molar ratio of the polyimide structural units composed of X ₁ and X ₂ and the polyimide structural units composed of X ₃ and X ₄ in the general formula (1) (number of moles of structural unit N: number of structural units M number of moles) is in the range of 60:40 to 95:5, the polyimide film according to any one of items 1 to 10.
<12>
A polyamic acid-imide copolymer represented by the following general formula (2):

{Wherein, X ₁ and X ₃ represent a tetravalent organic group, X ₂ and X ₄ represent a divalent organic group, n, m, and l are positive integers, and X ₁ and X ₂ is called structural unit N, and the structural unit made up of X ₁ and X ₂ is called structural unit M,
Except configuration 1 and 2 below:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or 2 , a group derived from 2′-bis(trifluoromethyl)benzidine;
Configuration 2. X ₃ is a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride}
Including a structural unit L represented by
When cured, the polyamic acid-imide copolymer has a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement, and a crystallinity of 0.11 in wide-angle X-ray diffraction measurement. characterized by being greater than
X ₂ in the above general formula (2) is represented by the following general formula (A-1):

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
has a structure represented by
The diamine component constituting X ₂ and the diamine component constituting X ₄ in the general formula (2) are different in either the diamine composition or the diamine species,
Polyamic acid-imide copolymer.
<13>
X ₃ in the above general formula (2) is represented by the following general formula (A-3):

{wherein R ₄ to R ₇ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; d to g each independently represent an integer of 0 to 4; ₁ indicates a linking group and * indicates a linking point}
The polyamic acid-imide copolymer according to item 12, which is at least one selected from the group consisting of a structure represented by and a structure derived from 4,4'-oxydiphthalic dianhydride (ODPA).
<14>
14. The polyamic acid-imide copolymer according to item 13, wherein X ₃ in general formula (2) is a structure represented by general formula (A-3).
<15>
X ₄ in the above general formula (2) is represented by the following general formula (A-4):

{Wherein, R ₈ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; ₂ indicates the linking group and * indicates the linking point}
and the following general formula (A-5):

{wherein R ₁₂ and R ₁₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; l and m each independently represent an integer of 0 to 4; * indicates a bond, provided that when X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), general formula (A-5 ) excludes groups derived from 4,4′-diaminodiphenylsulfone}
The polyamic acid-imide copolymer according to any one of items 12 to 14, which is at least one selected from the group consisting of structures represented by.
<16>
The polyamic acid-imide copolymer according to any one of items 12 to 15, wherein X ₁ in the general formula (2) contains a structure derived from biphenyltetracarboxylic dianhydride (BPDA).
<17>
The molar ratio (X ₂ /X ₁ ) of X ₁ and X ₂ contained in the general formula (2) is 0.84 to 1.00, and X ₃ and X 3 contained in the general formula (2) 17. The polyamic acid-imide copolymer according to any one of items 12 to 16, wherein the molar ratio of X ₄ (X ₄ /X ₃ ) is from 1.01 to 2.00.
<18>
The molar ratio of polyamic acid structural units composed of X ₁ and X ₂ and polyimide structural units composed of X ₃ and X ₄ in the general formula (2) (number of moles of structural unit N: structural unit M ) is in the range of 60:40 to 95:5, the polyamic acid-imide copolymer according to any one of items 12 to 17.
<19>
A resin composition comprising the polyamic acid-imide copolymer according to any one of items 12 to 18 and (d) an organic solvent.
<20>
20. The resin composition according to item 19, wherein the proportion of the polyamic acid structural unit M composed of X ₁ and X ₂ in the total polymer contained in the resin composition is 60 to 95 mol %.
<21>
21. The resin composition according to item 19 or 20, further comprising (e) an imidization catalyst.
<22>
22. The resin composition according to item 21, wherein the (e) imidization catalyst contains 1-methylimidazole or N-Boc-imidazole.
<23>
A method for producing a polyimide block copolymer polymer, comprising:
Using a polyamic acid-imide copolymer as a raw material,
The polyamic acid-imide copolymer has the following general formula (2):

{Wherein, X ₁ and X ₃ represent a tetravalent organic group, X ₂ and X ₄ represent a divalent organic group, n, m, and l are positive integers, and X ₁ and X ₂ is called structural unit N, and the structural unit made up of X ₁ and X ₂ is called structural unit M,
Except configuration 1 and 2 below:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or 2 , a group derived from 2′-bis(trifluoromethyl)benzidine;
Configuration 2. X ₃ is a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride}
Including a structural unit L represented by
The polyimide block copolymer polymer has a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement, and a crystallinity greater than 0.11 in wide-angle X-ray diffraction measurement. ,
X ₂ in the above general formula (2) is represented by the following general formula (A-1):

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
having a structure represented by
A method for producing a polyimide block copolymer polymer.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polyimide block copolymer film having good transparency, heat resistance and bending resistance, as well as its raw material, resin composition and production method.

1 is a one-dimensional WAXS profile of Example 1-1 and Comparative Example 4; It is an example of a crystalline peak and an amorphous peak in WAXS peak fitting. 7 is a graph for calculating a multiplier B from the relationship between the SAXS scattering intensity I and the scattering vector q in Example 1-1 and Comparative Example 3. FIG. 2 is a graph plotting Iq^2 against q in order to calculate the crystal long period d in SAXS of Example 1-1 and Comparative Example 2. FIG.

Exemplary embodiments of the present invention (hereinafter abbreviated as "present embodiments") will be described in detail below. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention. In addition, unless otherwise specified, the characteristic values described in the present disclosure are values measured by the method described in the [Examples] section or a method understood to be equivalent thereto by a person skilled in the art. Intend.

<Resin composition>
First, a polyamic acid-imide block copolymer resin composition for forming a polyimide film containing the polyimide block copolymer polymer of the present embodiment will be described. The polyamic acid-imide block copolymer resin composition according to the present embodiment contains a polyamic acid-imide block copolymer.

The polyamic acid-imide block copolymer resin composition provided by one aspect of the present invention comprises (a) a polyamic acid and (b) a polyimide, (c) a polyamic acid-imide copolymer, and (d) an organic It contains a solvent and (e) an imidization catalyst.

Each component will be described in order below.

｛式中、Ｘ_１及びＸ_３は、それぞれ独立に、４価の有機基を表し、Ｘ_２及びＸ_４は、それぞれ独立に、２価の有機基を表し、ｎ、ｍ及びｌは、それぞれ独立に、正の整数であり、Ｘ_１及びＸ_２から構成される構造単位を構造単位Ｎと呼び、そしてＸ_１及びＸ_２から構成される構造単位を構造単位Ｍと呼ぶ｝
で示される構造単位Ｌを含むポリアミド酸－イミド共重合体を提供する。 A first embodiment of the present disclosure is represented by the following general formula (2):

{Wherein, X ₁ and X ₃ each independently represent a tetravalent organic group, X ₂ and X ₄ each independently represent a divalent organic group, n, m and l each independently independently, a structural unit which is a positive integer and is composed of X ₁ and X ₂ is referred to as structural unit N, and a structural unit composed of X ₁ and X ₂ is referred to as structural unit M}
provides a polyamic acid-imide copolymer comprising a structural unit L represented by

｛式中、Ｒ_１及びＲ_２は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ａ及びｂは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示す｝
で表される構造を有することが好ましい。 X ₂ in the above general formula (2) is the following general formula (A-1) from the viewpoint of the haze degree of the obtained polyimide block copolymer film or polyimide film:

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
It is preferable to have a structure represented by

When the polyamic acid-imide copolymer according to the first embodiment is cured (cured), the crystal long period d (nm ) is 12.0 nm or more, and/or the crystallinity is greater than 0.11 in wide-angle X-ray diffraction measurement.

The polyamic acid-imide copolymer (hereinafter sometimes referred to as a polyimide precursor) according to the first embodiment has a low linear expansion coefficient, a low residual stress, and a haze value (Haze value) when made into a polyimide film. and low yellowness index (YI value). In addition, the polyamic acid-imide copolymer according to the first embodiment has a small yellowness (YI value) in a high temperature region, a small haze (Haze value), and a bending resistance when made into a polyimide film. Excellent for From this point of view, the polyamic acid-imide copolymer preferably excludes the following structures 1 and 2:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or A group derived from 2,2′-bis(trifluoromethyl)benzidine;
Configuration 2. X3 is a group derived from norbornane- ₂ -spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride.

(a) <Embodiment of polyamic acid moiety>
The polyamic acid portion constituting the polyamic acid-imide copolymer of the present invention is the portion represented by the structural unit N in the general formula (2).

In the general formula (2), X ₁ is a tetravalent organic group, and multiple X ₁ 's present in the polyimide precursor may be the same or different. X ₁ is exemplified by a tetravalent organic group derived from the following tetracarboxylic dianhydride.

The tetracarboxylic dianhydrides include aromatic tetracarboxylic dianhydrides having 8 to 36 carbon atoms, aliphatic tetracarboxylic dianhydrides having 6 to 50 carbon atoms, and 6 to 36 carbon atoms. can be exemplified by alicyclic tetracarboxylic dianhydrides. Among these, aromatic tetracarboxylic dianhydrides having 8 to 36 carbon atoms are preferred from the viewpoint of yellowness in a high temperature range. The number of carbon atoms as used herein also includes the number of carbon atoms contained in the carboxyl group.

Examples of the aromatic tetracarboxylic dianhydride having 8 to 36 carbon atoms include 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (hereinafter also referred to as 6FDA), 5-(2,5- dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2 dicarboxylic anhydride, pyromellitic dianhydride (hereinafter also referred to as PMDA), 1,2,3,4-benzenetetracarboxylic acid di anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 2,2′,3,3′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-biphenyl Tetracarboxylic dianhydride (hereinafter also referred to as BPDA), 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride (hereinafter also referred to as DSDA), 2,2′,3,3′- Biphenyltetracarboxylic dianhydride, methylene-4,4-diphthalic dianhydride, 1,1-ethylidene-4,4'-diphthalic dianhydride, 2,2-propylidene-4,4'-diphthalic dianhydride anhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic acid dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride (hereinafter also referred to as ODPA), p-phenylenebis(trimellitate anhydride ) (hereinafter also referred to as TAHQ) thio-4,4′-diphthalic dianhydride, sulfonyl-4,4′-diphthalic dianhydride, 1,3-bis(3,-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-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride and 1,2,7,8-phenanthrenetetracarboxylic dianhydride.

Examples of aliphatic tetracarboxylic dianhydrides having 6 to 50 carbon atoms include ethylenetetracarboxylic dianhydride and 1,2,3,4-butanetetracarboxylic dianhydride.

Alicyclic tetracarboxylic dianhydrides having 6 to 36 carbon atoms, such as 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2 ,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclopentanonebisspironorbornanetetracarboxylic dianhydride (hereinafter also referred to as CPODA), 3 ,3′,4,4′-bicyclohexyltetracarboxylic dianhydride, carbonyl-4,4′-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4′-bis(cyclohexane -12-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethylidene-4,4'-bis(cyclohexane -1,2-dicarboxylic acid) dianhydride, 2,2-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1 ,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, REL-[1S,5R,6R]-3-oxabicyclo[3, 2] octane-2,4-dione-6-spiro-3′-(tetrahydrofuran-2′,5′dione), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3, 4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, ethylene glycol-bis-3,4-dicarboxylic anhydride (phenyl)ether and the like.

