US2067703A - Electrolytic device - Google Patents
Electrolytic device Download PDFInfo
- Publication number
- US2067703A US2067703A US526118A US52611831A US2067703A US 2067703 A US2067703 A US 2067703A US 526118 A US526118 A US 526118A US 52611831 A US52611831 A US 52611831A US 2067703 A US2067703 A US 2067703A
- Authority
- US
- United States
- Prior art keywords
- aluminum
- electrode
- electrodes
- film
- cleaning
- 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.)
- Expired - Lifetime
Links
- 229910052782 aluminium Inorganic materials 0.000 description 23
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 23
- 238000000034 method Methods 0.000 description 18
- 238000004140 cleaning Methods 0.000 description 10
- 230000002378 acidificating effect Effects 0.000 description 8
- 239000003792 electrolyte Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 239000012670 alkaline solution Substances 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 6
- 229910021538 borax Inorganic materials 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000004328 sodium tetraborate Substances 0.000 description 6
- 235000010339 sodium tetraborate Nutrition 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 5
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 4
- 239000004327 boric acid Substances 0.000 description 4
- 239000003518 caustics Substances 0.000 description 3
- -1 filings Substances 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 2
- 235000011121 sodium hydroxide Nutrition 0.000 description 2
- 239000001488 sodium phosphate Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 2
- MXRIRQGCELJRSN-UHFFFAOYSA-N O.O.O.[Al] Chemical compound O.O.O.[Al] MXRIRQGCELJRSN-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000001464 adherent effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 235000013024 sodium fluoride Nutrition 0.000 description 1
- 239000011775 sodium fluoride Substances 0.000 description 1
- 235000019795 sodium metasilicate Nutrition 0.000 description 1
- 229910000162 sodium phosphate Inorganic materials 0.000 description 1
- 235000011008 sodium phosphates Nutrition 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229910000406 trisodium phosphate Inorganic materials 0.000 description 1
- 235000019801 trisodium phosphate Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
- H01G9/0029—Processes of manufacture
Definitions
- Such films consist of partially hydrated aluminum oxide and have a uni-directional character.
- the oxide layer which forms on aluminum when exposed to the action of acids or to air, While chemically similar to the substance of the film built up in the electrolytic forming process, substantially differs therefrom in its insulating and dielectric properties.
- the electrodes are preferably subjected to rinsing.
- This oxide layer is not removed film formed in an acidic cleaner.
- the capacity of the condenser using the first electrode was 6.2 MFD and its power factor 24%, while of the condenser using the second electrode, the capacity was 7.1 MFD and the power factor 15%.
- the electrodes instead of being subjected to a preliminary chemical cleaning, undergo a preliminary forming process, which consists of placing the electrodes in a slightly acidic electrolyte, for instance, borax and boric acid in which the electrodes are subjected to a short formation.
- a preliminary forming process which consists of placing the electrodes in a slightly acidic electrolyte, for instance, borax and boric acid in which the electrodes are subjected to a short formation.
- a thin oxide film covers the electrode, which film also includes the surface contaminations of the aluminum.
- the electrodes are submerged in an alkaline solution, for instance, borax, sodium phosphate, etc., which attacks and removes the preliminary film without oxidizing or attacking the aluminum. Thereafter, the electrodes are subjected to the regular forming process, preferably in a slightly acidic electrolyte.
- an alkaline solution for instance, borax, sodium phosphate, etc.
- the alkaline solution only dissolve such outerportion of the preliminary film which actually contains the impurities, and to leave the inner portion of the film adhering to the electrode.
- a third method of obtaining the same or similar results is the following:
- the electrode, without preliminary cleaning, is placed in the forming tank which contains an alkaline electrolyte,for instance, borax.
- Current is now applied, whereby a film is formed on the electrode but partly attacked by the borax..
- electrolyte is made slightly acidic by addition of boric acid and the electrode subjected to the regular formatiomprocess.
- a fourth method issimilar to the third and consists in placing the electrode without preliminary cleaning in the forming tank, which again comprises an alkaline solution as caustic soda, but instead of applying a forming current,
- the caustic soda is left chemically to clean the aluminum-preferably inthe presence of inhibitive agents-as described in connection with the first method.- After a short; period of alkaline cleaning of the electrode, the electrolyte is made acidic, for instance, by addition of boric acid and the forming process undertaken in the regular way.
- grade A aluminum having 99.6% to 99.7% aluminum is subjected to corrosion in air, an aluminum of 99.9% or higher purity, does not corrode in air.
- 'Electrodes made ofthis material can be cleaned from adherent contaminationsby means of an organic solvent and no further special precaution is required to prevent the electrode from corrodingin airbefore it is subjected toforma'tion.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
Description
STATES PATEN OFFICE 2,067,703 ELECTROLYTIC DEVICE Preston Robinson and Joseph L. Collins, North Adams, Mass, assignors to Sprague Specialties 00., Quincy, Mass, a corporation of Massachusetts No Drawing.
