All-aromatic liquid crystal polyester resin composition

Abstract

To provide an all-aromatic liquid crystal polyester resin composition that enables achievement of a superior balance of mechanical strength, fluidity, heat resistance, and Rockwell hardness.SOLUTION: The present invention relates to an all-aromatic liquid crystal polyester resin composition comprising 100 pts.mass of an all-aromatic liquid crystal polyester (A) including repeating units represented by formulas (I) to (IV), wherein Ar1 and Ar2 each represent one or more divalent aromatic groups, and p, q, r, and s respectively denote composition ratios (mol%) of the repeating units in the all-aromatic liquid crystal polyester and satisfy the conditions: 30≤(p+q)<60, 1≤q≤12, 20≤r≤35, and 20≤s≤35; and 5 to 150 pts.mass of a glass fiber having an average fiber diameter of 3 to 8 μm.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a wholly aromatic liquid crystal polyester resin composition having an excellent balance of mechanical strength, flowability, heat resistance and Rockwell hardness. [Background technology]

[0002] Liquid crystal polyesters 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 the molded body (thin-wall fluidity).

[0006] Furthermore, in order to meet the demand for smaller size and thinner walls, there is a risk that the connector will not be able to maintain its practical strength due to the thinner walls. Specifically, the connector may be deformed, chipped, or broken due to the load during transportation or insertion. Therefore, there is a need to improve the strength and hardness of the resin used in the molded product.

[0007] Liquid crystal polyester, which is used to form thin-walled connectors such as board-to-board connectors and FPC connectors, is required to have excellent thin-wall flowability and a good balance of high strength and hardness.

[0008] Patent Document 1 proposes a liquid crystal polyester resin composition that can produce a molded article having excellent thin-wall flowability and low warpage while maintaining excellent heat resistance by blending a fibrous inorganic filler and a plate-like inorganic filler in a predetermined ratio with a liquid crystal polyester resin. However, the hardness and strength of the resin composition leave room for improvement.

[0009] Patent Document 2 proposes a liquid crystalline resin composition that contains a liquid crystalline resin, a cyclic olefin resin, and a hollow filler, and thereby has excellent dielectric properties, heat resistance, and fluidity. However, this resin composition also has poor strength.

[0010] As described above, various studies have been conducted on liquid crystal polyester resin compositions, but it has been thought to be difficult to achieve a good balance of high strength, thin-wall flowability, heat resistance, and high hardness. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-190461 [Patent Document 2] Japanese Patent Application Publication No. 2023-32942 Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide a wholly aromatic liquid crystalline polyester resin composition having an excellent balance of mechanical strength, flowability, heat resistance and Rockwell hardness, and a molded article made from the wholly aromatic liquid crystalline polyester resin composition. [Means for solving the problem]

[0013] As a result of intensive research in view of the above problems, the present inventors have found that by blending a specific glass fiber with a wholly aromatic liquid crystalline polyester consisting of specific repeating units, a wholly aromatic liquid crystalline polyester resin composition having an excellent balance of mechanical strength, fluidity, heat resistance and Rockwell hardness can be obtained, and have thus completed the present invention.

[0014] That is, the present invention includes the following preferred embodiments. [1] Formula (I) ~ Formula (IV) [ka] [In the formula, Ar1 and Ar2 each represent one or more divalent aromatic groups, and p, q, r, and s each represent a composition ratio (mol %) of each repeating unit in the wholly aromatic liquid crystal polyester, and satisfy the following condition: 30≦(p+q)<60, 1≦q≦12, 20≦r≦35, 20≦s≦35] and 5 to 150 parts by mass of glass fibers having an average fiber diameter of 3 to 8 μm. [2] Formula (I) ~ Formula (IV) [ka] [In the formula, Ar1 and Ar2 each represent one or more divalent aromatic groups, and p, q, r, and s each represent a composition ratio (mol %) of each repeating unit in the wholly aromatic liquid crystal polyester, and satisfy the following condition: 30≦(p+q)<60, 1≦q≦12, 20≦r≦35, 20≦s≦35] a wholly aromatic liquid crystal polyester (A) containing a repeating unit represented by the formula: Formula (V) ~ Formula (VIII) [ka] [In the formula, t, u, v, and w are the composition ratios (mol %) of the respective repeating units in the liquid crystal polyester, and satisfy the following conditions: 60≦t+u≦78, 0.05≦u≦5, 11 ≤ v ≤ 20, and 11≦w≦20] a wholly aromatic liquid crystal polyester (B) containing a repeating unit represented by the formula: Glass fibers with an average fiber diameter of 3 to 8 μm A wholly aromatic liquid crystal polyester resin composition comprising: The mass ratio of (A) to (B) [A / B] is 95 / 5 to 20 / 80, The wholly aromatic liquid crystal polyester resin composition according to [1], wherein the content of the glass fiber is 5 to 150 parts by mass per 100 parts by mass of the total amount of (A) and (B). [3] In the repeating units represented by formulae (III) to (IV), Ar1 and Ar2 are each independently represented by formulae (1) to (4): [ka] The wholly aromatic liquid crystal polyester resin composition according to [1] or [2], wherein each of the repeating units is one or more types selected from aromatic groups represented by the following formula: [4] The wholly aromatic liquid crystal polyester resin composition according to [3], wherein the repeating unit represented by formula (III) comprises 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) comprises a repeating unit in which Ar2 is an aromatic group represented by formula (1) and / or formula (4). [5] The wholly aromatic liquid crystal polyester resin composition according to [3], wherein the repeating unit represented by formula (III) comprises a repeating unit in which Ar1 is an aromatic group represented by formulas (1) and (3), and the repeating unit represented by formula (IV) comprises a repeating unit in which Ar2 is an aromatic group represented by formula (1). [6] The wholly aromatic liquid crystal polyester resin composition according to any one of [1] to [5], which has a Rockwell hardness (M scale) of 50 or more. [7] The wholly aromatic liquid crystal polyester resin composition according to any one of [1] to [6], which has a tensile strength of 150 MPa or more as measured in accordance with ASTM D638. [8] The wholly aromatic liquid crystal polyester resin composition according to any one of [1] to [7], which has a deflection temperature under load of 240°C or higher, measured at a load of 1.82 MPa in accordance with ASTM D648. [9] A molded article made from the wholly aromatic liquid crystal polyester resin composition according to any one of [1] to [8].

