WO2014092756A1 - Cleaning composition for metal articles - Google Patents

Cleaning composition for metal articles Download PDF

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Publication number
WO2014092756A1
WO2014092756A1 PCT/US2013/031819 US2013031819W WO2014092756A1 WO 2014092756 A1 WO2014092756 A1 WO 2014092756A1 US 2013031819 W US2013031819 W US 2013031819W WO 2014092756 A1 WO2014092756 A1 WO 2014092756A1
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WO
WIPO (PCT)
Prior art keywords
acid
cleaning composition
urea
weight
bifluoride
Prior art date
Application number
PCT/US2013/031819
Other languages
French (fr)
Inventor
Charles L. Hawes
Original Assignee
Parker-Hannifin Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Parker-Hannifin Corporation filed Critical Parker-Hannifin Corporation
Priority to US14/651,050 priority Critical patent/US20150315712A1/en
Publication of WO2014092756A1 publication Critical patent/WO2014092756A1/en

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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
    • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
    • C11D3/02—Inorganic compounds ; Elemental compounds
    • C11D3/04—Water-soluble compounds
    • C11D3/046—Salts
    • 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
    • C11D3/16—Organic compounds
    • C11D3/26—Organic compounds containing nitrogen
    • C11D3/32—Amides; Substituted amides
    • C11D3/323—Amides; Substituted amides urea or derivatives 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
    • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
    • C11D3/43—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
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F3/00—Brightening metals by chemical means
    • C23F3/02—Light metals
    • C23F3/03—Light metals with acidic solutions
    • 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
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/12—Light metals
    • C23G1/125—Light metals aluminium
    • 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
    • C11D2111/00—Cleaning compositions characterised by the objects to be cleaned; Cleaning compositions characterised by non-standard cleaning or washing processes
    • C11D2111/10—Objects to be cleaned
    • C11D2111/14—Hard surfaces
    • C11D2111/16—Metals

