Liquid crystal polyester composition and film

Abstract

Provided are: a liquid crystal polyester composition capable of forming a film having high mechanical strength; and a film comprising the liquid crystal polyester composition. A liquid crystal polyester composition containing a liquid crystal polyester, an inorganic filler, and a leveling agent.

Description

Technical Field

[0001] The present invention relates to a liquid crystal polyester composition and a film. Background Art

[0002] Liquid crystal polyesters have attracted attention as materials for electronic substrates due to their excellent high-frequency characteristics and low hygroscopicity. In particular, solution compositions containing liquid crystal polyesters containing structural units derived from aromatic amine derivatives and organic solvents can be cast onto a support and then the solvent removed from the cast product to produce liquid crystal polyester films with low anisotropy, making them excellent materials for films used in electronic components.

[0003] The composition containing the liquid crystal polyester contains an inorganic filler as needed.

[0004] For example, Patent Document 1 discloses a liquid crystalline polyester film laminate, which is a liquid crystalline polyester film laminated with a metal film, and is a film formed by the following liquid crystalline polyester, wherein the liquid crystalline polyester contains 10 to 35 mol % of 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, relative to all structural units, and discloses that the liquid crystalline polyester film contains an inorganic filler in the range of 10 to 50 parts by weight relative to 100 parts by weight of the liquid crystalline polyester (Claim 2 of Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-342980 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] In the liquid crystal polyester film produced from the conventional liquid crystal polyester composition described in Patent Document 1, there is room for improvement in mechanical strength.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal polyester composition capable of forming a film having high mechanical strength, and a film comprising the liquid crystal polyester composition.

[0011] Means for solving problems

[0012] In the case of a composition in which an inorganic filler is added to a liquid crystal polyester, the inorganic filler may not be well dispersed in the composition, resulting in a decrease in the mechanical strength of the film.

[0013] On the other hand, the present inventors conducted intensive research and found that if a leveling agent is further added to the composition, the inorganic filler is uniformly dispersed in the composition through the interaction between the liquid crystal polyester, the inorganic filler, and the leveling agent, and a film with high mechanical strength can be produced, thereby completing the present invention.

[0014] In order to solve the above-mentioned problems, the present invention includes the following means.

[0015] [1] A liquid crystal polyester composition comprising a liquid crystal polyester, an inorganic filler, and a leveling agent.

[0016] [2] The liquid crystal polyester composition according to [1], wherein the liquid crystal polyester comprises a structural unit represented by the following formula (A1), a structural unit represented by the following formula (A2), and a structural unit represented by the following formula (A3),

[0017] The content of the structural unit represented by the formula (A1) is 30 mol% or more and 80 mol% or less relative to all structural units constituting the liquid crystal polyester.

[0018] The content of the structural unit represented by the formula (A2) is 10 mol% or more and 35 mol% or less relative to all structural units constituting the liquid crystal polyester.

[0019] The content of the structural unit represented by the formula (A3) is 10 mol% or more and 35 mol% or less based on the total structural units constituting the liquid crystal polyester.

[0020] (A1)-O-Ar1-CO-

[0021] (A2)-CO-Ar2-CO-

[0022] (A3)-X-Ar3-Y-

[0023] [In the formula, Ar1 represents 1,4-phenylene, 2,6-naphthylene, or 4,4'-biphenylene; Ar2 represents 1,4-phenylene, 1,3-phenylene, or 2,6-naphthylene; Ar3 represents 1,4-phenylene or 1,3-phenylene; X represents -NH-; and Y represents -O- or NH-.]

[0024] [3] The liquid crystal polyester composition according to [1] or [2], wherein the inorganic filler is talc or mica.

[0025] [4] The liquid crystal polyester composition according to any one of [1] to [3], wherein the average particle size D50 of the inorganic filler is 100 nm or more and 820 nm or less.

[0026] [5] The liquid crystal polyester composition according to any one of [1] to [4], wherein the content of the inorganic filler is 10 parts by mass or more and 25 parts by mass or less relative to 100 parts by mass of the total of the liquid crystal polyester, the inorganic filler, and the leveling agent.

