JP2016029126A - Resin composition and film formation method using the same, and substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which removes cloudiness of a resin solution and a film, and can achieve adhesiveness with a substrate, peelability, low warpage, high strength, and a low amount of out gas when the film is heated, which are required as application of a flexible substrate.SOLUTION: A resin composition contains a mixture in which 1-1,000 ppm of a cyclic siloxane compound is contained in a compound (2) represented by the formula (2), and a polyamic acid obtained by reacting an aromatic diamine represented by the formula (3) with tetracarboxylic acid dianhydride.SELECTED DRAWING: None

Description

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

  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, mechanical properties, etc., and is widely used as a film, coating agent, molded part and insulating material in fields such as electricity, battery, automobile and aerospace industry.

  When a conventional polyimide-forming composition is used to form a film on a support such as a glass substrate, there has been a problem that the substrate or the film itself is warped due to shrinkage deformation at the time of film formation. Patent Document 1 discloses a polyimide precursor resin composition for a flexible device substrate containing a polyimide precursor. A glass substrate that can be formed by coating on a carrier substrate such as a glass substrate, becomes a polyimide film having excellent heat resistance and a low coefficient of thermal expansion, and does not cause peeling from the carrier substrate in the process of forming a circuit, etc. It is described that it can be removed cleanly when peeled off. In particular, a polyimide precursor composition copolymerized with a flexible component is desirable for improving warpage.

  However, since the resin composition uses only a high boiling point solvent, there is a problem that the productivity of film formation is low. The productivity of film formation is improved by the use of a low boiling point solvent, but there is a drawback that a film having sufficient strength cannot be obtained only with a low boiling point solvent. On the other hand, when the high boiling point solvent is included in the resin composition, there is a problem that the solution and the film formed are clouded.

  In addition, when used for flexible substrate applications, it is necessary to prevent outgassing during heating in the process so as not to damage the element formed in the upper layer, but the resin composition contains a large amount of cyclic siloxane in the raw material. The cyclic siloxane which is a large amount of outgas volatilizes from the film after film formation.

JP 2010-202729 A

  The object of the present invention is to eliminate the cloudiness of the resin solution and the film, and to achieve compatibility with the substrate necessary for flexible substrate applications, peelability, low warpage, high strength, and low outgas amount when heating the film. An object of the present invention is to provide a resin composition and a film forming method.

As a result of intensive studies to solve the above-described problems, the present inventors have found that a polyimide precursor composition having a structure of the following formula (3) has a cyclic siloxane content of the raw material (following formula (2)) of 1000 ppm or less. It is found that the above-mentioned problems can be solved by using a solvent system containing a high boiling point solvent of 160 ° C. or higher and a low boiling point solvent of 160 ° C. or lower as a solvent for the resin composition. It came to complete.
That is, the present invention provides the following [1] to [4].

  [1] A mixture containing 1 to 1000 ppm of the compound (1) represented by the following formula (1) with respect to the compound (2) represented by the following formula (2) and an aromatic represented by the following formula (3) The resin composition containing the polyamic acid which made diamine react with the tetracarboxylic dianhydride represented by following formula (5).

In the formula (1), a plurality of R ⁰ and R ¹ each independently represents a monovalent organic group having 1 to 20 carbon atoms, x and y are integers of 0 to 16, and 3 ≦ x + y ≦ 16 Show.

In the formula (2), a plurality of R ⁰ , R ¹ and R ² each independently represents a monovalent organic group having 1 to 20 carbon atoms, and R ³ each independently represents a divalent organic group having 1 to 20 carbon atoms. Indicates. l is an integer of 1 to 200, m is an integer of 0 to 199, and 3 ≦ l + m ≦ 200.

In the formula (3), R ⁴ is a group selected from the group represented by the following formula (4).

In the formula (4), a plurality of R ⁵ are each independently an ether bond, thioether group, ketone group, ester bond, sulfonyl group, alkylene group, amide group or siloxane group-containing group, hydrogen atom, halogen atom, alkyl group. , A hydroxy group, a nitro group, a cyano group or a sulfo group, an arbitrary hydrogen atom of the group containing an alkylene group and an alkyl group may be substituted with a halogen atom. However, at least one of R ⁵ contained in one group contains a halogen atom or a halogenated alkyl group. a1 is an integer of 1 to 3, a2 is 1 or 2, a3 is each independently an integer of 1 to 4, and e is an integer of 0 to 3.

