▎ 摘　　要

NOVELTY - A polyvinylidene fluoride-based conductive composite material comprises 20-70 vol.% polyvinylidene fluoride (A) as a matrix with positive coefficient (PTC) effect and resistivity at an ambient temperature of 25 degrees C of 10 Omega .cm or less, 0.5-30 vol.% pre-irradiation crosslinked fluoropolymer (B), which is polytetrafluoroethylene (PTFE) crosslinked by irradiation with a dose of 0-200 Mrads, polytetrafluoroethylene (PTFE) crosslinked by irradiation with a dose of 3.2-200 Mrads, vinylidene fluoride, crosslinked polyperfluoroethylene propylene (FEP) with dose of 3.2-200 Mrads, and tetrafluoroethylene-ethylene copolymer (ETFE) with a dose of 3.2-200 Mrads, and dispersed in component (A), and 25-75 vol.% conductive filler dispersed in the polymer (A). USE - Polyvinylidene fluoride-based conductive composite material for manufacturing positive temperature coefficient element (all claimed). ADVANTAGE - The composite material provides positive temperature coefficient element having excellent resistance reproducibility, voltage resistance and environmental reliability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) positive temperature coefficient (PTC) element, which consists of the polyvinylidene fluoride-based conductive composite material sheet of thickness 0.01-3 mm, and metal electrodes tightly connected on both sides of the composite material sheet. The PTC element is divided into a single PTC element having a planar shape, and the PTC element has two surfaces perpendicular to the direction of current flow. The resistivity of the PTC element is 10 Omega .cm or less; and (2) manufacture of PTC element, which involves mixing filler and polymers (A) and (B) at temperature more than melting temperature of the polymer (A), pressing to form sheet having thickness of 0.01-3.0 mm through extrusion molding, compression molding or calender molding, heat-compressing by a roller or a flat plate to tightly connect the metal electrodes on the upper and lower surfaces of the sheet, punching, dicing or laser cutting, crosslinking and heating.