Abstract: A liquid crystal polyester comprising a repeating unit (A1) represented by the formula (A1) and a repeating unit (A2) represented by the formula (A2). A molar ratio (phenolic hydroxyl groups derived from the repeating unit (A2)/phenolic hydroxyl groups derived from the repeating unit (A1)) is 1 or lower, as calculated by 1H-NMR. A ratio [repeating unit (A2)/repeating unit (A1)] is 1.2 or larger. The number of the repeating unit (A1) is 20% or more and the number of the repeating unit (A2) is 58% or more based on 100% of a total number of all repeating units of the liquid crystal polyester. A flow starting temperature of the liquid crystal polyester is 250° C. or more. —O—Ar11—CO—??(A1) —O—Ar12—CO—??(A2) Ar11 represents a phenylene group and Ar12 represents a naphthylene group. A hydrogen atom is optionally substituted.

Abstract: 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.

Abstract: 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.

Abstract: A liquid crystal polyester comprising a repeating unit (A1) represented by the formula (A1) and a repeating unit (A2) represented by the formula (A2). A molar ratio (phenolic hydroxyl groups derived from the repeating unit (A2)/phenolic hydroxyl groups derived from the repeating unit (A1)) is 1 or lower, as calculated by 1H-NMR. A ratio [repeating unit (A2)/repeating unit (A1)] is 1.2 or larger. The number of the repeating unit (A1) is 20% or more and the number of the repeating unit (A2) is 58% or more based on 100% of a total number of all repeating units of the liquid crystal polyester. A flow starting temperature of the liquid crystal polyester is 250° C. or more. —O—Ar11—CO—??(A1) —O—Ar12—CO—??(A2) Ar11 represents a phenylene group and Ar12 represents a naphthylene group. A hydrogen atom is optionally substituted.

Abstract: A liquid crystal polyester comprising a repeating unit derived from an aromatic hydroxycarboxylic acid. The content of the repeating unit derived from an aromatic hydroxycarboxylic acid is 80% or more based on 100% of a total number of all repeating units of the liquid crystal polyester. The repeating unit derived from an aromatic hydroxycarboxylic acid comprises a repeating unit (A1) represented by the formula (A1) and a repeating unit (A2) represented by the formula (A2). A ratio [repeating unit (A2)/repeating unit (A1)] is 1.2 or larger. A molar ratio [phenolic hydroxyl groups/(the phenolic hydroxyl groups+acyl groups)] is 0.3 or lower, as calculated by 1H-NMR. —O—Ar11—CO—??(A1) —O—Ar12—CO—??(A1) Ar11 represents a phenylene group and Ar12 represents a naphthylene group. A hydrogen atom is optionally substituted.

Abstract: Provided is a liquid crystal polyester fiber comprising a liquid crystal polyester, wherein a maximum value of a crystallite size of 20×10?10 m or larger. The maximum value is obtained by D=K·?/? cos ? (wherein D represents a crystallite size, ? represents a wavelength of the measurement X-ray, ? represents a half-value width (radian), ? represents a diffraction angle, and K represents a Scherrer constant (0.9)) based on a diffraction peak on a 110 plane of an X-ray diffraction spectrum measured by a wide angle X-ray diffraction method using X-ray having a wavelength of 1×10?10 m.

Abstract: What is provided is a method for producing a liquid crystalline polyester, the method including reacting an aromatic diol (A), an aromatic hydroxycarboxylic acid (B), and a naphthalenedicarboxylic acid (C) to obtain a liquid crystalline polyester, in which the naphthalenedicarboxylic acid (C) is a naphthalenedicarboxylic acid powder including 90% by mass or more of naphthalenedicarboxylic acid particles (C1) having a particle size of less than 150 ?m as measured by the dry sieving test method of JIS K 0069 (1992).

Abstract: 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.

Abstract: Provided is a liquid crystal polyester powder including a liquid crystal polyester having a number average molecular weight of 10000 or less, in which an average particle diameter of the liquid crystal polyester powder is 0.5 to 20 ?m.

Abstract: A resin microparticle production method includes a step of pulverizing resin particles having a thermoplastic resin as a forming material and having a BET specific surface area of equal to or more than 5 m2/g using an impact type pulverizer.

Abstract: An aromatic polyester having a repeating unit represented by formula (1) shown below and a terminal structural unit represented by formula (1e) shown below, wherein the proportion of the terminal structural unit per unit mass of the aromatic polyester is not more than 50 ?mol/g. —O—Ar1—CO—??(1) —O—Ar1—CO—OH??(1e) (In the formulas, Ar1 represents a 1,4-phenylene group, a 2,6-naphthylene group or a 4,4?-biphenylylene group. The hydrogen atoms that exist in the groups represented by Ar1 may each be independently substituted with a halogen atom, an alkyl group or an aryl group.

Abstract: Aromatic polyether microparticles contain a plurality of particles containing an aromatic polyether in which a content of the particles having a particle diameter equal to or smaller than 50 ?m to a total volume of the aromatic polyether microparticles is equal to or higher than 50% by volume. The aromatic polyether microparticles contain phenolic hydroxyl groups in a content equal to or greater than 80 ?mol/g.

