Classifications

• • 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
  • C23G5/028—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons
  • C23G5/02809—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons containing chlorine and fluorine
  • C23G5/02812—Perhalogenated hydrocarbons
  • C23G5/02816—Ethanes
  • C23G5/02822—C2Cl4F2
• • 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
  • 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
• • 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
  • C23G5/028—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons
  • C23G5/02806—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons containing only chlorine as halogen atom

Definitions

• This invention relates to an azeotropic composition and particularly to the binary and ternary azeotropic mixture of tetrachlorodifiuoroethane and methanol or any one of the isomers, n-butanol or iso-butanol of sec.- butanol.
• the present invention also relates to ternary azeotropes of tetrachlorodifluoroethane and trichloroethylene with either methanol or ethanol or isopropanol.
• ternary azeotropes have been discovered comprising tetrachlorodifluoroethane, trichloroethane and either methanol or ethanol or isopropanol.
• chlorofiuoroethanes have attained widespread use as specialty solvents in recent years, particularly tetrachlorofluoroethant.
• This is a relatively high melting compound (CCl FCCl F, 24.5 C.), which is nontoxic and nonflammable, and which has satisfactory solvent power for greases, oils, waxes and the like under certain conditions. It has therefore found use in cleaning electric motors, compressors, lithographic plates, typewriters, instruments, gauges, 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. During manufacture, 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. After the 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. After the impervious coating is removed, 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 chlorofiuoroethane solvent does not have sufficient 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 cleaning or degreasing methods the solvent must also be both relatively nontoxic and nonflammable for safety reasons.
• Tetrachlorodifluoroethane is a relatively high boiling fluorocarbon and for this reason is 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 3,554,918 Patented Jan. 12, 1971 ice 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.
• Tetrachlorodifluoroethane also is a better solvent than materials such as trichlorotrifluoromethane, however, it suffers the disadvantage that it is solidus at room temperature whereas the latter is liquidus. Accordingly tetrachlorodifluoroethane is more diflicult to handle than liquid type cleaning solvents.
• the above object of this invention may be accomplished by a novel binary azeotropic composition of tetrachlorodifiuoroethane (e.g. 1,1,2,2-tetrachloro-1,2-difluoroethane) and either methanol or n-butanol or secondary butanol or iso-butanol; ternary azeotropes of tetrachlorodifluoroethane (e.g., 1,1,2,2-tetrachloro-1,2-difluoroethane) trichloroethylene and either methanol or ethanol or isopropanol; and ternary azeotropes of tetrachlorodifiuoroethane (e.g.
• 1,1,2,2-tetrachloro 1,Z-difluoroethane 1,1,2,2-tetrachloro 1,Z-difluoroethane
• trichloroethane e.g. 1,1,1-trichloroethane
• methanol or ethanol or isopropanol 1,1,2,2-tetrachloro-1,Z-difluoroethane
• 1,1,2,2-tetrachloro-1,Z-difluoroethane is a preferred tetrachlorodifluoroethane
• the isomer, 1,l,1,2-tetrachloro-2,2- difluoroethane may be substituted therefore in whole or in part and especially in minor amounts or trace amounts.
• the preferred trichloroethane comprises the 1,1,1-trichloroethane isomer.
• 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 nonflammable and nontoxic in both the liquid phase and the vapor phase.
• These mixtures are particularly. useful as solvents for greases, oils, waxes, and the like and cleaning electric motors, compressors, lithographic plates, typewriters, precision instruments, gauges, and the like and are particular 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 azeotropes of this invention as long as a three com ponent or 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 i about 25, especially 1 about 15 mm. Hg.
• Example IIX The method of Example I is repeated using different mixtures of alcohols and/or 1,1,1-trichloroethane or trichloroethylene and 1,1,2,2-tetrachloro-1,2-difluoroethane, the results of which are as follows:
• the board is then passed over a molten solder bath, contacting the desired joints with the molten metal, whereby the soldering is effected. After cooling, the excess rosin flux remaining on the board must be removed since, if present in the final assemly, it will lead to corrosion, poor electrical resistance and other deleterious properties.
• 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 1020 F. belowtheboiling point of the particular azeotrope for about one minute.
• An azeotropic mixture consisting essentially of about 24.3 parts 1,1,2,2-tetrachloro-1,2-di-fluorocthane,
• 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 screen method.
• excess copper is then removed by etching with a ferric about 30.9 parts i-propanol and about 44.8 parts trichloroethylene on a weight basis.

Landscapes

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

Applications Claiming Priority (8)

Publications (1)

Family

ID=27574375

Family Applications (8)

Family Applications Before (1)

Family Applications After (6)

Country Status (2)

Cited By (5)

Families Citing this family (10)

• 0
  • US US677715D patent/USB677715I5/en active Pending
• 1967
  • 1967-10-24 US US677715A patent/US3554918A/en not_active Expired - Lifetime
• 1968
  • 1968-08-13 CA CA027,298A patent/CA955820A/en not_active Expired
• 1970
  • 1970-06-02 US US54082A patent/US3671443A/en not_active Expired - Lifetime
  • 1970-06-02 US US54084A patent/US3671444A/en not_active Expired - Lifetime
  • 1970-06-02 US US54086A patent/US3671445A/en not_active Expired - Lifetime
  • 1970-06-02 US US54085A patent/US3671446A/en not_active Expired - Lifetime
  • 1970-06-02 US US54081A patent/US3671442A/en not_active Expired - Lifetime
• 1972
  • 1972-05-23 US US00255972A patent/US3833507A/en not_active Expired - Lifetime

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