[0027] [6] The liquid crystal polyester composition according to any one of [1] to [5], wherein the leveling agent comprises polyether-modified polydimethylsiloxane.

[0028] [7] The liquid crystal polyester composition according to any one of [1] to [6], wherein the content of the leveling agent is 0.01 parts by mass or more and 1.5 parts by mass or less relative to 100 parts by mass of the total of the liquid crystal polyester and the inorganic filler.

[0029] [8] The liquid crystal polyester composition according to any one of [1] to [7], further comprising an organic solvent.

[0030] [9] A film comprising the liquid crystal polyester composition according to any one of [1] to [7].

[0031] Effects of the Invention

[0032] According to the present invention, a liquid crystal polyester composition capable of forming a film having high mechanical strength and a film comprising the liquid crystal polyester composition can be provided. DETAILED DESCRIPTION

[0033] (Liquid Crystal Polyester Composition)

[0034] The liquid crystal polyester composition of the present embodiment contains a liquid crystal polyester, an inorganic filler, and a leveling agent.

[0035] <Liquid Crystal Polyester>

[0036] Liquid crystal polyester is a polyester resin that exhibits liquid crystallinity in a molten state.

[0037] The liquid crystal polyester is preferably soluble in an aprotic solvent. Solubility in an aprotic solvent can be confirmed by performing the following test.

[0038] Test methods

[0039] The liquid crystal polyester was stirred in an aprotic solvent at 120°C to 180°C for 1 to 6 hours, then cooled to room temperature. The mixture was then filtered using a 5μm membrane filter and a pressure filter, and the residue on the membrane filter was checked. If no solid matter was visually observed, the mixture was considered soluble in the aprotic solvent.

[0040] The liquid crystal polyester preferably includes a structural unit represented by the following formula (A1). The liquid crystal polyester more preferably includes a structural unit represented by the following formula (A1), a structural unit represented by the following formula (A2), and a structural unit represented by the following formula (A3).

[0041] (A1)-O-Ar1-CO-

[0042] (A2)-CO-Ar2-CO-

[0043] (A3)-X-Ar3-Y-

[0044] [In the formula, Ar1 represents 1,4-phenylene, 2,6-naphthylene, or 4,4'-biphenylene; Ar2 represents 1,4-phenylene, 1,3-phenylene, or 2,6-naphthylene; Ar3 represents 1,4-phenylene or 1,3-phenylene; X represents -NH-; and Y represents -O- or NH-.]

[0045] Examples of the structural unit represented by formula (A1) include a structural unit derived from p-hydroxybenzoic acid, a structural unit derived from 2-hydroxy-6-naphthoic acid, and a structural unit derived from 4-hydroxy-4′-biphenylcarboxylic acid.

[0046] The liquid crystal polyester may contain one type of the structural unit represented by the formula (A1), or may contain two or more types.

[0047] As the structural unit represented by formula (A1), among the above, a structural unit derived from 2-hydroxy-6-naphthoic acid in which Ar1 is 2,6-naphthylene is preferred.

[0048] The content of the structural unit represented by formula (A1) is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more, based on the total structural units constituting the liquid crystal polyester.

[0049] The content of the structural unit represented by formula (A1) is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less, based on all structural units constituting the liquid crystal polyester.

[0050] When the content of the structural unit represented by formula (A1) is equal to or less than the above-described preferred upper limit, when the liquid crystal polyester composition of the present embodiment contains a solvent, the solubility of the liquid crystal polyester in the solvent is further improved.

[0051] When the content of the structural unit represented by formula (A1) is at least the above-described preferred lower limit value, the liquid crystal polyester more easily exhibits liquid crystallinity.

[0052] For example, the content of the structural unit represented by formula (A1) is preferably 30 mol% to 80 mol%, more preferably 40 mol% to 70 mol%, and even more preferably 45 mol% to 65 mol%, relative to all structural units constituting the liquid crystal polyester.

[0053] Examples of the structural unit represented by formula (A2) include a structural unit derived from terephthalic acid, a structural unit derived from isophthalic acid, and a structural unit derived from 2,6-naphthalenedicarboxylic acid.

[0054] The liquid crystal polyester may contain one type of the structural unit represented by the formula (A2), or may contain two or more types.

