JP2019156921A - Polyimide, polyimide film, polyimide metal laminate, and polyamide acid - Google Patents

Abstract

To provide a polyimide in which thermal heat resistance, dimensional stability, high elastic modulus, and high strength, as well as an improvement of adhesive property to metal layer, a reduction of sagging, and/or a reduction of haze are realized.SOLUTION: The polyimide of the present invention is a polyimide obtained from a tetracarboxylic acid component and a diamine component, and in which, as the diamine component, at least a diamine having a triazine ring and an ethynyl anilino group, and a fluorine-free aromatic diamine having a structure other than the above and having 1 to 4 benzene nuclei are used.SELECTED DRAWING: None

Description

  The present invention relates to a polyimide, a polyimide film, a polyimide metal laminate, and a polyamic acid which is a polyimide precursor thereof.

  Polyimide films are widely used in industrial fields such as the electric / electronic device field and the semiconductor field because they are excellent in heat resistance, chemical resistance, mechanical strength, electrical properties, dimensional stability, and the like. For example, as a flexible printed wiring board (FPC), a copper-clad laminated board formed by laminating a copper foil on one side or both sides of a polyimide film is used.

  For example, Patent Document 1 includes a diamine having an ethynylanilino group at the 6-position of 1,3,5-triazine and a perfluorononenyl group as a polyimide having heat resistance, dimensional stability, high elastic modulus, and high strength. A fluorine-containing aromatic polyimide synthesized using diamine (FNDA) is described.

JP 2011-102259 A

  A polyimide film used for a flexible printed wiring board (FPC) is required to have excellent adhesion to a metal layer such as a copper foil. In addition, when a polyimide film is produced by heating while supporting the periphery with a support such as a pin tenter in a state of a self-supporting film containing a solvent, the film may sag due to its own weight. If the film sags, it cannot be used as a product, so how to reduce the sag is an issue. Furthermore, the polyimide film is also subject to the film becoming cloudy due to crystallization of the polyimide, that is, reducing haze.

  However, conventional polyimide films have room for improvement in terms of adhesion to metal layers, sagging, and haze.

  As a result of intensive studies, the present inventors have found that a polyimide composed of a diamine component having a ethynylanilino group at the 6-position of 1,3,5-triazine and a diamine component containing a specific diamine, and a tetracarboxylic acid component. Surprisingly, the inventors have found that the above-mentioned problems can be solved, and have reached the present invention.

That is, the present invention is a polyimide obtained from a tetracarboxylic acid component and a diamine component,
As the diamine component, at least a diamine represented by the following general formula (1) and a fluorine-free aromatic diamine having a structure other than the general formula (1) and having 1 to 4 benzene nuclei were used. The polyimide is provided.
(R ¹ , R ² , R ³ and R ⁴ in the formula each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

  Moreover, this invention provides the polyimide film containing the said polyimide, the polyimide metal laminated body using the said polyimide film, the polyamic acid which is the raw material of the said polyimide, and the method of manufacturing a polyimide film using this polyamic acid, respectively. is there.

  In addition to heat resistance, dimensional stability, high elastic modulus, and high strength by using the triazine-based diamine represented by the general formula (1), the polyimide of the present invention has improved adhesion to a metal layer, sagging Reduction and / or reduction of haze are realized. Moreover, this invention can provide the polyimide film using the polyimide which shows the said effect, the polyimide metal laminated body, the polyamic acid which is the polyimide precursor, and the method of manufacturing a polyimide film using this polyamic acid.

  The polyimide of the present invention is a polyimide obtained from a tetracarboxylic acid component and a diamine component, and has a structure other than the diamine represented by the following general formula (1) and the general formula (1) as the diamine component. One of the characteristics is that it contains a fluorine-free aromatic diamine having 1 to 4 benzene nuclei. Thereby, the polyimide of the present invention has heat resistance, dimensional stability, high elastic modulus, and high strength due to the use of the diamine represented by the general formula (1), and adhesion to the metal layer. Improvement, reduction of sagging, and / or reduction of haze are realized. A tetracarboxylic acid component is a component which becomes the origin of the tetravalent group which comprises a polyimide. The tetracarboxylic acid component has four carboxyl groups or groups derived therefrom (dehydration condensation group of two carboxyl groups or esterified product of lower alcohol). On the other hand, a diamine component is a component which becomes the origin of the bivalent group which comprises the polyimide of this invention. The diamine component has two amino groups.

In the benzene ring bonded to the 2,4 positions of 1,3,5-triazine in the general formula (1) via —NR ² — group and —NR ³ — group, respectively, NH ₂ group is —NR ² — group. And —NR ³ — group may be bonded to any position of ortho, meta, and para. In the benzene ring bonded to the 6-position of 1,3,5-triazine via the —NR ¹ — group, the ethynyl group (—C≡C—R ⁴ ) is ortho, meta to —NR ¹ —. It may be bonded to any position of the para. R ^{1 to} R ⁴ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, and isobutyl. The hydrogen atoms in the three benzene rings in the general formula (1) may be further substituted or unsubstituted, and the substituent in the case of being substituted has 1 to 10 carbon atoms (preferably Is an alkyl group having 1 to 4), an alkoxy group having 1 to 10 carbon atoms (preferably 1 to 4), an aromatic group having 1 to 12 carbon atoms (preferably 1 to 6), a carboxyl group, and a fluorine atom. A halogen atom, and the like.

Those wherein ^{R 4} is a hydrogen atom; as preferred diamine represented by general formula ^(1), at least one of R 1 to R ^3, preferable all ^R 1 to R ³ is a hydrogen atom ; respectively 2,4 position of 1,3,5-triazine -NR ² - group and -NR ³ - NH ₂ groups -NR the benzene ring bonded through a group ² - group and -NR ³ - based on In the benzene ring bonded to the 6-position of 1,3,5-triazine via the —NR ¹ — group, the ethynyl group is para-positioned to —NR ¹ —. The thing which has couple | bonded is mentioned. As a particularly preferred diamine, a compound represented by the following general formula (3), that is, 2,4-bis (p-aminoanilino) -6- (p-ethynylanilino) -1,3,5-triazine (EDA) ).

