FILTER MATERIAL FOR RESPIRATORS AND METHOD FOR MANUFACTURING WORKING LAYER OF FILTERING MATERIAL FOR RESPIRATORS Russian patent published in 1999 - IPC

FIELD: filtering materials. SUBSTANCE: filtering material contains outer and inner protective layers and working layer of fibrous polymer material consisting of fibers of perchlorovinyl polymers and styrene/methylmethacrylate/acrylonitrile copolymer at their weight ratio 10:1 to 1: 1. Manufacturing of filtering material for working layer of respirators includes electrostatic forming of fibrous nonwoven material from solution of above-indicated polymer mixture in dichloroethane in presence of 0.01-0.2 wt % of salts selected from the group including: tetraethylammonium iodide or bromide, tetrabutylammonium iodide or bromide, and ferrous chloride. Forming is conducted at dynamic viscosity of solution from 1 to 30 poise, conductivity 10^-4 to 10^-7 ohm^-1cm^-1, and voltage 10 to 150 kV, polymer concentration in dichloroethane solution ranging from 5 to 25%. EFFECT: enhanced filtration efficiency. 4 cl, 1 tbl