[0055] As the structural unit represented by formula (A2), among the above, a structural unit derived from isophthalic acid in which Ar2 is 1,3-phenylene is preferred.

[0056] The content of the structural unit represented by formula (A2) is preferably 10 mol% or more, more preferably 15 mol% or more, and even more preferably 17.5 mol% or more, based on all structural units constituting the liquid crystal polyester.

[0057] The content of the structural unit represented by formula (A2) is preferably 35 mol% or less, more preferably 30 mol% or less, and even more preferably 27.5 mol% or less, based on all structural units constituting the liquid crystal polyester.

[0058] When the content of the structural unit represented by formula (A2) is equal to or less than the above-described preferred upper limit, the liquid crystal polyester more easily exhibits liquid crystallinity.

[0059] When the content of the structural unit represented by formula (A2) is equal to or greater than the above-described preferred lower limit, when the liquid crystal polyester composition of the present embodiment contains a solvent, the solubility of the liquid crystal polyester in the solvent is further improved.

[0060] For example, the content of the structural unit represented by formula (A2) is preferably 10 mol% or more and 35 mol% or less, more preferably 15 mol% or more and 30 mol% or less, and further preferably 17.5 mol% or more and 27.5 mol% or less, relative to all the structural units constituting the liquid crystal polyester.

[0061] Examples of the structural unit represented by formula (A3) include a structural unit derived from 3-aminophenol, a structural unit derived from 4-aminophenol, a structural unit derived from 1,4-phenylenediamine, a structural unit derived from 1,3-phenylenediamine, and a structural unit derived from 4-aminobenzoic acid.

[0062] The liquid crystal polyester may contain one type of the structural unit represented by the formula (A3), or may contain two or more types.

[0063] As the structural unit represented by formula (A3), among the above, a structural unit derived from 4-aminophenol in which Ar3 is 1,4-phenylene, X is -NH-, and Y is -O- is preferred.

[0064] The content of the structural unit represented by formula (A3) is preferably 10 mol% or more, more preferably 15 mol% or more, and even more preferably 17.5 mol% or more, based on all structural units constituting the liquid crystal polyester.

[0065] The content of the structural unit represented by formula (A3) is preferably 35 mol% or less, more preferably 30 mol% or less, and even more preferably 27.5 mol% or less, based on all structural units constituting the liquid crystal polyester.

[0066] When the content of the structural unit represented by formula (A3) is equal to or less than the above-described preferred upper limit, the liquid crystal polyester more easily exhibits liquid crystallinity.

[0067] When the content of the structural unit represented by formula (A3) is equal to or greater than the above-described preferred lower limit, when the liquid crystal polyester composition of the present embodiment contains a solvent, the solubility of the liquid crystal polyester in the solvent is further improved.

[0068] For example, the content of the structural unit represented by formula (A3) is preferably 10 mol% or more and 35 mol% or less, more preferably 15 mol% or more and 30 mol% or less, and further preferably 17.5 mol% or more and 27.5 mol% or less, relative to all the structural units constituting the liquid crystal polyester.

[0069] The ratio of the content of the structural unit represented by formula (A2) to the content of the structural unit represented by formula (A3) is expressed as [content of the structural unit represented by formula (A2)] / [content of the structural unit represented by formula (A3)] (mol / mol), and is preferably 0.9 / 1 to 1 / 0.9, more preferably 0.95 / 1 to 1 / 0.95, and further preferably 0.98 / 1 to 1 / 0.98.

[0070] The flow initiation temperature of the liquid crystal polyester is preferably 250°C or higher, more preferably 250 to 350°C, and even more preferably 280 to 340°C.

[0071] The higher the flow start temperature, the more easily heat resistance and strength / rigidity are improved. However, if it is too high, the solubility in the solvent is likely to decrease, or the viscosity of the liquid composition is likely to increase.

