JP4935144B2 - Aromatic liquid crystal polyester film with support - Google Patents

Description

  The present invention relates to an aromatic liquid crystal polyester film with a support used for an electronic component substrate such as a printed wiring board or a module substrate.

  Aromatic liquid crystal polyesters are widely used mainly for precision electronic parts such as connectors obtained by injection molding because they exhibit excellent low moisture absorption, heat resistance, and mechanical strength. In recent years, attention has been paid to forming an aromatic liquid crystal polyester into a film by extrusion molding such as T-die molding or inflation molding and applying it to an insulating film for a multilayer printed board or a flexible printed board.

However, the conventional aromatic liquid crystal polyester film obtained by extrusion molding has a problem that the anisotropy is large and the tear strength in the direction perpendicular to the flow direction during molding is weak.
In order to solve such a problem, the present inventors have prepared an aromatic liquid crystal polyester liquid composition containing a solvent containing a chlorine-substituted phenol compound and an aromatic liquid crystal polyester, and the aromatic liquid crystal polyester liquid composition as, for example, a metal. We have already proposed an aromatic liquid crystal polyester film obtained by casting on a support such as foil and removing the solvent (see Patent Documents 1 and 2).

JP 2002-114894 A JP 2004-250688 A

  The objective of this invention is providing the aromatic liquid crystal polyester film with a support which further improved the adhesiveness of aromatic liquid crystal polyester and a support body.

（式中、Ａはハロゲン原子またはトリハロゲン化メチルを表わし、ｉは１〜５の整数を表わし、ｉが２以上の場合に複数あるＡは互いに同一でも異なっていてもよい。）
〔２〕流動開始温度が３１５℃以上３４０℃以下である〔１〕に記載の支持体付芳香族液晶ポリエステルフィルム。
〔３〕温度３１０℃以上３５０℃以下の温度で熱処理する〔１〕または〔２〕に記載の支持体付芳香族液晶ポリエステルフィルム。
〔４〕前記〔１〕〜〔３〕のいずれかに記載の支持体の十点平均粗さＲｚが４．０μｍ以下である支持体付芳香族液晶ポリエステルフィルム。
〔５〕前記〔１〕〜〔４〕のいずれかに記載の支持体が金属箔である金属箔付芳香族液晶ポリエステルフィルム。
〔６〕前記〔１〕〜〔４〕のいずれかに記載の支持体付芳香族液晶ポリエステルフィルムを用いたプリント配線基板。
〔７〕前記〔１〕〜〔４〕のいずれかに記載の支持体付芳香族液晶ポリエステルフィルムを用いたモジュール基板。
〔８〕前記〔５〕に記載の金属箔付芳香族液晶ポリエステルフィルムを用いたプリント配線基板。
〔９〕前記〔５〕に記載の金属箔付芳香族液晶ポリエステルフィルムを用いたモジュール基板。
〔１０〕流動開始温度が３１０℃以上である芳香族液晶ポリエステル及び下記溶媒を含有する芳香族液晶ポリエステル液状組成物を支持体に流延し、その後、温度３００℃以上で熱処理する支持体付芳香族液晶ポリエステルフィルムの製造方法。
溶媒：下記一般式（Ｉ）で示されるハロゲン置換フェノール化合物を３０重量％以上含有する溶媒。

（式中、Ａはハロゲン原子またはトリハロゲン化メチルを表わし、ｉは１〜５の整数を表わし、ｉが２以上の場合に複数あるＡは互いに同一でも異なっていてもよい。） That is, the present invention is as follows.
[1] A support obtained by casting an aromatic liquid crystal polyester having a flow initiation temperature of 310 ° C. or higher and an aromatic liquid crystal polyester liquid composition containing the following solvent to a support, followed by heat treatment at a temperature of 300 ° C. or higher. Body-attached aromatic liquid crystal polyester film.
Solvent: A solvent containing 30% by weight or more of the halogen-substituted phenol compound represented by the following general formula (I).

