EP3158046B1

EP3158046B1 - Stain treatment compositions

Info

Publication number: EP3158046B1
Application number: EP15729808.4A
Authority: EP
Inventors: Ravine Anthony Gungabissoon
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2014-06-20
Filing date: 2015-06-12
Publication date: 2018-08-15
Anticipated expiration: 2035-06-12
Also published as: BR112016029725A2; BR112016029725B1; CN106536700A; EP3158046A1; ZA201608405B; CN106536700B; WO2015193205A1

Description

This invention relates to stain removal compositions for ambient-active stains.
The objective of the invention is the removal of stains from stained substrates.
US3707505 discloses an enzyme-bearing detergent compositions which are enhanced in terms of enzyme storage stability by the presence of N-Acyl amino acid and its salts and esters, the N-acyl group being the radical of a fatty acid having 6-20 carbon atoms. Example 10 describes a liquid washing detergent obtained by adding 0.1g of protease and 1g. of amylase to a mixture of 15g. of lauryl alcohol ether sulphate, 10g. of alkylamide of coconut fatty acid, 5 g. of ethyl alcohol and 2g. of N-myristoyl-L-arginine butyl ester lactate.
WO97/45510 describes an acidic cleansing gel including amphoteric or non ionic surfactants, an acid and gelling agent forming an associative inter-polymer gel network.
DE1942236 describes detersive compositions containing C4-C11 amino acids optionally containing further carboxyl and/or amino groups and the use of such compositions in the removal of protein stains.
EP2305785 describes use of specific carboxylic or amino compounds for facilitating the removal of soil from a hard surface.
In a first aspect, the present invention provides an ambient-active stain removal composition comprising an arginine alkyl ester compound and a surfactant. Preferably the arginine alkyl ester compound is arginine methyl ester or arginine ethyl ester or any combination thereof.
In a second aspect, the invention provides a method for removing a stain from a stained substrate (for example, fabric), comprising the step of applying to the stain, the stain removal composition of the first aspect of the invention, said step taking place at ambient temperature. In a third aspect the invention provides a pre-treatment device comprising (i) a storage chamber storing the stain removal composition of the first aspect of the invention and a (i) dispenser for applying said composition to a stain on a substrate, the pre-treatment device preferably being suitable for use in the method of the second aspect.
In a further aspect the invention provides use of an arginine alkyl ester, in combination with a surfactant, in the removal of oil/fat stains from a stained substrate.
With the invention, the removal of stains at low temperatures is radically improved and so offers cost effective improved household e.g. laundry cleaning in regions where ambient washing occurs out of habit or necessity. Improved washing performance at lower temperatures is generally desirable but increased low temperature performance may also help inhibit the adoption of hot water washing in these countries, a rising trend as standards of living increase and more people are able to afford substrate washing machines. The invention provides stain removal performance of soil and/or stains in an ambient temperature cleaning processes (with low temperature wash liquor) without serious consideration to the temperature sensitivity of ingredients during storage. The formulation can therefore be designed more freely, on the basis of other considerations.
As used herein, the term "substrate" includes fabric, and clothing and other surfaces such as cutlery, crockery and other domestic hard surfaces.
As used herein, the term "arginine ester" and "arginine alkyl ester" is intended to include stereoisomeric and racemic forms and mixtures thereof.
The term "ambient-active" is intended to mean less than 25 degrees Celcius and preferably 22 degrees Celcius or less, more preferably 15 degrees or less but always greater than 1 degree Celcius and "active" means effective in achieving stain removal.
As used herein "stain removal" is means removal as measured in terms of Remission units or a Remission index. For a visible (by the human eye) effect, effective stain removal is represented by remission equal to or greater than 2 Remission units and preferably greater or equal to 5 units.
As used herein, the abbreviation "wt%" means "% by weight". Unless specified otherwise, all percentages mentioned herein are by weight calculated relative to the total composition.
The stain may comprise biological material such as fat, oil, blood, starch and combinations thereof.
The method of the invention preferably comprises an aqueous washing process. Accordingly it is preferred that the method comprises the step of adding water to the composition to form an aqueous wash liquor
Preferably the method comprises localised application of the composition to a stain or stained area of the substrate. The method may be pre-treatment method, and be followed by a subsequent aqueous washing step. Pre-treatment steps may take place without further addition of any water (beyond any contained in the composition). Alternatively or additionally, the pre-treatment process may comprise the step of soaking the substrate in an aqueous solution to which the treatment composition has been added. Alternatively the pre-treatment process may comprise the step of applying the composition by spraying, brushing, rubbing or scrubbing. The second step of the method of the invention may be a 'main' wash and may be a manual washing process and/or a washing process in a washing machine. The second step may use any suitable detergent composition. Preferably this detergent composition comprises one or more surfactants and/or other functional ingredients, adjuncts as described below.
