US2829108A - Nontarnishing detergent compositions containing a hydroxylamine salt and an alkali metal silicate - Google Patents

Description

tors.

ly used fordetergentand other purposes.

f r-.1 I

NONTARNISHING CONTAINING A HYDROXYLAMENE SALT AND AN ALKALI METALSILICATE Edgar E. Ruff, Bergenfielthand Elwin E. Smith, Paramus, N. J., assignors to Lever BrothersCompany, New York, N. Y., a corporation of Maine ,NoiDrawiug." Application August 16, 1955 7 Serial N0. 528, 813

17 Claims. (Cl. 252-137) This invention relates to detergent compositions containing tarnish inhibitors and more particularly to poly phosphate compositions containing a hydroxylamine salt and an alkali metal silicate as synergistic tarnish inhibi- Compositions containing polyphosphates are new widetions of polyphosphates' tend, when at certain pH values to tarnish copper, and nickel and copper alloys such as German silver (a nickel-zinc-copper alloylto a variety of shadesfrom-yellow to bluish-black, especially'ifthe solutions are at elevated temperatures and are allowed to remain in contact witha metal for several minutes. Since German silver is frequently used forhousehold articles commonly washed in polyphosphate-built detergent compositions, it is evident that this is a serious problem.

The tarnishing eiiect of polyphosphate compositions upon these metals and alloys may be readily tested by the following procedure. An amount of the polyphosphate composition is dissolved in somewhat less than onequart of water at a temperature under 170 F. to provide 2.25 f grams of polyphosphate per quart of solution.

DETERGENT COMPOSITIONS Aqueous solu- United States Patent I v 2,829,108 Patented Apr. 1, loss temperature under 170 F., hydroxylamine hydrochloride was added respectively at three concentrations, i. e.,

0.11%, 0.22%. and 0.88%, based on total weight of the composition, and-the three solutions were then diluted to onequart. A strip of German silver metal was placed in each of the three solutions for /2 hour at 160 F. to 170 F. The tarnish upon the German silver metal strips had.

a grading of 6, that is severe tarnish, in all three tests.

Examples 4, 5 and 6 Another polyphosphate, tetrasodium pyrophosphate, was tested in the same manner. as the pentasodium tripolyphosphate in Examples l,- 2 and 3 at the same concentrations'of hydroxylamine hydrochloride. The German silver metal strip again had a tarnish grading of 6,

i. e, severe tarnish, in all three tests.

hydroxylamine salt is also ineffective in inhibiting the formation of tarnish upon German silver when added ing six examples.

to polyphosphate compositions containing an organic nonsoap'detergent. This is clearly illustrated in the follow- Examples 7, 8 and 9 Three portions each 0100.9 gram ofsodium dodecylbenzenesulionateplus 2.25 grams of pentasodium tripolyphos- V phatewereld issolved separately in three portions of somewhatless-than one quart of distilled water at a tempera- A tarnish I inhibitor may then be added thereto in the form of asol lution. More water is then added thereto to give a total volume of one quart and the pH adjusted when necessary to'abou't 10. 300 mls of thesolution isplacd in a beaker and the temperature adjusted to 1'60F. to 170 F. A

strip ofmetal, suchas'fGerman silver, six-inches.by one inch, which has. been cleaned with a metal polish and rinsed and dried is partially immers in the solution and allowed to remain for hsur atfieo" F. to 170 F.

The metal strip is then removed, rinsed and dried with a cloth. The strip isyisually ex'amiinedr'or tarnish and the 1 efiectiveness of anytarnish inliibitorlgraded as follows;

Degree of. Tamish Grade N0 I No tarnish.

Interface stain only.

Barely noticeable tarnish.

Slight tarnish.

A Moderate tarnish.

Clonsidenble (heavy) tarnish. Severe, as when inhibitor is absent.

This. test procedure has .been used-throughout the ex' 7 Three 2.25 gram portionslof pentasodium tripolyphos- .phatewere dissolved separately in each -'o"f'three portions of somewhat "less than one quartet distilled waterat a "was substituted in an equal amount for the pentasodium ture under 170 F.,' hydroxylarnine' hydrochloride was added respectively at three concentrations, i. e., 0.63%, v 1.3% and 6.0%, based on total, weight of the composition, and thethree solutions were each diluted to one quart. A strip of German silver metal placed in each of the three solutions having a temp iature of 160 F. to 170. FL- had a tarnish grading of 6, indicating severe tarnish.

