Additive composition for automatic dishwashing

Abstract

The invention is related to n aqueous additive composition for automatic dishwashing machine comprising (a) from 0.5 to 25 percent by weight of a sophorolipid biosurfactant or salts thereof, (b) from 0.01 to 5 percent by weight of an acid, and (c) from 75 to 98 percent by weight of water; wherein the composition is substantially free of any non-ionic surfactant, any hydrotrope, any bleach material, any amino acids, and / or any enzyme.

Description

[0001] Additive composition for automatic dishwashing

[0002] FIELD OF INVENTION

[0003] The present invention relates to automatic dishwashing additive aqueous compositions.

[0004] BACKGROUND

[0005] Prior art contains many teachings directed to detergents and rinse aids that are environmentally friendlier while providing greater degree of cleaning. Although the prior art describes certain ingredients such as zinc, hydrotropes, and / or bismuth suitable to provide marginal protection against glassware corrosion, plastic discoloration and / or decor fade protection, there is still room to improve the dishwashing compositions. Recently there is a renewed interest in the use of sophorolipids for personal care industries.

[0006] Sophorolipids (SL) are new category of surfactants typically made up of a disaccharide (sophorose; 2-O-|3-D-glucopyranosyl-|3-D glucopyranose) attached to a hydroxy fatty acid through a glycosidic linkage. The specific location of those chemical bonds is dependent on the microbial strain used to produce the SLs. The most well-known SLs are naturally synthesized in high yields by the yeast Candida bombicola (Ashby, R. D., et al., Biotechnol. Lett., 30: 1093-1100 (2008)), and the glycosidic bond generally occurs between the 1' hydroxy group of the sophorose sugar and the OJ or OJ-1 carbon of the fatty acid. To a limited extent, structural variations; and hence control over physical properties, can be achieved by changing the hydrophobic carbon source which alters the sophorolipid fatty acid content.The sophorose acts as the hydrophilic head while the long chain hydroxyl fatty acid acts as the hydrophobic tail.

[0007] Sophorolipids are readily biodegradable, less toxic and have low toxicity profile as compared to other conventional non-ionic surfactants such as Triton-XlOO, pluronic L31 and polyoxyethylene lauryl ether. Moreover, their unique antimicrobial properties lends them as a suitable option to conventional surfactants.

[0008] The acidic form of SLs has been shown to be useful as moisturizing agents (Abe, Y., et al., U.S. Pat. No. 4,297,340; Tsutsumi, H. et al., U.S. Pat. No. 4,305,961). These characteristics have aided in the progress of the industrial utilization of SLs such that they are currently being successfully developed and used in dishwashing detergents by Saraya Co., Ltd. under the trade name Sophoron™, and by Ecover and Soliance for applications in laundry and dishwashing detergents, industrial and institutional cleaners, hand soaps, and cosmeceuticals.

[0009] Even though sophorolipids has been described in some cosmetic and pharmaceutical products, its use has not been fully examined in automatic dishwashing compositions and in particular not in additive compositions such as rinse aids. There is a demand for development of sustainable, environmentally friendly cleaning and dishwashing composition and replacing the conventional surfactants with sophorolipids. The present invention addresses such demand in providing dishwashing compositions that can improve glassware corrosion, decor against fade, and glass discoloration while using a sustainable and environmentally friendly compositions.

[0010] SUMMARY OF THE INVENTION

[0011] It is at least one objective of the present invention to generally provide a sustainable, environmentally friendly, and biodegradable automatic dishwashing (ADW) composition having a good washing power across a wide temperature range.

[0012] The present invention is related to an aqueous additive composition for automatic dishwashing machine comprising:

[0013] (a) from 0.5 to 25 percent by weight of a sophorolipid biosurfactant or salts thereof,

[0014] (b) from 0.01 to 5 percent by weight of an acid, and

[0015] (c) from 75 to 98 percent by weight of water; wherein the composition is substantially free of any non-ionic surfactant, any hydrotrope, any bleach material, any amino acids, and / or any enzyme.

[0016] In one embodiment, the sophorolipid biosurfactant is a mixture of ester- and acidic- form sophorolipid having a lactone component ranging between 30% to 90%, preferably 35% to 65%.

