Liquid crystal polymer composition

Abstract

The present invention aims to provide a liquid crystal polymer composition that maintains the mechanical strength and heat resistance of liquid crystal polymers while improving thin-walled fluidity and exhibiting excellent blister resistance. [Solution] The present invention relates to a liquid crystal polymer composition containing 100 parts by mass of liquid crystal polymer, 0.1 to 150 parts by mass of talc having a quartz content of 0 to 0.25% by mass, and 0.1 to 100 parts by mass of glass fiber.

Description

Technical Field

[0001] The present invention relates to a liquid crystal polymer composition having improved thin-wall fluidity and excellent blister resistance while maintaining the mechanical strength and heat resistance of the liquid crystal polymer.

Background Art

[0002] Liquid crystal polymers have excellent moldability and high heat resistance, and are mainly used for applications such as connectors, relays, and bobbins by taking advantage of these properties. In recent years, high integration, miniaturization, thinning, and downsizing of electronic components have been progressing. Among them, in connector components, the tendency toward miniaturization and thinning is remarkable.

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

[0004] Board-to-board connectors and FPC connectors are required to have heat resistance to withstand reflow soldering, and along with the miniaturization of electronic devices using printed wiring boards, miniaturization of the components themselves is demanded. For example, narrow pitch connectors with a pitch between the metal terminals of the connector of 0.3 mm to 0.4 mm are provided. Also, thin connectors with a stacking height of 0.6 mm when the connector is inserted are provided.

[0005] However, in order to meet the requirements of miniaturization and thinning, there is a risk of short shots and the like caused by insufficient fluidity of the resin during molding of the connector. Therefore, further improvement of the fluidity of the resin (thin-wall fluidity) in the thin-wall portion of the molded product is required.

[0006] Furthermore, when molded products were left in a high-temperature atmosphere for extended periods or subjected to soldering, blistering sometimes occurred on the surface. The exact cause of this phenomenon is unclear, but it is presumed that air trapped during the molding of the liquid crystal polymer or oligomer components contained in the resin are brought into the molded product, and then, during high-temperature heat treatment, the expansion of this air or gasification of the oligomer components occurs, pushing up the softened surface of the molded product and appearing as blistering.

[0007] Thus, liquid crystal polymers, which are used as forming materials for thin-walled connectors such as board-to-board connectors and FPC connectors, are required to maintain the properties of liquid crystal polymers, such as mechanical strength and heat resistance, while also improving thin-walled fluidity and exhibiting excellent blister resistance.

[0008] Patent Document 1 proposes a liquid crystalline polyester composition that, by containing a specific terphenyl and a liquid crystalline polyester, can produce a molded article with high fluidity and anisotropy reduction of the liquid crystalline polyester, while also sufficiently reducing gas generation to suppress blistering and other abnormalities. However, this resin composition lacked sufficient fluidity and had room for improvement.

[0009] Patent Document 2 proposes a liquid crystalline polyester resin composition that, by containing a specific liquid crystalline polyester and a plate-like filler in a predetermined ratio, can maintain high fluidity while exhibiting excellent rigidity at high temperatures and reducing blister formation. However, this resin composition lacked sufficient blister resistance and had room for improvement.

[0010] While lowering the viscosity of the resin can improve thin-wall fluidity, this makes it easier for air to be introduced into the molded product during molding, resulting in a higher likelihood of blistering. Thus, although various studies have been conducted on liquid crystal polymer compositions, it has been considered difficult to obtain a liquid crystal polymer composition that improves thin-wall fluidity while also exhibiting excellent blister resistance. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2009-30015 [Patent Document 2] Japanese Patent Publication No. 2016-89154 [Overview of the project] [Problems that the invention aims to solve]

[0012] The present invention has been made in view of the above circumstances, and aims to provide a liquid crystal polymer composition that maintains the mechanical strength and heat resistance of liquid crystal polymers while improving thin-walled fluidity and having excellent blister resistance. [Means for solving the problem]

[0013] In view of the above problems, the inventors of the present invention conducted diligent studies and found that by blending specific amounts of specific talc and glass fibers with a liquid crystal polymer, a liquid crystal polymer composition can be obtained that maintains the mechanical strength and heat resistance of the liquid crystal polymer while improving thin-wall fluidity and exhibiting excellent blister resistance, thus completing the present invention.

[0014] In other words, the present invention encompasses the following preferred embodiments. [1] A liquid crystal polymer composition containing 0.1 to 150 parts by mass of talc with a quartz content of 0 to 0.25% by mass and 0.1 to 100 parts by mass of glass fiber, per 100 parts by mass of liquid crystal polymer. [2] Liquid crystal polymers are those of formula (I) and / or formula (II) [ka] A liquid crystal polymer composition according to [1], comprising repeating units represented by . [3] Liquid crystal polymers are further (III) and (IV) [ka] [In the formula, Ar1 and Ar2 each independently represent a divalent aromatic group.] The liquid crystal polymer composition according to [2], which contains a repeating unit represented by [4] The repeating units represented by formulas (III) to (IV) are each one or more repeating units selected from aromatic groups represented by formulas (1) to (4), where Ar1 and Ar2 are each independent of the other. The liquid crystal polymer composition according to [3]. [Chemical formula] The liquid crystal polymer composition according to [3], which is each one or more repeating units selected from aromatic groups represented by [5] The liquid crystal polymer contains repeating units represented by formulas (I) and (II) [Chemical formula] The liquid crystal polymer composition according to any one of [1] to [4], which contains a repeating unit represented by [6] The repeating units represented by formulas (III) to (IV) are each one or more repeating units selected from aromatic groups represented by formulas (1) to (4), where Ar1 and Ar2 are each independent of the other. The liquid crystal polymer composition according to [5]. [Chemical formula] The liquid crystal polymer composition according to [5], which is each one or more repeating units selected from aromatic groups represented by [7] The liquid crystal polymer has a crystal melting temperature measured by a differential scanning calorimeter of 290 to 360 °C. The liquid crystal polymer composition according to any one of [1] to [6]. [8] The average particle diameter of the talc is 0.1 to 100 μm. The liquid crystal polymer composition according to any one of [1] to [7]. [9] The content of quartz in the liquid crystal polymer composition is 0 to 0.040% by mass. The liquid crystal polymer composition according to any one of [1] to [8].