Definitions

  • the invention related generally to a composition for cleaning metal surfaces, and in particular, to an aqueous composition for cleaning aluminum and aluminum alloys.
  • cleaning compositions require elevated temperatures, e.g., temperatures at or above 120°C, to be effective.
  • Other cleaning compositions are alkaline, which may cause corrosion and pitting of the metal surface.
  • Acidic cleaning compositions have been used, but many contain components that present a safety risk to the user and/or are harmful to the environment.
  • an aqueous cleaning composition including: at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; at least one mineral acid adduct with urea; at least one surfactant; and at least one organic solvent.
  • the mineral acid adduct with urea is selected from among the adducts of urea with perchloric acid (urea perchloride); hydroiodic acid (urea hydroiodide); hydrobromic acid (urea hydrobromide); hydrochloric acid (urea hydrochloride and urea dihydrochloride); sulfuric acid (urea sulfate); nitric acid (urea nitrate and urea dinitric acid); phosphoric acid (urea phosphate) and combinations of two or more thereof.
  • perchloric acid urea perchloride
  • hydroiodic acid urea hydroiodide
  • hydrobromic acid urea hydrobromide
  • hydrochloric acid urea hydrochloride and urea dihydrochloride
  • sulfuric acid urea sulfate
  • nitric acid urea nitrate and urea dinitric acid
  • phosphoric acid urea phosphate
  • the acid fluoride salt is ammonium bifluoride.
  • the surfactant includes a nonionic surfactant.
  • the nonionic surfactant may include an ethoxylated alcohol.
  • the surfactant includes an amphoteric surfactant.
  • the amphoteric surfactant may include cocoamidopropyl betaine.
  • the organic solvent includes diethylene glycol monobutyl ether.
  • an aqueous cleaning composition including: from about 1 % to about 10% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; from about 2% to about 20% by weight of at least one mineral acid adduct with urea; from about 1 % to about 10% by weight at least one surfactant; and from about 1 % to about 10% by weight at least one organic solvent.
  • at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof.
  • the aqueous cleaning composition may be diluted with water in a ratio of cleaning composition :water of 1 : 1 to 1 :10. In one embodiment, the aqueous cleaning composition is diluted with water in a ratio of 1 part cleaning composition to 3 parts water.
  • a method of cleaning a metal surface including: contacting the metal surface with an aqueous cleaning composition for a sufficient time to clean the metal surface, the aqueous cleaning composition including: at least one acid fluoride salt selected from
  • fluorophosphates sodium fluorosilicates, and combinations of two or more thereof; at least one mineral acid adduct with urea; at least one surfactant; and at least one organic solvent.
  • FIG. 1 is a plot of the percent clean of a soiled aluminum substrate vs. percent ammonium bifluoride content in a cleaning solution in accordance with the present invention.
  • FIG. 2 is a plot of the percent clean of an oxidized aluminum substrate vs. percent ammonium bifluoride content in a cleaning solution in accordance with the present invention.
  • FIG. 3 is a bar graph of the percent clean of a soiled aluminum substrate for cleaning solutions containing various mineral acid adducts with urea in accordance with the present invention.
  • FIG. 4 is a bar graph of the percent clean of an oxidized aluminum substrate for cleaning solutions containing various mineral acid adducts with urea in
  • FIG. 5 is a bar graph of the percent clean of an oxidized aluminum substrate for comparative cleaning solutions containing different concentrations of ammonium bifluoride.
  • the composition of the present invention is an aqueous acidic composition that is useful in cleaning metal surfaces, and in particular, aluminum and aluminum alloy surfaces. More specifically, the composition described herein is particularly useful for cleaning evaporator coils, heating coils and air-cooled condensers to remove deposits that build up on the coils, which can interfere with proper operation of the coils.
  • the cleaning composition is effective in producing a brightened surface for aluminum and aluminum alloys.
  • the invention described herein includes a concentrated cleaner that safely removes dirt and oxidation in a uniform manner resulting in a brightening effect on aluminum fin stock used in the HVAC industry. More specifically, the composition of the present invention provides for an effective cleaning composition that removes accumulated dirt and oxidation in a manner that is safer for the manufacturer, end user and the environment than conventional hydrofluoric acid and mineral acid compositions.
  • Hydrofluoric acid has been a staple ingredient in HVAC coil cleaning for many years. This is mainly because it effectively dissolves aluminum metal very rapidly at a rate unlike any other commonly used acid. It also has a brightening effect on the cleaned metal that is typically better than most conventional compositions. Any residual unreacted hydrofluoric acid quickly reacts with calcium in the environment and forms an inert compound that has very low solubility in water, thereby does not enter the water supply in a significant way.
  • These HF compositions usually contain a mineral co-acid such as sulfuric or phosphoric acids or other acid of a lower pKa to push the equilibrium for HF to the left as:
  • hydrofluoric acid is dangerous to use because of the reactivity with calcium ion in the body that can cause heart failure. It is very penetrating through the skin and is very volatile so as to be an inhalation route hazard as well as a skin corrodent.
  • hydrofluoric acid is a dangerous product to manufacture, to store, to blend into a formula, to dilute and during application.
  • Co-acids are typically chosen from two groups: mineral acids such as sulfuric and phosphoric acids; and organic co-acids such as citric and hydroxyacetic acids.
  • mineral acids such as sulfuric and phosphoric acids
  • organic co-acids such as citric and hydroxyacetic acids.
  • the benchmark for performance in aluminum cleaning and brightening as mentioned above, are the hydrofluoric acid containing formulations with the aforementioned hazards.
  • An example of a commercially available cleaning composition is Acti-Brite from Virginia Corporation, which contains about 15-18% hydrofluoric acid, 5-7% phosphoric acid and surfactants.
  • ammonium bifluoride with organic co-acid product is Calbrite from NuCalgon Corporation. Analysis of Calbrite shows it to contain about 10-13% ammonium bifluoride, about 3-5 % hydroxyacetic acid, and surfactants. As used herein, the term "brightening" means improving the clarity or distinctness of an image reflected by a metal surface.
  • the term "substantially free of” means the composition is completely lacking the component or having such a small amount of the component that the component does not affect the performance of the composition.
  • the component may be present as an impurity or as a contaminant, and is present in an amount that is less than 0.5% by weight. In another embodiment, the component is present in an amount that is less than 0.1 % by weight, and in yet another embodiment, the component is present in an amount that is less than 0.01 % by weight.
  • the cleaning composition of the present invention includes an acid fluoride salt, a mineral acid adduct of urea, at least one surfactant, a water miscible organic solvent and water.
  • Suitable acid fluoride salts include metal fluorides, including alkali metal fluorides, and ammonium fluorides.
  • Examples of such acid fluoride salts include ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium
  • the acid fluoride salt includes ammonium bifluoride.
  • the acid fluoride salt As part of an effective cleaning composition, the acid fluoride salt
  • concentration level may suitably be from about 1 to about 30% by weight, based on the total weight of the composition.
  • acid fluoride salt concentration level is within the range of about 1 to about 25% by weight, or within the range of about 1 to about 10% by weight, or within the range of about 4 to about 6% by weight.
  • the composition includes at least one adduct of a mineral acid with urea.
  • Particularly useful mineral acids are strong mineral acids.
  • Table 1 lists mineral acids with their respective relative strengths expressed by the pKa scale. Table 1
  • Suitable adducts of mineral acids with urea include adducts of urea with perchloric acid (urea perchloride); hydroiodic acid (urea hydroiodide); hydrobromic acid (urea hydrobromide); hydrochloric acid (urea hydrochloride and urea
  • Adducts of mineral acids with urea may be prepared directly from the components or their solutions or by the action of mineral acids on cyanamide, in which case the latter decompose to give urea, which then enters into the adduct with the acid.
  • Urea hydrochloride is an organic acid salt that can be prepared by reacting urea with hydrogen chloride.
  • urea hydrochloride is added in salt form to the cleaning composition.
  • the urea hydrochloride may be a
  • hydrochloride is formed in situ by adding urea and hydrochloric acid to the cleaning composition.
  • the composition is substantially free of added hydrofluoric acid.
  • the urea:mineral acid adduct concentration level may suitably be from about 1 to about 30% by weight, based on the total weight of the composition.
  • the urea hydrochloride concentration level is within the range of about 2 to about 25% by weight, or within the range of about 2 to about 20% by weight, or within the range of about 2 to about 15% by weight, or within the range of about 2 to about 10% by weight.
  • the pH of the composition is in the range of about 0.05 to 7. In one
  • the pH of the composition is between about 0.5 and about 6.5. In one embodiment, the pH of the composition is between about 1 .0 and about 5.0. In one embodiment, the pH of the composition is between about 0.5 and 4.5.
  • the cleaning composition contains at least one surfactant.
  • the surfactant or surfactant mixture may be selected from water soluble or water dispersible nonionic, anionic, cationic, zwitterionic or true amphoteric surfactants.
  • nonionic surfactants include polyoxyalkylene alkyi (or alkenyl) esters obtained by adding 3 moles to 30 moles of an alkylene oxide having 2 to 4 carbon atoms to an aliphatic alcohol having 10 to 18 carbon atoms, wherein examples of the aliphatic alcohol used include primary alcohols and secondary alcohols in which the alkyi group thereof may also be branched, and the aliphatic alcohol is preferably a primary alcohol; polyoxyethylene alkyi (or alkenyl)phenyl ethers; fatty acid alkyi ester alkoxylates obtained by adding an alkylene oxide between the ester bonds of a long chain fatty acid alkyi ester; polyoxyethylene sorbitan fatty acid esters; polyoxyethylene sorbitol fatty acid esters; polyoxyethylene fatty acid esters; polyoxyethylene hydrogenated castor oil; glycerin fatty acid esters; fatty acid alkanolamides; polyoxyethylene alkylamines; alkyi glycoside
