TW202227535A - Polyimide precursor composition, polyimide film, and polyimide film/substrate laminate - Google Patents

Abstract

Provided is a polyimide precursor composition with which it is possible to manufacture a polyimide film that has excellent thermal characteristics and/or thermal resistance, and that has excellent transparency. The polyimide precursor composition comprises a repeating unit including a repeating unit expressed by the following general Formula (I) and a repeating unit obtained by further imidizing the general Formula (I), and contains a polyimide precursor having an imidization ratio of more than 0% and less than 50% and a solvent. (where 70 mol% or more of X1 is a structure expressed by Formula (1-1), and 70 mol% or more of Y1 is a structure expressed by Formula (D-1) and/or (D-2).).

Description

Polyimide precursor composition, polyimide film, and polyimide film/substrate laminate

The present invention relates to a polyimide precursor composition preferably used in electronic device applications such as substrates for flexible devices, polyimide films with improved properties, and polyimide films/substrates Material laminate. In addition, it relates to a manufacturing method of a flexible electronic device using the above-mentioned composition.

Polyimide films are widely used in fields such as electrical, electronic device fields, and semiconductor fields due to their excellent heat resistance, chemical resistance, mechanical strength, electrical properties, and dimensional stability. On the other hand, in recent years, with the advent of a highly information-based society, optical materials such as liquid crystal alignment films and protective films for color filters are being developed for display devices such as optical fibers in the field of optical communication and optical waveguides. In particular, in the field of display devices, a light-weight and highly flexible plastic substrate is being actively researched to replace the glass substrate, and displays that can be bent or rolled are being actively developed.

In displays such as liquid crystal displays and organic EL (Electroluminescence) displays, semiconductor elements such as TFTs (thin-film transistors) for driving respective pixels are formed. Therefore, the substrate needs to have heat resistance and dimensional stability. Polyimide films are expected to be used as substrates for display applications due to their excellent heat resistance, chemical resistance, mechanical strength, electrical properties, dimensional stability, and the like.

Polyimide is generally colored yellow-brown, so its use in transmissive devices such as liquid crystal displays with backlights is limited. Polyimide films are further expected to be used as substrates for display applications (refer to Patent Documents 1 to 3).

In general, it is difficult for a flexible film to maintain planarity, so it is difficult to uniformly and precisely form semiconductor elements such as TFTs, fine wiring, and the like on the flexible film. For example, Patent Document 4 describes the following: "A method of manufacturing a flexible device as a display device or a light-receiving device, which includes the following steps: coating a specific precursor resin composition on a carrier substrate to form a film, The step of forming a solid polyimide resin film; the step of forming a circuit on the resin film; and the step of peeling the solid resin film with the circuit formed on the surface from the carrier substrate".

In addition, Patent Document 5 discloses a method of manufacturing a flexible device, which includes the steps of forming a polyimide film on a glass substrate, and forming a polyimide film/glass substrate laminate obtained on the obtained polyimide film After the components and circuits required for the device are irradiated with a laser from the glass substrate side, the glass substrate is peeled off.

Patent Document 6 discloses a polyimide precursor composition and a method for producing a polyimide film/glass substrate laminate using the polyimide precursor composition, the above-mentioned polyimide precursor composition The compound contains a polyimide precursor composition and an imidazole compound, the polyimide precursor composition including a compound having an alicyclic structure from one of the tetracarboxylic acid component and the diamine component and the other having an aromatic A repeating unit of a compound of a ring. The polyimide film obtained in the invention of Patent Document 6 has a small retardation (retardation) in the thickness direction, and is excellent in mechanical properties, and furthermore, excellent in transparency.

In addition, Patent Document 7 describes a polyimide precursor obtained from a tetracarboxylic acid and a specific diamine compound and having an imidization rate of 30 mol % or more and 90 mol % or less (see Claim 1). If a polyimide film is produced by using the polyimide precursor, the advantageous effect of reducing the coefficient of linear thermal expansion can be obtained without the stretching operation that is often performed in the production process of the polymer film. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2012/011590 [Patent Document 2] International Publication No. 2013/179727 [Patent Document 3] International Publication No. 2014/038715 [Patent Document 4] Japanese Patent Laid-Open No. 2010-202729 [Patent Document 5] International Publication No. 2018/221607 [Patent Document 6] International Publication No. 2015/080158 [Patent Document 7] International Publication No. 2014/067079

[Problems to be Solved by Invention]

As described above, the invention of Patent Document 7 can produce a polyimide film having excellent properties, but it is desirable to further improve various properties such as thermal properties, heat resistance, mechanical properties, and transparency in a well-balanced manner.

The present invention has been made in view of the foregoing problems, and its main object is to provide a polyimide precursor composition capable of producing a polyimide film having excellent thermal properties and/or heat resistance and also excellent in transparency. Another aspect of the present invention aims to provide a polyimide film obtained by using the above-mentioned polyimide precursor composition, and a polyimide film/substrate laminate, which is another difference of the present invention. An object of an aspect is to provide a method for manufacturing a flexible electronic device using the above-mentioned polyimide precursor composition, and a flexible electronic device. [Technical means to solve problems]

The main disclosures of this application are summarized as follows.

1. a polyimide precursor composition is characterized in that containing: A polyimide precursor, the repeating unit of which comprises the repeating unit represented by the following general formula (I) and the repeating unit formed by further imidization of the general formula (I), and the imidization rate exceeds 0% and less than 50%; and solvent.

(通式I中，X ₁係四價脂肪族基或芳香族基，Y ₁係二價脂肪族基或芳香族基，R ₁及R ₂彼此獨立，為氫原子、碳數1～6之烷基或碳數3～9之烷基矽烷基，其中，70莫耳%以上之X ₁係式(1-1)所表示之結構， [hua 1]

(In general formula I, X ₁ is a tetravalent aliphatic group or an aromatic group, Y ₁ is a divalent aliphatic group or an aromatic group, R ₁ and R ₂ are independent of each other, and are a hydrogen atom and a carbon number of 1 to 6. An alkyl group or an alkylsilyl group having 3 to 9 carbon atoms, wherein X ₁ of 70 mol% or more is the structure represented by the formula (1-1),

70莫耳%以上之Y ₁係式(D-1)及/或(D-2)所表示之結構， [hua 2]

More than 70 mol% of Y ₁ is the structure represented by formula (D-1) and/or (D-2),

) [hua 3]

)

2. The polyimide precursor composition according to the above item 1, wherein the polyimide film obtained from the polyimide precursor composition has a wavelength of 400 in a film with a thickness of 10 μm The transmittance of nm light is more than 79%.

3. The polyimide precursor composition according to the above item 1 or 2, wherein the polyimide film obtained from the polyimide precursor composition is in a film having a thickness of 10 μm. It has a linear thermal expansion coefficient below 20 ppm/K between 150°C and 250°C.

4. The polyimide precursor composition according to any one of the above items 1 to 3, wherein the polyimide obtained from the polyimide precursor composition has a temperature of 500°C or higher. 5% weight loss temperature.

5. The polyimide precursor composition according to any one of the above items 1 to 4, wherein the polyimide film obtained from the polyimide precursor composition has a thickness of 10 μm The elongation at break in the film is more than 10%.

6. The polyimide precursor composition according to any one of the above items 1 to 5, wherein 90 mol% or more of X ₁ is a structure represented by the above formula (1-1).

7. A polyimide film obtained from the polyimide precursor composition according to any one of the above items 1 to 6.

8. A polyimide film/substrate laminate, characterized in that it has: A polyimide film obtained from the polyimide precursor composition as described in any one of the above items 1 to 6; and substrate.

9. The laminate according to the above item 8, wherein the base material is a glass substrate.

10. A method for manufacturing a polyimide film/substrate laminate, comprising the steps of: (a) the step of coating the polyimide precursor composition as described in any one of the above items 1 to 6 on a substrate; and (b) the step of heating the above-mentioned polyimide precursor on the above-mentioned base material, and laminating the polyimide film on the above-mentioned base material.

11. The manufacturing method of the said item 10 whose said base material is a glass substrate.

12. A method for manufacturing a flexible electronic device, comprising the steps of: (a) the step of coating the polyimide precursor composition as described in any one of the above items 1 to 6 on a substrate; (b) heat-treating the above-mentioned polyimide precursor on the above-mentioned base material to manufacture a polyimide film/substrate laminate having a polyimide film laminated on the above-mentioned base material; (c) a step of forming at least one layer selected from a conductor layer and a semiconductor layer on the polyimide film of the laminate; and (d) The step of peeling the above-mentioned base material and the above-mentioned polyimide film.

13. The manufacturing method of the said item 12 whose said base material is a glass substrate. [Effect of invention]

According to the present invention, it is possible to provide a polyimide precursor capable of producing a polyimide film having excellent thermal properties (low coefficient of linear thermal expansion, etc.) and/or heat resistance (5% weight loss temperature, etc.) and also excellent in transparency body composition. According to the embodiment of the polyimide precursor composition of the present invention, it is possible to produce the effect that at least one of (i) thermal properties such as low linear thermal expansion coefficient and (ii) heat resistance such as 5% weight loss temperature can be produced. And transparency is also an excellent polyimide film.

According to another aspect of the present invention, a polyimide film obtained by using the above-described polyimide precursor composition, and a polyimide film/substrate laminate can be provided. According to yet another different aspect of the present invention, a method for manufacturing a flexible electronic device using the above-mentioned polyimide precursor composition, and a flexible electronic device can be provided.

In this application, "flexible (electronic) device" means that the device itself is flexible, and a semiconductor layer (transistor, diode, etc. as an element) is usually formed on a substrate to complete the device. "Flexible (electronic) device" is different from the previous FPC (Flexible Printed Wiring Board) mounted on "harder" semiconductor elements such as IC (Integrated Circuit) chips, such as COF (Chip On) Film, thin film on chip) and other devices. However, in order to operate or control the "flexible (electronic) device" of the present application, there is no such thing as mounting or electrically connecting a "hard" semiconductor element such as an IC chip on a flexible substrate and then fusing it. question. Suitable flexible (electronic) devices include display devices such as liquid crystal displays, organic EL displays, and electronic paper, solar cells, and light-receiving devices such as CMOS (complementary metal oxide semiconductor).

Hereinafter, the polyimide precursor composition of the present invention will be described, and then, the manufacturing method of the flexible electronic device will be described.

＜＜Polyimide precursor composition＞＞ The polyimide precursor composition for forming the polyimide film contains a polyimide precursor and a solvent. The polyimide precursor is dissolved in the solvent.

The polyimide precursor contains a repeating unit represented by the following general formula (I) and a repeating unit obtained by further imidization of the general formula (I).

(通式I中，X ₁係四價脂肪族基或芳香族基，Y ₁係二價脂肪族基或芳香族基，R ₁及R ₂彼此獨立，為氫原子、碳數1～6之烷基或碳數3～9之烷基矽烷基) [hua 4]

(In general formula I, X ₁ is a tetravalent aliphatic group or an aromatic group, Y ₁ is a divalent aliphatic group or an aromatic group, R ₁ and R ₂ are independent of each other, and are a hydrogen atom and a carbon number of 1 to 6. Alkyl or alkylsilyl with 3 to 9 carbon atoms)

The so-called repeating unit of the general formula (I) further imidized refers to the structure in which one or two of the two imide bonds existing in the general formula (I) are converted into imide bonds. Specifically, it is represented by the following general formulae (Ib), (Ic) and (II).

