A polycarbonate resin composition, which has favorable balance, excellent chemical resistance, flame retardancy, impact resistance, heat resistance and moist heat resistance. A polycarbonate resin composition, including 1 to 60 parts by mass of a liquid crystal polyester (B) containing a repeating unit represented by specific formulae (I) to (IV), 0.01 to 0.5 parts by mass of an organic metal salt flame retardant (C) and 0.05 to 1 parts by mass of a fluorinated resin (D) relative to 100 parts by mass of a polycarbonate resin (A), and having a notched Charpy impact strength of 15.5 kJ/m.sup.2 or more, as measured at 23° C. in accordance with ISO 179 by using an ISO dumbbell having a thickness of 3 mm.

The present disclosure relates to a liquid crystal polyester resin composition and an electronic component material comprising the same with low dust characteristics. Specifically, the present disclosure relates to a liquid crystal polyester resin composition for preventing dust generation comprising 65% by weight or more and 85% by weight or less of a liquid crystal polyester resin; more than 0.5% by weight and less than 10% by weight of a transition metal compound containing a Group 6 element of the periodic table; 2% by weight or more and 10% by weight or less of a barium compound; 2% by weight or more and 10% by weight or less of an organic filler; and 12% by weight or more and 30% by weight or less of a filler.

The present disclosure relates to a liquid crystal polyester resin composition comprising a liquid crystal polyester resin with a low dielectric constant and a low dielectric loss containing a naphthoic acid monomer as a main skeleton and a hydroxybenzoic acid; a glass bubble having a pressure resistance of 12,000 psi or more; and an inorganic filler such as mica. The present disclosure provides a liquid crystal polyester resin composition suitable for 5G communication materials, which can achieve low dielectric loss characteristics, and at the same time, the addition of glass bubbles with excellent pressure resistance can achieve a low dielectric constant and a low dielectric loss through the maintenance of the hollow body of the glass bubbles even after melt extrusion.

A liquid crystal polyester fibers containing a liquid crystal polyester, in which the liquid crystal polyester has repeating units represented by Formulae (1), (2) and (3), at least one of the repeating units contains 2,6-naphthylene, a content of the repeating unit containing the 2,6-naphthylene is 40 mol% or greater with respect to a total content of all the repeating units, and an orientation degree of the liquid crystal polyester in a length direction of the fiber is 89% to 95%:
—O—Ar.sup.1—CO—  (1),
—CO—Ar.sup.2—CO—  (2), and
—X—Ar.sup.3—Y—  (3), wherein Ar.sup.1 represents phenylene, naphthylene, or biphenylylene, Ar.sup.2 and Ar.sup.3 each independently represent phenylene, naphthylene, or biphenylylene, and at least one of Ar.sup.1, Ar.sup.2, and Ar.sup.3 contains 2,6-naphthylene, X and Y each independently represent oxygen or —NH—, Ar.sup.1, Ar.sup.2, or Ar.sup.3 may be each independently substituted with halogen, alkyl, or aryl.

The present disclosure relates to a liquid crystal polyester composition that can be injection molded into an ultra-thin film and has improved fluidity, and a manufacturing method thereof. The polyester resin composition for ultra-thin injection molding includes 60 to 85% by weight of a liquid crystal polyester resin and 15 to 40% by weight of an inorganic filler having an average cross-sectional aspect ratio of 2 to 6, based on the total weight of the composition, wherein the liquid crystal polyester resin includes 0.1 to 10 mol % of hydroxybenzoic acid (HBA), 40 to 60 mol % of hydroxynaphthoic acid, 20 to 30 mol % of biphenol, and 20 to 30 mol % of terephthalic acid. The liquid crystal polyester resin composition for ultra-thin injection molding according to the present disclosure not only has excellent mechanical strength and heat resistance, but also can exhibit very excellent fluidity in a high-speed injection process.

Provided is a film including a thermoplastic resin, in which a relative permittivity of the film at a frequency of 1 GHz is 3 or less, a dielectric loss tangent of the film at a frequency of 1 GHz is 0.005 or less, and a molecular orientation (MOR) value of the film, which is measured by a microwave orientation meter, is in a range of 1 to 1.1.

The invention provides a liquid crystal polyester resin which not only has a low-dielectric tangent, but also is excellent in balance between heat resistance and processing stability. The liquid crystal polyester resin comprises: a structural unit (I) derived from an aromatic hydroxycarboxylic acid; a structural unit (II) derived from an aromatic diol compound; and a structural unit (III) derived from an aromatic dicarboxylic acid, wherein the structural unit (I) contains a structural unit (IA) derived from 6-hydroxy-2-naphthoic acid, the structural unit (III) contains a structural unit (IIIA) derived from terephthalic acid, and a structural unit (IIIB) derived from isophthalic acid, the dielectric tangent at a measurement frequency of 10 GHz is 1.50×10.sup.−3 or less, the melting point is 295° C. or more, and the difference between the melting point and the crystallization point is 35° C. or more.

The resin composition includes a liquid crystal polyester resin (A) and a filler (B), in which (1) liquid crystal polyester resin (A) contains a structural unit (I) derived from 6-hydroxy-2-naphthoic acid, a structural unit (II) derived from an aromatic diol compound, and a structural unit (III) derived from an aromatic dicarboxylic acid compound, wherein structural unit (III) contains a structural unit (IIIA) derived from terephthalic acid and/or a structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid, (2) 40% by mol≤structural unit (I)≤75% by mol, 12% by mol≤structural unit (II)≤30% by mol, and 12% by mol≤structural unit (III)≤30% by mol, (3) filler (B) is at least one of silica, mica, and talc, and (4) the resin composition has a dielectric tangent of 1.0×10.sup.−3 or less as measured by a cavity resonator perturbation method at 10 GHz.

A resin composition containing a liquid crystal polymer (A) and a predetermined polyimide resin (B), wherein the liquid crystal polymer (A) contains at least one repeating structural unit selected from the group consisting of repeating structural units represented by the following formulas (I) to (IV), and a molded article containing the same:

##STR00001##

wherein a, b, and c represent an average number of repeating structural units.

The invention provides a liquid crystal polyester resin which not only has a low-dielectric tangent, but also is excellent in balance between heat resistance and processing stability. The liquid crystal polyester resin comprises: a structural unit (I) derived from an aromatic hydroxycarboxylic acid; a structural unit (II) derived from an aromatic diol compound; and a structural unit (III) derived from an aromatic dicarboxylic acid, wherein the structural unit (I) contains a structural unit (IA) derived from 6-hydroxy-2-naphthoic acid, the structural unit (III) contains a structural unit (IIIA) derived from isophthalic acid and a structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid, the dielectric tangent at a measurement frequency of 10 GHz is 1.50×10.sup.−3 or less, the melting point is 290° C. or more, and the difference in temperature between the melting point and the crystallization point is 30° C. or more.