Examples 10, 11 and Another polyphosphate,- 'tetrasodium p'yrophosphate,

tripoly-phosphate of Examples 7, 8 and 9. The German silver-metal strip again had a tarnish grading of 6, indicating severe tarnish. s I

A further attempt was made to solve the problem of the formation of tarnish upon metals suchas German silver by polyphosphate compositions by including in such compositions an alkali metal silicate, such'as sodium silicate.

However, about 13% or less of an alkali metal silicate based on the weight of polyphosphate in the compositions was ineffective as a tarnishinhi'oitor as shown by the following two examples.

Examples 13 and 14 2.25 grams of pentasodium tripolyphosphate were dis:

solved in distilled water and 13.3 of sodium silicate based on the weight of polyphosphate added thereto and the solution diluted to one quart. Also 2.25 grams of tetrasodium pyrophosphate were dissolved in distilled water and 13.3% of sodium silicate based on the weight of polyphosphate added thereto and "the solution diluted to one quart. A strip of Germansilver metal placed in each or less of a hydroxylamine salt based on the total weight .of the composition nor about 13% or less of an alkali of these solutions had a'tarni'sh grading of 6, indicating severe tarnish. v is It can thus be readily seen that neither about 0.9%

metal silicate based on theweight of polyphosphate when added separately to polyphosphate compositions act as tarnish inhibitors therein.

In accordance with the invention, however, it was found that polyphosphate compositions containing both an alkali metal silicate and ahydroxylamine salt had greatly improved tarnishing properties upon metals such as. German silver', since the alkali metal silicate and the by eral structure;

' hydroiodide, hydrobromide', hydrochloride, and nitrate. While the hydroxylamine salts are preferred, it willbe understood that the more unstablehydroxylamine is an obvious equivalent thereof. While only 0.2% of a watersoluble hydroxylamine salt :need, be employed in conjunction with an alkali metal silicate, a greater amount may be employed if desired. '1 The maximum amount of the hydroxylamine saltis not critical, but more than is necessary to give the desired effect usually would not be used, and, of course, an amount in excessof that soluble in the polyphosphate solution would not be used. In most cases, the maximum suggested would be about 12%. Typical examples of suitable alkali metal silicates, i. e., metasilicates, include sodium and potassium silicates, also known as sodium and potassium metasilicates. At least about 13% of an alkali metal silicate based on the weight of the polyphosphatein conjunction with a hydroxylamine salt is added to the polyphosphate compositions, although greater amounts of an alkali metal silicate may be added thereto if desired: Hence, the maximum amount of alkali metal silicate is not critical, but morethan is necessary to give the desired synergistic tarnish inhibiting effect usually would not be used, and, of course, an amount in excess of that soluble in the polyphosphate solution would not'be used. Concentrations as high as 35% of alkali metal silicate based on the weight of polyphosphate have been satisfactorily employed.

The alkali metal polyphosphates may include by way of examplepentasodium and pentapotassium triployphosphate, tetrasodium and tetrapotassium pyrophosphates, sodium and potassium hexametaphosphates, and hexasodium and hexapotassiurn tetrapolyphosphates. There is no critical amount of alkali metal polyphosphate which need be employed in the compositions, the amount of polyphosphate in the compositions being dictated only Examples of such additional optional components are an organic non-soap detergent which may be either an anionic, cationic, or :nonionic detergent and builders, water, and inert materials. These detergent compositions may contain an alkalimetal polyphosphate in any amount, usually between 5% and 50%, at least about 0.2% of a water-soluble hydroxylamine salt, at least about 13% of an alkali metal silicate based on the weight of polyphosphate, conventional proportions of active organic non-soap detergent, usually within the range between 5% to 40%, and the balance builders and inert materials.

