JPWO2013047451A1 - Resin composition and film forming method using the same - Google Patents

Abstract

A resin composition comprising a polyimide precursor containing a structural unit represented by the following formula (2) and having a structural unit represented by the following formula (1), and a solvent mainly comprising a non-amide solvent. (In the formula (1), R independently represents a hydrogen atom or a monovalent organic group, R 1 independently represents a divalent organic group, R 2 independently represents a tetravalent organic group, and n represents a positive number. Represents an integer, provided that at least one of R1 and R2 contains a halogen atom or a halogenated alkyl group. (In the formula (2), a plurality of R5 are each independently a monovalent organic group having 1 to 20 carbon atoms.) M represents an integer of 3 to 200.)

Description

  The present invention relates to a resin composition and a film forming method using the same.

  In general, wholly aromatic polyimide obtained from aromatic tetracarboxylic dianhydride and aromatic diamine is due to the rigidity of the molecule, the fact that the molecule is resonance-stabilized, the strong chemical bond, etc. It has excellent heat resistance and mechanical properties, and the polyimide or the polyimide-forming composition is used as a raw material for films, coating agents, molded parts and insulating materials in fields such as electricity, batteries, automobiles and aerospace industries. As widely used as.

  However, it has been pointed out that when the conventional polyimide forming composition is used to form a film on a support such as a glass substrate, the substrate or the film itself warps due to shrinkage deformation during the film formation. Yes.

Here, Patent Document 1 discloses a polyimide precursor resin composition for a flexible device substrate, which includes a polyimide precursor synthesized from p-phenylenediamine and s-biphenyltetracarboxylic anhydride.
In addition, the resin composition can be formed by coating on a carrier substrate such as a glass substrate and becomes a polyimide film having excellent heat resistance and a low thermal expansion coefficient. It is described that when peeling off from a glass substrate without causing peeling, it can be removed cleanly.

JP 2010-202729 A

  However, a conventional resin composition containing a polyimide precursor has a slow drying rate and poor productivity when the composition is applied onto a support such as a glass substrate to form a film.

  The object of the present invention is excellent in storage stability, fast in drying speed, excellent in productivity, excellent in adhesion and peelability with a substrate, has a high glass transition temperature, less warpage and cloudiness, An object of the present invention is to provide a resin composition and a film forming method capable of easily producing a film having excellent mechanical strength.

As a result of intensive studies to solve the above problems, the present inventor, according to a resin composition comprising a polyimide precursor (polyamic acid) having a specific structural unit and a solvent mainly composed of a non-amide solvent. The present inventors have found that the above problems can be solved, and have completed the present invention.
That is, the present invention provides the following [1] to [9].

  [1] A resin composition comprising a polyimide precursor containing a structural unit represented by the following formula (2) and having a structural unit represented by the following formula (1), and a solvent mainly composed of a non-amide solvent object.

（式（１）中、Ｒは独立に水素原子または一価の有機基を示し、Ｒ¹は独立に二価の有機基を示し、Ｒ²は独立に四価の有機基を示し、ｎは正の整数を示す。ただし、Ｒ¹またはＲ²の少なくとも一方は、ハロゲン原子またはハロゲン化アルキル基を含む。）

(In the formula (1), R independently represents a hydrogen atom or a monovalent organic group, R ¹ independently represents a divalent organic group, R ² independently represents a tetravalent organic group, and n represents Represents a positive integer, provided that at least one of R ^{1 and} R ² contains a halogen atom or a halogenated alkyl group.

（式（２）中、複数あるＲ⁵は各々独立に炭素数１〜２０の一価の有機基を示し、ｍは３〜２００の整数を示す。）

(In Formula (2), a plurality of R ^{5 s} each independently represent a monovalent organic group having 1 to 20 carbon atoms, and m represents an integer of 3 to 200.)

[2] The resin composition according to [1], wherein R ¹ includes a group selected from the group represented by the following formula (3).

（式（３）中、Ｒ³は独立にエーテル結合、チオエーテル基、ケトン基、エステル結合、スルフォニル基、アルキレン基、アミド基もしくはシロキサン基を含む基、水素原子、ハロゲン原子、アルキル基、ヒドロキシ基、ニトロ基、シアノ基またはスルホ基を示し、このアルキレン基を含む基およびアルキル基の任意の水素原子はハロゲン原子で置換されてもよい。ただし、１つの基に含まれる複数あるＲ³のうち少なくとも１つはハロゲン原子またはハロゲン化アルキル基を含む。ａ１は、１〜３の整数を示し、ａ２は、１または２を示し、ａ３は独立に１〜４の整数を示し、ｅは０〜３の整数を示す。）

(In formula (3), R ³ is independently an ether bond, a thioether group, a ketone group, an ester bond, a sulfonyl group, an alkylene group, an amide group, or a group containing a siloxane group, a hydrogen atom, a halogen atom, an alkyl group, or a hydroxy group. , A nitro group, a cyano group or a sulfo group, and any hydrogen atom of the group containing this alkylene group and the alkyl group may be substituted with a halogen atom, provided that among the plurality of R ³ contained in one group, At least one includes a halogen atom or a halogenated alkyl group, a1 represents an integer of 1 to 3, a2 represents 1 or 2, a3 independently represents an integer of 1 to 4, and e represents 0 to 0 Indicates an integer of 3.)

[3] The resin composition according to [1] or [2], wherein the solvent is a mixed solvent composed of two or more solvents.
[4] The resin composition according to [3], wherein the solvent contains 20% by weight or more of a solvent having the highest boiling point in the mixed solvent with respect to 100% by weight of the total mixed solvent.

  [5] The resin composition according to any one of [1] to [4], wherein the polyimide precursor has a weight average molecular weight of 10,000 to 1,000,000.

[6] The resin composition according to any one of [1] to [5], wherein the concentration of the polyimide precursor in the resin composition is 3 to 60% by mass.
[7] The resin composition according to any one of [1] to [6], wherein the viscosity measured with an E-type viscometer (25 ° C.) is in the range of 500 to 50000 mPa · s.

  [8] The resin composition according to any one of [1] to [7], which is for film formation.

[9] A step of coating the resin composition according to any one of [1] to [8] on a substrate to form a coating film;
Evaporating the solvent from the coating film;
A film forming method comprising a step of imidizing the precursor.

The resin composition according to the present invention is excellent in storage stability, and according to the composition, it is excellent in transparency and mechanical strength, has a high glass transition temperature, easily generates a film with less warpage and white turbidity, It can be manufactured in a short time with high productivity.
Further, according to the resin composition of the present invention, when a film is formed by applying the resin composition to a substrate such as a glass substrate, a film excellent in adhesion and peelability to the substrate is easily formed. be able to.

≪Resin composition≫
The resin composition of the present invention includes a structural unit represented by the following formula (2), a polyimide precursor having a structural unit represented by the following formula (1), and a non-amide solvent as main components. Contains solvent.
Since the resin composition of the present invention contains the polyimide precursor and the non-amide solvent, a film having a high glass transition temperature, less warpage and cloudiness, and excellent mechanical strength can be easily obtained in a short time. In addition, when a film is formed by applying a resin composition to a substrate such as a glass substrate, a film excellent in adhesion and peelability to the substrate can be easily formed. Can do.

  In the present invention, “adhesiveness” means, for example, when a film is formed on a substrate, or when a device is manufactured to produce a wiring made of metal or the like on the formed film. For example, it means that the coating film (film) and the substrate are difficult to peel off. “Peelability” means, for example, when you want to peel the film from the substrate (when applying force to peel the film from the substrate, etc.) In addition, it means the property that the film can be peeled off from the substrate with few peeling marks.

<Polyimide precursor>
The polyimide precursor includes a structural unit represented by the following formula (2) and has a structural unit represented by the following formula (1) (hereinafter also referred to as “structural unit (1)”). Therefore, the polyimide obtained from the precursor has a rigid skeleton part and a flexible skeleton part containing a structural unit represented by the following formula (2) (hereinafter also referred to as “structural unit (2)”). Then, it is considered that the rigid skeleton site becomes a sea part and a microphase separation structure is formed in which a flexible skeleton part becomes an island part. It is considered that a film having a reduced residual stress can be obtained when polyimide forms this microphase separation structure.
In the present invention, microphase separation means that islands made of a flexible skeleton part are dispersed in a size of about 1 nanometer to 1 micron in a sea part made of a rigid skeleton part.

  The “warp” is the roundness of the film judged visually, and the “residual stress” is the film remaining after the resin composition is applied on a substrate such as a glass substrate to form the film. This is a measure of the “warping” that can occur in the film. Specifically, it can be measured by the method described in the following examples.

In the formula (1), R independently represents a hydrogen atom or a monovalent organic group, preferably a hydrogen atom, R ¹ independently represents a divalent organic group, and R ² independently represents a tetravalent group. An organic group is shown. n represents a positive integer, preferably an integer of 1 to 2500.

Note that at least one of R ^{1 and} R ² contains a halogen atom or a halogenated alkyl group. Here, "R ¹ contains a halogen atom (fluorine atom)", for example, R ¹ is -CH ₂ -CHF-CH ₂ - it refers to a case where a group such as, "R ¹ is halogenated alkyl “Including a group (fluorinated alkyl group)” means, for example, a case where R ¹ is a group such as —CH ₂ —CH (CF ₃ ) —CH ₂ —.
Since the structural unit (1) contains a halogen atom or a halogenated alkyl group, a polyimide precursor having excellent solubility is obtained, and a polyimide having excellent heat resistance is obtained from the precursor.

In the formula (2), a plurality of R ⁵ is a monovalent organic group having 1 to 20 carbon atoms each independently, m is an integer of 3 to 200.

  In said Formula (1), as a monovalent organic group in R, a C1-C20 monovalent organic group is preferable. “C1-20” means “1 to 20 carbon atoms”. Similar descriptions in the present invention have similar meanings.

Examples of the monovalent organic group having 1 to 20 carbon atoms in R include a monovalent hydrocarbon group having 1 to 20 carbon atoms.
Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group having 1 to 20 carbon atoms.
The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, t- A butyl group, a pentyl group, a hexyl group, etc. are mentioned.

In the formula (1), in R ^1, examples of the divalent organic group is preferably a divalent organic group having 1 to 40 carbon atoms.
The divalent organic group having 1 to 40 carbon atoms is preferably a divalent aromatic hydrocarbon group having 6 to 40 carbon atoms, and more preferably a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms. In the case where the organic group contains two or more ring structures, a ring such as a polycyclic structure in which the rings share one or more bonds, a spiro hydrocarbon structure, or a biphenyl bond such as a single bond A structure bonded by a group is included. Examples of the bonding group include an ether bond, a thioether group, a ketone group, an ester bond, a sulfonyl group, an alkylene group, an amide group, and a siloxane group in addition to the single bond. When the divalent organic group contains a hydrogen atom, any hydrogen atom may be substituted with a halogen atom.