In one preferred embodiment, X ₁ is pyromellitic dianhydride (PMDA), biphenyltetracarboxylic dianhydride (BPDA), 4,4′-biphenylbis(trimellitic monoester anhydride) (TAHQ) , 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4′ - derived from at least one selected from the group consisting of oxydiphthalic anhydride (ODPA) and cyclopentanonebisspironorbornanetetracarboxylic dianhydride (CPODA).

PMDA, BPDA, DSDA, TAHQ, ODPA, and CPODA are preferable from the viewpoint of the balance of coefficient of linear expansion (CTE), chemical resistance, glass transition temperature (Tg), and yellowness in a high-temperature region, and BPDA, TAHQ, and ODPA. is preferred, and BPDA is more preferred.

The polyimide precursor in the present embodiment may be obtained by using a dicarboxylic acid in addition to the above-mentioned tetracarboxylic dianhydride within a range that does not impair its performance. By using such a precursor, it is possible to adjust various performances such as improvement in mechanical elongation, improvement in glass transition temperature and reduction in yellowness in the resulting film. Such dicarboxylic acids include dicarboxylic acids having aromatic rings and alicyclic dicarboxylic acids. At least one compound selected from the group consisting of aromatic dicarboxylic acids having 8 to 36 carbon atoms and alicyclic dicarboxylic acids having 6 to 34 carbon atoms is particularly preferred. The number of carbon atoms as used herein also includes the number of carbon atoms contained in the carboxyl group. Among these, dicarboxylic acids having an aromatic ring are preferred.

Specifically, for example, isophthalic acid, terephthalic acid, 4,4′-biphenyldicarboxylic acid, 3,4′-biphenyldicarboxylic acid, 3,3′-biphenyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,3 -naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-sulfonylbisbenzoic acid, 3,4'-sulfonylbisbenzoic acid, 3,3'-sulfonylbisbenzoic acid , 4,4′-oxybisbenzoic acid, 3,4′-oxybisbenzoic acid, 3,3′-oxybisbenzoic acid, 2,2-bis(4-carboxyphenyl)propane, 2,2-bis(3-carboxy phenyl)propane, 2,2'-dimethyl-4,4'-biphenyldicarboxylic acid, 3,3'-dimethyl-4,4'-biphenyldicarboxylic acid, 2,2'-dimethyl-3,3'-biphenyldicarboxylic acid acid, 9,9-bis(4-(4-carboxyphenoxy)phenyl)fluorene, 9,9-bis(4-(3-carboxyphenoxy)phenyl)fluorene, 4,4'-bis(4-carboxyphenoxy) Biphenyl, 4,4'-bis(3-carboxyphenoxy)biphenyl, 3,4'-bis(4-carboxyphenoxy)biphenyl, 3,4'-bis(3-carboxyphenoxy)biphenyl, 3,3'-bis (4-carboxyphenoxy)biphenyl, 3,3′-bis(3-carboxyphenoxy)biphenyl, 4,4′-bis(4-carboxyphenoxy)-p-terphenyl, 4,4′-bis(4-carboxy phenoxy)-m-terphenyl, 3,4′-bis(4-carboxyphenoxy)-p-terphenyl, 3,3′-bis(4-carboxyphenoxy)-p-terphenyl, 3,4′-bis (4-carboxyphenoxy)-m-terphenyl, 3,3′-bis(4-carboxyphenoxy)-m-terphenyl, 4,4′-bis(3-carboxyphenoxy)-p-terphenyl, 4, 4'-bis(3-carboxyphenoxy)-m-terphenyl, 3,4'-bis(3-carboxyphenoxy)-p-terphenyl, 3,3'-bis(3-carboxyphenoxy)-p-terphenyl Phenyl, 3,4'-bis(3-carboxyphenoxy)-m-terphenyl, 3,3'-bis(3-carboxyphenoxy)-m-terphenyl, 1,1-cyclobutanedicarboxylic acid, 1,4- cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4,4′-benzophenonedicarboxylic acid, 1,3-phenylenediacetic acid, 1,4-phenylenediacetic acid, etc.; and acid derivatives. When these dicarboxylic acids are actually copolymerized with a polymer, they may be used in the form of acid chlorides or active esters derived from thionyl chloride or the like.

In the above general formula (2), X ₂ is a divalent organic group, preferably the structures represented by the following general formulas (A-1) and (B-1), or BAFL, BFAF, Structures derived from BAOFL, 44DAS, and 33DAS. X ₂ is preferably a structure derived from 4-aminophenyl-4-aminobenzoate from the viewpoint of yellowness (YI value) in a high temperature region, and 4-amino-3- from the viewpoint of haze (HAZE value). Structures derived from fluorophenyl-4-aminobenzoate (APAB), paraphenylenediamine (pPD), BAFL, and BFAF are preferred.

｛式中、Ｒ_１及びＲ_２は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ａ及びｂは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示す｝
で表される。Ｘ_２として式（Ａ－１）で表される構造を用いて得られるポリイミドブロック共重合系高分子又はポリイミドフィルムは、曇り度に優れる傾向がある。 In one aspect, the structure of X ₂ in general formula (2) is the following general formula (A-1):

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
is represented by Polyimide block copolymer polymers or polyimide films obtained by using the structure represented by formula (A- ₁ ) as X2 tend to be excellent in haze.

Here, R ₁ and R ₂ are not limited as long as they are each independently a monovalent organic group having 1 to 20 carbon atoms, hydrogen, or halogen. Examples of such organic groups include alkyl groups such as methyl group, ethyl group and propyl group, halogen-containing groups such as trifluoromethyl group, alkoxy groups such as methoxy group and ethoxy group, hydrogen or fluorine. Among these, hydrogen and a phenyl group are preferred from the viewpoint of yellowness (YI value) in a high temperature range, and hydrogen, a methyl group and fluorine are preferred from the viewpoint of cloudiness (Haze value).

Here, a and b are not limited as long as they are integers from 0 to 4 respectively. Among these, an integer of 0 to 2 is preferable from the viewpoint of yellowness (YI value) and residual stress, and 0 is particularly preferable from the viewpoint of yellowness (YI value) in a high temperature region.

｛式中、Ｒ_１、Ｒ_２、ａ及びｂは、一般式（Ａ－１）と同様に定義される。｝
で表されるジアミンに由来する。 In one embodiment, the structural unit represented by general formula (A-1) has the following general formula (B-1):

{In the formula, R ₁ , R ₂ , a and b are defined in the same manner as in general formula (A-1). }
Derived from the diamine represented by

As the diamine represented by the general formula (B-1), more specifically, 4-aminophenyl-4-aminobenzoate (hereinafter also referred to as APAB) and 2-methyl-4-aminophenyl-4-aminobenzoate (hereinafter also referred to as 2Me-APAB), 3-methyl-4-aminophenyl-4-aminobenzoate (hereinafter also referred to as 3Me-APAB), 2-fluoro-4-aminophenyl-4-aminobenzoate (hereinafter referred to as 2F -APAB), 3-fluoro-4-aminophenyl-4-aminobenzoate (hereinafter also referred to as 3F-APAB), 3-methyl-4-aminophenyl-3-methyl-4-aminobenzoate (hereinafter referred to as 3 , also referred to as 3Me-APAB), etc., and from the viewpoint of yellowness (YI value) in a high temperature region, APAB is preferable, and from the viewpoint of reducing haze (Haze value), APAB, 3Me- APAB, 3F-APAB are preferred.

The polyamic acid, polyimide, polyamic acid-imide copolymer, and polyimide copolymer in the first and second embodiments are each represented by the general formula ( In addition to the diamine represented by B-1), other diamines can also be used.

Other diamines include, for example, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl , 3,3′-diaminobiphenyl, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′-diaminobenzophenone, 4,4′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 3 ,3′-diaminodiphenylmethane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4- (4-aminophenoxy)phenyl]sulfone, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis(4-aminophenyl ) anthracene, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl)propane, 2 , 2-bis[4-(4-aminophenoxy)phenyl)hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, etc., and one selected from these It is preferred to use the above. The content of the other diamines in the total diamine is preferably 20 mol % or less, particularly preferably 10 mol % or less. On the other hand, from the viewpoint of heat resistance at high temperatures, it is preferable not to contain a silicone diamine. For example, commercially available products such as “X-22-9409” and “X-22-1660B-3” manufactured by Shin-Etsu Chemical Co., Ltd. can be mentioned.

The molar ratio (X ₂ /X ₁ ) between X ₁ and X ₂ in the polyamic acid contained in the general formula (2) in the present embodiment is 0.84 to 1.00 or 0.85 to 1.2. It is preferably from 0.90 to 1.1, and even more preferably from 0.92 to 1,00. When X ₂ /X ₁ is 0.84 or more, residual stress is low and YI is low. When X ₂ /X ₁ is 1.2 or less or 1.00 or less, the mechanical properties such as elongation and breaking strength are excellent.

The weight average molecular weight (Mw) of the polyamic acid in this embodiment is preferably 1,000 to 300,000, particularly preferably 10,000 to 200,000. When the weight average molecular weight is 10,000 or more, the mechanical properties such as elongation and breaking strength are excellent, the residual stress is low, and the YI is low. When the weight-average molecular weight is 300,000 or less, the weight-average molecular weight can be easily controlled during the synthesis of the polyamic acid, a resin composition having an appropriate viscosity can be obtained, and the coating properties of the resin composition are improved. In the present disclosure, the weight average molecular weight is a value obtained as a standard polystyrene conversion value using gel permeation chromatography (hereinafter also referred to as GPC).

(b) <Embodiment of polyimide part>
The polyimide moiety constituting the polyamic acid-imide copolymer of the present invention is the moiety represented by the structural unit M in the general formula (2).

In the general formula (2), X ₃ is a tetravalent organic group, preferably the structure represented by the following general formula (A-3), or 4,4'-oxydiphthalic dianhydride (ODPA ), and the tetravalent organic group derived from the tetracarboxylic dianhydride described in <Embodiment of polyamic acid moiety> can be used. In addition, a plurality of _X3s present in the polyimide precursor may be the same or different from _each other, and may be the same as or different from X1.

As X3 _, a structure derived from BPAF is preferable from the viewpoint of yellowness (YI value) in a high temperature region, and a structure derived from ODPA is preferable from the viewpoint of residual stress.

