The present disclosure relates generally to detergent compositions and, more specifically, to low pH detergent compositions comprising nonionic surfactants that are suitable for washing of clothes, and methods of making and using the same. Traditional detergents used in laundry are typically formulated at a high pH (i.e., above 7), because high pH enables the use of traditional builders and surfactants. However, it has been found that certain acidic detergents (i.e., with pH below 7) may provide benefits such as improved removal of residues from fabrics and associated improvement in whiteness, improved bleachable stain removal, and self-preservation benefits. It is desirable to both the formulator and the consumer that such detergents have desirable viscosities. Compositions with viscosities that are too high may be difficult to process or to use; viscosities that are too low may indicate a lack of cleaning power or value to the consumer. In order to obtain desirable viscosities, many detergents, especially those that have high levels of water (e.g., above 60 percent), require the use of thickening agents. For example, a formulator may add salt, such as sodium chloride or sodium formate, to thicken compositions that have low viscosities.

Therefore, there is a need for an effective, low cost solution to thickening high water, low pH detergent compositions.

According to a first aspect of the invention there is provided a liquid laundry detergent composition comprising: a) from 20 percent to 40 percent by weight of the composition of a surfactant system, wherein the surfactant system comprises a first nonionic surfactant (A), a second nonionic surfactant (B), and anionic surfactants; b) from 0.1 wt% to 20wt% polyhydric C ₂ -C ₆ alcohol; c) a bleaching agent or enzymatic system; d) a pH regulating agent wherein the composition has a neat pH of from 2 to 7 and wherein the composition has a viscosity of above 200000 cps, measured at 1 s ^"1 at 20 degrees centigrade

It has been surprisingly discovered that the invention provides a high viscosity formulation at low pH, whilst providing a stable environment for bleaches (especially H2O2). Without wishing to be bound by theory it is postulated that this is due to the other ingredients of formula and its final pH.

According to a second aspect of the invention there is provided a method of

manufacturing a composition according to the first aspect of the invention.

The method of the invention has been found to be beneficial for thickened detergent compositions. In the method of the invention it has been found that on mixing the components of the formulation, the formulation is self-heating. The self -heating is postulated to be due to a neutralization process.

Preferably the self-heating and / or any other heating / cooling is controlled such that the temperature of the mixing process is in the range of about 45-50°C to guarantee H ₂ 0 ₂ /enzymes stability during the process.

The detergent compositions of the present invention may be in liquid, gel, or paste form. The compositions are typically gels. In some aspects, the compositions comprise from about 40 percent to about 60 percent, by weight of the composition, water.

In some aspects, the composition is in a unit dose form, where the composition is encapsulated in a water-soluble film or pouch; the water-soluble film or pouch may comprise polyvinyl alcohol, polyvinyl acetate, or mixtures thereof. In some aspects, the unit dose form comprises at least two compartments, or at least three compartments. In some aspects, at least one compartment may be superimposed on another

compartment. The surfactant system of the present compositions comprises a nonionic surfactant.

In some aspects, the detergent composition comprises from about 10 percent to about 20 percent, by weight of the detergent composition, of nonionic surfactant. Suitable nonionic surfactants useful herein include any of the conventional nonionic surfactants typically used in detergent products. These include, for example, alkoxylated fatty alcohols and amine oxide surfactants. Generally, the nonionic surfactants used herein are liquids. The nonionic surfactant may be an ethoxylated nonionic surfactant. These materials are described in U.S. Pat. No. 4,285,841, Barrat et a I, issued Aug. 25, 1981. In one aspect, the nonionic surfactant is selected from the ethoxylated alcohols and ethoxylated alkyl phenols of the formula R(OC ₂ H4) _n OH, where R is selected from the group consisting of aliphatic hydrocarbon radicals containing from about 8 to about 18 carbon atoms and alkyl phenyl radicals in which the alkyl groups contain from about 8 to about 16 carbon atoms, and the average value of n is from about 3 to about 15. These surfactants are more fully described in U.S. Pat. No. 4,284,532, Leikhim et a I, issued Aug. 18, 1981. In one aspect, the nonionic surfactant is selected from ethoxylated alcohols (also known as fatty alcohol ethoxylates) having an average of from about 10 to about 16 carbon atoms in the alcohol and an average degree of ethoxylation of from about 1 to about 12 moles of ethylene oxide per mole of alcohol.

