Poly(ethyleneterephthalate) tire cord, and tire comprising the same

摘要

Disclosed is a PET tire cord which has a flat spot index (FSI) defined by the following Calculation Formula 1 of 5.0% or less:
Flat Spot Index (FSI)(%)=(L1−L2)/L0×100  Calculation Formula 1
wherein, L0 is an initial length of the tire cord, L1 is a length of the tire cord that is measured after providing a load corresponding to 13% of the strength at break of the cord for 5 minutes at 120° C. and cooling the same to 24° C. while maintaining the load, and L2 is a length of the tire cord that is measured after providing a load corresponding to 13% of the strength at break of the cord for 5 minutes at 120° C. and cooling the same to 24° C. while remaining the load of 0.01 g/d only.

主权项

1. A poly(ethylene terephthalate) (PET) tire cord, of which a flat spot index (FSI) defined by the following Calculation Formula 1 is 5.0% or less,
Flat Spot Index (FSI)(%)=(L1−L2)/L0×100  Calculation Formula 1 wherein, L0 is an initial length of the tire cord, L1 is a length of the tire cord that is measured after providing a load corresponding to 13% of the strength at break of the cord for 5 minutes at 120° C. and cooling the same to 24° C. while maintaining the load, and L2 is a length of the tire cord that is measured after providing a load corresponding to 13% of the strength at break of the cord for 5 minutes at 120° C. and cooling the same to 24° C. while remaining the load of 0.01 g/d only, wherein the PET tire cord comprises a drawn PET fiber prepared by drawing an undrawn PET fiber at a draw ratio of 0.1-1.55, wherein the undrawn PET fiber has a crystallinity of 25 to 40% and an amorphous orientation factor (AOF) of 0.15 or less.