WO2017163698A1 - Polyimide film and process for producing same - Google Patents

Abstract

The present invention addresses the problem of: providing a polyimide film that has satisfactory transportability and has little plane-direction unevenness in haze; and providing a process for producing the polyimide film. The process of the present invention is for producing a polyimide film comprising fine inorganic particles and a polyimide which dissolves in 100 g of dimethylacetamide or 100 g of γ-butyrolactone at 60ºC in an amount of 1 g or larger, and is characterized by comprising: a step in which a mixture comprising the polyimide and the fine inorganic particles is prepared; a step in which a dope comprising the mixture, the polyimide, and a solvent is prepared; a step in which the dope is cast on a support to form a film; a step in which the film is separated from the support; and a drying step in which the separated film is dried.

Description

Polyimide film and method for producing the same

The present invention relates to a polyimide film and a method for producing the same, and more particularly relates to a polyimide film having good transportability and less variation in haze value in the surface direction and a method for producing the same.

The size of image display devices is increasing. In recent years, the size of television receivers in particular has been increasing, and there has been a demand for television receivers that can be bent to be carried into a room or that can be rolled up when not in use (flexible television receivers). Yes. There is also an increasing demand for curved television receivers (curved televisions).

Furthermore, in the medium-sized image display device or the small-sized image display device for mobile use, there is an increasing demand for a foldable image display device for carrying. As described above, it has been demanded that the image display device be a flexible display.

Since polyimide is excellent in bending resistance and has a high elastic modulus, its use for the flexible display has been studied (for example, see Non-Patent Document 1).

Also, as the display size increases, it is required to make the film wider and longer.

However, when the polyimide film is made long and wound into a roll, sticking between the films occurs, and thus there is a problem that transportability is deteriorated or surface defects are caused due to surface defects.

In order to prevent sticking, it is conceivable to improve the slipperiness by adding inorganic fine particles, but when inorganic fine particles are added to the polyimide film, the haze of the film becomes higher than other resins. There was a problem that it was easily unsuitable for display applications.

Also, there are mainly two types of manufacturing methods for producing a polyimide film. One is a method of obtaining a desired polyimide film by casting a solution of a polyamic acid compound, which is a polyimide precursor, on a support to form a film, and then performing a ring-closing reaction on the support. Second, a polyamic acid ring-closing reaction is performed in a liquid preparation kettle to prepare a polyimide resin that is soluble in the solvent (hereinafter referred to as a soluble polyimide), and the soluble polyimide resin is redissolved in the solvent. This is a method of obtaining a polyimide film by casting on a support (see, for example, Patent Document 1).

The former method of casting a solution of a polyamic acid compound on a support requires a step of subjecting the film to a high temperature in order to perform a ring-closing reaction after casting on the support. However, the latter method using a soluble polyimide resin does not have a step of treating the film like the former at a high temperature because the ring closure reaction is carried out in the reaction solution. Therefore, it is possible to cope with high flatness and uniformity of optical physical properties required for display applications.

Therefore, the present inventor studied various methods for producing a long roll by mixing inorganic fine particles with a soluble polyimide film.

However, when a long roll is manufactured by mixing inorganic fine particles with a soluble polyimide film, variation in haze occurs in the surface direction of the film, and the standard deviation of the haze value is increased. It was found that there were problems specific to the film.

Japanese Patent Laid-Open No. 2015-021022

The present invention has been made in view of the above-described problems and situations, and the solution to the problem is that when a long film is wound into a roll, the transportability is good and the haze value varies in the surface direction of the film. It is to provide a polyimide film with a small amount. Moreover, it is providing the manufacturing method of the said polyimide film.

In order to solve the above-mentioned problems according to the present invention, in the process of examining the cause of the above-mentioned problem, a mixture prepared by previously mixing soluble polyimide and inorganic fine particles is prepared, and this mixture is mixed with new soluble polyimide to prepare a dope. Then, by casting the solution, it was found that a polyimide film having good transportability and less variation in haze value in the surface direction of the film can be produced, and the present invention has been achieved.

That is, the problem according to the present invention is solved by the following means.

1. A method for producing a polyimide film containing polyimide and inorganic fine particles that are dissolved in an amount of 1 g or more per 100 g of dimethylacetamide or 100 g of γ-butyrolactone at 60 ° C., comprising preparing a mixture containing the polyimide and the inorganic fine particles A step of preparing a dope containing the mixture, the polyimide and a solvent, a step of casting the dope on a support to form a film, a step of peeling the film from the support, and a peeled film The manufacturing method of the polyimide film characterized by including the drying process which dries.

2. The method for producing a polyimide film according to claim 1, wherein the mixture is a crushed product obtained by crushing a polyimide film containing the polyimide and the inorganic fine particles.

3. The method for producing a polyimide film according to item 1, wherein the mixture is a dope containing the polyimide, the inorganic fine particles, and a solvent.

4. The method for producing a polyimide film according to any one of claims 1 to 3, wherein the mixture is contained in a mass ratio of 10 to 70 mass% with respect to the polyimide film to be produced. .

5. Polyimide film characterized by containing at least 1 g of polyimide dissolved in 100 g of dimethylacetamide or 100 g of γ-butyllactone at 60 ° C. and inorganic fine particles, and having a standard deviation of haze value in the plane direction of 1 or less. .

By the above means of the present invention, it is possible to provide a polyimide film having good film transportability and less variation in haze value in the surface direction of the film. Moreover, the manufacturing method of the said polyimide film can be provided.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

In the method for producing a polyimide film in which a solution is cast with polyamic acid, since the ring-closing reaction is not completed at the time of casting, a chemical reaction occurs at the time of film formation. For this reason, it is presumed that the film is formed in a state where the resin is easily oriented by the reaction and the inorganic particles are relatively uniformly distributed in the gaps between the resin molecular chains.

However, since the polyimide film manufacturing method using soluble polyimide has a chemical structure of polyimide that has already been closed at the time of casting, it is affected by the chemical composition such as the polarity of the resin, which makes it difficult for the resin to orient at the time of casting. Cheap. Therefore, it is presumed that the mixed inorganic fine particles are biased and haze variation is likely to occur in the surface direction.

In the present invention, a mixture in which inorganic fine particles are mixed in advance with soluble polyimide is prepared, and the mixture is further mixed with new soluble polyimide to prepare a dope, followed by casting. By mixing inorganic fine particles in advance with soluble polyimide, soluble polyimide resin is intertwined around the inorganic fine particles, so it is easy to adapt to new soluble polyimide, and even if new soluble polyimide is oriented during casting There is little bias of inorganic fine particles. Therefore, it is speculated that the haze variation in the surface direction of the film is small.

As described above, by preparing a mixture in which inorganic fine particles are premixed in soluble polyimide, mixing it with new soluble polyimide to prepare a dope and casting, the first time in the surface of the soluble polyimide film, A polyimide film having a standard deviation of haze value of 1 or less could be obtained.

The method for producing a polyimide film of the present invention is a method for producing a polyimide film containing 1 g or more of polyimide dissolved in 100 g of dimethylacetamide or 100 g of γ-butyrolactone at 60 ° C. and inorganic fine particles. A step of preparing a mixture containing inorganic fine particles, a step of preparing a dope containing the mixture, the polyimide and a solvent, a step of casting the dope on a support to form a film, and supporting the film It is a manufacturing method of a polyimide film characterized by including the process of peeling from a body, and the drying process of drying the peeled film | membrane. This feature is a technical feature common to the claimed invention.

As an embodiment of the present invention, it is preferable that the mixture is a crushed product obtained by crushing the polyimide film containing the polyimide and the inorganic fine particles from the viewpoint that the variation in the haze value in the surface direction is small.

Further, it is preferable that the mixture is a dope containing the polyimide, the inorganic fine particles, and a solvent from the viewpoint that variation in haze value in the plane direction is small.

Furthermore, it is preferable that the mixture is contained in a mass ratio of 10 to 70% by mass with respect to the manufactured polyimide film from the viewpoint of transportability and variation in haze value in the surface direction.

Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In the present application, “˜” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

<Outline of the polyimide film of the present invention>
The polyimide film of the present invention is a polyimide film containing soluble polyimide as a main component. As a measure of solubility, it is preferable that 1 g or more is dissolved in 100 g of dimethylacetamide or 100 g of γ-butyrolactone at 60 ° C.

In the present invention, containing polyimide as a main component means that the total amount of polyimide in the film is 50% by mass or more. Preferably it is 80 mass% or more.

<Polyimide>
The polyimide according to the present invention is a resin having an imide structure (hereinafter also referred to as a polyimide resin), and is a resin containing an imide bond in a repeating unit. The polyimide is preferably formed from diamine or a derivative thereof and an acid anhydride or a derivative thereof.

Preferred polyimides for the present invention include polyimide, polyamideimide, polyetherimide, and polyesterimide having a structure represented by the following formula (1.1).

(1) Polyimide having the structure represented by the formula (1.1) (1.1) Structure on the acid anhydride side The polyimide that can be used in the present invention is particularly represented by the following formula (1.1). A polyimide having a repeating unit is preferred.

In the formula (1.1), R represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, or a tetravalent aliphatic hydrocarbon group or alicyclic hydrocarbon group having 4 to 39 carbon atoms. A represents a group consisting of a divalent aliphatic hydrocarbon group having 2 to 39 carbon atoms, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof, and as a bonding group, —O—, — At least one selected from the group consisting of SO ₂ —, —CO—, —CH ₂ —, —C (CH ₃ ) ₂ —, —OSi (CH ₃ ) ₂ —, —C ₂ H ₄ O—, and —S—. One group may be contained.

Examples of the aromatic hydrocarbon ring represented by R include fluorene ring, benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o- Terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, pyranthrene ring, anthraanthre Ring.

Similarly, examples of the aromatic heterocycle represented by R include a silole ring, a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, and an oxadiene ring. Azole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzthiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, thienothiophene ring, carbazole ring, azacarbazole ring ( Any one of the carbon atoms constituting the dicarbosyl ring, dibenzofuran ring, dibenzothiophene ring, benzothiophene ring or dibenzofuran ring. More than one nitrogen Ring substituted with a child, benzodifuran ring, benzodithiophene ring, acridine ring, benzoquinoline ring, phenazine ring, phenanthridine ring, phenanthroline ring, cyclazine ring, quindrine ring, tepenidine ring, quinindrine ring, triphenodithiazine ring, Triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, naphthofuran ring, naphthothiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring, anthradithiophene ring, thianthrene Ring, phenoxathiin ring, dibenzocarbazole ring, indolocarbazole ring, dithienobenzene ring and the like.

Examples of the tetravalent aliphatic hydrocarbon group having 4 to 39 carbon atoms represented by R include a butane-1,1,4,4-tetrayl group, an octane-1,1,8,8-tetrayl group, Examples include decane-1,1,10,10-tetrayl group.

Examples of the tetravalent alicyclic hydrocarbon group having 4 to 39 carbon atoms represented by R include cyclobutane-1,2,3,4-tetrayl group, cyclopentane-1,2,4,5. -Tetrayl group, cyclohexane-1,2,4,5-tetrayl group, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetrayl group, bicyclo [2.2.2] Octane-2,3,5,6-tetrayl group, 3,3 ′, 4,4′-dicyclohexyltetrayl group, 3,6-dimethylcyclohexane-1,2,4,5-tetrayl group, 3,6- And groups such as diphenylcyclohexane-1,2,4,5-tetrayl group.

Examples of the divalent aliphatic hydrocarbon group having 2 to 39 carbon atoms which may or may not have the above linking group represented by A include groups represented by the following structural formula.

In the above structural formula, n represents the number of repeating units, preferably 1 to 5, and more preferably 1 to 3. X is an alkanediyl group having 1 to 3 carbon atoms, that is, a methylene group, an ethylene group, a trimethylene group, or a propane-1,2-diyl group, and a methylene group is preferable.

Examples of the divalent alicyclic hydrocarbon group having 2 to 39 carbon atoms which may or may not have the above linking group represented by A include groups represented by the following structural formula.

Examples of the divalent aromatic hydrocarbon group having 2 to 39 carbon atoms with or without the above-described bonding group represented by Φ include groups represented by the following structural formulas.

Examples of the group consisting of a combination of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group represented by A include groups represented by the following structural formulas.

The group represented by A is preferably a divalent aromatic hydrocarbon group having 2 to 39 carbon atoms having a linking group, or a combination of the aromatic hydrocarbon group and an aliphatic hydrocarbon group. A group represented by the following structural formula is preferred.

The acid anhydride used in the present invention is a carboxylic acid anhydride and is preferably a derivative of an aliphatic or alicyclic tetracarboxylic acid, such as an aliphatic or alicyclic tetracarboxylic acid ester, aliphatic or An alicyclic tetracarboxylic dianhydride etc. are mentioned. Of the aliphatic or alicyclic tetracarboxylic acids or derivatives thereof, alicyclic tetracarboxylic dianhydrides are preferred.

Here, the derivative is a compound that can be changed to an aliphatic or alicyclic tetracarboxylic acid. For example, in the case of an aliphatic tetracarboxylic dianhydride, a compound having two carboxy groups instead of the anhydride A compound in which one or both of these two carboxy groups is an esterified product, or an acid chloride in which one or both of these two carboxy groups are chlorinated is preferably used.

By using such an acyl compound, it is possible to obtain a polyimide film having high heat resistance and excellent optical properties and less coloring (yellowing).

Examples of the aliphatic tetracarboxylic acid include 1,2,3,4-butanetetracarboxylic acid. Examples of the alicyclic tetracarboxylic acid include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,4,5-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid. Bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid, etc. Can be mentioned.

Examples of the aliphatic tetracarboxylic acid esters include monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the above aliphatic tetracarboxylic acids. Examples of the alicyclic tetracarboxylic acid esters include monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the above alicyclic tetracarboxylic acids. The alkyl group site is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.

Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride. Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, , 4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] And octane-2,3,5,6-tetracarboxylic dianhydride. Particularly preferred is 1,2,4,5-cyclohexanetetracarboxylic dianhydride. Generally, a polyimide having an aliphatic diamine as a constituent component forms a strong salt between the polyamic acid, which is an intermediate product, and a diamine. Therefore, in order to increase the molecular weight, a solvent having a relatively high salt solubility (for example, cresol). N, N-dimethylacetamide, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) are preferably used. However, even with polyimides containing aliphatic diamine as a constituent, when 1,2,4,5-cyclohexanetetracarboxylic dianhydride is used as a constituent, the salt of polyamic acid and diamine is bound by a relatively weak bond. Therefore, high molecular weight is easy and a flexible film is easily obtained.

Other examples include 4,4′-biphthalic anhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 4- (2, 5-Dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3- Cyclohexene-1,2-dicarboxylic anhydride, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 3,4'-oxydiphthalic anhydride, 3,4,9,10-perylenete Dianhydride (Pigment Red 224) 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride tricyclo [6.4.0.0 ^{2, 7]} dodecane -1,8: 2,7-tetracarboxylic dianhydride and the like can be used.

