US2721119A - Stripping tin from copper - Google Patents
Stripping tin from copper Download PDFInfo
- Publication number
- US2721119A US2721119A US35518153A US2721119A US 2721119 A US2721119 A US 2721119A US 35518153 A US35518153 A US 35518153A US 2721119 A US2721119 A US 2721119A
- Authority
- US
- United States
- Prior art keywords
- copper
- tin
- metal
- stripping
- sulphuric acid
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B25/00—Obtaining tin
- C22B25/06—Obtaining tin from scrap, especially tin scrap
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- This invention relates to chemistry and more particularly to an improved method of stripping tin from a metal base.
- the customary method of stripping tin from a base metal such as copper or copper alloys is to immerse the coated metal in a bright dip solution.
- the ditficulty with this method is that selective etching frequently occurs and produces a Very poor surface. This makes the surface finish unsatisfactory and the base metal either must be scrapped or be salvaged by some form of polishing operation. There are several other methods but most of these methods are slow or otherwise objectionable.
- the aqueous dilute sulphuric acid solution contains about 6% sulphuric acid by volume.
- the optimum amount of copper ions in the solution is from 28 to 56 grams per liter or 3.8 to 7.6 ounces per gallon. Lesser concentrations slow down the rate of stripping while higher concentrations do not materially increase the rate of stripping.
- This solution strips a tin coating at the rate of .0001 of an inch for each to /2 minute of immersion when the temperature is maintained at the preferred temperature of about 180 F.
- the copper may be introduced into the solution either as pure metal or as an oxide or as a salt. Of course, the oxide or salt must be suflicient in amount to provide the copper ion concentration indicated above.
- copper sulphate For example between 50 and 100 grams per liter or between 6.7 and 13.5 ounces per gallon of copper sulphate will be required. Or between 37.5 and 75.0 grams per liter or between 5.0l0.0 ounces per gallon of anhydrous copper nitrate will be required to produce the ions or between 20 and 40 grams per liter or between 2.7 and 5.4 ounces per gallon of cuprous chloride or between 26.6 and 53 grams or 3.56 and 7.1 ounces per gallon of cupric chloride will be required to supply the copper ions for the optimum concentration. Copper nitrate is less satisfactory since its use causes a noticeable attack on the copper base metal.
- the advantage of this stripping method is that the base metal is not attacked appreciably except when copper nitrate is used and that it is reasonably fast.
- the cost of the stripping solution is low.
- This method also eliminates completely any scrap from too long an immersion in the stripping solution since the attack on the base metal is negligible except when copper nitrate is used.
- the dilute sulphuric acid does not attack copper much because any such attack forms a loose protective coating over the surface of copper.
Description
United States Patent STRlPPlNG TIN FROM COPPER Fredrick Bauch, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware No Drawing. Application May 14, 1953, Serial No. 355,181
3 Claims. (Cl. 41-42) This invention relates to chemistry and more particularly to an improved method of stripping tin from a metal base.
The customary method of stripping tin from a base metal such as copper or copper alloys is to immerse the coated metal in a bright dip solution. The ditficulty with this method is that selective etching frequently occurs and produces a Very poor surface. This makes the surface finish unsatisfactory and the base metal either must be scrapped or be salvaged by some form of polishing operation. There are several other methods but most of these methods are slow or otherwise objectionable.
It is an object of my invention to provide a rapid inexpensive method of stripping tin from a metal base, especially from bases of copper or copper alloy which will not selectively etch or otherwise damage the surface of the base metal.
These and other objects are attained by immersing the tin coated base metal in a dilute sulphuric acid solution containing copper ions for a period of time sufficient to remove the tin.
Preferably the aqueous dilute sulphuric acid solution contains about 6% sulphuric acid by volume. The optimum amount of copper ions in the solution is from 28 to 56 grams per liter or 3.8 to 7.6 ounces per gallon. Lesser concentrations slow down the rate of stripping while higher concentrations do not materially increase the rate of stripping. This solution strips a tin coating at the rate of .0001 of an inch for each to /2 minute of immersion when the temperature is maintained at the preferred temperature of about 180 F. The copper may be introduced into the solution either as pure metal or as an oxide or as a salt. Of course, the oxide or salt must be suflicient in amount to provide the copper ion concentration indicated above. For example between 50 and 100 grams per liter or between 6.7 and 13.5 ounces per gallon of copper sulphate will be required. Or between 37.5 and 75.0 grams per liter or between 5.0l0.0 ounces per gallon of anhydrous copper nitrate will be required to produce the ions or between 20 and 40 grams per liter or between 2.7 and 5.4 ounces per gallon of cuprous chloride or between 26.6 and 53 grams or 3.56 and 7.1 ounces per gallon of cupric chloride will be required to supply the copper ions for the optimum concentration. Copper nitrate is less satisfactory since its use causes a noticeable attack on the copper base metal.
