JP2008143964A - Liquid crystal polyester solution composition and application thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal polyester film in which the formation of curl is reduced and in which water absorption is excellently low; and to provide a liquid crystal polyester solution composition providing the liquid crystal polyester film. <P>SOLUTION: [1] The liquid crystal polyester solution composition contains a liquid crystal polyester, a polyamic acid having an ion-exchanging group, and a nonprotonic solvent. [2] The polyamic acid is obtained from an aromatic tetracarboxylic acid dihydrate derivative and a diamine derivative having both of two amino groups and one or more ion-exchanging groups in the solution composition of [1]. [3] The substrate for a flexible printed circuit board is obtained by casting the solution composition on a base material on which a layer comprising a conductor is formed, and heat-treating the resultant product. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solution composition containing a liquid crystal polyester and a film obtained from the solution composition.

Liquid crystal polyester is excellent in heat resistance or low water absorption, and thus is suitably used for electrical, electronic, mechanical parts and the like. In particular, various studies have been made on the use of liquid crystalline polyester as an insulating base film of a flexible wiring board (hereinafter also referred to as “FPC”) (for example, see Patent Document 1). However, an FPC substrate in which a liquid crystal polyester film and a metal foil that can be a conductor layer are laminated may cause curling or wrinkles on the surface of the liquid crystal polyester film in the manufacturing process. It is known that when a FPC is manufactured by forming a fine circuit in a conductor layer, a product that can withstand practical use cannot be obtained.
As measures for improving such problems, various films obtained by alloying other resins with liquid crystal polyester have been studied. As an example, Patent Document 2 discloses pyromellitic acid dihydrate and 4,4′-diamino. It is disclosed that when a film obtained by alloying polyimide obtained from diphenyl ether and liquid crystal polyester is applied to an insulating base film of an FPC substrate, curling of the obtained FPC substrate can be reduced.

JP-A-2005-342980 (Claims) JP 2006008976 A (Example)

While the insulating base film disclosed in Patent Document 2 exhibits a favorable effect of reducing curl, the insulating base film itself has high water absorption (hygroscopicity). Since migration of metal ions occurs and affects connection reliability, there is a concern that the electrical characteristics of the FPC may be adversely affected.
An object of the present invention is to provide a liquid crystal polyester film that can reduce curling and can significantly reduce water absorption that adversely affects electrical characteristics when applied to electric and electronic parts, and a solution composition that can form the liquid crystal polyester film I will provide a.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

（式中、Ａｒ¹〜Ａｒ¹²は、それぞれ独立に単環式芳香族基または縮合多環式芳香族基を表す。さらに、Ａｒ¹とＡｒ²のうちいずれか１つはイオン交換基を有する芳香族基であり、Ａｒ³、Ａｒ⁴およびＡｒ⁵から選ばれるいずれか１つはイオン交換基を有する芳香族基であり、Ａｒ⁶、Ａｒ⁷およびＡｒ⁸から選ばれるいずれか１つはイオン交換基を有する芳香族基であり、Ａｒ⁹、Ａｒ¹⁰、Ａｒ¹¹およびＡｒ¹²から選ばれるいずれか１つはイオン交換基を有する芳香族基である。Ｚ₁、Ｚ₂は、それぞれ独立に直接結合、酸素原子、スルホニル基、カルボニル基、炭素数１〜６のアルキレン基または炭素数１〜６のフッ素置換アルキレン基を表す。） That is, the present invention provides the following [1].
[1] 5 to 40 parts by weight of polyamic acid having at least one repeating unit selected from the formulas (11) to (14) and 100 to 100000 parts by weight of an aprotic solvent with respect to 100 parts by weight of the liquid crystalline polyester Solution composition

(In the formula, Ar ^{1 to} Ar ¹² each independently represents a monocyclic aromatic group or a condensed polycyclic aromatic group. Furthermore, any one of Ar ¹ and Ar ² has an ion exchange group. Any one selected from Ar ³ , Ar ⁴ and Ar ⁵ is an aromatic group having an ion exchange group, and any one selected from Ar ⁶ , Ar ⁷ and Ar ⁸ is an ion; An aromatic group having an exchange group, and any one selected from Ar ⁹ , Ar ¹⁰ , Ar ¹¹ and Ar ¹² is an aromatic group having an ion exchange group, and Z ₁ and Z ₂ are each independently (Represents a direct bond, an oxygen atom, a sulfonyl group, a carbonyl group, an alkylene group having 1 to 6 carbon atoms, or a fluorine-substituted alkylene group having 1 to 6 carbon atoms.)

Furthermore, the present invention provides the following [2] to [5] as preferred embodiments according to the above [1].
[2] The polyamic acid is a polyamic acid having a reduced viscosity at 25 ° C. of 0.20 to 0.60 dL / g when N-methylpyrrolidone is used as a solvent to form a 0.5 g / dl solution. Solution composition.
[3] The polyamic acid is a repeating unit in which Ar ² is an aromatic group having an ion exchange group in the formula (11), and Ar ⁴ and / or Ar ⁵ in the formula (12) is an aromatic group having an ion exchange group. A repeating unit which is an aromatic group, a repeating unit in which Ar ⁶ is an aromatic group having an ion exchange group in the formula (13), and an aromatic group in which Ar ¹¹ and / or Ar ¹² is an aromatic group having an ion exchange group in the formula (14) The solution composition [4] the liquid crystalline polyester according to [1] or [2], which is a polyamic acid having at least one repeating unit selected from repeating units that are group groups, is represented by the following formula (1) to 30 to 80 mol% of the structural unit represented by the formula (1) with respect to the total [(1) + (2) + (3)] of all structural units including the structural unit represented by (3) Indicated by (2) Structural units are 35 to 10 mol%, structural units represented by the formula (3) is 35 to 10 mol%, [1] to [3] either solution composition (1) -O-Ar ²¹ -CO-
(2) —X—Ar ²² —Y—
(3) —CO—Ar ²³ —CO—
(In the formula, Ar ²¹ is at least one selected from the group consisting of 1,4-phenylene, 2,6-naphthylene and 4,4′-biphenylene, and Ar ²² is 1,4-phenylene, 1, And at least one selected from the group consisting of 3-phenylene and 4,4′-biphenylene, X and Y each independently represents an oxygen atom or an amino group, Ar ²³ represents 1,4-phenylene, 1, (It is at least one selected from the group consisting of 3-phenylene, 2,6-naphthylene, and a divalent group represented by the following formula (4).)
^{(4) -Ar 24 -Z-Ar} 25 -
(In the formula, Ar ²⁴ and Ar ²⁵ are each independently an aromatic group selected from the group consisting of 1,4-phenylene, 2,6-naphthylene and 4,4′-biphenylene, and Z is an oxygen atom, (At least one selected from the group consisting of a sulfonyl group and a carbonyl group.)