The divalent organic group preferably includes a group selected from the group represented by the following formula (3), and more preferably a group selected from the group represented by the following formula (3). . When the divalent organic group in R ¹ is a group selected from the group represented by the following formula (3), the sea part has a more rigid structure. Therefore, it is preferable because a film in which residual stress is small and warpage is suppressed can be obtained.

In formula (3), R ³ is independently an ether bond, a thioether group, a ketone group, an ester bond, a sulfonyl group, an alkylene group, an amide group or a siloxane group; a hydrogen atom; a halogen atom; an alkyl group; a hydroxy group; A nitro group; a cyano group; or a sulfo group, wherein any hydrogen atom of the group containing the alkylene group and the alkyl group may be substituted with a halogen atom. However, at least one of a plurality of R ³ contained in one group contains a halogen atom or a halogenated alkyl group. a1 represents an integer of 1 to 3, a2 represents 1 or 2, a3 independently represents an integer of 1 to 4, and e represents an integer of 0 to 3.

  The ether bond, thioether group, ketone group, ester bond, sulfonyl group, alkylene group, amide group or siloxane group-containing group includes ether bond, thioether group, ketone group, ester bond, sulfonyl group, alkylene group, amide group. Or the C1-C10 organic group containing a siloxane group is mentioned.

In the formula (3), R ³ preferably contains 1 to 12 halogen atoms, so that a film having excellent mechanical strength can be easily produced in a short time with high productivity. More preferably, 3 to 8 are included.

In the present invention, when R ³ is a halogen atom, it is referred to as “including one halogen atom”, and when R ³ is, for example, a trifluoromethyl group, it is referred to as “including three halogen atoms”. .

In the formula (3), examples of the halogenated alkyl group for R ³ include a methyl group substituted with a halogen atom or an alkyl group having 2 to 20 carbon atoms.
The halogenated alkyl group having 2 to 20 carbon atoms is preferably an alkyl group having 2 to 10 carbon atoms substituted with a halogen atom, and an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, t -The group etc. with which the arbitrary hydrogen atoms of the butyl group, the pentyl group, and the hexyl group were substituted by the fluorine atom, the chlorine atom, the bromine atom, or the iodine atom are mentioned.

In the above formula (3), the halogenated alkyl group for R ³ is preferably an alkyl group having 1 to 2 carbon atoms substituted by a halogen atom, specifically, any hydrogen of a methyl group or an ethyl group Examples include groups in which the atom is substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

In the formula (3), the halogen atom in R ^{3 and} the halogen atom contained in the halogenated alkyl group can easily produce a film having excellent mechanical strength in a short time with high productivity. To a fluorine atom.

R ³ which does not contain a halogen atom is preferably a hydrogen atom, an alkyl group, a fluorene group, a hydroxy group, a nitro group, a cyano group or a sulfo group, and preferably a hydrogen atom or an alkyl group.

In the formula (3), the alkyl group in R ³ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, specifically a methyl group, Examples thereof include an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and a hexyl group.

In the formula (3), examples of the group containing an alkylene group in R ³ include a methylene group or an alkylene group having 2 to 20 carbon atoms, and any hydrogen atom of the alkylene group may be substituted with a halogen atom. Good.
The alkylene group having 2 to 20 carbon atoms is preferably an alkylene group having 2 to 10 carbon atoms, and examples thereof include a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and an isopropylidene group. It is done.

e is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.
a1 is preferably 1 or 3, a2 is preferably 2, a3 is preferably 1 or 2, and more preferably 1.

In the formula (1), the divalent organic group in R ¹ is preferably a group selected from the group represented by the following formula (3 ′).

In the formula (3 '), R ³ has the same meaning as R ³ in formula independently (3).

  Examples of the group represented by the formula (3 ′) include groups selected from the group represented by (3′-1) and (3′-2) below.

In the formula (1), the divalent organic group in R ¹ is more preferably a group selected from the group represented by the following formula (3 ″).

In the formula (1), in R ^2, as the tetravalent organic group, preferably tetravalent organic group having 1 to 40 carbon atoms.
The tetravalent organic group having 1 to 40 carbon atoms is preferably a tetravalent alicyclic hydrocarbon group having 3 to 40 carbon atoms or a tetravalent aromatic hydrocarbon group having 6 to 40 carbon atoms. In the case where the organic group contains two or more ring structures, a ring such as a polycyclic structure in which the rings share one or more bonds, a spiro hydrocarbon structure, or a biphenyl bond such as a single bond A structure bonded by a group is included. Examples of the bonding group include an ether bond, a thioether group, a ketone group, an ester bond, a sulfonyl group, an alkylene group, an amide group, and a siloxane group in addition to the single bond.

R ² is more preferably a group selected from the group represented by the following formula (4), and more preferably a group selected from the group represented by the following formula (4 ′). When the tetravalent organic group in R ² is a group selected from the group represented by the following formula (4), particularly a group selected from the group represented by the following formula (4 ′), from the polyimide precursor The obtained polyimide has a rigid skeleton and is easy to form a microphase-separated structure, which is preferable in that a film having a small residual stress and a suppressed warpage can be obtained.

In the formula (4), R ⁴ independently represents an ether bond, a thioether group, a ketone group, an ester bond, a sulfonyl group, an alkylene group, an amide group or a siloxane group; a hydrogen atom; a halogen atom; an alkyl group; a hydroxy group; A nitro group; a cyano group; or a sulfo group, wherein any hydrogen atom of the group containing the alkylene group and the alkyl group may be substituted with a halogen atom. D represents an ether bond, a thioether group, a ketone group, an ester bond, a sulfonyl group, an alkylene group, an amide group or a siloxane group, b independently represents 1 or 2, and c independently represents an integer of 1 to 3. , F represents an integer of 0-3.
However, at least one of the plurality of R ⁴ contained in one group preferably contains a halogen atom or a halogenated alkyl group.

  The ether bond, thioether group, ketone group, ester bond, sulfonyl group, alkylene group, amide group or siloxane group-containing group includes ether bond, thioether group, ketone group, ester bond, sulfonyl group, alkylene group, amide group. Or the C1-C10 organic group containing a siloxane group is mentioned.

In the formula (4), R ⁴ preferably contains 1 to 12 halogen atoms. From the viewpoint that a film having excellent mechanical strength can be easily produced in a short time with high productivity. More preferably, 3 to 8 are included.

In the formula (4), examples of the halogenated alkyl group for R ⁴ include a methyl group substituted with a halogen atom or an alkyl group having 2 to 20 carbon atoms.
The halogenated alkyl group having 2 to 20 carbon atoms is preferably an alkyl group having 2 to 10 carbon atoms substituted with a halogen atom, and an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, t -The group etc. with which the arbitrary hydrogen atoms of the butyl group, the pentyl group, and the hexyl group were substituted by the fluorine atom, the chlorine atom, the bromine atom, or the iodine atom are mentioned.

In the above formula (4), the halogenated alkyl group for R ⁴ is preferably an alkyl group having 1 to 2 carbon atoms substituted with a halogen atom, specifically, any hydrogen of a methyl group or an ethyl group Examples include groups in which the atom is substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

In the formula (4), the halogen atom in R ^{4 and} the halogen atom contained in the halogenated alkyl group can easily produce a film having excellent mechanical strength in a short time with high productivity. To a fluorine atom.

R ⁴ containing no halogen atom is preferably a hydrogen atom, an alkyl group, a fluorene group, a hydroxy group, a nitro group, a cyano group or a sulfo group, and more preferably a hydrogen atom or an alkyl group.

In the formula (4), the alkyl group in R ⁴ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, specifically a methyl group, Examples thereof include an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and a hexyl group.

In the formula (3), examples of the group containing an alkylene group in R ⁴ include a methylene group or an alkylene group having 2 to 20 carbon atoms, and any hydrogen atom of the alkylene group may be substituted with a halogen atom. Good.
The alkylene group having 2 to 20 carbon atoms is preferably an alkylene group having 2 to 10 carbon atoms, and examples thereof include a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and an isopropylidene group. It is done.

D is preferably an ether group, a thioether group, or a sulfonyl group.
c is preferably 1 or 2.
f is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.

  The group selected from the group represented by the formula (4) is preferably a group selected from the group represented by the following formula (4 ′).

The structural unit (1) includes a structural unit (2). The structural unit (2) may be contained in at least one group selected from the group consisting of a plurality of R ¹ and R ^{2 in the} structural unit (1), and is contained at the end of the structural unit (1). However, it is preferably contained in at least one group selected from the group consisting of a plurality of R ¹ and R ² . “At least one group selected from the group consisting of a plurality of R ¹ and R ² includes a structural unit represented by the following formula (2)” means that when n is 2 or more, R ¹ And R ² each exist in two or more structural units (1), and it means that at least one of the plurality of R ¹ and R ² includes a structural unit represented by the following formula (2). .
Since the polyimide precursor contains the structural unit (2), according to the resin composition containing the precursor, a film in which the residual stress is small and the occurrence of warpage is suppressed can be obtained.

In the formula (2), a plurality of R ⁵ is a monovalent organic group having 1 to 20 carbon atoms each independently, m is an integer of 3 to 200.

In the formula (2), the monovalent organic group having 1 to 20 carbon atoms in R ⁵ includes a monovalent hydrocarbon group having 1 to 20 carbon atoms and a monovalent alkoxy group having 1 to 20 carbon atoms. Can be mentioned.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms in R ⁵ include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms. It is done.
The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t -A butyl group, a pentyl group, a hexyl group, etc. are mentioned.
The cycloalkyl group having 3 to 20 carbon atoms is preferably a cycloalkyl group having 3 to 10 carbon atoms, and specific examples include a cyclopentyl group and a cyclohexyl group.
The aryl group having 6 to 20 carbon atoms is preferably an aryl group having 6 to 12 carbon atoms, and specific examples include a phenyl group, a tolyl group, and a naphthyl group.

Examples of the monovalent alkoxy group having 1 to 20 carbon atoms in R ⁵ include a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, a phenoxy group, a propenyloxy group, and a cyclohexyloxy group.

