EP0640153A1 - Method for cleaning aluminum at low temperatures. - Google Patents
Method for cleaning aluminum at low temperatures.Info
- Publication number
- EP0640153A1 EP0640153A1 EP93911127A EP93911127A EP0640153A1 EP 0640153 A1 EP0640153 A1 EP 0640153A1 EP 93911127 A EP93911127 A EP 93911127A EP 93911127 A EP93911127 A EP 93911127A EP 0640153 A1 EP0640153 A1 EP 0640153A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cleaner
- stage
- component
- surfactant
- washing
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- 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
- 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
Definitions
- This invention relates to the cleaning of aluminum surfaces.
- it is directed to the cleaning of the surfaces of aluminum cans formed by a cold forming operation.
- Binns proposed the addition of 0.05 to 0.1 grams per liter of hydrofluoric acid as a means of reducing the processing temperature to within the i5 range of 90 to 135 ° F (32 to 57 ° C).
- the compositions proposed by Binns preferably contain 0.1 to 10 grams per liter of a surfactant which could be anionic, cationic or nonionic.
- the 2o composition was also suitable for relatively low temperature use and preferably con ⁇ tained 0.01 to 0.4 weight percent of a fluoride accelerator.
- the surfactants proposed by King et al. (hereinafter abbreviated as simply "King") were a polyalkoxylated straight chain alcohol and a polyalkylene glycol-abietic acid surfactant.
- the King compositions are currently used in one or more, preferably at least two, cleaning
- the temperature of an aqueous surfactant composition is raised.
- foaming of the aqueous solution generally occurs quite easily, and it is desirable to avoid foaming in the present washing operations.
- the temperature of the composition is too far above the cloud point, separation of the surfactant from the aqueous medium occurs and ⁇ leads to a loss of detergent ability and a loss of the actual surfactant material. Accordingly, the present washing operations are normally conducted at or below the cloud point where the detergent ability of the composition is still effective and foaming can be minimized. Disclosure of the Invention
- the present invention is based on the discov ⁇ ery that the ratio of the concentration of polyalkoxylated alcohol surfactant to the concentration of polyalkylene glycol-abietic acid surfactant (this ratio being
- the surfactant ratio 5 hereinafter briefly denoted "the surfactant ratio" that is optimum for the acid cleaner stage as taught in the King patent already noted above is not usually optimum for the pre-cleaning stage used immediately before the acid cleaner.
- the acid composition normally used in an acid cleaning solution as taught by King can usefully be supplemented with additional ⁇ o sulfuric acid for the pre-cleaner stage. Accordingly, one embodiment of the invention is the provision of a prewashing solution composition with these improved characteristics before, preferably immediately before, a conventional acid cleaning solution in a cleaning operation with at least two stages.
- replenisher com ⁇ position that comprises, more preferably consists essentially of, or still more preferably consists of water, sulfuric acid, and a polyalkoxylated straight or branched, but preferably straight, chain alcohol surfactant.
- the content of sulfuric acid in the replenisher composition is preferably determined by the pH required in use of the
- the content of surfactant is adjusted to maintain the stability of the composition.
- the composition may contain 5 to 50 per cent by weight of sulfuric acid and 0.5 to 40 per cent by weight of said surfactant.
- such a composition is add ⁇ ed to a washing solution as a replenisher composition in a stage preceding, preferably
- a conventional acid cleaner stage such as is taught by Binns or King.
- the use of such a composition as a replenisher is another aspect of the present invention.
- the ratio be- tween these two types in the pre-cleaner stage of a process according to this invention prelsrably is within the range from to 3.0:1, more preferably within the range from 0.7:1 to 2.0:1, still more preferably within the range from 0.9:1.0 to 1.3:1.0, and most preferably within the range from 1.0:1.0 to 1.2:1.0.
- the pH of the pre-cleaning solution in a process according to this invention is preferably within the range from 1.4 to 2.0, more preferably within the range from 1.6 to 2.0, or still more preferably within the range from 1.75 to 1.85, and this pH is preferably achieved by adding to the water used for the pre-cleaning solution only sulfuric acid, in addition to whatever acid is added by countercurrent flow from the subsequent cleaner stage solution.
- the values as described above for the pre-cleaner stage solution are achieved by adding to the original solution during the continued operation of the process a pre-cleaner replenisher composition, in addition to a counterflow from the subsequent acid cleaner solution stage.
- a pre-cleaner replenisher composition for the present invention comprises, more preferably consists essentially of, or still more preferably consists of, a stable aqueous solution of sulfuric acid with a polyalkoxylated straight or branched chain alcohol surfactant. This improved composition is formulated to be used as a replenisher for the pre- cleaner washing solution which is actually applied to the aluminum surfaces.
- composition of the present invention may be used alone but is preferably formulated for use in co-operation with the type of composition proposed by King et al., using successive cleaning stages in the can washing equipment.
- concentration of the components in the composition of the present invention will preferably depend upon the type of system in which the composition is to be used, that is whether the composition is to be used alone or in conjunction with one of the known cleaning compositions.