In the case of pre-treatment according to the invention, subsequent steps may not require further application of the arginine alkyl ester.
Preferably the washing process of the invention is less than 90 minutes in duration, more preferably less than 60 minutes and most preferably less than 30 minutes. In pre-treatment embodiments, the pre-treatment step is preferably less than 5 minutes, and more preferably less than 2 minutes.
For the treatment of beef and lard fat stains, preferably the arginine alkyl ester is present in wash liquor in a concentration in the range 0.01mg/ml - 10mg/ml and more preferably in the range 0.31 mg/ml - 0.62mg/ml. For the treat of frying fat and butter fat, preferably the concentration of the arginine methyl/ethyl ester in the wash liquor is in the range 0.15mg/ml to 10mg/ml.
Preferably the arginine alkyl ester is present in any composition of the invention in a concentration in the range 40 mg - 5000 mg per dose, preferable 320mg - 4000 mg per dose. The composition may be provided as a single dose format or as multiple dose, free flowing format (powder, liquid, gel, paste) which is measured out by the consumer using a dosing device. The dose may range from 10 ml to 100ml.
Preferably the wash liquor has a pH in the range 4 - 9.5.
The pre-treatment device may be by any suitable device such as roll-on applicator or tube, sprays, aerosols, pastes, a pump-operated dispenser or stain treatment pen or brush. The pre-treatment device may comprise a scrubbing member having brush, bristles, tufts, projections, embossments or any combination thereof to further aid application of the detergent composition to a substrate.
Preferably the treatment composition is ambient-active. Accordingly, the temperature of the wash liquor step of aqueous washing process is therefore less than 40 °C and preferably less than 30°C and more preferably less than 25°C and more preferably less than or equal to 22°C further more preferably 15°C or less at all times during the washing but excluding drying. Encouraging low temperature wash liquor is advantageous environmentally and financially.
The treatment composition of the invention and/or any detergent composition used subsequently may comprise any of the following ingredients.
The surfactant may be a synthetic surfactant or a biosurfactant which is mircrobially synthesized e.g. from bacteria, fungi or other microbe. The biosurfactant preferably comprises a microbially-derived biosurfactant. Preferably it comprises a glycolipid biosurfactant which may be a rhamnolipid or sophorolipid or trehalolipid or a mannosylerythritol lipid (MEL). Alternatively, the biosurfactant may advantageously comprise a cellobiose, peptide based biosurfactants, lipoproteins and lipopeptides e.g. surfactin, fatty acids e.g. corynomucolic acids (preferably with hydrocarbon chain C12-C14), phospholipids e.g. Phosphatidylethanolamine produced by Rhodococcus erythropolis grown on n-alkane resulted in the lowering of interfacial tension between water and hexadecane to less than 1 mN m-1 and CMC of 30 mg L-1 (Kretschner et al., 1982) and Spiculisporic acid; polymeric biosurfactants including emulsan, liposan, mannoprotein and polysaccharide-protein complexes.
Preferably the biosurfactant comprises a rhamnolipid.
The surfactant may be present by weight in the compositions at a level of from 3 to 85% by weight, preferably from 3 to 60% by weight, more preferably from 3 to 40% by weight, most preferably from 3 to 35% by weight.
Preferably the anionic surfactant is present at a level of from 0.1 to 95% by weight, preferably from 1 to 50% by weight, more preferably from 1.5 to 25% by weight based on total weight of surfactants present.
Preferably the surfactant is an anionic surfactant.
Anionic surfactants are defined herein as amphiphilic molecules comprising one or more functional groups that exhibit a net anionic charge when in aqueous solution at the normal wash pH of between 6 and 11.
Preferred anionic biosurfactants are rhamnolipds and lactonic forms of sophorolipids. Biosurfactants which are not expressed biologically in anionic form but have been modified to provide/improve anionic properties are included in the invention.
Preferred synthetic anionic surfactants are the alkali metal salts of organic sulphur reaction products having in their molecular structure an alkyl radical containing from 6 to 24 carbon atoms and a radical selected from the group consisting of sulphonic and sulphuric acid ester radicals.
Although any anionic surfactant hereinafter described can be used, such as alkyl ether sulphates, soaps, fatty acid ester sulphonates, alkyl benzene sulphonates, sulphosuccinate esters, primary alkyl sulphates, olefin sulphonates, paraffin sulphonates and organic phosphate; preferred anionic surfactants are the alkali and alkaline earth metal salts of fatty acid carboxylates, fatty alcohol sulphates, preferably primary alkyl sulfates, more preferably they are ethoxylated, for example alkyl ether sulfates; and alkylbenzene sulfonates or mixtures thereof.
Amphoteric surfactants and/or zwitterionic surfactants may be present in the compositions according to the invention. For amphoteric the pH of the wash liquor is preferably of between 6 and 10. Preferably an amphoteric or zwitterionic surfactant is present at a level of from 0.1 to 20% by weight, more preferably from 0.25 to 15% by weight, even more preferably from 0.5 to 10% by weight.
Suitable zwitterionic surfactants are exemplified as those which can be broadly described as derivatives of aliphatic quaternary ammonium, sulfonium and phosphonium compounds with one long chain group having 8 to 18 carbon atoms and at least one water solubilizing radical selected from the group consisting of sulfate, sulfonate, carboxylate, phosphate or phosphonate. A general formula for these compounds is:

R₁(R₂)_xY⁺R₃Z^-

wherein R₁ contains an alkyl, alkenyl or hydroxyalkyl group with 8 to 18 carbon atoms, from 0 to 10 ethylene-oxy groups or from 0 to 2 glyceryl units; Y is a nitrogen, sulfur or phosphorous atom; R₂ is an alkyl or hydroxyalkyl group with 1 to 3 carbon atoms; x is 1 when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorous atom; R₃ is an alkyl or hydroxyalkyl group with 1 to 5 carbon atoms and Z is a radical selected from the group consisting of sulfate, sulfonate, carboxylate, phosphate or phosphonate.
Preferred amphoteric surfactants are amine oxides, for example coco dimethyl amine oxide. Preferred zwitterionic surfactants are betaines, and especially amidobetaines. Preferred betaines are C₈ to C₁₈ alkyl amidoalkyl betaines, for example coco amido betaine. These may be included as co-surfactants, preferably present in an amount of from 0 to 10 wt %, more preferably 1 to 5 wt %, based on the weight of the total composition.
Preferred amphoteric or zwitterionic surfactants for incorporation in the composition according to the present invention are betaine surfactants. Examples of these are mentioned in the following list.
The sulfatobetaines, such as 3-(dodecyldimethylammonium)-1-propane sulfate; and 2-(cocodimethylammonium)-1-ethane sulfate.
The sulfobetaines, such as: 3-(dodecyldimethyl-ammonium)-2-hydroxy-1-propane sulfonate; 3-(tetradecyl-dimethylammonium)-1-propane sulfonate; 3-(C₁₂-C₁₄ alkyl-amidopropyldimethylammonium)-2-hydroxy-1-propane sulfonate; and 3-(cocodimethylammonium)-1-propane sulfonate.
The carboxybetaines, such as (dodecyldimethylammonium) acetate (also known as lauryl betaine); (tetradecyldimethylammonium) acetate (also known as myristyl betaine); (cocodimethylammonium) acetate (also known as coconut betaine); (oleyldimethylammonium) acetate (also known as oleyl betaine); (dodecyloxymethyldimethylammonium) acetate; and (cocoamidopropyldimethylammonium) acetate (also known as cocoamido-propyl betaine or CAPB).
The sulfoniumbetaines, such as: (dodecyldimethylsulfonium) acetate; and 3-(cocodimethyl-sulfonium)-1-propane sulfonate.
The phosphoniumbetaines, such as 4-(trimethylphosphonium)-1-hexadecane sulfonate; 3-(dodecyldimethylphosphonium)-1-propanesulfonate; and 2-(dodecyldimethylphosphonium)-1-ethane sulfate.
The compositions according to the present invention preferably comprise carboxybetaines or sulphobetaines as amphoteric or zwitterionic surfactants, or mixtures thereof. Especially preferred is lauryl betaine.
Further optional ingredients include additional surfactants e.g non ionic and cationic surfactants, viscosity modifiers, foam boosting agents, preservatives (e.g. bactericides), pH buffering agents, polyelectrolytes, anti-shrinking agents, anti-wrinkle agents, antioxidants, sunscreens, anti-corrosion agents, drape imparting agents, anti-static agents and ironing aids. The compositions may further comprise, colorants, pearlisers and/or opacifiers, and shading dye. Fluorescent Agents.
The composition may comprise enzymes. The composition preferably excludes or is at least substantially free of protease and/or amylase.
The composition preferably excludes or is at least substantially free of alkyl amides of coconut fatty acid.

