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: 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: 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.) Vertical axis: 5% weight reduction temperature (° C.

Abstract: Disclosed is a method for producing a liquid crystal polyester, which includes the steps of: (1) polycondensing a mixture of 70.5 to 71.5 mol % of a compound represented by the defined formula (I) (for example, 4-acetoxybenzoic acid) with 28.5 to 29.5 mol % of a compound represented by the defined formula (II) (for example, 6-acetoxy-2-naphthoic acid) to form a prepolymer, wherein the prepolymer has a flow initiation temperature of 200° C. or higher, and the mixture is polycondensed until reaching the temperature which is at least 30° C. lower than the polycondensation temperature; (2) removing the prepolymer in a molten state, followed by solidification and further grinding to produce prepolymer particles; and (3) subjecting the prepolymer particles to a heat treatment at 200 to 310° C. under circulation of an inert gas while remaining in a solid phase state.

Abstract: A method is provided for producing a liquid crystal polyester including: (1) polycondensing a mixture of a compound of formula (I) with a compound of formula (II) in a polymerization tank at 260 to 350° C. to form a prepolymer, wherein a ratio of by-products to be distilled off to the theoretical amount of by-products formed when the compound of formula (I) is polycondensed with the compound of formula (II) in a stoichiometric relation is 95% or more; (2) continuously discharging the prepolymer from the polymerization tank in a molten state, solidifying the prepolymer while transferring, and continuously grinding the solidified prepolymer by a grinder provided downstream in a transfer direction to produce prepolymer particles; and (3) heat-treating the prepolymer particles in their solid state under an inert gas atmosphere, thereby subjecting them to solid phase polymerization.

Abstract: A method is provided for producing a liquid crystal polyester including: (1) polycondensing a mixture of a compound of formula (I) with a compound of formula (II) in a polymerization tank at 260 to 350° C. to form a prepolymer, wherein a ratio of by-products to be distilled off to the theoretical amount of by-products formed when the compound of formula (I) is polycondensed with the compound of formula (II) in a stoichiometric relation is 95% or more; (2) continuously discharging the prepolymer from the polymerization tank in a molten state, solidifying the prepolymer while transferring, and continuously grinding the solidified prepolymer by a grinder provided downstream in a transfer direction to produce prepolymer particles; and (3) heat-treating the prepolymer particles in their solid state under an inert gas atmosphere, thereby subjecting them to solid phase polymerization.

Abstract: Disclosed is a method for producing a liquid crystal polyester, which includes the steps of: (1) polycondensing a mixture of 70.5 to 71.5 mol % of a compound represented by the defined formula (I) (for example, 4-acetoxybenzoic acid) with 28.5 to 29.5 mol % of a compound represented by the defined formula (II) (for example, 6-acetoxy-2-naphthoic acid) to form a prepolymer, wherein the prepolymer has a flow initiation temperature of 200° C. or higher, and the mixture is polycondensed until reaching the temperature which is at least 30° C. lower than the polycondensation temperature; (2) removing the prepolymer in a molten state, followed by solidification and further grinding to produce prepolymer particles; and (3) subjecting the prepolymer particles to a heat treatment at 200 to 310° C. under circulation of an inert gas while remaining in a solid phase state.

Abstract: A process for producing a porous film containing a liquid crystal polyester comprising the following steps (a), (b) and (c) in this order: (a) dispersing 1 to 1,500 parts by weight of a filler, based on 100 parts by weight of a liquid crystal polyester, in a solution in which 100 parts by weight of the liquid crystal polyester is dissolved in a solvent to produce a slurry coating liquid; (b) coating the coating liquid on at least one side of a substrate to form a coating film; and (c) removing the solvent from the coating film, immersing the film in a solvent which does not dissolve the liquid crystal polyester, and drying the film to form a porous film containing a liquid crystal polyester.

Abstract: Provided is a laminated porous film comprising a laminate of a heat-resistant porous layer containing a liquid crystalline polyester and a shutdown layer containing a thermoplastic resin.

Abstract: Provided is a laminated porous film comprising a laminate of a heat-resistant porous layer containing a heat-resistant resin and a shutdown layer containing a thermoplastic resin, wherein the film has a free chlorine content of 1×102 ppm by weight or less.

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: 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 polyester film comprising a polymer having a repeating unit such as a unit derived from 4-hydroxy-carboxyphenyl is provided. The film is excellent in heat resistance and solvent resistance and can be obtained by a deposition polymerization method.

Abstract: An aromatic polyester film comprising a polymer having a repeating unit such as a unit derived from 4-hydroxy-carboxyphenyl is provided. The film is excellent in heat resistance and solvent resistance and can be obtained by a deposition polymerization method.

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: A liquid-crystalline polyester solution composition comprises an aprotic solvent and liquid-crystalline polyester. The liquid-crystalline polyester includes at least one of repeating unit selected from the group consisting of a repeating unit derived from aromatic diamine, a repeating unit derived from aromatic amine having a hydroxyl group and a repeating unit derived from aromatic amino acid, in from 10 to 35 mol % in the liquid-crystalline polyester.

Abstract: A liquid-crystalline polyester production method with a shortened reaction time and improved productivity per unit time by using an organic basic compound containing one nitrogen atom in a molecule is achieved by a liquid-crystalline polyester production method comprising carrying out acylation reaction and/or ester-exchange in the presence of an organic basic compound containing one nitrogen atom in one molecule and satisfying the following inequality (1): 0<A+0.4×B ??(1) wherein, A and B satisfy A={(Ech+?Ec)/(Eph+?Ep)}?1 and B=(?f/?fp)?1; Ec denotes the heat of formation of the organic basic compound; Ech+ denotes the heat of formation of a compound coordinated by proton; Ep denotes the heat of formation of pyridine; and Eph+ denotes the heat of formation of pyridine coordinated by proton to the nitrogen atom; ?f and ?fp independently denote parameters relevant to the steric angles.

Abstract: A liquid-crystalline polyester production method with a shortened reaction time and improved productivity per unit time by using an organic basic compound containing one nitrogen atom in a molecule is achieved by a liquid-crystalline polyester production method comprising carrying out acylation reaction and/or ester-exchange in the presence of an organic basic compound containing one nitrogen atom in one molecule and satisfying the following inequality (1): 0<A+0.4×B ??(1) wherein, A and B satisfy A={(Ech+?Ec)/(Eph+?Ep)}?1 and B=(?f/?fp)?1; Ec denotes the heat of formation of the organic basic compound; Ech+ denotes the heat of formation of a compound coordinated by proton; Ep denotes the heat of formation of pyridine; and Eph+ denotes the heat of formation of pyridine coordinated by proton to the nitrogen atom; ?f and ?fp independently denote parameters relevant to the steric angles.

Abstract: A liquid-crystalline polyester solution composition comprises an aprotic solvent and liquid-crystalline polyester. The liquid-crystalline polyester includes at least one of repeating unit selected from the group consisting of a repeating unit derived from aromatic diamine, a repeating unit derived from aromatic amine having a hydroxyl group and a repeating unit derived from aromatic amino acid, in from 10 to 35 mol % in the liquid-crystalline polyester.

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 %.