NO300333B1 - Liquid detergent mixture - Google Patents

Abstract

An aqueous liquid detergent composition for handwashing soiled dishware includes specific narrow classes and amounts of magnesium or sodium alkyl benzene sulfonate surfactant, alkyl ether sulfate surfactant, C12-C16 alkyl polyglucoside and alkanolamide foam stabilizer. A higher alkyl sulfosuccinate or sulfosuccinate, optionally ethoxylated, anionic surfactant may also be present. The compositions are capable of generating a stable foam and are effective in cleaning greasy soils with acceptable mildness for the consumer and with good rinseability.

Description

Background for the invention

Field of the invention

This invention relates to a liquid dishwashing detergent mixture particularly suitable for hand washing tableware, such as plates, kettles, saucepans, glassware and silverware/cutlery. More specifically, it relates to a liquid dishwashing detergent mixture with stable foaming properties which is gentle on the hands and is effective in removing greasy dirt.

Account of the subject area and the solved problems

Foaming of detergents is perceived by the consumer as good washing ability. Nevertheless, it is clear that long-lasting foam, whether assessed as abundant or medium to medium-low foam content, is not in itself a sufficient measure of cleaning ability. Nevertheless, much work has been put into optimizing the foaming properties, without necessarily improving the cleaning ability.

Grease stains are usually considered to be one of the most difficult types of stains to remove by hand washing. Effective grease removal is almost always associated with the need for high-temperature water to help remove the grease.

It would clearly be a great advantage to prepare a mild, foaming liquid dishwashing detergent mixture capable of effectively removing grease stains as well as other types of stains from tableware using water that is kept at ambient temperature or is from warm to keep high temperature.

It is known that among the anionic surfactants, those based on magnesium as a counterpart (i.e. cation) can improve the fat dissolving ability. Nevertheless, fat-dissolving ability is usually associated with increased skin irritation, e.g. on the hands, by the consumer.

It is also known to use generally milder types of surface-active agents to improve the somewhat rough properties of magnesium-based, anionic, surface-active agents. Alkyl polyglucoside (APG) nonionic surfactants have been proposed for this purpose. Although still exhibiting foaming properties to a certain extent, APG-type surfactants generally have poorer foaming properties than other common foaming surfactants. From the international patent application no. WO 90/02164, liquid delicate detergents are known comprising, among other things, a magnesium salt of alkylbenzene sulphonate, a polyglucoside and an alkanolamide (foam stabilizer).

Another important feature for the consumer of detergent mixtures is the ability to easily rinse away excess foam which is associated with good cleaning ability. Surfactant systems that provide APG-generating foam are not always acceptable in terms of cleaning performance.

Likewise, it is an object of this invention to provide aqueous detergent mixtures which combine acceptable mildness, foaming and grease removal ability.

Another object of the invention is to provide such mixtures with good defoaming ability.

The present invention relates to mixtures which avoid the highlighted problems and satisfy the preceding purposes. Although the mixtures are prepared from otherwise known ingredients, but in unique compositions and ratios, they are able to present a new and advantageous result, among other things compared to what is known from WO 90/02164.

Summary of the invention

According to the present invention, there is provided a liquid dishwashing detergent mixture with stable foaming properties and which is gentle on the hands and is effective in removing greasy dirt, which is characterized by the fact that it comprises:

(A) a surfactant system comprising

(1) from 7.5 to 20% by weight of an anionic surfactant containing a salt of a C10-C16 linear alkylbenzene sulfonate, wherein said salt is selected from the group consisting of alkali metal salts, alkaline metal salts and mixtures thereof; (2) from 0 to 8% of anionic C10-C18 alkyl sulfosuccinate or sulfosuccinamate, wherein the alkyl group may be ethoxylated with up to 8 moles of ethylene oxide; (3) from 8 to 20% anionic C10-C20 alkyl ether sulfate containing 1 to less than 3 moles of ethylene oxide per mol alkyl group; and (4) from 3 to 12% by weight of an alkyl polyglucoside having an average of 12 to 16 carbon atoms in the alkyl chain, and an average degree of polymerization in the range of 1 to 3; (B) from 0.5 to 6% by weight of a foam stabilizing system comprising at least one C2-C3 alkanolamide of C10-C16 alkanoic acid; the total weight of components (A) and (B) is in the range from 25 to 54% by weight of the mixture; (C) up to 10% by weight of a lower alcohol as a low-irritant solvent; (D) up to 8% by weight hydrotrope; (E) up to a total of 20% by weight of one or more possible

additives selected from chelating or sequestering

agents, dyes, colors, perfumes, bactericides, fungicides, preservatives, solar filtering agents, pH modifying agents, pH buffering agents, opacifying agents, antioxidants, thickening agents and proteins; and

(F) the rest water.