  • anionic surfactants include alcohol sulfates and sulfonates, alcohol phosphates and phosphonates, alkyi ester sulfates, alkyi diphenyl ether sulfonates, alkyi sulfates, alkyi ether sulfates, sulfate esters of an alkylphenoxy polyoxyethylene ethanol, alkyi monoglyceride sulfates, alkyi sulfonates, alkyi ether sulfates, alpha- olefin sulfonates, beta-alkoxy alkane sulfonates, alkyi ether sulfonates, ethoxylated alkyi sulfonates, alkylaryl sulfonates, alkylaryl sulfates, alkyi monoglyceride sulfonates, alkyi carboxylates, alkyi ether carboxylates, alkyi alkoxy carboxy
  • Exemplary cationic surfactants include quaternary ammonium surfactants, such as lauryl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, cetyl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide, lanolin fatty acid aminopropylethyldimethyl ammonium ethyl sulfate, stearyl trimethyl ammonium saccharine, cetyl trimethyl ammonium
  • quaternary ammonium surfactants such as lauryl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, cetyl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide, lanolin
  • amphoteric surfactants include fatty acid
  • amidopropyldimethylamino acetic acid betaine alkyldimethylaminoacetic acid betaine, N-acylaminoethyl-N-2-hydroxyethyl aminocarboxylate, N-acylaminoethyl-N- carboxymethoxy ethyl aminocarboxylate, and hydroxyalkyl (C12-14) hydroxyethyl sarcosine.
  • fatty acid amidopropyldimethylaminoacetic acid betaine include cocamidopropyl betaine, palm oil fatty acid amidopropyldimethylaminoacetic acid betaine, lauramidopropyl betaine, and ricinoleic acid
  • amidopropyldimethylaminoacetic acid betaine examples of the
  • alkyldimethylaminoacetic acid betaine include decyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, myristyldimethylaminoacetic acid betaine, cetyldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, oleyldimethylaminoacetic acid betaine, behenyldimethylaminoacetic acid betaine, and coconut oil alkyldimethylaminoacetic acid betaine.
  • N- acylaminoethyl-N-2-hydroxyethyl aminocarboxylate include sodium
  • N- acylaminoethyl-N-carboxymethoxy ethyl aminocarboxylate examples include sodium
  • cocoamphodiacetate sodium cocoamphodipropionate, and sodium
  • the surfactant concentration level of the cleaning composition may suitably be from about 0.5% to about 20% by weight, based on the total weight of the composition. In one embodiment, the surfactant concentration level is within the range of about 0.5 to about 15% by weight, or within the range of about 1 to about 10% by weight, or within the range of about 1 to about 7% by weight.
  • the composition includes at least one organic solvent.
  • Suitable organic solvents include one or more alcohols, glycols, acetates, ether acetates and glycol ethers.
  • Exemplary alcohols include isopropanol, ethanol, and methanol.
  • Exemplary glycols include propylene glycol and ethylene glycol.
  • Examples of ether acetates include diethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate.
  • Exemplary glycol ethers include propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol methyl ether, and dipropylene glycol monopropyl ether.
  • Other organic solvents include n-methyl pyrrolidone, ketones, lactones and terpenes such as d-limonene.
  • organic solvent includes diethylene glycol monobutyl ether.
  • the organic solvent concentration level may suitably be from about 0.5% to about 20% by weight, based on the total weight of the composition. In one embodiment, the organic solvent concentration level is within the range of about 1 to about 15% by weight, or within the range of about 1 to about 10% by weight, or within the range of about 1 to about 3% by weight.
  • compositions may be added to the composition, such as thickeners, gelling agents, fragrance, dispersants, anti-redeposition agents, dyes and
  • humectants for example.
  • the aqueous cleaning composition may be provided in a concentrate that includes from about 1 % to about 10% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; from about 2% to about 20% by weight of at least one mineral acid adduct with urea; from about 1 % to about 10% by weight at least one surfactant; and from about 1 % to about 10% by weight at least one organic solvent.
  • the concentrated aqueous cleaning composition includes from about 4% to about 6% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium
  • fluorophosphates sodium fluorosilicates, and combinations of two or more thereof; from about 2% to about 15% by weight of at least one mineral acid adduct with urea selected from the adducts of urea with perchloric acid; hydroiodic acid; hydrobromic acid; hydrochloric acid; sulfuric acid; nitric acid; phosphoric acid and combinations of two or more thereof; from about 1 % to about 7% by weight at least one surfactant; and from about 1 % to about 3% by weight at least one organic solvent.
  • the cleaning composition may be supplied in a concentrated form or in a variety of diluted forms.
  • concentration of the components in the supplied composition may vary widely.
  • the user may dilute the composition prior to use.
  • the final concentration may be reached from a wide range of supplied concentrations, using water to dilute the supplied concentration, by using an appropriate dilution factor.
  • the composition may be diluted with water in a concentration of composition :water ratio of 1 :1 , 1 :1 .5, 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, 1 :7, 1 :8, 1 :9, 1 :10, or by using many other dilution ratios.
  • a process for cleaning metal surfaces includes cleaning the metal surface by contacting the metal surface with the cleaning composition described herein for a time sufficient to clean the metal surface.
  • the cleaning composition can be applied to the metal surface using any of the contacting techniques known in the art.
  • the cleaning composition may be applied by conventional spraying or immersion methods.
  • the effectiveness of the cleaning compositions was tested through evaluation of aluminum panels, which have been soiled and then immersed in a diluted composition of the concentrated cleaning compositions.
  • the water and bentone are stirred until gel formation, approximately 30 minutes, using a regular overhead 3 bladed stirrer (ETK Model) at approximately 2500 rpm.
  • the remaining ingredients are then added with good mixing to disperse.
  • One square foot of fin stock (aluminum fin stock from JW Aluminum Corp.) is cut into a panel and cleaned using toluene followed by acetone, and then rinsed with deionized water.
  • the lab prepared soil is applied to cover the entire one foot square aluminum panel surface using a paint brush.
  • the panel is baked overnight in a 1 10°C lab oven. The panel is removed from the oven and allowed to cool to room temperature. The panel is then rinsed with water until the unattached soil is removed.
  • each of the cleaning compositions of Examples 1 -7 was evaluated using the soiled aluminum fin stock panel. Each composition was diluted 1 part to three parts water by weight. Panels of the aluminum soiled with the lab prepared soil were cut into coupons of approximately 1 inch X 2 inches and immersed in the diluted cleaner for 30 seconds. After 30 seconds the coupons were immediately rinsed with deionized water.
  • FIG. 1 shows the results of the evaluation.
  • the percent clean was determined by using a grid count under 22.5X magnification.
  • the graph shows that the composition containing 10% ABF (with no added urea hydrochloride) cleaned the surface 55% clean.
  • the effectiveness of the cleaning composition was tested through evaluation of aluminum panels, which have been oxidized and are then immersed in the cleaning composition.
  • Aluminum fin stock is cut into strips measuring 3 inches by 12 inches.
  • the strips are cleaned with toluene, acetone and deionized water and places in a 10% aqueous sodium chloride solution.
  • the aluminum strips are placed in the salt solution in a closed container at 50°C oven for 24 hours. The strips are then
  • FIG. 2 shows the results of the evaluation.
  • the percent clean was determined by using a grid count under 22.5X magnification.
  • the optimum performance range is 5-7% by weight ammonium bifluoride in the concentrated formulation for oxidation removal.
  • each of the cleaning compositions of Examples 15-18 was evaluated using the lab prepared soiled aluminum fin stock panel. Each composition was diluted 1 part to three parts water by weight. Panels of the aluminum soiled with the lab prepared soil were cut into coupons of approximately 1 inch X 2 inches and immersed in the diluted cleaner for 30 seconds. After 30 seconds the coupons were immediately rinsed with deionized water.
  • FIG. 3 shows the results of the evaluation on the lab prepared soil surface. The percent clean was determined by using a grid count under 22.5X magnification.
  • hydroxyacetic acid, and surfactants Calbrite
  • Comparative Example B containing about 15 -18% hydrofluoric acid, 5 -7% phosphoric acid and surfactants (Acti-Brite) were also evaluated.
  • Each composition was diluted 1 part to three parts water by weight. Strips of the oxidized aluminum were cut into coupons of approximately 1 inch X 2 inches. The oxidized coupons were immersed in the diluted cleaner for different lengths of time and then immediately rinsed with deionized water.
  • Table 6 shows the results of the evaluation on the oxidized surface. The percent clean was determined by using a grid count under 22.5X magnification.
  • Strips of aluminum fin stock were prepared by immersing the strips in a 10% sodium chloride solution at 50°C for 48 hours. This produced a much deeper layer of a dark oxide into the aluminum metal strips of fin stock.
  • Comparative Example B were diluted 1 part to three parts deionized water by weight.
  • the prepared strips of double oxidized aluminum were immersed in the diluted cleaner for one minute and then immediately rinsed with deionized water.
  • Table 7 shows the results of the evaluation on the double oxidized surface. Reflectance was measured using a Photovolt Model 577-A reflectometer in accordance with ASTM D 4488-95.
  • a cleaning composition is prepared containing various amounts of ammonium bifluoride in combination with the organic acid hydroacetic acid.
  • the effectiveness of the cleaning compositions of Comparative Example C was evaluated using oxidized aluminum fin stock strips. Each composition was diluted 1 part to three parts water by weight. Strips of the oxidized aluminum were cut into coupons of approximately 1 inch X 2 inches and immersed in the diluted cleaner for 1 minute. After 1 minute the coupons were immediately rinsed with deionized water.
  • FIG. 5 shows the results of varying the concentration of ammonium bifluoride in a cleaning composition containing hydroxyacetic acid.
  • a performance boost is obtained by using a cleaning composition containing a safe urea/mineral acid adduct in combination with ammonium bifluoride in place of a cleaning composition containing a safe organic acid, such as hydroacetic acid in combination with ammonium bifluoride. Similar results are expected with the safe organic acid citric acid.