Moreover, this invention provides following [5]-[8] as an embodiment of the molded object obtained using one of the said liquid crystalline polyester compositions.
[5] A film obtained by casting the solution composition according to any one of [1] to [4] on a support, followed by heat treatment and peeling the support.
[6] A laminated film comprising a layer made of the film of [5] and a layer made of a conductor.
[7] A laminated film obtained by casting the solution composition according to any one of [1] to [6] on a base material on which a layer made of a conductor is formed, and then heat-treating it.
[8] A substrate for a flexible printed wiring board obtained using the laminated film of [6] or [7].

  The laminated film provided with the film obtained from the solution composition of the present invention can remarkably reduce the occurrence of curls and wrinkles. When such a laminated film is used as an FPC, when a conductor layer is processed to produce a wiring, it is easy to form a fine circuit, and since the water absorption of the film is low, the electrical characteristics are improved, and the flexible printed wiring Since it can be suitably used as a plate, it is industrially useful.

The composition of the present invention contains a liquid crystal polyester, a polyamic acid having at least one repeating unit selected from the above formulas (11) to (14), and an aprotic solvent, and is based on 100 parts by weight of the liquid crystal polyester. The polyamic acid is 5 to 40 parts by weight and the aprotic solvent is 100 to 100,000 parts by weight. In addition, 2 or more types of this liquid crystalline polyester may be contained, and 2 or more types of this polyamic acid may also be contained. When 2 or more types of liquid crystalline polyester or polyamic acid are contained, the sum total should just be the compounding quantity of the said range.
If the amount of the polyamic acid is too small, curling tends to occur, and if it is too large, when a film is produced as a molded article, unevenness occurs in the film, and the bending resistance, which is a required characteristic of FPC, deteriorates. More preferably, the polyamic acid is 10 to 40 parts by weight and particularly preferably 10 to 20 parts by weight with respect to 100 parts by weight of the liquid crystalline polyester.

  The reason why the film obtained from the solution composition of the present invention can reduce the curl is not clear, but the present inventors have disclosed the film obtained from the solution composition of the present invention in Patent Document 2. It has been found that it is less likely to be heated and expanded as compared with a conventional film. That is, it is estimated that the film obtained from the solution composition of the present invention has a reduced linear expansion coefficient related to heating, and curl reduction is achieved by the effect of reducing the linear expansion coefficient.

The polyamic acid contained in the solution composition of the present invention contains a repeating unit having an ion exchange group.
Here, as the ion exchange group, an acid group such as a carboxyl group (—COOH), a phosphonic acid group (—PO ₃ H ₂ ), a sulfonic acid group (—SO ₃ H), or an amino group (—NR′R ′). ', Where R' and R '' each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms). More preferred ion exchange groups are weak acid groups or weak basic groups, and specifically, carboxyl groups and amino groups are preferred. The acid group may be protected with an ester that is easily converted to an acid group by heat treatment during molding, and the amino group is a group that can be easily converted into an amino group by heat treatment during molding, such as a formyl group. It may be an amino group protected with. Further, as the acid group, a part thereof may form a salt with an alkali metal ion, an alkaline earth metal ion, a quaternary ammonium ion or the like, but it is preferable that all the acid groups are in the form of a free acid. . Further, as this, a part thereof may form a salt with chlorine ion, sulfate ion, nitrate ion or the like, but it is preferable that all basic groups are in the form of free basic groups.

（式中、Ｘはイオン交換基を表す。ｎ１、ｍ１は、それぞれ独立に０〜２の整数であり、ｎ１＋ｍ１は１以上である。同一繰返し単位に、Ｘが複数あるとき、それらは同一でも異なっていてもよい。） Specific examples of the repeating unit represented by the formula (11) include the following (P1) to (P3).

(In the formula, X represents an ion exchange group. N1 and m1 are each independently an integer of 0 to 2, and n1 + m1 is 1 or more. When there are a plurality of X in the same repeating unit, they may be the same. May be different.)

（式中、Ｘはイオン交換基を表す。ｎ２、ｍ２１、ｍ２２は、それぞれ独立に０〜２の整数であり、ｎ２＋ｍ２１＋ｍ２２は１以上である。同一繰返し単位に、Ｘが複数あるとき、それらは同一でも異なっていてもよい。） Specific examples of the repeating unit represented by the formula (12) include the following (P4) to (P9).

(In the formula, X represents an ion exchange group. N2, m21 and m22 are each independently an integer of 0 to 2, and n2 + m21 + m22 is 1 or more. When there are a plurality of X in the same repeating unit, They may be the same or different.)

（式中、Ｘはイオン交換基を表す。ｎ３１、ｎ３２、ｍ３は、それぞれ独立に０〜２の整数であり、ｎ３１＋ｍ３２＋ｍ３は１以上である。同一繰返し単位に、Ｘが複数あるとき、それらは同一でも異なっていてもよい。） ,
Specific examples of the repeating unit represented by the formula (13) include the following (P10) to (P15).

(In the formula, X represents an ion exchange group. N31, n32 and m3 are each independently an integer of 0 to 2, and n31 + m32 + m3 is 1 or more. When there are a plurality of X in the same repeating unit, They may be the same or different.)

（式中、Ｘはイオン交換基を表す。ｎ４１、ｎ４２、ｍ４１、ｍ４２は、それぞれ独立に０〜２の整数であり、ｎ４１＋ｍ４２＋ｍ４１＋ｍ４２は１以上である。同一繰返し単位に、Ｘが複数あるとき、それらは同一でも異なっていてもよい。） Specific examples of the repeating unit represented by the formula (14) include the following (P16) to (P24).

(In the formula, X represents an ion exchange group. N41, n42, m41 and m42 are each independently an integer of 0 to 2, and n41 + m42 + m41 + m42 is 1 or more. When there are a plurality of X in the same repeating unit, They may be the same or different.)

  The polyamic acid preferably has a reduced viscosity at 25 ° C. of 0.20 to 0.60 dL / g when N-methylpyrrolidone is used as a solvent to form a 0.5 g / dl solution, and is preferably 0.25 to 0.55 dL. / G is more preferable. The solution composition using the polyamic acid having the reduced viscosity in the above range is preferable for curling reduction because the linear expansion coefficient of the film can be further reduced when the film is formed. Since the compatibility between the polyimide produced by the ring-closing reaction and the liquid crystalline polyester is good, it is preferable because the film obtained by molding hardly causes unevenness.

The polyamic acid applied to the present invention is obtained by polymerizing an aromatic tetracarboxylic dianhydride derivative and an aromatic diamine derivative as monomers, and a polymerization step for obtaining the polyamic acid as a monomer that produces these polyamic acids. Or a monomer having an ion exchange group that does not participate in the ring closing reaction in which the polyamic acid forms an imide ring.
A suitable polyamic acid is obtained by polymerizing the aromatic diamine derivative using, as a monomer, a diamine derivative having one or more ion-exchange groups not involved in polymerization in addition to the two amino groups involved in polymerization. These are also preferred because they are simple in production.

