EP4247927A1

EP4247927A1 - Aqueous cleaning composition comprising non-ionic surfactant, quaternary ammonium compound, and sequestrant

Info

Publication number: EP4247927A1
Application number: EP21807121.5A
Authority: EP
Inventors: Mara ABBATANGELO; Punam Bandyopadhyay; Nadia GROSSI
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Priority date: 2020-11-18
Filing date: 2021-11-15
Publication date: 2023-09-27
Anticipated expiration: 2041-11-15
Also published as: WO2022106354A1; HUE066787T2; CN116438285A; ZA202304292B; EP4247927B1; EP4247927C0; AR124076A1; PL4247927T3

Abstract

The invention relates to aqueous cleaning compositions comprising non-ionic surfactant, quaternary ammonium compound and sequestrant selected from MGDA, GLDA and combinations thereof, and organic acid, wherein the non-ionic surfactant comprises at least one alkyl polyglycoside surfactant. The compositions show a reduced pH drift. The invention also relates to a method and use to achieve the same.

Description

AQUEOUS CLEANING COMPOSITION COMPRISING NON-IONIC SURFACTANT, QUATERNARY AMMONIUM COMPOUND, AND SEQUESTRANT

Field of the Invention

The present invention relates to aqueous cleaning compositions. More specifically it relates to non-ionic surfactant comprising aqueous cleaning compositions with reduced pH drift, and a method and use to achieve the same.

Background of the Invention

Cleaning products are well-known and play an important role in everyday life. Such products will contain surfactant and, if disinfection is desired, usually also a disinfecting agent like for example a quaternary ammonium compound. Traditionally a distinction is made between personal hygiene, i.e. how one takes care of one’s own body; and home care including laundry and household care, the latter including the cleaning of hard surfaces like floors and kitchen tops.

More and more consumers prefer cleaning products with a good environmental profile. That is, they prefer products that are ‘eco-friendly’ and have less or no impact on the environment when the product is used. There is thus a growing need for cleaning products that mainly or only contain natural and/or biodegradable ingredients.

When washing laundry articles or cleaning hard surfaces like floors and kitchen tops, skin contact with the cleaning product usually occurs. A growing number of consumers expect cleaning products to be mild on skin such that it will not cause skin irritation, even when the cleaning product is not rinsed-off after contact. To address this need, a cleaning product may be formulated such that it has a neutral pH and therefore is mild on skin.

Storage stability of a cleaning product is an important attribute. That is to say, the product should maintain its product properties over its entire lifespan. For example, some ingredients may be less stable over time and/or under elevated temperatures and formulators may address this by including higher amounts of such ingredients to compensate for this loss. Another example is product appearance, as sometimes a product may develop sediment and/or become cloudy, resulting in a less appealing appearance of the cleaning product. For cleaning products that are formulated to be mild on skin and therefore have a specific, often neutral, pH it is important that consumers can rely on the product maintaining this characteristic during product lifetime as otherwise the product may, unexpectedly, result in skin irritation when used.

However, it may be that the pH of a product changes upon storage. This is sometimes referred to as ‘pH drift’. Inclusion of a buffer system like e.g. a bicarbonate buffer system, is a common method to address pH drift.

Some consumers especially expect that cleaning products that mainly or only contain natural and/or biodegradable ingredients are mild on skin and it is therefore especially important for such products to be storage stable, e.g. show reduced or no pH drift.

In view of the above, there remains a need for a cleaning compositions with a good environmental profile without compromising consumer satisfaction in terms of performance and/or storage stability.

Summary of the Invention

We have found that traditional buffer systems may not always prevent or reduce pH drift in nonionic surfactant comprising aqueous cleaning compositions but that certain sequestrants do prevent or reduce pH drift.

Accordingly, in a first aspect the invention relates to an aqueous cleaning composition comprising a. 0.1 to 30 wt% non-ionic surfactant comprising at least one alkyl polyglycoside surfactant; b. 0.01 to 20 wt% quaternary ammonium compound; c. 0.05 to 10 wt% sequestrant selected from MGDA, GLDA and combinations thereof; and d. 0.2 to 10 wt% organic acid wherein the composition has a pH between 6 and 8.