[0017] In one embodiment, the composition further comprises a Zn source, in particular a Zinc salt, which is selected from the group consisting of Zinc acetate, Zinc acetated dihydrate, Zinc gluconate, Zinc lactate, Zinc citrate, Zinc formate, Zinc butyrate, Zinc benzoate, and Zinc chloride; wherein preferably Zn acetate is preferred.

[0018] In one embodiment, the acid is an organic acid or any salts thereof having a pKa ranging between -2 to +7.

[0019] In a preferred embodiment thereof, the organic acid is selected from the group consisting of citric acid, lactic acid, sulfamic acid, methanesulfoic acid, acetic acid, sodium bisulfate, or any salts thereof.

[0020] In one embodiment, the composition further comprises a polycarboxylic acid or a salt thereof selected from the group consisting of trisodium dicarboxymethyl alaninate (MGDA), tetrasodium glutamate diacetate (GLDA) and trisodium citrate, preferably trisodium citrate.

[0021] In one embodiment, the composition further comprises a dye, a fragrance, and / or a preservative.

[0022] In a preferred embodiment thereof, the preservative is sodium benzoate.

[0023] In one embodiment, the composition comprises a. from about 5 to 10 percent by weight of a of a sophorolipid biosurfactant or salts thereof, b. from 0.05 to about 2 percent of citric acid, c. from 85 to about 95 percent by weight of water; wherein the composition is substantially free of any non-ionic surfactant, any hydrotrope, any bleach material, any amino acids, and / or any enzyme; and wherein the composition has a pH ranging between 3.0 to 4.9.

[0024] In one embodiment, the composition comprises

[0025] (a) from 5 to 10 percent by weight of a sophorolipid biosurfactant or salts thereof,

[0026] (b) from 0.5 to 3 percent of citric acid,

[0027] (c) from 0.2 to 0.5 percent a zinc salt,

[0028] (d) from 80 to 95 percent by weight of water; wherein the composition is substantially free of any non-ionic surfactant, any hydrotrope, any bleach material, any amino acids, and / or any enzyme; and wherein said composition is a rinse aid composition for use in an automatic dishwashing machine to provide protection of glassware.

[0029] The present invention is further related to a method of cleaning kitchenware and / or tableware in an automatic dishwasher comprising adding such an inventive composition in a rinsing step.

[0030] DETAILED DESCRIPTION OF THE INVENTION

[0031] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs and shall be understood to have the meanings described below. All publications and patents referred to herein are incorporated by reference in their entirety. Unless otherwise specified, a reference to a particular compound includes all ionic, salt, solvate (e.g., hydrate), protected forms, and other stereoisomers thereof, isomeric forms, including racemic and other mixtures thereof.

[0032] As used herein, any reference to the word "about" will mean up to plus or minus 2.5% of the particular term.

[0033] As used herein, the term "additive" or "additive composition" in the context of the present invention is referring to compositions other than common detergent containing compositions that are used during the main wash cycles of an automatic dishwashing machine which typically includes a combination of surfactants, enzymes, builders, bleaching agents, and other ancillary material which may be used in the production of such detergent compositions.

[0034] The additive compositions of the present invention are substantially or completely free of any enzymes and any amino acids intended to be introduced into the automatic dishwashing machine to enhance the dishwashing experience as compared to a typical dishwashing detergent.

[0035] The term "rinse aid" as used herein is a subset of additive compositions that contains a surfactant lowers the surface tension of water, so it more easily slides off dishes in the dishwasher. As used herein, and for the sake of clarity, the term "and / or" may mean "and," it may mean "or," it may mean it may mean "some, but not all," it may mean "both." The term "or" is intended to mean an inclusive or.

[0036] As used herein, "consisting essentially of" refers to excluding other active ingredients but including the recited optional excipients, up to 2.5% of the total weight of the composition.