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

[11] The molded article described in

[10] , wherein the molded article is a component that constitutes one selected from the group consisting of connectors, switches, relays, bobbins, capacitors, coils, motors, fans, test sockets, transformers, camera modules and antennas. [Effects of the Invention]

[0015] The liquid crystal polymer composition of the present invention maintains the mechanical strength and heat resistance of liquid crystal polymers while exhibiting excellent thin-wall fluidity and blister resistance, making it suitable for a wide range of applications, such as electrical and electronic components for various communication equipment and electronic devices, including connectors, switches, relays, bobbins, capacitors, coils, motors, fans, test sockets, transformers, camera modules, and antennas. [Brief explanation of the drawing]

[0016] [Figure 1] This is an X-ray diffraction chart that serves as the basis for a calibration curve, created to determine the quartz content of each talc product. [Figure 2] This is an X-ray diffraction chart used to determine the quartz content of each talc product. [Modes for carrying out 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 referred to as thermotropic liquid crystal polyester or thermotropic liquid crystal polyesteramide in the art.

[0018] The properties of the anisotropic molten phase of a liquid crystal polymer can be confirmed using a standard deflection inspection method with orthogonal deflectors, that is, by observing a sample placed on a hot stage under a nitrogen atmosphere.

[0019] In the present invention, the liquid crystal polymer used is preferably one whose crystal melting temperature, as measured by differential scanning calorimeter, is 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 crystal melting temperature of the liquid crystal polymer falls below 220°C, its heat resistance deteriorates, and if it exceeds 380°C, its moldability tends to decrease, which is undesirable.

[0021] In this specification and in the claims, "crystal melting temperature" refers to the peak temperature of the crystal melting temperature measured using a Differential Scanning Calorimeter (DSC) at a heating rate of 20°C / min. More specifically, after observing the endothermic peak temperature (Tm1) when measuring a liquid crystal polymer sample from room temperature under a heating condition of 20°C / min, the sample is held at a temperature 20 to 50°C higher than Tm1 for 10 minutes, then the sample is cooled to room temperature under a cooling condition of 20°C / min, and the endothermic peak is observed again under a heating condition of 20°C / min. The temperature at which the peak top is shown is defined as the crystal melting temperature (Tm) of the liquid crystal polymer. As a measuring instrument, for example, a DSC7020 manufactured by Hitachi High-Tech Science Corporation can be used.

[0022] Examples of polymerizable monomers that constitute the constituent units of the liquid crystal polymer in 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. Such polymerizable monomers may be used individually or in combination of two or more types. Preferably, polymerizable monomers having at least one hydroxyl group and a carboxyl group are used. Furthermore, it is more preferable that the liquid crystal polymer in the present invention is composed only of aromatic monomers and does not contain 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 their alkyl, alkoxy, or halogen-substituted derivatives, as well as ester-forming derivatives such as their acylids, 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, their alkyl, alkoxy, or halogen-substituted derivatives, and their ester derivatives and ester-forming derivatives such as acid halides. Among these, from the viewpoint of effectively improving 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, with terephthalic acid and / or 2,6-naphthalenedicarboxylic acid being 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, their alkyl, alkoxy, or halogen-substituted derivatives, and their acylated derivatives, etc. 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 such as acylated, ester derivatives, and acid halides thereof.

[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, their alkyl, alkoxy, or halogen-substituted derivatives, and their acylated derivatives, etc. Among these, 4-aminophenol is preferred from the viewpoint of easily balancing the heat resistance and mechanical strength of the resulting liquid crystal polymer.

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

[0029] Specific examples of aliphatic diols include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and their acylated products. Alternatively, polymers containing aliphatic diols such as polyethylene terephthalate and polybutylene terephthalate may be reacted with the aforementioned aromatic oxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols and their acylated products, ester derivatives, acid halides, etc.

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

[0031] The polymerizable monomers that form the constituent units of the liquid crystal polymer in the present invention may include, to the extent that the objectives of the present invention are not impaired, other copolymerizing components such as 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 acylated derivatives, ester derivatives, and acid halides. Preferably, the amount of these polymerizable monomers used is 10 mol% or less relative to the total constituent units of the liquid crystal polymer.

[0032] In the present invention, the liquid crystal polymer may contain thioester bonds, to the extent that it does not impair the objectives of the present invention. Examples of polymerizable monomers that provide such bonds include mercaptoaromatic carboxylic acids, aromatic dithiols, and hydroxyaromatic thiols. The content of these polymerizable monomers is preferably 10 mol% or less relative to the total constituent units of the liquid crystal polymer.

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

[0034] Specific examples of combinations of polymerizable monomers that form the constituent units of the liquid crystal polymer used in the present invention include, for example, 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.

[0035] Among these, liquid crystal polymers consisting of structural units derived from polymerizable monomers 1), 2), 3), 7), 9), 10), and 14) are preferred, liquid crystal polymers consisting of structural units derived from polymerizable monomers 9), 10), and 14) are more preferred, and liquid crystal polymers consisting of structural units derived from polymerizable monomer 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 is excellent in terms of fluidity and mechanical properties, and is of formula (I) and / or formula (II) [ka] Includes a repeating unit represented by .

[0037] In the liquid crystal polymer comprising repeating units represented by formula (I) and / or formula (II), it is preferable to further include repeating units represented by (III) and (IV) in terms of excellent 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 multiple types of repeating units, each containing a different Ar1, and the repeating unit represented by formula (IV) may be multiple types of repeating units, each containing a different Ar2. That is, the repeating unit represented by formula (III) may be multiple repeating units, such as a repeating unit of one type of Ar1 and a repeating unit of another type of Ar1, and similarly, the repeating unit represented by formula (IV) may be multiple repeating units, such as a repeating unit of one type of Ar2 and a repeating unit of another type of Ar2. Furthermore, "aromatic group" refers to an aromatic group that is a 6-membered monoring (including a biphenyl structure) or a fused ring with 2 rings.

[0039] In terms of excellent fluidity 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%, and more preferably 40 to 70 mol%. The repeating units represented by formula (III) and formula (IV) are preferably 10 to 35 mol%, and more preferably 15 to 30 mol%, respectively. It is preferable that the repeating units represented by formula (III) and formula (IV) are substantially equimolar.

[0040] In another preferred embodiment, the liquid crystal polymer further comprises repeating units represented by (III) and (IV), and it is preferable that it comprises both repeating units represented by formula (I) and formula (II) in terms of excellent fluidity and mechanical properties. [ka]

[0041] In terms of excellent fluidity and mechanical properties, the total composition ratio (mol%) of the repeating units represented by formulas (I) and (II) is preferably 30 to 80 mol%, and 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 formulas (III) and (IV) are preferably 10 to 35 mol%, and more preferably 20 to 32.5 mol%. It is preferable that the repeating units represented by formulas (III) and (IV) are substantially equimolar.

[0042] In terms of excellent fluidity and heat resistance, it is more preferable that the repeating units represented by formulas (III) to (IV) each consist of one or more repeating units in which Ar1 and Ar2 are independently selected from the aromatic groups represented by formulas (1) to (4) below. It is particularly preferable that the repeating unit represented by formula (III) is 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 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. A liquid crystal polymer can be obtained by subjecting a polymerizable monomer to a known polycondensation method that forms ester bonds or amide bonds, such as the molten acidolysis method or slurry polymerization method.

[0045] The molten acidolysis method is a preferred method for producing liquid crystal polymers used in the liquid crystal polymer composition of the present invention. In this method, polymerizable monomers are first heated to form a molten solution of reactants, and then a polycondensation reaction is continued to obtain a molten polymer. Vacuum may be applied to facilitate the removal of volatile by-products (e.g., acetic acid, water, etc.) produced in the final stage of condensation.

[0046] Slurry polymerization is a method of reacting polymerizable monomers in the presence of a heat exchange fluid, and the solid product is obtained suspended in the heat exchange medium.

[0047] In both the molten acidolysis method and the slurry polymerization method, the polymerizable monomers used in the production of liquid crystal polymers can also be used in the reaction at room temperature as modified forms with acylated hydroxyl and / or amino groups, i.e., lower acylated compounds.

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

[0049] The lower acylated polymers of polymerizable monomers may be synthesized beforehand by acylation, or they may be generated in the reaction system during the production of liquid crystal polymers by adding an acylation agent such as acetic anhydride to the polymerizable monomer.

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

[0051] Specific examples of catalysts include organotin compounds such as dialkyltin oxides (e.g., dibutyltin oxide) and diarylinoxides; 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, 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, relative to the total amount of polymerizable monomers.

[0053] The liquid crystal polymer obtained by such a polycondensation reaction is usually removed from the polymerization reactor in a molten state, processed into pellets, flakes, or powder, and then subjected to melt-kneading with other components.

[0054] Liquid crystal polymers in pellet, flake, or powder form may be subjected to heat treatment in a substantially solid state under reduced pressure, under vacuum, or in an atmosphere of an inert gas such as nitrogen or helium, in order to increase their molecular weight and improve their heat resistance.

[0055] The heat treatment temperature 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 this invention (measured with a capillary rheometer, crystal melting temperature + 10 to 30°C, 1000 s) -1The pressure 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] When the melt viscosity is less than 1 Pa·s, smudging and stringing tend to occur during injection molding, and when it exceeds 200 Pa·s, fluidity 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 median diameter (central value) measured by laser diffraction / scattering particle size distribution analysis.

[0059] The talc used in this invention preferably has a quartz content of 0 to 0.25 mass%, more preferably 0.20 mass% or less, even more preferably 0.15 mass% or less, particularly preferably 0.10 mass% or less, and most preferably 0.05 mass% or less, as measured by a powder X-ray diffractometer using the method described later. The closer the quartz content is to 0 mass%, the better the blister resistance and fluidity, while exceeding 0.25 mass% tends to decrease blister resistance or fluidity. In this invention, quartz refers to silicon dioxide (crystalline silica) with a crystalline structure, and is also called quartz. The method described later for evaluating the quartz content in talc using a powder X-ray diffractometer can also be applied to substances other than talc.