｛式中、Ｒ_４～Ｒ_７は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｄ～ｇは、それぞれ独立に、０～４の整数であり、Ｚ_１は、結合基を示し、そして＊は、結合部を示す｝
で表される構造、又は４，４’－オキシジフタル酸二無水物（ＯＤＰＡ）に由来する構造である。中でも、Ｘ_３として式（Ａ－３）で表される構造を用いて得られるポリイミドブロック共重合系高分子又はポリイミドフィルムは、黄色度と折曲耐性に優れる傾向がある。 In one aspect, the structure of X ₃ in general formula (2) is the following general formula (A-3):

{wherein R ₄ to R ₇ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; d to g each independently represent an integer of 0 to 4; ₁ indicates a linking group and * indicates a linking point}
or a structure derived from 4,4′-oxydiphthalic dianhydride (ODPA). Among them, the polyimide block copolymer polymer or polyimide film obtained by using the structure represented by the formula (A-3) as X ₃ tends to be excellent in yellowness and bending resistance.

Here, each of R ₄ to R ₇ is not limited as long as it is independently a monovalent organic group having 1 to 20 carbon atoms, hydrogen, or halogen. Examples of such organic groups include alkyl groups such as methyl group, ethyl group and propyl group, halogen-containing groups such as trifluoromethyl group, alkoxy groups such as methoxy group and ethoxy group, hydrogen or fluorine. Among these, hydrogen is preferable from the viewpoint of yellowness (YI value) in a high temperature range, and fluorine is preferable from the viewpoint of haze (Haze value).

Here, Z ₁ can be exemplified by single bond, methylene group, ethylene group, ether, ketone and the like. Among these, a single bond is more preferable from the viewpoint of YI in a high temperature region, and a single bond and an ether are preferable from the viewpoint of residual stress.

Here, d to g are not limited as long as they are integers of 0 to 4, respectively. Among these, an integer of 0 to 2 is preferable from the viewpoint of yellowness (YI value) and residual stress, and 0 is particularly preferable from the viewpoint of yellowness (YI value) in a high temperature region.

｛式中、Ｒ_４～Ｒ_７、ｄ～ｇ、Ｚ_１は、一般式（Ａ－３）と同様に定義される｝
で表される酸二無水物に由来する。 In one embodiment, the structural unit represented by general formula (A-2) has the following general formula (B-3):

{Wherein, R ₄ to R ₇ , d to g, and Z ₁ are defined in the same manner as in general formula (A-3)}
Derived from the acid dianhydride represented by.

As the diamine represented by the general formula (B-3), more specifically, 9,9-bis(3,4-dicarboxyphenyl)fluorene diacid anhydride (BPAF), 9,9-bis[4 -(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride (BPF-PA) and the like can be exemplified, and from the viewpoint of reducing the haze (Haze value) and high temperature range, BPAF is preferable residual stress BPAF and BPF-PA are preferred from the viewpoint of

In the general formula (2), X ₄ is a divalent organic group, preferably a structure represented by the following general formula (A-4) or (A-5), the <polyamic acid moiety Embodiment>, a divalent organic group derived from the diamine described in the above section can be used. In addition, a plurality of X ₄ present in the polyimide may be the same or different from each other, but from the viewpoint of achieving both heat resistance and transparency, which are contradictory properties, they are different from X ₂ . is preferred.

｛式中、Ｒ_８～Ｒ_１１は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｈ～ｋは、それぞれ独立に、０～４の整数であり、そしてＺ_２は、結合基を示し、そして＊は、結合部を示す｝ In one aspect, the structure of X ₄ in general formula (2) is the following general formula (A-4):

{wherein R ₈ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen, h to k each independently represent an integer of 0 to 4, and Z ₂ indicates the linking group and * indicates the linking point}

Here, R ₈ to R ₁₁ are not limited as long as they are each independently a monovalent organic group having 1 to 20 carbon atoms, hydrogen, or halogen. Examples of such organic groups include alkyl groups such as methyl group, ethyl group and propyl group, halogen-containing groups such as trifluoromethyl group, alkoxy groups such as methoxy group and ethoxy group, hydrogen or fluorine. Among these, hydrogen is preferable from the viewpoint of yellowness (YI value) in a high temperature range, and fluorine is preferable from the viewpoint of haze (Haze value).

Here, h to k are not limited as long as they are integers from 0 to 4, respectively. Among these, an integer of 0 to 2 is preferable from the viewpoint of yellowness (YI value) and residual stress, and 0 is particularly preferable from the viewpoint of yellowness (YI value) in a high temperature region.

Z2 can be exemplified by _single bond, methylene group, ethylene group, ether, ketone and the like. Among these, a single bond is more preferable from the viewpoint of YI in a high temperature region.

｛式中、Ｒ_１２及びＲ_１３は、それぞれ独立に、炭素数１～２０の１価の有機基、又はハロゲンを表し、ｌ及びｍは、それぞれ独立に、０～４の整数であり、そして＊は、結合部を示し、但し前記Ｘ_３が９，９－ビス（３，４－ジカルボキシフェニル）フルオレン二酸無水物（ＢＰＡＦ）に由来する基である場合は、一般式（Ａ－５）は、４，４’－ジアミノジフェニルスルホンに由来する基を除く｝
で表されるジアミンに由来する。 In one aspect, the structure of X ₄ in general formula (2) is the following general formula (A-5):

{wherein R ₁₂ and R ₁₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; l and m each independently represent an integer of 0 to 4; * indicates a bond, provided that when X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), general formula (A-5 ) excludes groups derived from 4,4′-diaminodiphenylsulfone}
Derived from the diamine represented by

Here, R ₁₂ and R ₁₃ are not limited as long as they are each independently a monovalent organic group having 1 to 20 carbon atoms. Examples of such organic groups include alkyl groups such as methyl group, ethyl group and propyl group; halogen-containing groups such as trifluoromethyl group; aryl groups such as phenyl group and naphthyl group; alkoxy groups such as methoxy group and ethoxy group; etc. Among these, a methyl group is preferable from the viewpoint of YI in a high temperature range.

Here, l and m are not limited as long as they are integers from 0 to 4. Among these, an integer of 0 to 2 is preferable from the viewpoint of YI and residual stress, and 0 is particularly preferable from the viewpoint of YI in a high temperature region.

｛式中、Ｒ_８～Ｒ_１１及びｈ～ｋは、一般式（Ａ－４）と同様に定義される｝
で表されるジアミンに由来する。 In one aspect, the structural unit represented by general formula (A-4) has the following general formula (B-4):

{Wherein, R ₈ to R ₁₁ and h to k are defined in the same manner as in general formula (A-4)}
Derived from the diamine represented by

As the diamine represented by the general formula (B-3), more specifically, 9,9-bis(4-aminophenyl)fluorene (BAFL), 9,9-bis(3-fluoro-4-aminophenyl ) fluorene (BFAF), 9,9-bis (4- (aminophenoxy) phenyl) fluorene (BAOFL), etc. can be exemplified, and from the viewpoint of yellowness at high temperature (YI value), BFAF is preferable, cloudy BAFL is preferable from the viewpoint of decreasing the degree (haze value).

又は下記一般式（Ｂ－５－２）：

｛式中、Ｒ_１２およびＲ_１３、並びにｌおよびｍは、一般式（Ａ－５）と同様に定義される｝
で表されるジアミンなどに由来する（但し、Ｘ_３が９，９－ビス（３，４－ジカルボキシフェニル）フルオレン二酸無水物（ＢＰＡＦ）に由来する基である場合は、Ｘ_４は、前記一般式（Ｂ－５－１）である場合を除く）。 Further, in one aspect, the structural unit represented by general formula (A-5) has the following general formula (B-5-1):

Or the following general formula (B-5-2):

{Wherein, R ₁₂ and R ₁₃ , l and m are defined in the same manner as in general formula (A-5)}
(However, when X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is Except for the case of general formula (B-5-1).

As diamines represented by general formulas (B-5-1) and (B-5-2), more specifically, 4,4′-diaminodiphenylsulfone (44DAS) and 3,3′-diaminodiphenylsulfone (33 DAS) can be exemplified. More specific examples of other diamines include bis[4-(4-aminophenoxy)phenyl]sulfone and bis[4-(3-aminophenoxy)phenyl]sulfone. 44 DAS is preferable from the viewpoint of yellowness (YI value) at high temperature, and 33 DAS is preferable from the viewpoint of low residual stress.

The weight average molecular weight (Mw) of the polyimide in this embodiment is preferably 1,000 to 100,000, more preferably 2,639 to 80,000, and particularly preferably 5,000 to 60,000. When the weight average molecular weight is 1,000 or more, the mechanical properties such as elongation and breaking strength are excellent, the residual stress is low, and the YI is low. When the weight-average molecular weight is 60,000 or less, phase separation is suppressed when a polyamic acid-imide copolymer film is formed, resulting in a low haze (HAZE value). In the present disclosure, the weight average molecular weight is a value obtained as a standard polystyrene conversion value using gel permeation chromatography (hereinafter also referred to as GPC).

In the polyimide or its precursor in the present embodiment, the molar ratio of X ₃ and X ₄ (X ₄ /X ₃ ) contained in the general formula (2) is preferably 0.85 to 2.0, It is more preferably 0.95 to 1.5 or 1.01 to 2.00, more preferably 1.01 to 1.25. When the molar ratio is 0.85 or more, the heat resistance in the high temperature range is excellent and the YI value is low. When the molar ratio is 2.0 or less, the reactivity with the polyamic acid moiety is improved, and the strength when formed into a film is increased, resulting in excellent mechanical properties such as elongation and breaking strength.

The content of molecules having a molecular weight of less than 1,000 in the polyimide or its precursor in the present embodiment is less than 5% by mass with respect to the total amount of the copolymer when converted to a polyamic acid-imide copolymer. preferably less than 1% by mass, more preferably less than 0.1% by mass. A polyimide film formed from a resin composition obtained using such a polyamic acid-imide copolymer has low residual stress, and the haze value formed on the polyimide film is low. The content of molecules having a molecular weight of less than 1,000 with respect to the total amount of the polyamic acid-imide copolymer can be calculated from the peak area obtained by GPC measurement using a solution in which the polyimide is dissolved.

The polyimide precursors in the first aspect and the second aspect have the above-described general formulas (B-1) to (B-5-2) within a range that does not impair elongation, strength, stress, yellowness, etc. In addition to the diamine represented by, other diamines can be used. Other diamines include, for example, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl , 3,3′-diaminobiphenyl, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′-diaminobenzophenone, 4,4′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 3 ,3′-diaminodiphenylmethane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4- (4-aminophenoxy)phenyl]sulfone, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis(4-aminophenyl ) anthracene, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl)propane, 2 , 2-bis[4-(4-aminophenoxy)phenyl)hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, etc., and at least one selected from these is preferably used.

The content of the other diamine in the total diamine is preferably 20 mol % or less, particularly preferably 10 mol % or less. From the viewpoint of heat resistance at high temperatures, it is also preferable for this to contain no silicone _- based diamine, as with X2.

(c) <Embodiment of polyamic acid-imide copolymer>
The polyamic acid-imide copolymer of the present invention contains a structural unit M that is a polyamic acid moiety represented by the general formula (2) and a structural unit L that includes a structural unit N that is a polyimide moiety. Embodiments are shown below.

