Patent ID: 6695973
Filing Date: 2004-02-24
Classification: C09K

Abstract:
Drop-in substitutes for R 12 consisting of ternary near-azeotropic compositions:1,1,1,2-tetrafluoroethane (R 134a)75-86%by weightpentafluoroethane (R 125)4-20%by weightn-butane (R 600)2-4%by weightor1,1,1,2-tetrafluoroethane (R 134a)75-93%by weight1,1,1,2,3,3,3-heptafluoropropane (R 227ea)5-20%by weightn-butane and/or isobutane (R 600 & R 600a)2-4%by weightsaid compositions having the feature that the percent variation of the vapor pressure after 50% percent evaporation of the liquid at a temperature of 25Â° C. is comprised between 0.5 and 7% of the vapor pressure before said evaporation.