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
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/02—Anionic compounds
  • C11D1/37—Mixtures of compounds all of which are anionic
• • 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
  • C23G5/06—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using emulsions
• • 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
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/02—Anionic compounds
  • C11D1/04—Carboxylic acids or salts thereof
• • 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
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
• • 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
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/0008—Detergent materials or soaps characterised by their shape or physical properties aqueous liquid non soap compositions
  • C11D17/0017—Multi-phase liquid compositions
  • C11D17/0021—Aqueous microemulsions
• • 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
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/43—Solvents
• • 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
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/02—Anionic compounds
  • C11D1/12—Sulfonic acids or sulfuric acid esters; Salts thereof
  • C11D1/14—Sulfonic acids or sulfuric acid esters; Salts thereof derived from aliphatic hydrocarbons or mono-alcohols
  • C11D1/143—Sulfonic acid esters
• • 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
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/02—Anionic compounds
  • C11D1/12—Sulfonic acids or sulfuric acid esters; Salts thereof
  • C11D1/22—Sulfonic acids or sulfuric acid esters; Salts thereof derived from aromatic compounds

Definitions

• This invention concerns microemulsions and emulsions, and their use in various applications.
• Microemulsions are well known. Typical components of microemulsions include water, an organic solvent, and surfactants. Often, microemulsions are used as cleaning formulations.
• U.S. Patent 4,909,962 describes a clear, single phase, pre-spotting composition provided in the form of a microemulsion, solution, or gel, this composition characterized as being infinitely dilutable with water without phase separation.
• U. S. Patent 5,462,692 describes water continuous microemulsions containing a perfume as their primary water-insoluble hydrocarbon component. The patent employs, among other components, tall oil fatty acids, in formulations useful as hard surface cleaners.
• Patent 5,597,792 describes oil continuous, high water content (water in oil) emulsions and microemulsions useful for cleaning purposes, which contain ionic surfactants soluble in the organic solvent phase, such surfactant being of average molecular weight ranging from 350 to 700, preferably greater than 400 and less than 600, exclusive of counterion.
• ionic surfactants soluble in the organic solvent phase
• compositions useful in cleaning applications In systems described as being oil continuous, the systems have low water contents. While predominately describing water continuous systems, some of the examples in U.S. Patent 4,909,962 exemplify low water containing, oil continuous (water in oil) systems. It is desirable to find new compositions for such purposes which possess high water contents and are oil continuous. Such oil continuous microemulsions are especially suitable to function as cleaning compositions to remove oil or grease.
• This invention in one respect, is a single phase oil continuous microemulsion useful as a liquid cleaning composition, comprising: A. water in an amount not less than about 40 percent by weight and not greater than about 75 percent by weight based on the total weight of the microemulsion;
• organic solvent or a mixture of two or more organic solvents wherein the organic solvent or mixture of organic solvents are characterized as containing no more than about 2 weight percent water at 25°C when the organic solvent is saturated with water in the absence of surfactants or other additives, and wherein the organic solvent or the mixture of two or more organic solvents are in an amount not less than about 10 percent and not greater than about 60 percent by weight based on the total weight of the microemulsion;
• one or more anionic surfactants which are at least partially soluble in the one or more organic solvents, wherein at least one of said surfactants is an olefinic or a saturated fatty acid salt, which has an average molecular weight in the range from 225 to 365 exclusive of the counterion group, and wherein the one or more anionic surfactants are present in a total amount greater than about 0.1 percent and not greater than about 10 percent by weight based on the total weight of the microemulsion.
• this invention is an emulsion, which upon standing at 25°C forms at least two phases wherein one phase is an oil continuous microemulsion, comprising:
• organic solvent or a mixture of two or more organic solvents wherein the organic solvent or mixture of organic solvents are characterized as containing no more than 2 weight percent water at 25 C C when the organic solvent is saturated with water in the absence of surfactants or other additives, and wherein the organic solvent or the mixture of two or more organic solvents are present in an amount not less than about 4 percent and not greater than about 40 percent by weight based on the total weight of the emulsion;
