Composition based on 1,1,1,3,3-pentafluorobutane, methylene chloride and methanol, for the cleaning and/or drying of solid surfaces
AssigneeElf Atochem S.A.
InventorPascal Michaud
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Abstract
To replace cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention provides a composition comprising, by weight, 30 to 69% 1,1,1,3,3-pentafluorobutane (F365-mfc), 30 to 60% methylene chloride and 1 to 10% methanol. These three compounds form a positive azeotrope (B.p.=32.1.degree. C. at normal pressure). The composition, optionally stabilized, can be used for the cleaning and/or the drying of solid surfaces, in particular for removing flux from printed circuits and for degreasing mechanical components.
Claims8
An azeotropic composition or a composition which has about the same composition in vapor phase as in liquid phase when employed at reflux, consisting essentially of, on a weight basis, from 30 to 69% 1,1,1,3,3-pentafluorobutane and from 30 to 60% methylene chloride and from 1 to 10% methanol and optionally an effective amount of at least one stabilizer, said composition boiling at about 32.1.degree. C. at normal atmospheric pressure.
An azeotrope, consisting essentially of, on a weight basis, about 57% 1,1,1,3,3-pentafluorobutane, about 39.5% methylene chloride and about 3.5% methanol boiling at about 32.1.degree. C. at normal atmospheric pressure.
Dependencies are inferred from the claim text.