COMPOSITIONS AND METHODS FOR REMOVING SOIL FROM SURFACES

Abstract

The present invention relates to a an aqueous composition for removing soils from a surface to be cleaned, formed from water, a detergent mixture and a rinse aid, wherein the detergent mixture comprises a peroxidation catalyst and wherein the rinse aid comprises an oxygen source. Such a composition may provide a more effective cleaning behaviour. The present invention further relates to a method for removing soil from a surface to be cleaned comprising applying to the surface to be cleaned a composition according to the invention.

Claims

1-14. (canceled)

15: A method for removing soil from a surface to be cleaned during a cleaning cycle comprising: performing a first washing step comprising bringing one or more soiled ware in contact with: (a) a detergent composition comprising about ≥20 wt. % to ≤80 wt. % of an alkalinity source, about ≥1 wt. % to ≤50 wt. % of one or more chelators, about ≥1 wt. % to ≤20 wt. % of a water conditioning agent, about ≥0.00001 wt. % to ≤1.0 wt. % of a peroxidation catalyst, and about ≥0.1 wt. % to ≤20 wt. % of a defoamer; and (b) a rinse aid composition comprising about ≥10 wt. % to ≤60 wt. % of an oxygen source, about ≥0.5 wt. % to ≤50 wt. % of a hydrotrope, about ≥0.5 wt. % to ≤50 wt. % of a surfactant, and about ≥0.5 wt. % to ≤50 wt. % of one or more additional chelators; and performing a first rinse step in which unused rinse aid composition is contacted with the one or more soiled ware; wherein the method is performed in a warewash machine.

16: The method of claim 15, wherein the method is performed in a commercial warewash machine.

17: The method of claim 15, wherein the rinse step is performed when the composition is in a cycle steady state.

18: The method of claim 15, wherein the first washing step is performed in a time range of about ≥20 seconds to ≤240 seconds.

19: The method of claim 15, wherein the rinse step is performed in a time range of about ≥5 seconds to ≤120 seconds.

20: The method of claim 15, wherein the peroxidation catalyst is MnTACN, MnDTNE, a bispidon type ligand, FeTamL, Mn(II)oxalate, 1,2:4,5-Di-O-isopropylidene-β-D-erythro-2,3-hexodiulo-2,6-pyranose, or a Mn bleaching catalyst.

21: The method of claim 15, wherein the oxygen source comprises a peroxygen compound, such as a peroxide and/or a percarboxylic acid.

22: The method of claim 21, wherein the peroxygen compound is a peroxide and/or a percarboxylic acid.

23: The method of claim 15, wherein the alkalinity source is an alkali metal hydroxide, a carbonate, a silicate, or a combination thereof.

24: The method of claim 23, wherein the alkalinity source is an alkali metal hydroxide.

25: The method of claim 15, wherein the alkalinity source is sodium hydroxide; the chelant is a phosphonate, sodium tripolyphosphate, methylglycinediacetic acid, or a combination thereof; the water conditioning agent is a polyacrylic acid; the defoamer is an ethylene oxide/propylene oxide block copolymer; the peroxidation catalyst is Mn(II) oxalate; the oxygen source is hydrogen peroxide; and the hydrotrope is sodium cumene sulfonate.

26: The method of claim 15, wherein the detergent composition is present during the first washing step at a concentration of ≥0.1 g/L to ≤10 g/L.

27: The method of claim 15, wherein the catalyst is present during the first washing step at a concentration of ≥0.000001 g/L to ≤0.1 g/L.

28: The method of claim 15, wherein the rinse aid composition is present during the first washing step at a concentration of 0.01 g/L to 10 g/L.

29: The method of claim 15, wherein the oxygen source is present during the first washing step at a concentration of ≥0.001 g/L to ≤6 g/L.

30: The method of claim 15, further comprising the step of contacting the oxygen source with the catalyst to degrade soil.

31: The method of claim 15, further comprising the step of adding the rinse aid composition directly to a sump or a rinse tank before the cleaning cycle.

32: The method of claim 31, further comprising the step of transferring the rinse aid composition from the rinse tank or the sump to a main wash tank during the first wash cycle or a subsequent wash cycle.

33: The method of claim 31, wherein a steady state concentration of the rinse aid composition is available in the sump after the first wash cycle.

34: The method of claim 15, wherein the soil is a starch.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0153] Additional details, features, characteristics and advantages of the object of the invention are disclosed in the subclaims, the FIGURE and the following description of the respective FIGURE and examples, which—in exemplary fashion—show several embodiments and examples of the invention.

[0154] In the drawing:

[0155] FIG. 1 is a diagram showing the improved cleaning behaviour of the inventive composition and method.