The diamine (X ₂ ) of the polyamic acid portion and the diamine (X ₄ ) of the polyimide portion may have the same composition or diamine species, or may have different compositions or diamine species. The term "same composition" as used herein means that, when the diamine used in the polyamic acid portion is composed of one or more types, the diamines in the polyimide portion have exactly the same composition. On the other hand, the "different composition" here means that when the diamine used in the polyamic acid portion is composed of one or more types, the diamine in the polyimide portion does not have exactly the same composition, but is composed of different diamines or the same This means that the ratios would be different even if more diamines were used.

The role of the polyamic acid moiety in one aspect of the present invention is to have high thermal stability and excellent dimensional stability in a high temperature range, high molecular planarity, and high heat resistance at high temperatures when made into a polyimide. A high skeleton is preferred.

As the acid dianhydride (X ₁ ) of the polyamic acid moiety, pyromellitic dianhydride (PMDA), biphenyltetracarboxylic dianhydride ( BPDA), 4,4′-biphenylbis(trimellitic monoester anhydride) (TAHQ), 9,9-bis(3,4-dicarboxyphenyl)fluorene diacid anhydride (BPAF), 3,3 consisting of ',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'-oxydiphthalic anhydride (ODPA), and cyclopentanonebisspironorbornanetetracarboxylic dianhydride (CPODA) It is derived from at least one species selected from the group.

PMDA, BPDA, DSDA, TAHQ, ODPA, and CPODA are preferable from the viewpoint of the balance of coefficient of linear expansion (CTE), chemical resistance, glass transition temperature (Tg), and yellowness in a high-temperature region, and BPDA, TAHQ, and ODPA. is more preferred, and BPDA is even more preferred. In addition to the acid dianhydrides shown above, X ₁ may be obtained by using a dicarboxylic acid in addition to the above-mentioned tetracarboxylic dianhydride within a range that does not impair its performance. Other tetracarboxylic dianhydrides may be added, but a skeleton derived from an aromatic tetracarboxylic dianhydride or an aromatic dicarboxylic acid is preferred. The _ratio of other acid dianhydrides and dicarboxylic acids in X1 is preferably 20 mol % or less, and preferably 10 mol % or less.

Examples of the diamine (X ₂ ) of the polyamic acid moiety include (4-aminophenyl-4-aminobenzoate (APAB), 2-methyl-4-aminophenyl-4-aminobenzoate, 3-methyl-4-aminophenyl- 4-aminobenzoate, 2-fluoro-4-aminophenyl-4-aminobenzoate (2F-APAB), 3-fluoro-4-aminophenyl-4-aminobenzoate (3F-APAB), 3-methyl-4-amino It is preferably at least one selected from the group consisting of phenyl-3-methyl-4-aminobenzoate, (2-phenyl-4-aminophenyl)-4-aminobenzoate (ph-APAB), and the coefficient of linear expansion ( CTE), chemical resistance, glass transition temperature (Tg), and yellowness in the high-temperature region, APAB, 2F-APAB, 3F-APAB, and Ph-APAB are preferable, and APAB is more preferable.X ₂ As, in addition to the acid dianhydrides shown above, other diamines may be added to the extent that their performance is not impaired, but they should be aromatic diamines that do not contain cyclohexane rings or cyclopentane rings. The ratio of other diamines in X ₂ is preferably 20 mol % or less, preferably ₁₀ mol % or less. Although it is preferable that they do not contain any structure, this is not the case unless they have exactly the same composition.

As the role of the imide moiety in one aspect of the present invention, a skeleton having high thermal stability in a high temperature range, excellent optical properties, and high solubility in a solvent is preferable.

As the acid dianhydride (X ₃ ) of the polyimide portion, a tetravalent organic group derived from a tetracarboxylic dianhydride can be used as described in (b) <Embodiment of polyimide portion>. In addition, a plurality of _X3s present in the polyimide precursor may be the same or different from _each other, and may be the same as or different from X1. X ₃ preferably includes a structure derived from BPAF from the viewpoint of excellent yellowness (YI value) and haze (Haze value) in a high-temperature region, and a structure derived from ODPA is preferable from the viewpoint of residual stress. . When using a skeleton derived from BPAF, a skeleton selected from PMDA, BPDA, DSDA, TAHQ, and ODPA can be used at the same time for the purpose of improving thermal stability in a high temperature range. Among them, it is more preferable to contain a skeleton selected from BPDA and TAHQ. The proportion of _BPAF in X3 is preferably 40 mol% or more, preferably 50 mol% or more, more preferably 70 mol% or more, and may be 100 mol%.

As the diamine of the imide portion, a divalent organic group derived from diamine can be used as described in (b) <Embodiment of polyimide portion>. Moreover _, a plurality of X3 present in the polyimide precursor may be the same or different, and may be the same or different from X1, but they should not be exactly the same. X3 is preferably at least one selected from the group selected from _44BAFL , 33BAFL, BFAF, BAOFL, BAHF, 33DAS, and 44DAS, and has a linear expansion coefficient (CTE), chemical resistance, glass transition temperature ( Tg) and yellowness balance in a high temperature range, 44BAFL, 33BAFL, BFAF, BAOFL, 33DAS and 44DAS are more preferable, and 44BAFL, BFAF, 33DAS and 44DAS are more preferable.

The polyamic acid-imide copolymer in the present embodiment includes a polyamic acid portion composed of X ₁ and X ₂ and a polyimide portion composed of X ₃ and X ₄ , and the constituent units of the polyamic acid and the polyimide The upper limit of the molar ratio of the structural units (the number of moles of the structural unit N: the number of moles of the structural unit M) may be 95:5, 90:10, 85:15, or 80:20, It is preferably 5/95 from the viewpoint of residual stress and haze (Haze value), and more preferably 80:20 from the viewpoint of yellowness (YI value). The lower limit of the molar ratio of the constituent units of the polyamic acid and the constituent units of the polyimide (the number of moles of the structural unit N: the number of moles of the structural unit M) may be 30: 70, 40: 60, or 50: 50. However, from the viewpoint of coexistence of residual stress and yellowness (YI value), the ratio is preferably 40:60.

The weight average molecular weight (Mw) of the polyamic acid-imide copolymer (structural unit L) in the present embodiment is preferably 2,639 to 300,000, more preferably 10,000 to 250,000, and 20,000 to 200,000 is more preferred, and 40,000 to 200,000 is particularly preferred. When the weight average molecular weight is 2,639 or more, the mechanical properties such as elongation and breaking strength are excellent, the residual stress is low, and the YI is low. When the weight-average molecular weight is 200,000 or less, the viscosity and concentration of the polyamic acid-imide copolymer varnish are well-balanced, workability is good, and film unevenness during coating is reduced. In the present disclosure, the weight average molecular weight is a value obtained as a standard polystyrene conversion value using gel permeation chromatography (hereinafter also referred to as GPC).

(d) Organic solvent The (d) organic solvent in the present embodiment includes (a) polyamic acid, (b) polyimide, (c) polyamic acid-imide copolymer and other optionally used components described above. There is no particular limitation as long as it can be dissolved.

Specific examples of such (d) organic solvents include aprotic solvents, phenolic solvents, ether and glycolic solvents, and the like. Specific examples thereof include the aprotic solvent such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), N-methyl Caprolactam, 1,3-dimethylimidazolidinone, tetramethylurea, Equamid M100 (trade name: manufactured by Idemitsu Kosan Co., Ltd.), Equamid B100 (trade name: manufactured by Idemitsu Kosan Co., Ltd.), γ-butyrolactone (GBL), γ-valerolactone , hexamethylphosphoricamide, hexamethylphosphinetriamide, dimethylsulfone, dimethylsulfoxide, sulfolane, cyclohexanone, methylcyclohexanone, picoline, pyridine, acetic acid (2-methoxy-1-methylethyl), phenol, o-creso- le, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4- xylenol, 3,5-xylenol, etc.: as the ether and glycol solvents, for example, 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, 1,2- bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1,4-dioxane, polyamic acid, polyimide, polyamic acid-imide copolymer from the viewpoint of the solubility of NMP, GBL, DMF, and DMAc.

[Other ingredients]
The resin composition of the present embodiment may further contain (e) an imidization catalyst, etc., in addition to the components (a), (b), (c) and (d).

On the other hand, the resin composition preferably does not contain inorganic particles from the viewpoint of not worsening the haze (haze value). Examples of inorganic particles include particles containing silicon atoms, and examples of particles containing silicon atoms include silica particles.

((e) imidization catalyst)
In the step of obtaining a polyimide resin film from the resin composition according to the present embodiment by imidization, an imidization catalyst can be added to the resin composition.

The resin composition may contain 0.01 to 0.5 mol % of the imidization catalyst per 1 mol of repeating units of the (c) polyamic acid-imide copolymer. When the content of the imidization catalyst is 0.01 mol % or more per 1 mol of the repeating unit of the polyamic acid-imide copolymer, the yellowness (YI value) of the film can be suppressed. From the viewpoint of the storage stability of the resin composition, the content of the imidization catalyst is preferably 0.5 mol % or less. The content of the imidization catalyst is more preferably 0.01 to 0.5 mol%, more preferably 0.02 to 0.5 mol%, relative to 1 mol of the repeating unit of the polyamic acid-imide copolymer. is more preferred, and 0.02 to 0.15 mol % is particularly preferred.

Examples of imidization catalysts include, but are not limited to, pyridine, triethylamine, 1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole, imidazole, and benzimidazole. 1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, imidazole and the like are preferred, and 1,2-dimethylimidazole, N-tert-butoxycarbonylimidazole (N-Boc-imidazole) and 1-methylimidazole are particularly N-Boc-imidazole is preferred from the viewpoint of storage stability, and 1-methylimidazole is preferred from the viewpoint of yellowness (YI value) at high temperatures, and both may be used at the same time.

[Method for producing polyamic acid-imide copolymer]
The polyamic acid, polyimide and polyamic acid-imide copolymer of the present invention can be synthesized by the following steps. A method for producing a polyamic acid-imide copolymer has, for example, the following steps 1 to 3:
Step 1: Step 2 of reacting the tetracarboxylic dianhydride component (X ₃ ) of the polyamic acid moiety constituting the general formula (2) with the diamine component (X ₄ ) to obtain a solvent-soluble polyimide solution. : A step of dissolving the diamine (X ₂ ) of the polyamic acid moiety in the general formula (2) in the polyimide obtained in step 1. Step 3: For the solution obtained in step 2, the general formula (2 ) to obtain a polyamic acid-imide copolymer by reacting the tetracarboxylic dianhydride component of the polyamic acid moiety (X 1 ) constituting the polyamic acid moiety (X ₁ ).

First, specific examples will be described in order from step 1. Step 1 is a step of synthesizing the polyimide portion in the general formula (2). It can be synthesized by subjecting a diamine (eg, 44BAFL) of the polyimide moiety in the general formula (2) and a tetracarboxylic dianhydride (eg, BPAF) to a polycondensation reaction. This reaction is preferably carried out in a solvent capable of dissolving the monomer and the polyimide to be purified, using a reaction vessel from which water generated during imidization is removed. Specifically, for example, a predetermined amount of BAFL and NMP are added to a separable flask equipped with a reflux tube and a Dean-Stark tube, and after BAFL is completely dissolved, a predetermined amount of BPAF and toluene as an azeotropic solvent of water are added. is added, heated to 180° C., and stirred. Water generated during heating at 180° C. and toluene as an azeotropic solvent are preferably discharged out of the container as appropriate.

