| 摘要 |
PROBLEM TO BE SOLVED: To obtain a rubber improved in the penetration of rubber and steel cord for tire reinforcement. SOLUTION: In this steel cord 1 having a three-layer structure, an innermost layer 2 consists of 3 filaments 2a twisted in one of left or right twist directions while having a twist pitch length of 5 to 18 mm and an intermediate layer 3 consists of 8 filaments 3a twisted in the same twist direction as that of the innermost layer while having a twist pitch length of 5 to 18 mm and an outermost layer 4 consists of 13 filaments 4a twisted in a left or right twist direction opposite to those of the innermost and intermediate layers while having a twist pitch length of 10 to 25 mm equal to or more than those of the innermost and intermediate layers and a spiral wrap 5 consists of a single filament adapted to be wrapped around the outermost layer, thereby preventing the steel cord from being unwound, the filament being twisted in a twisted direction opposite to that of the outermost layer while having a twist pitch length of 3 to 10 mm. |