[0156] For performing test methods in order to prove the inventive effect, the following materials were used:

[0157] Detergent: 89.7 wt. % sodium hydroxide, 1.3 wt. % complexing agent, 9.0 wt. % polyacrylate; rinse aid (without oxygen source): 2.8 wt. % sodium cumene sulfonate, 10.2 wt. % non-ionic surfactant, 2 wt. % complexing agent, ad 100 wt. % DI-water; Hydrogen peroxide: 50 wt. % solution, Sigma Aldrich (lot #BCBD7137V); rinse aid (with hydrogen peroxide): 40 wt. % hydrogen peroxide, 1.7 wt. % sodium cumene sulfonate, 6.1 wt. % non-ionic surfactant, 1.2 wt. % complexing agent, ad 100 wt. % DI-water; catalyst: Dragon-PF6: Catexel (batch 2008/001), namely MnTACN=[Mn.sub.2 (μ-O).sub.3 L.sub.2] [PF.sub.6].sub.2 with L=TACN=Trimethyl-1,4,7-trizacyclononane.

[0158] To obtain the plates with starch soil, a starch solution is heated to boiling. After cooling down, the solution is dosed onto each plate and coated onto the plate using a brush. After this, the plates are dried in an oven.

[0159] Before the experiments, a fresh peroxide containing rinse aid was prepared being a 30 wt. % solution of the aforementioned rinse aid containing hydrogen peroxide. For the baseline experiments, a 30 wt.-% aqueous solution of the rinse aid composition without hydrogen peroxide was prepared. In addition, a fresh solution of the catalyst in DI-water with a catalyst concentration of 0.2 wt % was prepared and shaken to dissolve the catalyst completely.

[0160] The cleaning performance test was applied comprising three wash cycles (i.e. lx 3-pass of 1 starch plate), with a randomized test program shown in table 1. The experiments were conducted using a Meiko DV 80.2 hood type dish washer with a standard program of 60 sec. total time (45 sec. wash step, 9 sec. rinse step, 3.21 rinse volume) leading to short total cleaning times of only 2-3 minutes per plate that are good for professional ware washing processes.

[0161] In all cases, the detergent and, when applied, the rinse aid solution and the catalyst solution, were added manually to the wash tank, with the mass calculated from the desired concentration (0.001 g/L=1 ppm for the catalyst) and the volume of water added to the wash tank, as measured by the water meter. Thereby, the steady state mass of the respective rinse aid in the wash tank was calculated through the approximate relation m.sub.RA,st=c.sub.RA*V.sub.tank, with c.sub.RA=0.5 g/L being the concentration of rinse aid in the rinse step (V.sub.tank=221). After adding the respective components to the wash tank, the sump solution was stirred for 30 sec. with a long spatula to ensure dissolution of the additives.

[0162] When the rinse aid was included in the rinse step, the external rinse aid solution (concentration 30 wt. % of the respective rinse aid composition in water) was added to the rinse water stream with an external pump (Topmater R47; used at a setting that doses a concentration of 1.5 g/L of a chosen liquid into the rinse water stream) to give concentration of 0.5 g/L of the rinse aid in the rinse water. After each cycle, additional detergent and, if applied, catalyst solution, were added to the wash tank to compensate the dilution of the wash tank solution through the rinse volume. It may be noted that no additional rinse aid solution needs to be added as this has been introduced in the required level through the rinse step.

[0163] Table 1 shows test examples performed with a water hardness of approximately 11.8° dH. All experiments are steady state experiments.

TABLE-US-00001 TABLE 1 detergent conc. catalyst conc. run # [g/L] rinse aid [g/L] 0 1 none 0 1 1 without H.sub.2O.sub.2 0 2 1 without H.sub.2O.sub.2 0 3 1 with H.sub.2O.sub.2 0 4 1 with H.sub.2O.sub.2 0.001 5 1 with H.sub.2O.sub.2 0 6 1 with H.sub.2O.sub.2 0.001

[0164] The starch plates obtained after the different cleaning performance tests were rated semi-quantitatively according to the percentage of starch removal, with the results for the different experimental conditions shown in Table 2.

TABLE-US-00002 TABLE 2 steady state experiments water hardness~11.8° dH catalyst run # rinse aid conc. [g/L] rating % starch removal 0 none 0 1 0 1 without H.sub.2O.sub.2 0 1 0 2 without H.sub.2O.sub.2 0 1 0 3 with H.sub.2O.sub.2 0 2 5 5 with H.sub.2O.sub.2 0 1 0 4 with H.sub.2O.sub.2 0.001 4 40 6 with H.sub.2O.sub.2 0.001 4 40

[0165] It can be seen from the data in table 2 that there is no removal of starch in the baseline tests (run #0, 1 and 2 in table 2) done i) without any catalyst (detergent level of 1.0 g/L) and ii) without any rinse aid, or with peroxide-free rinse aid (dosage of 0.5 g/L in the rinse water). Similarly poor, although in one case slightly improved starch removal is observed when the detergent composition without any catalyst is applied in combination with the rinse aid that contains hydrogen peroxide.