  In the polyimide of the present invention, the ratio of the diamine represented by the general formula (1) in the diamine component is 2 mol% or more, more preferably 4 mol% or more, and further effects of reducing sagging and haze are obtained. It is preferable because it is easy. Moreover, in the polyimide of this invention, it is 80 mol% or less, More preferably, the ratio of the diamine represented by General formula (1) in a diamine component is 60 mol% or less from the point of an adhesive improvement. preferable.

  As described above, in the present invention, a fluorine-free aromatic diamine having 1 to 4 benzene nuclei having a structure other than the general formula (1) is used as the diamine component. The aromatic diamine is more preferably a halogen atom-free diamine from the viewpoint of adhesion to the metal layer.

  Among fluorine-free aromatic diamines having a structure other than the general formula (1), examples of diamines having one benzene nucleus include p-phenylenediamine (1,4-diaminobenzene; PPD), 1,3 -Diaminobenzene, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene and the like.

  Among the aromatic diamines, examples of diamines having two benzene nuclei include diaminodiphenyl ethers such as 4,4′-diaminodiphenyl ether (ODA), 3,3′-diaminodiphenyl ether, and 3,4′-diaminodiphenyl ether. 3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, 3,3 '-Dicarboxy-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis (4-aminophenyl) sulfide, 4,4'-diaminobenz Anilide, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 2,2'-dimethyl Benzidine, 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'- Diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3,3'- Diamino-4,4′-dimethoxybenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane, 2,2 -Bis (4-aminophenyl) propane, 2,2-bis ( - aminophenyl) propane, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide.

  Among the aromatic diamines, examples of diamines having three benzene nuclei include 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, and 1,4-bis. (3-aminophenyl) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4 -Bis (4-aminophenoxy) benzene, 3,3'-diamino-4- (4-phenyl) phenoxybenzophenone, 3,3'-diamino-4,4'-di (4-phenylphenoxy) benzophenone, 1, 3-bis (3-aminophenylthio) benzene, 1,3-bis (4-aminophenylthio) benzene, 1,4-bis (4-aminophenylthio) benzene 1,3-bis (3-aminophenylsulfonyl) benzene, 1,3-bis (4-aminophenylsulfonyl) benzene, 1,4-bis (4-aminophenylsulfonyl) benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene, 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 1,4-bis [2- (4-aminophenyl) isopropyl] benzene and the like.

  Among the aromatic diamines, examples of diamines having four benzene nuclei include 3,3′-bis (3-aminophenoxy) biphenyl, 3,3′-bis (4-aminophenoxy) biphenyl, 4,4 '-Bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4-aminophenoxy) phenyl ] Ether, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phenyl] ketone, bis [3- ( 4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenyl) Noxy) phenyl] ketone, bis [3- (3-aminophenoxy) phenyl] sulfide, bis [3- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [ 4- (4-aminophenoxy) phenyl] sulfide, bis [3- (3-aminophenoxy) phenyl] sulfone, bis [3- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) Phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- (4-aminophenoxy) phenyl] methane, bis [4- (3-Aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl Methane, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-amino Phenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and the like.

  Furthermore, the triazine type diamine represented by the following general formula (2) is also mentioned as having 2 to 4 benzene rings in the aromatic diamine.

(In the formula, R ⁵ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an aromatic group having 1 to 12 carbon atoms, and R ⁶ represents an alkyl group having 1 to 12 carbon atoms or an aromatic group having 1 to 12 carbon atoms. R ⁷ and R ⁸ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

Examples of the alkyl group having 1 to 12 carbon atoms represented by R ⁵ and R ⁶ in the general formula (2) include those exemplified as the alkyl group having 1 to 4 carbon atoms represented by the above R ^{1 to} R ^4. In addition, amyl, iso-amyl, tert-amyl, hexyl, 2-hexyl, 3-hexyl, cyclohexyl, 1-methylcyclohexyl, heptyl, 2-heptyl, 3-heptyl, iso -Heptyl, tert-heptyl, octyl, iso-octyl, tert-octyl and the like. The alkyl group having 1 to 4 carbon atoms represented by R ⁷ and ^{R 8,} are the same as those of the alkyl group having 1 to 4 carbon atoms represented by R 1 to R ^4.

Examples of the aromatic group having 1 to 12 carbon atoms represented by R ⁵ and R ⁶ in the general formula (2) include an aryl group and an arylalkyl group, and specifically include a phenyl group, a naphthyl group, and benzyl. Group, methylphenyl group, biphenyl group and the like. Further, it may be a heteroaromatic group containing an oxygen atom, a nitrogen atom or a sulfur atom.

The hydrogen atom in the general formula (2) (particularly the two benzene rings and the hydrogen atom in the aromatic group represented by R ⁵ and R ⁶ ) may be further substituted or unsubstituted, As the substituent in the case of substitution, an alkyl group having 1 to 10 (preferably 1 to 4) carbon atoms, an alkoxy group having 1 to 10 (preferably 1 to 4) carbon atoms, and 1 to 1 carbon atoms. Examples include 12 (preferably 1 to 6) aromatic groups, carboxyl groups, halogen atoms other than fluorine atoms, and the like.

  As a specific compound represented by the general formula (2), 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-benzyl Amino-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-a Minoanilino) -6-dibenzylamino-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-tri Gin, 2,4-bis (4-aminoanilino) -6-diethylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-dipropylamino-1,3,5-triazine, Examples include 2,4-bis (4-aminoanilino) -6-dibutylamino-1,3,5-triazine.

What is R ⁵ is a hydrogen atom; as preferred diamine represented by general formula (2), at least one of R ⁷ and R ^8, preferably those both R ⁷ and R ⁸ are hydrogen atoms R ⁶ is an aromatic group, especially an aryl group; NH ₂ groups are bonded to the 2,4 positions of 1,3,5-triazine via —NR ⁷ —group and —NR ⁸ —group, respectively. Examples of the benzene ring include those bonded to the para position with respect to the —NR ⁷ — group and the —NR ⁸ — group.