If there is any organic material upon the tin coating this must be removed by other methods such as by immersion in concentrated sulphuric acid. Following ICC the stripping of the tin the base metal should be dipped in the conventional bright dip of nitric and sulphuric acid and properly rinsed before it is replated.
The advantage of this stripping method is that the base metal is not attacked appreciably except when copper nitrate is used and that it is reasonably fast. The cost of the stripping solution is low. This method also eliminates completely any scrap from too long an immersion in the stripping solution since the attack on the base metal is negligible except when copper nitrate is used. The dilute sulphuric acid does not attack copper much because any such attack forms a loose protective coating over the surface of copper.
While this process is primarily intended for the stripping of tin from copper and copper alloys it may also be used for stripping zinc, antimony, cadmium, silver and molybdenum from copper and copper alloys and steel.
While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted as may come within the scope of the claims which follow.
What is claimed is as follows:
1. The process of stripping tin from metal containing a substantial proportion of copper which includes immersing the tin coated metal containing copper in a dilute sulphuric acid solution containing as the essential ingredient copper ions in the amount of 28 to 56 grams per liter for a period of time sulficient to strip the tin from the metal.
2. The process of stripping tin from metal containing a' substantial proportion of copper which includes removing any organic material if any which may be covering the tin, immersing the tin coated metal containing copper in a dilute sulphuric acid solution containing as the essential ingredient copper ions in the amount of 28 to 56 grams per liter for a period of time suft'cient to strip the tin from the metal and then immersing the metal in a bright dip solution containing nitric and sulphuric acids.
3. The process of stripping tin from metal containing a substantial proportion of copper which includes immersing the tin coated metal containing copper in an aqueous sulphuric acid solution containing as the essential ingredient about 6% sulphuric acid by volume and copper ions in the amount of 28 to 56 grams per liter for a period of time substantially between and /2 minute for each .0001" thickness of the tin coating.
3), pages 1360-1361.
Claims (1)
- 2. THE PROCESS OF STRIPPING TIN FROM METAL CONTAINING A SUBSTANTIAL PROPORTION OF COPPER WHICH INCLUDES REMOVING ANY ORGANIC MATERIAL IF ANY WHICH MAY BE COVERING THE TIN, IMMERSING THE TIN COATED METAL CONTAINING COPPER IN A DILUTE SULPHURIC ACID SOLUTION CONTAINING AS THE ESSENTIAL INGREDIENT COPPER IONS IN THE AMOUNT OF 28 TO 56 GRAMS PER LITER FOR A PERIOD OF TIME SUFFCIENT TO STRIP THE TIN FROM THE METAL AND THE IMMERSING THE METAL IN A BRIGHT DIP SOLUTION CONTAINING NITRIC AND SULPHURIC ACIDS.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US35518153 US2721119A (en) | 1953-05-14 | 1953-05-14 | Stripping tin from copper |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US35518153 US2721119A (en) | 1953-05-14 | 1953-05-14 | Stripping tin from copper |
Publications (1)
Publication Number | Publication Date |
---|---|
US2721119A true US2721119A (en) | 1955-10-18 |
Family
ID=23396528
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US35518153 Expired - Lifetime US2721119A (en) | 1953-05-14 | 1953-05-14 | Stripping tin from copper |
Country Status (1)
Country | Link |
---|---|
US (1) | US2721119A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2842435A (en) * | 1955-12-01 | 1958-07-08 | Western Electric Co | Methods of stripping tin and tin alloy surface coatings from iron and iron alloy articles |
US4009299A (en) * | 1975-10-22 | 1977-02-22 | Motorola, Inc. | Tin strip formulation for metal to glass seal diodes |
DE3132427A1 (en) * | 1981-08-17 | 1983-02-24 | Elget Ing.-Büro für grafische und elektronische Technik, 8501 Oberasbach | Stripper |
US20050202180A1 (en) * | 2003-12-31 | 2005-09-15 | Microfabrica Inc. | Electrochemical fabrication methods for producing multilayer structures including the use of diamond machining in the planarization of deposits of material |