When at least one of the plurality of R ⁵ in the formula (2) includes an aryl group, the island part composed of the flexible skeleton part is excellent in affinity with the sea part composed of the rigid skeleton part. A size of about 1 micron is preferable because it is easy to disperse (uniform) (microphase separation). More specifically, the plurality of R ⁵ are preferably an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 12 carbon atoms. In this case, among all R ^{5 in} the structural unit (2), the ratio between the number of moles (i) of the alkyl group having 1 to 10 carbon atoms and the number of moles (ii) of the aryl group having 6 to 12 carbon atoms ( However, (i) + (ii) = 100) is preferably (i) :( ii) = 90 to 10:10 to 90, and more preferably (i) :( ii) = 85 to 15:15. It is -85, More preferably, it is (i) :( ii) = 85-65: 15-35. Of all R ^{5 in} the structural unit (2), when the ratio of the number of moles of alkyl groups (i) to the number of moles of aryl groups (ii) is out of the above range, the resulting polyimide has a microphase-separated structure. There is a possibility that it cannot be formed. When the ratio of the number of moles of alkyl groups (i) to the number of moles of aryl groups (ii) is within the above range, microphase separation (the skeleton containing the structural unit (2) is nano-dispersed) and low linear expansion is possible. A film having a coefficient, low residual stress, and the like, excellent in transparency and hardly clouded can be obtained.
The alkyl group having 1 to 10 carbon atoms is preferably a methyl group, and the aryl group having 6 to 12 carbon atoms is preferably a phenyl group.

When the whole polyimide precursor is 100% by mass, the structural unit (2) is preferably included in an amount of 5 to 40% by mass, more preferably 5 to 23% by mass, and 8 to 22% by mass. It is more preferable that 9.5 to 21% by mass is further included.
When the proportion of the structural unit (2) contained in the polyimide precursor exceeds the above range, when the resin composition of the present invention was applied to a substrate such as a glass substrate and a coating film was formed, the substrate was formed from the substrate. It tends to be difficult to peel the coating film. Moreover, when the quantity of the structural unit (2) contained in a polyimide precursor is less than the said range, when the resin composition of this invention is apply | coated to substrates, such as a glass substrate, and a coating film is formed, the coating film formed When the coating film is peeled off from the substrate, the resulting film may be warped.

  M in the formula (2) is an integer of 3 to 200, preferably 10 to 200, more preferably 20 to 150, still more preferably 30 to 100, and particularly preferably an integer of 35 to 80. When m is 2 or less, the polyimide obtained from the polyimide precursor may be difficult to form a microphase separation structure. When m exceeds 200, the size of the island composed of the skeleton part including the structural unit (2) is large. May exceed 1 μm, and the coating film may become cloudy or the mechanical strength may decrease.

  The polyimide precursor preferably contains 60% by mass or more, more preferably 77% by mass or more, and still more preferably 79% by mass or more of the structural unit (1) in 100% by mass of the polyimide precursor. When the proportion of the structural unit (1) is within the above range in the polyimide precursor, a film having a small residual stress and hardly warping can be obtained.

In addition, the content of the structural unit (1) of 60% by mass or more in 100% by mass of the polyimide precursor means that the structural unit —NH—R ¹ —NH—, the structural unit —NH—R ¹ —NH ₂ , or the structural unit— CO—R ² (COOR) ₂ —CO—, structural unit —CO—R ² (COOR) ₂ —COOH, structural unit (2), and structural unit — (Si (R ⁵ ) ₂ —O) _m —Si This means that the total of structural units including R ¹ , R ² such as (R ⁵ ) ₂ -R ¹⁰ -R ¹¹ and the structural unit (2) is 60% by mass or more.
(Note, R ^1, R ² and R have the same meanings as R ^1, R ² and R in the formula (1), R ⁵ has the same meaning as R ⁵ in the formula (2), R ¹⁰ and R ¹¹ has the same meaning as R ¹⁰ and R ^{11 in the following} formulas (7 ′) and (8 ′).)

  In the polyimide precursor, part of the structural unit (1) may be imidized.

In the structural unit (1), R ¹ is a group selected from the group represented by the formula (3), particularly a group selected from the group represented by the formula (3 ′), and R ² is It is a group selected from the group represented by the formula (4), particularly a group selected from the group represented by the formula (4 ′), and when m in the formula (2) is 3 or more, the polyimide The polyimide obtained from the precursor is particularly preferable from the viewpoint of reducing the residual stress of the obtained film because it becomes easier to take a microphase separation structure.

In addition to the structural unit included in the formula (1), the polyimide precursor has an ether bond, a thioether group, a ketone group, an ester in the main chain of the precursor, depending on the desired use and film forming conditions. A structural unit derived from a monomer (hereinafter also referred to as “monomer (I)”) containing at least one group selected from the group consisting of a bond, a sulfonyl group, an alkylene group, an amide group and a siloxane group (hereinafter also referred to as “monomer (I)”) (Also referred to as “structural unit (56)”).
Examples of the alkylene group include the same groups as the alkylene group for R ³ in the formula (3).

The “structural unit included in the formula (1)” means a structural unit —NH—R ¹ —NH—, a structural unit —NH—R ¹ —NH ₂ , or a structural unit —CO—R ² (COOR) _2. -CO-, structural units -CO-R ² (COOR) ₂ -COOH, the structural unit (2), and a structural unit _{^{- (Si (R 5) 2}} -O) m -Si (R 5) 2 -R 10 R ¹ a -R ¹¹ or the like, refers to a structural unit containing R ² and structural units (2) (Note, R ^1, R ² and R and R ^1, R ² and R in the formula (1) are synonymous, R ⁵ has the same meaning as R ⁵ in the formula (2), R ¹⁰ and R ¹¹ has the same meaning as R ¹⁰ and R ¹¹ of the formula (7 ') and (8') in. ).

The structural unit (56) is a tetracarboxylic acid that does not include the group represented by R ¹ and R ² in the structural unit (1) and the structural unit (2) contained in the main chain of the polyimide precursor. It refers to structural units derived from dianhydrides and their derivatives or imino forming compounds.

The main chain of the polyimide precursor means a chain containing R ¹ or R ² of the structural unit (1). For example, —COOR in the structural unit (1) is not a main chain but a side chain. .

  When the structural unit (56) is contained in the polyimide precursor, the linear expansion coefficient of the obtained film increases, and a film that can be stretched as desired is obtained.

  In the polyimide precursor, when the content of the structural unit (56) and / or the content of the structural unit (2) is increased, the linear expansion coefficient of the obtained film is increased, so that the substrate containing Cu or Si is contained. When the resin composition is applied onto a substrate or the like, the blending amount of the structural unit (56) and / or the structural unit (2) may be changed according to these substrates. Specifically, since the coefficient of linear expansion of Cu is 16.8 ppm / K, when the resin composition of the present invention is applied on a substrate made of Cu, the polyimide precursor has a structural unit (56). Since the linear expansion coefficient of Si is 3 ppm / K, when the resin composition of the present invention is applied on a substrate made of Si, the polyimide precursor contains structural units (56). It is preferably not included. In addition, the linear expansion coefficient of chromium is 8.2 ppm / K, the linear expansion coefficient of glass is 9 ppm / K, the linear expansion coefficient of stainless steel SUS430 is 10.4 ppm / K, and the linear expansion coefficient of nickel is 12.8 ppm / K. Therefore, in the case where the resin composition of the present invention is applied on a substrate composed of these, the polyimide precursor preferably contains 0 to 15% by mass of the structural unit (56) in 100% by mass of the polyimide precursor. .

  The monomer (I) is a compound represented by the following formula (5) (hereinafter also referred to as “compound (5)”) or a compound represented by the formula (6) (hereinafter also referred to as “compound (6)”). It is preferable that

In the formulas (5) and (6), each A independently represents an ether bond (—O—), a thioether group (—S—), a ketone group (—C (═O) —), an ester bond (—COO—). ), A sulfonyl group (—SO ₂ —), an alkylene group (—R ⁷ —), an amide group (—C (═O) —NR ⁸ —), a siloxane group (—Si (R ⁹ ) ₂ —O—Si ( R ⁹⁾ ₂ -) and a group containing at least one group chosen from the group consisting of fluorene group, R ⁶ is independently a hydrogen atom, a halogen atom, an alkyl group or a nitro group, any of the alkyl groups The hydrogen atom may be substituted with a halogen atom. d shows the integer of 1-4 independently.

R ⁸ and R ⁹ each independently represent a hydrogen atom, an alkyl group or a halogen atom, and the hydrogen atom of this alkyl group may be substituted with a halogen atom. Examples of the alkyl group in R ⁶ , R ⁸ and R ⁹ include the same groups as the alkyl group in R ³ in the formula (3). The halogen atom is preferably a chlorine atom or a fluorine atom.

A is preferably an ether bond, and R ⁶ is preferably a hydrogen atom.

In the formulas (5) and (6), the alkylene group (—R ⁷ —) in A includes the same groups as the alkylene group in R ³ in the formula (3). Among these, methylene Group, isopropylidene group, and hexafluoroisopropylidene group are preferred.

  Examples of the compounds (5) and (6) include compounds described in the following compound groups (5-1) to (6-9).

When the said polyimide precursor contains a structural unit (56), a polyimide precursor preferably contains 0-15 mass% of structural units (56) in 100 mass% of polyimide precursors, More preferably, it is 0-10 mass%. More preferably 0 to 9% by mass, particularly preferably 0 to 8% by mass.
When the content of the structural unit (56) exceeds 15% by mass, the elastic modulus of the rigid skeleton part is lowered, and it is difficult to transfer the residual stress to the flexible skeleton part. It may be easier.
Moreover, when content of a structural unit (56) exists in the said range, the film | membrane which is easy to stretch can be obtained, with generation | occurrence | production of curvature being suppressed.

Incidentally, the polyimide precursor, may include a structural unit (56), a polyimide precursor containing the structural unit (56), (i) the equation (1) in R ¹ and R ² in the structural unit (56) And (ii) a structure in which the structural unit (56) is included in a portion other than the structural unit (1) in the polyimide precursor. In the case of (i), assuming that the polyimide precursor includes a structural unit derived from the compound (5) in R ¹ in the formula (1), the polyimide precursor is represented by the following formula (5A), for example. It is expressed in In this case, “the structural unit (56) is preferably contained in an amount of 0 to 15% by mass in 100% by mass of the polyimide precursor” means “between two —NH— in the repeating unit n2 in 100% by mass of the polyimide precursor. It means that 0-15 mass% of structural units represented by the structure sandwiched between (including —NH— at both ends) are included.
In the case of (i), the structural unit (56) may be contained in at least one group selected from the group consisting of a plurality of R ¹ and R ^{2 in the} structural unit (1). It may be contained at the end of the unit (1).

In the formula (5A), R, R ¹ and R ² are each independently synonymous with R, R ¹ and R ² in the formula (1), and A, R ⁶ and d are each independently the above formula ( 5) is the same as A, R ⁶ and d in n), and n1 + n2 is synonymous with n in the formula (1).

