Abstract: A liquid-crystalline polymer composition with less warpage not only in molding but also in a high temperature treatment conducted after molding is provided. The liquid-crystalline polymer comprises (i) 30 to 95% by weight of a first liquid-crystalline polymer having a deflection temperature under load of 200° C. or higher and (ii) 5 to 70% by weight of a second liquid-crystalline polymer having a deflection temperature under load lower than that of the first liquid-crystalline polymer, a melting point from 270° C. to lower than 400° C. and a flow-beginning temperature of 270° C. or higher.

Abstract: An aromatic liquid-crystalline polyester film having a low water absorbing property, and additionally, showing small linear expansion coefficient is provided by an aromatic liquid-crystalline polyester film comprising an aromatic liquid-crystalline polyester with a weight average molecular weight of 5000 to 100000, which comprises a structural unit of the following formula (I) derived from p-hydrozybenzoic acid: a structural unit of the following formula (II) derived from hydroquinone, dihydroxybiphenyl: (wherein, n represents 0 or 1), and a structural unit of the following formula (III) derived from naphthalenecarboxylic acid: wherein each structural unit combines through ester-bonding.

Abstract: A resin composition comprising an inorganic material with a thermal conductivity of 10 W/mK or higher at a temperature of 20° C. and an aromatic polyester is provided. The aromatic polyester may have structural units derived from (I) 2-hydroxy-6-naphthoic acid, (II) a compound selected from hydroquinone, 4,4?-dihydroxybiphenyl and 2,6-dihydroxynaphthalene, (III) naphthalenedicarboxylic acid and (IV) a compound selected from terephthalic acid, isophthalic acid and phthalic acid.

Abstract: The present invention provides a conductive resin composition comprising a liquid crystalline polyester which comprises the following structure units having the formulas (i), (ii) and (iii), and has an aromatic group having 2,6-naphthalenediyl group in a ratio of not less than 5% by mole; and at least one filler selected from a metal oxide conductive filler and a carbon conductive filler. According to the present invention, the composition is easy to mold and can give molded products having high hydrolysis resistance. The resulting molded products are hardly to lower the strength even if they are exposed to high temperature and humid condition, and can be suitably used for a separator in a fuel cell.

Abstract: A method for producing a polyester is provided, the method comprising the step of reacting an acylated product of a compound having at least one phenolic hydroxyl group with an aromatic carboxylic acid under microwave irradiation. Polyester can be produced by the method in a relatively short period of time at high temperature with a suppressed thermal hysteresis.

Abstract: The present invention provides a liquid crystalline polyester comprising (a) a repeating unit derived from aromatic hydroxycarboxylic acid, (b) a repeating unit derived from aromatic dicarboxylic acid and (c) a repeating unit represented by —X—Ar1-O—Ar1-Y—, wherein Ar1 represents 1,4-phenylene which may be substituted by a halogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, and X and Y independently represent O or NH. The polyester in the preset invention has a sufficiently low dielectric constant and/or is a sufficiently high resistance in hydrolysis.

Abstract: An aromatic liquid-crystalline polyester having a small dielectric loss in a wide frequency region is provided. An aromatic liquid-crystalline polyester is provided that can manufacture a film having a small volume expansion by heating. An aromatic liquid-crystalline polyester substantially comprising a repeating structural unit originating in 2-hydroxy-6-naphthoic acid 30 to 80 mol %, a repeating structural unit originating in aromatic diol 35 to 10 mol %, and a repeating structural unit originating in aromatic dicarboxylic acid 35 to 10 mol %.

Abstract: An aromatic liquid-crystalline polyester with good moldability into a film is provided. The resulting film has small dielectric loss. The polyester comprises repeating units represented by formulae (I), (II), (III) and (IV), and the molar amounts of repeating units (I)–(IV) are 40–74.8%, 12.5–30%, 12.5–30% and 0.2–15%, respectively, wherein the molecular amounts of repeating units (III) and (IV) satisfy the relation of (III)/[(III)+(IV)]?0.5.

Abstract: A resin composition comprising an inorganic material with a thermal conductivity of 10 W/mK or higher at a temperature of 20° C. and an aromatic polyester is provided. The aromatic polyester may have structural units derived from (I) 2-hydroxy-6-naphthoic acid, (II) a compound selected from hydroquinone, 4,4?-dihydroxybiphenyl and 2,6-dihydroxynaphthalene, (III) naphthalenedicarboxylic acid and (IV) a compound selected from terephthalic acid, isophthalic acid and phthalic acid.

Abstract: An aromatic liquid-crystalline polyester with good moldability into a film is provided. The resulting film has small dielectric loss. The polyester comprises repeating units represented by formulae (I), (II), (III) and (IV), and the molar amounts of repeating units (I)-(IV) are 40-74.8%, 12.5-30%, 12.5-30% and 0.2-15%, respectively, wherein the molecular amounts of repeating units (III) and (IV) satisfy the relation of (III)/[(III)+(IV)]?0.5.

Abstract: The present invention provides an aromatic polyester which is obtained by condensation polymerization reaction of terephthalic acid, 2,6-naphthalenedicarboxylic acid and acylated product obtained by acylation of parahydroxybenzoic acid and hydroquinone with fatty acid anhydride, wherein said aromatic polyester satisfy the following conditions (A) to (D), and the acylation and/or the condensation polymerization reaction are conducted in the presence of heterocyclic organic compound containing at least two nitrogen atoms: (A): Number of moles of a monomer unit derived from parahydroxybenzoic acid (UNIT (1)) is 54-62 moles per 100 moles of UNIT (1), a monomer unit derived from hydroquinone (UNIT (2)), a monomer unit derived from terephthalic acid (UNIT (3)) and a monomer unit derived from 2,6-naphthalenedicarboxylic acid (UNIT (4)) in total; (B): Number of moles of UNIT (2) is 19-23 moles per 100 moles of UNIT (1), UNIT (2), UNIT (3) and UNIT (4) in total; (C): The molar ratio of UNIT (3) and UNIT (4), which is

Abstract: An aromatic liquid-crystalline polyester having a small dielectric loss in a wide frequency region is provided. An aromatic liquid-crystalline polyester is provided that can manufacture a film having a small volume expansion by heating. An aromatic liquid-crystalline polyester substantially comprising a repeating structural unit originating in 2-hydroxy-6-naphthoic acid 30 to 80 mol %, a repeating structural unit originating in aromatic diol 35 to 10 mol %, and a repeating structural unit originating in aromatic dicarboxylic acid 35 to 10 mol %.

Abstract: An aromatic liquid-crystalline polyester film having a low water absorbing property, and additionally, showing small linear expansion coefficient is provided by an aromatic liquid-crystalline polyester film comprising an aromatic liquid-crystalline polyester with a weight average molecular weight of 5000 to 100000, which comprises a structural unit of the following formula (I) derived from p-hydrozybenzoic acid: 1

Abstract: The present invention provides an aromatic polyester which is obtained by condensation polymerization reaction of terephthalic acid, 2,6-naphthalenedicarboxylic acid and acylated product obtained by acylation of parahydroxybenzoic acid and hydroquinone with fatty acid anhydride, wherein said aromatic polyester satisfy the following conditions (A) to (D), and the acylation and/or the condensation polymerization reaction are conducted in the presence of heterocyclic organic compound containing at least two nitrogen atoms: