| 摘要 |
PURPOSE:To obtain the title protective fluid which enables the cooling of a high- temperature superconducting material in a vapor phase at a constant temperature, by using an inert fluorine compound which is either liquid or enable of forming a vapor phase at service temperature. CONSTITUTION:The title protective fluid comprises an inert fluorine compound which is either liquid or capable of forming a vapor phase at service temperature [especially preferred is a substantially or completely fluorinated open-chain or cyclic perfluorocarbon that has a pour point of -170--20 deg.C, is gas or liquid at ordinary temperature, and contains neither of Cl atom nor at H atom, but may contain an O atom and/or an N atom, for example, a compound of formula I, II, III, IV, V or VI (wherein n, p, q, and r are each a positive integer)]. The above-mentioned perfluorocarbon is most suitable for the title protective fluid since it has all of the following characteristics: it is either liquid or capable of forming a vapor phase at service temperature; it has low viscosity, good heat transfer, good capability of wetting a high-temperature superconducting material, and electrical insulating properties; it is noninflammable, inert to a high-temperature superconducting material and a packaging material, and nontoxic to the human body. |
