Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/50—Solvents
  • C11D7/5036—Azeotropic mixtures containing halogenated solvents
  • C11D7/5068—Mixtures of halogenated and non-halogenated solvents
  • C11D7/5077—Mixtures of only oxygen-containing solvents
  • C11D7/5081—Mixtures of only oxygen-containing solvents the oxygen-containing solvents being alcohols only
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/02—Materials undergoing a change of physical state when used
  • C09K5/04—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa
  • C09K5/041—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems
  • C09K5/044—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems comprising halogenated compounds
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
  • C23G5/02—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents
  • C23G5/032—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing oxygen-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
  • C09K2205/10—Components
  • C09K2205/102—Alcohols
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
  • C09K2205/10—Components
  • C09K2205/108—Aldehydes or ketones
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
  • C09K2205/32—The mixture being azeotropic

Definitions

• This invention relates to an azeotropic composition and particularly to the azeotropic mixture of tetrachlorodifluoroethane and either one of the compounds ethanol, isopropanol, n-propanol, methyl ethyl ketone or methyl n-propyl ketone.
• chlorofiuoroethanes have attained widespread use as specialty solvents in recent years, particularly tetrachlorodifluoroethane.
• This is a relatively high melting compound (CCl FCCl F, 245 C.) which is nontoxic and nonfiammable, and which has satisfactory solvent power for greases, oils, waxes and the like under certain conditions. It has therefore found widespread use in cleaning electric motors, compressors, oxygen storage tanks, photographic film, lithographic plates, typewriters, instruments, gauges, sound tape, and as non-corrosive brines.
• Printed circuits are well known in the electronics art; and consist of a circuit formed from a soft metal on a solid, non-conducting surface such as a reinforced phenolic resin.
• the solid surface is coated with the metal, the desired portion of metal is coated with an impervious coating, and the excess metal is removed by etching with a suitable acid. Afterthe excess metal has been removed, it is necessary to remove the impervious coating because solder joints must be made to the printed circuit and these will not form if the coating is present.
• the circuits are coated with a rosin flux to permit the joints to be soldered, after which the rosin flux'must then be removed.
• the chlorofluoroethane solvent does not have suflicient solvent power to clean printed circuits; that is, to effectively remove the rosin flux.
• mixtures of solvents may be used for this purpose they have the disadvantage that they boil over a range of temperatures and consequently undergo fractionation in vapor degreasing or ultrasonic applications which are open to the atmosphere.
• the solvent When employing either of these methods the solvent must also be substantially nontoxic and nonflammable for safety reasons.
• Tetrachlorodifluoroethane is a relatively high boiling fluorocarbon and for this reason especially advantageous in vapor degreasing applications since at these temperatures the hot vapor has more of a tendency to dissolve high melting greases, or fluxes as well as oil residues and the like.
• the solvent vapors tend to condense on the article until the articles are heated by the vapors from room temperature up to the temperature of the vapor.
• the condensation thus formed on the articles tends to drip back into the solvent reservoir taking with it some of the soil on the article. For this reason the ability of a cleaning solvent to condense on the surface is especially advantageous.
• Tetrachlorotrifiuoroethane also is a better solvent than materials such as trichlorotrifiuoromethane however, it sufliers the disadvantage that it is solidus at room temperature whereas the latter is liquidus. Accordingly, tetrachlorodifiuoroethane is more difiicult to handle than liquid type cleaning solvents.
• the above object of this invention may be accomplished by a novel azeotropic composition of tetrachlorodifluoroethane (e.g. 1,1,2,2-tetrachloro 1,2 difluoroethane) and either one of the compounds ethanol, isopropanol, n-propanol, methyl ethyl ketone or methyl-n-propyl ketone.
• tetrachlorodifluoroethane e.g. 1,1,2,2-tetrachloro 1,2 difluoroethane
• 1,1,2,2-tetrac:hloro 1,2 difluoroethane is a preferred tetrachlorodifluoroethane
• the isomer l,1,l,2-tetrachloro-2,2-difluoroethane may be substituted therefor in whole or in part and especially in minor amounts or trace amounts. All of these mixtures form azeotropes which distill at a constant temperature, the liquid phase and the vapor phase in. equilibrium therewith having the same composition. Such mixture is relatively nonfiammable and nontoxic in both the liquid phase and the vapor phase.
• mixtures are particularly useful as solvents for greases, oils, waxes, and the like and cleaning electric motors, compressors, photographic films, lithographic plates, typewriters, precision instruments, gauges, sound tapes, and the like and are particularly useful for cleaning printed circuits.
• the azeotropic mixtures are obtained at approximately 760 mm. Hg a variation in pressure and consequently a change in the compositions and boiling points are also intended to be within the broad scope of the invention.
• the azeotropes may contain many different proportions of all of the aforementioned components provided a constant boiling mixture is obtained at the various pressures at which the compositions are used. Stated otherwise any pressure may be employed to obtain the aeotropes of this invention as long as a two component constant boiling mixture is obtained, and accordingly the ratio of components of the azeotropes of the invention will also vary.
• the present invention relates to the aforementioned azeotropes that boil at atmospheric pressure about 25, especially about 15 mm. Hg.
• the board is cleaned by placing it in an ultrasonic bath of any of the aforementioned azeotropes and operating at about 32 kilocycles per second at about 38 C., where it remains for about one minute.
• this component may vary from about 68.1 to about 83.1 parts by weight and so forth for the rest of the ranges of all the other above components and their equivalents.
• Printed circuit boards are usually prepared by impregnating glass cloth, nylon, or paper laminates with a phenolformaldehyde resin or an epoxy resin.
• Printed circuits are prepared by a variety of methods. In a typical procedure, the board consists originally of a phenolic resin impregnated base to which is bonded a sheet of copper, 2 to 4 mils thick, covering one surface of the board. The desired circuit is drawn on the copper With an asphalt based ink using the silk of this invention substantially all of the rosin flux is re moved without any detrimental eifect on the board which constitutes the backing of the printed circuit.
• An azeotropic composition consisting egsentially of about 72.2 parts by weight of 1,l,2,2-tetrachl0ro-l,2- difluoroethane and about 27.8 parts by weight of 'isopropanol.
• a method for cleaning a solid surface comprising contacting said surface with the composition of claim 1.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• General Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Physics & Mathematics (AREA)
• Combustion & Propulsion (AREA)
• Thermal Sciences (AREA)
• Detergent Compositions (AREA)
• Manufacturing Of Printed Wiring (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=27488005

Family Applications (4)

Family Applications After (3)

Country Status (2)

Cited By (6)

Families Citing this family (2)

Citations (1)

• 1968
  • 1968-10-30 US US772046A patent/US3527708A/en not_active Expired - Lifetime
• 1970
  • 1970-04-13 US US00032482A patent/US3737389A/en not_active Expired - Lifetime
  • 1970-04-13 US US00032483A patent/US3737390A/en not_active Expired - Lifetime
  • 1970-04-13 US US00032481A patent/US3737388A/en not_active Expired - Lifetime
  • 1970-05-28 BE BE751083D patent/BE751083A/fr unknown

Patent Citations (1)

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