TWI748180B - Polymer blend composition and polymer film - Google Patents

Abstract

The subject of the present invention is to provide a polymer blend composition and polymer film excellent in flatness, bending resistance, and colorless transparency. The solution is that the polymer blend composition of the present invention is a polymer blend composition containing two or more types of polyimine, which is characterized in that: the polyimide has electron withdrawing properties on the side chain The acyclic group, or at least any one of those having a ring, -CO-, -SO ₂ -or -CR- (R represents a 茀 skeleton) in the main chain; and, the aforementioned two or more polyimides The difference between the maximum weight average molecular weight and the minimum weight average molecular weight of is in the range of 20,000 to 200,000.

Description

Polymer blend composition and polymer film

The present invention relates to a polymer blend composition and a polymer film, and particularly relates to a polymer blend composition with excellent flatness, bending resistance, and colorless transparency.

Traditionally, glass has been used as a base material for various display members such as solar cells and displays. However, glass has the shortcomings of being fragile and bulky, and in recent years the display has become thinner, lighter, or more flexible, and its material is not enough to cope with it. Therefore, as a transparent member of a flexible device that replaces glass, a polyimide film has been studied (for example, refer to Patent Documents 1 and 2).

Fully aromatic polyimide, based on the viewpoints of physical/chemical heat resistance, electrical insulation, mechanical properties, flame retardancy, and ease of manufacturing steps, is currently the most important high-heat-resistant insulating resin material in the electronics field. However, the existing wholly aromatic polyimide film will interact due to the charge transfer interaction derived from the interaction of the electron precursor (derived from the aromatic group of the diamine) and the electron acceptor (bisimide structural unit). It is obviously colored, not suitable as a substitute for glass.

Furthermore, the polyimide film is generally formed by coating a varnish containing a polyimide precursor or polyimide acid and a solvent on the support, and the solvent is removed from the coated varnish, and then the imidization is completed. Manufactured by the method. To obtain a transparent polyimide film, it is more advantageous to use polyimide that is soluble in polar solvents, and to coat the varnish containing it on the support and then dry it without undergoing imidization. Method of forming polyimide film. However, the dehydration reaction during the synthesis of the polyimide used in the latter preparation method will seriously affect the water content in the reaction system. Therefore, the molecular weight (Mw) will vary with the synthesis environment, which has become a serious problem. . As soon as the molecular weight changes, the viscosity of the coating becomes unstable. As a result, the production stability decreases and it is impossible to obtain a transparent polyimide film. In addition, Patent Document 3 discloses a technique of mixing two or more components of polyimide in the former production method. The purpose is to control irregular crystallinity by mixing and improve mechanical properties or adhesion, but its It is a system with a structure with high colorability, and cannot maintain the colorless and transparency of the polyimide film. Just like the above-mentioned transparent substrates used in flexible devices, it is required to maintain colorless transparency, while improving productivity by stabilizing the viscosity of the coating, and having excellent flatness and high flexibility on the surface of the film. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Specification of US Patent No. 8207256 [Patent Document 2] JP 2008-163309 A [Patent Document 3] JP 2009-215548 A

[The problem to be solved by the invention]

The present invention was completed in view of the above-mentioned problems and the problem to be solved is to provide a polymer blend composition and a polymer film that are excellent in flatness, bending resistance, and colorless transparency. [Means to solve the problem]

In order to solve the above-mentioned problems, the inventors of this case discovered during the process of investigating the causes of the above-mentioned problems that two or more types of polyimines are included, and the polyimines have specific substituents, and that the two or more The difference in the weight average molecular weight of the polyimide is within a specific range, and it is possible to provide a polymer blend composition excellent in flatness, bending resistance, and colorless transparency, etc., and finally completed the present invention. That is, the above-mentioned problems of the present invention can be solved by the following means: 1. A polymer blend composition, which is a polymer blend composition containing two or more types of polyimine, characterized by: the polyimide Imine is: at least any one of acyclic groups having electron withdrawing properties on the side chain, or having a ring, -CO-, -SO ₂ -or -CR- (R represents a 茀 skeleton) on the main chain ; And, the difference between the maximum weight average molecular weight and the minimum weight average molecular weight of the two or more polyimides mentioned above is in the range of 20,000 to 200,000.

2. The polymer blend composition according to item 1, wherein the weight average molecular weight of the aforementioned two or more polyimides is in the range of 100,000 to 500,000.

3. The polymer blend composition of item 1 or 2, wherein the difference between the maximum weight average molecular weight and the minimum weight average molecular weight of the two or more polyimides mentioned above is in the range of 50,000 to 150,000.

4. The polymer blend composition according to any one of items 1 to 3, wherein the aforementioned polyimide has an acyclic group having electron withdrawing properties in the side chain.

5. A polymer film, which is a polymer film containing the polymer blend composition according to any one of items 1 to 4, characterized by: Its yellow index value is 5.0 or less.

6. For the polymer film of item 5, its haze is less than 1%. [Effects of the invention]

According to the above-mentioned means of the present invention, it is possible to provide a polymer blend composition and a polymer film having excellent flatness, bending resistance, and colorless transparency. The exhibiting mechanism or action mechanism of the effect of the present invention is still unclear, but it can be inferred as follows. In the research to improve the bending flexibility (bending resistance) of the film, the mechanism of the film's cracks is investigated. When the film surface has unevenness, the stress will be concentrated on the concave part when the film is bent, and the starting point will be generated there. crack. Therefore, it is determined that improving the flatness of the film surface will help improve the bending properties (bending resistance). Based on this hypothesis, the inventors of the present case have devoted themselves to conducting research to improve the flatness of the film surface by mixing polyimides of different molecular weights, thereby solving the aforementioned problem of bending resistance. It is inferred that the reason may be that in general, the smaller the surface area of a substance, the more stable it becomes, and it becomes a state with a smaller surface area, that is, a state with higher flatness. It is presumed that the reason for this is that the force that makes this possible stable state increases due to the increase in entropy due to the addition of different molecular weight components, resulting in an environment where the resin in the film is more likely to form a more stable state. Furthermore, by mixing different molecular weight components, the variation of paint viscosity between batches can be suppressed, and as a result, it is also helpful to improve productivity.

[The form of implementing the invention]

The polymer blend composition of the present invention is a polymer blend composition containing two or more types of polyimine, which is characterized in that the polyimine has an acyclic group with electron withdrawing side chain, Or the main chain has at least any one of a ring, -CO-, -SO ₂ -or -CR- (R represents a 茀 skeleton); and, the maximum weight average molecular weight and the minimum weight of the aforementioned two or more polyimides The difference in average molecular weight is in the range of 20,000 to 200,000. This feature is common or corresponds to the technical feature of each embodiment described below.

Regarding the implementation aspect of the present invention, the weight average molecular weight of the aforementioned two or more polyimides is preferably in the range of 100,000 to 500,000 in terms of good film formation and good handling. In addition, in terms of the effect of easily obtaining flatness, the difference between the maximum weight average molecular weight and the minimum weight average molecular weight of the two or more polyimides described above is preferably in the range of 50,000 to 150,000.

In terms of excellent colorlessness and transparency, the aforementioned polyimine preferably has an acyclic group with electron withdrawing properties in the side chain.

The polymer film of the present invention is a polymer film containing the aforementioned polymer blend composition. In terms of colorlessness and transparency, the yellow index value is preferably 5.0 or less, and the haze is preferably 1% or less.