The alkylaryl sulfonates are a class of anionic detergents which may be included ,in the detergent. compositions. One example thereofis the sulfonated phenyl polypropylene alkanes, characterized by the branched chain structure of polypropylene and a tertiary alkyl carbon at the benzene ring, and having the following gen- CHaRI where M is hydrogen, an alkali metal or an organic amine catiomand R and. R, are alkyl,of the type formula 4 i C H and at least one R is a polypropylene group, the whole alkyl group containing preferably 12 to 15 carbon atoms. These areknown compounds whose preparation and properties are set forth in United States Patent No. 2,477,383, to Lewis, issued July 26, 1949; they are available in commerce under the trade names Oronite, Ultrawet, and Neolene. t

Another class of useful non-soap detergents are the amidoalkane sulfonatesl which are characterized by the following structure:

where A is hydrogen or an alkali metal, i. e., ammonium, sodium, or potassium, n is a small whole number from i to about 5, preferably 2 or 3, R is hydrogen or an alkyl, aryl, or cycloaliphatic group, such as methyl, and R is an alkyl or alkylene radical, such as myristyl, palrnityl, oleyl and stearyl. Sodium palmitic tauride, sodium palmitic methyl tauride, sodium myristic methyl tauride, sodium palmiti-stearic methyl tauride and sodium palmitic methyl amidopropane sulfonate are typical examples.

These compounds are prepared by interacting the corresponding aliphatic acid anhydride or halide with an organic aliphatic aminosulfonic acid, such as taurine, NH CH CH,SO H, and the various N-substituted taurines, such as N-methyl taurine, or aminopropane sulfonic acid, NH2(CH2)3SO3H. Other water-soluble alkyl aromatic sulfonic acids may constitute optional components such as those prepared by alkylating benzene or naphthalene with a kerosene fraction followed by sulfonation to aliphatic sulfonic acids, esters of sulfuric acidwith aliphatic alcohols of 10 to 18 carbon atoms, particularly those derived by the reduction of coconut oil, palm oil and the like longchain fatty acids, sulfonated castor oil, esters and ethers of isethionic acid, long-chain fatty acid esters and longchain alkyl ethers of 2,3-dihydroxy propane sulfonieacid and sulfuric acid esters of monoglycerides and glycerol monoethers. The salts of these acids are ordinarily employed.

The synergistic tarnish inhibitors are also useful. with 'nonionic detergents containing polyphosphates, such as,

for example, alkyl oxyether and ester and thioetherand ester detergents having the following general formula: RA(CH CH O),,CH CH OH where 'R, a straight or branched chain saturated or unsaturatedhydrocarbon group having from 8 to 18 carbon atoms or an aralky] group having a straight or branched chain saturated or unsaturated hydrocarbon group of from 8 to 18 carbon atoms attached to the aryl nucleus, and attached to A through the aryl nucleus, A is selected from the group consisting of ethereal oxygen and sulfur, carboxylic ester and thiocarboxylic ester groups and x is a number from 8 to 20. R can, for example, be a straight or branched chain octyl, nonyl, decyl, lauryl, myristyl, cetyl, or stearyl group, or an alkylaryl group suchas octylbenzene, nonylbenzene, decylbenzene, stcarylbenzene, etc.

The sulfated ethoxynated derivatives of the above are also useful anionic detergents:

where M is hydrogen or an alkali'metal or organic amine cation and x, A and R are as above.

Where R is alkyl it will be evident that the detergent can be regarded as derived from an alcohol, mercaptan, oxy or thio fatty acid of high molecular weight, by condensation with ethylene oxide. Typical of this class of alkyl ether are the condensation products of oleyl or dodecyl alcohol or mercaptan with from 8 to 17 moles of ethylene oxide such as Emulfor ON. Typical alkyl esters are the polyoxyethylene ester of tall oil acids,

.Renexj and the higher fatty acid esters glycoL; Neutronyx 330. Wh'ereR is aralkyLthe detergent can berderived from Ian alkyl phenol or thiophenol. 7

of polyethylene The ethoxynated alkyl. phenols and'thiophenols have v the following general formula:

' 'tions are Examples. 17 through 21; In these examples" the amount of,alkali metal :silicatewas va'ried with .two It will bernoted fromthese examples that-only about 9%, ofian alkali .metal silicate 'basedjon the weight of polyphosphate need beused in" in-the compositions is'an alkalimetal:tripolyphosphate/ whereR a straight or branched chain saturated or unsaturated hydrocarbon group having at least. 8 :carbon atoms up to approximately 18 carbon atoms,-A is oxygen .or.,sulfur and .r is a number from 8 to 20. R can, for example, be a straight or branched chain octyl, nonyl, decyl, iauryi, cetyl, myristyl, or stea-ryl group. Typical are the condensation products of octyl and nonyl phenol and thiophenol withfrom 8 to '17 moles v.of ethylene oxide suchasfilgepalCA. The pdetergent compositions can contain supplemental inorganicibuildersin small amounts including: alkalir metal ple menta'l inorganic salts,.organic: materials;

any dry form; such asydruiir-dried or spray-drieddeten gent compositions, or maybe in liquid form.

