GB2391020A

GB2391020A - Stain removal

Info

Publication number: GB2391020A
Application number: GB0216950A
Authority: GB
Inventors: Giorgio Franzolin; Anthony Domenic Sidoti; Luca Spadoni
Original assignee: Reckitt Benckiser NV
Current assignee: Reckitt Benckiser NV
Priority date: 2002-07-20
Filing date: 2002-07-20
Publication date: 2004-01-28
Also published as: GB0216950D0

Abstract

Stains are removed from a surface by applying a mixture of pH 10 or less comprising (a) an aqueous composition comprising hydrogen peroxide or an organic peracid having a pH of greater than 0 but less than 7 and (b) an aqueous composition comprising an enzyme, wherein (a) and/or (b) additionally comprise at least one surfactant or water-soluble polymer and are mixed not more than two hours before being applied to the surface. Components (a) and (b) may be contained in a two-compartment dispenser and dispensed sequentially or simultaneously.

Description

11058P6GB

239 1 020

5 Stain Treating Composition This invention relates to an improved process for the removal of stains from surfaces, preferably from fabric, and to compositions used in such processes.

The use of oxygen bleaches with or without enzymes in compositions for stain removal has been known for a long time and many such compositions are available.

However a common difficulty in formulating such a 15 composition is to ensure that it remains stable during storage but is sufficiently active on use. This is particularly difficult to achieve in liquid compositions containing bleach. In addition it is extremely difficult to include enzymes into such systems. Many solutions 20 have been proposed to this problem but most of these require the use of expensive stabilizing components or of complex formulation processes.

One solution has been to formulate liquid peroxygen 25 bleaches at pHs between about 3 and 7 to produce a stable composition, but such compositions do not provide sufficient bleaching power to be useful for many household situations. Attempts have therefore also been made to formulate liquid peroxygen bleach compositions at 30 pHs above this range to improve the bleaching power.

However these generally require expensive stabilizing compounds to prevent loss of activity after manufacture.

The problem of protecting the enzymes from attack by 35 the peroxygen bleaches is also very difficult, WO0148139 discloses encapsulating the enzyme in a peroxide protective coating which dissolves at a certain pH.

The present invention provides a peroxide or peracid 40 bleach product which contains enzymes which has

5 acceptable stability of both the enzyme and the peroxide or peracid after manufacture, but which is capable of providing effective stain removal power when used by the consumer. 10 We have found that by separating the bleach from the enzyme system excellent stability is achieved.

In addition, It is usually believed that enzymes lose their cleaning performance in presence of strong 15 oxidant, such as hydrogen peroxide at alkaline pH.

Surprisinlgy, We have found that by the inclusion of a surfactant or a water-soluble polymer in either or both of the separate compositions, but preferably present in at least the enzyme composition, excellent cleaning 20 performance is achieved. Whilst not wishing to be bound by theory it is believed that the activity of the enzyme is maintained for a longer period after the peroxide is applied to the stained surface and mixed with the enzyme by the protective effects of the micelles formed in the 2s solution.

According to the invention there is provided a process for stain removal at a surface, comprising applying to that surface an aqueous composition of 30 hydrogen peroxide or an organic peracid, which composition has a pH of lo or less and comprises a mixture of: a) an aqueous composition comprising hydrogen peroxide 35 or an organic peracid having a pH of greater than O but less than 7 [hereinafter component (a)] and b) an aqueous composition [hereinafter component (b)] comprising an enzyme,

5 wherein components (a) and/or (b) additionally comprise at least one surfactant or water-soluble polymer and are mixed not more than two hours before being applied to the surface requiring stain removal.

lo Compositions suitable for carrying out the invention may be provided as separate components suitable for mixing by the consumer. Where the compositions are suitable for mixing they may be mixed either directly at the surface or remote from the surface before 15 application.

Component (a) preferably comprises hydrogen peroxide or peracetic acid.

20 In accordance with the invention the two components (a) and (b) may be mixed in any suitable proportions, depending upon their initial concentrations, suitably such that the finally applied mixture comprises 0.01-30% w/w of hydrogen peroxide or an organic peracid.

25 Preferably, the ratio of component Ha) to component (b) is from 10:1 to 1:10, most preferably from 2:1 to 1:2.

It is preferred that the two components (a) and (b) are mixed no more than 10 minutes before application to 30 the surface requiring stain removal.

It is most preferred that the two components (a) and (b) are mixed at the surface requiring stain removal, so that the improved stain removal effect may occur 35 immediately.

In this aspect component (a) may be applied to the surface followed by component (b) or vice versa.

Alternatively (and preferably) components (a) and (b) are 40 applied to the surface substantially simultaneously

- - s within 30 seconds.

According to a preferred embodiment of the presentation invention, the concentration of hydrogen peroxide or organic peracid in the composition 10 immediately after mixing is from 0.01 to 10% w/w. This would mean for example in a 1:1 mix of component (a) and (b) that component (a) prior to the mixing would contain from 0.02 to 20% w/w of hydrogen peroxide or an organic peracid. Where component (a) comprises hydrogen peroxide it is most preferred that the concentration of hydrogen peroxide in the mixture immediately after mixing should be from 1.5 to 5% w/w. For example, if a 1:1 mixture of 20 components (a) and (b) is to be mixed, then component (a) should comprise from 3 to 10% w/w hydrogen peroxide.

