Liquid crystal polyester composition, pellet, and molded article

Abstract

A liquid crystal polyester composition contains a liquid crystal polyester and glass flakes, the liquid crystal polyester containing a first monomer unit having a fused aromatic ring and a second monomer unit having a benzene ring. The content of the glass flakes is 1-30 parts by mass for 100 parts by mass of the total of the liquid crystal polyester and the glass flakes. The density of the glass flakes is 1.8 g / cm3 or more and 2.5 g / cm3 or less.

Description

Liquid crystal polyester composition, pellets and molded articles

[0001] The present disclosure relates to a liquid crystal polyester composition, pellets, and molded articles.

[0002] Liquid crystal polyesters are used in a variety of applications due to their high fluidity, heat resistance and dimensional accuracy.

[0003] Liquid crystal polyesters are usually used as liquid crystal polyester compositions containing fillers and the like to meet the required properties depending on the application. For example, Patent Document 1 describes a liquid crystal polymer composition containing 15% by mass or more of a specific flat glass fiber and 20% by mass or more of a specific plate-like filler.

[0004] Japanese Patent Application Laid-Open No. 2003-268252

[0005] However, compositions containing a large amount of inorganic filler may have an increased viscosity when melted, resulting in poor moldability.

[0006] An object of the present disclosure is to provide a liquid crystal polyester composition that has good fluidity in a melt, and good electrical and tensile properties of a molded article. Another object of the present disclosure is to provide a molded article that is formed from a liquid crystal polyester composition with excellent moldability and has good electrical and tensile properties.

[0007] The present disclosure provides, for example, the following: [1] A liquid crystal polyester and glass flakes, wherein the liquid crystal polyester contains a first monomer unit having a condensed aromatic ring and a second monomer unit having a benzene ring, the content of the glass flakes is 1 to 30 parts by mass with respect to 100 parts by mass of the total of the liquid crystal polyester and the glass flakes, and the density of the glass flakes is 1.8 g / cm ３ 2.5g / cm or more ３[2] The liquid crystal polyester composition according to [1], wherein the condensed aromatic ring is a naphthalene ring. [3] The liquid crystal polyester composition according to [1] or [2], wherein the content of the first monomer unit is 50 mol % or more with respect to the total of all monomer units constituting the liquid crystal polyester. [4] The liquid crystal polyester composition according to any one of [1] to [3], wherein the thickness of the glass flakes is 0.1 μm or more and 2 μm or less. [5] The liquid crystal polyester composition according to any one of [1] to [4], wherein the average particle size (D50) of the glass flakes is 1 μm or more and 50 μm or less. [6] The liquid crystal polyester composition according to any one of [1] to [5], wherein the content of inorganic fillers other than the glass flakes is 25 mass % or less. [7] A pellet comprising the liquid crystal polyester composition according to any one of [1] to [6]. [8] A molded article comprising the liquid crystal polyester composition according to any one of [1] to [6], the molded article being a connector, a socket, a relay part, a coil bobbin, an optical pickup, an oscillator, a semiconductor package, an IC tray, a wafer carrier, a household electrical appliance part, a lighting fixture part, an audio product part, a ferrule for an optical cable, a telephone part, a facsimile part, a modem part, a separation claw, a heater holder, an impeller, a fan gear, a gear, a bearing, a motor part, a motor case, an engine part, an engine room interior part, an electrical component, an automobile interior part, a microwave cooking pot, a heat-resistant tableware, a flooring material, a wall material, a beam, a pillar, a roofing material, an aircraft part, a spacecraft part, a space equipment part, a nuclear reactor, a marine facility member, a cleaning jig, an optical equipment part, a valve, a pipe, a nozzle, a filter, a membrane, a medical equipment part, a medical material, a sensor part, a sanitary fixture, a sporting goods, or a leisure goods.

[0008] According to the present disclosure, it is possible to provide a liquid crystal polyester composition that has good fluidity in a melt, and good electrical properties and tensile properties of a molded article. Furthermore, according to the present disclosure, it is possible to provide a molded article that is formed from a liquid crystal polyester composition with excellent moldability and has good electrical properties and good tensile properties.

[0009] Preferred embodiments of the present disclosure will be described in detail below.

[0010] The liquid crystal polyester composition of this embodiment (hereinafter also simply referred to as "liquid crystal polyester composition") contains a liquid crystal polyester and glass flakes. The liquid crystal polyester contains a first monomer unit having a condensed aromatic ring and a second monomer unit having a benzene ring. The content of the glass flakes is 1 to 30 parts by mass relative to 100 parts by mass of the total of the liquid crystal polyester and the glass flakes. In this embodiment, the liquid crystal polyester composition may or may not contain an inorganic filler other than the glass flakes, but the content of the inorganic filler other than the glass flakes is 10% by mass or less.

[0011] The liquid crystal polyester composition of the present embodiment has good fluidity when melted, and good electrical properties and tensile properties (tensile strength, nominal tensile strain at break) of the molded article.

[0012] The reason for this effect is not entirely clear, but the present inventors believe it to be as follows: Liquid crystal polyester is a rigid, rod-like polymer that rotates in various directions by itself and is therefore unlikely to align in the flow direction. In contrast, in a liquid crystal polyester composition containing a predetermined amount of glass flakes, the faces of the glass flakes are aligned parallel to the flow direction, and the liquid crystal polyester is oriented along the faces of the glass flakes, aligning the direction of the polymer chains of the liquid crystal polyester with the flow direction, which is thought to improve fluidity. It is also thought that the parallel alignment of the glass flakes forms pseudo-flow paths, which makes it easier to orient the polymer chains of the liquid crystal polyester.

[0013] In addition, in this embodiment, since the liquid crystal polyester contains a first monomer unit having a fused aromatic ring, the polymer chain of the liquid crystal polyester tends to become more rigid and rod-like. Furthermore, since the fused aromatic rings are highly planar, they tend to align parallel to the surface of the glass flakes, which not only promotes flow but also exhibits good interaction with the surface of the flakes, which is thought to improve mechanical properties. Furthermore, by using glass flakes with a lower density than general glass flakes, the density of the liquid crystal polyester and the density of the glass flakes become closer, which makes it less likely that the alignment of the liquid crystal polymers will be hindered, and therefore, it is thought that the mechanical properties will improve.

