Liquid crystal polymer composition

Abstract

An object of the present invention is to provide a liquid crystal polymer composition that has excellent thin-wall flowability and blister resistance while maintaining the mechanical strength and heat resistance inherent to liquid crystal polymers. The present invention relates to a liquid crystal polymer composition containing 0.1 to 150 parts by mass of talc having a tridymite content of 0.03 to 0.60% by mass relative to 100 parts by mass of a liquid crystal polymer.

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal polymer composition that has excellent thin-wall flowability and blister resistance while maintaining the mechanical strength and heat resistance inherent to liquid crystal polymers. [Background technology]

[0002] Liquid crystal polymers have excellent moldability and high heat resistance, and these properties are utilized to their advantage in applications such as electronic components such as connectors, relays, bobbins, etc. In recent years, electronic components have become more highly integrated, smaller, thinner, and thinner, with connector components in particular showing a notable trend toward smaller size and thinner wall thickness.

[0003] Typical examples of such thin-walled connectors include board-to-board connectors used to join printed wiring boards together, and FPC connectors used to connect flexible printed circuit boards (FPCs) to printed wiring boards.

[0004] Board-to-board connectors and FPC connectors require heat resistance to withstand reflow soldering, and as electronic devices that use printed wiring boards become smaller, the components themselves must also be made smaller. For example, narrow-pitch connectors with a pitch of 0.3 to 0.4 mm between the metal terminals of the connector are now available. Thin connectors with a stacking height of 0.6 mm when mated are also available.

[0005] However, in order to meet the demand for smaller size and thinner walls, there is a risk of short shots occurring due to insufficient fluidity of the resin during molding of the connector. Therefore, there is a need to further improve the fluidity of the resin in the thin-walled parts of molded products (thin-wall fluidity).

[0006] Furthermore, when molded products are left in a high-temperature atmosphere for a long period of time or when soldering is performed, swellings called blisters may occur on the surface. The cause of this phenomenon is not clear, but it is thought that air entrapped during the molding of the liquid crystal polymer and oligomer components contained in the resin are brought into the molded product, and then during high-temperature heat treatment, the air expands and the oligomer components gasify, pushing up against the surface of the molded product that has softened due to the heat, resulting in the appearance of blisters.

[0007] Liquid crystal polymers, which are used to form thin-walled connectors such as board-to-board connectors and FPC connectors, are required to have excellent thin-wall flowability and blister resistance while maintaining the properties of liquid crystal polymers, such as mechanical strength and heat resistance.

[0008] Patent Document 1 proposes a liquid crystalline polyester composition that contains a specific terphenyl and a liquid crystalline polyester, and thereby can obtain a molded article that has high fluidity and anisotropy relaxation of the liquid crystalline polyester, while sufficiently reducing gas generation to an extent that blister abnormalities, etc. However, the resin composition does not have sufficient fluidity, and there is room for improvement.

[0009] Patent Document 2 proposes a liquid crystalline polyester resin composition that contains a specific liquid crystalline polyester and a plate-like filler in a predetermined ratio, thereby maintaining high fluidity while exhibiting excellent rigidity at high temperatures and reducing the occurrence of blisters. However, the resin composition has insufficient blister resistance and there is room for improvement.

[0010] One way to improve thin-wall flow is to lower the viscosity of the resin, but this makes it easier for air to be trapped inside the molded product during molding, which results in blisters. As such, various studies have been conducted on liquid crystal polymer compositions, but it was thought to be difficult to achieve both thin-wall flow and blister resistance at high levels. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-30015 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-89154 Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a liquid crystal polymer composition that has excellent thin-wall flowability and blister resistance while maintaining the mechanical strength and heat resistance of liquid crystal polymers. [Means for solving the problem]

[0013] As a result of intensive research in view of the above problems, the inventors have discovered that by blending a specific amount of a specific talc with a liquid crystal polymer, a liquid crystal polymer composition can be obtained that has excellent thin-wall flowability and blister resistance while maintaining the mechanical strength and heat resistance of the liquid crystal polymer, and have thus completed the present invention.

[0014] That is, the present invention includes the following preferred embodiments. [1] A liquid crystal polymer composition containing 0.1 to 150 parts by mass of talc having a tridymite content of 0.03 to 0.60% by mass per 100 parts by mass of a liquid crystal polymer. [2] The liquid crystal polymer is represented by formula (I) and / or formula (II) [ka] The liquid crystal polymer composition according to [1], comprising a repeating unit represented by the following formula: [3] The liquid crystal polymer further comprises a compound represented by formula (III) and formula (IV): [ka] [In the formula, Ar1 and Ar2 each independently represent a divalent aromatic group] The liquid crystal polymer composition according to [2], comprising a repeating unit represented by the following formula: [4] In the repeating units represented by formulae (III) to (IV), Ar1 and Ar2 are each independently represented by formulae (1) to (4): [ka] The liquid crystal polymer composition according to [3], wherein each of the repeating units is one or more types selected from aromatic groups represented by the following formula: [5] The liquid crystal polymer is represented by the formula (I) and the formula (II) [ka] The liquid crystal polymer composition according to any one of [1] to [4], which contains a repeating unit represented by the following formula: [6] In the repeating units represented by formulae (III) to (IV), Ar1 and Ar2 are each independently represented by formulae (1) to (4): [ka] The liquid crystal polymer composition according to [5], wherein each of the repeating units is one or more types selected from aromatic groups represented by the following formula: [7] The liquid crystal polymer composition according to any one of [1] to [6], wherein the liquid crystal polymer has a crystalline melting temperature of 290 to 360°C as measured by a differential scanning calorimeter. [8] The liquid crystal polymer composition according to any one of [1] to [7], wherein the average particle size of the talc is 0.1 to 100 μm. [9] The liquid crystal polymer composition according to any one of [1] to [8], wherein the content of tridymite in the liquid crystal polymer composition is 0.008 to 0.200% by mass.

[10] A molded article made from the liquid crystal polymer composition according to any one of [1] to [9].

