Abstract: Disclosed is a method for producing a liquid crystal polyester, which includes the following steps of: (1) melt-polycondensing a compound as a monomer in a polymerization tank to produce a prepolymer; (2) discharging the prepolymer from the polymerization tank in a molten state, and solidifying the prepolymer through cooling to produce a sheet in which a portion having a thickness of 1.6 to 2 mm accounts for 80% by mass or more (of 100% by mass of the entire sheet); (3) crushing the sheet; and (4) subjecting the crushed product to solid-phase polymerization through heating.

Abstract: A method for producing an acylate by acylating a phenolic hydroxyl group contained in an aromatic hydroxycarboxylic acid and/or an aromatic diol with a fatty acid anhydride in an acylation reaction vessel, the method including refluxing a liquid, which is obtained by cooling an evaporant from the acylation reaction vessel, so as to allow the liquid to flow down an inner wall surface of the acylation reaction vessel in an amount of 10 kg/hour/m or more.

Abstract: The present invention provides a resin composition containing a liquid crystalline polyester and a high dielectric material filler. The present invention also provides a molded article of the liquid crystalline polyester resin composition. The liquid crystalline polyester resin composition of the present invention comprises 50 to 80% by volume of a liquid crystalline polyester which has 40% by mol or more of a 2,6-naphthalenediyl group as an aromatic group, also has a flow initiation temperature of 280° C. or higher, and shows a melt tension of 1 g or more measured at a temperature higher than flow initiation temperature; and 20 to 50% by volume of a high dielectric material filler. The liquid crystalline polyester resin composition can be formed into composition pellets easily and stably by a strand method, and a molded article obtained from the liquid crystalline polyester resin composition is excellent in flexural strength and dielectric characteristics.

Abstract: The invention relates to an insulating film for an electromagnetic coil which is composed of a liquid crystal polyester, in which the liquid crystal polyester has a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3), and the amount of the structural units including a 2,6-naphthalenediyl group is 40 mol % or more with respect to the total amount of all the structural units.

Abstract: A heat-resistant label containing a liquid crystalline polyester base material, wherein the liquid crystalline polyester in this liquid crystalline polyester base material contains a structural unit represented by the following formula (1), a structural unit represented by the following formula (2) and a structural unit represented by the following formula (3), and wherein the amount of structural units containing a 2,6 naphthalenediyl group is at least 40 mol % based on the total amount of all the structural units: (1) —O—Ar1—CO— (2) —CO—Ar2—CO— and (3) —O—Ar3—O— (wherein, Ar1 represents a 2,6-naphthalenediyl group, a 1,4-phenylene group, or a 4,4?-biphenylylene group; each of Ar2 and Ar3 independently represents a 2,6-naphthalenediyl group, a 1,4-phenylene group, a 1-3-phenylene group, or a 4,4?-biphenylylene group; and hydrogen atoms which are in the group represented by Ar1, Ar2 or Ar3 may be each independently substituted with a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl gro

Abstract: An object of the present invention is to provide a back sheet for a solar cell that improves weather resistance while also being advantageous in terms of cost. In a back sheet 7 for a solar cell of a preferred embodiment, a liquid crystal polyester that composes a liquid crystal polyester base material is formed of structural units represented by the following formulas (1), (2) and (3).

Abstract: A resin-impregnated sheet is provided in which a dielectric loss tangent is small. In a preferred embodiment the sheet is prepared by impregnating a fiber sheet with a liquid crystal polyester which has a repeating unit represented by formula (1), a repeating unit represented by formula (2), and a repeating unit represented by formula (3), in which a content of a repeating unit comprising a 2,6-naphthylene group is 40 mole % or more based on a total amount of all repeating units, as follows: (1)-O—Ar1—CO—; (2)-CO—Ar2—CO—; and (3)-O—Ar3—O— wherein Ar1 represents a 2,6-naphthylene group, a 1,4-phenylene group, or a 4,4?-biphenylylene group; Ar2 and Ar3 each independently represent a 2,6-naphthylene group, a 1,4-phenylene group, a 1,3-phenylene group, or a 4,4?-biphenylylene group; and hydrogen atoms present in the group represented by Ar1, Ar2, or Ar3 may each independently be replaced by a halogen atom, an alkyl group, or an aryl group.

Abstract: The present invention provides a method for producing a liquid-crystalline polyester powder, the method comprising: carrying out melt polycondensation of monomers and/or its acylated monomers to obtain a corresponding polyester having a flow initiation temperature of 240 to 300° C.; spreading and solidifying the polyester so as to be a layer thereof with a thickness of 1 cm or more: crushing the solidified substance to obtain a powder having a volume average particle diameter of 3 to 30 ?m; and subjecting the powder to a heat treatment to obtain a powder having a flow initiation temperature higher than the flow initiation temperature of the liquid-crystalline polyester after the melt polycondensation.