[0014] The liquid crystal polyester may be any polyester that exhibits liquid crystallinity in a molten state. The liquid crystal polyester composition may contain only one type of liquid crystal polyester, or may contain two or more types of liquid crystal polyester.

[0015] The flow initiation temperature of the liquid crystal polyester may be, for example, 250° C. or higher, or 270° C. or higher. The flow initiation temperature of the liquid crystal polyester may be, for example, 400° C. or lower, 360° C. or lower, or 340° C. or lower. That is, the flow initiation temperature of the liquid crystal polyester may be, for example, 250° C. or higher and 400° C. or lower, 250° C. or higher and 360° C. or lower, 250° C. or higher and 340° C. or lower, 270° C. or higher and 400° C. or lower, 270° C. or higher and 360° C. or lower, or 270° C. or higher and 340° C. or lower.

[0016] In this specification, the flow initiation temperature of the liquid crystal polyester is measured using a flow tester, and the liquid crystal polyester is subjected to a pressure of 9.8 MPa (100 kg / cm ２ The liquid crystalline polyester is melted while being heated at a rate of 4°C / min under a load of 1000 kJ / min, and the molten liquid crystalline polyester is extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm, and the temperature is the temperature at which the viscosity of the extruded liquid crystalline polyester is 4800 Pa·s (48,000 poise).

[0017] The liquid crystal polyester has constituent units (also referred to as monomer units) derived from raw material monomers. The liquid crystal polyester may have a main monomer unit (for example, 90 mol% or more, 95 mol% or more, or 99 mol% or more of the monomer units relative to the total of all monomer units, preferably all monomer units) derived from an aromatic compound. A liquid crystal polyester in which all monomer units are derived from an aromatic compound is also referred to as a wholly aromatic liquid crystal polyester.

[0018] The liquid crystal polyester has a first monomer unit having a condensed aromatic ring and a monomer unit having a benzene ring. The liquid crystal polyester may have one or more types of first monomer units. The liquid crystal polyester may also have one or more types of second monomer units. The second monomer unit may be a monomer unit having a benzene ring but not having a condensed aromatic ring.

[0019] The first monomer unit may be a monomer unit derived from an aromatic compound (1) having a fused aromatic ring, and the second monomer unit may be a monomer unit derived from an aromatic compound (2) having a benzene ring.

[0020] In this specification, "derived" means that in the monomer units of the liquid crystal polyester formed by polymerization of the raw material monomers, the chemical structure of the functional group that contributes to polymerization of the raw material monomers has changed, but other structural changes have not occurred. Here, "derived" is a concept that also includes cases where the monomer unit is derived from a polymerizable derivative of the raw material monomer (for example, a compound obtained by converting the functional group that contributes to polymerization of the raw material monomers into another polymerizable group).

[0021] Examples of the first monomer unit include a monomer unit derived from an aromatic hydroxycarboxylic acid (1-1) having a fused aromatic ring (hereinafter also referred to as a monomer unit (1-1)), a monomer unit derived from an aromatic dicarboxylic acid (1-2) having a fused aromatic ring (hereinafter also referred to as a monomer unit (1-2)), and a monomer unit derived from an aromatic diol (1-3) having a fused aromatic ring (hereinafter also referred to as a monomer unit (1-3)).

[0022] Examples of the second monomer unit include a monomer unit derived from an aromatic hydroxycarboxylic acid (2-1) (hereinafter also referred to as a monomer unit (2-1)), a monomer unit derived from an aromatic dicarboxylic acid (2-2) (hereinafter also referred to as a monomer unit (2-2)), and a monomer unit derived from an aromatic diol (2-3) (hereinafter also referred to as a monomer unit (2-3)).

[0023] Examples of the fused aromatic ring contained in the first monomer unit include a naphthalene ring, an anthracene ring, a phenanthrene ring, a tetracene ring, a pyrene ring, a triphenylene ring, a perylene ring, and a fluorene ring. Of these, a naphthalene ring is preferred from the viewpoints of availability and cost.

[0024] Examples of the monomer unit contained in the liquid crystal polyester include a monomer unit represented by the following formula (I) (hereinafter also referred to as monomer unit (I)), a monomer unit represented by the following formula (II) (hereinafter also referred to as monomer unit (II)), and a monomer unit represented by the following formula (III) (hereinafter also referred to as monomer unit (III)). １ -CO- (I) -CO-Ar ２ -CO- (II) -X-Ar ３ -Y- (III) [wherein, Ar １ , Ar ２ and Ar ３ each independently represents a phenylene group, a biphenylene group, a condensed polycyclic aromatic hydrocarbon group, or a group represented by formula (IV). １ , Ar ２ and Ar ３ Some or all of the hydrogen atoms in -Ar may be substituted with halogen atoms, alkyl groups, or aryl groups. X and Y each independently represent an oxygen atom or an imino group (—NH—). ４ -Z-Ar ５ - (IV) [wherein, Ar ４ and Ar ５ each independently represents a phenylene group or a condensed polycyclic aromatic hydrocarbon group; Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkanediyl group.

[0025] The phenylene group may be a 1,4-phenylene group or a 1,3-phenylene group, and is preferably a 1,4-phenylene group.

[0026] The biphenylene group may be a 4,4'-biphenylylene group.

[0027] The condensed polycyclic aromatic hydrocarbon group is a group in which two hydrogen atoms have been removed from a condensed polycyclic aromatic hydrocarbon. Examples of the condensed polycyclic aromatic hydrocarbon include naphthalene, anthracene, phenanthrene, tetracene, pyrene, triphenylene, perylene, and fluorene. Among these, naphthalene is preferred from the viewpoints of availability and cost.

[0028] The condensed polycyclic aromatic hydrocarbon group may be a naphthylene group. The naphthylene group may be a 2,6-naphthylene group or a 2,7-naphthylene group, and is preferably a 2,6-naphthylene group.

[0029] Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0030] The alkyl group as a substituent may be linear, branched, or cyclic. The alkyl group may be, for example, an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, and an n-decyl group.

[0031] The aryl group as a substituent may be a monocyclic ring or a fused ring. The aryl group may be, for example, an aryl group having 6 to 20 carbon atoms. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group. The aryl group may be a group in which a hydrogen atom of an aromatic ring is substituted with an alkyl group, such as a tolyl group.