- a stable and satisfactory pre-cleaner replenisher compo- sition in accordance with the present invention can be prepared containing 5 to 50 per cent by weight of sulfuric acid and 0.5 to 40 per cent by weight of surfactant.
- the composition contains 30 to 41 per cent by weight of sulfuric acid and 4 to 10 per cent by weight of surfactant; most preferably 41 per cent by weight of sulfuric acid is used.
- the sulfuric acid content can be varied depending on the way in which the composition is to be used and any such variation will preferably be ac ⁇ integrated by a corresponding variation in the range of surfactant material present. However, once the acid content has been determined, the surfactant content to provide an optimally stable and useful composition can also readily be determined.
- the acid content may require variation depending upon the amount and type of material to be cleaned from the surfaces being treated. This will vary with the type of lubricant used in the can formation and with other factors such as the condition of the forming equipment.
- Suitable polyalkoxylated straight or branched chain alcohol surfactants are known in the art as nonionic surfactants. They include those sold under the trade names Antarox LF 330, Teric 165 and Trycol LF 1. These surfactants are known to have a low cloud point and their use in the present compositions assists in further lowering the temperature at which the washing operation is conducted.
- compositions of the present invention can be used to significantly lower the pH of the pre-cleaner washing solution in use from the value that it would have if acidified by counterflow from a subsequent acid cleaner stage alone.
- the reduction in pH which can be thus achieved has been found to improve the cleaning efficiency of the washing solution and the efficiency with which oil can removed.
- the improved composition is used in the first of two stages of a washing operation, the second stage using either a known composition of the type proposed by King et al or a composition of this known type modified to co-operate with the composition of the present invention.
- a known composition of the type proposed by King et al or a composition of this known type modified to co-operate with the composition of the present invention.
- cans leaving the body maker-trimmer operation section travel on a perforated mat through a pre- cleaner washing stage (stage 1) and then through a cleaner stage (stage 2).
- washing solution is initially made up with the desired proportion of active ingredients.
- the composition of the washing so- lution is maintained by the addition of appropriate replenisher compositions to com ⁇ pensate for the depletion of active materials as the washing procedure continues.
- the washing solution is sprayed over the can surfaces in the second section and a portion of the washing composition, carrying aluminum, oils, and other materials removed from the can in stage 2, travels in countercurrent to the movement of the cans to stage 1.
- the washing solution used in the stage 2 process contains a polyalkylene glycol-abietic acid surfactant blended with a polyalkoxylated straight or branched chain alcohol.
- the amount of surfactant blend and acids used in accordance with this process may be varied to provide between 3 to 20 points of free acid.
- the washing solution from stage 2 is counterflowed to stage 1 at a rate deter ⁇ mined by measuring the amount of dissolved aluminum in the solution.
- the amount of sulfuric acid in the washing solution is depleted because the acid dissolves alumi- num in the course of its cleaning action.
- the balance of active components in the acid cleaner washing solution is maintained, most preferably by the addition of appropriate amounts of a replenisher composition.
- This replenisher composition for the acid cleaner will normally have different composition from the pre-cleaner replenisher that is part of this invention.
- the amount of active acid cleaner replenisher compo ⁇ sition is approximately 65 milliliters per minute.
- the rate at which the washing solution from stage 2 is added to the stage 1 washing process is also controlled to determine the amount of free acid remaining in the washing solution used in pre- cleaner stage 1. If the acid washing solution is added to stage 1 to provide one point of free acid, the pH is approximately 2.1. If two points of free acid are added by the stage 2 washing solution to stage 1, the pH is approximately 1.8.
- the known process described above can be improved by using a pre-cleaner replenisher composition according to the present invention.
- a pre-cleaner re ⁇ plenisher composition as described above can be added to stage 1 to supplement the free acid content of the total washing solution in this stage.
- the additional polyalkoxylated straight or branched chain alcohol added by the composition of the present invention changes the ratio of the concentration of polyalkoxylated alcohol surfactant to the concentration of polyalkylene glycol-abietic acid surfactant ("the surfactant ratio") from approximately 0.3 to approximately 1.1, thus significantly lowering the cloud point of the stage 1 washing solution.
- the surfactant ratio also alters the pH from approximately 2.1 to approximately 1.8.
- composition of the (generally different) replenisher solution added to the stage 2 cleaning process can be varied to take into account the effect of the improved cleaning achieved in the stage 1 process by use of the cleaning composition of the present invention.