In the formula (5), R ⁶ independently represents a tetravalent organic group.

  [2] The resin composition according to [1], wherein the resin composition includes a solvent having a boiling point of 160 ° C. or higher and a solvent having a boiling point of less than 160 ° C.

  [3] A step of applying the resin composition according to any one of [1] to [2] on a substrate to form a coating film, a step of evaporating a solvent from the coating film, The film formation method including the process of imidating the resin composition represented by [1].

  [4] A substrate obtained from the resin composition according to any one of [1] to [3].

According to the resin composition of the present invention, a film having excellent transparency and mechanical strength, a high glass transition temperature, less warpage and white turbidity, and less outgassing during heating of the film can be easily obtained in a short time. In addition, it can be manufactured 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 is a mixture containing the compound (1) represented by the following formula (1) in an amount of 1 to 1000 ppm based on the compound (2) represented by the following formula (2) (hereinafter referred to as the mixture (1)). And a polyamic acid obtained by reacting an aromatic diamine represented by the formula (3) with a tetracarboxylic dianhydride represented by the formula (5) (hereinafter also referred to as a polyimide precursor). .
The resin composition of the present invention can produce a film having a high glass transition temperature, little warpage and white turbidity, and excellent mechanical strength in a short time with high productivity. When a resin composition is applied to a substrate such as a substrate to form a film, it is possible to easily form a film that is excellent in adhesion and peelability to the substrate.

  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.

  Further, “warp” is the roundness of the film judged visually, and “residual stress” means that the resin composition remains on the inside of the film after the film is formed by applying the resin composition on a substrate such as a glass substrate. 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), a plurality of R ⁰ and R ¹ each independently represents a monovalent organic group having 1 to 20 carbon atoms, x and y are integers of 0 to 16, and 3 ≦ x + y ≦ 16 Show.

In the formula (2), a plurality of R ⁰ , R ¹ and R ² each independently represents a monovalent organic group having 1 to 20 carbon atoms, and R ³ each independently represents a divalent organic group having 1 to 20 carbon atoms. Indicates. l is an integer of 1 to 200, m is an integer of 0 to 199, and 3 ≦ l + m ≦ 200.

In the formula (3), R ⁴ is a group selected from the group represented by the following formula (4).

In the formula (4), a plurality of R ⁵ are each independently an ether bond, thioether group, ketone group, ester bond, sulfonyl group, alkylene group, amide group or siloxane group-containing group, hydrogen atom, halogen atom, alkyl group. , A hydroxy group, a nitro group, a cyano group or a sulfo group, an arbitrary hydrogen atom of the group containing an alkylene group and an alkyl group may be substituted with a halogen atom. However, at least one of R ⁵ contained in one group contains a halogen atom or a halogenated alkyl group. a1 is an integer of 1 to 3, a2 is 1 or 2, a3 is independently an integer of 1 to 4, and e is an integer of 0 to 3.

In the formula (5), R ⁶ independently represents a tetravalent organic group.

<Polyimide precursor>
The polyimide precursor can be obtained by reacting the component represented by the formula (5), the mixture (1), and the component represented by the formula (3).
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.
The polyimide obtained from the polyimide precursor has a rigid skeleton part derived from the aromatic diamine represented by the formula (3) and a flexible skeleton part derived from the compound (2), and the rigid skeleton part is A microphase separation structure is formed in which the sea part is formed and the flexible skeleton part is the 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 site are dispersed in a size of about 1 nanometer to 1 micron in a sea part made of a rigid structural site.

In the formula (1) or the formula (2), a plurality of R ^{0 to} R ² each independently represents a monovalent organic group having 1 to 20 carbon atoms, and m represents an integer of 3 to 200.

In the formula (1) or the formula (2), the monovalent organic group having 1 to 20 carbon atoms in R ^{0 to} R ² includes a monovalent hydrocarbon group having 1 to 20 carbon atoms and 1 to 1 carbon atoms. There may be mentioned 20 monovalent alkoxy groups.

The monovalent hydrocarbon group having 1 to 20 carbon atoms in R ^{0 to} R ² is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Etc.

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 ^{0 to} R ² 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. It is done.

