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 70% 1,1,1,3,3-pentafluorobutane (F365-mfc) and 70 to 30% methylene chloride. These two compounds form a positive azeotrope (B.p.=33.6.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.

Abstract: For replacing cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention provides a composition comprising 55 to 80% by weight of 1,1-dichloro-1-fluoroethane (F141b) and 45 to 20% by weight of methyl formate. These two compounds form a positive azeotrope (b.p.=28.4.degree. C. at atmospheric pressure).The composition, which may be stabilized, can be used for cleaning solid surfaces, in particular for removing flux from printed circuits and for degreasing mechanical parts.

Abstract: To replace 1,1,2-trichloro-1,2,2-trifluoroethane (F113) in its applications to the cleaning and drying of solid surfaces, the invention propose to employ a (perfluoroalkyl) ethylene of formula:R.sub.f CH.dbd.CH.sub.2in which R.sub.f denotes a linear or branched perfluoroalkyl radical containing from 3 to 6 carbon atoms.In contrast to F113, (perfluoroalkyl)ethylenes are not liable to degrade stratospheric ozone.

Abstract: To replace the cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention proposes a composition comprising, on a weight basis, 60 to 90% of 1,1-dichloro-1-fluoroethane (F141b), 9 to 33% of 1,1,1,3,3-pentafluorobutane (F365 mfc) and 1 to 7% of methanol. These three compounds form a positive azeotrope (b.p.=29.1.degree. C. at normal pressure).The composition, optionally stabilized, can be employed for the cleaning and/or drying of solid surfaces, in particular for the defluxing of printed circuits and for the degreasing of mechanical components.

Abstract: To replace cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention proposes a composition comprising, by weight, 93 to 99% of 1,1,1,3,3-pentafluorobutane (F365 mfc) and 7 to 1% of methanol. These two compounds form a positive azeotrope (b.p.=36.5.degree. C. at normal pressure).The composition, optionally stabilized, can be used for the cleaning and/or drying of solid surfaces, in particular for the removal of flux from printed circuits and for degreasing mechanical parts.

Abstract: For replacing cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention provides a composition comprising 55 to 79.5% by weight of 1,1-dichloro-1-fluoroethane (F141b), 20 to 40% by weight of methyl formate and 0.5 to 5% of methanol. These three compounds form a positive azeotrope (b.p.=28.3.degree. C. at atmospheric pressure).The composition, which may be stabilized, can be used for cleaning solid surfaces, in particular for removing flux from printed circuits and for degreasing mechanical parts.

Abstract: For replacing cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention provides a composition comprising 55 to 80% by weight of 1,1,1,2,2-pentalfuoro-3,3-dichloropropane (225ca) and 20 to 45% by weight of methyl tert-butyl ether.These two compounds form a negative azeotrope (b.p.=59.9.degree. C. at atmospheric pressure).The composition, which may be stabilized, can be used for cleaning solid surfaces, in particular for removing flux from printed circuits and for degreasing mechanical parts.

Abstract: The invention relates to the preparation of 1,1,2,2-tetrahydroperfluoroalkanols and their esters.A 2-(perfluoroalkyl)ethyl iodide is oxidized using peroxomonosulphuric acid or peroxodisulphuric acid in a carboxylic acid or carboxylic acid ester.

Abstract: The invention relates to the synthesis of 1,1,2,2-tetrahydroperfluoroalkanols and their esters by oxidizing a 2-(perfluoroalkyl)ethyl iodide using hydrogen peroxide in a carboxylic acid or carboxylic acid ester in the presence of sulphuric acid.In the process according to the invention, from 1 to 30 moles of sulphuric acid, from 1 to 50 moles of carboxylic acid or of an ester of such an acid, and from 3 to 20 moles of hydrogen peroxide per mole of 2-perfluoralkyl)ethyl iodide are used.