[10] The molded article according to [9], which is a part constituting one type selected from the group consisting of a connector, a switch, a relay, a capacitor, a coil, a motor, a fan, a test socket, an IC tray, a bearing, a shutter plate, a camera module, a transformer, and an antenna. [Effects of the Invention]

[0015] The wholly aromatic liquid crystal polyester resin composition of the present invention has an excellent balance of mechanical strength, fluidity, heat resistance, and Rockwell hardness, and is therefore suitable for a variety of applications, such as electrical and electronic parts for various communication equipment and electronic devices, for example, connectors, switches, relays, capacitors, coils, motors, fans, test sockets, IC trays, bearings, shutter plates, camera modules, transformers, and antennas. DETAILED DESCRIPTION OF THE INVENTION

[0016] The wholly aromatic liquid crystalline polyester (A) used in the wholly aromatic liquid crystalline polyester resin composition of the present invention and the optionally used wholly aromatic liquid crystalline polyester (B) are both wholly aromatic liquid crystalline polyesters that form an anisotropic molten phase known to those skilled in the art as thermotropic liquid crystalline polyesters.

[0017] The properties of the anisotropic molten phase of the wholly aromatic liquid crystal polyester 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.

[0018] The wholly aromatic liquid crystal polyester (A) will be described below.

[0019] The wholly aromatic liquid crystal polyester (A) used in the present invention contains repeating units represented by formulae (I) to (IV). [ka] [In the formula, Ar1 and Ar2 each represent one or more divalent aromatic groups, and p, q, r, and s each represent a composition ratio (mol %) of each repeating unit in the wholly aromatic liquid crystal polyester, and satisfy the following condition: 30≦(p+q)<60, 1≦q≦12, 20≦r≦35, 20≦s≦35]

[0020] The composition ratio p in formula (I) is preferably from 25 to 57 mol %, more preferably from 27 to 55 mol %, further preferably from 30 to 50 mol %, and particularly preferably from 32 to 45 mol %.

[0021] The composition ratio q in formula (II) is 1 to 12 mol %, preferably 1.5 to 10 mol %, more preferably 2 to 9 mol %, further preferably 2.5 to 8 mol %, and particularly preferably 3 to 7 mol %.

[0022] The sum of the composition ratio p according to formula (I) and the composition ratio q according to formula (II), p+q, is 30 to 60 mol%, preferably 32 to 58 mol%, more preferably 34 to 56 mol%, even more preferably 36 to 54 mol%, and particularly preferably 38 to 50 mol%.

[0023] The composition ratio r of formula (III) and the composition ratio s of formula (IV) are each 20 to 35 mol%, preferably 21 to 34 mol%, more preferably 22 to 33 mol%, even more preferably 23 to 32 mol%, and particularly preferably 25 to 31 mol%. It is preferable that r and s are substantially equimolar.

[0024] 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 an aromatic group that is a 6-membered monocyclic ring or a fused ring having two or more rings.

[0025] In the above repeating unit, for example, when Ar1 (or Ar2) represents two or more divalent aromatic groups, it means that the wholly aromatic liquid crystal polyester contains two or more repeating units represented by formula (III) (or (IV)) according to the type of divalent aromatic group. In this case, the composition ratio r according to formula (III) (or the composition ratio s according to formula (IV)) represents the total composition ratio of the two or more repeating units.

