TW202436505A - Liquid crystal polyester composition, film, laminate and method for producing the same - Google Patents

Abstract

The present invention pertains to a liquid crystal polyester composition which contains a liquid crystal polyester (A), and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimides and aromatic polysulfones, and in which the liquid crystal polyester (A) has a repeating unit derived from an aromatic hydroxylamine or a repeating unit derived from an aromatic diamine.

Description

Liquid crystal polyester composition, film, laminate and method for producing the same

The present invention relates to a liquid crystal polyester composition, a film, a laminate and a method for manufacturing the same. This case claims priority based on Japanese Patent Application No. 2023-016131 filed in Japan on February 6, 2023, and the contents thereof are cited herein.

Liquid crystal polyesters are known to have high chemical stability, heat resistance and dimensional accuracy, and are used in various fields such as electrical, electronic, mechanical, optical equipment, automobiles, aircraft and medical fields. In these fields, liquid crystal polyesters are particularly popular as materials for electronic parts due to their low dielectric loss and excellent electrical properties.

Patent document 1 discloses a method for producing a liquid crystal polyester film laminate, wherein the liquid crystal polyester film laminate is formed by laminating a liquid crystal polyester film and a metal layer. The method is to obtain the liquid crystal polyester film by casting a solution of the liquid crystal polyester into a film and then removing the solvent. The liquid crystal polyester comprises at least one structural unit selected from the group consisting of structural units derived from aromatic diamines, structural units derived from aromatic amines having phenolic hydroxyl groups, and structural units derived from aromatic amino acids, in an amount of 10 to 35 mol% relative to all structural units. [Prior art document] [Patent document]

[Patent Document 1] Japanese Patent No. 4479355

[The problem the invention is trying to solve]

However, there is still room for research on the technology of improving the adhesion strength between the metal layer and the film containing the liquid crystal polyester.

The present invention is made to solve the above-mentioned problems, and its purpose is to provide a liquid crystal polyester composition, film, laminate and its manufacturing method that can produce a film with excellent adhesion strength with a metal layer. [Technical means for solving the problem]

The inventors of the present invention have made great efforts to solve the above problems and have found that the film containing liquid crystal polyester and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone has excellent adhesion strength with the metal layer, thereby completing the present invention. That is, the present invention has the following aspects.

<1> A liquid crystal polyester composition comprising a liquid crystal polyester (A) and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, wherein the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines. <2> The liquid crystal polyester composition as described in <1> above, wherein the liquid crystal polyester (A) has repeating units represented by the following formula (A1), repeating units represented by the following formula (A2), and repeating units represented by the following formula (A3). (A1)-O-Ar ¹ -CO- (A2)-CO-Ar ² -CO- (A3)-X-Ar ³ -Y- (wherein, Ar ¹ represents 1,4-phenylene, 2,6-naphthylene, or 4,4'-biphenylene, Ar ² represents 1,4-phenylene, 1,3-phenylene, or 2,6-naphthylene, Ar ³ represents 1,4-phenylene or 1,3-phenylene, X represents -NH-, Y represents -O- or -NH-, and the hydrogen atom on the above groups represented by Ar ¹ , Ar ² or Ar ³ may be independently substituted by a halogen atom, an alkyl group, or an aryl group). <3> The liquid crystal polyester composition as described in <1> or <2>, further comprising liquid crystal polyester particles comprising a liquid crystal polyester (B), wherein the liquid crystal polyester (B) does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines. <4> The liquid crystal polyester composition as described in <3>, wherein the content of the liquid crystal polyester particles is 5 mass % or more and 80 mass % or less relative to 100 mass % of the total content of solid components contained in the liquid crystal polyester composition. <5> The liquid crystal polyester composition as described in any one of <1> to <4>, wherein in the liquid crystal polyester composition, the content of the thermoplastic resin is 1 mass part or more relative to 100 mass parts of the liquid crystal polyester (A). <6> A liquid crystal polyester composition as described in any one of <1> to <5> above, wherein the content of the liquid crystal polyester (A) in the liquid crystal polyester composition is 10% by mass or more and 90% by mass or less relative to 100% by mass of the total content of the solid components contained in the liquid crystal polyester composition. <7> A liquid crystal polyester composition as described in any one of <1> to <6> above, which further contains a solvent that can dissolve the liquid crystal polyester (A). <8> A liquid crystal polyester composition as described in any one of <1> to <7> above, wherein the thermoplastic resin is a thermoplastic polyimide. <9> A liquid crystal polyester composition as described in <8> above, wherein the thermoplastic polyimide has repeating units represented by the following formula (I) and repeating units represented by the following formula (II). [Chemistry 1] (wherein, _R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure, _R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms, and _X1 and _X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.) <10> The liquid crystal polyester composition as described in <9> above, wherein the content ratio of the repeating units of the above formula (I) in the above thermoplastic polyimide is 20 mol% or more and 70 mol% or less relative to 100 mol% of the total of the repeating units of the above formula (I) and the repeating units of the above formula (II). <11> A liquid crystal polyester composition comprising a liquid crystal polyester (A), at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfide, and a solvent capable of dissolving the liquid crystal polyester (A). <12> A film comprising a liquid crystal polyester (A) and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfide, wherein the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines. <13> A laminate having a metal layer, and the film described in <12> laminated on the metal layer. <14> A method for producing a laminate as described in <13> above, comprising the steps of: applying a liquid crystal polyester composition as described in any one of <1> to <11> above on a metal layer to form a film on the metal layer. [Effects of the Invention]

According to the present invention, a liquid crystal polyester composition can be provided, which contains a liquid crystal polyester and can produce a film having excellent adhesion strength with a metal layer. According to the present invention, a film having excellent adhesion strength with a metal layer can be provided. According to the present invention, a laminate having a metal layer and a film, and having excellent adhesion strength between the metal layer and the film can be provided.

The following describes the embodiments of the liquid crystal polyester composition, film, laminate and the manufacturing method thereof of the present invention.

<<Liquid Crystal Polyester Composition>> The liquid crystal polyester composition of the embodiment contains a liquid crystal polyester (A) and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, and the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines.

The liquid crystal polyester composition of the embodiment contains a liquid crystal polyester and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone. Compared with the case where the above-mentioned thermoplastic resin is not contained, the adhesion strength between the film and the metal layer when the film is laminated with the metal layer is improved.

In the above-mentioned liquid crystal polyester composition, the content of the above-mentioned thermoplastic resin is preferably 1 mass part or more, more preferably 3 mass parts or more, and further preferably 5 mass parts or more, relative to 100 mass parts of the liquid crystal polyester (A). The liquid crystal polyester composition containing the thermoplastic resin at or above the above lower limit has a more excellent effect of improving the adhesion strength between the metal layer and the composition.

In the above-mentioned liquid crystal polyester composition, the content of the above-mentioned thermoplastic resin is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and further preferably 65 parts by mass or less, relative to 100 parts by mass of the liquid crystal polyester (A). The liquid crystal polyester composition containing the thermoplastic resin below the above upper limit has a more excellent effect of improving the adhesion strength between the metal layer and the composition.

As an example of the numerical range of the content of the above-mentioned thermoplastic resin in the above-mentioned liquid crystal polyester composition relative to 100 parts by mass of the liquid crystal polyester (A), it can be 1 part by mass to 80 parts by mass, 3 parts by mass to 70 parts by mass, 5 parts by mass to 65 parts by mass, 5 parts by mass to 60 parts by mass, and 5 parts by mass to 55 parts by mass.

Furthermore, since the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamine or repeating units derived from aromatic diamine, it dissolves well in the following solvents. Furthermore, the adhesion strength with the metal layer when the film is laminated with the metal layer is also improved.

The liquid crystal polyester (A) may include an amide bond or may include a repeating unit having an imine group (—NH—).

The liquid crystal polyester (A) is soluble in the following solvents.

Whether the liquid crystal polyester is soluble in a solvent can be confirmed by performing the following test.

・Test method 5 parts by mass of liquid crystal polyester was added to 95 parts by mass of solvent at 180°C, stirred at 200 rpm using an anchor-type stirring blade for 6 hours, and then cooled to room temperature. Then, the mixture was filtered using a 5 μm-mesh membrane filter and a pressure filter, and the residue on the membrane filter was checked. At this time, if no residue was found, it was judged to be soluble in the solvent.

The liquid crystal polyester composition of the embodiment can contain the liquid crystal polyester (A), the above-mentioned thermoplastic resin, and any components that can be contained as needed in the following manner, that is, the total content (mass %) of the same in the liquid crystal polyester composition does not exceed the total mass (100 mass %) of the liquid crystal polyester composition of the embodiment.

<Liquid Crystalline Polyester (A)> The liquid crystal polyester is a liquid crystal polyester that exhibits liquid crystallinity in a molten state, and preferably melts at a temperature of 450° C. or less.

The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester having only repeating units derived from aromatic compounds.

Furthermore, in this specification, "derived from" means that in the polymerization of raw material monomers, the chemical structure of the functional group that contributes to the polymerization changes, while the other chemical structures remain unchanged. The concept of "derived from" here also includes the case where the derivative that can be used to polymerize the raw material monomer is the source.

Examples of polymerizable derivatives of compounds having a carboxyl group such as aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids include esters obtained by converting a carboxyl group to an alkoxycarbonyl group or an aryloxycarbonyl group; acylate halides obtained by converting a carboxyl group to a halogenated methyl group; and acid anhydrides obtained by converting a carboxyl group to an acyloxycarbonyl group.

Examples of polymerizable derivatives of compounds having a hydroxyl group such as aromatic hydroxycarboxylic acids, aromatic diols, and aromatic hydroxylamines include acylates obtained by acylation of a hydroxyl group to an acyloxy group. Examples of polymerizable derivatives of compounds having an amino group such as aromatic hydroxylamines and aromatic diamines include acylates obtained by acylation of an amino group to an acylamino group.

The liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamine or repeating units derived from aromatic diamine.

As an example of a liquid crystal polyester (A) having repeating units derived from an aromatic hydroxylamine or repeating units derived from an aromatic diamine, there can be exemplified a liquid crystal polyester having repeating units represented by the following formula (A1), repeating units represented by the following formula (A2), and repeating units represented by the following formula (A3).