• one or more anionic surfactants which are at least partially soluble in the one or more organic solvents, wherein at least one of said surfactants is an olefinic or a saturated fatty acid salt, which has an average molecular weight in the range from 225 to 365 exclusive of the counterion group, and wherein the one or more anionic surfactants are present in a total amount greater than 0.1 percent and less than about 5 percent by weight based on the total weight of the emulsion.
• this invention is a bicontinuous or water continuous microemulsion or emulsion, meeting all criteria mentioned above except the Z value, which is perturbable into the compositions of the invention described above, through addition of salt or a saturated hydrocarbon of molecular weight less than about 87, and which comprises:
• organic solvent or a mixture of two or more organic solvents wherein the organic solvent or mixture of organic solvents are characterized as containing no more than 2 weight percent water at 25°C when the organic solvent is saturated with water in the absence of surfactants or other additives;
• this invention is a method for cleaning metal having grease or oily soil on a surface of the metal which comprises applying the microemulsion or the emulsion described above to the metal which has grease or oily soil on the surface of the metal to remove at least a portion of the grease or oily soil from the metal.
• microemulsions and emulsions of this invention find utility as liquid cleaning compositions for use in metal cleaning, hard surface cleaning, circuit board defluxing, automotive cleaning, cold cleaning, dry cleaning, paint stripping and fabric cleaning. Further, the microemulsions and emulsions are particularly effective for removing grease and oily substances.
• the compositions of this invention can be used in laundry pretreaters, laundry detergents, coatings, skin cleansers, hair cleaning and conditioning formulations, and in aerosol, pump, spray or liquid pesticide formulations.
• the compositions can also be used in industrial coatings and sealants applications, such as in adhesives, inks, polishes, latexes and as processing solvents.
• compositions of this invention can be used in soil remediation and water desalinization as well as in applications to enhance oil recovery and in the delivery of acids and other additives to oil wells.
• the compositions of this invention can be used in pharmaceutical applications such as in vaccine adjuvants, topical drug delivery vehicles and in self- heating compositions.
• the compositions of this invention can be used as media for producing nanoparticles in ceramics applications as well as in applications for manufacture of catalysts such as zeolites and of semiconductors.
• the compositions of this invention can be used in fuels to solubilize alternative fuel materials such as alcohols.
• the compositions of this invention can be used to stabilize enzymes, facilitate heterophase reactions and increase surface area in reaction media applications.
• compositions of this invention can be used to produce latexes and water soluble polymers by microemulsion polymerization as well as to produce heterophase polymers such as self-reinforcing plastics and to make polymer dispersions. It may also be possible to employ these formulations to dissolve agricultural pesticides and the like with the resultant composition being used to apply on crops.
• the microemulsions and emulsions of this invention can be used in cleaning applications to deliver bleaching agent and enzyme in a formulation such that the bleaching agent limitedly degrades the enzyme.
• the compositions of this invention can also be employed as metal working fluids, including cutting fluids, forming fluids, quenching fluids and protecting fluids, and as force-transmitting hydraulic fluids.
• a unique aspect of this invention is the advantage of forming high water containing compositions which are low viscosity and oil continuous, using naturally occurring and renewable unsaturated and saturated fatty acid salts, in low concentrations, to give products having enhanced environmental compatibility and electrolyte tolerance over similar water in oil (“w/o") microemulsions which employ sulfonated surfactants.
• the microemulsions of this invention contain as essential components water, an organic solvent, and one or more anionic surfactants.
• Such microemulsions and emulsions are characterized as being oil continuous and having a high water content.
• Microemulsions are generally considered to be compositions in thermodynamic equilibrium which have suspended particle sizes in the range from 50 to 1000 angstroms.
• Electrode as used herein means any solvated salts in the microemulsions or emulsion including ionic surfactant or added salts such as magnesium sulfate, sodium carbonate and sodium chloride.
• a composition 0.02 molar in an electrolyte having a molar conductivity of 120,000 (microSiemens x liter/ centimeter x mol) and a volume fraction of water of 50 percent has a Z value of 200 and is therefore an oil continuous microemulsion below 200 microSiemens/ centimeter (Z).
• the compositions of this invention have an electrical conductivity below 0.5 Z, more preferably below 0.25 Z and most preferably below 0.1 Z.
