Field of the invention

The invention is in the field of detergent compositions, in particular detergent composition providing a hygiene benefit, more in particular detergent compositions comprising active ingredients derived from natural origins.

Background of the invention

Fast moving consumer goods for household cleaning have traditionally provided hygiene. Cleaning hard surfaces, such as kitchen tops, floors, windows, bathrooms and toilets, regularly reduces the spread of diseases caused by amongst others viruses and pathogenic bacteria. The widespread use of household cleaning products has contributed to an increased life expectancy.

In particular consumers are constantly looking for improved cleaning compositions to provide hygiene to their homes, that do not harm the environment. Compositions for mopping floors and cleaning toilets, where the hygiene requirements are high, are the most sought after.

Present day consumers are becoming more and more concerned about the burden of synthetic hygiene ingredients to the environment and nowadays prefer more natural ways for providing hygiene.

Hydrogen peroxide is naturally occurring hygiene ingredient that can be formed from water by exposure to sunlight and is naturally occurring in plant and animal cells. It is biodegradable into water and oxygen.

At low concentration, hydrogen peroxide is an active disinfectant against some gramnegative bacteria, but activity against most gram-positive bacteria remains to be desired.

Synthetic surfactants have been used for providing hygiene benefits for over a century.

Such surfactants are typically made from mineral oil and one or more synthesis steps to provide the required head group. These surfactants contribute to the carbon footprint, are usually not biodegradable and end up in wastewater treatment plants or surface water. An alternative to synthetic surfactants are amino acid based surfactants, which have become available at larger scale in the recent years and provide detergent activity based on a naturally derived backbone of an amino acid and an oily chain.

EP 109279 discloses an improved hydrogen peroxide-based sterilizing and disinfecting solution which is stabilized to prevent decomposition of hydrogen peroxide and to prevent corrosion damage to medical instruments contacted with the solution. As pointed out in this application the stabilisation of peroxide is a concern and one solution is a high peroxide concentration, which is not preferred in household cleaning compositions.

CN111793530 discloses high-performance, safe and environment-friendly foam cleaning agent for bracket-free invisible appliance, and preparation method thereof, comprising hydrogen peroxide and sodium lauryl sarcosinate and relatively high concentrations.

US2009324508AA discloses a composition for use in a foam dispenser comprising hydrogen peroxide, alcohol and a foam booster. The foam booster is capable of providing a stable foam. The composition provided as a foam is suitable for disinfecting skin and/or mucous membranes.

LIS2021139818 AA discloses a cleaning solution including a primary solvent, a secondary solvent, wherein the secondary solvent is at least partially miscible with the primary solvent, an oxidising agent, wherein the oxidising agent includes a peroxide, and a chelating agent.

US 2019/0297881 A1 discloses antimicrobial composition having a pH of from about 0 to about 4.5, and comprising a synergistic combination of at least one peroxygen compound, and at least one anionic surfactant selected from the group consisting of alkyl sarcosines and salts thereof. The solutions are free of percarboxylic acids and precursors thereof, essential oils, bleaching agents, low molecular weight organic diamines, cationic surfactants, C1 -C4 aldehydes, ferrous salts, parabens, enzymes, and a poly(alkylene glycol) alkyl ethers containing four or more ether linkages. Dry compositions, uses and methods for sanitization, disinfection and sterilization are also disclosed. However, there is still a need for phosphorous free acid compositions.

An effective hygiene composition at low peroxide and low amino acid surfactant levels remains to be desired.

It is therefore an object of the present invention to provide a biodegradable cleaning composition.

It is a further object of the invention to provide a low hydrogen peroxide, low amino acid surfactant based hygiene composition.

It is yet a further object of the invention to provide a hygiene composition that is active against both gram-positive and gram-negative organisms.

Surprisingly, it has been found that a composition comprising low amounts of hydrogen peroxide and low amounts of an amino acid surfactant, in the presence of a low amount of alkyl polyglycoside (APG) and a suitable sequestrant provides high hygiene efficacy against both gram-positive and gram-negative organisms.