(A1)-O-Ar ¹ -CO- (A2)-CO-Ar ² -CO- (A3)-X-Ar ³ -Y- (wherein, Ar ¹ represents 1,4-phenylene, 2,6-naphthylene or 4,4'-biphenylene, Ar ² represents 1,4-phenylene, 1,3-phenylene or 2,6-naphthylene, Ar ³ represents 1,4-phenylene or 1,3-phenylene, X represents -NH-, Y represents -O- or -NH-, and the hydrogen atom on the above groups represented by Ar ¹ , Ar ² or Ar ³ may be independently substituted by a halogen atom, an alkyl group or an aryl group).

Examples of the halogen atom that can substitute for the hydrogen atom possessed by Ar ¹ , Ar ² or Ar ³ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The alkyl group that can replace the hydrogen atom of Ar ¹ , Ar ² or Ar ³ is preferably an alkyl group having 1 to 10 carbon atoms. The alkyl group may be linear or branched, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-hexyl, 2-ethylhexyl, n-octyl, and n-decyl.

The aryl group that can substitute the hydrogen atom of Ar ¹ , Ar ² or Ar ³ is preferably an aryl group having 6 to 20 carbon atoms. The aryl group may be a monocyclic group or a condensed ring, and examples thereof include phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, and 2-naphthyl. In addition, the aryl group may be a group in which the hydrogen atom of the aromatic ring is substituted by an alkyl group, such as tolyl.

When the hydrogen atom contained in Ar ¹ , Ar ² or Ar ³ is substituted by the above-mentioned groups, the number of substitutions is preferably 1 or 2, more preferably 1. The hydrogen atom contained in Ar ¹ , Ar ² or Ar ³ may not be substituted by the above-mentioned groups.

In the present embodiment, as an example, it is preferred that Ar ¹ is 2,6-naphthylene, Ar ² is 1,4-phenylene, 1,3-phenylene, or 2,6-naphthylene, and Ar ³ is 1,4-phenylene or 1,3-phenylene.

In the present embodiment, it is particularly preferred that Ar ² is a 1,3-phenylene group. When Ar ² is a 1,3-phenylene group, the solubility in the following solvent is further improved. This is considered to be because when Ar ² is a 1,3-phenylene group, a bent structure is introduced into the polymer.

In the present embodiment, from the viewpoint of good solubility in the following solvents and easy expression of the adhesion strength and dielectric properties between the film and the metal layer when laminated, it is preferred that Ar ¹ is 2,6-naphthylene, Ar ² is 1,3-phenylene, Ar ³ is 1,4-phenylene, and Y is -O-.

The number of repeating units represented by the formula (A1) is preferably 30% to 80% of the total number of all repeating units constituting the liquid crystal polyester (A) (100%), more preferably 40% to 70%, and even more preferably 45% to 65%. If the number of repeating units (A1) is below the upper limit, the solubility in the solvent becomes good, and if it is above the lower limit, the liquid crystal properties become good.

The number of repeating units represented by the formula (A2) is preferably 10% to 35% relative to the total number (100%) of all repeating units constituting the liquid crystal polyester (A), more preferably 15% to 30%, and still more preferably 17.5% to 27.5%. If the number of repeating units (A2) is below the upper limit, the liquid crystal properties are good, and if it is above the lower limit, the solubility in the solvent is good.

The number of repeating units represented by the formula (A3) is preferably 10% to 35% relative to the total number (100%) of all repeating units constituting the liquid crystal polyester (A), more preferably 15% to 30%, and still more preferably 17.5% to 27.5%. If the number of repeating units (A3) is below the upper limit, the liquid crystal properties are good, and if it is above the lower limit, the solubility in the solvent is good.

Furthermore, it is preferred that the content of the repeating unit (A2) in the liquid crystal polyester (A) is equal to the content of the repeating unit (A3). However, when the content is different, the difference between the content of the repeating unit (A2) and the content of the repeating unit (A3) is preferably less than 10%.

Regarding the preferred ratio of the content of each repeating unit in the liquid crystal polyester (A), relative to the total content of all repeating units constituting the above-mentioned liquid crystal polyester (A), the content of the repeating unit represented by the above-mentioned formula (A1) is preferably greater than 30% and less than 80%, the content of the repeating unit represented by the above-mentioned formula (A2) is preferably greater than 10% and less than 35%, and the content of the repeating unit represented by the above-mentioned formula (A3) is preferably greater than 10% and less than 35%.

Regarding the preferred ratio of the content of each repeating unit in the liquid crystal polyester (A), relative to the total content of all repeating units constituting the above-mentioned liquid crystal polyester (A), the content of the repeating unit represented by the above-mentioned formula (A1) is preferably not less than 40% and not more than 70%, the content of the repeating unit represented by the above-mentioned formula (A2) is preferably not less than 15% and not more than 30%, and the content of the repeating unit represented by the above-mentioned formula (A3) is preferably not less than 15% and not more than 30%.

Regarding the preferred ratio of the content of each repeating unit in the liquid crystal polyester (A), relative to the total content of all repeating units constituting the above-mentioned liquid crystal polyester (A), the content of the repeating unit represented by the above-mentioned formula (A1) is further preferably greater than 45% and less than 65%, the content of the repeating unit represented by the above-mentioned formula (A2) is further preferably greater than 17.5% and less than 27.5%, and the content of the repeating unit represented by the above-mentioned formula (A3) is further preferably greater than 17.5% and less than 27.5%.

Furthermore, the liquid crystal polyester (A) may have two or more repeating units (A1) to (A3), respectively. Furthermore, the liquid crystal polyester (A) may have repeating units other than the repeating units (A1) to (A3), and the number of repeating units other than the repeating units (A1) to (A3) is preferably 10% or less, more preferably 5% or less, and may be 0% relative to the total number of all repeating units.

In this specification, the number of each repeating unit is obtained by the analysis method described in Japanese Patent Publication No. 2000-19168. Specifically, the number of each repeating unit relative to the total repeating units can be calculated by reacting the liquid crystal polyester with a lower alcohol in a supercritical state to depolymerize it and quantifying the depolymerization product (monomers derived from each repeating unit) by liquid chromatography.

The repeating unit (A1) may be a repeating unit derived from an aromatic hydroxycarboxylic acid. The repeating unit (A2) may be a repeating unit derived from an aromatic dicarboxylic acid. The repeating unit (A3) may be a repeating unit derived from an aromatic hydroxyamine or a repeating unit derived from an aromatic diamine. The repeating unit may also be an ester- or amide-forming derivative of the repeating unit instead of the above-mentioned repeating unit.

The method for producing the liquid crystal polyester (A) in the present embodiment is not particularly limited, and for example, the following method can be cited (see Japanese Patent Publication No. 2002-220444 and Japanese Patent Publication No. 2002-146003): an aromatic hydroxy acid corresponding to the repeating unit (A1), an aromatic amine having a phenolic hydroxyl group corresponding to the repeating unit (A3), or a phenolic hydroxyl group or an amine group of an aromatic diamine are acylated using an excess of fatty acid anhydride to obtain an acylate, and the obtained acylate is subjected to ester-amide exchange (condensation) with an aromatic dicarboxylic acid corresponding to the repeating unit (A2) to perform melt polymerization.

The polycondensation using ester-amide exchange is usually carried out by melt polymerization. The polycondensation can also be carried out by combining melt polymerization and solid phase polymerization.

The content of the liquid crystal polyester (A) relative to the total solid content of the liquid crystal polyester composition of the embodiment can be 10 mass % to 90 mass %, 15 mass % to 50 mass %, 25 mass % to 40 mass %, or 33 mass % to 40 mass %. The liquid crystal polyester composition containing the liquid crystal polyester (A) within the above numerical range can easily improve the adhesion strength and dielectric properties of the manufactured film and the metal layer.

In this specification, "solid content" refers to the components other than the solvent that can be contained in the liquid crystal polyester composition. That is, it is the following concept: as long as it is a component other than the solvent that can be contained in the liquid crystal polyester composition, it includes the components dissolved in the solvent. As a solvent, for example, the following aprotic solvent corresponds.

<Thermoplastic Polyimide> As one embodiment of the present invention, the thermoplastic resin may be a thermoplastic resin polyimide. The liquid crystal polyester composition of one embodiment of the present invention contains a liquid crystal polyester (A) and a thermoplastic polyimide, and the liquid crystal polyester (A) may have repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines.

The thermoplastic polyimide contained in the liquid crystal polyester composition of the embodiment shows a property of softening by heating (thermoplasticity). Hereinafter, the thermoplastic polyimide is sometimes referred to as polyimide. The thermoplastic polyimide may also be a crystalline polyimide.

The thermoplastic polyimide contained in the liquid crystal polyester composition of the embodiment may have a repeating unit represented by the following formula (I) and a repeating unit represented by the following formula (II).

[Chemistry 2]

(wherein, _R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure, _R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms, and _X1 and _X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring).

The liquid crystal polyester composition of the embodiment contains polyimide, which more effectively exerts the effect of improving the close contact strength with the metal layer. The polyimide has the above-mentioned specific combination of different polyimide structural units.

The repeating unit of formula (I) is described in detail below. _R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. Here, the alicyclic hydrocarbon structure means a ring derived from an alicyclic hydrocarbon compound, and the alicyclic hydrocarbon compound may be saturated or unsaturated, and may be monocyclic or polycyclic. Examples of the alicyclic hydrocarbon structure include, but are not limited to, cycloalkane rings such as cyclohexane ring, cycloalkene rings such as cyclohexene, dicycloalkane rings such as norbutyl ring, and dicycloalkene rings such as norbutylene. Among them, a cycloalkane ring is preferred, a cycloalkane ring having 4 to 7 carbon atoms is more preferred, and a cyclohexane ring is further preferred.

_R1 is preferably a divalent group represented by the following formula (R1-1) or (R1-2).

[Chemistry 3]

(wherein, _m11 and _m12 are independently integers of 0 to 2, preferably 0 or 1, and _m13 to _m15 are independently integers of 0 to 2, preferably 0 or 1).

_R1 is particularly preferably a divalent group represented by the following formula (R1-3).

[Chemistry 4]

Furthermore, in the divalent group represented by the above formula (R1-3), the positional relationship of the two methylene groups with respect to the cyclohexane ring may be cis or trans, and the ratio of cis to trans may be any value.

_X1 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. The aromatic ring may be a monocyclic ring or a condensed ring, and examples thereof include, but are not limited to, a benzene ring, a naphthalene ring, an anthracene ring, and a condensed tetraphenyl ring. Among these, a benzene ring and a naphthalene ring are preferred, and a benzene ring is more preferred.