Examples of the aromatic tetracarboxylic dianhydride derivative include 1,2,4,5-phenyltetracarboxylic dianhydride, 2,3,5,6-toluyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3 ′, 4′-biphenyltetracarboxylic acid Dianhydride (a-BPDA), pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 2,3,3 ′, 4′- Benzophenone tetracarboxylic dianhydride (a-BTDA), diphenylsulfone tetracarboxylic dianhydride, oxydiphthalic dianhydride (ODPA), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropa Dianhydride (6FDA), m-terphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, p-terphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride And 2,2-bis (3,4-dicarboxyphenyl) methane dianhydride.
Of these, tetracarboxylic dianhydrides having a biphenylene residue are preferable from the viewpoint of obtaining a high heat-resistant film. Specifically, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride is preferable. Products, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, and one or more selected from these are used. It is preferable.
As the repeating unit of polyamic acid using the aromatic tetracarboxylic dianhydride derivative having this biphenylene residue, in the above examples, (P10), (P16), (P17), (P19) or (P22).

In addition, as described above, the aromatic diamine compound derivative preferably has an ion exchange group that does not participate in a polymerization reaction for obtaining a polyamic acid in addition to two amino groups, and 1,3,5-triaminobenzene, 3,4-diaminobenzoic acid, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 3,3′-diaminobenzidine, 3,5-diaminobenzenesulfonic acid, 2,4-diaminobenzenesulfonic acid Can be mentioned. These can also use 2 or more types, and can also obtain a polyamic acid.
Of these aromatic diamine derivatives, 3,5-diaminobenzoic acid or 3,3′-diaminobenzidine is preferable from the viewpoint of obtaining a high heat-resistant film.
As described above, it is preferable to use an aromatic diamine derivative having an ion exchange group that does not participate in polymerization. However, the ion exchange group that does not participate in the polyamic acid polymerization reaction is not limited as long as the purpose of the present invention is not impaired. A part of the aromatic diamine derivative may be substituted with an aromatic diamine derivative that essentially does not have an ion exchange group that does not participate in the polyamic acid polymerization reaction, such as p-phenylenediamine.

Among the combinations of the aromatic tetracarboxylic dianhydride derivative and the aromatic diamine derivative, in order to obtain a polyamic acid for improving the heat resistance and dimensional stability of the obtained film in a balanced manner, the following (A) A combination selected from (D) is preferred.
(A): A combination comprising 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 3,5-diaminobenzoic acid.
(B): A combination consisting of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 3,3′-diaminobenzidine.
(C): A combination in which a part of 3,5-diaminobenzoic acid is substituted with p-phenylenediamine in the combination of (A).
(D): A combination in which a part of 3,3′-diaminobenzidine is substituted with p-phenylenediamine in the combination of (B).

  Here, the monomer ratio for obtaining the polyamic acid, that is, the use molar ratio of the aromatic tetracarboxylic dianhydride derivative to the aromatic diamine derivative is [aromatic tetracarboxylic dianhydride derivative]: [aromatic The diamine derivative] is preferably 1: 1.20 to 1: 0.80, more preferably 1: 1.15 to 1: 0.85. Thus, by using one of these monomers in excess with respect to the other, the resulting polyamic acid can be controlled within the preferred range of reduced viscosity.

  In the production of polyamic acid, for example, in the presence or absence of a reaction solvent, the reaction temperature is usually 0 to 80 ° C., preferably 5 to 60 ° C., and the reaction time is usually 0.5 to 48 hours, preferably 1 It can be carried out in 24 hours. The production conditions for obtaining these polyamic acids can be optimized as appropriate depending on the type of monomer from which the polyamic acid is obtained. When a reaction solvent is used, for example, a solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone (NMP), γ-butyrolactone, phenol, cresol, etc. can be used as the reaction solvent. it can. These reaction solvents may be used alone or in combination of two or more.

Thus, although the polyamic acid applied to the present invention can be obtained, the polyamic acid in which the carboxyl group in the polyamic acid is partially closed to form an imide ring is also applied to the solution composition of the present invention. As long as the solubility in an aprotic solvent is not significantly deteriorated, the present invention can be applied.
Examples of the method for producing the imide ring include i) a method of heating at a temperature of 0 to 140 ° C. in the presence of an imidizing agent, ii) a method of heating at a temperature of 150 to 350 ° C. for 5 to 180 minutes, Examples include a method using a chemical ring-closing agent.

Thus, when the carboxyl group in the polyamic acid is partially closed to form an imide ring, the progress of the reaction can be measured by infrared absorption spectroscopy. That is, it can be determined by the disappearance of the amide characteristic absorption band in the 2000 to 1000 cm ⁻¹ region and the generation of the imide absorption band, or by the disappearance of the amide group stretching vibration band per 3375 cm ⁻¹ . The infrared absorption spectrum may be measured by a transmission method using the polyamic acid powder or a solution method in which the polyamic acid is dissolved in an appropriate solvent.

Next, the liquid crystal polyester applied to the present invention will be described.
The liquid crystal polyester used in the present invention is a polymer called a thermotropic liquid crystal polymer, and forms a melt exhibiting optical anisotropy at a temperature of 450 ° C. or lower.

As a suitable liquid crystal polyester applied to the present invention, an aromatic liquid crystal polyester called I-type is preferable because of excellent heat resistance.
Aromatic liquid crystal polyesters mainly include structural units derived from aromatic hydroxycarboxylic acids, aromatic diols, aromatic diamines, aromatic amines having a hydroxyl group, aromatic dicarboxylic acids, etc. From the viewpoint of expression, when the total [(1) + (2) + (3)] of all structural units is 100 mol%, the structural unit represented by the formula (1) derived from the aromatic hydroxycarboxylic acid is 30 to 80 mol%, and the structural unit represented by the formula (2) derived from at least one compound selected from the group consisting of aromatic diols, aromatic diamines and aromatic amines having a hydroxyl group is 35 to 10 Preferred is an aromatic liquid crystal polyester in which the structural unit represented by the formula (3) derived from an aromatic dicarboxylic acid is composed of 35 to 10 mol%. Such aromatic liquid crystal polyester exhibits suitable liquid crystallinity and has good solubility in a suitable aprotic solvent described later.
(1) —O—Ar ²¹ —CO—
(2) —X—Ar ²² —Y—
(3) —CO—Ar ²³ —CO—
(In the formula, Ar ²¹ is at least one selected from the group consisting of 1,4-phenylene, 2,6-naphthylene and 4,4′-biphenylene, and Ar ²² is 1,4-phenylene, 1, And at least one selected from the group consisting of 3-phenylene and 4,4′-biphenylene, X and Y each independently represents an oxygen atom or an amino group, Ar ²³ represents 1,4-phenylene, 1, (It is at least one selected from the group consisting of 3-phenylene, 2,6-naphthylene, and a divalent group represented by the following formula (4).)
^{(4) -Ar 24 -Z-Ar} 25 -
(In the formula, Ar ²⁴ and Ar ²⁵ are each independently an aromatic group selected from the group consisting of 1,4-phenylene, 2,6-naphthylene and 4,4′-biphenylene, and Z is an oxygen atom, (At least one selected from the group consisting of a sulfonyl group and a carbonyl group.)