Summary of the invention

Accordingly, in a first aspect the invention provides a hard surface cleaning detergent composition comprising: 1-10 % wt based on the total detergent composition of hydrogen peroxide; 2-10 % wt based on the total detergent composition of an amino acid surfactant; 2-10 % wt based on the total detergent composition of an alkyl poly glycoside nonionic surfactant; a suitable amount of citric acid sequestrant; and wherein the pH of the composition is less than 5.

In a second aspect, the invention provides the use of a composition according to the invention. These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word “about”.

Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

Detailed description of the invention

The present invention provides a hard surface detergent composition comprising hydrogen peroxide, an amino acid surfactant, a non-ionic surfactant a sequestrant, and having a pH of less than 5.

In particular, the invention relates to compositions comprising low amounts of hygiene agents, to reduce the level of aggressive chemicals in the composition, while still maintaining a high hygiene efficacy. Hygiene efficacy for the purpose of this invention is determined by the bacterial kill rates of both gram-positive and gram-negative bacteria. The bacterial kill is generally measured in a “log kill number”, wherein the log refers to the logarithmic scale, that is measured as 1 point on the log scale, equalling a 10-fold change; for instance, a log kill of 1 , equals a 10 fold (=10 ¹ ) reduction in bacteria, or a log kill of 3 indicates a 1000 fold (=10 ³ ) reduction in bacteria. To provide hygiene in the context of this invention, the log kill rate is at least 2, more preferably at least 3, still more preferably at least 4 or even at least 5. Ultimately a full bacterial inhibition and full bacterial kill is the most preferred. The contact time at which the kill is achieved is also a relevant factor for use as a household cleaning formulation. Therefore, the contact time for obtaining the above bacterial kill is preferably less than 30 min, more preferably less than 20 min, still more preferably less than 15 min, even more preferably less than 10 min.

Hydrogen peroxide

The hydrogen peroxide is present in the composition in a concentration of 1-10 % wt based on the total detergent composition. Preferably the hydrogen peroxide is present in a concentration of at least 1 % wt, more preferably at least 2 % wt. For the best stability of the composition the peroxide is preferably present in a concentration of not more than 8 % wt, preferably not more than 6% wt, or even less than 5 % wt based on the total composition. By % wt is meant percent by weight.

Without wishing to be bound to a theory, it is found that the peroxide at low concentration provides anti-microbial (i.e. anti-bacterial) activity, in particular it provides the highest activity against gram-negative bacteria.

Amino acid surfactant

Amino acid surfactants are surfactants that may be produced by biotechnological and chemical methods using amino acids and (vegetable) oils or fat. Because amino acids and vegetable oils or fats are renewable sources, the class of amino acid surfactants are a suitable material in detergent compositions that are made from renewable sources. The combination of a polar amino acid and non-polar oil or fat chain provides molecules with high surface activity. Due to the wide variety of amino acids (and peptide) structures and the variety in the chain length of the oily or fat group, the properties of amino acid surfactant also vary, allowing for specific amino acid surfactants for specific purposes.

Without wishing to be bound to a theory, it is found that amino acid surfactants at low concentration provide anti-microbial (i.e. anti-bacterial) activity, in particular they provide enhanced activity against gram-positive bacteria. The amino acid surfactant is present in the composition in a concentration of 2-10 % wt based on the total detergent composition. Preferably the amino acid surfactant is present in a concentration of at least 2.5% wt, more preferably at least 3 % wt, but preferably not more than 8 % wt, more preferably not more than 6 % wt based on the total detergent composition.

The amino acid in the amino acid surfactant is preferably selected from glutamates, sarcosinates, glycinates or taurates; even more preferred are glutamates and sarcosinates. The oily of fatty chain is preferably a C6 - C16 fatty acid chain, more preferably C10 to C16, the most preferred fatty acid chains are lauroyl and cocoyl chains. The amino acid is preferably selected from disodium lauroyl glutamate, sodium lauroyl sarcosinate, sodium cocoyl glycinateand sodium methyl cocoyl taurate, even more preferred are lauroyl glutamate and sodium lauroyl sarcosinate.

Since the oily or fatty chain is typically derived from natural sources, the fatty acids and alcohols they are made of are not always a pure single chain length ingredient. By Cx- Cy is generally meant that at least 50% of the alkyl chains comprise of between x and y carbon atoms, preferably at least 60%, more preferably at least 70%, still more preferably at least 80%, even more preferably at least 90%, yet more preferably at least 95%, or even at least 98%, or ideally at least 99% of the alkyl chains comprise of between x and y carbon atoms.

