WO2025026664A1

WO2025026664A1 - A cleaning composition

Info

Publication number: WO2025026664A1
Application number: PCT/EP2024/069337
Authority: WO
Inventors: Shanthi APPAVOO; Manoj Vilas Dagaonkar; Faraaz Mohammed IKRAM; Sahiti MATTAPARTHI; Shrabani MITRA; Vishal Kumar TRIVEDI
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Priority date: 2023-08-01
Filing date: 2024-07-09
Publication date: 2025-02-06
Anticipated expiration: 2026-02-01

Abstract

The present invention relates to a hard surface cleaning composition that in addition to giving good cleaning benefits also delivers superior malodour reduction. This is achieved using a composition comprising Ca-LAS surfactant, alkoxylated fatty alcohol surfactant, phenoxyalkanol, and alkane diol.

Description

A CLEANING COMPOSITION

Field of the Invention

The present invention relates to a hard surface cleaning composition that in addition to giving good cleaning benefits also delivers superior malodour reduction.

Background of the Invention

Hard surface cleaning compositions are used to clean various surfaces at homes and other public places like offices, restaurants, and areas with high density of people like shopping malls, airports and railway stations. Areas which require frequent cleaning in such places include bathrooms, toilets and kitchens. Adequate hygiene is maintained by frequent cleaning but this alone may not deliver the desired sensorial cue freshness if they have an unpleasant residual malodour. Reducing malodour in such places is therefore important for the people utilising such facilities.

Cleaning products for such places are available in various formats. There was a time when powders were widely used. Then came bars which were shaped like soap bars. Bars are being gradually replaced by liquids and pastes. Abrasive pastes usually contain an anionic surfactant, generally sodium salt of linear alkyl benzene sulphonic acids (Na-LAS), a non-ionic surfactant and an abrasive. While such compositions deliver good cleaning, it was found wanting when it came to delivering malodour reduction even if such composition were formulated with perfumes. One patent application published as W02020/041063 seeks to solve this problem in a Na-LAS based composition through use of certain oligoamines. While some solutions have been proposed there is always the need to deliver superior malodour reduction through combination of actives that have been commonly used in the past. The present inventors with their extensive experience in formulating surfactant based cleaning composition and knowledge of malodour generation and mitigation sought out to find a solution to this problem. After extensive experiments they found that when a preservative component phenoxyalkanol was combined with an active like alkane diol, there was some malodour reduction. However, it is was not too significant in the conventional Na-LAS surfactant system. The present applicants have published patents e.g. EP3350298 on aqueous cleaning compositions comprising calcium and magnesium salts of linear alkyl benzene sulphonic acid (Ca-LAS and Mg-LAS) which are milder than the sodium salts as they are closer to neutral pH. After further extensive experiments with various surfactant systems including the above mentioned Ca-LAS and Mg-LAS surfactants, to their surprise they found that when Ca-LAS surfactant was combined with a non-ionic surfactant like alkoxylated fatty alcohol along with the abovementioned combination of phenoxyalkanol and alkane diol, significant malodour reduction was observed. It is thus an object of the present invention to provide for a hard surface cleaning composition that delivers superior malodour reduction compared to known composition of that type.

Summary of the Invention

The first aspect of the present invention relates to a cleaning composition comprising:

(i) calcium salt of linear alkyl benzene sulphonic acid;

(ii) alkoxylated fatty alcohol;

(iii) C2 - C3 phenoxyalkanol preferably phenoxyethanol; and

(iv) C3 to Cs alkane diol.

Another aspect of the present invention relates to a method of reducing malodour comprising the steps of cleaning a surface with a composition of the first aspect optionally diluted with water followed by the step of rinsing or wiping the composition from the surface.

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 " 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 25 degrees Celsius.

Hard surfaces include floors, walls, tiles, windows, cupboards, sinks, showers, wash basins, WCs, fixtures and fittings made of different materials like ceramic, vinyl, no-wax vinyl, linoleum, melamine, glass, Formica®, vitroceramic, plastified wood, metal or any painted or varnished or sealed surface. It also includes household appliances including, but not limited to refrigerators, freezers, washing machines, automatic dryers, ovens, microwave ovens and dishwashers. The term dishes include glasses, pots, pans, baking dishes and flatware made from ceramic, china, metal, glass, plastic (polyethylene, polypropylene, polystyrene), wood, enamel, Inox®, teflon, or any other material commonly used in the making of articles used for eating and/or cooking.

