Patented Jan. 29, 1952 2,584,017 UNITED STATES PATENT OFFICE ' WASHING COMPOSITION Vladimir Oworkovitz and Thomas G. Hawley, Jr., Chicago, Ill., assignors to The Diversey Cor poration, a corporation of Illinois No Drawing. Application September 30, 1947, Serial No. 777,112 3 Claims. (C. 252-156) 2 This invention relates to a composition that glassware and on parts of the equipment used in is particularly applicable for washing bottles and washing the glassWare that comes in contact other forms of glassware and to the washing with the washing and rinsing Solutions. We have solutions prepared from Such compositions. found that a composition comprising a water The industries that Wash large quantities of s Soluble alkali metal hydroxide Such as Sodium bottles and other glassware, such as the dairy, hydroxide or potassium hydroxide and an alkali brewery, and soft drink bottlers, have found it metal salt of a hydroxy carboxylic acid having expedient to adopt a continuous process wherein a total of at least three of the radicals: hydroxyl the bottles are conveyed first through a tank Ol' and carboxyl, will prevent Or at least minimize tanks containing a strongly alkaline solution and () the formation of an adherent hard water scale. then through a rinsing Solution. The glassware The hydroxides of sodium and potassium are is maintained in the alkaline solution until it preferred because of their inexpensiveness and has become cleaned. It has been found that availability, but the hydroxides of other elements when the glassware and those parts of the equip of the alkali metal group may be used if desired. ment adjacent the glassware pass through the One of the salts which has been found to be alkaline solutions, they are coated with a film particularly effective is sodium gluconate. The of alkali. When the alkali-coated objects are alkali metal Salts include those of gluconic acid, immersed in the rinse water, an immediate. citric acid, tartaric acid, mucic acid, and malic precipitation occurs of the dissolved calcium and acid as well as many others. The acids them magnesium Salts that are present in the rinse Selves may also be used. water. The precipitated Solids form a hard scale The fact that these salts will not form precipi On the glassware and particularly on the equip tates in the presence of sodium hydroxide is sur ment. Because of the intimate contact of the prising as it has been noted that precipitates will film of alkali with the glassware and equipment, form when such alkalis as sodium carbonate, the precipitate appears to be more adherent and a) Sodium Orthophosphate, sodium silicate and the accounts for the Scale type of deposition rather like are employed with the salts in the absence than the more desirable sludge or non-adherent of Sodium hydroxide and the like. These alkaline precipitate. This scale continues to build up materials may be used, however, if they are used on the equipment until it is necessary that the in combination with sodium hydroxide. Scale be removed. This removal involves a con 30 It has been found that even if some scale is siderable economic loss in time, labor and ma formed on the equipment or is mechanically terials employed in the scale removal. picked up by passage through a sludge, it is re The problem of the Scale formation has re dissolved when it is repassed through the caustic ceived considerable recognition and much effort soda-salt solution. has been Spent to overcome it. For example, 35 The solution is quite stable and can be main many complex alkali metal salts of phosphoric tained at 150 F. for two weeks or more without acid have the property of holding calcium and any apparent decomposition or precipitation. magnesium compounds in solution that are nor The compositions that are employed in making mally insoluble. Certain amino carboxylic acid the Washing Solutions preferably contain from derivatives have also been used for this purpose. 