JP5173207B2 - Solution composition - Google Patents

Description

  The present invention relates to a solution composition containing a liquid crystal polyester.

  The present invention relates to a liquid crystal polyester and a solution composition containing the liquid crystal polyester. Furthermore, it is related with the film which consists of this liquid crystalline polyester.

In recent years, electronic devices for communication and consumer use have been reduced in size, weight, and density. Under such circumstances, a flexible printed wiring board (hereinafter referred to as “FPC”) has flexibility, has a high degree of spatial freedom, and can be mounted with high density in three dimensions. Applications are expanding as composite parts with wiring, cable, or connector functions.
The FPC is obtained by laminating and integrating an electrically insulating base film and a metal foil, and producing a circuit on the metal foil. The base film is required to have high flexibility.

In order to provide the base film as described above, a solution composition containing an aromatic liquid crystal polyester containing a structural unit derived from an aromatic amine derivative and an aprotic solvent is cast on a support, and then the solvent is added. An aromatic liquid crystal polyester film obtained by removal has been proposed (Patent Document 1).
Furthermore, the base film is required to have characteristics such as dimensional stability and low warpage. As a technique for improving the dimensional stability, a filler such as an inorganic filler is added to the base film made of liquid crystal polyester. It was used extensively.

JP 2004-315678 A (Claims)

When the film made of the liquid crystalline polyester described in Patent Document 1 is used as a base film of a laminate such as FPC, an excellent flexibility can be obtained. In addition to the flexibility, dimensional stability and low warpage are obtained. There has been a demand for a base film that is more excellent.
However, the present inventors have found that when high dimensional stability and low warpage are sought and the base film is highly filled with filler, there are problems such as poor flexibility and easy tearing of the film. Found.
An object of the present invention is to provide a solution composition that provides a liquid crystal polyester film having a high degree of dimensional stability and excellent low warpage without using a means for highly filling a filler that impairs flexibility. .

  As a result of intensive studies aimed at finding a solution composition containing a liquid crystal polyester that solves the above-mentioned problems, the present inventors have completed the present invention.

That is, the present invention
[1] Liquid crystal having 10 to 35 mol% of at least one structural unit selected from the group consisting of a structural unit derived from an aromatic diamine and a structural unit derived from an aromatic amine having a phenolic hydroxyl group, based on the total of all the structural units. A solution composition obtained by dissolving polyester A in an organic solvent to reduce the molecular weight, and containing 0.1% by weight or more of the liquid crystal polyester A,
The intrinsic viscosity at 40 ° C. when the liquid crystal polyester A before the molecular weight reduction is dissolved in 3,5-bis (trifluoromethyl) phenol as a solvent to form a 0.2 g / dl solution of the liquid crystal polyester A is 1 .2 or more, and
When the solution obtained by reducing the molecular weight of the liquid crystal polyester A is diluted with the organic solvent to obtain a 0.5 g / dl solution of the liquid crystal polyester A, the intrinsic viscosity at 25 ° C. is 0.5 to 1.0. Is,
The solution composition is provided.

（式中、Ａｒ₅、Ａｒ₆はそれぞれ独立に、フェニレンまたはナフチレンを表し、Ｙは単結合、酸素原子、硫黄原子または−Ｏ−（ＣＨ２）_i−Ｏ−［ｉは１〜３の整数を表わす］を表し、ｎは１〜３の整数を表わし、ｎが２以上のとき、複数あるＡｒ₅は同一でも異なっていてもよく、複数あるＹは同一でも異なっていてもよい。）

（式中、Ａｒ₇は、フェニレンまたはナフチレンを表し、ｍは１〜３の整数を表わし、ｍが２以上のとき、複数あるＡｒ₇は同一でも異なっていてもよい。）
［３］式（１）で示される構造単位が、ｐ−ヒドロキシ安息香酸、２−ヒドロキシ−６−ナフトエ酸および４−ヒドロキシ−４’−ビフェニルカルボン酸からなる群から選ばれる芳香族ヒドロキシカルボン酸から誘導される構造単位であり、
式（２）で示される構造単位が、テレフタル酸、イソフタル酸、２，６−ナフタレンジカルボン酸およびジフェニルエーテル−４,４’−ジカルボン酸からなる群から選ばれる芳香族ジカルボン酸から誘導される構造単位であり、
式（３）で示される構造単位が４−アミノフェノール、３−アミノフェノール、２−アミノフェノール、１，４−フェニレンジアミン、１，３−フェニレンジアミンおよび４，４’−ジアミノジフェニルエーテルからなる群から選ばれる化合物から誘導される構造単位であることを特徴とする［２］の溶液組成物
［４］式（１）で示される構造単位が２−ヒドロキシ−６−ナフトエ酸由来の構造単位であり、
式（２）で示される構造単位がイソフタル酸および／またはジフェニルエーテル−４,４’−ジカルボン酸に由来の構造単位であり、
式（３）で示される構造単位が４−アミノフェノール由来の構造単位であることを特徴とする［２］または［３］の溶液組成物
［５］前記低分子量化が、前記液晶ポリエステルＡを加水分解することを包含する、［１］〜［４］のいずれかの溶液組成物
なお、固有粘度を測定する際に使用する有機溶媒（例えば、Ｎ−メチル−２−ピロリドン）は試薬グレードで充分であり、このような試薬グレードのＮ−メチル−２−ピロリドンは通常３０〜５００ｐｐｍ程度の水分を含有するものであるが、本発明においては、前記の範囲の水分を有する有機溶媒（例えば、Ｎ−メチル−２−ピロリドン）を用いた固有粘度の誤差が許容される。
［６］前記有機溶媒が非プロトン性有機溶媒である［１］〜［５］のいずれかの溶液組成物。 Furthermore, the present invention provides the following [2] to [7] as preferred embodiments according to [1].
[2] The liquid crystalline polyester A is composed of structural units represented by the following formulas (1), (2) and (3), and the total of all structural units is [(1) + (2) + (3)]. On the other hand, the structural unit represented by the formula (1) is 30 to 80 mol%, the structural unit represented by the formula (2) is 10 to 35 mol%, and the structural unit represented by the formula (3) is 10 to 35 mol%. Solution composition of [1] which is a liquid crystal polyester A of the formula: —O—Ar ₁ —CO— (1)
—CO—Ar ₂ —CO— (2)
—NH—Ar ₃ —X— (3)
(Wherein, Ar ₁ is phenylene, represent naphthylene or biphenylene, Ar ₂ is phenylene, a group selected from the group consisting of divalent groups represented by naphthylene and the following formula (4), Ar ₃ is (It is a group selected from the group consisting of phenylene and a divalent group represented by the following formula (5), and X represents O or NH.)