  As the aromatic diamine, the heat resistance, dimensional stability, high elastic modulus and improved adhesion to the metal layer without impairing the availability and the compound represented by the general formula (1), Or / and p-phenylenediamine, an aromatic diamine having two benzene nuclei represented by the following general formula (a), and a general formula (2) from the point that sagging and haze can be reduced. It is preferable that it is at least 1 sort (s) chosen from the compound to be made, and it is especially preferable that it is at least 1 sort (s) chosen from the compound represented by p-phenylenediamine, diamino diphenyl ethers, and General formula (2). In particular, it is preferable to use diaminodiphenyl ethers from the viewpoint of enhancing the adhesion to the metal layer and the effect of improving sagging and haze, and using the compound represented by the general formula (2) is adhesion to the metal layer. It is preferable from the point which raises. From these points, the aromatic diamine is particularly preferably at least one selected from diaminodiphenyl ethers and compounds represented by the general formula (2), and 4,4′-diaminodiphenyl ether (ODA). And at least one selected from compounds represented by formula (2) is particularly preferred.

(In the formula, X is an oxygen atom, a sulfur atom, —COO—, —OCO—, —SO ₂ —, —CONH—, —NHCO— or a direct bond, and the benzene nucleus in the formula has 1 carbon atom. -10 (preferably 1-4) alkyl group, C1-C10 (preferably 1-4) alkoxy group, C1-C12 (preferably 1-6) aromatic group, carboxyl group And may be substituted with a halogen atom other than a fluorine atom, etc.)

  The content of the fluorine-free aromatic diamine containing 1 to 4 benzene nuclei having a structure other than the general formula (1) is 98 mol% or less, more preferably 96 mol% or less in the diamine component. However, the amount of diamine represented by the general formula (1) is ensured to be sagging and haze is reduced. Further, the content of the aromatic diamine in the diamine component is preferably 20 mol% or more, more preferably 40 mol% or more, from the viewpoint of improving adhesive performance.

When the diamine component contains the aromatic diamine represented by the general formula (2), the ratio of the aromatic diamine represented by the general formula (2) in the diamine component is 16 mol% or more, more preferably 18 mol. % Or more, more preferably 20 mol% or more, from the viewpoint of increasing the adhesive strength of the resulting polyimide to the metal layer.
From the viewpoint of improving adhesiveness, the total proportion of the aromatic diamine represented by the general formula (1) and the aromatic diamine represented by the general formula (2) in the diamine component is 20 mol% or more and 22 mol. % Or more and 24 mol% or more are preferred.

  When the compound represented by the general formula (2) is used as the aromatic diamine having a structure other than the general formula (1), the diamine component is further a non-fluorine-containing aromatic having a structure other than the general formulas (1) and (2). It is preferable that diamine is included because it is easy to obtain an effect of improving adhesiveness to the metal layer, sagging and haze. Preferred aromatic diamines having structures other than those represented by the general formulas (1) and (2) include p-phenylenediamine and two aromatic diamines having a benzene nucleus represented by the above general formula (a). In particular, it is preferable to use an aromatic diamine represented by the general formula (a), particularly diaminodiphenyl ethers, because it is easy to obtain both an adhesive effect to the metal layer and an effect of improving sagging and haze.

  When the diamine component contains a non-fluorine-containing aromatic diamine having a structure other than the general formulas (1) and (2) and does not contain the aromatic diamine represented by the general formula (2), In the diamine component, the proportion of the non-fluorine-containing aromatic diamine having a structure other than those represented by the general formulas (1) and (2) is 40 mol% or more, particularly 50 mol% or more. It is preferable from the viewpoint of increasing sagging and haze. On the other hand, when the diamine component contains a non-fluorine-containing aromatic diamine having a structure other than the general formulas (1) and (2) together with the aromatic diamine represented by the general formula (2), the general formula (1) and The amount of the non-fluorine-containing aromatic diamine having a structure other than (2) is preferably 10 mol% or more, more preferably 20 mol% or more from the viewpoint of increasing the adhesive strength. The preferable upper limit and lower limit of other various diamines may be an amount such that the total amount of diamine components is 100% by mass.

Examples of the tetracarboxylic acid component include aromatic tetracarboxylic acids or their acid dianhydrides and esterified products of lower alcohols, alicyclic tetracarboxylic acids or their acid dianhydrides and lower alcohols. Preferable examples are esterified products.
Aromatic tetracarboxylic acids include biphenyltetracarboxylic acid, naphthalenetetracarboxylic acid, pyromellitic acid, and tetracarboxylic acid having a structure in which the benzene rings of two o-benzenedicarboxylic acid groups are bonded together by a linking group. Can be mentioned. As this linking group, —O—, —CO—, —SO ₂ —, an alkylene group (preferably having 1 to 3 carbon atoms, etc.), a halogenated alkylene group (preferably having 1 to 3 carbon atoms, etc.), a phenylene group or A group formed by combining these under conditions where oxygen atoms do not continue to each other is mentioned.
Examples of the biphenyltetracarboxylic acid include 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, and 2,2 ′, 3,3′-biphenyltetracarboxylic acid. Carboxylic acid is mentioned.
Examples of the naphthalenetetracarboxylic acid include 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,2,4,5-naphthalenetetracarboxylic acid, 4,5,8-naphthalenetetracarboxylic acid.
Examples of the tetracarboxylic acid having a structure in which the benzene rings of the two o-benzenedicarboxylic acid groups are bonded with a linking group include 3,3 ′, 4,4′-diphenylethertetracarboxylic acid, 3, 3 ′, 4,4′-diphenylsulfonetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 2,2-bis (3,4-benzenedicarboxylic acid) hexafluoropropane, 1,4 -Bis (3,4-benzenedicarboxylic acid) benzene, 2,2-bis [4- (3,4-phenoxydicarboxylic acid) phenyl] propane, 1,1-bis (2,3-dicarboxyphenyl) ethane, Aromatic tetracarboxylic acids such as 4,4 ′-(4,4′-isopropylidenebisphenoxy) diphthalic acid may be mentioned.