The invention further relates to a method of stabilizing the pH of an aqueous non-ionic surfactant comprising composition by including into the aqueous composition a sequestrant selected from MGDA, GLDA and combinations thereof.

The invention also relates to the use of MGDA, GLDA and combinations thereof to stabilize the pH of an aqueous non-ionic surfactant comprising composition. Detailed Description of the Invention

Any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of’ or “composed of.” In other words, the listed steps or options need not be exhaustive. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and is abbreviated as “wt%”. The use of any and all examples or exemplary language e.g. “such as” provided herein is intended merely to better illuminate the invention and does not in any way limit the scope of the invention otherwise claimed. Room temperature is defined as a temperature of about 20 degrees Celsius.

Aqueous cleaning composition

The cleaning composition of the present invention is an aqueous cleaning composition, that is to say that the composition comprises water. The amount of water will depend on the desired concentration of the other ingredients, preferably will at least be about 35 wt%. The composition will be liquid, that is it can be poured, and preferably has a water thin consistency.

The cleaning composition can be used for different product formats and can be offered to consumers as a ready-to-use product or as a concentrated composition that consumers can dilute at home with water to prepare the consumer-end-product. The concentrated product, or ‘dilute-at-home’ product, allows for an improved environmental profile as it requires less packaging because of smaller volume as well as reduced transportation cost. The consumer will then add water to prepare the consumer-end-product, the latter being the product that a consumer would traditionally buy from a store. Some cleaning products, like e.g. floor cleaners, will usually be dosed to an amount of water to prepare a cleaning liquid that is then subsequently used for cleaning. For the purpose of the present invention the preparation of a cleaning liquid by the consumer at home is not encompassed by the term ‘dilute-at-home’. Ready-to-use products will comprise a lower amount of active ingredients like surfactant and disinfecting agent. The amount of water will be at least 90 wt%, like for example at least 95 wt%.

For dilute-at-home products, that are more concentrated, the amount of water will be at least 35 wt%, but typically not more than 80 wt%.

Biodegradability

At least part of the ingredients of the cleaning composition, calculated on total product excluding water and inorganic materials, is biodegradable. To be truly biodegradable, a substance or material should break down into carbon dioxide (a nutrient for plants) and water. Naturally occurring minerals that do not cause harm to the ecosystem are already in their natural mineral state and do not need to biodegrade.

Preferably at least 70 wt%, more preferably at least 90 wt% and still more preferably at least 95 wt% of the ingredients is biodegradable. Preferably at least 99 wt% is biodegradable and even more preferably essentially all ingredients are biodegradable.

For the purpose of the invention the term ‘biodegradable’ refers to ‘Inherently and Ultimately biodegradable’ as per the OECD 302 guidelines/tests. Preferably the term ‘biodegradable’ refers to ‘Readily and Ultimately biodegradable’ as per the OECD 301 series or 310 guidelines/tests.

Preferably at least part of the organic ingredients of the cleaning composition, calculated on total product excluding water, is natural. For the purpose of this invention, natural is defined as the ingredient comprising at least 50 wt% plant derived, i.e. from a natural source, material; preferably at least 70 wt%, more preferably at least 90 wt% and still more preferably at least 95 wt%. Preferably at least 99 wt% is plant derived and even more preferably essentially all of a natural ingredient is plant derived.

Preferably at least 70 wt%, more preferably at least 90 wt% and still more preferably at least 95 wt% of the organic ingredients is natural. Preferably at least 99 wt% is natural and even more preferably essentially all organic ingredients are natural. Non-ionic surfactant

The aqueous cleaning composition of the present invention comprises 0.1 to 30 wt% non-ionic surfactant, like for example 0.5 to 20 wt% or 1 to 10 wt%. Ready-to-use products will typically comprise 0.1 to 10 wt% non-ionic surfactant and preferably 0.5 to 5 wt%. For dilute-at-home products, i.e. concentrated products, the amount of non-ionic surfactant will typically be 5 to 30 wt%.

