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United States Patent (19) 11 Patent Number: 4,640,713 Harris 45 Date of Patent: Feb

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United States Patent (19) 11 Patent Number: 4,640,713 Harris 45 Date of Patent: Feb United States Patent (19) 11 Patent Number: 4,640,713 Harris 45 Date of Patent: Feb. 3, 1987 (54) TARNESHREMOVER/METAL POLISH 3,458,300 7/1969 Duvall et al. ........................... 106/3 FORMULATION COMPRISING A METAL 3,502,503 3/1970 Bartlo et al. ............................ 134/2 IODIDE, ANACID, AND WATER 3,518,098 6/1970 Ford et al. .............................. O6/3 3,582,366 6/1971 Brieger et al. 75 Inventor: Robert B. Harris, Racine County, 3,687,855 8/1972 Halpern..... Wis. 3,879,216 4/1975 Austin ..................................... 134/4 3,914, 161 10/1975 Yonezawa et al. a 73 Assignee: S. C. Johnson & Son, Inc., Racine, 3,997,460 12A1976 Sirine ............. Wis. 4,097,590 6/1978 Weisz ..... 4,116,699 9/1978 Rooney...... ...10673 21 Appl. No.: 672,966 4,207,310 6/1980 Langford ... ... 252A106 22) Filed: Nov. 19, 1984 4,444,756 4/984 Schlissier ........................... 252/106 51 Int. Cl. .......................... C09G 1/04; C09G 1/06 Primary Examiner-Theodore Morris (52) U.S. C. ........................................... 106/3; 106/10 57 ABSTRACT 58) Field of Search ............................. 106/3; 252/106 A tarnish remover/metal polish formulation comprising 56 References Cited water, an acid, and metal iodide, such as potassium U.S. PATENT DOCUMENTS iodide, is described. The components of the formulation chemically react with the tarnish or stain on a metal 840,167 1/1907 Springborn et al. .................... 106/6 1,280,939 0/1918 Allen ................ ... 06/3 surface, removing the tarnish or stain while leaving the 1,737,222 11/1929 Dewey, Jr. ... 106/9 metal unaffected. The tarnish remover/metal polish can 1,995,219 3/1935 Pape ..................................... 106/9 be applied as a dip-rinse or as a polish. The composition 2,183,037 12/1939 Bayliss...... ... 252A106 is easily applied and easily removed. 2,992,946 7/1961 Arden et all ... 134/29 3,385,682 5/1968 Lowen ...... ... 106/3 17 Claims, No Drawings 4,640,713 2 surface due to scratches on the silverware. Some polish TARNISH REMOVER/METAL POLISH type formulations are believed to remove some of the FORMULATION COMPRISING A METAL metal surface when used. Additionally, a number of the IODIDE, ANACID, AND WATER prior art polishes or tarnish removers containing chemi cals, such as thiourea, have toxic characteristics, some FIELD OF INVENTION AND BACKGROUND suspected to be carcinogenic, and for that reason are not The present invention relates to an improved tarnish well received. remover. More particularly this invention relates to a tarnish remover/metal polish containing as essential PRIMARY OBJECTS AND GENERAL ingredients a metal iodide such as potassium iodide, an O DESCRIPTION OF INVENTION acid, and water. The tarnish removers/metal polishes of It is a primary object of the present invention to pro this invention are effective, safe, and low in cost. vide a tarnish remover for metal surfaces which will In the prior art many formulations have been pro rapidly remove tarnish from the metal with little or no posed for removing tarnish and oxides from silver, cop erosion of the metal surface. per, brass, and other metals. "Tarnish,' as the term is 15 It is another primary object of the present invention used herein, embraces a film discoloration of the metal to provide a tarnish remover which will rapidly remove surface which occurs as a result of a chemical change in tarnish and which is safe to use both from the standpoint the metal as opposed to a mere physical soiling. An of toxicity and from the standpoint of erosion of the example is the formation of a sulfide or oxide film which metal surfaces. is from all indications integral with the metal surface 20 and similar to metal corrosion. The prior art formula It is another object of the present invention to pro tions which have been proposed have been designed to vide a tarnish remover which is readily removed from either only remove the tarnish, etc., or to remove the the surface of the metal being polished or cleaned after tarnish, etc., and additionally repress the tendency of the cleaning application. metal surfaces to re-tarnish or stain upon exposure to 25 It is another object of the present invention to pro ordinary atmospheric conditions, thereby eliminating at vide a tarnish remover and metal polish composition least partially a periodic, time-consuming cleaning which will protect the cleaned metal surface against problem and to prevent a deterioration of the metal retarnishing. surfaces. It is another object of the present invention to pro The prior art tarnish removers or metal polishes de 30 vide an aqueous base metal polish or tarnish remover signed primarily to remove tarnish and stain conven composition which can be stored for a