• bicontinuous compositions are above Z and below 2Z and water continuous compositions are above 2Z.
• the water is present in an amount not less than about 40 percent by weight and not greater than about 75 percent by weight based on the total weight of the microemulsion.
• the microemulsion contains not less than about 45 weight percent water.
• the microemulsions contain not greater than about 70 weight percent water, more preferably not greater than about 65 weight percent and even more preferably not greater than about 60 weight percent.
• an organic solvent or a mixture of two or more organic solvents is employed, wherein the organic solvent or mixture of organic solvents are characterized as containing no more than 2 weight percent water at 25°C when the organic solvent is saturated with water in the absence of surfactants or other additives.
• the organic solvent or mixture of organic solvents contain no more than 1 weight percent water at 25°C when saturated, more preferably no more than 0.5 weight percent water.
• Water uptake of an organic solvent can be readily determined by water titration, for example, wherein water is added to the one or more organic solvents until cloudiness of solution is observed or an excess water phase develops.
• the organic solvent or the mixture of two or more organic solvents are present in an amount not less than about 10 percent and not greater than about 60 percent by weight based on the total weight of the microemulsion.
• the organic solvent or the mixture of two or more organic solvents are present in an amount not less than about 15 weight percent, more preferably not less than about 20 percent, most preferably not less than about 25 weight percent; and preferably, not greater than 50 weight percent.
• Classes of organic solvents that can be used in the practice of this invention include aliphatic alcohols, aliphatic esters, aliphatic hydrocarbons, chlorinated aliphatic hydrocarbons, aromatic hydrocarbons, aliphatic diesters, aliphatic ketones, and aliphatic ethers.
• a solvent can contain two or more of these functional groups or can contain combinations of these functional groups.
• alkylene glycol diethers, alkylene glycol monoethers and alkylene glycol ether acetates may be employed as solvents in the practice of this invention.
• alkylene glycol ethers includes dialkylene glycol ethers.
• the alkylene glycol monoethers and alkylene glycol diethers are particularly useful to decrease viscosity of a microemulsion.
• Preferred classes of organic solvents are the aliphatic hydrocarbons, aromatic hydrocarbons, alkylene glycol monoethers, alkylene glycol diethers, and alkylene glycol ether acetates. More preferred classes of organic solvents are the aliphatic hydrocarbons, alkylene glycol monoethers, and alkylene glycol diethers.
• the aliphatic alcohols can be primary, secondary or tertiary. Preferred aliphatic alcohols have 4 to 24 carbon atoms. Representative examples of more preferred aliphatic alcohols include 1-hexanol, isoheptyl alcohol, octanol, 2-ethyl-hexanol, nonanol, dodecanol, undecanol, and decanol.
• Preferred aliphatic esters have 4 to 24 carbon atoms.
• Representative examples of more preferred aliphatic esters include methyl laurate, methyl oleate, hexyl acetates, pentyl acetates, octyl acetates, nonyl acetates, and decyl acetates.
• the aliphatic hydrocarbons can be linear, branched, cyclic or combinations thereof.
• Preferred aliphatic hydrocarbons contain 3 to 24 carbon atoms, preferably 6 to 24 carbon atoms.
• Representative examples of more preferred aliphatic hydrocarbons include alkanes such as liquid propane, butane, pentane, hexane, heptane, octane, decane, dodecane, hexadecane, mineral oils, paraffin oils, decahydronaphthalene, bicyclohexane, cyclohexane, and olefins such as 1-decene, 1-dodecene, octadecene, and hexadecene.
• Examples of commercially available aliphatic hydrocarbons are NorparTM 12, 13, and 15 (normal paraffin solvents available from Exxon Corporation), Naphtha SC 140 petroleum distillate (also from Exxon), IsoparTM G, H, K, L, M, and V (isoparaffin solvents available from Exxon Corporation), and ShellsolTM solvents (Shell Chemical Company).
• Preferred chlorinated aliphatic hydrocarbons contain 1 to 12 carbon atoms, more preferably contain from 2 to 6 carbon atoms.
• Representative examples of more preferred chlorinated aliphatic hydrocarbons include methylene chloride, carbon tetrachloride, chloroform, 1 ,1 ,1 -trichloroethane, perchloroethylene, and trichloroethylene.
• Preferred aromatic hydrocarbons contain 6 to 24 carbon atoms.
• aromatic hydrocarbons include toluene, naphthalene, biphenyl, ethyl benzene, xylene, alkyl benzenes such as dodecyl benzene, octyl benzene, and nonyl benzene.
• Preferred aliphatic diesters contain 6 to 24 carbon atoms.
• Representative examples of more preferred aliphatic diesters include dimethyl adipate, dimethyl succinate, dimethyl glutarate, diisobutyl adipate, and diisobutyl maleate.
• Preferred aliphatic ketones have 4 to 24 carbon atoms.
• Representative examples of more preferred aliphatic ketones include methyl ethyl ketone, diethyl ketone, diisobutyl ketone, methyl isobutyl ketone, and methyl hexyl ketone.
• Preferred aliphatic ethers have 4 to 24 carbon atoms.