_X1 is preferably a tetravalent group represented by any one of the following formulae (X-1) to (X-4).

[Chemistry 5]

(In the formula, _R11 to _R18 are independently an alkyl group having 1 to 4 carbon atoms, _p11 to _p13 are independently an integer of 0 to 2, preferably 0, _p14 , _p15 , _p16 and _p18 are independently an integer of 0 to 3, preferably 0, _p17 is an integer of 0 to 4, preferably 0, and _L11 to _L13 are independently a single bond, an ether group, a carbonyl group or an alkylene group having 1 to 4 carbon atoms). Furthermore, _X1 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, so _R12 , _R13 , _p12 and _p13 in formula (X-2) are selected so that the carbon number of the tetravalent group represented by formula (X-2) falls within the range of 6 to 22. Similarly, _L11 , _R14 , _R15 , _p14 and _p15 in formula (X-3) are selected so that the carbon number of the tetravalent group represented by formula (X-3) falls within the range of 6 to 22, and _L12 , L13, _R16 , _R17 , _R18 , _p16 , _p17 and _p18 in formula (X-4) are selected so that the carbon number of the tetravalent group represented by formula (X-4) falls within the range of 6 to ₂₂ .

_X1 is particularly preferably a tetravalent group represented by the following formula (X-5) or (X-6).

[Chemistry 6]

Next, the repeating unit of formula (II) is described in detail below. _R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms, preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and further preferably 8 to 10 carbon atoms. Here, the chain aliphatic group means a group derived from a chain aliphatic compound, and the above-mentioned chain aliphatic compound may be saturated or unsaturated, may be straight chain or branched chain, and may also contain impurity atoms such as oxygen atoms. _R2 is preferably an alkylene group having 5 to 16 carbon atoms, more preferably an alkylene group having 6 to 14 carbon atoms, further preferably an alkylene group having 7 to 12 carbon atoms, and more preferably an alkylene group having 8 to 10 carbon atoms. The alkylene group may be a straight chain alkylene group or a branched alkylene group, but is preferably a straight chain alkylene group. _R2 is preferably at least one selected from octamethylene and decamethylene, and is particularly preferably octamethylene.

Another suitable form of _R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms including an ether group. The carbon atoms are preferably 6 to 14, more preferably 7 to 12, and even more preferably 8 to 10. Among them, a divalent group represented by the following formula (R2-1) or (R2-2) is preferred.

[Chemistry 7]

(wherein, _m21 and _m22 are each independently an integer of 1 to 15, preferably 1 to 13, more preferably 1 to 11, and further preferably 1 to 9; _m23 to _m25 are each independently an integer of 1 to 14, preferably 1 to 12, more preferably 1 to 10, and further preferably 1 to 8). Furthermore, _R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and further preferably 8 to 10 carbon atoms), so _m21 and _m22 in formula (R2-1) are selected so that the carbon number of the divalent group represented by formula (R2-1) falls within the range of 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and further preferably 8 to 10 carbon atoms). That is, _m21 + _m22 is 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and further preferably 8 to 10 carbon atoms). Similarly, m ₂₃ to m ₂₅ in formula (R2-2) are selected so that the carbon number of the divalent group represented by formula (R2-2) falls within the range of 5 to 16 (preferably 6 to 14 carbon numbers, more preferably 7 to 12 carbon numbers, and further preferably 8 to 10 carbon numbers). That is, m ₂₃ + m ₂₄ + m ₂₅ is 5 to 16 (preferably 6 to 14 carbon numbers, more preferably 7 to 12 carbon numbers, and further preferably 8 to 10 carbon numbers).

_X2 is defined the same as _X1 in formula (I), and the preferred forms are also the same.

The content ratio of the repeating unit of formula (I) may be 20 mol% to 70 mol% relative to the total of 100 mol% of the repeating unit of formula (I) and the repeating unit of formula (II), and may be 20 mol% to less than 40 mol%. From the viewpoint of formability, the content ratio of the repeating unit of formula (I) relative to the total of the repeating unit of formula (I) and the repeating unit of formula (II) is preferably 25 mol% or more, more preferably 30 mol% or more, and further preferably 32 mol% or more. From the viewpoint of improving heat resistance, it is preferably 38 mol% or less, more preferably 36 mol% or less, and further preferably 35 mol% or less.

Relative to 100 mol% of all repeating units constituting the above-mentioned polyimide, the total content ratio of the repeating units of formula (I) and the repeating units of formula (II) is preferably 50-100 mol%, more preferably 75-100 mol%, further preferably 80-100 mol%, and further preferably 85-100 mol%.

In the above-mentioned liquid crystal polyester composition, relative to 100 parts by mass of the liquid crystal polyester (A), the content of the thermoplastic polyimide may be from 1 part by mass to 80 parts by mass, from 3 parts by mass to 70 parts by mass, from 5 parts by mass to 65 parts by mass, from 5 parts by mass to 60 parts by mass, from 5 parts by mass to 55 parts by mass, or from 5 parts by mass to 15 parts by mass.

(Method for producing thermoplastic polyimide) The thermoplastic polyimide can be produced by reacting a tetracarboxylic acid component with a diamine component. The tetracarboxylic acid component contains a tetracarboxylic acid having at least one aromatic ring and/or its derivative, and the diamine component can contain a diamine having at least one alicyclic hydrocarbon structure and a chain aliphatic diamine.

As a polymerization method for producing thermoplastic polyimide, a known polymerization method capable of producing thermoplastic polyimide can be applied, for example, solution polymerization, melt polymerization, solid phase polymerization, suspension polymerization, etc.

<Aromatic Polysulfone> As one embodiment of the present invention, the thermoplastic resin may be an aromatic polymer.

The liquid crystal polyester composition of one embodiment of the present invention contains a liquid crystal polyester (A) and an aromatic polysulfone. The liquid crystal polyester (A) may have repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines.

In the present specification, an aromatic polysulfone is a resin having a repeating unit including a divalent aromatic group (a residue obtained by removing two hydrogen atoms bonded to an aromatic ring of an aromatic compound), an ether bond (-O-), and a sulfonyl group (-SO ₂ -).

The aromatic polysulfone may have at least one hydroxyl group, amino group, or halogen atom at the end of the main chain, and may have at least one hydroxyl group at the end of the main chain. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, and iodine atom, preferably chlorine atom.

From the perspective of excellent heat resistance or chemical resistance, the aromatic polysulfone preferably has a repeating unit represented by the following formula (S1) (hereinafter, sometimes referred to as "repeating unit (S1)"). In addition to the repeating unit (S1), it may further have one or more repeating units represented by the following formula (S2) (hereinafter, sometimes referred to as "repeating unit (S2)"), or a repeating unit represented by the following formula (S3) (hereinafter, sometimes referred to as "repeating unit (S3)"), etc.

(S1)-Ph ¹ -SO ₂ -Ph ² -O- [wherein Ph ¹ and Ph ² each independently represent a phenylene group, and the hydrogen atom on the phenylene group may be independently substituted by an alkyl group, an aryl group, a halogen atom, a sulfone group, a nitro group, an amino group, a carboxyl group, or a hydroxyl group].

(S2)-Ph ³ -R-Ph ⁴ -O- [wherein, Ph ³ and Ph ⁴ each independently represent a phenylene group, the hydrogen atom on the phenylene group may be independently substituted by an alkyl group, an aryl group, a halogen atom, a sulfone group, a nitro group, an amino group, a carboxyl group, or a hydroxyl group, and R represents an alkylene group, an oxygen atom, or a sulfur atom].

(S3)-(Ph ⁵ ) _n -O- [wherein, Ph ⁵ represents a phenylene group, the hydrogen atom on the phenylene group may be independently substituted by an alkyl group, an aryl group, a halogen atom, a sulfonate group, a nitro group, an amino group, a carboxyl group, or a hydroxyl group, and n represents an integer from 1 to 3. When n is 2 or more, a plurality of Ph ⁵ groups may be the same or different from each other].

The phenylene group represented by any one of Ph ¹ to Ph ⁵ may be a p-phenylene group, a m-phenylene group, or an o-phenylene group, and is preferably a p-phenylene group.

The alkyl group which may substitute the hydrogen atom on the phenylene group preferably has a carbon number of 1 to 10. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-hexyl, 2-ethylhexyl, n-octyl, and n-decyl.

The aryl group which may substitute the hydrogen atom on the phenylene group preferably has 6 to 20 carbon atoms. Specific examples thereof include phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, and 2-naphthyl.

Examples of the halogen atom which may substitute for the hydrogen atom on the phenylene group include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

When the hydrogen atom on the phenylene group is substituted by the above groups, the number of the substituted hydrogen atom on each phenylene group is preferably 2 or less, and more preferably 1. Among the above, the hydrogen atom on the phenylene group is preferably unsubstituted.

The alkylene group represented by R preferably has 1 to 5 carbon atoms. Specific examples thereof include methylene, ethylene, isopropylene, and 1-butylene.

The aromatic polysulfone preferably has 50% or more of the repeating unit (S1), more preferably 80% or more, as the repeating unit, relative to 100% of the total of all repeating units, and more preferably has substantially only the repeating unit (S1). Furthermore, the aromatic polysulfone may independently have two or more repeating units (S1) to (S3).

The viscosity of the following test solution containing aromatic polysulfate measured by a B-type viscometer (e.g., TV-22 manufactured by Toki Industry Co., Ltd.) at a sample temperature of 23°C and a rotor speed of 20 rpm is preferably 100 mPa·s to 5000 mPa·s, more preferably 300 mPa·s to 4000 mPa·s, and further preferably 2500 mPa·s to 3500 mPa·s. Test solution: A solution obtained by adding 25 parts by mass of the aromatic polysulfate powder to 75 parts by mass of N-methylpyrrolidone and stirring the mixture at 100°C for 4 hours under a nitrogen atmosphere.

If the viscosity of the above-mentioned measured solution is within the above-mentioned preferred range, the liquid crystal polyester composition containing aromatic polysulfate has a better effect of improving the adhesion strength between the liquid crystal polyester composition and the metal layer.

In this embodiment, the aromatic polysulfone may be used alone or in combination of two or more.

As an example of the numerical range of the content of the aromatic polysulfone in the above-mentioned liquid crystal polyester composition relative to 100 parts by mass of the liquid crystal polyester (A), it can be from 1 part by mass to 80 parts by mass, from 3 parts by mass to 70 parts by mass, from 5 parts by mass to 65 parts by mass, from 5 parts by mass to 60 parts by mass, and from 5 parts by mass to 55 parts by mass.

