Manual dishwashing composition with improved grease removal

Abstract

The invention is directed to a manual dishwashing cleaning composition comprising an anionic surfactant; an amphoteric surfactant; citric acid (salt) as a builder; diethylenetriamine penta(methylene phosphonic acid (DTPMP) as a chelator; and a carbonate as an alkalinity booster. The manual dishwashing cleaning composition exhibits improved grease removal.

Description

[0001] Henkel AG & Co. KGaA

[0002] Manual dishwashing composition with improved grease removal

[0003] Manual dishwashing compositions play a crucial role in the everyday task of cleaning dishes by hand. These compositions are designed to break down grease, remove food residues, and leave dishes sparkling clean. The most important components of manual dishwashing compositions are surfactants, which dissolve the grease and bind it in the water.

[0004] Manual dishwashing compositions typically contain anionic, nonionic, and small amounts of amphoteric surfactants. Anionic surfactants are typically found as the primary composition ingredient and are responsible for wetting, degreasing and foaming. Nonionic surfactants improve the functional properties and act as surfactant auxiliaries. Amphoteric surfactants regulate viscosity and improve foaming properties. In addition to the said ingredients, Manual dishwashing compositions also contain many additives that not only enhance the effectiveness of the product but also add clarity, color or fragrance.

[0005] Despite regular advancements in the formulation of manual dishwashing compositions, there remains a persistent need for improvement in cleaning performance, in particular in grease removal performance.

[0006] This problem is solved by the invention by providing a manual dishwashing cleaning composition comprising:

[0007] an anionic surfactant;

[0008] an amphoteric surfactant;

[0009] a builder, comprising citric acid (salt);

[0010] a chelator, comprising diethylenetriamine penta(methylene phosphonic acid (DTPMP); and an alkalinity booster, comprising a carbonate.

[0011] Surprisingly, it has been shown that a manual dishwashing cleaning composition according to the invention shows an improved degreasing effect.

[0012] The composition contains mandatorily an anionic surfactant. According to a preferred embodiment the composition is characterized in that the anionic surfactant comprises a linear alkylbenzene sulfonate.

[0013] According to another preferred embodiment of the composition, the linear alkylbenzene sulfonate is present in an amount of 8 to 20 wt.-%, more preferred 12 to 17 wt.-%, in relation to the total weight of the composition.

[0014] Alternatively, it can be preferred that the anionic surfactant comprises an alkyl sulfate surfactant. In a preferred embodiment, the composition is characterized in that the alkyl sulfate surfactant is present in an amount of 1 to 6 wt.-%, more preferred 2.5 to 4.5 wt.-%, in relation to the total weight of the composition.

[0015] According to a preferred embodiment, the alkyl sulfate surfactant comprises an alcohol ethoxy sulfate, A preferred alcohol ethoxy sulfate comprises sodium laureth sulfate.

[0016] In a very preferred embodiment, the composition is characterized in that the alkyl sulfate surfactant comprises an alcohol ethoxy sulfate, preferably sodium laureth sulfate, and the alkyl sulfate surfactant is present in an amount of 2.5 to 4.5 wt.-%, in relation to the total weight of the composition.

[0017] According to a more preferred embodiment the composition is characterized in that the anionic surfactant comprises a linear alkylbenzene sulfonate and an alcohol ethoxy sulfate surfactant. The linear alkylbenzene sulfonate and the alcohol ethoxy sulfate may preferably present in a ratio of 2:1 to 6: 1 , preferably 3:1 to 5: 1 , in particular about 4: 1.

[0018] The composition contains mandatorily an amphoteric surfactant. In a preferred embodiment of the invention does the amphoteric surfactant comprise an amine oxide. In an even more preferred embodiment does the amphoteric surfactant comprise an amine oxide that is lauramidopropyl amine oxide (LAPAO).

[0019] The composition preferably comprises lauramidopropylamine oxide, namely C12 alkyl amidopropylamine oxide. Preferably, the residues R2 and R3 of the amin nitrogen atom are C1-C4 alkyl groups, preferably methyl in that the lauramidopropylamine oxide is N-(3-(dimethylamino)propyl) laurylamid N-oxide.

[0020] In a preferred embodiment, the amine oxide is present in an amount of 0.4 wt.-% to 1.2 wt.-%, in relation to the total weight of the composition.

[0021] In a yet preferred embodiment, the amine oxide is present in an amount of 0.6 wt.-% to 0.9 wt.-%, in relation to the total weight of the composition.

[0022] It was discovered that a composition comprising an anionic surfactant and an amine oxide, wherein the amine oxide is lauramidopropylamine oxide shows clear benefits over the composition with betaines, in particular cocamidopropyl betaine.

[0023] In one embodiment, the composition comprises a linear alkylbenzene sulfonate, sodium laureth sulfate, an amine oxide as surfactants. Preferably, the composition is substantially free of cocamidopropyl betaine.

