Patent ID: 7824769

Claim:
An electrically conductive sheath-core conjugate fiber comprising an electrically conductive layer made of a thermoplastic polymer (A) containing electrically conductive carbon black fine particles which constitutes a sheath component and a protective layer made of a fiber-forming thermoplastic polymer (B) which constitutes a core component, wherein the conjugated fiber satisfies the following conditions (a) through (g): sheath component(electrically conductive layer)/core component(protective layer)[weight ratio]=10/90 to 35/65 (a) 1.04 ≦L 1 /L 0 ≦10.0 (b) 1.5≦fineness(dtex)≦20 (c) 1.8≦strength at break(cN/dtex)≦4.5 (d) 50≦elongation at break(%)≦90 (e) shrinkage in hot water at 100° C.≦20% (f) fiber surface coverage of sheath component≧85% (g) wherein L 1 represents the length of a boundary between the core component and the sheath component in a cross section of the conjugate fiber and L 0 represents the length of the circumference of a circle having an area equal to the cross sectional area of the core component.