EP4419639A1

EP4419639A1 - A stable liquid disinfecting composition

Info

Publication number: EP4419639A1
Application number: EP22802077.2A
Authority: EP
Inventors: Shanthi APPAVOO; Arijit BERA; Suma MENON
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Priority date: 2021-10-13
Filing date: 2022-10-11
Publication date: 2024-08-28
Also published as: WO2023061964A1

Abstract

The present invention relates to a liquid cleaning and disinfecting composition that can be used for cleaning inanimate surfaces at homes and outside while being stable over a wide temperature range. The composition maintains an even appearance without any clouding or precipitation at warm as well as cold conditions. This is achieved through a combination of well known and widely used surfactants and cleaning ingredients while not using conventional antimicrobial agents, while specifically including therein a fatty mono or di alcohol.

Description

A STABLE LIQUID DISINFECTING COMPOSITION

Field of the Invention

The present invention relates to a liquid disinfecting composition that is stable over a wide temperature range. It particularly relates to a liquid composition that not only cleans desired inanimate surfaces like in the homes and other places but remains stable (without any clouding or precipitation) over a wide temperature range. The disinfection is achieved through a combination of well known and widely used surfactants and cleaning ingredients while not using conventional antimicrobial agents.

Background of the Invention

Disinfecting and cleaning compositions are of great benefit to individuals, since proper use generally may reduce the number of germs and pathogens the individual is exposed to. Such compositions are used for cleaning hard surfaces e.g. cleaning of floors, table tops, kitchen surfaces and utensils. They are also used for cleaning bathrooms and toilets. The compositions may also include well known antimicrobial agents along with a cationic surfactant which not only help clean but also deliver the desired antimicrobial effect. Such compositions may for instance play an important role in reducing the occurrence and spread of infectious diseases. Disinfecting compositions comprising bleaches of the chlorine type are also known. They deliver excellent benefits but may sometimes be considered to be rather harsh as it may exhibit undesirable side effects, such as corrosion, malodour (like a chlorine smell) and skin irritation or skin-sensitizing effects when it comes in contact with a person’s skin or mucous membrane. Therefore, there is a need for a composition that not only cleans but also disinfects using commonly used milder ingredients.

The present inventors while trying to achieve the contrasting requirements of high cleaning and disinfecting efficacy while using only conventional cleaning agents, hit upon a narrow window of a combination of two anionic surfactants (alkyl sulphate surfactant and alkyl ether sulphate surfactant), an amphoteric surfactant (alkyl amidopropyl betaine), and a carboxylic acid which could achieve the desired benefit. However, this composition suffered from low temperature instability. It exhibited clouding and/ or precipitation at low temperatures of around 0 °C or lower. The present inventors have solved this problem with a surprising finding that inclusion of a Ce to C12 fatty mono or di alcohol not only ensured that the desired cleaning and disinfecting benefits could be obtained but the liquid composition was stable on storage at low temperatures of about 0 °C. To the knowledge of the present inventors such a combination of actives to achieve these contrasting requirements have not been disclosed or used in the past.

It is thus an object of the present invention to provide for a liquid cleaning and disinfecting composition which remains stable without precipitating or cloud formation at low temperatures of about 0 °C.

Summary of the Invention

According to the first aspect of the present invention there is provided a stable liquid disinfecting composition comprising

(a) 2 to 5 % alkyl sulphate surfactant;

(b) 2 to 5% alkyl ether sulphate surfactant;

(c) 1 to 2.5% alkyl amidopropyl betaine;

(d) 5 to 15 % carboxylic acid; and

(e) 0.25 to 2.5% C6 to C12 fatty mono or di alcohols preferably octanediol, decanol, decanediol, dodecanol, or dodecanediol.

Detailed Description of the Invention

For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of” or "composed of". Thus, the term "comprising" is meant not to be limiting to any subsequently stated elements, but rather to optionally also encompass nonspecified elements of major or minor functional importance. In other words, the listed steps or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Except in the 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". Unless specified otherwise, numerical ranges expressed in the format "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%”. Throughout this description, the term ‘disinfection’ refers to reduction of the number of viable microorganisms in a given medium or on a given surface. Typically, disinfection involves the destruction or inactivation of the microorganisms. Both animate and inanimate media and surfaces are contemplated, although inanimate surfaces are preferred.

The term " antimicrobial " refers to a compound capable of killing, inhibiting the growth of or controlling the growth of microorganisms at a locus; antimicrobials include bactericides, fungicides and algaecides. The term "microorganism" includes, for example, fungi (such as yeast and mould), bacteria and algae.

The compositions of the present invention are preferred for non-therapeutic use, and more particularly preferred for use in cleaning surfaces, preferably wherein the surface is a hard surface and more preferably for use in cleaning applications such as cleaning kitchen, bathroom and floor surfaces. They may also be used for cleaning fabrics.