A shorthand method of naming a fatty alcohol ethoxylate refers to its number of carbons in the alkyl chain and its average number of ethoxylate (EO) groups. For example, a fatty alcohol ethoxylate with from twelve to fourteen carbon atoms in its alkyl chain and an average of nine ethoxylate groups can be written as "C12,14 E09". This naming convention is used in this application.

In some aspects, the nonionic surfactant comprises C12-C18 alkyl ethoxylate. In some aspects, the C12-C18 alkyl ethoxylate is selected from the group consisting of: C12.16 E09; C12.16 E07; C12.16 E03; and mixtures thereof. In some aspects, the C12-C18 alkyl ethoxylate is C12,16 E07 and C12,16 E03, and in some aspects, the molar ratio of C12,16 E07 to C12,16 E03 is about 2: 1. In some aspects, the preferred HLB value of one of the nonionic surfactants is in the range from 5 to 10, most preferably from 7 to 9. The preferred HLB value of the other non-ionic surfactant may be in the range from 10 to 15, most preferably from 11 to 13. Further non-limiting examples of nonionic surfactants useful herein include: a) Ci ₂ - Ci8 alkyl ethoxylates, such as, NEODOL ^(R) nonionic surfactants from Shell; b) C6-C12 alkyl phenol alkoxylates where the alkoxylate units are a mixture of ethyleneoxy and propyleneoxy units; c) C12-C18 alcohol and C6-C12 alkyl phenol condensates with ethylene oxide/propylene oxide block polymers such as Pluronic ^(R) from BASF; d)

Alkylpolysaccharides as discussed in U.S. 4,565,647 to Llenado, issued January 26, 1986; specifically alkyl polyglycosides as discussed in US 4,483,780 and US 4,483,779; e) Polyhydroxy fatty acid amides as discussed in US 5,332,528, WO 92/06162, WO

93/19146, WO 93/19038, and WO 94/09099; and f) ether capped poly(oxyalkylated) alcohol surfactants as discussed in US 6,482,994 and WO 01/42408.

The surfactant system typically comprises anionic surfactants. In some aspects, the composition comprises, by weight of the detergent composition, from about 10 percent to about 20 percent, of anionic surfactants.

Suitable anionic surfactants include any conventional anionic surfactant or a mixture of them used in detergent products. These include, for example, the alkyl benzene sulfonic acids and their salts as well as alkoxylated or non-alkoxylated alkyl sulfate materials. The anionic surfactants may be present in acid form or in neutralized (e.g., salt) form. The anionic surfactants may be linear, branched, or a mixture thereof.

Exemplary anionic surfactants are the alkali metal salts of CurC alkyl benzene sulfonic acids or Cn-Ci ₄ alkyl benzene sulfonic acids. In some aspects, the alkyl group is linear, and such linear alkyl benzene sulfonates are known as "LAS." Alkyl benzene sulfonates, and particularly LAS, are well known in the art. Such surfactants and their preparation are described in, for example, U.S. Pat. Nos. 2,220,099 and 2,477,383. Especially useful are the sodium and potassium linear straight chain alkylbenzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 10 to about 14.

Sodium Cn-Ci ₄ , e.g., C12, LAS is a specific example of such surfactants. Another exemplary type of anionic surfactant is alkoxylated alkyl sulfate surfactants. Preferred are ethoxylated alkyl sulfate surfactants. Such materials are also known as alkyl ether sulfates, alkyl polyethoxylate sulfates, or simply "AES," and correspond to the formula: R'- O- (C2H ₄ 0)n- SO3M, where R' is a C8-C20 alkyl group; n is from about 0.5 to about 20, or from about 1 to about 20; and M is a salt-forming cation. In one aspect, R' is a CurC alkyl; n is from about 1 to about 15; and M is sodium, potassium, ammonium, alkylammonium, or alkanolammonium. In one aspect, R' is a Ci ₂ - Ci ₆ alkyl; n is from about 0.5 to about 6, or from about 1 to about 6; and M is sodium. Alkyl ether sulfates are generally available in the form of mixtures comprising varying R' chain lengths and varying degrees of ethoxylation. Frequently such mixtures also contain some non- ethoxylated alkyl sulfate ("AS") materials, i.e., surfactants of the above ethoxylated alkyl sulfate formula where n=0.