Application March 28, 1931,
Serial No. 526,118
2 Claims. (Cl. 175315) Our invention relates to electrolytic devices, such as electrolytic condensers, rectifiers, or the like, comprising film-forming electrodes.
In such devices use is made of the film-forming effect exhibited by certain metals, for in stance aluminum which, when placed in suitable electrolytes, upon application of the proper voltage are covered with a film. Such films consist of partially hydrated aluminum oxide and have a uni-directional character.
We shall describe our invention in its application to electrolytic condensers, using aluminum electrodes, although it should be well understood that our invention is not limited to such devices or electrode material.
We have found that the oxide layer which forms on aluminum, when exposed to the action of acids or to air, While chemically similar to the substance of the film built up in the electrolytic forming process, substantially differs therefrom in its insulating and dielectric properties. We
v have also found that if an aluminum electrode,
been prevented.
It is, therefore, one object of our invention to provide films of improved qualities by preventing oxidization of the electrode surface prior to the formation of the film.
Other objects of our invention will the specification progresses.
As in the manufacture and handling of the electrodes impurities such as filings, grease, etc., are deposited on and adhere to the electrode surface, the deleterious influences of which are well recognized, it is practice to clean the electrodes before subjecting them to the film-forming process.
In the past, such cleaning was effected by subjecting the aluminum electrodes to an aqueous acidic bath and subsequently rinsing them. in water. However, the acid while removing the impurities from the surface of the aluminum, also dissolves the outer layer of aluminum, and
appear as deleteriously affects the quality of the dielectric film.
We have found that by immersing the aluminum in a properly prepared alkaline solution, we can remove the impurities just as effectively as with an acidic cleanser without forming an oxide layer on the aluminum.
Attempts to use alkaline cleansersfor such p pose, have been unsuccessful so far, because an excessive amount of alkaline was required to properly clean the electrode. In addition, the alkaline attacked and pitted the aluminum to such an extent, particularly around metal impurities in the surface, that it was unfeasible to form a good quality film on the electrodes so cleaned, particularly in the neighborhood of the exposed impurities.
To prevent pitting of the aluminum, it has been suggested to treat the anodes in a weakly alkaline solution, such as borax or trisodium phosphate which will'attack aluminum oxide or hydroxide, but which will not strongly attack aluminum. However, in order to obtain complete cleaning with such reagents, it would be necesdium phosphate, sodium meta-silicate, sodium fluoride, etc. The strong local actionof the alkali is hereby transformed into an evenly distributed moderate action and the aluminum, instead of being pitted and damaged in spots, is evenly etched over its whole surface. At the same time, only a small amount of caustic reagent is required.
Thusbyusing a caustic cleanser in the presence ofiproper inhibiting agents, objectionable oxidization of the electrode is prevented, and at the same time through evenly distributed etching of the aluminum surface, the eifective area of the electrode is considerably increased.
' After their cleaning in a caustic solvent, the electrodes are preferably subjected to rinsing.
However, we have found that objectionable oxidization of the electrode before it is formed is not fully prevented even by alkaline cleaning because, as above stated, the cleaned electrode when left exposed to air, oxidizes on its surface and this due to thewater presentformsan oxide layer oxide layer is just as objectionable as the oxide through rinsing and its presence, as stated above,
on the electrode. This oxide layer is not removed film formed in an acidic cleaner.
Even relatively short exposures to air of the other to the forming process immediately afterits cleaning, we have found the following:
The capacity of the condenser using the first electrode was 6.2 MFD and its power factor 24%, while of the condenser using the second electrode, the capacity was 7.1 MFD and the power factor 15%.
In practice, therefore, after We have cleaned the electrodes in a proper alkaline solution and subsequently rinsed them preferably in a very weak alkaline solution-as a diluted solution of borax-we transfer the electrodes from the bathimmediately into the forming tank and subject them therein immediately to formation, whereby the electrolyte used in the formation process is preferably slightly acidic.
Instead of using the above described method, we have-found that undesirable oxidization of the electrode can be prevented bya second method as follows! The electrodes, instead of being subjected to a preliminary chemical cleaning, undergo a preliminary forming process, which consists of placing the electrodes in a slightly acidic electrolyte, for instance, borax and boric acid in which the electrodes are subjected to a short formation. As a result of this formation, a thin oxide film covers the electrode, which film also includes the surface contaminations of the aluminum.
After such preliminary formation, the electrodes are submerged in an alkaline solution, for instance, borax, sodium phosphate, etc., which attacks and removes the preliminary film without oxidizing or attacking the aluminum. Thereafter, the electrodes are subjected to the regular forming process, preferably in a slightly acidic electrolyte.
In using this method, it is-sometimes found advisable to have .the alkaline solution only dissolve such outerportion of the preliminary film which actually contains the impurities, and to leave the inner portion of the film adhering to the electrode.
. A third method of obtaining the same or similar results is the following: The electrode, without preliminary cleaning, is placed in the forming tank which contains an alkaline electrolyte,for instance, borax. Current is now applied, whereby a film is formed on the electrode but partly attacked by the borax..