The cleaning composition of the present invention comprises calcium salt of linear alkyl benzene sulphonic acid (abbreviated as Ca-LAS). It is preferably an aqueous composition.

Ca-LAS is formed by neutralising linear alkyl benzene sulphonic acid (LAS acid) with a calcium salt. Preferably the calcium salt is calcium hydroxide or calcium oxide. Preferably the LAS acid is neutralised with the calcium salt in absence of abrasive particles. Ca-LAS works as primary surfactant in the composition for cleaning benefit.

It is preferred that the composition according to the present invention comprises 0.1 to 15 wt% of calcium salt of linear alkyl benzene sulphonic acid, more preferably 0.5 to 10 wt%, even more preferably 1 to 5 wt% and most preferably 2 to 4 wt%. It is preferred that the composition comprises less than 1 wt%, more preferably less than 0.1 wt% of sodium salt of linear alkyl benzene sulphonic acid (Na-LAS). Any excess amount of Na-LAS could tend to destabilise the composition due to exchange of calcium ions with the sodium ions. Optimally, Na-LAS is absent from the composition.

Often dolomite is used as source of calcium salt for neutralising LAS acid, which may leave a part of magnesium salt of linear alkyl benzene sulphonic acid (Mg-LAS) in addition to Ca-LAS. However, dolomite is a naturally occurring mineral and often varies in its specification, particularly in the relative ratio of components therein, which may affect the product performance. Therefore, according to the present invention it is preferred to use non-dolomite source of calcium salt for neutralising LAS acid.

Magnesium salt of linear alkyl benzene sulphonic acid is in an amount not more than 1 wt% of the amount of said calcium salt. For example, if the total amount of Ca-LAS is 5 wt%, then the maximum amount of Mg-LAS is 0.05 wt%, which amounts to not more than 1 wt% of the amount of the calcium salt.

It is preferred that the composition does not contain magnesium salt of linear alkyl benzene sulphonic acid. Thus, the amount of magnesium salt of linear alkyl benzene sulphonic acid is from 0 to 1 wt% of the amount of the calcium salt.

The composition comprises one or more alkoxylated fatty alcohol. These are non-ionic surfactants. The HLB of the alkoxylated fatty alcohol is in the range of 11 to 20 and the carbon chain length of said fatty alcohol is in the range of 12 to 16. All non-ionic surfactants have an HLB value. The higher the number, the more hydrophilic the surfactant. On the other hand, surfactants having lower HLB value are more lipophilic.

Alkoxylated fatty alcohols lend stability to the composition. It is particularly preferred that the degree of ethoxylation in said alkoxylated fatty alcohol is from 5 to 8 moles of ethylene oxide units. Alkoxylated fatty alcohols having a degree of ethoxylation from 5 to 8 show particularly good technical effect by stabilizing the composition which is stored at temperatures higher or lower than the normal room temperature (i.e. , a temperature around 20 °C).

It is preferred that the composition comprises 0.05 to 10 wt% of alkoxylated fatty alcohol, more preferably 0.1 to 8 and most preferably 1 to 5 wt%. A combination of one or more such non-ionic surfactants may also be used.

Preferably the weight ratio of calcium salt linear alkyl benzene sulphonic acid to alkoxylated fatty alcohols is 1 :1 to 2:1.

The composition of the invention includes a C2-C3 phenoxy alkanol. Use of phenoxy ethanol is especially preferred. The phenoxyalkanol is preferably included in 0.05 to 1 wt% of the composition.

The composition comprises a C3 to Cs alkane diol. Preferred alkane diol is propanediol. Alkane diol is preferably included in 0.05 to 1.0% by weight of the composition.

Without wishing to be bound by theory the inventors believe that the combination of the phenoxy alkanol and the alkane diol in a Ca-LAS based cleaning composition works to deliver reduced malodour either by reducing the vapour pressure of the malodour molecules or through the mechanism of neutralisation of the malodour molecules or a combination of both of these mechanisms.

The composition of the invention preferably comprises abrasive particles having a Moh’s Index of 0.5 to 7. Preferred abrasive is calcite. When included, the abrasive particle is included in 10 to 50 wt%, preferably 20 to 50 wt%, more preferably 25 to 45 wt%. Other suitable abrasive particles are bentonite, china clay, dolomite or feldspar. It is preferred that of the total amount of abrasive particles, calcite is included in at least 50 wt% of the total amount of abrasives in the composition. It is preferred that the average particle size of abrasive particles is in the range 0.5 to 400 pm, more preferably 10 to 200 pm.