Abstract: The present invention provides a liquid-crystalline polyester having a structural unit represented by the formula (i), a structural unit represented by the formula (ii) and a structural unit represented by the formula (iii): wherein Ar1 is, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group and a 4,4?-biphenylene group; and Ar2 and Ar3 are, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group, a 1,3-phenylene group and a 4,4?-biphenylene group; wherein 40% by mole or more of all the groups Ar1, Ar2 and Ar3 are 2,6-naphthalenediyl groups; and wherein the polyester has a flow initiation temperature of from about 280 to about 320° C.

Abstract: The present invention provides a method for producing a liquid-crystalline polyester powder, the method comprising: carrying out melt polycondensation of monomers and/or its acylated monomers to obtain a corresponding polyester having a flow initiation temperature of 240 to 300° C.; spreading and solidifying the polyester so as to be a layer thereof with a thickness of 1 cm or more: crushing the solidified substance to obtain a powder having a volume average particle diameter of 3 to 30 ?m; and subjecting the powder to a heat treatment to obtain a powder having a flow initiation temperature higher than the flow initiation temperature of the liquid-crystalline polyester after the melt polycondensation.

Abstract: The present invention provides a resin composition comprising a liquid crystal polymer and a filler comprising a composite oxide containing Ba, Sm, and Ti. The resin composition can provide a molded article which has excellent dielectric characteristics and is excellent in dimension stability.

Abstract: The present invention provides a resin composition containing a liquid crystalline polyester and a high dielectric material filler. The present invention also provides a molded article of the liquid crystalline polyester resin composition. The liquid crystalline polyester resin composition of the present invention comprises 50 to 80% by volume of a liquid crystalline polyester which has 40% by mol or more of a 2,6-naphthalenediyl group as an aromatic group, also has a flow initiation temperature of 280° C. or higher, and shows a melt tension of 1 g or more measured at a temperature higher than flow initiation temperature; and 20 to 50% by volume of a high dielectric material filler. The liquid crystalline polyester resin composition can be formed into composition pellets easily and stably by a strand method, and a molded article obtained from the liquid crystalline polyester resin composition is excellent in flexural strength and dielectric characteristics.

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: The present invention provides a liquid-crystalline polyester having a structural unit represented by the formula (i), a structural unit represented by the formula (ii) and a structural unit represented by the formula (iii): wherein Ar1 is, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group and a 4,4?-biphenylene group; and Ar2 and Ar3 are, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group, a 1,3-phenylene group and a 4,4?-biphenylene group; wherein 40% by mole or more of all the groups Ar1, Ar2 and Ar3 are 2,6-naphthalenediyl groups; and wherein the polyester has a flow initiation temperature of from about 280 to about 320° C.

Abstract: The present invention provides a resin composition comprising a liquid crystal polymer and a filler comprising a composite oxide containing Ba, Sm, and Ti. The resin composition can provide a molded article which has excellent dielectric characteristics and is excellent in dimension stability.

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: 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: The present invention provides a method for producing a liquid crystal polyester fiber, the method comprising a step of spinning a liquid crystal polyester that has a glass transition temperature and a melting point, both observed by differential scanning calorimetry, and that has a flow initiation temperature of 250° C. or higher, followed by a heat treatment at 230° C. or lower. Even though the heat treatment is conducted at a low temperature, the obtained liquid crystal polyester fiber has a high strength.

Abstract: A method for producing a molded article is provided, the method comprising the step of press-molding a resin composition comprising a filler and a powder of a liquid crystal polymer having a flow starting temperature of 280° C. or higher and an average particle size of 0.5 to 50 ?m. In the molded article obtained by the method of the present invention, the functions provided by the filler, such as thermal conductivity and dielectric property, can be effectively and uniformly expressed.

Abstract: The present invention provides a liquid crystalline polymer composition comprising (A) a polymer including units of formula (I), and units of formula (II) and/or units of formula (III), the units of formula (I) being included in 15-80% by mol, based on the total units [(I)+(II)+(III)]; and (B) a polymer (B) including units of formula (IV), formula (V) and the formula (VI), each of units being included in 30-80% by mol, 10-35% by mol and 10-35% by mol, respectively, based on the total units [(IV)+(V)+(VI)], the component (B) being included in 5-80% by weight based on the total weight of the components (A) and (B); wherein (I) —(VI) are —OC—Ar1-0-, —O—Ar2—O—, —OC—Ar3—CO—, —OC—Ar4—O—, —O—Ar5—X— and —OC—Ar6—CO—, respectively.