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  • Oil, Petroleum & Natural Gas (AREA)
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Abstract

An aqueous cleaning composition includes at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; at least one mineral acid adduct of urea; at least one surfactant; and at least one organic solvent. The cleaning composition is effective in removing deposited soil and corrosion products on a metal surface, particularly aluminum and aluminum alloy surfaces.

Description

Title: CLEANING COMPOSITION FOR METAL ARTICLES
Technical Field
The invention related generally to a composition for cleaning metal surfaces, and in particular, to an aqueous composition for cleaning aluminum and aluminum alloys.
Background
Although aluminum is generally considered to be a bright metal, aluminum and aluminum alloy surfaces often present a dull appearance due to build up of grease and dirt, particularly on industrial machinery and equipment. Chemical and electrochemical solutions have been developed to create a highly-reflective surface on aluminum and aluminum alloy bodies.
Many of the available cleaning compositions require elevated temperatures, e.g., temperatures at or above 120°C, to be effective. Other cleaning compositions are alkaline, which may cause corrosion and pitting of the metal surface. Acidic cleaning compositions have been used, but many contain components that present a safety risk to the user and/or are harmful to the environment.
Summary
In one aspect of the invention, there is provided an aqueous cleaning composition including: at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; at least one mineral acid adduct with urea; at least one surfactant; and at least one organic solvent.
In one embodiment, the mineral acid adduct with urea is selected from among the adducts of urea with perchloric acid (urea perchloride); hydroiodic acid (urea hydroiodide); hydrobromic acid (urea hydrobromide); hydrochloric acid (urea hydrochloride and urea dihydrochloride); sulfuric acid (urea sulfate); nitric acid (urea nitrate and urea dinitric acid); phosphoric acid (urea phosphate) and combinations of two or more thereof.
In one embodiment, the acid fluoride salt is ammonium bifluoride. In one embodiment, the surfactant includes a nonionic surfactant. The nonionic surfactant may include an ethoxylated alcohol.
In one embodiment, the surfactant includes an amphoteric surfactant. The amphoteric surfactant may include cocoamidopropyl betaine.
In one embodiment, the organic solvent includes diethylene glycol monobutyl ether.
In one aspect of the invention, there is provided an aqueous cleaning composition including: from about 1 % to about 10% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; from about 2% to about 20% by weight of at least one mineral acid adduct with urea; from about 1 % to about 10% by weight at least one surfactant; and from about 1 % to about 10% by weight at least one organic solvent.
The aqueous cleaning composition may be diluted with water in a ratio of cleaning composition :water of 1 : 1 to 1 :10. In one embodiment, the aqueous cleaning composition is diluted with water in a ratio of 1 part cleaning composition to 3 parts water.
In one aspect of the invention, there is provided a method of cleaning a metal surface, the method including: contacting the metal surface with an aqueous cleaning composition for a sufficient time to clean the metal surface, the aqueous cleaning composition including: at least one acid fluoride salt selected from
ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium
fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; at least one mineral acid adduct with urea; at least one surfactant; and at least one organic solvent.
Brief Description of Drawings
FIG. 1 is a plot of the percent clean of a soiled aluminum substrate vs. percent ammonium bifluoride content in a cleaning solution in accordance with the present invention.
FIG. 2 is a plot of the percent clean of an oxidized aluminum substrate vs. percent ammonium bifluoride content in a cleaning solution in accordance with the present invention. FIG. 3 is a bar graph of the percent clean of a soiled aluminum substrate for cleaning solutions containing various mineral acid adducts with urea in accordance with the present invention.
FIG. 4 is a bar graph of the percent clean of an oxidized aluminum substrate for cleaning solutions containing various mineral acid adducts with urea in
accordance with the present invention.
FIG. 5 is a bar graph of the percent clean of an oxidized aluminum substrate for comparative cleaning solutions containing different concentrations of ammonium bifluoride.
Detailed Description
The composition of the present invention is an aqueous acidic composition that is useful in cleaning metal surfaces, and in particular, aluminum and aluminum alloy surfaces. More specifically, the composition described herein is particularly useful for cleaning evaporator coils, heating coils and air-cooled condensers to remove deposits that build up on the coils, which can interfere with proper operation of the coils. The cleaning composition is effective in producing a brightened surface for aluminum and aluminum alloys.
The invention described herein includes a concentrated cleaner that safely removes dirt and oxidation in a uniform manner resulting in a brightening effect on aluminum fin stock used in the HVAC industry. More specifically, the composition of the present invention provides for an effective cleaning composition that removes accumulated dirt and oxidation in a manner that is safer for the manufacturer, end user and the environment than conventional hydrofluoric acid and mineral acid compositions.
Hydrofluoric acid has been a staple ingredient in HVAC coil cleaning for many years. This is mainly because it effectively dissolves aluminum metal very rapidly at a rate unlike any other commonly used acid. It also has a brightening effect on the cleaned metal that is typically better than most conventional compositions. Any residual unreacted hydrofluoric acid quickly reacts with calcium in the environment and forms an inert compound that has very low solubility in water, thereby does not enter the water supply in a significant way. These HF compositions usually contain a mineral co-acid such as sulfuric or phosphoric acids or other acid of a lower pKa to push the equilibrium for HF to the left as:
i¾3
Figure imgf000005_0001
3HF + Al° AI+3(6H20) 3F + 3/2H2†
The above equations show that it is the HF species that attacks the aluminum metal underneath the oxide layer. Any soluble oxide is removed in the process along with oxide attached to the aluminum metal surface. When this reaction is quenched with rinse water, an aluminum fluoride film is left on the remaining fin stock giving an appearance of a brighter surface than an aluminum oxide surface.
However, the downside to using hydrofluoric acid is that it is extremely hazardous. Hydrofluoric acid is dangerous to use because of the reactivity with calcium ion in the body that can cause heart failure. It is very penetrating through the skin and is very volatile so as to be an inhalation route hazard as well as a skin corrodent. In addition, hydrofluoric acid is a dangerous product to manufacture, to store, to blend into a formula, to dilute and during application.
Some of the hazards of using hydrofluoric acid may be circumvented by the use of ammonium bifluoride and a co-acid. Co-acids are typically chosen from two groups: mineral acids such as sulfuric and phosphoric acids; and organic co-acids such as citric and hydroxyacetic acids. However, the cleaning performance and the brightening effect have been unsatisfactory with the available non-HF/organic acid formulations.
The benchmark for performance in aluminum cleaning and brightening as mentioned above, are the hydrofluoric acid containing formulations with the aforementioned hazards. An example of a commercially available cleaning composition is Acti-Brite from Virginia Corporation, which contains about 15-18% hydrofluoric acid, 5-7% phosphoric acid and surfactants. An example of a
commercially available ammonium bifluoride with organic co-acid product is Calbrite from NuCalgon Corporation. Analysis of Calbrite shows it to contain about 10-13% ammonium bifluoride, about 3-5 % hydroxyacetic acid, and surfactants. As used herein, the term "brightening" means improving the clarity or distinctness of an image reflected by a metal surface.
As used herein, the term "substantially free of means the composition is completely lacking the component or having such a small amount of the component that the component does not affect the performance of the composition. The component may be present as an impurity or as a contaminant, and is present in an amount that is less than 0.5% by weight. In another embodiment, the component is present in an amount that is less than 0.1 % by weight, and in yet another embodiment, the component is present in an amount that is less than 0.01 % by weight.
The cleaning composition of the present invention includes an acid fluoride salt, a mineral acid adduct of urea, at least one surfactant, a water miscible organic solvent and water.
Suitable acid fluoride salts include metal fluorides, including alkali metal fluorides, and ammonium fluorides. Examples of such acid fluoride salts include ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium
fluorophosphates and sodium fluorosilicates, and combinations of two or more thereof. Preferably, the acid fluoride salt includes ammonium bifluoride.
As part of an effective cleaning composition, the acid fluoride salt
