Patent ID: 6042664
Filing Date: 2000-03-28
Classification: A62C,A62D,Y10T

Abstract:
A method for the preparation of a pyrotechnical aerosol-forming composition for the purpose of extinguishing fires in confined spaces, said composition being formed from materials including phenolformaldehyde and powder-form constituents including potassium nitrate and dicyandiamide, said composition containing said potassium nitrate as particles in a quantity of about 67-72% by mass, phenolformaldehyde resin as particles in a quantity of about 8-12% by mass, and dicyandiamide as particles as a balance amount, wherein the particles of the potassium nitrate comprise a maximum average diameter of about 25 .mu.m, the particles of the phenolformaldehyde resin comprise a maximum average diameter of about 100 .mu.m and the particles of the dicyandiamide comprise a maximum average diameter of about 15 .mu.m, in which method a solution of said phenolformaldehyde resin is prepared in a mixture of ethyl alcohol with acetone in a ratio of about 30-50:70-50, the powder-form constituents are mixed with the phenolformaldehyde resin solution while adding portions of the solution until a uniform distribution of constituents is obtained so as to form a resulting mixture, and the mixture is granulated simultaneously during drying at a temperature of about 20-70.degree. C. until a concentration of not more than about 1% moisture and volatile constituents is present.