[0026] In the wholly aromatic liquid crystal polyester (A), specific examples of the monomer that provides the repeating unit represented by formula (I) include 4-hydroxybenzoic acid and its ester-forming derivatives such as acylates, ester derivatives, and acid halides.

[0027] Specific examples of the monomer that provides the repeating unit represented by formula (II) include 6-hydroxy-2-naphthoic acid and its ester-forming derivatives such as acylates, ester derivatives and acid halides.

[0028] Specific examples of monomers that provide the repeating unit represented by formula (III) include aromatic diols such as hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, alkyl-, alkoxy- or halogen-substituted products thereof, and ester-forming derivatives such as acylated products thereof.

[0029] Specific examples of monomers that provide the repeating unit represented by formula (IV) include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and 4,4'-dicarboxybiphenyl, as well as alkyl-, alkoxy-, or halogen-substituted derivatives thereof, and ester-forming derivatives thereof such as ester derivatives and acid halides.

[0030] Among these, it is preferable that the repeating units represented by formulas (III) to (IV) are each independently one or more repeating units selected from the aromatic groups represented by formulas (1) to (4) below. [ka]

[0031] Furthermore, it is more preferable that the repeating unit represented by formula (III) comprises a repeating unit in which Ar1 is an aromatic group represented by formula (1) and / or formula (3), and that the repeating unit represented by formula (IV) comprises a repeating unit in which Ar2 is an aromatic group represented by formula (1) and / or formula (4), because this makes it easier to adjust the mechanical properties, heat resistance, crystalline melting temperature, and molding processability of the wholly aromatic liquid crystal polyester (A) to appropriate levels.

[0032] Furthermore, it is more preferable that the repeating unit represented by formula (III) comprises a repeating unit in which Ar1 is an aromatic group represented by formulas (1) and (3), and that the repeating unit represented by formula (IV) comprises a repeating unit in which Ar2 is an aromatic group represented by formula (1), in terms of excellent fluidity.

[0033] In the wholly aromatic liquid crystal polyester (A) of the present invention, the total composition ratio of the repeating units [p+q+r+s] is preferably 100 mol %, but other repeating units may be further contained within a range that does not impair the object of the present invention.

[0034] Examples of monomers that provide other repeating units include other aromatic hydroxycarboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic aminocarboxylic acids, aromatic compounds with three or more valences, aromatic mercaptocarboxylic acids, aromatic dithiols, aromatic mercaptophenols, and combinations thereof.

[0035] The total composition ratio of repeating units provided by other monomer components is preferably 10 mol % or less, more preferably 5 mol % or less, of the total repeating units.

[0036] The wholly aromatic liquid crystal polyester (A) used in the present invention preferably has a crystalline melting temperature measured by a differential scanning calorimeter of 260 to 380° C., more preferably 290 to 360° C., and even more preferably 310 to 350° C. If the crystalline melting temperature is lower than 260° C., the heat resistance tends to be insufficient, and if it exceeds 380° C., the molding processability tends to be insufficient.

[0037] In this specification and claims, the term "crystalline melting temperature" refers to the peak crystalline melting temperature measured using a differential scanning calorimeter (hereinafter abbreviated as DSC) at a heating rate of 20 ° C. / min. More specifically, a sample of a wholly aromatic liquid crystalline polyester is measured at a heating rate of 20 ° C. / min from room temperature to the endothermic peak temperature (Tm1), and then held at a temperature 20 to 50 ° C. higher than Tm1 for 10 minutes. The sample is then cooled to room temperature at a cooling rate of 20 ° C. / min, and then measured again at a heating rate of 20 ° C. / min. The endothermic peak is observed, and the temperature at the peak top is taken as the crystalline melting temperature of the wholly aromatic liquid crystalline polyester. For example, a DSC7020 manufactured by Hitachi High-Tech Science Corporation can be used as the measuring instrument.

[0038] Next, the wholly aromatic liquid crystal polyester (B) will be described.

[0039] In the present invention, the wholly aromatic liquid crystal polyester (B) may be a polyester represented by the formula (V) to the formula (VIII): [ka] [In the formula, t, u, v, and w are the composition ratios (mol %) of the respective repeating units in the liquid crystal polyester, and satisfy the following conditions: 60≦t+u≦78, 0.05≦u≦5, 11 ≤ v ≤ 20, and 11≦w≦20] The repeating unit represented by the formula (I) is used.

[0040] The composition ratio t in formula (V) is preferably 58 to 76 mol %, more preferably 60 to 75 mol %, and even more preferably 66 to 74 mol %.

[0041] The composition ratio u in formula (VI) is 0.05 to 5 mol %, preferably 0.5 to 4 mol %, more preferably 1 to 3.5 mol %, and even more preferably 1.5 to 3 mol %.

[0042] The sum of the composition ratio t according to formula (V) and the composition ratio u according to formula (VI), ie, t+u, is 60 to 78 mol%, preferably 62 to 77 mol%, more preferably 64 to 76 mol%, and even more preferably 66 to 75 mol%.