(In the formula, Ar ₅ and Ar ₆ each independently represent phenylene or naphthylene, Y represents a single bond, an oxygen atom, a sulfur atom, or —O— (CH 2) _i —O— [i represents an integer of 1 to 3; And n represents an integer of 1 to 3, and when n is 2 or more, a plurality of Ar ₅ may be the same or different, and a plurality of Y may be the same or different.)

(In the formula, Ar ₇ represents phenylene or naphthylene, m represents an integer of 1 to 3, and when m is 2 or more, a plurality of Ar ₇ may be the same or different.)
[3] An aromatic hydroxycarboxylic acid wherein the structural unit represented by formula (1) is selected from the group consisting of p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid and 4-hydroxy-4′-biphenylcarboxylic acid A structural unit derived from
The structural unit represented by the formula (2) is derived from an aromatic dicarboxylic acid selected from the group consisting of terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid and diphenyl ether-4,4′-dicarboxylic acid. And
The structural unit represented by formula (3) is selected from the group consisting of 4-aminophenol, 3-aminophenol, 2-aminophenol, 1,4-phenylenediamine, 1,3-phenylenediamine, and 4,4′-diaminodiphenyl ether. The solution unit of [2], wherein the structural unit represented by the formula (1) is a structural unit derived from 2-hydroxy-6-naphthoic acid, which is a structural unit derived from a selected compound. ,
The structural unit represented by the formula (2) is a structural unit derived from isophthalic acid and / or diphenyl ether-4,4′-dicarboxylic acid,
The solution unit of [2] or [3], wherein the structural unit represented by the formula (3) is a structural unit derived from 4-aminophenol [5] The low molecular weight reduces the liquid crystal polyester A. The solution composition according to any one of [1] to [4], including hydrolysis. The organic solvent (for example, N-methyl-2-pyrrolidone) used for measuring the intrinsic viscosity is a reagent grade. Such a reagent grade N-methyl-2-pyrrolidone usually contains about 30 to 500 ppm of water, but in the present invention, an organic solvent having water in the above range (for example, Inherent viscosity errors with N-methyl-2-pyrrolidone) are acceptable.
[6] The solution composition according to any one of [1] to [5], wherein the organic solvent is an aprotic organic solvent.

Moreover, this invention provides the following [7]-[9] which uses the solution composition in any one of the said.
[7] A laminate obtained by casting the solution composition according to any one of the above on a substrate and removing the solvent.
[8] A flexible printed wiring board substrate obtained by casting the solution composition according to any one of the above on a metal foil and removing the solvent.
[9] The flexible printed wiring board substrate according to [8], wherein the metal foil is a copper foil.
Furthermore, the present invention provides the following [10] to [12].
[10] A liquid crystal having 10 to 35 mol% of at least one structural unit selected from the group consisting of a structural unit derived from an aromatic diamine and a structural unit derived from an aromatic amine having a phenolic hydroxyl group, based on the total of all the structural units. A polyester film,
The intrinsic viscosity at 25 ° C. when the liquid crystal polyester A is 0.5 g / dl organic solvent solution is 0.5 to 1.0,
The film of the above-mentioned liquid crystalline polyester, which is heated from room temperature to 250 ° C. under a nitrogen stream at 5 ° C./min and has a shrinkage ratio of 0.2 to 0.8% when cooled at 250 ° C. to 50 ° C.
[11] A liquid crystal having 10 to 35 mol% of at least one structural unit selected from the group consisting of a structural unit derived from an aromatic diamine and a structural unit derived from an aromatic amine having a phenolic hydroxyl group, based on the total of all the structural units. Polyester A is dissolved in an organic solvent to lower the molecular weight to form a solution composition containing 0.1% by weight or more of the liquid crystal polyester A; and the organic solvent is removed;
A process for producing a liquid crystal polyester film comprising:
The intrinsic viscosity at 40 ° C. when the liquid crystal polyester A before the molecular weight reduction is dissolved in 3,5-bis (trifluoromethyl) phenol as a solvent to form a 0.2 g / dl solution of the liquid crystal polyester A is 1 .2 or more, and
When the solution obtained by reducing the molecular weight of the liquid crystal polyester A is diluted with the organic solvent to obtain a 0.5 g / dl solution of the liquid crystal polyester A, the intrinsic viscosity at 25 ° C. is 0.5 to 1.0. And yet
The liquid crystal polyester film is heated from room temperature to 250 ° C. under a nitrogen stream at 5 ° C./min, and the shrinkage rate upon cooling at 250 ° C. to 50 ° C. is 0.2 to 0.8%.
A method for producing the liquid crystal polyester film.
[12] A liquid crystal having 10 to 35 mol% of at least one structural unit selected from the group consisting of a structural unit derived from an aromatic diamine and a structural unit derived from an aromatic amine having a phenolic hydroxyl group, based on the total of all the structural units. Polyester A is dissolved in an organic solvent to lower the molecular weight to form a solution composition containing 0.1% by weight or more of the liquid crystal polyester A;
Casting the solution composition onto a substrate; and removing the solvent;
A method of coating a substrate with a liquid crystalline polyester film comprising:
The intrinsic viscosity at 40 ° C. when the liquid crystal polyester A before the molecular weight reduction is dissolved in 3,5-bis (trifluoromethyl) phenol as a solvent to form a 0.2 g / dl solution of the liquid crystal polyester A is 1 .2 or more, and
When the solution obtained by reducing the molecular weight of the liquid crystal polyester A is diluted with the organic solvent to obtain a 0.5 g / dl solution of the liquid crystal polyester A, the intrinsic viscosity at 25 ° C. is 0.5 to 1.0. Is,
A method of coating the substrate with the liquid crystalline polyester film.