[Production Method of Aromatic Polysulfone] Aromatic polysulfone can be produced by condensing a dihalogenated sulfone compound corresponding to the repeating unit constituting the aromatic polysulfone with a dihydroxy compound.

For example, a resin having a repeating unit (S1) can be produced by using a compound represented by the following formula (S4) (hereinafter, also referred to as "compound (S4)") as a dihalogenated sulfonate compound and using a compound represented by the following formula (S5) as a dihydroxy compound.

For example, a resin having repeating units (S1) and repeating units (S2) can be produced by using compound (S4) as a dihalogenated sulfone compound and using a compound represented by the following formula (S6) as a dihydroxy compound.

For example, a resin having a repeating unit (S1) and a repeating unit (S3) can be produced by using the compound (S4) as a dihalogenated sulfone compound and using a compound represented by the following formula (S7) as a dihydroxy compound.

(S4) ^X1 - ^Ph1 - _SO2 - ^Ph2 - ^X2 [wherein, ^X1 and ^X2 each independently represent a halogen atom, and ^Ph1 and ^Ph2 have the same meanings as above]

(S5) HO- ^Ph1 - _SO2 - ^Ph2 -OH [wherein ^Ph1 and ^Ph2 have the same meanings as above].

(S6) HO-Ph ³ -R-Ph ⁴ -OH [wherein Ph ³ , Ph ⁴ and R have the same meanings as above].

(S7)HO-(Ph ⁵ ) _n -OH [wherein Ph ⁵ and n have the same meanings as above].

The condensation of aromatic polysulfate is preferably carried out using an alkali metal carbonate in a solvent. The alkali metal carbonate may be a carbonate as a normal salt, a bicarbonate as an acidic salt, or a mixture of the two. As the carbonate, sodium carbonate or potassium carbonate may be preferably used, and as the bicarbonate, sodium bicarbonate or potassium bicarbonate may be preferably used.

As the solvent for polycondensation, an organic polar solvent can be preferably used. Specific examples thereof include dimethyl sulfoxide, 1-methyl-2-pyrrolidone, cyclobutane sulfone (also known as 1,1-dioxytetrahydrothiophene), 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone.

<Optional Components> Optional components that the liquid crystal polyester composition of the embodiment may further contain as necessary include liquid crystal polyesters that do not correspond to the liquid crystal polyester (A), particles such as fillers, solvents that can dissolve the liquid crystal polyester (A), additives, and the like.

Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, flame retardants, and colorants.

As a liquid crystal polyester that does not correspond to the liquid crystal polyester (A), the following liquid crystal polyester (B) is exemplified. In addition, the above-mentioned particles may be liquid crystal polyester particles containing the liquid crystal polyester (B). In this specification, the liquid crystal polyester particles containing the liquid crystal polyester (B) may also be liquid crystal polyester particles composed only of the liquid crystal polyester (B).

The liquid crystal polyester (B) may be insoluble in the following solvents. When the liquid crystal polyester composition contains a solvent, the liquid crystal polyester (B) may exist in the composition in the form of particles.

(Liquid Crystalline Polyester (B)) The liquid crystal polyester composition may further contain a liquid crystal polyester (B).

The liquid crystal polyester (B) is a liquid crystal polyester that does not correspond to the above-mentioned liquid crystal polyester (A). The above-mentioned liquid crystal polyester (B) may be a liquid crystal polyester that does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines. The liquid crystal polyester (B) may be a liquid crystal polyester that has repeating units represented by the following formula (B1) and does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines.

The liquid crystal polyester (B) is preferably a liquid crystal polyester having a repeating unit represented by the following formula (B1): (B1) -O-Ar ^b1 -CO- (wherein Ar ^b1 represents a phenylene group, a naphthylene group or a biphenylene group, and the hydrogen atom on the above group represented by Ar ^b1 may be independently substituted by a halogen atom, an alkyl group or an aryl group).

Examples of the phenylene group, naphthylene group, and biphenylene group in Ar ^b1 include those exemplified in the above-mentioned liquid crystal polyester (A).

Examples of the halogen atom, and the alkyl group or aryl group in Ar ^b1 include those exemplified in the above-mentioned liquid crystal polyester (A).

In the liquid crystal polyester (B), the higher the content ratio of the repeating unit represented by the above formula (B1), the better the effect of suppressing the viscosity increase caused by the temperature drop of the above liquid crystal polyester composition when contained in the liquid crystal polyester composition, and the better the processing characteristics. From this point of view, the number of repeating units represented by the above formula (B1) is preferably more than 80%, preferably 85% to 100%, preferably 90% to 100%, more preferably 95% to 100%, further preferably 98% to 100%, and it is particularly preferred that the above liquid crystal polyester (B) substantially only contains the repeating units represented by the above formula (B1), that is, the number of repeating units represented by the above formula (B1) is 100%.

When contained in a liquid crystal polyester composition, from the viewpoint of suppressing the viscosity increase caused by the temperature drop of the liquid crystal polyester composition, the liquid crystal polyester (B) exemplified above preferably has a repeating unit represented by the following formula (B1-1): (B1-1)-O-Ar ^b1-1 -CO- (wherein Ar ^b1-1 represents a naphthyl group, and the hydrogen atoms on the above group represented by Ar ^b1-1 may be independently substituted by a halogen atom, an alkyl group or an aryl group).

The number of repeating units represented by the above formula (B1-1) is preferably more than 50% and less than 90%, and more preferably 65 to 80%, relative to the total number of repeating units corresponding to the above formula (B1) (100%). In the liquid crystal polyester (B), if the content ratio of the repeating units represented by the above formula (B1-1) is within the above numerical range, when contained in the liquid crystal polyester composition, the effect of suppressing the increase in viscosity caused by the temperature drop of the above liquid crystal polyester composition is better, and an excellent dielectric loss factor is exerted.

More specifically, as the liquid crystal polyester (B) exemplified above, the repeating units represented by the above formula (B1) preferably include repeating units represented by the following formula (B1-1) and repeating units represented by the following formula (B1-2), and more preferably only include repeating units represented by the following formula (B1-1) and repeating units represented by the following formula (B1-2). (B1-1)-O-Ar ^b1-1 -CO- (B1-2)-O-Ar ^b1-2 -CO- (wherein, Ar ^b1-1 represents a naphthyl group, Ar ^b1-2 represents a phenyl group, and the hydrogen atoms on the above groups represented by Ar ^b1-1 or Ar ^b1-2 may be independently substituted by halogen atoms, alkyl groups or aryl groups)

Examples of the naphthylene group in Ar ^b1-1 include those exemplified in the above-mentioned liquid crystal polyester (A). Examples of the phenylene group in Ar ^b1-2 include those exemplified in the above-mentioned liquid crystal polyester (A).

Examples of the halogen atom, alkyl group or aryl group in Ar ^b1-1 and Ar ^b1-2 include those exemplified in the above-mentioned liquid crystal polyester (A).

To be more specific, the liquid crystal polyester (B) exemplified above is preferably one that only comprises the repeating units represented by the above formula (B1), and the repeating units represented by the above formula (B1) include the repeating units represented by the following formula (B1-1-1) and the repeating units represented by the following formula (B1-2-1), and is more preferably one that only comprises the repeating units represented by the following formula (B1-1-1) and the repeating units represented by the following formula (B1-2-1). (B1-1-1)-O-Ar ^b1-1-1 -CO- (B1-2-1)-O-Ar ^b1-2-1 -CO- (wherein, Ar ^b1-1-1 represents a 2,6-naphthylene group, Ar ^b1-2-1 represents a 1,4-phenylene group, and the hydrogen atom on the above-mentioned group represented by Ar ^b1-1-1 or Ar ^b1-2-1 may be independently substituted by a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms).

The repeating unit represented by the above formula (B1) is a repeating unit derived from an aromatic hydroxycarboxylic acid. Examples of the repeating unit derived from an aromatic hydroxycarboxylic acid include those exemplified as the repeating unit represented by the above formula (A1).

In the case where the repeating unit represented by the above formula (B1) includes the repeating unit represented by the above formula (B1-1) and the repeating unit represented by the above formula (B1-2), relative to the total number (100%) of all repeating units constituting the above liquid crystal polyester (B), as an example, the number of repeating units represented by the above formula (B1-1) exceeds 50% and is less than 90%, and the number of repeating units represented by the above formula (B1-2) may be greater than 10% and less than 50%, the number of repeating units represented by the above formula (B1-1) is greater than 65% and less than 80%, and the number of repeating units represented by the above formula (B1-2) may be greater than 20% and less than 35%. Furthermore, when the repeating unit represented by the above formula (B1) includes the repeating unit represented by the above formula (B1-1-1) and the repeating unit represented by the above formula (B1-2-1), relative to the total number (100%) of all repeating units constituting the above liquid crystal polyester (B), as an example, the number of repeating units represented by the above formula (B1-1-1) exceeds 50% and is less than 90%, the number of repeating units represented by the above formula (B1-2-1) may be greater than 10% and less than 50%, and the number of repeating units represented by the above formula (B1-1-1) is greater than 65% and less than 80%, and the number of repeating units represented by the above formula (B1-2-1) may be greater than 20% and less than 35%.

Furthermore, the liquid crystal polyester (B) may have two or more repeating units represented by the above formula (B1) independently. In addition, the liquid crystal polyester may have repeating units other than the repeating units represented by the above formula (B1), and the content thereof is preferably 10% or less, more preferably 5% or less, and may be 0% relative to the total number (100%) of all repeating units constituting the liquid crystal polyester (B).

When the liquid crystal polyester composition contains the liquid crystal polyester (A) and the liquid crystal polyester (B), from the viewpoint of an excellent balance between dielectric properties and the above-mentioned adhesion strength, the ratio of the content of the liquid crystal polyester (A) to the liquid crystal polyester (B) in the liquid crystal polyester composition is preferably liquid crystal polyester (A)/liquid crystal polyester (B) = 80/20 to 10/90, more preferably 70/30 to 20/80, and further preferably 50/50 to 30/70, in terms of mass ratio.

Furthermore, relative to the total mass (100 mass %) of the liquid crystal polyester contained in the liquid crystal polyester composition of the embodiment, the ratio of the total content rate of the liquid crystal polyester (A) and the liquid crystal polyester (B) may be 15 mass % or more, 50 mass % or more, 80 mass % or more, or 100 mass %.

