Abstract: Provided is a process for producing an aromatic liquid crystalline polyester comprising the steps of: charging 80 20 mol % of a compound represented by the following formula (I) and 20 to 80 mol % of a compound represented by the following formula (II) into a reaction vessel; conducting polycondensation reaction at a temperature from 270 to 350° C. to produce a aromatic liquid crystalline polyester; discharging the aromatic liquid crystalline polyester in a molten state from the reaction vessel and solidifying; then, pulverizing the solidified polyester into particles; and heat-treating at a temperature from 200 to 310° C., The aromatic liquid crystalline polyester has improved low temperature molding processability, and the film thereof has sufficient heat-resistance and excellent gas barrier properties.

Abstract: Provided is a process for producing an aromatic liquid crystalline polyester comprising the steps of: charging 80 20 mol % of a compound represented by the following formula (I) and 20 to 80 mol % of a compound represented by the following formula (II) into a reaction vessel; conducting polycondensation reaction at a temperature from 270 to 350° C. to produce a aromatic liquid crystalline polyester; discharging the aromatic liquid crystalline polyester in a molten state from the reaction vessel and solidifying; then, pulverizing the solidified polyester into particles; and heat-treating at a temperature from 200 to 310° C.

Abstract: Provided is a process for producing an aromatic liquid crystalline polyester comprising the steps of: charging 80 to 20 mol % of a compound represented by the following formula (I) and 20 to 80 mol % of a compound represented by the following formula (II) into a reaction vessel; conducting polycondensation reaction at a temperature from 270 to 350° C. to produce an aromatic liquid crystalline polyester; discharging the aromatic liquid crystalline polyester in a molten state from the reaction vessel and solidifying; then, pulverizing the solidified polyester into particles; and heat-treating at a temperature from 200 to 310° C., The aromatic liquid crystalline polyester has improved low temperature molding processability, and the film thereof has sufficient heat-resistance and excellent gas barrier properties.

Abstract: Provided are a aromatic liquid crystalline polyester resin having improved low temperature processability, a film having excellent gas barrier property. The aromatic liquid crystalline polyester resin is obtained from an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid and an aromatic diol, by optimizing formulation ratio of the above-described three components. The aromatic liquid crystalline polyester resin comprises an aromatic hydroxycarboxylic acid unit, an aromatic dicarboxylic acid unit and an aromatic diol unit, as repeating units, wherein the repeating unit (A) as an aromatic hydroxycarboxylic acid unit, is contained in an amount of 30 mol % or more based on the total amount of repeating units, and the polyester has a logarithmic viscosity of 1.5 dl/g or more, a flow temperature of 300° C. or less, and a melt tension measured at a temperature higher than the flow temperature by 25° C. or more of 1.

Abstract: Provided are a aromatic liquid crystalline polyester resin having improved low temperature processability, a film having excellent gas barrier property. The aromatic liquid crystalline polyester resin is obtained from an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid and an aromatic diol, by optimizing formulation ratio of the above-described three components. The aromatic liquid crystalline polyester resin comprises an aromatic hydroxycarboxylic acid unit, an aromatic dicarboxylic acid unit and an aromatic diol unit, as repeating units, wherein the repeating unit (A) as an aromatic hydroxycarboxylic acid unit, is contained in an amount of 30 mol % or more based on the total amount of repeating units, and the polyester has a logarithmic viscosity of 1.5 dl/g or more, a flow temperature of 300° C. or less, and a melt tension measured at a temperature higher than the flow temperature by 25° C. or more of 1.

Abstract: A process for producing an aromatic polyamide film comprising forming a thin layer of an optically isotropic dope in which an aromatic polyamide is dissolved in a polar amide, immersing the thin layer dope in a polar solvent kept at a temperature not higher than -20.degree. C. to coagulate the dope to form a film and drying the film in the presence of an isocyanate compound. Said process can produce directly a transparent film from an aromatic polyamide dope without requiring the step of dissolving the aromatic polyamide in conc. sulfuric acid, does not require any acid resistant equipment and is inexpensive.

Abstract: A resin composition comprising a polyphenylene ether having, on the average, 0.01 to 10 terminal structures of the formula (1): ##STR1## wherein R.sub.1 to R.sub.5 are each hydrogen, halogen, a substituted or unsubstituted alkyl, alkenyl or alkynyl group, or a substituted or unsubstituted aryl group, R.sub.6 is a substituted or unsubstituted alkylene group, and R.sub.7 to R.sub.11 are each hydrogen, halogen, an alkyl group, an alkoxy group, a phenyl group, a phenoxy group, a nitro group or a cyano group per 100 phenylene ether units, and a primary aliphatic monoamine having an aromatic substituent, which composition has good thermal stability.

Abstract: An aromatic polyester comprising the repeating units (A), (B), (C) and (D) represented by the following formulae in amounts of 0 to 80 mole %, 10 to 50 mole %, 5 to 50 mole % and 0 to 30 mole %, respectively, having a logarithmic viscosity of 1.0 dl/g or more and capable of being melt-molded at a temperature of 350.degree. C. or less: ##STR1## where R represents a C.sub.2 -C.sub.6 alkylene, and--O--AR--O-- (D)where Ar represents a divalent aromatic residue, and a process for producing the same. The aromatic polyesters according to the present invention combine moldability and heat resistance in a good state and have mechanical properties of sufficient practical value. An aromatic polyester according to the present invention shows optical anisotropy at a molten state.

Abstract: An aromatic polyester superior in heat resistance and melt-moldability is obtained by carrying out the polycondensation reaction withComponent A consisting of at least one compound having the formula, ##STR1## wherein R.sub.1 is hydrogen, formyl, acetyl, propionyl or benzoyl, and R.sub.2 is hydrogen, a C.sub.1 -C.sub.6 alkyl or a C.sub.6 -C.sub.18 aryl, or a mixture containing not less than 50% by mole of said compound,Component B consisting of at least one compound having any one of the formulas, ##STR2## wherein R.sub.3 is hydroxyl, a C.sub.1 -C.sub.6 alkyloxy, a C.sub.6 -C.sub.18 aryloxy or halogen, or a mixture containing not less than 50% by mole of said compound, andComponent C consisting of at least one compound having the formula,R.sub.4 O--A.sub.1 --OR.sub.4wherein A.sub.1 is a divalent aromatic residue, and R.sub.4 is hydrogen, acetyl, propionyl or benzoylin a reaction vessel at a temperature of 270.degree. C. to 380.degree. C.

Abstract: An aromatic polyester of good processability and heat resistance is prepared by charging starting materials in a reaction vessel, carrying out polycondensation reaction in the vessel until the flow temperature of the produced aromatic polyester falls in the temperature range of from 240.degree. C. to a temperature of 20.degree. C. below the reaction temperature and discharging the reaction product from the vessel in the molten state.The aromatic polyester obtained by the present invention can be used molded into various forms such as fiber, film, etc. In addition, compositions comprising this aromatic polyester and glass fibers, mica, talc, silica, potassium titanate, wollastonite, calcium carbonate, quartz, iron oxide, graphite, carbon fibers, etc. can be used in machine parts, electric and electronic parts and automobile parts because of their excellent mechanical properties, electric properties, chemical resistance and oil resistance.

Abstract: A plastic optical cable comprising a core, a cladding layer and a protective layer made of an ester type thermoplastic elastomer, which has low degree of thermal shrinkage and low attenuation of light transmission even at high temperature.