[11] The molded article according to

[10] , which is a component constituting one selected from the group consisting of a connector, a switch, a relay, a bobbin, a capacitor, a coil, a motor, a fan, a test socket, a transformer, a camera module, and an antenna. [Effects of the Invention]

[0015] The liquid crystal polymer composition of the present invention has excellent thin-wall fluidity and blister resistance while maintaining the mechanical strength and heat resistance of liquid crystal polymers, and is therefore suitable for a variety of applications, such as electrical and electronic parts of various communication equipment and electronic devices, for example, connectors, switches, relays, bobbins, capacitors, coils, motors, fans, test sockets, transformers, camera modules, and antennas. [Brief explanation of the drawings]

[0016] [Figure 1] This is an X-ray diffraction chart that serves as the basis for a calibration curve created to determine the tridymite content of each talc. [Figure 2] 1 is a calibration curve for determining the tridymite content contained in each talc. [Figure 3] 1 is an X-ray diffraction chart for determining the tridymite content of each talc. DETAILED DESCRIPTION OF THE INVENTION

[0017] The liquid crystal polymer (hereinafter also referred to as LCP) used in the liquid crystal polymer composition of the present invention is a polyester or polyesteramide that forms an anisotropic molten phase, and is not particularly limited as long as it is what is called a thermotropic liquid crystal polyester or a thermotropic liquid crystal polyesteramide in the relevant technical field.

[0018] The anisotropic melt phase properties of the liquid crystal polymer can be confirmed by a conventional polarized light inspection method using cross polarizers, that is, by observing a sample placed on a hot stage under a nitrogen atmosphere.

[0019] The liquid crystal polymer used in the present invention preferably has a crystalline melting temperature measured by a differential scanning calorimeter of 220 to 380°C, more preferably 260 to 370°C, even more preferably 290 to 360°C, and particularly preferably 310 to 350°C.

[0020] If the crystalline melting temperature of the liquid crystal polymer is lower than 220°C, the heat resistance will be poor, and if it is higher than 380°C, the molding processability will tend to decrease, which is undesirable.

[0021] In this specification and claims, the term "crystalline melting temperature" refers to the peak crystalline melting temperature measured using a differential scanning calorimeter (DSC) at a heating rate of 20°C / min. More specifically, a liquid crystal polymer sample is measured at a temperature rise rate of 20°C / min from room temperature to reach an endothermic peak temperature (Tm1). The sample is then held at a temperature 20-50°C higher than Tm1 for 10 minutes, cooled to room temperature at a temperature drop rate of 20°C / min, and then measured again at a temperature rise rate of 20°C / min. The endothermic peak is observed, and the temperature at the peak top is taken as the crystalline melting temperature (Tm) of the liquid crystal polymer. For example, a DSC7020 manufactured by Hitachi High-Tech Science Corporation can be used as a measuring instrument.

[0022] Examples of polymerizable monomers constituting the structural units of the liquid crystal polymer of the present invention include aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic hydroxyamines, aromatic diamines, aliphatic diols, and aliphatic dicarboxylic acids. These polymerizable monomers may be used alone or in combination of two or more. Preferably, a polymerizable monomer having at least one hydroxyl group and one carboxyl group is used. Furthermore, the liquid crystal polymer of the present invention is more preferably a liquid crystal polymer composed only of aromatic monomers, without containing any aliphatic monomers.

[0023] Specific examples of aromatic hydroxycarboxylic acids include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, and alkyl-, alkoxy-, or halogen-substituted derivatives thereof, as well as ester-forming derivatives thereof such as acylation products, ester derivatives, and acid halides. Among these, 4-hydroxybenzoic acid and / or 6-hydroxy-2-naphthoic acid are preferred from the viewpoint of ease of adjusting the heat resistance, mechanical strength, and melting point of the resulting liquid crystal polymer.

[0024] Specific examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 3,4'-dicarboxybiphenyl, and 4,4"-dicarboxyterphenyl, as well as alkyl, alkoxy, or halogen-substituted derivatives thereof, and ester-forming derivatives thereof, such as ester derivatives and acid halides. Among these, from the viewpoint of effectively enhancing the heat resistance of the resulting liquid crystal polymer, one or more compounds selected from the group consisting of terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are preferred, and terephthalic acid and / or 2,6-naphthalenedicarboxylic acid are more preferred.

[0025] Specific examples of aromatic diols include hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, and 2,2'-dihydroxybinaphthyl, as well as ester-forming derivatives thereof such as alkyl-, alkoxy-, or halogen-substituted derivatives and acylated derivatives thereof. Among these, from the viewpoint of excellent reactivity during polymerization, one or more compounds selected from the group consisting of hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, and 2,6-dihydroxynaphthalene are preferred, and hydroquinone and / or 4,4'-dihydroxybiphenyl are more preferred.

[0026] Specific examples of aromatic aminocarboxylic acids include 4-aminobenzoic acid, 3-aminobenzoic acid, 6-amino-2-naphthoic acid, alkyl-, alkoxy-, or halogen-substituted derivatives thereof, and ester-forming derivatives thereof such as acylated products, ester derivatives, and acid halides.

[0027] Specific examples of aromatic hydroxyamines include 4-aminophenol, N-methyl-4-aminophenol, 3-aminophenol, 3-methyl-4-aminophenol, 4-amino-1-naphthol, 4-amino-4'-hydroxybiphenyl, 4-amino-4'-hydroxybiphenyl ether, 4-amino-4'-hydroxybiphenylmethane, 4-amino-4'-hydroxybiphenyl sulfide, and 2,2'-diaminobinaphthyl, as well as ester-forming derivatives thereof such as alkyl, alkoxy, or halogen-substituted derivatives thereof, and acylated derivatives thereof. Among these, 4-aminophenol is preferred from the viewpoint of easily achieving a balance between the heat resistance and mechanical strength of the resulting liquid crystal polymer.

[0028] Specific examples of aromatic diamines include amide-forming derivatives such as 1,4-phenylenediamine, 1,3-phenylenediamine, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, alkyl-, alkoxy- or halogen-substituted derivatives thereof, and acylated derivatives thereof.

[0029] Specific examples of the aliphatic diol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and acylated derivatives thereof. Also, a polymer containing an aliphatic diol, such as polyethylene terephthalate or polybutylene terephthalate, may be reacted with the aromatic oxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, and their acylated derivatives, ester derivatives, acid halides, etc.

[0030] Specific examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, fumaric acid, maleic acid, and hexahydroterephthalic acid. Among these, oxalic acid, succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid are preferred from the viewpoint of excellent reactivity during polymerization.