[0024] It may be advantageous if the total amount of surfactants in the composition is from 5 to 20 wt.-%. The composition mandatorily includes a builder, comprising citric acid (salt). Builders are used as a water softener. The use of citric acid (salt) is advantageous since it not only functions as builder but is also vital for maintaining the optimal pH level of the dishwashing liquid. The appropriate pH ensures the cleaning performance is maximized, while also improving the product’s compatibility with users’ skin.

[0025] The amount of citric acid (salt) in the composition ranges preferably from 0.5 up to 1 wt.-%, in relation to the total weight of the composition.

[0026] The composition further contains a chelator, comprising diethylenetriamine penta(methylene phosphonic acid (DTPMP).

[0027] The amount of diethylenetriamine penta(methylene phosphonic acid (DTPMP) in the composition ranges preferably from 0.05 up to 0.3 wt.-%, in relation to the total weight of the composition.

[0028] Chelating agents or chelators like DTPMP work by binding to metal ions in hard water, reducing soap scum and increasing cleaning efficiency. This helps prevent deposits and residue on dishes and glassware, ensuring they come out sparkling clean. DTPMP was found to be the most ideal and cost effective buffer with regard to degreasing performance.

[0029] The composition also contains an alkalinity booster, comprising a carbonate. The carbonate may comprise sodium carbonate, bicarbonates and / or sesquicarbonates, wherein sodium carbonate is most preferred.

[0030] The amount of carbonate, in particular sodium carbonate, in the composition ranges preferably from 0.25 up to 1 wt.-%, in relation to the total weight of the composition. Amounts of carbonate, in particular sodium carbonate above 1 wt.-%, in relation to the total weight of the composition, may lead to viscosity decrease and phase separation.

[0031] The presence of carbonate and citric acid in the liquid dishwashing composition may lead to a release of carbon dioxide and, thus, to an undesirable strong bottle expansion of the final liquid dishwashing product. Compared to other chelators, DTPMP has an unexpectedly high beneficial effect on preventing bottle expansion.

[0032] The composition itself can be described as a liquid dishwashing composition, a dishwashing composition, etc. In various embodiments, the composition has a pH of from about 3 to about 11. In a more preferred embodiment, the composition has a pH of greater than 7 and upto 8.5. In an even more preferred embodiment, the composition has a pH of between 7.5 and 8.5. Surprisingly, DTPMP was also found to be the most effective buffer with regard to controlling the pH of liquid dishwashing composition.

[0033] In various embodiments, the composition includes an additional component.

[0034] For example, the additional component may be a surfactant different from any of the components described above, e.g., one or more additional nonionic surfactants, cationic surfactants, or combinations thereof. For examples, one or more of these surfactants may be an alcohol ethoxy sulfate (AES), an alcohol ethoxylate (AE), and / or combinations thereof. In other embodiments, one or more of these surfactants may be a zwitterionic surfactant, a high ethoxylation nonionic surfactant, an alkyl polyglucoside (APG), and / or combinations thereof.

[0035] In other embodiments, the composition includes a further chelator. In some embodiments, the further chelator is ethylenediaminetetraacetic acid (EDTA), Ethylenediamine- / \ / , / \ / -disuccinic acid (EDDS), iminodisuccinic acid (IDS), 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP), methylglycinediacetic acid (MGDA), Glutamic acid N, / V-diacetic acid, tetrasodium salt (GLDA), diethylenetriaminepentaacetic acid (DTPA), Diethylenetriamine (DETA) or combinations thereof.

[0036] I

[0037] In other embodiments, the composition may comprise one or more additives chosen from enzymes, perfumes, colorants, hydrotropes, polyelectrolytes, pearlescers, anti-spotting agents, germicides, fungicides, anti-corrosion agents, crystal growth inhibitors, pH adjusting agents, and antioxidants.

[0038] A second object of the application is the use of a citric acid (salt); diethylenetriamine penta(methylene phosphonic acid (DTPMP); and a carbonate in a manual dishwashing cleaning composition comprising an anionic surfactant and an amphoteric surfactant to enhance grease removal.

[0039] A manual dishwashing cleaning composition according to the invention can be manufactured using known processes for the production of manual dishwashing cleaning composition.

[0040] However, it has proved to be advantageous, to add carbonate and citric acid to the main formula batch at late stage of the manufacturing process in order to control carbon dioxide development.

[0041] Accordingly, a third object of the application is a process for manufacturing a manual dishwashing cleaning composition comprising:

[0042] an anionic surfactant;

[0043] an amphoteric surfactant;

[0044] a builder, comprising citric acid (salt);

[0045] a chelator;

[0046] an alkalinity booster, comprising a carbonate; and

[0047] optional ingredients;

[0048] comprising the steps of providing first a mixture comprising water; anionic surfactant; amphoteric surfactant; chelator; and optional ingredients; and

[0049] secondly adding carbonate and citric acid.