Non-ethoxylated alkyl sulfates may also be added separately to the compositions of the invention. Specific examples of non-alkoxylated alkyl ether sulfate surfactants are those produced by the sulfation of higher C ₈ -C20 fatty alcohols. Conventional primary alkyl sulfate surfactants have the general formula: ROS03-M ⁺ where R is a linear Cs-C20 hydrocarbyl group and M is a water- solubilizing cation. In one aspect, R is a CKTQ.S alkyl and M is alkali metal, more specifically R is C12-C14 and M is sodium. More preferably the polyhydric C2-C6 alcohol is present in an amount of 2-18wt%, most preferably about 5-8 wt%.

Suitable polyhydric C2-C6 alcohol include sorbitol, glycerol, propylene glycol, butylene glycol, hexylene glycol or ethylene glycol. Most preferably the polyhydric C2-C6 alcohol is glycerol. Desirable viscosities in the present compositions are generally obtained through the careful selection of surfactants rather than through the addition of thickening agents. In some aspects, therefore, the compositions described herein are substantially free of thickening agents. In other aspects, the compositions comprise thickening agents to further build viscosity. Therefore, in some aspects, the composition comprises from about 0.01 percent to about 1 percent, or from about 0.02 percent to about 0.75 percent, or from about 0.05 percent to about 0.5 percent, by weight of the composition, of a thickening agent. Thickening agents include methylcellulose, hydroxypropylmethylcellulose, xanthan gum, gellan gum, guar gum and hydroxypropyl guar gum, succinoglycan, and trihydroxy stearin. Other thickening agents include methylcellulose and

hydroxypropylmethylcellulose thickeners available under the Methocel(R) trade name from Dow Chemical and Alcogum L520 from Akzo Nobel. For the removal of doubt, as used herein, "thickening agent" does not include detersive surfactants or their salts.

Thickening agents also includes certain salts, such as sodium chloride or sodium formate. In low pH formulations, however, salts may be particularly undesirable, as salts may contribute to corrosion and stability issues. In some aspects, therefore, the compositions of the present disclosure are substantially free of alkali metal halides, alkali earth metal halides, or mixtures thereof. In some aspects, no alkali metal halides or alkali earth metal halides are added to the compositions as free components. In some aspects, the compositions are substantially free of sodium chloride and/or sodium formate. In some aspects, the compositions are substantially free of chloride ion and/or formate ion. In some aspects, the compositions are substantially free of formic acid. The compositions may comprise less than about 0.5 percent, or less than about 0.1 percent, or less than about 0.01 percent, by weight of the composition, of sodium chloride, or of halide ions, or of chloride ions.

The compositions described herein are low pH detergent compositions. By "low pH," it is meant that the compositions have a neat pH of less than about 7, or, in some aspects, of less than about 6.5. In some aspects, the compositions have a neat pH of from about 1.5 to about 6.9, or from about 2 to about 5, or from about 2 to about 4, or from about 3 to about 4, or about 3.5.

In some aspects, a neutralizing (or alkalizing) agent is added to the composition in order to obtain the desired final neat pH of the composition. Suitable neutralizing agents include alkaline metal, alkaline earth metal or substituted ammonium hydroxide, carbonate, bicarbonate, silicate, or mixtures thereof. Alternatively, the neutralizing agent may be an amine or amide. In some aspects, the neutralizing agent is an alkanolamine selected from monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), 2-aminopropanol, monoisopropanol amine (MIPA), or mixtures thereof. In some aspects, the alkalizing agent is NaOH, TEA, or mixtures thereof. In some aspects, the composition comprises less than about 6 percent, or less than about 5 percent, by weight of the composition of NaOH, TEA, or mixtures thereof. . In some aspects, the composition comprises less than about 4 percent of the alkalizing agent used.