The detergent compositions containing a polyphosphate maybe prepared'by conventional methods, fas by compositions contained 0.80%, 0.77% and 0.73%, re-- spectively, of hydroxylaminehydrochloride. .A strip of I able tarnishgf I different p'olyphosphates.

detergent compositions containing atleast about 0.2% by Weight of a hydroxylamine salt when the-polyphosphate Examples 1 8'and 1 9 Three "2.25ugram portions? of pentasodiumgtrip l phos- 'phat'e were dissolved ingdi'stil'led water; 0.02: gra'm of hydroxylamine hydrochloride" was added :to' feach' of'the threesolutionsJ -,8.9%,=1 3.3 %;fland 22.2%, of sodium silicate based on the .Weight of polyphosphate w'ere-iadded respectively to the three solutions. Accordingly, the

German silver metal immersed in each of the three solutions had a tarnish grading of .Z indic'ating barelynotice- Exam te s'ea-ana"21- Two.2.25 gram portions ofitetrasodium pyrophosphate were dissolved in distilled water. 0.02 gram of hydroxyl- T amine hydrochloride was added to each of the solutions.

v 13.3% and 22.2% of sodiumsilicate wasadded respectively to the two solutions. Accordingly, the compositions contained 0.77% and 0.73%,respectively, of hydroxlyamine hydrochloride} .A strip of German silver metal immersed ineach of'the 'solutions had a tarnish grading of anionic non-soap detergent are Examples Nos. 22, 22A,

blending the components thereof in an aqueous solution or slurry and then drying the resulting mixture in a spray'or drum dryer at elevated temperatures; The hydroxylamine salt may be added to. solutions" of the heat-, 7 dried detergent compositions ,containing a polyphosphate and silicate or may be add'ed"in the powderedstate to heat-dried polyphosphate detergent compositions containing a silicate and have excellent inhibiting qualities. It was tound, however, that the, inhibiting properties ofa "hydroxylamine salt werealmost completelyflost if the hydroxylamine salt is added to the crutcher slurry and the slurry subsequently" drum dried.

Illustrative examples .of the PQlyphosphate;detergent compositions of this inventionand the synergistic inhibiting action of ai hydroxylamine salt andanzalltali I metal silicate upon 'such'conipositions are set forth below.

" In Examples 15 and 16 the compositions cohsisted'ot' a polyphosphate, .a hydroxylamine salt,'and .'a

Examples 15" and 16 a 2.25 grams of pentasodiurn tripolyphosphateand 2.25 7

grams of tetrasodium pyrophosphate, were dissolved respectively in two' portions of distilled water; 0.01 grams or" hydroxylamine hydrochloride, i. e., 0.4%, and 13.3% of sodium silicate based jon thefweight of polyphosphate.

were added to each of .theso'lutions, and each of the solutions was then diluted to' one quart. Astrip of German silvermetal immersed therein had. a tarnish grading stituted a considerable improvement overlthecomparable' compositions shown in Examples 1 through and l4-wherein either awater-soluble hydroxylami fsalt or an alkalimetal silicate respectively was added to a poly-.

phosphate.

Further examples showing how the, synergistic tarnish' inhibitors minimize the'formation of tarnish'upon copper and copper and nickel alloys .by polyphosphate composi- Composition y X' Y Sodium Dodecylbenzenesulionate 18.0 18.0 v .[etrasodium Pyrophosphate. 45.0

I Pentasodium Tripolyphosphate 45.0

Sodium Car onat 3.0 3.0 Sodium Silicate 1 6.0 6.0 SodiumCarboxymethy cellulose 0.5 0. 5 ater; 7.0 7.0 Sodium Sulfate and Miscellaneous Inert Mat 20.5 20. 5 Total 100.0 -10o.0

' Percent inhibitor, phosphate basis 13. 3 13. 3

.. 3'indicating slight tarnish. p Illustrative examples showingthe synergistic tarnishing actiorrof a-hydroxlyamine salt and an alkali metal silicate upon ,a composition containing a polyphosphate and an 23 and 23A wherein the concentrations are givenlin grams per liter and wherein the compositions were evaluated by the test proceduredescribed above.