[0031] The polymerizable monomers forming the structural units of the liquid crystal polymer of the present invention may contain, as other copolymerization components, dihydroxyterephthalic acid, 4-hydroxyisophthalic acid, 5-hydroxyisophthalic acid, trimellitic acid, 1,3,5-benzenetricarboxylic acid, pyromellitic acid, or alkyl, alkoxy, or halogen-substituted derivatives thereof, as well as ester-forming derivatives thereof such as acylation products, ester derivatives, and acid halides, within the scope of the present invention. The amount of these polymerizable monomers used is preferably 10 mol % or less of the total structural units constituting the liquid crystal polymer.

[0032] In the present invention, the liquid crystal polymer may contain a thioester bond, provided that the object of the present invention is not impaired. Polymerizable monomers that provide such bonds include mercapto aromatic carboxylic acids, aromatic dithiols, and hydroxy aromatic thiols. The content of these polymerizable monomers is preferably 10 mol% or less of the total structural units constituting the liquid crystal polymer.

[0033] Polymers that combine these repeating units may or may not form an anisotropic molten phase depending on the monomer structure, composition ratio, and sequence distribution of each repeating unit in the polymer. However, the liquid crystal polymers used in the present invention are limited to those that form an anisotropic molten phase.

[0034] Specific examples of the combination of polymerizable monomers forming the structural units of the liquid crystal polymer used in the present invention include the following. 1) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid, 2) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl, 3) 4-hydroxybenzoic acid / terephthalic acid / isophthalic acid / 4,4'-dihydroxybiphenyl, 4) 4-hydroxybenzoic acid / terephthalic acid / isophthalic acid / 4,4'-dihydroxybiphenyl / hydroquinone, 5) 4-hydroxybenzoic acid / terephthalic acid / hydroquinone, 6) 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone, 7) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl, 8) 6-hydroxy-2-naphthoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl, 9) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone, 10) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone / 4,4'-dihydroxybiphenyl, 11) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / 4,4'-dihydroxybiphenyl, 12) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone, 13) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone, 14) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone, 15) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone / 4,4'-dihydroxybiphenyl, 16) 4-hydroxybenzoic acid / terephthalic acid / 4-aminophenol, 17) 6-hydroxy-2-naphthoic acid / terephthalic acid / 4-aminophenol, 18) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / 4-aminophenol, 19) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / 4-aminophenol, 20) 4-hydroxybenzoic acid / terephthalic acid / ethylene glycol 21) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / ethylene glycol, 22) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / ethylene glycol 23) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / ethylene glycol 24) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / 4,4'-dihydroxybiphenyl, 25) 6-Hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone / 4,4'-dihydroxybiphenyl.

[0035] Among these, liquid crystal polymers comprising structural units derived from polymerizable monomers 1), 2), 3), 7), 9), 10), 14) and 25) are preferred, liquid crystal polymers comprising structural units derived from polymerizable monomers 9), 10), 14) and 25) are more preferred, and liquid crystal polymers comprising structural units derived from polymerizable monomers 10) are even more preferred.

[0036] In one preferred embodiment, the liquid crystal polymer used in the liquid crystal polymer composition of the present invention has excellent thin-wall fluidity and mechanical properties, and is represented by the formula (I) and / or the formula (II). [ka] It contains a repeating unit represented by the formula:

[0037] In the liquid crystal polymer containing repeating units represented by formula (I) and / or formula (II), it is preferable that the liquid crystal polymer further contains repeating units represented by formula (III) and formula (IV) in terms of excellent thin-wall fluidity and heat resistance. [ka] [In the formula, Ar1 and Ar2 each independently represent a divalent aromatic group.]

[0038] Here, the repeating unit represented by formula (III) may be a plurality of types of repeating units each containing a different Ar1, and the repeating unit represented by formula (IV) may be a plurality of types of repeating units each containing a different Ar2. That is, the repeating unit represented by formula (III) may be a plurality of repeating units, such as a repeating unit having one type of Ar1 and a repeating unit having another type of Ar1. Similarly, the repeating unit represented by formula (IV) may be a plurality of repeating units, such as a repeating unit having one type of Ar2 and a repeating unit having another type of Ar2. Furthermore, the term "aromatic group" refers to a 6-membered monocyclic (including biphenyl) or fused 2-ring aromatic group.

[0039] In terms of achieving excellent thin-wall flowability and mechanical properties, the composition ratio (mol %) of the repeating units represented by formula (I) and / or formula (II) is preferably 30 to 80 mol %, more preferably 40 to 70 mol %. The repeating units represented by formula (III) and formula (IV) are each preferably 10 to 35 mol %, more preferably 15 to 30 mol %. The repeating units represented by formula (III) and formula (IV) are preferably present in substantially equimolar amounts.

[0040] In another preferred embodiment, in the liquid crystal polymer further containing repeating units represented by formula (III) and formula (IV), it is preferable that the liquid crystal polymer contains both repeating units represented by formula (I) and formula (II) in terms of excellent Izod impact strength and blister resistance. [ka]

[0041] In terms of achieving excellent thin-wall flowability and mechanical properties, the total composition ratio (mol %) of the repeating units represented by formula (I) and formula (II) is preferably 30 to 80 mol %, more preferably 35 to 60 mol %. The repeating units represented by formula (II) are preferably 0.1 to 30 mol %, more preferably 0.5 to 25 mol %, and even more preferably 1 to 20 mol %. The repeating units represented by formula (III) and formula (IV) are each preferably 10 to 35 mol %, more preferably 20 to 32.5 mol %. The repeating units represented by formula (III) and formula (IV) are preferably present in substantially equimolar amounts.

[0042] In terms of excellent thin-wall flowability and heat resistance, it is more preferable that the repeating units represented by formulas (III) to (IV) are each independently one or more repeating units in which Ar1 and Ar2 are selected from the aromatic groups represented by formulas (1) to (4): The repeating unit represented by formula (III) is particularly preferably a repeating unit in which Ar1 is an aromatic group represented by formula (1) and / or formula (3), and the repeating unit represented by formula (IV) is particularly preferably a repeating unit in which Ar2 is an aromatic group represented by one or more selected from the group consisting of formulas (1), (2) and (4). [ka]

[0043] The method for producing the liquid crystal polymer used in the present invention will be described below.

[0044] There are no particular limitations on the method for producing the liquid crystal polymer used in the present invention, and the liquid crystal polymer can be obtained by subjecting a polymerizable monomer to a known polycondensation method for forming an ester bond or an amide bond, such as a melt acidolysis method or a slurry polymerization method.