• Representative examples of more preferred aliphatic ethers include diethyl ether, ethyl propyl ether, hexyl ether, butyl ether, and methyl t-butyl ether.
• Preferred alkylene glycol monoethers, dialkylene glycol monoethers, alkylene glycol diethers, and alkylene glycol ether acetates include propylene glycol diethers having 5 to 25 carbon atoms, propylene glycol ether acetates having 6 to 25 carbon atoms, propylene glycol monoethers having 7 to 25 carbon atoms, ethylene glycol ether acetates having 6 to 25 carbon atoms, ethylene glycol diethers having 6 to 25 carbon atoms, and ethylene glycol monoethers having 8 to 25 carbon atoms.
• solvents within this broad class include propylene glycol dimethyl ether, propylene glycol benzyl methyl ether, propylene glycol butyl methyl ether, propylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol butyl methyl ether, dipropylene glycol dibutyl ether; propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol butyl ether acetate; propylene glycol monobutyl ether, propylene glycol monohexyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monohexyl ether; ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol butyl ether acetate; ethylene glycol diethyl ether, ethylene glycol dibutyl ether;
• alkylene glycol monoethers are employed in admixture with one or more other organic solvents.
• the addition of alkylene glycol monoethers facilitates the preparation of low viscosity microemulsions and emulsions.
• the alkylene glycol monoether is present in an amount not less than about 5 weight percent based on the total weight of the microemulsion, preferably not less than about 10 weight percent, more preferably not less than about 15 weight percent; not greater than about 50 weight percent, preferably not greater than about 40 weight percent and more preferably not greater than about 25 weight percent.
• the ratio of glycol ether to total surfactants should be greater than 2 to 1 by weight, in both microemulsions and emulsions.
• the alkylene glycol monoether is present in the emulsions containing about 70 - 80 percent water in an amount not less than about 5 weight percent based on the total weight of the emulsion, and not greater than about 15 percent.
• one or more anionic surfactants of specified chemical structure are employed which are at least partially soluble in the one or more organic solvents.
• the one or more anionic surfactants are preferably also characterized as possessing greater solubility in the one or more organic solvents than in water and preferentially partitioning into the organic solvent in a mixture of water and organic solvent.
• the one or more anionic surfactants are no more than sparingly water soluble.
• solubility does not include dispersability or emulsifiability.
• the one or more anionic surfactants have a molecular weight greater than 225 and less than 365.
• molecular weight as used above is calculated based on the average of the molecular weights of the two or more anionic surfactants. Often the naturally occurring fatty acids used to prepare the anionic surfactants are available commercially as blends of various molecular weight components, in various degrees of unsaturation and carbon content.
• a preferred class of anionic surfactants are anionic surfactants of formula (R 1 - COO) y M (formula I) wherein R 1 represents an olefinically unsaturated or a saturated alkyl, y is 1 or 2, wherein M represents a cationic counterion and wherein the total number of carbons in R 1 is from 13 to 23.
• R 1 is unsaturated internally in the alkyl group and is not alpha.beta-unsaturated nor is the olefinic unsaturation conjugated with the carboxyl group.
• the molecular weight of an anionic surfactant of formula (I) is calculated exclusive of the weight of M; that is, molecular weight is calculated for R - COO only.
• the anionic surfactants containing M as a counterion can be readily prepared from their acid precursors wherein M is hydrogen, such as by reacting the carboxylic acid with a metal hydroxide including hydroxides of ammonium, lithium, sodium, potassium, magnesium, calcium, etc. Selection of a particular M counterion is not critical so long as the resulting surfactant remains at least partially soluble in the organic solvent and preferably is no more than sparingly water soluble and provides anionic surfactants which are capable of producing the microemulsions and emulsions of this invention.
• M is monovalent, and more preferably is selected from sodium, potassium and "onium" (e.g., quat. nitrogen as in ammonium, etc.) cations.
• the anionic surfactants have an ave. molecular weight of at least about 250, more preferably at least 280 and most preferably at least about 295.
• the anionic surfactants have a molecular weight not greater than 345 and more preferably not greater than 340, and most preferably not greater than 337, exclusive of the counterion M.
• anionic surfactants useful in the invention are salts of the following olefinic and saturated aliphatic and alicyclic carboxylic acids:
• Olefinic fatty acids myristoleic (cis-tetradec-9-enoic) acid; palmitoleic (cis-9-hexadecenoic) acid; linolenic (9,12,15-octadecatrienoic) acid; linoleic (9,12 or 13-octadecadienoic) acid; oleic (cis-9-octadecenoic) acid; arachidonic (5,8,11 ,14-eicosatetraenoic) acid; erucic (cis-13- docosenoic) acid; and unsaturated, 5-carbon alicyclic acids: hydnocarpic acid (C )6 H 28 O 2 ); chaulmoogric acid (C 18 H 32 O 2 ); and gorlic acid (C, ⁇ H 30 O 2 ); and
• Saturated fatty acids myristic (tetradecanoic - C 14 H 28 O 2 ) acid; palmitic (hexadecanoic C ⁇ H ⁇ O j ) acid; stearic (octadecanoic - C 18 H 36 O 2 ) acid; eicosanoic (arachidic - C 20 H ⁇ 0 O 2 ) acid; and docosanoic (behenic - C 22 H 44 O 2 ) acid.
• An advantage of using the preferred anionic surfactants is that relatively small amounts of the preferred anionic surfactants are needed to provide the high water content, oil continuous microemulsions and emulsions of this invention. Consequently, the amount of residual anionic surfactant left on a surface cleaned with the microemulsions and emulsions is minimal, and problems of streaking and so forth are also minimal.
• An additional advantage is that since the acids are mostly derivatives of natural products, they are considered by some to be more "environmentally friendly" than typical synthetic anionic surfactants.
• the preferred anionic surfactants are present in the microemulsions in an amount not less than about 0.5 weight percent and more preferably not less than about 1 weight percent.
• the preferred anionic surfactants are present in the microemulsions in an amount not greater than about 6 percent and more preferably in an amount not greater than about 5, weight percent.
• a carboxylic acid in addition to its salt may be included in the formulation, the acid acts not as a surfactant but much as the aliphatic alcohol organic solvents mentioned above. However, the acids act less effectively on a weight basis than such an alcohol, due to the generally higher molecular weight of the acids.
• the specific carboxylic acid salt surfactants previously described may be supplemented with other typical anionic, sulfonate surfactants of the sulfonated alkylbenzene/toluene/naphthalene-type commonly available.
• R represents alkyl
• x is 1 or 2
• B is a biradical when x is 1 or is a triradical when x is 2 and which is derived from an aromatic moiety and wherein M represents the same cationic counterion mentioned previously, and wherein the total number of carbons in R ⁇ is from 18 to 30.
• Molecular weight of an anionic surfactant of formula R x B-SO 3 M is calculated exclusive of the molecular weight of counterion M; that is, molecular weight is calculated for R x B-SO 3 only.
• Such adjunct sulfonate surfactants containing M as a counterion can be readily prepared from their precursor sulfonic acid by reacting it with a metal hydroxide including hydroxides of ammonium, lithium, sodium, potassium, magnesium, calcium.
• M counterion is not critical so long as the resulting surfactant remains at least partially soluble in the organic solvent and, preferably, no more than sparingly water soluble, and proves capable of assisting the specific carboxylic acid-derived anionic surfactants in producing the microemulsions and emulsions of this invention.
• M is monovalent.
• B is derived from benzene, toluene or naphthalene.
• the adjunct sulfonate surfactants have a molecular weight greater than 400.
• these adjunct surfactants have a molecular weight less than 600 and more preferably less than 550.
• one or more nonionic surfactants can be also be employed to supplement or enhance the effectiveness of the anionic surfactant(s).
• the one or more nonionic surfactants are employed in an amount from 0 to about 6 percent by weight based on the total weight of the microemulsion.
• the one or more nonionic surfactants are employed in an amount not greater than about 3, more preferably not greater than about 2, weight percent.
• the combined weight of the anionic surfactants and nonionic surfactants amounts to not greater than about 10, and more preferably not greater than about 8, weight percent of the microemulsion.
• Nonionic surfactants which may usefully be employed in this invention include alkylphenol alkoxylates and primary and secondary alcohol alkoxylates wherein the alkoxylate can be ethoxy, propoxy, butoxy or combinations thereof. Mixtures of alcohol alkoxylates can be used.
• Preferred nonionic surfactants are alkylphenol ethoxylates and primary and secondary alcohol ethoxylates. The alkylphenol ethoxylates and primary and secondary alcohol ethoxylates are represented by the formula:
• R is a hydrocarbon containing 9 to 24 carbon atoms and n is a number averaging from 1 to 9.
• nonionic surfactants are sold by Shell Chemical Company under the name NeodolTM and by Union Carbide Corporation under the name TergitolTM.
• Representative examples of preferred commercially available nonionic surfactants include TergitolTM 15-s-series and NeodolTM 91 or 25 series.
• nonionic surfactants include polyoxyethylated polypropylene glycols, polyoxyethylated polybutylene glycols, polyoxyethylated mercaptans, glyceryl and polyglyceryl esters of natural fatty acids, poiyoxyethylenated sorbitol esters, polyoxyethylenated fatty acids, alkanol amides, tertiary acetylinic glycols, N-alkyl- pyrrolidones, and alkyl polyglycosides.
• More preferred nonionic surfactants employed in this invention are secondary alcohol ethoxylates.
• Representative examples of preferred commercially available secondary alcohol ethoxylates include TergitolTM 15-S-3, TergitolTM 15-S-5 and TergitolTM 15-S-7.
• microemulsions of this invention may further contain other types of surfactants such as amphoteric surfactants with molecular weights above 350, betaines such as N-alkylbetaines including N,N,N-dimethyl- -hexadecyl-amino-(3-propionate), and sulfobetaines such as N,N,N-dimethyl-hexadecyl-amino-propylene sulfonate.
• surfactants such as amphoteric surfactants with molecular weights above 350
• betaines such as N-alkylbetaines including N,N,N-dimethyl- -hexadecyl-amino-(3-propionate)
• sulfobetaines such as N,N,N-dimethyl-hexadecyl-amino-propylene sulfonate.
• Conductivity of a microemulsion of this invention is measured at use temperatures as the conductivity can vary with temperature, because the phase behavior of the microemulsion can also change with temperature. It follows that it is possible to make a microemulsion which is not oil continuous and does not fall within the scope of this invention at room temperature, but which when heated to a higher use temperature is oil continuous and does fall within the scope of this invention. Electrical conductivity can be measured using standard techniques and conventional equipment, employing, for example, a Fisher brand model 326 conductivity meter which has a one centimeter gap between the anode and cathode in the probe.
• the probe When such a device is used, the probe is simply immersed in the solution, the instrument is allowed to equilibrate, and the conductivity value obsen ed from the device. It should be understood that the device must be calibrated using standard electrolyte solutions of known conductivity prior to measuring conductivity of compositions of this invention.
• the microemulsions of this invention have a viscosity less than 40 centistokes as measured at use temperatures. Viscosity is measured at use tempera-tures because viscosity can vary with temperature. It follows that it is possible to make a microemulsion which is not within the scope of this invention at room temperature, but which when heated to a higher use temperature possesses a viscosity which does fall within the scope of this invention.
• the single-phase, oil continuous microemulsions have a viscosity less than 30 centistokes, more preferably less than 20 centistokes, and even more preferably less than 10 centistokes and most preferably less than about 8 centistokes.
• Viscosity can be measured by well known methods using conventional equipment designed for such purpose.
• a capillary viscometer such as a Cannon-Fenske capillary viscometer equipped with a size 350 capillary can be used following the procedure of ASTM D 445.
• a Brookfield Model LVT Viscometer with a UL adapter can be used to measure viscosities in centipoise.
• the one or more surfactants are employed in an amount effective to form an oil continuous microemulsion. This amount varies depending on the amount and nature of the components in the entire microemulsion composition. It is equally important, however, that the microemulsions contain a high water content, generally above 40 weight percent based on the total weight of the composition. This being the case, the invention microemulsions are characterized as being compositions which are neither bicontinuous nor water continuous.
• a generalized methodology used to design high water, single phase microemulsion cleaning systems is as follows: (A) select an organic solvent or organic solvent blend having the desired low water uptake; (B) determine the relationship between surfactant structure (e.g., hydrophilicity) and conductivity, viscosity and phase behavior (e.g., the presence of liquid crystals) of compositions with the desired level of water, surfactants, organic solvent and additive contents by varying only the surfactant or surfactant blend composition; (C) the procedure of steps A and B may be repeated as necessary at several solvent and surfactant concentrations until the amount and types of solvent and surfactant necessary to give a single phase oil continuous structure at the desired water level (based on the information generated in step B) are determined; (D) determine the viscosity and conductivity of the oil continuous microemulsion; (E) if viscosity is too high, it may be adjusted by reducing surfactant concentration, by changing the solvent composition (e.g., by increasing the level of an oxygenated solvent such as glycol
• the minimum surfactant level is defined as the lowest surfactant level where one may traverse the region of microemulsion structures from water continuous to oil continuous without the generation of any excess phases.
• microemulsions described here may be transformed from their oil continuous structure through the bicontinuous region into the water continuous, via, e.g., evaporation of solvent components giving a new solvent balance; solubilization of soils which may favor a water continuous structure; or addition of water during a water rinsing procedure.
• the most preferred systems should maintain low viscosities not only in the oil continuous region but also in the bi- and water-continuous regions.
• a microemulsion having a conductivity, measured at its use temperature, of greater than its Z number may be perturbed (also referred to loosely as "titrated" with aqueous sodium carbonate electrolyte) to generate microemulsions.
