Azeotrope-like compositions and their use

An azeotrope-like composition including:

• (a) perfluorobutyl methyl ether, wherein said ether consists essentially of about 18 weight percent perfluoro-n-butyl ethyl ether, and about 82 weight percent perfluoroisobutyl ethyl ether, and (b) organic solvent, that is selected from the group consisting of:
• (i) compositions consisting essentially of the ether and methanol, wherein the compositions, when fractionally distilled, form a distillate fraction that is an azeotrope consisting essentially of about 84 weight percent of the ether and 16 percent of the methanol that boils at about 53.degree. C. at about 731 torr;
• (ii) compositions consisting essentially of the ether and ethanol, wherein the compositions, when fractionally distilled, form a distillate fraction that is an azeotrope consisting essentially of about 88 weight percent of the ether and about 12 percent of the ethanol that boils at about 62.degree. C. at about 731 torr;
• (iii) compositions consisting essentially of the ether and 2-propanol, wherein the compositions, when fractionally distilled, form a distillate fraction that is an azeotrope consisting essentially of about 87 weight percent of the ether and about 13 percent of the 2-propanol that boils at about 65.degree. C. at about 731 torr;
• (iv) compositions consisting essentially of the ether and t-butanol, wherein the compositions, when fractionally distilled, form a distillate fraction that is an azeotrope consisting essentially of about 84 weight percent of the ether and about 16 percent of the t-butanol that boils at about 67.degree. C. at about 741 torr;
• wherein the concentrations of the ether and the organic solvent in the azeotrope-like composition differ from the concentrations of such components in the corresponding azeotrope by no more than ten percent.