[hua 5]

[hua 6]

[hua 7]

The so-called imidization rate refers to the ratio at which the imide bond in the general formula (I) is converted into an imide bond. Therefore, when all repeating units in the polyimide precursor are of general formula (I), the imidization rate is 0%, and when all repeating units are of general formula (Ib) and/or (Ic) ), the imidization rate is 50%, and if all repeating units are of general formula (II), the imidization rate is 100% (ie, polyimide). In the present invention, the term "imidation rate exceeding 0% and less than 50%" means that in addition to the structure of general formula (I), there are general formulas (Ib), One or more of (Ic) and (II).

Regarding the imidization rate, the ¹ H-NMR (nuclear magnetic resonance, nuclear magnetic resonance) spectrum of the polyimide precursor (solution) can be measured. Calculated from the ratio of the integral value of the peak (9.5 to 10.5 ppm) of amine protons.

In addition, the polyimide precursor having an adjusted imidization rate can be produced by a production method comprising the following steps: when the tetracarboxylic acid component and the diamine component are reacted, or when the tetracarboxylic acid component and the diamine component are reacted After the component obtains a precursor having a repeating unit represented by the general formula (I), it is reacted for an appropriate time under appropriate conditions for the imidization reaction to proceed to achieve the desired imidization rate.

It is roughly divided into the following two methods: a method in which the imidization reaction is carried out evenly (or randomly) in the molecule (referred to as a single-stage supply method for convenience); the tetracarboxylic acid component and the diamine are separately supplied. For each component, a method (or in blocks) performed only between a part of the tetracarboxylic acid component and a part of the diamine component in the imidization reaction (for convenience, called a multi-stage supply method) is described in detail below.

In the single-stage supply method, when the tetracarboxylic acid component and the diamine component are reacted, or after obtaining a precursor having a repeating unit represented by the general formula (I) from the tetracarboxylic acid component and the diamine component, the reaction is performed at an appropriate temperature. The reaction is continued for an appropriate time so that the imidization proceeds to the target imidization rate. The temperature range is, for example, 0°C or higher, preferably 15°C or higher, for example, 180°C or lower, preferably 150°C or lower, and more preferably 130°C or lower. Regarding the time range, generally speaking, the higher the temperature, the shorter the time, and the lower the temperature, the longer the time. The imidization rate can be adjusted accordingly, but it is preferably, for example, several seconds or more, for example, one minute or more to about one year. Choose appropriately from the following ranges. In addition, the reaction temperature and the reaction time are preferably also changed depending on whether the following imidazole compound is added or not, and the type and amount of the following imidazole compound. The single-stage feed method is preferably carried out by thermal imidization, and preferably does not include a dehydrating agent for chemical imidization.

In the two-stage supply method, the imidization rate is adjusted by separately supplying the tetracarboxylic acid component and the diamine component to a plurality of steps, and performing the reaction under different conditions in the plurality of steps. Taking the case of two-stage supply as an example, the method is as follows: the first step includes supplying only a part of the tetracarboxylic acid component and a part of the diamine component, and the imidization reaction proceeds rapidly at high temperature, and as a result, complete imidization is obtained. Alternatively, after the high imidization rate precursor, in the second step, the remaining tetracarboxylic acid component and the diamine component are supplied and reacted under conditions that suppress the imidization reaction. The high temperature heating conditions of the first step are preferably 100°C or higher, more preferably 120°C to 250°C, and the temperature conditions of the second step are less than 100°C, more preferably less than 90°C. It is usually 0°C or higher, preferably 15°C or higher. The imidization rate can be adjusted according to the distribution ratio of the tetracarboxylic acid component and the diamine component in the first step and the second step. The method is also preferably carried out by thermal imidization, preferably without the dehydrating agent used to perform the chemical imidization.

The general formulae (Ib), (Ic) and (II) are repeating units formed by further imidization of the structure of the general formula (I). Therefore, X in the general formulae (Ib), (Ic) and (II) ₁ , Y ₁ , R ₁ and R ₂ have groups derived from the general formula (I). Therefore, the descriptions of the preferred structures of the general formula (I) below also apply to the structures of the general formulae (Ib), (Ic) and (II).

The precursor represented by the general formula (I) is particularly preferably a polyamic acid in which R ₁ and R ₂ are hydrogen atoms. When X ₁ and Y ₁ are an aliphatic group, the aliphatic group is preferably a group having an alicyclic structure.

Among all the repeating units in the polyimide precursor, preferably 70 mol% or more of X ₁ is the structure represented by the following formula (1-1), that is, derived from noralkane-2-spiro-α -The structure of cyclopentanone-α'-spiro-2"-noroxane-5,5",6,6"-tetracarboxylic dianhydride (hereinafter, abbreviated as CpODA if necessary).

[hua 8]

Among all the repeating units in the polyimide precursor, preferably 70 mol% or more of Y ₁ is the structure represented by the following formula (D-1) and/or (D-2), that is, derived from 4 , The structure of 4'-diaminobenzylaniline (abbreviated as DABAN if necessary).

[Chemical 9]

By using the composition containing such a polyimide precursor, a polyimide film excellent in thermal properties such as a low coefficient of linear thermal expansion and also excellent in transparency can be produced.

The polyimide precursor will be described based on the monomers (tetracarboxylic acid component, diamine component, and other components) that provide X ₁ and Y ₁ in the general formula (I), and then the production method will be described.

In this specification, the tetracarboxylic acid component includes tetracarboxylic acid, tetracarboxylic dianhydride, other tetracarboxylic acid silane ester, tetracarboxylic acid ester, tetracarboxylic acid chloride and other tetracarboxylic acids used as raw materials for the production of polyimide derivative. Although it is simple to use a tetracarboxylic dianhydride for manufacture, it does not specifically limit, In the following description, the example which uses a tetracarboxylic dianhydride as a tetracarboxylic-acid component is demonstrated. Moreover, a diamine component is a diamine compound which has two amine groups ( _-NH2 ) used as a raw material for manufacture of polyimide.

In addition, in this specification, a polyimide film is formed on a (carrier) base material and means both what exists in a laminated body, and the film after the base material is peeled off. Moreover, the material obtained by heat-processing (imidation) the polyimide precursor composition which is the material which comprises a polyimide film may be called "polyimide material".

<X ₁ and tetracarboxylic acid components> As described above, in all repeating units in the polyimide precursor, X ₁ is preferably 70 mol% or more of the structure represented by the formula (1-1), More preferably, it is 80 mol % or more, still more preferably 90 mol % or more, and most preferably 95 mol % or more (also very preferably 100 mol %) is the structure represented by the formula (1-1). The structure of formula (1-1) is provided as X ₁ tetracarboxylic dianhydride-based CpODA.

CpODA may be a mixture of stereoisomers, or may be one specific stereoisomer. As a preferred stereoisomer, trans-endo-endo-noroxane-2-spiro-α-cyclopentanone-α'-spiro-2"-noroxane-5,5",6 ,6"-tetracarboxylic dianhydride (CpODA-tee) and cis-endo-endo-nor alkane-2-spiro-α-cyclopentanone-α'-spiro-2"-nor alkane-5,5 ",6,6"-tetracarboxylic dianhydride (CpODA-cee), but is not particularly limited.

[Chemical 10]

In a preferred embodiment, at least 50 mol% or more of CpODA, more preferably 63 mol% or more, is CpODA-tee. In a different preferred embodiment, at least 30 mol % or more of CpODA, more preferably 37 mol % or more, is CpODA-cee. In another different preferred embodiment, the total of CpODA-tee and CpODA-cee in CpODA is at least 80 mol% or more, and more preferably 83 mol% or more.

In the present invention, a tetravalent aliphatic group or an aromatic group other than the structure represented by the formula (1-1) (abbreviated as "other X ₁ ") may be contained as X in an amount within a range that does not impair the effects of the present invention. ₁ . That is, in addition to CpODA, the tetracarboxylic acid component may contain other tetracarboxylic acid derivatives in an amount within a range that does not impair the effects of the present invention. The amount of other tetracarboxylic acid derivatives is less than 30 mol %, more preferably less than 20 mol %, more preferably less than 10 mol % (also preferably less than 10 mol % relative to 100 mol % of the tetracarboxylic acid component is 0 mol%).

When "other X ₁ " is a tetravalent group having an aromatic ring, it is preferably a tetravalent group having an aromatic ring having 6 to 40 carbon atoms.

As a tetravalent group which has an aromatic ring, the following are mentioned, for example.

(式中，Z ₁係直接鍵、或下述二價基中任一者；其中，式中之Z ₂係二價有機基，Z ₃、Z ₄分別獨立，係醯胺鍵、酯鍵、羰基鍵，Z ₅係包含芳香環之有機基) [Chemical 11]

(in the formula, Z ₁ is a direct bond, or any one of the following divalent groups; wherein, Z ₂ in the formula is a divalent organic group, Z ₃ and Z ₄ are independently, respectively, an amide bond, an ester bond, Carbonyl bond, Z ₅ is an organic group containing an aromatic ring)

[Chemical 12]

Specific examples of Z ₂ include aliphatic hydrocarbon groups having 2 to 24 carbon atoms, and aromatic hydrocarbon groups having 6 to 24 carbon atoms.

Specifically, as Z ₅ , an aromatic hydrocarbon group having 6 to 24 carbon atoms may be mentioned.

As a tetravalent group which has an aromatic ring, what is mentioned below is especially preferable, since it can achieve both high heat resistance and high transparency of the polyimide film obtained by this.

(式中，Z ₁係直接鍵、或六氟亞異丙基鍵) [Chemical 13]

(in the formula, Z ₁ is a direct bond or a hexafluoroisopropylidene bond)

Among them, Z ₁ is more preferably a direct bond, because it can take into account the high heat resistance, high transparency, and low coefficient of linear thermal expansion of the obtained polyimide film.

Moreover, as a preferable group, the compound which Z ₁ in the said formula (9) is a perylene group-containing group represented by the following formula (3A) can be mentioned.

Z ₁₁及Z ₁₂分別獨立，較佳為同為單鍵或二價有機基。作為Z ₁₁及Z ₁₂，較佳為包含芳香環之有機基，例如較佳為式(3A1)所表示之結構。 [Chemical 14]

Z ₁₁ and Z ₁₂ are each independently, preferably both are a single bond or a divalent organic group. As Z ₁₁ and Z ₁₂ , an organic group containing an aromatic ring is preferable, and for example, a structure represented by formula (3A1) is preferable.