[0072] In this specification, the flow start temperature of the liquid crystal polyester is also referred to as the fluid temperature or the flow temperature. It is the temperature at which the liquid crystal polyester shows a viscosity of 4800 Pa·s when extruded from a nozzle with an inner diameter of 1 mm and a length of 10 mm while melting the liquid crystal polyester at a rate of 4°C / min under a load of 9.8 MPa using a capillary rheometer. It is the target temperature for the molecular weight of the liquid crystal polyester (see Naoyuki Koide, ed., "Liquid Crystal Polymers - Synthesis, Molding, and Applications -", ​​CMC Co., Ltd., June 5, 1987, p. 95).

[0073] In the liquid crystal polyester composition of the present embodiment, the liquid crystal polyester may be used alone or in combination of two or more.

[0074] As a method for producing the liquid crystal polyester in this embodiment, for example, the following method can be cited: an aromatic hydroxy acid corresponding to the structural unit represented by formula (A1), an aromatic amine having a phenolic hydroxyl group corresponding to the structural unit represented by formula (A3), or a phenolic hydroxyl group or amino group of an aromatic diamine is acylated with an excess of fatty acid anhydride to obtain an acylate, and the obtained acylate is subjected to ester / amide exchange (polycondensation) with an aromatic dicarboxylic acid corresponding to the structural unit represented by formula (A2) to carry out melt polymerization (for example, refer to Japanese Patent Application Publication No. 2002-220444 and Japanese Patent Application Publication No. 2002-146003).

[0075] In the acylation reaction, the amount of fatty acid anhydride added is preferably 1.0 to 1.2 equivalents, more preferably 1.05 to 1.1 equivalents, relative to the total number of phenolic hydroxyl groups and amino groups. If the amount of fatty acid anhydride added is too small, the acylate, raw material monomers, etc., will sublime during transesterification / transamidation (polycondensation), and the reaction system may be easily clogged. If the amount of fatty acid anhydride added is too large, the resulting liquid crystalline polyester may be significantly colored.

[0076] The acylation reaction is preferably carried out at 130 to 180°C for 5 minutes to 10 hours, more preferably at 140 to 160°C for 10 minutes to 3 hours.

[0077] The fatty acid anhydride used in the acylation reaction is not particularly limited, but examples thereof include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, 2-ethylhexanoic anhydride, monochloroacetic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, glutaric anhydride, maleic anhydride, succinic anhydride, and β-bromopropionic anhydride. Two or more of these may be used in combination.

[0078] In this embodiment, acetic anhydride, propionic anhydride, butyric anhydride, or isobutyric anhydride is preferred, and acetic anhydride is more preferred.

[0079] In the transesterification / transamidation (polycondensation), the acyl group of the acylated product is preferably 0.8 to 1.2 times the equivalent of the carboxyl group.

[0080] The transesterification / transamidation (polycondensation) is preferably performed while increasing the temperature to 400° C. at a rate of 0.1 to 50° C. / min, and more preferably while increasing the temperature to 350° C. at a rate of 0.3 to 5° C. / min.

[0081] When the acylate and the carboxylic acid are subjected to transesterification / transamidation (polycondensation), the by-produced fatty acid and the unreacted fatty acid anhydride are preferably removed from the system by distillation or the like by evaporation.

[0082] It should be noted that the acylation reaction and transesterification / transamidation (polycondensation) can also be carried out in the presence of a catalyst. As such catalyst, catalysts conventionally known as polyester polymerization catalysts can be used, for example, metal salt catalysts such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide; and organic compound catalysts such as N,N-dimethylaminopyridine and N-methylimidazole.

[0083] Among these catalysts, heterocyclic compounds containing two or more nitrogen atoms, such as N,N-dimethylaminopyridine and N-methylimidazole, are preferably used (see JP-A-2002-146003).

[0084] The catalyst is usually added when the monomers are added, and does not necessarily need to be removed after acylation. Transesterification can be carried out directly without removing the catalyst.

[0085] Condensation polymerization by transesterification / transamide exchange is usually carried out by melt polymerization, but melt polymerization and solid phase polymerization can also be used together. Solid phase polymerization is preferably carried out by extracting the polymer from the melt polymerization process, crushing it into powder or flakes, and then performing it by a known solid phase polymerization method. Specifically, for example, a method of heat treatment in a solid phase state at 20 to 350°C for 1 to 30 hours under an inert atmosphere such as nitrogen can be cited. Solid phase polymerization can be carried out while stirring or in a static state without stirring. It should be noted that the melt polymerization tank and the solid phase polymerization tank can also be set as the same reaction tank by providing an appropriate stirring mechanism. After solid phase polymerization, the obtained liquid crystalline polyester can also be pelletized and formed by a known method.