[0043] The composition ratio v of formula (VII) and the composition ratio w of formula (VIII) are each 11 to 20 mol %, preferably 11.5 to 18 mol %, more preferably 12 to 16 mol %, and even more preferably 12.5 to 15 mol %. Preferably, v and w are substantially equimolar.

[0044] In the wholly aromatic liquid crystal polyester (B), specific examples of the monomer that provides the repeating unit represented by formula (V) include 4-hydroxybenzoic acid and its ester-forming derivatives such as acylates, ester derivatives, and acid halides.

[0045] Specific examples of the monomer that provides the repeating unit represented by formula (VI) include 6-hydroxy-2-naphthoic acid and its ester-forming derivatives such as acylates, ester derivatives and acid halides.

[0046] Specific examples of monomers that provide the repeating unit represented by formula (VII) include hydroquinone and its ester-forming derivatives such as acylated products.

[0047] Specific examples of the monomer that provides the repeating unit represented by formula (IV) include 2,6-naphthalenedicarboxylic acid, and its ester-forming derivatives such as ester derivatives and acid halides.

[0048] In the wholly aromatic liquid crystal polyester (B) of the present invention, the total composition ratio of the repeating units [t+u+v+w] is preferably 100 mol %, but other repeating units may be further contained within a range that does not impair the object of the present invention.

[0049] Examples of monomers that provide other repeating units include other aromatic hydroxycarboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic aminocarboxylic acids, aromatic compounds with three or more valences, aromatic mercaptocarboxylic acids, aromatic dithiols, aromatic mercaptophenols, and combinations thereof.

[0050] The total composition ratio of repeating units provided by other monomer components is preferably 10 mol % or less, more preferably 5 mol % or less, and even more preferably substantially free of repeating units, based on the total repeating units.

[0051] The wholly aromatic liquid crystal polyester (B) used in the present invention preferably has a crystalline melting temperature measured by a differential scanning calorimeter of 260 to 380° C., more preferably 290 to 360° C., and even more preferably 310 to 350° C. If the crystalline melting temperature is lower than 260° C., the heat resistance tends to be insufficient, and if it exceeds 380° C., the molding processability tends to be insufficient.

[0052] The method for producing the wholly aromatic liquid crystal polyester (A) and the wholly aromatic liquid crystal polyester (B) used in the present invention will be described below.

[0053] There are no particular limitations on the method for producing the wholly aromatic liquid crystalline polyester (A) used in the present invention and the optionally used wholly aromatic liquid crystalline polyester (B), and the wholly aromatic liquid crystalline polyester can be obtained by subjecting a polymerizable monomer to a known polycondensation method for forming an ester bond, such as a melt acidolysis method or a slurry polymerization method.

[0054] The melt acidolysis method is a preferred method for producing the wholly aromatic liquid crystalline polyester used in the wholly aromatic liquid crystalline polyester composition of the present invention. This method involves first heating polymerizable monomers to form a molten solution of 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 in the final stage of condensation.

[0055] 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.

[0056] In either the melt acidolysis method or the slurry polymerization method, the polymerizable monomer used in producing the wholly aromatic liquid crystalline polyester can also be subjected to the reaction at room temperature in a modified form in which the hydroxyl group is acylated, i.e., as a lower acylated product.

[0057] The lower acyl group preferably has 2 to 5 carbon atoms, more preferably 2 or 3. Particularly preferred is a method in which an acetylated product of the above-mentioned monomer component is used in the reaction.

[0058] The lower acylated product of the polymerizable monomer may be a product previously synthesized 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 wholly aromatic liquid crystal polyester.

[0059] 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.

[0060] 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).

[0061] 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.

[0062] The wholly aromatic liquid crystal polyester 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 subjected to melt-kneading with other components.

[0063] The wholly aromatic liquid crystal polyester in the form of pellets, flakes, or powder 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.

[0064] The thus-obtained wholly aromatic liquid crystalline polyester (A) and optionally the wholly aromatic liquid crystalline polyester (B) processed into pellets, flakes, or powder can be melt-kneaded with glass fibers having an average fiber diameter of 3 to 8 μm using a Banbury mixer, kneader, single-screw or twin-screw extruder, etc. to obtain the wholly aromatic liquid crystalline polyester resin composition of the present invention. In an embodiment using the wholly aromatic liquid crystalline polyester (A) and the wholly aromatic liquid crystalline polyester (B), a wholly aromatic liquid crystalline polyester resin composition (hereinafter sometimes referred to as a melt-blended resin) containing the wholly aromatic liquid crystalline polyester (A) and the wholly aromatic liquid crystalline polyester (B) that does not contain glass fibers can also be prepared in advance, and then the wholly aromatic liquid crystalline polyester resin composition of the present invention can be obtained by blending the glass fibers therewith in the same manner as above.

[0065] In the wholly aromatic liquid crystal polyester composition of the present invention, it is preferable to use a blend composition of the wholly aromatic liquid crystal polyester (A) and the wholly aromatic liquid crystal polyester (B) in terms of better fluidity and mechanical strength.

[0066] In an embodiment using a wholly aromatic liquid crystalline polyester (A) and a wholly aromatic liquid crystalline polyester (B), the mass ratio [A / B] of the wholly aromatic liquid crystalline polyester (A) to the wholly aromatic liquid crystalline polyester (B) is usually 95 / 5 to 20 / 80, preferably 90 / 10 to 25 / 75, and more preferably 80 / 20 to 30 / 70.

[0067] If [A / B] exceeds 95 / 5, it is difficult to obtain the effect of further improving the fluidity and mechanical strength by blending the wholly aromatic liquid crystal polyester (B), and if [A / B] is less than 20 / 80, the fluidity of the liquid crystal polyester resin composition may be insufficient.

[0068] The mass ratio of the liquid crystal polyester (A) to the liquid crystal polyester (B) may be adjusted in advance when preparing a molten blend resin by melt-kneading or the like, or may be adjusted when (A) and (B) are individually or simultaneously blended with glass fibers to prepare a wholly aromatic liquid crystal polyester resin composition.

[0069] Examples of glass fibers that can be used in the present invention include those produced by various methods, such as chopped glass fibers of long fiber type and milled glass fibers of short fiber type. Two or more of these can also be used in combination.

[0070] The types of glass fibers used in the present invention include E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S-glass, etc., and mixtures thereof. Among these, E-glass is preferred because it has excellent strength and is easily available.

[0071] The glass fibers used in the present invention may be treated with a coupling agent such as a silane coupling agent or a titanium coupling agent, if necessary.

[0072] The glass fibers used in the present invention may be coated with a thermoplastic resin such as a urethane resin, an acrylic resin, or an ethylene / vinyl acetate copolymer, or a thermosetting resin such as an epoxy resin, or may be treated with a sizing agent.

[0073] The average fiber diameter of the glass fibers used as a raw material in the wholly aromatic liquid crystal polyester resin composition of the present invention is 3 to 8 μm, preferably 4 to 7.5 μm, and more preferably 5 to 7 μm. If the average fiber diameter exceeds 8 μm, the mechanical strength and Rockwell hardness tend to be inferior. The average fiber diameter of the glass fibers in the obtained wholly aromatic liquid crystal polyester resin composition does not substantially change even after melt-kneading.

[0074] The cut fiber length of the glass fibers used as a raw material in the wholly aromatic liquid crystal polyester resin composition of the present invention is preferably 10 mm or less, more preferably 1.5 to 6 mm, and even more preferably 2 to 4 mm. The number average fiber length of the glass fibers in the resulting wholly aromatic 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 are usually broken or crushed during blending with the wholly aromatic liquid crystal polyester, etc., resulting in the number average fiber length in the wholly aromatic liquid crystal polyester resin composition. To obtain a wholly aromatic liquid crystal polyester resin composition containing glass fibers of the desired fiber length, the melt-kneading conditions can be set and adjusted depending on the cut fiber length of the glass fibers used.

[0075] The average fiber diameter and number-average fiber length of glass fibers can be measured by observation under a microscope. First, 1.0 g of a wholly aromatic liquid crystal polyester resin composition is placed in a crucible and incinerated in an electric furnace at 500°C for 5 hours. The residue is dispersed in methanol and spread on a glass slide to prepare a sample. Next, in the projected image of the glass fibers in the microscope field, the length in the longitudinal direction is read as the fiber length, and the length in the direction perpendicular to the longitudinal direction is read as the fiber diameter, and the arithmetic mean is calculated. The modulus of the average value is 200 or more.

[0076] The content of the glass fiber in the wholly aromatic liquid crystalline polyester resin composition of the present invention is 5 to 150 parts by mass, preferably 7 to 100 parts by mass, more preferably 10 to 70 parts by mass, even more preferably 12 to 50 parts by mass, and particularly preferably 15 to 45 parts by mass, per 100 parts by mass of the wholly aromatic liquid crystalline polyester (A), or, in an embodiment using the wholly aromatic liquid crystalline polyester (A) and the wholly aromatic liquid crystalline polyester (B), per 100 parts by mass of the total amount of the wholly aromatic liquid crystalline polyester (A) and the wholly aromatic liquid crystalline polyester (B).

[0077] If the glass fiber content is less than 5 parts by mass, it is difficult to obtain the mechanical strength and Rockwell hardness of the wholly aromatic liquid crystal polyester resin composition, and if the glass fiber content exceeds 150 parts by mass, the fluidity tends to decrease.