(Z ₁₃及Z ₁₄彼此獨立，係單鍵、-COO-、-OCO-或-O-，其中，於Z ₁₄鍵結於茀基之情形時，較佳為Z ₁₃係-COO-、-OCO-或-O-且Z ₁₄係單鍵之結構；R ₉₁係碳數1～4之烷基或苯基，較佳為甲基，n係0～4之整數，較佳為1) [Chemical 15]

(Z ₁₃ and Z ₁₄ are independent of each other, and are single bond, -COO-, -OCO- or -O-, wherein, when Z ₁₄ is bonded to a phenyl group, preferably Z ₁₃ is -COO-, - OCO- or -O- and Z ₁₄ is the structure of a single bond; R ₉₁ is an alkyl group or a phenyl group with a carbon number of 1 to 4, preferably a methyl group, and n is an integer of 0 to 4, preferably 1)

As the tetracarboxylic acid component that provides the repeating unit of the general formula ( _I ) having a tetravalent group of an aromatic ring, for example, 2,2-bis(3,4-dicarboxyphenyl)hexafluoro Propane, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, pyromellitic acid, 3,3',4 ,4'-benzophenone tetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 4,4'-oxygen Diphthalic acid, bis(3,4-dicarboxyphenyl) bismuth, m-triphenyl-3,4,3',4'-tetracarboxylic acid, p-triphenyl-3,4,3',4 '-Tetracarboxylic acid, biscarboxyphenyldimethylsilane, bisdicarboxyphenoxydiphenyl sulfide, sulfonyldiphthalic acid, or its tetracarboxylic dianhydride, tetracarboxylic silane ester , tetracarboxylate, tetracarboxylic acid chloride and other derivatives. As the tetracarboxylic acid component that provides the repeating unit of the general formula ( _I ) having a tetravalent group of an aromatic ring containing a fluorine atom, for example, 2,2-bis(3,4-dicarboxyphenyl) ) hexafluoropropane, or derivatives thereof such as tetracarboxylic dianhydride, tetracarboxylic silane ester, tetracarboxylic acid ester, tetracarboxylic acid chloride and the like. Furthermore, as a preferable compound, (9H-perylene-9,9-diyl)bis(2-methyl-4,1-phenylene)bis(1,3-dioxo-1,3) can be mentioned. - dihydroisobenzofuran-5-carboxylate). The tetracarboxylic acid component may be used alone or in combination of two or more.

When "other X ₁ " is a tetravalent group having an alicyclic structure, it is preferably a tetravalent group having an alicyclic structure with 4 to 40 carbon atoms, more preferably at least one aliphatic 4 to 12-membered ring , more preferably having an aliphatic 4-membered ring or an aliphatic 6-membered ring. As a tetravalent group which has a preferable aliphatic 4-membered ring or aliphatic 6-membered ring, the following can be mentioned.

(式中，R ₃₁～R ₃₈分別獨立，係直接鍵或二價有機基；R ₄₁～R ₄₇及R ₇₁～R ₇₃分別獨立地表示選自由式：-CH ₂-、-CH=CH-、-CH ₂CH ₂-、-O-、-S-所表示之基所組成之群中之1種；R ₄₈係包含芳香環或脂環結構之有機基) [Chemical 16]

(in the formula, R ₃₁ to R ₃₈ are each independently, and are a direct bond or a divalent organic group; R ₄₁ to R ₄₇ and R ₇₁ to R ₇₃ are independently selected from the formula: -CH ₂ -, -CH=CH- , -CH ₂ CH ₂ -, -O-, -S- is one of the group consisting of groups; R ₄₈ is an organic group containing an aromatic ring or alicyclic structure)

Specific examples of R ₃₁ , R ₃₂ , R ₃₃ , R ₃₄ , R ₃₅ , R ₃₆ , R ₃₇ , and R ₃₈ include a direct bond, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, or an oxygen atom. (-O-), sulfur atom (-S-), carbonyl bond, ester bond, amide bond.

As an organic group containing an aromatic ring as R _<48 >, the following are mentioned, for example.

(式中，W ₁係直接鍵或二價有機基，n ₁₁～n ₁₃分別獨立地表示0～4之整數，R ₅₁、R ₅₂、R ₅₃分別獨立，係碳數1～6之烷基、鹵基、羥基、羧基或三氟甲基) [Chemical 17]

(In the formula, W ₁ is a direct bond or a divalent organic group, n ₁₁ to n ₁₃ are each independently an integer of 0 to 4, R ₅₁ , R ₅₂ and R ₅₃ are each independently, and are an alkyl group with 1 to 6 carbon atoms. , halogen, hydroxyl, carboxyl or trifluoromethyl)

As W1, _a direct bond, the divalent group represented by following formula (5), and the divalent group represented by following formula (6) are mentioned specifically,.

(式(6)中之R ₆₁～R ₆₈分別獨立地表示直接鍵或上述式(5)所表示之二價基中任一者) [Chemical 18]

(R ₆₁ to R ₆₈ in the formula (6) each independently represent a direct bond or any of the divalent groups represented by the above formula (5))

As the tetravalent group having an alicyclic structure, the following ones are particularly preferable, since the high heat resistance, high transparency, and low coefficient of linear thermal expansion of the obtained polyimide can be achieved.

[Chemical 19]

As the tetracarboxylic acid component that provides the repeating unit of the formula (I) having a tetravalent group with an alicyclic structure, X ₁ may, for example, include 1,2,3,4-cyclobutanetetracarboxylic acid, isopropylene Diphenoxydiphthalic acid, cyclohexane-1,2,4,5-tetracarboxylic acid, [1,1'-bis(cyclohexane)]-3,3',4,4' -Tetracarboxylic acid, [1,1'-bi(cyclohexane)]-2,3,3',4'-tetracarboxylic acid, [1,1'-bi(cyclohexane)]-2,2 ',3,3'-tetracarboxylic acid, 4,4'-methylenebis(cyclohexane-1,2-dicarboxylic acid), 4,4'-(propane-2,2-diyl)bis (cyclohexane-1,2-dicarboxylic acid), 4,4'-oxybis(cyclohexane-1,2-dicarboxylic acid), 4,4'-thiobis(cyclohexane-1 , 2-dicarboxylic acid), 4,4'-sulfonylbis(cyclohexane-1,2-dicarboxylic acid), 4,4'-(dimethylsilanediyl)bis(cyclohexane- 1,2-dicarboxylic acid), 4,4'-(tetrafluoropropane-2,2-diyl)bis(cyclohexane-1,2-dicarboxylic acid), octahydrocyclopentadiene-1 ,3,4,6-tetracarboxylic acid, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid, 6-(carboxymethyl)bicyclo[2.2.1]heptane-2, 3,5-Tricarboxylic acid, Bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid, Bicyclo[2.2.2]-5-octene-2,3,7,8-tetra Carboxylic acid, tricyclo[4.2.2.02,5]decane-3,4,7,8-tetracarboxylic acid, tricyclo[4.2.2.02,5]-7-decene-3,4,9,10- Tetracarboxylic acid, 9-oxatricyclo[4.2.1.02,5]nonane-3,4,7,8-tetracarboxylic acid, (4arH,8acH)-decahydro-1t,4t:5c,8c-di Naphthalene-2c,3c,6c,7c-tetracarboxylic acid, (4arH,8acH)-decahydro-1t,4t:5c,8c-dimethylnaphthalene-2t,3t,6c,7c-tetracarboxylic acid, Decahydro-1,4-ethyl-5,8-methyl-naphthalene-2,3,6,7-tetracarboxylic acid, tetradecahydro-1,4:5,8:9,10-trimethyl-anthracene- 2,3,6,7-tetracarboxylic acid, its derivatives such as tetracarboxylic dianhydride, tetracarboxylic silane ester, tetracarboxylic acid ester, tetracarboxylic acid chloride and the like. The tetracarboxylic acid component may be used alone or in combination of two or more.

<Y ₁ and diamine component> As described above, in all repeating units in the polyimide precursor, preferably 70 mol % or more of Y ₁ is of formula (D-1) and/or (D- 2) The represented structure is more preferably 80 mol% or more, and more preferably 90 mol% or more (also preferably 100 mol%) is the formula (D-1) and/or (D-2) represented structure. The diamine compound that provides the structure of formula (D-1) and formula (D-2) as Y ₁ is 4,4'-diaminobenzylaniline (abbreviation: DABAN).

In the present invention, a divalent aliphatic group or an aromatic group other than the structures represented by the formulae (D-1) and (D-2) may be contained in an amount within a range that does not impair the effects of the present invention (abbreviated as "other groups"). Y ₁ ") as Y ₁ . That is, in addition to DABAN, the diamine component may contain other diamine compounds in an amount within a range that does not impair the effects of the present invention. The amount of other diamine compounds is less than 30 mol %, more preferably less than 20 mol %, more preferably less than 10 mol % (also preferably 0 mol %, relative to 100 mol % of the diamine component). Ear%).

When "other Y ₁ " is a divalent group having an aromatic ring, it is preferably a divalent group having an aromatic ring having 6 to 40 carbon atoms, and more preferably a divalent group having an aromatic ring having 6 to 20 carbon atoms.

As a divalent group which has an aromatic ring, the following are mentioned, for example.

(式中，W ₁係直接鍵或二價有機基，n ₁₁～n ₁₃分別獨立地表示0～4之整數，R ₅₁、R ₅₂、R ₅₃分別獨立，係碳數1～6之烷基、鹵基、羥基、羧基或三氟甲基) [hua 20]

(In the formula, W ₁ is a direct bond or a divalent organic group, n ₁₁ to n ₁₃ each independently represent an integer of 0 to 4, R ₅₁ , R ₅₂ and R ₅₃ are each independently, and are an alkyl group with 1 to 6 carbon atoms. , halogen, hydroxyl, carboxyl or trifluoromethyl)

As W1, _a direct bond, the divalent group represented by following formula (5), and the divalent group represented by following formula (6) are mentioned specifically,.

[Chemical 21]

(式(6)中之R ₆₁～R ₆₈分別獨立地表示直接鍵或上述式(5)所表示之二價基中之任一者) [Chemical 22]

(R ₆₁ to R ₆₈ in the formula (6) each independently represent a direct bond or any one of the divalent groups represented by the above formula (5))

Among them, W ₁ is preferably a direct bond, or one selected from the group consisting of bases represented by the formula: -NHCO-, -CONH-, -COO-, -OCO-, because it can take into account the obtained Polyimide has high heat resistance, high transparency and low coefficient of linear thermal expansion. Moreover, W ₁ is also particularly preferably a direct bond of R ₆₁ to R ₆₈ , or one selected from the group consisting of groups represented by the formulae: -NHCO-, -CONH-, -COO-, and -OCO- Any of the divalent groups represented by the above formula (6). Among them, when -NHCO- or -CONH- is selected, "other Y ₁ " is selected in a manner different from formula (D-1) or formula (D-2).

Moreover, as a preferable group, W ₁ in the said formula (4) is a compound containing a perylene group represented by the following formula (3B).

Z ₁₁及Z ₁₂分別獨立，較佳為同為單鍵或二價有機基。作為Z ₁₁及Z ₁₂，較佳為包含芳香環之有機基，例如較佳為式(3B1)所表示之結構。 [Chemical 23]

Z ₁₁ and Z ₁₂ are each independently, preferably both are a single bond or a divalent organic group. As Z ₁₁ and Z ₁₂ , an organic group containing an aromatic ring is preferable, and for example, a structure represented by formula (3B1) is preferable.

(Z ₁₃及Z ₁₄彼此獨立，係單鍵、-COO-、-OCO-或-O-，其中，於Z ₁₄鍵結於茀基之情形時，較佳為Z ₁₃係-COO-、-OCO-或-O-且Z ₁₄係單鍵之結構；R ₉₁係碳數1～4之烷基或苯基，較佳為苯基，n係0～4之整數，較佳為1) [Chemical 24]

(Z ₁₃ and Z ₁₄ are independent of each other, and are single bond, -COO-, -OCO- or -O-, wherein, when Z ₁₄ is bonded to a phenyl group, preferably Z ₁₃ is -COO-, - OCO- or -O- and Z ₁₄ is the structure of a single bond; R ₉₁ is an alkyl group with 1 to 4 carbon atoms or a phenyl group, preferably a phenyl group, and n is an integer of 0 to 4, preferably 1)

As another preferred group, the compound in which W ₁ is a phenylene group in the above formula (4) can be exemplified, that is, a bitriphenylenediamine compound, especially a compound which is a para-bond.

