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
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
• • 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
  • C23G5/02825—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 containing hydrogen
  • C23G5/02829—Ethanes
  • C23G5/02835—C2H2Cl2F2
• • 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

Definitions

• solder fluxes generally consist of rosin, either used alone or with activating additives, such as amine hydrochlorides or oxalic acid derivatives.
• Defluxing solvents should have the following characteristics: a low boiling point, be nonflammable, have low toxicity and have high solvency power, so that flux and flux-residues can be removed without damaging the substrate being cleaned.
• azeotropic mixtures with their constant boiling points and constant compositions, have been found to be very useful for these applications.
• Azeotropic mixtures exhibit either a maximum or minimum boiling point and they do not fractionate on boiling. These characteristics are also important when using solvent compositions to remove solder fluxes and flux-residues from printed circuit boards. Preferential evaporation of the more volatile solvent mixture components would occur, if the mixtures were not azeotropic and would result in mixtures with changed compositions, and with less-desirable solvency properties, such as lower rosin flux solvency and lower inertness toward the electrical components being cleaned.
• the azeotropic character is also desirable in vapor degreasing operations, where redistilled solvent is generally employed for final rinse cleaning.
• vapor defluxing and degreasing systems act as a still. Unless the solvent composition exhibits a constant boiling point, i.e., is a single material, or is an azeotrope, fractionation will occur and undesirable solvent distributions will result, which could detrimentally affect the safety and efficacy of the cleaning operation.
• U.S. Patent No, 3,903,009 discloses the ternary azeotrope of 1,1,2-trichloro-1,2,2-trifluoroethane with ethanol and nitromethane
• U.S. Patent No. 2,999,815 discloses the binary azeotrope of 1,1,2-trichloro-1,2,2-trifluoroethane and acetone.
• 2,999,816 discloses the binary azeotrope of 1,1,2-trichloro-1,2,2-trifluoroethane and methyl alcohol.
• U.S. Patent No. 4,767,561 discloses the ternary azeotrope of 1,1,2-trichloro-1,2,2-trifluoroethane, methanol and 1,2-dichloroethylene.
• azeotropic compositions comprising admixtures of effective amounts of 1,1-dichloro-1,2-difluoroethane with trans-1,2-dichloroethylene plus an alcohol from the group consisting of methanol, ethanol and isopropanol.
• the azeotropic mixtures are: an admixture of about 51-61 weight percent 1,1-dichloro-1,2-difluoroethane and about 31-41 weight percent trans-1,2-dichloroethylene and about 4-10 weight percent methanol; an admixture of about 65-75 weight percent 1,1-dichloro-1,2-difluoroethane and about 19-29 weight percent trans-1,2-dichloroethylene and about 3-7 weight percent ethanol; an admixture of about 61-71 weight percent 1,1-dichloro-1,2-difluoroethane and about 27-37 weight percent trans-1,2-dichloroethylene and about 0.7-1.7 weight percent isopropanol.
• the present invention provides nonflammable azeotropic compositions which are well suited for solvent cleaning applications.
• the halogenated materials are known as HCFC-132c and T-HCC-1130, respectively, in the nomenclature conventional to the halocarbon field.
• azeotropic composition a constant boiling liquid admixture of three or more substances, whose admixture behaves as a single substance, in that the vapor, produced by partial evaporation or distillation of the liquid has substantially the same composition as the liquid, i.e., the admixture distills without substantial compositional change.
• Constant boiling compositions which are characterized as azeotropic, exhibit either a maximum or minimum boiling point, as compared with that of the nonazeotropic mixtures of the same substances.
• effective amount is defined as the amount of each component of the instant invention admixture which, when combined, results in the formation of the azeotropic compositions of the instant invention.
• This definition includes the amounts of each component, which amounts may vary depending upon the pressure applied to the composition so long as the azeotropic compositions continue to exist at the different pressures, but with possible different boiling points. Therefore, effective amount includes each components, weight percentage for each composition of the instant invention, which form azeotropic compositions at pressures other than atmospheric pressure.
• an azeotropic composition consisting essentially of is not intended to exclude the inclusion of minor amounts of other materials which do not significantly alter the azeotropic character of the composition.
• composition can be defined as an azeotrope of A, B, and C since the very term "azeotrope" is at once both definitive and limitative, and requires that effective amounts of A, B and C form this unique composition of matter, which is a constant boiling admixture.
• azeotrope is at once both definitive and limitative, and requires that effective amounts of A, B and C form this unique composition of matter, which is a constant boiling admixture.
• an azeotrope of A, B and C represents a unique type of relationship but with a variable composition which depends on temperature and/or pressure. Therefore compositional ranges, rather than fixed compositions, are often used to define azeotropes.
• the composition can be defined as a particular weight percent relationship or mole percent relationship of A, B and C, while recognizing that such specific values point out only one particular such relationship and that in actuality, a series of such relationships, represented by A, B and C actually exist for a given azeotrope, varied by the influence of pressure.
• Azeotrope A, B and C can be characterized by defining the composition as an azeotrope characterized by a boiling point at a given pressure, thus giving identifying characteristics without unduly limiting the scope of the invention by a specific numerical composition, which is limited by and is only as accurate as the analytical equipment available.