  The weight average molecular weight (Mw) of the polyimide precursor is preferably 10,000 to 1,000,000, more preferably 10,000 to 200,000, and further preferably 20000 to 150,000. The number average molecular weight (Mn) is 5,000 to 10,000,000, preferably 5,000 to 500,000, particularly preferably 15,000 to 200,000.

  When the weight average molecular weight or number average molecular weight of the polyimide precursor is less than the lower limit, the strength of the resulting film may be lowered. Furthermore, the linear expansion coefficient of the obtained film may be increased more than necessary. On the other hand, when the weight average molecular weight or number average molecular weight of the polyimide precursor exceeds the upper limit, the viscosity of the resin composition increases, and thus when the resin composition is applied to a substrate such as a glass substrate to form a film. The amount of the polyimide precursor that can be blended in the resin composition is reduced, and the film thickness accuracy such as the flatness of the obtained coating film may be deteriorated.

  The molecular weight distribution (Mw / Mn) of the polyimide precursor is preferably 1.0 to 10.0, more preferably 1.5 to 5.0, and particularly preferably 1.5 to 4.0.

  The weight average molecular weight, number average molecular weight, and molecular weight distribution were measured using a TOSOH HLC-8220 GPC device (guard column: TSK guard column ALPHA column: TSKgel ALPHA-M, developing solvent: N-methylpyrrolidone (NMP)). Measured value.

<Synthesis Method of Polyimide Precursor>
The polyimide precursor having the structural unit (1) is preferably a component containing at least one acyl compound selected from the group consisting of tetracarboxylic dianhydride and a reactive derivative thereof (hereinafter referred to as “component (A)”). And a component containing an imino forming compound (hereinafter also referred to as “component (B)”). However, in the synthesis of the polyimide, it is preferable to use a compound containing the structural unit (2).
According to this reaction, a polyimide precursor corresponding to the structure of the raw material compound to be used can be obtained, and a polyimide precursor having a structural unit derived from the compound in an amount corresponding to the amount of the raw material compound to be used is obtained. be able to.

  In this case, an acyl compound containing the structural unit (2) as the component (A) (hereinafter also referred to as “compound (A-2)”) is used, or imino formation containing the structural unit (2) as the component (B). It is preferable to use a compound (hereinafter also referred to as “compound (B-2)”). Moreover, both a compound (A-2) and a compound (B-2) can also be used.

[(A) component]
The component (A) is at least one acyl compound selected from the group consisting of tetracarboxylic dianhydride and this reactive derivative. Preferably, at least one compound selected from the group consisting of the compound (A-2) and an acyl compound (A-1) other than the compound (A-2) is included.

  Examples of the acyl compound (A-1) include at least one compound selected from the group consisting of aromatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic acids, the compound (6), and reactive derivatives thereof. Is mentioned.

Specific examples of the acyl compound (A-1) include 4,4′-oxydiphthalic dianhydride, pyromellitic dianhydride (PMDA), 1,4,5,8-naphthalene tetracarboxylic dianhydride. 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilane Tetracarboxylic dianhydride, 2,3,4,5-furantetracarboxylic dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylide Diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide Dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride , Aromatic tetracarboxylic dianhydrides such as bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, and reactive derivatives thereof;
Butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl Acetic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid Dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene-2,3 Aliphatic tetracarboxylic dianhydrides or alicyclic tetracarboxylic dianhydrides such as 5,6-tetracarboxylic dianhydride, 3,3 ′, 4,4′-bicyclohexyltetracarboxylic dianhydride, And reactive derivatives thereof.
These compounds can be used alone or in combination of two or more.

  Examples of the reactive derivative include tetracarboxylic acid, acid esterified product of tetracarboxylic acid, and acid chloride of tetracarboxylic acid.

  Of these, aliphatic tetracarboxylic dianhydride or alicyclic tetracarboxylic dianhydride is preferably used from the viewpoint of excellent transparency and good solubility in an organic solvent. In addition, aromatic tetracarboxylic dianhydrides are preferably used from the viewpoints of heat resistance, low linear expansion coefficient (dimensional stability), and low water absorption.

Moreover, as said acyl compound (A-1), it is a compound which has a group chosen from the group represented by the said Formula (4) or Formula (4 '), In the said sea part with a high elastic modulus, The flexible skeleton part can be (uniformly) dispersed in a very small size of about 1 nanometer to 1 micron (micro phase separation structure), and the stress generated in the film forming process can be efficiently absorbed by the flexible skeleton part. For this reason, it is more preferable from the viewpoint of obtaining a film having a small residual stress and suppressed warpage.
Specifically, as such a compound, pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), the following group (4-1) ), And the like. These compounds can be used alone or in combination of two or more.

  The compounding amount of the compound (A-1) (excluding compounds (6) and (6 ′)) is not particularly limited, and the total amount of all acyl compounds (component (A)) is 100% by mass. 100% by mass, but when the compound (A-2) and / or the compound (6) is contained in the component (A), the preferable blending amount of each of these compounds from 100% by mass What is necessary is just to mix | blend in the quantity which subtracted.

Specific examples of the compound (A-2) include a tetracarboxylic dianhydride having a structural unit represented by the formula (2) and at least one acyl compound selected from the reactive derivatives. Preferably, the compound represented by the following formula (7) (hereinafter also referred to as “compound (7)”) and the compound represented by the following formula (7 ′) (hereinafter also referred to as “compound (7 ′)”). ), A compound represented by the following formula (8) (hereinafter also referred to as “compound (8)”) and a compound represented by the following formula (8 ′) (hereinafter also referred to as “compound (8 ′)”). And at least one compound selected from the group consisting of:
These compounds can be used alone or in combination of two or more.

  Examples of the reactive derivative include a tetracarboxylic acid having a structural unit represented by the formula (2), an acid esterified product of the tetracarboxylic acid, and an acid chloride of the tetracarboxylic acid.

In the case where it is desired to synthesize a polyimide precursor in which the structural unit (2) is contained in at least one group of R ^{2 in} the structural unit (1), the compounds (7) and / or (8) are synthesized. Preferably, the compound (7 ′) and / or (8 ′) is preferably used when the structural unit (2) is to synthesize a polyimide precursor contained at the terminal of the structural unit (1). Is preferred.

In the formulas (7), (7 ′), (8) and (8 ′), R ⁵ and m are each independently synonymous with R ⁵ and m in the formula (2). R ¹⁰ independently represents a single bond or a divalent organic group having 1 to 20 carbon atoms. In the formulas (7 ′) and (8 ′), R ¹¹ independently represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. As the monovalent organic group having 1 to 20 carbon atoms, in the formula (2), such as the same groups as the monovalent organic group having 1 to 20 carbon atoms in R ⁵ and the like.

Examples of the divalent organic group having 1 to 20 carbon atoms in R ¹⁰ include a methylene group, an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, and an arylene group having 6 to 20 carbon atoms. Is mentioned.
The alkylene group having 2 to 20 carbon atoms is preferably an alkylene group having 2 to 10 carbon atoms, and examples thereof include a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group.
The cycloalkylene group having 3 to 20 carbon atoms is preferably a cycloalkylene group having 3 to 10 carbon atoms, and examples thereof include a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group.
The arylene group having 6 to 20 carbon atoms is preferably an arylene group having 6 to 12 carbon atoms, and examples thereof include a phenylene group and a naphthylene group.

  The compound (A-2) preferably has a number average molecular weight of 200 to 10,000, more preferably 500 to 10 from the viewpoint of obtaining a film excellent in heat resistance (high glass transition temperature) and water resistance. 000, particularly preferably 500 to 6000. The amine value is preferably 100 to 5000, more preferably 250 to 5,000, and still more preferably 1000 to 3000.

  The degree of polymerization m in the compounds (7), (7 ′), (8) and (8 ′) is the same as that in the formula (2), and the preferred range is also the same.

In the formulas (7), (7 ′), (8) and (8 ′), R ⁵ is preferably a methyl group or a phenyl group, and at least one of a plurality of R ⁵ is preferably a phenyl group. When all of the plurality of R ⁵ are a methyl group or a phenyl group, at least one of which is a methyl group, and at least one of which is a phenyl group, the ratio of the mol% of the methyl group to the mol% of the phenyl group (Mole% of methyl group + mol% of phenyl group = 100) is preferably methyl group: phenyl group = 5-95: 95-5, more preferably methyl group: phenyl group = 15-85: 85. 15 and more preferably methyl group: phenyl group = 85-65: 15-35. If at least one R ^{5 in the} formulas (7), (7 ′), (8) and (8 ′) is not a phenyl group, the compatibility between the sea part and the island part deteriorates and the dispersion of the island part A film having a size exceeding 1 micron and inferior heat resistance and film strength may be obtained.

  Specific examples of the compound (A-2) include DMS-Z21 (number average molecular weight 600 to 800, amine value 300 to 400, m = 4 to 7) manufactured by Gerest Co., Ltd. In addition, a compound (A-2) can be used individually by 1 type or in combination of 2 or more types.

  When the compound (A-2) is contained in the component (A), when the total amount of all raw material compounds (component (A) + component (B)) is 100% by mass, the compound (A-2) The blending amount is preferably 5 to 40% by mass, more preferably 5 to 23% by mass, and still more preferably 8 to 8% from the viewpoint of obtaining a film that is excellent in peelability from the substrate and hardly warps. It is 22 mass%, Most preferably, it is 9.5-21 mass%. However, the preferable compounding quantity of the said compound (A-2) is a case where the said compound (B-2) is not used when synthesize | combining a polyimide precursor, When synthesize | combining a polyimide precursor, it is as a raw material. When the compound (A-2) and the compound (B-2) are used, the total amount of the compound (A-2) and the compound (B-2) to be used is preferably a blending amount of the compound (A-2). It is preferable to make it to the same degree.

In addition, the component (A) includes a compound represented by the compound (6) and / or the following formula (6 ′) (hereinafter referred to as “compound”), depending on the desired use, from the viewpoint of improving the elongation of the obtained film. (6 ') ") may also be included. In addition, when it is desired to synthesize a polyimide precursor containing the structural unit (56) in the main chain (excluding the terminal) of the polyimide precursor, it is preferable to use the compound (6), and the main chain terminal of the polyimide precursor is used. When it is desired to synthesize a polyimide precursor containing the structural unit (56), it is preferable to use the compound (6 ′).
These compounds can be used alone or in combination of two or more.

In the formula (6 ′), A has the same meaning as A in the formulas (5) and (6), and R ¹² represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. Examples of the monovalent organic group having 1 to 20 carbon atoms include the same groups as the monovalent organic group having 1 to 20 carbon atoms in R ⁵ in the formula (2).