Unless otherwise stated, all percentages are and

percentages herein given on a weight basis.

The components of the invented mixtures will now be described in more detail.

Detailed description and preferred embodiments

The present invention is partly based on the completely unexpected discovery that the foam-stabilizing, foam-promoting combination of alkyl polyglucoside (APG) and alkanolamide components has a significant effect on the grease removal ability of the mixture at a constant level of total surface-active/foam-stabilizing components. More specifically, it has now been found that while some improved degreasing can be provided with the foam stabilizing alkanolamide alone, when compared to existing best commercial products, degreasing performance is further dramatically improved in the system containing both the foam stabilizing alkanolamide and APG. Furthermore, using alkyl ether sulfate (AEOS) with less than 3 moles of ethylene oxide, e.g. AE0S-1E0 or AE0S-2E0, a richer foam is obtained when compared to the same mixture containing AE0S-3E0 (eg 3 moles of ethylene oxide) while an acceptable mildness is still maintained. By using low levels of the foam-promoting alkanolamide component (B) together with the specified surface-active system (A), good cleaning ability of bed linen is also achieved without impairing washing ability. Applicant's currently commercially available liquid dishwashing detergent product, "Liquid Palmolive" (17% NaLAS, 13% AE0S-3E0, 4% LMMEA, 3.3% SCS+SXS, 0.5% inorganic salts; remainder perfume, dye, ethanol , water) removed e.g. approximately 25 milligrams (mg) of fat stains (cooking fat) while compared to only 5 mg for the same preparation with 0% LMMEA. In a mixture according to the invention containing APG, the fat removal is nevertheless increased by about 80 mg above the level of LMMEA between about 1 and about 4% by weight of the mixture. These observations were based on surfactant systems in which the counterpart of the anionic surfactant(s) was sodium. In systems where magnesium salts of the anionic surface-active agent ABS are used, both the concentration of the Mg ion and the alkanolamide have a strong effect on the removal of grease. When e.g. tested in Baumgartner's degreasing test with a surfactant system containing 10% by weight linear dodecylbenzenesulfonate (LAS)/

12% by weight aliphatic C12-C16 alcohol ethoxylate (1 mol ethylene oxide (1E0))/6% by weight APG (C12 to C16 alkyl; D.P. == 1.6) a grease removal capacity was achieved as indicated in the following table 1 at the Mg - and LMMEA levels as indicated here.

The components in the mixtures according to the invention will now be described.

(A) The surfactant system

(1) The first essential surfactant component

is the anionic salt of an alkylbenzenesulfonic acid (ABS), preferably a linear C10 to C16 alkylbenzenesulfonate (LAS).

Furthermore, when the magnesium salt is used, it can e.g. be a magnesium oxide neutralized linear dodecylbenzenesulfonic acid, or alternatively the magnesium salt can be formed by adding an electrolytic magnesium salt such as magnesium chloride, magnesium sulfate etc. to sodium alkylbenzenesulfonate. In the latter option, an excess of the magnesium salt electrolyte can increase the "cloud/clear" point of the mixture. This unwanted effect can nevertheless be compensated for by adding a hydrotrope as described below.

The anionic surfactant (1) is present in an amount of from about 7.5% to about 20%, based on the total mixture, or in an amount of from about 28 to 40%, based on the total amount of surfactants (A) (1), (2), (3) and (4). The more preferred amount ranges of the anionic surfactant ABS salt are from about 8 to

12 or 15%, especially about 9 to 11%, e.g. approximately

10%, based on the total amount of mixture, or about 29 to 35%, especially about 30 to 33%, based on the sum of the surfactants (A) (1), (2), (3) and (4).

Below the 7.5% (total) level, the improvement in low-temperature degreasing becomes insufficient, while the composition containing the magnesium salt tends to become mildly irritating to the hands at amounts above 20% (total).

The anionic ABS in the surfactant system can be present as alkali metal or alkaline earth metal salts, or mixtures thereof. The preferred alkali metals are sodium and potassium, preferably sodium. The preferred alkaline earth metals are calcium and magnesium, preferably magnesium. The linear alkyl group preferably contains from 10 to 13 carbon atoms, especially about 11 carbon atoms on average, e.g. linear sodium and/or magnesium dodecylbenzene sulfonate.