concentration level may suitably be from about 1 to about 30% by weight, based on the total weight of the composition. In one embodiment, the acid fluoride salt concentration level is within the range of about 1 to about 25% by weight, or within the range of about 1 to about 10% by weight, or within the range of about 4 to about 6% by weight.
The composition includes at least one adduct of a mineral acid with urea.
Particularly useful mineral acids are strong mineral acids. Table 1 below lists mineral acids with their respective relative strengths expressed by the pKa scale. Table 1
Figure imgf000007_0001
Suitable adducts of mineral acids with urea include adducts of urea with perchloric acid (urea perchloride); hydroiodic acid (urea hydroiodide); hydrobromic acid (urea hydrobromide); hydrochloric acid (urea hydrochloride and urea
dihydrochloride); sulfuric acid (urea sulfate); nitric acid (urea nitrate and urea dinitric acid); phosphoric acid (urea phosphate) and combinations of two or more thereof.
Adducts of mineral acids with urea may be prepared directly from the components or their solutions or by the action of mineral acids on cyanamide, in which case the latter decompose to give urea, which then enters into the adduct with the acid.
Urea hydrochloride is an organic acid salt that can be prepared by reacting urea with hydrogen chloride. In one embodiment, urea hydrochloride is added in salt form to the cleaning composition. The urea hydrochloride may be a
monohydrochloride or a dihydrochloride. In another embodiment, the urea
hydrochloride is formed in situ by adding urea and hydrochloric acid to the cleaning composition.
According to certain preferred embodiments, the composition is substantially free of added hydrofluoric acid.
As part of an effective cleaning composition, the urea:mineral acid adduct concentration level may suitably be from about 1 to about 30% by weight, based on the total weight of the composition. In one embodiment, the urea hydrochloride concentration level is within the range of about 2 to about 25% by weight, or within the range of about 2 to about 20% by weight, or within the range of about 2 to about 15% by weight, or within the range of about 2 to about 10% by weight.
The pH of the composition is in the range of about 0.05 to 7. In one
embodiment, the pH of the composition is between about 0.5 and about 6.5. In one embodiment, the pH of the composition is between about 1 .0 and about 5.0. In one embodiment, the pH of the composition is between about 0.5 and 4.5.
The cleaning composition contains at least one surfactant. The surfactant or surfactant mixture may be selected from water soluble or water dispersible nonionic, anionic, cationic, zwitterionic or true amphoteric surfactants.
Exemplary nonionic surfactants include polyoxyalkylene alkyi (or alkenyl) esters obtained by adding 3 moles to 30 moles of an alkylene oxide having 2 to 4 carbon atoms to an aliphatic alcohol having 10 to 18 carbon atoms, wherein examples of the aliphatic alcohol used include primary alcohols and secondary alcohols in which the alkyi group thereof may also be branched, and the aliphatic alcohol is preferably a primary alcohol; polyoxyethylene alkyi (or alkenyl)phenyl ethers; fatty acid alkyi ester alkoxylates obtained by adding an alkylene oxide between the ester bonds of a long chain fatty acid alkyi ester; polyoxyethylene sorbitan fatty acid esters; polyoxyethylene sorbitol fatty acid esters; polyoxyethylene fatty acid esters; polyoxyethylene hydrogenated castor oil; glycerin fatty acid esters; fatty acid alkanolamides; polyoxyethylene alkylamines; alkyi glycosides; and alkylamine oxides. In certain embodiments, the nonionic surfactant includes an ethoxylated alcohol.
Exemplary anionic surfactants include alcohol sulfates and sulfonates, alcohol phosphates and phosphonates, alkyi ester sulfates, alkyi diphenyl ether sulfonates, alkyi sulfates, alkyi ether sulfates, sulfate esters of an alkylphenoxy polyoxyethylene ethanol, alkyi monoglyceride sulfates, alkyi sulfonates, alkyi ether sulfates, alpha- olefin sulfonates, beta-alkoxy alkane sulfonates, alkyi ether sulfonates, ethoxylated alkyi sulfonates, alkylaryl sulfonates, alkylaryl sulfates, alkyi monoglyceride sulfonates, alkyi carboxylates, alkyi ether carboxylates, alkyi alkoxy carboxylates having 1 to 5 moles of ethylene oxide, alkylpolyglycolether sulfates (containing up to 10 moles of ethylene oxide), sulfosuccinates, octoxynol or nonoxynol phosphates, taurates, fatty taurides, fatty acid amide polyoxyethylene sulfates, acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkyi phenol ethylene oxide ether sulfates, paraffin sulfonates, alkyl phosphates, isethionates, N-acyl taurates, alkyl succinamates and sulfosuccinates, alkylpolysaccharide sulfates, alkylpolyglucoside sulfates, alkyl polyethoxy carboxylates, and sarcosinates or mixtures thereof. These anionic surfactants may be provided as salts with one or more organic counterions, e.g, ammonium, or inorganic counteraions.
Exemplary cationic surfactants include quaternary ammonium surfactants, such as lauryl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, cetyl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide, lanolin fatty acid aminopropylethyldimethyl ammonium ethyl sulfate, stearyl trimethyl ammonium saccharine, cetyl trimethyl ammonium
saccharine, methacryloyloxyethyl trimethyl ammonium chloride, and behenyl trimethyl ammonium methyl sulfate.
Exemplary amphoteric surfactants include fatty acid
amidopropyldimethylamino acetic acid betaine, alkyldimethylaminoacetic acid betaine, N-acylaminoethyl-N-2-hydroxyethyl aminocarboxylate, N-acylaminoethyl-N- carboxymethoxy ethyl aminocarboxylate, and hydroxyalkyl (C12-14) hydroxyethyl sarcosine. Examples of the fatty acid amidopropyldimethylaminoacetic acid betaine include cocamidopropyl betaine, palm oil fatty acid amidopropyldimethylaminoacetic acid betaine, lauramidopropyl betaine, and ricinoleic acid
amidopropyldimethylaminoacetic acid betaine. Examples of the
alkyldimethylaminoacetic acid betaine include decyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, myristyldimethylaminoacetic acid betaine, cetyldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, oleyldimethylaminoacetic acid betaine, behenyldimethylaminoacetic acid betaine, and coconut oil alkyldimethylaminoacetic acid betaine. Examples of the N- acylaminoethyl-N-2-hydroxyethyl aminocarboxylate include sodium
cocoamphoacetate and sodium cocoamphopropionate. Examples of the N- acylaminoethyl-N-carboxymethoxy ethyl aminocarboxylate include sodium
cocoamphodiacetate, sodium cocoamphodipropionate, and sodium
lauroamphodiacetate.
The surfactant concentration level of the cleaning composition may suitably be from about 0.5% to about 20% by weight, based on the total weight of the composition. In one embodiment, the surfactant concentration level is within the range of about 0.5 to about 15% by weight, or within the range of about 1 to about 10% by weight, or within the range of about 1 to about 7% by weight.
The composition includes at least one organic solvent. Suitable organic solvents include one or more alcohols, glycols, acetates, ether acetates and glycol ethers. Exemplary alcohols include isopropanol, ethanol, and methanol. Exemplary glycols include propylene glycol and ethylene glycol. Examples of ether acetates include diethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate. Exemplary glycol ethers include propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol methyl ether, and dipropylene glycol monopropyl ether. Other organic solvents include n-methyl pyrrolidone, ketones, lactones and terpenes such as d-limonene.
Mixtures of two or more organic solvents may be used. Alternatively, a single organic solvent may be used. In one embodiment, the organic solvent includes diethylene glycol monobutyl ether.
As part of an effective cleaning composition, the organic solvent concentration level may suitably be from about 0.5% to about 20% by weight, based on the total weight of the composition. In one embodiment, the organic solvent concentration level is within the range of about 1 to about 15% by weight, or within the range of about 1 to about 10% by weight, or within the range of about 1 to about 3% by weight.
Other components may be added to the composition, such as thickeners, gelling agents, fragrance, dispersants, anti-redeposition agents, dyes and
humectants for example.
The aqueous cleaning composition may be provided in a concentrate that includes from about 1 % to about 10% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; from about 2% to about 20% by weight of at least one mineral acid adduct with urea; from about 1 % to about 10% by weight at least one surfactant; and from about 1 % to about 10% by weight at least one organic solvent. In one embodiment, the concentrated aqueous cleaning composition includes from about 4% to about 6% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium
fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; from about 2% to about 15% by weight of at least one mineral acid adduct with urea selected from the adducts of urea with perchloric acid; hydroiodic acid; hydrobromic acid; hydrochloric acid; sulfuric acid; nitric acid; phosphoric acid and combinations of two or more thereof; from about 1 % to about 7% by weight at least one surfactant; and from about 1 % to about 3% by weight at least one organic solvent.
The cleaning composition may be supplied in a concentrated form or in a variety of diluted forms. Thus, the concentration of the components in the supplied composition may vary widely. Depending upon the application and the concentration of the composition supplied, the user may dilute the composition prior to use. The final concentration may be reached from a wide range of supplied concentrations, using water to dilute the supplied concentration, by using an appropriate dilution factor. For example, the composition may be diluted with water in a concentration of composition :water ratio of 1 :1 , 1 :1 .5, 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, 1 :7, 1 :8, 1 :9, 1 :10, or by using many other dilution ratios.