[0078] The content of glass fibers in the wholly aromatic liquid crystal polyester resin composition is preferably 5 to 60 mass%, more preferably 7 to 50 mass%, even more preferably 10 to 42 mass%, particularly preferably 11 to 35 mass%, and most preferably 13 to 30 mass%.

[0079] In addition, the wholly aromatic liquid crystal polyester resin composition of the present invention can contain, in addition to the above-mentioned glass fiber, for example, other fibrous, plate-like, or granular inorganic or organic fillers, as long as the object of the present invention is not impaired. Preferably, the wholly aromatic liquid crystal polyester resin composition of the present invention contains only glass fiber as a filler.

[0080] Other fibrous fillers that can be 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 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.

[0081] Other plate-like fillers that can be used in the present invention include, for example, talc, mica, kaolin, clay, 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, quartz, 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.

[0082] 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, etc., and these can be used alone or in combination of two or more.

[0083] The wholly aromatic liquid crystal polyester resin composition of the present invention may contain other additives within the range that does not impair the effects of the present invention.

[0084] 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.

[0085] The content of these other additives is preferably 10 parts by mass or less, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the wholly aromatic liquid crystalline polyester (A), or per 100 parts by mass of the total amount of the wholly aromatic liquid crystalline polyester (A) and the wholly aromatic liquid crystalline polyester (B) in an embodiment using both the wholly aromatic liquid crystalline polyester (A) and the wholly aromatic liquid crystalline polyester (B). If the content of these other additives exceeds 10 parts by mass, the thermal stability tends to deteriorate.

[0086] A substance having an external lubricant effect, such as a higher fatty acid, a higher fatty acid ester, a higher fatty acid metal salt, or a fluorocarbon surfactant, may be attached to the surface of a pellet of the wholly aromatic liquid crystal polyester resin composition in advance when molding the wholly aromatic liquid crystal polyester resin composition.

[0087] The wholly aromatic liquid crystal polyester resin 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, and the like, and thermosetting resins such as phenolic resin, epoxy resin, polyimide resin, and the like.

[0088] The other resin components may 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 wholly aromatic liquid crystal polyester resin composition. Typically, the total content of the other resins is preferably added in a range of 0.1 to 100 parts by mass, particularly 0.1 to 80 parts by mass, per 100 parts by mass of the wholly aromatic liquid crystal polyester.

[0089] A wholly aromatic liquid crystalline polyester resin composition can be prepared by blending the wholly aromatic liquid crystalline polyester (A), any wholly aromatic liquid crystalline polyester (B), and glass fiber, 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.

[0090] The wholly aromatic liquid crystal polyester resin 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.

[0091] The wholly aromatic liquid crystal polyester resin composition of the present invention preferably has a Rockwell hardness of 50 or more, more preferably 52 or more, and even more preferably 55 or more, on the M scale according to JIS K 7202-2. If the Rockwell hardness is less than 50, defects such as scratches and deformation tend to occur. The upper limit of the Rockwell hardness is not particularly limited, but is, for example, 120.

[0092] The wholly aromatic liquid crystal polyester resin composition of the present invention preferably has a tensile strength of 150 MPa or more, more preferably 155 MPa or more, and even more preferably 160 MPa 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 strength is less than 150 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.

[0093] The wholly aromatic liquid crystal polyester resin composition of the present invention preferably has a tensile modulus of 8 GPa or more, more preferably 10 GPa or more, and even more preferably 12 GPa 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 modulus is less than 8 GPa, the resin tends to be easily broken when used as a small, thin-walled part. The upper limit of the tensile modulus is not particularly limited, but is, for example, 25 GPa.

[0094] The wholly aromatic liquid crystal polyester resin composition of the present invention preferably has a deflection temperature under load (DTUL, load 1.82 MPa) of 240°C or higher, more preferably 245°C or higher, and even more preferably 250°C or higher, according to ASTM D648, when a 3.2 mm thick strip test piece (length 127 mm, width 12.7 mm) is used. If the deflection temperature under load is lower than 240°C, deformation tends 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, 300°C.

[0095] The wholly aromatic liquid crystalline polyester resin composition of the present invention preferably has a melt viscosity of 5 to 70 Pa·s, more preferably 10 to 50 Pa·s, and even more preferably 15 to 30 Pa·s, measured at the crystal melting temperature +20 to 40°C using a melt viscosity measuring device with a 1.0 mmφ×10 mm capillary. If the melt viscosity is less than 5 Pa·s, problems such as drooling are likely to occur during injection molding, and if it exceeds 70 Pa·s, the flowability tends to be insufficient.

[0096] The wholly aromatic liquid crystal polyester resin composition of the present invention has a 0.1 mm thickness flow length, measured by the method described below, of preferably 10 mm or more, more preferably 11 mm or more. If the 0.1 mm thickness flow length is less than 10 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.