Examples 22, 22 232m "23 I Example No 22 22A 23 23A 0. 02 0. 02 0.3..- O-3 0.3 'larnish Grading 2. 6 3

Percent; inhibitor, total weightbasissn; 06 LL... 0.6 9 Percent inhibitor, phosphate basis 13. 3 13. 3 13.3 13. 3

In Examples22 and 23 hydroxylamine hydrochloride, I Y. one of the synergistic tarnish inhibitors, was omitted from 55,

' and 23A. A noticeable improvement in the tarnish formthe compositions while it was included inExamples 22A ing properties of the compositions is apparent in Examples 22A and'23A wherein the synergistic tarnish inhibitors were included in the compositions. i

The remaining examples make use of the following two drum-dried compositions or modifications thereof'as described in the examples.

. The components of the above compositions are given C in'percent by weightof the total composition. Both compositions X and..Y thus contain one of the synergistic tarnish inhibitors, namely, sodium silicate, an alkali metal polyphosphate, an organic anionic non-soapdetergent, and

supplementalorganic and inorganic builders.

3 1 Examples 24 through-29 show that when'at least about 0.2% of a water-soluble :hydroxylamine salt based on the total weight of theicomposition and at least about 13% of an alkali metal silicate based on the weight of the polyphosphate are added to a detergent composition. conmining tetrasodium pyrophosphate and an anionic non- "soap'detergent plus organic and inorganic supplemental builders that the formation of tarnish upon German silver is greatlyreduced. t 4

Examples Z1 29 Six gram portions ofCompositionX were dissolved 'separat'elyin one liter of distilled water and hydroxylamine hydrochloride added thereto at the concentrations indicated below. The tarnish grading ofthe German silver metal strips is also indicated.

. n m m-.. ,2 4. a w Percent Hydroxyla min e hydrol l i chlorlde,totalwelght bests"; 0.1 0.2 0.4 -4' 6 Tarnlabgrede -L". 3:36 1.5 1 3 2 1 1 The following Examples 30 through 35 show that at least .about0.2% of a water-soluble hydroxylamine salt based on the total weight of the composition and at least about l3% of an alkali metal silicate based on the weight of polyphosphate when added-to a detergent composition containing a different polyphosphate from that used .in

, Examples 24-29,"thatis, pentasodium tripolyphosph'ate,

and an anionic non-soap detergent plus inorganic and or ganic supplemental builders that. the composition had improved tarnish formation properties.

Examples 30-35 S ix5.0 gram portionsof Composition Ywere dissolved in one liter of distilled water and hydroxylamine hydrochloride was added at the concentrations indicated below.

The tarnish grading of strips of Germansilver metalinserte d ineach of the solutions is also set forth.

Example Nd I. so 31 32 3a 34 35 Percent Hydroxylamine hydro I chloride, total weight basis. 0 0. 1 0.2 0. 4 4 'Q 6 Tarnlsh gmdlng i 5, 3 1 2 i 3 Examples 36-39 show that the synergistic tarnish inhibitors are efiective in'compositions containing still other alkali, metal ,polyphosphates, namely, sodium hexametaphosphate and hexasodium tetrapolyphosphate.

Examples 36-39 Sodium hexametaphosphate and hexasodium tetrapolyphosphate both tarnished German silver to grade 6 when these polyphosphates were substituted for the tetrasodium pyrophosph-ate in 5.0 gram portions of Composition 'X. The tarnish wasreduced to grade l with 0.4% hydroxylaminehydrochloride, total .weight basis, added "thereto whenthe polyphosphate; was sodium hexametaphosphate F and to grade 2 when thepolyphosphate was hexasodium tetrapolyphosphate. l

Examples40, and 40A show that the synergistic tarnish inhibitors are efiective in detergent compositions containing an organic cationic non-soap detergent.

