WO2023078887A1

WO2023078887A1 - Biocidal compositions for laundry washing processes

Info

Publication number: WO2023078887A1
Application number: PCT/EP2022/080488
Authority: WO
Inventors: Roger BRUNET I ESPINOSA; Ana COSTAN LONGARES
Original assignee: La Superquimica, S.A.
Priority date: 2021-11-03
Filing date: 2022-11-02
Publication date: 2023-05-11

Abstract

The invention discloses biocidal compositions comprising quaternary ammonium compounds and a pH buffer system. The biocidal components in the composition are salts of octyl decyl dimethyl ammonium (ODDA), salts of dioctyl dimethyl ammonium (DODA), and salts of didecyl dimethyl ammonium (DDA). These biocidal compositions are useful as additives for laundry processes to eliminate and to control the growth of wide spectrum of microorganisms on the washed fabrics. A laundry process is also disclosed.

Description

Biocidal compositions for laundry washing processes

This application claims the benefit of European Patent Application 21382992.2 filed on 03.11.2021.

Present invention relates to the field of biocidal compositions comprising quaternary ammonium salts (abbreviated as quats) used in laundry washing processes.

Background Art

Due to certain particularities of fabrics constituting clothes, or simply because time and energy wants to be spared, laundry at home or at industrial level is increasingly carried out at low temperatures. During laundry the main object is obviously that clothes or fabrics (woven or non-woven) are effectively cleaned and any spot and/or malodour disappear.

These washing procedures at low temperature make, however, that sometimes a complete hygienic levels or standards are not achieved. For example, certain microorganisms adhered to clothes are sometimes not well eliminated, occasioning later not only malodour in the already washed clothes, but also facilitating possible contamination. This later is of relevance if pathological microorganisms could have been adhered on the fabrics (e.g., clothes with spots of infected wounds), since even washed, the clothes are still possible focus or source of infections.

This is the reason why, even from remote times, bleach and other disinfectants have been added during laundry. However, it is widely known that bleach is highly toxic, and it can damage fabrics and affect coloured or stained clothes.

For this reason, other disinfectants, such as certain biocides have been used as additives during rinsing. A biocide is defined in the European legislation as a chemical substance or microorganism intended to destroy, deter, render harmless, or exert a controlling effect on any harmful organism. The US Environmental Protection Agency (EPA) uses a slightly different definition for biocides as "a diverse group of poisonous substances including preservatives, insecticides, disinfectants, and pesticides used for the control of organisms that are harmful to human or animal health or that cause damage to natural or manufactured products". When compared, the two definitions roughly imply the same, although the US EPA definition includes plant protection products and some veterinary medicines.

Among the biocidal compounds used in many fields, quaternary ammonium salts have been widely used due to their high efficacy against a wide spectrum of microorganisms. Indeed, many of them are also employed adsorbed in wipe tissues as cleaning or disinfecting means of surfaces or medical instrumentation.

Quaternary ammonium compounds have also been proposed as biocidal compounds in compositions for laundry (additives for rinsing). As a mode of example, international patent application with publication number WO2018108466 (CONPCO) discloses compositions comprising didecyldimethyl ammonium chloride (DDAC), benzyl C12-16 alkyl dimethyl chlorides (ADBAC) and C12-14-alkyl[(ethylphenyl)methyl]dimethyl chlorides (ADEBAC), which act synergistically with lactic acid as biocidal mixture for laundry purposes. Good results are shown with Pseudomonas aeruginosa using an assay (EN1276) in which microorganisms are grown in suspension. The biocidal compositions proposed by authors are complex mixtures with many components.

Also, international patent applications with publication numbers W02002023990 and W02002023992 (both of LONZA AG), provide disinfectant compositions for laundry and including several quaternary ammonium compounds and/or alkanolamine compounds (W02002023990) or guanidine salts (W02002023992). They are, in particular, effective for controlling growth of Aspergillus niger. These are, therefore, effective but complex compositions.

Although quaternary ammonium compounds are not exempted of toxicity and certain caution is to be taken in consideration, their toxicity is lower than bleach. This makes however that their amounts in the compositions must be adjusted with the consequent reduction of their efficacy. Compositions for laundry, in addition, must be conceived thinking that the active components will be highly dissolved in the wash liquor (i ,e. , in the final volume of water and additional components in which clothes and fabrics will be immersed). Therefore, adjusting of amounts is certainly an issue, in order efficacy is maintained once these compounds are dissolved during laundry, in particular during the rinsing in the laundry process.

In addition, it is widely known that quaternary ammonium compounds tend to be adsorbed to the fibres of fabrics, due to negatively charged groups in these fibres that attract and fix cationic compounds as quaternary ammonium compounds (i.e., salts). This is, indeed, the main reason why many quaternary ammonium compounds are used adsorbed in hygienic wipes for surface disinfection, as previously indicated. An in-depth analysis of causes involved in adsorption of ADBAC onto cotton nonwoven substrates is disclosed by Hinchliffe et al., "The adsorption of alkyl-dimethyl-benzyl-ammonium chloride onto nonwoven hydroentangled substrates at the solid-liquid interface is minimized by additive chemistries”, Textile Research Journal 0(00) 1- 11 . A more alkaline solution increases the amount of ADBAC adsorbed onto nonwoven fabrics, while a more acidic solution reduces ADBAC adsorption. Likewise, increasing the temperature and concentration of salts in the solution reduces the adsorption onto the fabrics too. Thus, at least acid environments are preferred to avoid adsorption of the quaternary ammonium compounds.

However, an added problem of using compositions with a low pH to avoid adsorption onto fibres of quaternary ammonium compounds, is that very acidic compositions are corrosive to user's skin in case of drop, and also for the clothes to be washed.

The international patent application with publication number WC2021156297 (ARCH UK BIOCIDES, LTD) discloses acidic compositions with pH in a controlled range and including one or more quaternary ammonium compounds. Some of the compositions, in particular those including tartaric acid are proved to be effective against Klebsiella pneumoniae. Other mixtures including several quaternary ammonium compounds were proved effective against Pseudomonas aeruginosa and Staphylococcus aureus with logarithmic reductions around 3.0-4.0 (Example 9). Reductions about 2.0-2.5 were supposedly also achieved in Pseudomonas with compositions including certain quaternary ammonium compounds and buffer systems including sodium citrate and chlorhydric acid (Example 7). However, in order to reach some of the indicated pH on use, the amount of chlorhydric acid needed is too high, giving corrosive concentrated formulas, which odour cannot be masked with any perfume. Besides, the reproduction of the formulas with sodium citrate and HCI at the indicated pHs (i.e., from 2.5 in concentrated formula to 3.61 on use at the indicated dilutions), are difficult to be obtained, since at the indicated dilution on use the pH reaches values around 6. Other examples in WO2021156297 attempt to disclose the effect of the final amounts on use of the quaternary ammonium compositions at different pHs on use, although the buffer system is not disclosed (Example 8). When a pH on use is fixed, the higher the amount of quaternary ammonium compounds (i.e., ppm), the higher the effectivity on Pseudomonas, as expected. Notwithstanding this, the data in this Example 8 cannot be conclusive, since the applied standard for the analysis is not disclosed.

Therefore, there is still a need of effective biocidal compositions to be used during laundry washing, particularly as additive during rinsing, and that can avoid or reduce the above-mentioned drawbacks.

Summary of Invention

Inventors have surprisingly realised that with only three (or four) quaternary ammonium compounds (quats), biocidal compositions useful as additives for rinsing during laundry can be obtained. They are highly effective against a wide spectrum of microorganisms, including yeast and bacteria.

The compositions of the invention suppose an optimal solution balancing toxicity of these compounds and efficacy in use. Indeed, a synergistic effect was observed if these quaternary ammonium compounds were combined with adequate pH adjuster compounds, such as pH buffer systems, which adjusters (e.g., buffer systems) allowed a pH on use during laundry processes within an interval (3.0-5.0). This synergistic effect of the combination of quaternary ammonium compounds and the pH on use was unexpectedly not due to a differential adsorption of the compounds to fibres. Thus, high efficacy observed was independent of the adsorption of these compounds to the fibres of fabrics at low pHs.

Due to this synergy, even low amounts of the compositions provide high reduction of microorganism counts in the clothes or fabrics that are washed.

Thus, a first aspect of the invention relates to an aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the acid is a multicarboxylic acid, and it is selected from succinic acid or a composition comprising succinic acid, and/or citric acid in a composition comprising citric acid and a chelating agent, or, alternatively

- the acid is other than a multicarboxylic acid and it is in a pH buffer composition, or pH buffer system, that comprises the base selected from an alkaline hydroxide or an amine;

- the quaternary ammonium compounds comprise a salt of octyl decyl dimethyl ammonium (ODDA), a salt of dioctyl dimethyl ammonium (DODA), and a salt of didecyl dimethyl ammonium (DDA), these quaternary ammonium compounds in a total amount in the composition that when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w, the sum of the amounts of these quaternary ammonium compounds in the diluted composition is of at least 120 parts per million (PPm);

- the pH of the composition is from 1 .5 to 3.0; and

- the pH adjuster is in an amount such that is capable of giving a pH from 3.0 to 5.0 when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w.

Particularly, an aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the acid is a multicarboxylic acid, which is citric acid in a composition comprising citric acid and a chelating agent,

- the quaternary ammonium compounds comprise a salt of octyl decyl dimethyl ammonium (ODDA), a salt of dioctyl dimethyl ammonium (DODA), and a salt of didecyl dimethyl ammonium (DDA), these quaternary ammonium compounds in a total amount that when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w, the sum of the amounts of the quaternary ammonium compounds in the diluted composition is of at least 120 parts per million (ppm);

- the pH of the composition is from 1 .5 to 3.0; and

These compositions are, indeed, biocidal compositions and they imply the advantages of being simple compositions that contain low amounts of the active biocidal components. Albeit these low amounts of active ingredients, the compositions provide high reduction grades of microorganisms adhered in fabrics or clothes.