• This perturbation is accomplished by the introduction, by total weight of the composition, of either up to about 0.5 percent of an electrolyte as mentioned above, or up to about 20 percent, preferably up to 10 percent or less, of an aliphatic or alicyclic hydrocarbon of not greater than 100 molecular weight.
• the electrolyte selected for this purpose can be one or more of the salts mentioned previously or a soluble polymer electrolyte, for example, a water-soluble polyacrylic acid or polyacrylate salt.
• the low molecular weight hydrocarbon can, for example, be propane, butane, pentane, hexane or cyclohexane. Generally the lower weight the hydrocarbon, the more effective in perturbation.
• Example 13 a number of Sample formulations were prepared using the methodology noted above, until the properties were appropriately adjusted by varying the levels and types of the formulations' components and the Na Carb electrolyte in Samples S-1 through S-5, where the w/o microemulsion of conductivity less than Z was ultimately prepared by perturbation.
• the cleaning emulsions of this invention are well dispersed when sufficiently mixed; however, upon standing the emulsions form at least two phases wherein one phase is an oil continuous microemulsion. Typically, only two phases form when the emulsions are allowed to stand. As used herein, "standing” means allowed to sit undisturbed for 7 days at 25°C.
• the emulsions of this invention contain water in an amount greater than 60 percent by weight and less than 95 percent by weight based on the total weight of the emulsion.
• the emulsions contain water in an amount greater than 70 weight percent, more preferably greater than 75 weight percent; preferably less than 90 weight percent, more preferably less than 88 weight percent.
• the types of organic solvents employed in the emulsions of this invention are the same as those described above under the Microemulsions heading, including all the classes of solvents, physical characteristics of the solvents, representative examples and preferred solvents.
• the amount of solvent employed in the emulsions of this invention is greater than 4 percent and less than 40 percent by weight based on the total weight of the emulsion.
• the amount of solvent employed for an emulsion is greater than 8 weight percent, more preferably greater than 10 weight percent; preferably less than 25 weight percent, and more preferably less than 15 weight percent.
• the amounts of ionic surfactant employed is from about 0.1 percent to about 5 percent by weight based on the total weight of the emulsion. Preferably, the amount employed is less than about 3 weight percent.
• oil continuous compositions are also used to describe the emulsions.
• Conductivity is measured, after agitation and before phase separation occurs, at use temperatures as the conductivity can vary with temperature because the phase behavior of the emulsion can also change with temperature. It follows that it is possible to make an emulsion which is not oil continuous and does not fall within the scope of this invention at room temperature, but which when heated to a higher use temperature is oil continuous and does fall within the scope of this invention.
• the emulsions have a viscosity less than 40 centistokes as measured at use temperatures. Viscosity is measured at use temperatures because viscosity can vary with temperature. It follows that it is possible to make an emulsion which is not within the scope of this invention at room temperature, but which when heated to a higher use temperature possesses a viscosity which does fall within the scope of this invention.
• the emulsions Preferably, have a viscosity less than 20 centistokes, more preferably less than 10 centistokes.
• a generalized methodology utilized to design high water emulsion cleaning systems is as follows: (A) select an organic solvent or organic solvent blend having the desired low water uptake; (B) determine the relationship between surfactant structure (e.g., hydrophilicity) and conductivity of a composition with the desired water, surfactants, organic solvent, and additive contents by varying only the surfactant or surfactant blend composition; (C) the procedure of steps A and B may be repeated as necessary at several solvent and surfactant concentrations until the amount and types of solvent and surfactant necessary to give an oil continuous emulsion structure at the desired water level (based on the information generated in step B) are determined; (D) determine the viscosity, conductivity and water content of the emulsion, stability (time to phase separation) of the oil continuous emulsion; (E) if viscosity is too high, it may be adjusted by varying the surfactant concentration, organic solvent to surfactant ratio, or by addition of an additional organic solvent, such as a glycol ether, to decrease vis
• microemulsions and emulsions a variety of optional materials may be added depending on end use, desired physical properties of the microemulsion or emulsion, and the like.
• various detergent additives such as tetrasodium ethylenediamine tetraacetate "EDTA"
• EDTA tetrasodium ethylenediamine tetraacetate
• sequestering agents such as tetrasodium ethylenediamine tetraacetate "EDTA”
• sequestering agents such as tetrasodium ethylenediamine tetraacetate "EDTA")
• sequestering agents such as tetrasodium ethylenediamine tetraacetate "EDTA”