(In the formula, A represents a halogen atom or trihalogenated methyl, i represents an integer of 1 to 5, and when i is 2 or more, a plurality of A may be the same or different from each other.)
[2] The aromatic liquid crystal polyester film with a support according to [1], wherein the flow start temperature is 315 ° C. or higher and 340 ° C. or lower.
[3] The aromatic liquid crystal polyester film with a support according to [1] or [2], which is heat-treated at a temperature of 310 ° C. or higher and 350 ° C. or lower.
[4] An aromatic liquid crystal polyester film with a support, wherein the support according to any one of [1] to [3] has a ten-point average roughness Rz of 4.0 μm or less.
[5] An aromatic liquid crystal polyester film with metal foil, wherein the support according to any one of [1] to [4] is a metal foil.
[6] A printed wiring board using the aromatic liquid crystal polyester film with a support according to any one of [1] to [4].
[7] A module substrate using the support-attached aromatic liquid crystal polyester film according to any one of [1] to [4].
[8] A printed wiring board using the aromatic liquid crystal polyester film with metal foil according to [5].
[9] A module substrate using the aromatic liquid crystal polyester film with metal foil according to [5].
[10] Aromatic liquid crystal polyester having a flow starting temperature of 310 ° C. or higher and an aromatic liquid crystal polyester liquid composition containing the following solvent are cast on a support, and then heat-treated at a temperature of 300 ° C. or higher. Of manufacturing liquid crystalline polyester film.
Solvent: A solvent containing 30% by weight or more of the halogen-substituted phenol compound represented by the following general formula (I).

(In the formula, A represents a halogen atom or trihalogenated methyl, i represents an integer of 1 to 5, and when i is 2 or more, a plurality of A may be the same or different from each other.)

  ADVANTAGE OF THE INVENTION According to this invention, the aromatic liquid-crystal polyester film with a support excellent in adhesiveness with a support can be provided.

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

As an aromatic liquid crystal polyester, for example,
(1) What is obtained by polymerizing a combination of an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid and an aromatic diol,
(2) those obtained by polymerizing the same or different aromatic hydroxycarboxylic acids,
(3) What is obtained by polymerizing a combination of an aromatic dicarboxylic acid and an aromatic diol,
(4) Crystalline polyesters such as polyethylene terephthalate are reacted with an aromatic hydroxycarboxylic acid.
Here, the aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, and aromatic diol may be substituted with a halogen atom, an alkyl group, an aryl group, or the like as long as the ester-forming property is not inhibited.
Examples of the alkyl group include an alkyl group having 1 to 10 carbon atoms, and a methyl group, an ethyl group, or a butyl group is more preferable. As an aryl group, a C6-C20 aryl group is mentioned, A phenyl group is more preferable.
Examples of the halogen atom include a chlorine atom and a fluorine atom.
In addition, you may use those ester-forming derivatives instead of these aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, or aromatic diol.

Examples of the ester-forming derivative of carboxylic acid include those in which the carboxyl group is a highly reactive derivative such as an acid chloride or an acid anhydride that promotes the polyester formation reaction, and the carboxyl group is an ester. Examples include those that form esters with alcohols, ethylene glycol, or the like that form polyesters by an exchange 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 repeating structural unit of the aromatic liquid crystal polyester in the present invention include the following, but are not limited thereto.

上記の繰り返し構造単位は、前記のようなハロゲン原子、アルキル基またはアリール基で置換されていてもよい。 Repeating structural units derived from aromatic hydroxycarboxylic acids:

The above repeating structural unit may be substituted with a halogen atom, an alkyl group or an aryl group as described above.

上記の繰り返し構造単位は、前記のようなハロゲン原子、アルキル基またはアリール基で置換されていてもよい。 Repeating structural units derived from aromatic dicarboxylic acids:

The above repeating structural unit may be substituted with a halogen atom, an alkyl group or an aryl group as described above.

上記の繰り返し構造単位は、前記のようなハロゲン原子、アルキル基またはアリール基で置換されていてもよい。 Repeating structural units derived from aromatic diols:

The above repeating structural unit may be substituted with a halogen atom, an alkyl group or an aryl group as described above.

Examples of preferable combinations of the repeating structural units of the aromatic liquid crystal polyester include the following (a) to (f).
(A):
A combination of the repeating structural units (A ₁ ), (B ₂ ) and (C ₃ ),
A combination of the repeating structural units (A ₂ ), (B ₂ ) and (C ₃ ),
A combination of the repeating structural units (A ₁ ), (B ₁ ), (B ₂ ) and (C ₃ ), or
A combination of the repeating structural units (A ₂ ), (B ₁ ), (B ₂ ) and (C ₃ ).
(B): In each of the combination of said (a), by substituting a part or all of (C ₃₎ to (C ₁₎ in combination.
(C): In each of the combination of said (a), by substituting a part or all of (C ₃₎ to (C ₂₎ combined.
(D): In each of the combination of said (a), by substituting a part or all of (C ₃₎ to (C ₄₎ combinations.
(E): In each of the combination of said (a), was replaced with a mixture of (C ₃₎ of some or all the (C ₄₎ (C ₅₎ combinations.
(F): In each of the combination of said (a), by replacing part of (A ₁₎ to (A ₂₎ in combination.