[0037] By the term "substantially free" it is meant that the final composition is free of any traces of the identified ingredient to the extent that it could be detected by general quantitative assays known in the art for detection of such ingredient in the final composition or if detected, but less than 1% of the total weight of the respective composition only in the form of residual content of the ingredient or the composition containing such ingredient. For example, the phrase substantially free of any surfactant would mean that the respective composition contains less than 1% of any surfactant material. The term phrase "completely free" refers to the absence of any amounts of the identified ingredient to the extent that it could be detected by general quantitative assays known in the art for detection of such ingredient in the final composition.

[0038] In some embodiments, the compositions according to the present invention may include a non-ionic surfactant such as fatty alcohol ethoxylate, alkyl phenol ethoxylate and fatty acid alkoxylate.

[0039] The following Examples illustrate the invention and facilitate its understanding.

[0040] Example 1: Comparative and test (=inventive) formulations were prepared according to the ingredients listed in Table 1.

[0041] Table 1: Overview of Comparative and inventive Rinse Aid Formulations.

[0042] 5 a. PLURAFAC® LF 300- C12-15, 6 E0, 2 -4 P0 (Oxirane, methyl-, polymer with oxirane, monoisotridecyl ether, block CAS #

[0043] 196823-11-7) (BTC Chemical Distri bution)- b. Lutensol® T06- Cj3, 6 E0 - Isotridecanol, CAS # 69011-36-5, (BASF) c. Rewoferm® SL one - Sophorolipid with 40% lactone content (Evonik)

[0044] EXAMPLE 2: Screening of the inventive compositions

[0045] In the initial experiment, a standard benchmark detergent without any rinse aid used in the wash cycle was compared to the use of the same benchmark detergent and a comparative rinse aid composition (Comparative formulation 2); and to the use of the same benchmark detergent and an inventive rinse aid composition (Test formula 1) containing the actives listed in Table 1 above with the goal of understanding whether dosing the formula meets the acceptable shine standards.

[0046] The technical testing was performed in the Bosch SMS46MW03E / 41, using 65° C / 65° C Standard EU Program. The water hardness was 21° GH, meaning that very hard water was used representing the worst-case conditions. The formula according to the present invention was dosed in the wash, approximately after 3 cycles or after 10 cycles. The Table 2 below provides an outline of the testing evaluation:

[0047] Table 2

[0048] The degree of spotting and filming was evaluated visually using a scale of 1-5, where the score was given in accordance with the Table (3) below:

[0049] TABLE 3

[0050] Following the testing parameters and evaluation criteria, the results are provided in Table

[0051] 4 below: By comparing the results, it was realized that the inventive Test formula (1) provided superior benefits in decreasing the glass spotting filming and cutlery spotting and filming as shown by the measurements of scale after evaluating such effects after 3 cycles of wash. While, the performance of the inventive Test formula (1) was far better after 10 cycles of wash as compared to the benchmark while substantially similar when evaluated against the benchmark plus comparative 2 formula. In general, one can conclude that the shine performance overall is better when using the inventive Test formula (1) in addition to a benchmark detergent versus the benchmark detergent alone.

[0052] EXAMPLE 3: Further screening of the inventive compositions

[0053] In said additional experiment, the same standard benchmark detergent without any rinse aid as in Example 2 was used in the wash cycle. It was compared to the use of the same benchmark detergent and another comparative rinse aid composition (Comparative formulation 1); and to the use of the same benchmark detergent and another inventive rinse aid composition (Test formula 2) containing the actives listed in Table 1 above with the goal of understanding whether dosing the formula meets the acceptable shine standards.

[0054] The technical testing was performed in accordance to the same methodology as in Example 2. The degree of shine was evaluated visually using a scale of 1-5 of Table 3, where the score was given in accordance with the Table (4) below.

[0055] Surprisingly, the initial results from both Examples 2 and 3 indicated a parity performance of the biosurfactant based rinse aid compared to the comparative rinse aid (comparative 1). Even more striking, the newly crafted formulation Test Formula (2) is free from the conventional hydrotrope, standard fatty alcohol alkoxylate surfactants. The Rewoferm SL ONE sophorolipid was employed only as a 50% aqueous solution.

[0056] The tests described above in Tables 4 demonstrated that the sophorolipid containing compositions were already modeled even closer to the benchmark rinse aid formulations and included the additional ingredients. Notably, care must be taken to prevent the formation of precipitates or emergence of turbidity as was found for inventive Formulation (2), a challenge that may be overcome by switching the preservative. Further, Table 4 shows a superior Shine performance by the Inventive Test Formula 2.