The composition comprises an alkyl sulphate surfactant. The alkyl sulphate surfactant for inclusion in the composition of the invention preferably has 10 to 18 carbon atoms, more preferably C10 to C12 carbon atoms. The surfactant has a counterion which is an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine (DEA) or triethanolamine (TEA). Preferably it is sodium or potassium, most preferably it is sodium. The most preferred surfactant of this class for inclusion in the composition of the invention is sodium lauryl sulphate. The alkyl sulphate surfactant is included in 2 to 5%, preferably 3 to 4% by weight of the composition. It has been found that inclusion of this surfactant is important as it not only gives high cleaning but is found effective as an antibacterial agent especially against gram positive bacteria. The selective concentration of this surfactant is important as including too low a concentration affects the antimicrobial efficacy while including too high a concentration affects the low temperature stability.

The composition comprises an alkyl ether sulphate surfactant. The alkyl ether sulphate surfactant for inclusion in the composition of the invention preferably has 10 to 18 carbon atoms, more preferably C10 to C12 carbon atoms. The alkyl ether sulphate surfactant preferably has one to ten ethylene oxide or propylene oxide units per molecule, preferably one to three ethylene oxide units per molecule. The surfactant has a counterion which is an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine (DEA) or triethanolamine (TEA). Preferably it is sodium or potassium, most preferably it is sodium. The most preferred surfactant of this class for inclusion in the composition is sodium laureth sulphate 1 EO. The alkyl sulphate surfactant is included in 2 to 5%, preferably 3 to 4.5% by weight of the composition. It has been found that inclusion of this surfactant is important as it as it has a positive effect on the low temperature stability.

The composition as per the invention comprises an amphoteric surfactant which is an alkyl amidopropyl betaine. Preferred alkyl amidopropyl betaine is cocoamido propyl betaine. The betaine is included in 1 to 2.5%, preferably 1.5 to 2.2% by weight of the composition. It has been found that this surfactant has to be included in this narrow range of concentration in order to get all the benefits of the invention. In addition to providing the cleaning benefits from being a surfactant, inclusion of too high an amount has been found to negatively impact the antimicrobial efficacy while including too small an amount negatively impacts the desired low temperature stability.

The composition of the invention includes 5 to 15%, preferably 7.5 to 12.5%, further more preferably 8 to 12 % a carboxylic acid or salt thereof, by weight of the composition. The carboxylic acid is preferably chosen from one or more of citric acid, glycolic acid, lactic acid, malic acid, tartaric and benzoic acid. Further more preferably it is chosen from one or more of lactic acid, glycolic acid and citric acid. Most preferably it is a combination of a glycolic acid and lactic acid. The applicant has determined that in this multidimensional composition the contrasting requirements make it necessary that in the case of carboxylic acid also, it is necessary to include it in the specific concentration range claimed. It was observed that the inclusion of carboxylic acid in this range ensures that it helps in low temperature stability while ensuring that gram negative bacteria are effectively inhibited.

The composition of the invention includes 0.25 to 2.5% C6 to C12 fatty mono or di alcohols as an essential ingredient to ensure that the final requirement of low temperature stability is obtained. The fatty alcohol is preferably of the C8 to C11 alkyl chain length. It is more preferably chosen from one or more of octanediol, .decanol, decanediol, dodecanol, and dodecanediol. Most preferably, it is octanediol. It may be hypothesized that these fatty alcohols act as a solubliizer. However, the finding is surprising in that the present inventors tried very many similar type of compounds which are known to be solubilisers but they did not provide the desired benefit for the present specific mixture of ingredients claimed in the present invention. The other materials which were tried included 1 ,2 propanediol, glycerol, sodium xylene sulphonate, sodium cumene sulphonate, PEG 200, PEG 400, Tergitol 15S7, lauramine oxide, Neodol 257, butanol and sorbitol but none of them provided the benefit that the C6 to C12 fatty mono or di alcohols provided.

The composition is in liquid form. It contains high amount of water. Water is generally present in 70 to 90%, preferably 75 to 85 % by weight of the composition.

The composition may optionally comprise other ingredients, such as fragrance and/or colour.

The composition preferably has a pH in the range of 2 to 4 preferably in the range of 2.5 to 3. The formulation is homogenized and the pH of the formulation is directly measured using a precalibrated pH meter.

The composition of the invention is preferably used for home care applications. A "home care product" is a product for the treatment, cleaning, caring or conditioning of the home or any of its contents. The foregoing includes, but is not limited to, compositions, products, or combinations thereof relating to or having use or application in the treatment, cleaning, cleansing, caring or conditioning of surfaces, furniture and atmosphere of the home and household contents, such as clothes, fabrics and/or cloth fibres and the manufacture of all of the foregoing products.