  The liquid crystal polyester film obtained by the solution composition of the present invention has a high degree of dimensional stability, and when used as a base film of a laminate such as FPC, the resulting laminate maintains a high degree of flexibility, Since a laminate having excellent low warpage can be obtained, it is industrially useful.

  Hereinafter, embodiments of the present invention will be described in detail.

<Liquid crystal polyester A>
The liquid crystal polyester A applied to the solution composition of the present invention is preferably a polyester called a thermotropic liquid crystal polymer capable of forming a melt exhibiting optical anisotropy at a temperature of 450 ° C. or lower, derived from an aromatic diamine. And at least one structural unit selected from the group consisting of structural units derived from aromatic amines having a phenolic hydroxyl group, with respect to the total of all structural units, It is a liquid crystal polyester having an intrinsic viscosity at 40 ° C. of 1.2 or more when the liquid crystal polyester A is dissolved in 5-bis (trifluoromethyl) phenol as a solvent to form a 0.2 g / dl solution of the liquid crystal polyester A. Furthermore, when the solution composition of the present invention is diluted with an organic solvent (for example, N-methyl-2-pyrrolidone) to obtain a 0.5 g / dl solution of the liquid crystal polyester A, the intrinsic viscosity at 25 ° C. is 0.5. -1.0.

（式中、Ａｒ₅、Ａｒ₆はそれぞれ独立に、フェニレンまたはナフチレンを表し、Ｙは単結合、酸素原子、硫黄原子または−Ｏ−（ＣＨ２）_i−Ｏ−［ｉは１〜３の整数を表わす］を表し、ｎは１〜３の整数を表わし、ｎが２以上のとき、複数あるＡｒ₅は同一でも異なっていてもよく、複数あるＹは同一でも異なっていてもよい。）

（式中、Ａｒ₇は、フェニレンまたはナフチレンを表し、ｍは１〜３の整数を表わし、ｍが２以上のとき、複数あるＡｒ₇は同一でも異なっていてもよい。） The liquid crystal polyester is preferably composed of structural units represented by the following formulas (1), (2) and (3), and represented by the formula (1) with respect to the total of all the structural units. The structural unit derived from aromatic hydroxycarboxylic acid (hereinafter referred to as “formula (1) structural unit”) is 30 to 80 mol%, and the structural unit derived from aromatic dicarboxylic acid represented by formula (2) (hereinafter referred to as “formula”) The structural unit (hereinafter referred to as “(2) structural unit”) selected from 10 to 35 mol%, a structural unit derived from the aromatic diamine represented by the formula (3) and a structural unit derived from an aromatic amine having a phenolic hydroxyl group , Referred to as “formula (3) structural unit”) is 10 to 35 mol% liquid crystal polyester.
—O—Ar ₁ —CO— (1)
—CO—Ar ₂ —CO— (2)
—NH—Ar ₃ —X— (3)
(In the formula, Ar ₁ represents phenylene, naphthylene or biphenylene, Ar ₂ represents a group selected from phenylene, naphthylene and a divalent group represented by the following formula (4); Ar ₃ represents phenylene and (It is a group selected from divalent groups represented by the formula (5), and X represents —O— or —NH—.)

(In the formula, Ar ₅ and Ar ₆ each independently represent phenylene or naphthylene, Y represents a single bond, an oxygen atom, a sulfur atom, or —O— (CH 2) _i —O— [i represents an integer of 1 to 3; And n represents an integer of 1 to 3, and when n is 2 or more, a plurality of Ar ₅ may be the same or different, and a plurality of Y may be the same or different.)

(In the formula, Ar ₇ represents phenylene or naphthylene, m represents an integer of 1 to 3, and when m is 2 or more, a plurality of Ar ₇ may be the same or different.)

  The structural unit (1) is preferably 30 to 80 mol%, more preferably 40 to 70 mol%, still more preferably 45 to 65 mol%, based on the total structural units. When the structural unit of the formula (1) is within this range, the obtained liquid crystal polyester has sufficient liquid crystallinity, and is preferable because the solubility in a solvent is good when the solution composition of the present invention is obtained.

The structural unit (2) is preferably 35 to 10 mol%, more preferably 30 to 15 mol%, and more preferably 27.5 to 17.5 mol% with respect to the total structural units. Further preferred.
On the other hand, the structural unit of the formula (3) is preferably 35 to 10 mol%, more preferably 30 to 15 mol%, further preferably 27.5 to 17.5 mol%.
When the structural unit of the formula (2) and the structural unit of the formula (3) are in the above ranges, the liquid crystal polyester obtained has sufficient liquid crystallinity and has good solubility in the solvent when obtaining the solution composition of the present invention. This is preferable.

  Examples of the structural unit include the following, but are not limited thereto.

Examples of the structural unit represented by the formula ( ¹ ) include those represented by the following formulas (A ¹ ) to (A ⁵ ). In the structural units described below, a hydrogen atom bonded to an aromatic ring may be substituted with a halogen atom, an alkyl group, or an aryl group.