  The structural units represented by the formulas (1) to (3) are structural units derived from the above-mentioned compounds, respectively, and aromatic liquid crystal polyesters are obtained by condensing these structural unit-derived compounds by a known method. Can be obtained. Further, instead of the compounds that derive these structural units, ester-forming derivatives or amide-forming derivatives of these compounds may be used.

Here, an ester-forming derivative or an amide-forming derivative will be described.
As an ester-forming derivative of a compound having a carboxyl group, for example, the carboxyl group is a derivative having a high reaction activity such as an acid chloride or an acid anhydride that promotes a reaction to form a polyester or polyamide. And those in which the carboxyl group forms an ester with an alcohol or ethylene glycol that forms a polyester by a transesterification reaction.

  Examples of the ester-forming derivative of a phenolic hydroxyl group include those in which a phenolic hydroxyl group forms an ester with a carboxylic acid so that a polyester is produced by a transesterification reaction.

  Examples of the amide-forming derivative of an amino group include those in which an amino group forms an amide with a carboxylic acid so that a polyamide is formed by an amide exchange reaction.

Examples of the repeating structural unit of the aromatic liquid crystal polyester applied to the present invention include the following, but are not limited thereto.
Examples of the structural unit represented by the formula (1) include structural units derived from p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 4-hydroxy-4′-biphenylcarboxylic acid, and the like. Two or more structural units represented by (1) may be contained in the aromatic liquid crystal polyester. Among these structural units, an aromatic liquid crystal polyester containing a structural unit derived from 2-hydroxy-6-naphthoic acid is preferable.
The structural unit represented by the formula (1) is preferably 30 to 80% by mole, more preferably 35 to 65% by mole, and 40 to 55% by mole based on the total of all the structural units. Is more preferable. When the structural unit represented by the formula (1) is in the above range, the solubility in a solvent is good, and therefore the aromatic liquid crystal polyester can be easily converted into a film form by using a solution casting method described later. It is preferable from the above, and also from the viewpoint of maintaining liquid crystallinity.

Examples of the structural unit represented by the formula (2) include resorcin, hydroquinone, 3-aminophenol, 4-aminophenol, 1,4-phenylenediamine, 1,3-phenylenediamine, or 4,4′-diaminodiphenyl ether. , 4-hydroxy-4′-biphenyl alcohol and the like, and two or more structural units represented by the formula (2) may be contained in the aromatic liquid crystal polyester. Among these structural units, an aromatic liquid crystal polyester containing a structural unit derived from 4-aminophenol is preferable from the viewpoint of reactivity.
The structural unit represented by the formula (2) is preferably 10 to 35 mol%, more preferably 17.5 to 32.5 mol%, and more preferably 22.5 mol based on the total of all structural units. More preferably, it is ˜30.0 mol%. When the structural unit represented by the formula (2) is in the above range, liquid crystallinity is maintained, and the solubility in a solvent tends to be good.

  Examples of the structural unit represented by the formula (3) include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl ether-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid or benzophenone. The structural unit derived from -4,4'- dicarboxylic acid is mentioned, The structural unit shown by 2 or more types of Formula (3) may be contained in all the structural units. Among these structural units, an aromatic liquid crystal polyester containing a structural unit derived from isophthalic acid is preferable from the viewpoint of solubility in a solvent.

  The structural unit represented by the formula (3) is more preferably 10 to 35 mol%, more preferably 17.5 to 32.5 mol%, based on the total of all structural units, and 22. More preferably, it is 5 to 30.0 mol%.

Furthermore, from the viewpoint of improving the solubility in a solvent, Ar ²³ in the formula (3) is a structural unit derived from isophthalic acid or a structural unit that is a divalent group represented by the above (4). , Preferably at least 1 mol% or more, more preferably 1 to 35 mol%, even more preferably 10 to 30 mol%, even more preferably, particularly preferably An aromatic liquid crystal polyester containing 15 to 25 mol% of such structural units.

  The structural unit represented by the formula (2) is preferably substantially equimolarly equivalent to the structural unit represented by the formula (3). [Copolymerization ratio of the structural unit represented by the formula (2)] / [Copolymerization ratio of structural unit represented by formula (3)], and by setting it to 0.85 to 1.25, the degree of polymerization of the obtained aromatic liquid crystal polyester can also be controlled.

  The liquid crystal polyester applied to the present invention is a compound (monomer) for deriving each structural unit, that is, aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic amine, aromatic amine having a hydroxyl group, aromatic diol, or these Can be produced by polymerizing according to known methods (for example, methods described in JP-A Nos. 2002-220444 and 2002-146003).

  More specifically, the method for producing the liquid crystalline polyester of the present invention includes, for example, an aromatic hydroxycarboxylic acid corresponding to the structural unit represented by the formula (1) and a phenolic corresponding to the structural unit represented by the formula (2). Aromatic amine having a hydroxyl group, phenolic hydroxyl group and amino group of aromatic diamine are acylated with an excess amount of fatty acid anhydride to obtain an acylated product, and the resulting acylated product and a structural unit represented by formula (3) And an aromatic dicarboxylic acid corresponding to the structural unit represented by the formula (4) and a method of melt polymerization by transesterification / amide exchange.

  In the acylation reaction, the addition amount of the fatty acid anhydride is preferably 1.0 to 1.2 times equivalent to the total of the phenolic hydroxyl group and amino group, more preferably 1.05 to 1. .1 equivalent. If the addition amount of the fatty acid anhydride is within this range, it is possible to avoid the problem that the acylated product and the raw material monomer are not easily sublimated during transesterification / amide exchange (polycondensation), and the reaction system is blocked. There is a tendency that coloring of the obtained liquid crystal polyester is remarkably reduced.

  The acylation reaction is preferably performed at 130 to 180 ° C. for 5 minutes to 10 hours, more preferably at 140 to 160 ° C. for 10 minutes to 3 hours.

  The fatty acid anhydride used in the acylation reaction is not particularly limited, and examples thereof include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, anhydrous 2-ethylhexanoic acid, and monochloroacetic anhydride. , Dichloroacetic anhydride, trichloroacetic anhydride, monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, glutaric anhydride, maleic anhydride, succinic anhydride, β- Examples thereof include bromopropionic acid, and two or more of these may be used in combination. From the viewpoint of price and handleability, acetic anhydride, propionic anhydride, butyric anhydride or isobutyric anhydride is preferable, and acetic anhydride is more preferable.

  In the polymerization by transesterification / amide exchange, the acyl group in the acylated product is preferably 0.8 to 1.2 times equivalent to the carboxyl group.

  Polymerization by transesterification / amide exchange is preferably performed while increasing the temperature to 400 ° C. at a rate of 0.1 to 50 ° C./min, while increasing the temperature to 350 ° C. at a rate of 0.3 to 5 ° C./min. More preferably.