  When the compound (6) and / or the compound (6 ′) is included in the component (A), the total amount of all raw material compounds (component (A) + component (B)) is 100% by mass, The compounding amount of the compound (6) and the compound (6 ′) is preferably 0 to 15% by mass, more preferably 0 to 10% by mass, and still more preferably, from the viewpoint of obtaining a film that hardly warps. It is 0-9 mass%, Most preferably, it is 0-8 mass%. However, the preferable compounding amount of the compound (6) and the compound (6 ′) is a case where the compound (5) and / or the following compound (5 ′) is not used when the polyimide precursor is synthesized. When the compound (6) and / or compound (6 ′) and the compound (5) and / or compound (5 ′) are used as raw materials when the precursor is synthesized, the compound (6) to be used, It is preferable that the total amount of the compound (6 ′), the compound (5) and the compound (5 ′) is approximately the same as the preferable blending amount of the compound (6) and the compound (6 ′).

[Component (B)]
The component (B) is an imino forming compound. Here, the “imino forming compound” refers to a compound that reacts with the component (A) to form an imino (group), and specifically includes a diamine compound, a diisocyanate compound, and a bis (trialkylsilyl) amino compound. Etc.

The component (B) preferably includes at least one compound selected from the group consisting of the compound (B-2) and an imino forming compound (B-1) other than the compound (B-2).
Examples of the compound (B-1) include at least one compound selected from the group of aromatic diamines, the compound (5), and the like.

  Examples of the compound (B-1) include p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether (ODA), 3,4 ′. -Diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl (o-tolidine), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-tolidine) ), 3,3′-diethyl-4,4′-diaminobiphenyl, 2,2′-diethyl-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) Biphenyl (TFMB), 4,4′-diamino-2,2′-bis (trifluoroethyl) biphenyl, 4,4′-diamino-2,2′-bis (trifluoro) Acetyl) biphenyl, 3,7-diamino-dimethyldibenzothiophene-5,5-dioxide, 4,4′-diaminobenzophenone, 3,3′-diaminobenzophenone, 4,4′-bis (4-aminophenyl) sulfide, 4,4′-diaminodiphenylsulfone, 4,4′-diaminobenzanilide, 1, n-bis (4-aminophenoxy) alkane, 1,3-bis [2- (4-aminophenoxyethoxy)] ethane, 9 , 9-bis (4-aminophenyl) fluorene, 9,9-bis (4-aminophenoxyphenyl) fluorene, 5 (6) -amino-1- (4-aminomethyl) -1,3,3-trimethylindane 1,4-bis (4-aminophenoxy) benzene (TPE-Q), 1,3-bis (4-aminophenoxy) benzene (TPE) -R), 1,3-bis (3-aminophenoxy) benzene (APB), 2,5-bis (4-aminophenoxy) biphenyl (P-TPEQ), 4,4'-bis (4-aminophenoxy) Biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxyphenyl)] propane, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, Bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, benzidine, 3,3-dimethoxy-4,4-diaminobiphenyl, 2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 4,4′-methylene-bis (2-chloroaniline), 2,2′-difluoro-4,4′-diamino- 5,5′-dimethoxybiphenyl, 2,2 ′, 5,5′-tetrafluoro-4,4′-diaminobiphenyl, 4,4′-methylene-bis (2-fluoroaniline), 9,10-bis ( 4-aminophenyl) anthracene, o-tolidine sulfone and the like. These aromatic diamines can be used singly or in combination of two or more.

  The compound (B-1) is selected from the group represented by the formulas (3), (3 ′), (3′-1) to (3′-2) and (3 ″). The compound having a group can disperse the flexible skeletal site in the sea part having a high elastic modulus in a very small size of about 1 nanometer to 1 micron (micro phase separation structure), and the film forming process Since the stress generated in step (b) can be efficiently absorbed by the flexible skeleton portion, it is preferable from the viewpoint of obtaining a film in which the residual stress is small and the occurrence of warpage is suppressed. Specific examples of such compounds include 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB), 4,4′-diamino-2,2′-bis (trifluoro). Ethyl) biphenyl, 4,4′-diamino-2,2′-bis (trifluoroacetyl) biphenyl, and the like, among them 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl Is preferred.

  The amount of compound (B-1) (excluding compounds (5) and (5 ′)) is not particularly limited, and the total amount of all imide-forming compounds (component (B)) is 100% by mass. May be 100% by mass, but when the compound (B-2) and / or the compound (5) is contained in the component (B), the preferable blending of each of these compounds from 100% by mass What is necessary is just to mix | blend in the quantity which subtracted the quantity.

The compound (B-2) is not particularly limited as long as it is an imino forming compound containing the structural unit (2), but is preferably a compound represented by the following formula (9) (hereinafter also referred to as “compound (9)”). And the compound represented by the following formula (9 ′) (hereinafter also referred to as “compound (9 ′)”), and the like.
In the case where it is desired to synthesize a polyimide precursor in which the structural unit (2) is contained in at least one group selected from the group consisting of a plurality of R ¹ and R ^{2 in the} structural unit (1), the compound (9 ) Is preferably used, and when it is desired to synthesize a polyimide precursor contained at the terminal of the structural unit (1), it is preferable to use the compound (9 ′).
These compounds can be used alone or in combination of two or more.

In the formulas (9) and (9 ′), R ⁵ and m each independently have the same meaning as R ⁵ and m in the formula (2), and R ¹⁰ each independently represents the formula (7), ( 7 '), (8) and (8') in the same definition as R ¹⁰ in, R ¹¹ has the same meaning as R ¹¹ each in the formula independently (7 ') and (8').

  As the compound (B-2), the flexible skeleton part can be finely dispersed in the sea part composed of the rigid skeleton part with a size of about nano to micron, and has heat resistance (high glass transition temperature) and water resistance. From the viewpoint of obtaining an excellent film, the number average molecular weight is preferably 500 to 12,000, more preferably 1,000 to 8,000, and further preferably 3,000 to 6,000. preferable. The amine value is preferably 250 to 6,000, more preferably 500 to 4,000, and further preferably 1,500 to 3,000.

  The polymerization degree m in the formulas (9) and (9 ′) is the same as that in the formula (2), and the preferred range is also the same.

In the formulas (9) and (9 ′), R ⁵ is preferably a methyl group or a phenyl group, and at least one of a plurality of R ⁵ is preferably a phenyl group. When all of the plurality of R ⁵ are a methyl group or a phenyl group, at least one of which is a methyl group, and at least one of which is a phenyl group, the ratio of the mol% of the methyl group to the mol% of the phenyl group (Mole% of methyl group + mol% of phenyl group = 100) is preferably methyl group: phenyl group = 5-95: 95-5, more preferably methyl group: phenyl group = 15-85: 85. 15 and more preferably methyl group: phenyl group = 85-65: 15-35. If at least one R ^{5 in the} formulas (9) and (9 ′) is not a phenyl group, the compatibility between the sea part and the island part deteriorates, and the dispersion size of the island part exceeds 1 micron, and the heat resistance In some cases, a film having poor film strength may be obtained.

As the compound (B-2), specifically, both terminal amino-modified methylphenyl silicone (manufactured by Shin-Etsu Chemical Co., Ltd .; X22-1660B-3 (number average molecular weight 4,400, polymerization degree m = 41, phenyl group: methyl) Group = 25: 75 mol%), X22-9409 (number average molecular weight 1,300)), both-terminal amino-modified dimethyl silicone (manufactured by Shin-Etsu Chemical Co., Ltd .; X22-161A (number average molecular weight 1,600, polymerization degree m = 20)) X22-161B (number average molecular weight 3,000, polymerization degree m = 39), KF-8012 (number average molecular weight 4400, polymerization degree m = 58), manufactured by Toray Dow Corning; BY16-835U (number average molecular weight 900, polymerization) Degree m = 11)). In addition, the said imino formation compound (B-2) can be used individually by 1 type or in combination of 2 or more types. The degree of polymerization m can be calculated by the following equation, for example. (When both ends are aminopropyl groups, R ⁵ in the formula (2) is a methyl group or a phenyl group)
m = (number average molecular weight−molecular weight 116.2 of both terminal groups (aminopropyl group)) / (74.15 × mol% of methyl group × 0.01 + 198.29 × mol% of phenyl group × 0.01)

  When the compound (B-2) is contained in the component (B), the total amount of all raw material compounds (component (A) + component (B)) is 100% by mass, and the compound (B-2) The blending amount is preferably 5 to 40% by mass, more preferably 5 to 23% by mass, and still more preferably 8 to 8% from the viewpoint of obtaining a film that is excellent in peelability from the substrate and hardly warps. It is 22 mass%, Most preferably, it is 9.5-21 mass%. However, the preferable compounding quantity of the said compound (B-2) is the quantity when not using the said compound (A-2) when synthesize | combining a polyimide precursor.

In addition, the component (B) includes a compound represented by the compound (5) and / or the following formula (5 ′) (hereinafter referred to as “compound”), depending on the desired use, from the viewpoint of improving the elongation of the obtained film. (5 ') ") may also be included. In addition, when it is desired to synthesize a polyimide precursor including the structural unit (56) in the main chain (excluding the terminal) of the polyimide precursor, it is preferable to use the compound (5), and the main chain terminal of the polyimide precursor is used. When it is desired to synthesize a polyimide precursor containing the structural unit (56), it is preferable to use the compound (5 ′).
These compounds can be used alone or in combination of two or more.

', A represents the formula (5) and (6) in the same meaning as A, R ¹² is the formula (6 Formula (5)' is synonymous with R ¹² in).

  When the compound (5) and / or the compound (5 ′) is contained in the component (B), the total amount of all raw material compounds (component (A) + component (B)) is 100% by mass, The compounding amount of the compound (5) and the compound (5 ′) is preferably 0 to 15% by mass, more preferably 0 to 10% by mass, and still more preferably, from the viewpoint of obtaining a film that hardly generates warpage. It is 0-9 mass%, Most preferably, it is 0-8 mass%. However, the preferable compounding amount of the compound (5) and the compound (5 ′) is an amount when the compound (6) and / or the compound (6 ′) is not used when the polyimide precursor is synthesized.

  The polyimide precursor is composed of the component (A) and the component (B) as a use ratio (amount ratio), and a molar ratio of the component (A) to the component (B) (component (A) / component (B). ) Is preferably in the range of 0.8 to 1.2, more preferably in the range of 0.90 to 1.0. When the molar ratio of the component (A) to the component (B) is less than 0.8 equivalent or more than 1.2 equivalent, the molecular weight may be lowered and it may be difficult to form a polyimide film.