Examples of the structural unit of the formula (2) include those represented by the following formulas (B ¹ ) to (B ⁸ ). In the structural units described below, a hydrogen atom bonded to an aromatic ring may be substituted with a halogen atom, an alkyl group, or an aryl group.

  The structural unit of the formula (3) is at least one structural unit selected from the group consisting of a structural unit derived from an aromatic amine having a phenolic hydroxyl group and a structural unit derived from an aromatic diamine. This is illustrated in

Examples of the structural unit derived from an aromatic amine having a phenolic hydroxyl group include those represented by the following chemical formulas (D ¹ ) to (D ⁶ ). In the structural units described below, a hydrogen atom bonded to an aromatic ring may be substituted with a halogen atom, an alkyl group, or an aryl group.

As the structural unit derived from an aromatic diamine, include those represented by the following formula ^{(E 1) ~ (E 6} ). In the structural units described below, a hydrogen atom bonded to an aromatic ring may be substituted with a halogen atom, an alkyl group, or an aryl group.

  A hydrogen atom bonded to an aromatic ring in the structural unit may be substituted. As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, and among them, a methyl group, an ethyl group, a propyl group. Or a butyl group is preferable. Moreover, as an aryl group, a C6-C20 aryl group is suitable, and a phenyl group is especially preferable.

In order to achieve the heat resistance of the liquid crystal polyester and the dimensional stability of the film obtained from the liquid crystal polyester at a high level, the liquid crystal polyester has the structure of the above formula (1) of (A ¹ ) and / or (A ³ ). It is preferable to include a unit and a structural unit of the formula (2) selected from the group consisting of (B ¹ ), (B ² ), (B ³ ) and (B ⁶ ). Examples of preferred combinations of these structural units include the following (a) to (d).
(A):
A combination of structural units (A ¹ ), (B ² ) and (D ¹ ),
A combination of structural units (A ³ ), (B ² ) and (D ¹ ),
A combination of structural units (A ¹ ), (B ¹ ) and (D ¹ ),
A combination of structural units (A ³ ), (B ³ ) and (D ¹ ), or a combination of structural units (A ³ ), (B ² ), (B ⁶ ) and (D ¹ );
A combination of structural units (A ¹ ), (B ² ) or (B ³ ), and (D ¹ ).
(B): (a) above in each combination of, (D ¹⁾ of the part or combination was replaced by all (D ²⁾ (c): In each of the combinations of the above (a), (A ¹⁾ Combination (d) in which part or all of is replaced with (A ³ ): In each of the combinations of (a) above, part or all of (D ¹ ) is replaced with (E ¹ ) or (E ⁵ ) combination.

As a more preferable combination of the structural units constituting the liquid crystal polyester applied to the present invention, formula (1) derived from p-hydroxybenzoic acid and / or 2-hydroxy-6-naphthoic acid, 30 to 80 mol%, Formula (3) derived from 4-aminophenol and / or 4,4′-diaminodiphenyl ether, selected from the group consisting of 10-35 mol% structural unit, terephthalic acid, isophthalic acid and diphenyl ether-4,4′-dicarboxylic acid What consists of 10-35 mol% of formula (2) structural units derived from at least 1 type of compound is mentioned.
As a particularly preferred combination of structural units, the formula (1) derived from 2-hydroxy-6-naphthoic acid (1) 30 to 80 mol%, the formula derived from 4-aminophenol (3) structural unit 10 to 35 mol% , Isophthalic acid and / or diphenyl ether-4,4′-dicarboxylic acid derived from the formula (2) structural unit 10 to 35 mol%.

<Method for producing liquid crystal polyester>
The production method of the liquid crystal polyester A used in the present invention is a production method satisfying the above intrinsic viscosity, and preferably an aromatic hydroxycarboxylic acid derived from the formula (1) structural unit, a formula (3) structure. An acylated product is obtained by acylating a hydroxy group or an amino group of an aromatic amine having a hydroxy group for deriving a unit and / or an aromatic diamine with an excess amount of a fatty acid anhydride, and the resulting acylated product, and the formula (2) A structural unit-derived aromatic dicarboxylic acid is transesterified and amide-exchanged and melt-polymerized in advance to obtain a high molecular weight liquid crystal polyester, preferably 0.2 g / liter of 3,5-bis (trifluoromethyl) phenol as a solvent. A liquid crystal polyester A having an intrinsic viscosity of 1.2 or more at 40 ° C. when made into a dl solution is obtained. Examples thereof include a method for producing a liquid crystal polyester solution having an intrinsic viscosity of 0.5 to 1.0 using methyl-2-pyrrolidone as a solvent.

First, the melt polymerization for producing the liquid crystal polyester A will be described.
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 hydroxy group and amino group, more preferably 1.05 to 1. .1 equivalent. If the amount of fatty acid anhydride added is less than 1.0 times equivalent, acylated products, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids and the like tend to sublimate during melt polymerization by transesterification / amide exchange, and the reaction system tends to block. In addition, when the amount exceeds 1.2 times equivalent, the resulting liquid crystal polymer tends to be remarkably colored.

  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. For example, acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, 2-ethylhexanoic anhydride, 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, and isobutyric anhydride are preferable, and acetic anhydride is more preferable.

  In the melt polymerization by transesterification / amide exchange, the acyl group of the acylated product is preferably 0.8 to 1.2 times the equivalent of the carboxyl group of the aromatic dicarboxylic acid derived from the structural unit of formula (2).

  The melt polymerization by transesterification / amide exchange is preferably carried out at 130 to 400 ° C. while raising the temperature at a rate of 0.1 to 50 ° C./min, and at 150 to 350 ° C. at a rate of 0.3 to 5 ° C./min. It is more preferable to carry out while raising the temperature. At this time, in order to move the equilibrium, it is preferable to distill out the by-product fatty acid and the unreacted fatty acid anhydride, for example, by evaporating.