Non-ionic surfactant

The composition further comprises an alkyl poly glycoside non-ionic surfactant (APG).

The alkyl poly glycoside surfactant is present in the composition in a concentration of 2 to 10 % wt based on the total detergent composition. Preferably, the alkyl poly glycoside is present in a concentration of at least 2.5 % wt, more preferably at least 3 % wt, but preferably not more than 8% wt, or even not more than 7 % wt based on the total detergent composition.

Preferably, the ratio of alkyl poly glycoside surfactant to the amino acid surfactant is between 2:1 and 1 :6, more preferably between 1 :1 and 1:4. Preferably, the ratio of alkyl poly glycoside surfactant to the peroxide is between 2:1 and 1 :6, more preferably between 1 :1 and 1:4.

The common non-ionic surfactants are ethoxylated alcohol non-ionic surfactants, being a condensation products of a fatty alcohol chain of between 8 and 22 carbon atoms and between 3 and 15 ethylene oxide units, but do not provide the right level of fast hygiene.

Without wishing to be bound by a theory, it is found that a low concentration of a specific class of non-ionic surfactants, alkyl polyglycosides, enhance the hygiene efficacy imparted by the combination of peroxide and amino acid surfactant; in particular, the alkyl polyglycoside provides for faster hygiene efficacy, requiring a shorter contact time.

The alkyl chain length is generally defined as an average alkyl chain length. The alkyl chain length of the alkyl poly glycoside preferably comprises between 4 and 18 carbon atoms, more preferably at least 6 carbon atoms, still more preferably at least 8 carbon atoms, but preferably not more than 14 carbon atoms, more preferably not more than 12 carbon atoms. The most preferred is 8 - 10 carbon atoms, such as a mixture of a C8 and C10 alkyl chains. The alkyl chain is preferably a linear alkyl chain. The alkyl chain is preferably derived from fatty alcohols, more preferably the alkyl chain is derived from natural fatty alcohols.

Surprisingly, the alkyl polyglycosides provides their hygiene efficacy enhancement effect at very low levels. Even more surprisingly, the effect is the strongest on hard-to- kill gram negative bacteria, such as E. coli. The amount of alkyl polyglycoside is therefore preferably present in a lower amount than the sum of the amount of peroxide and the amino acid surfactant; i.e. in a lower concentration than the sum of the concentrations of peroxide and amino acid surfactant taken together. Sequestrant

To avoid that the activity of the surfactants in the composition, especially the amino acid surfactant, is reduced, the composition further comprises a suitable amount of sequestrant.

Such sequestrant may be preferably selected from phosphonate based sequestrants, sequestrant that are selected from natural, naturally derived, bio-sourced, biodegradable; or combinations thereof.

Natural sequestrant are typically selected from organic acid salts having their lowest dissociation constant (pK _a i) in water at a pK _a value of between 2.5 and 4, measured at a temperature of 20 degrees Celsius (20 °C), more preferably at least 2.75, but preferably not more than 3.75, or even not more than 3.5. The most preferred organic acids are naturally sourced organic acids.

The most preferred organic acid sequestrant is sodium citrate.

The sequestrant is preferably present in the composition in a concentration of 0.5-5% wt based on the total composition, preferably at least 1 % wt, still more preferably at least 1.5 % wt, but preferably not more than 4 % wt, more preferably not more than 3.5 % wt based on the total composition. pH of the composition

The pH of the composition is less than 5, preferably, the pH is between 2.5 and 5. More preferably the pH of the composition is at least 2.75, or even at least 3, while it is preferably not more than 4.5, still more preferably not more than 4, even more preferably not more than 3.5.

Further ingredients.

The composition may further comprise common additives such as preservative, hydrotrope, solvent, organic acids, chelating agent, buffer, salt, perfume and/or dye. Without wishing to be bound to a particular theory, it is noted that additives having a negative influence one the hygiene efficacy if the composition are not preferred in the composition.