8 Examples 40 and 40A The. lauric ester of N-(beta-hydroxyethyl)-alpha- '(chlbropyridinium) acetamide was substituted for sodium .dodecylbenzenesulfonate in two 5.0 gram portions of Composition X. 4% of hydroxylamine hydrochloride based on the total weight of the composition was added to one portion of the composition. A strip of German silver metal was tarnished to grade 6 by the composition which contained the alkali metal silicate but which did not contain a hydroxylamine salt whereas a strip of German silver metal was tarnished only to grade 2 when immersed in a solution of the composition which contained the synergistic tarnish inhibitors.

Examples 41 and 41A show that the synergistic tarnish inhibitors are effective in polyphosphate compositions containing an organic nonionic non-soap detergent.

i p 1. Examples 41 and 41A Whehi4% of hydroxylamine hydrochloride based on the total weight of the composition was added to a 5.0 gram portion of Composition X wherein the organic non- .ionic non-soap detergent, Pluronic L-64 [a compound having the empirical formula sodium salt of N-palmitoyl-N-methyl taurine and sodium- 3-dodecyloxy-Z-hydroxylvropane sulfonate, were substituted for the sodium dodecylbenzenes'ulfonate in Composition X, both compositions tarnished German silver metal to grade 6. The tarnish was reduced to grade 3 .in both instances when 0.4% hydroxylamine hydrochloride (totalweight basis) was included in the formula.

That the syngeristic tarnish inhibitors are also effective in hard water is shown by the following Example 42;

Example 42 l portion of Composition X tarnished German silver metal to grade 6 in water of 180 p. p. m. hardness without the presence of hydroxylamine hydrochloride while va strip' of German silver metal was tarnished only to grade 3 when 0.4% of hydroxylamine by Composition X to which was added drochloride, total weight basis, was added to a 5.0 gram portion of Composition X in water having a hardness of p. p. m.

' as noted above, the hydroxylaminesalt maybe added in a powdered state to the heat-dried polyphosphate detergent compositions containing an alkali metal silicate.

This is illustrated in Example 43.

' Example 43 To'l0 grams of Composition X were added 0.04 grams of powdered hydroxylamine hydrochloride, i. e., 0;4%-hydroxylamine hydrochloride based on the total weight of the composition. The two powders were thoroughly mixed and 5 grams removed and tested for tarnishingtendenciesy A grade 3 rating was obtained, indicating satisfactory tarnish inhibition.

The effectiveness of the synergistic tarnish inhibitors in inhibiting tarnish formation by polyphosphate compositionson metals other than German silver was tested by theprocedure given above using a 5 gram portionof 0.5% of hydroxylamine hydrochloride based on the total weight of the 9 10 composition. The results of these tests are presented be- 5. A detergent composition as set forth in claim 1 low in Table 1. I wherein the alkali metal metasilicate is sodium metasili- TABLE 1 gate,

g 6. A detergent composition consisting essentially of Metal or Alloy Tammi from about 5% to about 50% of an alkali metal poly- Gmdmg phosphate which in aqueous solution tarnishes copper and copper and nickel alloys, from about 5% to about @Siiiiiiitfiifi; ithtiiaaa'ssas:::::::::::'"::: i 40% of an Organ fmmfibwt 01% Copper. 4 to about 12% of a water-soluble inorganic hydroxyl- Mme! (alloy fn1ke11 mp1)", mangaFese and mm) 1 amine salt, and from about 13% to about 35% of an alkali metal metasilicate based on the weight of poly- The test data indicates that the synergistic tarnish 1nphosphate; the amounts f i hydroxylamjne l d hi it r When used in p yp p Composltlons are metasilicatc being sufficient to inhibit such tarnishing. effective against the tarnishing q pp and pp and 7. A detergent composition as set forth in claim 6 nickel y Such as cfllllage nlckel, pp and Monel- 15 wherein the alkali metal polyphosphate is pentasodium The synergistic tarnish inhibitors are less eflective when t j l h h t used in the cleaning of copper and are inelfective when 3 A detergent composition as set f -fh i l i 5 s i the Cleaning of brass which is all W of copper wherein the alkali metal polyphosphate is tetrasodium and zlnc. pyrophosphate.