[0045] The melt acidolysis method is a preferred method for preparing the liquid crystalline polymer used in the liquid crystalline polymer composition of the present invention. This method involves first heating the polymerizable monomers to form a molten solution of the reactants, followed by a polycondensation reaction to obtain a molten polymer. A vacuum may be applied to facilitate removal of volatile by-products (e.g., acetic acid, water, etc.) produced during the final stage of condensation.

[0046] Slurry polymerization is a process in which polymerizable monomers are reacted in the presence of a heat exchange fluid, resulting in a solid product suspended in the heat exchange medium.

[0047] In both the melt acidolysis method and the slurry polymerization method, the polymerizable monomer used in producing the liquid crystal polymer can also be subjected to the reaction at room temperature in a modified form in which the hydroxyl group and / or amino group is acylated, i.e., as a lower acylated product.

[0048] The lower acyl group preferably has 2 to 5 carbon atoms, more preferably 2 or 3. In a preferred embodiment of the present invention, an acetylated product of the polymerizable monomer is subjected to the reaction.

[0049] The lower acylated polymerizable monomer may be a pre-synthesized product obtained by separate acylation, or may be produced in the reaction system by adding an acylating agent such as acetic anhydride to the polymerizable monomer during the production of the liquid crystal polymer.

[0050] In either the melt acidolysis method or the slurry polymerization method, the polycondensation reaction is carried out at a temperature of 150 to 400°C, preferably 250 to 370°C, under normal pressure and / or reduced pressure, and a catalyst may be used as necessary.

[0051] Specific examples of catalysts include organotin compounds such as dialkyltin oxides (e.g., dibutyltin oxide) and diaryltin oxides; titanium dioxide; antimony trioxide; organotitanium compounds such as alkoxytitanium silicates and titanium alkoxides; alkali and alkaline earth metal salts of carboxylic acids (e.g., sodium acetate and potassium acetate); and gaseous acid catalysts such as Lewis acids (e.g., boron trifluoride) and hydrogen halides (e.g., hydrogen chloride).

[0052] When a catalyst is used, the amount of the catalyst is preferably 1 to 1000 ppm, more preferably 2 to 100 ppm, based on the total amount of polymerizable monomers.

[0053] The liquid crystal polymer obtained by such a polycondensation reaction is usually extracted in a molten state from a polymerization reaction vessel, processed into pellets, flakes, or powder, and then melt-kneaded with other components.

[0054] The liquid crystal polymer in pellet, flake, or powder form may be heat-treated in a substantially solid state under reduced pressure, vacuum, or an atmosphere of an inert gas such as nitrogen or helium, in order to increase the molecular weight and improve the heat resistance.

[0055] The temperature for the heat treatment is not particularly limited as long as the liquid crystal polymer does not melt, but is preferably 260 to 350°C, more preferably 280 to 320°C.

[0056] The melt viscosity of the liquid crystal polymer used in the present invention (measured with a capillary rheometer, crystal melting temperature + 10 to 30°C, 1000 s -1 ) is preferably 1 to 200 Pa·s, more preferably 3 to 100 Pa·s, even more preferably 4 to 80 Pa·s, and particularly preferably 5 to 40 Pa·s.

[0057] If the melt viscosity is less than 1 Pa·s, drooling and stringiness tend to occur during injection molding, and if it exceeds 200 Pa·s, thin-wall flow tends to decrease.

[0058] The average particle size of the talc used in the liquid crystal polymer composition of the present invention is preferably 0.1 to 100 μm, more preferably 0.5 to 80 μm, and even more preferably 3 to 50 μm. In this specification, the average particle size refers to the volume-based median value (median diameter) measured by a laser diffraction / scattering particle size distribution measurement method.

[0059] The talc used in the present invention has excellent blister resistance and thin-wall flowability. Therefore, the tridymite content measured by a powder X-ray diffractometer using the method described below is 0.03 to 0.60% by mass, preferably 0.04 to 0.50% by mass, more preferably 0.05 to 0.45% by mass, even more preferably 0.06 to 0.40% by mass, and particularly preferably 0.07 to 0.35% by mass. In the present invention, tridymite refers to silicon dioxide (crystalline silica) with a crystalline structure, also known as tridymite. Talc with a tridymite content within the above range is primarily obtained by mining talc deposits in China and India. However, the tridymite content in talc varies depending on the formation process of the talc deposit, such as hydrothermal activity and crustal movement history (environmental conditions such as temperature and pressure), making it difficult to determine or predict the content in advance. Therefore, it is preferable to measure the tridymite content in talc for each deposit before use. The method described below for evaluating the tridymite content in talc using a powder X-ray diffractometer can also be applied to substances other than talc.

[0060] The talc may be treated with a known surface treatment agent before use.

[0061] In the liquid crystal polymer composition of the present invention, the content of talc is 0.1 to 150 parts by mass, preferably 1 to 100 parts by mass, more preferably 5 to 80 parts by mass, and even more preferably 7 to 50 parts by mass, relative to 100 parts by mass of the liquid crystal polymer. If the content of talc is less than 0.1 part by mass, blister resistance tends to be insufficient, and if it exceeds 150 parts by mass, thin-wall flowability tends to decrease.

[0062] Furthermore, the liquid crystal polymer composition of the present invention may contain, in addition to the above-mentioned talc, for example, other fibrous, plate-like, or granular inorganic or organic fillers, as long as the object of the present invention is not impaired.

[0063] Other fibrous fillers that can be used in the present invention include, for example, silica alumina fibers, alumina fibers, carbon fibers, glass fibers, aramid fibers, polyarylate fibers, polybenzimidazole fibers, potassium titanate whiskers, aluminum borate whiskers, acicular titanium oxide, calcium silicates such as wollastonite, xonotlite, calcium titanate, aluminum borate, acicular calcium carbonate, basalt fibers, and tetrapod-type zinc oxide, and these can be used alone or in combination of two or more.

[0064] Other plate-like fillers that can be used in the present invention include, for example, mica, kaolin, clay, graphite, vermiculite, calcium silicate, aluminum silicate, feldspar powder, acid clay, rosewood clay, sericite, sillimanite, bentonite, glass flakes, slate powder, silicates such as silane, carbonates such as calcium carbonate, chalk, barium carbonate, magnesium carbonate, and dolomite, barite powder, precipitated calcium sulfate, gypsum, sulfates such as barium sulfate, hydroxides such as hydrated alumina, oxides such as alumina, antimony oxide, magnesia, titanium oxide, zinc oxide, silica, silica sand, white carbon, and diatomaceous earth, sulfides such as molybdenum disulfide, and plate-like wollastonite, and these can be used alone or in combination of two or more.