US20090020433A1 (en) * | 2003-12-31 | 2009-01-22 | Microfabrica Inc. | Electrochemical Fabrication Methods for Producing Multilayer Structures Including the use of Diamond Machining in the Planarization of Deposits of Material |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US150957A (en) * | 1874-05-19 | Improvement in precipitating copper by means of tin-scrap | ||
US511846A (en) * | 1894-01-02 | Process of removing tin from tin-scrap | ||
US529863A (en) * | 1894-11-27 | Process of removing and recovering metal coatings from metallic bases | ||
US529864A (en) * | 1894-11-27 | Process of removing and recovering metal coatings from-metallic bases | ||
US2172171A (en) * | 1938-08-10 | 1939-09-05 | Gen Electric | Production of bright copper |
US2208138A (en) * | 1937-02-27 | 1940-07-16 | Roger T Robinson | Process for recovering tin and steel from tin plate |
-
1953
- 1953-05-14 US US35518153 patent/US2721119A/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US150957A (en) * | 1874-05-19 | Improvement in precipitating copper by means of tin-scrap | ||
US511846A (en) * | 1894-01-02 | Process of removing tin from tin-scrap | ||
US529863A (en) * | 1894-11-27 | Process of removing and recovering metal coatings from metallic bases | ||
US529864A (en) * | 1894-11-27 | Process of removing and recovering metal coatings from-metallic bases | ||
US2208138A (en) * | 1937-02-27 | 1940-07-16 | Roger T Robinson | Process for recovering tin and steel from tin plate |
US2172171A (en) * | 1938-08-10 | 1939-09-05 | Gen Electric | Production of bright copper |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2842435A (en) * | 1955-12-01 | 1958-07-08 | Western Electric Co | Methods of stripping tin and tin alloy surface coatings from iron and iron alloy articles |
US4009299A (en) * | 1975-10-22 | 1977-02-22 | Motorola, Inc. | Tin strip formulation for metal to glass seal diodes |
DE3132427A1 (en) * | 1981-08-17 | 1983-02-24 | Elget Ing.-Büro für grafische und elektronische Technik, 8501 Oberasbach | Stripper |
US20050202180A1 (en) * | 2003-12-31 | 2005-09-15 | Microfabrica Inc. | Electrochemical fabrication methods for producing multilayer structures including the use of diamond machining in the planarization of deposits of material |
US20090020433A1 (en) * | 2003-12-31 | 2009-01-22 | Microfabrica Inc. | Electrochemical Fabrication Methods for Producing Multilayer Structures Including the use of Diamond Machining in the Planarization of Deposits of Material |
US20120114861A1 (en) * | 2003-12-31 | 2012-05-10 | Microfabrica Inc. | Electrochemical Fabrication Methods for Producing Multilayer Structures Including the use of Diamond Machining in the Planarization of Deposits of Material |
US9714473B2 (en) | 2003-12-31 | 2017-07-25 | Microfabrica Inc. | Method and apparatus for maintaining parallelism of layers and/or achieving desired thicknesses of layers during the electrochemical fabrication of structures |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2446060A (en) | Chemical polishing of metal surfaces | |
US2369620A (en) | Method of coating cupreous metal with tin | |
US4713144A (en) | Composition and method for stripping films from printed circuit boards | |
DE3201475C2 (en) | ||
GB1035970A (en) | Process for dissolving metals | |
US2593449A (en) | Method and composition for treating aluminum and aluminum alloys | |
US2883311A (en) | Method and composition for treating aluminum and aluminum alloys | |
US2721119A (en) | Stripping tin from copper | |
US2982625A (en) | Etchant and method | |
US3104167A (en) | Method and solution for selectively stripping electroless nickel from a substrate | |
US2928168A (en) | Iron coated uranium and its production | |
CN108359989B (en) | Nickel-copper alloy layer chemical stripping composition for circuit board and stripping method thereof | |
US3935005A (en) | Composition and method for stripping gold and silver | |
US2620265A (en) | Composition for treating aluminum and aluminum alloys | |
US1867527A (en) | Process for anodic removal of surface metal film | |
US2872302A (en) | Etchant | |
US2625468A (en) | Method of conditioning brightening baths | |
US2938841A (en) | Preparation of zirconium for cold working | |
US2975073A (en) | Corrosion resistance of electroless nickel plate | |
US3345225A (en) | Method of chemically polishing copper and copper alloys | |
US3859149A (en) | Method for etching aluminium alloys | |
JPH044397B2 (en) | ||
US3562039A (en) | Method of improving the solderability of conductor plates | |
US3930081A (en) | Composition and process for displacement plating of zinc surfaces | |
US2954289A (en) | Dissolving of nickel-phosphorous alloys |