[0060] The talc mentioned above may be used after being treated with a known surface treatment agent.

[0061] In the liquid crystal polymer composition of the present invention, the talc content is 0.1 to 150 parts by mass per 100 parts by mass of liquid crystal polymer, preferably 1 to 100 parts by mass, more preferably 5 to 80 parts by mass, and even more preferably 10 to 50 parts by mass. If the content of the plate-like filler is less than 0.1 parts by mass, blister resistance tends to be insufficient, and if it exceeds 150 parts by mass, fluidity tends to decrease.

[0062] The glass fibers used in the liquid crystal polymer composition of the present invention preferably have a number-average fiber diameter of 0.1 to 50 μm and a number-average fiber length of 20 μm to 10 mm.

[0063] Examples of glass fibers used in this invention include long-fiber chopped glass fibers, short-fiber milled glass fibers, and other types manufactured by various methods. Two or more of these can also be used in combination.

[0064] Examples of glass fibers used in the present invention include E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S-glass, and mixtures thereof. Among these, E-glass is preferred because it has excellent strength and is readily available.

[0065] The glass fibers used in this invention may be treated with a coupling agent such as a silane-based coupling agent or a titanium-based coupling agent, if necessary.

[0066] The glass fibers used in the present invention may be coated with a thermoplastic resin such as urethane resin, acrylic resin, or ethylene / vinyl acetate copolymer, or a thermosetting resin such as epoxy resin, or treated with a consolidating agent.

[0067] The number-average fiber diameter of the glass fibers used in the present invention is preferably 3 to 20 μm, more preferably 5 to 16 μm, and even more preferably 7 to 13 μm. The number-average fiber diameter of the glass fibers in the resulting liquid crystal polyester resin composition remains substantially unchanged even after melt kneading.

[0068] The raw material glass fibers used preferably have a cut fiber length of 10 mm or less. If the glass fibers are long-fiber chopped glass fibers, 1.5 to 6 mm is more preferable, and 2 to 4 mm is even more preferable. If the glass fibers are short-fiber milled glass fibers, 10 μm to 200 μm is more preferable, and 20 to 150 μm is even more preferable. From the viewpoint of availability and ease of handling, it is preferable to use long-fiber chopped glass fibers. The number-average fiber length of the glass fibers in the resulting liquid crystal polyester resin composition is preferably 10 to 600 μm, more preferably 30 to 500 μm, and even more preferably 50 to 450 μm. The glass fibers usually break or shatter during compounding and kneading with liquid crystal polyester resin, etc., to obtain the number-average fiber length in the liquid crystal polyester resin composition. To obtain a liquid crystal polyester resin composition containing glass fibers of a desired fiber length, the melt kneading conditions can be set and adjusted according to the cut fiber length of the glass fibers used.

[0069] The number-average fiber diameter and fiber length of glass fibers in a liquid crystal polymer composition can be measured by observation with a microscope. First, 1.0 g of the liquid crystal polymer composition is placed in a crucible and treated in an electric furnace at 500-600°C for 5 hours to ash it. The residue is dispersed in methanol and spread onto a glass slide to prepare the sample. Next, the length in the longitudinal direction is read as the fiber length and the length in the direction perpendicular to the longitudinal direction as the fiber diameter in the projected image of the glass fibers in the field of view of the microscope, and the arithmetic mean is calculated. The denominator for the mean value should be 200 or more.

[0070] In the liquid crystal polymer composition of the present invention, the content of glass fibers is 0.1 to 100 parts by mass per 100 parts by mass of liquid crystal polymer, preferably 1 to 70 parts by mass, more preferably 3 to 50 parts by mass, even more preferably 5 to 40 parts by mass, and particularly preferably 8 to 30 parts by mass. If the content of plate-like filler is less than 0.1 parts by mass, the strength improvement effect due to the use of fibrous filler tends not to be obtained, and if it exceeds 100 parts by mass, the fluidity tends to decrease.

[0071] In the liquid crystal polymer composition of the present invention, the talc content ratio to glass fibers is preferably 0.5 or more, more preferably 0.7 to 10, even more preferably 0.9 to 7, and particularly preferably 0.95 to 5. When the talc / glass fiber content ratio is less than 0.5, blister resistance or fluidity tends to decrease.

[0072] Furthermore, the liquid crystal polymer composition of the present invention may contain, in addition to the talc and glass fibers described above, other fibrous, plate-like, or granular inorganic or organic fillers, to the extent that it does not impair the objectives of the present invention.

[0073] Other fibrous fillers used in the present invention include, for example, silica-alumina fibers, alumina fibers, carbon fibers, aramid fibers, polyarylate fibers, polybenzimidazole fibers, potassium titanate whiskers, aluminum borate whiskers, acicular titanium oxide, calcium silicate such as wollastonite, xonotlite, calcium titanate, aluminum borate, acicular calcium carbonate, basalt fibers, and tetrapod-type zinc oxide, which can be used individually or in combination of two or more.

[0074] Other plate-shaped fillers used in the present invention include, for example, mica, kaolin, clay, vermiculite, calcium silicate, aluminum silicate, feldspar powder, acid clay, pyrophyllite clay, sericite, sillimanite, bentonite, glass flakes, slate powder, silicates such as silane, calcium carbonate, white gesso, barium carbonate, magnesium carbonate, carbonates such as dolomite, barite powder, precipitated calcium sulfate, calcined 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, diatomaceous earth, sulfides such as molybdenum disulfide, and plate-shaped wollastonite. These can be used individually or in combination of two or more.