In one aspect of the invention, a process for cleaning metal surfaces is provided. The process includes cleaning the metal surface by contacting the metal surface with the cleaning composition described herein for a time sufficient to clean the metal surface. The cleaning composition can be applied to the metal surface using any of the contacting techniques known in the art. For example, the cleaning composition may be applied by conventional spraying or immersion methods.
EXAMPLES
Examples 1 -7:
Cleaning compositions containing varying amounts of ammonium bifluoride and the adduct of hydrochloric acid with urea are prepared as shown in Table 2. The amount of each ingredient for Examples 1 -7 is given in weight percent. Table 2
Figure imgf000012_0001
* ethoxylated alcohols, C9-1 1
The effectiveness of the cleaning compositions was tested through evaluation of aluminum panels, which have been soiled and then immersed in a diluted composition of the concentrated cleaning compositions.
Formula for lab prepared deposit soil:
Ingredient Wt. %
Deionized Water 51 .3%
Bentone EW (Elementis Corp.) 1 .5%
Sodium Tripolyphosphate Low Density 0.2%
Minucil 5 (US Silica Corp.) 25.0%
Aluminum Oxide # 19 (Graystar Corp.) 21 .0%
CW 5317 Black (Elementis Corp.) 1 .0%
The water and bentone are stirred until gel formation, approximately 30 minutes, using a regular overhead 3 bladed stirrer (ETK Model) at approximately 2500 rpm. The remaining ingredients are then added with good mixing to disperse.
One square foot of fin stock (aluminum fin stock from JW Aluminum Corp.) is cut into a panel and cleaned using toluene followed by acetone, and then rinsed with deionized water. The lab prepared soil is applied to cover the entire one foot square aluminum panel surface using a paint brush. The panel is baked overnight in a 1 10°C lab oven. The panel is removed from the oven and allowed to cool to room temperature. The panel is then rinsed with water until the unattached soil is removed.
Testing of Formulations 1 -7:
The effectiveness of each of the cleaning compositions of Examples 1 -7 was evaluated using the soiled aluminum fin stock panel. Each composition was diluted 1 part to three parts water by weight. Panels of the aluminum soiled with the lab prepared soil were cut into coupons of approximately 1 inch X 2 inches and immersed in the diluted cleaner for 30 seconds. After 30 seconds the coupons were immediately rinsed with deionized water.
FIG. 1 shows the results of the evaluation. The percent clean was determined by using a grid count under 22.5X magnification. The graph shows that the composition containing 10% ABF (with no added urea hydrochloride) cleaned the surface 55% clean. The composition containing 10% of the urea hydrochloride adduct (with no ABF) had zero % cleaning. These results were surprising, as it was expected that the % cleaning would increase as the amount of ABF was increased.
Example 8-14:
Cleaning compositions containing varying amounts of ammonium bifluoride and the adduct of hydrochloric acid with urea are prepared as shown in Table 3. The amount of each ingredient for Examples 8-14 is given in weight percent.
Table 3
Figure imgf000013_0001
**cocoamidopropyl betaine 29-31 %
The effectiveness of the cleaning composition was tested through evaluation of aluminum panels, which have been oxidized and are then immersed in the cleaning composition.
Preparation of Oxidized Panels:
Aluminum fin stock is cut into strips measuring 3 inches by 12 inches. The strips are cleaned with toluene, acetone and deionized water and places in a 10% aqueous sodium chloride solution. The aluminum strips are placed in the salt solution in a closed container at 50°C oven for 24 hours. The strips are then
removed, and allowed to cool to room temperature and dry.
Testing of Formulations 8-14:
The effectiveness of each of the cleaning compositions of Examples 8-14 was evaluated using the oxidized aluminum fin stock strips. Each composition was
diluted 1 part to three parts water by weight. Strips of the oxidized aluminum were
cut into coupons of approximately 1 inch X 2 inches and immersed in the diluted
cleaner for 1 minute. After 1 minute the coupons were immediately rinsed with
deionized water.
FIG. 2 shows the results of the evaluation. The percent clean was determined by using a grid count under 22.5X magnification. As can be seen from Fig. 2, the optimum performance range is 5-7% by weight ammonium bifluoride in the concentrated formulation for oxidation removal.
It is understood that the total percentage of acids may be increased with increasing performance upon dilution for soil and oxidation removal. However, with the compositions of the present invention, it can be seen that lower concentrations of fluoride ion are effective based on the average level of soils and considerably safer to use from the point of manufacturing to the end user than currently available bifluoride technologies using safe organic co-acids.
Examples 15-18:
Cleaning compositions containing adducts of various mineral acids with urea are prepared as shown in Table 4. The amount of each ingredient for Examples 15- 18 is given in weight percent.
Table 4
Figure imgf000014_0001
Testing of Formulations 15-18:
The effectiveness of each of the cleaning compositions of Examples 15-18 was evaluated using the lab prepared soiled aluminum fin stock panel. Each composition was diluted 1 part to three parts water by weight. Panels of the aluminum soiled with the lab prepared soil were cut into coupons of approximately 1 inch X 2 inches and immersed in the diluted cleaner for 30 seconds. After 30 seconds the coupons were immediately rinsed with deionized water.
FIG. 3 shows the results of the evaluation on the lab prepared soil surface. The percent clean was determined by using a grid count under 22.5X magnification.
Examples 19-22 and Comparative Examples A-B:
Cleaning compositions containing adducts of various mineral acids with urea are prepared as shown in Table 5. The amount of each ingredient for Examples 19- 22 is given in weight percent.
Table 5
Figure imgf000015_0001
Testing of Formulations 19-22 - Oxidized Surface:
The effectiveness of each of the cleaning compositions of Examples 19-22 was evaluated using the oxidized aluminum fin stock strips. In addition, Comparative Example A containing about 10-13% ammonium bifluoride, about 3-5 %
hydroxyacetic acid, and surfactants (Calbrite) and Comparative Example B containing about 15 -18% hydrofluoric acid, 5 -7% phosphoric acid and surfactants (Acti-Brite) were also evaluated. Each composition was diluted 1 part to three parts water by weight. Strips of the oxidized aluminum were cut into coupons of approximately 1 inch X 2 inches. The oxidized coupons were immersed in the diluted cleaner for different lengths of time and then immediately rinsed with deionized water.
Table 6 shows the results of the evaluation on the oxidized surface. The percent clean was determined by using a grid count under 22.5X magnification.
Table 6
Figure imgf000016_0001
Testing of Formulations 19-22 - Double Oxidized Surface:
Strips of aluminum fin stock were prepared by immersing the strips in a 10% sodium chloride solution at 50°C for 48 hours. This produced a much deeper layer of a dark oxide into the aluminum metal strips of fin stock.
Each of the composition of Examples 19-22 and the composition of
Comparative Example B were diluted 1 part to three parts deionized water by weight. The prepared strips of double oxidized aluminum were immersed in the diluted cleaner for one minute and then immediately rinsed with deionized water.
Table 7 shows the results of the evaluation on the double oxidized surface. Reflectance was measured using a Photovolt Model 577-A reflectometer in accordance with ASTM D 4488-95.
Table 7
Figure imgf000016_0002
The results obtained with the compositions prepared in accordance with the present invention are very similar to the results obtained with the hydrofluoric acid containing composition of Comparative Example B. Comparative Example C:
A cleaning composition is prepared containing various amounts of ammonium bifluoride in combination with the organic acid hydroacetic acid.
Table 8
Figure imgf000017_0001
The effectiveness of the cleaning compositions of Comparative Example C was evaluated using oxidized aluminum fin stock strips. Each composition was diluted 1 part to three parts water by weight. Strips of the oxidized aluminum were cut into coupons of approximately 1 inch X 2 inches and immersed in the diluted cleaner for 1 minute. After 1 minute the coupons were immediately rinsed with deionized water.
FIG. 5 shows the results of varying the concentration of ammonium bifluoride in a cleaning composition containing hydroxyacetic acid. By comparing the results shown in FIG. 5 to those of FIG. 2, it can be seen that a performance boost is obtained by using a cleaning composition containing a safe urea/mineral acid adduct in combination with ammonium bifluoride in place of a cleaning composition containing a safe organic acid, such as hydroacetic acid in combination with ammonium bifluoride. Similar results are expected with the safe organic acid citric acid.
While the invention has been explained in relation to various embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading this specification. Therefore, it is to be understood that the invention provided herein is intended to cover such modifications as may fall within the scope of the appended claims.