  When transesterification and amide exchange (polycondensation) of acylated products and carboxylic acids are performed, the equilibrium is shifted so that by-product fatty acids and unreacted fatty acid anhydrides are distilled out of the system, such as by evaporation. Is preferred.

The acylation reaction, transesterification / amide exchange (polymerization) may be performed in the presence of a catalyst. As the catalyst, those conventionally known as polyester polymerization catalysts can be used, such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, antimony trioxide and the like. And organic compound catalysts such as N, N-dimethylaminopyridine and N-methylimidazole.
Among these catalysts, heterocyclic compounds containing two or more nitrogen atoms such as N, N-dimethylaminopyridine and N-methylimidazole are preferably used (see JP 2002-146003 A).
The catalyst is usually added at the time of adding monomers, and it is not always necessary to remove it after acylation. If the catalyst is not removed, transesterification can be carried out as it is.

Polymerization by transesterification / amide exchange is usually carried out by melt polymerization, but melt polymerization and solid phase polymerization may be used in combination. The solid phase polymerization is preferably carried out by a known solid phase polymerization method after the polymer is extracted from the melt polymerization step and then pulverized into powder or flakes. Specifically, for example, a method of heat treatment in a solid state at 20 to 350 ° C. for 1 to 30 hours under an inert atmosphere such as nitrogen can be used. Solid phase polymerization may be carried out while stirring or in a state of standing without stirring. In addition, by providing an appropriate stirring mechanism, the melt polymerization tank and the solid phase polymerization tank can be made the same reaction tank. After the solid phase polymerization, the obtained aromatic liquid crystal polyester may be pelletized and molded by a known method.
Manufacture of liquid crystalline polyester can be performed using a batch apparatus, a continuous apparatus, etc., for example.

  The solution composition of the present invention can be obtained by dissolving the polyamic acid and the liquid crystal polyester obtained as described above in an aprotic solvent. The means for dissolving is not particularly limited, and a known method may be used. For example, a method of adding and mixing the polyamic acid and the liquid crystal polyester in an aprotic solvent, a solution in which the polyamic acid is dissolved in the aprotic solvent, and a solution in which the liquid crystal polyester is dissolved in the aprotic solvent Can be prepared separately and mixed. In this case, the resin concentration in the separately prepared solution may be obtained by a known method so as to be the number of parts by weight constituting the solution composition of the present invention. In addition, when polyamic acid and / or liquid crystalline polyester is dissolved in an aprotic solvent, heat treatment can be performed. However, when such heat treatment is performed, the polyamic acid becomes a polyimide by a ring-closing reaction, and the polyimide The heating temperature is set within a range not insolubilizing in the protic solvent.

  Examples of the aprotic solvent include halogen solvents such as 1-chlorobutane, chlorobenzene, 1,1-dichloroethane, 1,2-dichloroethane, chloroform, 1,1,2,2-tetrachloroethane, diethyl ether, tetrahydrofuran Ether solvents such as 1,4-dioxane, ketone solvents such as acetone and cyclohexanone, ester solvents such as ethyl acetate, lactone solvents such as γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate Nitrile solvents such as acetonitrile and succinonitrile, amide solvents such as N, N′-dimethylformamide, N, N′-dimethylacetamide, tetramethylurea and N-methylpyrrolidone, nitro solvents such as nitromethane and nitrobenzene , Jimechi And sulfur-containing solvents such as sulfoxide and sulfolane, and phosphorus-containing solvents such as hexamethylphosphoric acid amide and tri-n-butylphosphoric acid.

Among these, a solvent containing no halogen atom is preferable from the viewpoint of influence on the environment, and a solvent having a dipole moment of 3 to 5 is preferable from the viewpoint of solubility. Specifically, an amide solvent such as N, N′-dimethylformamide, N, N′-dimethylacetamide, tetramethylurea, N-methylpyrrolidone or a lactone solvent such as γ-butyrolactone is more preferable. '-Dimethylformamide, N, N'-dimethylacetamide or N-methylpyrrolidone is more preferably used.
The solution composition may contain a solvent other than the aprotic solvent as long as the production of the laminated film is not impaired.

The solution composition of the present invention comprises 5 to 40 parts by weight of the polyamic acid and 100 to 100000 parts by weight of the aprotic solvent with respect to 100 parts by weight of the liquid crystal polyester. The solution composition mixed in such a weight part becomes a solution composition having a solution viscosity that enables uniform coating on the substrate when cast and coated on the substrate to form a film.
Furthermore, from the viewpoint of workability and economy, the aprotic solvent is more preferably 100 to 9900 parts by weight, and further preferably 300 to 9800 parts by weight with respect to 100 parts by weight of the liquid crystal polyester.

  Moreover, the solution composition of this invention may be filtered with a filter etc. as needed, and may remove the fine foreign material contained in a solution composition.

  Furthermore, the solution composition of the present invention may contain a known filler or additive in addition to the liquid crystal polyester and polyamic acid as long as the purpose of the present invention is not impaired.

As the filler applied to the solution composition, an inorganic filler is preferable in terms of improving mechanical strength.
It is preferable that the compounding quantity of this inorganic filler is 10-50 weight part with respect to 100 weight of liquid crystalline polyester. It is preferable that the blending amount of the inorganic filler is in such a range because an effect of further reducing the linear expansion coefficient can be expected. More preferably, the blending amount is 20 to 40 parts by weight of the inorganic filler with respect to 100 parts by weight of the liquid crystalline polyester.

  Examples of the inorganic filler include silica, alumina, mica, glass, calcium carbonate, titanium oxide, aluminum borate, potassium titanate, barium titanate, strontium titanate, etc. It is preferable to use a fibrous or plate-like inorganic filler in view of expecting a reduction in the linear expansion coefficient.

Examples of the fibrous inorganic filler include alumina whisker, titanium oxide whisker, aluminum borate whisker, potassium titanate whisker, barium titanate whisker, basic magnesium sulfate whisker, zinc oxide whisker, and silicon carbide whisker. Among these, alumina whiskers or aluminum borate whiskers are particularly suitable.
The shape of the fibrous inorganic filler is preferably an average fiber length of 0.1 to 100 μm, more preferably an average fiber length of 0.1 to 10 μm, and most preferably an average fiber length of 0.2 to 1 μm. The aspect ratio (ratio of average fiber length to average fiber diameter) is preferably 3 or more, and more preferably 10 or more.

Examples of the plate-like inorganic filler include mica (mica), talc, plate-like alumina, and glass flakes.
The plate-like inorganic filler preferably has an average particle size of 0.1 to 100 μm, more preferably an average particle size of 0.1 to 10 μm. The aspect ratio (ratio of average particle diameter to average thickness) is preferably 3 or more, and more preferably 10 or more.