[0086] The liquid crystalline polyester can be produced using, for example, a batch device or a continuous device.

[0087] <Inorganic filler>

[0088] The average particle size D50 of the inorganic filler is preferably 100 nm or more, more preferably 300 nm or more, and even more preferably 500 nm or more.

[0089] The average particle size D50 of the inorganic filler is preferably 820 nm or less, more preferably 750 nm or less, and even more preferably 700 nm or less.

[0090] For example, the average particle diameter D50 of the inorganic filler is preferably 100 nm or more and 820 nm or less, more preferably 300 nm or more and 750 nm or less, and even more preferably 500 nm or more and 700 nm or less.

[0091] When the average particle size D50 of the inorganic filler is within the above-mentioned preferred range, the mechanical strength is further improved.

[0092] In this specification, the average particle diameter D50 is a particle diameter at which the cumulative volume ratio from the small particle side becomes 50% in a volume-based cumulative particle size distribution curve by laser diffraction / scattering particle size distribution measurement.

[0093] The average particle size D50 of the inorganic filler can be measured using, for example, a laser diffraction / scattering particle size distribution analyzer (for example, "LA-950V2" manufactured by HORIBA Corporation).

[0094] Specific examples of the inorganic filler include plate-like inorganic fillers and fibrous inorganic fillers.

[0095] Examples of the plate-like inorganic filler include talc, mica, plate-like alumina, and glass flakes.

[0096] Examples of the fibrous inorganic filler include aluminum oxide whiskers, titanium oxide whiskers, aluminum borate whiskers, potassium titanate whiskers, barium titanate whiskers, basic magnesium sulfate whiskers, zinc oxide whiskers, and silicon carbide whiskers.

[0097] As the inorganic filler, among the above, plate-like inorganic fillers are preferred, and talc and mica are more preferred.

[0098] In the liquid crystal polyester composition of the present embodiment, the inorganic filler may be used alone or in combination of two or more.

[0099] <Leveling agent>

[0100] Specific examples of the leveling agent include polyether-modified polydimethylsiloxane, fluorine-modified polymers, and polyester-modified polydimethylsiloxane.

[0101] As the leveling agent, among the above, polyether-modified polydimethylsiloxane is preferred.

[0102] Polyether modified polydimethylsiloxane

[0103] As the polyether-modified polydimethylsiloxane, a structure in which a polyalkylene oxide group is introduced into a terminal of the polydimethylsiloxane is used.

[0104] As the polyether-modified polydimethylsiloxane, a compound represented by the following formula (S1) is preferred.

[0105] [Chemical Formula 1]

[0106]

[0107] [Where R 1 、R 2 、R 3 、R 4 、R 5 、R 6 and R 7 Each independently represents H, CH3, C2H5, C3H7, OCH3, or OC2H5. x, y, and z each independently represent an integer from 1 to 20. R is a group represented by the following formula (E1).

[0108] [Chemical Formula 2]

[0109]

[0110] [Where R 8 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a group containing a cationically polymerizable group, or a group containing an ethylenically unsaturated group. b is each independently an integer of 1 to 20. * represents a bonding point.]

[0111] In the above formula (S1), R 1 、R 2 、R 3 、R 4 、R 5 、R 6 and R 7 Each independently selected is preferably CH3, C2H5, OCH3, or OC2H5, and each independently selected is more preferably CH3 or OC2H5.

[0112] In the above formula (S1), x, y, and z are each independently preferably an integer of 1 to 10, and more preferably an integer of 1 to 5.

[0113] In the above formula (E1), R 8 The group containing a cationically polymerizable group in , specifically, an epoxy group, an oxetanyl group, etc. Further, as the group containing an ethylenically unsaturated group, specifically, a vinyl group, an acryloyloxy group, a methacryloyloxy group, etc. can be mentioned.

[0114] Among them, R 8 It is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom.