When the liquid crystal polyester composition contains the liquid crystal polyester (A) and the liquid crystal polyester (B), the content of the thermoplastic resin is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and further preferably 2 parts by mass or more, relative to 100 parts by mass of the total of the liquid crystal polyester (A) and the liquid crystal polyester (B) in the liquid crystal polyester composition. The liquid crystal polyester composition containing the thermoplastic resin at or above the lower limit has a more excellent effect of improving the adhesion strength between the metal layer and the composition.

In the above-mentioned liquid crystal polyester composition, the content of the above-mentioned thermoplastic resin is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and further preferably 25 parts by mass or less, relative to 100 parts by mass of the total of the liquid crystal polyester (A) and the liquid crystal polyester (B). The dielectric properties of the liquid crystal polyester composition containing the thermoplastic resin below the above upper limit are more excellent.

As an example of the numerical range of the content of the thermoplastic resin, relative to 100 parts by mass of the total of the liquid crystal polyester (A) and the liquid crystal polyester (B) in the liquid crystal polyester composition, it can be 0.5 parts by mass to 50 parts by mass, 1 part by mass to 30 parts by mass, or 2 parts by mass to 25 parts by mass.

As an example of a liquid crystal polyester composition according to an embodiment of the present invention, the liquid crystal polyester composition described in any one of items <1> to <11> is exemplified, which further comprises a liquid crystal polyester (B), and the ratio of the content of the liquid crystal polyester (A) to the liquid crystal polyester (B) in the liquid crystal polyester composition is liquid crystal polyester (A)/liquid crystal polyester (B) = 80/20 to 10/90 in terms of mass ratio, and the content of the thermoplastic resin is not less than 0.5 parts by mass and not more than 50 parts by mass relative to 100 parts by mass of the total of the liquid crystal polyester (A) and the liquid crystal polyester (B).

The total of the liquid crystal polyester (A) and the liquid crystal polyester (B) herein is preferably the total of the following liquid crystal polyester particles containing the liquid crystal polyester (A) and the liquid crystal polyester (B), and the content thereof can also be exemplified by the same values as those exemplified above.

The flow starting temperature of the liquid crystal polyester composition of the embodiment containing the liquid crystal polyester (A) and the liquid crystal polyester (B) is preferably 260°C or more, more preferably 260°C or more and 400°C or less, and further preferably 260°C or more and 380°C or less. The higher the flow starting temperature of the liquid crystal polyester composition, the higher the heat resistance and strength of the liquid crystal polyester composition tend to be. On the other hand, if the flow starting temperature of the liquid crystal polyester composition exceeds 400°C, the melting temperature or melt viscosity of the liquid crystal polyester composition tends to increase. Therefore, the temperature required for forming the liquid crystal polyester composition tends to increase.

In addition, as the value of the flow initiation temperature of the liquid crystal polyester (A), the same numerical values as the numerical values exemplified as the flow initiation temperature of the liquid crystal polyester composition of the embodiment can be cited.

In addition, as the value of the flow initiation temperature of the liquid crystal polyester (B), the same values as the respective values exemplified as the flow initiation temperature of the liquid crystal polyester composition of the embodiment can be cited.

In this specification, the flow initiation temperature of the liquid crystal polyester composition is also called the flow temperature or flow temperature, which is the temperature that serves as the standard for the molecular weight of the liquid crystal polyester (see Naoyuki Koide, ed., "Liquid Crystal Polymers - Synthesis, Forming, Applications -", CMC Co., Ltd., June 5, 1987, p. 95). The flow initiation temperature is the following temperature: using a rheometer, while heating the liquid crystal polyester composition at a rate of 4°C/min under a load of 9.8 mPa (100 kg/cm ² ), while melting it, and extruding it from a nozzle with an inner diameter of 1 mm and a length of 10 mm, the liquid crystal polyester composition shows a viscosity of 4800 Pa·s (48000 poise).

(Particles) The liquid crystal polyester composition of the embodiment may also contain particles. Examples of the particles include liquid crystal polyester particles in addition to fillers.

When the liquid crystal polyester composition contains particles, the adhesion strength with the metal layer when the film is laminated with the metal layer may be reduced. However, the liquid crystal polyester composition of one embodiment of the present invention contains at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, which can make the adhesion strength with the metal layer excellent.

・Liquid Crystalline Polyester Particles The liquid crystalline polyester particles are preferably liquid crystal polyester particles containing the above-mentioned liquid crystal polyester (B).

The D ₅₀ of the liquid crystal polyester particles is preferably 30 μm or less, more preferably 20 μm or less, more preferably 18 μm or less, further preferably 15 μm or less, and particularly preferably 12 μm or less. Furthermore, if the D ₅₀ of the liquid crystal polyester is 20 μm or less, a film having good surface smoothness can be easily produced with a thickness suitable for a film for electronic components (e.g., 50 μm or less). Furthermore, from the perspective of ease of use of the particles, the D ₅₀ of the liquid crystal polyester particles is preferably 0.1 μm or more, more preferably 0.5 μm or more, further preferably 3 μm or more, and particularly preferably 5 μm or more. The upper limit and lower limit of the D ₅₀ value of the above-mentioned liquid crystal polyester particles can be freely combined. The _D50 value of the liquid crystal polyester particles may range from 0.1 to 30 μm, from 0.5 μm to 30 μm, from 0.5 μm to 20 μm, from 3 μm to 18 μm, from 5 μm to 15 μm, or from 5 μm to 12 μm.

The particle size _D50 of the liquid crystal polyester particles is a value determined by the following measurement method.

[Measurement of particle size _D50 of liquid crystal polyester particles] The particle size _D50 of the liquid crystal polyester particles is measured using a scattering particle size distribution measuring device (e.g., LA-950V2 manufactured by Horiba, Ltd.). The refractive index of pure water is set to 1.333, and the volume-based cumulative particle size distribution of the liquid crystal polyester particles is measured. The particle size (μm) at which the cumulative volume ratio is 50% is calculated as the particle size _D50 .

As a liquid crystal polyester composition of one embodiment of the present invention, there is exemplified a liquid crystal polyester composition as described in any one of the above <1> to <11>, which contains a liquid crystal polyester (A), a thermoplastic polyimide, and liquid crystal polyester particles containing a liquid crystal polyester (B), wherein the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines, and the liquid crystal polyester (B) does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines.

As a liquid crystal polyester composition of one embodiment of the present invention, there is exemplified a liquid crystal polyester composition as described in any one of the above <1> to <11>, which contains a liquid crystal polyester (A), an aromatic polyester, and liquid crystal polyester particles containing a liquid crystal polyester (B), and the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines, and the liquid crystal polyester (B) does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines.

・Filling material The filling material may be a fibrous filling material, a plate-like filling material, or a granular filling material. Examples of the filling material include inorganic filling materials such as silicon dioxide, aluminum oxide, titanium oxide, barium titanium oxide, strontium titanium oxide, aluminum hydroxide, and calcium carbonate; and organic filling materials such as hardened epoxy resin, cross-linked benzoguanamine resin, and cross-linked acrylic resin.

When the liquid crystal polyester composition of the embodiment includes particles, the content of the particles (preferably liquid crystal polyester particles) is preferably 5% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, and particularly preferably 50% by mass or more relative to the total solid content of the liquid crystal polyester composition of 100% by mass. The content of the particles (preferably liquid crystal polyester particles) in the liquid crystal polyester composition of the embodiment is preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 60% by mass or less relative to the total solid content of the liquid crystal polyester composition of 100% by mass. As an example of the numerical range of the content of the above-mentioned particles (preferably liquid crystal polyester particles) in the liquid crystal polyester composition of the implementation method, relative to the total mass of the liquid crystal polyester composition, it can be greater than 5 mass% and less than 80 mass%, greater than 20 mass% and less than 70 mass%, greater than 30 mass% and less than 60 mass%, and greater than 50 mass% and less than 60 mass%.

By containing, for example, liquid crystal polyester particles in an amount greater than the above lower limit, the properties of the particles can be well exerted. For example, the dielectric properties of the manufactured film can be further improved. In addition, by using a liquid crystal polyester composition containing liquid crystal polyester particles in an amount less than the above upper limit, the adhesion strength between the manufactured film and the metal layer can be further improved.

(Solvent) The liquid crystal polyester composition of the embodiment may further contain a solvent that can dissolve the liquid crystal polyester (A).

As an embodiment of the present invention, a liquid crystal polyester composition can be provided, which contains a liquid crystal polyester (A), at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, and a solvent capable of dissolving the liquid crystal polyester (A). The liquid crystal polyester composition of <11> can be used in place of the liquid crystal polyester composition of <1> and in place of the liquid crystal polyester composition of <2> to <10>.

The above-mentioned solvent may be an aprotic solvent. Aprotic solvents have the advantages of low corrosiveness and easy handling. In the present embodiment, the aprotic solvent is a solvent comprising an aprotic compound. In the present embodiment, examples of the above-mentioned aprotic solvent include: 1-chlorobutane, chlorobenzene, 1,1-dichloroethane, 1,2-dichloroethane, chloroform, 1,1,2,2-tetrachloroethane and other halogen solvents; diethyl ether, tetrahydrofuran, and 1,4-dioxane and other ether solvents; acetone, cyclohexanone and other ketone solvents; ethyl acetate and other ester solvents; γ-butyrolactone and other lactone solvents; ethylene carbonate, propylene carbonate and other carbonates; Ester solvents; amine solvents such as triethylamine and pyridine; 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; sulfide solvents such as dimethyl sulfoxide and cyclobutane sulfone; phosphoric acid solvents such as hexamethylphosphatide and tri-n-butylphosphoric acid, etc., and mixtures of two or more thereof may also be used.

Among them, from the perspective of environmental impact, aprotic compounds without halogen atoms are preferably used, and from the perspective of solubility, solvents having a dipole moment of 3 or more and 5 or less are preferably used. Specifically, amide solvents such as N,N'-dimethylformamide, N,N'-dimethylacetamide, tetramethylurea, and N-methylpyrrolidone are more preferably used; or lactone solvents such as γ-butyrolactone are more preferably used, and N,N'-dimethylformamide, N,N'-dimethylacetamide, or N-methylpyrrolidone is further preferably used.

In the liquid crystal polyester composition of the embodiment, from the viewpoint of reducing the viscosity of the liquid crystal polyester composition and making it easier to apply to the support, the ratio of the content of the solvent to the total mass of the liquid crystal polyester composition can be greater than 20 mass %, can be greater than 20 mass % and less than 99 mass %, and can also be greater than 50 mass % and less than 95 mass %.

