The present invention relates to a method for manufacturing a wholly aromatic liquid-crystalline polyester fiber with enhanced spinnability, and more specifically, to a method for manufacturing a wholly aromatic liquid-crystalline polyester fiber including: pelletizing a resin manufactured by adding 1.08 equivalents to 1.12 equivalents of acetic anhydride to raw material monomers including hydroxy benzoic acid, hydroxy naphthoic acid, biphenol, terephthalic acid, and isophthalic acid, followed by solid-phase polycondensation, and melt-spinning under oil conditions in which winding-up improving oil is diluted to 0.5% to 2% and silicone spinning oil for high temperature is diluted to 0.5% to 2%, respectively, with water as a solvent.

The present invention relates to a method for manufacturing a wholly aromatic liquid-crystalline polyester fiber with enhanced spinnability, and more specifically, to a method for manufacturing a wholly aromatic liquid-crystalline polyester fiber including: pelletizing a resin manufactured by adding 1.08 equivalents to 1.12 equivalents of acetic anhydride to raw material monomers including hydroxy benzoic acid, hydroxy naphthoic acid, biphenol, terephthalic acid, and isophthalic acid, followed by solid-phase polycondensation, and melt-spinning under oil conditions in which winding-up improving oil is diluted to 0.5% to 2% and silicone spinning oil for high temperature is diluted to 0.5% to 2%, respectively, with water as a solvent.

Provided is a liquid crystal polyester fiber in which gas generation from the liquid crystal polyester fiber can be suppressed when being heated. The liquid crystal polyester fiber has a total amount of carboxy end groups (total CEG amount) of 5.0 mEq/kg or less and a tenacity of 18 cN/dtex or higher. For example, the liquid crystal polyester fiber may have an initial elastic modulus variation of 3.0% or less. The liquid crystal polyester fiber may contain carboxy end groups as carboxyphenyl terminus at a CEG amount of 4.0 mEq/kg or less.

Provided is a liquid crystal polyester fiber in which gas generation from the liquid crystal polyester fiber can be suppressed when being heated. The liquid crystal polyester fiber has a total amount of carboxy end groups (total CEG amount) of 5.0 mEq/kg or less and a tenacity of 18 cN/dtex or higher. For example, the liquid crystal polyester fiber may have an initial elastic modulus variation of 3.0% or less. The liquid crystal polyester fiber may contain carboxy end groups as carboxyphenyl terminus at a CEG amount of 4.0 mEq/kg or less.

The present invention relates to a polyester container. The polyester container is formed from a polyester resin containing a particular content of diol moieties derived from isosorbide and diethylene glycol, and thus can show high transparency in spite of a great wall thickness thereof.

The present invention relates to a polyester container. The polyester container is formed from a polyester resin containing a particular content of diol moieties derived from isosorbide and diethylene glycol, and thus can show high transparency in spite of a great wall thickness thereof.

The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction of a dicarboxylic acid or an ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a water-insoluble or hardly water-soluble phosphate having on the surfaces a coating layer of titanic acid in an amount, of 0.1 to 100 parts by weight in terms of TiO.sub.2 per 100 parts by weight of the phosphate.

The instant disclosure relates to a polyester composition and method for preparing the same, as well as products comprising the polyester composition and applications thereof. The polyester composition comprises aliphatic polyester, titanium and zirconium, wherein the weight ratio of titanium/zirconium is greater than 0.05. The polyester composition of the present invention has a specific titanium/zirconium weight ratio range, can reduce the process time, and can obtain a biodegradable composition with a lower acid value.

The instant disclosure relates to a polyester composition and method for preparing the same, as well as products comprising the polyester composition and applications thereof. The polyester composition comprises aliphatic polyester, titanium and zirconium, wherein the weight ratio of titanium/zirconium is greater than 0.05. The polyester composition of the present invention has a specific titanium/zirconium weight ratio range, can reduce the process time, and can obtain a biodegradable composition with a lower acid value.

A polyethylene terephthalate bulked continuous filament is manufactured by steps of melt-spinning, multi-step stretching a polyethylene terephthalate chip and a master batch chip for coloring, passing through a texturing nozzle, cooling, and winding and has an elastic modulus of 1.00E+07 to 5.00E+09 Pa at a temperature range of 10° C. to 200° C., the filament being manufactured by steps of melt-spinning a polyethylene terephthalate chip and a master batch chip for coloring, multi-step stretching, passing through a texturing nozzle, cooling, and winding.