The anionic sodium salt is generally considered to be a milder detergent than the magnesium salt, but is less effective at degreasing and is also less effective at foaming, especially in the presence of contaminants. When used in combination with APG, AEOS-1 to 2E0, and alkanolamide foam stabilizer, satisfactory foaming, degreasing and mildness can still be achieved at the same time.

On the other hand, increased fat removal ability can be achieved with the anionic Mg salt. Because the level of the Mg ion can still be lowered for any level of degreasing ability, it is still possible to achieve degrees of mildness acceptable to the consumer. This appears to be particularly the case, expressed as the degree of perceived mildness stated by small test panels of consumers, in mixtures which also contain the below-described sulfosuccinate or sulfosuccinamate anionic surfactants. (2) According to one embodiment of the invention, a mono-alkyl C8-C18 sulfosuccinate or sulfosuccinamate anionic surfactant can be incorporated into the mixtures according to the present invention, especially when the magnesium salt of ABS is used as, or as part of, component (1).

It is stated in US patent 4,839,098 by Wisotski, et al. to incorporate into an APG (C10 to C18 alkyl, D.P. = 1 to 5) containing liquid detergent mixture from 10 to 80 parts by weight of a C7 to C9 dialkyl sulfosuccinate, based on a total amount of surfactant of 15 to 50% by weight, to increase foaming and cleaning effect. This patent suggests that such mixtures should be free of petroleum-based, anionic, surfactants, such as alkylbenzene sulfonates and alkane sulfonates. Nevertheless, other anionic surfactants such as alkyl ether sulfate or alkyl sulfate can replace part of the APG or the dialkyl sulfosuccinate. The di(C7-C9) alkyl sulfosuccinate is not considered to be a mild surfactant and may contribute to discomfort or irritation in the consumer.

In the mixtures according to the invention, the sulfosuccinate or sulfosuccinamate is present as the monoalkylsuccinate (MAS) or the monoalkylsulfosuccinamate (MASA) where R is an aliphatic radical, preferably alkyl, with from 10 to 18 carbon atoms, especially from 12 to 16 carbon atoms, and preferably lauryl (C12) , and M is a cation, such as an alkali metal, e.g. sodium or potassium, preferably sodium, ammonium, alkanolamine, e.g. ethanolamine, or magnesium. The alkyl radical may be ethoxylated with an average of up to about 8 moles, preferably up to about 6 moles, e.g. 2, 3 or 4 mol, ethylene oxide per moles of alkyl group.

Smaller quantities, e.g. up to about 5%, dialkyl sulfosuccinates may be present along with the monoalkyl sulfosuccinate or monoalkyl sulfosuccinamate. The monoalkyl ester which is essentially free of dialkyl esters, and especially sodium monolauryl ester which can be ethoxylated with up to 4 moles of ethylene oxide, and mono-C16 alkylsulfosuccinamate monoethanolamine salt, is preferred.

When used, the anionic sulfosuccinate or sulfosuccinamate surfactants are present in amounts from about 2 to 20% by weight, preferably from about 3 to 15% by weight, based on the total amount of surfactant

(A) (l)-(4). The preferred amounts, based on the total composition, of sulfosuccinate anionic surfactant are

from 0.5 to 8% by weight, more preferably 0.8 to 7% by weight.

(3) The mixtures according to the invention also include an anionic alkyl ether sulfate (usually also referred to as aliphatic alcohol ether ethylene oxysulfate AE0S*nE0, where n is the average number of moles of ethylene oxide (EO)) containing from about 10 to 20 carbon atoms in the alkyl moiety, preferably from about 12 to 14 or 16 carbon atoms and from 1 to less than 3 moles, preferably 1 to 2 moles, especially 1 mole, of ethylene oxide, on average, per moles of alkyl sulfate. The alkyl ether sulfate, which can be represented by the formula R(OC2H4)nOS03M, where R is the residue of an aliphatic alcohol having from about 10 to 20 carbon atoms, n is a number from 1 to less than 3, and M is a cation, is usually present as the alkali metal salt, especially the sodium salt, but may also be present as the potassium salt, ammonium salt, alkanolamine salt or magnesium salt.

The amount of the alkyl ether sulfate will generally be in the range of from about 32 to about 50% by weight, preferably from about 34 to 48% by weight, based on the total weight of the surfactants (A) (l)-(4) or from about 8 to 20%, preferably 9 to 18%, and more preferably 10 to

16% by weight of the total mixture.

(4) Another essential surfactant in the mixtures according to the invention is (4) an alkyl glucoside, preferably an alkyl polyglucoside, although alkyl monoglucoside can also be used.