The above fibrous and plate-like inorganic fillers may be used in combination, and other spherical inorganic fillers such as silica, alumina, glass, calcium carbonate, titanium oxide, barium titanate, and strontium titanate are further added. It doesn't matter.
Such an inorganic filler can be applied to the solution composition, and can also be suitably used for a composition applied to the cast molding.

  The inorganic filler may be subjected to a surface treatment with a known coupling agent, anti-settling agent or the like.

  The solution composition obtained as described above can obtain a film by, for example, a known molding method such as a solution casting method, and the obtained film has a remarkably low linear expansion coefficient related to heat treatment, and can be used for electric / electronic parts. It can be a molded article having suitable low water absorption.

Especially, the suitable embodiment concerning the manufacturing method of the laminated | multilayer film suitable for FPC obtained using the solution composition of this invention is demonstrated.
First, the solution composition is applied to a substrate. Examples of the coating method include various means such as a roller coating method, a dip coater method, a spray coater method, a spin coating method, a curtain coating method, a slot coating method, and a screen printing method.

Next, the remaining solvent is removed from the coating film applied on the substrate. The method for removing the solvent is not particularly limited, but it is preferably performed by evaporation of the solvent. Examples of the method for evaporating the solvent include methods such as heating, reduced pressure, and ventilation. Among them, it is preferable to evaporate by heating from the viewpoint of production efficiency and handleability, and it is possible to evaporate by heating while ventilating. More preferred.
Drying is performed so that the amount of the solvent remaining in the coating film is 18% by weight or less in the coating film. Although drying temperature and time are arbitrary, in this invention, it is 160 degrees C or less, Preferably it is 150 degrees C or less, More preferably, it is 140 degrees C or less. If the drying temperature is too high, defects tend to occur on the coating film surface. Further, if the drying temperature is too low, it takes a long time to dry and the productivity is lowered. Pre-drying is performed so that the residual solvent amount in the coating film is 18% by weight or less, preferably 15% by weight or less. In the heat treatment, the treatment temperature is preferably in the range of 200 ° C. to 350 ° C., and the lower limit of the treatment temperature is more preferably 250 ° C. or more, and particularly preferably 280 ° C. or more. On the other hand, the upper limit of the treatment temperature is more preferably 340 ° C. or less, and particularly preferably 330 ° C. or less. The processing time is in the range of 10 minutes to 15 hours. The lower limit of the treatment time is more preferably 20 minutes or more, and particularly preferably 40 minutes or more. On the other hand, the upper limit of the treatment time is more preferably 12 hours or less, and particularly preferably 10 hours or less.
From the viewpoint of preventing deterioration of the base material, it is preferable to replace the processing environment with an inert gas such as nitrogen, argon, or neon, or to perform processing in a vacuum.

  Thus, by peeling the film produced on the base material from the base material, a film having a remarkably low linear expansion coefficient can be formed, and the film can be applied to various uses. In particular, the film obtained from the solution composition of the present invention has practical water absorption as an electric / electronic component and has a significantly reduced linear expansion coefficient, so it is preferably used as an insulating base film for FPC. Can do.

Although the film obtained as described above can be used by being attached to a metal foil to be a conductor layer of FPC, the solution composition of the present invention is directly cast-coated on the metal foil, An insulating base film can be produced on the foil. In this case, except for peeling the film from the base material, the above-mentioned “base material” can be replaced with “metal foil” and can be easily carried out. As the metal foil, gold, silver, copper, aluminum, A metal foil made of nickel is used, and copper foil is preferable.

  The thickness of the insulating base film formed on the metal foil obtained by such a method is not particularly limited, but is preferably about 1 to 500 μm from the viewpoint of film forming properties and mechanical properties. From the viewpoint of handleability, the thickness is more preferably 1 to 350 μm. When particularly high insulation is required, the thickness may be increased to 350 μm or more. The surface of the insulating base film may be subjected to a treatment such as a polishing treatment, a treatment with a chemical solution such as an acid or an oxidant, an ultraviolet irradiation treatment, or a plasma irradiation as necessary.

Since the laminated film obtained in this way has a significantly reduced linear expansion coefficient, it also exhibits the effect of suppressing curling and being excellent in dimensional stability. In addition, because of its low water absorption, not only FPC insulation base film, but also semiconductor package by build-up method, multilayer printed circuit board film for motherboard, flexible printed wiring board film, tape automated bondering film, It can also be suitably used for tag tape films, microwave oven packaging films, electromagnetic wave shielding films, high-frequency printed wiring boards, high-frequency cables, communication equipment circuits, package boards, and the like.
In addition, when applied to the substrate for FPC, the thickness of the insulating base film obtained from the solution composition of the present invention is preferably within the above range. However, when particularly high insulation is required for FPC use, the thickness is 350 μm or more. You can also
Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is defined by the terms of the claims, and further includes meanings equivalent to the description of the claims and all modifications within the scope.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely using an Example, this invention is not limited by an Example.
In addition, for the copper clad laminated films obtained in the following examples and comparative examples, the curling property, the linear expansion coefficient of the liquid crystal polyester film, the reduced viscosity of the polyamic acid solution composition, and the liquid crystal polyester-containing monolayer film are as follows. The water absorption of was measured.

(Curlability of copper-clad laminated film)
The liquid crystal polyester laminated film was cut out to 150 mm × 150 mm, placed on a surface plate with the copper foil side of the copper clad laminated film facing down, and the distance D (unit: mm) between both ends of the copper foil in the liquid crystal polyester laminated film was measured. .
When the degree of curling of the copper-clad laminate film was small, the curl amount (unit: mm) of the copper-clad laminate film was determined by the following formula (see FIG. 1. In FIG. 1, both ends of the copper foil of the copper-clad laminate film It is indicated by a distance D (unit: mm). The curl amount is in the range of 0 to 1.0 mm.
Curling amount of copper clad laminated film = (150−D) / 150
When the degree of curling of the copper-clad laminated film is large and rounds, it is said that the curl amount exceeds 1. Such a case is shown in FIG.
The smaller the curling amount, the smaller the curling property and the better.

(Linear expansion coefficient of liquid crystal polyester film)
Using a thermomechanical analyzer TMA manufactured by Seiko Electronics Co., Ltd., the temperature was increased at 5 ° C./min under a nitrogen stream, and the linear expansion coefficient of a liquid crystal polyester film at 50 to 100 ° C. was measured. When the take-up direction was MD and the perpendicular direction was TD, the respective linear expansion coefficients were measured.

(Reduced viscosity of polyamic acid solution composition)
A polyamic acid polymer solution was prepared by dissolving polyamic acid in N-methylpyrrolidone to a concentration of 0.5 g / dl. According to JIS-K6721, the passage time (t) was measured at 25 ° C. using an Uverode viscometer (capillary viscosity automatic measuring device manufactured by Shibayama Chemical Equipment Co., Ltd.). On the other hand, for the solvent N-methylpyrrolidone, the passage time (t0) at 25 ° C. was measured using the same apparatus, and the reduced viscosity (ηred) was calculated by the following formula.
ηred = (t / t0 -1) / C
In the above formula, C means the concentration (g / dL) of the polymer solution.