From the viewpoint of heat resistance, the aromatic liquid crystalline polyester is a repeating structural unit derived from at least one compound selected from the group consisting of p-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acids, that is, (A ₁ ) and derived from a repeating structural unit derived from at least one compound selected from the group consisting of (a ₂₎ 30~80mol%, at least one compound selected from the group consisting of hydroquinone and 4,4'-dihydroxy biphenyls 10 to 35 mol% of repeating structural units derived from at least one compound selected from the group consisting of (C ₁ ) and (C ₃ ), and selected from the group consisting of terephthalic acid and isophthalic acids Repeating structural units derived from at least one compound, ie (B ₁ ) and (B ₂ ) Preferably comprising a repeating structural unit derived from at least one compound selected from Ranaru group from 10～35Mol% Further, the heat resistance, the aromatic liquid crystal polyester from the viewpoint of the balance of mechanical properties, the (A ₁₎ It is preferable to contain at least 30 mol% of the repeating unit represented by the formula.

  The method for producing the aromatic liquid crystal polyester used in the present invention is not particularly limited. For example, at least one selected from the group consisting of an aromatic hydroxycarboxylic acid and an aromatic diol is acylated with an excess amount of a fatty acid anhydride. A method of melt polymerization by obtaining an acylated product and subjecting the obtained acylated product to at least one selected from the group consisting of an aromatic hydroxycarboxylic acid and an aromatic dicarboxylic acid by transesterification (polycondensation) may be mentioned.

  In the acylation reaction, the addition amount of the fatty acid anhydride is preferably 1.0 to 1.2 times equivalent, more preferably 1.05 to 1.1 times equivalent to the phenolic hydroxyl group. If the amount of fatty acid anhydride added is small, acylated products, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, etc. will sublimate during transesterification (polycondensation), and the reaction system tends to be clogged. The aromatic liquid crystal polyester obtained tends to be remarkably colored.

  The acylation reaction is preferably performed at 130 ° C. to 180 ° C. for 5 minutes to 10 hours, more preferably at 140 ° C. 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, or isobutyric anhydride is preferably used, and acetic anhydride is more preferably used.

  In the transesterification, the acyl group of the acylated product is preferably 0.8 to 1.2 times the carboxyl group.

  The transesterification is preferably performed while increasing the temperature up to 400 ° C. at a rate of 0.1 to 50 ° C./min, and more preferably performed while increasing the temperature up to 350 ° C. at a rate of 0.3 to 5 ° C./min. .

  When transesterifying a fatty acid ester obtained by acylation with a carboxylic acid, it is preferable to distill out the by-product fatty acid and the unreacted fatty acid anhydride by evaporating or the like in order to move the equilibrium. .

  The acylation reaction and transesterification 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. 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.

Polycondensation by transesterification is usually performed 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. Specific examples include a method of heat treatment in a solid state at 250 ° C. to 350 ° C. for 1 to 30 hours under an inert atmosphere such as nitrogen. Solid phase polymerization is stirred even while stirring. You may carry out in the state left still. 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 state polymerization, the obtained aromatic liquid crystal polyester may be pelletized and molded by a known method.
The aromatic liquid crystal polyester can be produced using, for example, a batch apparatus, a continuous apparatus or the like.

  The aromatic liquid crystal polyester used in the present invention has a flow start temperature of the aromatic liquid crystal polyester of 310 ° C. or higher.

The flow start temperature here refers to a temperature at which the melt viscosity of the aromatic polyester becomes 4800 Pa · s or less under a pressure of 9.8 MPa in the evaluation of the melt viscosity by a flow tester.
According to the book “Liquid Crystal Polymer -Synthesis / Molding / Application-” published in 1987 (Naide Koide, pp. 95-105, CMC, published on June 5, 1987), liquid crystal polyester resin in the 1970s. Has been developed, the flow temperature (definition equivalent to the flow start temperature in the present invention) has been used as a measure of the molecular weight of the liquid crystal polyester resin.