[0115] In the above formula (E1), b is preferably an integer of 1-10, more preferably an integer of 1-5.

[0116] As the polyether-modified polydimethylsiloxane, a compound represented by the following formula (S2) is more preferable.

[0117] [Chemical Formula 3]

[0118]

[0119] [In the formula, x', y', z' and b" are each independently an integer of 1 to 5, and n' is an integer of 1 to 3.]

[0120] As the polyether-modified polydimethylsiloxane, commercially available polyether-modified polydimethylsiloxanes can be used. Specific examples include BYK-300, BYK-306, BYK-307, BYK-330, BYK-331, BYK-333, BYK-337, BYK-341, BYK-344, and BYK-378 manufactured by BYK-Chemie Japan, GLANOL 410 manufactured by Kyoeisha Chemical Co., Ltd., and KF-351 manufactured by Shin-Etsu Chemical Co., Ltd.

[0121] In the liquid crystal polyester composition of the present embodiment, the leveling agent may be used alone or in combination of two or more.

[0122] The content of the inorganic filler is preferably 10 parts by mass or more and 25 parts by mass or less, more preferably 15 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the total of the liquid crystal polyester, the inorganic filler, and the leveling agent.

[0123] The content of the leveling agent is preferably 0.01 to 1.5 parts by mass, more preferably 0.1 to 1.0 parts by mass, and even more preferably 0.5 to 1.0 parts by mass, relative to 100 parts by mass of the total of the liquid crystal polyester and the inorganic filler.

[0124] <Optional Ingredients>

[0125] The liquid crystal polyester composition of the present embodiment may contain optional components other than the above-mentioned liquid crystal polyester, inorganic filler, and leveling agent.

[0126] Optional components include organic solvents, defoaming agents, antioxidants, ultraviolet absorbers, flame retardants, dispersants, dyes, pigments, and the like.

[0127] Organic Solvents

[0128] Examples of the organic solvent include halogenated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, and o-dichlorobenzene; halogenated phenols such as p-chlorophenol, pentachlorophenol, and pentafluorophenol; ethers such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; ketones such as acetone and cyclohexanone; esters such as ethyl acetate and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; amines such as triethylamine; nitrogen-containing heterocyclic aromatic compounds such as pyridine; nitriles such as acetonitrile and succinonitrile; amide solvents (organic solvents having an amide bond) such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; urea compounds such as tetramethylurea; nitro compounds such as nitromethane and nitrobenzene; sulfur compounds such as dimethyl sulfoxide and sulfolane; and phosphorus compounds such as hexamethylphosphoramide and tri-n-butyl phosphate.

[0129] As the organic solvent, among the above, an amide solvent is preferred, and N-methylpyrrolidone is more preferred.

[0130] (Liquid Crystal Polyester Solution)

[0131] In this specification, a liquid crystal polyester composition containing an organic solvent is also referred to as a liquid crystal polyester solution.

[0132] The liquid crystal polyester solution of the present embodiment may be a solution obtained by further mixing an inorganic filler and a leveling agent with a mixed solution of the liquid crystal polyester and an organic solvent.

[0133] The content of the liquid crystal polyester is preferably 3% to 30% by mass, more preferably 3% to 20% by mass, and even more preferably 5% to 10% by mass, based on the total amount of the liquid crystal polyester solution.

[0134] The content of the inorganic filler is preferably 5% by mass to 40% by mass, more preferably 10% by mass to 30% by mass, and even more preferably 15% by mass to 25% by mass, based on the total amount of the liquid crystal polyester solution.

[0135] The content of the leveling agent is preferably 0.01% by mass to 1% by mass, more preferably 0.03% by mass to 0.5% by mass, and even more preferably 0.05% by mass to 0.1% by mass, based on the total amount of the liquid crystal polyester solution.

[0136] (membrane)

[0137] The film of this embodiment can be produced by melt-molding the above-mentioned liquid crystal polyester composition.

[0138] Examples of the melt molding method include extrusion molding methods such as a T-die method and an inflation method.

[0139] Since the film of the present embodiment is formed from the above-mentioned liquid crystal polyester composition, it has high mechanical strength.