  As the alicyclic tetracarboxylic acid, a substituted or unsubstituted cycloalkyl group (preferably having 4 to 7 carbon atoms), a polyalicyclic type in which a plurality of alicyclic rings are composed of two or more common carbon atoms ( Preferably, 4 hydrogen atoms in a bridged ring type (preferably having 7 to 12 carbon atoms) in which the ring-forming carbon atoms further form a ring by a chemical bond are substituted with carboxylic acid groups. Specifically, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetra Carboxylic acid, 3-methyl-4-cyclohexene-1,2,4,5-tetracarboxylic acid, 5- (1,2-dicarboxyethyl) -3-methyl-3-cyclohexene-1,2-dica Boronic acid, [1,1′-bi (cyclohexane)]-3,3 ′, 4,4′-tetracarboxylic acid, [1,1′-bi (cyclohexane)]-2,3,3 ′, 4 ′ Tetracarboxylic acid, [1,1′-bi (cyclohexane)]-2,2 ′, 3,3′-tetracarboxylic acid, 4,4′-methylenebis (cyclohexane-1,2-dicarboxylic acid), 4, 4 ′-(propane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), 4,4′-oxybis (cyclohexane-1,2-dicarboxylic acid), 4,4′-thiobis (cyclohexane-) 1,2-dicarboxylic acid), 4,4′-sulfonylbis (cyclohexane-1,2-dicarboxylic acid), 4,4 ′-(dimethylsilanediyl) bis (cyclohexane-1,2-dicarboxylic acid), 4, 4 '-(tetrafluoro Lopan-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), octahydropentalene-1,3,4,6-tetracarboxylic acid, bicyclo [2.2.1] heptane-2,3 , 5,6-tetracarboxylic acid, 6- (carboxymethyl) bicyclo [2.2.1] heptane-2,3,5-tricarboxylic acid, bicyclo [2.2.2] octane-2,3,5, 6-tetracarboxylic acid, bicyclo [2.2.2] oct-5-ene-2,3,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] decane-3,4 7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] dec-7-ene-3,4,9,10-tetracarboxylic acid, 9-oxatricyclo [4.2.1. Suitable examples include [02,5] nonane-3,4,7,8-tetracarboxylic acid. Door can be. These can be used alone or in combination of two or more.

  Examples of the lower alcohol include methanol, ethanol, 2-propanol and the like.

  Although it does not specifically limit as a tetracarboxylic-acid component, The improvement of the availability, the adhesiveness to the metal layer which is the effect of this invention, the reduction | decrease of a sagging, and / or the reduction of a haze effectively show | play. In view of the above, aromatic tetracarboxylic acid is preferably used, and in particular, tetramellitic acid, biphenyltetracarboxylic acid, and tetra having a structure in which benzene rings of two o-benzenedicarboxylic acid groups are bonded to each other through a linking group. It is preferably at least one selected from carboxylic acids, dianhydrides of these acids, and esterified products of lower alcohols of these acids, and in particular, biphenyltetracarboxylic acid (especially 3,3 ′, 4,4 ′). -Biphenyltetracarboxylic acid), pyromellitic acid, and acid anhydrides and esterified products of these lower alcohols. It is preferable that a kind.

  In the present invention, in addition to the fluorine-free aromatic diamine having a structure other than the general formula (1) and having 1 to 4 benzene nuclei, the polyimide itself may be fluorine-free. preferable. Therefore, it is preferable that the polyimide of the present invention is produced from a fluorine-free tetracarboxylic acid and a fluorine-free diamine component. More preferably, the polyimide of the present invention is preferably a halogen-free one prepared from a halogen-free tetracarboxylic acid and a halogen-free diamine component.

  The ratio of the tetracarboxylic acid component and the diamine component used in the present invention is approximately equimolar, preferably 0.8 to 1.2, more preferably 0.9 to tetracarboxylic acid component per 1 mol of diamine component. The ratio is about 1.1 mol.

  The polyimide of the present invention can be produced by reacting a tetracarboxylic acid component and a diamine component in a solvent. Here, “reacting” means that a tetracarboxylic acid component and a diamine component react to form an imide ring while forming a polyimide skeleton, that is, polymerization / imidization. Therefore, conventionally known polymerization and imidization methods can be suitably used. For example, the tetracarboxylic acid component and the diamine component can be heated at a temperature of about 100 to 200 ° C. in a solvent to be polymerized and imidized in one step. Further, a tetracarboxylic acid component and a diamine component are reacted in a solvent at a temperature of less than about 100 ° C. to obtain a polyimide precursor (polyamic acid), and then heated to about 100 to 200 ° C. for imidization or dehydration. It can also be imidized by a chemical imidizing agent such as acetic anhydride / pyridine system or dicyclohexylcarbodiimide which is a cyclizing reagent. In the imidization reaction, an azeotropic agent such as toluene or xylene may be added and reacted to remove the generated water from the system.

  The solvent used in the reaction is not particularly limited as long as it provides a solvent environment for obtaining a polyimide by suitably reacting (polymerizing / imidizing) a tetracarboxylic acid component and a diamine component. N, N-dimethylformamide Amide solvents such as N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, Cyclic ester solvents such as γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), tetraglyme, etc. The grits Lumpur solvents, m- cresol, p- cresol, 3-chlorophenol, phenol solvents such as 4-chlorophenol, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide or the like is employed. Furthermore, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, tetrahydrofuran Dimethoxyethane, diethoxyethane, dibutyl ether, ethanol, methanol and the like can also be used. These may be mixed and used as long as they provide a solvent environment for obtaining polyimide. If necessary, an aromatic hydrocarbon solvent such as benzene, toluene or xylene may be used in combination.

  In the present invention, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-, which is aprotic and has a boiling point of 150 to 220 ° C. Ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, γ-butyrolactone and the like can be suitably used.

When the polyimide of the present invention is produced by thermal imidization or chemical imidization in a solvent, the structural unit represented by the following formula (7) and the structural unit represented by the following formula (8) May be represented as having
(In the formula, A ¹ is a tetravalent tetracarboxylic acid residue, and D ¹ is a divalent group represented by the general formula (6).)