Alternatively, an acid anhydride having a fluorene skeleton or a derivative thereof may be used. It has the effect of improving the coloring unique to polyimide. Examples of the acid anhydride having a fluorene skeleton include 9,9-bis (3,4-dicarboxyphenyl) fluorenic dianhydride and 9,9-bis [4- (3,4-dicarboxyphenoxy) phenyl. Fluoronic acid dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -3-phenylphenyl] fluoric acid dianhydride, and the like can be used.

Aromatic, aliphatic or alicyclic tetracarboxylic acids or their derivatives may be used alone or in combination of two or more. Further, other tetracarboxylic acids or derivatives thereof (particularly dianhydrides) may be used in combination as long as the solvent solubility of polyimide, the flexibility of the polyimide film, thermocompression bonding, and transparency are not impaired.

Examples of such other tetracarboxylic acids or derivatives thereof include pyromellitic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2, 2-bis (3,4-dicarboxyphenyl) propane, 2,2-bis (2,3-dicarboxyphenyl) propane, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1 , 3,3,3-hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, bis (3,4-dicarboxy) Phenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, bis (2,3-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 2,2 ′ 3,3′-benzophenonetetracarboxylic acid, 4,4- (p-phenylenedioxy) diphthalic acid, 4,4- (m-phenylenedioxy) diphthalic acid, 1,1-bis (2,3-dicarboxyl) Aromatic tetracarboxylic acids such as phenyl) ethane, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane and their derivatives (especially dianhydrides); ethylenetetracarboxylic acid Examples thereof include aliphatic tetracarboxylic acids having 1 to 3 carbon atoms and derivatives thereof (particularly dianhydrides).

As the acid dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride or biphenyltetracarboxylic dianhydride is excellent in transparency and heat due to heat shrinkage. This is preferable from the viewpoint of easy correction.

The repeating unit represented by the formula (1.1) is preferably 10 to 100 mol%, more preferably 50 to 100 mol%, still more preferably 80 to 100 mol%, particularly preferably all the repeating units. Is 90 to 100 mol%. The number of repeating units of the formula (1.1) in one molecule of the polyimide is 10 to 2000, preferably 20 to 200. In this range, the glass transition temperature (Tg) is 230 to 350 ° C. It is preferable that the temperature is 250 to 330 ° C.

(1.2) Structure on the diamine side As the diamine or derivative thereof, for example, aromatic diamine or isocyanate is preferable, and aromatic diamine is preferable.

The diamine or derivative thereof used in the present invention may be an aromatic diamine, an aliphatic diamine or a mixture thereof, and is preferably an aromatic diamine from the viewpoint of suppressing whitening of the polyimide film.

In the present invention, the term “aromatic diamine” refers to a diamine in which an amino group is directly bonded to an aromatic ring, and an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or any other part of its structure. A substituent (for example, a halogen atom, a sulfonyl group, a carbonyl group, an oxygen atom, etc.) may be contained. The term “aliphatic diamine” refers to a diamine in which an amino group is directly bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group or other substituent ( For example, a halogen atom, a sulfonyl group, a carbonyl group, an oxygen atom, etc.) may be included.

Examples of aromatic diamines include, for example, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, benzidine, o-tolidine, m-tolidine, bis (trifluoromethyl) Benzidine, octafluorobenzidine, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl 3,3'-difluoro-4,4'-diaminobiphenyl, 2,6-diaminonaphthalene, 1,5-diaminonaphthalene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4 ' -Diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,4'- Aminodiphenylsulfone, 4,4'-diaminobenzophenone, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (2-methyl-4-aminophenoxy) phenyl) Propane, 2,2-bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2- Bis (4- (2-methyl-4-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) hexafluoropropane, 4,4 ′ -Bis (4-aminophenoxy) biphenyl, 4,4'-bis (2-methyl-4-aminophenoxy) biphenyl, 4,4'-bis (2 6-dimethyl-4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (2-methyl-4-) Aminophenoxy) phenyl) sulfone, bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) ether, bis (4- (2-methyl- 4-aminophenoxy) phenyl) ether, bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) ether, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (2- Methyl-4-aminophenoxy) benzene, 1,4-bis (2,6-dimethyl-4-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,3-bis (2-methyl-4-aminophenoxy) benzene, 1,3-bis (2,6-dimethyl-4-aminophenoxy) benzene, 2,2-bis (4- Aminophenyl) propane, 2,2-bis (2-methyl-4-aminophenyl) propane, 2,2-bis (3-methyl-4-aminophenyl) propane, 2,2-bis (3-ethyl-4) -Aminophenyl) propane, 2,2-bis (3,5-dimethyl-4-aminophenyl) propane, 2,2-bis (2,6-dimethyl-4-aminophenyl) propane, 2,2-bis ( 4-aminophenyl) hexafluoropropane, 2,2-bis (2-methyl-4-aminophenyl) hexafluoropropane, 2,2-bis (2,6-dimethyl-4-aminophenyl) Hexafluoropropane, α, α'-bis (4-aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (2-methyl-4-aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (2,6-dimethyl-4-aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (3-aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (4-aminophenyl) -1,3-diisopropylbenzene, α, α'-bis (2-methyl-4-aminophenyl) -1,3-diisopropylbenzene, α, α'-bis (2,6-dimethyl) -4-aminophenyl) -1,3-diisopropylbenzene, α, α'-bis (3-aminophenyl) -1,3-diisopropylbenzene, 1,1-bis (4-aminophenyl) ) Cyclopentane, 1,1-bis (2-methyl-4-aminophenyl) cyclopentane, 1,1-bis (2,6-dimethyl-4-aminophenyl) cyclopentane, 1,1-bis (4- Aminophenyl) cyclohexane, 1,1-bis (2-methyl-4-aminophenyl) cyclohexane, 1,1-bis (2,6-dimethyl-4-aminophenyl) cyclohexane, 1,1-bis (4-amino) Phenyl) 4-methyl-cyclohexane, 1,1-bis (4-aminophenyl) norbornane, 1,1-bis (2-methyl-4-aminophenyl) norbornane, 1,1-bis (2,6-dimethyl-) 4-aminophenyl) norbornane, 1,1-bis (4-aminophenyl) adamantane, 1,1-bis (2-methyl-4-aminophenyl) adaman 1,1-bis (2,6-dimethyl-4-aminophenyl) adamantane, 1,4-phenylenediamine, 3,3'-diaminobenzophenone, 2,2-bis (3-aminophenyl) hexafluoropropane 3-aminobenzylamine, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] sulfone, 1,3-bis [2- (4-aminophenyl) -2-propyl] benzene, bis (2-aminophenyl) sulfide Bis (4-aminophenyl) sulfide, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 4,4'-dia -3,3'-dimethyldiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-ethylenedianiline, 4,4'-methylenebis (cyclohexylamine), 4,4'-methylenebis (2,6-diethyl) Aniline), 4,4'-methylenebis (2-methylcyclohexylamine) and the like.

Examples of the aliphatic diamine include ethylene diamine, hexamethylene diamine, polyethylene glycol bis (3-aminopropyl) ether, polypropylene glycol bis (3-aminopropyl) ether, 1,3-bis (aminomethyl) cyclohexane, 1,4 -Bis (aminomethyl) cyclohexane, m-xylylenediamine, p-xylylenediamine, 1,4-bis (2-amino-isopropyl) benzene, 1,3-bis (2-amino-isopropyl) benzene, isophorone Diamine, norbornanediamine, siloxane diamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3,3'-diethyl-4,4'-diaminodicyclohexylmethane, 3 , 3 , 5,5'-tetramethyl-4,4'-diaminodicyclohexylmethane, 2,3-bis (aminomethyl) -bicyclo [2.2.1] heptane, 2,5-bis (aminomethyl) -bicyclo [ 2.2.1] heptane, 2,6-bis (aminomethyl) -bicyclo [2.2.1] heptane, 2,2-bis (4,4'-diaminocyclohexyl) propane, 2,2-bis ( 4,4'-diaminomethylcyclohexyl) propane and the like.

Further, a diamine having a fluorene skeleton or a derivative thereof may be used for the purpose of improving the coloring unique to polyimide. For example, 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene, 9,9-bis [4- (4-aminophenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-aminophenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2-aminophenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-3 -Methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino) -3-Ethylphenoxy) -3-phenylphenyl] fluorene and the like can be used.

Also, a diamine compound having a triazine mother nucleus represented by the following formula can be preferably used.

In the diamine compound of the above formula having a triazine mother nucleus, R ¹ represents a hydrogen atom or an alkyl group or an aryl group having 1 to 12 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), R ² represents an alkyl group or an aryl group having 1 to 12 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), and R ¹ and R ² may be different or the same. May be.

Specific examples of the alkyl group or aryl group having 1 to 12 carbon atoms of R ¹ and R ² include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, phenyl, benzyl, naphthyl, methylphenyl, and biphenyl. Etc.

The aminoanilino group connected to the two NH groups of triazine is 4-aminoanilino or 3-aminoanilino, which may be the same or different, but 4-aminoanilino is preferred.

Specific examples of the diamine compound represented by the above formula having a triazine mother nucleus include 2,4-bis (4-aminoanilino) -6-anilino-1,3,5-triazine, 2,4-bis ( 3-aminoanilino) -6-anilino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-benzylamino-1,3,5-triazine, 2,4-bis (3-aminoanilino ) -6-Benzylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-naphthylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino)- 6-biphenylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-diphenylamino-1,3,5-triazine, 2,4-bis (3-aminoanilino) -6 Diphenylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-dibenzylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-di Naphtylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-N-methylanilino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-N -Methylnaphthylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-methylamino-1,3,5-triazine, 2,4-bis (3-aminoanilino) -6- Methylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-ethylamino-1,3,5-triazine, 2,4-bis (3-aminoanilino) -6-ethylamino -1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-dimethylamino-1,3,5-triazine, 2,4-bis (3-aminoanilino) -6-dimethylamino-1 , 3,5-triazine, 2,4-bis (4-aminoanilino) -6-diethylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-dibutylamino-1,3 5-triazine, 2,4-bis (4-aminoanilino) -6-amino-1,3,5-triazine, 2,4-bis (3-aminoanilino) -6-amino-1,3,5-triazine, etc. Is mentioned.

Examples of isocyanate esters that are diamine derivatives include diisocyanates obtained by reacting the above aromatic or aliphatic diamines with phosgene.

In addition, examples of other diamine derivatives include diaminodisilanes, such as trimethylsilylated aromatic or aliphatic diamines obtained by reacting the above aromatic or aliphatic diamines with chlorotrimethylsilane.

The diamine is preferably 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl from the viewpoint of excellent transparency and easy thermal correction by heat shrinkage.

The above diamines and derivatives thereof may be used in any mixture, but the amount of diamine in them is preferably 50 to 100 mol%, more preferably 80 to 100 mol%.

(1.3) Synthesis Method and Imidization of Polyamic Acid (1.3.1) Synthesis of Polyamic Acid In a suitable solvent, the polyamic acid is at least one of the tetracarboxylic acids and at least one of the diamines. It is obtained by polymerizing the kind.

The polyamic acid ester is diesterified by ring-opening the tetracarboxylic dianhydride with an alcohol such as methanol, ethanol, isopropanol, or n-propanol, and the obtained diester is converted into the above-mentioned diester in an appropriate solvent. It can be obtained by reacting with a diamine compound. Furthermore, the polyamic acid ester can also be obtained by esterification by reacting the carboxylic acid group of the polyamic acid obtained as described above with an alcohol as described above.

The reaction between the tetracarboxylic dianhydride and the diamine compound can be carried out under conventionally known conditions. There are no particular limitations on the order of addition or addition method of the tetracarboxylic dianhydride and the diamine compound. For example, a polycarboxylic acid can be obtained by sequentially adding a tetracarboxylic dianhydride and a diamine compound to a solvent and stirring at an appropriate temperature.

The amount of the diamine compound is usually 0.8 mol or more, preferably 1 mol or more with respect to 1 mol of tetracarboxylic dianhydride. On the other hand, it is 1.2 mol or less normally, Preferably it is 1.1 mol or less. The yield of the polyamic acid obtained can be improved by making the quantity of a diamine compound into such a range.

The concentration of tetracarboxylic dianhydride and diamine compound in the solvent is appropriately set according to the reaction conditions and the viscosity of the polyamic acid solution. For example, the total mass of the tetracarboxylic dianhydride and the diamine compound is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more with respect to the total amount of the solution, while usually 70%. It is not more than mass%, preferably not more than 30 mass%. By setting the amount of the reaction substrate in such a range, the polyamic acid can be obtained at a low cost and in a high yield.

The reaction temperature is not particularly limited, but is usually 0 ° C. or higher, preferably 20 ° C. or higher, and is usually 100 ° C. or lower, preferably 80 ° C. or lower. The reaction time is not particularly limited but is usually 1 hour or longer, preferably 2 hours or longer, and is usually 100 hours or shorter, preferably 24 hours or shorter. By performing the reaction under such conditions, the polyamic acid can be obtained at a low cost and in a high yield.

Examples of the polymerization solvent used in this reaction include hydrocarbon solvents such as hexane, cyclohexane, heptane, benzene, toluene, xylene and mesitylene; carbon tetrachloride, dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene and dichlorobenzene. And halogenated hydrocarbon solvents such as fluorobenzene; ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane and methoxybenzene; ketone solvents such as acetone and methyl ethyl ketone; N, N-dimethylformamide, N, N— Amide solvents such as dimethylacetamide and N-methyl-2-pyrrolidone; aprotic polar solvents such as dimethyl sulfoxide and γ-butyrolactone; pyridine, picoline, lutidine, quinoline and isoquinoline Ring-based solvents; phenols and phenolic solvents such as cresol, but and the like, but is not particularly limited. As a polymerization solvent, only 1 type can also be used and 2 or more types of solvents can also be mixed and used.

As the terminal group of the polyamic acid, an acid anhydride group or an amino group can be arbitrarily selected by using either one of a tetracarboxylic dianhydride and a diamine compound in excess during the polymerization reaction.

In the case where the terminal group is an acid anhydride terminal, the acid anhydride terminal may be left without performing the subsequent treatment, or may be hydrolyzed to obtain a dicarboxylic acid. Moreover, it is good also as ester using C4 or less alcohol. Furthermore, you may seal a terminal | end using a monofunctional amine compound or an isocyanate compound. The amine compound or isocyanate compound used here is not particularly limited as long as it is a monofunctional primary amine compound or isocyanate compound. For example, aniline, methylaniline, dimethylaniline, trimethylaniline, ethylaniline, diethylaniline, triethylaniline, aminophenol, methoxyaniline, aminobenzoic acid, biphenylamine, naphthylamine, cyclohexylamine, phenyl isocyanate, xylylene isocyanate, cyclohexyl isocyanate , Methylphenyl isocyanate, trifluoromethylphenyl isocyanate, and the like.