The composition according to the present invention is preferably alkaline in nature. The composition preferably has a pH in the range of 9 to 12, preferably from 9.5 to 11 .5 at 20 °C.

The composition according to the present invention preferably comprises magnesium oxide. It is observed that in the composition of the present invention the magnesium oxide helps in stabilising the composition and maintaining the pH in different storage conditions. Preferably magnesium oxide is added in the composition post neutralisation of LAS acid. It is preferred that the composition comprises 0.01 to 2 wt% magnesium oxide, more preferably 0.05 to 0.5 wt% magnesium oxide.

Most hard surface cleaning compositions like dish wash composition and kitchen cleaners need a certain viscosity inter alia for ease of application and spreadability. The composition according to the invention has a viscosity of 500 to 2000 mPa.S at 20 S'¹ and 20 °C. The viscosity may be measured by any suitable method. It is preferably measured at 20 °C at a shear rate from 1 s'¹ to 50 s'¹, using a Haake® AR1000 Rheometer with cone and plate assembly.

The composition preferably comprises a polymer. The purpose of the polymer is to provide some viscosity to the composition. It is preferred that the polymer is a water-swellable polymer or an associative polymer. It is preferred that the polymer provides the desired viscosity when the pH of the composition is in the range of 9 to 12. Whenever the polymer is present, it is preferred that the amount thereof is 0.005 to 10 wt%. It is preferred that the polymer is one or more of polyacrylic acid, polyacrylates, cross-linked acrylates, guar gum or its derivatives, starch-acrylic grafted copolymers, hydrolysate of starch-acrylonitrile grafted copolymers, crosslinked polyoxyethylene, cross-linked methyl cellulose, sodium carboxymethylcellulose or partially cross-linked water- swellable polymers of polyethylene oxides and polyacrylamide or isobutylene/maleic acid copolymer. Whenever present, it is preferred that the composition comprises 0.008 wt% to 5 wt% polymer, more preferably 0.01 wt% to 2.5 wt% of the polymer. A particularly preferred polymer is Acusol® 880/882/883. The composition according to the present invention is aqueous, i.e. , water based. It is preferred that the composition comprises 20 to 80 wt% water and more preferably 30 to 75 wt%, even more preferably 40 to 70 wt% and most preferably 50 to 60 wt%.

The composition may contain other ingredients which are disclosed hereinafter. The cleaning composition may further comprise other anionic surfactants, amphoteric and zwitterionic surfactants, provided they do not interfere with the performance or stability of the composition. It is preferred that the amount of such other surfactants is in the range 0.1 to 20 wt%. Preferably the composition comprises less than 1 wt% cationic surfactant. It is further preferred that in the composition, the total amount of surfactants is not greater than 40 wt%. In other words, the Active Detergent (AD) level is not greater than 40 wt%. The term total surfactant means the sum of all surfactants contained in the composition, which includes calcium salt of linear alkyl benzene sulphonic acid. Preferably the AD level is not more than 30 wt%, with a preferred level being not more than 20 wt%, and even more preferred not more than 10 wt%.

The composition according to the present invention may include additional ingredients to improve or enhance the in-use performance. Such ingredients include colour, fragrance, soil suspending agents, detersive enzymes, compatible bleaching agents, freeze-thaw stabilisers, bactericides, preservatives, hydrotrope, and perfumes.

It is preferred that the composition according to the present invention is liquid or cream or paste form, which may be directly applied to the hard surface.

The composition according to the invention can be packaged in any suitable container. Preferably, the composition is packaged in a plastic bottle with a detachable closure /pouring spout. The bottle may be rigid or deformable. A deformable bottle allows the bottle to be squeezed for dispensing. If clear bottle is used, they may be made of PET or Polyethylene. Preferably, if non-transparent bottle is used, they may be made of high-density polyethylene (HDPE). The bottle may be provided with one or more labels, or with a shrink-wrap sleeve, which is desirably at least partially transparent, for example 50% of the area of the sleeve is transparent. The adhesive used for any transparent label should preferably not adversely affect the transparency. The composition can also be packed in other formats like sachets and pouches. Conventional methods to prepare Ca-LAS containing cleaning compositions include the step of neutralizing acid-LAS with Dolomite or e.g., calcite. This way any deliberate excess of the neutralizing agent (i.e., Dolomite or calcite) will act as the abrasive in the final composition.