Hereinafter, the present invention, its constituent elements, and the forms and aspects for implementing the present invention will be described. In addition, in this case, "~" is used to include the numerical value described before and after it as the lower limit and the upper limit.

[Polymer blending composition] The polymer blending composition of the present invention is a polymer blending composition containing two or more kinds of polyimine, and is characterized in that: the polyimine is on the side chain An acyclic group with electron withdrawing properties, or at least one of a ring, -CO-, -SO ₂ -, or -CR- (R represents a 茀 frame) in the main chain; and, one of the above two or more The difference between the maximum weight average molecular weight and the minimum weight average molecular weight of polyimide is in the range of 20,000 to 200,000. In particular, it is preferable that the aforementioned polyimine has an acyclic group with electron withdrawing properties in the side chain.

[1] Polyimine The polymer blend composition system of the present invention contains two or more types of polyimine. In the present invention, "2 species" refers to either or both of the chemical structure or molecular weight is different; specifically, it refers to a combination of the same chemical structure and different molecular weight, and a combination of different chemical structure and different molecular weight . In addition, the polyimide of the present invention has an acyclic group with electron withdrawing properties in the side chain, or a ring in the main chain, -CO-, -SO ₂ -or -CR- (R represents a 茀 frame) At least any one is a feature. In the present invention, the "main chain" refers to the longest and linearly bonded part. "Side chain" refers to a molecular chain branched from the main chain, meaning the part outside the main chain.

The aforementioned acyclic group with electron withdrawing property includes, for example, a cyano group, a trifluoromethyl group, a halogen atom, a substituted carbonyl group, a substituted sulfonyl group, and a substituted benzene substituted by an oxyboron group. Ring, carbazole ring, dibenzofuran ring, azadibenzofuran ring, dibenzothiophene dioxide ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline ring , Isoquinoline ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, phenanthridine ring, phenanthroline ring, azacarbazole ring, diazacarbazole ring, two Oxidation of benzofuran ring, dibenzosilole ring, azadibenzofuran ring, diazadibenzofuran ring, dibenzoborole ring, dibenzophosphorene ring Material ring, carboline ring, etc. In addition, it may be formed by connecting two or more of the same or different substituents. Among the above-mentioned substituents, trifluoromethyl is preferred.

Examples of the aforementioned ring include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, norbornyl, decahydronaphthalene, adamantyl, cyclohexenyl, and the like.

The aforementioned acyclic group having electron withdrawing properties in the side chain, or having _{at least any one of a ring, -CO-, -SO 2} -or -CR- (R represents a 茀 skeleton) in the main chain, according to the present invention Examples of the imines include polyimines A to K shown below.

It is characterized in that the difference between the maximum weight average molecular weight and the minimum weight average molecular weight of the aforementioned two or more polyimides is within the range of 20,000 to 200,000. In terms of the effect of easily obtaining flatness, it is preferably in the range of 50,000 to 150,000. In addition, the weight average molecular weight of the aforementioned two or more polyimides is preferably in the range of 100,000 to 500,000 in terms of excellent film formation and good handling.

In the present invention, the weight average molecular weight (Mw) is a value calculated in terms of polystyrene measured by gel permeation chromatography (GPC).

Regarding the mixing ratio of the aforementioned two or more types of polyimines, for example, when two types of polyimines are used, the polyimines having a larger weight average molecular weight are preferably mixed by 50% by mass or more, and more preferably by 70% by mass or more.

The polyimine of the present invention is a transparent heat-resistant resin (also called polyimine resin) having an amide structure, and is a transparent heat-resistant resin in which the repeating unit contains an imine bond. The polyimide of the present invention is preferably formed from a diamine or its derivative and an acid anhydride or its derivative.

(1.1) Polyimide having the structure represented by the general formula (1.1) (1.1.1) The structure of the acid anhydride side The polyimine that can be used in the present invention is particularly preferably a polyimide having a repeating unit represented by the following general formula (1.1):

In the general formula (1.1), R is an aromatic hydrocarbon ring or an aromatic heterocyclic ring, or a tetravalent aliphatic hydrocarbon group having 4 to 39 carbon atoms or an alicyclic hydrocarbon group (ring). Φ is a divalent aliphatic hydrocarbon group with a carbon number of 2 to 39, an alicyclic hydrocarbon group (ring), an aromatic hydrocarbon group, or a group composed of a combination of these; as a bonding group, it may contain a group selected from -O- , -SO ₂ -, _{-CO-, -CH 2} -, -C(CH ₃ ) ₂ -, -OSi(CH ₃ ) ₂ -, -C ₂ H ₄ O- and -S- at least A group.

The aromatic hydrocarbon ring represented by R includes, for example, a pyrene ring, a benzene ring, a biphenyl ring, a naphthalene ring, a azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a pyrene ring, a fused tetraphenyl ring, a terphenyl ring, Ortho-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthylene ring, pyrene ring, fluoranthene ring, fused tetraphenyl ring, fused pentaphenyl ring, perylene ring, pentophene ring, pyrene ring, pyrene ring, pyrene ring Ring, ananthrene ring, etc.

Also, similarly, the aromatic heterocyclic ring represented by R includes, for example, 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, and a triazine ring. Ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring , Phthalazine ring, thienothiophene ring, carbazole ring, azacarbazole ring (representing any one or more of the carbon atoms constituting the carbazole ring substituted by a nitrogen atom), dibenzosilole ring, dibenzofuran Ring, dibenzothiophene ring, ring in which any one or more carbon atoms constituting benzothiophene ring or dibenzofuran ring is replaced by nitrogen atom, benzodifuran ring, benzodithiophene ring, acridine ring, benzene Quinoline ring, phenazine ring, phenanthrene ring, toluidine ring, phenanthroline ring, cycloazine ring, quinoline ring, tepenizine ring, quinindoline ring, triphenyl dithiazine ring, triphenyl dioxane Pyrazine ring, phenanthrazine ring, anthracene azine ring, pyridine ring, naphthofuran ring, naphthothiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring , Anthracene dithiophene ring, thianthracene ring, phenoxathi ring, dibenzocarbazole ring, indolocarbazole ring, dithiphenacene ring, etc.

The tetravalent aliphatic hydrocarbon group with 4 to 39 carbon atoms represented by R includes, for example, butane-1,1,4,4-tetrayl, octane-1,1,8,8-tetrayl, and decane- Groups such as 1,1,10,10-tetrakis.

In addition, the tetravalent alicyclic hydrocarbon group having 4 to 39 carbon atoms represented by R includes, for example, cyclobutane-1,2,3,4-tetrayl, cyclopentane-1,2,4,5-tetra Cyclohexane-1,2,4,5-tetrayl, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetrayl, bicyclo[2.2,2]octane-2 ,3,5,6-tetrayl, 3,3',4,4'-dicyclohexyltetrayl, 3,6-dimethylcyclohexane-1,2,4,5-tetrayl, 3, 6-Diphenylcyclohexane-1,2,4,5-tetrayl and other groups.

Examples of the divalent aliphatic hydrocarbon group having 2 to 39 carbon atoms and having or not having the above-mentioned bonding group represented by Φ include groups represented by the following structural formulas.

In the above structural formula, n represents the number of repeating units, preferably 1 to 5, more preferably 1 to 3. In addition, 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, preferably a methylene group.

Examples of the bivalent alicyclic hydrocarbon group having 2 to 39 carbon atoms and having or not having the above-mentioned bonding group represented by Φ include groups represented by the following structural formulas.

Examples of the divalent aromatic hydrocarbon group having 2 to 39 carbon atoms and having or not having the above-mentioned 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 Φ include groups represented by the following structural formulas.