Further, when the terminal group is an amine terminal, it is possible to prevent the amino group from remaining at the terminal by sealing the terminal amino group with a monofunctional acid anhydride. As an acid anhydride used here, if it is a monofunctional acid anhydride which becomes dicarboxylic acid or tricarboxylic acid when hydrolyzed, it can be used without particular limitation. For example, maleic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, succinic anhydride, norbornene dicarboxylic acid anhydride, 4- (phenylethynyl) phthalic anhydride, 4-ethynylphthalic anhydride, phthalate Acid anhydride, methylphthalic anhydride, dimethylphthalic anhydride, trimellitic anhydride, naphthalenedicarboxylic anhydride, 7-oxabicyclo [2.2.1] heptane-2,3-dicarboxylic anhydride, bicyclo [2.2.1] Heptane-2,3-dicarboxylic anhydride, bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic anhydride, 4-oxatricyclo [5.2 .2.0 ^2,6] undecane-3,5-dione, octahydro-1,3-dioxo-isobenzofuran-5-carboxylic acid, hexahydrophthalic anhydride Methylhexahydrophthalic anhydride, dimethylcyclohexanedicarboxylic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, methyl-4-cyclohexene-1,2-dicarboxylic anhydride, etc. .

(1.3.2) Imidization method Here, polyimide is a method in which a polyamic acid solution is heated to imidize the polyamic acid (thermal imidization method), or a ring closure catalyst (imidation catalyst) in the polyamic acid solution. Can be obtained by a method (chemical imidization method) in which polyamic acid is imidized by adding.

Also, a method of imidizing polyamic acid by heating the polyamic acid solution (thermal imidization method), or a method of imidizing polyamic acid by adding a ring-closing catalyst (imidation catalyst) to the polyamic acid solution (chemical imide) As for the conversion method), a reaction vessel for polymerizing polyamic acid from an acid anhydride and a diamine may be continued as it is and imidized in the reaction vessel.

In the thermal imidization method in the reaction kettle, the polyamic acid in the polymerization solvent is heated for, for example, 80 to 300 ° C. for 0.1 to 200 hours to advance imidization. Further, the temperature range is preferably 150 to 200 ° C., and by setting the temperature range to 150 ° C. or higher, imidization can be reliably progressed and completed. It is possible to prevent the resin concentration from increasing due to oxidation of unreacted raw materials and volatilization of the solvent.

Further, in the thermal imidization method, an azeotropic solvent can be added to the polymerization solvent in order to efficiently remove water generated by the imidization reaction. As the azeotropic solvent, for example, aromatic hydrocarbons such as toluene, xylene and solvent naphtha, and alicyclic hydrocarbons such as cyclohexane, methylcyclohexane and dimethylcyclohexane can be used. When an azeotropic solvent is used, the amount added is about 1 to 30% by mass, preferably 5 to 20% by mass, based on the total amount of organic solvent.

On the other hand, in the chemical imidization method, a known ring closure catalyst is added to the polyamic acid in the polymerization solvent to advance imidization. Specific examples of the ring-closing catalyst include aliphatic tertiary amines such as trimethylamine and triethylenediamine, and heterocyclic tertiary amines such as isoquinoline, pyridine and picoline. Examples thereof include substituted nitrogen-containing heterocyclic compounds, N-oxide compounds of nitrogen-containing heterocyclic compounds, substituted or unsubstituted amino acid compounds, aromatic hydrocarbon compounds having an hydroxy group, or aromatic heterocyclic compounds. -Lower alkyl imidazole such as dimethylimidazole, N-methylimidazole, N-benzyl-2-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 5-methylbenzimidazole, N-benzyl-2-methyl Imidazole derivatives such as imidazole, isoquinoline, 3 A substituted pyridine such as 5-dimethylpyridine, 3,4-dimethylpyridine, 2,5-dimethylpyridine, 2,4-dimethylpyridine, 4-n-propylpyridine, p-toluenesulfonic acid, etc. can be preferably used. it can. The addition amount of the ring closure catalyst is preferably about 0.01 to 2 times equivalent, particularly about 0.02 to 1 time equivalent to the amic acid unit of the polyamic acid. By using a ring-closing catalyst, the properties of the resulting polyimide, particularly elongation and breaking resistance, may be improved.

In the thermal imidization method or chemical imidization method, a dehydrating agent may be added to the polyamic acid solution. Examples of such a dehydrating agent include aliphatic acid anhydrides such as acetic anhydride, phthalates, and the like. Examples thereof include aromatic acid anhydrides such as acid anhydrides, and these can be used alone or in combination. In addition, it is preferable to use a dehydrating agent because the reaction can proceed at a low temperature. Although it is possible to imidize polyamic acid only by adding a dehydrating agent to the polyamic acid solution, it is preferable to imidize by heating or addition of a ring-closing catalyst as described above because the reaction rate is slow. .

Thus, the polyimide solution imidized in the reaction vessel is advantageous because it is difficult for the molecular weight to decrease due to hydrolysis over time.

Also, since the imidization reaction has progressed in advance, for example, in the case of a polyimide having an imidization rate of 100%, imidization on a cast film or film becomes unnecessary and the drying temperature can be lowered.

Alternatively, the ring-closed polyimide may be reprecipitated using a poor solvent or the like, purified to a solid, dissolved in a solvent, and cast and dried to form a film.

According to this method, the polymerization solvent and the solvent to be cast can be made different types, and the performance of the polyimide film can be further extracted by selecting the optimum solvent for each.

For example, in order to increase the molecular weight of polyamic acid, it is polymerized and cyclized with dimethylacetamide, solidified with methanol, dried, dissolved in dichloromethane, cast, and dried, so that the high molecular weight is obtained. And low temperature drying are possible.

Also, when dichloromethane is used as a solvent, it can be used in combination with other solvents. A co-solvent such as tetrahydrofuran (THF), dioxolane, cyclohexanone, cyclopentanone, γ-butyrolactone, ethanol, methanol, butanol, or isopropyl alcohol can be used as appropriate.

(1.4) Other polyimides In addition to the polyimides described above, polyimides containing atoms such as phosphorus, silicon, and sulfur can also be used.

For example, as the polyimide containing phosphorus, the polyimides described in paragraphs [0010]-[0021] of JP2011-74209A and paragraphs [0011]-[0025] of JP2011-074177A are used. Can do.

As the polyimide containing silicon, a polyimide obtained by imidizing a polyimide precursor described in paragraphs [0030] to [0045] of JP2013-028796A can be used.

Examples of the polyimide containing sulfur include paragraphs [0009]-[0025] of JP 2010-189322 A, paragraphs [0012]-[0025] of JP 2008-274234 A, and paragraphs of JP 2008-274229 A. Polyimides obtained by imidizing polyimide precursors described in [0012]-[0023] can be used.

In addition, alicyclic polyimides described in paragraphs [0008]-[0012] of JP-A-2009-256590 and paragraphs [0008]-[0012] of JP-A-2009-256589 are preferably used. it can.

(2) Polyamideimide The polyamideimide used in the present invention is a polyamideimide containing tricarboxylic acid or tetracarboxylic acid, dicarboxylic acid as an acid component, and diamine as a structural unit as an amine component.

The polyamideimide used is an acid component
a) Tricarboxylic acid; diphenyl ether-3,3 ', 4'-tricarboxylic acid, diphenylsulfone-3,3', 4'-tricarboxylic acid, benzophenone-3,3 ', 4'-tricarboxylic acid, naphthalene-1,2 , 4-tricarboxylic acid, butan-1,2,4-tricarboxylic acid and other tricarboxylic acid monoanhydrides, esterified products and the like, or a mixture of two or more.

b) Tetracarboxylic acid; diphenylsulfone-3,3 ′, 4,4′-tetracarboxylic acid, naphthalene-2,3,6,7-tetracarboxylic acid, naphthalene-1,2,4,5-tetracarboxylic acid , Naphthalene-1,4,5,8-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, cyclopentane-1,2,3,4-tetracarboxylic acid monoanhydride, dianhydride , Esterified compounds alone, or a mixture of two or more.

C) Dicarboxylic acid; adipic acid, azelaic acid, sebacic acid, dicarboxylic acid of cyclohexane-4,4′-dicarboxylic acid, and monoanhydrides and esterified products thereof.

As an amine component,
d) Amine component 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-diethoxy-4,4'-diaminobiphenyl, p-phenylenediamine, m -Phenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminobiphenyl, 3,3 ' -Diaminobiphenyl, 3,3'-diaminobenzanilide, 4,4'-diaminobenzanilide, 4,4'-diaminobenzene Nzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 2,6-tolylenediamine, 2,4-tolylenediamine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl Sulfide, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, p-xylenediamine, m-xylenediamine, 2,2 ' -Bis (4-aminophenyl) propane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2 , 2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4 Aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] propane, 4,4′-bis (4-aminophenoxy) biphenyl, 4 , 4'-bis (3-aminophenoxy) biphenyl, tetramethylenediamine, hexamethylenediamine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, cyclohexane-1,4-diamine, diaminosiloxane, or their corresponding diisocyanates These may be used alone or in combination of two or more.

In particular, trimellitic anhydride (TMA), 3,3,4 ', 4'-benzophenone tetracarboxylic dianhydride (BTDA), and 3,3,4', 4'-biphenyltetracarboxylic acid as acid components Polyamideimide resin polymerized with a raw material containing dianhydride (BPDA) and 1,5-naphthalene diisocyanate (NDI) as an isocyanate component is preferable.

The molar ratio between the imide bond and the amide bond of the polyamideimide is preferably 99/1 to 60/40, more preferably 99/1 to 75/25, and even more preferably 90/10 to 80/20. is there. When the molar ratio of the imide bond to the amide bond is 60/40 or more, the heat resistance, moisture resistance reliability, and heat resistance reliability are improved. On the other hand, if it is 99/1 or less, the elastic modulus tends to be low, and the folding resistance and bending characteristics tend to be improved.

(2.1) Polyamideimide having the structure represented by the formula (2) as an essential component One preferred embodiment includes the structure represented by the formula (2) as an essential component, and further comprising the formula (3) and the formula It is a polyamide-imide resin containing at least one structure selected from the group represented by (4) and formula (5) in the molecular chain as a repeating unit.

(X represents an oxygen atom, CO, SO ₂ , or a bond. N represents 0 or 1.)

(Y represents an oxygen atom, CO, or OOC—R—COO. N represents 0 or 1, and R represents a divalent organic group.)

Here, in Formula (3), X is preferably SO ₂ or a bond (biphenyl bond), or n = 0. More preferably, X is a bond (biphenyl bond) or n = 0. In formula (4), Y is preferably a benzophenone type (CO) or a bond type (biphenyl bond).

One preferred embodiment is that formula (2) is a repeating unit from trimellitic anhydride and 1,5-naphthalene diisocyanate, formula (3) is a repeating unit from terephthalic acid and 1,5-naphthalene diisocyanate, formula (4) Is a repeating unit from biphenyltetracarboxylic dianhydride or benzophenonetetracarboxylic dianhydride and 1,5-naphthalene diisocyanate, the content ratio of which is the formula (2) / {formula (3) + formula (4) + Formula (5)} = 1/99 to 40/60 mole ratio, and Formula (3) / Formula (4) = 10/90 to 90/10 mole ratio is preferable.

The higher the imidization rate, the more preferable upper limit is 100%. The polyamideimide resin can be synthesized by a usual method. For example, an isocyanate method, an amine method (acid chloride method, low temperature solution polymerization method, room temperature solution polymerization method, etc.), etc., but the polyamideimide resin used in the present invention is preferably soluble in an organic solvent, as described above. For reasons such as ensuring the reliability of peel strength (adhesive strength), production by the isocyanate method is preferred. Also, industrially, it is preferable because the solution at the time of polymerization can be applied as it is.

(2.2) Polyamideimide having a structure represented by formula (6) or formula (7) As a preferred polyamideimide resin, a compound containing the following formula (6) as a structural unit can be preferably used. Hereinafter, the compound having a structure represented by the formula (6) will be described.

(In the formula, R ₁ is an aryl group or a cycloalkane group, and may contain nitrogen, oxygen, sulfur, or halogen.)
(Diamine component of polyamideimide resin)
The diamine component includes p-phenylenediamine, m-phenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone. 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 3,3'-diaminobenzanilide, 4,4'-diaminobenzanilide, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone 3,4'-diaminobenzophenone, 2,6-tolylenediamine, 2,4-tolylenediamine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl Propane, 3,3′-diaminodiphenylpropane, , 3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, P-xylenediamine, m-xylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2,7- Naphthalenediamine, 2,2'-bis (4-aminophenyl) propane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4 -Aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] Sulfone, bis [4- (3-aminophenoxy) phenyl] propane, 4,4′-bis (4-aminophen Xyl) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4-methyl-1,3-phenylenediamine, 3,3'-diethyl -4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4 ' -Diaminobiphenyl, 3,3'-diethoxy-4,4'-diaminobiphenyl, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-diaminocyclohexane (trans / cis mixture), 1,3-diaminocyclohexane, dicyclohexylmethane-4,4'-diamine (trans isomer, cis isomer, trans / cis mixture) , Isophoronediamine, 1,4-cyclohexanebis (methylamine), 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) bicyclo [2.2.1] ] Heptane, 3,8-bis (aminomethyl) tricyclo [5.2.1.0] decane, 1,3-diaminoadamantane, 4,4'-methylenebis (2-methylcyclohexylamine), 4,4'- Methylenebis (2-ethylcyclohexylamine), 4,4'-methylenebis (2,6-dimethylcyclohexylamine), 4,4'-methylenebis (2,6-diethylcyclohexylamine), 2,2-bis (4-amino) (Cyclohexyl) propane, 2,2-bis (4-aminocyclohexyl) hexafluoropropane, 1,3-propanediamine, 4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine alone, or A mixture of two or more, or a diisocyanate corresponding to these, or a mixture of two or more can be used as the diamine component.

Preferably, 3,3′-dimethyl-4,4′-diaminobiphenyl, dicyclohexylmethane-4,4′-diamine (trans isomer, cis isomer, trans / cis mixture), 4,4′-diaminodiphenyl ether, p- Use of phenylenediamine, 4-methyl-1,3-phenylenediamine, or the like alone, or a mixture of two or more thereof, or a diisocyanate corresponding to these alone, or a mixture of two or more, as the diamine component. it can.

More preferably, 3,3′-dimethyl-4,4′-diaminobiphenyl, dicyclohexylmethane-4,4′-diamine (trans isomer, cis isomer, trans / cis mixture), 4,4′-diaminodiphenyl ether, 4 -Methyl-1,3-phenylenediamine or the like alone, or a mixture of two or more kinds, or the corresponding diisocyanate or the like alone or a mixture of two or more kinds can be used as the diamine component.

More preferably, 3,3′-dimethyl-4,4′-diaminobiphenyl, dicyclohexylmethane-4,4′-diamine (trans isomer, cis isomer, trans / cis mixture), 4-methyl-1,3-phenylene A diamine or the like alone, or a mixture of two or more kinds, or a diisocyanate corresponding to these alone or a mixture of two or more kinds can be used as the diamine component.

(Preferable combination of acid component and diamine component)
Among the above acid components and diamine components, the following components are obtained from the heat resistance, solvent resistance, and durability in the process of forming a film, and the heat resistance, surface smoothness, and transparency of the produced polyamideimide film. Is preferably used.