In some aspects, the detergent compositions of the present disclosure are capable of delivering a pH to the wash water ("wash water pH"), for example of a standard laundry bucket, of less than about 6.5, or less than about 6.2, or less than about 6.0. In practical terms, the detergent compositions of the present invention are provided to the wash water in a sufficient amount such that the wash water contains from about 0.02 percent to about 4 percent, by weight of the wash water, of the detergent composition. In one aspect, the wash water contains from about 0.03 percent to about 3 percent, by weight of the wash water, of the detergent, alternatively from about 0.04 percent to about 2 percent (about 400 to about 20,000 ppm). As used herein, "reserve acidity" refers to the grams of NaOH per 100 g of product required to attain a pH of 7.00. The reserve acidity measurement as used herein is based upon titration (at standard temperature and pressure) of a 1 percent product solution in distilled water to an end point of pH 7.00, using standardized NaOH solution. Without being limited by theory, the reserve acidity measurement is found to be the best measure of the acidifying power of a composition, or the ability of a composition to provide a target acidic wash pH when added at high dilution into tap water, as opposed to pure or distilled water. The reserve acidity is controlled by the level of formulated organic acid along with the neat product pH.

The compositions described herein have a reserve acidity of at least about 1, or at least about 3, or at least about 5. In some aspects, the compositions herein have a reserve acidity to pH 7.00 of from about 3 to about 10, or from about 4 to about 7.

In some aspects, the compositions have viscosities greater than about 200000 cps (centipoise) measured at 1 s ^"1 at 20 degrees centigrade. In these definitions and unless specifically indicated to the contrary, all viscosities stated herein are measured at a shear rate of 1 s ^"1 and at a temperature of 20 degrees centigrade Viscosities can be measured with any suitable Rheology-measuring instrument, e.g., Haake RheoStress 1 Rheometer.

The compositions of the present invention may comprise one or more laundry adjuncts, such as dyes, bleaching agents, chelants, radical scavengers, perfumes, fluorescent whitening agents, suds supressors, soil suspension polymers, soil release polymers, dye- transfer inhibitors, fabric softening additives, structurant, builders, enzymes,

preservatives, solvents, clay soil removal / anti-redeposition agents, and/or other benefit agents. In some aspects, the composition may comprise from about 0.01 percent to about 50 percent of an adjunct listed herein. In other aspects, the composition may be substantially free of adjuncts. Suitable laundry adjuncts are further described, for example, in US Patent Application No. 13/623/128, incorporated herein by reference.

The compositions may comprise a dye to either provide a particular color to the composition itself (non-fabric substantive dyes) or to provide a hue to the fabric (hueing dyes). In one aspect, the compositions of the present invention comprise from about 0.0001 percent to about 0.01 percent, by weight of the composition, of a non-fabric substantive dye and/or a hueing dye. Examples of dyes useful herein include Basic Violet 3 (CI 42555) and Basic Violet 4 (CI 42600), both commercially available from Standard Dyes (High Point, NC), and Liquitint Violet 200 from Milliken Company. The compositions may comprise a bleaching agent. In some aspects, the compositions of the present invention may contain from about 0.10 percent to about 10 percent, by weight of the composition, of an activebleaching agent. Bleaching agents useful herein include hydrogen peroxide or peroxyacids, such as 6- phthalimidoperoxyhexanoic acid. In some aspects, the compositions may comprise a bleach activator, such as TAED or NOBS. When the composition is in a unit dose form having at least two, or at least three, compartments, the bleaching agent may be in a different compartment than the surfactant. In some aspects, the compositions are substantially free of bleaching agents. The compositions may comprise a chelant. Chelants useful herein include DTPA, HEDP, DTPMP, polyfunctionally-substituted aromatic chelants (such as l,2-dihydroxy-3,5- disulfobenzene (Tiron)), dipicolinic acid, and mixtures thereof.

The compositions may comprise a radical scavenger which may be used with liquid hydrogen peroxide to provide stability. Radical scavengers useful herein include trimethoxybenzoic acid.

The compositions of the present invention may comprise perfume. The perfume is typically an acid- stable perfume. The compositions may comprise from about 0.1 percent to about 5 percent, or from about 0.5 percent to about 4 percent, or from about 1 percent to about 3 percent, or from about 2 percent to about 2.5 percent, by weight of the composition, of perfume.