When synthesizing the polyimide, the ratio (molar ratio) of the tetracarboxylic dianhydride component and the diamine component is the thermal linear expansion coefficient, residual stress, elongation, and yellowness of the resulting resin film (hereinafter also referred to as YI from the viewpoint of controlling to the desired range, tetracarboxylic dianhydride: diamine = 100: 85 to 100: 200 (diamine 0.85 to 2.00 per 1 mole part of tetracarboxylic dianhydride 100:101 to 100:125 (1.01 to 1.25 mol parts of diamine to 1 mol part of acid dianhydride) is more preferable. By setting it as said range, reaction with a polyamic acid becomes easy and it is preferable at the point of a haze degree (Haze value) falling.

The reaction temperature is preferably 140° C. or higher, more preferably 160° C., from the viewpoint of achieving both imidization and water removal. From the viewpoint of suppressing coloration due to decomposition of the solvent and reaction with the monomer, the temperature is preferably 200° C. or lower, more preferably 190° C. or lower, and preferably 100° C. or lower immediately after completion of the reaction.

From the viewpoint of increasing the molecular weight, the reaction time is preferably 2 hours or longer, preferably 3 hours or longer. On the other hand, it is preferably 12 hours or less, preferably 6 hours or less, from the viewpoint of suppressing coloration due to decomposition of the solvent and reaction with the monomer.

Next, step 2 will be described. Step 2 is a step of dissolving the diamine (X ₂ ) of the polyamic acid moiety in the general formula (2) in the polyimide obtained in the step 1 above. After synthesizing polyimide in step 1, predetermined amounts of diamine (for example, APAB) and NMP are added and thoroughly stirred to dissolve the diamine. From the viewpoint of controlling the thermal linear expansion coefficient, residual stress, elongation, and yellowness (hereinafter also referred to as YI) of the finally obtained polyimide copolymer film within a desired range, the tetracarboxylic dianhydride of the polyimide part component (X ₃ ) derived from the product: component (X ₂ and X ₄ ) derived from the diamine component of the polyimide part and the polyamic acid part = 100: 150 to 100: 3000 (per 1 mol part of tetracarboxylic dianhydride 1.50 to 30 mole parts of diamine) is preferably in the range of 100:225 to 100:2000 (2.25 to 30 mole parts of diamine per 1 mole part of tetracarboxylic dianhydride). more preferably. By setting the above range, the reaction uniformity when reacting the tetracarboxylic dianhydride in step 3 is improved, the molecular weight distribution is close to 2.00, and the proportion of oligomers having a molecular weight of 1,000 or less is low Polyamic acid - An imide copolymer is obtained, and the thermal stability in a high-temperature region when made into a film is improved.

The temperature for dissolving the diamine is preferably 40° C. or higher, more preferably 60° C. or higher, from the viewpoint of enhancing the solubility of the diamine and improving the uniformity. On the other hand, from the viewpoint of suppressing coloration due to a side reaction with the solvent, the temperature is preferably 120° C. or lower, more preferably 100° C. or lower.

Next, step 3 will be described. In step 3, a tetracarboxylic dianhydride of the polyamic acid moiety in the general formula (2) is added to the solution in which the polyimide and diamine in step 2 are dissolved, and polycondensation reaction is performed to obtain polyamic acid-imide. Copolymers can be synthesized.

When synthesizing the polyamic acid-imide copolymer, the molar ratio (X ₂ /X ₁ ) of the tetracarboxylic dianhydride component (X ₁ ) and the diamine component (X ₂ ) in the polyamic acid moiety is obtained From the viewpoint of controlling the coefficient of linear thermal expansion, residual stress, elongation, and yellowness (hereinafter also referred to as YI) of the resin film within a desired range, it is preferably 0.85 to 1.2, and 0.90 to 1.0. 1 is more preferred, and 0.92 to 1,00 is preferred. By setting it as said range, reaction with a polyimide easily occurs, and it is preferable at the point of haze degree (Haze value) falling.

Further, when synthesizing the polyamic acid-imide copolymer, the molar ratio (X ₄ /X ₃ ) of the tetracarboxylic dianhydride component (X ₃ ) and the diamine component (X ₄ ) in the polyimide part is From the viewpoint of controlling the coefficient of thermal expansion, residual stress, elongation, and yellowness (hereinafter also referred to as YI) of the resin film to be within a desired range, it is preferably in the range of 0.85 to 2.0, It is more preferably in the range of 0.95 to 1.5, more preferably in the range of 1.01 to 1.25. The above range is preferable in that the heat resistance at high temperatures is improved, the decomposition reaction during heating is suppressed, and the yellowness (YI value) and haze (Haze value) are lowered.

Further, when synthesizing the polyamic _{acid -} imide copolymer _, the molar ratio ₍ (Number of moles of X ₂ + Number of moles of X ₄ ) / (Number of moles of X ₁ + Number of moles of X ₃ )) is the thermal linear expansion coefficient, residual stress, elongation, and yellowness of the resulting resin film (hereinafter, YI ) is preferably in the range of 0.92 to 1.05, more preferably in the range of 0.94 to 01.00. By setting the above range, the molecular weight of the polyamic acid-imide copolymer is easily improved, the processability as a resin composition is improved, coating unevenness when producing a film can be suppressed, and the haze (Haze value ) is reduced. In addition, the amount of terminal amines in the polyamic acid-imide copolymer is reduced, the decomposition reaction during heating is suppressed, the thermal stability at high temperatures is improved, and the yellowness index (YI value) is lowered.

In this embodiment, when synthesizing the preferred polyamic acid-imide copolymer, the molecular weight is controlled by adjusting the ratio of the tetracarboxylic dianhydride component and the diamine component, and adding a terminal blocker. It is possible. The closer the ratio of the acid dianhydride component to the diamine component is to 1:1 and the less the amount of the terminal blocker used, the higher the molecular weight of the polyimide.

It is recommended to use high-purity products as the tetracarboxylic dianhydride component and the diamine component. The purity is preferably 98% by mass or more, more preferably 99% by mass or more, and even more preferably 99.5% by mass or more. When multiple types of acid dianhydride components or diamine components are used in combination, it is sufficient if the acid dianhydride component or diamine component as a whole has the above purity, but all types of acid dianhydrides used It is preferred that the component and the diamine component each have the purity specified above.

As the solvent for the reaction, the solvent shown in (d) organic solvent can be used, but is not limited thereto.

As other components, the compounds described in (e) imidization catalyst can be used, but are not limited thereto.

The boiling point at normal pressure of the solvent used for polyimide synthesis is preferably 60 to 300°C, more preferably 140 to 280°C, and particularly preferably 170 to 270°C. If the boiling point of the solvent is higher than 300°C, the drying process will take a long time. On the other hand, if the boiling point of the solvent is lower than 60° C., the surface of the resin film may become rough during the drying process, air bubbles may be mixed into the resin film, and a uniform film may not be obtained.

Thus, it is preferable to use a solvent having a boiling point of preferably 170 to 270° C., more preferably a vapor pressure of 250 Pa or less at 20° C., from the viewpoint of solubility and edge repellency during coating. More specifically, it consists of compounds represented by N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (GBL), N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF). It is preferable to use one or more selected from the group, and the solvent described in (d) Container solvent can be used as appropriate. The water content in the solvent is preferably 3000 mass ppm or less. These solvents may be used alone or in combination of two or more.

｛式中、Ｘ₁及びＸ_３は、それぞれ独立に、４価の有機基を表し、Ｘ_２及びＸ_４は、それぞれ独立に、２価の有機基を表し、ｎ及びｍは、それぞれ独立に、正の整数である｝
で示される構造単位を含み、かつＸ_２として上記一般式（Ａ－１）で表される構造を有することを特徴とするポリイミドブロック共重合系高分子を提供できる。 <Polyimide block copolymer polymer>
As a second aspect of the present embodiment, a film containing a polyimide block copolymer polymer in which the (c) polyamic acid-imide copolymer contained in the resin composition is imidated (hereinafter referred to as a polyimide film sometimes called). Therefore, the following general formula (1):

{Wherein, X ₁ and X ₃ each independently represent a tetravalent organic group, X ₂ and X ₄ each independently represent a divalent organic group, n and m each independently , is a positive integer}
It is possible to provide a polyimide block copolymer polymer characterized by comprising a structural unit represented by and having a structure represented by the above general formula (A-1) as X ₂ .

The structures represented by general formulas (A-1) to (A-5) are defined in the same manner as <polyamic acid-imide copolymer>. The polyimide block copolymer polymer preferably excludes the following configurations 1 and 2 from the same viewpoint as the polyamic acid-imide copolymer described above:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or A group derived from 2,2′-bis(trifluoromethyl)benzidine;
Configuration 2. X3 is a group derived from norbornane- ₂ -spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride.

The thickness of the polyimide block copolymer polymer of the present invention is appropriately adjusted depending on the application, and is usually 3 to 500 μm, preferably 5 to 100 μm, more preferably 8 to 50 μm.

The polyimide block copolymer polymer of the present invention has a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement, and/or has a crystallinity of 0.07 in wide-angle X-ray diffraction measurement. Greater than eleven. When the crystal long period d (nm) is 12.0 nm or more and/or the crystallinity is greater than 0.11, the crystallinity of the polyimide contained in the polyimide block copolymer polymer is sufficiently high, This indicates that the distance between the crystal domains is sufficiently long. High crystallinity indicates strong intermolecular interaction, excellent thermal stability in a high-temperature region, and excellent linear expansion coefficient. In other words, this indicates that the polyimide is excellent in haze (haze value) and residual stress when cured at a high temperature of 400° C. or higher. In addition, the fact that the distance between the crystal domains is sufficiently long indicates that there is a flexible amorphous region between the crystal domains. The existence of this amorphous region suppresses the orientation and aggregation of the crystalline domains, indicating that the transparency (YI value and Haze value) in the high temperature region and the bending resistance are excellent. In other words, having both of these properties indicates that the polyimide block copolymer polymer has excellent heat resistance at high temperatures, high transparency, and excellent bending resistance.

The crystal long period d (nm) is preferably 12.0 nm or more, more preferably larger than 12.3 nm, more preferably larger than 12.9 nm, from the viewpoint of not worsening the haze (haze value) during the bending test. Larger is more preferred. In addition, from the viewpoint of excellent residual stress, the crystal long period d (nm) is preferably less than 30.0 nm, preferably less than 20 nm, preferably less than 18.0 nm, and more than 17.9 nm. Smaller is more preferred.

From the viewpoint of excellent residual stress, the crystallinity is preferably greater than 0.11, more preferably greater than 0.12, and even more preferably greater than 0.13.