(In the formula, A ² is a tetravalent tetracarboxylic acid residue and may be the same as or different from A ^1. D ² has a structure other than that of the general formula (6) and has a benzene nucleus. Is a fluorine-free divalent aromatic diamine residue having 1 to 4

(Wherein R ¹ , R ² , R ³ and R ⁴ are the same as those in the general formula (1))

The tetracarboxylic acid residue represented by A ¹ and A ^2, include residues of the tetracarboxylic acid component, the above description of the tetracarboxylic acid component are all the tetracarboxylic acid residue is derived from tetra This applies to carboxylic acids. The fluorine-free divalent aromatic diamine residue having a structure other than the general formula (6) represented by D ² and having 1 to 4 benzene nuclei is other than the general formula (1) described above. And a fluorine-free divalent aromatic diamine residue having 1 to 4 benzene nuclei, and all the explanations of the aromatic diamine described above are derived from the aromatic diamine residue. This is true for aromatic diamines. Moreover, the ratio of the preferable mole number of the structural unit represented by Formula (7) in all the structural units of the said polyimide is the preferable mole number of the diamine compound represented by the said Formula (1) in the diamine component mentioned above. It is the same as the ratio. Similarly, in the total structural units of the polyimide, preferred proportion of the structural unit is the residue of a diamine D ² a structural unit represented by the formula (8) is represented by the general formula (2) described above It is the same as the preferable ratio of the diamine represented by General formula (2) in a diamine component. Similarly, among all the structural units of the polyimide, structural units represented by the formula (8), wherein D ² is a residue of a diamine having a structure other than the general formulas (1) and (2) A preferable ratio is the same as the preferable ratio of the diamine of structures other than General formula (1) and (2) in the diamine component mentioned above.

  The diamine represented by the general formula (1) used for the production of the polyimide of the present invention has an ethynyl group as described above. And when the polyimide of this invention is manufactured by thermal imidation of 200 degreeC or more, for example, this ethynyl group may raise | generate a random crosslinking reaction in a molecule | numerator in the case of thermal imidation. Such crosslinked polyimide is also included in the polyimide of the present invention.

Next, the polyimide film of the present invention will be described. The polyimide film of the present invention is a polyimide film containing the polyimide of the present invention. The polyimide film of the present invention includes those using the polyimide of the present invention as a part of the constituent material of the film. For example, a single layer film using the polyimide of the present invention, a multilayer film using the polyimide of the present invention in one layer, a film having the polyimide of the present invention on the surface layer of the film, a polyimide of the present invention in the film Is also included. Although not particularly limited, the thickness of the polyimide film of the present invention is 0.1 μm to 500 μm, preferably 1 μm to 250 μm, more preferably 2.5 μm to 120 μm, still more preferably 5 μm to 75 μm, particularly Preferably, it is 7.5 micrometers-50 micrometers.
As a method for producing a polyimide film, a known method can be arbitrarily used.

  Next, the polyimide metal laminate of the present invention will be described. The polyimide metal laminate of the present invention is characterized in that a metal layer is laminated directly or via an adhesive on the polyimide film of the present invention. Examples of the metal layer include copper, aluminum, iron, gold, and alloys thereof such as stainless steel. Especially the polyimide film of this invention is excellent in adhesiveness with materials, such as base materials, such as metal foil, and an adhesive agent. For this reason, as a polyimide laminated body of this invention, the polyimide metal laminated body by which the polyimide film and the metal layer were laminated | stacked directly or via the adhesive agent can be obtained suitably.

  Although not necessarily limited, as a method for producing a polyimide metal laminate, (1) a polyimide film and a substrate (for example, a metal foil) are pressed or heated and pressed directly or via an adhesive. (2) A method of directly forming a metal layer on a polyimide film by a wet method (plating) or a dry method (metalizing such as vacuum deposition or sputtering), (3) On a substrate such as a metal foil , A method of applying the above-described polyamic acid-containing liquid or polyimide-containing liquid, and drying and imidizing (drying in the case of a polyimide-containing liquid).

  As described above, the polyimide film and polyimide metal laminate of the present invention (including both laminates in which a film and a metal layer are laminated via an adhesive layer, and laminates in which a metal layer is directly formed on the film) Are printed circuit boards, flexible printed circuit boards, TAB tapes, COF tapes or metal wiring, and cover substrates such as metal wiring and chip members such as IC chips, liquid crystal displays, organic electroluminescence displays, electronic paper, It can be used as a material for electronic parts such as a base substrate such as a solar cell and electronic equipment.

Next, the polyamic acid of the present invention will be described.
One feature of the polyamic acid of the present invention is that it has a structural unit represented by the general formula (4) and a structural unit represented by the following general formula (5). The polyamic acid of the present invention is used as a precursor for obtaining the above-described polyimide of the present invention.

(In the formula, A ¹ is a tetravalent tetracarboxylic acid residue, D ¹ is a divalent group represented by the general formula (6), and X ¹ and X ² are each independently hydrogen. An atom, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.)

(In the formula, A ² is a tetravalent tetracarboxylic acid residue and may be the same as or different from A ^1. D ² has a structure other than that of the general formula (6) and has a benzene nucleus. 1 to 4 fluorine-free divalent aromatic diamine residues, and X ³ and X ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 to 9 carbon atoms. A silyl group.)
(Wherein R ¹ , R ² , R ³ and R ⁴ are the same as those in the general formula (1))

The tetracarboxylic acid residue represented by A ¹ and A ^2, include residues of the tetracarboxylic acid component, the above description of the tetracarboxylic acid component are all the tetracarboxylic acid residue is derived from tetra This applies to carboxylic acids. The fluorine-free divalent aromatic diamine residue having a structure other than the general formula (6) represented by D ² and having 1 to 4 benzene nuclei is other than the general formula (1) described above. And a fluorine-free divalent aromatic diamine residue having 1 to 4 benzene nuclei, and all the explanations of the aromatic diamine described above are derived from the aromatic diamine residue. This is true for aromatic diamines. Moreover, the ratio of the preferable molar number of the structural unit represented by Formula (4) in all the structural units of the polyamic acid of this invention is preferable of the diamine compound represented by the said Formula (1) in the diamine component mentioned above. It is the same as the mole ratio. Similarly, in the total structural units of the polyamic acid of the present invention, a preferred proportion of structural units represented by formula (5), wherein D ² is a residue of a diamine represented by general formula (2) Is the same as the preferable ratio of the diamine represented by the general formula (2) in the diamine component described above. Similarly, among all the structural units of the polyamic acid of the present invention, the structural unit represented by the formula (5), and D ² is a residue of a diamine having a structure other than the general formulas (1) and (2). The preferable ratio of the structural unit is the same as the preferable ratio of the diamine having a structure other than the general formulas (1) and (2) in the diamine component.