The group represented by Φ is preferably a bivalent aromatic hydrocarbon group with a carbon number of 2 to 39 having a bonding group, or a combination of the aromatic hydrocarbon group and an aliphatic hydrocarbon group, and the group represented by the following structural formula is particularly preferable.

The acid anhydride used in the present invention is a carboxylic acid anhydride, preferably a derivative of aliphatic or alicyclic tetracarboxylic acid, for example, aliphatic or alicyclic tetracarboxylic acid esters, aliphatic or alicyclic tetracarboxylic acid Dianhydride and so on. In addition, among aliphatic or alicyclic tetracarboxylic acid or derivatives thereof, alicyclic tetracarboxylic dianhydride is preferred.

Here, the derivative refers to a compound that can be converted into aliphatic or alicyclic tetracarboxylic acid. For example, in the case of aliphatic tetracarboxylic dianhydride, it is suitable to use a compound having two carboxyl groups instead of the anhydride, and the two One or both of the carboxyl groups are esterified compounds, or one or both of the two carboxyl groups are chlorinated, and the like.

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

Examples of the aliphatic tetracarboxylic acid include 1,2,3,4-butane tetracarboxylic acid and the like. Alicyclic tetracarboxylic acid, for example, 1,2,3,4-cyclobutane tetracarboxylic acid, 1,2,4,5-cyclopentane tetracarboxylic acid, 1,2,4,5-cyclohexane Alkyltetracarboxylic 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. .

Aliphatic tetracarboxylic acid esters include, for example, monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the above-mentioned aliphatic tetracarboxylic acid. The alicyclic tetracarboxylic acid esters include, for example, monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the above-mentioned alicyclic tetracarboxylic acid. In addition, the alkyl portion is preferably an alkyl group having 1 to 5 carbons, and more preferably an alkyl group having 1 to 3 carbons.

Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butane tetracarboxylic dianhydride. Alicyclic tetracarboxylic dianhydride, for example, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,4,5-cyclopentane tetracarboxylic dianhydride, 1,2, 4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2, 3,5,6-tetracarboxylic dianhydride, etc. Particularly preferred is 1,2,4,5-cyclohexanetetracarboxylic dianhydride. Generally speaking, for polyimide with aliphatic diamine as its constituent, the intermediate product of polyimide and diamine will form a strong salt. Therefore, in order to achieve high molecular weight, it is better to use salt with higher solubility. Solvents (for example, cresol, N,N-dimethylacetamide, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). However, the polyimide with aliphatic diamine as the constituent, in the case of 1,2,4,5-cyclohexanetetracarboxylic dianhydride as the constituent, the salt system of polyamide and diamine It is combined with a weak bond, so it is easy to achieve high molecular weight, and it is easy to obtain a flexible film.

Others can also use, for example, 4,4'-biphenyltetracarboxylic anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride , 4,4'-oxydiphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic 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-dioxotetrahydrofuran-3-yl)-3- Methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 3,4'-oxydiphthalic anhydride, 3,4, 9,10-perylene tetracarboxylic dianhydride (Pigment Red 224) 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride tricyclic [6.4.0.02, 7] Dodecane-1,8: 2,7-tetracarboxylic dianhydride and the like.

In addition, acid anhydrides having a sulphur skeleton or derivatives thereof can also be used. It has the effect of improving the unique coloring of polyimide. For acid anhydrides with a stilbene skeleton, for example, 9,9-bis(3,4-dicarboxyphenyl) dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl ]Tentanic acid dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)-3-phenylphenyl]Tentanic acid dianhydride, etc.

Aromatic, aliphatic or alicyclic tetracarboxylic acid or its derivative can be used individually by 1 type or in combination of 2 or more types. In addition, other tetracarboxylic acids or their derivatives (especially dianhydrides) may be used in combination in a range that does not impair the solvent solubility of the polyimide, the flexibility of the film, the thermocompression bonding properties, and the transparency.

The other tetracarboxylic acids or derivatives thereof include, for example, 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-Dicarboxyphenyl) sulfide, bis(3,4-dicarboxyphenyl) ether, bis(2,3-dicarboxyphenyl) ether, 3,3',4,4'-diphenyl Ketonetetracarboxylic acid, 2,2',3,3'-benzophenonetetracarboxylic acid, 4,4-(terephthalic acid), 4,4-(isophthalic acid) Acid, 1,1-bis(2,3-dicarboxyphenyl)ethane, bis(2,3-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)methane and other aromatic systems Tetracarboxylic acids and these derivatives (especially dianhydrides); C1-C3 aliphatic tetracarboxylic acids such as ethylene tetracarboxylic acids and these derivatives (especially dianhydrides), etc. The repeating unit represented by the aforementioned general formula (1.1) is preferably 10-100 mol%, more preferably 50-100 mol%, and still more preferably 80-100 mol% relative to all repeating units. Preferably, it is 90-100 mol%. In addition, the number of repeating units of general formula (1.1) in one molecule of polyimide is 10 to 2000, preferably 20 to 200; within this range, the glass transition temperature is more preferably 230 to 350°C , More preferably 250～330℃.

(1.1.2) The structure of the diamine side The diamine or its derivative is preferably, for example, an aromatic diamine or isocyanate, and more preferably an aromatic diamine.

The diamine or its derivative used in the present invention may be any one of aromatic diamine, aliphatic diamine, or a mixture of these, and is preferably an aromatic diamine from the viewpoint that the whitening of the film can be suppressed.

In addition, the term "aromatic diamine" in the present invention refers to a diamine in which an amine group is directly bonded to an aromatic ring, and a part of its structure may also contain aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and other substituents (such as Halogen atom, sulfonyl group, carbonyl group, oxygen atom, etc.). The so-called "aliphatic diamine" refers to a diamine in which an amine group is directly bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group. A part of its structure may also contain aromatic hydrocarbon groups and other substituents (such as halogen atoms, sulfonamides, etc.). Group, carbonyl group, oxygen atom, etc.).

Examples of aromatic diamines include, for example, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, benzidine, o-tolidine, and m-tolidine , Bis(trifluoromethyl)benzidine, octafluorobenzidine, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'- Diamino biphenyl, 3,3'-dichloro-4,4'-diamino biphenyl, 3,3'-difluoro-4,4'-diamino biphenyl, 2,6-diamine Naphthalene, 1,5-diaminonaphthalene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4 ,4'-Diaminobenzophenone, 3,4'-Diaminobenzophenone, 4,4'-Diaminobenzophenone, 2,2-bis(4-(4-aminophenoxy) Yl)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) Chrysene, bis(4-(2-methyl-4-aminophenoxy)phenyl) chrysene, bis(4-(2,6-dimethyl-4-aminophenoxy)phenyl) chrysanthemum , 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-aminobenzene) Oxy)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-aminophenoxy) Phenyl) 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-diiso Propylbenzene, 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-amino) Phenyl) cyclohexane, 1,1-bis(4-aminophenyl)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)adamantane, 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-amino) Phenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfite, 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'- Diamino-3,3'-dimethyldiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-ethylene diphenylamine, 4,4'-methylene bis(cyclo Hexylamine), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2-methylcyclohexylamine), etc.

Aliphatic diamines, for example, 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, stubble diamine, p-stubble diamine, 1,4-bis(2-amino-isopropyl)benzene, 1,3-bis(2-amino-isopropyl)benzene, isophorone diamine, norbornane diamine, siloxane diamine, 4,4'-diamino dicyclohexyl methane, 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 so on.