In addition, in the small-angle X-ray scattering measurement, the polyimide block copolymer polymer of the present invention has a scattering intensity I=A×q ^−B with a multiplier B of 0.04<q<0.05. In the range, it is 3.6 or less.

The fact that the multiplier B is in the range of 3.6 or less suggests that macrophase separation has not occurred, and the polyimides contained in the polyimide block copolymer polymer are in a compatible state, and the haze value ) is small. In other words, a film formed of a polyimide block copolymer polymer having a multiplier B of 3.6 or less has a haze value of 1.0% or less, and can be suitably used as a flexible display substrate. can be done. On the other hand, a multiplier B greater than 3.6 indicates greater film scattering in the small angle region. In other words, the polyimide is partially phase-separated or aggregated, and the film has a large haze value, which is unsuitable for use as a substrate for a flexible display.

Therefore, the value of the multiplier B is preferably less than 3.6, more preferably less than 3.0, and even more preferably less than 2.34, from the viewpoint of excellent haze (haze value). Less than 2.23 is particularly preferred.
Also, the value of the multiplier B may be a negative value, greater than −3, greater than −2, greater than −1, or greater than 0.

<Method for producing polyimide>
As a third aspect of the present disclosure, a method for producing polyimide is provided. The method for producing a polyimide is characterized by using a polyamic acid-imide copolymer having a structure represented by the general formula (2) as a raw material or a polyimide precursor, and the resulting polyimide is obtained by block copolymerization. form a system having a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement and a crystallinity greater than 0.11 in wide-angle X-ray diffraction measurement.

A polyimide block copolymer polymer resin film produced using the polyamic acid-imide copolymer and resin composition according to the present embodiment can be used, for example, as a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, or the like. In addition to being applicable, it can be suitably used particularly as a substrate in the production of flexible devices. Flexible devices to which the resin film and laminate according to the present embodiment can be applied include, for example, flexible displays, flexible solar cells, flexible touch panel electrode substrates, flexible lighting, and flexible batteries. Moreover, it can be used particularly preferably in the manufacture of optical devices using low-temperature polysilicon as TFTs. Examples of flexible devices to which the resin film and laminate according to the present embodiment can be applied include displays and touch panel electrode substrates.

The present invention will be described in more detail below based on examples, but these are described for the sake of explanation and the scope of the present invention is not limited to the following examples.

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

<Measurement of Weight Average Molecular Weight and Number Average Molecular Weight>
Weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) under the following conditions.

As a solvent, N,N-dimethylformamide (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., for high-performance liquid chromatography, 24.8 mmol / L of lithium bromide monohydrate immediately before measurement (manufactured by FUJIFILM Wako Pure Chemical Industries, purity 99.5%) and 63.2 mmol/L of phosphoric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., for high-performance liquid chromatograph) were added and dissolved) were used. A calibration curve for calculating the weight average molecular weight was prepared using standard polystyrene (Easical Type PS-1, manufactured by Agilent Technologies).
Apparatus: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: 2 Tsk gel Super HM-H (manufactured by Tosoh Corporation)
Flow rate: 0.5 mL/min Column temperature: 40°C
Detector: UV-8220 (UV-VIS: UV-visible spectrophotometer, manufactured by Tosoh Corporation)

<Evaluation of residual stress>
Each resin composition was applied by a spin coater onto a 6-inch silicon wafer having a thickness of 625 μm±25 μm and pre-baked at 100° C. for 7 minutes. After that, the oxygen concentration in the chamber was adjusted to 10 mass ppm or less, heat curing treatment (cure treatment) was performed at 430 ° C. for 1 hour, and a silicon wafer with a polyimide resin film having a film thickness of 10 μm after curing was attached. was made.

The amount of warpage of this wafer was measured using a residual stress measuring device (manufactured by Tencor, model name: FLX-230) to evaluate the residual stress generated between the silicon wafer and the resin film.
◎: Residual stress is more than -5 MPa and 15 MPa or less (residual stress evaluation "excellent")
○: Residual stress is more than 15 MPa and 25 MPa or less (residual stress evaluation “good”)
×: Residual stress is over 25 MPa (residual stress evaluation “bad”)

<Evaluation of yellowness (YI value) and haze (Haze value)>
Each resin composition was applied on a 100 mm square (0.7 mm thick) Eagle XG glass with a spin coater and prebaked at 80° C. for 30 minutes. After that, the oxygen concentration in the chamber was adjusted to 10 ppm by mass or less, heat curing treatment (curing treatment) was performed at 430 ° C. for 1 hour, and the glass substrate with a polyimide resin film having a film thickness of 10 μm after curing was attached. was made.

For the obtained polyimide-coated glass substrate, the yellowness (YI value) was measured using a D65 light source with a Spectotometer (SE6000) manufactured by Nippon Denshoku Industries Co., Ltd., and a spectrophotometer manufactured by Konica Minolta Co., Ltd. (CM −3600 A) using a D65 light source to measure the haze (haze value). "*" indicates that measurement is not possible due to whitening.
◎: YI value is 8 or more and 12 or less (YI value evaluation "◎")
○: YI value is 12 or more and 15 or less (YI value evaluation “○”)
×: YI value is 15 or more (YI value evaluation “×”)
◎: Haze value is 0.2% or less (Haze value evaluation "◎")
○: Haze value is 0.2% or more and 0.5% or less (Haze value evaluation “◯”)
△: Haze value is 0.5% or more and 1.0% or less (Haze value evaluation “△”)
×: Haze value is 1.0% or more (Haze value evaluation “×”)

<Evaluation of bending resistance>
Each resin composition was applied by a spin coater onto a 6-inch silicon wafer having a thickness of 625 μm±25 μm on which aluminum (Al) was previously sputtered to a thickness of about 100 nm, and prebaked at 100° C. for 7 minutes. After that, the oxygen concentration in the chamber was adjusted to 10 ppm by mass or less, heat curing treatment (cure treatment) was performed at 430 ° C. for 1 hour, and Al sputtering with a polyimide resin film having a film thickness of 10 μm after curing was attached. A film-coated silicon wafer was produced. The prepared sample was immersed in a 10% by mass hydrochloric acid aqueous solution for one day, and the polyimide resin film was peeled off from the silicon wafer. A test piece was prepared by cutting the peeled polyimide film into a size of 15 mm×100 mm.

Using an MIT-type repeated bending tester (MIT-DA, manufactured by Toyo Seiki), a load of 250 g is applied to the prepared test piece, and the bending radius is R2 mm, the bending angle is 135 °, and the speed is 90 times / minute. ,000 reciprocating cycles of repeated bending tests were conducted. After the test, the sample was removed from the apparatus, and the sample was visually observed as ◯ if it was not scratched, and as x if it was scratched.

・ピークフィッティングの初期値と拘束条件：
表１で示した初期値を用いてピークフィッティングを実施した。構造の規則性が高くピーク幅が狭いピーク０、２、４、５、７を結晶ピークとした。また、構造の規則性が低いピーク１、３、６を非晶ピークとした。結晶ピークのｗｉｄｔｈパラメータを０°より大きく１°以下になるように拘束した。また、結晶ピークのピーク位置（ｘ０）は、表１の初期ピーク位置に固定してフィッティングを実施した（図２）。 <Evaluation of crystallinity>
Crystallinity was analyzed using wide-angle X-ray scattering (WAXS). The measurement conditions are shown below:
・Equipment: NANOPIX manufactured by Rigaku Corporation
・X-ray wavelength λ: 0.154 nm
・Optical system: Point collimation (1st slit: 0.55mmφ,
2nd slit: Open, guard slit: 0.35mmφ)
・Beam stop: 2mmφ
・Detector: HyPix-6000
・Camera length: 86.1mm
・Exposure time: 15 min
・Measurement temperature: 25°C
X-rays were applied from the direction normal to the film, and transmitted scattered light was detected. Empty cell scattering correction was performed on the obtained two-dimensional pattern, and a one-dimensional WAXS profile was obtained by circular averaging (Fig. 1). The horizontal axis is the scattering angle 2θ. Peak separation was performed to calculate crystallinity:
・ Analysis software: igor pro 8.00 (WaveMetrics)
・Package: Multi-peak fitting
・Peak fitting range: 5°<2θ<35°
・Number of peaks: 8 ・Baseline: linear ・Fitting function: The Gaussian function of the analysis software is Formula A below.

・Initial values and constraints for peak fitting:
Peak fitting was performed using the initial values shown in Table 1. Peaks 0, 2, 4, 5, and 7 with high structural regularity and narrow peak widths were defined as crystal peaks. Also, peaks 1, 3, and 6 with low structural regularity were defined as amorphous peaks. The width parameter of the crystal peak was constrained to be greater than 0° and 1° or less. Moreover, the peak position (x0) of the crystal peak was fixed to the initial peak position in Table 1, and fitting was performed (Fig. 2).

Crystallinity is the value obtained by dividing the sum of crystal peak areas by the sum of all peak areas. In addition, when no peaks derived from peaks 0, 2, 4, 5, and 7 with high structural regularity and narrow peak widths were observed, and only peaks with low structural regularity were observed, the crystallinity and the crystal long period are indicated by "*" (Comparative Example 4).

<Evaluation of Multiplier B and Crystal Long Period d>
The multiplier B and the crystal long period d were analyzed using the small-angle X-ray scattering method (SAXS). The measurement conditions are shown below:
・Equipment: NANOPIX manufactured by Rigaku Corporation
・X-ray wavelength λ: 0.154 nm
・Optical system: Point collimation (1st slit: 0.55mmφ,
2nd slit: Open, guard slit: 0.35mmφ)
・Beam stop: 2mmφ
・Detector: HyPix-6000
・Camera length: 1312mm
・Exposure time: 15 min
・Measurement temperature: 25°C

X-rays were applied from the direction normal to the film, and transmitted scattered light was detected. Empty cell scattering correction and sample thickness correction were performed on the resulting two-dimensional pattern, and a one-dimensional SAXS profile was obtained by circular averaging. The horizontal axis is the scattering vector q defined by the following equation.
q=4πsin(θ/2)/λ
λ: X-ray wavelength (0.154 nm)
θ: Scattering angle

(1) Multiplier B
The scattering intensity I was plotted against the scattering vector q to calculate the multiplier B (Fig. 3). Then, the scattering intensity I was fitted in the range of 0.04<q (nm ⁻¹ ) <0.05 by the following formula, and the multiplier B was calculated.
I=A×q^(-B)
I: scattering intensity, A: intensity, B: multiplier As data analysis software, WaveMetrics software Igor Pro 8.00 was used. As initial values for fitting, intensity A=200 and multiplier B=4 were used.

(2) crystal long period d
To calculate the crystal long period d, Iq^2, which is the scattering intensity I multiplied by the square of the scattering vector q, was plotted against the scattering vector q (Fig. 4). A Gaussian function (Formula A) was used to fit peaks in the range of 0.3<q (nm ⁻¹ ) <0.6 to obtain the peak position (x0). The crystal long period d was calculated by dividing 2π by the peak position (x0) obtained from fitting. WaveMetrics software Igor Pro 8.00 was used as data analysis software.