The polyamic acid can be obtained by reacting the tetracarboxylic acid component and the diamine component. For example, an approximately equimolar amount is reacted in an organic solvent to maintain a polyamic acid solution (a uniform solution state is maintained). Part of which may be imidized). Alternatively, it combines the two or more polyamic acid is excessive advance either component, after combining the respective polyamic acid solution may be mixed under reaction conditions. The polyamic acid solution thus obtained can be used for the production of a self-supporting film as it is or after removing or adding a solvent if necessary.
In carrying out the polymerization reaction of the polyamic acid, the organic solvent described above can be used. The concentration of all monomers in the organic solvent may be appropriately selected according to the purpose of use and the purpose of production. It is preferably from 25% by mass, particularly from 10% by mass to 22% by mass, from the viewpoints of efficiently promoting the reaction and suppressing the production of by-products.

  As an example of the production of polyamic acid, the polymerization reaction of a tetracarboxylic acid component and a diamine component is carried out, for example, by mixing both components in the above-mentioned quantitative ratio, and at a reaction temperature of 100 ° C. or less, preferably about 80 ° C. or less. The reaction can be carried out by reacting for 2 to 60 hours to obtain a polyamic acid solution.

  If necessary, an imidization catalyst, an organic phosphorus-containing compound, inorganic fine particles, and the like may be added to the polyamic acid solution as long as it is thermal imidization. In the case of chemical imidization, a cyclization catalyst, a dehydrating agent, inorganic fine particles and the like may be added to the polyamic acid solution as necessary.

  Examples of the imidization catalyst include a substituted or unsubstituted nitrogen-containing heterocyclic compound, an N-oxide compound of the nitrogen-containing heterocyclic compound, a substituted or unsubstituted amino acid compound, an aromatic hydrocarbon compound having a hydroxyl group, or an aromatic heterocyclic compound. Cyclic compounds, particularly 1,2-dimethylimidazole, N-methylimidazole, N-benzyl-2-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, N-benzyl-2-methylimidazole. Lower alkyl imidazole, benzimidazole such as 5-methylbenzimidazole, isoquinoline, 3,5-dimethylpyridine, 3,4-dimethylpyridine, 2,5-dimethylpyridine, 2,4-dimethylpyridine, 4-n- Suitable for substituted pyridines such as propylpyridine It can be used. The amount of the imidization catalyst used is preferably about 0.01 to 2 times equivalent, particularly about 0.02 to 1 times equivalent to the amic acid unit of the polyamic acid. By using an imidization catalyst, properties of the resulting polyimide film, particularly elongation and end resistance, may be improved.

  Cyclization catalysts include aliphatic tertiary amines such as trimethylamine and triethylenediamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as isoquinoline, pyridine, α-picoline and β-picoline. Etc.

  Examples of the dehydrating agent include aliphatic carboxylic acid anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride, and aromatic carboxylic acid anhydrides such as benzoic anhydride.

In order to produce a polyimide precursor containing a structural unit in which the general formulas (4) and (5), X ^{1 to} X ⁴ are an alkyl group having 1 to 6 carbon atoms or an alkyl silyl group having carbon atoms, After the polyamic acid is produced as described above, it can be produced by reacting with an esterifying agent to carry out esterification, or by reacting with a known silylating agent to carry out a silylation reaction.

<Preferable production method of polyimide film>
As described above, the polyimide film of the present invention is not limited by its production method, but one of the preferred methods for producing a polyimide film is shown below in terms of exhibiting the effect of reducing sagging. In this production method, a solution in which the above polyamic acid is dissolved in a solvent is cast or applied on a support and then heated to obtain a self-supporting film which is long in one direction, and the obtained self-supporting film Is peeled off from the support and heated at a maximum heating temperature of 250 ° C. or more and 500 ° C. or less in a state where both edges in the width direction of the film are fixed.

<Production of self-supporting film of polyamic acid solution>
For the self-supporting film of the polyamic acid solution, the polyamic acid solution is cast-coated on the support to the extent that it becomes self-supporting (meaning the stage before the normal curing process), for example, peeling from the support. It is manufactured by heating to such an extent that it can be produced.

  The solid content concentration of the polyamic acid solution used in the present invention is not particularly limited as long as it has a viscosity range suitable for production, but is usually preferably 5% by mass to 30% by mass, and more preferably 8% by mass to 25% by mass. More preferably, it is more preferably 10% by mass to 22% by mass.

  The heating temperature and heating time during the production of the self-supporting film can be appropriately determined. In the thermal imidization, for example, the heating may be performed at a temperature of 50 to 180 ° C. for about 1 to 60 minutes.

  The support is not particularly limited as long as it can cast a polyamic acid solution, but a smooth base material is preferably used. For example, a glass substrate, a metal drum or belt such as stainless steel, or the like is used. Usually, the self-supporting film obtained has a long shape in one direction, for example, a long shape.

<Heat treatment (imidization) step>
Next, the self-supporting film is heat-treated to obtain a polyimide film. In the heat treatment step, heating is performed so that the maximum heating temperature is preferably 250 ° C. or higher, 300 ° C. or higher, more preferably 350 ° C. or higher, and further preferably 400 ° C. or higher. The upper limit of the heating temperature may be a temperature at which the properties of the polyimide film do not deteriorate, and is preferably 500 ° C. or less, more preferably 490 ° C. or less, further preferably 480 ° C. or less, and particularly preferably 450 ° C. or less.

  Examples of the heat treatment include the following forms. It is appropriate that the imidation of the polymer and the evaporation / removal of the solvent are first carried out gradually at a temperature of about 100 ° C. to less than 350 ° C. for about 0.05 to 5 hours, particularly 0.1 to 3 hours. In particular, the heat treatment is performed stepwise at a relatively low temperature of about 100 ° C. to about 170 ° C. for about 0.5-30 minutes, and then at a temperature above 170 ° C. and below 220 ° C. The secondary heat treatment is preferably performed for 0.5 to 30 minutes, and then the third heat treatment is performed at a high temperature exceeding 220 ° C. and lower than 350 ° C. for about 0.5 to 30 minutes. Furthermore, it is preferable to perform the fourth high-temperature heat treatment at a high temperature of 350 ° C. to 500 ° C. Also, this heating process can be performed sequentially or continuously.