Furthermore, the effective composition with the only biocidal components being the quaternary ammonium compounds, allows avoiding the use of other components with biocidal activity that are usually employed, and which would suppose adding more toxic compounds to the mixture. This is achieved even with only the three previously disclosed quaternary ammonium compounds.

In addition, due to high solubility of the quaternary ammonium compounds and the pH adjuster, manufacturing of the composition is costly effective and a non-complex process.

As will be illustrated below, this first aspect can also be defined as an aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the acid is other than a multicarboxylic acid and it is in a pH buffer composition, or pH buffer system, that comprises the base selected from an alkaline hydroxide or an amine,

- the quaternary ammonium compounds comprise a salt of octyl decyl dimethyl ammonium (ODDA), a salt of dioctyl dimethyl ammonium (DODA), and a salt of didecyl dimethyl ammonium (DDA), these quaternary ammonium compounds in a total amount in the composition from 1.5 % w/w to 5.0 % w/w; and

- the pH of the composition is from 1 .5 to 3.0.

Particularly, the aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the pH of the composition is from 1 .5 to 3.0.

Disclosed is herewith a method of manufacturing an aqueous composition as defined above, the method comprising the steps of:

(i) adding in a recipient an amount of water which is the half amount of total water in the composition, and the salts of quaternary ammonium, and stir the mixture until the salts are dissolved;

(ii) add, in any order while stirring, the pH adjuster system (e.g., the components of the pH buffer system), and optionally the one or more of the additives, wherein if perfume is added as an additive, at least one surfactant is added first and the mixture is stirred to obtain homogeneous distribution of the said surfactant; and

(iii) add while stirring an additional amount of water, which is the other half amount of total water in the biocidal composition and keep stirring at least for 5 minutes or for a period allowing dissolution of all components.

Thus, the aqueous compositions of the invention are suitable compositions or ingredients to be employed during laundry, in order to eliminate any microorganism, that either could have been adsorbed at fabrics, or that were released/suspended at water bath. Moreover, the compositions of the invention are free of any mal odour, at the same time they are useful to extract mal odours, of any surfaces or materials to which they are applied to remove (i.e., to kill) the microorganisms causing any mal odour.

For this reason, another aspect of the invention is the non-therapeutic use of the aqueous composition as defined in the first aspect, as a biocidal composition.

Advantageously, the compositions are effective in either hard or soft water, which make them worldwide distributable.

This biocidal composition is used as rinsing additive in the laundry washing processes, in the same way other compositions, such textile softeners, are employed. Thus, the compositions are conceived as additives to be added or put into contact with clothes during rinsing, for example after a previous washing step with common detergents. Therefore, another aspect of the invention is the use of the aqueous composition as biocidal additive composition for laundry.

Finally, it is also another aspect, a method for laundry washing comprising adding to a recipient for laundry comprising water, a dose of the aqueous biocidal composition as defined above.

Detailed description of the invention

All terms as used herein in this application, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. Other more specific definitions for certain terms as used in the present application are as set forth below and are intended to apply uniformly through-out the specification and claims unless an otherwise expressly set out definition provides a broader definition.

As used herein, the indefinite articles "a” and "an” are synonymous with "at least one” or "one or more.” Unless indicated otherwise, definite articles used herein, such as "the,” also include the plural of the noun.

The "laundry wash liquor” or "washing liquor” (used interchangeably) is the mixture of water and mixture of the biocidal composition.

As previously disclosed, one aspect of the invention is an aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the quaternary ammonium compounds comprise a salt of octyl decyl dimethyl ammonium (ODDA), a salt of dioctyl dimethyl ammonium (DODA), and a salt of didecyl dimethyl ammonium (DD A), these quaternary ammonium compounds in a total amount that when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w, the sum of the amounts of these quaternary ammonium compounds in the diluted composition is of at least 120 parts per million (ppm);

- the pH of the composition is from 1 .5 to 3.0; and

- the pH adjuster system is in an amount such that is capable of giving a pH from 3.0 to 5.0 when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w.

- the pH of the composition is from 1 .5 to 3.0; and

Also as before, the first aspect can also be defined as an aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the acid is a multicarboxylic acid, and it is selected from succinic acid or a composition comprising succinic acid, and/or citric acid in a composition comprising citric acid and a chelating agent, or, alternatively - the acid is other than a multicarboxylic acid and it is in a pH buffer composition, or pH buffer system, that comprises the base selected from an alkaline hydroxide or an amine,

- the pH of the composition is from 1 .5 to 3.0.

All the embodiments apply equally to any of the definition modes of this first aspect. pH values indicated in this description are those obtained by commonly known measure methods, using pH meters, such as equipment HANNA HI 2250, at room temperature conditions (i.e., T^a of 20-30°C, and atmospheric pressure). A pH meter is a scientific instrument that measures the hydrogen-ion activity in waterbased solutions, indicating its acidity or alkalinity expressed as pH. The pH meter measures the difference in electrical potential between a pH electrode and a reference electrode, and so the pH meter is sometimes referred to as a "potentiometric pH meter". The difference in electrical potential relates to the acidity or pH of the solution.

In chemistry, pH is a scale used to specify how acidic or basic a water-based solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH. At room temperature (in particular 25 °C), pure water is neither acidic nor basic and has a pH of 7.

The pH scale is logarithmic and approximates the negative of the base 10 logarithm of the molar concentration (measured in units of moles per litre) of hydrogen ions in a solution. More precisely it is the negative of the base 10 logarithm of the activity of the hydrogen ion. At 25 °C, solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. The neutral value of the pH depends on the temperature, being lower than 7 if the temperature increases. The pH value can be less than 0 for very strong acids, or greater than 14 for very strong bases. The term "pH adjuster” or "pH adjuster compound(s)” or "pH adjuster system” or "pH buffer composition/system” (used in this description as synonymous) relates to one or more compounds used for providing to a composition where it(they) is(are) added a nearly constant pH value. Particular pH adjusters systems include multicarboxylic acids, as well as pairs of acids and bases (i.e. , pH buffer systems). In the particular cases of multicarboxylic acids, the pH adjuster system comprises the acid and its conjugated base in the proportion according to the thermodynamic equilibrium, which depends in part of the dissociation constant or constants of each of the protons of the carboxylic (-COOH) groups. The term "pH buffer system” relates to aqueous solutions of acids and bases that are used as a means of keeping pH at a nearly constant value, since pH changes very little when a small amount of another acid or base is added to it.

At a pH from 3.0 to 5.0, once the composition of the invention was diluted, observed reduction of microorganism population was unexpectedly high for several species, such as Enterococcus hirae and in Pseudomonas aeruginosa.

In more a particular embodiment of the first aspect, the pH adjuster system (either the indicated multicarboxylic acids or an acid other than a multicarboxylic acid in a buffer composition comprising an alkaline hydroxide as accompanying base) is in an amount such that is capable of giving a pH from 3.0 to 4.0 when the biocidal aqueous composition is diluted with water at a final weight percentage of the biocidal composition from 0.2 % w/w to 3.5 % w/w, in particular from 0.5 % w/w to 3.5 % w/w, in particular from 1 .0 % w/w to 3.5 % w/w, in particular from 0.5 % w/w to 2% w/w. At this pH range on use (i.e., once diluted in water or in a wash liquor) most of the microorganisms are effectively killed with logarithm reductions that amount from 3.5 to near 7 (6.65). pH on use from 3.0 to 4.0, when the biocidal aqueous composition of the invention was diluted with water at a final weight percentage of the biocidal composition from 0.2 % w/w to 3.5 % w/w, in particular from 1 .0 % w/w to 2.5 % w/w, was already effective against populations of Pseudomonas aeruginosa, Candida albicans, Staphylococcus aureus and Enterococcus hirae.

In a particular embodiment of the first aspect, the pH adjuster system is in an amount such that is capable of giving a pH selected from 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8,

4.9, and 5.0, when the biocidal aqueous composition is diluted with water at a final weight percentage of the biocidal composition from 0.2 % w/w to 4.0 % w/w. In another particular embodiment, the pH adjuster is in an amount such that is capable of giving a pH selected from 3.0 up to 4.8, when the biocidal aqueous composition is diluted with water at a final weight percentage of the biocidal composition from 0.2 % w/w to 4.0 % w/w. pH of the aqueous composition (i.e., biocidal composition), prior to any dilution in water, is from 1 .5 to 3.0. In a particular embodiment pH of the composition prior to any dilution in water is selected from 1 .5, 1 .6, 1 .7, 1 .8,

1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, and 3.0. In another particular embodiment, optionally with one or more features of the embodiments of the composition of the first aspect, the pH of the composition prior to any dilution in water is from 1.8 to 2.8. More in particular it is selected from 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7 and 2.8. In another particular embodiment of the first aspect, the pH adjuster system is a composition comprising citric acid and a chelating agent. "Chelating agents”, also referred as chelants, chelators, or sequestering agents, are compounds acting as ligands to metal ions, in such a way that the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom is involved. The presence of this chelating agent in the formula of the invention, is to allow the maintenance of the pH in the composition of the invention, as well as when diluted for its use. Moreover, the combination of citric acid or a salt thereof with a chelating agent allows a concentrated composition which is non- dermatologically corrosive. Examples of chelating agents include the L-glutamic acid N,N-diacetic (Dissolvine GL) or a salt thereof, such as an alkaline or alkaline-earth salt, the acid ethylene diamine tetra acetic acid (EDTA) or their salts, such as alkaline or alkaline-earth salts (in particular the sodium salt), Methylglicine N,N- diacetic acid or a salt thereof, such as alkaline or alkaline-earth salts (in particular the trisodium salt ), Ethanoldiglycinic acid or a salt thereof, such as alkaline or alkaline-earth salts (in particular the disodium salt), Diethylenetriaminepentaacetic acid or a salt thereof, such as alkaline or alkaline-earth salts (in particular the pentasodium salt), Hydroxyethylethylenediaminetriacetic acid, such as alkaline or alkaline-earth salts (in particular the trisodium salt), and combinations of the said chelating agents. In a most particular embodiment, the pH adjuster system comprises citric acid and the L-glutamic acid N, N-diacetic acid or its sodium salt (i.e., tetrasodium salt).