  In addition, you may perform melt polymerization by acylation reaction, transesterification, and amide exchange in 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. The catalyst is usually present during the acylation reaction, and it is not always necessary to remove it after acylation. If the catalyst is not removed, the next treatment can be carried out as it is. Moreover, you may further add the above catalysts when performing the next process.

Polymerization by transesterification / amide exchange is carried out by melt polymerization as described above, but melt polymerization and solid phase polymerization may be used in combination. The solid phase polymerization can be carried out by a known solid phase polymerization method after the polymer is extracted from the melt polymerization step, solidified, pulverized into powder or flakes. Specifically, for example, a method of heat treatment in a solid state at 200 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 liquid crystal polyester A may be pelletized by a known method and applied to lower molecular weight described later. In such solid phase polymerization, if the reaction temperature is 230 to 300 ° C. and the reaction time is 1 to 6 hours, the intrinsic viscosity of the liquid crystal polyester A is usually 1.2 or more, preferably 1.2 to 2.2. Can be.
In addition, manufacture of liquid crystalline polyester A can be performed using a batch apparatus, a continuous apparatus, etc., for example.

Thus, the intrinsic viscosity at 40 ° C. when a relatively high molecular weight, preferably 3,5-bis (trifluoromethyl) phenol is used as a solvent to form a 0.2 g / dl solution is 1.2 or more, preferably 1. 2 to 2.2 liquid crystal polyester A is obtained, and the intrinsic viscosity at 25 ° C. when the liquid crystal polyester A is reduced in molecular weight and made into a 0.5 g / dl solution using N-methyl-2-pyrrolidone as a solvent is 0. Convert to liquid crystal polyester of .5 to 1.0.
The molecular weight reduction is usually performed by a method of reducing the molecular weight by chemical decomposition using a decomposing agent.

  As the decomposing agent, water or an alkali typified by ammonia or organic amine is preferable, and water is particularly preferable from the viewpoint of simplicity of post-treatment and the like. That is, the low molecular weight is preferably hydrolyzed. .

Here, the molecular weight reduction of the liquid crystal polyester A (the intrinsic viscosity; 1.2 or more, preferably 1.2 to 2.2) by hydrolysis will be described.
The liquid crystal polyester A obtained as described above is used as an organic solvent, preferably N-methyl-2-pyrrolidone, as a reaction solvent, and the concentration of the liquid crystal polyester A is 1 to 40% by weight, preferably 5 to 5%. A 30% by weight liquid crystal polyester A solution is obtained, and 0.02 to 10% by weight, preferably 0.03 to 3% by weight, of water is added to the liquid crystal polyester A solution. . A method of reacting the liquid crystal polyester A solution to which water has been added in this manner at a reaction temperature of 80 to 170 ° C., preferably 100 to 160 ° C., for a reaction time of 2 to 10 hours is applied. The reaction temperature can also be determined by sampling the liquid crystal polyester A solution during the reaction and tracing the reaction by obtaining the intrinsic viscosity by the above method.

  The liquid crystal polyester thus obtained can be taken out from the reaction solution after hydrolysis by a known means in advance to prepare the solution composition of the present invention, or the reaction solvent in which the hydrolysis reaction has been carried out can be prepared. The solvent composition of the present invention can be used as it is as a solvent.

<Solution composition>
Next, the solution composition will be described.
The organic solvent used to prepare the solution composition is not particularly limited as long as it dissolves the liquid crystal polymer. For example, N, N′-dimethylacetamide, N-methyl-2-pyrrolidone, N -Methylcaprolactam, N, N'-dimethylformamide, N, N'-diethylformamide, N, N'-diethylacetamide, N-methylpropionamide, dimethylsulfoxide, γ-butyrolactone, dimethylimidazolidinone, tetramethylphosphoric Examples thereof include amides and ethyl cellosolve acetate, and halogenated phenols such as parafluorophenol, parachlorophenol, and perfluorophenol. These solvents can be used alone or in combination.
Among such solvents, from the viewpoint of handling, N, N′-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, N, N′-dimethylformamide, N, N′-diethylformamide, N, N Preferred are aprotic organic solvents selected from the group consisting of '-diethylacetamide, N-methylpropionamide, dimethyl sulfoxide, γ-butyrolactone, dimethylimidazolidinone, tetramethylphosphoric amide and ethyl cellosolve acetate.

  The amount of the solvent used can be appropriately selected according to the type of the solvent to be applied, as long as it is an amount capable of preparing a solution composition containing 0.1% by weight or more of the liquid crystal polyester A. It is preferable that it is 0.5-50 mass parts with respect to 100 mass parts, and it is more preferable that it is 10-20 mass parts. If the liquid crystalline polyester is less than 0.5 parts by mass, the solution viscosity tends to be too low to uniformly coat, and if it exceeds 50 parts by mass, the viscosity tends to increase. The intrinsic viscosity at 25 ° C. when the solution composition thus obtained is diluted with the organic solvent to form a 0.5 g / dl solution of the liquid crystal polyester A is 0.5 to 1.0.

The solution composition of the present invention can provide a liquid crystal polyester film having a high degree of dimensional stability without adding a filler such as an inorganic filler that has been widely used in the past. A small amount of an inorganic filler may be blended. The blending amount when blending the filler is selected within a range that does not impair the flexibility of the liquid crystal polyester film, and is usually preferably 5% by weight or less in the solution composition. Suitable fillers include fillers made of inorganic substances such as aluminum borate, potassium titanate, magnesium sulfate, zinc oxide, silicon carbide, silicon nitride, glass or alumina. These fillers are fibrous, plate-like, Any of particles may be used.
Moreover, the solution composition of the present invention may contain, for example, an additive represented by a silane coupling agent and an antioxidant. The additive is preferably soluble in the solvent used in the solution composition of the present invention.