Alkyl mono- and polysaccharides have recently received a lot of attention for their beneficial cleaning, foaming and viscosity-modifying properties. Examples of patent literature dealing with liquid dish detergent mixtures containing alkyl monosaccharides include US Patents 4,732,704 and 4,732,696. The alkyl polysaccharides are used in the liquid detergent mixtures mentioned in e.g. US Patents 4,396,520, 4,536,318, 4,565,647, 4,599,177, 4,663,069, and 4,668,422 (including monoglucosides), as well as many of the patents and literature cited in these patents.

In the present invention, a small subset of alkyl saccharides have been found to effectively enhance degreasing with acceptable mildness, when used in conjunction with the other surfactants (A) (1)-(3) and the foam stabilizer (B).

The alkyl glucosides used in this invention are those having an alkyl group with from 12 to 16 carbon atoms on average, and a hydrophilic glucoside group containing from about 1 to about 3, preferably from about 1.2 to about 3, and most preferably from about 1.3 to 2.7, glucoside units, such as 1.3, 1.4, 1.5, 1.6, 2.0 or 2.6 glucoside units. Naturally, the number of glucoside units in any surfactant molecule will be a whole number (ie an integer), but nevertheless for any given physical sample of alkyl glucoside surfactants there will usually be a range of glucoside units, and it is the average value that characterizes a especially surfactant product. The alkyl glucosides with lower D.P. values tend to give richer foaming, while those with higher D.P. values tend to be more soluble, at equal alkyl chain length. If the alkyl group contains less than 12 carbon atoms, it is difficult to achieve satisfactory mildness.

The alkyl group is preferably attached to the 1-position of the sugar molecule, but may be attached to the 1-, 3- or 4-positions, thus giving a glucosyl instead of a glucoside. Furthermore, the additional glucoside units in the poly-glucosides are essentially bound to the previous glucoside at the 2-position, but binding at the 3-, 4- and 6-positions can also occur.

Optionally, and less desirably, a polyalkylene oxide chain (e.g., polyethylene oxide) can be attached to the alkyl moiety and the glucoside units.

The preferred alkyl glucosides have the formula

wherein 2 is derived from glucose, R<2> is an alkyl group containing from 12 to about 16 carbon atoms, m is 2 or 3, preferably 2, t is from 0 to about 6, preferably 0, and x is from 1 to 3 ( on average), preferably from 1.2 to 3, most preferably from 1.3 to 2.7. To prepare these compounds, a long-chain alcohol (R<2>OH) can be reacted with glucose, in the presence of an acid catalyst so that the desired glucoside

is formed. Alternatively, the alkylpolyglucosides can be prepared by a two-step process in which a short-chain alcohol {C1-C6) is reacted with glucose or a polyglucoside (x = 2 to 3) so that a short-chain alkylglucoside (x = 1 to 3) is formed, which can then be reacted with a longer chain alcohol (R<2>OH) to replace the short chain alcohol, thereby forming the desired alkyl glucoside. If this two-step method is used, the content of short-chain alkyl glucoside in it should

final alkylglucoside material be less than 50%, preferably less than 10%, more preferably less than 5% and most preferably 0%.

The amount of reacted alcohol (amount of free aliphatic alcohol) in the desired alkyl polyglucoside surfactant is preferably less than about 2%, more preferably less than about 0.5% by weight of the total amount of the alkyl polyglucoside plus reacted alcohol. The amount of alkyl monoglucoside, if present, is preferably no more than about 40%, more preferably no more than about 20% by weight of the total amount of alkyl polyglucoside. For some applications, it is desirable to have the alkyl monoglucoside content less than about 10%, preferably less than about 5%.

The amount of alkylglucoside surfactant which provides the desired foaming and cleaning properties is in the range of from about 14 to 32%, preferably from about 16 to 30%, based on the sum of the surfactants (A) (1), (2), ( 3) and (4). Preferred amount is from 3 to 12%, preferably from 4 or 5 to 10%, based on the total mixture.

Within these ranges, the relative amounts of the surfactant alkylbenzene sulfonate (ABS) and the surfactant alkyl glucoside (APG) are not particularly critical, but will usually be in the range ABS:APG of from about 2.5:1 to 1:2, preferably from about 2:1 to 1:1.2.

In the mixtures according to the invention, the total amount of active surfactant components (A) plus (B) will be in the range from about 25 to 54% of the total mixture, preferably from about 28 to 50%, more preferably from about 28 to 42%, for example 30%, 32%, 34%, 35% or 40%.

