Patent ID: RE42652

Claim:
Drop-in substitutes for R 12 consisting of ternary near-azeotropic compositions: 1,1,1,2-tetrafluoroethane (R 134a) 75-86% by weight pentafluoroethane (R125) 4-20% by weight n-butane (R 600) 2-4% by weight or 1,1,1,2-tetrafluoroethane (R 134a) 75-93% by weight 1,1,1,2,3,3,3-heptafluoropropane (R 227ea) 5-20% by weight n-butane and/or isobutane (R 600 & R 600a) 2-4% by weight said compositions having the feature that the percent variation of the vapor pressure after 50% percent evaporation of the liquid at a temperature of 25° C. is comprised between 0.5 and 7% of the vapor pressure before said evaporation.