[Synthesis Examples 1 and 2]
(Synthesis Example 1-1-1)
After purging a 500 ml four-necked flask equipped with a reflux tube and a Dean-Stark tube with nitrogen, 20 g of N-methyl-2-pyrrolidone (NMP) and 22 g of 9,9-bis(aminophenyl)fluorene (BAFL) were added. .22 mmol and stirred to dissolve the BAFL. Then, 20.00 mmol of 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 11.41 g of N-methyl-2-pyrrolidone (NMP), and 21.76 g of toluene were added at 40°C. After the addition, a polymerization reaction was carried out at 180° C. for 4 hours under nitrogen flow. One hour after reaching 180° C., a mixture of water and toluene was extracted from the Dean-Stark tube. After 4 hours of reaction, the imide had a weight average molecular weight (Mw) of 19,178 and a number average molecular weight (Mn) of 8,283.

After 4 hours of reaction, the internal temperature was cooled to 80° C., 82.82 mmol of 4-aminophenyl-4′-aminobenzoate (APAB) and 100 g of NMP were added, and APAB was completely dissolved with stirring. After visually confirming that APAB was completely dissolved, 86.17 mmol of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) was added, and the mixture was stirred at 80° C. for 1 hour under nitrogen flow. After stirring for 2 hours at 60° C., the polymerization reaction was carried out overnight at room temperature. Thereafter, the NMP was added to adjust the solid content to 12% by mass, thereby obtaining an NMP solution of polyimide-polyamic acid copolymer (hereinafter also referred to as varnish). The resulting polyamic acid-imide copolymer had a weight average molecular weight (Mw) of 155,382 and a number average molecular weight (Mn) of 64,063.

(Synthesis Example 1-1-2)
(a) Polyimide synthesis After purging a 500 ml four-necked flask equipped with a reflux tube and a Dean-Stark tube with nitrogen, 20 g of N-methyl-2-pyrrolidone (NMP) and 9,9-bis(aminophenyl)fluorene were added. 22.22 mmol of (BAFL) was added and stirred to dissolve BAFL. Then, 20.00 mmol of 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 11.41 g of N-methyl-2-pyrrolidone (NMP), and 21.76 g of toluene were added at 40°C. After the addition, a polymerization reaction was carried out at 180° C. for 4 hours under nitrogen flow. One hour after reaching 180° C., a mixture of water and toluene was extracted from the Dean-Stark tube. After 4 hours of reaction, the imide had a weight average molecular weight (Mw) of 19,804 and a number average molecular weight (Mn) of 8,886. After 4 hours of reaction, the inside temperature was cooled to 80° C., and NMP was added to obtain a polyimide NMP solution with a concentration of 20% by mass (hereinafter also referred to as polyimide varnish).

(b) Synthesis of polyamic acid After purging a 500 ml four-necked flask with nitrogen, 82.82 mmol of 4-aminophenyl-4′-aminobenzoate (APAB) and 100 g of NMP were added, and APAB was completely dissolved while stirring. . After visually confirming that APAB was completely dissolved, 86.17 mmol of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) was added, and the mixture was stirred at 80° C. for 5 hours under nitrogen flow. After that, the polymerization reaction was carried out overnight at room temperature. Thereafter, the NMP was added to adjust the solid content to 20% by mass, thereby obtaining an NMP solution of polyamic acid (hereinafter also referred to as polyamic acid varnish). The resulting polyamic acid had a weight average molecular weight (Mw) of 73,044 and a number average molecular weight (Mn) of 34,917.

(c) Synthesis of polyamic acid-imide copolymer The total amount of polyimide varnish obtained in (a) and the total amount of (b) polyamic acid varnish are mixed and stirred at room temperature for 24 hours to form a polyamic acid-imide copolymer. An NMP solution was obtained.

(Synthesis Examples 1-2 to 1-9-1))
Polyamic acid-imide copolymer varnish was prepared in the same manner as in Synthesis Example 1-1-1, except that the amounts of raw materials charged in Synthesis Example 1-1-1 were changed as shown in Table 1. Obtained.

(Synthesis Example 1-9-2)
In the NMP solution synthesized in Synthesis Example 1-1-1 above, 0.04 mol of 1-methylimidazole and 0.04 mol of N-Boc-imidazole are added to 1 mol of the repeating unit of the polyimide-polyamic acid copolymer. In addition, a polyamic acid-imide copolymer varnish was obtained.

(Synthesis Example 2-1)
After purging a 500 ml four-necked flask with nitrogen, 49.50 mmol of 4-aminophenyl-4′-aminobenzoate (APAB) and 80 g of NMP were added, and APAB was completely dissolved while stirring. After visually confirming that APAB was completely dissolved, 50.00 mmol of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) was added and stirred at 80° C. for 5 hours under nitrogen flow. After that, the polymerization reaction was carried out overnight at room temperature. Thereafter, the NMP was added to adjust the solid content to 12% by mass, thereby obtaining an NMP solution of polyamic acid (hereinafter also referred to as polyamic acid varnish). The polyamic acid obtained had a weight average molecular weight (Mw) of 63,353 and a number average molecular weight (Mn) of 29,472.

(Synthesis Example 2-2)
After purging a 500 ml four-necked flask with nitrogen, 31.68 mmol of 4-aminophenyl-4′-aminobenzoate (APAB), 7.92 mmol of 9,9-bis(aminophenyl)fluorene (BAFL) and 70 g of NMP were added. , the APAB and BAFL were completely dissolved with stirring. After visually confirming that APAB and BAFL were completely dissolved, 32.00 mmol of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 9,9-bis(3,4 -Dicarboxyphenyl)fluorene dianhydride (BPAF) (8.00 mmol) and NMP (22.29 g) were added, and after stirring at 80°C for 5 hours under nitrogen flow, a polymerization reaction was carried out overnight at room temperature. Thereafter, the NMP was added to adjust the solid content to 12% by mass, thereby obtaining an NMP solution of polyamic acid (hereinafter also referred to as polyamic acid varnish). The polyamic acid thus obtained had a weight average molecular weight (Mw) of 72,118 and a number average molecular weight (Mn) of 33,741.

(Synthesis Example 2-3)
(a) Polyimide synthesis After purging a 500 ml four-necked flask equipped with a reflux tube and a Dean-Stark tube with nitrogen, 20 g of N-methyl-2-pyrrolidone (NMP) and 9,9-bis(aminophenyl)fluorene were added. 19.80 mmol of (BAFL) was added and stirred to dissolve BAFL. After that, 20.00 mmol of 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 9.84 g of N-methyl-2-pyrrolidone (NMP), and 21 g of toluene were added at 40°C. After that, a polymerization reaction was carried out at 180° C. for 4 hours under nitrogen flow. One hour after reaching 180° C., a mixture of water and toluene was extracted from the Dean-Stark tube. After 4 hours of reaction, the imide had a weight average molecular weight (Mw) of 69,204 and a number average molecular weight (Mn) of 30,126. After 4 hours of reaction, the inside temperature was cooled to 80° C., and NMP was added to obtain an NMP solution of polyimide having a concentration of 20% by mass (hereinafter also referred to as polyimide varnish).

(b) Synthesis of polyamic acid After purging a 500 ml four-necked flask with nitrogen, 79.20 mmol of 4-aminophenyl-4′-aminobenzoate (APAB) and 100 g of NMP were added, and APAB was completely dissolved while stirring. . After visually confirming that APAB was completely dissolved, 80.00 mmol of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 98.04 g of NMP were added, and the temperature was raised to 80° C. under nitrogen flow. After stirring for 5 hours at room temperature, the polymerization reaction was carried out overnight. Thereafter, the above NMP was added to adjust the solid content to 20% by mass, thereby obtaining an NMP solution of polyamic acid (hereinafter also referred to as polyamic acid varnish). The resulting polyamic acid had a weight average molecular weight (Mw) of 73,044 and a number average molecular weight (Mn) of 34,917.

(c) polyamic acid-imide copolymer synthesis The polyimide varnish obtained in (a) and the polyamic acid varnish obtained in (b) are mixed and stirred at room temperature for 24 hours to produce a polyamic acid-imide copolymer. of NMP solution was obtained.

(Synthesis Example 2-4)
After purging a 500 ml four-necked flask equipped with a reflux tube and a Dean-Stark tube with nitrogen, 56.41 g of N-methyl-2-pyrrolidone (NMP) and 9,9-bis(aminophenyl)fluorene (BAFL) were added. was added and stirred to dissolve BAFL. After that, 30.00 mmol of 9,9-bis(3,4-dicarboxyphenyl)fluorene diacid anhydride (BPAF), 40 g of N-methyl-2-pyrrolidone (NMP), and 27.96 g of toluene were added at 80°C. After that, a polymerization reaction was carried out at 180° C. for 4 hours under nitrogen flow. One hour after reaching 180° C., a mixture of water and toluene was extracted from the Dean-Stark tube. After 5 hours of reaction, the imide had a weight average molecular weight (Mw) of 66,208 and a number average molecular weight (Mn) of 33,869. After 4 hours of reaction, the inside temperature was cooled to 80° C., and NMP was added to obtain an NMP solution of polyimide having a concentration of 15% by mass (hereinafter also referred to as polyimide varnish).

The abbreviations of each component in Table 1 have the following meanings.
BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride ODPA: 4,4'-oxydiphthalic dianhydride BPAF: 9,9-bis(3,4-dicarboxyphenyl)fluorenedioic acid Anhydride APAB: 4-aminophenyl-4-aminobenzoate 44BAFL: 9,9-bis(4-aminophenyl)fluorene BFAF: 9,9-bis(3-fluoro-4-aminophenyl)fluorene 33DAS: 3,3 '-diaminodiphenylsulfone 44DAS: 4,4'-diaminodiphenylsulfone NMP: N-methyl-2-pyrrolidone DMF: N,N-dimethylformamide

The varnish obtained in each synthesis example was used as it was as a resin composition, and was evaluated according to the method described above. The synthesis results are shown in Table 2, and the evaluation results are shown in Table 3.

As can be seen from Example 1-1, the polyimide has a crystal long period d (nm) of 12.0 nm or more at a small X-ray scattering angle and a crystallinity greater than 0.11 in wide-angle X-ray diffraction measurement. The block copolymer film had a low yellowness index (YI value) of 15 or less and a haze value (Haze value) of 1.0% or less, which was sufficient for use as a substrate for optical displays. In addition, the film had a low residual stress of 25 MPa or less, excellent bending resistance, and sufficient mechanical properties. From the above, the polyimide resin film obtained from the resin composition according to the present invention has a small yellowness, a small haze, a low residual stress, and an excellent bending resistance. It was confirmed that it is a resin film. . Specifically, a polyimide film obtained from a polyamic acid-imide copolymer containing a structural unit represented by general formula (1) and a structure represented by general formula (A-1) as X ₂ is In the present invention, a resin film having a residual stress of 25 MPa or less, a yellowness of 15 or less, a haze of 1.0% or less, and excellent bending resistance can be obtained.

