Organic amine impregnated activated carbon

A process for impregnating activated carbon with a low vapour pressure organic amine, comprising the steps of placing the amine in contact with substantially dry activated carbon, subjecting the carbon and amine to positive pressure of 1-5 Pa in an oxygen-free inert gas atmosphere and then heating the carbon and amine for an extended period while maintaining the positive pressure of 1-5 Pa in an oxygen-free inert gas atmosphere, including the step of pre-treating the activated carbon with a compound selected from the group consisting of an alkaline hydroxide in an amount of 0.1 to 10% by weight, based on the weight of the carbon, a suitable halogen and a suitable halide salt.

A process for impregnating activated carbon with a solid amine compound, comprising dissolving the amine in a solvent selected from water and organic solvents and adding the amine solution to the activated carbon, including the step of pre-treating the activated carbon with a compound selected from the group consisting of an alkaline hydroxide in an amount of 0.1 to 10% by weight, based on the weight of the carbon, a suitable halogen and a suitable halide salt.

A breathing gas filter composition providing protection against toxic perfluorocarbons, comprising substantially dry activated carbon and an organic amine impregnant, said organic amine being selected from the group consisting of ethylenediamine, dipropylamine, isopropylamine, aniline, N,N-diethyl-1,4-phenylenediamine, 4-phenylazoaniline, diisopropylamine, diethylamine, diethylenetriamine, diphenylamine, pyrrole, piperidine, triethylamine, triisobutylamine, tricotylamine, N,N-diethylaniline, 4-(4-nitrobenzyl)-pyridine, hexamethyleneamine, monoethanolamine, urea, N,N-dimethylformamide, o-toluenesulfonamide and p-toluenesulfonamide, in an amount of 1.5 to 18 percent by weight, based on the weight of the carbon and additionally comprising 0.1 to 10% by weight, based on the weight of the carbon of an alkaline hydroxide.