Azeotrope-like compositions and their use

An azeotrope-like composition including perfluorobutyl methyl ether, wherein said ether consists essentially of about 95 weight percent perfluoro-n-butyl methyl ether, and about 5 weight percent perfluoroisobutyl methyl ether, and one organic solvent, and is selected from the group consisting of:

• (i) compositions consisting essentially of the ether and cyclohexane which, when fractionally distilled, form a distillate fraction that is an azeotrope that consists essentially of about 88 weight percent of the ether and about 12 weight percent of the cyclohexane and boils at about 54° C. at about 738 torr;
• (ii) compositions consisting essentially of the ether and methylcyclohexane which, when fractionally distilled, form a distillate fraction that is an azeotrope that consists essentially of about 96 weight percent of the ether and about 4 weight percent of the methylcyclohexane and boils at about 58° C. at about 734 torr;
• (iii) compositions consisting essentially of the ether and heptane which, when fractionally distilled, form a distillate fraction that is an azeotrope that consists essentially of about 95 weight percent of the ether and 5 weight percent of the heptane and boils at about 57° C. at about 725 torr;
• (iv) compositions consisting essentially of the ether and isooctane which, when fractionally distilled, produce a distillate fraction that is an azeotrope that consists essentially of about 96 weight percent of the ether and about 4 weight percent of the isooctane and boils at about 58° C. at about 725 torr;
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• (v) compositions consisting essentially of the ether and hexane which, when fractionally distilled, produce a distillate fraction that is an azeotrope that consists essentially of about 79 weight percent of the ether and about 21 weight percent of the isooctane and boils at about 51° C. at about 730 torr.

An azeotrope-like composition including perfluorobutyl methyl ether, wherein said ether consists essentially of about 35 weight percent perfluoro-n-butyl methyl ether, and about 65 weight percent perfluoroisobutyl methyl ether, and one organic solvent, and is selected from the group consisting of:

• (i) compositions consisting essentially of the ether and methylcyclohexane, the compositions ,when fractionally distilled, form a distillate fraction that is an azeotrope that consists essentially of about 97 weight percent of the ether and about 3 weight percent of the methylcyclohexane and boils at about 59° C. at about 738 torr;
• (ii) compositions consisting essentially of the ether and heptane, the compositions, when fractionally distilled, form a distillate fraction that is an azeotrope that consists essentially of about 94 weight percent of the ether and 6 weight percent of the heptane and boils at about 59° C. at about 730 torr;
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• (iii) compositions consisting essentially of the ether and isooctane, the compositions, when fractionally distilled, produce a distillate fraction that is an azeotrope that consists essentially of about 96 weight percent of the ether and about 4 weight percent of the isooctane and boils at about 58° C. at about 731 torr.