As the acid component, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride can be used. Polyamideimide resin containing cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride as an acid component can be used.

As the diamine component, at least one or two compounds selected from the group consisting of 3,3′-dimethyl-4,4′-diaminobiphenyl and 4-methyl-1,3-phenylenediamine, or 3,3 At least one or two compounds selected from the group consisting of '-dimethyl-4,4'-diisocyanate biphenyl (o-tolidine diisocyanate) and 4-methyl-1,3-phenylene diisocyanate (tolylene diisocyanate); Can be used.

Further, as a preferred polyamideimide resin, a compound containing a structure represented by the following formula (7) as a structural unit can be used.

(Wherein R ₂ and R ₃ each represent hydrogen, an alkyl group having 1 to 3 carbon atoms, or an aryl group, and may contain nitrogen, oxygen, sulfur, or halogen.)
When the total acid component is 100 mol%, the exemplified acid component is preferably contained in an amount of 50 mol% to 100%, more preferably 70 mol% to 100%. When the total diamine component is 100 mol%, the exemplified diamine component may be contained in an amount of 50 mol% to 100%, more preferably 70 mol% to 100%. Within these ranges, heat resistance and durability in the process of forming a film are good, and heat resistance, surface smoothness and transparency of the resulting polyamideimide film are particularly improved.

The molecular weight of the polyamideimide resin used is a molecular weight corresponding to 0.3 to 2.5 cm ³ / g in N-methyl-2-pyrrolidone (polymer concentration 0.5 g / cm ³ ) in terms of logarithmic viscosity at 30 ° C. And more preferably those having a molecular weight corresponding to 0.5 to 2.0 cm ³ / g. When the logarithmic viscosity is 0.3 cm ³ / g or more, mechanical properties are sufficient when formed into a molded product such as a film. On the other hand, if it is 2.0 cm ³ / g or less, the solution viscosity does not become too high and the molding process becomes easy.

(3) Polyetherimide The polyetherimide used in the present invention is a thermoplastic resin containing an aromatic nucleus bond and an imide bond in its structural unit, and is not particularly limited. Specifically, the following formula ( 8) or a polyetherimide having a repeating unit having a structure represented by the following formula (9).

Polyetherimides having a repeating unit having the structure represented by the above formula (8) are trade names “Ultem 1000” (glass transition temperature: 216 ° C.) and “Ultem 1010” (glass transition temperature: 216) manufactured by General Electric. ° C), polyetherimide having a repeating unit having the structure represented by the above formula (9) includes “Ultem CRS5001” (glass transition temperature Tg 226 ° C.), and other specific examples are manufactured by Mitsui Chemicals, Inc. Trade name “Aurum PL500AM” (glass transition temperature 258 ° C.).

The method for producing the polyetherimide is not particularly limited. Usually, the amorphous polyetherimide having the structure represented by the above formula (8) is 4,4 ′-[isopropylidenebis (p -Phenyleneoxy)] diphthalic acid dianhydride and m-phenylenediamine as a polycondensate, and polyetherimide having the structure represented by the above structural formula (9) is 4,4 ′-[isopropylidenebis (P-phenyleneoxy)] diphthalic dianhydride and p-phenylenediamine are synthesized by a known method.

Further, the polyetherimide may contain other copolymerizable monomer units such as an amide group, an ester group, and a sulfonyl group within the range not exceeding the gist of the present invention. In addition, polyetherimide can be used individually by 1 type or in combination of 2 or more types.

(4) Polyesterimide It is preferable that resin which has an imide structure used for this invention contains the polyesterimide structure represented by Formula (10) in a structural unit.

(In formula (10), R ₁ represents a divalent group having a specific structure. R ₂ represents a divalent chain aliphatic group, a divalent cycloaliphatic group or a divalent aromatic group. To express.)
In Formula (10), R ₁ represents a divalent group having a structure represented by Formula (11), Formula (12), or Formula (13), respectively.

(Divalent group having a structure represented by the formula (11))

In formula (11), each R represents a divalent chain aliphatic group, cycloaliphatic group or aromatic group, and a plurality of R may be the same or different from each other. . These chain aliphatic groups, cycloaliphatic groups or aromatic groups can be used alone or in combination of two or more.

M is a positive integer of 1 or more, preferably 2 or more, more preferably 3 or more, and still more preferably 4 or more. Moreover, although the upper limit of m is not specifically limited, Preferably it is 25 or less, More preferably, it is 20 or less, More preferably, it is 10 or less. When it exceeds 25, the heat resistance tends to decrease.

The chain aliphatic group, cycloaliphatic group or aromatic group is “chain aliphatic compound having a divalent hydroxy group”, “cycloaliphatic compound having a divalent hydroxy group” or “2 A residue derived from a diol such as an “aromatic compound having a valent hydroxy group” is desirable. Further, it may be a residue derived from “polycarbonate diol” which can be polymerized from the diol and carbonates or phosgene.

As the “chain aliphatic compound having a divalent hydroxy group”, a branched or linear diol having two hydroxy groups can be used. For example, alkylene diol, polyoxyalkylene diol, polyester diol, polycaprolactone diol and the like can be mentioned. Examples of branched or linear diols having two hydroxy groups that can be used as the “chain aliphatic compound having a divalent hydroxy group” are listed below.

Examples of the alkylene diol include ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanediol, 1,4- And cyclohexanedimethanol.

Examples of the polyoxyalkylene diol include dimethylolpropionic acid (2,2-bis (hydroxymethyl) propionic acid), dimethylolbutanoic acid (2,2-bis (hydroxymethyl) butanoic acid), polyethylene glycol, polypropylene glycol, Examples include polytetramethylene glycol, polyoxytetramethylene glycol, and a random copolymer of tetramethylene glycol and neopentyl glycol. Polyoxytetramethylene glycol is preferable.

Examples of the polyester diol include polyester diols obtained by reacting polyhydric alcohols and polybasic acids exemplified below.

Any “polyhydric alcohol” can be used as the “polyhydric alcohol component” used in the polyester diol. For example, ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5 -Pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanemethanol, Neopentylhydroxypiparic acid ester, ethylene oxide adduct and propylene oxide adduct of bisphenol A, ethylene oxide adduct and propylene oxide adduct of water-added bisphenol A, 1,9-nonanediol, 2-methyloctanediol , 1,10-dodecane diol, 2-butyl-2-ethyl-1,3-propanediol, tricyclodecane methanol, polyethylene glycol, polypropylene glycol, polyether polyol such as polytetramethylene glycol or the like can be used.

As the “polybasic acid component” used in the polyester diol, any of various polybasic acids can be used. For example, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, 4,4'-diphenyldicarboxylic acid, 2,2'-diphenyldicarboxylic acid, 4,4'-diphenylether dicarboxylic acid Acids, adipic acid, sebacic acid, azelaic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dimer acid, etc. Aliphatic and alicyclic dibasic acids can be used.

Specific examples of the commercially available polyester diol include ODX-688 (aliphatic polyester diol manufactured by DIC Corporation: adipic acid / neopentyl glycol / 1,6-hexanediol, number average molecular weight of about 2000), Vylon (registered). (Trademark) 220 (polyester diol manufactured by Toyobo Co., Ltd., number average molecular weight of about 2000).

Examples of polycaprolactone diol include polycaprolactone diol obtained by ring-opening addition reaction of lactones such as γ-butyllactone, ε-caprolactone, and δ-valerolactone.

The above-mentioned “chain aliphatic compound having a divalent hydroxy group” can be used alone or in combination of two or more.

“Cycloaliphatic compound having a divalent hydroxy group” or “aromatic compound having a divalent hydroxy group” includes “a compound having two hydroxy groups in an aromatic ring or cyclohexane ring”, “two "Compounds in which phenol or alicyclic alcohol is bonded with a divalent functional group", "Compounds having one hydroxy group in both nuclei of the biphenyl structure", "Compounds having two hydroxy groups in the naphthalene skeleton", etc. Is used.

Examples of the “compound having two hydroxy groups in the aromatic ring or cyclohexane ring” include hydroquinone, 2-methylhydroquinone, resorcinol, catechol, 2-phenylhydroquinone, cyclohexanedimethanol, tricyclodecanemethanol, 1,4-dihydroxycyclohexane, , 3-dihydroxycyclohexane, 1,2-dihydroxycyclohexane, 1,3-adamantanediol, dicyclopentadiene dihydrate, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxy Carboxy group-containing diols such as benzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and 3,5-dihydroxybenzoic acid can be used.

Examples of “two phenols” or “a compound in which an alicyclic alcohol is bonded with a divalent functional group” include 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, 4, 4 '-(9-fluorenylidene) diphenol, 4,4'-dihydroxydicyclohexyl ether, 4,4'-dihydroxydicyclohexyl sulfone, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, and the like can be used.

Examples of “compound having one hydroxy group in both nuclei of biphenyl structure” include 4,4′-biphenol, 3,4′-biphenol, 2,2′-biphenol, 3,3 ′, 5. 5,5'-tetramethyl-4,4'-biphenol and the like can be used.

As examples of “compounds having two hydroxy groups in the naphthalene skeleton”, 2,6-naphthalenediol, 1,4-naphthalenediol, 1,5-naphthalenediol, 1,8-naphthalenediol, and the like can be used.

The number average molecular weight of the diol is preferably 100 or more and 30000 or less, more preferably 150 or more and 20000 or less, and further preferably 200 or more and 10,000 or less. When the number average molecular weight is less than 100, low hygroscopicity and flexibility cannot be sufficiently exhibited.

On the other hand, if it is greater than 30000, depending on the composition and structure of the “diol” and the composition and structure of the diamine component (or isocyanate component), which will be described later, phase separation may occur and the mechanical properties and colorless transparency may not be fully exhibited. .

The polycarbonate diol may be a polycarbonate diol having a plurality of types of alkylene groups as described above in the skeleton (copolymerized polycarbonate diol). For example, a combination of 2-methyl-1,8-octanediol and 1,9-nonanediol, a combination of 3-methyl-1,5-pentanediol and 1,6-hexanediol, 1,5-pentanediol and 1 , 6-hexanediol, and the like can be synthesized as a copolymerized polycarbonate diol. A copolymer polycarbonate diol that can be synthesized from a combination of 2-methyl-1,8-octanediol and 1,9-nonanediol is preferable. Two or more of these polycarbonate diols can be used in combination.

Commercially available products of polycarbonate diol include Kuraray Kuraray Polyol C Series, Asahi Kasei Chemicals Duranol Series, etc. For example, Kuraray polyol C-1015N, Kuraray polyol C-1065N (Kuraray Co., Ltd. carbonate diol: 2-methyl-1,8-octanediol / 1,9-nonanediol, number average molecular weight about 1000), Kuraray polyol C -2015N, Kuraray polyol C2065N (Kuraray Co., Ltd. carbonate diol: 2-methyl-1,8-octanediol / 1,9-nonanediol, number average molecular weight about 2000), Kuraray polyol C-1050, Kuraray polyol C- 1090 (Carbonate diol manufactured by Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1,6-hexanediol, number average molecular weight of about 1000), Kuraray polyol C-2050, Kuraray polyol C-2090 (Corporation) Kuraray carbonate diol: 3 Methyl-1,5-pentanediol / 1,6-hexanediol, number-average molecular weight of about 2000), Duranol T5650E (polycarbonate diol manufactured by Asahi Kasei Chemicals Corporation: 1,5-pentanediol / 1,6-hexanediol, number Average molecular weight of about 500), Duranol T5651 (Asahi Kasei Chemicals Co., Ltd. polycarbonate diol: 1,5-pentanediol / 1,6-hexanediol, number average molecular weight of about 1000), Duranol T5652 (Asahi Kasei Chemicals Co., Ltd. polycarbonate diol) : 1,5-pentanediol / 1,6-hexanediol, number average molecular weight of about 2000). Preferably, Kuraray polyol C-1015N is used.

Examples of the method for producing the polycarbonate diol include transesterification between the raw diol and carbonates, and dehydrochlorination reaction between the raw diol and phosgene. Examples of the carbonic acid ester as a raw material include dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; diaryl carbonates such as diphenyl carbonate; and alkylene carbonates such as ethylene carbonate and propylene carbonate.

(Divalent group having a structure represented by the formula (12))
A divalent group having a structure represented by the formula (12) will be described.

In the formula (12), R ₃ is a direct bond, an alkylene group (—C _n H _2n —), a perfluoroalkylene group (—C _n F _2n —), an ether bond (—O—), an ester bond (—COO—). ), Carbonyl group (—CO—), sulfonyl group (—S (═O) ₂ —), sulfinyl group (—SO—), sulfenyl group (—S—), carbonate group (—OCOO—), or fluorenylidene Represents a group. n is a positive integer of 1 or more. The upper limit of n is not particularly limited, but is preferably 10 or less, more preferably 5 or less, and still more preferably 3 or less. X ₁ to X ₈ may be the same or different and each represents a hydrogen, halogen or alkyl group.

Specific examples of the divalent group having a structure represented by the formula (12) are not particularly limited, but include diphenyl ether skeleton, diphenyl sulfone skeleton, 9-fluorenylidene diphenol skeleton, bisphenol A skeleton, bisphenol F skeleton, Examples thereof include an ethylene oxide adduct skeleton of bisphenol A, a propylene oxide adduct skeleton of bisphenol A, a biphenyl skeleton, and a naphthalene skeleton.

The skeleton is preferably a residue derived from a compound having one hydroxy group on each of the benzene rings in the formula (12). Examples of the raw material for the divalent group having the structure represented by the formula (12) include 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, 4,4 ′-(9-fluorenylidene) diphenol, Bisphenol A, bisphenol F, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, 4,4'-biphenol, 3,4'-biphenol, 2,2'-biphenol, 3,3 ', 5 5'-tetramethyl-4,4'-biphenol, 2,6-naphthalenediol, 1,4-naphthalenediol, 1,5-naphthalenediol, 1,8-naphthalenediol, and the like can be used.

Preferably, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, 4,4 ′-(9-fluorenylidene) diphenol or bisphenol A ethylene oxide adduct is preferred. More preferably, 4,4′-dihydroxydiphenyl ether or ethylene oxide adduct of bisphenol A is used.

These compounds can be used alone or in combination of two or more. By using these raw materials, the diphenyl ether skeleton or the like can be introduced into the R ₁ position of the formula (10).

(Divalent group having a structure represented by the formula (13))

In the formula (13), R ₄ represents a direct bond, an alkylene group (—C _n H _2n —), a perfluoroalkylene group (—C _n F _2n —), an ether bond (—O—), an ester bond (—COO—). ), Carbonyl group (—CO—), sulfonyl group (—S (═O) ₂ —), sulfinyl group (—SO—), sulfenyl group (—S—), carbonate group (—OCOO—), or fluorenylidene Represents a group. n is a positive integer of 1 or more. The upper limit of n is not particularly limited, but is preferably 10 or less, more preferably 5 or less, and still more preferably 3 or less. X ₁ ′ to X ₈ ′ may be the same or different and each represents a hydrogen, halogen or alkyl group.