[0097] The wholly aromatic liquid crystalline polyester resin composition of the present invention has an excellent balance of mechanical strength, fluidity, and Rockwell hardness, and therefore can be used as a molded product, and is particularly suitable for use in electronic parts such as connectors, switches, relays, capacitors, coils, motors, fans, test sockets, IC trays, bearings, shutter plates, camera modules, transformers, and antennas. [Example]

[0098] 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.

[0099] In the examples, the crystal melting temperature, tensile strength, tensile modulus, deflection temperature under load, melt viscosity, 0.1 mm thickness flow length and Rockwell hardness (M scale) were measured and evaluated by the methods described below.

[0100] (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 peak top temperature of the exothermic peak observed at this time was taken as the crystallization temperature (Tc) of the wholly aromatic liquid crystalline polyester. Further, the endothermic peak was observed when measuring again at a temperature increase of 20°C / min, and the temperature showing the peak top was taken as the crystalline melting temperature (Tm) of the wholly aromatic liquid crystalline polyester.

[0101] (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 20 to 40°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.

[0102] (3) Tensile modulus The same test pieces as those used for measuring the tensile strength were used and the measurement was carried out in the same manner as for the tensile strength.

[0103] (4) 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 20 to 40°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.

[0104] (5) 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 (320°C for Comparative Example 7).

[0105] (6) 0.1mm 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 was measured when the material was filled into the bar flow mold. Only for Comparative Example 7, the cylinder temperature was set to 320-320-260°C due to the low crystalline melting temperature.

[0106] [Table 1]

[0107] (7) Rockwell hardness (M scale) 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 20 to 40°C above the crystal melting temperature and a mold temperature of 70°C.The Rockwell hardness on the M scale was measured using a twin Rockwell hardness tester (HR-511, manufactured by Akashi Corporation) in accordance with JIS K 7202-2.

[0108] The synthesis examples of the wholly aromatic liquid crystal polyesters used in the Examples and Comparative Examples are described below. The abbreviations for the compounds in the synthesis examples are as follows:

[0109] [Monomers used in the synthesis of fully aromatic liquid crystal polyesters] POB: 4-hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid BP: 4,4'-dihydroxybiphenyl HQ: Hydroquinone TPA: Terephthalic acid NDA: 2,6-naphthalenedicarboxylic acid

[0110] 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 ratio shown in Table 2 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.

[0111] [Table 2]

[0112] 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 into pellets of a wholly aromatic liquid crystalline polyester resin. The amount of acetic acid distilled during polymerization was nearly the theoretical value. The crystalline melting temperature (Tm) of the resulting pellets was 335°C.

[0113] 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 NDA in the composition ratio 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.

[0114] [Table 3]

[0115] The temperature was raised from room temperature to 150°C in 1 hour under a nitrogen gas atmosphere and maintained at the same temperature for 30 minutes. Next, the temperature was raised to 350°C over 7 hours while distilling off the by-product acetic acid, and then the temperature was raised to 350°C over 80 minutes. The pressure was reduced to 5 mmHg. When the specified torque was reached, the polymerization reaction was terminated, the contents of the reactor were removed, and pellets of wholly aromatic liquid crystalline polyester resin were obtained using a crusher. The amount of acetic acid distilled during polymerization was almost the theoretical value. The crystalline melting temperature (Tm) of the obtained pellets was 321°C.

[0116] 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 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.

[0117] [Table 4]

[0118] The temperature was raised from room temperature to 150°C in 1 hour under a nitrogen gas atmosphere and maintained at the same temperature for 30 minutes. Next, the temperature was raised to 350°C over 7 hours while distilling off the by-product acetic acid, and then the temperature was raised to 350°C over 80 minutes. The pressure was reduced to 5 mmHg. When the specified torque was reached, the polymerization reaction was terminated, the contents of the reactor were removed, and pellets of wholly aromatic liquid crystalline polyester resin were obtained using a crusher. The amount of acetic acid distilled during polymerization was almost the theoretical value. The crystalline melting temperature (Tm) of the obtained pellets was 332°C.

[0119] Synthesis Example 4 (LCP4) POB and BON6 were charged in a reaction vessel equipped with a stirrer with a torque meter and a distillation tube in a total amount of 6.5 mol in the composition ratio shown in Table 5, and acetic anhydride was charged in an amount of 1.03 times the moles of the hydroxyl groups (moles) of all monomers, and deacetic acid polymerization was carried out under the following conditions.

[0120] [Table 5]

[0121] 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. Next, the temperature was rapidly raised to 210°C while distilling off the by-product acetic acid and maintained at that temperature for 30 minutes. The temperature was then raised to 325°C over 5 hours, and the pressure was then reduced to 20 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 pellets of a wholly aromatic liquid crystalline polyester resin. The amount of acetic acid distilled during polymerization was nearly the theoretical value. The crystalline melting temperature (Tm) of the resulting pellets was 278°C.