  Here, the flow start temperature is more preferably 315 ° C. or higher and 340 ° C. or lower. If the flow start temperature is 315 ° C. or higher, the adhesion to the metal foil tends to be higher. Conversely, if the flow start temperature is 340 ° C. or lower, the solubility in the solvent tends to be improved. It is done. The flow starting temperature is more preferably in the range of 315 ° C. or higher and 330 ° C., and the flow starting temperature is particularly preferably in the range of 15 ° C. or higher and 325 ° C.

  Of the total amount of the aromatic liquid crystal polyester used in the present invention, the amount exceeding at least 80% by weight preferably includes the aromatic liquid crystal polyester having a flow start temperature of 310 ° C. or higher. More preferably, an aromatic liquid crystal polyester having a flow initiation temperature of 310 ° C. or higher is used for the entire amount.

  As a method for obtaining the aromatic liquid crystal polyester used in the present invention, for example, the polymer is extracted from the melt polymerization step, and then pulverized into powder or flakes, and then the flow start temperature is adjusted by a known solid phase polymerization method The method of doing is mentioned.

  More specifically, for example, after the melt polymerization step, heat treatment is performed in a solid state at a temperature exceeding 255 ° C., more preferably at a temperature of 255 ° C. to 350 ° C. for 1 to 10 hours under an inert atmosphere such as nitrogen. Is obtained by the method of Solid phase polymerization may be carried out while stirring or in a state of standing without stirring. For example, there may be mentioned a method in which solid state polymerization is carried out at a state temperature of 276 ° C. for 3 hours in a nitrogen inert atmosphere without stirring.

（式中、Ａはハロゲン原子またはトリハロゲン化メチル基を表わし、ｉはＡの個数であって１〜５の整数を表わす。ｉが２以上の場合、複数あるＡは互いに同一でも異なっていてもよい） In the present invention, the solvent used for the preparation of the aromatic liquid crystal polyester liquid composition is a solvent containing 30% by weight or more of the halogen-substituted phenol compound represented by the following general formula (I). The solvent is preferably a solvent containing 60% by weight or more of the phenol compound, and more preferably 100% by weight of the phenol compound is used as the solvent because it is not necessary to mix with other components. .
Formula (I)

(In the formula, A represents a halogen atom or a trihalogenated methyl group, i represents the number of A and represents an integer of 1 to 5. When i is 2 or more, a plurality of A's are the same or different from each other. Also good)

In the general formula (I), i is preferably 1 to 3, more preferably 1 or 2. When i is 1, the substitution position of A is preferably the 4-position, and when i is 2 or more, the substitution position of at least one A is preferably the 4-position (the hydroxyl substitution position is the 1-position). .
When a plurality of A are present, A may be the same as or different from each other, and is preferably the same.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. A fluorine atom or a chlorine atom is preferable, and a chlorine atom is particularly preferable.
Examples of the halogen-substituted phenol compound represented by the general formula (I) in which the halogen atom is a fluorine atom include pentafluorophenol and tetrafluorophenol.
Examples of the halogen-substituted phenol compound represented by the general formula (I) in which the halogen atom is a chlorine atom include p-chlorophenol.

Examples of the halogen atom of the trihalogenated methyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the halogen-substituted phenol compound represented by the general formula (I) in which the halogen atom of the trihalogenated methyl group is a fluorine atom include 3,5-bistrifluoromethylphenol.

  As the halogen-substituted phenol compound represented by the general formula (I), a chlorine-substituted phenol compound such as p-chlorophenol is preferable from the viewpoint of price and availability.

The solvent may contain other components in addition to the halogen-substituted phenolic compound as long as the aromatic liquid crystalline polyester is not deposited when the aromatic liquid crystalline polyester liquid composition is stored or casted later. Good.
Other components that may be contained are not particularly limited, and examples thereof include chlorine compounds such as chloroform, methylene chloride, and tetrachloroethane.

  The aromatic liquid crystal polyester liquid composition of the present invention can be obtained by dissolving the aromatic liquid crystal polyester in the solvent.

In the aromatic liquid crystal polyester liquid composition of the present invention, the aromatic liquid crystal polyester is usually 0.5 to 100 parts by weight, preferably 1 to 50 parts by weight, more preferably 3 to 20 parts per 100 parts by weight of the solvent. Contained in parts by weight.
If the total amount of the aromatic liquid crystal polyester is 0.5 parts by weight or more, the production efficiency of the aromatic liquid crystal polyester film tends to be further improved, and if it is 100 parts by weight or less, the solubility in the solvent tends to be further improved. There is.
Thereafter, the liquid composition may be further filtered through a filter or the like as necessary to remove fine foreign substances contained in the liquid composition.