As another preferred group, W ₁ in the above formula (4) is a compound in which R ₆₁ and R ₆₂ are 2,2-propylene groups in the structure of the first benzene ring of the formula (6).

As another preferable group, the compound represented by the following formula (3B2) in which W ₁ in the above-mentioned formula (4) is exemplified.

[Chemical 25]

As a diamine component that provides a repeating unit of the general formula ( _I ) having a divalent group of an aromatic ring, for example, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3'- Diaminobiphenyl, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-bis(trifluoromethyl)benzidine, m-tolidine, 3,4'-diaminobenzene Tolylamine, N,N'-bis(4-aminophenyl)terephthalamide, N,N'-p-phenylene bis(p-aminobenzylamine), 4-aminobenzene Oxy-4-diaminobenzoate, bis(4-aminophenyl)terephthalate, biphenyl-4,4'-dicarboxylate bis(4-aminophenyl)ester , p-phenylene bis(p-aminobenzoate), bis(4-aminophenyl)-[1,1'-biphenyl]-4,4'-dicarboxylate, [1,1 '-Biphenyl]-4,4'-diylbis(4-aminobenzoate), 4,4'-oxydiphenylamine, 3,4'-oxydiphenylamine, 3,3'-oxydiphenylamine Aniline, p-methylenebis(phenylenediamine), 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis (4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, 2,2 -Bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, bis(4-aminophenyl)sulfane, 3 ,3'-bis(trifluoromethyl)benzidine, 3,3'-bis((aminophenoxy)phenyl)propane, 2,2'-bis(3-amino-4-hydroxyphenyl) ) Hexafluoropropane, bis(4-(4-aminophenoxy)diphenyl)sine, bis(4-(3-aminophenoxy)diphenyl)sine, octafluorobenzidine, 3, 3'-Dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4' -Diaminobiphenyl, 2,4-Bis(4-aminoanilino)-6-amino-1,3,5-tris𠯤, 2,4-bis(4-aminoanilino)-6 -Methylamino-1,3,5-tris𠯤, 2,4-bis(4-aminoanilino)-6-ethylamino-1,3,5-tris𠯤, 2,4-bis (4-Aminoanilino)-6-anilino-1,3,5-tris𠯤. As a diamine component that provides a repeating unit of the general formula ( _I ) having a divalent group of an aromatic ring containing a fluorine atom, for example, 2,2'-bis(trifluoromethyl)benzidine is exemplified. , 3,3'-bis(trifluoromethyl)benzidine, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenoxy) phenyl) hexafluoropropane, 2,2'-bis(3-amino-4-hydroxyphenyl)hexafluoropropane. In addition, as a preferable diamine compound, 9,9-bis(4-aminophenyl)perylene, 4,4'-(((9H-perylene-9,9-diyl)bis([ 1,1'-biphenyl]-5,2-diyl))bis(oxy))diamine, [1,1':4',1"-triphenyl]-4,4"-diamine , 4,4'-([1,1'-binaphthyl]-2,2'-diylbis(oxy))diamine. The diamine component may be used alone or in combination of two or more.

When "other Y ₁ " is a divalent group having an alicyclic structure, it is preferably a divalent group having an alicyclic structure with 4 to 40 carbon atoms, and more preferably has at least one aliphatic 4 to 12 members The ring, more preferably, has an aliphatic 6-membered ring.

As a divalent group which has an alicyclic structure, the following are mentioned, for example.

(式中，V ₁、V ₂分別獨立，係直接鍵或二價有機基，n ₂₁～n ₂₆分別獨立地表示0～4之整數，R ₈₁～R ₈₆分別獨立，係碳數1～6之烷基、鹵基、羥基、羧基或三氟甲基，R ₉₁、R ₉₂、R ₉₃分別獨立，係選自由式：-CH ₂-、-CH=CH-、-CH ₂CH ₂-、-O-、-S-所表示之基所組成之群中之1種) [Chemical 26]

(in the formula, V ₁ and V ₂ are each independently and are a direct bond or a divalent organic group, n ₂₁ to n ₂₆ are each independently an integer of 0 to 4, R ₈₁ to R ₈₆ are each independently, and the number of carbon atoms is 1 to 6. The alkyl group, halogen group, hydroxyl group, carboxyl group or trifluoromethyl group, R ₉₁ , R ₉₂ , R ₉₃ are each independently, and are selected from the formula: -CH ₂ -, -CH=CH-, -CH ₂ CH ₂ -, One of the group consisting of the bases represented by -O- and -S-)

Specific examples of V ₁ and V ₂ include a direct bond and a divalent group represented by the above formula (5).

As the divalent group having an alicyclic structure, the one described below is particularly preferable, since it is possible to achieve both high heat resistance and low coefficient of linear thermal expansion of the obtained polyimide.

作為具有脂環結構之二價基，其中，較佳為如下所述者。 [Chemical 27]

Among them, the following ones are preferable as the divalent group having an alicyclic structure.

[Chemical 28]

As a diamine component that provides a repeating unit of the general formula ( _I ) having a divalent group with an alicyclic structure, for example, 1,4-diaminocyclohexane, 1,4-diaminocyclohexane may be mentioned. -2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propylcyclohexane, 1,4-diamino- 2-isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino -2-2-butylcyclohexane, 1,4-diamino-2-tert-butylcyclohexane, 1,2-diaminocyclohexane, 1,3-diaminocyclobutane , 1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, diaminobicycloheptane, diaminomethylbicycloheptane, two Aminooxybicycloheptane, diaminomethyloxybicycloheptane, isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis(amino) Cyclohexyl)methane, bis(aminocyclohexyl)isopropene, 6,6'-bis(3-aminophenoxy)-3,3,3',3'-tetramethyl-1,1' - Spirobisindan, 6,6'-bis(4-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobisindan. The diamine component may be used alone or in combination of two or more.

As the tetracarboxylic acid component and the diamine component that provide the repeating unit represented by the general formula (I), aliphatic tetracarboxylic acids (especially dianhydrides) and/or aliphatic diamines other than alicyclic can be used Any one, its content is preferably 100 mol % relative to the total of the tetracarboxylic acid component and the diamine component, preferably less than 30 mol %, more preferably less than 20 mol %, and more preferably Less than 10 mol% (including 0%).

By including the structure represented by the formula (4) as "other Y ₁ ", p-phenylenediamine, 3,3'-bis(trifluoromethyl)benzidine, m-tolidine, 4, Diamine compounds such as 4'-bis(4-aminophenoxy)biphenyl are used as specific compounds to improve the transparency of the obtained polyimide film. In addition, the Tg may be increased by including a structure represented by the formula (3B) as "other Y ₁ " and a diamine compound such as 9,9-bis(4-aminophenyl)pyridine as a specific compound. , reducing the retardation (retardation) in the film thickness direction.

The polyimide precursor can be produced from the above-mentioned tetracarboxylic acid component and diamine component. The polyimide precursor used in the present invention (the polyimide precursor containing at least one of the repeating units represented by the above formula (I)) can be classified according to the chemical structures taken by R ₁ and R ₂ They are as follows: 1) Polyamic acid (R ₁ and R ₂ are hydrogen; another name is Polyamic acid), 2) Polyamic acid ester (at least a part of R ₁ and R ₂ is an alkyl group; another name is Polyamic acid ester), 3 ) 4) Polyamic acid silyl ester (at least a part of R ₁ and R ₂ is an alkyl silyl group; alias Polyamic acid silyl ester). In addition, each classification of the polyimide precursor can be easily produced by the following production methods. However, the production method of the polyimide precursor used in the present invention is not limited to the following production methods.

1) Polyamide In the case where the repeating unit represented by the formula (I) is a polyamide, any one of the single-stage supply method and the multi-stage supply method can be used, and the above-mentioned single-stage supply method is to make the imidization reaction in the molecule. Evenly (or randomly); the above-mentioned multi-stage supply method is to supply each of the tetracarboxylic acid component and the diamine component separately, and only between a part of the tetracarboxylic acid component and a part of the diamine component in the imidization reaction ( or blockwise).

A production example of the polyimide precursor by the single-stage supply method will be described. In a solvent, the tetracarboxylic dianhydride and the diamine component as the tetracarboxylic acid component are approximately equimolar, preferably the molar ratio of the diamine component to the tetracarboxylic acid component [the number of moles of the diamine component/ The molar ratio of the tetracarboxylic acid component is preferably 0.90 to 1.10, more preferably 0.95 to 1.05, and the reaction proceeds while suppressing excessive imidization at a relatively low temperature such as 120°C or lower. More specifically, diamine is dissolved in an organic solvent or water, tetracarboxylic dianhydride is slowly added to the solution while stirring, and the mixture is stirred at 0 to 120° C., preferably 5 to 80° C. for 1 . -72 hours, but not limited to this. In addition, after that, if necessary, the imidization rate may be adjusted by storing at 5° C. to 40° C. for a predetermined period of time, for example, for a period of one day to about one year, and further performing imidization. The order of addition of the diamine and the tetracarboxylic dianhydride is preferable because it is easy to increase the molecular weight of the polyimide precursor. Moreover, the addition order of the diamine and the tetracarboxylic dianhydride in the said manufacturing method can also be reversed, and it is preferable because this reduces the amount of precipitates. In the case of using water as a solvent, it is preferable to add imidazoles such as 1,2-dimethylimidazole, or a base such as triethylamine in the following amounts relative to the amount of polyamide (polyamide) to be produced. The carboxyl group of the amine precursor) is preferably 0.8 times or more equivalent. When the reaction of the tetracarboxylic acid component and the diamine component is carried out at a relatively high temperature, for example, at 80°C or higher, 90°C or higher, or 100°C or higher, the excessive imidization reaction can be suppressed at the same time. , while achieving the target imidization rate in a relatively short time, the "polyimide precursor composition of the present invention" can be directly prepared.

On the other hand, the temperature (heating) stage of the reaction can also be divided into two stages. In one embodiment, it can be obtained by reacting a tetracarboxylic acid component and a diamine component at a relatively low temperature (for example, 0°C or more and, for example, 80°C or less, and further 70°C or less, etc.) in the first stage. A polyimide precursor with low imidization rate (including 0% imidization rate), and then in the second stage, at a relatively high temperature, such as 80°C or higher, preferably 90°C or higher, and more It is preferable to heat at a temperature of 100° C. or higher, for example, for 5 minutes to 72 hours, and to achieve the target imidization rate while suppressing an excessive imidization reaction. In addition, in a different embodiment, in the first stage, the tetracarboxylic acid component and the diamine component can also be mixed at a relatively low temperature (for example, 0°C or higher, for example, 80°C or lower, and further 70°C or lower). Reaction to obtain a polyimide precursor with a low imidization rate (including 0% imidization rate), and then in the second stage, also at a relatively low temperature, such as above 0 °C and below 80 °C ( or less than 80° C.), preferably at a temperature of 70° C. or lower, the imidization rate is adjusted by performing imidization for a predetermined period of time, for example, about 1 day to about 1 year. If the temperature (heating) stage of the reaction is divided into two stages, a stable polymerization reaction can be achieved by carrying out the reaction of the tetracarboxylic acid component and the diamine component at a relatively low temperature in the first stage, and in this respect more favorable.

