▎ 摘　　要

NOVELTY - An air-purifying composite sheet comprises 30-40 pts. wt. polycarbonate, 18-25 pts. wt. acrylonitrile-butadiene-styrene terpolymer, 10-16 pts. wt. silica fume powder, 6-12 pts. wt. diatomaceous earth, 5-10 pts. wt. lignocellulose, 4-8 pts. wt. graphene, 4-8 pts. wt. glass fiber, 5-9 pts. wt. polypropylene fiber, 3-6 pts. wt. modified tourmaline powder, 4-8 pts. wt. bamboo charcoal powder, 3-6 pts. wt. tea powder, 2-5 pts. wt. zinc oxide, 2.5-4.5 pts. wt. plasticizer, 1.8-3.2 pts. wt. flame-retardant and 1.2-2.5 pts. wt. lubricant. The preparation of modified tourmaline powder is carried out by immersing tourmaline powder in toluene solvent, ultrasonically shaking for 20-30 minutes, stirring in four-necked flask, heating in water bath at 55-70 degrees C, adding sorbitol monostearate equivalent to 0.2-0.3 times the weight of tourmaline powder, stirring at constant temperature for 2-4 hours, rinsing for 3-5 times with absolute ethanol, filtering and drying in oven at 80-90 degrees C for 3-5 hours. USE - Air-purifying composite sheet for building. ADVANTAGE - The air-purifying composite sheet has stability, excellent pressure resistance, dimensional stability, heat resistance, weather resistance, corrosion resistance and long service life, and absorbs harmful gases in the air and purifies indoor air. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of air-purifying composite sheet, which involves (1) mixing silica fume, diatomaceous earth, lignocellulose, graphene, glass fiber, polypropylene fiber, modified tourmaline powder, bamboo charcoal powder, tea powder and zinc oxide, placing in ball mill, crushing over 200-500 mesh screen to obtain mixed powder, (2) mixing the mixed powder with 5 %mass silane coupling agent solution in a mass ratio of 1:15-20, mixing, placing in an ultrasonic disperser at high frequency oscillation for 2-4 hours, filtering, placing the filter material in oven at 80-90 degrees C, drying for more than 12 hours to obtain material (A), (3) adding material (A), polycarbonate, acrylonitrile-butadiene-styrene terpolymer, plasticizer, flame-retardant, crosslinking agent and lubricant in twin-screw mixer, mixing, granulating, molding the pellets, cooling and cutting to obtain final product.