Specific examples of the divalent group having the structure represented by the formula (13) are not particularly limited, but include a dicyclohexyl ether skeleton, a dicyclohexyl sulfone skeleton, a hydrogenated bisphenol A skeleton, a hydrogenated bisphenol F skeleton, and a hydrogenated bisphenol A. And the propylene oxide adduct skeleton of hydrogenated bisphenol A.

The skeleton is preferably a residue derived from a compound having one hydroxy group on each of the cyclohexane rings of the formula (13). Examples of the raw material for the divalent group having the structure represented by the formula (13) include 4,4′-dihydroxydicyclohexyl ether, 4,4′-dihydroxydicyclohexylsulfone, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated An ethylene oxide adduct of bisphenol A or a propylene oxide adduct of hydrogenated bisphenol A can be used.

Preferably, 4,4′-dihydroxydicyclohexyl ether or 4,4′-dihydroxydicyclohexyl sulfone is used.

These compounds can be used alone or in combination of two or more. By using these raw materials, the dicyclohexyl ether skeleton or the like can be introduced at the R ₁ position of the formula (10).

As an example of the structure of formula (10), a halide of cyclohexanetricarboxylic anhydride and a diol are reacted to obtain an ester group-containing tetracarboxylic dianhydride, and then the ester group-containing tetracarboxylic acid. It can be obtained by condensation reaction (polyimidation) of dianhydride and diamine or diisocyanate.

(Divalent group having a structure represented by formula (14))
The polyesterimide resin may further contain a structure represented by the formula (14) in the structural unit.

R _{2 in} Formula (10) and R ₂ ′ in Formula (14) will be described. R ₂ and R ₂ ′ are not particularly limited as long as they are each independently a divalent chain aliphatic group, a divalent cycloaliphatic group, or a divalent aromatic group. These “divalent chain aliphatic group”, “divalent cycloaliphatic group”, and “divalent aromatic group” can be used alone or in combination of two or more.

Preferably, R ₂ is a divalent group having a structure represented by the following formula (15), and R ₂ ′ is a divalent group having a structure represented by the following formula (16).

(Divalent group having a structure represented by the formula (15))
R ₂ in the formula (10) is preferably a divalent group having a structure represented by the formula (15) from the balance of heat resistance, flexibility, low hygroscopicity, and the like.

In formula (15), R ₅ represents a direct bond, an alkylene group (—C _n H _2n —), a perfluoroalkylene group (—C _n F _2n —), an ether bond (—O—), an ester bond (—COO—). ), A carbonyl group (—CO—), a sulfonyl group (—S (═O) ₂ —), a sulfinyl group (—SO—) or a sulfenyl group (—S—). n is preferably a positive integer of 1 to 10, more preferably 1 to 5, and still more preferably 1 to 3. X ₉ to X ₁₆ may be the same or different and each represents a hydrogen, halogen or alkyl group.

(Divalent group having a structure represented by the formula (16))
R ₂ ′ in the formula (14) is preferably a divalent group having a structure represented by the formula (16) from the viewpoint of heat resistance, flexibility, low hygroscopic balance, and the like.

In the formula (16), R ₅ ′ is a direct bond, an alkylene group (—C _n H _2n —), a perfluoroalkylene group (—C _n F _2n —), an ether bond (—O—), an ester bond (—COO -), A carbonyl group (—CO—), a sulfonyl group (—S (═O) ₂ —), a sulfinyl group (—SO—) or a sulfenyl group (—S—). n is preferably a positive integer of 1 to 10, more preferably 1 to 5, and still more preferably 1 to 3. X ₉ ′ to X ₁₆ ′ may be the same or different and each represents a hydrogen, halogen or alkyl group.

In the formula (10) and the formula (14), “a divalent chain aliphatic group”, “a divalent cyclic aliphatic group”, or “a divalent aromatic group” is represented by the R ₂ position of the formula (10) And a corresponding diamine component or diisocyanate component is preferably used for introduction into the R ₂ ′ position of the formula (14). That is, “aromatic diamine or the corresponding aromatic diisocyanate”, “cycloaliphatic diamine or the corresponding cycloaliphatic diisocyanate”, “chain aliphatic diamine or the corresponding chain aliphatic diisocyanate” are appropriately used. By selecting, a polyesterimide resin excellent in heat resistance, flexibility and low hygroscopicity can be obtained.

The diamine component of R _{2 of} formula (10) and R ₂ ′ of formula (14) or the corresponding diisocyanate component may be the same or different. If based on the preferable manufacturing method mentioned later, it is preferable that it is the same.

A diamine component having R ₂ and R ₂ ′ as a basic skeleton or a corresponding diisocyanate component will be described.

Specific examples of the “aromatic diamine or the corresponding aromatic diisocyanate” include 2,2′-bis (trifluoromethyl) benzidine, p-phenylenediamine, m-phenylenediamine, , 4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, 4,4'-diaminodiphenylmethane, 4,4'-methylenebis (2-methylaniline), 4, 4'-methylenebis (2-ethylaniline), 4,4'-methylenebis (2,6-dimethylaniline), 4,4'-methylenebis (2,6-diethylaniline), 4,4'-diaminodiphenyl ether, 3 , 4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4 -Diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenyl sulfide, 3,3 '-Diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminobenzanilide, P-xylenediamine, m-xylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2,7-naphthalenediamine, benzidine, 3,3'-dihydroxybenzidine, 3,3'-dimethoxybenzidine, 3,3'-dimethyl-4,4 ' -Diaminobiphenyl, 3,3'-diethyl -4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4 ' -Diaminobiphenyl, 3,3'-diethoxy-4,4'-diaminobiphenyl, o-tolidine, m-tolidine, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) ) Benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4 -Aminophenoxy) phenyl) sulfone, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl Phenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, diaminoterphenyl and the like. These can be used in combination of two or more.

Examples of the “cycloaliphatic diamine or the corresponding cycloaliphatic diisocyanate” include trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-diamino, as diamine compounds. Cyclohexane (trans / cis mixture), 1,3-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine) (trans isomer, cis isomer, trans / cis mixture), isophorone diamine, 1
, 4-cyclohexanebis (methylamine), 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 3, 8-bis (aminomethyl) tricyclo [5.2.1.0] decane, 1,3-diaminoadamantane, 4,4'-methylenebis (2-methylcyclohexylamine), 4,4'-methylenebis (2-ethyl) Cyclohexylamine), 4,4'-methylenebis (2,6-dimethylcyclohexylamine), 4,4'-methylenebis (2,6-diethylcyclohexylamine), 2,2-bis (4-aminocyclohexyl) propane, , 2-bis (4-aminocyclohexyl) hexafluoropropane and the like. These can be used in combination of two or more.

Examples of the “chain aliphatic diamine or the corresponding chain aliphatic diisocyanate” include 1,3-propanediamine, 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1, Examples include 6-hexamethylene diamine, 1,7-heptamethylene diamine, 1,8-octamethylene diamine, and 1,9-nonamethylene diamine. These can be used in combination of two or more.

In view of the balance of heat resistance, flexibility, low hygroscopicity, and the like, R ₂ in formula (10) and R ₂ ′ in formula (14) or a preferred diisocyanate component corresponding thereto are exemplified as diamine compounds. Then, p-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 1,5-naphthalenediamine, o-tolidine, diaminoterphenyl, 4,4'- It is a residue derived from methylenebis (cyclohexylamine), isophoronediamine or the like. More preferred are 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 1,5-naphthalenediamine, o-tolidine, and further preferred is 4,4′-diaminodiphenylmethane, 4,4 ′. -Diaminodiphenyl ether, o-tolidine. Most preferred is a residue derived from 4,4'-diaminodiphenylmethane, o-tolidine.

The polyimide according to the present invention preferably contains a fluorinated polyimide from the viewpoint of excellent transparency of the polyimide film and easy thermal correction by thermal shrinkage. The fluorine content is more preferably in the range of 1 to 40% by mass in the film because the effect of the present invention is great.

<Physical properties of polyimide film>
(Total light transmittance)
The polyimide film of the present invention is preferably a transparent polyimide film, and as a measure of transparency, the total light transmittance when a sample having a thickness of 55 μm is prepared is preferably 80% or more. It is more preferably 85% or more, and still more preferably 90% or more. A higher total light transmittance is preferable because transparency increases. The description of the numerical value that the total light transmittance is 80% or more shows the preferable range.

The total light transmittance of the polyimide film can be measured according to JIS K 7375-2008 for one polyimide film sample conditioned for 24 hours in an air-conditioned room at 23 ° C. and 55% RH. For the measurement, the transmittance in the visible light region (range of 400 to 700 nm) can be measured using a spectrophotometer U-3300 manufactured by Hitachi High-Technologies Corporation.

全 To make the total light transmittance 80% or more, it can be adjusted by selecting the type of polyimide.

(Yellow index value (YI value))
The polyimide film of the present invention is preferably a colorless polyimide film. As a guideline for being colorless, the yellow index value (YI value) is preferably 4.0 or less. More preferably, it is in the range of 0.3 to 2.0, and particularly preferably in the range of 0.3 to 1.6. A smaller yellow index value (YI value) is preferable because coloring is less. The description of the numerical value that the yellow index value (YI value) is 4.0 or less indicates the preferable range.

The YI value can be adjusted by selecting the type of polyimide.

The yellow index value can be obtained according to the YI (yellow index: yellowness index) of the film defined in JIS K 7103.

The yellow index value is measured by preparing a film sample and using a spectrophotometer U-3300 manufactured by Hitachi High-Technologies Corporation and the attached saturation calculation program, etc., as a light source specified in JIS Z 8701. The tristimulus values X, Y and Z of the color are obtained, and the yellow index value is obtained according to the definition of the following formula.

Yellow index value (YI value) = 100 (1.28X-1.06Z) / Y
(solubility)
The polyimide according to the present invention has a limit amount (solubility) that can be dissolved in 100 g of dimethylacetamide or 100 g of γ-butyrolactone at 60 ° C. is 1 g or more. The solubility may be 1 g or more with respect to either 100 g of dimethylacetamide or 100 g of γ-butyrolactone. If the solubility is 1 g or more, it can be easily produced by the solution casting method. Higher solubility is preferred because it facilitates production by the solution casting method. The description of the numerical value that the solubility is 1 g or more shows an indication of a preferable range as the soluble polyimide.

The solubility of the polyimide according to the present invention can be adjusted by selecting the type of polyimide used in the present invention.

In order to make polyimides soluble, it is effective to reduce the ratio of the structure of imide groups and aromatic hydrocarbons that work in the direction of increasing the planarity of the molecular skeleton of polyimide. It is also effective to introduce structural isomers, bending groups, aliphatic groups or alicyclic groups instead of aromatic groups, and bulky skeletons such as fluorine atoms and fluorenes.

Examples of compounds include alicyclic, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4, 5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, (bicyclo [4.2.0] octane -3,4,7,8-tetracarboxylic dianhydride) bicyclo [2.2.1] heptanedimethanamine, the structure having a bending group is 2,3 ', 3,4'-biphenyltetracarboxylic Acid dianhydride, 3,4'-oxydiphthalic anhydride, 4,4 'oxydiphthalic anhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4 ′ -Difeni Sulfonetetracarboxylic dianhydride, 2,2-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane dianhydride, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2- Bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) ) Benzene, bis (3-aminophenyl) sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminodiphenyl ether.

The compounds containing fluorine atoms include 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, 2,2'-bis (trifluoromethyl) benzidine, 2,2-bis (3-amino- 4-Hydroxyphenyl) hexafluoropropane and compounds containing a fluorene group include 9,9-bis (4-amino-3-fluorophenyl) fluorene, 9,9-bis [4- (3,4-dicarboxyl). Phenoxy) -phenyl] fluorene anhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -phenyl] fluorene anhydride, 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride Things.

(Haze value)
In this invention, about the polyimide film of the roll body after heat processing, it is preferable from a viewpoint that the transparency of a polyimide film is high that a haze value is 4% or less.

The haze can be measured according to JIS K 7136 using a haze meter NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). Measured under the conditions of 23 ° C. and 55% RH, the light source of the haze meter is a halogen bulb of 5V9W, and the light receiving part is a silicon photocell (with a relative visibility filter).

(Haze value variation in surface direction (standard deviation))
In this invention, about the polyimide film of the roll body after heat processing, the variation in the surface direction of a haze value is small, and the standard deviation is 1 or less. More preferably, it is 0.6 or less.

The standard deviation (σ) is the square root of the variance σ ² with respect to the average value of the measured values.

The average value is calculated by the following equation (where x _i is each measured value and n is the number of measurement points).

The variance σ ² is calculated by the following formula.

For measurement of the standard deviation of the haze value in the surface direction, a polyimide film of a roll body having a width of 1000 to 1900 mm is used. The above haze value is measured at five points at 100 mm intervals in the width direction of the roll body. This is performed for three rolls, and haze is measured for a total of 150 to 285 points.

The standard deviation of haze values of a total of 150 to 285 points can be calculated to obtain the haze value variation (standard deviation) in the surface method.

<Inorganic fine particles>
The polyimide film of the present invention is mixed with inorganic fine particles.

The slip ratio is improved when the mixing ratio of the inorganic fine particles into the polyimide film is 0.01% by mass or more. Therefore, the flatness deterioration in the long-winding polyimide film hardly occurs. Moreover, there exists an effect which prevents the haze increase of a polyimide film by setting it as 2.0 mass% or less.

As the inorganic fine particles, the following inorganic compound fine particles are preferably used. Examples of fine particles of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. Etc. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

The average primary particle size of the fine particles is preferably in the range of 5 to 400 nm, and more preferably in the range of 10 to 300 nm. These may be mainly contained as secondary aggregates having a particle size in the range of 0.05 to 0.3 μm. If the particles have an average particle size in the range of 80 to 400 nm, the primary particles are not aggregated. It is also preferable that it is contained.

It is preferable that the average particle size of the primary particles of the inorganic fine particles is small from the viewpoint of less variation in the haze value in the surface direction, which is an effect of the present invention. The average particle size of the primary particles is preferably 30 nm or less, and more preferably 10 nm or less.

In addition, it is preferable that the surface of the inorganic fine particles is modified and that the surface is more hydrophobic from the viewpoint of less variation in the haze value in the plane direction, which is an effect of the present invention.

For hydrophobic treatment of inorganic fine particles, as a surface modifier, methyl (trimethoxy) silane, ethyl (trimethoxy) silane, hexyl (trimethoxy) silane, decyl (trimethoxy) silane, vinyl (trimethoxy) silane, 2-[(3, 4) -Epoxycyclohexyl] ethyl (trimethoxy) silane, 3-glycidoxypropyl (trimethoxy) silane, 3-methacryloxypropyl (trimethoxy) silane, 3-acryloxypropyl (trimethoxy) silane, dimethylsilyl, alkylsilane, trimethylsilyl , Silicone oil, dodecylbenzenesulfonic acid and the like.

For example, as having an epoxy group, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidyloxypropyl (dimethoxy) methylsilane, 3-glycidyloxypropyltrimethoxysilane, diethoxy (3-glycol Illustrative examples include (sidioxypropyl) methylsilane.