<Laminated body>
The solution composition obtained as described above is cast-coated on a substrate, for example, to form a solution composition film, and the solvent is removed from the solution composition film obtained on the substrate. Thus, a laminate including a liquid crystal polyester film can be obtained.
The thickness of the liquid crystal polyester film is preferably 0.5 to 500 μm from the viewpoint of film forming properties and mechanical properties, and more preferably 1 to 100 μm from the viewpoint of handleability. In addition, the thickness of the liquid crystal polyester film can be adjusted by the number of times of coating at the time of forming the layer or the viscosity of the solution composition used. Moreover, the shrinkage | contraction rate at the time of cooling of 250 degreeC-50 degreeC of this liquid crystal polyester film becomes like this. Preferably it is 0.2-0.8%, More preferably, it is 0.25-0.7%.

  In particular, when a metal foil is used as the base material in the laminate, the obtained laminate has a liquid crystal polyester film as an insulating layer and the metal foil as a conductor layer, and is a suitable laminate as a substrate for a flexible wiring board. obtain.

  Examples of means for casting and applying the solution composition of the present invention to a substrate (metal foil) include 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. Various means such as a printing method may be mentioned.

  The method for removing the solvent from the cast-coated film 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 more preferable to evaporate by heating while ventilating. preferable. What is necessary is just to hold | maintain for 10 to 120 minutes at the temperature of 80-200 degreeC, when removing a solvent by heating.

  The liquid crystal polyester film from which the solvent has been removed may be held at a temperature of 250 to 350 ° C. for 30 to 3000 minutes, preferably 60 to 1200 minutes, when aligning the liquid crystal polyester molecules in the liquid crystal polyester film. In addition, you may implement the process of orienting the molecule | numerator of a liquid crystal polymer, without implementing the process of removing a solvent. In this case, from the viewpoint of preventing the occurrence of voids and the like due to the rapid evaporation of the solvent in the coating film, it is preferable to slow the temperature increase rate as compared with the case of performing the step of removing the solvent. .

  The laminate thus obtained, that is, the flexible printed wiring board substrate, has excellent characteristics such as high dimensional stability and high heat resistance, and low water absorption, so the use thereof is flexible printed wiring board. However, the present invention is suitably used for semiconductor packages, multilayer printed boards for motherboards, films for tape automated bonding, and the like obtained by a build-up method or the like that has attracted attention in recent years.

  EXAMPLES Hereinafter, although this invention is demonstrated using an Example, it cannot be overemphasized that this invention is not what is limited by an Example.

(Measurement of intrinsic viscosity of liquid crystal polyester solution)
A portion of the N-methyl-2-pyrrolidone (BASF, standard grade, hereinafter referred to as “NMP”) solution of the liquid crystalline polyester obtained in the following Examples and Comparative Examples was taken and diluted with NMP. Thus, a measurement solution adjusted to a concentration of 0.5 g / dl was prepared. The intrinsic viscosity of the measurement solution was measured at a measurement temperature of 25 ° C. using an Ostwald viscometer. The intrinsic viscosity of the liquid crystal polyester solution thus obtained is shown as “Intrinsic Viscosity of Solution” in Tables 1 and 2.

(Measurement of the amount of warpage of the laminate)
The warpage of the flexible printed circuit board obtained in the following examples and comparative examples was measured as follows. That is, the flexible printed wiring board substrate was cut out to 15 × 15 cm ² and placed on a surface plate, and the largest lifted portions at the four corners of the flexible printed wiring board substrate were measured as the amount of warpage. The measurement was performed by adjusting the room temperature to 23 ° C. and 50% RH. Moreover, when it became a cylindrical shape after cutting out, the diameter (φ) of the cylinder was measured in millimeters and used as the amount of warpage.

(Linear expansion coefficient and shrinkage ratio of liquid crystal polyester film)
By immersing the flexible printed wiring board substrates obtained in the following examples and comparative examples in a ferric chloride aqueous solution (Baume degree 40 °, manufactured by Kida Co., Ltd.), the copper foil is removed by etching, and a liquid crystal polymer film Got. Next, using a thermomechanical analyzer TMA120U manufactured by SII NanoTechnology Co., Ltd., the temperature was increased at a rate of 5 ° C./min under a load of 2.5 g and a nitrogen stream, and the linear expansion coefficient of a liquid crystal polyester film of 50 to 100 ° C. Was measured. When the coating direction of the film was MD and the perpendicular direction was TD, the respective linear expansion coefficients were measured. Moreover, it heated up at 5 degree-C / min from nitrogen flow to room temperature to 250 degreeC, and the shrinkage | contraction rate at the time of cooling of 250 to 50 degreeC was measured.

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 140 ° C. over 15 minutes under a nitrogen gas stream, and the mixture was stirred for 4 hours while maintaining the temperature.

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 resin was pulverized with a coarse pulverizer and then subjected to solid phase polymerization in a nitrogen atmosphere at 258 ° C. for 3 hours. Part of the obtained powder was heated at 10 ° C./min while observing with a polarizing microscope, and as a result, a schlieren pattern peculiar to the liquid crystal phase was shown at 400 ° C.
The liquid crystal polyester 1 thus obtained was adjusted to have an intrinsic viscosity of 0.2 g / dl solution using 3,5-bis (trifluoromethyl) phenol as a solvent and completely dissolved at 60 ° C. for 24 hours. It was 1.72 as a result of measuring the intrinsic viscosity in 40 degreeC using the viscometer. The intrinsic viscosity of the liquid crystal polyester thus obtained is shown as “Intrinsic Viscosity of Resin” in Tables 1 and 2.