Further, as in Synthesis Example 1-1-2, a polyamic acid-imide copolymer varnish can be obtained by synthesizing polyamic acid and polyimide separately and then mixing and reacting them. The polyimide film obtained from this varnish had performance equivalent to that of Example 1-1, as shown in Example 1-2. This indicates that (c) polyamic acid-imide copolymer can be obtained by mixing and reacting (a) polyamic acid and (b) polyimide synthesized at a predetermined molar ratio.

Further, in Table 3, the film obtained in Comparative Example 1 (Synthesis Example 2-1) is composed only of the polyamic acid structure derived from the structural unit N in the structures represented by the general formulas (1) and (2). It is a polyimide film obtained by curing a polyamic acid varnish at 430 ° C., and has a high degree of crystallinity of 0.21, and the crystallinity is too high. The film became cloudy during the test. In addition, the film was colored yellow due to the high flatness of the monomer, and was insufficient for use as a substrate for optical displays.

Further, in Table 3, the film obtained in Comparative Example 2 (Synthesis Example 2-2) is a polyamic acid synthesized with the same monomer composition as the polyamic acid-imide copolymer shown in Synthesis Example 1-1-1. It is a polyimide film obtained by curing at 430 ° C., and the degree of crystallinity is 0.11, which is low crystallinity, so the residual stress is inferior and the substrate warps greatly, which is insufficient for use as a substrate for optical displays. Met. On the other hand, the film shown in Example 1 had a degree of crystallinity greater than 0.11 and had high crystallinity, so the residual stress was excellent at 25 MPa or less. In particular, the film shown in Example 2 had the highest residual stress due to its high crystallinity of 0.18.

Further, in Table 3, as shown in Comparative Example 3 (Synthesis Example 2-3), in the structures represented by the general formulas (1) and (2), X of the imide moiety derived from the structural unit M Since the ₄ /X3 ratio was 0.99 and the acid dianhydride ratio was _high , after the film was cured at 430°C, the polyimide caused phase separation and the film became cloudy. This is because the acid dianhydride ratio in the terminal structure of polyimide is high, and the reactivity becomes poor when reacted with polyamic acid, resulting in phase separation. In small-angle X-ray scattering measurement, this film has a scattering intensity I=A×q ^−B with a multiplier B of 4.29 in the range of 0.04<q<0.05. It is understood that On the other hand, the films of Examples 1-1, 1-2, 2 to 4, Reference Examples 5 and 6, Examples 7, 8, 9-1, and 9-2 had scattering intensity I= The multiplier B calculated by the A×q ^−B formula is smaller than 3.6 in the range of 0.04<q<0.05, indicating that the polyimides are compatible with each other. That is, a film having a haze value of 1.0% or less can be obtained.

Further, in Table 3, as shown in Comparative Example 4 (Synthesis Example 2-4), in the structures represented by general formulas (1) and (2), composed only of polyimide derived from structural unit M A polyimide film obtained by curing the polyimide varnish at 430 ° C., and in wide-angle X-ray scattering measurement, only peaks derived from amorphous could be observed, and the crystallinity could not be calculated. In other words, the degree of crystallinity was lower than 0.11, the residual stress was poor, and the warp of the substrate was large, which was insufficient for use as a substrate for optical displays.

In Table 3, as shown in Example 9-2, a film obtained from a polyimide-polyamic acid copolymer containing 1-methylimidazole and N-Boc-imidazole as imidization catalysts has a yellowness index (YI value ) is low and can be suitably used as a substrate for displays.

Claims (23)

including a polyimide block copolymer polymer,
In wide-angle X-ray diffraction measurement, the degree of crystallinity is greater than 0.11,
The polyimide block copolymer polymer has the following general formula (1):

{Wherein, X ₁ and X ₃ each independently represent a tetravalent organic group, X ₂ and X ₄ each independently represent a divalent organic group, and n and m each independently , is a positive integer, and
Except configuration 1 and 2 below:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or A group derived from 2,2′-bis(trifluoromethyl)benzidine;
Configuration 2. X ₃ is a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride}
and as X ₂ , the following general formula (A-1):

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
having a structure represented by
polyimide film. 2. The polyimide film according to claim 1, which has a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement. In the small-angle X-ray scattering measurement, the multiplier B calculated by the scattering intensity I = A × q − ^B formula is 3.6 or less in the range of 0.04 < q < 0.05, or The polyimide film according to claim 2. The polyimide film according to any one of claims 1 to 3, which has a haze value of 1.0% or less. The polyimide film according to any one of claims 1 to 4, wherein the degree of crystallinity is less than 0.21. In the general formula (1), the X ₃ is represented by the following general formula (A-3):

{wherein R ₄ to R ₇ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; d to g each independently represent an integer of 0 to 4; ₁ indicates a linking group and * indicates a linking point}
and at least one selected from the group consisting of structures derived from 4,4'-oxydiphthalic dianhydride (ODPA), polyimide according to any one of claims 1 to 5 the film. In the general formula (1), the X ₃ is represented by the following general formula (A-3):

{wherein R ₄ to R ₇ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; d to g each independently represent an integer of 0 to 4; ₁ indicates a linking group and * indicates a linking point}
The polyimide film according to any one of claims 1 to 6, which has a structure represented by X ₄ in the above general formula (1) is represented by the following general formula (A-4):

{Wherein, R ₈ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; ₂ indicates the linking group and * indicates the linking point}
and the following general formula (A-5):

{wherein R ₁₂ and R ₁₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; l and m each independently represent an integer of 0 to 4; * indicates a bond, provided that when X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), general formula (A-5 ) excludes groups derived from 4,4′-diaminodiphenylsulfone}
The polyimide film according to any one of claims 1 to 7, which is at least one selected from the group consisting of structures represented by The polyimide film according to any one of claims 1 to 8, wherein X ₁ in the general formula (1) contains a structure derived from biphenyltetracarboxylic dianhydride (BPDA). The molar ratio (X ₂ /X ₁ ) between X ₁ and X ₂ contained in the general formula (1) is 0.84 to 1.00, and X ₃ contained in the general formula (2) and X ₄ (X ₄ /X ₃ ) in a molar ratio of 1.01 to 2.00, the polyimide film according to any one of claims 1 to 9. The molar ratio of the polyimide structural units composed of X ₁ and X ₂ and the polyimide structural units composed of X ₃ and X ₄ in the general formula (1) (number of moles of structural unit N: number of structural units M number of moles) is in the range of 60:40 to 95:5, the polyimide film according to any one of claims 1 to 10. A polyamic acid-imide copolymer represented by the following general formula (2):

{Wherein, X ₁ and X ₃ represent a tetravalent organic group, X ₂ and X ₄ represent a divalent organic group, n, m, and l are positive integers, and X ₁ and X ₂ is called structural unit N, and the structural unit made up of X ₁ and X ₂ is called structural unit M,
Except configuration 1 and 2 below:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or 2 , a group derived from 2′-bis(trifluoromethyl)benzidine;
Configuration 2. X ₃ is a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride}
Including a structural unit L represented by
When cured, the polyamic acid-imide copolymer has a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement, and a crystallinity of 0.11 in wide-angle X-ray diffraction measurement. characterized by being greater than
X ₂ in the above general formula (2) is represented by the following general formula (A-1):

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
has a structure represented by
The diamine component constituting X ₂ and the diamine component constituting X ₄ in the general formula (2) are different in either the diamine composition or the diamine species,
Polyamic acid-imide copolymer. X ₃ in the above general formula (2) is represented by the following general formula (A-3):

{wherein R ₄ to R ₇ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; d to g each independently represent an integer of 0 to 4; ₁ indicates a linking group and * indicates a linking point}
The polyamic acid-imide copolymer according to claim 12, which is at least one selected from the group consisting of a structure represented by and a structure derived from 4,4'-oxydiphthalic dianhydride (ODPA). 14. The polyamic acid-imide copolymer according to claim 13, wherein X ₃ in the general formula (2) has a structure represented by the general formula (A-3). X ₄ in the above general formula (2) is represented by the following general formula (A-4):

{Wherein, R ₈ to R ₁₁ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; ₂ indicates the linking group and * indicates the linking point}
and the following general formula (A-5):

{wherein R ₁₂ and R ₁₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; l and m each independently represent an integer of 0 to 4; * indicates a bond, provided that when X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), general formula (A-5 ) excludes groups derived from 4,4′-diaminodiphenylsulfone}
Polyamic acid-imide copolymer according to any one of claims 12 to 14, which is at least one selected from the group consisting of structures represented by The polyamic acid-imide copolymer according to any one of claims 12 to 15, wherein X ₁ in the general formula (2) contains a structure derived from biphenyltetracarboxylic dianhydride (BPDA). The molar ratio (X ₂ /X ₁ ) of X ₁ and X ₂ contained in the general formula (2) is 0.84 to 1.00, and X ₃ and X 3 contained in the general formula (2) The polyamic acid-imide copolymer according to any one of claims 12 to 16, wherein the molar ratio of X ₄ (X ₄ /X ₃ ) is from 1.01 to 2.00. The molar ratio of polyamic acid structural units composed of X ₁ and X ₂ and polyimide structural units composed of X ₃ and X ₄ in the general formula (2) (number of moles of structural unit N: structural unit M ) is in the range of 60:40 to 95:5, the polyamic acid-imide copolymer according to any one of claims 12 to 17. A resin composition comprising the polyamic acid-imide copolymer according to any one of claims 12 to 18 and (d) an organic solvent. 20. The resin composition according to claim 19, wherein the ratio of the polyamic acid structural unit M composed of X ₁ and X ₂ is 60 to 95 mol % in the total polymer contained in the resin composition. 21. The resin composition according to claim 19 or 20, further comprising (e) an imidization catalyst. The resin composition according to claim 21, wherein the (e) imidization catalyst comprises 1-methylimidazole or N-Boc-imidazole. A method for producing a polyimide block copolymer polymer, comprising:
Using a polyamic acid-imide copolymer as a raw material,
The polyamic acid-imide copolymer has the following general formula (2):

{Wherein, X ₁ and X ₃ represent a tetravalent organic group, X ₂ and X ₄ represent a divalent organic group, n, m, and l are positive integers, and X ₁ and X ₂ is called structural unit N, and the structural unit made up of X ₁ and X ₂ is called structural unit M,
Except configuration 1 and 2 below:
Configuration 1. When X ₃ is a group derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), X ₄ is 4,4′-diaminodiphenyl sulfone, and/or 2 , a group derived from 2′-bis(trifluoromethyl)benzidine;
Configuration 2. X ₃ is a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride}
Including a structural unit L represented by
The polyimide block copolymer polymer has a crystal long period d (nm) of 12.0 nm or more in small-angle X-ray scattering measurement, and a crystallinity greater than 0.11 in wide-angle X-ray diffraction measurement. ,
X ₂ in the above general formula (2) is represented by the following general formula (A-1):

{wherein R ₁ and R ₂ each independently represent a monovalent organic group having 1 to 20 carbon atoms or halogen; a and b each independently represent an integer of 0 to 4; * indicates a joint}
having a structure represented by
A method for producing a polyimide block copolymer polymer.

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