The effectiveness of the synergistic tarnish inhibitors 9. A detergent composition as s f h i l i 6 with liquid polyphosphate detergent compositions is wherein the water-soluble inorganic hydroxylamine salt' clearly illustrated in Examples 44-47. is hydroxylamine hydrochloride.

Examples 4447 10. A detergent composition as set forth in claim 6 a wherein the alkali metal metasilicate is sodium meta- Four 5 gram portions of the following l1qu1d detcrsflicaw gent composition were dissolved separately in one liter IL A detergent composition as set forth in claim 6 of distilled water and hydroxylamine hydrochlorideadd- 'wherein the i' nomsoap detergent is an organic ed thereto at the concentrations indicated below. The anionic nomsoap detergent tarnish grading of strips of German silver metal inserted A detergent composition as set forth in claim 5 m each of the solutlons also set form wherein the organic non-soap detergent is an organic cationic non-soap detergent. 13. A detergent composition as set forth in claim 6 mg wherein the organic non-soap detergent is an organic nonionic non-soap detergent. igciiiii i ilii iliiffilffif 332 14. A detergent composition as set forth in claim 11 Egg: lgfgggfigfififi 2:: wherein the organic anionic non-soap detergent is sodium Tetrapotassium Pyrophosphate 2n 0 dodecylbenzenesulfonate. fgg silicate g-g 15. A detergent composition as set forth in claim 12 wherein the organic cationic non-soap detergent is the 100-0 40 lauric ester of N-(beta-hydroxyethyl)-alpha-(chloropyridinium) acetamide. Permit mhiblwhphmphate b85181 16. A detergent composition as set forth in claim 13 wherein the organic nonionic non-soap detergent is a Example 44 45 46 47 compound having the empirical formula Percent hydroxylamlne hydrochl ide, total weight bases Tarnlsh grade prepared by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol where b is an integer selected from the group consisting of 26 to 30 and a plus c is an integer such that the molecule contains from 40%v to 50% of ethylene oxide.

17. A detergent composition consisting essentially of an alkali metal tripolyphosphate which in aqueous solution tarnishes copper and copper and nickel alloys, from about 0.2% to about 12% of a water-soluble inorganic hydroxylamine salt, and from about 9% to about 35% of an alkali metal metasilicate based on the weight of tripolyphosphate; the amounts of said hydroxylamine salt and metasilicate being sufiicient to inhibit such tar- Many modifications and variations may be made in the invention herein set forth without departing from 50 the spirit thereof, and only such limitations of the invention should be imposed as are indicated by the scope of the appended claims.

We claim:

1. A detergent composition consisting essentially of an alkali metal polyphosphate which in aqueous solution tarnishes copper and copper and nickel alloys, from about 0.2% to about 12% of a water-soluble inorganic hydroxylarnine salt, and from about 13% to about 35% of an alkali metal metasilicate based on the weight of polyphosphate; the amounts of said hydroxylamine salt and metasilicate being suflicient to inhibit such tarnishn mg. i n

2. A detergent composition as set forth in claim 1 Refmnces Cited m the file of thls patent wherein the alkali metal polyphosphate is pentasodium UNITED STATES PATENTS p yp p H 1,912,175 Blough May 30, 1933 3. A detergent composition as set forth in claim 1 2,522,44 Harris Sept, 12, 1950 wherein the alkali metal polyphosphate is tetrasodium 2,731,420 Sylvester Jan, 17, 1956 pyrophosphate.

4. A detergent composition as set forth in claim 1 OTHER REFERENCES wherein the water-soluble inorganic hydroxylamine salt Iler: Colloid Che-m. of Silica and Silicates, 1955, pp.

is hydroxylamine hydrochloride. 28-3 0.

Claims (1)

1. A DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF AN ALKALI METAL POLYPHOSPHATE WHICH IN AQUEOUS SOLUTION TARNISHES COPPER AND COPPER AND NICKEL ALLOYS, FROM ABOUT 0.2% TO ABOUT 12% OF A WATER-SOLUBLE INORGANIC HYDROXYLAMINE SALT, AND FROM ABOUT 13% TO ABOUT 35% OF AN ALKALI METAL METASILICATE BASED ON THE WEIGHT OF POLYPHOSPHATE, THE AMOUNTS OF SAID HYDROXYLAMINE SALT AND METASILICATE BEING SUFFICIENT TO INHIBIT SUCH TARNISHING.