Next, 10 g of liquid crystal polyester 1 powder was added to 90 g of NMP, and pure water was adjusted so that the water weight was 1 wt% with respect to the NMP weight. By heating this mixture at 140 ° C. for 4 hours, the liquid crystal polyester was completely dissolved, and a brown transparent liquid crystal polyester solution 1 was obtained. This solution was stirred and degassed, and applied on a commercially available electrolytic copper foil (trade name: 3EC-VLP, manufactured by Mitsui Kinzoku Mining Co., Ltd., thickness 18 μ) using a film applicator (application thickness 400 μ), and then on a hot plate And dried at 80 ° C. for 6 hours.
Thereafter, heat treatment was performed in a hot air oven in a nitrogen atmosphere at a temperature increase rate of 3.2 ° C./min from 30 ° C. to 320 ° C. and held at 320 ° C. for 3 hours. The temperature was lowered to room temperature to obtain a flexible printed wiring board substrate. Table 1 shows the intrinsic viscosity of the liquid crystal polyester solution 1, the amount of warpage of the obtained flexible printed wiring board substrate, the linear expansion coefficient, and the shrinkage rate.

(Example 2)
A liquid crystal polyester solution 2 was obtained in the same manner as in Example 1 except that pure water was adjusted so that the amount of pure water added was 2% by weight with respect to the weight of NMP. Using this liquid crystalline polyester solution 2, a flexible printed wiring board substrate was obtained in the same manner as in Example 1, and various evaluation tests were also carried out in the same manner. The results are shown in Table 1.

(Example 3)
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 847 g (4.5 mol) of 2-hydroxy-6-naphthoic acid and 416 g (2.75 mol) of 4-aminophenol were added. ), 125 g (0.75 mol) of isophthalic acid, 517 g (2.0 mol) of diphenyl ether-4,4′-dicarboxylic acid, and 817 g (11 mol) of acetic anhydride. After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature was raised to 140 ° C. over 15 minutes under a nitrogen gas stream, and the mixture was stirred for 4 hours while maintaining the temperature.

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 resin was pulverized with a coarse pulverizer and then subjected to solid phase polymerization in a nitrogen atmosphere at 249 ° C. for 3 hours. Part of the obtained powder was heated at 10 ° C./min while observing with a polarizing microscope, and as a result, a schlieren pattern peculiar to the liquid crystal phase was shown at 400 ° C.
The intrinsic viscosity of the liquid crystal polyester 3 thus obtained was adjusted to a 0.2 g / dl solution using 3,5-bis (trifluoromethyl) phenol as a solvent and subjected to 24 hours at 60 ° C. It was 1.43 as a result of having dissolved completely and measuring the intrinsic viscosity in 40 degreeC using the Ubbelohde viscometer.

Next, 10 g of liquid crystal polyester 3 powder was added to 90 g of NMP, and pure water was adjusted so that the water weight was 0.03% by weight with respect to the weight of NMP. By heating this mixture at 120 ° C. for 4 hours, the liquid crystal polyester was completely dissolved, and a brown transparent liquid crystal polyester solution 3 was obtained. This solution was stirred and degassed, and applied on a commercially available electrolytic copper foil (trade name: 3EC-VLP, manufactured by Mitsui Kinzoku Mining Co., Ltd., thickness 18 μ) using a film applicator (application thickness 400 μ), and then on a hot plate And dried at 80 ° C. for 6 hours.
Thereafter, heat treatment was performed in a hot air oven in a nitrogen atmosphere at a temperature increase rate of 3.2 ° C./min from 30 ° C. to 320 ° C. and held at 320 ° C. for 3 hours. After cooling to room temperature, a flexible printed wiring board substrate was obtained. Table 1 shows the intrinsic viscosity of the liquid crystal polyester solution 3, the amount of warpage of the obtained flexible printed wiring board substrate, the linear expansion coefficient, and the shrinkage rate.

Example 4
A liquid crystal polyester solution 4 was obtained in the same manner as in Example 3 except that pure water was adjusted so that the amount of pure water added was 0.05% by weight with respect to the weight of NMP. . Using this liquid crystalline polyester solution 4, a flexible printed wiring board substrate was obtained in the same manner as in Example 3, and various evaluation tests were conducted in the same manner. The results are shown in Table 1.

(Comparative Example 1)
A liquid crystal polyester solution 5 was obtained in the same manner as in Example 1 except that the amount of pure water was adjusted so that the water weight was 0.05% by weight with respect to the NMP weight. . Using this liquid crystalline polyester solution 5, a flexible printed wiring board substrate was obtained in the same manner as in Example 1, and various evaluation tests were also carried out in the same manner. The results are shown in Table 2.

(Comparative Example 2)
20 g of liquid crystalline polyester 1 powder obtained in the same manner as in Example 1 was added to 80 g of NMP, and pure water was adjusted so that the water weight was 0.05% by weight relative to the weight of NMP. By heating this mixture at 180 ° C. for 4 hours, the liquid crystal polymer was completely dissolved, and a brown transparent liquid crystal polyester solution 6 was obtained. Using this liquid crystalline polyester solution 6, a flexible printed wiring board substrate was obtained in the same manner as in Example 1, and various evaluation tests were conducted in the same manner. The evaluation results are shown in Table 2.