[0032] Ar １ , Ar ２ and Ar ３ The number of substituents that the has may be, for example, 0 to 2, or may be 0 or 1, or may be 0.

[0033] X and Y are preferably oxygen atoms.

[0034] The alkanediyl group in Z may be linear or branched. The alkanediyl group may be an alkanediyl group having 1 to 10 carbon atoms. Examples of the alkanediyl group include a methylene group, an ethanediyl group, a propanediyl group (e.g., a propane-2,2-diyl group), a butanediyl group, and an octanediyl group (e.g., an octane-3,3-diyl group).

[0035] Z is preferably an oxygen atom, a sulfur atom, a methylene group, an ethanediyl group, or a propanediyl group, and more preferably an oxygen atom.

[0036] The first monomer unit is a monomer unit represented by formula (I) (Ar １ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５ and a monomer unit represented by formula (II) (Ar ２ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５ and a monomer unit represented by formula (III) (Ar ２ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５ and at least one of which is a condensed polycyclic aromatic hydrocarbon group, may be a group represented by formula (IV).

[0037] The first monomer unit may be a monomer unit derived from an aromatic compound (1) having a fused aromatic ring. Examples of the aromatic compound (1) include 2-hydroxy-6-naphthoic acid, 2,6-naphthalenedicarboxylic acid, 2,6-dihydroxynaphthalene, 2-hydroxy-3-naphthoic acid, 1-hydroxy-5-naphthoic acid, and 2,7-naphthalenediol.

[0038] The second monomer unit is a monomer unit represented by formula (I) (Ar １is a phenylene group, a biphenylene group, or Ar ４ and Ar ５ is a phenylene group), and the monomer unit represented by formula (II) (Ar ２ is a phenylene group, a biphenylene group, or Ar ４ and Ar ５ is a phenylene group), and the monomer unit represented by formula (III) (Ar ３ is a phenylene group, a biphenylene group, or Ar ４ and Ar ５ is a phenylene group).

[0039] The second monomer unit may be a monomer unit derived from an aromatic compound (2) that does not have a fused aromatic ring but has a benzene ring. Examples of the aromatic compound (2) include p-hydroxybenzoic acid, terephthalic acid, hydroquinone, isophthalic acid, and 4,4'-biphenol.

[0040] In the liquid crystal polyester, the content of the first monomer unit may be, for example, 20 mol% or more, 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, or 70 mol% or more, based on the total of all monomer units constituting the liquid crystal polyester. A high content of the first monomer unit tends to further improve dielectric properties. Furthermore, the content of the first monomer unit may be, for example, 90 mol% or less, 85 mol% or less, or even 80 mol% or less, based on the total of all monomer units constituting the liquid crystal polyester. This tends to improve moldability and processability at low temperatures. That is, the content of the first monomer unit, relative to the total of all monomer units constituting the liquid crystal polyester, may be, for example, 20 mol% to 90 mol%, 20 mol% to 85 mol%, 20 mol% to 80 mol%, 30 mol% to 90 mol%, 30 mol% to 85 mol%, 30 mol% to 80 mol%, 40 mol% to 40 mol%, 40 mol% to 85 mol%, 40 mol% to 80 mol%, 50 mol% to 90 mol%, 50 mol% to 85 mol%, 50 mol% to 80 mol%, 60 mol% to 90 mol%, 60 mol% to 85 mol%, 60 mol% to 80 mol%, 70 mol% to 90 mol%, 70 mol% to 85 mol%, or 70 mol% to 80 mol%.

[0041] In the liquid crystal polyester, the content of the second monomer unit may be, for example, 10 mol% or more, 15 mol% or more, or 20 mol% or more, relative to the total of all monomer units constituting the liquid crystal polyester. This tends to be advantageous in terms of cost. Furthermore, the content of the second monomer unit may be, for example, 80 mol% or less, 70 mol% or less, 60 mol% or less, 50 mol% or less, 40 mol% or less, or 30 mol% or less, relative to the total of all monomer units constituting the liquid crystal polyester. That is, the content of the second monomer unit may be, for example, 10 mol% or more and 80 mol% or less, 10 mol% or more and 70 mol% or less, 10 mol% or more and 60 mol% or less, 10 mol% or more and 50 mol% or less, 10 mol% or more and 40 mol% or less, 10 mol% or more and 30 mol% or less, 15 mol% or more and 80 mol% or less, 15 mol% or more and 70 mol% or less, 15 mol% or more and 60 mol% or less, 15 mol% or more and 50 mol% or less, 15 mol% or more and 40 mol% or less, 15 mol% or more and 30 mol% or less, 20 mol% or more and 80 mol% or less, 20 mol% or more and 70 mol% or less, 20 mol% or more and 60 mol% or less, 20 mol% or more and 50 mol% or less, 20 mol% or more and 40 mol% or less, or 20 mol% or more and 30 mol% or less.

[0042] In the liquid crystal polyester, the total amount of the first monomer unit and the second monomer unit may be, for example, 90 mol% or more, 95 mol% or more, 99 mol% or more, or 100 mol% relative to the total of all monomer units constituting the liquid crystal polyester.

[0043] The liquid crystal polyester may be a polymer having two or more types of monomer unit (I), or may be a polymer having monomer unit (I), monomer unit (II) and monomer unit (III).

[0044] When the liquid crystal polyester has the monomer unit (I), the monomer unit (II) and the monomer unit (III), the content of the monomer unit (I) may be, for example, 30 mol% or more, 40 mol% or more, 45 mol% or more, 50 mol% or more, or 55 mol% or more, based on the total of all the monomer units of the liquid crystal polyester. Also, when the liquid crystal polyester has the monomer unit (I), the monomer unit (II) and the monomer unit (III), the content of the monomer unit (I) may be, for example, 80% or less, or 70% or less, based on the total of all the monomer units of the liquid crystal polyester. That is, when the liquid crystal polyester has the monomer unit (I), the monomer unit (II), and the monomer unit (III), the content of the monomer unit (I) may be, for example, 30 mol% or more and 80 mol% or less, 30 mol% or more and 70 mol% or less, 40 mol% or more and 80 mol% or less, 40 mol% or more and 70 mol% or less, 45 mol% or more and 80 mol% or less, 45 mol% or more and 70 mol% or less, 50 mol% or more and 80 mol% or less, 50 mol% or more and 70 mol% or less, 55 mol% or more and 80 mol% or less, or 55 mol% or more and 70 mol% or less, based on the total of all the monomer units of the liquid crystal polyester.

