FLAME RETARDANT ELECTROMAGNETIC WAVE ABSORBING SHEET AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a thin and lightweight flame retardant electromagnetic wave absorbing sheet having electromagnetic wave absorbing properties in relatively wide band and good flame retardancy. SOLUTION: This sheet includes 5-80 wt.% electromagnetic wave absorbing material consisting of coiled carbon microfibril based on oven dry weight of total material and, as the rest other than the coiled carbon microfibril, 15-40 wt.% organic ingredient mainly consisting of cellulose fiber on a solid basis and 60-85 wt.% hydrous inorganic powder on a solid basis and, in addition, the content of the above-mentioned coiled carbon microfibril is 0.02-0.35 g/cm<3> . The paper stock is obtained by mixing an aqueous dispersion of the coiled carbon microfibril using a surfactant with a slurry of the organic ingredient mainly consisting of cellulose fiber and the hydrous inorganic powder and the sheet is formed by a conventional paper making method.