(B) Foam stabilizing system

The foam stabilizing system, as well as itself

can contribute to the foaming capacity as well as the foam stabilizing effect, the lower alkanolamide of higher comprises

alkanoic acid which is the reaction product of a lower alkanol having 2 to 3 carbon atoms and an alkanoic acid having 10 to 16 carbon atoms, preferably 80% or more of the lower alkanol being ethanol and a similar proportion of the alkanoic acid having 12 to 14 carbon atoms

atoms. Other useful lower alkanols are n-propanol and isopropanol. The preferred alkanoic acid is a mixture of lauryl and myristic acid, with about 50% of each being the preferred. Alternatively, coconut oil or hydrogenated coconut oil can be used as a source of alkanoic acids. Suitable alkanoic acid alkanolamides include monoethanolamides, diethanolamides and monoisopropanolamides.

Specific examples include mixed lauryl/myristic diethanolamide, lauryl/myristic monoethanolamide, lauryl monoethanolamide, lauryl diethanolamide, coco diethanolamide, coco monoethanolamide and the like.

The amount of alkanoic acid alkanolamide can be up to about 6% of the mixture, for example 0.5 to 6%, preferably 1 to

5%, more preferably 1 to 4%, for example 1.5, 2, 3 or

4% of the mixture.

The mixtures according to the invention which comprise the salts of the surfactants (A) (1), (A) (3), (A) (4) and optionally (A) (2) and the foam stabilizing system (B), in the indicated proportions , as essential ingredients, are formulated in an aqueous carrier to provide mild, stable, foaming, liquid mixtures particularly effective for cleaning by hand washing tableware, such as plates, glasses, cutlery, pots, pans, etc., at ambient temperature on the wash water as well as , of course, with lukewarm or hot washing water. The mixtures according to the invention are gentle on the hands and are clear and homogeneous. However, clarity and homogeneity can often be improved by including e.g. organic solvents and/or hydrotropes, and these and other possible additives can also be included in the mixtures in amounts that do not adversely affect the desired properties.

(C) Organic solvent

Cosmetically acceptable organic solvents, usually lower alcohols, such as ethanol, propanol, isopropanol, propylene glycol, or mixtures thereof, may be included in the composition for their diluting effect, lowering of the clear point, and for their solubilizing effect on other less readily soluble components in the aqueous main medium. The amount of solvent, when present, will usually be limited to about 10%, preferably 8%, and especially not more than about 6% of the mixture, for example from 2 to 5%. Ethanol is the preferred organic solvent.

(D) Hydrotropic

To aid in the dissolution of various components in the mixture, and to maintain a low clear point, and if possible to modify the viscosity, it is common to include a hydrotropic compound in the mixture. Typical hydrotropes include primarily urea and the lower alkylarylsulfonate salts, such as sodium xylenesulfonate, potassium xylenesulfonate, sodium cumenesulfonate, ammonium xylenesulfonate and the like. Mixtures of two or more hydrotropes can also be used. The hydrotrope, when used, is usually present in an amount below about 8%, preferably below about 6%, for example from 1 or 2 to 6%.

(E) Other optional, functional and aesthetic additives

Various other materials may also be included in the present compositions for their desired functional or aesthetic effects. Among these, the materials added to increase the gentleness of the detergent mixture to the hands, such as water-soluble proteins, are very useful.

Although the solvents, including water, have a tendency to make the products clear liquids, it is sometimes desirable to make the products cloudy or pearly. For such purposes, opacifying agents can be used, e.g. behenic acid, or a pearl promoting mixture, such as an approximately equal mixture of high aliphatic acid ester of polyethoxyethanol, aliphatic coconut oleic acid alkanolamide and sodium lauryl ether sulfate. The higher aliphatic acid will usually have 10 to 18 carbon atoms and the polyethoxy content will be 1 to 20, preferably 1 to 10 ethoxy groups. The alkanolamide will preferably be ethanolamide, but can also be mixed with isopropanolamide.

Additional additives to the present compositions include perfumes; sequestering agents, e.g. monohydrogenethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, trisodium nitrilotriacetate; bactericides, e.g. trichlorocarbanilide, tetrachlorosalicylanilide, hexachlorophene, chlorobromosalicylanilide; antioxidants; thickeners, e.g. sodium carboxymethyl cellulose, polyacrylamide, carrageenan; dyes, water-dispersible pigments; salts, e.g. sodium sulfate, magnesium sulfate, such as the heptahydrate or anhydrous sodium chloride; preservatives, such as formaldehyde or hydrogen peroxide, pH-regulating agents, etc.