[0075] Other granular fillers 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, which can be used individually or in combination of two or more.

[0076] 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, per 100 parts by mass of liquid crystal polymer. If the content of these other fibrous, plate-like, or granular inorganic or organic fillers exceeds 50 parts by mass, the fluidity tends to decrease.

[0077] Furthermore, the liquid crystal polymer composition of the present invention may contain other additives, as long as they do not impair the effects of the present invention.

[0078] 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 (where higher fatty acids refer to those with 10 to 25 carbon atoms, for example); mold 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; weathering agents, heat stabilizers, and neutralizing agents. These additives may be used individually or in combination of two or more.

[0079] The content of these other additives is preferably 10 parts by mass or less, more preferably 0.01 to 5 parts by mass, per 100 parts by mass of liquid crystal polymer. If the content of these other additives exceeds 10 parts by mass, the thermal stability tends to deteriorate.

[0080] In the case of substances having an external lubricating effect, such as higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon-based surfactants, these may be attached to the surface of the liquid crystal polymer composition pellets in advance when molding the liquid crystal polymer composition.

[0081] Furthermore, the liquid crystal polymer composition of the present invention may contain other resin components, to the extent that it does not impair the objectives of the present invention. Examples of other resin components include thermoplastic resins such as polyamide, polyester, polyacetal, polyphenylene ether and its modified products, polysulfone, polyethersulfone, polyetherimide, polyamideimide, and elastomer, as well as thermosetting resins such as phenolic resin, epoxy resin, and polyimide resin.

[0082] Other resin components may be included individually or in combination of two or more. The content of other resin components is not particularly limited and can be determined as appropriate depending on the application and purpose of the liquid crystal polymer composition. Typically, the total content of other resins is preferably 100 parts by mass or less, and particularly 50 parts by mass or less, per 100 parts by mass of liquid crystal polymer.

[0083] A liquid crystal polymer composition can be obtained by blending liquid crystal polymer, talc, and glass fibers with other inorganic and / or organic fillers, other additives, and other resin components in a predetermined composition, and then melt-kneading them using a Banbury mixer, kneader, single-screw or twin-screw extruder, etc.

[0084] The liquid crystal polymer composition of the present invention obtained in this manner is molded or processed by known molding methods using an injection molding machine, an extruder, or the like.

[0085] The liquid crystal polymer composition of the present invention preferably has a tensile strength of 80 MPa or higher, more preferably 90 MPa or higher, and even more preferably 100 MPa or higher, in a tensile test conducted in accordance with ASTM D638 using an ASTM No. 4 dumbbell test specimen with a thickness of 3.2 mm. If the tensile strength is less than 80 MPa, it tends to break easily when used as a small, thin-walled part. The upper limit of the above tensile strength is not particularly limited, but for example, it is 250 MPa.

[0086] The liquid crystal polymer composition of the present invention preferably exhibits a tensile elongation at break of 1% or more, more preferably 2% or more, and even more preferably 2.5% or more, in a tensile test conducted in accordance with ASTM D638 using an ASTM No. 4 dumbbell test specimen with a thickness of 3.2 mm. If the tensile elongation at break is less than 1%, it tends to be prone to breakage when used as a small, thin-walled part. The upper limit of the tensile elongation at break is not particularly limited, but for example, it is 10%.

[0087] The liquid crystal polymer composition of the present invention exhibits an Izod impact strength of preferably 25 J / m or more, more preferably 50 J / m or more, even more preferably 100 J / m or more, and particularly preferably 150 J / m or more, in an Izod impact test compliant with ASTM D256 using a notched strip-shaped test piece measuring 63.5 mm in length, 12.7 mm in width, and 3.2 mm in thickness. If the Izod impact strength is less than 25 J / m, the material tends to be prone to breakage when used as a small, thin-walled part. The upper limit of the Izod impact strength is not particularly limited, but for example, it is 600 J / m.

[0088] The liquid crystal polymer composition of the present invention preferably has a load deflection temperature (DTUL, load 1.82 MPa) of 220°C or higher, more preferably 230°C or higher, and even more preferably 240°C or higher, when used in a strip-shaped test piece (length 127 mm, width 12.7 mm) with a thickness of 3.2 mm, in accordance with ASTM D648. If the load deflection temperature is below 220°C, deformation is likely to occur during the reflow process, which is a processing step for electronic components, and the heat resistance tends to be poor. The upper limit of the above load deflection temperature is not particularly limited, but for example, it is 320°C.

[0089] The liquid crystal polymer composition of the present invention has a melt viscosity, measured at the crystal melting temperature + 10 to 30°C using a melt viscosity measuring device with a 1.0 mmφ × 10 mm capillary, preferably 3 to 70 Pa·s, more preferably 5 to 50 Pa·s, and even more preferably 10 to 40 Pa·s. If the melt viscosity is less than 3 Pa·s, problems such as dripping are likely to occur during injection molding, and if it exceeds 70 Pa·s, the fluidity tends to be insufficient.

[0090] The liquid crystal polymer composition of the present invention has a flow length of 0.1 mm thickness, measured by the method described later, preferably 7 mm or more, more preferably 8 mm or more, even more preferably 9 mm or more, and particularly preferably 10 mm or more. When the flow length of 0.1 mm thickness is less than 7 mm, defects such as short shots tend to occur when forming small, thin-walled parts. The upper limit of the above flow length of 0.1 mm thickness is not particularly limited, but for example it is 50 mm.

