Abstract: A polyester tire cord having improved dimensional stability and methods of manufacturing the polyester tire cord are provided. The method includes forming a discharge yarn, extruded while a polyester containing 85 mol % or more of ethylene terephthalate units is melted and passes through a nozzle; forming an undrawn yarn by spinning the discharged yarn; manufacturing a yarn by multistep drawing the undrawn yarn; plying the yarn by twisting; and dipping the plied yard in a dipping solution, and then drying, drawing, and heat-setting the plied yarn before dipping the plied yarn in resorcinol-formaldehyde latex and again drying an heat-setting the plied yarn. An intermediate elongation of the formed polyester tire cord after vulcanization for 20 minutes at 170° C. is E2, an intermediate elongation of the polyester tire cord before vulcanization is E1, and a difference between E2 and E1 is ?E. ?E divided by E1 is 0.5 or less.

Abstract: The present invention relates to a polyester tire cord with excellent dimensional stability which utilizes a yarn manufactured by adjusting spinning and drawing conditions, and a method for manufacturing the same.

Abstract: The present invention relates to a polyethylene terephthalate nanocomposite fiber with enhanced modulus, and specifically to a technique for preparing a PET nanocomposite fiber with excellent initial and high-temperature modulus, which comprises adding 1 to 4% by weight of a compound selected from the group consisting of C56H122O12Si7, C31H71NO12Si8n, C59H127NO12Si8, and C33H76N2O12Si8, each of which is an organic/inorganic hybrid nanocompound, based on the total weight of the polymers, to prepare a polyethylene terephthalate nanocomposite chip having 85 mol % or more of the ethylene terephthalate units and an intrinsic viscosity in the range of 0.50 to 1.20, and then melt-spinning and stretching the composite chip.

Abstract: The present invention relates to a polyethylene terephthalate nanocomposite fiber with enhanced modulus, and specifically to a technique for preparing a PET nanocomposite fiber with excellent initial and high-temperature modulus, which comprises adding 1 to 4% by weight of a compound selected from the group consisting of C56H122O12Si7, C31H71NO12Si8n, C59H127NO12Si8, and C33H76N2O12Si8, each of which is an organic/inorganic hybrid nanocompound, based on the total weight of the polymers, to prepare a polyethylene terephthalate nanocomposite chip having 85 mol % or more of the ethylene terephthalate units and an intrinsic viscosity in the range of 0.50 to 1.20, and then melt-spinning and stretching the composite chip.