[0045] When the liquid crystal polyester has the monomer unit (I), the monomer unit (II), and the monomer unit (III), the content of the monomer unit (II) and the content of the monomer unit (III) may be, for example, 35 mol% or less, or 30 mol% or less, based on the total of all the monomer units of the liquid crystal polyester. When the liquid crystal polyester has the monomer unit (I), the monomer unit (II), and the monomer unit (III), the content of the monomer unit (II) and the content of the monomer unit (III) may be, for example, 5 mol% or more, 10 mol% or more, or 15 mol% or more, based on the total of all the monomer units of the liquid crystal polyester. That is, when the liquid crystal polyester has the monomer unit (I), the monomer unit (II), and the monomer unit (III), the content of the monomer unit (II) and the content of the monomer unit (III) may be, for example, 5 mol% or more and 35 mol% or less, 5 mol% or more and 30 mol% or less, 10 mol% or more and 35 mol% or less, 10 mol% or more and 30 mol% or less, 15 mol% or more and 35 mol% or less, or 15 mol% or more and 30 mol% or less, relative to the total of all the monomer units of the liquid crystal polyester.

[0046] The liquid crystal polyester may have monomer units other than the monomer unit (I), the monomer unit (II) and the monomer unit (III), and the number of such monomer units may be 10 mol % or less, 5 mol % or less, 2 mol % or less, 1 mol % or less, or even 0 mol %, based on the total of all the monomer units of the liquid crystal polyester.

[0047] In this specification, the number of each monomer unit contained in the liquid crystal polyester is determined by the analytical method described in JP 2000-19168 A. Specifically, the liquid crystal polyester is depolymerized by reacting it with a lower alcohol in a supercritical state, and the depolymerization product (monomers that derive each monomer unit) is quantified by liquid chromatography, whereby the number of each monomer unit relative to the total monomer units can be calculated.

[0048] The liquid crystal polyester can be produced by polymerizing raw material monomers corresponding to the monomer units that constitute the polyester, for example, according to the method described in Japanese Patent No. 6439027.

[0049] The dielectric loss tangent of the liquid crystal polyester at 10 GHz may be, for example, 0.002 or less, preferably 0.0015 or less, more preferably 0.0012 or less. This makes it easier to obtain a liquid crystal polyester composition having a suitable dielectric loss tangent, as described below. The dielectric loss tangent of the liquid crystal polyester at 10 GHz may be, for example, 0.0001 or more and 0.002 or less, 0.0001 or more and 0.0015 or less, or 0.0001 or more and 0.0012 or less.

[0050] The dielectric constant of the liquid crystal polyester at 10 GHz may be, for example, 4.0 or less, or may be 3.8 or less. The dielectric constant of the liquid crystal polyester at 10 GHz may be, for example, 2.8 or more, or may be 3.0 or more. The dielectric constant of the liquid crystal polyester at 10 GHz may be, for example, 2.8 or more and 4.0 or less, or may be 3.0 or more and 3.8 or less.

[0051] In this specification, the dielectric loss tangent and relative permittivity of the liquid crystal polyester at 10 GHz are measured by the following method. Using an injection molding machine (ROBOSHOT S-2000i 30B, manufactured by FANUC Corporation), a cylinder temperature of 335°C, a mold temperature of 130°C, and an injection speed of 50 mm / s, a test piece having a width of 50 mm, a length of 50 mm, and a thickness of 0.5 mm is obtained using a liquid crystal polyester pellet as the molding material. The relative permittivity and dielectric loss tangent of the obtained test piece at 10 GHz are measured using a vector network analyzer (N5290A, manufactured by Keysight Technologies Inc.) and a split cylinder resonator (CR710, manufactured by EM Lab Co., Ltd.). The measurement environment is 23°C and 50% RH.

[0052] Glass flakes are scaly glass fillers.

[0053] The thickness of the glass flakes may be, for example, 0.1 μm or more. From the viewpoint of increasing the strength of the glass flakes and preventing breakage of the glass flakes, thereby making it easier to maintain the viscosity-reducing effect, the thickness may be 0.2 μm or more, 0.3 μm or more, or 0.4 μm or more. Furthermore, the thickness of the glass flakes may be, for example, 2 μm or less. From the viewpoint of easily aligning the glass flakes in the flow direction and more significantly obtaining the above-mentioned effect, the thickness may be 1.8 μm or less, 1.6 μm or less, or 1.3 μm or less. The thickness of the glass flakes may be, for example, 0.1 μm or more and 1.8 μm or less, 0.2 μm or more and 1.6 μm or less, or 0.3 μm or more and 1.3 μm or less.

[0054] In this specification, the thickness of the glass flakes is measured by the following method. The glass flakes are observed with a scanning electron microscope (SEM), and the thickness of 10 glass flakes randomly selected from the obtained image is measured and the average value is calculated. Since the thickness of the glass flakes usually does not change during a granulation process, the measurement may be performed on the glass flakes before granulation, or the ash remaining after thermal decomposition of the organic components of pellets or molded products may be measured.

[0055] The average particle size (D50) of the glass flakes may be, for example, 2 μm or more. From the viewpoint of easily aligning in the flow direction and more significantly obtaining the above-mentioned effects, it may be 2.4 μm or more, 2.7 μm or more, or 3 μm or more. Furthermore, the average particle size (D50) of the glass flakes may be, for example, 50 μm or less. From the viewpoint of easily producing small or thin-walled molded products, it may be 40 μm or less, 35 μm or less, or 30 μm or less. The average particle size (D50) of the glass flakes may be, for example, 2 μm or more and 50 μm or less, 2.4 μm or more and 40 μm or less, 2.7 μm or more and 35 μm or less, or 3 μm or more and 30 μm or less. Generally, the D50 of the glass flakes changes during the granulation and molding processes, so the organic components of the pellets or molded products are thermally decomposed and the remaining ash is measured.