The reaction between the component (A) and the component (B) is usually performed in an organic solvent. The organic solvent is preferably dehydrated.
As the organic solvent, it is preferable to use the following non-amide solvents from the viewpoint of the ease of production of the resin composition of the present invention and the properties of the resulting film (haze, warpage, etc.).
As a specific method for reacting the component (A) and the component (B), at least one component (B) is dissolved in an organic solvent, and then the resulting solution is mixed with at least one component (A). Examples include a method of adding components and stirring at a temperature of 0 to 100 ° C. for 1 to 60 hours.

In addition, it is preferable that the total amount of (A) component and (B) component in a reaction liquid is 3-60 mass% of reaction liquid whole quantity, More preferably, it is 5-40 mass%, More preferably, it is 10-10 mass%. It is 40 mass%, Most preferably, it is 10-30 mass%.
When the total amount of the component (A) and the component (B) in the reaction solution is in the above range, a resin composition in which the concentration of the polyimide precursor in the obtained resin composition is in the following preferable range can be obtained. Therefore, it is preferable.

  When a solvent containing the following non-amide solvent as a main component is used as the organic solvent, the composition containing the polyimide precursor obtained by the reaction and the organic solvent is used as it is as the resin composition of the present invention. However, the resin composition of the present invention is obtained by isolating the polyimide precursor obtained in the above reaction as a solid component and then re-dissolving it in a solvent mainly composed of the following non-amide solvent. You can also.

  As a method for isolating the polyimide precursor, a solution containing the polyimide precursor and an organic solvent is poured into a poor solvent for the polyimide precursor such as methanol or isopropanol to precipitate the polyimide precursor, and is filtered, washed and dried. The method etc. which isolate | separate a polyimide precursor as solid content by the above etc. are mentioned.

<Solvent mainly composed of non-amide solvent>
Examples of the non-amide solvent used in the resin composition of the present invention include at least one organic solvent selected from the group consisting of ether solvents, ester solvents, nitrile solvents, sulfoxide solvents, and ketone solvents.
Since the resin composition of the present invention contains a solvent containing the non-amide solvent as a main component, the drying rate at the time of film formation is increased, the film quality is less deteriorated due to white turbidity, and the film productivity is excellent. Moreover, the resin composition with a high density | concentration of a polyimide precursor can be obtained by using the solvent which has the said non-amide type solvent as a main component. A film having excellent productivity and good film quality can be obtained for the first time by using a composition containing the polyimide precursor and a solvent containing the non-amide solvent as a main component.

  In the present invention, the “solvent having a non-amide solvent as a main component” is preferably 70% by mass or more, more preferably 90% by mass or more, and more preferably 90% by mass or more, based on 100% by mass of the whole solvent. The solvent preferably contains 95% by mass or more.

The ketone solvent is preferably a ketone having 3 to 10 carbon atoms, and more preferably a ketone having 3 to 6 carbon atoms from the viewpoint of boiling point and cost. Preferable ketone solvents include acetone (boiling point = 57 ° C.), methyl ethyl ketone (boiling point = 80 ° C.), methyl-n-propyl ketone (boiling point = 105 ° C.), methyl-iso-propyl ketone (boiling point = 116). ° C.), diethyl ketone (boiling point = 101 ° C.), methyl-n-butyl ketone (boiling point = 127 ° C.), methyl-iso-butyl ketone (boiling point = 116 ° C.), methyl-sec-butyl ketone (boiling point = 118 ° C.), methyl- Dialkyl ketones such as tert-butyl ketone (boiling point = 116 ° C), cyclopentanone (boiling point = 130 ° C), cyclohexanone (CHN, boiling point = 155 ° C), cycloheptanone (boiling point = 185 ° C), γ-butyrolactone (boiling point) = 204 ° C) and the like. Among these, cyclohexanone is preferable from the viewpoint that a resin composition excellent in drying property, productivity and the like can be obtained.
These ketone solvents can be used singly or in combination of two or more.

The ether solvent is preferably an ether having 3 to 10 carbon atoms, and more preferably an ether having 3 to 7 carbon atoms. Specific preferred ether solvents include mono- or dialkyl ethers such as ethylene glycol, diethylene glycol, ethylene glycol monoethyl ether, propylene glycol monoethyl ether (119 ° C.), cyclic ethers such as dioxane and tetrahydrofuran, anisole. And aromatic ethers such as Among these, use of propylene glycol monoethyl ether is preferable from the viewpoints of obtaining a resin composition having good storage stability and a transparent and excellent mechanical strength.
These ether solvents can be used singly or in combination of two or more.

The nitrile solvent is preferably a nitrile having 2 to 10 carbon atoms, and more preferably a nitrile having 2 to 7 carbon atoms. Preferred nitrile solvents include acetonitrile (bp = 82 ° C.), propanenitrile (bp = 97 ° C.), butyronitrile (bp = 116 ° C.), isobutyronitrile (bp = 107 ° C.), valeronitrile (bp = 140 ° C.). ), Isovaleronitrile (bp = 129 ° C.), benzonitrile (bp = 191 ° C.) and the like. Among these, acetonitrile is preferable from the viewpoint of a low boiling point.
These nitrile solvents can be used singly or in combination of two or more.

The ester solvent is preferably an ester having 3 to 10 carbon atoms, and more preferably an ester having 3 to 6 carbon atoms. Preferred ester solvents include ethyl acetate (bp = 77 ° C.), propyl acetate (bp = 97 ° C.), acetic acid-i-propyl (bp = 89 ° C.), butyl acetate (bp = 126 ° C.), propylene glycol monoethyl Examples thereof include alkyl esters such as acetate (bp = 146 ° C.) and cyclic esters such as β-propiolactone (bp = 155 ° C.).
These ester solvents can be used singly or in combination of two or more.

The sulfoxide solvent is preferably a sulfoxide having 3 to 10 carbon atoms, and preferred sulfoxide solvents include dimethyl sulfoxide.
In addition, these sulfoxide type | system | group solvents can be used individually by 1 type or in combination of 2 or more types.

  The solvent mainly composed of the non-amide solvent preferably includes at least one organic solvent selected from the group consisting of a nitrile solvent, an ether solvent, and a ketone solvent, and more preferably a ketone solvent. And at least one solvent selected from the group consisting of ether solvents. These solvents have high solubility of the precursor having the structural unit (1), and by using these solvents, a resin composition having excellent storage stability can be obtained.

  Moreover, as the solvent having the non-amide solvent as a main component, it is preferable to use a mixed solvent in which two or more kinds are combined. In consideration of physical properties of the obtained film, a solvent in which solvents having different boiling points of 20 ° C. or more are mixed. preferable.

  When the resin composition of this invention contains the said mixed solvent, the resin composition with a high density | concentration of a polyimide precursor can be obtained.

  The mixed solvent includes propylene glycol monoethyl ether (boiling point = 119 ° C.), acetic acid in consideration of film drying characteristics, productivity, film quality characteristics such as cloudiness and tensile strength, and storage stability of the resin composition. Butyl (boiling point = 126 ° C.), methyl-iso-butyl ketone, propylene glycol monoethyl acetate, cyclohexanone (boiling point = 155 ° C.), cycloheptanone (boiling point = 185 ° C.), γ-butyrolactone (boiling point = 204 ° C.) and dimethyl sulfoxide At least two mixed solvents selected from the group consisting of (boiling point = 189 ° C.) are preferred.

  The mixed solvent preferably contains 5 to 95 parts by mass, more preferably 20 to 95 parts by mass of the solvent having the highest boiling point in the mixed solvent with respect to 100 parts by mass of the mixed solvent. Is more preferably 20 to 65 parts by mass. Further, the mixed solvent particularly preferably contains 20 to 55 parts by mass of the solvent having the highest boiling point in the mixed solvent with respect to 100 parts by mass of the mixed solvent, and this solvent contains the solvent having the highest boiling point in this amount. In this case, a certain solvent remains even after drying at a temperature exceeding 120 ° C. and can be fixed without film breakage, so that not only a resin composition with excellent productivity can be obtained, A film having excellent film quality characteristics such as tensile strength, storage stability, and the like, excellent adhesion to the substrate and peelability, and hardly warping can be obtained.

<Others>
In addition, you may mix | blend additives, such as antioxidant, a ultraviolet absorber, and surfactant, in the resin composition of this invention in the range which does not impair the objective of this invention.

<Physical properties of resin composition>
The viscosity of the resin composition of the present invention is usually 500 to 50,000 mPa · s, preferably 500 to 20,000 mPa · s, although it depends on the molecular weight and concentration of the polyimide precursor. When the viscosity of the resin composition is in the above range, the resin composition is excellent in retention during film formation, and the film thickness can be easily adjusted, so that the film can be easily formed.
The viscosity of the resin composition is a value measured at 25 ° C. in the atmosphere using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., viscometer MODEL RE100).

  The polyimide precursor concentration in the resin composition of the present invention is preferably adjusted so that the viscosity of the resin composition falls within the above range, and depends on the molecular weight of the polyimide precursor, but preferably 3 to 60% by mass, more Preferably it is 5-40 mass%, More preferably, it is 10-40 mass%, Most preferably, it is 10-30 mass%. When the concentration of the polyimide precursor in the resin composition is within the above range, it is possible to form a film that can be thickened, hardly causes pinholes, and has excellent surface smoothness.

  When the viscosity of the resin composition of the present invention and the polyimide precursor concentration in the composition are in the above ranges, the resin composition can be applied onto a substrate using a slit coating method that is excellent in productivity and the like. A film having excellent film thickness accuracy and the like can be formed with high productivity in a short time.

≪Film formation method≫
The film forming method of the present invention includes a step of applying the resin composition of the present invention on a substrate to form a coating film, and evaporating a solvent mainly composed of the non-amide solvent from the coating film. Examples include a step and a method including a step of imidizing the precursor.

  As a method of forming a coating film by applying the resin composition on a substrate, a roll coating method, a gravure coating method, a spin coating method, a slit coating method, a dipping method and a doctor blade, a die, a coater, a spray, a brush, The method etc. which apply | coat using a roll etc. are mentioned. The film thickness and surface smoothness may be controlled by repeating the coating. Among these, the slit coat method is preferable.

  The thickness of the coating film is appropriately selected according to the desired application and is not particularly limited, but is, for example, 1 to 500 μm, preferably 1 to 450 μm, more preferably 2 to 250 μm, and still more preferably. It is 2-150 micrometers, Most preferably, it is 5-125 micrometers.

  As the substrate, polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polybutylene terephthalate (PBT) film, nylon 6 film, nylon 6,6 film, polypropylene film, polytetrafluoroethylene belt, silicon wafer , Glass wafers, oxide wafers, glass substrates (including non-alkali glass substrates), Cu substrates and SUS plates. In particular, since the resin composition of the present invention is excellent in adhesion and peelability to a substrate, it is possible to form a thin film on a silicon wafer, a glass wafer, a glass substrate, a Cu substrate, a SUS plate, or the like.