Claims (11)

Liquid crystal polyester A having 10 to 35 mol% of at least one structural unit selected from the group consisting of a structural unit derived from an aromatic diamine and a structural unit derived from an aromatic amine having a phenolic hydroxyl group based on the total of all structural units , you reduce the molecular weight is dissolved in an organic solvent, the liquid crystal polyester a a method for producing a solution composition containing more than 0.1 wt%,
The intrinsic viscosity at 40 ° C. when the liquid crystal polyester A before the molecular weight reduction is dissolved in 3,5-bis (trifluoromethyl) phenol as a solvent to form a 0.2 g / dl solution of the liquid crystal polyester A is 1 .2 or more, and
When the solution obtained by reducing the molecular weight of the liquid crystal polyester A is diluted with the organic solvent to obtain a 0.5 g / dl solution of the liquid crystal polyester A, the intrinsic viscosity at 25 ° C. is 0.5 to 1.0. Is,
A method for producing the solution composition. The liquid crystal polyester A is composed of structural units represented by the following formulas (1), (2) and (3), and the total [(1) + (2) + (3)] of all structural units: Liquid crystalline polyester having a structural unit represented by the formula (1) of 30 to 80 mol%, a structural unit represented by the formula (2) of 10 to 35 mol%, and a structural unit represented by the formula (3) of 10 to 35 mol%. The method for producing a solution composition according to claim 1, which is A.
—O—Ar ₁ —CO— (1)
—CO—Ar ₂ —CO— (2)
—NH—Ar ₃ —X— (3)
(Wherein, Ar ₁ is phenylene, represent naphthylene or biphenylene, Ar ₂ is phenylene, a group selected from the group consisting of divalent groups represented by naphthylene and the following formula (4), Ar ₃ is (It is a group selected from the group consisting of phenylene and a divalent group represented by the following formula (5), and X represents O or NH.)

(In the formula, Ar ₅ and Ar ₆ each independently represent phenylene or naphthylene, Y represents a single bond, an oxygen atom, a sulfur atom, or —O— (CH 2) _i —O— [i represents an integer of 1 to 3; And n represents an integer of 1 to 3, and when n is 2 or more, a plurality of Ar ₅ may be the same or different, and a plurality of Y may be the same or different.)

(In the formula, Ar ₇ represents phenylene or naphthylene, m represents an integer of 1 to 3, and when m is 2 or more, a plurality of Ar ₇ may be the same or different.) The structural unit represented by formula (1) is derived from an aromatic hydroxycarboxylic acid selected from the group consisting of p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid and 4-hydroxy-4'-biphenylcarboxylic acid. Structural unit
The structural unit represented by the formula (2) is derived from an aromatic dicarboxylic acid selected from the group consisting of terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid and diphenyl ether-4,4′-dicarboxylic acid. And
The structural unit represented by formula (3) is selected from the group consisting of 4-aminophenol, 3-aminophenol, 2-aminophenol, 1,4-phenylenediamine, 1,3-phenylenediamine, and 4,4′-diaminodiphenyl ether. The method for producing a solution composition according to claim 2, wherein the unit is a structural unit derived from a selected compound. The structural unit represented by the formula (1) is a structural unit derived from 2-hydroxy-6-naphthoic acid,
The structural unit represented by the formula (2) is a structural unit derived from isophthalic acid and / or diphenyl ether-4,4′-dicarboxylic acid,
The method for producing a solution composition according to claim 2 or 3, wherein the structural unit represented by the formula (3) is a structural unit derived from 4-aminophenol. The method for producing a solution composition according to any one of claims 1 to 4 , wherein the low molecular weight includes hydrolyzing the liquid crystal polyester A. The method for producing a solution composition according to claim 1, wherein the organic solvent is an aprotic organic solvent. To give a solution composition by the method according to any one of claims 1 to 6, the solution composition was cast coated on a substrate, the solvent is removed, the production method of the laminate. The process according to any one of claims 1 to 6 to give a solution composition, the solution composition was casted on a metal foil, removing the solvent, method for manufacturing a substrate for a flexible printed wiring board. The method for producing a substrate for a flexible printed wiring board according to claim 8, wherein the metal foil is a copper foil. Liquid crystal polyester A having 10 to 35 mol% of at least one structural unit selected from the group consisting of a structural unit derived from an aromatic diamine and a structural unit derived from an aromatic amine having a phenolic hydroxyl group based on the total of all structural units Dissolving in an organic solvent to lower the molecular weight to form a solution composition containing 0.1% by weight or more of the liquid crystal polyester A; and removing the organic solvent;
A process for producing a liquid crystal polyester film comprising:
The intrinsic viscosity at 40 ° C. when the liquid crystal polyester A before the molecular weight reduction is dissolved in 3,5-bis (trifluoromethyl) phenol as a solvent to form a 0.2 g / dl solution of the liquid crystal polyester A is 1 .2 or more, and
When the solution obtained by reducing the molecular weight of the liquid crystal polyester A is diluted with the organic solvent to obtain a 0.5 g / dl solution of the liquid crystal polyester A, the intrinsic viscosity at 25 ° C. is 0.5 to 1.0. And yet
The liquid crystal polyester film is heated from room temperature to 250 ° C. under a nitrogen stream at 5 ° C./min, and the shrinkage rate upon cooling at 250 ° C. to 50 ° C. is 0.2 to 0.8%.
A method for producing the liquid crystal polyester film. Liquid crystal polyester A having 10 to 35 mol% of at least one structural unit selected from the group consisting of a structural unit derived from an aromatic diamine and a structural unit derived from an aromatic amine having a phenolic hydroxyl group based on the total of all structural units Dissolving in an organic solvent to lower the molecular weight to form a solution composition containing 0.1% by weight or more of the liquid crystal polyester A;
Casting the solution composition onto a substrate; and removing the solvent;
A method of coating a substrate with a liquid crystalline polyester film comprising:
The intrinsic viscosity at 40 ° C. when the liquid crystal polyester A before the molecular weight reduction is dissolved in 3,5-bis (trifluoromethyl) phenol as a solvent to form a 0.2 g / dl solution of the liquid crystal polyester A is 1 .2 or more, and
When the solution obtained by reducing the molecular weight of the liquid crystal polyester A is diluted with the organic solvent to obtain a 0.5 g / dl solution of the liquid crystal polyester A, the intrinsic viscosity at 25 ° C. is 0.5 to 1.0. Is,
A method of coating the substrate with the liquid crystalline polyester film.