Experimental

Examples

An exemplary laundry detergent composition is described below, to which arginine alkyl esters can be added.

Ingredient	% by weight of total Composition A
Non-ionic surfactant Neodol 25-7	6.2
Anionic surfactant LAS acid	11.8
Anionic surfactant SLES 3EO	6.5
Lauric Fatty Acid P5908	5.2
Glycerol	5.0
Monopropylene Glycol	9.0
Citric acid	3.9
Minors	2.0
Water	balance to 100

Wherein:

Neodol 25-7 ex.Shell = C₁₂-C₁₅ alcohol 7-ethoxylate
LAS acid = C₁₀-C₁₄ alkyl benzene sulphonic acid;
SLES = C12-C13 alcohol 3-ethoxylate sulphate, Na salt: = sodium lauryl ether sulphate (with on average 3 ethylene oxide groups);

In these examples, arginine alkyl esters in laundry detergent compositions were tested to determine their ability to treat i.e. stains from cotton fabric in various ways. All values throughout are wt%.

End-point Stain Removal Assay

Reagents:

The following soiled cotton fabric samples (Centre from Testmaterials BV) were hole punched into discs and transferred to 300 µl 96 well plates:
Fat soils: Violet Dyed Used Frying Fat (CS-46), Coloured Beef Fat (CS-61)
Laundry detergent composition: Working concentration stock dilution = 1:428 (i.e. the below stock was diluted 1:428 times in the wash liquor)
enzyme free laundry detergent composition
Arginine methyl ester (as L-Arginine methyl ester dihydrochloride Sigma Cat No. 26340-89-6 , EC no. 247-622-0 )

Procedure:

Pre-washing of soiled fabric

The soiled fabric discs were pre-washed to remove any residual free stain as follows:

200 µl of distilled water was added to each well
Plates agitated on a plate shaker at 250 rpm for 2 mins
Water removed

Pre-treatment of soiled fabric with diamines followed by main wash

The following Test and Control Mixtures were added to the wells:

• Test Mixture:

Laundry detergent composition 100 ul
Distilled Water 80 ul
Arginine methyl ester dilution* 20 ul

*The arginine alkyl ester compounds were diluted to a final concentration of 5 mg/ml

• Control Mixture (Laundry detergent composition only negative control)

Laundry detergent composition 100 ul
Distilled Water 100 ul

The soiled fabric was incubated in the pre-treatment solution for 5 mins at room temperature with no agitation. The pre-treatment wash liquor was then removed. Following pre-treatment, the soiled fabric was washed (250 rpm, 1 hour, room temperature) in the following mixture:

Laundry detergent composition 100 ul
Distilled Water 100 ul

After washing, the wash liquor was then removed and fabric washed 4 X 5 mins with 200 ul distilled water on a plate shaker at 250 rpm. The fabric was then left to dry over night at room temperature before scanning.