The aromatic liquid crystal polyester liquid composition of the present invention may contain an inorganic filler. Examples of the inorganic filler include titanates such as silica, aluminum hydroxide, calcium carbonate, alumina, mica, mica, aluminum borate, potassium titanate, barium titanate, strontium titanate, and titanium titanate. TiO ₂ with at least two kinds selected from the group consisting of BaO, Bi ₂ O ₃ , La ₂ O ₃ , Nd ₂ O ₃ , Sm ₂ O ₃ , and Al ₂ O ₃ , partially replaced with other metals A combination of these can be used. The shape of the inorganic filler may be spherical, crushed, plate-like, or needle-like.

The content of the inorganic filler in the aromatic liquid crystal polyester liquid composition of the present invention is usually 10 to 1000 parts by weight with respect to 100 parts by weight of the aromatic liquid crystal polyester.
If the content of the inorganic filler is 100 parts by weight or less, the adhesiveness with the support is further improved, so the range of 10 to 100 parts by weight with respect to 100 parts by weight of the aromatic liquid crystal polyester is preferable, and the high film Depending on the application (flexible substrate, etc.) requiring flexibility, the range of 10 to 50 parts by weight is more preferable.

  Further, the aromatic liquid crystal polyester liquid composition includes polyamide, polyester, polyphenylene sulfide, polyetherketone, polycarbonate, polyethersulfone, polyphenylether and modified products thereof, polyetherimide, and other thermoplastic resins, phenolic resin, epoxy Various additives such as a thermosetting resin such as a resin, a polyimide resin, and a cyanate resin, a silane coupling agent, an antioxidant, and an ultraviolet absorber may be contained.

  The aromatic liquid crystal polyester film with a support of the present invention is superior in adhesion to the support as compared with a conventional aromatic liquid crystal polyester film with a support.

  The aromatic liquid crystal polyester film of the present invention can be obtained, for example, by a method in which the aromatic liquid crystal polyester liquid composition is cast into a film on a support and then the solvent is removed.

As a method of casting the liquid composition in the form of a film, a roller coating method, a dip coating method, a spray coating method, a spinner coating method, a curtain coating method, a slot coating method, a screen printing method, a die coating method on a support. And various means such as a knife coating method.
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, heating is preferable from the viewpoints of production efficiency and handleability, and heating while ventilating is more preferable. As heating conditions at this time, preliminary drying is performed at 60 to 200 ° C. for 10 minutes to 2 hours.
The present invention is characterized by heat treatment at 300 ° C. or higher. The heat treatment time is preferably 1 minute to 5 hours. More preferably, it includes a step of performing heat treatment at a temperature of 310 ° C. to 350 ° C. for 1 minute to 5 hours.
If the heat treatment temperature is too high, the aromatic liquid crystal polyester resin is decomposed and the film physical properties tend to deteriorate. The heat treatment temperature is more preferably 310 ° C. or higher and 340 ° C. or lower, and preferably 315 ° C. or higher and 325 ° C. or lower. Further preferred. The heat treatment time is preferably 60 minutes or less from the viewpoint of productivity, and a more preferable heat treatment time is 30 minutes or less.
The heat treatment is preferably performed in an inert gas atmosphere such as nitrogen or argon.

  The aromatic liquid crystal polyester film with a support of the present invention uses, for example, a metal foil such as a copper foil, a silver foil, a gold foil, an aluminum foil, and a stainless steel foil as a support, and the aromatic liquid crystal polyester of the present invention on the metal foil. It can be obtained by casting the liquid composition into a film and then removing the solvent. The surface roughness (ten-point average roughness Rz) of such a metal foil is preferably a low roughness of 4.0 μm or less from the viewpoint of transmission characteristics. Furthermore, the surface roughness of the metal foil is more preferably 2.5 μm or less. Furthermore, it is most preferable that it is 2.2 micrometers or less. It is preferable to use a copper foil as the metal foil in view of electrical characteristics such as conductor resistance and migration, and cost. As the copper foil, any of an electrolytic copper foil, a rolled copper foil or a special electrolytic copper foil can be suitably used. For example, a special electrolytic copper foil or a rolled copper foil having high flexibility is more preferably used for applications requiring flexibility such as a flexible substrate.