In addition, for the purpose of improving the peculiar coloration of polyimine, a diamine having a sulphur skeleton or a derivative thereof may also be used. For example, 9,9-bis[4-(4-aminophenoxy)phenyl]sulfonate, 9,9-bis[4-(4-aminophenoxy)-3-phenylphenyl] can be used茀, 9,9-bis[4-(3-aminophenoxy)-3-phenylphenyl] 茀, 9,9-bis[4-(2-aminophenoxy)-3-benzene Phenylphenyl] 茀, 9,9-bis[4-(4-amino-3-methylphenoxy)-3-phenylphenyl] 茀, 9,9-bis[4-(4-amine -2-methylphenoxy)-3-phenylphenyl]茀、9,9-bis[4-(4-amino-3-ethylphenoxy)-3-phenylphenyl]茀Wait.

In addition, a diamine compound having a triazine core represented by the following formula can be suitably used.

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

R ¹ and R ^{2 are} alkyl or aromatic groups with 1 to 12 carbon atoms, specifically methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, phenyl , Benzyl, naphthyl, methylphenyl, biphenyl, etc.

The aminoanilino groups connected to the two NH groups of the triazine are 4-aminoanilino groups or 3-aminoanilino groups, which may be the same or different, and are preferably 4-aminoanilino groups.

The diamine compound represented by the above formula having a triazine core, specifically 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-benzylamino- 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-dinaphthylamine 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-di Butylamino-1,3,5-triazine, 2,4-bis(4-aminoanilino)-6-amino-1,3,5-triazine, 2,4-bis(3-amine (Anilino)-6-amino-1,3,5-triazine and the like.

Examples of the isocyanate of the diamine derivative include the diisocyanate obtained by reacting the above-mentioned aromatic or aliphatic diamine with phosgene.

In addition, other diamine derivatives can also include diaminodisilanes, such as trimethylsilylated aromatic or aliphatic obtained by reacting the above-mentioned aromatic or aliphatic diamine with chlorotrimethylsilane Diamine.

The above diamines and their derivatives can also be mixed arbitrarily; the amount of the diamines in them is preferably 50-100 mol%, more preferably 80-100 mol%.

The polyimide contained in the polymer blend composition of the present invention is as described above, and has an electron-withdrawing acyclic group in the side chain, or has a ring, -CO-, -SO ₂ -in the main chain, or -CR- (R represents a 茀 skeleton) at least any one; and, the difference between the maximum weight average molecular weight and the minimum weight average molecular weight of the aforementioned two or more polyimides is within the range of 20,000 to 200,000, which can be The above-mentioned diamines or their derivatives and acid anhydrides or their derivatives are appropriately selected to form the polyimide of the present invention.

[Polymer Film] The polymer film of the present invention (hereinafter referred to as polyimide film) is a polymer film containing the aforementioned polymer blend composition, and is characterized by a yellow index value of 5.0 or less.

[2] Physical properties of polymer film (2.1) Yellow index value The yellow index (YI) value of the polymer film of the present invention is preferably in the range of 0.2 to 2.0. The smaller the yellow index value, the less coloring and better. The yellow index value can be adjusted by selecting the composition of the polyimide; in order to make the yellow index value 5.0 or less, it is preferable to use a monomer having an electron withdrawing group.

The yellow index value can be obtained according to the YI (yellow index: index with yellow color) of the film defined by JIS K 7103. As a method for measuring the yellow index value, a sample of a polymer film is produced, and the spectrophotometer U-3300 of Hitachi High-Technologies (stock) and the attached color calculation program are used to determine the JIS Z 8701 The three stimulus values X, Y, Z of the light source color of, calculate the yellow index value according to the definition of the following formula. Yellow index value (YI value)=100(1.28X-1.06Z)/Y

(2.2) Haze The haze of the polymer film of the present invention is preferably 1% or less, more preferably 0.5% or less. The haze (total haze) can be measured in accordance with JIS K-7136 using a haze meter, for example, NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

(2.3) Film length, width and thickness The polymer film of the present invention is preferably a long size, specifically, preferably a length in the range of about 100 to 10000 m, and is wound into a roll shape. In addition, the width of the polymer 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.

From the viewpoint of strength and transparency as a flexible printed circuit board, the film thickness of the film is preferably in the range of 1 to 200 μm. If the film thickness is 1 μm or more, a certain degree of film strength can be exhibited. If the film thickness is 200 μm or less, it has flexibility as a thin film substrate. It is particularly preferable to be in the range of 1 to 100 μm.

(2.4) Total light transmittance For the polymer film of the present invention, a sample with a thickness of 55 μm is prepared, and the total light transmittance is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. By making the total light transmittance more than 80%, it has the advantage of being a film for optical purposes and suitable for a wide range of electronic devices.

The total light transmittance of the film sample can be measured in accordance with JIS K-7375 in an air-conditioned room at 23°C and 55RH on a sample that has been humidified for 24 hours.

[3] Composition of polymer film The polymer film of the present invention preferably contains the following additives in addition to the aforementioned polymer blend composition. (3.1) Matting agent The polyimide film of the present invention preferably contains, for example, silica, titania, alumina, zirconia, calcium carbonate, kaolin, talc, calcined calcium silicate, calcium silicate hydrate, Matting agents such as aluminum silicate, magnesium silicate, calcium phosphate and other inorganic particles or cross-linked polymers. Among them, silicon dioxide is preferred because it can reduce the haze of the film.

The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm.

The fine particles are preferably contained in polyimide to form secondary particles with a particle diameter of 0.1-5 μm, and the average particle diameter is preferably 0.1-2 μm, more preferably 0.2-0.6 μm. As a result, irregularities with a height of about 0.1 to 1.0 μm can be formed on the surface of the film, thereby imparting appropriate sliding properties to the surface of the film.

The measurement of the primary average particle size of the fine particles used in the present invention is to observe the particles with a transmission electron microscope (magnification of 500,000 to 2 million), observe 100 particles, measure the particle size, and use the average value as The primary average particle size.

(3.2) Ultraviolet absorber From the viewpoint of improving light resistance, the polyimide film of the present invention preferably contains an ultraviolet absorber. Since the ultraviolet absorber can absorb ultraviolet light below 400nm, it is for the purpose of improving the light resistance. Especially the transmittance at a wavelength of 370nm is preferably in the range of 0.1-30%, more preferably in the range of 1-20%, and more Preferably, it is in the range of 2-10%.

UV absorbers suitable for use in the present invention are benzotriazole UV absorbers, benzophenone UV absorbers, triazine UV absorbers, particularly preferably benzotriazole UV absorbers and benzophenone It is an ultraviolet absorber.

For example, 5-chloro-2-(3,5-di-second-butyl-2-hydroxyphenyl)-2H-benzotriazole, (2-2H-benzotriazol-2-yl)-6 -(Straight chain and side chain dodecyl)-4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc., in addition to TINUVIN 109, TINUVIN 171, TINUVIN 234, TINUVIN 326, TINUVIN 327, TINUVIN 328, TINUVIN 928, etc., are commercially available products made by BASF Japan Co., Ltd. and are suitable for use. Among them, halogen-free ones are preferred.

In addition, a disc-shaped compound such as a compound having a 1,3,5-triazine ring can also be suitably used as an ultraviolet absorber.

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

In addition, it is also suitable to use a polymer ultraviolet absorber as an ultraviolet absorber, especially a polymer-type ultraviolet absorber described in Japanese Patent Application Laid-Open No. 6-148430. In addition, the ultraviolet absorber preferably does not have a halogen group.

