Aramid tire cord and manufacturing method thereof

摘要

Disclosed is aramid tire cord and a method for manufacturing the same, wherein the aramid tire cord has superior properties on initial modulus change rate, tensile strain, initial modulus and strength retention rate, wherein the initial modulus change rate is not more than 5% after the aramid tire cord is repetitively extended 10 times at 120° C. under the condition that the load corresponding to 10% of the strength at break is applied thereto. Thus, the aramid tire cord of the present invention has the most optimal modulus, optimal crystallization constant and optimal crystalline orientation constant so that the aramid tire cord is superior in its initial modulus change rate, tensile strain and initial modulus retention rate, to thereby obtain good fatigue resistance. Thus, if the aramid tire cord of the present invention is used for a tire-reinforcing material, it is possible to obtain high traveling performance by preventing the property deterioration during the high-speed traveling with repetitively-occurring sequence of high temperature and high pressure.

主权项

1. Aramid tire cord comprising a twisted yarn of plies prepared by primarily twisting aramid multifilament containing poly(paraphenylene terephthalamide) with 20 to 60 turns per 10 cm to form a ply and finally twisting the plies with 20 to 60 turns per 10 cm,
wherein an initial modulus change rate of the aramid tire cord is defined by the following calculation 1, and the initial modulus change rate is not more than 5% after the aramid tire cord is repetitively extended 10 times at 120° C. under the condition that the load corresponding to 10% of the strength at break is applied thereto,
Initial modulus change rate (%)=[(M1−M2)/M1]×100,  [Calculation 1] wherein ‘M1’ is the value of initial modulus (g/d) before the repetitive extension tests, and ‘M2’ is the value of initial modulus (g/d) after the repetitive extension tests.