[0065] Other granular fillers that can be used in the present invention include, for example, silica, alumina, titanium oxide, calcium carbonate, glass beads, glass balloons, barium sulfate, boron nitride, silicon carbide, and resin beads, and these can be used alone or in combination of two or more.

[0066] The content of these other fibrous, plate-like, or granular inorganic or organic fillers is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, relative to 100 parts by mass of the liquid crystal polymer. If the content of these other fibrous, plate-like, or granular inorganic or organic fillers exceeds 50 parts by mass, the thin-wall flowability tends to decrease.

[0067] The liquid crystal polymer composition of the present invention may contain other additives within the range that does not impair the effects of the present invention.

[0068] Other additives used in the present invention include, for example, lubricants such as higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acid metal salts (here, higher fatty acids refer to, for example, those having 10 to 25 carbon atoms), release improvers such as polysiloxanes and fluororesins, colorants such as dyes, pigments, and carbon black, flame retardants, antistatic agents, surfactants, antioxidants such as phosphorus-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants, weather resistance agents, heat stabilizers, and neutralizing agents. These additives may be used alone or in combination of two or more.

[0069] The content of these other additives is preferably 10 parts by mass or less, more preferably 0.01 to 5 parts by mass, relative to 100 parts by mass of the liquid crystal polymer. If the content of these other additives exceeds 10 parts by mass, the thermal stability tends to deteriorate.

[0070] When molding the liquid crystal polymer composition, substances having an external lubricant effect, such as higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon surfactants, may be attached to the surface of the pellets of the liquid crystal polymer composition in advance.

[0071] The liquid crystal polymer composition of the present invention may further contain other resin components within the scope of the present invention, such as thermoplastic resins such as polyamide, polyester, polyacetal, polyphenylene ether and its modified products, polysulfone, polyethersulfone, polyetherimide, polyamideimide, elastomer, and the like, and thermosetting resins such as phenolic resin, epoxy resin, polyimide resin, and the like.

[0072] The other resin components can be contained alone or in combination of two or more. The content of the other resin components is not particularly limited and may be appropriately determined depending on the use and purpose of the liquid crystal polymer composition. Typically, the total content of the other resins is preferably added in a range of 100 parts by mass or less, particularly 50 parts by mass or less, per 100 parts by mass of the liquid crystal polymer.

[0073] A liquid crystal polymer composition can be prepared by blending a liquid crystal polymer and talc, and optionally other inorganic fillers and / or organic fillers, other additives, other resin components, etc. in a predetermined composition, and melt-kneading the mixture using a Banbury mixer, kneader, single-screw or twin-screw extruder, etc.

[0074] The liquid crystal polymer composition of the present invention thus obtained is molded or processed by a known molding method using an injection molding machine, an extruder, or the like.

[0075] The liquid crystal polymer composition of the present invention preferably has a tensile strength of 80 MPa or more, more preferably 90 MPa or more, and even more preferably 100 MPa or more, in a tensile test in accordance with ASTM D638 using a 3.2 mm thick ASTM No. 4 dumbbell test piece. If the tensile strength is less than 80 MPa, the composition tends to be easily broken when used as a small, thin-walled part. The upper limit of the tensile strength is not particularly limited, but is, for example, 250 MPa.

[0076] The liquid crystal polymer composition of the present invention preferably has a tensile elongation at break of 1% or more, more preferably 2% or more, and even more preferably 3% or more, in a tensile test in accordance with ASTM D638 using an ASTM No. 4 dumbbell test piece having a thickness of 3.2 mm. If the tensile elongation at break is less than 1%, the composition tends to be easily broken when used as a small, thin-walled part. The upper limit of the tensile elongation at break is not particularly limited, but is, for example, 10%.

[0077] In an Izod impact test according to ASTM D256 using a notched strip specimen having a length of 63.5 mm, a width of 12.7 mm, and a thickness of 3.2 mm, the liquid crystal polymer composition of the present invention preferably has an Izod impact strength of 110 J / m or more, more preferably 120 J / m or more, even more preferably 150 J / m or more, and particularly preferably 180 J / m or more. If the Izod impact strength is less than 110 J / m, the composition tends to be easily broken when used as a small, thin-walled part. The upper limit of the Izod impact strength is not particularly limited, but is, for example, 600 J / m.

[0078] The liquid crystal polymer composition of the present invention preferably has a deflection temperature under load (DTUL, load 1.82 MPa) according to ASTM D648 of 200°C or higher, more preferably 210°C or higher, even more preferably 220°C or higher, and particularly preferably 230°C or higher, when used on a 3.2 mm thick strip test piece (length 127 mm, width 12.7 mm). If the deflection temperature under load is lower than 200°C, deformation is likely to occur during the reflow process, which is a processing step for electronic components, and heat resistance tends to be poor. The upper limit of the deflection temperature under load is not particularly limited, but is, for example, 320°C.

[0079] The liquid crystal polymer composition of the present invention preferably has a melt viscosity of 3 to 70 Pa·s, more preferably 5 to 50 Pa·s, and even more preferably 10 to 40 Pa·s, measured at the crystal melting temperature +10 to 30°C using a melt viscosity measuring device with a 1.0 mmφ×10 mm capillary. If the melt viscosity is less than 3 Pa·s, problems such as drooling are likely to occur during injection molding, and if it exceeds 70 Pa·s, thin-wall flowability tends to be insufficient.

[0080] The liquid crystal polymer composition of the present invention has a 0.1 mm thickness flow length, measured by the method described below, of preferably 9.5 mm or more, more preferably 10 mm or more, even more preferably 11 mm or more, and particularly preferably 12 mm or more. If the 0.1 mm thickness flow length is less than 9.5 mm, defects such as short shots tend to occur when molding small, thin-walled parts. The upper limit of the 0.1 mm thickness flow length is not particularly limited, but is, for example, 50 mm.

[0081] The liquid crystal polymer composition of the present invention preferably has a blister incidence rate of 15% or less, more preferably 10% or less, and even more preferably 5% or less, in a step blister test measured by the method described below. The lower the incidence rate, the closer to 0%, the better the blister resistance. Since this test is a severe test, a blister incidence rate of 15% or less in this test is sufficient for practical use. If the blister incidence rate exceeds 15%, blisters may occur even during actual use depending on the molding conditions.

