Patent ID: 7926531
Filing Date: 2011-04-19
Classification: B60C,Y10T

Abstract:
1. A pneumatic tire comprising a carcass having a carcass ply with carcass cords extending from a tread portion to a bead core of a bead portion through a sidewall portion, wherein: the carcass cords are made of high tenacity vinylon fiber or polyalylate fiber; viscoelasticity characteristics per one cord at 120° C. satisfy the following equations (1) to (3): wherein “A” represents a product of complex modulus E*(N/cm 2 ) and cross-sectional area “S”(cm 2 ) of the cord, “A” is 340 to 1800 N, and “B” represents a loss tangent tanδ which is 0.02 or higher; the carcass cords have a two-ply twist structure, and the number of twists n of the cord is 30 to 70 per 10 cm; and a twist coefficient “T” of the cord defined in the following equation (5) is 0.45 to 0.75: wherein “n” represents the number of twists per 10 cm, “D” represents total fineness based on corrected mass (dtex) of the cord, and “ρ” represents specific gravity of fiber.