The sea part in which at least one of a plurality of R ^{0 to} R ^{2 in} the formula (1) or the formula (2) includes an aryl group, the island part formed of the flexible skeleton part is formed of the rigid skeleton part It is preferable because it is excellent in affinity with the polymer and easily (uniformly) dispersed (microphase separation) with a size of about 1 nanometer to 1 micron. More specifically, the plurality of R ^{0 to} R ² are preferably an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 12 carbon atoms.

In said Formula (1), x and y are integers of 0-16, and show 3 <= x + y <= 16.

  In said formula (2), l is an integer of 1-200, m is an integer of 0-199, 3 <= l + m <= 200 is shown, Preferably it is 10-200, More preferably, it is 20-150, More preferably Is an integer of 30-100, particularly preferably 35-80. When l + m is 2 or less, the polyimide obtained from the polyimide precursor may not easily form a microphase separation structure. When l + m exceeds 200, the size of the island composed of the skeleton part including the structural unit (2) is increased. May exceed 1 μm, and the coating film may become cloudy or the mechanical strength may decrease.

In the formula (2), a plurality of R ³ each independently represents a divalent organic group of 1 to 20.

Examples of the divalent organic group having 1 to 20 carbon atoms in R ³ 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.

  As the compound (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 excellent heat resistance (high glass transition temperature) and water resistance. The number average molecular weight is preferably 500 to 12,000, more preferably 1,000 to 8,000, and still more preferably 3,000 to 6,000 from the viewpoint of obtaining a thick film. The amine value is preferably 250 to 6,000, more preferably 500 to 4,000, and further preferably 1,500 to 3,000.

  The compound (2) is preferably a compound represented by the following formula.

In the formula (3), R ⁴ is a group selected from the group represented by the formula (4). When R ⁴ is a group selected from the group represented by Formula (4), the sea part has a more rigid skeleton. Therefore, it is preferable because a film in which residual stress is small and warpage is suppressed can be obtained.

In the formula (4), R ⁵ 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 an alkyl group and an alkylene group may be substituted with a halogen atom. However, R ⁵ contains a halogen atom or a halogenated alkyl group. a1 is an integer of 1 to 3, a2 is 1 or 2, a3 is independently an integer of 1 to 4, and e is 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 (4), R ⁵ preferably contains 1 to 12 halogen atoms. From the viewpoint that a film excellent in mechanical strength can be easily produced in a short time with high productivity, etc. 3 It is more preferable to contain ~ 8 pieces.

In the present invention, when R ⁵ is a halogen atom, it is said that “one halogen atom is contained”, and when R ⁵ is a halogenated alkyl group such as a trifluoromethyl group, “three halogen atoms are present”. It is included.

In the formula (4), examples of the halogenated alkyl group for R ⁵ include a methyl group substituted with a halogen, an alkyl group having 2 to 20 carbon atoms, and the like.
The halogenated alkyl group having 2 to 20 carbon atoms is preferably an alkyl group having 2 to 10 carbon atoms, and includes an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, and a pentyl group. , A group in which an arbitrary hydrogen atom of a hexyl group or a fluorene group is substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

In the formula (4), the halogenated alkyl group for R ⁵ is preferably an alkyl group having 1 to 2 carbon atoms. Specifically, any hydrogen atom of a methyl group or an ethyl group is a fluorine atom, Examples thereof include a group substituted with a chlorine atom, a bromine atom or an iodine atom.

In the formula (4), the halogen atom in R ^{5 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 ⁵ containing no halogen atom is preferably a hydrogen atom, an alkyl 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 ⁵ 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 (4), examples of the group containing an alkylene group in R ⁵ 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 is a dimethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, isopropylidene group, fluorene group. Etc.

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, and a3 is preferably 1.

In the formula (3), the divalent organic group in R ⁴ is preferably a group selected from the group represented by the following formula (4 ′).

In the formula (4 ′), R ⁸ has the same meaning as R ⁵ in the formula (4).

  Examples of the group represented by the formula (4 ′) include groups selected from the group represented by the following (4′-1) and (4′-2).

(4'-1)
(4'-2)

In the formula (3), the divalent organic group in R ⁴ is more preferably a group selected from the group represented by the following formula (4 ″).