Next, the production example of the polyimide precursor by the multi-stage supply method will be described here by taking the two-stage supply as an example. First, in the first step, tetracarboxylic dianhydride, which is a tetracarboxylic acid component, and a diamine component are allowed to react under conditions that allow the imidization reaction to proceed, specifically, at a temperature of 100° C. or higher. . More specifically, the diamine is dissolved in the solvent, tetracarboxylic dianhydride is slowly added to the solution while stirring, and the mixture is stirred for 0.5 to 72 hours at 100°C or higher, preferably 120 to 250°C. Thereby, a soluble imide compound is obtained. The addition order of the diamine and the tetracarboxylic dianhydride can also be reversed.

The degree of polymerization of the imide compound can be determined so as to be soluble according to the molar ratio of the tetracarboxylic acid component and the diamine component to be reacted. Both ends of the soluble imine compound may be an acid anhydride group, a carboxyl group, or an amine group.

The imidization can be carried out by thermal imidization, therefore, chemical imidization agents are not used. Here, the chemical imidizing agent refers to an acid anhydride (dehydrating agent) such as acetic anhydride, and an amine compound (catalyst) such as pyridine and isoquinoline.

Then, in the second step, the tetracarboxylic acid component and/or the diamine component is added to the reaction solution containing the soluble imide compound obtained in the first step, and the reaction is carried out to obtain the polyimide precursor of the present invention. body. In the second step, the molar ratio of the total amount of the tetracarboxylic acid component reacted in the first step and the second step and the total amount of the diamine component is approximately equimolar, preferably the diamine component is relatively The tetracarboxylic acid component and/or the diamine are added so that the molar ratio of the tetracarboxylic acid component [the number of moles of the diamine component/the number of moles of the tetracarboxylic acid component] is 0.90 to 1.10, more preferably 0.95 to 1.05 Element.

In the second step, the reaction is carried out under conditions that inhibit imidization, specifically, at a temperature below 100°C. More specifically, diamine is added to the reaction solution containing the soluble imide compound obtained in the first step, and the mixture is stirred at a temperature of less than 100° C., preferably -20 to 80° C. After 72 hours, add tetracarboxylic dianhydride, and stir for 1-72 hours at a temperature below 100°C, preferably -20-80°C, thereby obtaining the polyimide precursor of the present invention. The addition order of the diamine and the tetracarboxylic dianhydride may be reversed, or the diamine and the tetracarboxylic dianhydride may be added simultaneously. In addition, when adding the total amount of the tetracarboxylic acid component to be reacted to the solvent in the first step, only diamine is added, and the total amount of the diamine component to be reacted is added to the solvent in the first step. In the case of a solvent, only tetracarboxylic dianhydride was added.

In the second step, imidization may be performed, and the reaction temperature and reaction time may be appropriately selected so that the rate of imidization of the finally obtained polyimide precursor falls within a predetermined range. In this way, in the first step, the repeating unit of the imide structure (the structure of the general formula (II)) can be mainly generated, and in the second step, the repeating unit of the imide structure represented by the above chemical formula (I) can be mainly generated, Thereby, the imidization rate is adjusted.

2) Polyurethane When the repeating unit represented by the formula (I) is a polyamic acid ester, it can be obtained by the following reaction. First, tetracarboxylic dianhydride is reacted with any alcohol to obtain diester dicarboxylic acid, and then it is reacted with a chlorinating reagent (thionine chloride, oxalic chloride, etc.) to obtain diester dicarboxylate chlorine. The diester dicarboxylate chloride and diamine are stirred at -20 to 120°C, preferably -5 to 80°C for 1 to 72 hours, thereby obtaining a polyimide precursor (polyamide ester). ). When the reaction is carried out at a temperature of 80°C or higher, the molecular weight varies according to the temperature history during polymerization, and imidization is carried out by heat. Therefore, there is a possibility that a polyimide precursor cannot be produced stably. body. Moreover, a polyimide precursor can also be obtained simply by dehydrating and condensing diester dicarboxylic acid and diamine using a phosphorus-based condensing agent, a carbodiimide condensing agent, or the like.

The polyimide precursor obtained by this method is relatively stable, so it is also possible to add a solvent such as water or alcohol for purification such as reprecipitation.

It can be used in the same way as 1) the item of polyamide (refer to the single-stage supply method, that is, the second stage of the method in which the temperature of the first stage is low - the temperature of the second stage is high and the temperature of the first stage is low - the temperature of the second stage is low. stage) to react the obtained polyimide precursor (polyamide). That is, in one embodiment, it can be heated at a relatively high temperature, for example, 80°C or higher, preferably 90°C or higher, and more preferably 100°C or higher, for example, for 5 minutes to 72 hours, in order to suppress excessive glutathione. The target imidization rate is achieved at the same time as the imidization reaction. In addition, in different embodiments, it can also be carried out at a relatively low temperature, for example, above 0°C and below 80°C (or below 80°C), preferably below 70°C, for a predetermined period of time, such as 1 day The imidization rate is adjusted by performing imidization in about one year.

3) Polyamide silyl ester (indirect method) When the repeating unit represented by the formula (I) is a polyamide silyl ester, it can be obtained by the reaction of the indirect method described in this section or the direct method described in the next section. First, in the indirect method, a diamine and a silylating agent are reacted in advance to obtain a silylated diamine. The silanated diamine is purified by distillation or the like as necessary. Then, the silanized diamine is dissolved in the dehydrated solvent, and while stirring, the tetracarboxylic dianhydride is slowly added at a temperature in the range of 0 to 120°C, preferably 5 to 80°C. The polyimide precursor is obtained by stirring for 1 to 72 hours. When the reaction is carried out at a temperature of 80°C or higher, the molecular weight varies according to the temperature history during polymerization, and imidization is carried out by heat. Therefore, there is a possibility that a polyimide precursor cannot be produced stably. body.

It can be used in the same way as 1) the item of polyamide (refer to the single-stage supply method, that is, the second stage of the method in which the temperature of the first stage is low - the temperature of the second stage is high and the temperature of the first stage is low - the temperature of the second stage is low. stage) to react the obtained polyimide precursor (polyamide silyl ester). That is, in one embodiment, it can be heated at a relatively high temperature, for example, 80°C or higher, preferably 90°C or higher, and more preferably 100°C or higher, for example, for 5 minutes to 72 hours, in order to suppress excessive glutathione. The target imidization rate is achieved at the same time as the imidization reaction. In addition, in different embodiments, it can also be carried out at a relatively low temperature, for example, above 0°C and below 80°C (or below 80°C), preferably below 70°C, for a predetermined period of time, such as 1 day The imidization rate is adjusted by performing imidization in about one year.

4) Polyamide silyl ester (direct method) Mix the polyamic acid solution with the specified imidization rate obtained by the method 1) and the silylating agent, and stir at a temperature in the range of 0 to 120°C, preferably 5 to 80°C for 1 to 72 hours , thereby obtaining a polysiloxane with a specified imidization rate.

Alternatively, the tetracarboxylic dianhydride as the tetracarboxylic acid component and the diamine component are reacted under conditions that inhibit imidization, for example, at a temperature of less than 100° C. to obtain a polymer with a low imidization rate. Amino acid (refer to the first step when the heating stage is divided into two steps in the single-stage supply method of the item 1) polyamide acid above). Mix the silylating agent with the obtained polyamic acid solution, and stir at a temperature in the range of 0 to 120°C, preferably 5 to 80°C for 1 to 72 hours, so as to obtain a solution with a low imidization rate. Polysiloxanes. The obtained polyimide precursor (polysiloxane) can be reacted in the same manner as the above-mentioned 3) silylpolysilate (indirect method) to achieve the target imidization rate.

As the silylating agent used in method 3) and method 4), it is preferable to use a chlorine-free silylating agent, because it is not necessary to use the silanized polyamic acid or the obtained polyimide. Purify. As a silylating agent that does not contain a chlorine atom, N,O-bis(trimethylsilyl)trifluoroacetamide, N,O-bis(trimethylsilyl)acetamide, hexamethylene base disilazane. Particularly preferred are N,O-bis(trimethylsilyl)acetamide and hexamethyldisilazane in terms of no fluorine atom and low cost.

In addition, in order to accelerate the reaction, an amine-based catalyst such as pyridine, piperidine, and triethylamine can be used for the silylation reaction of the diamine in the method 3). The catalyst can be used directly as a polymerization catalyst for a polyimide precursor.

The solvent used in the preparation of the polyimide precursor is preferably water, or, for example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidine Ketone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide and other aprotic solvents, as long as the raw material monomer components and the polyamide to be produced are When the imine precursor is dissolved, any kind of solvent can be used, and therefore its structure is not particularly limited. As a solvent, water, or N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone are preferably used Isocarboxamide solvents, cyclic ester solvents such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, etc. , carbonate solvents such as ethylene carbonate and propylene carbonate, glycol solvents such as triethylene glycol, phenolic solvents such as m-cresol, p-cresol, 3-chlorophenol and 4-chlorophenol, acetophenone , 1,3-dimethyl-2-imidazolidinone, cyclobutane, dimethyl sulfoxide, etc. Furthermore, other general organic solvents, ie, phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl ether acetate, ethyl cellosolve, butyl cellosolve, 2- Methyl Cellosolve Acetate, Ethyl Cellosolve Acetate, Butyl Cellosolve Acetate, Tetrahydrofuran, Dimethoxyethane, Diethoxyethane, Dibutyl Ether, Diethylene Glycol Diethylene Glycol Methyl ether, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methyl ethyl ketone, acetone, butanol, ethanol, xylene, toluene, chlorobenzene, turpentine, mineral spirits , Naphtha-based solvents, etc. In addition, the solvent may be used in combination of two or more.

In the production of the polyimide precursor, a monomer and a solvent are added and reacted so that the solid content concentration (polyimide-converted mass concentration) of the polyimide precursor is, for example, 5 to 45% by mass. , but not particularly limited.

The logarithmic viscosity of the polyimide precursor is not particularly limited, and the logarithmic viscosity of the N,N-dimethylacetamide solution with a concentration of 0.5 g/dL at 30°C is 0.2 dL/g or more, more preferably 0.3 dL/g or more, preferably 0.4 dL/g or more. If the logarithmic viscosity is 0.2 dL/g or more, the molecular weight of the polyimide precursor is high, and the obtained polyimide has excellent mechanical strength and heat resistance.

＜Preferable Additives＞ The polyimide precursor composition may contain imidazole compounds. The addition of an imidazole compound may be effective in improving the light transmittance and/or reducing the coefficient of linear thermal expansion, but the imidization rate may easily increase depending on the selection of the compound. Therefore, in the case of adding an imidazole compound, it is preferable to appropriately select the compound and/or appropriately adjust the imidization rate.

Although it does not specifically limit as an imidazole compound, 1, 2- dimethylimidazole, 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole, imidazole, benzimidazole, etc. are mentioned. In terms of the stability of the polyimide precursor composition, it is preferable to use at least one imidazole compound selected from the group consisting of 2-phenylimidazole and benzimidazole.

The content of the imidazole compound in the polyimide precursor composition can be appropriately selected in consideration of the balance between the addition effect and the stability of the polyimide precursor composition. The amount of the imidazole compound is preferably more than 0.01 mol and less than 1 mol relative to 1 mol of the repeating unit of the polyimide precursor. By adding an imidazole compound, generally, mechanical properties such as elongation at break are improved. On the other hand, when the content of the imidazole compound is too large, the storage stability of the polyimide precursor composition may be deteriorated.