As such the present invention further provides a method of preparing a composition of the present invention comprising a step of preparing the calcium salt of linear alkyl benzene sulphonic acid by reacting linear alkyl benzene sulphonic acid with calcium oxide and/or calcium hydroxide. Preferably said step of preparation of Ca-LAS takes place in the absence of the abrasive particles, present in the final composition.

The invention also further provides for a method of reducing malodour comprising the steps of cleaning a surface with a composition of the invention optionally diluted with water followed by the step of rinsing or wiping the composition from the surface.

The invention will now be further described with reference to the following non-limiting examples.

Examples

Examples 1 , 2, A, B: Comparison of malodour reduction provided by compositions of the invention as compared to close prior art

Compositions as shown in table - 1 below were prepared

Table - 1

The composition as shown in Table - 1 above were assessed for malodour using the following protocol.

The scoring was done on only one single attribute which is ‘malodour intensity’. 11 trained sensory panellists scored on a scale of 0 to 10 where 0 is less malodour and 10 is more malodour. A tile was taken and 0.1 ml of a malodour mix was applied on it uniformly using a loop. The malodour mix was a mixture of the following malodour molecules: dimethyl disulfide, n-methyl morpholine, 2-ethyl 1-hexanol, p-tolyl isovalerate, benzothiazole, p-cresol, m-cresol, skatole in propylene glycol.

The malodour from the tile was evaluated by the panelists at regular time intervals (0 hour, 30 minutes, 1 hour and 2 hours). 1 ml of the product was then applied on the tile over the malodour mix and spread evenly. The panellists evaluated the malodour on the tile after the application of the product at the same time intervals (0 hr, 30 minutes, 1 hr and 2 hr).

The difference in malodour score at the various time points was calculated and the average is summarised in table -2 below.

Table - 2: Reduction in malodour score after application of product with respect to before application of the product

The data in the table - 2 above indicates that composition as per the invention (without fragrance) Example -1 scored higher in malodour reduction over extended period of time as compared to prior art sample (Example A). The same trend was observed for samples with fragrance (Example 2 as per the invention as compared to Example B which is for prior art sample). Further, it has been proven by way of Examples 1 and 2 vs. comparative examples A1 and A2 that inclusion of alkane diol does indeed provide improved reduction in malodour as compared to ones without alkane diol in a Ca-LAS containing cleaning composition.

Claims

1. A cleaning composition comprising:

(i) calcium salt of linear alkyl benzene sulphonic acid;

(ii) alkoxylated fatty alcohol;

(iii) C2 - C3 phenoxyalkanol preferably phenoxyethanol; and

(iv) C3 to Cs alkane diol .

2. A composition as claimed in claim 1 comprising 0.1 to 15% calcium salt of linear alkyl benzene sulphonic acid.

3. A composition as claimed in claim 1 or 2 wherein the alkoxylated fatty alcohol has an HLB value in the range 11 to 20, carbon chain length 12 to 16 and ethoxylation degree 5 to 8.

4. A composition as claimed in any one of the preceding claims comprising 0.05 to 10 wt% alkoxylated fatty alcohol.

5. A composition as claimed in any one of the preceding claims comprising 0.05 to 1 wt% phenoxyalkanol.

6. A composition as claimed in any one of the preceding claims wherein said alkanediol is propane diol.

7. A composition as claimed in any one of the preceding claims comprising 0.05 to 1 wt% alkane diol.

8. A composition as claimed in any one of the preceding claims comprising 20 to 80 wt% water.

9. A composition as claimed in any one of the preceding claims comprising 10 to 50% of an abrasive particle selected from one or more of calcite, bentonite, china clay, dolomite or feldspar preferably calcite.

10. A composition as claimed in any one of the preceding claims comprising less than 1 wt% sodium salt of linear alkyl benzene sulphonic acid.

11. A composition as claimed in any one of the preceding claims comprising less than 1 wt% cationic surfactant.

12. A composition as claimed in any one of the preceding claims comprising not more than 40 wt% surfactant.

13. A method of reducing malodour comprising the steps of cleaning a surface with a composition as claimed in any one of the preceding claims optionally diluted with water followed by the step of rinsing or wiping the composition from the surface.