For the purpose of the invention, the terms "L-glutamic acid-diacetic acid tetrasodium salt” and "tetrasodium N,N-Bis(carboxymethyl)-L-glutamate” have the same meaning and are used interchangeable. They refer to a compound having the CAS number 51981-21-6 commercially available with the trademark Dissolvine® (Dissolvine GL by Nouryon). For the purpose of the invention, the L-glutamic acid-diacetic acid tetrasodium salt is an amino-based chelating agent.

In a more particular embodiment, the weight ratio of citric acid:chelating agent is from 3:1 to 15:1. Even in a more particular embodiment, it is from 5:1 to 13:1, being more in particular 5.3; 1 or 6.5:1.

"Multicarboxylic acid” or "polyprotic acid” (used interchangeably) is to be understood as an organic carboxylic acid with two or more carboxylic (-COOH) groups, in particular selected from two, three, and four carboxylic groups. In a more particular embodiment, the pH adjuster system is a multicarboxylic acid containing composition, said multicarboxylic acid with pKa(s) from 1 .0 to 6.5 for each of the carboxylic groups. More in particular with pKa(s) from 2.0 to 6.5, more in particular selected from 1 .0, 1 .2, 1 .4, 1.6, 1 .8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.5, and combinations of these pKa values. In a particular embodiment, the pH adjuster system is a multicarboxylic acid containing composition, said multicarboxylic acid with pKa(s) from 3.0 to 6.5 for each of the carboxylic groups

"pKa” is the negative of the logarithm of the acid dissociation constant (Ka) of the one or more protons (H+) in an acid. The values indicated are those determined at extrapolated to zero ionic strength at 20°C-25 °C. For example, lactic acid (CH3CH(OH)CO2H) has a pKa of 3.86 for dissociation of the proton in the carboxylic group; formic acid (HCOOH) has a pKa of 3.77 for dissociation of the proton in the carboxylic group; and citric acid (HOC(COOH)(CH2COOH)2 ) acid is normally considered to be a tribasic acid (polyprotic), with pKa values, extrapolated to zero ionic strength, of 3.13, 4.76, and 6.4 at 25 °C.

As indicated, the pH adjuster system comprising an acid with a pKa from 1.0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine, it is selected from:

(b1 ) a multicarboxylic acid, further selected from a succinic acid or composition comprising succinic acid, and/or citric acid in a composition comprising citric acid and a chelating agent, or, alternatively

(b2) an acid other than a multicarboxylic acid, in which case the acid is then in a pH buffer composition, or pH buffer system, that comprises the base selected from an alkaline hydroxide or an amine.

When in particular the pH adjuster system chosen is (b1 ), or comprises a system as defined in (b1 ), the multicarboxylic succinic or citric acid are present in combination with one or more of other different from succinic or citric acids and selected from citric acid, malic acid, succinic acid, and tartaric acid. In another more particular embodiment, the pH adjuster system further comprises a base selected from an alkaline hydroxide or an amine.

In another particular embodiment of the first aspect, the pH adjuster is a pH buffer system (b2) that comprises an acid with a pKa from 1 .0 to 6.5 and a base selected from an alkaline hydroxide or an amine.

As used herein, the term "amine" refers to an organic compound that includes at least one amine moiety, containing a basic nitrogen atom with a lone pair. In a particular embodiment, optionally in combination with one or more features of the composition of the invention, amines are selected from primary amines (R^XN H2), such as ethanolamine (CH3CH2NH2), secondary amines (R^xRyNH2) and tertiary amines (R¹R²R³NH2). R^x and R7 as well as R¹ R² and R³are organic radicals, including (Ci-C_n)alkyl radicals, being n from 0 to 8, and aromatic radicals. (Ci-C_n)alkyl radicals can be branched or lineal radicals and optionally include chemical functional groups, such as hydroxyl groups (-OH).

In a particular embodiment of the first aspect, the pH adjuster is a pH buffer system that comprises an acid with a pKa from 1 .0 to 6.5, in particular a pKa from 2.0 to 6.5, and a base selected from an alkaline hydroxide or a tertiary amine of formula (I):

wherein R¹, R² and R³ are independently selected from -(CH2)_n-C00M,

being M a metal selected from alkaline and alkaline-earth metals; and n and m are integers independently selected from 1 to 3.

In a more particular embodiment M is an alkaline metal selected from Na and K. In also another more particular embodiment is sodium. Alternatively, in another particular embodiment M is an alkaline-earth metal selected from Be, Mg, and Ca.

(C1 -C3)-alkyl relates to linear or ramified alkyl radicals from 1 to 3 carbon atoms, being in particular selected from methyl, ethyl, propyl, and iso-propyl. In a particular embodiment, it is methyl (-CH3).

In another particular embodiment, in the pH buffer system the base is a tertiary amine of formula (I) in which, R¹ and R² are equal and are -(CH2)_n-COOM, and R³ is

-(CH)-COOM

(C1-C3)alkyl being, M and n as previously disclosed.

In another particular embodiment, in the pH buffer system the base is a tertiary amine of formula (I) in which, R¹ and R are equal and are -(CH2)_n-COOM, and R3 is

being, M and n as previously disclosed.

In yet another more particular embodiment of the first aspect, the base in the pH buffer system is a tertiary amine of formula (I) selected from tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate of formula (la) and trisodium salt of methylglycinediacetic acid of formula (lb):

In even a more particular embodiment of the composition, the pH buffer system is selected from the group of acid-base pairs consisting of formic acid and sodium hydroxide; formic acid and tetrasodium N, N- bis(carboxylatomethyl)-L-glutamate of formula (la); citric acid and sodium hydroxide of formula (la); citric acid and tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate of formula (la); and lactic acid and trisodium salt of methylglycinediacetic acid of formula (lb).

The terms "acid” and "base” in this description take the common meaning in the field. An acid is a molecule or ion capable of donating a proton (hydrogen ion H+), or, alternatively, capable of forming a covalent bond with an electron pair (a Lewis acid). In chemistry, "bases” are substances that, in aqueous solution, release hydroxide (OH-) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH- ions. When in the present description the concept "acid” is used, it encompasses the protonated form of the compound (i.e., acid), as well as their salts that in an aqueous composition give the two forms in equilibrium (i.e., the acid and the conjugated base according to the pKa of the one or more dissociable protons, such as for example citric-citrate, lactic-lactate, or succinic-succinate).

The term "acid-base pair” refers to the combination of an acid and a base, which base is different from the conjugate base of the acid. Therefore, in the pH buffer system co-exist in equilibrium the acid form of the acid, its conjugated base and the base different from said conjugate base, and the conjugated acid of this different base.

Thus, in some embodiments, the pH buffer/adjuster systems used in the compositions of the invention comprise an acid with a pKa from 1 .0 to 6.5 and a base different from the conjugate base of the acid.

In a particular embodiment of the compositions of the first aspect, the pH adjuster systems comprise an acid with a pKa from 2.0 to 6.5, more in particular from 2.9 to 6.4. Thus, the pH buffer systems comprise an acid with a pKa selected from 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.5, and combinations of these pKa values in case of a polyprotic acid (able to donate more than one proton per acid molecule; i.e., a multicarboxylic acid).

In a more particular embodiment of the pH buffer/adjuster systems, the acid is selected from the group consisting of formic acid, lactic acid, citric acid in a composition comprising also a chelating agent, malic acid, succinic acid, tartaric acid and combinations thereof, and the system comprises a base selected from an alkaline hydroxide or an amine.

In yet another particular embodiment of the biocidal composition according to the invention, optionally in combination with one or more features of the embodiments above or below, said composition comprises as the pH buffer system: - the acid-base pair formic acid and tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate of formula (la), the pH of the biocidal composition being from 1 .5 to 3.5, more in particular the pH of the biocidal composition being from 1.8 to 2.8, and even more in particular being 2.4; or alternatively

- the acid-base pair formic acid and sodium hydroxide the pH of the biocidal composition being from 1 .5 to 3.0, more in particular the pH of the biocidal composition being from 1 .8 to 2.8, and even more in particular being 2.2.

Skilled person in the art will know how to calculate the amounts and percentages by weight of the components in the pH buffer system in relation to the total weight of the biocidal composition, to obtain particular values of pH in said biocidal composition, said amounts allowing to achieve a desired pH on use after dilution from 0.2% to 4.0% in water. For example, by fixing a particular amount of the acid, the skilled person can calculate the amount of the selected base to achieve a final pH in the composition and a desired pH on use after the said dilution.

In yet another particular embodiment of the biocidal composition according to the invention, optionally in combination with one or more features of the embodiments above or below, said composition comprises as the pH buffer system:

- the acid-base pair formic acid and tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate of formula (la), wherein the percentage by weight of formic acid and of tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate in relation to the total weight of the biocidal composition is, respectively, 2.6 % w/w and 1 .20 % w/w, and the pH of the biocidal composition is 2.4; or alternatively

- the acid-base pair formic acid and sodium hydroxide, and wherein the percentage by weight of formic acid and of sodium hydroxide in relation to the total weight of the biocidal composition is, respectively, 2.6 % w/w and 0.50 % w/w and pH of the biocidal composition is 2.2.

In another alternative particular embodiment of the biocidal composition according to the invention, optionally in combination with one or more features of the embodiments above or below, said composition comprises as the pH buffer system:

- the acid-base pair citric acid and of sodium hydroxide, and being the pH of the biocidal composition from 1 .5 to 3.0, more in particular the pH of the biocidal composition being from 1.8 to 2.8, and even more in particular being 1.8; or alternatively

- the acid-base pair citric acid and tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate of formula (la), the pH of the biocidal composition being from 1 .5 to 3.0, more in particular the pH of the biocidal composition being from 1.8 to 2.8, and even more in particular being 2.2.