(4 '')

In the formula (5), the tetravalent organic group represented by R ^6, 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. When the alicyclic hydrocarbon group and the aromatic hydrocarbon group include two or more ring structures, a polycyclic structure in which rings share one or more bonds, a spiro hydrocarbon structure, and biphenyl, etc. The structure etc. which couple | bonded the ring with the coupling groups, such as a single bond, are 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 ⁶ is more preferably a group selected from the group represented by the following formula (6). When the tetravalent organic group in R ⁵ is a group selected from the group represented by the following formula (6), the polyimide obtained from the polyimide precursor has a structure having a rigid skeleton, and has a microphase separation structure. Therefore, it is preferable in that a film having a small residual stress and a suppressed warpage can be obtained.

In the formula (6), R ⁹ 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 an alkyl group and an alkylene 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, R ⁹ 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 above formula (6), R ⁹ preferably contains 1 to 12 halogen atoms. From the viewpoint that a film excellent in mechanical strength can be easily produced in a short time with high productivity. It is more preferable to contain ~ 8 pieces.

In the formula (6), examples of the halogenated alkyl group for R ⁹ include a methyl group substituted with a halogen 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, and includes an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, and a pentyl group. , A group in which an arbitrary hydrogen atom of a hexyl group or a fluorene group is substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

In the formula (6), the halogenated alkyl group for R ⁹ is preferably an alkyl group having 1 to 2 carbon atoms. Specifically, an arbitrary hydrogen atom of a methyl group or an ethyl group is a fluorine atom, Examples thereof include a group substituted with a chlorine atom, a bromine atom or an iodine atom.

In the formula (6), the halogen atom in R ^{9 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 ⁹ containing no halogen atom is preferably a hydrogen atom, an alkyl 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 (6), the alkyl group for R ⁹ 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 (6), examples of the group containing an alkylene group in R ⁹ 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 is a dimethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, isopropylidene group, fluorene group. Etc.

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 (6) is preferably a group selected from the group represented by the following formula (6 ′).

(6 ')

  Specific examples of the tetracarboxylic dianhydride represented by the formula (5) include 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,3,4-cyclopentanetetracarboxylic acid. Dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4 ′ -Biphenyltetracarboxylic dianhydride, 2,3,4,4'-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6- Naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetra Mosquito Boronic acid dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,3 ′, 4,4 ′ -Diphenylsulfone tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3', 4,4'-tetraphenylsilane tetracarboxylic dianhydride, 2, 3 ', 4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3', 4,4'-diphenyl sulfide tetracarboxylic dianhydride, 2,3 ', 4,4'-diphenyl sulfide tetracarboxylic acid Dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′- The E methane dianhydride, 2,3 ', 4,4'-diphenylmethane tetracarboxylic dianhydride is preferred.

  Pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid, preferably from the viewpoint of a structure having a rigid skeleton Dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyl And sulfide tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylmethane tetracarboxylic dianhydride, and the like. That.

  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 20,000 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 the number average molecular weight of the polyimide precursor exceeds the upper limit, the viscosity of the resin composition increases, so when the film is formed by applying the resin composition to a substrate such as a glass substrate. 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 to 10, more preferably 2 to 5, and particularly preferably 2 to 4.

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

When the total amount of all raw material compounds (mixture (1) component + formula (3)) is 100% by mass, the blending amount of the mixture (1) is a substrate that is excellent in peelability from the substrate and hardly warps. From the point to obtain, Preferably it is 0.1-40 mass%, More preferably, it is 2-30 mass%, More preferably, it is 5-25 mass%, Most preferably, it is 7-20 mass%. Moreover, the preferable compounding quantity of Formula (5) with respect to Mixture (1) and Formula (3) is 80 from the viewpoint of the strength of the film to be formed, assuming that the total molar amount of Mixtures (1) and (3) is 100. -120 mol is preferable and 90-110 mol is more preferable.

<Mixture (1)>
The mixture (1) is a mixture containing 1 to 1000 ppm of the compound (1) represented by the formula (1) with respect to the compound (2) represented by the formula (2).

Compound (2) usually contains more than 1000 ppm of compound (1) by its production process. However, since the compound (1) generates outgas during film formation, if it is 1% or more in the resin composition of the present invention, the upper element substrate is significantly damaged. Therefore, it is necessary to reduce the content of compound (1).
Examples of the method for reducing the compound (1) include extraction, column chromatography, distillation, and ultrafiltration. Among these, extraction is preferable from the viewpoint of productivity such as yield.