Claims

Claims
1 . An aqueous cleaning composition comprising:
at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof;
at least one mineral acid adduct with urea;
at least one surfactant; and
at least one organic solvent.
2. The aqueous cleaning composition of claim 1 wherein the acid fluoride salt is ammonium bifluoride.
3. The aqueous cleaning composition of claim 1 or 2 wherein the mineral acid adduct with urea is selected from among the adducts of urea with perchloric acid; hydroiodic acid; hydrobromic acid; hydrochloric acid; sulfuric acid; nitric acid;
phosphoric acid and combinations of two or more thereof.
4. The aqueous cleaning composition of any one of claims 1 to 3 wherein the surfactant comprises a nonionic surfactant.
5. The aqueous cleaning composition of claim 4 wherein the nonionic surfactant comprises an ethoxylated alcohol.
6. The aqueous cleaning composition of any one of claims 1 to 3 wherein the surfactant comprises a cationic surfactant.
7. The aqueous cleaning composition of claim 6 wherein the cationic surfactant comprises dicocodimethyl ammonium chloride.
8. The aqueous cleaning composition of any one of claims 1 to 3 wherein the surfactant comprises an amphoteric surfactant.
9. The aqueous cleaning composition of claim 8 wherein the amphoteric surfactant comprises cocoamidopropyl betaine.
10. The aqueous cleaning composition of any one of the preceding claims wherein the organic solvent comprises diethylene glycol monobutyl ether.
1 1 . The aqueous cleaning composition of any one of the preceding claims wherein the composition is diluted with water in a ratio of cleaning composition :water of 1 :1 to 1 :10.
12. An aqueous cleaning composition comprising:
from about 1 % to about 10% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof; from about 2% to about 20% by weight of at least one mineral acid adduct with urea;
from about 1 % to about 10% by weight at least one surfactant; and
from about 1 % to about 10% by weight at least one organic solvent.
13. The aqueous cleaning composition of claim 12 comprising:
from about 1 % to about 10% by weight of ammonium bifluoride;
from about 2% to about 20% by weight of at least one mineral acid adduct with urea selected from the adducts of urea with perchloric acid; hydroiodic acid; hydrobromic acid; hydrochloric acid; sulfuric acid; nitric acid; phosphoric acid and combinations of two or more thereof;
from about 1 % to about 10% by weight at least one surfactant; and
from about 1 % to about 10% by weight at least one organic solvent.
14. A method of cleaning a metal surface, the method comprising:
contacting the metal surface with an aqueous cleaning composition for a sufficient time to clean the metal surface, the aqueous cleaning composition comprising: at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium
fluorosilicates, and combinations of two or more thereof;
at least one mineral acid adduct with urea;
at least one surfactant; and
at least one organic solvent.
15. The method of claim 14 wherein the acid fluoride salt is ammonium bifluoride.
16. The method of claim 14 or 15 wherein the mineral acid adduct with urea is selected from among the adducts of urea with perchloric acid; hydroiodic acid;
hydrobromic acid; hydrochloric acid; sulfuric acid; nitric acid; phosphoric acid and combinations of two or more thereof.
17. A method of cleaning a metal surface, the method comprising:
contacting the metal surface with an aqueous cleaning composition for a sufficient time to clean the metal surface, the aqueous cleaning composition comprising:
from about 1 % to about 10% by weight of at least one acid fluoride salt selected from ammonium bifluoride, sodium bifluoride, potassium bifluoride, calcium fluorophosphates, sodium fluorosilicates, and combinations of two or more thereof;
from about 2% to about 20% by weight of at least one mineral acid adduct with urea;
from about 1 % to about 10% by weight at least one surfactant; and from about 1 % to about 10% by weight at least one organic solvent.
18. The method of claim 17 wherein the mineral acid adduct with urea is selected from among the adducts of urea with perchloric acid; hydroiodic acid; hydrobromic acid; hydrochloric acid; sulfuric acid; nitric acid; phosphoric acid and combinations of two or more thereof.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105112927A (en) * 2015-09-14 2015-12-02 夏良文 Novel aluminum product wax removing agent and preparation method thereof