[0091] The liquid crystal polymer composition of the present invention has a blister occurrence rate of preferably 15% or less, more preferably 10% or less, and even more preferably 5% or less in the step blister test measured by the method described later. The lower the occurrence rate and the closer it is to 0%, the better the blister resistance. Since this test is a harsh test, a blister occurrence rate of 15% or less in this test indicates sufficient practicality. If the blister occurrence rate exceeds 15%, blistering may occur in actual use depending on the molding conditions.

[0092] The liquid crystal polymer composition of the present invention preferably has a quartz content of 0 to 0.040% by mass or less, more preferably 0.030% by mass or less, even more preferably 0.020% by mass or less, and particularly preferably 0.010% by mass or less, relative to the total liquid crystal polymer composition. If the quartz content exceeds 0.040% by mass, there is a tendency for blister resistance or fluidity to be poor. The quartz content in the liquid crystal polymer composition can be calculated by pre-measuring the quartz content of each substance, such as inorganic fillers like talc, contained in the liquid crystal polymer composition and calculating the content ratio accordingly. Alternatively, 1.0 g of the liquid crystal polymer composition can be placed in a crucible, treated in an electric furnace at 500 to 600°C for 5 hours to ash it, the mass of the resulting residue can be measured, and the amount of quartz contained in the residue can be calculated and evaluated by measuring the residue using a powder X-ray diffractometer as described later.

[0093] The liquid crystal polymer composition of the present invention maintains the mechanical strength and heat resistance of liquid crystal polymers while exhibiting excellent thin-wall fluidity and blister resistance, making it suitable for use in molded articles. It is particularly suitable for use in electronic components such as connectors, switches, relays, bobbins, capacitors, coils, motors, fans, test sockets, transformers, camera modules, and antennas. [Examples]

[0094] The present invention will be described below with reference to examples, but the present invention is not limited in any way to the following examples.

[0095] The crystal melting temperature, tensile strength, tensile elongation at break, Izod impact strength, load deflection temperature, melt viscosity, 0.1 mm thickness flow length, step blister, and quartz content in the talc in the examples were measured and evaluated using the method described below.

[0096] (1) Crystal melting temperature Using a differential scanning calorimeter (DSC7020, Hitachi High-Tech Science Co., Ltd.), the endothermic peak temperature (Tm1) observed when the temperature was raised from room temperature at a rate of 20°C / min was recorded. The sample was then held at a temperature 20-50°C higher than Tm1 for 10 minutes. Next, the sample was cooled to room temperature at a rate of 20°C / min, and the temperature at the peak of the exothermic peak observed at this time was defined as the crystallization temperature (Tc) of the liquid crystal polymer. Furthermore, the endothermic peak was observed again when the temperature was raised at a rate of 20°C / min, and the temperature at the peak of that peak was defined as the crystallization temperature (Tm) of the liquid crystal polymer.

[0097] (2) Tensile strength Using an injection molding machine (UH1000-110, manufactured by Nissei Plastic Industrial Co., Ltd.), dumbbell-shaped tensile test specimens (ASTM No. 4, 3.2 mm thick) were obtained by injection molding at a cylinder temperature of +10 to 30°C above the crystal melting temperature and a mold temperature of 70°C. 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.

[0098] (3) Tensile elongation at fracture The same test specimens used for tensile strength measurement were used, and the measurement was performed under the same conditions as for tensile strength measurement.

[0099] (4) Izod impact strength Using an injection molding machine (UH1000-110, manufactured by Nissei Plastic Industrial Co., Ltd.), a strip-shaped test specimen measuring 127 mm in length, 12.7 mm in width, and 3.2 mm in thickness was molded at a cylinder temperature of 350°C and a mold temperature of 70°C. The center of this test specimen was cut perpendicular to its length to obtain a strip-shaped test specimen measuring 63.5 mm in length, 12.7 mm in width, and 3.2 mm in thickness. After notching, it was measured in accordance with ASTM D256.

[0100] (5) Load deflection temperature (DTUL) Using an injection molding machine (UH1000-110, manufactured by Nissei Plastic Industrial Co., Ltd.), strip-shaped test pieces measuring 127 mm in length, 12.7 mm in width, and 3.2 mm in thickness were molded 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, with a load of 1.82 MPa and a heating rate of 2°C / min.

[0101] (6) Melt viscosity Using a melt viscosity measuring device (Capillograph 1D, manufactured by Toyo Seiki Co., Ltd.), a 1.0 mmφ × 10 mm capillary was measured at a shear rate of 1000 sec. -1 The melt viscosity was measured under conditions of 350°C.

[0102] (7) 0.1 mm thickness flow length A rectangular bar flow mold measuring 50 mm in length, 2.0 mm in width, and 0.1 mm in thickness was used for injection molding with an injection molding machine (NEX-15-1E, manufactured by Nissei Plastic Industrial Co., Ltd.) under the molding conditions shown in Table 1. The flow length was then measured when the bar flow mold was filled with the injected material.

