A method for controlling the expansion properties of thermally expandable sulfuric acid - graphite particles and their use

摘要

A method for controlling the expansion properties of thermally expandable sulfuric acid - graphite particles, characterized in that the reaction of graphite particles with sulfuric acid in the presence of an oxidizing agent produced sulfuric acid - graphite particles having a expansion properties compounds which influence the aqueous scrubbing liquid containing up to a ph - value in the range from 2 to 8, preferably 3 to 7, measured in the of the washed sulfuric acid - graphite particles separated washing liquid, washed and then dried, wherein the washing liquid than the expansion properties of the sulfuric acid - graphite particles and / or at least one representative of the sulfates, hydrogen sulfates, sulfites, /, nitrates, phosphates, hydrogen phosphates, dihydrogen phosphates and acetates of sodium, potassium, manganese, iron, copper, zinc and aluminum; iodine outer, bromine acid, permanganic acid, perchloric acid and of peroxodisulfuric acid; peroxides, iodates, bromate, permanganates, perchlorates and peroxodisulfates of sodium and potassium; sodium salts of benzenesulfonic acid, benzene - 1,3 - disulfonic acid, c₁-C.₃₀-Alkyl benzene sulfonic acids, naphthalenesulfonic acid, aromatic and aliphatic aminosulfonic acids and c₁-C.₃₀-Alkylsulfonic acids; sodium - c₁-C.₃₀-alkyl sulfates; sodium salts of saturated or unsaturated, aliphatic c₂-C.₃₀-Carboxylic acids; and saturated or unsaturated, aliphatic, quaternary ammonium salts of the formula n (r)₄⁺X^–, in the r independently of one another are c₁-C.₃₀-Alkyl groups and..