[0140] Example

[0141] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[0142] [Flow start temperature of liquid crystal polyester]

[0143] First, using a flow tester ("CFT-500" manufactured by Shimadzu Corporation), about 2 g of the liquid crystal polyester was filled into a cylinder equipped with a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm.

[0144] Then, at 9.8 MPa (100 kg / cm 2 ) while heating at a rate of 4°C / min under a load, the liquid crystal polyester was melted and extruded from a nozzle, and the temperature at which a viscosity of 4800 Pa·s (48000 poise) was measured as the flow start temperature of the liquid crystal polyester.

[0145] [Synthesis of Liquid Crystalline Polyester]

[0146] Into a reactor equipped with a stirrer, a torque meter, a nitrogen inlet tube, a thermometer, and a reflux cooler, 941 g (5.0 mol) of 2-hydroxy-6-naphthoic acid, 273 g (2.5 mol) of 4-aminophenol, 415.3 g (2.5 mol) of isophthalic acid, and 1123 g (11 mol) of acetic anhydride were added. After the reactor was thoroughly purged with nitrogen, the temperature was raised to 150°C over 15 minutes under a nitrogen stream, maintained at that temperature, and refluxed for 3 hours. Subsequently, while distilling off by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 150°C to 290°C over 4 hours and 15 minutes, maintained at 290°C for 30 minutes, and the contents were removed from the reactor and cooled to room temperature.

[0147] The obtained solid matter was crushed with a grinder to obtain a powdered prepolymer. The flow starting temperature of the prepolymer was 181°C. Next, the prepolymer was heated from room temperature to 250°C in a nitrogen atmosphere for 6 hours, maintained at 250°C for 10 hours, and solid-phase polymerized, and then cooled to obtain a solid liquid crystal polyester. The obtained solid matter was crushed with a grinder to obtain a powdered liquid crystal polyester. The flow starting temperature of the liquid crystal polyester was 240°C. The liquid crystal polyester was heated from room temperature to 255°C in a nitrogen atmosphere for 6 hours, maintained at 255°C for 3 hours, and solid-phase polymerized, and then cooled to obtain a powdered liquid crystal polyester. The flow starting temperature of the liquid crystal polyester was 325°C.

[0148] [Preparation of mixed solution]

[0149] 8 g of the liquid crystal polyester obtained above was added to 92 g of N-methylpyrrolidone, and the mixture was stirred at 140° C. for 4 hours under a nitrogen atmosphere to obtain a mixed liquid X.

[0150] (Liquid crystal polyester solution of Example 1)

[0151] Talc A (NanoAce600: manufactured by Nippon Talc: D50670 nm) and polyether-modified polydimethylsiloxane (BYK300: manufactured by BYK-Chemie) were added to the mixed solution X and stirred using a stirring degasser (AR-500 manufactured by THINKY) to prepare a liquid crystal polyester solution of Example 1.

[0152] The amount of the mixed solution X added was set to 80 parts by mass, the amount of talc added was set to 20 parts by mass, and the amount of polyether-modified polydimethylsiloxane added was set to 0.15 parts by mass relative to the total amount of the liquid crystal polyester solution.

[0153] (Liquid Crystal Polyester Composition Solution of Comparative Example 1)

[0154] The liquid crystal polyester composition of Comparative Example 1 is mixed liquid X.

[0155] (Liquid Crystal Polyester Composition of Comparative Example 2)

[0156] Only talc A was added to the mixed solution X obtained above, and the mixture was stirred using a stirring degassing machine (AR-500 manufactured by THINKY Corporation) to produce a liquid crystal polyester composition solution of Comparative Example 2.

[0157] The amount of the mixed solution X added was set to 80 parts by mass, and the amount of talc A added was set to 20 parts by mass, relative to the total amount of the liquid crystal polyester solution.

[0158] (Liquid Crystal Polyester Composition Solution of Comparative Example 3)

[0159] Only talc B (NanoAce800: manufactured by Nippon Talc Co., Ltd.: D50830 nm) was added to the mixed solution X obtained above, and the mixture was stirred using a stirring degassing machine (manufactured by THINKY Co., Ltd.: AR-500) to produce a liquid crystal polyester composition of Comparative Example 3.