[0103] [Table 1]

[0104] (8) Step blister Plate-shaped test specimens were prepared by injection molding using an injection molding machine (NEX-15-1E, manufactured by Nissei Plastic Co., Ltd.) under the molding conditions shown in Table 2. Each plate-shaped test specimen has a plate-like section measuring 24 mm in length, 16 mm in width, and 0.3 mm in thickness. On one flat side of this section, there are a total of six evenly spaced protrusions (4 mm in length, 4 mm in width, and 0.5 mm in height, with a total thickness of 0.8 mm) arranged in three rows vertically and two rows horizontally, with a spacing of 4 mm between each protrusion. This shape is designed to intentionally trap air in the resin during injection molding, making blistering more likely upon heating and enabling rigorous testing. The plate-shaped test specimen was left to stand for 24 hours at 23°C and 50% relative humidity. Then, it was reflowed using an IR reflow apparatus (SAI-2604, manufactured by Senju Metal Industry Co., Ltd.) under the following conditions: preheating temperature of 190°C, preheating time of 30-50 seconds, main heating temperature of 250°C or higher, main heating time of 20-30 seconds, and peak temperature of 260-265°C. After the reflow treatment, the occurrence of blisters on the surface was counted by visual inspection. For the counting method, lines were drawn using a writing instrument to divide the plate-shaped test specimen into six sections centered on the six protrusions. The presence or absence of blisters was checked in each of the six sections, and if a blister occurred in one section, it was counted as 1; if not, it was counted as 0. In other words, the maximum number of blisters per plate-shaped test specimen is 6. Fifteen test specimens (90 regions) were evaluated for each injection speed condition, and a total of 60 test specimens (360 regions) were evaluated for a total of four injection speed conditions. A blister occurrence rate of 0-5% was marked with ◎, over 5% to 15% with ○, over 15% to 25% with △, and over 25% with ×.

[0105] [Table 2]

[0106] (9) Evaluation of the quartz content in talc The quartz content in the talc was determined using a powder X-ray diffractometer (Bruker D8 ADVANCE) as follows: Six samples were prepared by mixing talc with an extremely low quartz content (TP-40B manufactured by Tamura Namite Industry Co., Ltd., described below) and quartz (JAWE4513 manufactured by the Japan Association for Occupational Environment Measurement, SiO2 content 99.6%) in fixed proportions (quartz ratios of 0.1 mass%, 0.3 mass%, 0.5 mass%, 1.0 mass%, 2.0 mass%, and 3.0 mass%) using a powder X-ray diffractometer. A calibration curve was created using the peak intensity derived from quartz observed around 2θ of 26.6-26.7°. Subsequently, talc used in liquid crystal polymer compositions was measured using a powder X-ray diffractometer, and the quartz content was calculated by comparing it with the calibration curve.

[0107] The measurements were taken under the following conditions. X-ray generator: CuKα source, voltage 40kV, current 40mA Slit: 0.3° Scan step: 0.02° Scan range: 25~28° Scan speed: 0.12 deg / min Rotation speed: 15 rpm X-ray detector: One-dimensional semiconductor detector Measurement atmosphere: Air atmosphere Sample stage: Sample stage for powder measurement (made of PMMA)

[0108] As a talc with an extremely close to zero quartz content, TP-40B manufactured by Tamura Namite Industry Co., Ltd. was selected because no quartz-derived peaks around 26.6-26.7° 2θ were detected in the above measurements. Since no quartz-derived peaks were detected, the quartz content of TP-40B was assumed to be 0.00% in this example. If any talc with even lower peak intensity than TP-40B is found due to the influence of small noises, etc., the quartz content of these talcs will also be assumed to be 0.00%.

[0109] Figure 1 shows the X-ray diffraction charts used to create calibration curves for 100% talc with a near-zero quartz content and a mixture of 97% talc and 3% quartz. Figure 2 shows the X-ray diffraction charts used to determine the quartz content of each talc. In each of the following experimental examples, the quartz content in the liquid crystal polymer composition was calculated from the quartz content in the talc obtained by the above evaluation.

[0110] The following describes the synthesis examples of the liquid crystal polymers used in the examples and comparative examples. The abbreviations for the compounds used in the synthesis examples are as follows.

[0111] [Monomers used in the synthesis of liquid crystal polymers (LCPs)] POB: 4-Hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid BP: 4,4'-Dihydroxybiphenyl HQ: Hydroquinone TPA: Terephthalic acid NDA: 2,6-Naphthalenedicarboxylic acid

[0112] Synthesis Example 1 (LCP1) In a reaction vessel equipped with a torque meter-equipped stirrer and distillation tube, POB, BON6, HQ, BP, and TPA were charged in the composition ratios shown in Table 3 to a total volume of 6.5 mol. Furthermore, acetic anhydride was charged at a concentration of 1.03 moles relative to the total amount of hydroxyl groups (moles) of monomers, and deacetic acid polymerization was carried out under the following conditions.

[0113] [Table 3]

[0114] The mixture was heated from room temperature to 150°C in 1 hour under a nitrogen gas atmosphere and held at that temperature for 30 minutes. Then, the mixture was heated to 350°C over 7 hours while distilling off the by-product acetic acid, and the pressure was reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when the predetermined torque was reached, the contents of the reaction vessel were removed, and liquid crystal polymer pellets were obtained using a pulverizer. The amount of acetic acid distilled during polymerization was approximately as per the theoretical value. The crystal melting temperature (Tm) of the obtained pellets was 340°C.

[0115] Synthesis example 2 (LCP2) In a reaction vessel equipped with a torque meter-equipped stirrer and distillation tube, POB, BON6, HQ, and TPA were charged in the composition ratios shown in Table 4 to a total volume of 6.5 mol. Furthermore, acetic anhydride was charged at a ratio of 1.03 moles to the total amount of hydroxyl groups (moles) of monomers, and deacetic acid polymerization was carried out under the following conditions.

