Abstract: The invention relates to a method for producing nitrogen trifluoride by gas-solid reaction. This method includes the steps of (a) providing a packed-bed-type vessel filled with a particulate solid of an ammonium complex of a metal fluoride; (b) introducing a fluorine-containing gas into the vessel to allow the fluorine-containing gas to flow upwardly through the vessel such that fluorine of the fluorine-containing gas is reacted with the particulate solid in the vessel, thereby to obtain a reaction gas containing nitrogen trifluoride; and (c) separating the nitrogen trifluoride from the reaction gas. A part of the reaction gas flowing out of the vessel may be introduced into the vessel, and thereby circulated through the vessel. The yield of nitrogen trifluoride becomes substantially improved by this method.

Abstract: Graphite fluoride in the form of submicron particles is easily obtained at high yield by using, exclusively, acetylene black as the carbon material to be fluorinated with fluorine gas. Use of any other type of carbon black does not give comparable results. Graphite fluoride produced from acetylene black is superior in dispersibility.

Abstract: A lubricant comprising a partially defluorinated graphite fluoride obtained by exposing a dispersion of raw material graphite fluoride to electromagnetic radiation, followed by the separation of the resulting partially degraded graphite fluoride. The partially defluorinated graphite fluoride is not only excellent in lubricating properties but also has excellent compatibilities with resins, greases and oils. The excellent compatibilities of the partially defluorinated graphite fluoride are effective in preventing the unfavorable deposition of the graphite fluoride in a liquid lubricant composition and advantageously lead to improvement in the moldability of any graphite fluoride-resin composition, thereby enabling the ultimate composition to exhibit excellent lubricating properties.