The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1992
Filed:
Mar. 15, 1988
Michinori Yokozawa, Shimizu, JP;
Hideaki Kikuchi, Shimizu, JP;
Du Pont - Mitsui Fluorochemicals Co. Ltd., Tokyo, JP;
Abstract
The cleaning method of the present invention comprises; (a) immersing a material to be cleaned in a mixed solvent contained in the first open vessel, wherein the mixed solvent consists of a chlorofluoro-hydrocarbon with a boiling point of 20.degree.-50.degree. C. and an organic solvent with a boiling point of 50.degree. C. or more higher than that of said chlorofluoro-hydrocarbon and compatible therewith, but not azeotropic therewith, and kept at a temperature within a range between the boiling point of the chlorofluoro-hydrocarbon and a temperature of at least 30.degree. C. lower than the boiling point of the organic solvent, (b) then transferring the material into a boiling liquid essentially consisting of said chlorofluoro-hydrocarbon contained in the second open vessel, (c) and taking out the material from the boiling liquid, (d) wherein, constituting a saturated vapor zone of the chlorofluoro-hydrocarbon by the evaporated vapor from the boiling liquid essentially consisting of the chlorofluoro-hydrocarbon and the mixed solvent in an open container equipped with cooling apparatus in the upper part and holding the open vessels in the lower part, (e) and keeping a constant state of the ratio of the chlorofluoro-hydrocarbon and the organic solvent in the mixed solvent, with a equilibrium of the evaporation of the chlorofluoro-hydrocarbon from the mixed solvent and its absorption from the saturated vapor zone of the chlorofluoro-hydrocarbon, by keeping the temperature of the mixed solvent at a constant temperature.