Aramid fiber cord and method for manufacturing the same

Abstract

The present invention relates to an aramid fiber cord which has high strength as well as good disk fatigue property such that, when it is used as a tire reinforcement, the degradation of its physical properties and the degradation of its adhesion strength with respect to a rubber after long and high speed driving can be minimized, and to a method for manufacturing the same. The aramid fiber cord of the present invention comprises an aramid cabled yarn; and an adhesive coated on an outer surface of the aramid cabled yarn, wherein penetration rate of the adhesive into the aramid cabled yarn is 3.5 to 9%.

1 . An aramid fiber cord comprising:
 an aramid cabled yarn; and   an adhesive coated on an outer surface of the aramid cabled yarn,   wherein penetration rate of the adhesive into the aramid cabled yarn is 3.5 to 9%.   
     
     
         2 . The aramid fiber cord of  claim 1 , wherein the aramid fiber cord has strength at 3% elongation of 6.3 to 8 g/d. 
     
     
         3 . The aramid fiber cord of  claim 1 , wherein the aramid fiber cord has tenacity retention rate of 95% or more after a disc fatigue test performed according to JIS-L 1017 method of Japanese Standard Association. 
     
     
         4 . The aramid fiber cord of  claim 1 , wherein the adhesive is a resorcinol-formaldehyde-latex adhesive. 
     
     
         5 . The aramid fiber cord of  claim 1 , wherein the aramid cabled yarn comprises at least 2 plies of aramid single yarns secondarily-twisted together at a first twist number, and each of the aramid single yarns is an aramid multifilament primarily-twisted at a second twist number. 
     
     
         6 . The aramid fiber cord of  claim 5 , wherein each of the first and second twist numbers is 200 to 600 TPM. 
     
     
         7 . The aramid fiber cord of  claim 1 , wherein the penetration rate of the adhesive into the aramid cabled yarn is 5 to 7%. 
     
     
         8 . A method for manufacturing an aramid fiber cord, the method comprising:
 preparing an aramid cabled yarn; and   dipping the aramid cabled yarn into an adhesive solution,   wherein a tension of 0.2 to 5 kg/cord is applied to the aramid cabled yarn when the aramid cabled yarn is dipped into the adhesive solution.   
     
     
         9 . The method of  claim 8 , wherein the preparing the aramid cabled yarn comprises:
 primarily-twisting aramid multifilament at a first twist number to prepare an aramid single yarn; and   secondarily-twisting two plies of the aramid single yarns together at a second twist number.   
     
     
         10 . The method of  claim 9 , wherein each of the first and second twist numbers is 200 to 600 TPM. 
     
     
         11 . The method of  claim 8 , further comprising:
 drying the aramid cabled yarn containing the adhesive solution after the dipping;   heat-treating the dried aramid cabled yarn.