[0166] The rating values of the other baseline experiments were obtained from results of experiments 0, 2 and 5 (see table 1). The results are summarized in FIG. 1 after semi quantitative rating of the starch results as a function of the applied treatment like will be described in detail down below. According to FIG. 1, runs 1 and 2 mean two respective runs under the same conditions.

[0167] When using the above described detergent at a level of 1.0 g/L without any catalyst, and the bare rinse aid, i.e. without hydrogen peroxide, at a dosage of 0.5 g/L in the rinse water it could be seen that hardly any starch was removed under these base conditions, since the original thick crusty layer of starch, visible as thick dark black layer on the plate, is still remaining on the plate. In fact, nothing of the original starch soil has been removed under these conditions. This was the same result as compared to a run with a conventional detergent only, like can be seen in the first and second bar arrangements.

[0168] Further, according to a second baseline experiment, again the detergent was applied at a level of 1.0 g/L without any catalyst, but now using a 40 wt.-% solution of hydrogen peroxide in rinse aid, used at a dosage of 0.5 g/L in the rinse water. After this treatment, most of the area of the plate that was initially covered by starch soil is still covered by the original thick and crusty layer of starch. Still, in this case thin blue-grey stripes can be observed that interrupt the thick dark black starch layers. These blue-grey stripes indicate a more complete starch removal in these regions, i.e. locally better cleaning result compared to the larger are of almost no removal. This is visualized in the third bar arrangement in FIG. 1.

[0169] According to a further experiment, the results obtained when the detergent is used at a level of 1.0 g/L with the catalyst Dragon-PF6 being dosed at a level of 0.001 g/L into the wash tank, again in combination with a 40 wt. % solution of hydrogen peroxide in as rinse aid, used at a dosage of 0.5 g/L in the rinse water. As it could clearly be seen only minor areas of the plates are covered with the original thick and crusty layer of starch after this treatment. Instead, the larger part of the area that was initially covered by starch soil is covered with the blue-grey thin starch layer after this treatment, indicating the removal of the thick starch layers in these regions. This is shown in the fourth bar arrangement of FIG. 1.

[0170] Therefore, the removal of starch is dramatically improved even at short washing times when the detergent composition with the catalyst MnTACN is used (detergent level of 1.0 g/L, catalyst being dosed separately into the wash tank at a level of 0.001 g/L) in combination with the rinse aid containing hydrogen peroxide (rinse aid dosage of 0.5 g/L in the rinse water). Here, 40% of the starch is removed, compared to no starch removal in all the baseline experiments. All these findings are summarized in FIG. 1. The error bars correspond to an experimental error of ±1 that was assumed as an estimate for the experimental uncertainty of this method using a rating scale with integer-resolution. Thus, the data presented in FIG. 1 nicely shows the significant improvement of starch removal by using the combination of the MnTACN catalyst in the detergent and a rinse aid that contains hydrogen peroxide.

[0171] To summarize, in the presented experiments it was observed that the removal of starch baked on plates is dramatically improved when the commercially available catalyst MnTACN (=[Mn.sub.2 (μ-O)3 L2] [PF6]2 with L=TACN=Trimethyl-1,4,7-trizacyclononane) was used in combination with hydrogen peroxide in the rinse aid, compared to the respective baseline experiments without any catalyst or the peroxide-catalyst-combination. Thereby, a peroxide-containing rinse aid was added to the sump in the so-called steady state concentration, i.e. with a concentration of a peroxide-containing rinse aid in the wash tank of the dish washer that is established after multiple (typically ca. 50) cleaning cycles. Thereby it turned out that this steady state concentration of a peroxide-containing rinse aid in the sump is sufficient to lead to the catalyst-supported removal of starch from plates. In addition, this effect was observed in short cleaning times of only 2-3 minutes per plate that are typical for professional ware washing processes. The experiments were performed using city water (water hardness ˜12° dH).

[0172] Cleaning performance experiments using the combination of the MnTACN catalyst in the detergent and a rinse aid that contains hydrogen peroxide have shown the process of improving the cleaning performance through a catalyst in a detergent in combination with an oxygen source within the rinse aid can be successfully applied compared to a solution without catalyst. This is proven by the observation that this mentioned combination dramatically improves the removal of starch from plates, compared to the baseline experiments run without the catalyst. Importantly, from the way the experiments were performed it can be excluded that the improved results in starch removal are just related to a bleaching of the back dye by the peroxide.