The total amount of the additional additives is usually not more than about 20% of the mixture, preferably not more than 15%, while none of the substances individually normally exceeds 10%, especially 5%, and usually not more than 2 or 3%.

In the above description of the mixtures according to the invention, and the various additives used in them, and in the claims, it is within the scope of the invention that mixtures of these can be used even if the various components are indicated for different classes or types of components, such as mixtures of two or three anionic detergents or mixtures of nonionic detergents, which was possible both with other known anionic and nonionic detergents, including mixtures of skin soothing substances and mixtures of solvents.

Under special conditions, e.g. surface-active paraffin sulphonates, such as sodium or magnesium (C12-C18) paraffin sulphonate, are used to replace part or all of the ABS surfactant, and achieve good foaming and grease removal properties. Amphoteric surfactants, such as betaine, e.g. acylamidopropyldimethylammonium betaine, can often also provide improvements in the overall properties.

The viscosities of the detergent mixtures can also be varied by adding thickeners, such as rubber and cellulose derivatives. The product viscosity and flow characteristics should be such that it is pourable from a bottle and not so thin that it tends to splash or that it is poured too quickly, as usually only small amounts of the liquid detergent are used in use. Viscosities from 20 to 1000 centipoise (Brookfield Viscometer spindle no. 1,

12 r.p.m.) have been found to be usable, those from 100 to 500 eps are preferred and a viscosity of about 200 centipoise is considered by consumers to be best, although consumer reception is almost the same at somewhat lower viscosities, e.g. 100 eps.

When preparing the described mixtures, it is usually preferred to heat the detergent components to a somewhat elevated temperature, e.g. 40 to 50 °C, and then mix them with water and, optionally, all or part of the ethanol. Other anionic and non-ionic detergents, urea, amide, protein and other additives are then added together with the more volatile substances, such as perfumes, preferably added last and after cooling the mixture to approximately room temperature. When preparing opaque or beading detergents, the beading mixture will also be added near the end at approximately room temperature. Although the described method for preparing the mixtures is preferred, a number of other known techniques can also be used, depending on the individual detergent mixture.

The preparation's pH value will usually be close to neutral, e.g. about 5 to 8, preferably about 6.5 to 7.5.

The following representative examples will provide further understanding of the present invention.

Example I

The following mixtures L and L' were prepared:

Example II

The following mixtures WJ' and WJ'' were prepared:

Example III

Mixtures A-E were prepared in the same manner as Mixtures WJ' and WJ' except that the amounts of APG-625 and LMMEA were changed as follows:

The mixtures of Examples II and III were tested in the "Shake-Foam" test, the "Shell-Foam" test and the Baumgartner fat removal (fat) test as described below.

(1) Baumgartner dirt removal

This test measures the ability of a diluted (1%) solution in water with a hardness of 150 ppm to remove greasy soil (grease) from a test surface (a cleaned specimen glass 2.5 cm x 0.1 cm). The dirt is applied by spreading approximately 0.2 to approximately 0.3 g of cooking fat on each cleaned specimen slide. The soiled specimen slides are cleaned in a 1% product solution by dipping the soiled specimen slide in the solution 600 times. The solution is kept at room temperature (24 °C). After washing, the specimen slides are dried in a desiccator for 2 hours. The weight difference of the food fat before and after the cleaning process is taken as a measure of fat removal, the greater the difference, the more effective the detergent mixture.

(2) "Shake-Foam" test

100 ml of diluted (1%) test solution in water with 100 ppm hardness (45 °C) is filled into a 500 ml measuring cylinder with a stopper. The corked cylinder is placed on a shaking machine which rotates the cylinder for 20 periods at 30 rpm. The height of the foam in the cylinder is read. A piece of sugar whose surface has adsorbed 0.01 ± 0.001 g of mixed dirt (potato sprouts, "Crisco", milk, olive oil and water) is then added to the cylinder and the test repeated. The procedure is repeated until a total amount of 0.03 g of dirt has been added.

(3) "Shell-Foam" test

250 ml of water (150 ppm hardness, 45 °C) containing the test solution at a concentration of 0.04% is filled into a water-cooled vessel with flow switches having a constant stirring speed (mixing at 300 rpm). Stirring is maintained until the formed foam covers the entire surface of the test solution. Mixed dirt (olive oil, milk, "Crisco" and potato sprouts) is slowly injected at a constant rate sufficient to uniformly disperse the dirt below the surface of the solution. The dirt first reacts with the surfactant in the solution until the surfactant is diluted and then begins to dilute the surfactant from the foam. The amount of dirt (in grams) added before the foam rapidly collapses is determined. The results (final value) are indicated in

table 2 in grams.