[0056] The ratio A of the thickness to the average particle size (D50) of the glass flakes (thickness / average particle size (D50)) may be, for example, 3 or more, and from the viewpoint of having a good flake shape and more significantly obtaining the above-mentioned effects, may be 3.5 or more, 4 or more, or 4.5 or more. Furthermore, the ratio A may be, for example, 500 or less, and from the viewpoint of facilitating the production of small or thin-walled molded products, may be 200 or less, 100 or less, or 50 or less. The ratio A may be, for example, 3.5 or more and 500 or less, 4 or more and 200 or less, 4.5 or more and 100 or less, or 4.5 or more and 50 or less.

[0057] In this specification, the average particle size (D50) of glass flakes refers to a value measured by the following method. The glass flakes are measured by a laser diffraction method to determine the average particle size (D50). Specifically, the glass flakes are dispersed in water, and the particle size is measured under the following measurement conditions using a laser diffraction / scattering particle size distribution measuring device (manufactured by Horiba Co., Ltd., "LA-950V2"). [Measurement conditions] Particle refractive index: 1.56 Dispersion medium: water Dispersion medium refractive index: 1.33

[0058] The density of the glass flakes is 1.8 g / cm ３ or more, and 1.85 g / cm ３ Above, 1.9g / cm ３ or more or 1.95 g / cm ３ The density of the glass flakes may be 2.5 g / cm or more. ３ From the viewpoint that the density is closer to that of the liquid crystal polyester, the orientation in the composition is easier, and the above-mentioned effect is more significantly obtained, it is 2.45 g / cm or less. ３ Below, 2.4g / cm ３ or less than 2.35 g / cm ３ The density of the glass flakes may be 1.8 g / cm or less. ３ 2.5g / cm or more ３ or less, for example, 1.85 g / cm ３ 2.45g / cm or more ３ or less, and ３ 2.4g / cm or more ３ or less, 1.95 g / cm ３ 2.35g / cm or more３ It may be the following:

[0059] In this specification, the density of glass flakes refers to a value calculated from the following formula based on the measurement results obtained by the pycnometer method according to JIS K0061. If the glass flakes contain air bubbles, the measurement may be performed after crushing the glass flakes. Water is used as the solution. If air bubbles are present at the interface between the glass flakes and the water, a small amount of surfactant may be added to the water to remove the bubbles. Density = {(Wb - Wa) / (Wb - Wa - Wc + Wd)} × Density of Solution [where Wa is the weight of the pycnometer, Wb is the weight of (pycnometer + sample), Wc is the weight of (pycnometer + sample + weight of solution up to the pycnometer mark), and Wc is the weight of (pycnometer + weight of solution up to the pycnometer mark)].

[0060] The glass constituting the glass flakes may be, for example, SL glass (manufactured by Nippon Sheet Glass Co., Ltd.), LLD glass (manufactured by Nippon Sheet Glass Co., Ltd.), D glass, etc., and from the viewpoint of easily satisfying the above-mentioned suitable density and from the viewpoint of good dielectric properties, SL glass (manufactured by Nippon Sheet Glass Co., Ltd.) and LLD glass (manufactured by Nippon Sheet Glass Co., Ltd.) are preferred, and SL glass (manufactured by Nippon Sheet Glass Co., Ltd.) is more preferred.

[0061] The content of glass flakes in the liquid crystal polyester composition is 1 part by mass or more, 2 parts by mass or more, or 5 parts by mass or more, relative to 100 parts by mass of the total of the liquid crystal polyester and the glass flakes. Increasing the content of glass flakes tends to further improve the flexibility of molded articles of the liquid crystal polyester composition. Furthermore, the content of glass flakes in the liquid crystal polyester composition may be 30 parts by mass or less, 25 parts by mass or less, 20 parts by mass or less, or 15 parts by mass or less, relative to 100 parts by mass of the total of the liquid crystal polyester and the glass flakes. Reducing the content of glass flakes tends to further improve good fluidity during melting. The content of glass flakes in the liquid crystal polyester composition is 1 part by mass or more and 30 parts by mass or less, for example, 2 parts by mass or more and 25 parts by mass or less, 5 parts by mass or more and 20 parts by mass or less, or 5 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the total of the liquid crystal polyester and the glass flakes.

[0062] The liquid crystal polyester composition may further contain other components in addition to the liquid crystal polyester and the glass flakes.

[0063] For example, the liquid crystal polyester composition may contain one or more resins other than the liquid crystal polyester, such as polyolefins, cyclic polyolefins, polyvinyl chloride, polysulfones, (meth)acrylic resins, polyphenylene ether resins, polyacetal resins, polyamide resins, imide resins, cellulose resins, polyether ether ketone resins, fluororesins, polycarbonate resins, styrene-based resins, and thermosetting resins.

[0064] The liquid crystal polyester composition may further contain an inorganic filler, a colorant, a dispersant, a plasticizer, an antioxidant, a curing agent, a flame retardant, a heat stabilizer, an ultraviolet absorber, an antistatic agent, a surfactant, a lubricant, a release agent, or the like.

[0065] However, the content of inorganic fillers other than glass flakes in the liquid crystal polyester composition may be, for example, 25% by mass or less, preferably 20% by mass or less, based on the total amount of the liquid crystal polyester composition. By reducing the content of inorganic fillers other than glass flakes, it is possible to avoid the inorganic fillers from interfering with the relationship between the glass flakes and the polymer chains of the liquid crystal polyester, and the above-mentioned effects can be more significantly obtained. From the viewpoint of obtaining the above-mentioned effects more significantly, the content of inorganic fillers other than glass flakes may be 15% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total amount of the liquid crystal polyester composition, or may be 0% by mass.

[0066] The liquid crystal polyester composition has excellent fluidity when melted, and therefore can be suitably used as a molding material. The liquid crystal polyester composition may be used, for example, in the form of pellets.

[0067] The molded article of the present embodiment comprises the above-mentioned liquid crystal polyester composition.The molded article of the present embodiment can be connector, socket, relay parts, coil bobbin, optical pickup, oscillator, semiconductor package, IC tray, wafer carrier, household electrical appliance parts, lighting fixture parts, audio product parts, ferrule for optical cable, telephone parts, facsimile parts, modem parts, separation claw, heater holder, impeller, fan gear, gear, bearing, motor parts, motor case, engine parts, engine room parts, electrical equipment parts, automobile interior parts, microwave cooking pot, heat-resistant tableware, flooring, wall material, beam, pillar, roofing material, aircraft parts, spacecraft parts, space equipment parts, nuclear reactor, marine facility parts, cleaning tool, optical equipment parts, valves, pipes, nozzles, filters, membranes, medical equipment parts, medical materials, sensor parts, sanitary equipment, sporting goods or leisure goods.

