US 2196992 A
Description (OCR text may contain errors)
Patented Apr. 16, 1 940 I p n 7 2,196,992 7 LIQUID POLISHING COMPOSITION Edwin W. Keller, Allentown, 'Pa.
1 N0 Drawing." Application October 29, 1936 i Serial No.-108,212
3 Claims- (or. 134- 24) I 1 This invention relates to polishes and particularly to an improved polish foruseon bright -.;metals including metal plating. In thepolishing of metals there are essentially two typ s of'materials which must be removed from themetal to be polished. These are, first,
' V, the metallic compounds including metallic oxides ill) 1' and sulfides which are formed when the metal is exposed to the atmosphere, and, secondly, an
accumulated surface film composed of dust, oil and the like.
Heretofore, many polishes for use on bright meta-ls have been unsatisfactory becomplish the removal of the surfacefilm by means 'of-various alkali substances are objectionable because they leave. a film which is caused by the action of fatty acid soaps orthe like or solvents present in the polish, Moreover, where fatty-acid soaps are used there is the further diilicultyof a tendency for the polish to turn rancid, Another disadvantage inherent in many of the prior art liquidpolishes is the tendency to form a hard cake on standing, thus necessitating vigorous and prolonged shaking before the polish can be used. Moreover, most polishes are unsatisfactory, because of the inclusion of ingredi-.
ents which are so abrasive as to scratch a smooth metal surface; Furthermore, some of the prior art polishes have, toxic propertiesas well as dis agreeable odors. I One of the most serious difficulties encountered in the preparation of metal polishes has to do withthe formation of a hard cake of material when. the polish is allowed to stand. The term hard cake as used throughout this specification refers to a conglomeratewhich can be re-distributed by'shaking, only with much difficulty if at all and is to be distinguished from soft settlings which can be rc -dis tributed easily by shaking.
' The principal object ofthe present invention is to provide a liquid'polish which will be substantially free from the formation of a hard cake. A further object is to provide a polish In the development of the present invention I have proceeded in accordance with the following theory which I haveevolved after an extended investigation of the problem; Anabrasive alone is not sufiicient in viewof the two different types of materialsthat a polish must remove and in Therefore an assistant ingredient with detergent properties as well as suspending properties must be used and this ingredient must not include highly alkaline substances else an alkali film will form after the polish ,is used. I Sodium silicate,
well known as a detergent, also has the property of assisting in the suspension of finely divided abrasives. Finally a third ingredient is neces sary for the prevention of the-formation of a hard cake due to thenatural aflinity of the abra- 1Q sive and its assistant. This third ingredient must coact with the abrasive substance so as to substantially prevent. a hard-caking effect caused by the affinity of the assistant for the abrasive and v at the same "time it must be compatible with both the abrasive and its assistant.
I have discovered that finely divided tin, oxide in a substantially pure state is an admirable abrasive for bright metals including metal plat- .in'g since its polishing qualities are good while at!) "its abrasive qualities are such as to preclude v fact that the particlesof tin oxide settle rapidly to the bottom of the container; -I- Iowever,the
difiiculties connected with the use of a suspension of tin oxide alone can be partially. overcome by the use of sodium silicate which acts as a de tergent for the surface film of dirt, oil or the like and at the same time contributes to main- *taining a suspension of the particles of tin oxide. As already generallystated with respect to finely divided abrasives and assistant detergents like sodium silicate, a marked tendency for the sodium silicate to combine physically with the particles 10' oftin oxide in such a way as to form a hard cake of material within the container, necessitating an undue" amount of shaking before the polish can be used. According to the present invention,
this difficulty of the formation of a hard cake v is substantially obviated by the use of a third ingredientwhich notonly acts substantially to prevent t-he form ation of a hard cake, but also aids the sodium silicate in the attack on the surface film and' at the same time has the remarkable quality of retarding. the retarnishing of the metallic surface which is polished. This added ingredient is marketed under a number of trade names such as fGardinol, Duponol and Orvus, but these products are substantially the sodium salt of lauryl alcohol sulfate. The prevention of the formation of a hard cake by this added ingredient, hereinafter referred to as Duponol, is apparently effected by the action of lauryl alcohol sulfate upon the particles of tin oxide which appear to be insulated by the Dupo- 1101 from the cohesive action of the sodium silicate. It is also important to note that Duponol and sodium silicate are compatible as well as completely rinsable from the polished surface. Moreover, Duponol is a neutral compound and does not hydrolyze to give an alkaline reaction.
One of the preferred ways of carrying out the present invention is as follows: Three grains of powdered Duponol, preferably Duponol M. E.
Dry, are added to four gallons'of water and agitated until completely dissolved. To eight". ounces of the Duponol solution so obtained :tained when the mixture of 'Duponol and tin oxide abrasive is made prior to the addition of the sodium silicate detergent. 'tained by mixing in this order are far superior The results obto the results obtained when the sodium silicate is mixed with the Duponol solution prior to the addition of the 'tin oxide.
The sodium silicate mentioned above is preferably one having an alkali to silica ratio of about 1:3.86 corresponding to a density of 33.5" Baum, but of course it will be understood that silicates of different ratios may be used to advantage provided the alkali ratio is kept relatively low. It is to be understood, however, that the silicates used in the practice of this invention are not to be confused with certain abrasive sili con dioxide compounds, such as silex, which have heretofore been used in some polishes.
The polish prepared as above described may be applied by rubbing a small: quantity of it on the material to be polished, allowing the polish to dry slightly, and removing the residue with a soft cloth. Remarkable results are obtained with a inhibited.
composition, it is tobe understood that various changes in the amounts of the ingredients used are within. the contemplation of 'the invention and should not be deemed to constitute a departure from the spirit of the invention as here inafter claimed,
Having thus described my invention, I claim:
1. An aqueous liquid 1po1ishingcomposition comprising finely divided'tin oxide, sodium sili-I calm, as a detergent, having a low alkali silica,-
ratio, so that an objectionable alkali film will notform on the polished work, and the sodium salt] of lauryl alcohol sulfate for preventing hard caking of the aforesaid ingredients on standing, besides assisting the detergent action ofthe so-Q .dium silicate andretarding tarnishing of metal surfaces polished with the composition.
2. A liquid polishing composition as set forth, in claim 1 "further characterized :in that, thesodium silicate has an alkali silica ratiosubstan-n tially corresponding to a densityof 33.5 Baum.
, 3. A method of preparing the composition's'et" forth in claim 1 which comprises first mixing the tin oxide and the -lauryl alcohol sulfate together in water, and. thereafter adding and mixing in the sodium silicate.