Each of these tests was performed in triplicate, and the reported results represent the average of the three tests.

The results of the tests are shown in table 2.

Both formulations WJ' and L had superior cleaning performance when compared to "Liquid Palmolive" and a commercial product containing a high level of magnesium for degreasing, but not believed to contain any alkyl polyglucoside.

The above mixtures A-E were statistically analyzed to identify the main and interaction effects of LMMEA and APG on fat removal. Only the LMMEA level was found to have an impact on fat removal ability. All other mixing factors (surfactants) had no particular effect on fat removal. Mixtures A and D, containing 4% LMMEA, removed a large portion of the grease compared to regular "Liquid Palmolive" which removed 25 to 30 mg of dirt. For reference, another leading commercial product, containing a high level of magnesium for effective degreasing, removes 120 mg of dirt. However, it is significantly more irritating than "Liquid Palmolive" in a clinical hand wetting test. Preparations L and L' also contain high Mg levels and also remove more fat. These blends are clinically milder than the commercially available high Mg product. The product WJ'' containing 6% APG and 4% LMMEA, which had comparable degreasing properties to mixtures A and D, was clinically tested and found to be as mild as "Liquid Palmolive".

Blends WJ' and WJ'' were both rated as mild as "Liquid Palmolive" and superiorly milder than the commercially available high Mg product.

While the representative mixture WJ' (NaLAS) was not as effective as "Liquid Palmolive" or the commercially available product with a high Mg level in a standard Baumgartner grease removal test (cooking grease), it is found to be superior in removing grease of the " Crisco" monoglyceride in a softening test.

Similar mixtures containing 17% LAS/13 AE0S-3E0 with 0% APG and with 0% LMMEA or 4% LMMEA were tested in

the fat removal test. The mixture containing 0% LMMEA removed approximately 5 mg of soil while the mixture with 4% LMMEA removed 25 mg of soil. This shows the interaction between LMMEA and APG, which gives an increased fat removal ability.

Example 4

To test the effect of the anionic sulfosuccinate/sulfosuccinamate surfactant in Blend L of Example 1, four surfactants were tested at 0%, 1.5%, and 3% sulfosuccinate/sulfosuccinamate levels in Blend L and were compared to "Liquid Palmolive " (POL) in Baumgartner's fat removal test and "Shake-Foam" tests described above. The surfactants tested were sodium monolauryl sulfosuccinate used in L, sodium monolauryl(3E.0.)sulfosuccinate used in L' (laureth), sodium dioctyl sulfosuccinate, and mono-C16-alkyl sulfosuccinamate, monoethanolamine salt (rice). All these surfactants come from Rhone Poulenc (France).

These results are shown in Table 3.

Conclusion by comparison with the properties of sulfosuccinate Fat removal ability

The results of the fat removal ability of the various sulfosuccinates tested at 0%, 1.5% and 3% in the L preparation (MgLAS) indicate that all four sulfosuccinates give a high and comparable level on Baumgartner's test at all levels tested. Dioctyl SS gives a higher peak than the other materials at 1.5% in the test.

The "Shake-Foam" test

Generally, there is a slightly noticeable trend in foam volume at each dirt addition level as the sulfosuccinate increases from 0% to 3%. The property is not considered to be significantly different unless a difference in foam volume greater than 50 ml is observed. The lowest to highest foam volume at each condition, regardless of sulfosuccinate type or level, is typically within 50 mL. Based on minimal influence on the foam volume, any of the four materials can therefore be used. The more important factors are the mildness of the preparation and its reception by the consumer.

The dioctyl sulfosuccinate is not believed to provide the same degree of mildness as the higher chain length alkyl esters.

Claims (8)

