Heretofore, fluorinated solvents, etc. have been used as solvents for diluting various organic substances such as lubricants, which contain as active components, perfluorocarbons (hereinafter referred to as PFC) such as trichlorotrifluoroethane (hereinafter referred to as R113), dichloropentafluoropropane (hereinafter referred to as R225) and perfluorohexane, perfluorohexyloxymethane and tridecafluorohexane, which are excellent in non-flammability and in chemical and thermal stability (JP-A-2001-262171).
However, R113 or R225 has an ozone-depleting coefficient, and PFC has a very high global warming coefficient. Thus, they respectively present adverse effects to the global environment. With respect to chlorofluorocarbons such as R113, the production has already been banned, and in advanced countries, also hydrochlorofluorocarbons such as R225 are expected to be totally banned in 2020. Further, PFC is a substance regulated by Kyoto Protocol for prevention of global warming. Further, R225 presents a high solubility to a synthetic resin and has had a problem such that when R225 is used for washing an article made of a synthetic resin, whitening or cracking is likely to result. Tridecafluorohexane presents a low solubility to an organic chemical substance.
It is an object of the present invention to provide a lubricant solution employing a solvent which has a performance equal to such R113, R225 or PFC without presenting adverse effects to the global environment and which presents an excellent solubility to a lubricant and little influence to a synthetic resin.