A polymer composition comprising a semiconductive material distributed within a polymer matrix is provided. The semiconductive material includes inorganic particles and an electrically conductive material, the inorganic particles having an average particle size of from about 0.1 to about 100 μm and an electrical conductivity about 500 μS/cm or less. The polymer matrix contains at least one thermoplastic high performance polymer having a deflection under load of about 40° C. or more. The polymer composition exhibits a dielectric constant of about 4 or more and a dissipation factor of about 0.3 or less, as determined at a frequency of 2 GHz.

A liquid crystal polyester resin composition includes, as essential components: a component (A): liquid crystal polyester; a component (B): a glass fiber; and a component (C): a fibrous inorganic filling material different from the component (B), in which a blending amount of the component (B) with respect to 100 parts by mass of the component (A) is 50 parts by mass or more and 90 parts by mass or less, a blending amount of the component (C) with respect to 100 parts by mass of the component (A) is 1 part by mass or more and 40 parts by mass or less, and a condition (1) and a condition (2) are satisfied.

The present invention relates to a pellet of a liquid crystal polyester resin composition, including a liquid crystal polyester resin (A) and an inorganic filler (B), in which the pellet has voids with a sphere equivalent diameter of 10 μm to 1000 μm, an abundance ratio of voids having a sphere equivalent diameter of less than 400 μm in a total amount of the voids is in a range of 40% to 90%, and an average number of the voids in one pellet having a length of 1 mm to 5 mm and a maximum diameter of 1 mm to 3 mm is in a range of 4 to 9.

The invention provides a resin composition that is capable of relaxing anisotropy while keeping the crystalline structure derived from liquid crystallinity and that has isotropic structure and physicality from a macroscopic view, even after the melt-processed molded article obtained by applying shear has been molded, cooled and fused without applying shear stress and subsequently re-cooled. The resin composition comprises a liquid crystal polyester resin (A) comprising structural unit (I) derived from a hydroxycarboxylic acid, structural unit (II) derived from a diol compound, and structural unit (III) derived from a dicarboxylic acid, and a resin (B) other than the liquid crystal polyester resin (A), and has an X-ray diffraction measured after fusing the resin composition that satisfies a specific condition.

The present invention relates to a process for preparing fine particles of an aromatic copolyester, the process comprising the melt-blending of the aromatic copolyester with a polyester polymer (PE), the cooling the blend and the recovery of the particles by dissolution of the PE into water. The present invention also relates to aromatic copolyester particles obtained therefrom and to the use of these particles in to make coatings or films.

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) is a structural unit (IA) derived from 6-hydroxy-2-naphthoic acid, the structural unit (III) contains a structural unit (IIIA) derived from terephthalic acid, a structural unit (IIIB) derived from isophthalic acid, and a structural unit (IIIC) 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.

Described herein are polymer compositions including a liquid crystal polymer (“LCP”) and 1 weight percent (“wt. %”) to 25 wt. % of a semi-aromatic, semi-crystalline polyester, relative to the total weight of the LCP and semi-aromatic, semi-crystalline polyester. It was surprisingly discovered that polymer compositions including an LCP in conjunction with a semi-aromatic, semi-crystalline polymer could be melt-extruded into desirable films, as opposed to corresponding polymer compositions. It was further surprisingly discovered that the polymer compositions described herein had improved mechanical performance (tensile strength and tensile elongation), relative to corresponding polymer compositions. Still further, the polymer compositions also unexpectedly had reduced (Tm-Tc) relative to corresponding polymer compositions and, therefore, provided faster cycle times for molded articles formed from the polymer compositions.

A liquid crystal polyester resin for laminate, wherein, in a molecular weight distribution of an absolute molecular weight measured by a gel permeation chromatograph/light scattering method, an area fraction of a portion having an absolute molecular weight of 10,000 or less is 10 to 40%, and an area fraction of a portion having an absolute molecular weight of 50,000 or more is 3 to 20%, relative to 100% of the total peak area.

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.

The present invention relates to: a liquid crystal polyester resin composition which contains a liquid crystal polyester resin and carbon fibers with a sizing agent; and a method for producing this liquid crystal polyester resin composition. The content of the carbon fibers with a sizing-agent is from 5 parts by mass to 120 parts by mass relative to 100 parts by mass of the liquid crystal polyester resin. With respect to the carbon fibers with a sizing-agent, the adhesion amount of the sizing agent with respect to the carbon fibers is from 0.1 parts by mass to 1.2 parts by mass relative to 100 parts by mass of the carbon fibers. If the carbon fibers with a sizing agent are heated from 25° C. to 400° C. in the air at a heating rate of 50° C./min, the mass loss rate within the range from 300° C. to 400° C. is less than 0.8% by mass.