United States Patent (19) 11 Patent Number: 4,640,713 Harris 45 Date of Patent: Feb. 3, 1987

(54) TARNESHREMOVER/ 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 from silver, cop erosion of the metal surface. per, , and other . "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 film which metal surfaces. is from all indications integral with the metal surface 20 and similar to metal . 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. 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 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%. The metal polish when applied to silverware sulfide or silver oxide, or the like, which is the tarnish or removed the tarnish and stain with light rubbing. The stain product usually associated with tarnish or discol polish was easily washed off with warm water to pro oration of metal surfaces. 20 vide a bright metal surface. The proportions and method of mixing the ingredi ents of the tarnish remover/metal polishes of the pres Example 2 ent invention are not particularly critical, there being a A brass and copper polish was prepared by mixing fairly wide range of operable proportions depending ingredients as follows: 12% by weight potassium iodide; upon whether the preparation is to be used as an aque 25 8% by weight phosphoric acid; 5% by weight diatoma ous polish or as a dip-rinse preparation. The metal io ceous earth; 15% by weight alumina; 0.5% by weight dide and acid, however, must be present in an amount bentonite; 3% by weight butyl cellosolve; 0.5% by sufficient to react with the tarnish- or stain-forming weight surfactant (an ethoxylated linear alcohol), 0.1% ingredient on the metal surface in the presence of water. by weight stabilizer (sodium sulfite), and the balance The metal iodide should be present, therefore, in an 30 water to make 100%. The brass and copper polish when i amount of from about 5 to 25% by weight, the acid applied to brass and copper removed the tarnish and should be present in an amount of from about 0.1 to stain with light rubbing. The polish was easily washed 25% by weight, with the balance of the formulation off with warm water to provide a bright metal surface. being water or an ancillary material such as an abrasive, 35 surfactant, co-solvent, or the like which in certain prep Example 3 arations will enhance the cleaning and removability A dip-rinse tarnish remover was prepared utilizing characteristics of the tarnish remover or metal polish. the ingredients as follows: 3% by weight sulfuric acid; Preferred percentages by weight are from about 3 to 12% by weight potassium iodide; and 85% by weight 8% of acid, 8 to 15% of the metal iodide, 0 to 15% water. When silverware is dipped into the dip-rinse abrasive, 0 to 3% surfactant, and up to about 10% of the formulation, the tarnish is rapidly removed to provide a carrier being an organic co-solvent. bright metal surface. The tarnish remover polish compositions, while being capable of being utilized as the aqueous solution Example 4 of only an acid and metal iodide, can also be used in 45 A dip-rinse tarnish remover was prepared utilizing combination with other ingredients such as abrasives, the ingredients as follows: 4% by weight citric acid; surfactants, co-solvents, perfumes, humectants, and 12% by weight potassium iodide; and 85% by weight stabilizers in the amount as stated above. The presence water. When silverware is dipped into the dip-rinse of the additional materials will provide enhanced clean formulation, the tarnish was rapidly removed to pro ing and/or contribute to the removability of the formu 50 vide a bright metal surface. lation after application. Abrasives which have been In the aforesaid examples the potassium iodide can be found useful include the abrasives conventionally em replaced by other metal iodides including sodium io ployed as cleaners such as , the sili dide, lithium iodide, magnesium iodide, calcium iodide, cas, aluminas, diatomaceous earth, bentonite, charcoal, rubidium iodide, cesium iodide, or a mixture of the infusorial earth, pumice, brick clay, tripoli, and the like. 55 metal iodides. The acid can be replaced with other The surfactants which are useful according to the pres acids, including sulfuric acid, tartaric acid, and hydro ent invention include the nonionic, cationic, and anionic chloric acid. The abrasive and surfactant can be re surfactants which are conventionally used in cleaner placed by other conventionally employed abrasives and compositions and as wetting agents such as the nonyl surfactants for cleaning and as wetting agents. phenols, ethoxylated alcohols, alkyl sulfates, coconut As will be apparent to one skilled in the art, various fatty acid, alkanolamine condensates, and the like. The modifications can be made within the scope of the stabilizers which can be utilized include the conven aforesaid description. Such modifications being within tional stabilizers such as the hydroquinones, sodium the ability of one skilled in the art form a part of the sulfide, glycerine, and the like. The co-solvents include present invention and are embraced by the appended the conventionally used solvents for use in cleaner com 65 claims. positions such as the cellosolves, hydrocarbons such as It is claimed: the isopars, low molecular weight alcohols, and the like. 1. An improved tarnish remover/metal polish formu The humectants which can be utilized include propy lation comprising: 4,640,713 5 6 (a) at least one metal iodide in an amount of from 10. The metal polish of claim 1 including in addition about 8 to 25% by weight; to said essential ingredients an organic solvent. (b) an acid in an amount of from about 0.1 to 25% by 11. An improved tarnish remover/metal polish for weight; mulation suitable as dip rinse comprising: (c) a surfactant in an amount of from about 0.5 to 3% (a) from about 3 to 6% by weight of an acid, by weight, and; (b) from about 8 to 15% by weight of a metal iodide, (d) the balance water. (c) a surfactant in an amount of about 0.5 to 3% by 2. The improved tarnish remover/metal polish for weight; and mulation of claim 1 wherein the metal iodide is a mem (d) the balance water. 10 12. The improved tarnish remover/metal polish for ber of the group consisting of potassium iodide, sodium mulation of claim 11 wherein the metal iodide is a mem iodide, lithium iodide, magnesium iodide, calcium io ber of the group consisting of potassium iodide, sodium dide, rubidium iodide, cesium iodide, and mixtures iodide, lithium iodide, magnesium iodide, calcium io thereof. dide, rubidium iodide, cesium iodide, and mixtures 3. The improved tarnish remover/metal polish for 15 thereof. mulation of claim 2 wherein the metal iodide is potas 13. The improved tarnish remover/metal polish for sium iodide. mulation of claim 12 wherein the metal iodide is potas 4. The improved silver polish formulation of claim 1 sium iodide. wherein said acid is phosphoric acid which is present at 14. An improved tarnish remover/metal polish for from about 3 to 8% by weight. 20 mulation suitable for use as a metal polish comprising 5. The improved silver polish formulation of claim 1 from about 3 to 6% by weight of an acid, 8 to 15% by wherein said acid is citric acid which is present at from weight of a metal iodide, 4 to 15% of an abrasive, 0.5 to about 3 to 8% by weight. 3% of a surfactant, and the balance water. 6. The improved silver polish formulation of claim 1 15. The improved tarnish remover/metal polish for 25 mulation of claim 14 wherein the metal iodide is a mem wherein said acid is sulfuric acid which is present at ber of the group consisting of potassium iodide, sodium from about 3 to 8% by weight. iodide, lithium iodide, magnesium iodide, calcium io 7. The improved silver polish formulation of claim 1 dide, rubidium iodide, cesium iodide, and mixtures wherein said acid is sulfonic acid which is present at thereof. from about 3 to 8% by weight. 30 16. The improved tarnish remover/metal polish for 8. The improved tarnish remover/metal polish for mulation of claim 15 wherein the metal iodide is potas mulation of claim 1 wherein said potassium iodide is sium iodide. present at from about 8 to 15% by weight. 17. The metal polish of claim 1 including in addition 9. The metal polish of claim 1 including in addition to to said essential ingredients an abrasive. said essential ingredients a thickening agent. 35 k . . k

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