[0082] The liquid crystal polymer composition of the present invention has excellent blister resistance and thin-wall flowability. Therefore, the tridymite content of the liquid crystal polymer composition is preferably 0.008 to 0.200 mass%, more preferably 0.009 to 0.150 mass%, even more preferably 0.010 to 0.100 mass%, and particularly preferably 0.011 to 0.080 mass%. The tridymite content in the liquid crystal polymer composition can be calculated based on the content ratio by measuring the tridymite content of each substance, such as talc or other inorganic fillers, contained in the liquid crystal polymer composition in advance using a powder X-ray diffractometer as described below, and using a pre-prepared calibration curve. Alternatively, 1.0 g of the liquid crystal polymer composition is placed in a crucible and incinerated in an electric furnace at 500 to 600°C for 5 hours. The mass of the resulting residue is measured, and the residue is measured using a powder X-ray diffractometer as described below. The amount of tridymite contained in the residue can be calculated using a pre-prepared calibration curve.

[0083] The liquid crystal polymer composition of the present invention has excellent thin-wall flowability and blister resistance while maintaining the mechanical strength and heat resistance of liquid crystal polymers, and therefore can be used as molded articles, and is particularly suitable for use in electronic parts such as connectors, switches, relays, bobbins, capacitors, coils, motors, fans, test sockets, transformers, camera modules, and antennas. [Example]

[0084] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples in any way.

[0085] In the examples, the crystal melting temperature, tensile strength, tensile elongation at break, Izod impact strength, deflection temperature under load, melt viscosity, 0.1 mm thickness flow length, step blisters, and tridymite content contained in talc were measured and evaluated by the methods described below.

[0086] (1) Crystal melting temperature Using a differential scanning calorimeter (DSC7020, manufactured by Hitachi High-Tech Science Corporation), the endothermic peak temperature (Tm1) observed when measuring at a temperature increase of 20°C / min from room temperature was observed, and then the temperature was held at a temperature 20 to 50°C higher than Tm1 for 10 minutes. Next, the sample was cooled to room temperature at a temperature decrease of 20°C / min, and the temperature at the top of the exothermic peak observed at this time was taken as the crystallization temperature (Tc) of the liquid crystal polymer. Further, the endothermic peak was observed when measuring again at a temperature increase of 20°C / min, and the temperature showing the top of this peak was taken as the crystalline melting temperature (Tm) of the liquid crystal polymer.

[0087] (2) Tensile strength Using an injection molding machine (UH1000-110 manufactured by Nissei Plastic Industrial Co., Ltd.), the specimens were injection molded at a cylinder temperature of 10 to 30°C above the crystal melting temperature and a mold temperature of 70°C to obtain dumbbell-shaped tensile test specimens (ASTM No. 4, thickness 3.2 mm). Tensile tests were performed using an autograph AG-X plus manufactured by Shimadzu Corporation in accordance with ASTM D638, with a span distance of 64.0 mm and a tensile speed of 5 mm / min.

[0088] (3) Tensile elongation at break The same test pieces as those used for measuring the tensile strength were used and the measurement was carried out under the same conditions as those for measuring the tensile strength.

[0089] (4) Izod impact strength Using an injection molding machine (UH1000-110 manufactured by Nissei Plastic Industrial Co., Ltd.), strip-shaped test specimens measuring 127 mm in length, 12.7 mm in width, and 3.2 mm in thickness were molded at a cylinder temperature of 350° C. and a mold temperature of 70° C. The center of each test specimen was cut perpendicular to the longitudinal direction to obtain strip-shaped test specimens measuring 63.5 mm in length, 12.7 mm in width, and 3.2 mm in thickness. After notching, the specimens were measured in accordance with ASTM D256.

[0090] (5) Deflection temperature under load (DTUL) Using an injection molding machine (UH1000-110, manufactured by Nissei Plastic Industrial Co., Ltd.), the specimens were molded into strip-shaped test pieces measuring 127 mm in length, 12.7 mm in width, and 3.2 mm in thickness at a cylinder temperature of 10 to 30°C above the crystal melting temperature and a mold temperature of 70°C. These were then measured in accordance with ASTM D648 at a load of 1.82 MPa and a heating rate of 2°C / min.

[0091] (6) Melt viscosity The melt viscosity was measured using a melt viscosity measuring device (Capillograph 1D manufactured by Toyo Seiki Co., Ltd.) with a 1.0 mm diameter x 10 mm capillary at a shear rate of 1000 sec -1 The melt viscosity was measured under the conditions of 350°C.

[0092] (7) 0.1 mm thickness flow length Using a rectangular bar flow mold measuring 50 mm in length, 2.0 mm in width, and 0.1 mm in thickness, injection molding was performed using an injection molding machine (NEX-15-1E, manufactured by Nissei Plastic Industrial Co., Ltd.) under the molding conditions shown in Table 1, and the flow length when the material was filled into the bar flow mold was measured.

[0093] [Table 1]

[0094] (8) Step blisters Plate-shaped test specimens were prepared by injection molding using an injection molding machine (NEX-15-1E, manufactured by Nissei Plastics Co., Ltd.) under the molding conditions listed in Table 2. These plate-shaped test specimens had a plate-shaped portion measuring 24 mm in length, 16 mm in width, and 0.3 mm in thickness. Six convex portions (4 mm in length, 4 mm in width, 0.5 mm in height, total thickness 0.8 mm) were evenly spaced 4 mm apart on one flat surface (arranged in three vertical rows and two horizontal rows). This shape was intentionally designed to facilitate air entrapment in the resin during injection molding, which facilitated the formation of blisters upon heating, making severe testing possible. The plate specimens were left at 23°C and 50% relative humidity for 24 hours, and then reflow-treated using an IR reflow machine (SAI-2604, manufactured by Senju Metal Industry Co., Ltd.) under the following conditions: preheating temperature: 190°C, preheating time: 30-50 seconds, main heating temperature: 250°C or higher, main heating time: 20-30 seconds, and peak temperature: 260-265°C. The occurrence of blisters on the surface was visually counted. The counting method involved drawing lines using a writing implement to divide the plate specimen into six regions centered on six convex portions. The presence or absence of blisters in each region was confirmed, and a score of 1 was assigned for each region if blisters were present, and a score of 0 if not. In other words, the maximum number of blisters counted per plate specimen was 6. Fifteen test pieces (90 areas) were evaluated for each injection speed condition, for a total of 60 test pieces (360 areas in total) under four injection speed conditions. If the blister incidence rate was 0-5%, it was marked as ◎, if it was over 5% to 15%, it was marked as 〇, if it was over 15% to 25%, it was marked as △, and if it was over 25%, it was marked as ×.