Preferably the non-ionic surfactant is biodegradable and even more preferably the non-ionic surfactant is both natural and biodegradable.

The non-ionic surfactant comprises at least one alkyl polyglycoside surfactant and preferably the non-ionic surfactant is alkyl polyglycoside surfactant.

As used herein alkyl polyglycosides are compounds having formula I: R1O(R2O)b(Z)_a, wherein R1 is a alkyl radical, having from about 1 to about 30 carbon atoms; R2 is an alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; and a is a number having a value from 1 to about 6 (the degree of polymerization). Due to the method by which they are synthesized, alkyl polyglycosides are generally present as mixtures of alkyl polyglycosides having varying amounts of carbon atoms in the alkyl radical and varying degrees of polymerization. Thus, when referring to alkyl polyglycosides, the alkyl radical is generally referred to as having a range of carbon atoms (e.g. C4/22 referring to a range of alkyl radicals having from 4-22 carbon atoms) and the degree of polymerization is generally referred to as the average degree of polymerization of the mixture.

Preferably the alkyl plolyglycoside surfactant comprises alkyl polyglucoside surfactant and more preferably it is alkyl polyglucoside surfacant.

Prefered alkyl polyglycosides suitable for use in the disclosed cleaning formulation include those having the formula I wherein Z is a glucose residue, b is zero, R1 is an alkyl group that contains 4 to 22 carbon atoms, and the average value of a is about 1-2. Preferably R1 is an alkyl group that contains 8 to 16 carbon atoms, and the average value of a is about 1-2. Such alkyl polyglucosides are commercially available, for example, as GLUCOPON branded alkyl polyglucoside compositions from Cognis Corporation. Quaternary ammonium compound

The aqueous cleaning composition of the present invention comprises 0.01 to 20 wt% quaternary ammonium compound, like for example 0.1 to 10 wt%. Ready-to-use products will typically comprise 0.01 to 3 wt% quaternary ammonium compound and preferably 0.05 to 2.5 wt% like for example 0.1 to 2 wt%. For dilute-at-home products, i.e. concentrated products, the amount of quaternary ammonium compound will typically be 5 to 20 wt%.

Any quaternary ammonium compound can be used in the presently described technology. Examples of quaternary ammonium compounds include, for example, alkyl ammonium halides such as cetyl trimethyl ammonium bromide, alkyl aryl ammonium halides such as octadecyl dimethyl ammonium bromide, N-alkyl pyridinium halides such as N-cetyl pyridinium bromide, and the like. One suitable type of quaternary ammonium compound includes, for example, those in which the molecules contain amine, ether or ester linkages such as octyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, N-(laurylcocoaminoformylmethyl)-pyridinium chloride, and the like. Another effective type of quaternary ammonium compound include, for example, those in which the hydrophobic radical is characterized by a substituted aromatic nucleus as the case of lauryloxyphenyltrimehyl ammonium chloride, cetylaminophenyltrimethyl ammonium methosulfate, dodecylphenyltrimethyl ammonium methosulfate, dodecylbenzyltrimethylammonium chloride, chlorinated dodecylbenzyltrimethyl ammonium chloride, and the like. Preferably, the quaternary ammonium compound utilized in the practice of the present technology exhibit biocidal activity or are biocidal in nature.

Particularly useful quaternary ammonium compound germicides include compositions which include a single quaternary compound, as well as mixtures of two or more different quaternary compounds. Such useful quaternary compounds are available under the EMPIGEN, BARDAC, BARQUAT, HYAMINE, LONZABAC, and ONYXIDE trademarks, which are more fully described in, for example, McCutcheon's Functional Materials (Vol. 2), North American Edition, 1998, as well as the respective product literature from the suppliers identified below.