In another more particular embodiment, the biocidal composition comprises as the pH buffer system:

- the acid-base pair citric acid and sodium hydroxide, and wherein the percentage by weight of citric acid and of sodium hydroxide in relation to the total weight of the biocidal composition is, respectively, 4.7 % w/w and 0.20 % w/w, and the pH of the biocidal composition is 1 .8; or alternatively - the acid-base pair of citric acid and tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate of formula (la), and wherein the percentage by weight of citric acid and of tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate in relation to the total weight of the biocidal composition is, respectively, 4.5% w/w and 1 .0 % w/w, and pH of the biocidal composition is 2.2.

In also another alternative particular embodiment of the biocidal composition of the first aspect, said biocidal composition comprises as the pH buffer system the acid-base pair lactic acid and trisodium salt of methylglycinediacetic acid of formula (lb), and being the pH of the biocidal composition from 1 .5 to 3.0, more in particular the pH of the biocidal composition being from 1 .8 to 2.8, and even more in particular being 2.6 or 2.7.

In also another alternative more particular embodiment of the biocidal composition of the first aspect, said biocidal composition comprises as the pH buffer system the acid-base pair lactic acid and trisodium salt of methylglycinediacetic acid of formula (lb), and the percentage by weight of lactic acid and of trisodium salt of methylglycinediacetic acid in relation to the total weight of the biocidal composition is, respectively, 4.6 % w/w and 1 .0 % w/w, and the pH of the biocidal composition is 2.6.

In another particular embodiment of the first aspect of the invention, optionally in combination with any embodiment above or below, the quaternary ammonium compounds consist of a mixture of a salt of ODDA, a salt of DODA and a salt of DDA. Thus, these three are the only quaternary ammonium compounds in the composition of the invention.

In other words, in another particular embodiment of the aqueous composition, the only biocidal components are salts of DDA, ODDA and DODA and the sum of the amounts of the three quaternary ammonium compounds is such that, when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w, the concentration of the total quaternary ammonium compounds is of at least 120 parts per million (ppm).

In another particular embodiment of the first aspect, the composition comprises a salt of ODDA, of DODA and of DDA, and a salt of one or more additional quaternary ammonium compounds. In a more particular embodiment, the composition comprises a salt of ODDA, of DODA and of DDA, and a salt of which is a salt of alkyl dimethyl benzyl ammonium (ADBA).

In another particular embodiment of the first aspect, the composition comprises a salt of ODDA, a salt of DODA, a salt of DDA, and a salt of ADBA; and one or more multicarboxylic acids as a pH adjuster. In a more particular embodiment, when the salt of ADBA is present the pH adjuster system comprises a multicarboxylic acid selected from a succinic acid or a composition comprising succinic acid (i.e., succinic acid is provided with other compounds in a composition), and/or a composition comprising citric acid and a chelating agent. In a more particular embodiment when the salt of ADBA is present, the composition comprises succinic acid, optionally in combination with one or more multicarboxylic acids as a pH adjuster. In even a more particular embodiment, said additional carboxylic acids, besides the succinic acid, are selected from malic acid, citric acid, tartaric acid and a combination thereof. The expressions "a composition comprising succinic acid” or "a composition comprising citric acid and a chelating agent” mean that the acids are provided as ingredients of a composition, for example water composition that can also comprise other ingredients, such as other acids (for example, other carboxylic acids), chelating agents, etc.

In another particular embodiment of the composition of the invention, the ratio of salts of DDA:ODDA:DODA in the aqueous composition is from 3:5:2 to 6.5:2.5: 1. This ratio is maintained in such compositions of the invention that a part of the three salts of DDA, ODDA and DODA, further include another quaternary ammonium as the only biocidal compounds.

In another particular embodiment of the composition according to the first aspect, optionally in combination with one or more features of the embodiments above or below, the sum of the amounts of the quaternary ammonium compounds is such that, when the biocidal aqueous composition is diluted with water at a final weight percentage of the biocidal composition from 0.2 % w/w to 4.0 % w/w, the concentration of the total quaternary ammonium compounds is of at least 120 parts per million (ppm) (i.e. mg of quaternary ammonium compounds per Kg of total composition). In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is of at least 150 ppm, more in particular is of at least 260 ppm, more in particular is of 260 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is of at least 320 ppm, more in particular is of 320 ppm.

In even a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is selected from 120 ppm, 150 ppm, 175 ppm, 200 ppm, 225 ppm, 250 ppm, 260 ppm, 261 ppm, 262 ppm, 263 ppm, 264 ppm, 265 ppm, 266 ppm, 267 ppm, 268 ppm, 269 ppm, 270 ppm, 275 ppm, 300 ppm, 320 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, 550 ppm, 560 ppm, 600 ppm, 650 ppm, 700 ppm, 750 ppm, 800 ppm, and 850 ppm. The skilled person in the art will know the available techniques for the analysis of these ppm. As an example, the concentration of the quaternary ammonium compounds in the compositions of the examples of this description were determined by HPLC (Infiniti I1 1290 of Agilent Technologies) at a temperature of the column of 40 °C. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 120 to 750 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 150 to 700 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 175 to 650 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 260 to 600 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 320 to 560 ppm.

In a particular embodiment of the composition according to the first aspect, optionally in combination with one or more features of the embodiments above or below, the percentage by weight of the sum of the quaternary ammonium compounds is from 1 .5 % w/w to 5.0 % w/w, in relation to the total weight of the biocidal composition. In even a more particular embodiment, the percentage by weight of the sum of the amount of the quaternary ammonium compounds is from 2.0% w/w to 5.0 % w/w. In yet another particular embodiment, it is selected from 1 .5 % w/w, 1 .6 % w/w, 1 .8% w/w, 2.0 % w/w, 2.2 % w/w, 2.4 % w/w, 2.6 % w/w, 2.8 % w/w, 3.0 % w/w, 3.2 % w/w, 3.4 % w/w, 3.6 % w/w, 3.8 % w/w, 4.0 % w/w, 4.2 % w/w, 4.4 % w/w, 4.6 % w/w, 4.8 % w/w, and 5.0 % w/w.

When only DDA, ODDA, and DODA are in the composition as the only biocidal compound, the previously indicated percentages apply to the sum of the three. If, in addition, another different quaternary ammonium compound is within the only biocidal compounds in the composition, the percentages are also applicable but with a more complex mixture of quaternary ammonium compounds.

The quaternary ammonium compounds in the aqueous biocidal composition are in form of their salts. In a particular embodiment, the salts are halide salts selected from chloride salts, bromide salts, fluoride salts, iodine salts and mixtures of these halide salts. More in particular the salts of quaternary ammonium compounds are all three chloride salts; octyl decyl dimethyl ammonium chloride (ODDAC), dioctyl dimethyl ammonium chloride (DODAC), and didecyl dimethyl ammonium chloride (DDAC)

This ternary mixture including ODDAC, DODAC, and DDAC is the germicide (biocidal) composition commercially available as Bardac® 2080 and Bardac® 2050 (Lonza). However, the same mixture could be obtained by combining the compounds previously synthesized individually; or by using commercially available individual compounds or individual compounds with binary mixtures of the two others. Other commercially available compositions including ODDAC, DODAC, and DDAC are the one labelled as BTC 818-80% or BTC 818 of Nouryon Chemicals, S.A., the latter with DDAC:ODDAC:DODAC of 1 :2:1.

The particular salt of alkyl dimethyl benzyl ammonium chloride (ADBAC) is also a particularly used salt of ADBA. ADBAC is also known as benzalkonium chloride (CAS 68424-85-1). It is for example commercially available as Bardquat®-DM-50 (Lonza), as a blend of selected alkyl dimethyl benzyl ammonium chloride, where the alkyl is a C12-C16-alkyl (in particular 76 % C12-alkyl, 26 % C14-alkyl and 4 % C16-alkyl).

Aqueous compositions of the invention, comprising the mixture of quaternary ammonium salts and the pH adjuster (e.g., buffer system), are conceived in such a way that a pH from 3.0 to 5.0 is obtained when the aqueous composition is diluted with water at a final weight percentage of the biocidal composition selected from 0.2 % w/w, 0.3 % w/w, 0.4 % w/w, 0.5 % w/w, 0.6 % w/w, 0.7 % w/w, 0.8 % w/w, 0.9 % w/w, 1 .0 % w/w, 1.1 % w/w, 1.2 % w/w, 1 .3 % w/w, 1 .4 % w/w, 1 .5 % w/w, 1 .6 % w/w, 1 .7 % w/w, 1 .8 % w/w, 1 .9 % w/w, 2.0 % w/w, 2.1 % w/w, 2.2 % w/w, 2.3 % w/w, 2.4 % w/w, 2.5 % w/w, 2.6 % w/w, 2.7 % w/w, 2.8 % w/w, 2.9 % w/w, 3.0 % w/w, 3.1 % w/w, 3.2 % w/w, 3.3 % w/w, 3.4 % w/w, 3.5 % w/w, 3.6 % w/w, 3.7 % w/w, 3.8 % w/w, 3.9 % w/w and 4.0 %. Thus, these listed weight percentage are in the so-called washing liquor, which is the mixture of water and the composition of the invention.

Biocidal compositions of the invention comprise, in another particular embodiment one or more additives selected from perfume, surfactants, and organic solvents.

Among the surfactants, which are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid, cationic, amphoteric and non-ionic surfactants are used.

In a more particular embodiment, the surfactants are non-ionic surfactants, and even in a more particular embodiment they are selected from the group consisting of alkanolamides, alkyl polyglycosides, fatty acid N- methylglucamides, alkylphenol ethoxylates, fatty acid ethoxylates, fatty acid EO glycerol ester, sorbitan ethoxylated fatty acid ester, polyoxyethylene alkyl ether, and combinations thereof.