[0122] The glass fibers used in the following examples and comparative examples are shown below. GF1: Nippon Electric Glass Co., Ltd., ECS03T-790DE (average fiber diameter 6.5 μm, average fiber length 3 mm) GF2: Nitto Boseki Co., Ltd., CS3DE-256 (average fiber diameter 6.5 μm, average fiber length 3 mm) GF3: Nippon Electric Glass Co., Ltd., ECS03T-747H (average fiber diameter 10.5 μm, average fiber length 3 mm)

[0123] Examples 1 to 7 and Comparative Examples 1 to 7 The synthesized LCP and the above glass fibers were compounded to the contents (parts by mass) shown in Table 6, and melt-kneaded using a twin-screw extruder (TEX-30 manufactured by Nippon Steel Corporation) at a cylinder temperature of 20 to 40°C above the crystalline melting temperature of the LCP to obtain pellets of a wholly aromatic liquid crystal polyester resin composition. The tensile strength, tensile modulus, deflection temperature under load, melt viscosity, 0.1 mm thickness flow length, and Rockwell hardness (M scale) were then measured and evaluated using the methods described above. The results are shown in Table 6. The theoretical monomer composition (mol %) when multiple LCPs are mixed is also shown in Table 6.

[0124] As shown in Table 6, all of the wholly aromatic liquid crystal polyester resin compositions of Examples 1 to 7 satisfied the requirements of high strength, thin-wall flowability, heat resistance, and high hardness, and had an excellent balance of properties.

[0125] In contrast, the wholly aromatic liquid crystal polyester resin compositions of Comparative Examples 1 to 7 were inferior in any one of strength, fluidity, heat resistance and hardness, and did not fully satisfy the balance of performance.

[0126] [Table 6]

Claims

1. Formula (I) to formula (IV) 【Chemistry 1】 [In the formula, Ar １ and Ar ２ each represents one or more divalent aromatic groups, and p, q, r, and s each represent a composition ratio (mol %) of each repeating unit in the wholly aromatic liquid crystal polyester, and satisfy the following condition: 30≦(p+q)<60, 1≦q≦12, 20≦r≦35, 20≦s≦35] and 5 to 150 parts by mass of glass fibers having an average fiber diameter of 3 to 8 μm.

2. Formula (I) to formula (IV) 【Chemistry 2】 [In the formula, Ar １ and Ar ２ each represents one or more divalent aromatic groups, and p, q, r, and s each represent a composition ratio (mol %) of each repeating unit in the wholly aromatic liquid crystal polyester, and satisfy the following condition: 30≦(p+q)<60, 1≦q≦12, 20≦r≦35, 20≦s≦35] a wholly aromatic liquid crystal polyester (A) containing a repeating unit represented by the formula: Formula (V) to Formula (VIII) 【Transformation 3】 [In the formula, t, u, v, and w are the composition ratios (mol %) of the respective repeating units in the liquid crystal polyester, and satisfy the following conditions: 60≦t+u≦78, 0.05≦u≦5, 11≦v≦20, and 11≦w≦20] a wholly aromatic liquid crystal polyester (B) containing a repeating unit represented by the formula: Glass fibers with an average fiber diameter of 3 to 8 μm A wholly aromatic liquid crystal polyester resin composition comprising: The mass ratio of (A) to (B) [A / B] is 95 / 5 to 20 / 80, 2. The wholly aromatic liquid crystal polyester resin composition according to claim 1, wherein the content of the glass fiber is 5 to 150 parts by mass per 100 parts by mass of the total amount of (A) and (B).

3. 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) 【Chemistry 4】 3. The wholly aromatic liquid crystal polyester resin composition according to claim 1, wherein each of the repeating units is one or more types selected from aromatic groups represented by the following formula:

4. The repeating unit represented by formula (III) is Ar １ is an aromatic group represented by formula (1) and / or formula (3), and the repeating unit represented by formula (IV) is ２ The wholly aromatic liquid crystal polyester resin composition according to claim 3, comprising a repeating unit in which R is an aromatic group represented by formula (1) and / or formula (4).

5. The repeating unit represented by formula (III) is Ar １ is an aromatic group represented by formula (1) and (3), and the repeating unit represented by formula (IV) is ２ The wholly aromatic liquid crystal polyester resin composition according to claim 3, comprising a repeating unit in which is an aromatic group represented by formula (1):

6. 3. The wholly aromatic liquid crystal polyester resin composition according to claim 1, which has a Rockwell hardness (M scale) of 50 or more.

7. 3. The wholly aromatic liquid crystal polyester resin composition according to claim 1, which has a tensile strength of 150 MPa or more as measured in accordance with ASTM D638.

8. 3. The wholly aromatic liquid crystal polyester resin composition according to claim 1, wherein the deflection temperature under load measured in accordance with ASTM D648 at a load of 1.82 MPa is 240°C or higher.

9. A molded article made from the wholly aromatic liquid crystal polyester resin composition according to claim 1 or 2.

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

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