40 5 to 99% by weight of an alkaline material in It has been found, however, that none of these cluding an alkali metal hydroxide and from 95 compounds work effectively in the presence of to 1% of the alkali metal salt of the hydroxy car sodium hydroxide. Thus, a sufficient quantity boxylic acid. The major proportion of the al of Sodium hexametaphosphate will hold the hard kaline material should be the hydroxide. An water precipitates usually obtained by adding 45 alkali stable wetting agent may also be used in Sodium carbonate or sodium orthophosphate to preparing the solutions. a hard water Solution. However, long standing In testing the value of the invention, solutions of the product or standing at less time at elevated Were prepared employing a Chicago city water temperatures causes hydrolysis of the resulting that had an approximate hardness of 150 complex and causes precipitation of the calcium 50 and magnesium compounds. This effect is even P. P. M., 3% by weight of sodium hydroxide and more pronounced if even small quantities of 0.2% of various sequestering or repressing agents. caustic alkalis are present. The Solutions were formed and their appearance The present invention is concerned with means was noted. They were all heated until the water for preventing the formation of this scale on is boilednoted. andSome any ofdifference the materials in appearance prevented was prealso 2,584,017 3 4. cipitation at room temperatures and at moder soda-salt solutions as cleansing agents avoids this ately elevated temperatures, but most were such softening and dissolving. Tests were made to that on raising the temperature precipitation prove this fact. Warious solutions were prepared Occurred. In Some cases this was due to the de using 5% concentrations of sodium hydroxide. *omposition of the agent employed and in other The materials used and the results obtained are cases was probably caused by the inability to shown in the following table. In obtaining these maintain the precipitate in solution at the higher results, the glass was held in contact with each temperatures. Solution for 72 hours at 145 F. Some of the results that were obtained are as TABLE follows: O ABE weightPer s: of clearS. in weightPer S;E. of green i Composition milk bottle soft drink 3% NaOH solution in Chicago tap water glass bottle glass Appearance Appearance Sequestering or Repressing Agent at 25°C. at 100° C. % NaOH Per cent : Pef cent 906. Sodium8.------gluconate- } .037 .034 .2% Sodiurn gluconate clear. E. N.3, ------... 102 92 .2% Glucose.------ppt. 95.056% sodium801------Aluminate. I} .077 7 .2% SodiumSorbitol------hexanetaphosphate ppt. 96.0% NaOH------267 3 .2% Tripolyphosphate.------ppt. 2) 4.0% Na2HPO--- - r .2% Sodium tetraphosphate.-- ppt. 94.5% NaOH------.2% Tetrasodium pyrophosphate ppt. 5.0% Sodium glucona 054 . (52 .2% Nullapon A------ppt. .5% Nullapon B----- .2% Nullapon B------ppt. 93.0% NaOH------.2%. Alrose Water softener Alro- ppt. 4.0% Trisodiurn phosphate. - - 17|------3% Saccharic acid ppt. 2.0% Sodium aluminate------2 5 .2% AceticCitric acid. acid... ppppt. slight... ppt. .2% Tartaric acid- clear------ppt. .2% Itaconic acid- ppt------ppt. .2% Ascorbic acid ppt.--- -- ppt. of sodium-hydroxide-salt combination is that the .2% Pinelic------ppt.--- - ppt. solution serves as a better inhibitor of rust and .2% Lactobionic acid - ppt.--- - ppt. corrosion of steel and iron than Sodium hy .2% Glutamic acid------ppt.------ppt. 30 droxide solutions alone. Still another advan .2%2%. SuccinicMucic acid------acid------clear------ppt. Ppt.slight ppt. .2% Sodium carboxy methyl cellulose ----- do------Do. tage is that the solutions are relatively non (med. visc.) foaming. .2% Malic acid------do------ppt. The following table lists, on a dry basis, some of the many possible combinations that have been If the 3% caustic soda solution were added to used successfully in cleaning operations and hard water containing as high as 3% of a com which because of the incorporation of a caustic plex phOSphate Such as Sodium hexametaphos soda-sodium gluconate combination do not give phate, a precipitate would form. It has been precipitation or reduce precipitation to a marked found that the effect of the Salt of the hydroxy degree in hard Water Solutions. carboxylic acid is in the main independent of 40 TABLE III the concentration of the caustic soda. Thus, Solutions of caustic soda as high as 30% can be used when Only 0.2% of the salt is used. How Components Components by Wgt. ever, very minute quantities of caustic soda can Caustic soda------90 80 89.5. 