In a more particular embodiment, the surfactants are non-ionic surfactants, and even in a more particular embodiment they are selected from the group consisting of alkanolamides, alkyl polyglycosides, fatty acid N- methylglucamides, alkylphenol ethoxylates, fatty acid ethoxylates, fatty acid EO glycerol ester, sorbitan ethoxylated fatty acid ester, and combinations thereof.

In a more particular embodiment, the surfactants are non-ionic surfactants, and even in a more particular embodiment they are selected from the group consisting of polyoxyethylene(6) alkyl(C8-i2) ether, polyoxyethylene sorbitan monolaurate (20) and a mixture thereof.

In another more particular embodiment, the surfactants are cationic surfactants, and even in a more particular embodiment they are selected from the group consisting of triethanolamine esterquats, ethoxylated quaternary ammonium compounds, and combinations thereof.

In another more particular embodiment, the surfactants are amphoteric surfactants, and even in a more particular embodiment they are selected from the group consisting of alkylbetains, alkylamidopropyl betaine, amine oxides, amphoacetates, and combinations thereof.

None of the surfactants provide a biocidal effect. In the case of surfactants also categorized as biocidal compounds, they are used in the composition in amounts lower than those providing this effect.

Particular organic solvents are selected from (C1-C4)-alcohols, such as ethanol; dipropylene glycol, dipropylene glycol n-butyl ether, and combinations thereof.

The term (C1-C4)-alcohol includes methanol, ethanol, propanol, iso-propanol, n-butanol, iso-butanol and tertbutanol.

In yet another more particular embodiment, the aqueous biocidal composition is selected from the group consisting of:

(a) A buffered composition A comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- lactic acid;

- trisodium salt of methylglycinediacetic acid of formula (lb);

- surfactant, and

- water,

(b) A pH adjusted composition B comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- optionally alkyl dimethyl benzyl ammonium chloride (ADBAC);

- succinic acid;

- malic acid;

- surfactant, and

- water,

(c) A pH adjusted composition C comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- succinic acid;

- surfactant, and

- water,

(d) A pH adjusted composition D comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride(DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- succinic acid;

- tartaric acid;

- surfactant, and

- water,

(e) A pH adjusted composition E comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC); - dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- citric acid;

- chelating agent, in particular selected from L-glutamic acid N, N-diacetic acid or salt thereof, such as the tetrasodium salt, Methylglicine N, N-diacetic acid or a salt thereof, such as alkaline or alkaline-earth salts (in particular the trisodium salt), Ethanoldiglycinic acid or a salt thereof, such as alkaline or alkaline-earth salts (in particular the disodium salt), Diethylenetriaminepentaacetic acid or a salt thereof, such as alkaline or alkaline- earth salts (in particular the pentasodium salt), Hydroxyethylethylenediaminetriacetic acid, such as alkaline or alkaline-earth salts (in particular the trisodium salt), and combinations of the said chelating agents.

- surfactant, and

- water.

A more in particular pH adjusted compositions E are those comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- citric acid;

- chelating agent selected from L-glutamic acid N, N-diacetic acid tetrasodium salt; Methylglicine N, N-diacetic acid trisodium salt; Ethanoldiglycinic acid disodium salt; diethylenetriaminepentaacetic acid pentasodium salt; Hydroxyethylethylenediaminetriacetic acid trisodium salt; and a mixture thereof;

- surfactant, and

- water.

A more in particular pH adjusted compositions E are those comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride(DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- citric acid;

- L-glutamic acid N, N-diacetic acid or salt thereof, such as the tetrasodium salt, as chelating agent.

- surfactant, and

- water.

A more in particular pH adjusted compositions A are those comprising in percentage by weight of the total composition (w/w): 3% w/w of a mixture comprising 24 % w/w of DDAC, 40% w/w of ODDAC, 16 % w/w of DODAC and 20% w/w of water; 5.80 % w/w of lactic acid (at 80% w/w); 1 % w/w of trisodium salt of methylglycinediacetic acid; 0.45% w/w of polyoxyethylene(6) alkyl(C8-12) ethers (as surfactant); 1.30 % of Polyoxyethylene (20) sorbitan monolaurate (as surfactant); 0.80 % w/w of perfume, and the amount of water up to 100% w/w. Another embodiment of the aqueous pH adjusted composition A of the first aspect comprises:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- lactic acid;

- trisodium salt of methylglycinediacetic acid;

- surfactant;

- dipropylene glycol;

- dipropylene glycol n-butyl ether

- ethanol;

- perfume; and

- water.

More in particular, the composition comprises in percentage by weight of the total composition (w/w): 3 % w/w of a mixture comprising 24 % w/w of DDAC, 40% w/w of ODDAC, 16 % w/w of DODAC and 20 % w/w of water; 5.80 % w/w of lactic acid (at 80% w/w); 1 % w/w of trisodium salt of methylglycinediacetic acid; 0.89 % w/w of polyoxyethylene(6) alkyl(C8-12) ethers (as surfactant); 0.80 % w/w of perfume, 5.0% w/w of ethanol, 3.50 % w/w of dipropylene glycol; 4.0 % w/w of dipropylene glycol n-butyl ether, and the amount of water up to 100 % w/w.

Other compositions according to notation compositions A to E are listed in Tables of examples below. Table 10 to 14 illustrate compositions of the invention including multicarboxylic acids as the pH adjusters.

In a more particular embodiment of the composition B, it comprises 4.0 % w/w of succinic acid, and 3.0 % w/w of malic acid, in relation to the total weight of the aqueous biocidal composition.

In a more particular embodiment of the composition C, it comprises 0.8 % w/w of succinic acid, in relation to the total weight of the aqueous biocidal composition.

In a more particular embodiment of the composition D, it comprises from 1 .5 w/w to 4.0 % w/w of succinic acid, and from 0.4 % w/w to 2.0 % w/w of tartaric acid, in relation to the total weight of the aqueous biocidal composition.

In a more particular embodiment of the composition E, it comprises from 1 .5 w/w % to 4.5 % w/w of citric acid, in relation to the total weight of the aqueous biocidal composition. In a more particular embodiment of the composition E, it comprises from 1 .5 w/w % to 2.5 % w/w of citric acid, in relation to the total weight of the aqueous biocidal composition. The process for the manufacturing of the biocidal compositions of the invention is cost- effective as above exposed. Briefly, the method comprises:

(I) adding in a recipient half amount of the water in the batch composition, and the salts of quaternary ammonium, and stir the mixture until the salts are dissolved;

(ii) adding, in any order while stirring, the components of the pH buffer system in an appropriate amount that is capable of giving a pH from 3.0 to 5.0 when the biocidal aqueous composition is dissolved in an additional water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w, and optionally adding the one or more of the additives, wherein if perfume is added as an additive, at least one surfactant is added first and the mixture is stirred to obtain homogeneous distribution of the said surfactant; and

(ill) adding while stirring the other half amount of total water in the biocidal batch composition and keep stirring at least for 5 minutes or for a period allowing dissolution of all components.

Technical chemical grades of all the ingredients are preferred, in particular those grades of purity from 80% to 100%. Deionized water is preferably used in order to have a more controlled ionic force of the composition.

The composition of the invention is used as biocidal according to one aspect of the invention.

As will be depicted in examples below, this biocidal composition is suitable for laundry washing, either domestic or industrial. Therefore, the composition is prepared to be applied by users during laundry washing as an additive for rinsing during said laundry process. Thus, the invention encompasses also the use of the composition as a biocidal additive composition for laundry. In particular, as a biocidal additive for the rinsing within the laundry process.

In a particular embodiment of such use, the dose of the aqueous composition (i.e., biocidal composition) is such that in a laundry wash liquor the final percentage by weight of the composition is from 0.2 % w/w to 4.0 % w/w. In a more particular embodiment, the final percentage by weight of the composition is from 0.2 % w/w to 3.5 % w/w. In another more particular embodiment is the final percentage by weight of the composition is from 1 .0 % w/w to 3.5 % w/w.

The invention relates also to methods for laundry washing comprising adding to a recipient for laundry comprising water, a dose of the aqueous biocidal composition as defined above.

In a particular embodiment, the method for laundry washing is a method for hand washing. In another particular embodiment, the method is for automatic washing.

In yet another particular embodiment of the method for laundry washing, optionally in combination with one or more features of the embodiments of the method, it comprises adding to a recipient for laundry comprising water, a dose of the aqueous biocidal composition as defined above, such that the final percentage by weight of the biocidal composition is from 0.2 % w/w to 2.0 % w/w, in relation with the total weight of the laundry wash liquor in the recipient, said laundry wash liquor defined as the mixture comprising water and the dose of aqueous biocidal composition.

In yet another particular embodiment of the method, optionally in combination with one or more features of the embodiments of the method, the step of adding to a recipient for laundry comprising water, a dose of the aqueous biocidal composition is carried out for the rinsing of the laundry process. This particular embodiment includes either the option that previously to the rinsing a washing step with detergents has been carried out; as well as the option that no previous washing is performed and laundry process consists only in assuring that microorganisms in clothes are eliminated or reduced to non-hazardous levels.

In a method for hand washing or when the use of the aqueous biocidal composition of the invention is for hand washing, the pH adjuster is in an amount in the said biocidal composition, such that it is capable of giving a pH from 3.0 to 4.5 when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w. More in particular in an amount of giving a pH from 3.0 to 4.5 when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.5 % w/w to 3.5 % w/w, or from 1 .0 % w/w to 3.5 % w/w or from 0.5 % w/w to 2% w/w. More in particular in an amount of giving a pH from 3.0 to 4.5 when the aqueous composition is diluted with water at a final weight percentage of the biocidal composition in the diluted one selected from 1.1 % w/w, 1.32 % w/w, 2.33 % w/w and 3.50 % w/w. In all these embodiments, and as indicated, the sum of the amounts of the quaternary ammonium compounds in the diluted composition is of at least 120 parts per million (ppm). More in particular is of at least 150 ppm. Even more in particular is of at least is of at least 260 ppm, more in particular is of 260 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is of at least 320 ppm, more in particular is of 320 ppm. In even a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is selected from 120 ppm, 150 ppm, 175 ppm, 200 ppm, 225 ppm, 250 ppm, 260 ppm, 261 ppm, 262 ppm, 263 ppm, 264 ppm, 265 ppm, 266 ppm, 267 ppm, 268 ppm, 269 ppm, 270 ppm, 275 ppm, 300 ppm, 320 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, 550 ppm, 560 ppm, 600 ppm, 650 ppm, 700 ppm, 750 ppm, 800 ppm, and 850 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 120 to 750 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 150 to 700 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 175 to 650 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 260 to 600 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 320 to 560 ppm.