The compositions may comprise a fluorescent whitening agent. Fluorescent whitening agents useful herein include those that are compatible with an acidic environment, such as Tinopal CBS-X. The compositions may comprise suds suppressor. In some aspects, the compositions comprise from about 0.001 percent to about 0.02 percent, by weight of the

composition, of suds suppressor. Examples of suds suppressors useful herein include silica/silicone type, silicone oil, branched alcohols, or mixtures thereof.

The compositions may comprise from about 0.001 percent to about 0.5 percent by weight of the composition of soil suspension polymers. Soil suspension polymers include, without limitation, PEI ethoxylates, HMDA diquat ethoxylates, sulfonated derivatives, and hydrophobically modified anionic copolymers.

The compositions may comprise from about 0.001 percent to about 1 percent by weight of the composition of soil release polymers. Soil release polymers include, without limitation, a PET alkoxylate short block copolymer, an anionic derivative thereof, or mixtures thereof. The compositions may comprise dye transfer inhibitors and/or dye fixatives. Examples of dye transfer inhibitors useful herein include polyvinylpyrrolidone, poly-4-vinylpyridine- N-oxide, copolymers of N-vinyl-2-pyrrolidone and N-vinylimidazole, or mixtures thereof. Useful dye fixatives for this application are disclosed in US Patent No. 6,753,307. The compositions may comprise a fabric softening additive. Examples of fabric softening additives useful herein include alkyl quaternary ammonium compounds, ester quaternary ammonium compounds, silicones, cationic silicones, or mixtures thereof.

The compositions of the present invention typically rely on internal structuring rather than external structuring. By "internal structuring," it is meant that the detergent surfactants are relied on for structuring effect. On the other hand, "external structuring" means structuring that relies on a non- surfactant, e.g., crystallized glyceride(s), as structurants to achieve the desired rheology and particle suspending power.

In some aspects, the compositions of the present invention are substantially free of external structuring systems. In some aspects, the compositions are substantially free of hydroxyfunctional crystalline materials, including but not limited to hydrogenated castor oil (HCO). In some aspects, the compositions comprise less than about 0.01 percent, or less than about 0.001 percent, by weight of the composition, of hydroxyfunctional crystalline materials, or of hydrogenated castor oil. In other aspects, where additional structuring is desired, the compositions may comprise from about 0.01 percent to about 6 percent, by weight of the compositions, of hydroxyfunctional crystalline materials.

The compositions may comprise from about 0.00001 percent to about 0.1 percent active enzymes that are stable and effective in a low-pH environment. Suitable enzymes include carbohydrase, pectinase, mannanase, amylase, cellulase, lipase, protease, or mixtures thereof. The composition may comprise a builder. Suitable builders herein can be selected from the group consisting of phosphates and polyphosphates, especially the sodium salts; aluminosilicates and silicates; carbonates, bicarbonates, sesquicarbonates and carbonate minerals other than sodium carbonate or sesquicarbonate; organic mono-, di-, tri-, and tetracarboxylates especially water-soluble nonsurfactant carboxylates in acid, sodium, potassium or alkanolammonium salt form, as well as oligomeric or water- soluble low molecular weight polymer carboxylates including aliphatic and aromatic types; and phytic acid. These may be complemented by borates, e.g., for pH-buffering purposes, or by sulfates, especially sodium sulfate and any other fillers or carriers which may be important to the engineering of stable surfactant and/or builder-containing detergent compositions.

The compositions may comprise a preservative. Suitable preservatives may be selected by one of ordinary skill in the art and may include Proxel™ (available from Arch

Chemicals / Lonza). The composition may comprise from about 0.01 percent to about 2.0 percent, or about 0.1 percent to about 1.0 percent, or about 0.1 percent to about 0.3 percent, by weight of the composition, of preservative. In some aspects, the

compositions comprise less than 0.01 percent of a preservative. In some aspects, the compositions are substantially free of preservatives.

Solvents In some aspects, the composition comprises water and is substantially free of organic solvent. In other aspects, the composition may comprise organic solvent.