<Solvent>
The solvent used in the resin composition of the present invention is selected from the group consisting of ether solvents, ester solvents, nitrile solvents, sulfoxide solvents, and ketone solvents, a high boiling point solvent of 160 ° C or higher, and 160 ° C or lower. Of low boiling point solvents.
Since the resin composition of the present invention contains a low-boiling solvent, the drying rate at the time of film formation is high, the film quality is not deteriorated due to white turbidity, and the film productivity is excellent. In addition, by containing a certain amount of a high-boiling solvent as a mixed solvent, a resin composition having a high concentration of polyimide precursor can be obtained, and a strong and good quality film can be obtained.

  The low boiling point is, as a ketone solvent, 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 = 118 ° C.), methyl-sec-butyl ketone (boiling point = 118 ° C.), methyl-tert- Dialkyl ketones such as butyl ketone (boiling point = 116 ° C), cyclopentanone (boiling point = 130 ° C), cyclohexanone (156 ° C), ether solvents such as ethylene glycol dimethyl ether (85 ° C), propylene glycol dimethyl ether (120 ° C), 1-methoxy-2-propanol (120 ° C.), Trahydrofuran (66 ° C.), anisole (154 ° C.), etc. are ester solvents such as ethyl acetate (bp = 77 ° C.), propyl acetate (bp = 97 ° C.), acetic acid-i-propyl (bp = 89 ° C.). ), Alkyl esters such as butyl acetate (bp = 126 ° C.), β-propiolactone (bp = 155 ° C.), propylene glycol methyl ether acetate (146 ° C.) and the like as acetonitrile (bp = 82 ° C), propanenitrile (bp = 97 ° C), butyronitrile (bp = 116 ° C), isobutyronitrile (bp = 107 ° C), valeronitrile (bp = 140 ° C), isovaleronitrile (bp = 129 ° C) Is mentioned. Among these, a low boiling point solvent of 130 ° C. or lower is particularly preferable from the viewpoint of film formation productivity.

  Examples of the high-boiling solvent include dimethyl sulfoxide (boiling point 189 ° C.) as a sulfoxide solvent, γ-butyrolactone (boiling point 202 ° C.) and the like as an ester solvent, N-ethylpyrrolidone and ecamide B100 (boiling point 252) as an amide solvent. C: a solvent selected from the group consisting of Idemitsu Kosan Co., Ltd., Examide M100 (boiling point 216 ° C .: Idemitsu Kosan Co., Ltd.) and the like. In particular, a non-amide solvent is more preferable from the viewpoint of safety.

  The mixed solvent preferably contains 5 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, more preferably 25 to 95 parts by mass, and physical properties of the obtained film. Is more preferably 35 to 65 parts by mass. Furthermore, the mixed solvent particularly preferably contains 40 to 60 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 addition to providing a resin composition with a high drying rate and excellent productivity, it also has excellent film quality characteristics such as cloudiness and tensile strength, storage stability, and adhesion / peelability to the substrate. A film which is excellent and hardly warps 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.

<Synthesis Method of Polyimide Precursor>
The reaction of the mixture (1), the formula (3) and the component of the formula (5) is usually performed in a reaction solvent. Examples of the reaction solvent include the above solvents, and the solvent is preferably dehydrated. As a specific method for the reaction, after the mixture (1) and the formula (3) are dissolved in a solvent, at least one tetracarboxylic dianhydride represented by the formula (5) is added to the obtained solution. And a method of stirring at a temperature of 0 to 100 ° C. for 1 to 60 hours.

<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 is usually 5 to 40% by mass, although it depends on the molecular weight of the polyimide precursor. Is 10 to 40% by mass, more preferably 10 to 30% by mass. When the concentration of the polymer (I) in the resin composition is in 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 method for forming a film of the present invention includes a step of applying the resin composition of the present invention on a substrate to form a coating film, a step of evaporating the solvent from the coating film, and imidizing the precursor The method including the process to do is mentioned.

  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. In addition, you may control the thickness of a film, surface smoothness, etc. by repetition of application | 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, 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 these substrates, it is possible to form a thin film on a silicon wafer, glass wafer, glass substrate, Cu substrate and SUS plate.

  The step of evaporating the solvent from the coating film may be performed by specifically drying or heating the coating film, but considering the transparency of the film after imidation, the solvent may be evaporated without cloudiness. preferable. 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. For example, the heating temperature is preferably 60 ° C to 200 ° C, more preferably 90 ° C. ~ 180 ° C. The heating time is preferably 10 minutes to 1 hour. When the heating temperature is lower than 60 ° C., it takes time to remove the solvent, resulting in poor productivity. When it exceeds 200 ° C., imidization proceeds before the removal of the solvent, and the film quality of the resulting film may be deteriorated.