[0095] [Table 2]

[0096] (9) Evaluation of tridymite content in talc The tridymite (tridymite) content in talc was determined using a powder X-ray diffractometer (D8 ADVANCE manufactured by Bruker) as follows. Mixtures of talc (NK-64, manufactured by Fuji Talc Industries Co., Ltd., described below) substantially free of tridymite and tridymite (JAWE6104, manufactured by the Japan Working Environment Measurement Association, a public interest incorporated association) in fixed proportions (four samples, with tridymite concentrations of 0.1%, 0.3%, 0.5%, and 1.0% by mass) were measured using a powder X-ray diffractometer. A calibration curve passing through the origin was created using the tridymite-derived peak intensities observed at 2θ values ​​between 20.3 and 20.7°. This calibration curve allowed the tridymite content to be calculated relative to the tridymite-derived peak intensities. Subsequently, talc alone used in the liquid crystal polymer composition was measured using a powder X-ray diffractometer to determine the tridymite-derived peak intensities. The tridymite content was calculated by comparing the intensity of the tridymite-derived peaks with the calibration curve prepared by the above method.

[0097] The measurements were carried out under the following conditions: X-ray generator: CuKα source, voltage 40 kV, current 40 mA Slit: 1.0° Scan step: 0.02° Scan range: 19~23° Scan speed: 0.12° / min Rotation speed: 15 rpm X-ray detector: One-dimensional semiconductor detector Measurement atmosphere: Air Sample stage: Powder measurement sample stage (PMMA)

[0098] As a talc that is substantially free of tridymite, NK-64 (Talc 4, described below) manufactured by Fuji Talc Industries Co., Ltd. was selected, in which no tridymite-derived peaks were detected in the above measurement at 2θ values ​​of approximately 20.3 to 20.7°. Because no tridymite-derived peaks were detected, the tridymite content of NK-64 in this example was determined to be 0.00% by mass. Note that, if there were talcs with peak intensities even lower than NK-64 due to the influence of small noise, etc., the tridymite content of these talcs would also be determined to be 0.00% by mass.

[0099] Figure 1 shows the X-ray diffraction charts used to create the calibration curves: 100% talc substantially free of tridymite, and 99% talc substantially free of tridymite mixed with 1% tridymite. Figure 2 shows the calibration curves created based on the peak intensities derived from tridymite obtained under the above-mentioned evaluation and measurement conditions. Figure 3 shows the X-ray diffraction charts used to determine the tridymite content of each talc. Note that because peak intensities in X-ray diffraction charts vary depending on the equipment and measurement conditions, the calibration curves shown here cannot be used for other purposes, even if the equipment and measurement conditions are matched as closely as possible. Calibration curves should be created as needed for evaluation. In each of the following experimental examples, the tridymite content in the liquid crystal polymer composition was calculated from the talc content contained in the liquid crystal polymer composition and the tridymite content in the talc obtained by the above evaluation.

[0100] The synthesis examples of the liquid crystal polymers used in the Examples and Comparative Examples are described below. The abbreviations for the compounds in the synthesis examples are as follows:

[0101] [Monomers used in the synthesis of liquid crystal polymers (LCP)] POB: 4-hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid BP: 4,4'-dihydroxybiphenyl HQ: Hydroquinone TPA: Terephthalic acid NDA: 2,6-naphthalenedicarboxylic acid

[0102] Synthesis Example 1 (LCP1) A reaction vessel equipped with a stirrer with a torque meter and a distillation tube was charged with POB, BON6, HQ, BP, and TPA in the composition ratios shown in Table 3 so that the total amount was 6.5 mol. Furthermore, acetic anhydride was charged in an amount of 1.03 times the moles of the hydroxyl groups (moles) of all the monomers, and deacetic acid polymerization was carried out under the following conditions.

[0103] [Table 3]

[0104] The temperature was raised from room temperature to 150°C in a nitrogen gas atmosphere over 1 hour and maintained at that temperature for 30 minutes. The temperature was then raised to 350°C over 7 hours while distilling off the by-product acetic acid, and the pressure was then reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when a predetermined torque was reached, and the contents of the reactor were removed and crushed to obtain liquid crystal polymer pellets (LCP1). The amount of acetic acid distilled during polymerization was nearly the theoretical value. The crystalline melting temperature (Tm) of the resulting pellets was 340°C.

[0105] Synthesis example 2 (LCP2) A reaction vessel equipped with a stirrer with a torque meter and a distillation tube was charged with POB, BON6, HQ, and TPA in the composition ratio shown in Table 4 so that the total amount was 6.5 mol. Furthermore, acetic anhydride was charged in an amount of 1.03 times the moles of the hydroxyl groups (moles) of all the monomers, and deacetic acid polymerization was carried out under the following conditions.

[0106] [Table 4]

[0107] The temperature was raised from room temperature to 150°C in a nitrogen gas atmosphere over 1 hour and maintained at that temperature for 30 minutes. The temperature was then raised to 350°C over 7 hours while distilling off the by-product acetic acid, and the pressure was then reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when the specified torque was reached, and the contents of the reactor were removed and crushed into pellets of liquid crystal polymer (LCP2). The amount of acetic acid distilled during polymerization was nearly the theoretical value. The crystalline melting temperature (Tm) of the resulting pellets was 332°C.

[0108] Synthesis Example 3 (LCP3) A reaction vessel equipped with a stirrer with a torque meter and a distillation tube was charged with POB, BON6, HQ, and NDA in the composition ratio shown in Table 5 so that the total amount was 6.5 mol. Further, 1.03 times the moles of acetic anhydride relative to the amount (moles) of hydroxyl groups in all monomers was charged, and deacetic acid polymerization was carried out under the following conditions.