Preferred organic solvents include 1,2- propanediol, ethanol, glycerol, dipropylene glycol, monoethyleneglycol, methyl propane diol and mixtures thereof. Other lower alcohols, such C 1-C4 alkanolamines, e.g. monoethanolamine and/or triethanolamine, can also be used. In some aspects, the compositions comprise from about 0.05 percent to about 25 percent, or from about 0.1 percent to about 15 percent, or from about 1 percent to about 10 percent, or from about 2 percent to about 9 percent, by weight of the composition, organic solvent. In some aspects, the composition comprises less than 9 percent or less than 1 percent of organic solvent. The compositions may comprise clay soil removal / anti-redeposition agents, such as water-soluble ethoxylated amines. Other exemplary clay soil removal and anti- redeposition agents are described in U.S. Pat. Nos. 4,597,898; 548,744; 4,891, 160; European Patent Application Nos. 111,965; 111,984; 112,592; and WO 95/32272. In some aspects, the concentrated compositions comprise about 0.005 percent to about 5 percent by weight of clay soil removal / anti-redeposition agents. In some aspects, the composition is substantially free of clay soil removal / anti-redeposition agents.

The method of manufacturing for this invention is considered to be key to allow incorporating into the formula bleach (i.e. H ₂ 0 ₂ ) and/or enzymes without being degradated by the high temperatures generated while formulating and hence, allowing these ingredients to be stable for long period of time during storage.

In the method of the invention it has been found that on mixing the components of the formulation, the formulation is self-heating. The self -heating is postulated to be due to a neutralization process. Preferably the self-heating is controlled such that the temperature of the mixing process is in the range of about 45-50°C. Neutralization process is done in many separate steps as necessary until reaching the desired final pH and guaranteeing a constant

temperature in the range before mentioned. To guarantee H ₂ 0 ₂ /enzymes stability during the process, 45-50°C are kept constant long enough to allow processing but short enough to guarantee bleach/enzyme stability during manufacturing. According to a third aspect of the invention there is provided a method of use of a composition according to the first aspect of the invention.

Preferably the use is on fabrics / laundry.

Most preferably the method is for treating a stain. Generally the method involves one or more of the following steps:- a) The formulation is applied to an item of fabric (e.g. to a stain);

b) The item of fabric is washed (e.g. in an automatic laundry washing machine).

Preferably steps (a) and (b) are carried out in the order above.

The method of the invention has been found to be advantageous. Due to the consistency of the composition it does not leak in storage / application; also it stays for more time on the stain through the wash vs regular liquid laundry detergents. Further there is no residue left after washing. The present disclosure provides a method for treating a surface, for example, fabric, with the compositions disclosed herein. Following the treatment of the surface with the disclosed composition, the surface may optionally be dried. The surface may be contacted with the composition in neat form or in dilute form; in some aspects, the composition may be mixed with wash water. The method for treating a surface may be performed manually, such as by hand washing, or in an automated fashion, such as by a machine, e.g., a laundry washing machine.

The invention is now described with reference to the following non-limiting examples.

Example 1 - 3

Water 40-50

Polyhydric C2-C6 alcohol 5-8

C12-C16 Non ionic surfactant A 10-20 C12-C16 non ionic surfactant B 5 0

AlkyI benzene sulfonate 3-10

H202 50% 10

Chelant 0.01-0.2

TEA 1-5

Dye 1% 1

AlkyI ether sulfate 5-10

Total formula 100

Water 50-70

Polyhydric C2-C6 alcohol 5-8

C12-C16 Non ionic surfactant A 10-20

C12-C16 non ionic surfactant B 5-10

AlkyI benzene sulfonate 3-10

TEA 1-5

Dye 1% 1

AlkyI ether sulfate 5-10

Mannanase 0.1-1

Amylase 0.1-1

Protease 0.1-1

Stabilizer 0.05-1

Preservative 0.1-0.30

Total formula 100 Example 4

The H2O2 stability of formulation 2 was tested as below.

The formulation has been found to be physically stable under these conditions. H2O2 stable even at harsh conditions such 3w at 60°C and almost none gets lost during the manufacturing process even at high temperature.