[0068] The molded article of the present embodiment can be obtained, for example, by molding the liquid crystal polyester composition described above into a desired shape and subjecting it to processing treatment as necessary.

[0069] The molding method for the molded article is preferably melt molding, and examples of the melt molding method include injection molding, extrusion molding, compression molding, blow molding, vacuum molding, foam molding, and press molding.

[0070] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments.

[0071] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Hereinafter, percentages and parts representing the content or amount used are based on mass unless otherwise specified.

[0072] (Example 1-1) (1) Production of Liquid Crystal Polyester (LCP1) A reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser was charged with 1035.0 g (5.5 mol) of 2-hydroxy-6-naphthoic acid, 378.3 g (1.75 mol) of 2,6-naphthalenedicarboxylic acid (Ueno Pharmaceutical Co., Ltd.), 83.1 g (0.5 mol) of terephthalic acid, 255.2 g of hydroquinone, 1226.87 g (12 mol) of acetic anhydride, and 0.17 g of 1-methylimidazole as a catalyst. After thoroughly purging the reactor with nitrogen gas, the temperature was raised to 140°C over 1 hour under a nitrogen gas stream, and the temperature was maintained while refluxing for 1 hour. Thereafter, the temperature was raised to 310°C over 4 hours and 35 minutes while distilling off the by-product acetic acid. The reaction was considered to be complete when an increase in torque was observed, and the contents were removed. The flow initiation temperature of the obtained solid content was 270° C. The obtained solid content was cooled to room temperature and pulverized in a coarse pulverizer, and then heated in a nitrogen atmosphere from room temperature to 250° C. over 1 hour, then from 250° C. to 286° C. over 7 hours and 40 minutes, and maintained at 286° C. for 6 hours, thereby performing solid-phase polymerization to obtain a powdered liquid crystal polyester (LCP1).

[0073] The flow initiation temperature of the liquid crystal polyester (LCP1) was measured by the following method and found to be 311° C. <Measurement of Flow Initiation Temperature> Using a flow tester (Shimadzu Corporation, CFT-500 model), about 2 g of liquid crystal polyester pellets were filled into a cylinder equipped with a die having a nozzle with an inner diameter of 1 mm and a length of 10 mm, and the temperature was raised to 9.8 MPa (100 kg / cm ２ The liquid crystalline polyester was melted and extruded from a nozzle while increasing the temperature at a rate of 4°C / min under a load of 1000 kJ / min, and the temperature (FT) at which the viscosity reached 4800 Pa s (48000 P) was measured, and this temperature was defined as the flow initiation temperature. "About 2 g" can be estimated as 2 g ± 0.1 g.

[0074] The liquid crystal polyester (LCP1) had a relative dielectric constant of 3.5 and a dielectric loss tangent of 0.00081 at 10 GHz.

[0075] (2) Preparation of glass flakes (G1) The glass flakes had an average particle size (D50) of 7.2 μm, a thickness of 0.89 μm, and a density of 2.03 g / cm３ Glass flakes (G1) (manufactured by Nippon Sheet Glass Co., Ltd.) composed of SL glass (silica content: 97% by mass or more) were prepared.

[0076] (3) Preparation of Liquid Crystal Polyester Composition and Pellets A liquid crystal polyester composition was obtained by mixing the liquid crystal polyester (LCP1) and the glass flakes (G1) in a mass ratio of 97: 3. The liquid crystal polyester composition was then granulated at a cylinder temperature of 320°C using a twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd., PCM-30) to obtain pellets of the liquid crystal polyester composition.

[0077] (4) Evaluation of Liquid Crystal Polyester Composition and Molded Article The melt viscosity, tensile strength, nominal tensile strain at break, relative dielectric constant, and dielectric loss tangent were determined by the following methods. The average particle size (D50) of the glass flakes in the pellets was also determined by the following method. The results are shown in Table 1. <Evaluation of Fluidity During Melt> Using a capillary rheometer (Capillograph 1D, manufactured by Toyo Seiki Seisaku-sho, Ltd.), a capillary with an inner diameter of 0.5 mm and a length of 10 mm was attached to the tip of the cylinder. Pellets of the liquid crystal polyester composition were melted in the cylinder heated to 340°C and extruded through a nozzle. The viscosity of the extruded liquid crystal polyester composition was measured at a shear rate of 1000 / s, and this viscosity was evaluated as the melt viscosity of the liquid crystal polyester composition.

[0078] <Measurement of Tensile Strength and Nominal Tensile Strain at Break> Using an injection molding machine (Nissei Plastic Industrial Co., Ltd., PNX-40-5A), ASTM D638 dumbbell-shaped test pieces Type IV (thickness 2.5 mm) were injection molded using pellets of the liquid crystal polyester composition as the molding material under conditions of a cylinder temperature of 340°C, a mold temperature of 130°C, and an injection speed of 75 mm / s. Five samples of the resulting dumbbell test pieces were subjected to a tensile test using a tensile tester (A&D Co., Ltd., Tensilon RTG-1310) at a chuck distance of 50 mm, a crosshead speed of 10 mm / min, and a test temperature of 23°C. The elongation at break was measured, and the average values ​​of the tensile strength at break (MPa) and nominal tensile strain at break (%) for the five samples were calculated. The nominal tensile strain at break was calculated using the following formula: Nominal tensile fracture strain (%) = (L - Lo) / Lo x 100, where Lo is the distance between the chucks before the test (mm), and L is the distance between the chucks at fracture (mm).