The thus obtained aromatic liquid crystal polyester film with a support of the present invention has high adhesion with a low-roughness support and excellent transmission characteristics, and a printed wiring board such as a rigid printed circuit board and a flexible printed circuit board, Or it is used suitably for the use of a module board | substrate, and it utilizes suitably especially as a high frequency board | substrate used for the frequency body of 1 GHz or more.
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 using an Example, this invention is not limited by an Example.

[Synthesis example]
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 128 g (0.68 mol) of 2-hydroxy-6-naphthoic acid and 63.3 g of 4,4′-dihydroxybiphenyl were added. (0.34 mol), isophthalic acid 56.5 g (0.34 mol) and acetic anhydride 152.7 g (1.50 mol) were charged. After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature was raised to 140 ° C. at an internal temperature under a nitrogen gas stream, and the temperature was maintained and refluxed for 3 hours.
Thereafter, while distilling off distilling by-product acetic acid and unreacted acetic anhydride, the temperature was raised to 300 ° C. at the internal temperature. The time point at which an increase in torque was observed was regarded as completion of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature and pulverized with a coarse pulverizer.

Further, the obtained aromatic liquid crystal polyester powder was subjected to solid phase polymerization reaction in a nitrogen atmosphere to obtain an aromatic liquid crystal polyester powder. The flow start temperature of the obtained aromatic liquid crystal polyester powder was evaluated by a flow tester CFT-500 (manufactured by Shimadzu Corporation).

[Example of dissolution process]
As a result of adding 5 g of aromatic liquid crystal polyester powder obtained by the above process to 95 g of p-chlorophenol (hereinafter sometimes referred to as PCP), and then heating to 120 ° C. and holding for 8 hours, aromatic liquid crystal A polyester liquid composition was obtained. The solution viscosity (50 ° C.) of the liquid composition was measured using a B-type viscometer TV-20 (manufactured by Tokimec). As the rotor, an appropriate rotor was selected according to the viscosity of each solution, and the rotation speed of the rotor was constant at 10 rpm.

[Film]
Wet the obtained liquid crystal composition of the present invention in the form of a liquid on the support, on a special electrolytic copper foil F2WS made by Furukawa Electric (thickness = 18 μm, 10-point average roughness Rz = 2.1 μm)). Casting to a thickness of 350 μm, evaporating the solvent with a hot air dryer at a set temperature of 100 ° C. for 20 minutes, and then heat-treating in a nitrogen atmosphere with the hot air dryer, the aromatic liquid crystalline polyester with support of the present invention A film was obtained.

[Evaluation of copper foil adhesion]
The adhesion of the obtained aromatic liquid crystal polyester film with a support material to the support (copper foil) was evaluated by Autograph AG-IS (manufactured by Shimadzu Corporation) (90-degree tensile, tensile speed 50 mm / min). .
The results are shown in Tables 1 and 2.

Claims (7)

An aromatic liquid crystal polyester having a flow start temperature of 310 ° C. or higher and an aromatic liquid crystal polyester liquid composition containing the following solvent are cast on a support, and then heat-treated at a temperature of 300 ° C. or higher. A method for producing a film.
Solvent: A solvent containing 30% by weight or more of the halogen-substituted phenol compound represented by the following general formula (I).

(In the formula, A represents a halogen atom or trihalogenated methyl, i represents an integer of 1 to 5, and when i is 2 or more, a plurality of A may be the same or different from each other.) The method for producing an aromatic liquid crystal polyester film with a support according to claim 1, wherein the flow start temperature of the aromatic liquid crystal polyester is 315 ° C or higher and 340 ° C or lower. The method for producing an aromatic liquid crystal polyester film with a support according to claim 1 or 2, wherein the heat treatment is performed at a temperature of 310 ° C to 350 ° C. Method for producing a support with an aromatic liquid crystal polyester film according to any one of claims 1 to 3 ten-point average roughness Rz supporting region thereof is less than 4.0 .mu.m. The process for producing an aromatic liquid crystal polyester film with support according to claim 1 supported lifting body is a metal foil. Method for producing a support with an aromatic liquid crystal polyester film according to any one supporting lifting aromatic liquid crystal polyester film with body of claims 1 to 5 is an aromatic liquid crystal polyester film with a support for the printed wiring board. Method for producing a support with an aromatic liquid crystal polyester film according to claim 1 is an aromatic liquid crystal polyester film with a support for the module substrate aromatic liquid crystal polyester film with supporting lifting body.