85 81.5 9 allow the formation of a precipitate, and it has 45 Sodium gluconate.---- 10 20 10.0 5 7.5 5 Trisodium phosphate------.0 2 thus been found that the Solution must have a Sodium carbonate------10 10.0 - pH higher than 12 for effective results. Zinc oxide. ------. 2 The results shown in Table I show the differ Sodium salt of higher alkylsulfates.------.5 ------ence between precipitation and the prevention of precipitation. The table does not, however, in 50 The Wetting agent that may be used includes dicate where the amount of precipitate is re any alkali stable wetting agent such as alkali duced. It was discovered that some of the hy Salts of higher alkyl Sulfates, Sodium dodecyl droxy carboxylic acids and their salts might per benzene Sulfonate, alkyl naphthalene sodium sul mit the formation of a considerable amount of fonates, Sodium salts of sulfonated ethers, as well precipitate, but the amount of Scale deposited 55 as many others. on the glassware or equipment was reduced. This Although it has been found that the combina effect in preventing scale as apart from pre tion of sodium hydroxide and an alkali metal venting precipitation might be due to some effect salt of a hydroxy carboxylic acid containing at which delays the precipitation and prevents its least three of the radicals: hydroxyl and carboxyl, deposition. On the glassWare and equipment. All serve to prevent a marked formation of a hard the hydroxy carboxylic acids and their salts ap - water scale, it has also been found that this com pear to have at least this latter effect. bination has been further improved by the pro The caustic soda-salt combination also serves vision of an alkali metal Salt of an amino car to prevent Softening and Subsequent Scratching boxylic acid derivative having the general formula of the glassware. It has been found that the ad CICO OE dition of Such agents as triSOdium phOSphate, Sodium carbonate, or the like, to sodium hy R-NY droxide solutions assist in the cleaning of glass Yoh, cooh ware. However, these agents have a marked ef where R is a member of the class consisting of fect in that they serve as catalysts for the Sodium 70 -C-COOH hydroxide and cause it to soften and partially M dissolve the glass. Hence, the glass is more . -C-COOE HC Yoh, easily marked by the machinery or by abrasion against other pieces of glass and SOOn receives an unsightly appearance. The use of the caustic 75 2,584,017 8 to the hard water and then 5% of caustic soda CBCOOH CHCOOH and 5% of sodium carbonate added, a clear solu -CH-N/ tion results that stays clear even when heated YoH, cooh Yctic OO to boiling and then permitted to stand overnight. Similarly, the sodium carbonate may be sub where R1 and R2 are members of the class con stituted by trisodium phosphate and the resulting sisting of hydrogen and aliphatic and aromatic Solution remains clear even when brought to the groups. The groups may contain substituents so boiling point and permitted to stand overnight. long as the resulting compounds are still water The use of sodium gluconate only does not per soluble. O mit such high concentration of sodium carbonate The combination of the above amino carboxylic or trisodium phosphate without the formation of acid derivatives together with, for example, So a precipitate. dium gluconate are effective agents for repress . Acids such as acetic acid or polyalcohols such ing precipitates that would normally be formed as glycerine or sorbitol do not have this effect if mixtures of caustic soda with other alkalis 5 with the amino polycarboxylic acid salt, but hy such as soda ash or the alkali metal Salts of droxy acids, for example, citric acid, maleic phospohric acid were added to hard water. It acid, tartaric acid, and mucic acid to prevent or has also been found that other combinations of reduce the formation of precipitates when used alkali metal salts of amino carboxylic