• Ternary mixtures of about 51-61 weight percent 1,1-dichloro-1,2-difluoroethane and about 31-41 weight percent trans-1,2-dichloroethylene and about 4-10 weight percent methanol are characterized as azeotropic, in that mixtures within this range exhibit a substantially constant boiling point at constant pressure. Being substantially constant boiling, the mixtures do not tend to fractionate to any great extent upon evaporation. After evaporation, only a small difference exists between the composition of the vapor and the composition of the initial liquid phase. This difference is such that the compositions of the vapor and liquid phases are considered substantially identical. Accordingly, any mixture within this range exhibits properties which are characteristic of a true ternary azeotrope.
• the ternary composition consisting of about 56.5 weight percent 1,1-dichloro-1,2-difluoroethane, about 36.5 weight percent trans-1,2-dichloroethylene and about 7.0 weight percent methanol has been established, within the accuracy of the fractional distillation method, as a true ternary azeotrope, boiling at about 41.0°C, at substantially atmospheric pressure.
• ternary mixtures of about 65-75 weight percent 1,1-dichloro-1,2-difluoroethane, about 19-29 weight percent trans-1,2-dichloroethylene and about 3-7 weight percent ethanol are characterized as azeotropic, in that mixtures within this range exhibit a substantially constant boiling point at constant pressure. Being substantially constant boiling, the mixtures do not tend to fractionate to any great extent upon evaporation. After evaporation, only a small difference exists between the composition of the vapor and the composition of the initial liquid phase. This difference is such that the compositions of the vapor and liquid phases are considered substantially identical. Accordingly, any mixture within this range exhibits properties which are characteristic of a true ternary azeotrope.
• the ternary composition consisting of about 70.0 weight percent 1,1-dichloro-1,2-difluoroethane, about 24.6 weight percent trans-1,2-dichloroethylene and about 5.4 weight percent ethanol has been established, within the accuracy of the fractional distillation method, as a true ternary azeotrope, boiling at about 44.5°C, at substantially atmospheric pressure.
• ternary mixtures of about 61-71 weight percent 1,1-dichloro-1,2-difluoroethane, about 27-37 weight percent trans-1,2-dichloroethylene and about 0.7-1.7 weight percent isopropanol are characterized as azeotropic, in that mixtures within this range exhibit a substantially constant boiling point at constant pressure. Being substantially constant boiling, the mixtures do not tend to fractionate to any great extent upon evaporation. After evaporation, only a small difference exists between the composition of the vapor and the composition of the initial liquid phase. This difference is such that the compositions of the vapor and liquid phases are considered substantially identical.
• any mixture within this range exhibits properties which are characteristic of a true ternary azeotrope.
• the ternary composition consisting of about 66.3 weight percent 1,1-dichloro-1,2-difluoroethane, about 32.5 weight percent trans-1,2-dichloroethylene and about 1.2 weight percent isopropanol has been established, within the accuracy of the fractional distillation method, as a true ternary azeotrope, boiling at about 46.5°C, at substantially atmospheric pressure.
• the aforestated azeotropes have low ozone-depletion potentials and are expected to decompose almost completely, prior to reaching the stratosphere.
• the azeotropic compositions of the present invention permit easy recovery and reuse of the solvent from vapor defluxing and decreasing operations because of their azeotropic nature.
• the azeotropic mixtures of this invention can be used in cleaning processes such as described in U.S. Patent No. 3,881,949, which is incorporated herein by reference.
• azeotropic compositions of the instant invention can be prepared by any convenient method including mixing or combining the desired component amounts.
• a preferred method is to weigh the desired component amounts and thereafter combine them in an appropriate container.
• a solution which contained 61.7 weight percent 1,1-dichloro-1,2-difluoroethane, 31.8 weight percent trans-1,2-dichloroethylene and 6.5 weight percent methanol was prepared in a suitable container and mixed thoroughly.
• a solution which contained 76.3 weight percent 1,1-dichloro-1,2-difluoroethane, 16.8 weight percent trans-1,2-dichloroethylene 6.9 weight percent ethanol was prepared in a suitable container and mixed thoroughly.
• a solution which contained 64.6 weight percent 1,1-dichloro-1,2-difluoroethane, 30.0 weight percent trans-1,2-dichloroethylene and 5.4 weight percent isopropanol was prepared in a suitable container and mixed thoroughly.
• circuit boards were coated with activated rosin flux and soldered by passing the board over a preheater to obtain a top side board temperature of approximately 200°F (93°C) and then through 500°F (260°C) molten solder.
• the soldered boards were defluxed separately with the three azeotropic mixtures cited in Examples 1, 2 and 3 above, by suspending a circuit board, first, for three minutes in the boiling sump, which contained the azeotropic mixture, then, for one minute in the rinse sump, which contained the same azeotropic mixture, and finally, for one minute in the solvent vapor above the boiling sump.
• the boards cleaned in each azeotropic mixture had no visible residue remaining thereon.

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• 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)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Manufacturing Of Printed Wiring (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 1990
  • 1990-09-28 CA CA002026487A patent/CA2026487A1/en not_active Abandoned
  • 1990-10-02 EP EP90310776A patent/EP0421730A2/en not_active Withdrawn
  • 1990-10-02 KR KR1019900015859A patent/KR910008168A/ko not_active Withdrawn
  • 1990-10-02 BR BR909004950A patent/BR9004950A/pt unknown
  • 1990-10-03 HU HU906326A patent/HUT55739A/hu unknown
  • 1990-10-04 CN CN90108980A patent/CN1051387A/zh active Pending
  • 1990-10-04 AU AU63830/90A patent/AU6383090A/en not_active Abandoned
  • 1990-10-04 JP JP2265270A patent/JPH03223399A/ja active Pending

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