(2b) Main wash of soiled fabric with diamines

The following Test and Control Mixtures were added to the wells:

• Test Mixture

Laundry detergent composition 100 ul
Distilled Water 80 ul
Arginine methyl ester 20 ul

• Control Mixture (Laundry detergent composition only negative control)

Laundry detergent composition 100 ul
Distilled Water 100 ul

The soiled fabrics were washed at 250 rpm for 1 hour at room temperature. After washing, the wash liquor was then removed and fabric washed 4 X 5 mins with 200 ul distilled water on a plate shaker at 250 rpm. The fabric was then left to dry over night at room temperature before scanning.
After drying, the stain plates were digitally scanned and their deltaE measured. This value is used to express cleaning effect and is defined as the colour difference between a white cloth and that of the stained cloth after being washed. Mathematically, the definition of deltaE is: $deltaE = {[{(ΔL)}^{2} + {(Δa)}^{2} + {(Δb)}^{2}]}^{1 / 2}$
wherein ΔL is a measure of the difference in darkness between the washed and white cloth; Δa and Δb are measures for the difference in redness and yellowness respectively between both cloths. From this equation, it is clear that the lower the value of deltaE, the whiter the cloth will be. With regard to this colour measurement technique, reference is made to Commission International de l'Eclairage (CIE); Recommendation on Uniform Colour Spaces, colour difference equations, psychometric colour terms, supplement no. 2 to CIE Publication, no. 15, Colormetry, Bureau Central de la CIE, Paris 1978.
In the tables below the cleaning effect is expressed in the form of a stain removal index (SRI): $SRI = 100 - deltaE .$
The higher the SRI the cleaner the cloth, SRI = 100 (white).

Results:

Frying fat stain Results

dSRI	Main wash	Pre-treatment
Amount of arginine methyl ester mg/ml		1 minute	3 minutes	5 minutes
5	6.3	10.3	10.6	10.7
2.5	6.9	9.7	8.8	9.5
1	7.0	8.5	9.7	9.4
0.5	8.8	8.5	7.4	9.1
0.1	9.6	-0.7	1.4	3.8
0.05	6.8	2.1	0.9	1.8
0.01	-0.3	-0.8	2.3	0.2
0	0.0	0.0	0.0	0.0

Beef Fat Stain Results

dSRI	Main wash	Pre-treatment
Amount of arginine methyl ester mg/ml Mg/ml		1 minute	3 minutes	5 minutes
5	15.2	17.2	13.9	17.7
2.5	13.8	14.3	12.8	13.0
1	16.2	6.6	2.4	9.0
0.5	11.9	2.8	-2.1	5.8
0.1	5.9	-2.5	-3.2	2.6
0.05	-1.0	-5.5	-3.6	1.6
0.01	-1.6	-2.4	-1.5	-0.1
0	0.0	0.0	0.0	0.0

Conclusions:

The results show that arginine alkyl esters can improve the cleaning of fat soiled fabrics in combination with a laundry detergent composition when applied both as both a pre-treatment before the main wash and when included directly in the main wash. Generally, cleaning improvement is dose dependent.

Claims

An ambient-active stain removal composition for removal of stains from stained substrates, the composition comprising an arginine alkyl ester and a surfactant.
An ambient-active stain removal composition according to claim 1 wherein the arginine alkyl ester is arginine methyl ester or arginine ethyl ester or any combination thereof.
An ambient-active stain removal composition according to claim 1 or claim 2 wherein the surfactant comprises an anionic surfactant.
An ambient-active stain removal composition according to claim 1 or claim 2 wherein the surfactant comprises a rhamnolipid.
A pre-treatment device comprising (i) a storage chamber storing the ambient-active stain removal composition of any of claims 1-4 and (ii) a dispenser for locally applying said composition to a stain on a substrate.
A method for removing a stain from a stained substrate, comprising the step of applying to the stain, the ambient-active stain removal composition of any of claims 1-4, said step taking place at ambient temperature.
A method according to claim 6 comprising the step of adding water to the ambient-active stain removal composition to form an aqueous wash liquor, said liquor being at ambient temperature.
A method according to claim 6 comprising localised application to a stain on a stained fabric, of the ambient-active stain removal composition of any of claims 1-4.
A method according to claim 6 or claim 7 wherein the step of applying the ambient-active stain removal composition is a pre-treatment step using the pre-treatment device of claim 5.
A method according to claim 7 wherein the arginine alkyl ester is present in the wash liquor in the range of 0.01 - 10mg/ml.
A method according to any of claims 6, 7, 9 or 10 wherein said substrate comprises cutlery, crockery and other domestic hard surface.
Use of an arginine alkyl ester in the removal of oil/fat stains, in combination with surfactant.