The content of the imidazole compound is relative to 1 mol of the repeating unit, more preferably 0.02 mol or more, more preferably 0.025 mol or more, still more preferably 0.05 mol or more, and more preferably 0.8 mol or less, More preferably, it is 0.6 mol or less, still more preferably 0.4 mol or less, still more preferably less than 0.4 mol, and most preferably 0.3 mol or less.

Furthermore, Patent Document 6 (International Publication No. 2015/080158) describes a polyimide precursor composition containing an imidazole compound, but does not disclose a polyimide containing 2-phenylimidazole and/or benzimidazole. The content of the excellent storage stability of the imide precursor composition. Furthermore, the examples of this document show that, compared with 1,2-dimethylimidazole, 1-methylimidazole and 2-methylimidazole, the polymer produced from the composition containing 2-phenylimidazole or benzimidazole The 400 nm light transmittance of the imide film decreases. On the other hand, by combining 2-phenylimidazole and/or benzimidazole with a preferred polyimide precursor of the present invention (more than 70 mol % of X ₁ comes from CpODA, and more than 70 mol % of Y ₁ comes from The transparency of the polyimide film produced from the composition in which DABAN) was combined was improved, and contrary to the disclosure of Patent Document 6, a light transmittance of 400 nm that was equal to or higher than that of 2-methylimidazole was obtained. Furthermore, it was confirmed that 2-phenylimidazole and benzimidazole are more effective in reducing the coefficient of linear thermal expansion than other imidazoles.

<Composition of polyimide precursor composition> The polyimide precursor composition used in the present invention contains at least one polyimide precursor and a solvent, and may further optionally contain at least one of the above-mentioned imidazole compounds.

As the solvent, those described above as the solvent used in the preparation of the polyimide precursor can be used. Usually, the solvent used in the preparation of the polyimide precursor can be directly used, that is, the polyimide precursor solution can be kept and used, but it can also be used by diluting or concentrating as needed. The imidazole compound is present by being dissolved in the polyimide precursor composition. The concentration of the polyimide precursor is not particularly limited, but is usually 5 to 45% by mass in terms of polyimide-equivalent mass concentration (solid content concentration). Here, the mass in terms of polyimide refers to the mass when all repeating units are completely imidized.

The viscosity (rotational viscosity) of the polyimide precursor of the present invention is not particularly limited, and the rotational viscosity measured using an E-type rotational viscometer at a temperature of 25°C and a shear rate of 20 sec ^-1 is preferably 0.01 to 1000 Pa·sec, more preferably 0.1 to 100 Pa·sec. In addition, thixotropy may be imparted as necessary. When the viscosity is within the above-mentioned range, it is easy to handle when applying or forming a film, and the mutual repulsion is suppressed and the leveling property is excellent, so that a favorable film can be obtained.

The polyimide precursor composition of the present invention may optionally contain antioxidants, ultraviolet absorbers, fillers (inorganic particles such as silicon dioxide, etc.), dyes, pigments, coupling agents such as silane coupling agents, primers, and flame retardant materials. , defoamer, leveling agent, rheology control agent (flow aid), etc. The polyimide precursor composition of the present invention is preferably free of chemical imidizing agents.

Furthermore, according to the research of the present inventors, it was confirmed that the warpage of the polyimide film/glass substrate laminate produced was reduced by using the polyimide precursor composition to which the specific siloxane compound was added. In the present invention, a siloxane compound of a type that does not impair transparency may be added in an appropriate amount to the polyimide precursor composition, and the siloxane compound may not be included at all.

Regarding the preparation of the polyimide precursor composition, it can be prepared by adding an imidazole compound or a solution of an imidazole compound to the polyimide precursor solution obtained by the method described above and mixing. A tetracarboxylic-acid component and a diamine component can also be made to react in presence of an imidazole compound.

<<Applications and Film Properties of Polyimide Precursor Compositions>> Polyimide can be produced by further advancing the imidization of the polyimide precursor of the present invention. In the present invention, any known imidization method can be preferably applied, and is not particularly limited. The form of the obtained polyimide can preferably be exemplified by films, laminates of polyimide films and other substrates, coating films, powders, beads, moldings, foams, and the like.

The thickness of the polyimide film is preferably 1 μm or more, more preferably 2 μm or more, further preferably 5 μm or more, and for example, 250 μm or less, preferably 150 μm or less, more preferably 100 μm or less, More preferably, it is 50 μm or less, but it varies depending on the application.

In one embodiment of the present invention, when measured in a film with a thickness of 10 μm, the 400 nm light transmittance of the polyimide film is preferably 79% or more, more preferably 80% or more. In addition, when measured in a film having a thickness of 10 μm, the yellowness (YI) of the polyimide film is preferably 3.2 or less, more preferably 3.0 or less, and most preferably 2.7 or less.

The polymer film of the present invention has an extremely low coefficient of linear thermal expansion. In one embodiment of the present invention, when measured in a film with a thickness of 10 μm, the coefficient of linear thermal expansion (CTE) of the polyimide film at 150°C to 250°C is preferably 20 ppm/K or less, more preferably Less than 20 ppm, the best is below 15 ppm/K.

The polymer film of the present invention has extremely high heat resistance. In one embodiment of the present invention, the 5% weight loss temperature of the polyimide is preferably 500°C or higher, more preferably 505°C or higher, and still more preferably 510°C or higher. In the case of forming a transistor or the like on polyimide and forming a gas barrier film on polyimide, if the heat resistance is low, the polyimide and the barrier film may be caused by polyimide. Expansion occurs due to outgassing caused by the decomposition of amines. Generally speaking, the higher the heat resistance, the better. However, depending on the application, properties other than heat resistance may be required, and the 5% weight loss temperature may be 500°C or lower.

In yet another embodiment of the present invention, regarding the polyimide film, the elongation at break of the film having a thickness of 10 μm is preferably 10% or more.

In addition, in a different preferred embodiment of the present invention, the breaking strength of the polyimide film is preferably 150 MPa or more, more preferably 170 MPa or more, more preferably 180 MPa or more, and more preferably 200 MPa or more. MPa or more, more preferably 210 MPa or more. For the breaking strength, for example, a value obtained from a film having a thickness of about 5 to 100 μm can be used.

It is particularly preferred to simultaneously satisfy the above-mentioned preferred properties with respect to the polyimide film.

The polyimide film can be produced by a known method. A representative method is a method of casting and coating a polyimide precursor composition on a substrate, and then performing heating imidization on the substrate to obtain a polyimide film. This method will be described below in relation to the production of the polyimide film/substrate laminate. In addition, the polyimide precursor composition can also be cast-coated on the substrate and heated and dried to produce a self-sustaining film, and then the self-sustaining film can be peeled off from the substrate, and the film can be held by, for example, a tenter, and then separated from the film. Both sides were heated imidized in a degassable state to obtain a polyimide film.

<<Polyimide film/substrate laminate, and manufacture of flexible electronic devices>> The polyimide film/substrate laminate of the present invention can be produced by the following steps: (a) the step of coating the polyimide precursor composition on the substrate; (b) the above-mentioned substrate A step of heat-treating the polyimide precursor to produce a laminate (polyimide film/substrate laminate) in which the polyimide film is laminated on the base material. The manufacturing method of the flexible electronic device of the present invention uses the polyimide film/substrate laminate produced in the above-mentioned steps (a) and (b), and has a further step of (c) in the above-mentioned laminate. A step of forming at least one layer selected from a conductor layer and a semiconductor layer on the polyimide film, and (d) a step of peeling the above-mentioned base material and the above-mentioned polyimide film.

Polyimide precursor compositions useful in the methods of the present invention contain a polyimide precursor and a solvent. As the polyimide precursor, those described in the polyimide precursor composition can be used. The preferred polyimide precursors described in the section of the polyimide precursor composition are also preferred in the method of the present invention, but are not particularly limited.

First, in step (a), the polyimide precursor composition is cast on the substrate, and the polyimide film is formed by heating treatment for imidization and desolvation, thereby obtaining the substrate and the Polyimide film laminate (polyimide film/substrate laminate).

As the substrate, a heat-resistant material is used, for example, a plate or sheet substrate such as a ceramic material (glass, alumina, etc.), metal material (iron, stainless steel, copper, aluminum, etc.), semiconductor material (silicon, compound semiconductor, etc.) materials, or heat-resistant plastic materials (polyimide, etc.) and other film or sheet substrates. Generally speaking, a flat and smooth plate shape is preferred. Glass substrates such as soda lime glass, borosilicate glass, alkali-free glass, and sapphire glass are generally used; semiconductor (including compound semiconductor) substrates such as silicon, GaAs, InP, and GaN are generally used. ; Iron, stainless steel, copper, aluminum and other metal substrates.

In this invention, a glass substrate is especially preferable. As for the glass substrate, a flat, smooth and large-area one has been developed and can be easily obtained. The problem of warpage is particularly obvious when the area of the substrate is larger, and the glass substrate is relatively easy to warp in terms of rigidity. Therefore, by applying the present invention, the problem when using a glass substrate can be solved. The thickness of a plate-shaped base material such as a glass substrate is not limited, but from the viewpoint of ease of handling, it is, for example, 20 μm to 4 mm, or preferably 100 μm to 2 mm. In addition, the size of the plate-like base material is not particularly limited, but one side (when it is a rectangle, the long side) is, for example, about 100 mm to about 4000 mm, preferably about 200 mm to about 3000 mm, more preferably about 300 mm. mm to about 2500 mm.

The substrates such as these glass substrates may also have inorganic thin films (eg, silicon oxide films) or resin thin films formed on their surfaces.

The casting method of the polyimide precursor composition on the substrate is not particularly limited, for example, slit coating method, die nozzle coating method, blade coating method, spray coating method, ink jet coating method can be mentioned. The cloth method, the nozzle coating method, the spin coating method, the screen printing method, the bar coating method, the electrodeposition method and the like are previously known methods.

In step (b), the polyimide precursor composition is heat-treated on the substrate to convert it into a polyimide film to obtain a polyimide film/substrate laminate. The heating treatment conditions are not particularly limited, but preferably after drying in a temperature range of 50°C to 150°C, the highest heating temperature, for example, 150°C to 600°C, preferably 200°C to 550°C, more preferably 250 ℃ ~ 500 ℃ for treatment. The heat treatment conditions when using the polyimide solution are not particularly limited, but the maximum heating temperature is, for example, 100°C to 600°C, preferably 150°C or higher, more preferably 200°C or higher, and preferably 500°C Below, it is more preferable that it is 450 degrees C or less.

The thickness of the polyimide film is preferably 1 μm or more, more preferably 2 μm or more, and still more preferably 5 μm or more. When the thickness is less than 1 μm, the polyimide film cannot maintain sufficient mechanical strength, and when used as a substrate for flexible electronic devices, for example, it may not be able to fully withstand stress and be damaged. In addition, the thickness of the polyimide film is preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 20 μm or less. When the thickness of the polyimide film increases, it may be difficult to reduce the thickness of the flexible device. In order to further thin the flexible device while maintaining sufficient resistance, the thickness of the polyimide film is preferably 2 to 50 μm.

In yet another embodiment of the present invention, regarding the polyimide film, the elongation at break of the film having a thickness of 10 μm is preferably 10% or more.