Further, as silane coupling agents having an amino group, 3- (2-aminoethylamino) propyldimethoxymethylsilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propyl Triethoxysilane, 3- (3-aminopropylamino) propyltriethoxysilane, 3- (3-aminopropylamino) propyltrimethoxysilane, 3-aminopropyldiethoxymethylsilane, 3-aminopropyltriethoxysilane, 3 -Aminopropyltrimethoxysilane and the like are exemplified.

Examples of the trifunctional alkoxysilane include 2-[(3,4) -epoxycyclohexyl] ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and the like. Can be used alone or in combination of two or more.

Trifunctional alkoxysilane can be synthesized according to a known method. Commercially available products include “KBM-303” (manufactured by Shin-Etsu Chemical Co., Ltd.) as 2-[(3,4) -epoxycyclohexyl] ethyltrimethoxysilane, and “KBM-” as 3-glycidoxypropyltriethoxysilane. 403 "(manufactured by Shin-Etsu Chemical Co., Ltd.) is preferably used.

Examples of the surface treating agent having an amino group include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl)- 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3- (2-aminoethylamino) propyldimethoxymethylsilane, 3- (2-aminoethylamino) propyltri Methoxysilane, 3- (2-aminoethylamino) propyltriethoxysilane, 3- (3-aminopropylamino) propyltriethoxysilane, 3- (3-aminopropylamino) propyltrimethoxysilane, 3-aminopropyldi Ethoxymethylsilane, 3-aminopropy Triethoxysilane, 3-aminopropyltrimethoxysilane, O-phosphorylethanolamine fluorine-containing alkoxysilane is triethoxyfluorosilane, triethoxytrifluoromethylsilane, 1,1,2,2-tetrahydroperfluorohexyltriethoxysilane, triethoxy -3,3,4,4,5,5,6,6,6-nonafluorohexylsilane, triethoxy [4- (trifluoromethyl) phenyl] silane, and triethoxy (3,3,4,4,5, 5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl) silane.

The content of these fine particles in the polyimide film is more preferably in the range of 0.01 to 1% by mass, and particularly preferably in the range of 0.05 to 0.5% by mass.

In the case of a polyimide film having a multilayer structure formed by a co-casting method, it is preferable to contain fine particles of this addition amount on the surface.

Silicon dioxide fine particles are commercially available, for example, under the trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (Nippon Aerosil Co., Ltd.). it can.

Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

Examples of resin fine particles include silicone resin, fluororesin and acrylic resin. Silicone resins are preferred, and those having a three-dimensional network structure are particularly preferred. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (above Momentive Performance Materials Japan Joint) It is commercially available under the trade name (made by company) and can be used.

Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the haze of the polyimide film low.

<Other additives>
(UV absorber)
The polyimide film of the present invention preferably contains an ultraviolet absorber from the viewpoint of improving light resistance. The ultraviolet absorber is intended to improve light resistance by absorbing ultraviolet rays of 400 nm or less, and the transmittance at a wavelength of 370 nm is preferably in the range of 0.1 to 30%, more preferably. Is in the range of 1-20%, more preferably in the range of 2-10%.

The UV absorbers preferably used in the present invention are benzotriazole UV absorbers, benzophenone UV absorbers, and triazine UV absorbers, and particularly preferably benzotriazole UV absorbers and benzophenone UV absorbers.

For example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6- (linear and side Chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc., and tinuvin 109, tinuvin 171, tinuvin 234, tinuvin 326, tinuvin 327, tinuvin 328, There are tinuvins such as tinuvin 928, and these are all commercial products manufactured by BASF Japan Ltd. and can be preferably used. Of these, halogen-free ones are preferred.

In addition, a discotic compound such as a compound having a 1,3,5-triazine ring is also preferably used as the ultraviolet absorber.

The polyimide film of the present invention preferably contains two or more ultraviolet absorbers.

Also, as the ultraviolet absorber, a polymeric ultraviolet absorber can be preferably used, and in particular, a polymer type ultraviolet absorber described in JP-A-6-148430 is preferably used. Moreover, it is preferable that the ultraviolet absorber does not have a halogen group.

The method of adding the UV absorber is to add the UV absorber to the dope after dissolving the UV absorber in an alcohol such as methanol, ethanol or butanol, an organic solvent such as dichloromethane, methyl acetate, acetone or dioxolane, or a mixed solvent thereof, or You may add directly in dope composition.

The amount of the UV absorber used is not uniform depending on the type of UV absorber, the operating conditions, etc., but when the polyimide film has a dry film thickness of 15 to 50 μm, it is 0.5 to 10% by mass relative to the polyimide film. The range is preferably 0.6 to 4% by mass.

(Antioxidant)
Antioxidants are also referred to as deterioration inhibitors. When an electronic device or the like is placed in a high humidity and high temperature state, the polyimide film may be deteriorated.

Since the antioxidant has a role of delaying or preventing the polyimide film from being decomposed by, for example, the residual solvent amount of halogen in the polyimide film or phosphoric acid of the phosphoric acid plasticizer, the polyimide film of the present invention is used. It is preferable to make it contain in.

As such an antioxidant, the compounds described in paragraph numbers 0108 to 0119 of JP 2010-271619 A can be preferably used.

The amount of these compounds added is preferably in the range of 1 ppm to 1.0% by mass relative to the polyimide film, and more preferably in the range of 10 to 1000 ppm.

(Phase difference control agent)
In order to improve the display quality of image display devices such as liquid crystal display devices, a retardation control agent is added to the polyimide film, or an alignment film is formed to provide a liquid crystal layer. By compounding the phase difference, an optical compensation ability can be imparted to the polyimide film.

Examples of the retardation control agent include aromatic compounds having two or more aromatic rings as described in European Patent No. 91656A2, and rod-shaped compounds described in JP-A-2006-2025. Two or more aromatic compounds may be used in combination. The aromatic ring of the aromatic compound is preferably an aromatic heterocyclic ring including an aromatic heterocyclic ring in addition to the aromatic hydrocarbon ring. The aromatic heterocycle is generally an unsaturated heterocycle. Of these, the 1,3,5-triazine ring described in JP-A-2006-2026 is preferable.

The addition amount of these retardation control agents is preferably in the range of 0.5 to 20% by mass, and preferably in the range of 1 to 10% by mass with respect to 100% by mass of the polyimide film resin. More preferred.

(Peeling accelerator)
A peeling accelerator may be added to the polyimide film of the present invention in order to improve the peelability during film production.

As additives for reducing the peeling resistance of the polyimide film, many surfactants have a remarkable effect, and preferred release agents include phosphate ester type surfactants, carboxylic acid or carboxylate type surfactants, A sulfonic acid or sulfonate surfactant and a sulfate ester surfactant are effective. A fluorine-based surfactant in which part of the hydrogen atoms bonded to the hydrocarbon chain of the surfactant is substituted with fluorine atoms is also effective. Examples of the release agent are given below.
RZ-1 C ₈ H ₁₇ O—P (═O) — (OH) ₂
RZ-2 C ₁₂ H ₂₅ O—P (═O) — (OK) ₂
RZ-3 C ₁₂ H ₂₅ OCH ₂ CH ₂ O—P (═O) — (OK) ₂
RZ-4 C ₁₅ H ₃₁ (OCH ₂ CH ₂ ) ₅ O—P (═O) — (OK) _{2
RZ-5 {C 12 H 25} O (CH 2 CH 2 O) 5} 2 -P (= O) -OH
RZ-6 {C ₁₈ H ₃₅ (OCH ₂ CH ₂ ) ₈ O} ₂ —P (═O) —ONH ₄
RZ-7 (tC ₄ H ₉ ) ₃ —C ₆ H ₂ —OCH ₂ CH ₂ O—P (═O) — (OK) ₂ RZ-8 (iso-C ₉ H ₁₉ —C ₆ H ₄ — O— (CH ₂ CH ₂ O) ₅ —P (═O) — (OK) (OH)
RZ-9 C ₁₂ H ₂₅ SO ₃ Na
RZ-10 C ₁₂ H ₂₅ OSO ₃ Na
RZ-11 C ₁₇ H ₃₃ COOH
RZ-12 C ₁₇ H ₃₃ COOH · N (CH ₂ CH ₂ OH) ₃
RZ-13 iso-C ₈ H ₁₇ —C ₆ H ₄ —O— (CH ₂ CH ₂ O) ₃ — (CH ₂ ) ₂ SO ₃ Na
_{RZ-14 (iso-C 9} H 19) 2 -C 6 H 3 -O- (CH 2 CH 2 O) 3 - (CH 2) 4 SO 3 Na
RZ-15 sodium triisopropyl naphthalene sulfonate RZ-16 sodium tri-t-butyl naphthalene sulfonate RZ-17 C ₁₇ H ₃₃ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ Na
RZ-18 C ₁₂ H ₂₅ -C ₆ H ₄ SO ₃ .NH ₄
The addition amount of the peeling accelerator is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass, and most preferably 0.1 to 0.5% by mass with respect to the polyimide.

<Manufacturing method of polyimide film>
The specific example of the manufacturing method of the said polyimide film is demonstrated below.

The method for producing a polyimide film of the present invention includes a step of preparing a mixture containing the soluble polyimide and the inorganic fine particles (mixture preparation step), and a step of preparing a dope containing the mixture, the polyimide and a solvent (dope). Preparation step), a step of casting the dope on a support to form a film (casting step), a step of evaporating the solvent from the cast film on the support (solvent evaporation step), and the support of the membrane. And a drying step of drying the peeled film.

As a manufacturing method of the polyimide film of the present invention, a step of preparing a mixture containing the soluble polyimide and the inorganic fine particles (mixture preparation step), a step of preparing a dope containing the mixture, the polyimide and a solvent ( A dope preparation step), a step of casting the dope on a support to form a membrane (casting step), a step of peeling the membrane from the support (peeling step), and drying the obtained cast membrane Step of obtaining a film (first drying step), step of stretching the dried film (stretching step), step of further drying the stretched film (second drying step), step of winding up the obtained polyimide film It is more preferable to include a step (winding step) and, if necessary, a step of heating the film to imidize it (heating step).

Hereinafter, each process will be described in detail.

(Mixture preparation process)
The mixture preparation step according to the present invention is a step of preparing a mixture containing soluble polyimide and inorganic fine particles dissolved at least 1 g in 100 g of dimethylacetamide or 100 g of γ-butyrolactone at 60 ° C.

The mixture may be in any form as long as it contains soluble polyimide and inorganic fine particles, for example, a dope containing the soluble polyimide, inorganic fine particles and solvent. Alternatively, it is preferably a crushed product obtained by crushing a polyimide film containing the soluble polyimide and the inorganic fine particles. It is more preferable that the mixture is a crushed product obtained by crushing a polyimide film containing soluble polyimide and inorganic fine particles because the deviation of the haze value in the film thickness direction is smaller.

In the case where the mixture is a dope containing the soluble polyimide, the inorganic fine particles, and a solvent, by storing the dissolved dope in an environment of 60 ° C. or more for 2 hours or more, the haze variation in the film surface direction is It is more preferable because it becomes smaller.

<A crushed product obtained by crushing a polyimide film containing soluble polyimide and inorganic fine particles>
The mixture according to the present invention is preferably a crushed product obtained by crushing a polyimide film containing the soluble polyimide and the inorganic fine particles.

The crushed product is preferably contained in a mass ratio of 10 to 70% by mass with respect to the polyimide film. If it is 10% by mass or more, it is preferable from the viewpoint that the variation in the haze value in the surface direction is small, and if it is 70% by mass or less, it is preferable from the viewpoint of good transportability. Although the crushed product is good in resin and is good in terms of variation in haze, the effect of the inorganic fine particles is difficult to be produced and the transportability becomes less effective.

The crushed product is reused when the polyimide film is dried or at the final stage, scraping off both ends of the film roll, loss immediately after starting work or adjusting conditions, or web or film that did not become a product due to a sudden accident It is preferable to do.

When reusing these as a mixture, first, the film is crushed to a size of 0.5 to 40 mm, preferably 10 to 30 mm, with a crusher to obtain chips.

At this time, by removing the charge from the chip, it is possible to prevent the chip from sticking or clogging to the crusher, aggregating the chips, and sticking the chip to the wall surface.

¡Pulverized chips are transferred to a storage container by pneumatic transportation means such as a blower, temporarily stored in a storage container, and then the determined input amount is weighed with a measuring instrument and put into a dissolution tank.

In the dissolution tank, the dope is prepared by dissolving with heating and stirring together with new soluble polyimide and solvent. After the dissolution is completed, the solution is fed by a liquid feed pump, impurities are filtered by a filter, and gently stored in a stationary storage tank 13 for defoaming.

In the present invention, there is a method in which a crushed product is separately dissolved and charged as a returned material solution in addition to a method in which the crushed product is charged as chips into a dissolution tank.

(Dope preparation process)
The method for producing a polyimide film of the present invention comprises preparing a dope by dissolving a mixture containing the soluble polyimide and inorganic fine particles and a new soluble polyimide in a solvent, and using the dope, a solution casting film forming method It is preferable to form a film. More preferably, a dope is prepared by dissolving a mixture containing soluble polyimide and inorganic fine particles, new soluble polyimide and new inorganic fine particles in a solvent, and using the dope by a solution casting film forming method. Is to film.

As the solvent, it is preferable to use a low-boiling solvent having a boiling point of 80 ° C. or lower as the main solvent since the film production process temperature (particularly the drying temperature) can be reduced, and coloring and thermal shrinkage can be reduced. Here, “used as a main solvent” means that if it is a mixed solvent, 55% by mass or more is used with respect to the total amount of the solvent, preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably Is 90% by mass or more. Of course, if it is used alone, it becomes 100% by mass.

The low boiling point solvent only needs to dissolve polyimide and other additives at the same time. For example, as the chlorinated solvent, dichloromethane, as the non-chlorinated solvent, methyl acetate, ethyl acetate, amyl acetate, acetone, Methyl ethyl ketone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3- Difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2, 2,3,3,3-pentafluoro-1-propanol, nitroethane, methanol, ethanol, n-propanol, so- propanol, n- butanol, sec- butanol, tert- butanol and the like.

Among them, as the low boiling point solvent having a boiling point of 80 ° C. or less, among the above solvents, dichloromethane (40 ° C.), ethyl acetate (77 ° C.), methyl ethyl ketone (79 ° C.), tetrahydrofuran (66 ° C.), acetone (56.5 ° C.) And at least one selected from 1,3-dioxolane (75 ° C.) as a main solvent (the parentheses each represent a boiling point).

Moreover, as a solvent contained in the case of a mixed solvent, as long as it can dissolve the polyimide according to the present invention, it can be used within a range that does not hinder the effects of the present invention. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N-methylcaprolactam, hexamethylphosphoramide, tetramethylene Sulfone, dimethyl sulfoxide, m-cresol, phenol, p-chlorophenol, 2-chloro-4-hydroxytoluene, diglyme, triglyme, tetraglyme, dioxane, γ-butyrolactone, dioxolane, cyclopentanone, epsilon caprolactam, chloroform, etc. use Is a function, it may be used in combination of two or more thereof. In addition to these solvents, a poor solvent such as hexane, heptane, benzene, toluene, xylene, chlorobenzene, or o-dichlorobenzene is used to such an extent that the polyimide and the organic compound having a carbonyl group according to the present invention do not precipitate. May be.