On the alternative, in a method for automatic washing or when the use of the aqueous biocidal composition of the invention is for automatic washing, the pH adjuster is in an amount in the said biocidal composition, such that it is capable of giving a pH from 3.0 to 5.0 when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w. More in particular in an amount of giving a pH from 3.0 to 5.0, when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.5 % w/w to 3.5 % w/w, or from 1 .0 % w/w to 3.5 % w/w, or from 0.5 % w/w to 2% w/w. More in particular in an amount of giving a pH from 3.0 to 5.0 when the aqueous composition is diluted with water at a final weight percentage of the biocidal composition in the diluted one selected from 1.1 % w/w, 1 .32 % w/w, 2.33 % w/w and 3.50 % w/w. In all these embodiments, and as indicated, the sum of the amounts of the quaternary ammonium compounds in the diluted composition is of at least 120 parts per million (ppm). More in particular is of at least 150 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is of at least 320 ppm, more in particular is of 320 ppm. Even more in particular is of at least is of at least 260 ppm, more in particular is of 260 ppm. In even a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is selected from 120 ppm, 150 ppm, 175 ppm, 200 ppm, 225 ppm, 250 ppm, 260 ppm, 261 ppm, 262 ppm, 263 ppm, 264 ppm, 265 ppm, 266 ppm, 267 ppm, 268 ppm, 269 ppm, 270 ppm, 275 ppm, 300 ppm, 320 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, 550 ppm, 560 ppm, 600 ppm, 650 ppm, 700 ppm, 750 ppm, 800 ppm, and 850 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 120 to 750 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 150 to 700 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 175 to 650 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 260 to 600 ppm. In a more particular embodiment, the concentration of the total quaternary ammonium compounds, once the composition is dissolved as indicated, is from 320 to 560 ppm.

It is widely known that efficacy of laundry washing is dependent not only of the actives used to clean clothes or fabrics, but also due to the quality of the water used during the laundry. Quality of water depends mostly on the region where the user lives. Water is classified as soft water or hard water depending on the minerals (salts) that are dissolved or suspended therein, which depend on the source of the water.

In a particular embodiment of the method for laundry, the amount or dose of the biocidal composition is such that in the laundry wash liquor is from 0.2 % w/w to 0.9 % w/w, when the water used for the washing comprises 50 mg/l or less of calcium carbonate. This particular embodiment is suitable for regions (cities, villages) with water classified as soft water.

In another particular embodiment of the method for laundry, the amount or dose of the biocidal composition is such that in the laundry wash liquor is from 0.7 % w/w to 2.0 % w/w, when the water used for the washing comprises more than 50 mg/l of calcium carbonate. This particular embodiment is suitable for regions (cities, villages) with water classified as hard water. Water's hardness is determined by the concentration of multivalent cations in the water. Multivalent cations are positively charged metal complexes with a charge greater than 1 +. Usually, the cations have the charge of 2+. Common cations found in hard water include Ca²⁺ and Mg²⁺. These ions enter a water supply by leaching from minerals within an aquifer. Common calcium-containing minerals are calcite and gypsum. A common magnesium mineral is dolomite (which also contains calcium). Rainwater and distilled water are soft, because they contain few ions.

Hardness can be quantified by instrumental analysis. The total water hardness is the sum of the molar concentrations of Ca2+ and Mg2+, in mol/L or mmol/L units. Although water hardness usually measures only the total concentrations of calcium and magnesium (the two most prevalent divalent metal ions), iron, aluminium, and manganese can also be present at elevated levels in some locations. The presence of iron characteristically confers a brownish (rust-like) colour to the calcification, instead of white (the color of most of the other compounds). Water hardness is often not expressed as a molar concentration, but rather in various units, such as degrees of general hardness (dGH), German degrees (°dH), parts per million (ppm, mg/L, or American degrees), grains per gallon (gpg), English degrees (°e, e, or “Clark), or French degrees (°fH, °f or °HF; lowercase f is used to prevent confusion with degrees Fahrenheit). Classification into soft or the different hardness degrees of water is also dependent on national authorities' standards. In the UK, water is regarded as soft if the hardness is less than 50 mg/l of calcium carbonate. Water containing more than 50 mg/l of calcium carbonate is termed hard water. In the United States soft water is classified as having less than 60 mg/l of calcium carbonate.

Any type of fabrics and manufactured clothes can be treated with the biocidal composition of the invention. These include wove and non-woven fabrics, such as textile materials, linen, cotton and synthetic fibres of technical textiles. In particular, the biocidal composition of the invention is useful to treat fabrics of cotton and polyesters.

Throughout the description and claims the word "comprise" and variations of the word, are not intended to exclude other technical features, additives, components, or steps. Furthermore, the word "comprise” encompasses the case of "consisting of'. Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. The following examples are provided by way of illustration, and they are not intended to be limiting of the present invention. Furthermore, the present invention covers all possible combinations of particular and preferred embodiments described herein.

Examples

Example 1. Preparation of biocidal compositions

Several biocidal compositions were prepared by adding half of the deionized water in a flask containing a magnetic stirrer. Then the quaternary ammonium compounds were added, and the mixture was stirred. Next, the pH buffer system (acid-base pair) and the surfactants were added (they can be added in any order). Lastly, the perfume and the rest of the deionized water were added and stirring was kept for at least 5 minutes until a homogeneous mixture was obtained.

Particular biocidal compositions were manufactured using different acid-base pairs as pH buffer systems, all of them allowing to achieve a pH within the range 3.0-5.0 in the wash liquor, more in particular within the range of 3.5 and 4.0.

5 tested buffers were:

• Tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate - Formic acid

• Sodium hydroxide - Critric acid • Tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate - Citric acid

• Sodium hydroxide - Formic acid

• trisodium salt of methylglycinediacetic acid - Lactic acid

The composition of all buffered formulas as well as the pH values of the wash liquor and the formula are shown in Table 1 below: Table 1 :

Data on next Table 2 demonstrate that the 5 different buffered formulas are very robust in terms of pH and can remain in the pH range of 3.5-4.0 in a wide range of dilution. The range of dilution was determined with hard and soft water.

Table 2:

Of note is the fact that the higher the dilution the lower the concentration of quaternary ammonium compounds, even though the pH remains in the range 3.5-4.0 after the dilution, according to this Table 2. Advantageously, also in this scenario the biocidal composition is effective if the sum of the amounts of the three quaternary ammonium compounds is such that, when the biocidal aqueous composition is diluted with water at a final weight percentage of the biocidal composition from 0.2 % w/w to 4.0 % w/w, the concentration of the total quaternary ammonium compounds is of at least 120 parts per million (ppm), in particular the assay contained 260 ppm.

Example 2. Biocidal activity of the compositions

Two different biocidal compositions according to the invention (called in this example Formula A, which corresponded to Formula 5 in Table 1, and Formula B) are disclosed and used in several assays allowing to prove the synergistic effect of the quaternary ammonium salts within the previously disclosed particular pH range on use (i.e., during laundry). Formula A (or formula 5 in Table 1):

Formula B (with organic solvents):

In order to assess the bactericidal and levuricidal efficiency of Formula A and Formula B, several methods can be carried out based on different standards, such as European Standards EN 1276 (for bacteria), EN 1650 (for yeast) and American Standard ASTM 2406 (for bacteria and yeast), all containing microorganism inoculated carriers. When standards EN 1276 and EN 1650 were used, the following adaptations of the same were performed in order to work with microorganism inoculated carriers:

Presence of ballast and carrier (100% cotton). Microorganisms inoculated in the Carrier.

• Wash liquor to ballast ratio - 10:1 • Temperature: 20 °C

• Water used for dilution had a concentration of 375 ppm CaC03 and a pH of 7.

• No movement when simulating hand wash. Movement when simulating automatic wash.

• 60 min contact time.

Briefly, following any of the above-mentioned standards, a particular volume of each of the Formula A and Formula B, separately, were added to a recipient with water with a hardness measured as calcium carbonate concentration of > 400 mg/l. Final concentration in the wash liquor of the three quaternary ammonium salts was of 0.026 % w/w (260 ppm), and the final pH of the wash liquor (i.e., pH on use) was of 3.7. The wash liquor included microorganism inoculated carriers (small textile pieces), and a ballast consisting of a mixture of polyester and cotton. Temperature of assay and contact time were about 20 °C, and around 1-2 hours, respectively.

The microorganism reduction values presented in table 3 are those that were measured in the carrier, following standard ASTM 2406 (ASTM E2406-16, Standard Test Method for Evaluation of Laundry Sanitizers and Disinfectants for Use in High Efficiency Washing Operations, ASTM International, West Conshohocken, PA, 2016, www.astm.org) with the inoculated carriers and the ballast.

Table 3: Microorganism reduction

Reduction values correspond to the logarithm of the difference of the colony formation units (cfu) detected at the end of the test assays with the biocidal composition, in relation with control assay with inoculated microorganisms but without the biocidal composition (water as wash liquior). Calculation of cfu was performed as indicated by the standard. The two formulas gave very high reduction values. Two formulas were comparable in terms of results, although Formula B has 3 co-formulants more than the Formula A. These biocide efficacies were due to the three quaternary ammonium salts in combination with pH on use.

Further, in order to see if these high efficacies in all microorganisms could be due to the lower adsorption of the quaternary ammonium salts at this low pH, a new assay with Formula B was performed at two different pHs (3.7 and 4.5) in the same conditions and standards previously disclosed with Pseudomonas aeruginosa (PA) as inoculated microorganism.