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015126397A1 (en) * 2014-02-20 2015-08-27 Halliburton Energy Services, Inc. Substantially solid acidizing composition for treatment of subterranean formations
WO2016003729A1 (en) * 2014-06-30 2016-01-07 Entegris, Inc. Aqueous and semi-aqueous cleaners for the removal of post-etch residues with tungsten and cobalt compatibility
US10538718B2 (en) * 2015-04-13 2020-01-21 Mitsubishi Gas Chemical Company, Inc. Cleaning solution and cleaning method for material comprising carbon-incorporated silicon oxide for use in recycling wafer
US10894935B2 (en) 2015-12-04 2021-01-19 Samsung Electronics Co., Ltd. Composition for removing silicone resins and method of thinning substrate by using the same
CN107034028B (en) * 2015-12-04 2021-05-25 三星电子株式会社 Composition for removing silicone resin, method for thinning substrate and manufacturing semiconductor package using the same, and system using the same
CN105754742A (en) * 2016-04-10 2016-07-13 张耀忠 Disinfectant detergent and preparation method thereof
CN107541731A (en) * 2017-09-05 2018-01-05 江苏飞拓界面工程科技有限公司 A kind of aluminium and aluminium alloy high-efficiency environment friendly polishing fluid and preparation method thereof
BR112020011036A2 (en) * 2017-12-01 2020-11-17 Houghton Technical Corp. method and compositions for cleaning aluminum cans
GB2573546B (en) * 2018-05-09 2021-03-31 Twi Ltd A method of diffusion bonding
JP7183290B2 (en) * 2018-10-02 2022-12-05 日本ペイント・サーフケミカルズ株式会社 Surface treatment agent
CN115110088B (en) * 2022-08-26 2022-11-29 易生科技(北京)有限公司 Cobalt-chromium alloy member treatment liquid, preparation method and application thereof, and cleaning method of cobalt-chromium alloy member

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1393591A (en) * 1963-02-20 1965-03-26 Parker Ste Continentale Composition and process for brightening metals
US3228816A (en) * 1962-02-21 1966-01-11 Rohr Corp Process and composition for cleaning and polishing aluminum and its alloys
US3326803A (en) * 1964-04-27 1967-06-20 Wyandotte Chemicals Corp Aluminum brightener composition
WO1995016006A1 (en) * 1993-12-10 1995-06-15 Armor All Products Corporation Wheel cleaning composition containing acid fluoride salts

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4116853A (en) * 1974-02-14 1978-09-26 Amchem Products, Inc. Composition for cleaning aluminum at low temperatures
US4614607A (en) * 1984-09-26 1986-09-30 The Boeing Company Non-chromated deoxidizer
US7144848B2 (en) * 1992-07-09 2006-12-05 Ekc Technology, Inc. Cleaning compositions containing hydroxylamine derivatives and processes using same for residue removal
US5669980A (en) * 1995-03-24 1997-09-23 Atotech Usa, Inc. Aluminum desmut composition and process
US6896826B2 (en) * 1997-01-09 2005-05-24 Advanced Technology Materials, Inc. Aqueous cleaning composition containing copper-specific corrosion inhibitor for cleaning inorganic residues on semiconductor substrate
AU1373199A (en) * 1997-11-13 1999-06-07 Henkel Corporation Composition and process for cleaning and deoxidizing aluminum
US6465404B2 (en) * 2000-03-21 2002-10-15 Bbj Environmental Solutions, Inc. Aqueous cleaning composition with controlled PH
US6627587B2 (en) * 2001-04-19 2003-09-30 Esc Inc. Cleaning compositions
US20040147422A1 (en) * 2003-01-23 2004-07-29 Hatch Andrew M. Cleaner composition for formed metal articles
JP5051679B2 (en) * 2003-08-29 2012-10-17 日本パーカライジング株式会社 Alkali cleaning method for aluminum or aluminum alloy DI can
EP1715510B2 (en) * 2004-02-09 2016-02-24 Mitsubishi Chemical Corporation Substrate cleaning liquid for semiconductor device and cleaning method
US7384902B2 (en) * 2004-05-14 2008-06-10 Cleaning Systems, Inc. Metal brightener and surface cleaner
CA2525205C (en) * 2004-11-08 2013-06-25 Ecolab Inc. Foam cleaning and brightening composition, and methods
EP1931817A2 (en) * 2005-08-19 2008-06-18 Houghton Metal Finishing Company Methods and compositions for acid treatment of a metal surface
US7977294B2 (en) * 2006-12-14 2011-07-12 The Boeing Company Gelled adhesive remover composition and method of use

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3228816A (en) * 1962-02-21 1966-01-11 Rohr Corp Process and composition for cleaning and polishing aluminum and its alloys
FR1393591A (en) * 1963-02-20 1965-03-26 Parker Ste Continentale Composition and process for brightening metals
US3326803A (en) * 1964-04-27 1967-06-20 Wyandotte Chemicals Corp Aluminum brightener composition
WO1995016006A1 (en) * 1993-12-10 1995-06-15 Armor All Products Corporation Wheel cleaning composition containing acid fluoride salts

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105112927A (en) * 2015-09-14 2015-12-02 夏良文 Novel aluminum product wax removing agent and preparation method thereof

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