1. Liquid detergent mixture with stable foaming properties and which is gentle on the hands and is effective in removing greasy dirt, characterized in that it includes: (A) a surfactant system comprising (1) from 7.5 to 20% by weight of an anionic surfactant containing a salt of a C10 -C16 linear alkylbenzene sulfonate, wherein said salt is selected from the group consisting of alkali metal salts, alkaline earth metal salts and mixtures thereof; (2) from 0 to 8% of anionic C10 -C18 alkylsulfosuccinate or -sulfosuccinamate, wherein the alkyl group may be ethoxylated with up to 8 moles of ethylene oxide; (3) from 8 to 20% anionic C10 -C20 alkyl ether sulfate containing 1 to less than 3 moles of ethylene oxide per mol alkyl group; and (4) from 3 to 12% by weight of an alkyl polyglucoside having an average of 12 to 16 carbon atoms in the alkyl chain, and an average degree of polymerization in the range of 1 to 3; (B) from 0.5 to 6% by weight of a foam stabilizing system comprising at least one C 2 -C 3 -alkanolamide of C 10 -C 16 -alkanoic acid; the total weight of components (A) and (B) is in the range from 25 to 54% by weight of the mixture; (C) up to 10% by weight of a lower alcohol as a low-irritant solvent; (D) up to 8% by weight hydrotrope; (E) up to a total of 20% by weight of one or more possible additives selected from chelating or sequestering agents, dyes, colors, perfumes, bactericides, fungicides, preservatives, solar filtering agents, pH modifying agents, pH buffering agents, opacifying agents agents, antioxidants, thickeners and proteins; and (F) the rest water. 2. Mixture according to claim 1, characterized in that it includes (A) : from 28 to 50%; (B) : from 1 to 5%; (C) : from 2 to 5%; (D) : from 1 to 6%; (E) : up to 10%; (F) : the rest water. 3. Mixture according to claim 2, characterized in that the surfactant system. (A) comprises (1) from 8 to 15% of a C10 to C14 alkylbenzene sulfonate, (2) 0 to 8% sodium salt of C10 to C14 monoalkyl sulfosuccinate or -sulfosuccinamate, (3) 10 to 16% sodium salt of C10 to C14 alkyl ether sulfate containing 1 to 2 moles of ethylene oxide, and (4) from 4 to 10% of an alkyl polyglucoside containing from 12 to 16 carbon atoms in the alkyl group and from 1.2 to 3 glucoside units. 4. Mixture according to claim 3, characterized in that the foam stabilizing system (B) comprises at least one compound selected from the group consisting of lauric diethanolamide, lauric monoethanolamide, myristic diethanolamide, myristic monoethanolamide, coconut diethanolamide and coconut monoethanolamide. 5. Mixture according to claim 4, characterized in that the foam stabilizing system (B) comprises from 1 to 5% of the mixture. 6. Mixture according to claim 1, characterized in that it comprises (A) a surface-active system comprising (1) 8 to 12% C10 -C14 linear alkylbenzene sulfonate, (2) 0 to 6% sodium C10 -C16 -<m>onoalkylsulfosuccinate or -sulfosuccinamate, (3) 9 to 18% C10 -C16 alkyl ether sulfates containing from 1 to 2 ethylene oxide groups, and (4) from 5 to 10% of said alkyl polyglucoside, (B) from 1 to 5% of said foam stabilizing system comprising lauric/myristic monoethanolamide; the total amount of (A) + (B) is in the range from 28 to 42% of the mixture; (C) up to 5% ethanol; (D) up to 4% hydrotropic; (E) up to a total of 6% of said one or more additives; and (F) water. 7. Mixture according to claim 1, characterized in that it includes (A) a surfactant system comprising (1) 9 to 11% sodium dodecylbenzenesulfonate, (2) 0 to 2% sodium C10 -C14 monoalkyl sulfosuccinate or sulfosuccinamate, the alkyl group of which may be ethoxylated with up to 6 moles of ethylene oxide; (3) 10 to 16% C10 - <C>16 alkyl ether sulfates containing 1 to 2 ethylene oxide groups, and (4) 6 to 9% of said alkyl polyglucoside; (B) 1 to 3% of said foam stabilizing system comprising lauric/myristic monoethanolamide; (C) 0.2 to 2% ethanol; (D) 0.5 to 4% sodium xylene sulfonate, sodium cumene sulfonate, or mixtures thereof; (E) a total of 0.5 to 5% of one or more of magnesium sulfate, sodium chloride, color and odorant; and (F) water. 8. Mixture according to claim 1, characterized in that it includes (A) a surfactant system comprising (1) 9 to 11% magnesium C10 -C12 alkylbenzene sulfonate, (2) 0.8 to 7% C10 -C16 monoalkyl sulfosuccinate or -sulfosuccinamate, in which the alkyl group may be ethoxylated with up to 5 moles of ethylene oxide, (3) 8 to 14% C10 -C16 alkyl ether sulfate, ethoxylated with 1 to 2 moles of ethylene oxide, and (4) 4 to 8% of said alkyl polyglucoside; (B) 1 to 3% of said foam stabilizing system comprising lauric/myristic monoethanolamide; (C) 0 to 2% ethanol; (D) 0.5 to 4% sodium xylene sulfonate, sodium cumene sulfonate, or mixtures thereof; (E) a total of 0.5 to 5% of one or more of magnesium sulfate, sodium chloride, color and odorant; and (F) water.