When the liquid crystal polyester composition of the embodiment further comprises the above-mentioned solvent, the liquid crystal polyester composition may be a liquid composition.

In this specification, "liquid composition" means a solution or dispersion that is liquid at normal temperature and pressure (25°C, 1 atm). A dispersion means a dispersion of solid components that are insoluble in a solution. Examples of the solid components to be dispersed include the above-mentioned liquid crystal polyester particles, or thermoplastic polyimide, fillers, etc.

As a liquid crystal polyester composition of one embodiment of the present invention, there is exemplified a liquid crystal polyester composition as described in any one of the above <1> to <11>, which contains a liquid crystal polyester (A), a thermoplastic polyimide, liquid crystal polyester particles containing a liquid crystal polyester (B), and a solvent capable of dissolving the liquid crystal polyester (A), wherein the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines, and the liquid crystal polyester (B) does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines.

As a liquid crystal polyester composition of one embodiment of the present invention, there is exemplified a liquid crystal polyester composition as described in any one of the above <1> to <11>, which contains a liquid crystal polyester (A), an aromatic polyester, liquid crystal polyester particles containing a liquid crystal polyester (B), and a solvent capable of dissolving the liquid crystal polyester (A), wherein the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines or repeating units derived from aromatic diamines, and the liquid crystal polyester (B) does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines.

The liquid crystal polyester composition of the embodiment contains a liquid crystal polyester and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone. Compared with the case where the above-mentioned thermoplastic resin is not contained, the adhesion strength between the film and the metal layer when the film is laminated with the metal layer is improved.

The liquid crystal polyester composition of the embodiment further contains the liquid crystal polyester (B), which can be endowed with the properties possessed by the liquid crystal polyester (B). The above-mentioned properties also depend on the composition of the liquid crystal polyester (B), for example, excellent dielectric properties and good processing properties.

Furthermore, by containing the liquid crystal polyester (B) in the form of liquid crystal polyester particles, even when a solvent that does not dissolve the liquid crystal polyester (B) is contained, the dispersibility of the liquid crystal polyester (B) in the composition is improved, and a high-quality film can be obtained.

<<Film>> The film of the embodiment contains a liquid crystal polyester (A) and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, and the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamine or repeating units derived from aromatic diamine.

FIG. 1 is a cross-sectional view showing the structure of a membrane 10 according to an embodiment.

As the liquid crystal polyester (A), the liquid crystal polyester (A) described in the above-mentioned <<Liquid Crystalline Polyester Composition>> can be cited, and the detailed description here is omitted. Furthermore, the liquid crystal polyester (A) in the state of being formed into a film may also be insoluble in a solvent (for example, an aprotic solvent) due to changes in physical properties during the film formation process. The above-mentioned change in physical properties is, for example, an increase in the degree of polymerization.

As the at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, those described in the above-mentioned "Liquid Crystalline Polyester Composition" can be cited, and the detailed description is omitted here.

The film described in <12> above may have the following aspects.

<15> The film as an implementation method is the film as described in <12> above, wherein the above-mentioned liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamines, or repeating units derived from aromatic diamines, and the above-mentioned liquid crystal polyester (A) has repeating units represented by the following formula (A1), repeating units represented by the following formula (A2), and repeating units represented by the following formula (A3). (A1)-O-Ar ¹ -CO- (A2)-CO-Ar ² -CO- (A3)-X-Ar ³ -Y- (wherein, Ar ¹ represents 1,4-phenylene, 2,6-naphthylene or 4,4'-biphenylene, Ar ² represents 1,4-phenylene, 1,3-phenylene or 2,6-naphthylene, Ar ³ represents 1,4-phenylene or 1,3-phenylene, X represents -NH-, Y represents -O- or -NH-, and the hydrogen atom on the above groups represented by Ar ¹ , Ar ² or Ar ³ may be independently substituted by a halogen atom, an alkyl group or an aryl group).

<16> The film as described in <12> or <15> above, further comprising liquid crystal polyester particles comprising a liquid crystal polyester (B), wherein the liquid crystal polyester (B) does not have repeating units derived from an aromatic hydroxylamine and repeating units derived from an aromatic diamine.

<17> The film as described in <16> above, wherein the content of the liquid crystal polyester particles is 5 mass % to 80 mass % based on 100 mass % of the total solid content of the liquid crystal polyester composition.

<18> The film according to any one of <12> and <15> to <17>, wherein the content of the thermoplastic resin is 1 part by mass or more per 100 parts by mass of the liquid crystal polyester (A).

<19> The film according to any one of <12>, <15> to <18>, wherein the content of the liquid crystal polyester (A) is 10% by mass or more and 90% by mass or less relative to 100% by mass of the total mass of the film.

<20> The film as described in any one of <12> and <15> to <19> above, wherein the thermoplastic resin is thermoplastic polyimide.

<21> The film as described in <20> above, wherein the thermoplastic polyimide has repeating units represented by the above formula (I) and repeating units represented by the following formula (II).

<22> The film as described in <21> above, wherein the content ratio of the repeating units of the above-mentioned thermoplastic polyimide with respect to the total 100 mol % of the repeating units of the above-mentioned formula (I) and the repeating units of the above-mentioned formula (II) is greater than 20 mol % and less than 70 mol %.

The film of the embodiment is similar to the liquid crystal polyester composition of the above-mentioned embodiment. In addition to containing the liquid crystal polyester (A) and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, it can also contain other arbitrary components as needed, and the detailed description is omitted here.

The film of the embodiment preferably contains a liquid crystal polyester (A), at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, and particles. In the film of the embodiment, the particles are preferably liquid crystal polyester particles. Furthermore, the liquid crystal polyester particles in the state of being formed into a film may not be able to distinguish the particle shape due to the change of physical properties during the film formation process.

The contents of the various components in the film of the embodiment can be the same as the contents of the various components as the solid components of the liquid crystal polyester composition of the embodiment exemplified above.

The thickness of the film of the embodiment is not particularly limited, but is preferably 5 to 50 μm, more preferably 7 to 40 μm, further preferably 10 to 33 μm, and particularly preferably 15 to 30 μm as a thickness suitable for use as a film for electronic components.

The method for producing the film of the embodiment is not particularly limited, and can be obtained, for example, by forming the liquid crystal polyester composition of the embodiment into a film. From the perspective of being able to produce an isotropic film having excellent properties, the film of the embodiment is preferably produced by the following <<film production method>>.

<<Film Manufacturing Method>> The film manufacturing method of the embodiment includes the following steps: coating the liquid crystal polyester composition of the embodiment on a support to obtain a film.

When the liquid crystal polyester composition contains a solvent, the method for producing the film of the embodiment may include the following steps: coating the liquid crystal polyester composition of the embodiment on a support, and removing the solvent from the liquid crystal polyester composition to obtain a film. The above-mentioned production method may correspond to the solution casting method.

The liquid crystal polyester composition of the embodiment may be exemplified by those exemplified in the above-mentioned "Liquid Crystalline Polyester Composition".

The film manufacturing method may also include the following steps: A step of coating the liquid crystal polyester composition of the embodiment on a support (coating step). A step of removing the solvent from the coated liquid crystal polyester composition (drying step).

The film manufacturing method of the embodiment may also include the following step (heat treatment step): after the coating step, heat treating the liquid crystal polyester composition or the film precursor from which the solvent is removed.

The method for producing the film of the embodiment may also include the following steps: coating the liquid crystal polyester composition of the embodiment on a support, removing the solvent from the liquid crystal polyester composition, and performing heat treatment to obtain a film. The heat treatment can promote the polymerization reaction of the polymer in the liquid crystal polyester composition, thereby promoting the volatility of the solvent.

The heat treatment may also serve as the above-mentioned drying step. The method for producing the film of the embodiment may also include the following steps: coating the liquid crystal polyester composition of the embodiment on a support, and performing heat treatment to obtain a film.

Furthermore, the film production method may further include a step of separating the support from the laminate (separation step). Furthermore, the film can also be suitably used as a film for electronic components in a state where the film is formed on the support as a laminate, so the separation step is not an essential step in the film production step.

Hereinafter, an example of a method for producing a film according to an embodiment in which the liquid crystal polyester composition contains a solvent will be described with reference to the drawings.

3A to 3D are schematic diagrams showing an example of the film production process of the embodiment. First, the liquid crystal polyester composition 30 is coated on the support 12 (Fig. 3A: coating step).

As the support 12, for example, a glass plate, a resin film or a metal foil can be cited. Among them, the support 12 is preferably a resin film or a metal foil, and copper foil is particularly preferred from the perspective of excellent heat resistance, easy coating of the liquid crystal polyester composition, and easy removal from the film. The thickness of the resin film is usually 25 μm to 75 μm, preferably 50 μm to 75 μm. The thickness of the metal foil is usually 3 μm to 75 μm, preferably 5 μm to 30 μm, and more preferably 10 μm to 25 μm.

Next, the solvent is removed from the liquid crystal polyester composition 30 coated on the support 12 (Drying step in FIG. 3B ). The liquid crystal polyester composition from which the solvent has been removed becomes a film precursor 40 to be subjected to heat treatment. Furthermore, the solvent does not need to be completely removed from the liquid crystal polyester composition, and a portion of the solvent contained in the liquid crystal polyester composition may be removed, or the entire solvent may be removed.

The solvent is preferably removed by evaporating the solvent. The solvent is preferably removed at a temperature lower than the melting point of the liquid crystal polyester, for example, 40° C. to 200° C.

The laminate precursor 22 having the support 12 and the membrane precursor 40 thus obtained is heat-treated to obtain a laminate 20 having the support 12 and the membrane 10 (a membrane formed by heat-treating the membrane precursor 40) (Figure 3C: heat-treatment step). At this time, the membrane 10 formed on the support can be obtained. The heat-treatment conditions can be exemplified as follows: after the temperature is raised from -50°C, which is the boiling point of the medium, to the heat-treatment temperature, the heat-treatment is performed at a temperature above the melting point of the liquid crystal polyester.

The heat treatment and the removal of the solvent can be performed in a continuous manner or in a single-chip manner. From the perspective of productivity and operability, the heat treatment is preferably performed in a continuous manner, and more preferably performed in a continuous manner after the removal of the solvent.