  The process of evaporating the solvent mainly composed of the non-amide solvent from the coating film may be performed by specifically drying or heating the coating film, but considering the transparency of the film after imidization, there is no cloudiness. It is preferable to evaporate a solvent containing the non-amide solvent as a main component. In consideration of productivity, it is preferable to carry out only by heating without vacuum drying.

  The heating conditions may be determined by evaporating a certain amount of the solvent, and may be appropriately determined according to the substrate to be used, the polyimide precursor, and the solvent. ~ 180 ° C. The heating time is preferably 10 minutes to 1 hour. When the heating temperature is lower than 60 ° C., it takes a long time to evaporate a certain amount of solvent, resulting in poor productivity. When the heating temperature exceeds 200 ° C., imidization proceeds before the solvent evaporates, and the film quality of the obtained film may deteriorate. is there.

  A solvent having a high boiling point as the non-amide solvent (preferably a solvent having a boiling point equal to or higher than the heating temperature in the step of evaporating the solvent mainly composed of the non-amide solvent from the coating film, more preferably a boiling point of 120 ° C. If a mixed solvent containing the above solvent, more preferably a solvent having a boiling point of 150 to 250 ° C. is used, the evaporation does not proceed more than necessary in the step of evaporating the solvent. (High boiling point solvent) is considered to be contained in the coating film. It is thought that the strength of the film after the imidization process is improved by including a high boiling point solvent during the imidization process. For this reason, in the film formation method of this invention, in order to obtain the film | membrane excellent in mechanical strength, it is preferable to use the resin composition containing the mixed solvent containing a high boiling point solvent.

The step of imidizing the coating precursor can be performed by heating.
The heating condition may be determined as appropriate depending on the substrate and the polyimide precursor as long as the solvent evaporates and the polyimide precursor is imidized. For example, the temperature is 200 to 450 ° C. for 30 minutes to 2 hours. Heating is preferred. More preferably, heating is performed at a temperature of 300 to 450 ° C. for 30 minutes to 2 hours, and further preferably heating is performed at a temperature of 350 to 450 ° C. for 30 minutes to 1 hour. Moreover, you may heat under reduced pressure as needed.

  The heating atmosphere is not particularly limited, but is preferably in the air or in an inert gas atmosphere, and particularly preferably in an inert gas atmosphere. Examples of the inert gas include nitrogen, argon, helium and the like from the viewpoint of colorability, and nitrogen is preferable.

  In addition, the heating may dry the coating film formed on the substrate together with the substrate, but after being dried to some extent (for example, after the step of evaporating the solvent) because it is not affected by the properties of the substrate. The coating film formed on the substrate may be peeled off from the substrate and then heated.

  The film obtained through the above film formation process can be used after being peeled off from the substrate, or can be used as it is without being peeled off.

  The thickness of the obtained film is appropriately selected according to the desired application, but is preferably 1 to 200 μm, more preferably 5 to 100 μm, still more preferably 10 to 50 μm, and particularly preferably 20 to 40 μm. .

  The tensile strength of the film obtained from the resin composition of the present invention is 100 MPa or more, particularly preferably 200 MPa or more. If the elastic modulus of the film is less than 100 MPa, there may be a problem of breaking when the film is peeled off from the substrate.

  The glass transition temperature of the film is 250 ° C. or higher, preferably 350 ° C. or higher, particularly preferably 450 ° C. or higher. Since it is heated to 250 ° C. or higher at the time of solder reflow process or device fabrication, when the film is used for such applications, if the glass transition temperature is less than 250 ° C., the film may be deformed. .

Suitable applications of the film include flexible substrates such as flexible printed circuit boards and flexible display substrates, semiconductor elements, thin film transistor type liquid crystal display elements, magnetic head elements, integrated circuit elements, solid-state imaging elements, mounting substrates, and other electronic components. Examples thereof include an insulating film used and films for various capacitors. These electronic components are generally provided with an interlayer insulating film, a planarizing insulating film, a surface protecting insulating film (overcoat film, passivation film, etc.) in order to insulate between wirings arranged in layers. These insulating films can be suitably used.
Moreover, the said film | membrane can be conveniently used as films, such as a light-guide plate, a polarizing plate, a film for a display, a film for optical disks, a transparent conductive film, a waveguide board.
In particular, since the film is excellent in adhesion and peelability to a glass substrate, there is no need to provide an adhesive layer or the like between the film and the substrate, and the number of steps when producing a flexible substrate can be reduced. There is sex.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example 1]
In a three-necked flask equipped with a thermometer, a nitrogen introduction tube and a stirring blade at 25 ° C. under a nitrogen stream, 15.3050 g (0.35 g) of 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB). 0478 mol), both terminal amino-modified side chain phenyl methyl type silicone X-22-1660B-3 (manufactured by Shin-Etsu Chemical Co., Ltd.) [4.2925 g (0.000976 mol)], and polyimide precursor in the resin composition 184.527 g of dehydrated cyclohexanone (CHN) was added so that the concentration of was 14%, and the mixture was stirred for 10 minutes until a completely homogeneous solution was obtained. Then, pyromellitic dianhydride (PMDA) 10.9797 g (0.047679 mol) was added, and the reaction was terminated by stirring for 60 minutes. Then, using a polytetrafluoroethylene filter (pore size 1 μm), precision was obtained. The resin composition 1 was produced by performing filtration.
(PMDA moles / (TFMB moles + X-22-1660B-3 moles) = 0.977 equivalent)

[Method for forming film after drying]
A glass substrate (width: 300 mm x length: 350 mm x thickness: 0.7 mm) is fixed to a control coater base installed so as to be perpendicular to gravity, and the gap interval is set so that the film thickness of the film after drying is 30 μm. The thickness was set to 405 μm, and the resin composition 1 (12 g) was cast on the central part of the glass substrate so as to form a coating film of width: 200 mm × length: 220 mm. Three glass substrates with a coating film were produced.

Subsequently, the obtained glass substrate with a coating film was dried by the following methods (1) to (3) to obtain a film after drying.
(1) After reducing the pressure to 0.1 mmHg after 10 minutes at 25 ° C. in a vacuum dryer, return to normal pressure (760 mmHg), and then heat-dry at 140 ° C. for 10 minutes. (2) On hot plate Heat drying at 155 ° C for 10 minutes (3) Heat drying at 170 ° C for 10 minutes on a hot plate

[Formation method of polyimide film]
A glass substrate (horizontal: 300 mm x vertical: 350 mm x thickness: 0.7 mm) is fixed to a control coater base installed so as to be perpendicular to gravity, and the gap interval is set so that the film thickness becomes 30 μm after secondary drying. The thickness was set to 405 μm, and the resin composition 1 (12 g) was cast on the central part of the glass substrate so as to form a coating film of width: 200 mm × length: 220 mm.
Subsequently, the obtained glass substrate with a coating film was put into a vacuum dryer, and the pressure was reduced to 0.1 mmHg after 10 minutes at 25 ° C., and then the pressure was returned to normal pressure (760 mmHg) to complete the vacuum drying. Then, the glass substrate with the coated film after vacuum drying is heated and dried at 140 ° C. for 10 minutes (primary drying), and then heated and dried at 400 ° C. for 30 minutes in a variable atmosphere dryer (secondary drying). By doing so, a polyimide film with a substrate was obtained.

[Example 2]
Instead of TFMB (15.3050 g), TFMB (12.6570 g) and 4,4′-diaminodiphenyl ether (ODA) 2.0370 g were used, and the amounts of X-22-1660B-3, PMDA and CHN used were shown in Table 1. A resin composition 2 was obtained in the same manner as in Example 1 except that the composition was changed as shown in FIG.
Moreover, the film after drying was formed by the method similar to Example 1 except having used the resin composition 2 instead of the resin composition 1. FIG.
Further, a polyimide film was formed in the same manner as in Example 1 except that the resin composition 2 was used instead of the resin composition 1 and the secondary drying temperature was changed to 300 ° C.

[Example 3]
Example 1 except that CHN147.622g and γ-butyrolactone 36.905g were used instead of CHN184.527g, and the amounts of TFMB, X-22-1660B-3 and PMDA were changed as shown in Table 1. The resin composition 3 was obtained.
Moreover, the film and polyimide film were formed after drying by the method similar to Example 2 except having used the resin composition 3 instead of the resin composition 2. FIG.

[Example 4]
Example 1 except that CHN 92.920 g and γ-butyrolactone 92.264 g were used instead of CHN 184.527 g, and the amounts of TFMB, X-22-1660B-3 and PMDA were changed as shown in Table 1. The resin composition 4 was obtained.
Further, a film and a polyimide film after drying were formed in the same manner as in Example 2 except that the resin composition 4 was used instead of the resin composition 2.

[Example 5]
Example 2 except that CHN 91.804 g and γ-butyrolactone 91.804 g were used instead of CHN 183.607 g, and the amounts of TFMB, ODA, X-22-1660B-3 and PMDA were changed as shown in Table 1. The resin composition 5 was obtained in the same manner.
Moreover, the film and polyimide film were formed after drying by the same method as Example 2 except having used the resin composition 5 instead of the resin composition 2. FIG.

[Example 6]
The same procedure as in Example 1 was conducted except that 92.000 g of CHN and 92.000 g of dimethyl sulfoxide were used instead of CHN 184.527 g, and the amounts of TFMB, X-22-1660B-3 and PMDA were changed as shown in Table 1. A resin composition 6 was obtained.
Further, a film and a polyimide film after drying were formed in the same manner as in Example 2 except that the resin composition 6 was used instead of the resin composition 2.

[Example 7]
Resin composition 7 was carried out in the same manner as in Example 1 except that 184.527 g of propylene glycol monoethyl ether was used in place of CHN 184.527 g and TFMB, X-22-1660B-3 and PMDA were used in the amounts shown in Table 1. Got.
Further, a dried film and a polyimide film were formed in the same manner as in Example 1 except that the resin composition 7 was used instead of the resin composition 1.

[Example 8]
Conducted by using 92.2635 g of propylene glycol monoethyl ether and 92.2635 g of propylene glycol monoethyl ether acetate instead of CHN 184.527 g, using TFMB, X-22-1660B-3 and PMDA in the amounts shown in Table 1. Resin composition 8 was obtained in the same manner as in Example 1.
Moreover, the film and polyimide film were formed after drying by the same method as Example 1 except having used the resin composition 8 instead of the resin composition 1. FIG.