The method of adding the ultraviolet absorber is to dissolve the ultraviolet absorber in an alcohol such as methanol, ethanol, butanol, or an organic solvent such as dichloromethane, methyl acetate, acetone, dioxpentane, etc., or a mixed solvent of these, and then Add to paint, or can be directly added to paint composition.

UV absorbers that are insoluble in organic solvents like inorganic powders can be dispersed in organic solvents and polyimide films using a dissolver or sand mixer, and then added to the coating.

The amount of ultraviolet absorber varies with the type of ultraviolet absorber and usage conditions. When the dry film thickness of the polyimide film is 15-50μm, it is better than that of the polyimide film. It is in the range of 0.5 to 10% by mass, more preferably in the range of 0.6 to 4% by mass.

(3.3) Antioxidants Antioxidants are also called deterioration inhibitors. When electronic devices, etc. are placed in a high humidity and high temperature state, the polyimide film may deteriorate.

Antioxidant system has the function of delaying and preventing the decomposition of polyimide film due to the residual solvent amount of halogen in polyimide film or phosphoric acid of phosphoric acid plasticizer. Therefore, it is suitable to be contained in the polyimide film of the present invention. In the imine film.

Such antioxidants are preferably hindered phenolic compounds, such as 2,6-di-tert-butyl-p-cresol, pentaerythritol-four[3-(3,5-di-tert-butyl-4) -Hydroxyphenyl) propionate], triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol -Bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5 -Di-tert-butylanilino)-1,3,5-triazine, 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propane Acid ester), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N,N'-hexamethylene bis(3,5-di-third Butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-ginseng (3,5-di-tert-butyl-4-hydroxybenzyl)benzene, ginseng -(3,5-Di-tert-butyl-4-hydroxybenzyl)-isocyanurate and the like.

Especially 2,6-di-tert-butyl-p-cresol, pentaerythritol group-four [3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethyl Diol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate] is preferred. In addition, for example, N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine and other hydrazine-based metal deactivators or reference (2,4 -Phosphorus-based processing stabilizers such as di-tert-butylphenyl) phosphite.

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

(3.4) 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 can be added to the polyimide film, or an alignment film can be formed, and a liquid crystal layer can be provided to make the phase difference between the polarizing plate protective film and the liquid crystal layer Compounding, and impart optical compensation to the polyimide film.

The phase difference control agent includes aromatic compounds having two or more aromatic rings as described in European Patent No. 911656A2, rod-shaped compounds described in JP 2006-2025 A, and the like. In addition, two or more aromatic compounds may be used in combination. In addition to the aromatic hydrocarbon ring, the aromatic ring of the aromatic compound is preferably an aromatic heterocyclic ring containing an aromatic heterocyclic ring. The aromatic heterocyclic ring is generally an unsaturated heterocyclic ring. Among them, the 1,3,5-triazine ring described in JP 2006-2026 A is preferable.

The addition amount of these retardation control agents is preferably in the range of 0.5 to 20% by mass, and more preferably in the range of 1 to 10% by mass relative to 100% by mass of the polyimide film-based resin.

剝離促進劑的添加量，相對於環狀聚醯亞胺較佳為0.05～5質量%，更佳為0.1～2質量%，最佳為0.1～0.5質量%。(3.5) Peeling accelerators are additives that reduce the peeling resistance of polyimide films. Many surfactants have significant effects. Suitable peeling agents, such as phosphate-based surfactants, carboxylic acid or carboxylate-based interface Active agents, sulfonic acid or sulfonate-based surfactants, and sulfate-based surfactants are effective. In addition, a fluorine-based surfactant in which a part of the hydrogen atoms bonded to the hydrocarbon chain of the surfactant is replaced by a fluorine atom is also effective. The release agent is exemplified below.

The addition amount of the peeling accelerator is preferably 0.05 to 5% by mass relative to the cyclic polyimide, more preferably 0.1 to 2% by mass, and most preferably 0.1 to 0.5% by mass.

In addition, the additives contained in the polyimide film of the present invention are not limited to the above-mentioned fine particles.

[4] Manufacturing method of polyimide film Hereinafter, a specific example of the manufacturing method of the above-mentioned polyimide film will be described.

The manufacturing method of the polyimide film preferably includes a step of dissolving the above-mentioned polyimide acid or polyimide in a solvent to prepare a paint (paint preparation step), and casting the above-mentioned paint on a support. The step of casting the film (casting step), the step of evaporating the solvent from the cast film on the support (solvent evaporation step), the step of peeling the cast film from the support (peeling step), the step of drying the obtained film (first Drying step), a step of stretching the film (stretching step), a step of further drying the stretched film (second drying step), a step of winding the obtained polyimide film (winding step), and the like.

The steps are described in detail below.

(4.1) Paint preparation steps The manufacturing method of the polyimide film of the present invention is preferably to dissolve the polyimide and the hydrogen bond compound in a low boiling point solvent at least to prepare a paint, and use the paint to form a film by a solution casting film forming method.

The low-boiling point solvent is preferably a low-boiling point solvent with a boiling point below 80°C as the main solvent. As used herein, "used as a main solvent", if it is a mixed solvent, it means to use 55% by mass or more relative to the total solvent, preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass %above. Of course, if it is used alone, it is 100% by mass.

The low boiling point solvent can dissolve polyimide, hydrogen bond compound and other additives at the same time. For example, chlorinated solvents include dichloromethane; non-chlorinated solvents include methyl acetate, ethyl acetate, and ethyl acetate. Ester, acetone, methyl ethyl ketone, tetrahydrofuran, 1,3-dioxpentane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2 ,3,3-Tetrafluoro-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 , Isopropanol, n-butanol, second butanol, tertiary butanol, etc.

Among them, the low-boiling point solvent with a boiling point of 80°C or less should preferably contain dichloromethane (40°C), ethyl acetate (77°C), methyl ethyl ketone (79°C), and tetrahydrofuran (66°C) among the above-mentioned solvents. ), acetone (56.5°C), and 1,3-dioxpentane (75°C) as the main solvent (boiling points are indicated in parentheses).

In the case of a mixed solvent, as long as the solvent contained can dissolve the polyimide of the present invention, it can be used in a range that does not impair the effect of the present invention. Solvents other than the above can be used, for example, N-methyl -2-pyrrolidone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N -Methyl caprolactam, hexamethylphosphoramide, tetramethylene sulfide, dimethyl sulfide, m-cresol, phenol, p-chlorophenol, 2-chloro-4-hydroxytoluene, diglyme Ether, triglyme, tetraglyme, dioxane, γ-butyrolactone, dioxpentane, cyclopentanone, ε-caprolactam, chloroform, etc., can also be used together above. In addition, to the extent that the polyimide and carbonyl-containing organic compounds of the present invention do not precipitate, these solvents can also be combined with poor solvents such as hexane, heptane, benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene, etc. And use.

In addition, alcohol-based solvents can also be used. From the viewpoint of improving releasability and casting at high speed, the alcohol-based solvent is preferably selected from methanol, ethanol, and butanol. It is particularly suitable to use methanol or ethanol. If the ratio of alcohol in the paint becomes higher, the web will be colloidal and easily peeled off from the metal support.

The dissolution of polyimide and other additives can be carried out under normal pressure; the method carried out below the boiling point of the main solvent; the method carried out under pressure above the boiling point of the main solvent; according to Japanese Patent Application Publication No. 9-95544 Various methods such as cooling and dissolving method described in Japanese Patent Application Publication No. 9-95557, or Japanese Patent Application Publication No. 9-95538; method under high pressure described in Japanese Patent Application Publication No. 11-21379 Dissolution method.