• sequestering agents such as tetrasodium ethylenediamine tetraacetate "EDTA”
• sequestering agents such as tetrasodium ethylenediamine tetraacetate "EDTA”
• any sodium alkyl toluene sulfonates used to supplement the anionic carboxylate surfactant in the preparation of microemulsions should be treated to remove residual sulfate salts and alkyl toluene disulfonate by extraction of a solution of surfactant in PnB using aqueous hydrogen peroxide followed by neutralization using aqueous sodium hydroxide.
• PnB denotes propylene glycol n-butyl ether (DOWANOLTM PnB obtained from The Dow Chemical Company)
• PnP denotes propylene glycol n-propyl ether (DOWANOLTM PnP obtained from The Dow Chemical Company)
• w/o denotes oil continuous microemulsions
• o/w denotes water continuous microemulsions
• Naphtha SC 140 is a commercial petroleum distillate obtained from Exxon Corporation
• ExxalTM 7 is a commercial isoheptyl alcohol (5-methyl hexanol), also obtained from Exxon.
• Na Erucate is the sodium salt of erucic acid and is prepared in situ, by neutralization of erucic acid with 5N aqueous sodium hydroxide solution.
• the other acid salts are prepared by neutralization of their respective carboxylic acid with sodium hydroxide or other aqueous alkaline metal or alkaline earth base, e.g. potassium hydroxide or the like.
• a concentrate solution is prepared by mixing 16.2 parts ExxalTM 7 isoheptyl alcohol with 16.2 parts DOWANOLTM PnP propylene glycol n-propyl ether (“PnP”) and 41.7 parts DOWANOLTM PnB propylene glycol n-butyl ether (“PnB”), in which erucic acid is combined and then neutralized with a 5N aqueous sodium hydroxide solution, to yield 16.2 parts Na erucate and 9.7 parts water. The result is a low viscosity, stable, clear single- phase solution.
• This concentrate solution may subsequently be "perturbed", by the addition of electrolyte, water and organic solvent, into a resulting w/o microemulsion of the invention.
• the two-phase product is "titrated” with a 10 percent sodium carbonate ("Na Carb”) solution.
• Example 1 a sample is prepared from the same components in slightly modified ratios, by varying amounts of the two glycol ethers - employing instead 14.9 parts PnB and 3 parts PnP.
• This is a perturbable microemulsion which can be converted into a w/o microemulsion by addition of electrolyte.
• the electrolyte the electrolyte
• Example 1 a sample is prepared, substituting a petroleum distillate - Naphtha SC 140 supplied by Exxon Chemical, for the previous heptane organic solvent base.
• the components of the sample and their respective amounts are: Naphtha
• the 1110 ⁇ S/cm conductivity, low viscosity w/o microemulsion prepared as described in Example 4 is contacted with steel coupons coated with Lithium grease in accordance with the standard Conoco cleaning test. Excellent grease removal and cleaning is observed.
• d-limonene is an organic base solvent component commonly employed in a wide range of cleaning products.
• perturbable o/w emulsion containing an excess of the oil phase are added varying amounts of the Na Carb, passing through intermediate bicontinuous formulations, until a clear w/o microemulsion with some excess water phase results. Upon agitation, this gives an emulsion which has a conductivity of approximately .5Z and a viscosity of 12.5 cSt.
• Table 1 Samples A-1 through A-4.
• various formulations are prepared employing a variety of sodium carboxylic acid salts in place of the Na erucate found in the previous Examples.
• the other components of the formulations are selected from Na Carb, n-heptane, PnB, 1 -hexanol and Dl water, and in some formulations, cyclohexane.
• a series of formulations are prepared - adjusting the ratios of the various components to attain the desired properties of conductivity lees than 1Z and a low viscosity. From these series, one can observe how the methodology described in the teachings above is used for the preparation and then fine tuning of each formulation. The properties of each microemulsion or emulsion formulation can also be observed in these Examples.
• the formulations' various compositions and their respective resulting physical properties and calculated Z numbers are presented in Tables 2 - 7, found below.

Landscapes

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

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=21810780

Family Applications (1)

Country Status (10)

Cited By (10)

Families Citing this family (12)

Citations (6)

• 1997
  • 1997-07-24 ES ES97935130T patent/ES2163188T3/es not_active Expired - Lifetime
  • 1997-07-24 AU AU38147/97A patent/AU711474B2/en not_active Ceased
  • 1997-07-24 WO PCT/US1997/013145 patent/WO1998004761A1/en not_active Application Discontinuation
  • 1997-07-24 JP JP10509025A patent/JPH11513077A/ja active Pending
  • 1997-07-24 CN CN97191142A patent/CN1199430A/zh active Pending
  • 1997-07-24 BR BR9702359A patent/BR9702359A/pt unknown
  • 1997-07-24 EP EP97935130A patent/EP0866889B1/en not_active Expired - Lifetime
  • 1997-07-24 DE DE69708459T patent/DE69708459T2/de not_active Expired - Lifetime
  • 1997-07-24 CA CA002232976A patent/CA2232976A1/en not_active Abandoned
  • 1997-07-24 KR KR1019980702179A patent/KR19990063712A/ko not_active Application Discontinuation

Patent Citations (7)

Also Published As

Similar Documents

Legal Events