Application and format

The composition is preferably applied to a surface after dilution. The surface may be wiped or rinsed before and after application, but may also be left to dry after application of the composition.

The composition may be applied in any conventional means, such as by means of a cloth, wipe or sponge, or by means of a trigger spray dispenser or any mechanical means for ejecting the liquid in spray or aerosol form.

The composition may be packaged in a closable container, such as a bottle of any conventional shape or form. The container preferably has a volume of between 50 and 1500 ml, preferably at least 100 ml, more preferably at least 150 ml, or even at least 200 ml. As a general purpose composition, the container is preferably a bottle for pouring the composition into a bucket of water, the volume of the bottle is preferably not more than 1500 ml, more preferably not more than 1000 ml.

For application of mopping floors, the use of the composition according to the invention is provided. Typically the composition is used for mopping in a 1 :10-1 :100 dilution with water.

For application of toilet cleaning, the use of the composition according to the invention is provided. Typically the composition is used for toilet cleaning in 1 :10-1:20 dilution with water.

Examples

The invention will now be illustrated by means of the following non limiting examples.

In these examples, the compositions according to invention are compared to comparative compositions by means of a suspension test. The suspension test in this example is according to the common test protocol of EN1276.

The bacterial cultures as used have a bacterial count of having 10 ⁸ bacteria per ml)

In this test 8ml of formulation was used together with 1 ml of bacterial and 1 ml of BSA solution. The BSA solution is at a concentration of 0.03% to mimic a “clean” surface condition.

Therefore, after mixing 1 ml of culture with 8 ml of formulation and 1 ml of BSA solution the bacterial count is diluted 10 times, thus resulting in a bacterial count at the start of the experiment of 10 ⁷ bacteria per ml.

The formulation and bacteria are in contact for appropriate time points (1 to 15 min, as specified in the examples below) and then neutralized (to quench the efficacy of the actives and stop its action against bacteria). With respect to a water control, the bacterial log reduction through formulations is be calculated and marked in the respective tables in the examples below. Evaluation of antimicrobial efficacy is done as such or after dilutions as specified in the data set.

The examples are carried out at room temperature of 23 °C.

Target organism:”

Pseudomonas aeruginosa ATCC 15442

Staphylococcus aureus ATCC 6538

Enterococcus hirae ATCC 10541

Escherichia coli ATCC 10536

E. coli and P. aeruginosa are gram-negative bacteria and S. aureus and E. hirae are gram-positive.

The ingredients in the below examples are generic pure ingredients, available from Sigma Aldrich, except those in the table below, which are specifically defined.

In the examples hereinbelow, the concentrations are the actual concentrations in the composition, corrected for their purities. This means - in a theoretical example - that if the concentration of an ingredient in the examples below is indicated as e.g. 2%, while the purity of the ingredient is 50%, the amount of ingredient used, would be 4%.

Example 1: anti-bacterial efficacy test; variation of non-ionic surfactant.

In this example the effect of alkyl poly glycoside is compared to a common ethoxylated alcohol surfactant.

The amino acid surfactant is Di-Sodium Lauroyl Glutamate surfactant and the pH of the formulation is adjusted to 4.5 using HCI solution. Sodium citrate is added as sequestrant for hard water ions (required according to EN1276 protocol when the assay is done at higher dilution). Mono Propylene Glycol was added as solubiliser, but is not required for the invention.

The following formulations were prepared:

Example formulations 1 is according to the invention, formulation A is a comparative example formulation. All the ingredients are homogenised in a conventional manner for 15 min. The final pH of the formulation is adjusted using HCL solution.

The formulations were diluted 1:20 before mixing with the bacterial culture and BSA solution and tested according to the above mentioned protocol against the target micro organisms for a contact time of 15 min.

The table above shows the log kill number for all experiments after 15 min of contact time before quenching. Considering that the cell culture had a bacterial count of 10 ⁸ bacteria per ml, and that it was diluted 10 times by mixing with the cleaning composition and BSA solution, the starting amount of bacteria was 10 ⁷ per ml (i.e. 10,000,000), while a 5 log reduction means a reduction by a factor 10 ⁵ (i.e. a factor 100,000). At a kill rate of >5 it is difficult to get a reliable count on the remaining bacteria. Therefore no specific count numbers are given above 5 log kill.