The prepared paint can be filtered by guiding it to the filter by a liquid feeding pump or the like. For example, when the main solvent of the paint is methylene chloride, by filtering the paint at a temperature above the boiling point of the methylene chloride at 1 atm + 5° C., the colloidal foreign matter in the paint can be removed. The suitable temperature range is 45-120°C, preferably 45-70°C, more preferably 45-55°C.

In addition, in most cases, recycled materials in the main paint will account for a range of 10-50% by mass. Recycled materials refer to the parts that are reused as raw materials for some reasons. For example, the polyimide film can be crushed into fine particles, and the polyimide film is produced when the film is formed. The two sides of the film are cut. Falling objects, or polyimide film materials that exceed the specified value of the film due to scratches, etc.

In addition, as the raw material of the resin used for the preparation of the coating material, it is also suitable to use a material obtained by pelletizing polyimide and other compounds in advance.

(4.2) Cast film formation steps The prepared paint is delivered to the die through a liquid feeding pump (such as a pressurized quantitative gear pump), and the casting position on a metal support such as a stainless steel belt or a rotating metal drum on an endless support that is transported indefinitely , The coating is cast by the die.

The surface of the cast metal support should be mirror-finished. The support is suitable for use with stainless steel belts or cast rollers with surface plating, or metal supports such as stainless steel belts or stainless steel conveyor belts. The casting width can be set in the range of 1~4m, preferably in the range of 1.5~3m, more preferably in the range of 2~2.8m. In addition, the support can be made of non-metal, for example, polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polybutylene terephthalate (PBT) film, Nylon 6 film, nylon 6,6 film, polypropylene film, PTFE tape, etc. In the case of using polyimide as the flexible substrate, the polyimide can be wound together with the metal support on which the polyimide is cast.

The moving speed of the metal support is not particularly limited, and is usually 5 m/min or more, preferably 10 to 180 m/min, and particularly preferably in the range of 80 to 150 m/min. The higher the moving speed of the metal support, the more likely it is to generate entrained gas, and the more obvious the unevenness of the film thickness caused by disturbance.

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

Regarding the surface temperature of the metal support, the higher the temperature, the faster the drying speed of the cast film, which is better. However, if it is too high, the cast film may foam or the flatness may deteriorate. The boiling point is in the temperature range of -50 to -10°C.

The die has a cross-section perpendicular to the width direction, and has a shape that gradually becomes thinner toward the discharge port. In general, the die head specifically has inclined surfaces in the lower moving direction and on the downstream side and the upstream side, and a discharge port is formed between the inclined surfaces in a slit shape. As the die head, a die head made of metal is suitably used, and specific examples include stainless steel, titanium, and the like. In the present invention, when producing films with different thicknesses, it is not necessary to change to a die with a different slit gap.

The die head should be a pressure die head that can adjust the slit shape of the metal nozzle part of the die head to easily make the film thickness uniform. The pressure die head includes a coat hanger die head or a T die head, etc., either of which is suitable for use. Even in the continuous production of films with different thicknesses, the discharge rate of the die will be maintained at approximately a certain value. Therefore, when a pressurized die is used, conditions such as extrusion pressure and shear rate will also be maintained at approximately A certain value. In addition, in order to increase the film forming speed, two or more pressure dies may be installed on the metal support, and the coating amount may be divided and laminated.

(4.3) Solvent evaporation step The agent evaporation step is performed on the metal support, and the cast film is heated on the metal support to evaporate the solvent as a preliminary drying step.

In order to evaporate the solvent, for example, a method in which heating air is blown from the cast film side and the back side of the metal support by a dryer, a method in which heat is transferred from the back of the metal support by a heated liquid, and a method in which heat is transferred from the front and back by radiant heat Methods of heat transfer, etc. Appropriate selection of these combined methods is also suitable. The surface temperature of the metal support may be the same for the whole, or may be different according to the position. The temperature of the heating air should be within the range of 10~220℃.

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

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

Residual solvent amount (mass%)=((M-N)/N)×100 Here, M is the mass of the cast film (thin film) at a predetermined point in time, and N is the mass of the film with the mass M being dried at 200° C. for 3 hours. Especially in the solvent evaporation step, when calculating the achieved residual solvent amount, M is the mass of the cast film just before the start of the peeling step.

(4.4) Peeling step On the metal support, the cast film after the solvent has evaporated is peeled off at the peeling position.

The peeling tension when peeling the metal support from the cast film is usually in the range of 60 to 400 N/m. If wrinkles are likely to occur during peeling, it is preferable to peel with a tension of 190 N/m or less.

In the present invention, it is preferable to set the temperature of the peeling position on the metal support in the range of -50 to 60°C, preferably in the range of 10 to 40°C, and in the range of 15 to 40°C. optimal.

The peeled film may be directly transported to the stretching step, or may be transported to the first drying step to achieve the desired residual solvent amount, and then transported to the stretching step. In the present invention, based on the viewpoint of stably conveying in the stretching step, after the peeling step, the film is preferably conveyed to the first drying step and the stretching step in order.

(4.5) The first drying step The first drying step is a drying step in which the film is heated to further evaporate the solvent. The drying means is not particularly limited, and, for example, hot air, infrared rays, heating rollers, microwaves, etc. can be used. From the standpoint of simplicity, it is advisable to transport the film with jagged rolls while drying it with hot air or the like. Considering the amount of residual solvent and the expansion and contraction rate during transportation, the drying temperature should be in the range of 30 to 200°C.

(4.6) Extension steps By stretching the film peeled from the metal support, the film thickness, flatness, and orientation of the film can be controlled.

In the manufacturing method of the polyimide film of the present invention, it is preferable to extend in the length direction and/or the width direction.

The extension operation can be implemented in multiple stages. In addition, in the case of performing biaxial stretching, the biaxial stretching may be performed at the same time, or it may be implemented in stages. In this case, the term “stages” means that, for example, extensions in different extension directions can be performed sequentially, or extensions in the same direction can be divided into multiple stages, and extensions in different directions can be added to any of the stages.

That is, for example, it can also be the following extension step: ・Extend in the length direction → extend in the width direction → extend in the length direction → extend in the length direction ・Extend in the width direction→Extend in the width direction→Extend in the length direction→Extend in the length direction In addition, simultaneous biaxial stretching also includes stretching in one direction and relaxing and contracting the tension in the other direction.

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

If the residual solvent content is less than 0.1% by mass, the effect of improving the flatness by stretching cannot be obtained; if it exceeds 200%, the film will not be easily stretched due to low film strength.

In the manufacturing method of the polyimide film of the present invention, the film may be stretched in the length direction or the width direction so that the film thickness after stretching is in a desired range, and it is preferably stretched in the width direction. Relative to the glass transition temperature (Tg) of the film, it is better to extend in the temperature range of (Tg-200℃)~(Tg+100℃). If the stretching is performed in the above temperature range, the stretching stress can be reduced, and the haze can be lowered. In addition, it is possible to obtain a polyimide film that suppresses the occurrence of cracks, is excellent in flatness, and is excellent in coloration resistance of the film itself. The stretching temperature is more preferably performed in the range of (TgL-150) to (TgH+50)°C.

In the manufacturing method of the polyimide film of the present invention, by controlling the moving speed with a stretching roll, the self-supporting film peeled from the support can be stretched in the longitudinal direction.