[0079] <Evaluation of Dielectric Properties> Using an injection molding machine (ROBOSHOT S-2000i 30B, manufactured by FANUC Corporation), test pieces having a width of 50 mm, a length of 50 mm, and a thickness of 0.5 mm were obtained using pellets of the liquid crystal polyester composition as the molding material under conditions of a cylinder temperature of 335°C, a mold temperature of 130°C, and an injection speed of 50 mm / s. The relative permittivity and dielectric loss tangent at 10 GHz of the obtained test pieces were measured using a vector network analyzer (N5290A, manufactured by Keysight Technologies Inc.) and a split cylinder resonator (CR710, manufactured by EM Lab Co., Ltd.). Measurement environment: 23°C, 50% RH

[0080] <Measurement of average particle size (D50) of glass flakes> The pellets were heated at 600°C for 3 hours to remove organic components, and the glass flakes were recovered. The average particle size (D50) of the recovered glass flakes was determined by the method described above.

[0081] Example 1-2 A liquid crystal polyester composition and pellets were produced in the same manner as in Example 1-1, except that the ratio of the liquid crystal polyester (LCP1) to the glass flakes (G1) was changed from 97: 3 to 92: 8. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 1.

[0082] Example 1-3 A liquid crystal polyester composition and pellets were produced in the same manner as in Example 1-1, except that the ratio of the liquid crystal polyester (LCP1) to the glass flakes (G1) was changed from 97: 3 to 80: 20. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 1.

[0083] A liquid crystal polyester composition and pellets were produced in the same manner as in Example 1-1, except that glass flakes (G1) were not added and only liquid crystal polyester (LCP1) was used. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 1.

[0084]

[0085] (Example 2-1) (1) Preparation of glass flakes (G2) Glass flakes having an average particle size (D50) of 27 μm, a thickness of 0.77 μm, and a density of 2.00 g / cm ３ Glass flakes (G2) (manufactured by Nippon Sheet Glass Co., Ltd.) made of SL glass were prepared.

[0086] (2) Preparation and Evaluation of Liquid Crystal Polyester Composition and Pellets A liquid crystal polyester (LCP1) and glass flakes (G2) were mixed in a mass ratio of 92:8 to obtain a liquid crystal polyester composition. The liquid crystal polyester composition was then granulated at a cylinder temperature of 320°C using a twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd., PCM-30) to obtain pellets of the liquid crystal polyester composition. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 2.

[0087] (Example 2-2) (1) Preparation of glass flakes (G3) The glass flakes had an average particle size (D50) of 11 μm, a thickness of 0.44 μm, and a density of 2.13 g / cm ３Glass flakes (G3) (manufactured by Nippon Sheet Glass Co., Ltd.) composed of LLD glass (silica content: 45 to 60 mass %) were prepared.

[0088] (2) Preparation and Evaluation of Liquid Crystal Polyester Composition and Pellets A liquid crystal polyester (LCP1) and glass flakes (G3) were mixed in a mass ratio of 92:8 to obtain a liquid crystal polyester composition. The liquid crystal polyester composition was then granulated at a cylinder temperature of 320°C using a twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd., PCM-30) to obtain pellets of the liquid crystal polyester composition. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 2.

[0089] (Example 2-3) (1) Preparation of glass flakes (G4) Glass flakes having an average particle size (D50) of 22 μm, a thickness of 0.71 μm, and a density of 2.33 g / cm ３ Glass flakes (G4) (manufactured by Nippon Sheet Glass Co., Ltd.) made of LLD glass were prepared.

[0090] (2) Preparation and Evaluation of Liquid Crystal Polyester Composition and Pellets A liquid crystal polyester (LCP1) and glass flakes (G4) were mixed in a mass ratio of 92:8 to obtain a liquid crystal polyester composition. The liquid crystal polyester composition was then granulated at a cylinder temperature of 320°C using a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) to obtain pellets of the liquid crystal polyester composition. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 2.

[0091] (Comparative Example 2-1) (1) Preparation of glass flakes (g1) Glass flakes having an average particle size (D50) of 57 μm, a thickness of 0.56 μm, and a density of 2.71 g / cm ３ Glass flakes (g1) (manufactured by Nippon Sheet Glass Co., Ltd.) made of E-glass were prepared.

[0092] (2) Preparation and Evaluation of Liquid Crystal Polyester Composition and Pellets A liquid crystal polyester (LCP1) and glass flakes (g1) were mixed in a mass ratio of 92:8 to obtain a liquid crystal polyester composition. The liquid crystal polyester composition was then granulated at a cylinder temperature of 320°C using a twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd., PCM-30) to obtain pellets of the liquid crystal polyester composition. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 2.

[0093]

[0094] (Example 3-1) (1) Production of Liquid Crystal Polyester (LCP2) 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 0.058 g of 1-methylimidazole as a catalyst were placed in a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser. After thoroughly purging the reactor with nitrogen gas, the temperature was raised to 140°C over 30 minutes under a nitrogen gas stream, and the temperature was maintained while refluxing for 1 hour. The temperature was then raised to 275°C over 4 hours while distilling off the by-product acetic acid. The reaction was considered complete when an increase in torque was observed, and the contents were removed. The flow initiation temperature of the resulting solid content was 217°C. The obtained solid content was cooled to room temperature and crushed in a coarse crusher. The temperature was then raised from room temperature to 200°C over 1 hour under a nitrogen atmosphere, then raised from 200°C to 242°C over 7 hours, and maintained at 242°C for 10 hours, thereby carrying out solid-phase polymerization to obtain a powdered liquid crystal polyester (LCP2).

[0095] The flow initiation temperature of the liquid crystal polyester (LCP2) was measured in the same manner as in Example 1-1 and was found to be 292° C. The liquid crystal polyester (LCP2) also had a relative dielectric constant of 3.5 and a dielectric dissipation factor of 0.0011 at 10 GHz.

[0096] (2) Preparation and Evaluation of Liquid Crystal Polyester Composition and Pellets Liquid crystal polyester (LCP1), liquid crystal polyester (LCP2), and glass flakes (G1) were mixed in a mass ratio of 55.2:36.8:8 to obtain a liquid crystal polyester composition. Next, using a twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd., PCM-30), the liquid crystal polyester composition was granulated at a cylinder temperature of 320°C to obtain pellets of the liquid crystal polyester composition. Using the obtained pellets, evaluations similar to those in Example 1-1 were carried out, and the results are shown in Table 3.

[0097] (Comparative Example 3-1) (1) Production and Evaluation of Liquid Crystal Polyester Composition and Pellets A liquid crystal polyester (LCP1) and a liquid crystal polyester (LCP2) were mixed in a mass ratio of 60:40 to obtain a liquid crystal polyester composition. Next, using a twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd., PCM-30), the liquid crystal polyester composition was granulated at a cylinder temperature of 320°C to obtain pellets of the liquid crystal polyester composition. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 3.