[0109] [Table 5]

[0110] The temperature was raised from room temperature to 150°C in a nitrogen gas atmosphere over 1 hour and maintained at that temperature for 30 minutes. The temperature was then raised to 350°C over 7 hours while distilling off the by-product acetic acid, and the pressure was then reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when a predetermined torque was reached, and the contents of the reactor were removed and crushed to obtain liquid crystal polymer pellets (LCP3). The amount of acetic acid distilled during polymerization was nearly the theoretical value. The crystalline melting temperature (Tm) of the resulting pellets was 321°C.

[0111] Synthesis Example 4 (LCP4) A reaction vessel equipped with a stirrer with a torque meter and a distillation tube was charged with BON6, BP, HQ, and TPA in the composition ratio shown in Table 6 so that the total amount was 6.5 mol. Furthermore, acetic anhydride was charged in an amount of 1.03 times the moles of the hydroxyl groups (moles) of all the monomers, and deacetic acid polymerization was carried out under the following conditions.

[0112] [Table 6]

[0113] The temperature was raised from room temperature to 150°C in a nitrogen gas atmosphere over 1 hour and maintained at that temperature for 60 minutes. The temperature was then raised to 350°C over 7 hours while distilling off the by-product acetic acid, and the pressure was then reduced to 5 mmHg over 90 minutes. The polymerization reaction was terminated when a predetermined torque was reached, and the contents of the reactor were removed and crushed to obtain liquid crystal polymer pellets (LCP4). The amount of acetic acid distilled during polymerization was nearly the theoretical value. The crystalline melting temperature (Tm) of the resulting pellets was 338°C.

[0114] The talc used in the examples and comparative examples is shown below. Talc 1: Talc obtained in Production Example 1 below (average particle size: 23 μm, tridymite content: 0.09% by mass) Talc 2: Talc obtained in Production Example 2 below (average particle size: 11 μm, tridymite content: 0.14% by mass) Talc 3: Talc obtained in Production Example 3 below (average particle size: 19 μm, tridymite content: 0.23% by mass) Talc 4: Talc "NK-64" (average particle size: 17 μm, tridymite content: 0.00% by mass), manufactured by Fuji Talc Kogyo Co., Ltd. Talc 5: Talc "DS-34" (average particle size: 13 μm, tridymite content: 0.02% by mass), manufactured by Fuji Talc Kogyo Co., Ltd.

[0115] Manufacturing Example 1 (Talc 1) Talc raw material from Liaoning Province, China was coarsely crushed to a particle size of 10 mm or less using a roll crusher, and then finely crushed and classified using a Pulverizer impact crusher with a built-in classifier (Hosokawa Micron Corporation, ACM-10A) to obtain Talc 1.

[0116] Manufacturing Example 2 (Talc 2) Talc raw material from the Guangxi Zhuang Autonomous Region of China was coarsely crushed to a particle size of 10 mm or less using a roll crusher, and then finely crushed and classified using a VX Mill (VX015, manufactured by Kurimoto, Ltd.) with a built-in classifier, to obtain Talc 2.

[0117] Manufacturing Example 3 (Talc 3) Talc raw material from Rajasthan, India was coarsely pulverized using a hammer mill to a particle size of 10 mm or less, and then finely pulverized and classified using a Pulverizer impact pulverizer with built-in classifier (Hosokawa Micron Corporation, ACM-10A) to obtain Talc 3.

[0118] Examples 1 to 8 and Comparative Examples 1 to 5 The synthesized LCP and the above talc were blended to the contents (parts by mass) shown in Table 7, and melt-kneaded using a twin-screw extruder (TEX-30 manufactured by Nippon Steel Corporation) at a cylinder temperature of 350°C to obtain pellets of a liquid crystal polymer composition. Thereafter, the tensile strength, tensile elongation at break, Izod impact strength, deflection temperature under load, melt viscosity, 0.1 mm thickness flow length, and step blister were measured and evaluated by the methods described above. The results are shown in Table 7.

[0119] As shown in Table 7, all of the liquid crystal polymer compositions of Examples 1 to 8 maintained the mechanical strength and heat resistance of liquid crystal polymers at a certain level, while having a 0.1 mm thickness flow length of 10 mm or more and a step blister evaluation of ◎, demonstrating excellent thin-wall flowability and blister resistance.

[0120] In contrast, the liquid crystal polymer compositions of Comparative Examples 1 to 5 were inferior in any one of mechanical strength, heat resistance, thin-wall fluidity, and blister resistance, and did not fully satisfy the balance of performance. [Table 7]

Claims

1. A liquid crystal polymer composition containing 5 to 100 parts by mass of talc having a tridymite content of 0.05 to 0.45% by mass relative to 100 parts by mass of a liquid crystal polymer, The liquid crystal polymer may be represented by formula (I) and / or formula (II): 【Chemistry 1】 and further comprising a repeating unit represented by formula (III) and formula (IV): 【Chemistry 2】 [In the formula, Ar 1 and Ar 2 each independently represent a divalent aromatic group] A liquid crystal polymer composition comprising a repeating unit represented by the formula:

2. The repeating units represented by formulas (III) to (IV) are Ar １ and Ar ２ are each independently represented by the formulas (1) to (4) 【Transformation 3】 2. The liquid crystal polymer composition according to claim 1, wherein each repeating unit is one or more types selected from aromatic groups represented by the following formula:

3. The liquid crystal polymer is represented by formula (I) and formula (II): 【Chemistry 4】 The liquid crystal polymer composition according to claim 1, comprising a repeating unit represented by:

4. The repeating units represented by formulas (III) to (IV) are Ar １ and Ar ２ are each independently represented by the formulas (1) to (4) 【Transformation 5】 4. The liquid crystal polymer composition according to claim 3, wherein each repeating unit is one or more types selected from aromatic groups represented by the following formula:

5. 2. The liquid crystal polymer composition according to claim 1, wherein the liquid crystal polymer has a crystalline melting temperature of 290 to 360° C. as measured by a differential scanning calorimeter.

6. 2. The liquid crystal polymer composition according to claim 1, wherein the average particle size of the talc is 0.1 to 100 μm.

7. 2. The liquid crystal polymer composition according to claim 1, wherein the content of tridymite in the liquid crystal polymer composition is 0.008 to 0.200% by mass.

8. A molded article made from the liquid crystal polymer composition according to any one of claims 1 to 7.

9. The molded article according to claim 8, wherein the molded article is a part constituting one selected from the group consisting of a connector, a switch, a relay, a bobbin, a capacitor, a coil, a motor, a fan, a test socket, a transformer, a camera module, and an antenna.

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