  If a mixed solvent containing a high-boiling solvent is used as the solvent, the solvent will not evaporate more than necessary in the step of evaporating the solvent. Therefore, some solvent (high-boiling solvent) is added to the coating during the imidization step. It is considered to be contained in the 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 during the solder reflow process or device fabrication, when the glass coating temperature is less than 250 ° C., the coating film is deformed when the coating film is used for such applications. There is.

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.

[Synthesis Example of Amino-modified Silicone Oil at Both Ends (Prepared Product)]
Mixture (1): Acetone (1000 g) was added to X-22-161A (manufactured by Shin-Etsu Chemical Co., Ltd., 100 g), stirred at room temperature for 30 minutes, and then centrifuged at 2500 rpm for 15 minutes with acetone and silicone oil. After separation, acetone was removed by decantation. After repeating the above operation three times, acetone was distilled off with an evaporator to obtain 2.5 g of raw material silicone oil (refined product; compound (2-1)). The molecular weight of the obtained silicone oil is equivalent to Mn = 4400, and the content of the compound selected from the group represented by the following formula (1-1) derived from the compound (1) is less than 50 ppm from gas chromatography measurement. there were.

[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, 6,8.6303 g (0.002) of 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB). 2143 mol), an amino-modified silicone oil at both ends (refined product; compound (2-1), 6.6475 g (0.00151 mol)), and 315 g of cyclopentanone (CPN) until 10 to obtain a completely homogeneous solution. Then, pyromellitic dianhydride (PMDA) (10.997 g, 0.2050 mol) was added and reacted for 60 minutes, then γ-butyrolactone (315 g) was added and stirred at room temperature for 30 minutes to homogeneity. After preparing the solution, the resin composition 1 is obtained by performing microfiltration using a polytetrafluoroethylene filter (pore size 1 μm). It was produced.

[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. Set to 405 μm, resin composition 1 (12 g) was cast in the center of the glass substrate to form a coating of width: 200 mm × length: 220 mm, 70 ° C. for 15 minutes, 120 ° C. for 15 minutes, 400 ° C. for 30 minutes ( A film was prepared by heating under a nitrogen atmosphere. The resulting film was transparent. Moreover, the outgas amount of the cyclic siloxane derived from the compound (1) generated by heat extraction at 350 ° C. for 30 minutes was 5 ppm.

[Example 2]
Resin composition 2 was obtained in the same manner as in Example 1 except that N-ethylpyrrolidone was used instead of γ-butyrolactone and the amounts of γ-butyrolactone and N-ethylpyrrolidone were changed as shown in Table 1. It was. Moreover, it carried out similarly to Example 1 and created the film.

[Example 3]
Resin composition 2 was obtained in the same manner as in Example 1 except that ecamide B100 was used instead of γ-butyrolactone and the amounts of γ-butyrolactone and ecamide B100 were changed as shown in Table 1. Moreover, it carried out similarly to Example 1 and created the film.

[Example 4]
Instead of 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB), 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB), diamino Resin composition 4 was obtained in the same manner as in Example 1 except that diphenyl ether (ODA) was used and the amounts of TFMB and ODA were changed as shown in Table 1. Moreover, it carried out similarly to Example 1 and created the film.

[Comparative Example 1]
Instead of both-terminal amino-modified silicone oil (refined product; compound (2-1)), both-terminal amino-modified silicone oil KF-8012 was used, and the amounts of compound (2-1) and KF-8012 used are shown in Table 1. Except having changed as shown, it carried out like Example 1 and obtained resin composition 5. Moreover, it carried out similarly to Example 1 and created the film.

[Comparative Example 2]
Resin composition 6 was prepared in the same manner as in Comparative Example 1 except that cyclopentanone was used instead of γ-butyrolactone and cyclopentanone, and the amounts of γ-butyrolactone and cyclopentanone were changed as shown in Table 1. Obtained. Moreover, it carried out similarly to Example 1 and created the film.