Extending in the width direction, it is suitable to use, for example, all the drying treatments or part of the treatments disclosed in Japanese Patent Laid-Open No. 62-46625. Tenter type), especially suitable for the tenter type using clamps.

The film that is stretched in the length direction or the unstretched film should preferably be held by clamps at both ends in the width direction. In this state, it is introduced into the tenter and moved together with the tenter clamp while extending in the width direction.

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

As long as the extension speed is 50%/min or more, the flatness can be improved, and the film can be processed at high speed, so it is suitable from the viewpoint of production suitability; as long as it is within 1000%/min, the film can be prevented from breaking For processing, and for fit.

More preferably, the extension speed is in the range of 100 to 500%/min. The extension 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 of the stretched resin film in the stretching direction, and d ₂ is the stretch The width dimension in the stretching direction of the previous resin film, t is the time required for stretching (min)). In the stretching step, the system is usually maintained and relaxed after stretching. That is, in this step, it is preferable to sequentially perform the stretching stage of stretching the film, the holding stage of keeping the film in the stretched state, and the relaxation stage of relaxing the film in the stretching direction. In the holding phase, the extension of the extension ratio achieved in the extension phase is maintained at the extension temperature in the extension phase. In the relaxation phase, after the extension in the extension phase is maintained in the holding phase, the extension is relaxed by releasing the tension required for the extension. The relaxation stage only needs to be carried out at a temperature below the stretching temperature in stages.

(4.7) The second drying step Next, the stretched film is heated and dried. In the case of heating the film by hot air, it is also suitable to install a nozzle that can discharge the hot air (air containing solvent or humid air) after use to prevent the hot air from mixing after use. The temperature of the hot air is more preferably in the range of 40 to 220°C. In addition, the drying time is preferably about 5 seconds to 30 minutes, more preferably 10 seconds to 15 minutes.

In addition, the heating and drying means are not limited to hot air, and, for example, infrared rays, heating rollers, microwaves, etc. can be used. From the viewpoint of simplicity, it is advisable to transport the film with jagged rolls and dry it with hot air or the like. Considering the amount of residual solvent and the expansion and contraction rate during transportation, the drying temperature is more preferably in the range of 40 to 220°C.

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

(4.8) Winding step The winding step is a step of winding and cooling the obtained film to room temperature. The winding machine can be a commonly used machine, and can be wound by a winding method such as a constant tension method, a constant torque method, a taper tension method, and a programmed tension control method with a constant internal stress.

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

In the winding step, at the time of stretching and conveying, both ends of the film clamped by a tenter clamp or the like may be cut and processed. The cut ends of the film should preferably be cut to a width of 1 to 30 mm and then dissolved in a solvent to be reused as a recycled material.

The portion of the formed polyimide film to be reused as a recycled material is preferably within a range of 10 to 90% by mass, more preferably 20 to 80% by mass, and still more preferably 30 to 70% by mass.

Depending on the amount of recycled material produced in the middle of the filming step or at the end, the added amount will vary slightly; usually, the mixing rate of recycled material relative to the total solids in the coating is about 10-50% by mass, which is 15-40%. Within the range of about mass%. In terms of stable production, the mixing rate of recycled materials should be as certain as possible.

The steps from the solvent evaporation step to the winding step can be carried out in an air environment or in an inert gas environment such as nitrogen. In addition, each step, especially the drying step or the extension step, needs to be carried out in consideration of the explosive limit concentration of the solvent in the gas environment.

In addition, after the winding step, a step of cutting off the ends of the polyimide film in the width direction may be further performed, or a step of removing charges when the polyimide film is charged.

[use] When the polyimide film of the present invention is laminated with an electronic device, the warpage caused by the fluctuation of the temperature and humidity environment can be suppressed. Applicable electronic devices are not particularly limited, and examples include organic EL devices, liquid crystal display devices (LCD), organic photoelectric conversion devices, printed substrates, thin film transistors, touch panels, polarizers, retardation films, and the like. From the viewpoint of obtaining the effects of the present invention more effectively, it can be suitably used for flexible printed circuit boards, LED lighting devices, and front surface members for flexible displays.

[Flexible printed circuit board] The flexible printed circuit board of the present invention is obtained by using the polyimide film of the present invention as a base film and pressing metal foil to it through an adhesive. Examples of the adhesive used here include acrylic, polyimide, and epoxy adhesives.

In addition, the metal foil thermally bonded to the polyimide film via the adhesive is preferably copper foil from the viewpoint of cost reduction, but may also be other metal foils such as aluminum, gold, silver, nickel, and tin.

[LED lighting device] The LED lighting device of the present invention is not particularly limited as long as the substrate for LED using the polyimide film of the present invention is used. For example, a double-sided substrate or a composite substrate with an aluminum plate can be mentioned. When the heat dissipation performance is further required as the brightness of the LED becomes higher, the heat dissipation performance can be improved by compounding with an aluminum plate. It can also be applied to organic electroluminescence lighting devices using organic materials.

[Front surface member for flexible display] The front surface member for a flexible display of the present invention is not particularly limited as long as it is formed by using the polyimide film of the present invention. The flexible display equipped with the front surface member for the flexible display of the present invention is, for example, an organic EL device, a gas barrier film, and a film formed by laminating an organic functional layer such as a light-emitting layer on a substrate. It is composed of a filter, a polarizing plate with a polarizing plate protective film on one or both sides, a thin-film touch sensor, etc. The front surface member for a flexible display of the present invention is laminated on a thin-film touch sensor of the flexible display constructed as described above, for example.

In addition, the polyimide film of the present invention can be used for the substrate of the organic EL device constituting the flexible display, and can also be used for the polarizing plate protective film constituting the polarizing plate of the flexible display. [Example]

The following examples are given to specifically illustrate the present invention, but the present invention is not limited by these. The structures of the compounds used in the following examples are listed here.

The purchasers of the commercial products of the above-mentioned compounds are as follows: Anhydride 1: Daikin Industrial Co., Ltd. Anhydride 2: manufactured by Manac Co., Ltd. Anhydride 3: manufactured by DAICEL Co., Ltd. Anhydride 4: Tokyo Chemical Industry Co., Ltd. Anhydride 5: manufactured by Mitsubishi Chemical Corporation Diamine 1: manufactured by Daikin Industrial Co., Ltd. Diamine 2: manufactured by Mitsui Chemicals Fine Co., Ltd. Diamine 3: manufactured by Tokyo Chemical Industry Co., Ltd. Diamine 4: manufactured by Wakayama Fine Chemical Industry Co., Ltd. Diamine 5: manufactured by FUJIFILM-Wako Pure Chemical Co., Ltd. Diamine 6: manufactured by FUJIFILM-Wako Pure Chemical Co., Ltd.

[Production of Polyimide Film 1] ＜Preparation of polyimide A (Mw=257000)＞ Put 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3 in a four-necked flask equipped with a dry nitrogen inlet pipe, a cooler, a Dean-Stark agglomerator filled with toluene, and a stirrer. , 3,3-hexafluoropropane dianhydride (anhydride 1) (manufactured by Daikin Industrial Co., Ltd.) 25.59g (57.6mmol) was added to N,N-dimethylacetamide (134g), and under nitrogen flow, in the room Stir at low temperature. 19.2 g (60 mmol) of 4,4′-diamino-2,2′-bis(trifluoromethyl)biphenyl (diamine 1) (manufactured by Daikin Industrial Co., Ltd.) was added thereto, and the mixture was heated and stirred at 80°C for 6 hours . Thereafter, the external temperature was heated to 190°C, and the water produced by the imidization was azeotropically distilled together with toluene. Continue heating for 6 hours, reflux and stir, and gradually no water production is observed. Next, heating for 7 hours while distilling off toluene, further distilling off toluene, adding methanol for reprecipitation, and drying the solid content to obtain 31.5 g of polyimide A (Mw=257000) (yield 75%).