  The heat treatment (imidization) of the self-supporting film may be carried out on the support or may be peeled off from the support. However, in this production method, the heat treatment is performed in order to exert the slack effect. At this time, the self-supporting film is peeled off from the support, and the heat treatment is performed in a state where both edges in the width direction of the film are fixed. The heat treatment is performed, for example, in a curing furnace. The width direction of the film is a direction perpendicular to the longitudinal direction of the long self-supporting film and is a direction horizontal to the surface of the film. Fixing of both end edges in the width direction of the film is performed by a support member such as a pin tenter, a clip, a chuck, or a frame. At the time of heating, you may expand / contract in the width direction of a film, or the length direction as needed.

  Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples. In addition, this invention is not limited to a following example.

<Used diamine, tetracarboxylic dianhydride, solvent>
(Diamine)
2,4-bis (4-aminoanilino) -6-anilino-1,3,5-triazine (p-ATDA)
2,4-bis (p-aminoanilino) -6- (p-ethynylanilino) -1,3,5-triazine (EDA)
・ 4,4'-diaminodiphenyl ether (ODA)
・ P-Phenylenediamine (PPD)
(Tetracarboxylic dianhydride)
・ 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (s-BPDA)
・ Pyromellitic dianhydride (PMDA)
(solvent)
・ N, N-dimethylacetamide (DMAc)

[Comparative Example 1]
After adding a predetermined amount of DMAc and p-ATDA and ODA as a diamine component to the polymerization tank, s-BPDA as an acid component is gradually added to the diamine component and allowed to react while stirring at room temperature. A polyamic acid polymerization solution (polyimide precursor solution) having a solid content concentration of 18% by mass was obtained. Then, monostearyl phosphate triethanolamine salt is added to the polyamic acid polymerization solution at a ratio of 0.25 parts by mass with respect to 100 parts by mass of the polyamic acid, mixed uniformly, filtered under pressure, and subjected to polyamide filtration. An acid solution was obtained. The molar ratio of p-ATDA: ODA was 20:80.

[Comparative Examples 2 and 3]
A polyamic acid solution was obtained in the same manner as in Comparative Example 1 except that the amount of p-ATDA and ODA was changed so that the molar ratio of s-BPDA: ODA: p-ATDA was the ratio described in Table 1 below. .

[Examples 1 to 5]
Polyamide in the same manner as in Comparative Example 1, except that EDA was used without using p-ATDA, and the amount of raw materials was adjusted so that the molar ratio of s-BPDA: ODA: EDA was the ratio shown in Table 1 below. An acid solution was obtained.

[Examples 6 and 7]
Except for using EDA in addition to s-BPDA, ODA, and p-ATDA, and adjusting the amount of raw material so that the molar ratio of s-BPDA: ODA: p-ATDA: EDA is the ratio described in Table 1 below, A polyamic acid solution was obtained in the same manner as in Comparative Example 1.

[Production of polyimide film]
The polyamic acid solution was cast into a thin film on a glass plate, heated at 132 ° C. for 6 minutes using an oven, and then peeled from the glass plate to obtain a self-supporting film. The self-supporting film was fixed to a pin tenter, heated from 150 ° C. to 350 ° C. at a heating rate of 20 ° C./min using an oven, and further maintained at 350 ° C. for 9 minutes to obtain a 35 μm thick polyimide film. .

<Evaluation of film properties>
[Sag]
The film was placed on the upper surface of a flat table in a state where the film was turned upside down. Both ends in the film width direction were fixed with a tape, and the height from the top surface of the base at the top of the convex portion convex upward was measured using a ruler. The results are shown in Table 1.

[Haze]
The haze of the polyimide film was measured using HAZE MATER NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with the standard of JIS K7136. The results are shown in Table 1.

[Adhesive strength (for thermocompression bonding)]
Copper foil (3EC-III (35 μm) manufactured by Mitsui Mining & Smelting Co., Ltd.)) was pressed and bonded to both surfaces of the polyimide film for 10 minutes at 340 ° C. and 4 MPa. The polyimide film was pressure-bonded to the roughened surface of the copper foil. The obtained polyimide metal laminate was cut into a width of 5 mm to obtain a peel test piece. Peel strength was measured using a small tensile testing machine (EZ-S500N) manufactured by Shimadzu Corporation, with a T peel and the A side (the side opposite to the substrate side when making a self-supporting film) facing up. Measurement was performed under the condition of 50 mm / min. Table 2 shows the adhesive strength measured for the polyimide films of Examples 6 and 7. Table 2 shows the average value of five series. In peeling of a polyimide film and copper foil, it peels on the surface with the weaker adhesive force among the copper foil laminated | stacked on both surfaces of the polyimide film. Therefore, the measured peel strength is the peel strength of the surface with weaker adhesive force. The measurement was performed in an environment of a temperature of 23 ° C. and a relative humidity of 50%.

[Tg]
The solid viscoelasticity of the film in a temperature range from room temperature (about 25 ° C.) to 500 ° C. was measured using a solid viscoelasticity analyzer RSAIII manufactured by Rheometric Scientific F.E. under the following measurement conditions. The temperature at which the maximum of the obtained E ″ curve was located was defined as the glass transition temperature (Tg). The results are shown in Table 3.
(Measurement condition)
Measurement mode: Tensile mode Dynamic measurement frequency: 62.8 rad / sec (10 Hz)
Temperature rise: 3 ℃ / step
Atmosphere: In a nitrogen stream

[Linear thermal expansion coefficient (CTE)]
A polyimide film is cut into a strip with a width of 4 mm to make a test piece, and TMA / SS6100 (manufactured by SII NanoTechnology Co., Ltd.) is used. The temperature started to increase. After raising the temperature to 220 ° C. (1st), the temperature was immediately returned to room temperature, and again raised to 500 ° C. at 20 ° C./min (2nd). Table 3 shows the linear thermal expansion coefficient calculated between 50 ° C. and 200 ° C. at the time of 2nd measurement.

[5% weight loss temperature (Td5)]
Using a polyimide film as a test piece, the temperature was increased from 30 ° C. to 700 ° C. at a temperature increase rate of 10 ° C./min in a nitrogen stream using a calorimeter measuring device (Q5000IR) manufactured by TA Instruments. From the obtained weight curve, a 5% weight loss temperature was determined. The results are shown in Table 3.

[Initial elastic modulus, elongation at break, strength at break]
The polyimide film is punched into a IEC-540 (S) standard dumbbell shape to obtain a test piece (width: 4 mm), and the initial tensile elastic modulus is 30 mm between chucks and a tensile speed of 2 mm / min, using TENSILON manufactured by ORIENTEC. The elongation at break and the strength at break were measured. The results are shown in Table 3.