In addition, in a different preferred embodiment of the present invention, the breaking strength of the polyimide film is preferably 150 MPa or more, more preferably 170 MPa or more, more preferably 180 MPa or more, and more preferably 200 MPa or more. MPa or more, more preferably 210 MPa or more. For the breaking strength, for example, a value obtained from a film having a thickness of about 5 to 100 μm can be used.

It is especially preferable to satisfy the above-mentioned preferable characteristics regarding the polyimide film and the laminate at the same time.

The polyimide film in the polyimide film/substrate laminate may have a second layer such as a resin film or an inorganic film on the surface. That is, after forming the polyimide film on the base material, the second layer can be laminated to form a flexible electronic device substrate. It is preferable to have at least an inorganic film, and it is especially preferable that it functions as a barrier layer of water vapor, oxygen (air), or the like. Examples of the water vapor barrier layer include those selected from the group consisting of silicon nitride (SiN _x ), silicon oxide (SiO _x ), silicon oxynitride (SiO _x N _y ), aluminum oxide (Al ₂ O ₃ ), and titanium oxide. Inorganic film of inorganic substances in the group consisting of metal oxides such as (TiO ₂ ) and zirconium oxide (ZrO ₂ ), metal nitrides and metal oxynitrides. Generally, as a film formation method of these thin films, a vacuum evaporation method, a sputtering method, a physical evaporation method such as an ion plating method, a plasma CVD (chemical vapor deposition, chemical vapor deposition) method, Chemical vapor deposition methods (chemical vapor deposition methods) such as catalytic chemical vapor deposition methods (Cat-CVD methods) and the like. The second layer may be a plurality of layers.

When the second layer is a plurality of layers, the resin film and the inorganic film can also be combined, for example, forming a barrier layer/polyimide film on the polyimide film in the polyimide film/substrate laminate. Examples of 3-layer structure of imide layer/barrier layer, etc.

In step (c), the polyimide/substrate laminate obtained in step (b) is used to laminate a second layer such as an inorganic film on the surface of the polyimide film (including the polyimide film). ) is formed on at least one layer selected from a conductor layer and a semiconductor layer. These layers may be formed directly on the polyimide film (including those having a second layer laminated), or may be formed after other layers required by the lamination device, ie, indirectly.

Regarding the conductor layer and/or the semiconductor layer, appropriate conductor layers and (inorganic, organic) semiconductor layers can be selected according to the elements and circuits required by the target electronic device. In the step (c) of the present invention, when at least one of the conductor layer and the semiconductor layer is formed, it is also preferable to form at least one of the conductor layer and the semiconductor layer on the polyimide film on which the inorganic film is formed. Floor.

The conductor layer and the semiconductor layer include both those formed on the entire surface of the polyimide film and those formed on a part of the polyimide film. The present invention may proceed to step (d) immediately after step (c), or may proceed to step (d) after forming at least one layer selected from a conductor layer and a semiconductor layer in step (c) to form a device structure and then proceed to step (d) .

In the case of manufacturing a TFT liquid crystal display device as a flexible device, for example, metal wirings, TFTs formed of amorphous silicon or polysilicon, transparent pictures, etc. are formed on the polyimide film with an inorganic film formed on the entire surface as required. element electrode. The TFT includes, for example, a gate metal layer, a semiconductor layer such as an amorphous silicon film, a gate insulating layer, wirings connected to pixel electrodes, and the like. The structures required for the liquid crystal display can also be formed thereon by well-known methods. In addition, a transparent electrode and a color filter may be formed on the polyimide film.

In the case of manufacturing an organic EL display, for example, if necessary, on the polyimide film with an inorganic film formed on the entire surface, in addition to forming a transparent electrode, a light-emitting layer, a hole transport layer, an electron transport layer, etc. TFT needs to be formed.

The preferred polyimide film in the present invention is excellent in various properties such as heat resistance and toughness, so the method for forming circuits, elements, and other structures required for the device is not particularly limited.

Next, in step (d), the base material and the polyimide film are peeled off. The peeling method may be a mechanical peeling method of physically peeling off by applying an external force, or a so-called laser peeling method of peeling off by irradiating laser light from the surface of the substrate.

The device is completed by forming or incorporating the structure or parts required for the device in the (semi) product using the polyimide film after peeling off the substrate as the substrate. [Example]

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples. Furthermore, the present invention is not limited to the following examples.

In each of the following examples, evaluation was performed by the following method.

<Evaluation of Polyimide Precursor Solution (Varnish)> [Imide Rate] Using dimethylsulfoxide-d ₆ as a solvent, M-AL400 manufactured by JEOL Ltd. was used for the evaluation of polyimide precursor solution. ¹ H-NMR measurement, based on the ratio of the integral value of the peak of the aromatic proton and the integral value of the peak of the carboxylic acid proton, the imidization rate was calculated by the following formula (I) [repetition represented by the chemical formula (2)] unit content relative to all repeating units].

Imidization rate (%)={X-(Y/Z)×A}/2×100 (I) X: imidization rate when the rate of imidization calculated from the amount of monomer added is 0% Integral value of proton peaks Y: Integral value of amide proton peaks obtained by ¹ H-NMR measurement Z: Integral value of aromatic proton peaks obtained by ¹ H-NMR measurement A: Calculated from the amount of monomer added The integrated value of the aromatic proton peaks

＜Evaluation of Polyimide Film＞ [400 nm light transmittance] Using a UV-Vis spectrophotometer/V-650DS (manufactured by JASCO Corporation), the transmittance at 400 nm of a polyimide film with a film thickness of about 10 μm was measured. [Yellowness (YI)] Using a UV-Vis spectrophotometer/V-650DS (manufactured by Nippon Co., Ltd.), according to the standard of ASTEM E313, the YI of the polyimide film was measured. The light source was set to D65, and the viewing angle was set to 2°.

[Elastic modulus, elongation at break, breaking strength] The polyimide film with a film thickness of about 10 μm was punched into a dumbbell shape of IEC450 specification, and it was used as a test piece. Tensilon manufactured by ORIENTEC was used. The length between the chucks was 30 mm and the tensile speed was 2 mm/min. The initial elastic modulus, elongation at break and breaking strength were measured under the same conditions.

[Coefficient of Linear Thermal Expansion (CTE)] The polyimide film with a film thickness of about 10 μm was cut into a short strip with a width of 4 mm, and this was used as a test piece. TMA/SS6100 (manufactured by SII NanoTechnology Co., Ltd.) was used. The temperature was raised to 500°C under the conditions of a load of 2 g and a heating rate of 20°C/min. According to the obtained TMA (thermomechanical analysis, thermomechanical analysis) curve, the coefficient of linear thermal expansion from 150°C to 250°C was obtained.

[5% weight loss temperature] A polyimide film with a film thickness of about 10 μm was used as a test piece, and a calorimeter measuring device (Q5000IR) manufactured by TA Instruments was used, and the temperature was increased from 25°C to 600°C at a heating rate of 10°C/min in a nitrogen gas stream. . The 5% weight loss temperature was determined from the obtained weight curve.

＜Raw materials＞ The abbreviations, purities, etc. of the raw materials used in the following examples are as follows.

[diamine component] DABAN: 4,4'-Diaminobenzylaniline PPD: p-phenylenediamine BAPB: 4,4'-bis(4-aminophenoxy)biphenyl TPE-Q: 1,4-bis(4-aminophenoxy)benzene TFMB: 2,2'-bis(trifluoromethyl)benzidine

[Tetracarboxylic acid component] CpODA: nor𦯉alkane-2-spiro-α-cyclopentanone-α'-spiro-2"-noralkane-5,5",6,6"-tetracarboxylic dianhydride DNDAxx: (4arH,8acH)-decahydro-1t,4t:5c,8c-dimethylnaphthalene-2t,3t,6c,7c-tetracarboxylic dianhydride PMDA-H: Cyclohexanetetracarboxylic dianhydride CBDA: Cyclobutanetetracarboxylic dianhydride

[imidazole compound] 2-Pz: 2-phenylimidazole Bz: benzimidazole 2-Mz: 2-methylimidazole

[solvent] NMP: N-methyl-2-pyrrolidone DMAc: Dimethylacetamide

The tetracarboxylic acid component and the diamine component used in the Examples and Comparative Examples are described in Table 1-1, and the structural formulas of the imidazole compounds used in the Examples and Comparative Examples are described in Table 1-2.

[Table 1-1]

[Table 1-2]

<Example 1> [Preparation of Polyimide Precursor Composition] To the reaction vessel substituted with nitrogen, 2.27 g (0.010 mol) of DABAN and 32.11 g of N-methyl-2-pyrrolidone were added so that the total mass of the monomers (the sum of the diamine component and the carboxylic acid component) was added. It was 16 mass %, and it stirred at 50 degreeC for 1 hour. To this solution was slowly added CpODA 3.84 g (0.010 moles). Stir at 70° C. for 4 hours to obtain a homogeneous and viscous polyimide precursor solution.

2-phenylimidazole as an imidazole compound was dissolved in 4 times the mass of N-methyl-2-pyrrolidone to obtain a uniform solution with a solid content concentration of 20% by mass of 2-phenylimidazole. With respect to 1 mol of the repeating unit of the polyimide precursor, the amount of the imidazole compound is 0.025 mol, and the solution of the imidazole compound is mixed with the polyimide precursor solution synthesized above, at room temperature. After stirring for 3 hours, a homogeneous and viscous polyimide precursor composition was obtained. The imidization rate of the polyimide precursor in the obtained polyimide precursor composition was measured and found to be 18%.

[Manufacture of Polyimide Film] A 6-inch Eagle-XG (registered trademark) (500 μm thick) manufactured by Corning Incorporated was used as a glass substrate. The polyimide precursor composition was coated on the glass substrate by a spin coater, and in a nitrogen atmosphere (oxygen concentration below 200 ppm), the glass substrate was heated from room temperature to 415 ℃ for thermal imidization. Thus, a polyimide film/substrate laminate was obtained. The laminated body is immersed in 40 degreeC water (for example, the temperature range of 20 degreeC - 100 degreeC), the polyimide film is peeled from a glass substrate, and after drying, the characteristic of a polyimide film is evaluated. The film thickness of the polyimide film is about 10 μm. The evaluation results are shown in Table 2.

<Examples 2 to 10> Except that the imidazole compound in Example 1 was changed to the compound shown in Table 2 (the blank column indicates no addition), in the same manner as in Example 1, a polymer containing the imidization ratio shown in Table 2 was obtained. Polyimide Precursor Compositions of Imide Precursors. Thereafter, in the same manner as in Example 1, a polyimide film was produced and the film properties were evaluated. The results are shown in Table 2. Furthermore, among Examples 1-10, the long-term stability of the polyimide precursor compositions of Examples 1-5 and 8-10 is also very excellent. The physical properties of Examples 1 to 5 are all excellent.

<Examples 11 to 17, Comparative Examples 1 to 3> The imidazole compound in Example 1 was changed to the compound shown in Table 3. In addition, the temperature and time after adding CpODA in Example 1 were changed, thereby obtaining a polyimide precursor composition containing a polyimide precursor having the imidization ratio shown in Table 3. Thereafter, in the same manner as in Example 1, a polyimide film was produced and the film properties were evaluated. The results are shown in Table 3.