Preferably, the composition used in the present invention is used to clean a hard surface, more preferably wherein the hard surface is a kitchen, bathroom or floor surface. Typically, such hard surfaces are surfaces that require frequent cleaning and preferably also sanitisation and/or disinfection. Such surfaces may be found in many household or industrial environments, and may include kitchen and bathroom surfaces, tabletops, floors, walls, windows, utensils, cutlery, and crockery. Such surfaces may be made from many different materials, including for instance plastics, wood, metal, ceramics, glass, concrete, marble, and painted surfaces. The composition may be applied to the surface by any suitable means known to the skilled person. For instance, a suitable means may be pouring, dropping, spraying or wiping in case of liquid compositions.

The composition may be used as is, i.e. neat, preferably the composition is diluted with water before use. For example, if applied in a diluted form, the composition is diluted with water preferably in a ratio in the range of 1 :1 to 1 :1000, more preferably 1 :50 to 1 :500, even more preferably 1 :100 to 1 :300.

In most hard surface cleaning application, the diluted solution is applied on to the desired surface by using a brush or a mop and allowing it to dry. In certain vertical surfaces, it may be sprayed on using a hand held spray pump. In certain cases, the compositions after it is applied on to the desired surface, may be wiped off to a substantially dry condition using a dry cloth or wipe. In toilet cleaning applications, the composition is generally applied on to the toilet bowl, allowed to stay thereon for a few minutes, and then the toilet is flushed, preferably after brushing with a toilet brush.

Another preferred embodiment of the invention relates to compositions according to the invention for use as or incorporation in industrial and/or institutional products. More preferably, this embodiment of the invention relates to a composition according to the invention which is an industrial and/or an institutional product. Industrial and institutional products are for example products being marketed under professional brands, with non-limiting examples being products for industrial, institutional, janitorial, and medical cleaning, cleaning-in-place, food services, veterinary, and agricultural products.

The invention shall now be exemplified by the following non-limiting examples.

Examples

Examples A-F: Effect of the compositional ingredients on temperature stability

Liquid cleaning composition as shown in Table -1 were prepared. The compositions were stored in plastic transparent bottles at 25 °C and 0°C. The compositions which showed cloudiness and/or precipitation at 0 °C are therefore marked F (failed) for low temperature stability in the table below. At 25 °C, they were clear and transparent and so are marked as P (passed).

Table -1

In the above table,

SLS is sodium lauryl sulphate

SLES1E0 is sodium lauryl ether sulphate 1EO

CAPB is Coco amido propyl betaine

The data in the table above indicates that compositions outside the invention (Examples A to F) do not pass the low temperature stability.

Example G,H, 1-3: Effect of the compositional ingredients on temperature stability and disinfection efficacy

Compositions as shown in Table - 2 below were prepared and the low temperature stability was observed. The hygiene performance was also measured as described below and the data is summarised in Table - 2 below.

The composition is diluted at 1 :200 ratio with water and standard EN1276 protocol was used using BSA at 0.3 g/L at 15 minute contact time. If the composition was found to give >5 log reduction for all four microbes testes (S. aureus, E. hirae, P. aeruginosa and E. coli), then the sample was marked as passed (P) . If not it was marked as failed (F).

Table -2

The data in the table -2 above indicates that compositions as per the invention (Examples 1 to 3) meet all the performance expectations (stability at 25 °C and 0 °C and hygiene performance) while those outside the invention (Examples G and H) fail in one or the other criterion.

Claims

9

Claims A stable liquid disinfecting composition comprising

(a) 2 to 5 wt% alkyl sulphate surfactant;

(b) 2 to 5 wt% alkyl ether sulphate surfactant;

(c) 1 to 2.5 wt% alkyl amidopropyl betaine;

(d) 5 to 15 wt% carboxylic acid; and

(e) 0.25 to 2.5 wt% C6 to C12 fatty mono or di alcohols preferably octanediol, decanol, decanediol, dodecanol, or dodecanediol. A composition as claimed in claim 1 wherein the alkyl sulphate surfactant has 10 to 18 carbon atoms. A composition as claimed in claim 1 or 2 wherein the alkyl ether sulphate surfactant has 10 to 18 carbon atoms. A composition as claimed in any one of the preceding claims wherein the alkyl ether sulphate surfactant has one to ten ethylene oxide or propylene oxide units per molecule, preferably one to three ethylene oxide units per molecule. A composition as claimed in any one of the preceding claims wherein the alkyl sulphate surfactant and the alkyl ether sulphate surfactant have a counterion which is an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine (DEA) or triethanolamine (TEA); preferably sodium or potassium. A composition as claimed in any one of the preceding claims wherein the alkyl sulphate surfactant is sodium lauryl sulphate. A composition as claimed in any one of the preceding claims wherein the alkyl ether sulphate is sodium laureth sulphate 1EO. A composition as claimed in any one of the preceding claims wherein the alkyl amido propyl betaine is cocoamidopropyl betaine. A composition as claimed in any one of the preceding claims wherein the carboxylic acid is chosen from one or more of citric acid, glycolic acid, lactic acid, malic, tartaric and benzoic acid. A composition as claimed in any one of the preceding claims comprising 70 to 90 wt% water.