<Preparation of Polyimide A (Mw=142000)> Put 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3 in a four-necked flask equipped with a dry nitrogen inlet pipe, a cooler, a Dean-Stark agglomerator filled with toluene, and a stirrer. , 3,3-hexafluoropropane dianhydride (anhydride 1) (manufactured by Daikin Industrial Co., Ltd.) 24.39g (54.9mmol) was added to N,N-dimethylacetamide (134g), and placed in a room under a stream of nitrogen Stir at low temperature. 19.2 g (60 mmol) of 4,4′-diamino-2,2′-bis(trifluoromethyl)biphenyl (diamine 1) (manufactured by Daikin Industrial Co., Ltd.) was added thereto, and the mixture was heated and stirred at 80°C for 6 hours . Thereafter, the external temperature was heated to 190°C, and the water produced by the imidization was azeotropically distilled together with toluene. Continue heating for 6 hours, reflux and stir, and gradually no water production is observed. Next, heating for 7 hours while distilling off toluene, further distilling off toluene, adding methanol for reprecipitation, and drying the solid content to obtain 28.8 g of polyimide A (Mw=142000) (yield 72%).

＜Preparation of paint＞ Prepare the main paint with the following composition. First, dichloromethane (boiling point 40°C) and ethanol are added to the pressurized dissolution tank. While stirring the prepared polyimide A (Mw=257000) and polyimide A (Mw=142000), they were put into a pressure dissolution tank containing a solvent. It was heated, and it was completely dissolved while stirring, and it was filtered using Azumi filter paper No. 244 manufactured by Azumi filter paper (stock) to prepare the main paint. (The composition of the main paint) Dichloromethane 340 parts by mass Ethanol 10 parts by mass Polyimide A (Mw=257000) 70 parts by mass Polyimide A (Mw=142000) 30 parts by mass

＜Film production＞ After the obtained paint was applied on a smooth glass plate with a very small amount of release agent dispersed with a coater, it was heated on a hot plate at 40° C. for 30 minutes to form a self-supporting film. The film peeled from the glass plate was fixed to a stainless steel mold frame at multiple places with jigs, and then placed in a vacuum dryer at 150°C for 2 hours to almost completely remove the organic solvent (less than 1% by mass) to obtain polyimide Film 1.

[Production of Polyimide Film 2～17] In addition to the production of the above-mentioned polyimide film 1, the preparation of polyimide with acid anhydrides and diamines as described in Table I was further changed to the two types of polyimine (polyimine) described in Table II. Except for the combination (blending ratio) of I and polyimide II), polyimide films 2-17 were prepared in the same manner as polyimide film 1. In addition, in the production of the polyimide films 2-17, the acid anhydride and the diamine system used the same number of moles as in the case of the polyimide film 1, respectively.

[Production of polyimide film 18]: Thermal imidization Dissolve 41.05 kg (0.1 kilomole) of diamine 4 in 190.6 kg of dry N,N-dimethylacetamide (DMAc), and add the purified powder in small amounts while stirring at 20°C 329.4 kg (0.1 kilomole) of the acid anhydride, and continue to stir for 1 hour to obtain a transparent polyamic acid solution. Next, the organic compound 1 having a carbonyl group was added to the varnish-like polyamic acid solution at 8% by mass per unit weight of the resin, and after thorough stirring, a varnish-like polyamic acid solution was obtained. For this varnish-like polyamic acid solution, acetic anhydride (molecular weight 102.09) and β-picoline were mixed and stirred at a ratio of 17% by mass and 17% by mass with respect to the polyamic acid solution. After casting the obtained mixture on a rotating stainless steel drum at 75°C from a T-slot die, the gel film is peeled off from the drum, and both ends are grasped and processed in a heating furnace at 400°C for 2 hours to obtain the width Polyimide film 18 with a thickness of 2.2 m and a thickness of 60 μm.

[assessment] ＜Bending resistance＞ For each of the polyimide films obtained above, a sample film with a width of 30 mm and a length of 150 mm was used, and the bending tester (manufactured by Yuasa System Co., Ltd.) was used to set the condition that the inner diameter (diameter) during bending was 2 mm. , With bending and 180° recovery shape as 1 cycle, and even the number of cycles before breaking. The greater the number of times to break, the better the bending resistance, and the better the repeated bending resistance. The number of times to break is ◎: 20000 times or more ○: 15000～19999 times △: 10000～14999 times ×: Less than 9999 times

<Planarity> The planarity is evaluated by observing the light and shadow when the light penetrating the film is projected on the wall surface by the lighting device (S-Light (model: SA160) manufactured by Japan Technology Center Co., Ltd.). The number of waves per unit area (cm ² ) was visually counted, and the number was classified according to the following evaluation criteria. ◎, ○, △ are considered as those with no practical problems. ◎: 0 to 3 pieces ○: 3 to 9 pieces △: 10 to 19 pieces ×: more than 20 pieces

＜Colorless and transparent＞ The colorlessness and transparency are measured by measuring the yellow index (YI) value and the haze (Hz) value, and based on these values, the following evaluation criteria are used for evaluation. The yellow index value is obtained according to the YI (yellow index: index with yellow color) of the film defined by JIS K 7103. As a method for measuring the yellow index value, a sample of the polyimide film is prepared, and the spectrophotometer U-3300 of Hitachi High-Technologies (stock) and the attached color calculation program are used to obtain the JIS Z 8701 Determine the three stimulus values X, Y, and Z of the light source color, and calculate the yellow index value according to the definition of the following formula. Yellow index value (YI value)=100(1.28X-1.06Z)/Y The haze (total haze) is measured in accordance with JIS K-7136 using a haze meter (NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). The ○ and △ systems are considered to have no practical problems. ○: Hz value is 0.2% or less and YI value is 5.0 or less △: Hz value is greater than 0.2%, YI value is less than 5.0 or Hz value is less than 0.2% and YI value is greater than 5.0 ×: Hz value is greater than 0.2% and YI value is greater than 5.0

From the above results, it can be seen that the polyimide film of the present invention is superior to the polyimide film of the comparative example in terms of bending resistance, flatness, and colorless transparency.

Claims (4)

A polymer film, which contains a polymer blend composition containing two or more kinds of polyimine, the polyimine is: a non-cyclic group with electron withdrawing on the side chain, or in the main chain At least one of the alicyclic hydrocarbon group, -CO-, -SO ₂ -or -CR- (R represents the 茀 skeleton); and the maximum weight average molecular weight and minimum weight of the above two or more polyimides The difference in average molecular weight is within the range of 20,000 to 200,000, and the yellow index value of the polymer film is 5.0 or less, the haze is 1% or less, and the film thickness is 1 to 200 μm. The polymer film of claim 1, wherein the weight average molecular weight of the aforementioned two or more polyimides is in the range of 100,000 to 500,000. Such as the polymer film of claim 1 or claim 2, wherein the difference between the maximum weight average molecular weight and the minimum weight average molecular weight of the aforementioned two or more polyimides is in the range of 50,000 to 150,000. The polymer film of claim 1 or claim 2, wherein the aforementioned polyimide has an acyclic group with electron withdrawing properties in the side chain.