▎ 摘　　要

NOVELTY - A graphene polypropylene composite material comprises 5-10 pts. wt. graphene material, 0.1-2 pts. wt. electret material, 0.5-2 pts. wt. hydrocarbon material which is liquid at normal temperature and 85-94 pts. wt. polypropylene. USE - Graphene polypropylene composite material for melt-blown cloth used in filter device e.g. mask (all claimed). ADVANTAGE - The composite material uses hydrocarbon material as additive which is compatible with the other raw materials, has synergistic effect, and provides melt-blown cloth with improved filtration efficiency (about 99.9%) and capable of filtering dust and bacteria in air. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of graphene polypropylene composite material, which involves mixing the graphene material and the electret material after mixing the polypropylene and the hydrocarbon material uniformly, and then adding to the polypropylene and the hydrocarbon material and stirring; (2) melt-blown cloth, which is prepared by self-bonding or heating and curing fibers formed using the composite material; and (3) filter device, which comprises intermediate layer comprising the melt-blown cloth and a surface layer.