(Water absorption rate of liquid crystal polyester-containing monolayer film)
Using a flow tester (manufactured by Shimadzu Corporation, “CFT-500 type”), 0.3 g of a liquid crystal polyester-containing monolayer film was pressurized at 320 ° C. for 5 minutes under a load of 100 kg and cooled to 200 ° C. Produced. Next, the tablets were dried at 100 ° C. for 1 hour and stored overnight in a desiccator. Subsequently, using a pressure cooker, the water absorption was measured based on the weight change before and after the moisture absorption treatment after standing for 168 hours at 85 ° C. and 85% RH.

(Synthesis Example 1)
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 941 g (5.0 mol) of 2-hydroxy-6-naphthoic acid and 273 g (2.5 mol) of 4-aminophenol were added. ), 415.3 g (2.5 mol) of isophthalic acid and 1123 g (11 mol) of acetic anhydride. After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature was raised to 150 ° C. over 15 minutes under a nitrogen gas stream, and the temperature was maintained and refluxed for 3 hours.
Thereafter, the temperature was raised to 320 ° C. over 170 minutes while distilling off the by-product acetic acid and unreacted acetic anhydride, and the time when an increase in torque was observed was regarded as the completion of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature, pulverized with a coarse pulverizer, held at 250 ° C. for 10 hours in a nitrogen atmosphere, and the polymerization reaction proceeded in a solid phase. When 36 g of the obtained powder was added to 364 g of N-methyl-2-pyrrolidone and heated to 140 ° C., it completely dissolved and a brown transparent liquid crystal polyester solution composition was obtained. This solution composition was designated as Solution L1.

(Synthesis Example 2)
The inside of a 100 ml four-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then charged with 4.2 g (27.5 mmol) of 3,5-diaminobenzoic acid. Next, after 103.8 g of N-methyl-2-pyrrolidone was added and completely dissolved, 7.4 g (25.0 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added, After stirring for 8 hours at a reaction temperature of 25 ° C., a brown polyamic acid A solution composition was obtained. This solution composition was designated as Solution L2. The reduced viscosity of the solution L2 was 0.44 (dl / g).

(Synthesis Example 3)
The inside of a 100 ml four-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then charged with 7.1 g (33.0 mmol) of 3,3′-diaminobenzidine. Next, after 143.1 g of N-methyl-2-pyrrolidone was added and completely dissolved, 8.8 g (30.0 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added, After stirring for 8 hours at a reaction temperature of 25 ° C., a brown polyamic acid B solution composition was obtained. This solution composition was designated as Solution L3. The reduced viscosity of the solution L3 was 0.34 (dl / g).

(Synthesis Example 4)
The inside of a 100 ml four-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 1.0 g (6.6 mmol) of 3,5-diaminobenzoic acid and 2.3 g of p-phenylenediamine. (20.9 mmol) was charged. Next, after 95.6 g of N-methyl-2-pyrrolidone was added and completely dissolved, 7.4 g (25.0 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added, After stirring for 8 hours at a reaction temperature of 25 ° C., a brown polyamic acid C solution composition was obtained. This solution composition was designated as Solution L4. The reduced viscosity of the solution L4 was 0.32 (dl / g).

(Synthesis Example 5)
The inside of a 100 ml four-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring bar was purged with nitrogen, and then 1.4 g (6.6 mmol) of 3,3′-diaminobenzidine and 2.3 g of p-phenylenediamine. (20.9 mmol) was charged. Next, after 99.3 g of N-methyl-2-pyrrolidone was added and completely dissolved, 7.4 g (25.0 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added, After stirring for 8 hours at a reaction temperature of 25 ° C., a brown polyamic acid D solution composition was obtained. This solution composition was designated as Solution L5. The reduced viscosity of the solution L5 was 0.35 (dl / g).

(Synthesis Example 6)
The inside of a 100 ml four-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 4.6 g (30.0 mmol) of 3,5-diaminobenzoic acid was charged. Next, 120.6 g of N-methyl-2-pyrrolidone was added and completely dissolved, and then 8.8 g (30.0 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added, After stirring for 8 hours at a reaction temperature of 25 ° C., a brown and viscous polyamic acid E solution composition was obtained. This solution composition was designated as Solution L6. The reduced viscosity of the solution L6 was 0.75 (dl / g).

(Synthesis Example 7)
The inside of a 100 ml four-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 6.4 g (30.0 mmol) of 3,3′-diaminobenzidine was charged. Next, after 136.8 g of N-methyl-2-pyrrolidone was added and completely dissolved, 8.8 g (30.0 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added, After stirring for 8 hours at a reaction temperature of 25 ° C., a brown and viscous polyamic acid F solution composition was obtained. This solution composition was designated as Solution L7. The reduced viscosity of the solution L7 was 0.70 (dl / g).

(Synthesis Example 8)
The inside of a 100 ml four-necked flask equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 3.0 g (27.5 mmol) of 3,5-diaminobenzene was charged. Next, after 106.8 g of N-methyl-2-pyrrolidone was added and completely dissolved, 7.4 g (25.0 mmol) of pyromellitic dianhydride was added and stirred at a reaction temperature of 25 ° C. for 8 hours. A brown polyamic acid G solution composition was obtained. This solution composition was designated as Solution L8. The reduced viscosity of the solution L8 was 0.49 (dl / g).

(Example 1)
30 g of the solution L1 obtained in Synthesis Example 1 and 5.4 g of the solution L2 obtained in Synthesis Example 2 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After removing the solvent by heating at 120 ° C. in a drier so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere. A stretched laminated film was obtained. Table 1 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

(Example 2)
30 g of the solution L1 obtained in Synthesis Example 1 and 10.8 g of the solution L2 obtained in Synthesis Example 2 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After removing the solvent by heating at 120 ° C. in a drier so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere. A stretched laminated film was obtained. Table 1 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

(Example 3)
30 g of the solution L1 obtained in Synthesis Example 1 and 5.4 g of the solution L3 obtained in Synthesis Example 3 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After removing the solvent by heating at 120 ° C. in a drier so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere. A stretched laminated film was obtained. Table 1 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

Example 4
30 g of the solution L1 obtained in Synthesis Example 1 and 5.4 g of the solution L4 obtained in Synthesis Example 4 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After removing the solvent by heating at 120 ° C. in a drier so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere. A stretched laminated film was obtained. Table 1 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

(Example 5)
30 g of the solution L1 obtained in Synthesis Example 1 and 5.4 g of the solution L5 obtained in Synthesis Example 5 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After removing the solvent by heating at 120 ° C. in a drier so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere. A stretched laminated film was obtained. Table 1 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

(Comparative Example 1)
30 g of the solution L1 obtained in Synthesis Example 1 and 5.4 g of the solution L6 obtained in Synthesis Example 6 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After heating at 120 ° C. with a dryer to remove the solvent so that the amount of residual solvent in the resin layer was 18% by weight or less, heat treatment was performed at 320 ° C. in a nitrogen atmosphere. Many defects were observed on the surface of the obtained copper-clad laminate film, and the curlability and linear expansion coefficient could not be measured.