Abstract: An aromatic liquid crystal polyester containing repeating structural units represented by formulas (A1), (B), (C) and (D) shown below. —O—Ar1—CO—??(A1) —CO—Ar2—CO—??(B) —O—Ar3—O—??(C) —O—Ar4—O—??(D) (In the formulas, Ar1 represents a 2,6-naphthalene group, Art represents at least one group selected from the group consisting of a 2,6-naphthalenediyl group, 1,4-phe vlene group, 1,3-phenvIene group and 4,4?-biphenylene group, Ar3 represents at least one group selected from the group consisting of a 2, mphthalenediyl group, 1,6-naphthalenediyl group and 1,5-naphthalenediyl group, Ar4 represents at least one group selected from the group consisting of a 2,6-naphthalenediyl group, 1,4-phenylene group, 1,3-phenylene group and 4,4?-hiphenylene group, and each of the groups represented by Ar1, Ar3 or Ar4 may have a halogen atom, an alkyl group of 1 to 10 carbon atoms Of alt aryl group of 6 to 20 carbon atoms as a substituent.

Abstract: A thermoplastic aromatic polysulfone is obtained by polymerizing a dihalogeno compound (A) and a dihydric phenol (B). The ratio (Mw/Mn) between a number average molecular weight (Mn) and a weight average molecular weight (Mw) is at least 1.91, and the number average molecular weight (Mn) is at least 6,000 and less than 14,000, In (A) and (B), each of X and X? independently represents a halogen atom; each of R1, R2, R3 and R4 independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; each of n1, n2, n3 and n4 independently represents an integer of 0 to 4; and when n1, n2, n3 or n4 is an integer of 2 to 4, a plurality of R1, R2, R3 or R4 groups may be the same or different from each other.

Abstract: The present invention relates to a method for producing thermoplastic aromatic polysulfone resin, in which a polymerization reaction is performed in an organic solvent by using compound (A), a dihalogeno compound represented by Formula (I), compound (B), a divalent phenol represented by Formula (II), and compound (C), an alkali metal carbonate, at a charging molar ratio satisfying the following Formulae (1) to (3): (1) 0.900<(A)/(B)<0.990; (2) {(A)/(B)}?0.02<(C)/(B)<{(A)/(B)}+0.01; and (3) (C)/(B)<1.00, In Formulae (I) and (II), R1 to R4 represent an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, X and X? represent a halogen atom, Y represents one or more groups selected from the group consisting of —SO2—, —C(CH3)2—, —CH2—, —O— and —CO—, or a single bond, and n1, n2, n3 and n4 represent an integer of 0 to 4.

Abstract: A thermoplastic aromatic polysulfone is obtained by polymerizing a dihalogeno compound (A) and a dihydric phenol (B). The ratio (Mw/Mn) between a number average molecular weight (Mn) and a weight average molecular weight (Mw) is at least 1.80 and less than 1.90, and the number average molecular weight (Mn) is at least 6,000 and less than 14,000. In (A) and (B), each of X and X? independently represents a halogen atom; each of R1, R2, R3 and R4 independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; each of n1, n2, n3 and n4 independently represents an integer of 0 to 4; and when n1, n2, n3 or n4 is an integer of 2 to 4, a plurality of R1, R2, R3 or R4 groups may be the same or different from each other.

Abstract: A resin microparticle production method includes a step of pulverizing resin particles having a thermoplastic resin as a forming material and having a BET specific surface area of equal to or more than 5 m2/g using an impact type pulverizer

Abstract: Aromatic polyether microparticles contain a plurality of particles containing an aromatic polyether in which a content of the particles having a particle diameter equal to or smaller than 50 ?m to a total volume of the aromatic polyether microparticles is equal to or higher than 50% by volume. The aromatic polyether microparticles contain phenolic hydroxyl groups in a content equal to or greater than 80 ?mol/g.

Abstract: An aromatic polysulfone produced by polymerizing a dihalogeno compound represented by general formula (A) shown below, and a dihydric phenol represented by general formula (B) shown below, the aromatic polysulfone having a value (Mw/Mn) for the ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of less than 1.8, and having a number average molecular weight (Mn) of at least 6,000 but less than 14,000. (In the formula, each of X and X? independently represents a halogen atom; each of R1, R2, R3 and R4 independently represents an alkyl group having a carbon number of 1 to 4 or an alkoxy group having a carbon number of 1 to 4; each of n1, n2, n3 and n4 independently represents an integer of 0 to 4; and when n1, n2, n3 or n4 is an integer of 2 to 4, the plurality of R1, R2, R3 or R4 groups may be the same as, or different from, each other).

Abstract: A thermoplastic aromatic polysulfone is obtained by polymerizing a dihalogeno compound (A) and a dihydric phenol (B). The ratio (Mw/Mn) between a number average molecular weight (Mn) and a weight average molecular weight (Mw) is at least 1.91, and the number average molecular weight (Mn) is at least 6,000 and less than 14,000, In (A) and (B), each of X and X? independently represents a halogen atom; each of R1, R2, R3 and R4 independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; each of n1, n2, n3 and n4 independently represents an integer of 0 to 4; and when n1, n2, n3 or n4 is an integer of 2 to 4, a plurality of R1, R2, R3 or R4 groups may be the same or different from each other.