METHOD OF PREPARING POROUS MATERIAL Russian patent published in 1999 - IPC

FIELD: manufacture of filters for purification of liquid and gaseous agents and encapsulation of repellents, toxic chemicals, fragrant agents containers, and inner soles for footwear. SUBSTANCE: described is method of preparing porous material by molding from 0.2-1.9% aqueous suspension containing cellulose and filler of at least one layer, subsequently dehydrating it by gravity and vacuum treatment at residual pressure of 0.2-0.8 Kgf/sq. cm, pressing under pressure and drying on heating. Filler is powder of thermoplastic polymer with particle size of not greater than 0.5 mm in amount of 0.1-25 wt %. Pressing is carried out under pressure at effort of 0.5-5.0 kgf/sq. cm and drying is carried out at 80-140 C for 10-40 minutes. After drying, molded material is heat treated with air or steam at temperature of thermoplastic polymer melt and temperature is thereafter reduced to temperature lower than temperature of thermoplastic polymer melt, and material is further pressed at effort of 5.0-50 kgf/sq.cm for 1-30 sec to prepare material with predetermined thickness. EFFECT: non-toxic porous material with improved strength in moist state and resistance to attrition. 6 cl, 1 tbl