<Examples 18 to 22, Comparative Example 4> The diamine component and the imidazole compound in Example 1 were changed to the compounds shown in Table 4. In addition, the temperature and time after adding CpODA in Example 1 were changed, whereby a polyimide precursor composition containing a polyimide precursor having the imidization ratio shown in Table 4 was obtained. Thereafter, in the same manner as in Example 1, a polyimide film was produced and the film properties were evaluated. The results are shown in Table 4.

<Examples 23 to 29, Comparative Examples 5 and 6> The tetracarboxylic acid component, the diamine component, and the imidazole compound in Example 1 were changed to the compounds shown in Table 5. In addition, the temperature and time after adding CpODA in Example 1 were changed, whereby a polyimide precursor composition containing a polyimide precursor having the imidization ratio shown in Table 5 was obtained. Thereafter, in the same manner as in Example 1, a polyimide film was produced and the film properties were evaluated. The results are shown in Table 5.

<Comparative Examples 7 to 10> The tetracarboxylic acid component, the diamine component, and the imidazole compound in Example 1 were changed to the compounds shown in Table 6. In addition, the temperature and time after adding CpODA in Example 1 were changed, whereby a polyimide precursor composition containing a polyimide precursor having the imidization ratio shown in Table 6 was obtained. Thereafter, in the same manner as in Example 1, a polyimide film was produced and the film properties were evaluated. The results are shown in Table 6.

<Comparative Example 11> To the reaction vessel substituted with nitrogen, 0.713 g (3.136 mmol) of DABAN and 1.004 g (3.136 mmol) of TFMB were added, and 16.5 g of DMAc was added so that the total mass of the monomers (the ratio of the diamine component and the carboxylic acid component) was added. The total amount) was 20% by mass, and the mixture was stirred at room temperature for 1 hour. To this solution, 2.411 g (6.272 mmol) of CpODA was slowly added, and the mixture was stirred at room temperature for 24 hours. Then, the temperature was raised to 160°C, 25 mL of toluene was added, and the toluene was refluxed for 10 minutes, then the toluene was extracted and cooled to room temperature to obtain a uniform and viscous polyimide precursor solution (imidation rate: 44%). ). Thereafter, in the same manner as in Example 1, a polyimide film was produced and the film properties were evaluated. The results are shown in Table 6.

[Table 2] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Tetracarboxylic acid composition (mmol) CpODA 10 10 10 10 10 10 10 10 10 10 PMDA-H Diamine content (mmol) DABAN 10 10 10 10 10 10 10 10 10 10 PPD TPE-Q BAPB Catalyst Composition (mmol) 1,2-DMz 2-Pz 0.25 0.5 1 2 0.1 Bz 1.0 0.10 1-Mz 2-Mz 0.5 2 imidization rate 18 17 17 18 16 17 17 18 19 19 Polyimide film Linear Thermal Expansion Coefficient (ppm/K) 12 12 12 12 12 15 14 12 12 12 Elastic Modulus (GPa) 6.6 6.7 6.5 6.4 6.7 6.6 6.0 6.5 7 7.3 Elongation at break (%) 10 14 17 16 18 14 18 6 8 8 Breaking Strength(MPa) 219 234 247 227 265 226 209 205 206 223 5% weight loss temperature (℃) 512 513 511 512 513 511 510 511 512 512 400 nm line transmittance (%) 80 81 81 81 81 81 80 79 79 79 YI 2.7 2.6 2.6 2.6 2.6 2.6 2.7 2.9 2.9 2.9

[table 3] Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tetracarboxylic acid composition (mmol) CpODA 10 10 10 10 10 10 10 10 10 10 PMDA-H Diamine content (mmol) DABAN 10 10 10 10 10 10 10 10 10 10 PPD TPE-Q BAPB Catalyst Composition (mmol) 1,2-DMz 0.5 0.5 0.5 1 0.5 0.5 1 2-Pz Bz 1-Mz 1.0 1.0 2-Mz 1.0 imidization rate 12 twenty three 28 35 40 44 47 56 62 72 Polyimide film Linear Thermal Expansion Coefficient (ppm/K) 12 12 12 12 12 12 13 16 16 18 Elastic Modulus (GPa) 6.5 6.4 6.6 6.5 6.6 6.4 6.4 6.5 6.4 6.5 Elongation at break (%) 20 twenty one 20 25 20 18 twenty four 17 14 10 Breaking Strength(MPa) 252 265 238 240 267 224 263 246 216 232 5% weight loss temperature (℃) 512 511 511 512 512 513 511 511 512 511 400 nm line transmittance (%) 81 80 80 80 79 82 81 76 78 76 YI 2.8 2.8 2.7 2.6 2.9 2.1 2.7 3.7 3.5 4.8

[Table 4] Example 18 Example 19 Example 20 Example 21 Example 22 Comparative Example 4 Tetracarboxylic acid composition (mmol) CpODA 10 10 10 10 10 10 PMDA-H Diamine content (mmol) DABAN 9.9 9.9 9.9 9.9 9.9 9.9 PPD TPE-Q BAPB 0.1 0.1 0.1 0.1 0.1 0.1 Catalyst Composition (mmol) 1,2-DMz 2-Pz 1 1 1 1 1 1 Bz 1-Mz 2-Mz imidization rate 17 twenty one 38 41 46 53 Polyimide film Linear Thermal Expansion Coefficient (ppm/K) 12.3 12.7 13 13.6 13.3 16.7 Elastic Modulus (GPa) 6.4 6.4 6.3 6.2 6.2 6.1 Elongation at break (%) 19 20 twenty one twenty four twenty three twenty three Breaking Strength(MPa) 249 250 240 260 255 250 5% weight loss temperature (℃) 512 512 513 510 510 511 400 nm line transmittance (%) 81 81 81 80 80 78 YI 2.5 2.3 2.3 2.4 2.5 3.3

[table 5] Example 23 Example 24 Comparative Example 5 Example 25 Comparative Example 6 Example 26 Example 27 Example 28 Example 29 Tetracarboxylic acid composition (mmol) CpODA 10 10 10 10 10 10 10 7 7 PMDA-H 3 3 Diamine content (mmol) DABAN 7 7 7 7 7 7 7 10 10 PPD 1 1 TPE-Q 3 3 BAPB 3 3 3 2 2 Catalyst Composition (mmol) 1,2-DMz 2-Pz 1 1 1 1 1 1 1 1 1 Bz 1-Mz 2-Mz imidization rate 19 38 62 twenty one 58 20 40 twenty three 43 Polyimide film Linear Thermal Expansion Coefficient (ppm/K) 20 20 twenty three 20 25 18 18 18 19 Elastic Modulus (GPa) 4.6 4.6 3.7 5.3 4.6 5.3 5.5 5.5 5 Elongation at break (%) 40 46 42 40 38 33.8 36.6 35 38 Breaking Strength(MPa) 298 310 247 299 308 267 276 303 282 5% weight loss temperature (℃) 510 510 510 513 513 511 511 504 504 400 nm line transmittance (%) 83 83 82 82 82 83 83 80 80 YI 1.9 1.9 1.9 2.1 2.1 1.8 1.9 2.7 2.7

[Table 6] Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Tetracarboxylic acid composition (mmol) CpODA 10 10 DNDAxx 10 PMDA-H 10 CBDA 10 Diamine content (mmol) DABAN 6.0 10 10 10 5 BAPB 4.0 TFMB 5 Catalyst Composition (mmol) 2-Pz 1 2 2 2 imidization rate 18 18 18 18 44 Polyimide film Linear Thermal Expansion Coefficient (ppm/K) 26 27 55 13 41 Elastic Modulus (GPa) 4.3 4.5 4.7 8.6 - Elongation at break (%) 43 19 37 14 - Breaking Strength(MPa) 270 162 185 237 - 5% weight loss temperature (℃) 504 523 480 479 499 400 nm line transmittance (%) 83 80 82 53 84

From the above results, it can be seen that the ratio of CpODA in the tetracarboxylic acid component is 70 mol % or more, and the ratio of DABAN in the diamine component is 70 mol % or more, and the imidization rate is within the range of less than 50%. The 400 nm light transmittance of the polyimide film obtained by the polyimide precursor composition within the film is larger, the linear thermal expansion coefficient is smaller, and the 5% weight loss temperature is higher. [Industrial Availability]

The present invention can be preferably applied to the manufacture of flexible electronic devices, such as liquid crystal displays, organic EL displays, and electronic paper and other display devices, solar cells, and CMOS and other light-receiving devices.

Claims (13)

A polyimide precursor composition, characterized in that it contains: a polyimide precursor, the repeating unit of which comprises the repeating unit represented by the following general formula (I), and the further imidization of the general formula (I) The repeating unit formed by the amide, and the imidization rate is more than 0% and less than 50%; and the solvent; [Chemical 1]

(In general formula I, X ₁ is a tetravalent aliphatic group or an aromatic group, Y ₁ is a divalent aliphatic group or an aromatic group, R ₁ and R ₂ are independent of each other, and are a hydrogen atom and a carbon number of 1 to 6. An alkyl group or an alkylsilyl group having 3 to 9 carbon atoms, wherein 70 mol% or more of X ₁ is the structure represented by the formula (1-1), [Chemical 2]

70 mol% or more of Y ₁ is the structure represented by formula (D-1) and/or (D-2), [Chemical 3]

). The polyimide precursor composition as claimed in claim 1, wherein the polyimide film obtained from the polyimide precursor composition has a light transmittance of 79% at a wavelength of 400 nm in a film with a thickness of 10 μm above. The polyimide precursor composition of claim 1 or 2, wherein the polyimide film obtained from the polyimide precursor composition is between 150°C and 250°C in a film with a thickness of 10 μm Has a linear thermal expansion coefficient below 20 ppm/K. The polyimide precursor composition of any one of claims 1 to 3, wherein the polyimide obtained from the polyimide precursor composition has a 5% weight loss temperature above 500°C. The polyimide precursor composition according to any one of claims 1 to 4, wherein the elongation at break of the polyimide film obtained from the polyimide precursor composition in a film with a thickness of 10 μm more than 10%. The polyimide precursor composition according to any one of claims 1 to 5, wherein more than 90 mol% of X ₁ is the structure represented by the above formula (1-1). A polyimide film obtained from the polyimide precursor composition according to any one of claims 1 to 6. A polyimide film/substrate laminate, characterized in that it has: A polyimide film obtained from the polyimide precursor composition of any one of claims 1 to 6; and substrate. The laminate according to claim 8, wherein the base material is a glass substrate. A manufacturing method of a polyimide film/substrate laminate, comprising the following steps: (a) the step of coating the polyimide precursor composition according to any one of claims 1 to 6 on a substrate; and (b) the step of heating the above-mentioned polyimide precursor on the above-mentioned base material, and laminating the polyimide film on the above-mentioned base material. The manufacturing method of claim 10, wherein the base material is a glass substrate. A manufacturing method of a flexible electronic device, which has the following steps: (a) the step of coating the polyimide precursor composition according to any one of claims 1 to 6 on a substrate; (b) heat-treating the above-mentioned polyimide precursor on the above-mentioned base material to manufacture a polyimide film/substrate laminate having a polyimide film laminated on the above-mentioned base material; (c) a step of forming at least one layer selected from a conductor layer and a semiconductor layer on the polyimide film of the laminate; and (d) The step of peeling the above-mentioned base material and the above-mentioned polyimide film. The manufacturing method of claim 12, wherein the base material is a glass substrate.