Then, the film 10 can be obtained as a single-layer film by separating the film 10 from the laminate 20 having the support 12 and the film 10 (separation step in FIG. 3D ). When a metal foil is used as a support, the laminate 20 can be used as a metal laminate for a printed wiring board without separating the film from the laminate 20.

According to the film manufacturing method of the embodiment, a film having excellent adhesion strength with a metal layer and excellent isotropy can be manufactured.

＜＜Laminate body＞＞ The laminate of the embodiment has a metal layer, and a film of the embodiment laminated on the metal layer. FIG2 is a cross-sectional view showing the structure of a laminate 21 of one embodiment of the present invention. The laminate 21 has a metal layer 13, and a film 10 laminated on the metal layer 13. Regarding the film 10 possessed by the laminate, those exemplified above can be cited, and the description is omitted. Regarding the metal layer possessed by the laminate, those exemplified as the support in the above-mentioned ＜＜Method for producing film＞＞ and the following ＜＜Method for producing laminate＞＞ can be cited, and metal foil is preferably used. From the perspective of conductivity and cost, copper is preferably used as the metal constituting the metal layer, and copper foil is preferably used as the metal foil.

The thickness of the laminate of the embodiment is not particularly limited, but is preferably 5 to 130 μm, more preferably 10 to 70 μm, and even more preferably 15 to 60 μm.

The method for manufacturing the laminate of the embodiment is not particularly limited. The laminate of the embodiment can be manufactured by the following <<method for manufacturing laminate>>.

As an embodiment of the present invention, a laminate can be provided, which comprises a metal layer and a film formed by coating the liquid crystal polyester composition of the embodiment on the metal layer.

The laminate of the embodiment can be suitably used as a film for electronic components such as printed wiring boards.

<<Method for producing a laminate>> The method for producing a laminate of the embodiment includes the following steps: coating the liquid crystal polyester composition of the embodiment on a support, forming a film on the support, thereby obtaining a laminate having the support and the film. The support may be a metal foil. The laminated metal foil becomes the metal layer.

When the liquid crystal polyester composition contains a solvent, the method for producing the laminate of the embodiment may include the following steps: coating the liquid crystal polyester composition of the embodiment on a support, removing the solvent from the liquid crystal polyester composition, and forming a film on the support, thereby obtaining a laminate having the support and the film.

The method for manufacturing the laminate of the embodiment may also include the following steps: A step of coating the liquid crystal polyester composition of the embodiment on a support (coating step). A step of removing the solvent from the coated liquid crystal polyester composition (drying step).

Similar to the above-mentioned film manufacturing method, the laminate manufacturing method of the embodiment may also include a step of heat-treating the above-mentioned liquid crystal polyester composition or the film precursor from which the solvent is removed after the above-mentioned coating step (heat-treatment step).

The method for manufacturing the laminate of the embodiment may also include the following steps: coating the liquid crystal polyester composition of the embodiment on a support, removing the solvent from the liquid crystal polyester composition, performing heat treatment, forming a film on the support, thereby obtaining a laminate having the support and the film. The heat treatment can promote the polymerization reaction of the polymer in the liquid crystal polyester composition, thereby promoting the volatilization of the solvent.

The heat treatment may also serve as the drying step. The method for manufacturing the laminate of the embodiment may also include the following steps: coating the liquid crystal polyester composition of the embodiment on a support, performing heat treatment, forming a film on the support, thereby obtaining a laminate having the support and the film.

3A to 3C are schematic diagrams showing an example of the manufacturing process of the film and the laminate according to the embodiment. The manufacturing method of the laminate shown in FIG3A to 3C is the same as the manufacturing method described in the above-mentioned film manufacturing method, except that the above-mentioned separation step (FIG3D) is not performed.

According to the method for manufacturing a laminate of the embodiment, a laminate having the film of the embodiment can be manufactured. [Example]

Next, the present invention will be described in more detail by showing embodiments, but the present invention is not limited to the following embodiments.

[Determination of the flow starting temperature of liquid crystal polyester] Using a rheometer (manufactured by Shimadzu Corporation, CFT-500 model), about 2 g of liquid crystal polyester was filled into a cylinder equipped with a die having an inner diameter of 1 mm and a length of 10 mm. The temperature was raised at a rate of 4°C/min under a load of 9.8 mPa (100 kg/cm ² ) while the liquid crystal polyester was melted and extruded from the nozzle. The temperature (FT) at which a viscosity of 4800 Pa・s (48000 P) was measured.

[Measurement of particle size _D50 of liquid crystal polyester particles] The particle size _D50 of the liquid crystal polyester particles was measured using a scattering particle size distribution measuring apparatus (manufactured by Horiba, Ltd., LA-950V2). The refractive index of pure water was set to 1.333, and the volume-based cumulative particle size distribution of the liquid crystal polyester particles was measured. The particle size (μm) at which the cumulative volume ratio was 50% was calculated as the particle size _D50 .

[Viscosity measurement of polyether sulphate solution and liquid crystal polyester solution] Viscosity measurement was performed using a B-type viscometer (TV-22, manufactured by Toki Industry Co., Ltd.). Measurement conditions: sample temperature 23°C, rotor speed 20 rpm

[Determination of the peel strength of the film with copper foil] The film with copper foil was cut into short strips with a width of 10 mm to prepare three test pieces. For each test piece, the copper foil was peeled off at a peeling speed of 50 mm/min along a direction 90° relative to the film using an automatic stereogrammer (AG-1KNIS, manufactured by Shimadzu Corporation) while the film was fixed. The peel strength of the film with copper foil (90° peel strength) was measured, and the average value of the three test pieces was then calculated.

[Example of Preparation of Liquid Crystal Polyester (a) Powder] 940.9 g (5.0 mol) of 6-hydroxy-2-naphthoic acid, 377.9 g (2.5 mol) of 4-hydroxyacetaniline, 415.3 g (2.5 mol) of isophthalic acid and 867.8 g (8.4 mol) of acetic anhydride were added to a reactor equipped with a stirring device, a torque meter, a nitrogen inlet tube, a thermometer and a reflux condenser. After replacing the gas in the reactor with nitrogen, the temperature was raised from room temperature to 140°C over 60 minutes under a nitrogen flow while stirring, and refluxed at 140°C for 3 hours. Then, while removing the by-product acetic acid and unreacted acetic anhydride by distillation, the temperature was raised from 150°C to 300°C over 5 hours. After being kept at 300°C for 30 minutes, the contents were taken out from the reactor and cooled to room temperature. The obtained solid was crushed by a grinder to obtain a powdered liquid crystal polyester (a1). The flow starting temperature of the liquid crystal polyester (a1) was 193.3°C.

The liquid crystal polyester (a1) was heated from room temperature to 160°C in a nitrogen atmosphere for 2 hours and 20 minutes, then heated from 160°C to 180°C for 3 hours and 20 minutes, and kept at 180°C for 5 hours to perform solid phase polymerization, followed by cooling and then pulverization by a pulverizer to obtain a powdered liquid crystal polyester (a2). The flow starting temperature of the liquid crystal polyester (a2) was 220°C.

Liquid crystal polyester (a2) was heated from room temperature to 180°C in a nitrogen atmosphere for 1 hour and 25 minutes, then heated from 180°C to 255°C for 6 hours and 40 minutes, and kept at 255°C for 5 hours to perform solid phase polymerization, followed by cooling to obtain powdered liquid crystal polyester (a). The flow starting temperature of the liquid crystal polyester (a) powder was 302°C.

[Preparation of Liquid Crystal Polyester Solution (a)] 8 parts by mass of liquid crystal polyester (a) powder was added to 92 parts by mass of N-methylpyrrolidone (boiling point (1 atmosphere) 204°C), and stirred at 140°C for 4 hours under a nitrogen atmosphere to prepare a liquid crystal polyester solution (a). The viscosity of the liquid crystal polyester solution (a) at 23°C was 955 mPa·s.

[Example of Preparation of Liquid Crystal Polyester (b2) Powder] 1511.1 g (8.03 mol) of 2-hydroxy-6-naphthoic acid, 410.2 g (2.97 mol) of p-hydroxybenzoic acid, 1291.4 g (12.65 mol) of acetic anhydride and 0.057 g of 1-methylimidazole were added to a reactor equipped with a stirring device, a torque meter, a nitrogen inlet tube, a thermometer and a reflux condenser. After stirring at room temperature for 5 minutes, the temperature was raised while stirring. Just after the internal temperature reached 140°C, the temperature was maintained at 140°C and stirred for 1 hour. Next, the by-product acetic acid and unreacted acetic anhydride were distilled off while the temperature was raised from 140°C to 275°C over 3 hours. The mixture was kept at 275°C for 3 hours and 30 minutes, and the contents were taken out. The contents were cooled to room temperature and pulverized by a pulverizer to obtain a powdered liquid crystal polyester (b1). The flow starting temperature of the liquid crystal polyester (b1) was 211.8°C.

Liquid crystal polyester (b1) was heated from room temperature to 180°C in a nitrogen atmosphere for 1 hour, then from 180°C to 190°C for 10 minutes, then from 190°C to 240°C for 8 hours and 20 minutes, and then kept at 240°C for 5 hours to perform solid phase polymerization. The obtained solid phase polymer was cooled to room temperature to obtain powdered liquid crystal polyester (b2). The flow starting temperature of the liquid crystal polyester (b2) powder was 266.6°C.

[Preparation of Liquid Crystal Polyester (b3) Powder] Liquid crystal polyester (b2) was pulverized using a jet mill ("KJ-200" manufactured by Kurimoto Iron Works) to obtain liquid crystal polyester (b3) powder. The particle size _D50 of the liquid crystal polyester (b3) powder was 10 μm.

[Production of polyether sulfone (c1)] In a polymerization tank equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser with a receiver at the front end, bis(4-hydroxyphenyl)sulfone (300.3 g), bis(4-chlorophenyl)sulfone (346.3 g), and diphenylsulfone (570.1 g) as a polymerization solvent were added, and the temperature was raised to 180°C while nitrogen was circulated in the system to obtain a solution. Potassium carbonate (170.8 g) was added to the obtained solution, and the temperature was slowly raised to 290°C, and the reaction was further carried out at 290°C for 1 hour and 30 minutes. The obtained reaction solution was cooled to room temperature to solidify, crushed into fine powder, and then washed several times with warm water and a mixed solvent of acetone and methanol, and then dried by heating at 150°C to obtain polyether sulfone (c1) powder.