acids and in combination with the above-mentioned amino hydroxy carboxylic acids are effective in pre 20 carboxylic acid derivatives. Thus, if 0.05% of the venting or diminishing the formation of pre amino derivative and 0.25% of mucic acid are cipitates when alkalis containing free caustic added to Chicago tap water and 4.5% of caustic alkalis are added to hard water. Thus, the com Soda and 0.5% of trisodium phosphate are added, pounds obtained from the phenylene diamines by a clear solution results in the cold, but on warm reaction with chloroacetic acid are effective in 5 ing a light gelatinous precipitate begins to sepa combination with, for example, sodium gluconate rate at about 190° F. If the mucic acid is sub in preventing the precipitation of calcium and stituted by tartaric acid, the same results are magnesium salts from hard water. obtained. If 0.5% of an alkali metal Salt of an amino Furthermore, if 0.25% of sodium gluconate and polycarboxylic acid derivative is added to hard 30 0.2% of the alkali metal salt of the amino car water of 150 P. P. M. hardness and then 5% boxylic acid derived from the reaction of para of caustic soda added, an immediate gelatinous phenylene diamine with chloroacetic acid are precipitate is formed which does not go into added to Chicago tap water and then a mixture solution on raising the temperature above Ordi of 2.5% caustic soda and 2.5% soda ash are added, nary room temperature. If instead of using the the resulting solution is free from precipitates caustic soda, 5% of soda ash or 5% of trisodium . and can be brought to the boiling point and still phosphate is added, either no precipitate is remain clear. formed or a light gelatinous precipitate is formed Various other tests were performed to show that dissolves on Warming the Solution. If a the effectiveness of the present invention in elimi mixture of caustic Soda with either soda ash 4) nating or reducing the precipitates formed when or trisodium phosphate is added to the water using Caustic soda in hard water. These tests containing the alkali metal salt of an amino and their results are summarized in the follow polycarboxylic acid derivative, a precipitate is ing table: TABLE IV Hydroxy Acid or Salt Alkali Combina- thereof (or other Anino carboxylic CS: of tion 8 ) in cases Acid derivative 6F Were . . .5% NaOH------Glycerin ------0: E. E. precipitate. 0 diacetate. 2. 5% NaOH.------Sorbitol ------.05% sodium ethylene Do. 3. 4.5% NaOH bis imino diacetate,

4. 4.5%NOf....Ems, .Tartario acid. "Eftagew 's Qsphate.Esm er -r- or - r ------{: ity precipitate. 5. 4.5% NaOH...--- 3, 08Esm .5% Tartaric acid------Do. 6. issismRf. 25% Gluconic acid.---"Si."f.05% sodium eth ylene clear. 7. 4.5% NaOH---- .05%RASS NN, N'N' tetra Precipprecipitate. .5% Trisodium ------boxylic acid deriv. phosphate. of phenylene di 8e. 8. 4.5%5%iodium NaOH----- } % sodium gluconate. .05%o NN,p N'N'"a tetra clear. phosphate. filia. A 9. 4.5% NaOH---- .5%Shosphati, Trisodium .5% sodiumW. gluconate------precipitate. formed regardless of the relative concentration 70 When 5gm. of the sodium salt of trimethyl so long as at least 5% of the total alkali is caustic amino a, a', a', tricarboxylic acid is added to alkali. 100 grams of Chicago tap water and then 5 As an example of the effectiveness of sodium grams of NaOH be added, a light gelatinous pre gluconate or the like, if 0.5% of the amino.com cipitate results. If instead of adding 5 gms. of pound and 0.5% of sodium gluconate are added 75 NaOH, 5 gms. of soda ash had been added the 2,584,017 7 8 resultant solution would have been clear, Now, that such pH is obtained in the presence of suff if to this clear carbonate solution 5 grins. Of NaOH cient water to give a pH reading. is added a precipitate results. Now, however, if Having described our invention as related to .5 gm. of the sodium salt of trimethyl amino a, the embodiment described herein, it is our inten a", a', tricarboxylic acid together with .5 gm. tion that the invention be not limited by any of of sodium gluconate and then 5 gms. of NaOH the details of description unless otherwise speci and 5 gms. of Na2CO3 