[Comparative Example 3]
Comparative Example 1 except that TFMB and diaminodiphenyl ether (ODA) were used instead of 2,2′-bis (trifluoromethyl) biphenyl (TFMB) and the amounts of TFMB and ODA were changed as shown in Table 1. In the same manner, a resin composition 7 was obtained. Moreover, it carried out similarly to Example 1 and created the film.

[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.

(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.

[Evaluation of film after drying]
(3) Immobilization The film after drying was rubbed strongly with a metal spatula and evaluated as "immobilization" when the film did not move and "no immobilization" when the film moved. The results are shown in Table 1.

(4) Presence or absence of cloudiness The presence or absence of cloudiness of the film after drying was confirmed visually. The results are shown in Table 1.

[Evaluation of polyimide film]
(5) 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.

(6) Film strength Using a JISK6251 No. 7 dumbbell, the polyimide films obtained in 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.

(7) Releasability from glass substrate Cut off excess portion of the 30 μm polyimide film with glass substrate after secondary drying so that the width becomes 10 mm × length 50 mm, and the film remaining on the glass substrate reaches 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.

(8) 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.

(9) Warpage of film The 30 μm polyimide film with 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.

(10) Outgas The amount of outgas of the cyclic siloxane derived from the compound (1) obtained in Examples and Comparative Examples was analyzed by gas chromatography after thermally extracting the film (g) at 400 ° C. for 30 minutes. The outgas amount was calculated by converting to the gas amount in terms of octadodecane.

[Evaluation results]
The post-drying films obtained from the resin compositions 1 to 4 were excellent in that the film was transparent and tough, and the outgas amount of the compound (1) -derived cyclic siloxane generated by heating the film was small. Also, adhesion to glass. It was possible to obtain a polyimide film having good heat resistance, no warping during peeling, a Tg of 450 ° C. or higher, and a low thermal expansion coefficient and good heat resistance.

Since the polyimide precursor contained in the resin compositions 5 and 7 contains a large amount of the cyclic siloxane derived from the compound (1), the film becomes cloudy when the resin composition is formed, and the outgas amount of the cyclic siloxane generated by heating the film There were many. In addition, since the resin composition 6 is composed only of a low boiling point solvent in addition to the cloudiness of the film during film formation and the generation of a large amount of cyclic siloxane during film heating, the film strength is low, and the film cracks when peeled from the glass. There has occurred.

Claims (4)

The compound (1) represented by the following formula (1) is mixed with 1 to 1000 ppm of the compound (2) represented by the following formula (2) and the aromatic diamine represented by the formula (3) is represented by the formula (3). The resin composition containing the polyamic acid made to react with the tetracarboxylic dianhydride represented by 5).

(In the formula (1), a plurality of R ⁰ and R ¹ each independently represents a monovalent organic group having 1 to 20 carbon atoms, x and y are integers of 0 to 16, and 3 ≦ x + y ≦ 16. Show.)

(In the formula (2), plural R ⁰ , R ¹ and R ² each independently represents a monovalent organic group having 1 to 20 carbon atoms, and R ³ each independently represents a divalent organic group having 1 to 20 carbon atoms. L is an integer of 1 to 200, m is an integer of 0 to 199, and 3 ≦ l + m ≦ 200.

(In formula (3), R ⁴ is a group selected from the group represented by the following formula (4).)

(In the formula (4), a plurality of R ⁵ are each independently an ether bond, thioether group, ketone group, ester bond, sulfonyl group, alkylene group, amide group or siloxane group-containing group, hydrogen atom, halogen atom, alkyl group. , A hydroxy group, a nitro group, a cyano group or a sulfo group, and any hydrogen atom of the group containing the alkylene group and the alkyl group may be substituted with a halogen atom, provided that a plurality of Rs contained in one group ^And at least one of ⁵ contains a halogen atom or a halogenated alkyl group, a1 is an integer of 1 to 3, a2 is 1 or 2, a3 is each independently an integer of 1 to 4, and e is an integer of 0 to 3. Show.)

(In formula (5), R ⁶ independently represents a tetravalent organic group.) The resin composition according to claim 1, wherein the resin composition contains a solvent having a boiling point of 160 ° C or higher and a solvent having a boiling point of less than 160 ° C.   A resin composition represented by any one of claims 1 to 2, a step of applying a resin composition on a substrate to form a coating film, a step of evaporating a solvent from the coating film, and a resin represented by claim 1. The film formation method including the process of imidating a composition. The board | substrate obtained from the resin composition of any one of Claims 1-3.