[0160] The amount of the mixed solution X added was set to 80 parts by mass, and the amount of talc B added was set to 20 parts by mass, relative to the total amount of the liquid crystal polyester solution.

[0161] <Film Preparation>

[0162] An electrolytic copper foil ("3EC-VLP", 18μ, manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed in an automatic coating device Type I (manufactured by TESTER SANGYO), and the gap of a film-making apparatus with a micrometer (manufactured by SHEEN) was set to 550 microns. The liquid crystal polyester solution of each example was applied to the shiny surface of the copper foil to produce a resin film laminate of each example.

[0163] Next, drying and removal of the copper foil were performed by the following method to produce a film of each example having a thickness of approximately 30 μm.

[0164] Pre-dry at 60°C for 3 hours and then at 70°C for 3 hours.

[0165] Annealing was performed at 30°C, drying was performed at 300°C for 4 hours, and drying was performed at 300°C for 2 hours.

[0166] Copper foil etching (immersion in ferric chloride aqueous solution) immersion for 30 minutes

[0167] Dry at 70°C for 10 minutes.

[0168] [Determination of elastic modulus (GPa), breaking point test force (N), and breaking point stress (MPa)]

[0169] Tensile tests were conducted using AUTOGRAPH AG-IS manufactured by Shimadzu Corporation under the following test conditions to measure the elastic modulus (GPa), breaking point test force (N), and breaking point stress (MPa) of the film of each example. The results are shown in Table 1.

[0170] Test conditions:

[0171] Temperature and humidity 23℃50%RH

[0172] Test speed 5mm / min

[0173]

[0174] As shown in Table 1, it was confirmed that the liquid crystal polyester composition of Example 1 could improve mechanical strength compared with the liquid crystal polyester compositions of Comparative Examples 1 to 3.

Claims

1. A liquid crystal polyester composition comprising a liquid crystal polyester, an inorganic filler and a leveling agent.

2. The liquid crystal polyester composition according to claim 1, wherein The liquid crystal polyester comprises a structural unit represented by the following formula (A1), a structural unit represented by the following formula (A2), and a structural unit represented by the following formula (A3). The content of the structural unit represented by the formula (A1) is 30 mol% or more and 80 mol% or less relative to all structural units constituting the liquid crystal polyester. The content of the structural unit represented by the formula (A2) is 10 mol% or more and 35 mol% or less relative to all structural units constituting the liquid crystal polyester. The content of the structural unit represented by the formula (A3) is 10 mol% or more and 35 mol% or less relative to all structural units constituting the liquid crystal polyester, (A1)-O-Ar1-CO- (A2)-CO-Ar2-CO- (A3)-X-Ar3-Y- In the formula, Ar1 represents 1,4-phenylene, 2,6-naphthylene, or 4,4'-biphenylene, Ar2 represents 1,4-phenylene, 1,3-phenylene, or 2,6-naphthylene, Ar3 represents 1,4-phenylene or 1,3-phenylene, X represents -NH-, and Y represents -O- or NH-.

3. The liquid crystal polyester composition according to claim 1 or 2, wherein The inorganic filler is talc or mica.

4. The liquid crystal polyester composition according to claim 1 or 2, wherein The average particle size D50 of the inorganic filler is greater than or equal to 100 nm and less than or equal to 820 nm.

5. The liquid crystal polyester composition according to claim 1 or 2, wherein The content of the inorganic filler is 10 parts by mass or more and 25 parts by mass or less relative to 100 parts by mass of the total of the liquid crystal polyester, the inorganic filler, and the leveling agent.

6. The liquid crystal polyester composition according to claim 1 or 2, wherein The leveling agent comprises polyether-modified polydimethylsiloxane.

7. The liquid crystal polyester composition according to claim 1 or 2, wherein The content of the leveling agent is 0.01 parts by mass or more and 1.5 parts by mass or less relative to 100 parts by mass of the total of the liquid crystal polyester and the inorganic filler.

8. The liquid crystal polyester composition according to claim 1 or 2, wherein It further contains an organic solvent. 9 . A film comprising the liquid crystal polyester composition according to claim 1 .

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