substantial per tionally comprise an abrasive material and a carrier iod without separation of the components of the compo such as water, a hydrocarbon solvent, or glycerine, sition. either with or without a soap or an emulsified agent. These and other objects of the invention will become Tarnish removers and metal polishes designed to re 35 more apparent from the following detailed description, press tarnish and stain have included a film-forming with particular reference to the preferred embodiments material in the compositions such as waxes and resins so set forth in the working examples. as to leave behind a thin coating, and in addition the use According to the present invention an improved tar of anti-tarnish components such as a mercaptain or thio nish remover/metal polish formulation is provided con urea for the prevention of retarnishing. Exemplary taining as essential ingredients water, an acid, and a prior art tarnish removers or metal polishes include the metal iodide, such as potassium iodide. It is theorized compositions described in U.S. Pat. No. 2,628,199 that the components of the formulation react with the which utilize thiourea in an acidic dip-type silver and tarnish on the metal to chemically remove the tarnish. copper cleaning composition; U.S. Pat. No. 2,691,593 Although the reaction mechanism is not completely which discloses silver cleaning compositions in paste or 45 understood, it is theorized that in the case of silver liquid form containing abrasives, an emulsifying agent, a tarnish caused by sulfur in the atmosphere one possible hydrocarbon carrier and, if desired, a mercaptain or reaction is thiourea; and U.S. Pat. No. 2,841,501 which discloses a silver polish containing a mild abrasive and a long chain alkyl mercaptain as an anti-tarnishing agent. The ner 50 H3PO4 + 2KI + Ag2S -G) captan apparently forms a thin protective film upon the silver and prevents retarnishing. phosphoric potassium silver The aforesaid silver and copper cleaners and polishes acid iodide sulfide are useful and have met with substantial approval. H2S + 2Ag + K2HPO4 + 12 However, each has disadvantages and limitations. It has 55 been found that certain of the acidic dip type formula hydrogen silver potassium iodine tions have a deleterious effect upon silverware, possibly sulfide biphosphate resulting in more rapid retarnishing after the silver is again exposed to normal use and possibly causing re The aforesaid reaction is proposed as only a possible moval of the silver surface. The compositions appar 60 reaction and may, in fact, not be the actual reaction that ently function primarily as a cleaner and provide little takes place. It is believed clear, however, that the silver or no protective coating. On the other hand, polishing polish of this invention does function in removing tar compositions of the type described in U.S. Pat. No. nish and stains through a chemical reaction. The reac 2,691,593, because of the hydrophobic carrier em tion, while removing tarnish and stain, does not damage ployed, are relatively difficult to wash off the silver 65 or erode the metal surface. Moreover, the composition after polishing. There is also an indication that the silver is safe in the sense that the materials are not in and of tarnishes more easily after initial cleaning. The rapid themselves toxic, nor are they toxic when used in com retarnishing may be a result of more exposed silver bination. 4,640,713 3 4. In the tarnish remover/metal polish formulations of lene glycol, ethylene glycol, glycerine, and other the present invention the metal iodide can be any metal known humectants. - iodide which is reactive with a metal salt such as silver sulfide in the presence of an acid. The metal iodides WORKING EXAMPLES AND PRESENTLY found particularly useful are potassium iodide, sodium PREFERRED EMBODIMENTS iodide, lithium iodide, magnesium iodide, calcium io In order to set forth working examples and presently dide, rubidium iodide, and cesium iodide. Other metal preferred embodiments, the following examples of the iodides, however, can be utilized as long as the metal present invention are set forth. iodide as previously stated is reactive with a tarnish- or stain-producing compound in the presence of an acid. 10 Example 1 The acid which can be utilized in the present invention A silver polish was prepared by mixing ingredients as can be either an inorganic or organic acid. Acids which follows: 12% by weight potassium iodide; 6% by have been found to be particularly suitable include sul weight phosphoric acid; 0.6% by weight bentonite; furic acid, citric acid, phosphoric acid, sulfonic acid, 10% by weight diatomaceous earth; 2% by weight tartaric acid, and acetic acid. The acids which are to be 15 butyl cellosolve; 0.5% by weight surfactant (an ethoxyl employed include any of the acids which will react with ated linear alcohol), and the balance water to make the metal iodide and a silver compound such as silver 100%.
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