[0057] Those of ordinary skill in the art can appreciate that across the Shine performance tests of Tables 1, 2, 3, and 4, it is apparent that the biosurfactant-based formulations seem to provide a demonstrable improvement on Filming both on Glass and Cutlery items. Furthermore, a rinse aid formulation not relying on the conventional combinations of rinse surfactant and aryl sulfonate hydrotrope may deliver a superior performance compared to current products. EXAMPLE 4: Further screening of the inventive compositions

[0058] Similar processes were used as above in Examples 2 and 3 to test the additive inventive composition test formula (3). Those of ordinary skill in the art can easily appreciate that it was demonstrated that a rinse aid formulation not relying on the conventional combinations of rinse surfactant and aryl sulfonate hydrotrope is able to deliver a superior performance compared to current, commercial products. White biosurfactants are currently are more expensive than their oil-derived counterparts, it is expected that their costs will decrease considerably in the coming years due to.

[0059] Although illustrative embodiments of the present invention have been described herein, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention.

Claims

CLAIMS1. An aqueous additive composition for automatic dishwashing machine comprising(a) from 0.5 to 25 percent by weight of a sophorolipid biosurfactant or salts thereof,(b) from 0.01 to 5 percent by weight of an acid, and(c) from 75 to 98 percent by weight of water; wherein the composition is substantially free of any non-ionic surfactant, any hydrotrope, any bleach material, any amino acids, and / or any enzyme.

2. The composition of claim 1, wherein the sophorolipid biosurfactant is a mixture of ester- and acidic-form sophorolipid having a lactone component ranging between 30% to 90%, preferably 35% to 65%.

3. The composition of claim 1 or claim 2, wherein the composition further comprises a Zn source, in particular a Zinc salt, which is selected from the group consisting of Zinc acetate, Zinc acetated dihydrate, Zinc gluconate, Zinc lactate, Zinc citrate,Zinc formate, Zinc butyrate, Zinc benzoate, and Zinc chloride; wherein preferably Zn acetate is preferred.

4. The composition according to anyone of the prior claims, wherein the acid is an organic acid or any salts thereof having a pKa ranging between -2 to +7.

5. The composition according to claim 4; wherein the organic acid is selected from the group consisting of citric acid, lactic acid, sulfamic acid, methanesulfoic acid, acetic acid, sodium bisulfate, or any salts thereof.

6. The composition according to anyone of the prior claims, wherein the composition further comprises a polycarboxylic acid or a salt thereof selected from the group consisting of trisodium dicarboxymethyl alaninate (MGDA), tetrasodium glutamate diacetate (GLDA) and trisodium citrate, preferably trisodium citrate.

7. The composition according to anyone of the prior claims, wherein the composition further comprises a dye, a fragrance, and / or a preservative.

8. The composition according to claim 7, wherein the preservative is sodium benzoate.

9. The composition according to anyone of the prior claims comprising a. from about 5 to 10 percent by weight of a of a sophorolipid biosurfactant or salts thereof, b. from 0.05 to about 2 percent of citric acid, c. from 85 to about 95 percent by weight of water; wherein the composition is substantially free of any non-ionic surfactant, any hydrotrope, any bleach material, any amino acids, and / or any enzyme; and wherein the composition has a pH ranging between 3.0 to 4.9.

10. The composition according to anyone of the prior claims comprising:(e) from 5 to 10 percent by weight of a sophorolipid biosurfactant or salts thereof,(f) from 0.5 to 3 percent of citric acid,(g) from 0.2 to 0.5 percent a zinc salt,(h) from 80 to 95 percent by weight of water; wherein the composition is substantially free of any non-ionic surfactant, any hydrotrope, any bleach material, any amino acids, and / or any enzyme; and wherein said composition is a rinse aid composition for use in an automatic dishwashing machine to provide protection of glassware.

11. A method of cleaning kitchenware and / or tableware in an automatic dishwasher comprising adding a composition according to claims 1-10 in a rinsing step.

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