▎ 摘　　要

NOVELTY - A flame-retardant composite sheet comprises a primer layer for increasing adhesion to an adherend, an elastic layer formed on the primer layer, a nonwoven fabric layer formed on the elastic layer, and a plastic sheet formed on the nonwoven fabric layer. The primer layer is formed using a composition (a) comprising acrylic polymer resin, acrylic mixture, magnesium carbonate, silane-surface-treated antimony trioxide, melamine polyphosphate, silver nanoparticles, zinc oxide nanoparticles, 10,10'-oxybisphenoxarsine, methyl cellulose, graphene oxide-coated carbon fibers and water. The nonwoven fabric layer is prepared using composite yarns in which graphene oxide-coated carbon fibers and polypropylene fibers are mixed in a weight ratio of 1:1-5. The plastic sheet is formed using a composition (c) comprising polypropylene, talc, magnesium carbonate, silane-surface-treated antimony trioxide, melamine polyphosphate, ethylene bis(stearamide) and calcium stearate. USE - Flame-retardant composite sheet. ADVANTAGE - The flame-retardant composite sheet is environmentally-friendly, and has excellent mechanical property, due to the presence of polypropylene-containing plastic sheet. DETAILED DESCRIPTION - A flame-retardant composite sheet comprises a primer layer for increasing adhesion to an adherend, an elastic layer formed on the primer layer, a nonwoven fabric layer formed on the elastic layer, and a plastic sheet formed on the nonwoven fabric layer. The primer layer is formed using a composition (a) comprising 38-42 pts. wt. acrylic polymer resin, 7-11 pts. wt. acrylic mixture, 3-7 pts. wt. magnesium carbonate, 3-7 pts. wt. silane-surface-treated antimony trioxide, 3-7 pts. wt. melamine polyphosphate, 2-6 pts. wt. silver nanoparticles having a particle size of 20-30 nm, 1-5 pts. wt. zinc oxide nanoparticles having a particle size of 20-30 nm, 0.1-1 pt. wt. 10,10'-oxybisphenoxarsine, 0.1-1 pt. wt. methyl cellulose, 0.1-1 pt. wt. graphene oxide-coated carbon fibers and 21-25 pts. wt. water. The acrylic polymer resin is a mixture comprising an acrylate-based copolymer comprising 23-27 wt.% ethyl methacrylate monomer unit, 23-27 wt.% n-butyl methacrylate monomer unit, 23-27 wt.% glycidyl methacrylate monomer unit and 23-27 wt.% hydroxyethyl methacrylate monomer unit, and a polyurethane acrylate having a weight average molecular weight of 15000-20000, in a weight ratio of 68-72:28-32. The acrylic mixture is a mixture comprising ethyl methacrylate, lauryl methacrylate and dimethacrylate diethylene glycol in a weight ratio of 4:4:2. The elastic layer is formed using a composition (b) comprising 64-68 pts. wt. polysiloxane of formula (I), 12-16 pts. wt. urethane-based additive, 6-10 pts. wt. chlorosulfonated polyethylene rubber, 3-7 pts. wt. dihexyl sodium sulfosuccinate, 2-6 pts. wt. polyhydrosiloxane of formula (II) and 1-5 pts. wt. silane-surface-treated antimony trioxide. The urethane-based additive is prepared by mixing polytetramethylene glycol, dimethylolpropionic acid, N-methylpyrrolidone solution and isophorone diisocyanate to obtain a prepolymer, neutralizing the prepolymer with triethylamine diluted in N-methylpyrrolidone solution, adding distilled water to the neutralized prepolymer to disperse, adding ethylene diamine as a chain extender to obtain polyurethane, adding ethyl methacrylate and azobisisobutyronitrile to the polyurethane, and stirring. The nonwoven fabric layer is prepared using composite yarns in which graphene oxide-coated carbon fibers and polypropylene fibers are mixed in a weight ratio of 1:1-5. The plastic sheet is formed using a composition (c) comprising 68-72 pts. wt. polypropylene, 10-14 pts. wt. talc, 3-7 pts. wt. magnesium carbonate, 3-7 pts. wt. silane-surface-treated antimony trioxide, 3-7 pts. wt. melamine polyphosphate, 0.5-4 pts. wt. ethylene bis(stearamide) and 0.3-3 pts. wt. calcium stearate. p=30-200; q=10-100; r=5-50;and n,m=1-10.