(Comparative Example 2)
30 g of the solution L1 obtained in Synthesis Example 1 and 5.4 g of the solution L7 obtained in Synthesis Example 7 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After heating at 120 ° C. with a dryer to remove the solvent so that the amount of residual solvent in the resin layer was 18% by weight or less, heat treatment was performed at 320 ° C. in a nitrogen atmosphere. Many defects were observed on the surface of the obtained copper-clad laminate film, and curling properties and linear expansion coefficient could not be measured.

(Comparative Example 3)
30 g of the solution L1 obtained in Synthesis Example 1 and 5.4 g of the solution L8 obtained in Synthesis Example 8 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After removing the solvent by heating at 120 ° C. in a dryer so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere, so that the copper-clad laminated film of liquid crystal polyester was gotten. Table 2 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

(Comparative Example 4)
30 g of the solution L1 obtained in Synthesis Example 1 and 13.5 g of the solution L2 obtained in Synthesis Example 2 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After heating at 120 ° C. with a dryer to remove the solvent so that the amount of residual solvent in the resin layer was 18% by weight or less, heat treatment was performed at 320 ° C. in a nitrogen atmosphere. Many defects were observed on the surface of the obtained copper-clad laminate film, and curling and linear expansion coefficient could not be measured.

(Comparative Example 5)
After casting the solution L1 obtained in Synthesis Example 1 on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment is 25 μm After removing the solvent by heating at 120 ° C. with a high-temperature hot air dryer so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere, so that the liquid crystal polyester copper A stretched laminated film was obtained. Table 2 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

(Comparative Example 6)
30 g of the solution L1 obtained in Synthesis Example 1 and 0.8 g of the solution L2 obtained in Synthesis Example 2 were mixed at room temperature and stirred. Next, this solution composition was cast on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment was 25 μm, and then hot hot air After removing the solvent by heating at 120 ° C. in a dryer so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere, so that the copper-clad laminated film of liquid crystal polyester was gotten. Table 2 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

(Comparative Example 7)
After casting the solution L2 obtained in Synthesis Example 2 on an electrolytic copper foil (3EC-VLP, thickness 18 μm, manufactured by Mitsui Kinzoku Co., Ltd.) using a film applicator so that the resin layer thickness after heat treatment is 25 μm After removing the solvent by heating at 120 ° C. with a high-temperature hot air dryer so that the residual solvent amount in the resin layer is 18% by weight or less, heat treatment is performed at 320 ° C. in a nitrogen atmosphere, so that the liquid crystal polyester copper A stretched laminated film was obtained. Table 2 shows the curlability, water absorption, and linear expansion coefficient of the obtained film.

It is a schematic diagram showing the curl property (when curl amount is 1 or less) of a copper clad laminated film. It is a schematic diagram showing the curl property (when the curl amount exceeds 1) of a copper clad laminated film.

Explanation of symbols

1 ... Metal foil (copper foil) of liquid crystal polyester laminated film
2 ... Resin layer of liquid crystal polyester laminated film

Claims (8)

A solution composition comprising 5 to 40 parts by weight of a polyamic acid having at least one repeating unit selected from the formulas (11) to (14) and 100 to 100000 parts by weight of an aprotic solvent with respect to 100 parts by weight of the liquid crystalline polyester .

(In the formula, Ar ^{1 to} Ar ¹² each independently represents a monocyclic aromatic group or a condensed polycyclic aromatic group. Furthermore, any one of Ar ¹ and Ar ² has an ion exchange group. Any one selected from Ar ³ , Ar ⁴ and Ar ⁵ is an aromatic group having an ion exchange group, and any one selected from Ar ⁶ , Ar ⁷ and Ar ⁸ is an ion; An aromatic group having an exchange group, and any one selected from Ar ⁹ , Ar ¹⁰ , Ar ¹¹ and Ar ¹² is an aromatic group having an ion exchange group, and Z ₁ and Z ₂ are each independently (Represents a direct bond, an oxygen atom, a sulfonyl group, a carbonyl group, an alkylene group having 1 to 6 carbon atoms, or a fluorine-substituted alkylene group having 1 to 6 carbon atoms.)   2. The solution composition according to claim 1, wherein the polyamic acid is a polyamic acid having a reduced viscosity at 25 ° C. of 0.20 to 0.60 dL / g when N-methylpyrrolidone is used as a solvent to form a 0.5 g / dl solution. . The polyamic acid is a repeating unit in which Ar ² is an aromatic group having an ion exchange group in the formula (11), and Ar ⁴ and / or Ar ⁵ is an aromatic group having an ion exchange group in the formula (12). A certain repeating unit, a repeating unit in which Ar ⁶ in the formula (13) is an aromatic group having an ion exchange group, and Ar ¹¹ and / or Ar ¹² in the formula (14) are an aromatic group having an ion exchange group. The solution composition according to claim 1 or 2, which is a polyamic acid having at least one repeating unit selected from certain repeating units. The liquid crystal polyester includes structural units represented by the following formulas (1) to (3), and the total [(1) + (2) + (3)] of all structural units is represented by the formula (1). The structural unit shown is 30 to 80 mol%, the structural unit represented by the formula (2) is 35 to 10 mol%, and the structural unit represented by the formula (3) is 35 to 10 mol%. The solution composition in any one of -3.
(1) —O—Ar ²¹ —CO—
(2) —X—Ar ²² —Y—
(3) —CO—Ar ²³ —CO—
(In the formula, Ar ²¹ is at least one selected from the group consisting of 1,4-phenylene, 2,6-naphthylene and 4,4′-biphenylene, and Ar ²² is 1,4-phenylene, 1, And at least one selected from the group consisting of 3-phenylene and 4,4′-biphenylene, X and Y each independently represents an oxygen atom or an amino group, Ar ²³ represents 1,4-phenylene, 1, (It is at least one selected from the group consisting of 3-phenylene, 2,6-naphthylene, and a divalent group represented by the following formula (4).)
^{(4) -Ar 24 -Z-Ar} 25 -
(In the formula, Ar ²⁴ and Ar ²⁵ are each independently an aromatic group selected from the group consisting of 1,4-phenylene, 2,6-naphthylene and 4,4′-biphenylene, and Z is an oxygen atom, (At least one selected from the group consisting of a sulfonyl group and a carbonyl group.)   The film obtained by heat-processing, after casting the solution composition in any one of Claims 1-4 on a support body, and peeling a support body.   A laminated film comprising a layer made of the film according to claim 5 and a layer made of a conductor.   A laminated film obtained by heat-treating the solution composition according to any one of claims 1 to 6 on a substrate on which a layer made of a conductor is formed. The board | substrate for flexible printed wiring boards obtained using the laminated | multilayer film of Claim 6 or 7.

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