are added, a clear Solu fied, but rather be construed broadly within its tion results. This shows the effect therefore of Spirit and Scope as set out in the accompanying the use of a combination of hydroxy acid and claims. s amino carboxylic acid derivative in preventing () We cairn: precipitation. i. A composition consisting essentially of a As examples of the invention, an identical ex Enixture of 1 to 20% sodium gluconate and 99 to periment was repeated, using different Solutions 80% alkaline material, with some of the alkaline whereby a continuous steel chain of known weight material being Sodium carbonate in an amount was passed through a caustic solution and then up to about 10% thereof and the remainder being through a rinse water of 1000 P. P. M. hard Sodium hydroxide. ness and back through the caustic solution. This 2. A composition adapted for making a wash was repeated continuously for a period of eight ing solution with water for washing glassware, hours when the chain Was removed from the sys comprising about 90 to 99 parts by weight of a tem, dried, and weighed and its appearance noted. caustic alkali, and sufficient gluconate of the The scale, when present, was visible and the exact class consisting of sodium gluconate and potas weights of Scale were obtained. Both the caustic Sium gluconate to prevent the formation of a and the rinse solutions were raintained at 150 hard adherent Scale from the hardness constitu F, the results were as follows: ents of the water and to inhibit the attack by TABLE W Weight of scale in 5% alcali solutions comprising: Appearance of Chain grams

Caustic Soda------100% Heavy white Scale------.2586 Caustic Soda------... 172 Sodium carbonate }Heavy white scale------Caustic Soda--- % . 54.09 Disodiurn phospha 4% }Heavy white scale------Caustic Soda------.90% Sodium Hexametaphosphate }Heavy white scale------115 Caustic Soda.---- -90% Heavy White Scale.------.59 Sorbitol------. -10% if Caustic Soda---- 1.0039 Sodium gluconate.-- }Bright like new.------Caustic Soda.--- Sodium gluconat Bright, very slight scale.--- .046 }Bright, very slight scale---. .0458 sityCaustic Symethylcellulose:g;Soda------E.}Bright, very slight scale----- ,0262 Tartarie acid------.10% }Bright, very slight scale.---- ... lol 373 3-6Eyleneasonic D Glucosaccharolactone.------acid.: 10% }Slightser Scale------1336

Slight increase. The Nullapon B is ethylene bis imino diacetic the alkali on glassware, the gluconate being pres acid, Or a Salt thereof; specifically, it is Sodium 50 ent in an amount up to about 10 parts by weight. ethylene bis innino diacetate. 3. A composition adapted for making a wash The hydroxy carboxylic acids are known to give ing solution with water for washing glassware, lactones when subjected to an intermolecular de comprising about 90 parts by Weight of Sodium hydration process. This dehydration is shown hydroxide and about 10 parts by weight of so in the following equation: 55 dium gluconate. VLADIMIR, DVORKOVITZ. ---, -, -b-c-d THOMAS G. HAWLEY, JR. ÖH. cooh o c=o Hydroxy acid Lactone 60 REFERENCEs CITED In an aqueous solution of the alkali, the lactone The following references are of record in the can hydrolyze to give the alkali Salt of the hy file of this patent: droxy carboxylic acid. Thus, it is possible to use UNITED STATES PATENTS lactones in place of the acids or the salts and the o 5 description and the claims herein are intended Number . Name Date to include the use of such lactOnes tha are hydro 729,600 Jones ------June 2, 1903 lyzed in solution to the salt of a hydroxy car 2,145,827 Chester ------Jan. 31, 1939 boxylic acid. 2,291,085 Lehmkuhl et al.---- July 28, 1942 In preparing the compositions the hydroxy to 2,346,562 De Long ------Apr. 11, 1944 carboxylic acid and/or the amino carboxylic acid 2,419,805 - Wegst et al. ------Apr. 29, 1947 may be used instead of the Salts thereof as the FOREIGN PATENTS acids are converted into the Salts when in solu tion with the alkaline compounds. Number w Country Date When in the specification and claims it is stated 885,521 France ------May 31, 1943 that a pH of at least 12 is obtained, this means '