[0050] The carbonate is preferably sodium carbonate. The carbonate is preferably added in form of a premix of carbonate and water. Citric acid can be added in form of an aqueous citric acid solution but more preferred as a powder.

[0051] It is highly beneficial to add citric acid in two portions: the first portion before the addition of carbonate, preferably sodium carbonate, and the second portion after the addition of carbonate, preferably sodium carbonate, to the mixture. The split of citric acid in two dosage steps avoids large amounts of citric acid reacting with carbonate, preferably sodium carbonate. Thus, the dosage split prevents undesirably heavy foaming due to carbon dioxide release.

[0052] In a particularly preferred embodiment of the manufacturing process, the pH of the batch is kept above 7 after the addition of carbonate, preferably sodium carbonate. A pH above 7 avoids a reaction of carbonate, preferably sodium carbonate, and a release of carbon dioxide.

[0053] EXAMPLES

[0054] The following example compositions were provided:

[0055]

[0056] Composition 11 is stable in terms of transparency, cloud point, pH and as well as packaging (only low bottle expansion after 4 weeks storage at room temperature).

[0057] The cleaning power of composition 11 was determined with the following test method: Stainless steel plates were soiled of the with a grease soiling . First the stainless steel plates were cleaned with ethanol. After the plates had been rubbed dry, 2 ml of the grease soil was applied to each plate using a paint roller so that 0.7±0.1 g of grease soil is applied per plate.

[0058] The grease soil was comprised of 75 ml of plant oils (corn oil, sunflower oil and peanut oil in equal parts), 25 g of albumin powder and 0.05 g of a dye.

[0059] Afterwards, the soil and the plates were baked for 2h 45min at 135°C.

[0060] To determine the cleaning power of the compositions, the following procedure was carried out: 1. sponges were immersed in tap water (22±2g)

[0061] 2. the dipped sponges were clamped into the holder of the multi-track wiper

[0062] 3. 10 ml of a 20% aqueous solution of one of the compositions was applied to each sponge 4. the soiled plates are clamped into the multi-track wiper and placed in the aqueous washing solution

[0063] 5. cleaning / wiping (20 strokes / minute) was started

[0064] 6. assessment after 20 strokes

[0065] 7. if necessary, further 20 strokes are carried out (up to 100 strokes)

[0066] Composition 11 showed a better instant cleaning performance than a benchmark composition comprising the same surfactant system but no sodium carbonate, no DTPMP and no citric acid (62.6 strokes vs. 99.9 strokes)

Claims

Patent claims:

1. A manual dishwashing cleaning composition comprising:an anionic surfactant;an amphoteric surfactant;a builder, comprising citric acid (salt);a chelator, comprising diethylenetriamine penta(methylene phosphonic acid (DTPMP); and an alkalinity booster, comprising a carbonate.

2. The manual dishwashing composition according to claim 1, wherein the amphoteric surfactant comprises an amine oxide.

3. The manual dishwashing composition according to claim 2, wherein the amine oxide comprises lauramidopropyl amine oxide.

4. The manual dishwashing composition according to any of the previous claims, wherein the anionic surfactant comprises a linear alkylbenzene sulfonate.

5. The manual dishwashing composition according to any of the previous claims, wherein the anionic surfactant comprises an alkyl sulfate surfactant.

6. The manual dishwashing composition according to the previous claim, wherein the carbonate comprises sodium carbonate.

7. The manual dishwashing composition according to the previous claim, wherein the alkyl sulfate surfactant is sodium laureth sulfate.

8. The manual dishwashing composition according to any of the previous claims, wherein the anionic surfactant comprises a linear alkylbenzene sulfonate and an alcohol ethoxy sulfate surfactant, wherein the linear alkylbenzene sulfonate and the alcohol ethoxy sulfate are present in a ratio of 2:1 to 6:1, preferably 3:1 to 5: 1 , in particular about 4: 1.

9. Use of a citric acid (salt); diethylenetriamine penta(methylene phosphonic acid (DTPMP); and a carbonate in a manual dishwashing cleaning composition comprising an anionic surfactant and an amphoteric surfactant to enhance grease removal.

10. Process for manufacturing a manual dishwashing cleaning composition comprising:an anionic surfactant;an amphoteric surfactant;a builder, comprising citric acid (salt);a chelator;an alkalinity booster, comprising a carbonate; andoptional ingredients,comprising the steps:providing first a mixture comprising water; anionic surfactant; amphoteric surfactant; chelator, comprising diethylenetriamine penta(methylene phosphonic acid (DTPMP); and optional ingredients; andsecondly adding citric acid and carbonate, preferably sodium carbonate.

11. Process for manufacturing a manual dishwashing cleaning composition according to claim 10, wherein the citric acid is added in two portions: a first portion before adding carbonate, and a second portion after the addition of carbonate to the mixture.

12. Process for manufacturing a manual dishwashing cleaning composition according to claim 10 or claim 11 , wherein the pH of the mixture is kept above 7 after addition of carbonate.

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