[0098]

[0099] Example 4-1 A liquid crystal polyester (LCP1), glass flakes (G1), and glass fiber (SC3J260S, manufactured by Nitto Boseki Co., Ltd.) were mixed in a mass ratio of 87.6:7.6:4.8 to obtain a resin composition. Next, using a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.), the liquid crystal polyester composition was granulated at a cylinder temperature of 330°C to obtain pellets of the liquid crystal polyester composition. Using the obtained pellets, evaluations similar to those in Example 1-1 were performed, and the results are shown in Table 4.

[0100] Example 4-2 A liquid crystal polyester (LCP1), glass flakes (G1), and glass fiber (SC3J260S, manufactured by Nitto Boseki Co., Ltd.) were mixed in a mass ratio of 83.6:7.3:9.1 to obtain a resin composition. Next, using a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.), the liquid crystal polyester composition was granulated at a cylinder temperature of 330°C to obtain pellets of the liquid crystal polyester composition. Using the obtained pellets, evaluations similar to those in Example 1-1 were performed, and the results are shown in Table 4.

[0101] Example 4-3 A liquid crystal polyester (LCP1), glass flakes (G1), and glass fiber (SC3J260S, manufactured by Nitto Boseki Co., Ltd.) were mixed in a mass ratio of 70.8:6.2:23 to obtain a resin composition. Next, using a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.), the liquid crystal polyester composition was granulated at a cylinder temperature of 330°C to obtain pellets of the liquid crystal polyester composition. Using the obtained pellets, evaluations similar to those in Example 1-1 were performed, and the results are shown in Table 4.

[0102]

[0103] (Comparative Example 5-1) (1) Production of Liquid Crystal Polyester (LCP3) A reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser was charged with 994.5 g (7.2 mol) of 4-hydroxybenzoic acid, 446.9 g (2.4 mol) of 4,4'-dihydroxybiphenyl, 299.0 g (1.8 mol) of terephthalic acid, 99.7 g (0.6 mol) of isophthalic acid, and 1347.6 g (13.2 mol) of acetic anhydride, and 0.19 g of 1-methylimidazole was added as a catalyst. After thoroughly replacing the atmosphere in the reactor with nitrogen gas, the temperature was raised to 140°C over 30 minutes under a nitrogen gas stream, and the temperature was maintained and refluxed for 1 hour. Next, 0.92 g of 1-methylimidazole was added. The temperature was then raised to 300°C over 4 hours and 20 minutes while distilling off the by-product acetic acid. The reaction was considered complete when an increase in torque was observed, and the contents were removed. The flow initiation temperature of the resulting solid was 245°C. The resulting solid was cooled to room temperature and pulverized using a coarse pulverizer. Under a nitrogen atmosphere, the temperature was raised from room temperature to 240°C over 1 hour, then from 240°C to 284°C over 5 hours and 40 minutes, and maintained at 284°C for 5 hours. Polymerization proceeded in the solid phase, yielding a liquid crystal polyester (LCP3). The flow initiation temperature of the resulting liquid crystal polyester (LCP3) was 330°C.

[0104] (2) Preparation and Evaluation of Liquid Crystal Polyester Composition and Pellets Liquid crystal polyester (LCP3) and glass flakes (G1) were mixed in a mass ratio of 92:8 to obtain a liquid crystal polyester composition. Next, using a twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd., PCM-30), the liquid crystal polyester composition was granulated at a cylinder temperature of 330°C to obtain pellets of the liquid crystal polyester composition. Using the obtained pellets, evaluations similar to those in Example 1-1 were carried out, and the results are shown in Table 5.

[0105] Comparative Example 5-2 A liquid crystal polyester composition and pellets were produced in the same manner as in Example 5-1, except that glass flakes (G1) were not added and only liquid crystal polyester (LCP3) was used. The obtained pellets were evaluated in the same manner as in Example 1-1, and the results are shown in Table 5.

[0106]

Claims

1. A liquid crystal polyester and glass flakes, the liquid crystal polyester contains a first monomer unit having a condensed aromatic ring and a second monomer unit having a benzene ring, the content of the glass flakes is 1 to 30 parts by mass per 100 parts by mass of the liquid crystal polyester and the glass flakes in total, and the density of the glass flakes is 1.8 g / cm ３ 2.5g / cm or more ３ A liquid crystal polyester composition, which is:

2. The liquid crystal polyester composition according to claim 1, wherein the condensed aromatic ring is a naphthalene ring.

3. The liquid crystal polyester composition according to claim 1, wherein the content of the first monomer unit is 50 mol % or more based on the total of all monomer units constituting the liquid crystal polyester.

4. The liquid crystal polyester composition according to claim 1, wherein the glass flakes have a thickness of 0.1 μm or more and 2 μm or less.

5. The liquid crystal polyester composition according to claim 1, wherein the glass flakes have an average particle size (D50) of 1 μm or more and 50 μm or less.

6. The liquid crystal polyester composition according to claim 1, wherein the content of the inorganic filler other than the glass flakes is 25 mass % or less.

7. A pellet comprising the liquid crystal polyester composition according to any one of claims 1 to 6.

8. A molded article comprising the liquid crystal polyester composition according to any one of claims 1 to 6, which is a connector, a socket, a relay part, a coil bobbin, an optical pickup, an oscillator, a semiconductor package, an IC tray, a wafer carrier, a home electric appliance part, a lighting fixture part, an audio product part, a ferrule for an optical cable, a telephone part, a facsimile part, a modem part, a separation claw, a heater holder, an impeller, a fan gear, a gear, a bearing, a motor part, a motor case, an engine part, an engine room part, an electrical component part, an automobile interior part, a microwave cooking pot, a heat-resistant tableware, a floor material, a wall material, a beam, a pillar, a roof material, an aircraft part, a spacecraft part, a space equipment part, a nuclear reactor, a marine facility member, a cleaning tool, an optical equipment part, a valve, a pipe, a nozzle, a filter, a membrane, a medical equipment part, a medical material, a sensor part, a sanitary equipment, a sporting goods, or a leisure goods.

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