| 摘要 |
1,240,811. Solvent mixtures; hydraulic fluids. ALLIED CHEMICAL CORP. 1 Jan., 1970 [6 Feb., 1969], No. 120/70. Headings C5D and C5F. A composition for removing rosin flux from a printed circuit board comprises essentially tetrachlorodifluoroethane and acetonitrile containing 70 to 95% by weight of tetrachlorodifluoroethane (A). Constant boiling compositions containing 75 to 85% wt. of (A) are preferred. (A) may be CCl 2 FCCl 2 F, CClF 1 CCl 3 or a mixture thereof. Additives for specialized purposes may be present, e.g. lubricants and detergents. The compositions may also be used for removing greases and oils, for cleaning photographic films and prints and for use as hydraulic fluids. |
