▎ 摘　　要

NOVELTY - Production of silver particle-graphene composite material involves adding N-methyl-2-pyrrolidone, stirring, mechanically exfoliating and dispersing the wet graphite to preparing a graphene-containing composition, adding silver particles, and further mechanically exfoliating and dispersing. USE - Production of silver particle-graphene composite material used for manufacturing positive temperature co-efficient constant temperature heating element for planar heating element used in heating device (all claimed) for automobile seats. ADVANTAGE - The method enables production of silver particle-graphene composite material having excellent PTC characteristics, heating characteristics, while reducing power consumption and preventing damage to the heating element. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: manufacture of positive temperature co-efficient (PTC) constant temperature heating element (AA), which involves mixing the silver particle-graphene composite with a polymer binder to prepare a PTC constant-temperature heating paste, and printing or coating the silver particle-graphene composite-based PTC constant-temperature heating paste using a silver particle-graphene composite-based polymer nanocomposite material; the positive temperature coefficient (PTC) constant-temperature heating element, which comprises a silver particle-graphene composite and a polymer binder, and has a PTC strength (ratio of resistance value of the graphene PTC composition measured at 100° C with respect to resistance value at 20° C) of 10000% or more; and a planar heating element, which comprises a planar heating layer including a PTC constant temperature heating element, a heat insulation layer (CC), and foamed adhesive layer (BB) between the planar heating layer and the heat insulating layer. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the planar heating element. (Drawing includes non-English language text) AAGraphene-metal nanocomposite material-based PTC constant temperature heating element BBFoamed adhesive layer CCInsulation layer DDFoam-insulation composite material having increased insulation effect and leakage current reduction function