[0116] [Table 4]

[0117] The mixture was heated from room temperature to 150°C in 1 hour under a nitrogen gas atmosphere and held at that temperature for 30 minutes. Then, the mixture was heated to 350°C over 7 hours while distilling off the by-product acetic acid, and the pressure was reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when the predetermined torque was reached, the contents of the reaction vessel were removed, and pellets of all aromatic liquid crystal polyester resin were obtained by grinding. The amount of acetic acid distilled during polymerization was approximately as per the theoretical value. The crystallization temperature (Tm) of the obtained pellets was 332°C.

[0118] Synthesis Example 3 (LCP3) In a reaction vessel equipped with a torque meter-equipped stirrer and distillation tube, POB, BON6, HQ, and NDA were charged in the composition ratios shown in Table 5 to a total volume of 6.5 mol. Furthermore, acetic anhydride was charged at a ratio of 1.03 moles to the total amount of hydroxyl groups (moles) of monomers, and deacetic acid polymerization was carried out under the following conditions.

[0119] [Table 5]

[0120] The mixture was heated from room temperature to 150°C in 1 hour under a nitrogen gas atmosphere and held at that temperature for 30 minutes. Then, the mixture was heated to 350°C over 7 hours while distilling off the by-product acetic acid, and the pressure was reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when the predetermined torque was reached, the contents of the reaction vessel were removed, and pellets of all aromatic liquid crystal polyester resin were obtained by grinding. The amount of acetic acid distilled during polymerization was approximately as per the theoretical value. The crystallization melting temperature (Tm) of the obtained pellets was 321°C.

[0121] The talc and glass fibers used in the examples and comparative examples are shown below. Talc 1: Talc "MS-SF" manufactured by Nippon Talc Co., Ltd. (average particle size: 16 μm, quartz content: 0.02%) Talc 2: Talc "TP-40B" manufactured by Tamura Talc Industrial Co., Ltd. (average particle size: 16 μm, quartz content: 0.00%) Talc 3: Manufactured by Fuji Talc Industries Co., Ltd., Talc "NK-64" (average particle size: 17 μm, quartz content: 0.28%) Talc 4: Manufactured by Fuji Talc Industries Co., Ltd., Talc "DS-34" (average particle size: 13 μm, quartz content: 0.80%) Glass fiber: CPIC Corporation, ECS3010A (number-average fiber diameter 10.5 μm, number-average fiber length 3 mm, quartz content: 0.00%)

[0122] Examples 1-5 and Comparative Examples 1-4 The synthesized LCP, talc, and glass fibers were blended to the content (parts by mass) shown in Table 6, and melt-kneaded at a cylinder temperature of 350°C using a twin-screw extruder (TEX-30, manufactured by Japan Steel Works Co., Ltd.) to obtain pellets of the liquid crystal polymer composition. Subsequently, tensile strength, tensile elongation at fracture, Izod impact strength, load deflection temperature, melt viscosity, 0.1 mm thickness flow length, and step blister were measured and evaluated using the method described above. The results are shown in Table 6.

[0123] As shown in Table 6, all of the liquid crystal polymer compositions of Examples 1 to 5 exhibited excellent blister resistance while maintaining a certain level of mechanical strength and heat resistance characteristic of liquid crystal polymers.

[0124] In contrast, the liquid crystal polymer compositions of Comparative Examples 1 to 4 exhibited poor blister resistance.

[0125] Comparing Examples 1-2 with Comparative Examples 1-2, Example 4 with Comparative Example 3, and Example 5 with Comparative Example 4, in all cases, using talc with a low quartz content tends to result in a superior 0.1 mm thickness flow length, indicating that thin-walled fluidity is improved. [Table 6]

Claims

1. A liquid crystal polymer composition containing 0.1 to 150 parts by mass of talc with a quartz content of 0 to 0.25% by mass and 0.1 to 100 parts by mass of glass fiber, per 100 parts by mass of liquid crystal polymer.

2. Liquid crystal polymers are given by formula (I) and / or formula (II) 【Chemistry 1】 The liquid crystal polymer composition according to claim 1, comprising repeating units represented by .

3. Liquid crystal polymers are further (III) and (IV) 【Chemistry 2】 [In the formula, Ar １ and Ar ２ Each of these independently represents a divalent aromatic group. The liquid crystal polymer composition according to claim 2, comprising repeating units represented by .

4. The repeating unit represented by equations (III) to (IV) is Ar １ and Ar ２ Each of these is independent of the others, and equations (1) to (4) 【Transformation 3】 The liquid crystal polymer composition according to claim 3, wherein each of the aromatic groups represented is selected from one or more repeating units.

5. Liquid crystal polymers are given by formulas (I) and (II) 【Chemistry 4】 The liquid crystal polymer composition according to claim 3, comprising repeating units represented by .

6. The repeating unit represented by equations (III) to (IV) is Ar １ and Ar ２ Each of these is independent of the others, and equations (1) to (4) 【Transformation 5】 The liquid crystal polymer composition according to claim 5, wherein each of the aromatic groups represented is selected from one or more repeating units.

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

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

9. The liquid crystal polymer composition according to claim 1, wherein the quartz content in the liquid crystal polymer composition is 0 to 0.040% by mass.

10. A molded article comprising a liquid crystal polymer composition according to any one of claims 1 to 9.

11. The molded article according to claim 10, wherein the molded article is a component that constitutes one selected from the group consisting of connectors, switches, relays, bobbins, capacitors, coils, motors, fans, test sockets, transformers, camera modules, and antennas.

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