Thereafter the electrolyte is made slightly acidic by addition of boric acid and the electrode subjected to the regular formatiomprocess.
A fourth method issimilar to the third and consists in placing the electrode without preliminary cleaning in the forming tank, which again comprises an alkaline solution as caustic soda, but instead of applying a forming current,
the caustic soda is left chemically to clean the aluminum-preferably inthe presence of inhibitive agents-as described in connection with the first method.- After a short; period of alkaline cleaning of the electrode, the electrolyte is made acidic, for instance, by addition of boric acid and the forming process undertaken in the regular way.
We have also found that while the highest 1 quality commercially available aluminum, the
so-called grade A aluminum, having 99.6% to 99.7% aluminum is subjected to corrosion in air, an aluminum of 99.9% or higher purity, does not corrode in air. 'Electrodes made ofthis material can be cleaned from adherent contaminationsby means of an organic solvent and no further special precaution is required to prevent the electrode from corrodingin airbefore it is subjected toforma'tion.
In the foregoing we have described various methods to prevent objectionable oxidation of aluminum electrodes during or subsequent to their cleaning and to obtain higher quality oxide films. While we have illustrated our invention in connection with electrolytic condensers, using aluminum electrodes, and, described specific methods, we do not wish to be limited to such devices, material or methods, but desire the appended claims to beconstrued as broad as permissible in view of the prior art.
Since claims relating to the second and third method hereinabove described are made in our Patent #2,035,022, of March '24, 1936,'which issued on' anapplication, Ser. No. 1,432, filed January 11, 1935, as a division of the present application, claims to said second and third methods are not madeherein. 9
What we, therefore, claimand desire to secure by Letters Patent is:
, 1. In the manufacture of aluminum electrodes and subjecting the electrode to film formationin the solution of borax and boric acid.
. PRESTON ROBINSON.
JOSEPH L. COLLINS.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US526118A US2067703A (en) | 1931-03-28 | 1931-03-28 | Electrolytic device |
US1432A US2035022A (en) | 1931-03-28 | 1935-01-11 | Electrolytic device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US526118A US2067703A (en) | 1931-03-28 | 1931-03-28 | Electrolytic device |
Publications (1)
Publication Number | Publication Date |
---|---|
US2067703A true US2067703A (en) | 1937-01-12 |
Family
ID=24095983
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US526118A Expired - Lifetime US2067703A (en) | 1931-03-28 | 1931-03-28 | Electrolytic device |
Country Status (1)
Country | Link |
---|---|
US (1) | US2067703A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4126483A (en) * | 1977-06-03 | 1978-11-21 | Ford Motor Company | Method of adherency of electrodeposits on light weight metals |
US4225397A (en) * | 1978-11-06 | 1980-09-30 | Ford Motor Company | New and unique aluminum plating method |
-
1931
- 1931-03-28 US US526118A patent/US2067703A/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4126483A (en) * | 1977-06-03 | 1978-11-21 | Ford Motor Company | Method of adherency of electrodeposits on light weight metals |
US4225397A (en) * | 1978-11-06 | 1980-09-30 | Ford Motor Company | New and unique aluminum plating method |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP3111979B2 (en) | Wafer cleaning method | |
US4432846A (en) | Cleaning and treatment of etched cathode aluminum capacitor foil | |
KR102317276B1 (en) | Method for manufacturing electrode foil for surface mount aluminum electrolytic capacitors | |
CN107658135A (en) | A kind of preprocess method for improving electrode foil for aluminum electrolytic capacitors hair engaging aperture density | |
US2079516A (en) | Aluminum electrode and method of preparing | |
JPS6349364B2 (en) | ||
US2035022A (en) | Electrolytic device | |
CN1094997C (en) | Manufacture of anode foil used in aluminium electrolytic capactiance | |
KR810002105B1 (en) | Plating on aluminium alloys | |
US2067703A (en) | Electrolytic device | |
US1935395A (en) | Film formation on valve metals | |
CN109112605B (en) | Regeneration treatment liquid and regeneration method of titanium-based iridium-tantalum oxide coating anode for electrolytic copper foil | |
US3519779A (en) | Method of making non-porous weld beads | |
JPS5825218A (en) | Method of producing low voltage electrolytic condenser electrode foil | |
US2193711A (en) | Electrolytic device | |
US2339806A (en) | Surface treatment of aluminum and aluminum alloys | |
JP2007059499A (en) | Manufacturing method of aluminum electrode foil for electrolytic capacitor | |
US3378668A (en) | Method of making non-porous weld beads | |
US2086993A (en) | Condenser and method of producing same | |
CN106190649A (en) | A kind of method that cleanout fluid and cleaning PCB thereof move back molten tin bath | |
TW518713B (en) | Method to prevent metal tungsten plug from corrosion | |
JPH1197298A (en) | Method of manufacturing electrode foil for aluminum electrolytic capacitor | |
US1705944A (en) | Electrolytic device | |
US2830942A (en) | Electrocleaner for brass | |
JP4709069B2 (en) | Method for producing aluminum electrode foil for electrolytic capacitor |