The method used to measure the adsorption of quats on the textile consisted in measuring the concentration of each quat in the washing liquid with HPLC and it was assumed that the rest is adsorbed on the textile. The detector was a mass spectrometer (MS) with a column C18 with an eluent containing acetronitrile and amonium formate. Data are depicted in Table 4.

Table 4. Reduction values of Formula B at pH 3.7 and pH 4.5 (amount of lactic acid was adjusted to have this final pH), ASTM 2406. Adsorption of quaternary ammonium salts.

The logarithmic reduction of Formula B at pH 4.5 is much lower than reduction at pH 3.7. This shows that pH plays a very important role. Similar values for quaternary adsorption demonstrate that such difference between pH on use was not due to a difference on adsorption levels. Thus, although according to common general knowledge, a low pH reduces adsorption, this was not the cause of difference in the assay. Of note, these data validate that those of Table 3 are due to the combination of the quaternary ammonium salts working within a particular pH.

This synergic effect of increased activity of the salts within the pH range is unexpected and does not result from any intuitive or suggested cause.

Next Table 5 shows the effect of the combination of the three quaternary ammonium salts (Formula A) in relation to the use in the composition of only DDAC. Assay was performed at pH 3.7 with Formula A and with a composition equal to said Formula B but with only DDAC. The amount of DDAC or of the ternary combination was of 0.026% w/w in the wash liquor (260 ppm). Textiles were independently inoculated with Pseudomonas aeruginosa (PA) and Candida albicans (CA) The rest of the conditions were as indicated according to previously disclosed standards (ASTM 2406).

Table 5. Microorganism reduction values

Logarithmic reductions when DDAC is used are much lower as when the ternary quaternary ammonium mixture is used, despite working at same pH 3.7. This implies that the pH is not solely responsible for the high values of reduction of table 3. Quaternary ammonium used has so much weight as the pH in the reduction of microorganisms

Finally, possible impact on biocidal effect of other ingredients in the biocidal compositions was also assayed.

Formula A was changed (one change of a compound per assay) and tested following the same Standard methods as before and using 260 ppm of the quaternary ammonium compounds. Data are illustrated in Table 6.

Table 6. Microorganism reduction of Formula A with diferent co-formulant ingredients (adaptation of EN 1276 and EN 1650 for the tests without movement; hand-washing simulation (H.W.S.))

Results show that changing nonionic surfactant (Polyoxyethylene(6) alkyl(C8-12) ethers), does not result in a significant difference in the logarithmic reduction of PA and CA. The same thing happens when citric acid (with the chelating agent trisodium salt of methylglycinediacetic acid) was used instead of lactic acid. Finally, if no co-formulant is added (simpler mixture with the quaternary ammonium salts and lactic acid to regulate pH), the reduction values are also comparable to those of the Formula A. All data in this Example 2 allow concluding that unexpected high values of Formulas A and B are only due to pH on use of a ternary mixture comprising DDAC, DODAC and ODDAC.

Example 3. Biocidal activity of other compositions of the invention

Following the same scheme as in Example 2, biocidal compositions of the invention differing only in pH buffer system amount were tested for the logarithm reduction of microorganisms in carrier.

Compositions in Table 7 were assayed in Pseudomonas aureuginosa (PA) and Enterococcus hirae (EH) (adaptation of EN 1276 for the tests without movement; hand-washing simulation (H.W.S.)).

Table 7. Microorganism reduction at diferent pH in wash liquor.

All values are in % by weight of the components in the composition prior to dilution. The sum of the quats was of 260 ppm at 1 .1 % w/w of biocidal composition in water. Form means Formula.

Example 4. Biocidal activity at diferent pH and final w/w concentrations of the aqueous compositions of the invention.

In order to further exemplify the efficacy of the aqueous composition of the invention at different conditions (%, pH, and hand washing simulation or automatic washing simulation), several tests with Pseudomonas aeruginosa (PA) as inoculated microorganism were carried out. Results are listed in Table 8 (data from adapted EN 1276, as indicated).

Table 8. Efficacy measured as logarithmic reduction of PA

H.W.S.: Hand washing simulation; A.W.S: Automatic washing simulation; mov: in movement; - means no data or nondetermined.

Underlined values correspond to logarithmic reduction values over or equal to 3.0, which is considered as a very good efficiency value in H.W.S and in A.W.S. Letters in parenthesis (e.g. (T)) refer to the formulations used and listed in Table 9 (A to D) below. As deducible from previous table, in the hand washing simulation, no difference is observed when the w/w percentage of the aqueous composition of the invention in the liquor wash was of 2.33 % or 3.50 %. In the automatic washing simulation, a dose increased at 2.33 % maintained high efficacies all along the tested pHs. Anyway, a lower dose of 1.32 % was equally efficacious, which is moreover a dose commonly employed of these kinds of compositions during automatic laundry washing processes.

This Table 8 illustrates the effectiveness of the biocidal compositions of the invention either in A.W.S (i.e., in washing machine) mode, or in H.W.S (i.e., static or hand washing) mode.

The Table 8 also illustrates that the quaternary ammonium compounds at particular ppm on use (i.e., at particular dilutions of the formula of the invention) in combination with the selected pH supposes a combination of features that operate synergistically. A dose of the formulas of the invention from 1 .0 % w/w to 3.5 % w/w when used in H.W.S at a final pH from, 3.0 to 4.0, gave logarithmic reductions higher than 4.0. On the other hand, in A.W.S, are the doses of the formulas of the invention from higher than 1 .0 % w/w working at pH from 3.0 to 4.5, those working in combination synergistically to achieve logarithmic reductions about higher than 5.0, although at higher pHs logarithmic reduction values over or equal to 3.0 were achievable too.

Table 9(A). Compositions by weight

Table 9(B). Compositions by weight

Table 9(C). Compositions by weight

Table 9(D). Compositions by weight

Example 5. Compositions of the invention

Next tables 10 to 14 illustrate other biocidal compositions of the invention, grouped according the acids used as pH adjusters. The amounts of the compounds are indicated as percentage by weight in relation to the total weight of the composition: Table 10. Compositions (in weight) with the combination succinic and malic acids

Table 11. Compositions (in weight) with succinic acid

Table 12. Compositions (in weight) with lactic acid

Table 13. Compositions (in weight) with citric acid

Table 14. Compositions (in weight) with succinic acid, or with the combinations succinic and tartaric acids

All the formulations in Tables 10 to 14 are appropriate as biocides during laundry, even against very resistant species of microorganisms.

Example 6. Compositions of the invention comprising citric acid and a chelating agent (tetrasodium salt of L- glutamic acid N,N-diacetic acid). Comparison with a prior art biocidal composition for laundry.

The formulas of next Table 15 (formulas labelled as in previous Table 13) were assayed at a dose of 1 .32 % w/w and following the previous standards (adapted EN1276). Formula Base 021C/D-B (without D) means without tetrasodium salt of L-glutamic acid N, N-diacetic acid_ Dissolvine GL47 S). For a comparative example with the formula of Table 16, the composition Base 021C/D-B was also tested but including a higher amount of quaternary ammonium compounds (3.75%) to make it comparable with the amount in formula of prior art.

The effect of the chelating agent in a composition of the invention comprising citric acid in the pH adjuster system was tested in an assay on Pseudomonas aeruginosa (PA).

Table 15. Biocidal compositions of the invention comprising citric acid. Effect on P. aeruginosa.

pH of formula "Base 021 C/D-B” without the chelating agent was of 1 .9. Thus, the chelating agent is compulsory with the citric acid in the pH adjuster system, in order to comply with a pH>2.0 due to regulatory to avoid corrosive commercial formulas for domestic use. pH on use was of 4.5 for Base 021C/D-B (3.75%) and Base 021C/D-B. The pH of Base 021C/D-B (without D) on use was of 4.3.

Table 16. Comparative example

As illustrated in the Tables 15 and 16, the efficacy on PA of Base 021 C/D-B (3.75%) is very much higher than that of the formula in Table 16. This means that the compositions of the invention with citric acid have an improved effect. In addition, data with Base 021 C/D-B and Base 021 C/D-B (without D) demonstrate that the presence of the chelating agent, when citric acidic is employed, is important even for the pH in formula and in use, as well as in terms of efficacy over the microorganisms in a "laundry scenario”.

Example 7. Compositions of the invention reduce malodour

The malodour reduction capacity of formula labelled as Machine 076 and all the compositions with citric acid and Dissolvine GL47 S (tetrasodium salt of L-glutamic acid N, N-diacetic acid as chelating agent) of the invention, were assayed using a dose 1.33 % w/w and the method was that disclosed in Zin et al., "Smells like teen Spirit-A model to generate laundry-associated malodour in vitro”, Microorganisms-2021, vol. 9, pp.-974, https:// doi.org/10.3390/microorganisms9050974. The composition with succinic acid (Machine 076) achieved a malodour reduction of 45%, while the citric-dissolvine containing formulas achieved a malodour reduction of 65%.

Thus, another advantage of the proposed compositions of the invention is that they are effective as reducers of the known as “wet-and-dirty-dustcloth-li ke” or "wet fabric” malodour, which is a problem that occurs with laundry when it is hung to dry indoors, or even with textiles that have already been dried and stored in damp conditions (see Zin et al., supra).

For reasons of completeness, various aspects of the invention are set out in the following numbered clauses: Clause 1.- An aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the acid is a multicarboxylic acid, and it is selected from succinic acid or a composition comprising succinic acid, and/or citric acid in a composition comprising citric acid and a chelating agent, or, alternatively,

- the acid is other than a multicarboxylic acid and it is in a pH buffer composition that comprises a base selected from an alkaline hydroxide or an amine;

- the pH of the composition is from 1 .5 to 3.0; and

Clause 2.- The composition according to clause 1, wherein the pH adjuster system is a composition comprising citric acid and a chelating agent.