The results show that at a contact time of 15 min, bacterial kill is achieved with APG vs an alternative non-ionic (C12-15 EO7), In household cleaning the contact time matters a lot while mopping a floor or cleaning a toilet the acceptable contact time is about 15 min.

Example 2: anti-bacterial efficacy test; variation of non-ionic surfactant and amino acid surfactant concentration were both varied.

In this example the effect of alkyl poly glycoside is compared to a common ethoxylated alcohol surfactant, while the concentration of the amino acid surfactant is also varied.

The amino acid surfactant is Sodium Lauroyl Sarcosinate surfactant and the pH of the formulation is adjusted to 4.5 using HCI solution. Sodium citrate is added as sequestrant for hard water ions (required according to EN1276 protocol when the assay is done at higher dilution). Mono Propylene Glycol was added as solubiliser, but is not required for the invention.

The following formulations were prepared:

Example formulations 1 is according to the invention, formulation A is a comparative example formulation.

All the ingredients are homogenised in a conventional manner for 15 min. The final pH of the formulation is adjusted using HCL solution.

The formulations were diluted 1:20 before mixing with the bacterial culture and BSA solution and tested according to the above mentioned protocol against the target micro organisms for a contact time of 15 min.

The below results were all carried out under clean surface conditions, after 15 min contact time with the compositions, before being neutralised to quench the hygiene activity.

Results after 15 min contact time before quenching. Results after 5 min contact time before quenching (gram positive organisms only).

The table above shows the log kill number for all experiments after 15 min of contact time before quenching. Considering that the cell culture had a bacterial count of 10 ⁸ bacteria per ml, and that it was diluted 10 times by mixing with the cleaning composition and BSA solution, the starting amount of bacteria was 10 ⁷ per ml (i.e. 10,000,000), while a 5 log reduction means a reduction by a factor 10 ⁵ (i.e. a factor 100,000). At a kill rate of >5 it is difficult to get a reliable count on the remaining bacteria. Therefore, no specific count numbers are given above 5 log kill.

The results show that at a contact time of 15 min, bacterial kill is achieved with APG vs an alternative non-ionic (C12-15 EO7), In household cleaning the contact time matters a lot while mopping a floor or cleaning a toilet the acceptable contact time is about 15 min. Additionally the results show that even after only 5 min, the composition according to the invention provides a good kill rate against the gram-positive bacteria.

Example 3: comparing different organic sequestrants.

In this example the effect of alkyl poly glycoside is compared to a common ethoxylated alcohol surfactant, while the concentration of the amino acid surfactant is also varied.

The amino acid surfactant is Sodium Lauroyl Sarcosinate surfactant and the pH of the formulation is adjusted to 4.5 using HCI solution. Sodium citrate is added as sequestrant for hard water ions (required according to EN1276 protocol when the assay is done at higher dilution). The following formulations were prepared:

Example formulations 4 is according to the invention, formulation D is a comparative example formulation.

All the ingredients are homogenised in a conventional manner for 15 min. The final pH of the formulation is adjusted using HCL solution.

The formulations were diluted 1:20 and 1 :15 respectively (see below) before mixing with the bacterial culture and BSA solution and tested according to the above mentioned protocol against the target micro organisms for a contact time of 15 min.

The below results were all carried out under clean surface conditions, after 15 min contact time with the compositions, before being neutralised to quench the hygiene activity.

Results for 1 :20 dilution after 15 min contact time before quenching.

Results for 1 :15 dilution after 15 min contact time before quenching. The table above shows the log kill number for all experiments after 15 min of contact time before quenching. Considering that the cell culture had a bacterial count of 10 ⁸ bacteria per ml, and that it was diluted 10 times by mixing with the cleaning composition and BSA solution, the starting amount of bacteria was 10 ⁷ per ml (i.e. 10,000,000), while a 5 log reduction means a reduction by a factor 10 ⁵ (i.e. a factor 100,000). At a kill rate of >5 it is difficult to get a reliable count on the remaining bacteria. Therefore, no specific count numbers are given above 5 log kill. The results show that at a contact time of 15 min, the bacterial kill achieved with citric acid sequestrant is far superior to salicylic acid as sequestrant.