[Preparation of polyether sulfone solution (c)] 25 parts by mass of polyether sulfone (c1) powder was added to 75 parts by mass of N-methylpyrrolidone (boiling point (1 atmosphere) 204°C), and stirred at 100°C for 4 hours under a nitrogen atmosphere to prepare a polyether sulfone solution (c). The viscosity of the polyether sulfone solution (c) at 23°C was 3194 mPa·s.

[Production of polyether sulfone (d1)] In a polymerization tank equipped with a stirrer, a nitrogen inlet pipe, a thermometer, and a condenser with a receiver at the front end, bis(4-hydroxyphenyl)sulfone (300.3 g), bis(4-chlorophenyl)sulfone (330.8 g), and diphenylsulfone (560.3 g) as a polymerization solvent were added, and the temperature was raised to 180°C while nitrogen was circulated in the system to obtain a solution. Potassium carbonate (159.7 g) was added to the obtained solution, and the temperature was slowly raised to 290°C, and the reaction was further carried out at 290°C for 3 hours. The obtained reaction solution was cooled to room temperature to solidify, crushed into fine powder, and then washed several times with warm water and a mixed solvent of acetone and methanol. Then, it was heated and dried at 150°C to obtain aromatic polysulfide (d1) powder.

[Preparation of polyether sulfone solution (d)] 25 parts by mass of polyether sulfone (d1) powder was added to 75 parts by mass of N-methylpyrrolidone (boiling point (1 atmosphere) 204°C), and stirred at 100°C for 4 hours under a nitrogen atmosphere to prepare a polyether sulfone solution (d). The viscosity of the polyether sulfone solution (d) at 23°C was 380 mPa·s.

[Production of thermoplastic polyimide (e)] In a reactor equipped with a stirrer, a Dean-Stark apparatus, and a thermometer, 600 g of 2-(2-methoxyethoxy)ethanol and 218.58 g (1.00 mol) of pyromellitic dianhydride were mixed, and stirred at a stirring speed of 150 rpm under a nitrogen flow. Separately, 49.42 g (0.347 mol) of 1,3-bis(aminomethyl)cyclohexane, 93.16 g (0.645 mol) of 1,8-octamethylenediamine, and 250 g of 2-(2-methoxyethoxy)ethanol were mixed to obtain a solution. The stirring speed of the above reactor was set to 250 rpm, and the above solution was slowly added dropwise to the reactor under a nitrogen flow. After all the solution has been added dropwise, add a mixture of 130 g of 2-(2-methoxyethoxy)ethanol and 1.934 g (0.0149 mol) of n-octylamine prepared separately, and stir in the above reactor. Next, set the stirring speed of the above reactor to 200 rpm, raise the internal temperature of the reactor to 190°C, and maintain for 30 minutes. Allow to cool until the temperature of the contents in the reactor reaches room temperature, then filter the contents to obtain the resin. Wash and filter the above resin with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, and then dry the resin in a dryer at 180°C for 10 hours. The obtained resin is crushed into fine powder to prepare thermoplastic polyimide (e) powder.

[Preparation of dispersion] (Examples 1 to 12, Comparative Example 1) Liquid crystal polyester (b3) powder, polyether sulphate solution (c), polyether sulphate solution (d), and any one of thermoplastic polyimide (e) were added to the liquid crystal polyester solution (a) obtained above so as to prepare the amounts (parts by mass) of the components shown in Table 1, and a dispersion was prepared using a stirring defoaming device (manufactured by KEYENCE Co., Ltd., HM-500). The liquid crystal polyester (b3) powder and the thermoplastic polyimide (e) powder are insoluble in N-methylpyrrolidone.

[Production of films and laminates] The dispersions of Examples 1 to 12 and Comparative Example 1 were cast on the roughened surface of a copper foil (JXEFL-V2 manufactured by JX Metal Co., Ltd., thickness 12 μm) using a coating machine with a micrometer (SA204 manufactured by Tester Sangyo Co., Ltd.) and an automatic coating device (Type I manufactured by Tester Sangyo Co., Ltd.) so that the thickness of the cast film was 300 μm. Thereafter, the film was dried at 40°C and normal pressure (1 atmosphere) for 4 hours to partially remove the solvent from the cast film.

The dried films with copper foil prepared in Examples 1 to 12 and Comparative Example 1 were further heat treated in a hot air oven under a nitrogen atmosphere by raising the temperature from room temperature to 310°C over 4 hours and maintaining the temperature for 2 hours. As a result, a heat-treated film with copper foil (total thickness of the laminated body 42 μm) was obtained. The peel strength of the film with copper foil was measured and is shown in Table 1.

[Table 1] Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Embodiment 7 Embodiment 8 Embodiment 9 Embodiment 10 Embodiment 11 Embodiment 12 Comparison Example 1 Composition Liquid crystal polyester (a) Quality 4 4 4 4 4 4 4 4 4 4 4 4 4 Liquid crystal polyester (b3) Quality 6 6 6 6 6 6 6 6 6 6 6 6 6 Polyether sulfide (c1) Quality 0.21 0.44 1.05 2.11 Polyether sulfide (d1) Quality 0.21 0.44 1.05 2.11 Thermoplastic polyimide (e) Quality 0.21 0.44 1.05 2.11 N-Methylpyrrolidone Quality 46.63 47.34 49.16 52.32 46.63 47.34 49.16 52.32 46 46 46 46 46 Reviews Peel strength N/cm 5.2 5.2 4.6 5.3 4.2 4.7 4.4 4.7 5.6 5.7 5.1 5.0 4.0

The peeling strength of the copper foil film obtained from the composition of Comparative Example 1, which contains the liquid crystal polyester (a) and the liquid crystal polyester (b3), is 4.0 N/cm. In contrast, the copper foil film obtained from the compositions of Examples 1 to 12 has improved adhesion strength with the copper foil (metal layer) measured in the form of peeling strength. The compositions of Examples 1 to 12 are those in which the composition of Comparative Example 1 further contains polyether sulfone (c1), polyether sulfone (d1), or thermoplastic resin polyimide (e).

Each configuration and combination thereof in each embodiment is an example, and modifications such as addition, omission, and replacement of the configuration may be made within the scope of the subject matter of the present invention. In addition, the present invention is not limited to each embodiment but is limited only to the scope of the patent application (claim).

10: Film 12: Support 13: Metal layer 20: Laminated body 21: Laminated body 22: Laminated body precursor 30: Liquid crystal polyester composition 40: Film precursor

Fig. 1 is a cross-sectional view showing the structure of a membrane according to one embodiment of the present invention. Fig. 2 is a cross-sectional view showing the structure of a laminate according to one embodiment of the present invention. Fig. 3A is a schematic view showing the manufacturing process of a membrane and a laminate according to one embodiment of the present invention. Fig. 3B is a schematic view showing the manufacturing process of a membrane and a laminate according to one embodiment of the present invention. Fig. 3C is a schematic view showing the manufacturing process of a membrane and a laminate according to one embodiment of the present invention. Fig. 3D is a schematic view showing the manufacturing process of a membrane according to one embodiment of the present invention.

Claims (14)

A liquid crystal polyester composition comprises a liquid crystal polyester (A) and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, wherein the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamine or repeating units derived from aromatic diamine. The liquid crystal polyester composition of claim 1, wherein the liquid crystal polyester (A) has repeating units represented by the following formula (A1), repeating units represented by the following formula (A2), and repeating units represented by the following formula (A3), (A1)-O-Ar ¹ -CO- (A2)-CO-Ar ² -CO- (A3)-X-Ar ³ -Y- (wherein, Ar ¹ represents 1,4-phenylene, 2,6-naphthylene, or 4,4'-biphenylene, Ar ² represents 1,4-phenylene, 1,3-phenylene, or 2,6-naphthylene, Ar ³ represents 1,4-phenylene or 1,3-phenylene, X represents -NH-, Y represents -O- or -NH-, and the hydrogen atoms on the above groups represented by Ar ¹ , Ar ² , or Ar ³ may be independently substituted by halogen atoms, alkyl groups, or aryl groups.) The liquid crystal polyester composition of claim 1 or 2 further comprises liquid crystal polyester particles comprising a liquid crystal polyester (B), wherein the liquid crystal polyester (B) does not have repeating units derived from aromatic hydroxylamines and repeating units derived from aromatic diamines. The liquid crystal polyester composition of claim 3, wherein the content of the liquid crystal polyester particles is greater than 5 mass % and less than 80 mass % relative to 100 mass % of the total content of solid components contained in the liquid crystal polyester composition. The liquid crystal polyester composition of claim 1 or 2, wherein in the liquid crystal polyester composition, the content of the thermoplastic resin is 1 part by mass or more relative to 100 parts by mass of the liquid crystal polyester (A). The liquid crystal polyester composition of claim 1 or 2, wherein the content of the liquid crystal polyester (A) in the liquid crystal polyester composition is 10 mass % or more and 90 mass % or less relative to 100 mass % of the total content of solid components contained in the liquid crystal polyester composition. The liquid crystal polyester composition of claim 1 or 2 further comprises a solvent capable of dissolving the liquid crystal polyester (A). The liquid crystal polyester composition of claim 1 or 2, wherein the thermoplastic resin is thermoplastic polyimide. The liquid crystal polyester composition of claim 8, wherein the thermoplastic polyimide has repeating units represented by the following formula (I) and repeating units represented by the following formula (II), [Chemical 1] (wherein, _R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure, _R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms, and _X1 and _X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring). A liquid crystal polyester composition as claimed in claim 9, wherein the content ratio of the repeating units of the above-mentioned thermoplastic polyimide of the above-mentioned formula (I) relative to the total 100 mol % of the repeating units of the above-mentioned formula (I) and the repeating units of the above-mentioned formula (II) is greater than 20 mol % and less than 70 mol %. A liquid crystal polyester composition comprises a liquid crystal polyester (A), at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, and a solvent capable of dissolving the liquid crystal polyester (A). A film comprising a liquid crystal polyester (A) and at least one thermoplastic resin selected from the group consisting of thermoplastic polyimide and aromatic polysulfone, wherein the liquid crystal polyester (A) has repeating units derived from aromatic hydroxylamine or repeating units derived from aromatic diamine. A laminate comprising a metal layer and a film as claimed in claim 12 laminated on the metal layer. A method for manufacturing a laminate as claimed in claim 13, comprising the following steps: coating the liquid crystal polyester composition as claimed in claim 1, 2 or 11 on a metal layer to form a film on the metal layer.