Clause 3.- The composition according to any clause 2, wherein the weight ratio of citric acid : chel ating agent is from 3:1 to 15:1.

Clause 4.- The composition according to clause 3, wherein the chelating agent is L-glutamic acid N,N-diacetic acid or salt thereof.

Clause 5.- The composition according to any one of clauses 1-2, wherein the pH adjuster is a buffer system that comprises an acid with a pKa from 1 .0 to 6.5, and a base selected from an alkaline hydroxide or a tertiary amine of formula (I):

wherein R¹, R² and R³ are independently selected from -(CH2)_n-COOM,

being M a metal ion selected from alkaline and alkaline-earth metals; and n and m are integers independently selected from 1 to 3.

Clause 6. The composition according to any one of clauses 1-5, wherein the weight ratio of salts of DDA:ODDA:DODA in the composition is from 3:5:2 to 6.5:2.5:1 .

Clause 7.- The composition according to any one of clauses 1-6, wherein the quaternary ammonium compounds comprise a salt of octyl decyl dimethyl ammonium (ODDA), a salt of dioctyl dimethyl ammonium (DODA), a salt of didecyl dimethyl ammonium (DDA), and a salt of alkyl dimethyl benzyl ammonium (ADBA); and the pH adjuster system comprises a multicarboxylic acid selected from succinic acid, and/or a composition comprising citric acid and a chelating agent.

Clause 8. The composition according to any one of clauses 1-7, wherein the only biocidal components are DDA:ODDA:DODA and the sum of the amounts of the three quaternary ammonium compounds is such that, when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w, the concentration of the total quaternary ammonium compounds is of at least 120 parts per million (ppm). Clause 9.- The composition according to any one of clauses 1-8, wherein the salts of quaternary ammonium compounds are halide salts selected from chloride salts, bromide salts, fluoride salts, iodine salts and mixtures of these halide salts.

Clause 10.- The composition according to clause 9, wherein the salts of quaternary ammonium compounds are all three chloride salts.

Clause 11 .- The composition according to any one of clauses 1-10, further comprising one or more additives selected from perfume, surfactants, and organic solvents.

Clause 12.- The composition according to any one of clauses 1-11, selected from the group consisting of:

(a) A buffered composition A comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride(DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- lactic acid;

- trisodium salt of methylglycinediacetic acid of formula (lb);

- surfactant, and

- water,

(b) A pH adjusted composition B comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride(DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- optionally alkyl dimethyl benzyl ammonium chloride (ADBAC);

- succinic acid;

- malic acid;

- surfactant, and

- water,

(c) A pH adjusted composition C comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- succinic acid;

- surfactant, and

- water,

(d) A pH adjusted composition D comprising: - octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride(DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- succinic acid;

- tartaric acid;

- surfactant, and

- water,

(e) A pH adjusted composition E comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride(DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- citric acid;

- chelating agent, in particular L-glutamic acid N,N-diacetic acid sodium salt,

- surfactant, and

- water.

Clause 13.- Non-therapeutic use of the composition as defined in any one of clauses 1-12, as biocidal.

Clause 14.- Use of the composition as defined in any one of clauses 1-12, as biocidal additive composition for laundry.

Clause 15.- A method for laundry washing comprising adding to a recipient for laundry comprising water, a dose of the aqueous composition as defined in any one of clauses 1-12.

Citation List

Patent Literature

- WC2018108466

- WC200223990

- WC200223992

- WC2021156297

Non-Patent Literature

Hinchliffe et al., "The adsorption of alkyl-dimethyl-benzyl-ammonium chloride onto nonwoven hydroentangled substrates at the solid-liquid interface is minimized by additive chemistries”, Textile Research Journal 0(00) 1-11

Zin et al., "Smells like teen Spirit-A model to generate laundry-associated malodour in vitro”, Microorganisms-2021, vol. 9, pp.-974, https:// doi.org/10.3390/microorganisms9050974.

Claims

45 Claims

1.- An aqueous composition which comprises: a) quaternary ammonium compounds as the only biocidal components of the composition; and b) a pH adjuster system comprising an acid with a pKa from 1 .0 to 6.5, and optionally a base selected from an alkaline hydroxide or an amine; wherein:

- the pH of the composition is from 1 .5 to 3.0; and

2.- The composition according to claim 1, wherein the weight ratio of citric acid:chelating agent is from 3:1 to 15:1.

3.- The composition according to claim 2, wherein the chelating agent is L-glutamic acid N,N-diacetic acid or salt thereof.

4.- The composition according to claim 1, wherein the pH adjuster is a buffer system that comprises an acid with a pKa from 1 .0 to 6.5, and a base selected from an alkaline hydroxide or a tertiary amine of formula (I):

wherein R¹, R² and R³ are independently selected from -(CH2)_n-COOM,

-(CHXCH2)m-COOM -(CHJ-COOM

COOM _and (C1-C3)alkyl being M a metal ion selected from alkaline and alkaline-earth metals; and n and m are integers independently selected from 1 to 3. 46

5. The composition according to any one of claims 1-4, wherein the weight ratio of salts of DDA:ODDA:DODA in the composition is from 3:5:2 to 6.5:2.5: 1.

6.- The composition according to any one of claims 1-5, wherein the quaternary ammonium compounds comprise a salt of octyl decyl dimethyl ammonium (ODDA), a salt of dioctyl dimethyl ammonium (DODA), a salt of didecyl dimethyl ammonium (DDA), and a salt of alkyl dimethyl benzyl ammonium (ADBA); and the pH adjuster system comprises a multicarboxylic acid, which is a composition comprising citric acid and a chelating agent.

7. The composition according to any one of claims 1-6, wherein the only biocidal components are DDA:ODDA:DODA and the sum of the amounts of the three quaternary ammonium compounds is such that, when the aqueous composition is diluted with water at a final weight percentage of the composition from 0.2 % w/w to 4.0 % w/w, the concentration of the total quaternary ammonium compounds is of at least 120 parts per million (ppm).

8.- The composition according to any one of claims 1-7, wherein the salts of quaternary ammonium compounds are halide salts selected from chloride salts, bromide salts, fluoride salts, iodine salts and mixtures of these halide salts.

9.- The composition according to claim 8, wherein the salts of quaternary ammonium compounds are all three chloride salts.

10.- The composition according to any one of claims 1-9, further comprising one or more additives selected from perfume, surfactants, and organic solvents.

11.- The composition according to any one of claims 1-10, which is a pH adjusted composition E comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- citric acid;

- chelating agent selected from L-glutamic acid N, N-diacetic acid or salt thereof, particularly L-glutamic acid N, N-diacetic acid tetrasodium salt; Methylglicine N, N-diacetic acid or a salt thereof, such as alkaline or alkaline-earth salts, particularly the Methylglicine N, N-diacetic acid trisodium salt; Ethanoldiglycinic acid or a salt thereof, such as alkaline or alkaline-earth salts, particularly Ethanoldiglycinic acid disodium salt; Diethylenetriaminepentaacetic acid or a salt thereof, such as alkaline or alkaline-earth salts, particularly diethylenetriaminepentaacetic acid pentasodium salt; Hydroxyethylethylenediaminetriacetic acid, such as alkaline or alkaline-earth salts, particularly Hydroxyethylethylenediaminetriacetic acid trisodium salt; and a mixture thereof;

- surfactant, and 47

- water;

12. -The composition according to any one of claims 1-11, which is a pH adjusted composition E comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride (DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- citric acid;

- surfactant, and

- water.

13.- The composition according to any one of claims 1-12, which is a pH adjusted composition E comprising:

- octyl decyl dimethyl ammonium chloride (ODDAC);

- dioctyl dimethyl ammonium chloride(DODAC);

- didecyl dimethyl ammonium chloride (DDAC);

- citric acid;

- chelating agent, which is L-glutamic acid N, N-diacetic acid sodium salt; particularly L-glutamic acid N,N- diacetic acid tetrasodium salt,

- surfactant, and

- water.

14.- The composition to any of claims 1-13, wherein the surfactant comprises: at least one non-ionic surfactants; particularly selected from the group consisting of alkanolamides, alkyl polyglycosides, fatty acid N-methylglucamides, alkylphenol ethoxylates, fatty acid ethoxylates, fatty acid EO glycerol ester, sorbitan ethoxylated fatty acid ester, polyoxyethylene alkyl ether, and combinations thereof; or alternatively, at least one cationic surfactants; particularly selected from the group consisting of triethanolamine esterquats, ethoxylated quaternary ammonium compounds, and combinations thereof; or alternatively, at least one amphoteric surfactant; particularly selected from the group consisting of alkylbetains, alkylamidopropyl betaine, amine oxides, amphoacetates, and combinations thereof.

15.- The composition to any of claims 1-14, wherein the surfactant comprises at least one non-ionic surfactants selected from the group consisting of alkanolamides, alkyl polyglycosides, fatty acid N- methylglucamides, alkylphenol ethoxylates, fatty acid ethoxylates, fatty acid EO glycerol ester, sorbitan ethoxylated fatty acid ester, polyoxyethylene alkyl ether, and combinations thereof.

16.- The composition to claim 15, wherein the surfactant comprises at least one non-ionic surfactants selected from the group consisting of alkanolamides, alkyl polyglycosides, fatty acid N-methylglucamides, alkylphenol ethoxylates, fatty acid ethoxylates, fatty acid EO glycerol ester, sorbitan ethoxylated fatty acid ester, and combinations thereof.

17.- The composition to any of claims 15-16, wherein the surfactant comprises at least one non-ionic surfactants selected from the group consisting of polyoxyethylene(6) alkyl(C8-12) ether, polyoxyethylene sorbitan monolaurate (20) and a mixture thereof.

18.- Non-therapeutic use of the composition as defined in any one of claims 1-17, as biocidal.

19.- Use of the composition as defined in any one of claims 1-17, as biocidal additive composition for laundry.

20.- A method for laundry washing comprising adding to a recipient for laundry comprising water, a dose of the aqueous composition as defined in any one of claims 1-17.