- the composition of the replenisher added to the stage 2 processing may also be varied to allow for the effect, on the concentrations and ratios of its active materials, of the materials which may be carried over into the stage 2 process, by the cans moving from stage 1, when an improved composition according to this invention is used for the washing solution in pre-cleaner stage 1.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Detergent Compositions (AREA)
- Photoreceptors In Electrophotography (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPL241092 | 1992-05-14 | ||
AU2410/92 | 1992-05-14 | ||
PCT/US1993/004316 WO1993023590A1 (en) | 1992-05-14 | 1993-05-12 | Method for cleaning aluminum at low temperatures |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0640153A1 true EP0640153A1 (en) | 1995-03-01 |
EP0640153B1 EP0640153B1 (en) | 1997-04-02 |
Family
ID=3776161
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP93911127A Expired - Lifetime EP0640153B1 (en) | 1992-05-14 | 1993-05-12 | Method for cleaning aluminum at low temperatures |
Country Status (13)
Country | Link |
---|---|
EP (1) | EP0640153B1 (en) |
JP (1) | JPH07508074A (en) |
KR (1) | KR950701691A (en) |
AT (1) | ATE151120T1 (en) |
BR (1) | BR9306357A (en) |
CA (1) | CA2135391A1 (en) |
DE (1) | DE69309460T2 (en) |
ES (1) | ES2101315T3 (en) |
GR (1) | GR3023464T3 (en) |
MY (1) | MY110663A (en) |
SG (1) | SG68573A1 (en) |
WO (1) | WO1993023590A1 (en) |
ZA (1) | ZA933362B (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3570495B2 (en) | 1999-01-29 | 2004-09-29 | セイコーエプソン株式会社 | Ink jet recording head |
CA2682515C (en) * | 2007-03-28 | 2015-06-02 | Whiteley Corporation Pty Ltd | Low foaming aqueous sterilizing compositions |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4124407A (en) * | 1975-08-25 | 1978-11-07 | Amchem Products, Inc. | Method for cleaning aluminum at low temperatures |
US3969135A (en) * | 1975-02-13 | 1976-07-13 | Oxy Metal Industries Corporation | Low temperature aluminum cleaning composition and process |
US4111722A (en) * | 1976-02-09 | 1978-09-05 | Oxy Metal Industries Corporation | Tannin treatment of aluminum with a fluoride cleaner |
US4348294A (en) * | 1980-06-26 | 1982-09-07 | Occidental Chemical Corporation | One package replenisher for aluminum cleaner |
ZA823166B (en) * | 1981-05-15 | 1983-03-30 | Amchem Prod | Composition and methods for the acid cleaning of aluminium surfaces |
AT377539B (en) * | 1981-06-24 | 1985-03-25 | Badische Corp | MONOFILER, ELECTRICALLY CONDUCTING TEXTILE THREAD OF TWO COMPONENTS |
AU553134B2 (en) * | 1982-04-07 | 1986-07-03 | Parker Chemical Company | Acid cleaning of aluminium |
DE3511514A1 (en) * | 1984-04-02 | 1985-10-10 | Parker Chemical Co., Madison Heights, Mich. | METHOD AND AQUEOUS, ACIDIC CLEANING SOLUTION FOR CLEANING ALUMINUM SURFACES |
-
1993
- 1993-05-12 EP EP93911127A patent/EP0640153B1/en not_active Expired - Lifetime
- 1993-05-12 WO PCT/US1993/004316 patent/WO1993023590A1/en active IP Right Grant
- 1993-05-12 KR KR1019940704066A patent/KR950701691A/en not_active Application Discontinuation
- 1993-05-12 JP JP6503640A patent/JPH07508074A/en active Pending
- 1993-05-12 AT AT93911127T patent/ATE151120T1/en not_active IP Right Cessation
- 1993-05-12 CA CA002135391A patent/CA2135391A1/en not_active Abandoned
- 1993-05-12 ES ES93911127T patent/ES2101315T3/en not_active Expired - Lifetime
- 1993-05-12 BR BR9306357A patent/BR9306357A/en not_active Application Discontinuation
- 1993-05-12 SG SG1996007008A patent/SG68573A1/en unknown
- 1993-05-12 DE DE69309460T patent/DE69309460T2/en not_active Expired - Fee Related
- 1993-05-13 ZA ZA933362A patent/ZA933362B/en unknown
- 1993-05-14 MY MYPI93000896A patent/MY110663A/en unknown
-
1997
- 1997-05-16 GR GR970401113T patent/GR3023464T3/en unknown
Non-Patent Citations (1)
Title |
---|
See references of WO9323590A1 * |
Also Published As
Publication number | Publication date |
---|---|
CA2135391A1 (en) | 1993-11-25 |
BR9306357A (en) | 1998-06-30 |
KR950701691A (en) | 1995-04-28 |
DE69309460D1 (en) | 1997-05-07 |
JPH07508074A (en) | 1995-09-07 |
DE69309460T2 (en) | 1997-10-09 |
ZA933362B (en) | 1993-12-08 |
ATE151120T1 (en) | 1997-04-15 |
EP0640153B1 (en) | 1997-04-02 |
GR3023464T3 (en) | 1997-08-29 |
ES2101315T3 (en) | 1997-07-01 |
MY110663A (en) | 1999-01-30 |
WO1993023590A1 (en) | 1993-11-25 |
SG68573A1 (en) | 1999-11-16 |
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