Further, it is also preferable to use an alcohol solvent, and it is preferable that the alcohol solvent is selected from methanol, ethanol and butanol from the viewpoint of improving peelability and enabling high-speed casting. Of these, methanol or ethanol is preferably used. When the ratio of the alcohol in the dope increases, the web gels and peeling from the metal support becomes easy.

For dissolving polyimide and other additives, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, JP-A-9-95544, JP-A-9- Various dissolution methods can be used, such as a method using the cooling dissolution method described in JP-A-95557 or JP-A-9-95538, and a method using high pressure described in JP-A-11-21379.

The prepared dope is guided to a filter by a liquid feed pump or the like and filtered. For example, when the main solvent of the dope is dichloromethane, the gel-like foreign matter in the dope can be removed by filtering the dope at a temperature of boiling point at 1 atm of the dichloromethane + 5 ° C. or more. A preferred temperature range is 45 to 120 ° C, more preferably 45 to 70 ° C, and even more preferably within a range of 45 to 55 ° C.

Further, as a raw material for the resin used for preparing the dope, a material obtained by pelletizing polyimide and other compounds in advance can be preferably used.

(Casting film forming process)
The prepared dope is fed to a die through a feed pump (for example, a pressurized metering gear pump), and the flow on an endless support that moves indefinitely, for example, a stainless steel belt or a metal support such as a rotating metal drum. The dope is cast from the die at the extending position.

The metal support in casting is preferably a mirror-finished surface, and the support is preferably a metal support such as a stainless steel belt or a drum whose surface is plated with a casting. The cast width can be in the range of 1 to 4 m, preferably in the range of 1.5 to 3 m, more preferably in the range of 2 to 2.8 m. The support may not be made of metal, for example, polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polybutylene terephthalate (PBT) film, nylon 6 film, nylon 6,6 film, polypropylene film. A belt made of polytetrafluoroethylene or the like can be used. When using a polyimide as a flexible substrate, you may wind up a polyimide with the metal support body and the said film which cast the polyimide.

The traveling speed of the metal support is not particularly limited, but is usually 5 m / min or more, preferably 10 to 180 m / min, particularly preferably 80 to 150 m / min. As the traveling speed of the metal support increases, entrained gas is more likely to be generated, and the occurrence of film thickness unevenness due to disturbance is more pronounced.

The traveling speed of the metal support is the moving speed of the outer surface of the metal support.

The surface temperature of the metal support is preferable because the higher the temperature, the faster the casting film can be dried. However, if the surface temperature is too high, the casting film may foam or the flatness may deteriorate. It is preferably carried out within a temperature range of −50 to −10 ° C. with respect to the boiling point of the solvent to be used.

The die has a shape that becomes gradually narrower toward the discharge port in the vertical cross section with respect to the width direction. In general, the die usually has tapered surfaces on the downstream side and the upstream side in the lower traveling direction, and a discharge port is formed in a slit shape between the tapered surfaces. A die made of metal is preferably used, and specific examples include stainless steel, titanium, and the like. In the present invention, when manufacturing films having different thicknesses, it is not necessary to change to dies having different slit gaps.

As the die, it is preferable to use a pressure die which can adjust the slit shape of the die portion of the die and easily make the film thickness uniform. Examples of the pressure die include a coat hanger die and a T die, and any of them is preferably used. Even when films with different thicknesses are continuously manufactured, the discharge rate of the dies is maintained at a substantially constant value. Therefore, when a pressure die is used, conditions such as extrusion pressure and shear rate are also substantially reduced. Maintained at a constant value. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and laminated.

(Solvent evaporation process)
The solvent evaporation step is a pre-drying step which is performed on a metal support and the cast film is heated on the metal support to evaporate the solvent.

To evaporate the solvent, for example, a method of blowing heated air from the casting membrane side and the back side of the metal support by a dryer, a method of transferring heat from the back side of the metal support by a heating liquid, a method of transferring heat from the front and back by radiant heat Etc. A method of appropriately selecting and combining them is also preferable. The surface temperature of the metal support may be the same as a whole or may vary depending on the position. The temperature of the heating air is preferably in the range of 10 to 220 ° C.

The temperature of the heating air (drying temperature) is preferably 200 ° C. or lower, more preferably 140 ° C. or lower, and further preferably 120 ° C. or lower.

In the solvent evaporation step, it is preferable to dry the cast film until the residual solvent amount is in the range of 10 to 150% by mass from the viewpoint of the peelability of the cast film and the transportability after peeling.

In the present invention, the amount of residual solvent can be expressed by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Here, M is the mass at a predetermined point of the casting membrane (film), and N is the mass when M is dried at 200 ° C. for 3 hours. In particular, M when calculating the amount of residual solvent achieved in the solvent evaporation step is the mass of the cast film immediately before the peeling step.

(Peeling process)
The cast film from which the solvent has evaporated on the metal support is peeled off at the peeling position.

The peeling tension when peeling the metal support from the casting film is usually in the range of 60 to 400 N / m. However, if wrinkles are likely to occur during peeling, peeling is performed with a tension of 190 N / m or less. It is preferable.

In the present invention, the temperature at the peeling position on the metal support is preferably in the range of −50 to 60 ° C., more preferably in the range of 10 to 40 ° C., and in the range of 15 to 40 ° C. Is most preferred.

The peeled cast film (the cast film after peeling is also referred to as a film) may be sent directly to the stretching process or sent to the first drying process so as to achieve a desired residual solvent amount. May be sent to the stretching step. In the present invention, from the viewpoint of stable conveyance in the stretching step, it is preferable that the film is sequentially sent to the first drying step and the stretching step after the peeling step.

(First drying step)
The first drying step is a drying step in which the film is heated and the solvent is further evaporated. The drying means is not particularly limited, and for example, hot air, infrared rays, a heating roller, microwaves and the like can be used. From the viewpoint of simplicity, it is preferable to dry with hot air or the like while transporting the film with rollers arranged in a staggered manner. The drying temperature is preferably in the range of 30 to 200 ° C., taking into account the amount of residual solvent and the stretching ratio during conveyance.

The drying temperature is preferably 200 ° C. or lower, more preferably 140 ° C. or lower, and further preferably 120 ° C. or lower.

¡By reducing the drying temperature, the heat shrinkage rate of the film can be increased.

(Stretching process)
By stretching the film peeled from the metal support, the film thickness, flatness, orientation and the like of the film can be controlled.

In the film production method of the present invention, it is preferable to stretch in the longitudinal direction or the width direction.

The stretching operation may be performed in multiple stages. Moreover, when performing biaxial stretching, simultaneous biaxial stretching may be performed and you may implement in steps. In this case, stepwise means that, for example, stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any one of the stages. Is also possible.

Thus, for example, the following stretching steps are possible:
-Stretch in the longitudinal direction-> Stretch in the width direction-> Stretch in the longitudinal direction-> Stretch in the longitudinal direction-Stretch in the width direction-> Stretch in the width direction-> Stretch in the longitudinal direction-> Stretch in the longitudinal direction Includes stretching in one direction and contracting the other while relaxing the tension. A preferred stretching ratio can be in the range of x1.01 to x1.5 times in both the width direction and the longitudinal direction. Here, the draw ratio is (width or longitudinal length after stretching of film) / (width or longitudinal length before stretching of film).

The amount of residual solvent at the start of stretching is preferably in the range of 0.1 to 200% by mass.

If the amount of the residual solvent is 0.1% by mass or more, the effect of improving the flatness by stretching is obtained, and if it is 200% or less, stretching is easy.

In the method for producing a polyimide film of the present invention, the film may be stretched in the longitudinal direction or the lateral direction, preferably in the lateral direction so that the film thickness after stretching is in a desired range. The polyimide film is preferably stretched in a temperature range of (Tg−200) to (Tg + 100) ° C. with respect to the glass transition temperature (Tg). If it extends in the said temperature range, since a extending | stretching stress can be reduced, a haze will become low. Moreover, generation | occurrence | production of a fracture | rupture is suppressed and the polyimide film excellent in planarity and the coloring property of the polyimide film itself is obtained. The stretching temperature is more preferably in the range of (TgL−150) to (TgH + 50) ° C.

In the method for producing a polyimide film according to the present invention, the self-supporting film peeled from the support can be stretched in the longitudinal direction by regulating the running speed with a stretching roller.

In order to stretch the film in the width direction, for example, the entire width of the film is held with clips or pins in the width direction in the entire drying process or a part of the process as disclosed in JP-A-62-46625. A method of drying while drying (referred to as a tenter method), among which a tenter method using a clip is preferably used.

The film stretched in the longitudinal direction or the unstretched film is preferably introduced into the tenter in a state where both ends in the width direction are held by the clip, and stretched in the width direction while running with the tenter clip.

When stretching in the width direction, stretching in the width direction of the film at a stretching speed in the range of 50 to 1000% / min is preferable from the viewpoint of improving the flatness of the film.

If the stretching speed is 50% / min or more, the planarity is improved and the film can be processed at high speed, which is preferable from the viewpoint of production aptitude, and if it is within 1000% / min, the film is broken. Can be processed without any problem.

More preferable stretching speed is in the range of 100 to 500% / min. The stretching speed is defined by the following formula.

Stretching speed (% / min) = [(d ₁ / d ₂ ) −1] × 100 (%) / t
(In the above formula, d ₁ is the width dimension in the stretching direction of the resin film after stretching, d ₂ is the width dimension in the stretching direction of the resin film before stretching, and t is the time (min) required for stretching. .)
In the stretching step, usually, after stretching, holding and relaxation are performed. That is, in this step, it is preferable to perform a stretching step for stretching the film, a holding step for holding the film in a stretched state, and a relaxation step for relaxing the film in the stretched direction in this order. In the holding step, the drawing at the draw ratio achieved in the drawing step is held at the drawing temperature in the drawing step. In the relaxation stage, the stretching in the stretching stage is held in the holding stage, and then the stretching is relaxed by releasing the tension for stretching. The relaxation step may be performed at a temperature lower than the stretching temperature in the stretching step.

(Second drying step)
Next, the stretched film is heated and dried. In the case of heating the film with hot air or the like, a means for preventing the mixing of used hot air by installing a nozzle capable of exhausting used hot air (air containing solvent or wet air) is also preferably used. The hot air temperature is more preferably in the range of 40 to 350 ° C. The drying time is preferably about 5 seconds to 30 minutes, more preferably 10 seconds to 15 minutes.

Further, the heating and drying means is not limited to hot air, and for example, infrared rays, heating rollers, microwaves, etc. can be used. From the viewpoint of simplicity, it is preferable to dry with hot air or the like while transporting the film with rollers arranged in a staggered manner. The drying temperature is preferably in the range of 40 to 150 ° C. from the viewpoint of easy heating shrinkage. More preferably, it is 40 to 120 ° C.

In the second drying step, it is preferable to dry the film until the residual solvent amount is 0.5% by mass or less.

(Winding process)
A winding process is a process of winding up the obtained polyimide film and cooling to room temperature. The winding machine may be a commonly used one, and can be wound by a winding method such as a constant tension method, a constant torque method, a taper tension method, a program tension control method with a constant internal stress, or the like.

The thickness of the polyimide film is not particularly limited, and is preferably in the range of 1 to 200 μm, particularly 1 to 100 μm, for example.

In the winding process, both ends of the polyimide film sandwiched between tenter clips when stretched and conveyed may be slit. The slit polyimide film end is preferably cut into a width of 1 to 30 mm, then dissolved in a solvent and reused as a recycled material.

Each process from the solvent evaporation process to the winding process described above may be performed in an air atmosphere or an inert gas atmosphere such as nitrogen gas. Moreover, each process, especially a drying process and a extending process, are performed in consideration of the explosion limit concentration of the solvent in the atmosphere.

(Heating process)
After the winding step, a heating step is further performed to further heat-treat the polyimide film dried in the second drying step in order to improve imidization in the polymer chain molecules and between the polymer chain molecules to improve mechanical properties. Also good.

In addition, the said 2nd drying process may serve as a heating process.

The heating means is performed using a known means such as hot air, an electric heater, or a microwave. As the electric heater, the above-described infrared heater can be used.

In the heating step, when the polyimide film is heated rapidly, problems such as an increase in surface defects occur, and therefore it is preferable to select a heating method as appropriate. The heating step is preferably performed in a low oxygen atmosphere.

When the heating temperature in the second drying step and the heating step exceeds 450 ° C., the energy required for heating becomes very large, resulting in an increase in manufacturing cost and an increase in environmental load. The following is preferable.

In addition, after the winding process, before or after the heating process, a process of slitting the width direction end of the polyimide film, or a process of neutralizing the polyimide film if charged, etc. It is also good.

<Shape of polyimide film>
The polyimide film of the present invention is preferably long, specifically, preferably has a length in the range of about 100 to 10,000 m, and is wound up in a roll shape. The width of the polyimide film of the present invention is preferably 1 m or more, more preferably 1.4 m or more, and particularly preferably 1.4 to 4 m.

<Application>
The polyimide film of the present invention can be used as a transparent film of an image display device. In particular, it can be preferably applied to a flexible image display device. The device to be applied is not particularly limited, and examples thereof include an organic electroluminescence (EL) image display device, a liquid crystal image display device (LCD), an organic photoelectric conversion device, a touch panel, a polarizing plate, and a retardation film. . From the viewpoint that the effect of the present invention can be obtained more efficiently, it is preferably used for a flexible television receiver such as an organic electroluminescence (EL) image display device and a liquid crystal image display device (LCD), and a front member for flexible display.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

[Example 1]
The structures of the compounds used in the examples are listed below.

Acid anhydride A: Bicyclo [4.2.0] octane-3,4,7,8-tetracarboxylic dianhydride diamine compound B: 2,2'-dimethylbiphenyl-4,4'-diamine The commercial source of the compound is as follows.
Acid anhydride 1: Daikin Industries, Ltd. Acid anhydride 2: Manac Corporation, Acid anhydride 3: Daicel Diamine Co., Ltd. 1: Daikin Industries, Ltd. Diamine 2: Mitsui Chemicals Fine, Inc. Diamine 6: Wakayama Seika Co., Ltd. Diamine Compound B: Showa Chemical Co., Ltd. <Preparation of polyimide film 101A (polyimide film for mixture)>
(Preparation of polyimide solution A)
In a four-necked flask equipped with a dry nitrogen gas introduction tube, a condenser, a Dean-Stark agglomerator filled with toluene, and a stirrer, 17.87 g (57.6 mmol) of the acid anhydride 2 (manac) was added. , N-dimethylacetamide (134 g) and stirred at room temperature under a nitrogen stream.