For example, BARDAC 205M is described to be a liquid containing alkyl dimethyl benzyl ammonium chloride (BKC), octyl decyl dimethyl ammonium chloride; didecyl dimethyl ammonium chloride, and dioctyl dimethyl ammonium chloride (50% active) (also available as 80% active (BARDAC 208M)); described generally in McCutcheon's as a combination of alkyl dimethyl benzyl ammonium chloride and dialkyl dimethyl ammonium chloride); BARDAC 2050 is described to be a combination of octyl decyl dimethyl ammonium chloridedidecyl dimethyl ammonium chloride, and dioctyl dimethyl ammonium chloride (50% active) (also available as 80% active (BARDAC 2080)); BARDAC 2250 is described to be didecyl dimethyl ammonium chloride (50% active); BARDAC LF (or BARDAC LF-80), described as being based on dioctyl dimethyl ammonium chloride (BARQUAT MB-50, MX-50, OJ-50 (each 50% liquid) and MB-80 or MX-80 (each 80% liquid) are each described as an alkyl dimethyl benzyl ammonium chloride; BARDAC 4250 and BARQUAT 4250 Z (each 50% active) or BARQUAT 4280 and BARQUAT 4280Z (each 80% active) are each described as alkyl dimethyl benzyl ammonium chloride/alkyl dimethyl ethyl benzyl ammonium chloride. Also, HYAMINE 1622, described as diisobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride (50% solution); HYAMINE 3500 (50% actives), described as alkyl dimethyl benzyl ammonium chloride (also available as 80% active (HYAMINE 3500-80)); and HYMAINE 2389 described as being based on methyldodecylbenzyl ammonium chloride and/or methyldodecylxylene-bis-trimethyl ammonium chloride.

(BARDAC, BARQUAT and HYAMINE are presently commercially available from Lonza, Inc., Fairlawn, N. J.). BTC 50 NF (or BTC 65 NF) is described to be alkyl dimethyl benzyl ammonium chloride (50% active); BTC 99 is described as didecyl dimethyl ammonium chloride (50% active); BTC 776 is described to be myrisalkonium chloride (50% active); BTC 818 is described as being octyl decyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, and dioctyl dimethyl ammonium chloride (50% active) (available also as 80% active (BTC 818- 80%)); BTC 824 and BTC 835 are each described as being of alkyl dimethyl benzyl ammonium chloride (each 50% active); BTC 885 is described as a combination of BTC 835 and BTC 818 (50% active) (available also as 80% active (BTC 888)); BTC 1010 is described as didecyl dimethyl ammonium chloride (50% active) (also available as 80% active (BTC 1010-80)); BTC 2125 (or BTC 2125 M) is described as alkyl dimethyl benzyl ammonium chloride and alkyl dimethyl ethylbenzyl ammonium chloride (each 50% active) (also available as 80% active (BTC 2125 80 or BTC 2125 M)); BTC 2565 is described as alkyl dimethyl benzyl ammonium chlorides (50% active) (also available as 80% active (BTC 2568)); BTC 8248 (or BTC 8358) is described as alkyl dimethyl benzyl ammonium chloride (80% active) (also available as 90% active (BTC 8249)); ONYXIDE 3300 is described as n-alkyl dimethyl benzyl ammonium saccharinate (95% active). (BTC and ONYXIDE are presently commercially available from Stepan Company, Northfield, III).

Benzyl-C12-14-alkyldimethylammonium chlorides benzyl C12-C16- alkyl dimethyl chlorides also available as EMPIGEN BAC 50 and EMPIGEN BAC 80. It is an aqueous solution of benzalkonium chloride at ca. 50% or 80% in water respectively. EMPIGEN BAC 50 and EMPIGEN 80 are readily biodegradable, EMPIGEN is commercially available from Innospec Performance Chemicals

Polymeric quaternary ammonium salts based on these monomeric structures are also considered desirable for the present invention. One example is POLYQUAT, described as being a 2-butenyldimethyl ammonium chloride polymer.

Preferably the quaternary ammonium compound is benzalkonium chloride.

Sequestrant

The aqueous cleaning composition of the present invention comprises 0.05 to 10 wt% sequestrant selected from MGDA, GLDA and combinations thereof. MGDA is the common abbreviation used for methylglycine diacetic acid trisodium salt and also known as trisodium dicarboxymethyl alaninate. GLDA is the common abbreviation used for glutamic acid diacetic acid tetra sodium salt.