[Example 9]
Example 1 was used except that 147.6216 g of propylene glycol monoethyl ether and 36.905 g of γ-butyrolactone were used in place of CHN 184.527 g, and TFMB, X-22-1660B-3 and PMDA were used in the amounts shown in Table 1. In the same manner, a resin composition 9 was obtained.
Moreover, the film and polyimide film were formed after drying by the same method as Example 1 except having used the resin composition 9 instead of the resin composition 1. FIG.

[Example 10]
Instead of CHN184.527 g, 73.8108 g of propylene glycol monoethyl ether, 73.8108 g of propylene glycol monoethyl ether acetate and 36.905 g of γ-butyrolactone are used, and TFMB, X-22-1660B-3 and PMDA are shown in Table 1. Resin composition 10 was obtained in the same manner as in Example 1, using the amount used.
Moreover, the film and polyimide film were formed after drying by the same method as Example 1 except having used the resin composition 10 instead of the resin composition 1. FIG.

[Example 11]
As in Example 1, using 138.3935 g of propylene glycol monoethyl ether and 46.1318 g of butyl acetate instead of 184.527 g of CHN and using TFMB, X-22-1660B-3 and PMDA in the amounts shown in Table 2. The resin composition 11 was obtained.
Further, a dried film and a polyimide film were formed in the same manner as in Example 1 except that the resin composition 11 was used instead of the resin composition 1.

[Example 12]
110.7162 g of propylene glycol monoethyl ether, 36.905 g of butyl acetate and 36.905 g of γ-butyrolactone were used in place of CHN 184.527 g, and TFMB, X-22-1660B-3 and PMDA were used in the usage amounts shown in Table 2. In the same manner as in Example 1, a resin composition 12 was obtained.
Further, a dried film and a polyimide film were formed in the same manner as in Example 1 except that the resin composition 12 was used instead of the resin composition 1.

[Example 13]
Example 9 Using 92.6635 g of methyl isobutyl ketone, 46.132 g of CHN and 46.132 g of γ-butyrolactone instead of 184.527 g of CHN, and using TFMB, X-22-1660B-3 and PMDA in the usage amounts shown in Table 2. In the same manner as in Example 1, a resin composition 13 was obtained.
Further, a film and a polyimide film after drying were formed in the same manner as in Example 1 except that the resin composition 13 was used instead of the resin composition 1.

[Example 14]
Instead of CHN 184.527 g, 110.7162 g of propylene glycol monoethyl ether, 36.905 g of butyl acetate and 36.905 g of γ-butyrolactone were used, and TFMB, both-terminal amino-modified dimethyl silicone KF-8012 (manufactured by Shin-Etsu Chemical Co., Ltd.) The resin composition 14 was obtained in the same manner as in Example 1 using PMDA in the amounts shown in Table 2.
Further, a film and a polyimide film after drying were formed in the same manner as in Example 1 except that the resin composition 14 was used instead of the resin composition 1.

[Example 15]
In the same manner as in Example 1, using 92.2635 g of methyl isobutyl ketone, 46.132 g of CHN and 46.132 g of γ-butyrolactone instead of 184.527 g of CHN, and using TFMB, KF-8012 and PMDA in the amounts shown in Table 2. The resin composition 15 was obtained.
In addition, after drying, a film and a polyimide film were formed in the same manner as in Example 1 except that the resin composition 15 was used instead of the resin composition 1.

[Comparative Example 1]
Example 1 except that 12.2531 g of m-tolidine (mTB) was used instead of TFMB (15.3050 g) and the amounts of X-22-1660B-3, PMDA and CHN were changed as shown in Table 2. In the same manner as above, a resin composition 16 was obtained.
An attempt was made to form a film and a polyimide film after drying using the obtained resin composition 16 in the same manner as in Example 1, but the film and film could not be formed.

[Comparative Example 2]
Resin used in the same manner as in Example 1 except that 184.527 g of N-methylpyrrolidone was used instead of 184.527 g of CHN, and the amounts of TFMB, X-22-1660B-3 and PMDA were changed as shown in Table 2. A composition 17 was obtained.
Further, a film and a polyimide film after drying were formed in the same manner as in Example 1 except that the resin composition 17 was used instead of the resin composition 1.

[Characteristic evaluation of resin composition]
(1) Resin composition viscosity The resin composition viscosity at 25 ° C was measured using 1.5 g of the resin composition obtained in Examples and Comparative Examples. Specifically, it was measured using a viscometer MODEL RE100 manufactured by Toki Sangyo. The results are shown in Table 1 or 2.

(2) Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw / Mn)
The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of the polyimide precursor in the resin compositions obtained in the examples and comparative examples were measured by the TOSOH HLC-8220 GPC device ( Guard column: TSK guard column ALPHA column: TSKgel ALPHA-M, developing solvent: NMP). The results are shown in Table 1 or 2.

(3) Storage stability at −15 ° C. The resin compositions obtained in Examples and Comparative Examples were stored at −15 ° C. for 48 hours. By visual observation, a transparent and no precipitate was evaluated as “◯”, and an opaque precipitate was evaluated as “x”. The results are shown in Table 1 or 2.

[Evaluation of film after drying]
(4) Immobilization The film after being dried by the method of (1) to (3) is rubbed strongly with a metal spatula, "immobilization" when the film does not move, and "immobilization" when the film moves ". The results are shown in Table 1 or 2.

(5) Presence or absence of cloudiness The presence or absence of cloudiness of the film after drying by the methods (1) to (3) was visually confirmed. The results are shown in Table 1 or 2.

[Evaluation of polyimide film]
(6) Glass transition temperature (Tg)
The polyimide films obtained in the examples and comparative examples were peeled from the glass substrate, and the peeled film was made using Rigaku Thermo Plus DSC8230, under nitrogen, at a heating rate of 20 ° C./min, and at 40 to 450 ° C. Measured in range. The results are shown in Table 1 or 2.

(7) Linear expansion coefficient The polyimide films obtained in Examples and Comparative Examples were peeled from the glass substrate, and the peeled film was used with Seiko Instrument SSC / 5200, the temperature rising rate was 6 ° C./min, and 25 to 350 Measured in the range of ° C. A linear expansion coefficient of 100 to 200 ° C. was calculated from the measurement result. The results are shown in Table 1 or 2.

(8) Film strength Using a JISK6251 No. 7 dumbbell, the polyimide films obtained in the examples and comparative examples were peeled from the glass substrate, and the peeled 30 μm film was subjected to a tensile test at a speed of 50 mm / min at 23 ° C. Carried out and measured the tensile strength. The results are shown in Table 1 or 2.

(9) Peelability from glass substrate Extra portion of a 30 μm polyimide film with a glass substrate after secondary drying is cut with a cutter so that the width is 10 mm × length is 50 mm, and the film remaining on the glass substrate is up to 20 mm in length. After peeling, a force was applied to the peeled portion in the direction of 180 degrees at a speed of 50 mm / min, and the peel strength was measured. The results are shown in Table 1 or 2.

(10) Transparency The polyimide films obtained in Examples and Comparative Examples were peeled from the glass substrate, and the haze of the peeled film was measured according to the JIS K7105 transparency test method. Specifically, it measured using SC-3H type haze meter by Suga Test Instruments Co., Ltd. The results are shown in Table 1 or 2.

(11) Warpage of film The 30 μm polyimide film with a glass substrate obtained in the examples and comparative examples was cut into a size of 60 mm × 60 mm with a cutter, and then the lift of the four ends was measured, and the average value was calculated. The results are shown in Table 1 or 2.

[Evaluation results]
The post-drying films obtained from the resin compositions 1 to 15 had a fast drying speed and excellent adhesion to the glass substrate. Further, a tough polyimide film having no warpage, excellent heat resistance with Tg of 450 ° C. or higher, excellent transparency, excellent peelability from a glass substrate, and low linear expansion coefficient could be obtained.

  Since the polyimide precursor contained in the resin composition 16 does not have the structural unit (1), the resulting resin composition has a viscosity of 50,000 or more and white turbidity is observed, and a coating film can be formed on the substrate. There wasn't. From the above results, it was found that if the polyimide precursor does not have the structural unit (1), a resin composition having excellent productivity cannot be obtained.

  Since the resin composition 17 did not contain a non-amide solvent, white turbidity was observed immediately after preparation of the composition, and the storage stability was remarkably deteriorated. From the above results, it was found that a resin composition having excellent storage stability cannot be obtained unless a non-amide solvent is used.

Claims (9)

A resin composition comprising a polyimide precursor containing a structural unit represented by the following formula (2) and having a structural unit represented by the following formula (1), and a solvent mainly comprising a non-amide solvent.

(In the formula (1), R independently represents a hydrogen atom or a monovalent organic group, R ¹ independently represents a divalent organic group, R ² independently represents a tetravalent organic group, and n represents Represents a positive integer, provided that at least one of R ^{1 and} R ² contains a halogen atom or a halogenated alkyl group.

(In Formula (2), a plurality of R ^{5 s} each independently represent a monovalent organic group having 1 to 20 carbon atoms, and m represents an integer of 3 to 200.) The resin composition according to claim 1, wherein R ¹ includes a group selected from the group represented by the following formula (3).

(In formula (3), R ³ is independently an ether bond, a thioether group, a ketone group, an ester bond, a sulfonyl group, an alkylene group, an amide group, or a group containing a siloxane group, a hydrogen atom, a halogen atom, an alkyl group, or a hydroxy group. , A nitro group, a cyano group or a sulfo group, and any hydrogen atom of the group containing this alkylene group and the alkyl group may be substituted with a halogen atom, provided that among the plurality of R ³ contained in one group, At least one includes a halogen atom or a halogenated alkyl group, a1 represents an integer of 1 to 3, a2 represents 1 or 2, a3 independently represents an integer of 1 to 4, and e represents 0 to 0 Indicates an integer of 3.)   The resin composition according to claim 1 or 2, wherein the solvent is a mixed solvent composed of two or more kinds of solvents.   The resin composition according to claim 3, wherein the solvent contains a solvent having the highest boiling point in the mixed solvent at 20% by weight or more with respect to 100% by weight of the total mixed solvent.   The resin composition according to any one of claims 1 to 4, wherein the polyimide precursor has a weight average molecular weight of 10,000 to 1,000,000.   The resin composition of any one of Claims 1-5 whose density | concentration of the polyimide precursor in the said resin composition is 3-60 mass%.   The resin composition according to any one of claims 1 to 6, wherein the viscosity measured with an E-type viscometer (25 ° C) is in the range of 500 to 50,000 mPa · s.   The resin composition according to any one of claims 1 to 7, which is used for film formation. Applying the resin composition according to any one of claims 1 to 8 on a substrate to form a coating film;
Evaporating the solvent from the coating film;
A film forming method comprising a step of imidizing the precursor.