Then, 11.53 g (60 mmol) of the diamine 2 (manufactured by Mitsui Chemical Fine Co., Ltd.) was added, and the mixture was heated and stirred at 80 ° C. for 6 hours. Thereafter, the external temperature was heated to 190 ° C., and water generated along with imidization was distilled off azeotropically with toluene. When heating, refluxing, and stirring were continued for 6 hours, generation of water was not observed. Subsequently, the mixture was heated for 7 hours while distilling off toluene, and after methanol was distilled off, methanol was added for reprecipitation, and the solid content was dried and converted into an 8% by mass dichloromethane solution to prepare polyimide solution A containing polyimide resin A. did.

(Preparation of main dope for crushed product production)
A main dope for producing a crushed product having the following composition was prepared. First, dichloromethane (boiling point 40 ° C.) was added to the pressure dissolution tank. The prepared polyimide solution A and the remaining components were charged into a pressure dissolution tank containing a solvent while stirring. While this was heated and stirred, it was completely dissolved, and this was dissolved in Azumi Filter Paper No. Filtration was performed using 244 to prepare a main dope for producing a crushed product.

(Composition of main dope for crushed product production)
Dichloromethane 30 parts by mass Polyimide solution A 100 parts by mass Inorganic fine particles (Aerosil R972V, manufactured by Nippon Aerosil Co., Ltd.)
0.04 parts by mass (casting process)
Next, using an endless belt casting apparatus, the dope was cast uniformly on a stainless steel belt support at a temperature of 30 ° C. and a width of 1500 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

(Peeling process)
On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 180 N / m.

(Stretching process)
The peeled film was stretched 1.40 times in the width direction using a clip type tenter while applying heat at 120 ° C. at a stretching rate of 100% / min. The residual solvent amount at the start of stretching was 8% by mass.

(Drying process)
The stretched film was dried at a drying temperature of 120 ° C. until the residual solvent amount was less than 0.5% by mass with a transport tension of 100 N / m and a drying time of 15 minutes, to obtain a polyimide film having a dry film thickness of 51 μm. The obtained polyimide film was wound up to obtain a polyimide film 101A for a mixture.

<Preparation of polyimide films 102A to 108A and 110A (mixing polyimide film)>
In the production of the mixing polyimide film 101A, except that the acid anhydride used, the type of diamine, and the mass mixing ratio of the inorganic fine particles were changed as shown in Table 2, as in the mixing polyimide film 101A, Mixing polyimide films 102A to 108A and 110A were prepared. In the production of the mixing polyimide films 101A to 108A and 110A, the acid anhydride and diamine used as raw materials for the used polyimide film are the compounds described in Table 1, and each has the same molar amount as the mixing polyimide film 101A. Using.

Each of the above mixing polyimide films was prepared in the form of a long film having a width of 1900 mm and a length of 8000 m.

<Production of roll bodies 101A to 108A and 110A>
Winding roll bodies of the above-mentioned mixing polyimide films 101A to 110A (width 1900 mm, length 8000 m) were produced under the following winding conditions to obtain roll bodies 101A to 108A and 110A.

(Winding condition)
Touch roller: diameter 120mm, length 2600mm
Touch roller material: NBR rubber (Maywa Rubber Industrial Co., Ltd.) White Elecon Hardness 35 degrees, thickness 10 mm, CFRP (Carbon Fiber Reinforced Plastics) core Touch roller pressure: 50 N / m
Winding tension: Initial tension 250N / m taper 90% corner 25%
Winding speed: 100 m / min
Winding shaft diameter: 15.24 cm
Winding shaft material: FRP (Fiber Reinforced Plastics)
(Production of crushed products)
Films were collected from both widthwise ends of the roll bodies 101A to 108A and 110A, and crushed into chips of 10 to 30 mm by a crusher to obtain chips, which were crushed products 101A to 108A and 110A, respectively.

<Preparation of polyimide film 101>
(Preparation of polyimide solution A)
In a four-necked flask equipped with a dry nitrogen gas introduction tube, a condenser, a Dean-Stark agglomerator filled with toluene, and a stirrer, 17.87 g (57.6 mmol) of the acid anhydride 2 (manac) was added. , N-dimethylacetamide (134 g) and stirred at room temperature under a nitrogen stream.

Then, 11.53 g (60 mmol) of the diamine 2 (manufactured by Mitsui Chemical Fine Co., Ltd.) was added, and the mixture was heated and stirred at 80 ° C. for 6 hours. Thereafter, the external temperature was heated to 190 ° C., and water generated along with imidization was distilled off azeotropically with toluene. When heating, refluxing, and stirring were continued for 6 hours, generation of water was not observed. Subsequently, the mixture was heated for 7 hours while distilling off toluene, and after methanol was distilled off, methanol was added for reprecipitation, and the solid content was dried and converted into an 8% by mass dichloromethane solution to prepare polyimide solution A containing polyimide resin A. did.

(Preparation of dope)
A main dope having the following composition was prepared. First, dichloromethane (boiling point 40 ° C.) was added to the pressure dissolution tank. The prepared polyimide solution A and the remaining components were charged into a pressure dissolution tank containing a solvent while stirring. While this was heated and stirred, it was completely dissolved, and this was dissolved in Azumi Filter Paper No. The main dope was prepared by filtration using 244.

(Main dope composition)
Dichloromethane 30 parts by mass Polyimide solution A 100 parts by mass Inorganic fine particles (Aerosil R972V, manufactured by Nippon Aerosil Co., Ltd.)
0.04 part by mass This main dope was designated as main dope 101. The crushed product 101A was added to the main dope 101 so that the mixed substance amount ratio was 5% by mass, and mixed and dissolved again.

In addition, it was used for mixing with respect to the sum total of the mass (X) of the polyimide resin in the main dope 101 used for mixing, and the mass (Y) of the polyimide resin in the crushed product 101A used for mixing. The ratio of the mass (Y) of the polyimide resin in the crushed product 101A is expressed in mass%.

(Casting process)
Next, using an endless belt casting apparatus, the dope was cast uniformly on a stainless steel belt support at a temperature of 30 ° C. and a width of 1500 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

(Peeling process)
On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 180 N / m.

(Stretching process)
The peeled film was stretched 1.40 times in the width direction using a clip type tenter while applying heat at 120 ° C. at a stretching rate of 100% / min. The residual solvent amount at the start of stretching was 8% by mass.

(Drying process)
The stretched film was dried at a drying temperature of 120 ° C. until the residual solvent amount was less than 0.5% by mass with a transport tension of 100 N / m and a drying time of 15 minutes, to obtain a polyimide film having a dry film thickness of 51 μm. The obtained polyimide film was wound up to obtain a polyimide film 101.

<Preparation of polyimide films 102-110>
In the production of the polyimide film 101, the same as the polyimide film 101 for mixing except that the acid anhydride, the type of diamine, the mass ratio of the inorganic fine particles, and the mixed substance amount ratio were changed as shown in Table 2. Polyimide films 102 to 110 were produced. In the production of the polyimide films 101 to 110, the acid anhydride and diamine used as raw materials for the polyimide film used are the compounds described in Table 1, and the same molar amount as that of the polyimide film 101 was used.

Each of the above polyimide films was prepared in the form of a long film having a width of 1900 mm and a length of 8000 m.

<Production of roll bodies 101 to 110>
Winding roll bodies of the polyimide films 101 to 110 (width 1900 mm, length 8000 m) were produced under the following winding conditions to obtain roll bodies 101 to 110.

(Winding condition)
Touch roller: diameter 120mm, length 2600mm
Touch roller material: NBR rubber (Maywa Rubber Industrial Co., Ltd.) White Elecon Hardness 35 degrees, thickness 10 mm, CFRP (Carbon Fiber Reinforced Plastics) core Touch roller pressure: 50 N / m
Winding tension: Initial tension 250N / m taper 90% corner 25%
Winding speed: 100 m / min
Winding shaft diameter: 15.24 cm
Winding shaft material: FRP (Fiber Reinforced Plastics)
(solubility)
Each polyimide used for production of the polyimide film was dissolved in 100 g of dimethylacetamide at 60 ° C., and the upper limit at which the polyimide film could be dissolved was measured.

(Haze)
About the polyimide film of each roll body, haze (all haze) was measured with the haze meter NDH 2000 (made by Nippon Denshoku Industries Co., Ltd.) based on JISK7136, and the following references | standards evaluated. The light source of the haze meter was a 5V9W halogen sphere, and the light receiving part was a silicon photocell (with a relative visibility filter). The haze was measured under the conditions of 23 ° C. and 55% RH.

(Fluctuation of haze value in surface direction (standard deviation))
A polyimide film of each roll body having a width of 1900 mm was used. The above haze values were measured at five points at 10 mm intervals in the width direction of the roll body. This was performed for three rolls, and haze was measured for a total of 285 points.

The standard deviation of haze values at 285 points was calculated, and the variation (standard deviation) in haze values in the surface direction was measured. After measuring the standard deviation, the variation was evaluated according to the following evaluation criteria.

◎: Standard deviation of haze value in surface direction is less than 0.3 ○: Standard deviation of haze value in surface direction is 0.3 or more and less than 0.6 ×: Standard deviation of haze value in surface direction is 0.6 or more ( Transportability)
About the polyimide film of each roll body, the conveyance property was evaluated as follows.

When transporting at a feed tension of 100 N / m and a winding tension of 150 N / m, the amount of meandering in 10 minutes was evaluated at a location where the roll contact surface (mirror surface) had a width of 2 m and a roll span of 50 cm.

A: Meandering amount 3 mm or less (pass)
○: The meandering amount is larger than 3 mm and the meandering amount is 5 mm or less (pass).
X: The meandering amount is larger than 5 mm (failed)
Table 2 shows the composition of each polyimide film and the evaluation results of the transportability and the haze value variation (standard deviation) in the surface direction.

As shown in Table 2, it can be seen that the polyimide film of the present invention obtained a polyimide film having good transportability and small haze value variation (standard deviation) in the surface direction.

[Example 2]
The polyimide film 101 and the polyimide film 109 of Example 1 were evaluated for bending resistance as follows.

(Bending resistance)
The produced polyimide film was subjected to a bending resistance test (sliding bending test) using a bending fatigue tester specified in JIS C5016. It should be noted that, under the conditions of a bending radius of 2.5 mm, a bending speed of 2000 times / min, and a bending stroke of 25 mm, the wiring formed on the outer side in the bending direction is repeatedly bent in one direction so that the wiring forming surface becomes the outer side during bending. The number of bendings (number of bending resistances) that led to disconnection was determined.

：: More than 5000 times ○: More than 1000 times and less than 5000 times ×: Less than 1000 times Table 3 shows the evaluation results of bending resistance.

As shown in Table 3, it can be seen that bending resistance is improved in the polyimide film of the present invention.

[Example 3]
In the preparation of the main dope in the preparation of the polyimide film 101 of Example 1, the polyimide film 101 and the polyimide film 101 except that the following mixing dope 301A was added instead of the crushed product 101A so as to have a mixed substance amount ratio shown in Table 4 A similar polyimide film 301 was produced.

(Adjustment of mixing dope 301A)
(Preparation of polyimide solution 301A)
In a four-necked flask equipped with a dry nitrogen gas introduction tube, a condenser, a Dean-Stark agglomerator filled with toluene, and a stirrer, 17.87 g (57.6 mmol) of the acid anhydride 2 (manac) was added. , N-dimethylacetamide (134 g) and stirred at room temperature under a nitrogen stream.

Then, 11.53 g (60 mmol) of the diamine 2 (manufactured by Mitsui Chemical Fine Co., Ltd.) was added, and the mixture was heated and stirred at 80 ° C. for 6 hours. Thereafter, the external temperature was heated to 190 ° C., and water generated along with imidization was distilled off azeotropically with toluene. When heating, refluxing, and stirring were continued for 6 hours, generation of water was not observed. Subsequently, the mixture was heated for 7 hours while distilling off toluene, and after methanol was distilled off, methanol was added for reprecipitation, and the solid content was dried and converted into an 8% by mass dichloromethane solution to prepare polyimide solution A containing polyimide resin A. did.

(Preparation of mixing dope 301A)
A main dope having the following composition was prepared. First, dichloromethane (boiling point 40 ° C.) was added to the pressure dissolution tank. The prepared polyimide solution A and the remaining components were charged into a pressure dissolution tank containing a solvent while stirring. While this was heated and stirred, it was completely dissolved, and this was dissolved in Azumi Filter Paper No. The main dope was prepared by filtration using 244.

(Composition of dope 301A for mixing)
Dichloromethane 30 parts by weight Polyimide solution A 0.3 part by weight Inorganic fine particles (Aerosil R972V, manufactured by Nippon Aerosil Co., Ltd.)
0.03 parts by mass As for the polyimide film 301 produced in this way and the polyimide film 101 and the polyimide film 109 produced in Example 1, as in Example 1, the transportability and the variation in the surface direction (standard deviation) ) Was evaluated.

The results are shown in Table 4.

As shown in Table 4, it can be seen that the effects of the present invention are obtained even when the dope for mixing is used.

Also, it can be seen that a polyimide film using a crushed product is more effective.

[Example 4]
Instead of the inorganic fine particles (Aerosil R972V, manufactured by Nippon Aerosil Co., Ltd.) used in the production of the polyimide film 101 of Example 1, the type of inorganic fine particles (produced by Nippon Aerosil Co., Ltd.) was changed as shown in Table 5. Except for the above, polyimide films 401 to 405 similar to the polyimide film 101 were produced in the same manner as in Example 1.

For the polyimide film 101 and the polyimide films 401 to 405, the haze value variation (standard deviation) in the transportability and surface method was measured in the same manner as in Example 1.

The results are shown in Table 5.

As shown in Table 5, it can be seen that the modified inorganic fine particles have a greater effect of the present invention. It can also be seen that the effect of the present invention is greater when the average primary particle size of the inorganic fine particles is smaller.

The method for producing a polyimide film of the present invention can provide a polyimide film having good transportability and less haze variation in the surface direction of the film, and therefore the polyimide film is used for flexible displays ranging from small to large. It is suitable as a member.

Claims (5)

1. A method for producing a polyimide film containing at least 1 g of polyimide dissolved in 100 g of dimethylacetamide or 100 g of γ-butyrolactone at 60 ° C. and inorganic fine particles,
   Preparing a mixture containing the polyimide and the inorganic fine particles,
   Preparing a dope containing the mixture, the polyimide and a solvent;
   Casting the dope on a support to form a film;
   Peeling the membrane from the support; and
   The manufacturing method of the polyimide film characterized by including the drying process which dries the peeled film | membrane.
2. The method for producing a polyimide film according to claim 1, wherein the mixture is a crushed product obtained by crushing a polyimide film containing the polyimide and the inorganic fine particles.
3. The method for producing a polyimide film according to claim 1, wherein the mixture is a dope containing the polyimide, the inorganic fine particles, and a solvent.
4. The method for producing a polyimide film according to any one of claims 1 to 3, wherein the mixture is contained at a mass ratio of 10 to 70 mass% with respect to the polyimide film to be produced. .
5. Containing 60 g of polyimide dissolved in 1 g or more per 100 g of dimethylacetamide or 100 g of γ-butyllactone and inorganic fine particles;
   A polyimide film having a standard deviation of a haze value in a plane direction of 1 or less.