Ready-to-use products will typically comprise 0.05 to 5 wt% sequestrant selected from MGDA, GLDA and combinations thereof, preferably 0.1 to 5 wt% and more preferably 0.2 to 5 wt%. For dilute-at-home products, i.e. concentrated products, the amount of sequestrant selected from MGDA, GLDA and combinations thereof will typically be 1 to 10 wt% and preferably 2 to 8 wt%.

Preferably the sequestrant comprises MGDA and more preferably the sequestrant is MGDA.

It was surprisingly found that these sequestrants were able to reduce or even prevent pH drift contrary to traditional buffer systems. nh

The aqueous cleaning composition of the present invention has a pH between 6 and 8 and preferably is between 6.5 and 7.5. A pH that is more or less neutral will provide for a cleaning composition that is mild on skin.

Compositions of the present invention show reduced pH drift upon storage. Preferably the pH of the initial composition does not change over time in that the pH does not change more than plus or minus 0.5, more preferably plus or minus 0.3 and even more preferably plus or minus 0.1. Preferably this reduced pH drift remains for at least 3 months, more preferably at least 6 and even more preferably at least 12 months after initial production.

Organic acid the aqueous cleaning composition of the present invention comprise organic acid. Preferably the organic acid may be selected from organic acids having a pKa value in the range from 2 to 5.5.

Preferably the organic acid is selected from citric acid (pKa = 3.1), lactic acid (pka = 3.86), acetic acid (pKa = 4.76), malonic acid (pKa = 2.85), adipic acid (pKa = 4.43), glutaric acid (pKa = 3.76), and glycolic acid (pKa = 3.83) and combinations thereof.

Even more preferably the organic acid is citric acid, lactic acid and combinations thereof.

Further ingredients

The aqueous cleaning composition of the present invention may comprise further ingredients like for example fragrance. Preferably the composition comprises a biodegradable fragrance.

The composition may also comprise other surfactants, but preferably the composition is free from anionic surfactants as these may interfere with the biocidal efficacy of the quaternary ammonium compound.

Method of stabilizing pH

The invention also relates to a method of stabilizing the pH of an aqueous non-ionic surfactant comprising composition by including into the aqueous composition a sequestrant selected from MGDA, GLDA and combinations thereof. Preferably the method stabilizes the pH of any one of the aqueous non-ionic surfactant comprising compositions of the present invention. Stabilizing the pH of the composition herein refers to reducing pH drift of the composition under different storage conditions.

The invention further relates to use of MGDA, GLDA and combinations thereof to stabilize the pH of an aqueous non-ionic surfactant comprising composition, preferably any one of the aqueous non-ionic surfactant comprising compositions of the present invention. Product format

The composition may be used as a ready-to-use product or as a dilute-at-home product for cleaning of surfaces including household hard surfaces like floors and kitchen tops, clothes, and human skin.

For a ready-to-use floor cleaner or multi-purpose cleaner the product will usually be provided in bottle. A ready-to-use cleaning spray like a kitchen spray may preferably be provided in a trigger spray bottle. The ready-to-use cleaning spray may also be used to freshen up clothes or human skin like for example hands by spraying the cleaning composition on the desired surface. For a dilute-at-home product the consumer will first have to dilute the composition with water, preferably by diluting it 5 to 15 times with water, more preferably 8 to 12 times and even more preferably 10 times.

The composition may be packaged in the form of any commercially available bottle for storing the liquid. The bottle containing the liquid can be of different sizes and shapes to accommodate different volumes of the liquid; preferably between 0.05 and 2 L with ready-to-use products typically 0.1 and 1.5 L or even between 0.25 and 1 L and dilute-at home products preferably between 0.05 and 0.2 L. The bottle is preferably provided with a dispenser, which enables the consumer an easier mode of dispersion of the liquid. Spray or pump-dispensers may also be used.

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

Examples

Example 1

Formulations according to Table 1 were prepared and adjusted to pH 7 using citric acid.

TABLE 1 (wt% calculated on total product)

The formulations were then subjected to a storage stability study as follows.