  From the results shown in Table 1, the polyimide of the present invention has an excellent effect in reducing sagging and haze due to the structure using the specific diamine represented by the general formula (1) and the specific aromatic diamine. Recognize. Moreover, it turns out that the polyimide of this invention is excellent in the adhesive strength with metal foil from the result shown in Table 2.

  From the results shown in Table 3, the polyimide of the present invention has the heat resistance, low linear thermal expansion coefficient, high elastic modulus, and high strength equivalent to those of conventional polyimide while exhibiting the effects described above for sagging, haze, and adhesive strength. Understand

[Examples 8 to 13, Comparative Examples 4 to 6]
A polyamic acid solution was obtained in the same manner as in Example 1 except that the type and amount of the diamine used were changed so that the composition of the tetracarboxylic acid used and / or the composition of the diamine was as described in Table 4. It was.

[Production of polyimide metal laminate]
A polyimide metal laminate was prepared using a polyamic acid solution. The polyimide metal laminate is prepared by applying a polyamic acid solution to a rolled copper foil (manufactured by JX Nippon Mining & Metals, BHY-13H-T, 18 μm thickness), heating at 120 ° C. for 10 minutes, and further to 400 ° C. for 20 minutes. It was obtained by heating up over time. The thickness of the polyimide film of the polyimide metal laminate was as shown in Table 4 below.

[Peel strength of polyimide metal laminate]
A 90 ° peel test was performed on the obtained polyimide metal laminate. The 90 ° peel strength was measured at a peel rate of 50 mm / min using a small tensile tester (EZ-S500N) manufactured by Shimadzu Corporation as a tester in an environment of a temperature of 23 ° C. and a relative humidity of 50%. The results are shown in Table 4.

  From the results of Table 4 above, the adhesive strength of the polyimide metal laminate obtained by applying and heating the polyamic acid solution on the polyimide metal laminate in the present invention is also as high as that of the laminate produced by thermocompression bonding. I understand.

[Examples 14 to 20]
In the following examples, the polyimide of the present invention is obtained by chemical imidization.
Kind and use so that tetracarboxylic acid component is 2.5 mmol in total, and diamine component used is 2.5 mmol in total so that the composition of tetracarboxylic acid used and / or the composition of diamine is as described in Table 5. A polyamic acid solution (solid content concentration: 13 to 20% by mass) was obtained in the same manner as in Example 1 except that the amount was changed and N-methyl-2-pyrrolidone (NMP) was used as a solvent. The obtained polyamic acid solution was diluted with NMP so that the solid content concentration was 5% by mass, and then 1.6 mL of acetic anhydride and 1.8 mL of pyridine were added dropwise with stirring, and the mixture was stirred at 100 ° C. for 24 hours for chemical reaction. Imidization was performed. After the chemical imidization was completed, the polyimide was precipitated with methanol, collected by filtration, and then dried under reduced pressure at room temperature to obtain a polyimide. The obtained polyimide was redissolved in NMP to obtain a polyimide solution having a concentration of 15% by mass. The polyimide solution thus obtained was cast into a thin film on a glass plate, and from room temperature, using an oven, 40 ° C., 60 ° C., 100 ° C., 150 ° C., 200 ° C., 250 ° C., 300 ° C., 350 ° C. And gradually increase the temperature,
Finally, it was cured at 350 ° C. for 30 minutes and peeled from the glass plate to obtain a polyimide film having a thickness of 35 μm.

Claims (11)

A polyimide obtained from a tetracarboxylic acid component and a diamine component,
As the diamine component, at least a diamine represented by the following general formula (1) and a fluorine-free aromatic diamine having a structure other than the general formula (1) and having 1 to 4 benzene nuclei are used. Polyimide.
(R ¹ , R ² , R ³ and R ⁴ in the formula each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.) The polyimide of Claim 1 whose said aromatic diamine is at least 1 sort (s) chosen from the compound represented by p-phenylenediamine, diamino diphenyl ethers, and following General formula (2).
(In the formula, R ⁵ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an aromatic group having 1 to 12 carbon atoms, and R ⁶ represents an alkyl group having 1 to 12 carbon atoms or an aromatic group having 1 to 12 carbon atoms. R ⁷ and R ⁸ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)   The polyimide according to claim 2, wherein the aromatic diamine is at least one selected from 4,4'-diaminodiphenyl ether and the compound represented by the general formula (2).   The tetracarboxylic acid component is at least one selected from pyromellitic acid, biphenyltetracarboxylic acid, dianhydrides of these acids, and esterified products of lower alcohols of these acids. Polyimide. The polyimide according to any one of claims 1 to 4, wherein the diamine represented by the general formula (1) is a compound represented by the following chemical formula (3).
  The polyimide according to any one of claims 1 to 5, wherein a proportion of the diamine represented by the general formula (1) is 2 mol% or more in the diamine component.   The polyimide in any one of Claims 1-6 whose ratio of the diamine represented by the said General formula (1) is 80 mol% or less in the said diamine component.   The polyimide film containing the polyimide in any one of Claims 1-7.   A polyimide metal laminate comprising the polyimide film according to claim 1 and a metal layer laminated on the polyimide film directly or via an adhesive. A polyamic acid having a structural unit represented by the following general formula (4) and a structural unit represented by the following general formula (5).
(In the formula, A ¹ is a tetravalent tetracarboxylic acid residue, D ¹ is a divalent group represented by the general formula (6), and X ¹ and X ² are each independently hydrogen. An atom, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.)

(In the formula, A ² is a tetravalent tetracarboxylic acid residue and may be the same as or different from A ^1. D ² has a structure other than that of the general formula (6) and has a benzene nucleus. 1 to 4 fluorine-free divalent aromatic diamine residues, and X ³ and X ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 to 9 carbon atoms. A silyl group.)
(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) A solution in which the polyamic acid according to claim 10 is dissolved in a solvent is cast or applied on a support and then heated to obtain a self-supporting film which is long in one direction, and the obtained self-supporting film The polyimide film is produced by heating at a maximum heating temperature of 250 ° C. or more and 500 ° C. or less in a state where both ends of the film in the width direction are fixed by peeling off the support.