• pH was measured for neat formulation using a pH meter (Mettler Toledo)

• Stability study was conducted at room temperature (RT).

• pH of the samples recorded at zero time point and then at the end of 2 or 4 or 6 or 8 weeks of storage. pH drift was determined by a plot of pH vs storage time (weeks). pH values represented in Table 2 are at 4 weeks of storage as calculated from the plot of pH drift over storage time.

• Samples were stored in state-of-the-art temperature test chambers depending on the storage conditions.

TABLE 2, pH values at zero time point and after 4 weeks

Example 2

Formulations according to Table 3 were prepared and adjusted to pH 7 using citric acid.

TABLE 3 (wt% calculated on total product)

The formulations were then subjected to a storage stability study as described above for Example 1 . Samples 4 and 5 were also tested as dilutes by diluting 10x with water having 23 FH. This was done by adding water to a total volume of 10x cleaning formulation 4 or 5 (i.e. 100 ml of formulation 4 or 5 was diluted with water to a total volume of 1000 ml). Test results can be found in Table 4.

TABLE 4, pH values at zero time point and after 4 weeks

Samples 6 and 7 were also tested as dilutes by diluting 15x with water having 23 FH. This was done by adding water to a total volume of 15x cleaning formulation 6 or 7 (i.e. 100 ml of formulation 6 or 7 was diluted with water to a total volume of 1500 ml). Test results can be found in Table 5.

TABLE 5, pH values at zero time point and after 4 weeks

Claims

1. Aqueous cleaning composition comprising a. 0.1 to 30 wt% non-ionic surfactant comprising at least one alkyl polyglycoside surfactant; b. 0.01 to 20 wt% quaternary ammonium compound; c. 0.05 to 10 wt% sequestrant selected from MGDA, GLDA and combinations thereof; d. 0.2 to 10 wt% organic acid; and wherein the composition has a pH between 6 and 8.

2. Composition according to claim 1 wherein the alkyl polyglycoside surfactant comprises alkyl polyglucoside surfactant.

3. Composition according to claims 1 or 2 wherein the alkyl polyglycoside surfactant is alkyl polyglucoside surfactant.

4. Composition according to any one of claims 1 to 3 wherein the quaternary ammonium compound is selected from didecyl dimethyl ammonium chloride, dioctyl dimethyl ammonium chloride, alkyl dimethyl benzyl ammonium chloride, diisobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, alkyl dimethyl benzyl ammonium saccharinate, octyl decyl dimethyl ammonium chloride, alkyl dimethyl ethyl benzyl ammonium chloride, methyldodecylbenzyl ammonium chloride, methyldodecylxylene-bis-trimethyl ammonium chloride, methyl benzethonium chloride, cetyl pyrinidinium chloride, cetrimonium bromide and combinations thereof.

5. Composition according to claim 4 wherein the quaternary ammonium compound is benzalkonium chloride.

6. Composition according to any one of claims 1 to 5 wherein the sequestrant comprises MGDA.

7. Composition according to any one of claims 1 to 6 wherein the organic acid has a pKa value in the range from 2.0 to 5.5.

8. Composition according to claim 7 wherein the organic acid is selected from citric acid (pKa = 3.1), lactic acid (pka = 3.86), acetic acid (pKa = 4.76), malonic acid (pKa = 2.85), adipic acid (pKa = 4.43), glutaric acid (pKa = 3.76), glycolic acid (pKa = 3.83) and combinations thereof. Composition according to claim 8 wherein the organic acid is citric acid, lactic acid and combinations thereof. Composition according to any one of claims 1 to 9 wherein the pH is between 6.5 and 7.5 Composition according to any one of claims 1 to 10 further comprising a biodegradable fragrance. Method of stabilizing the pH of an aqueous non-ionic surfactant comprising composition by including into the aqueous composition a sequestrant selected from MGDA, GLDA and combinations thereof. Method according to claim 12 wherein the composition is according to any one of claims 1 to 11. Use of MGDA, GLDA and combinations thereof to stabilize the pH of an aqueous non-ionic surfactant comprising composition. Use according to claim 14 wherein the composition is according to any one of claims 1 to 11.