The concentration of the enzyme in component (b) will be less than 1% wt.

The process of the present invention alleviates the need to use further stabilizing components for the hydrogen peroxide/organic peracid or enzyme when preparing commercial products.

The components suitable for use in the process according to the invention may further include any other conventional additives known to the art. Examples of these include fragrances, dyes, sequesterants, chelating 35 agents, germicides, preservatives, corrosion inhibitors or antioxidants.

The above auxiliary components may be included in the compositions suitable for use in the process of the 40 present invention at concentrations of from 0.01% w/w to

s- 5 10% w/w. These auxiliary ingredients may be included in either component (a), or component (b) or both if appropriate. Compositions suitable for use in the process lo according to the present invention may be stored in any appropriate containers known to the art. For example, the two components may be stored in two-compartment packs suitable for sequential or simultaneous dispensing.

IS Where both components (a) and (b) are liquids, most preferably they may be stored in a two-compartment dispenser, one compartment containing each component and the dispenser being adapted to dispense each component on to a surface, either sequentially or, preferably, 20 simultaneously.

According to a further aspect of the invention, there is provided a twocompartment dispenser comprising 2s a first compartment containing an aqueous composition comprising hydrogen peroxide or an organic peracid and having a pH of greater than O but less than 7: 30 a second compartment containing an aqueous composition comprising an enzyme and; dispensing means adapted to dispense the contents (or part thereof) of the compartments on to a surface 35 either sequentially or simultaneously to form a mixture thereof. Preferably wherein the first compartment and/or the second comapartment additionally comprise at least one 40 surfactant or water-soluble polymer.

Preferably, the first compartment contains an aqueous composition comprising 3 to 10% w/w hydrogen peroxide; and the second compartment contains an aqueous composition comprising less than 1% w/w of an enzyme.

Surfactant Preferably, the surfactant is found at levels of 0.1 to 25%wt, ideally from 1 to 10%wt.

Preferably non-ionic surfactants are used. Examples of non-ionic surfactants are fatty acid alkoxylates, such as fatty acid ethoxylates, especially those of formula: R(C2H4O)nOH 20 wherein R is a straight or branched Ca-Cl6 alkyl group, preferably a C,-Cl5, for example Cl0-Cl., alkyl group and n is at least 1, for example from 1 to 16, preferably 2 to 12, more preferably 3 to 10.

25 The alkoxylated fatty alcohol non-ionic surfactant will frequently have a hydrophilic-lipophilic balance (HLB) which ranges from 3 to 17, more preferably from 6 to 15, most preferably from 7 to 13.

30 Examples of fatty alcohol ethoxylates are those made from alcohols of 12 to 15 carbon atoms and which contain about 7 moles of ethylene oxide. Such materials are commercially marketed under the trademarks Neodol 25-7 and Neodol 23-6.5 by Shell Chemical Company. Other 3s useful Neodols include Neodol 1-5, an ethoxylated fatty alcohol averaging 11 carbon atoms in its alkyl chain with about 5 moles of ethylene oxide; Neodol 23- 9, an

5 ethoxylated primary C12-Cl3 alcohol having about 9 moles of ethylene oxide; and Neodol 91-10, an ethoxylated C,-C primary alcohol having about 10 moles of ethylene oxide.

Alcohol ethoxylated of this type have also been marketed! 10 by Shell Chemical Company under the Dobanol trademark.

Dobanol 91-5 is an ethoxylated C,-Cll fatty alcohol with an average of 5 moles ethylene oxide and Dobanol 25-7 is an ethoxylated Cl2-Cl5 fatty alcohol with an average of 7 moles of ethylene oxide per mole of fatty alcohol.

15! Other examples of suitable ethoxylated alcohol non ionic surfactants include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are linear secondary alcohol ethoxylated available from Union Carbide Corporation.

20 Tergitol 15-S-7 is a mixed ethoxylated product of a Cll-

C1s linear secondary alkanol with 7 moles of ethylene oxide and Tergitol 15-S-9 is the same but with 9 moles of ethylene oxide.

25 Other suitable alcohol ethoxylated non-ionic surfactants are Neodol 4511, which isle similar ethylene oxide condensation products of a fatty alcohol having 14 15 carbon atoms and the number of ethylene oxide groups per mole being about 11. Such products are also 30 available from Shell Chemical Company.

Further non-ionic surfactants are, for example, C10 C1 alkyl polyglycosides, such s C12-Cl6 alkyl polyglycosides, especially the polyglucosides. These are 35 especially useful when high foaming compositions are desired. Further surfactants are polyhydroxy fatty acid

5 amides, such as C1O-Cl8 N-(3-methoxypropyl) glycamides and ethylene oxide-propylene oxide block polymers of the Pluronic type.

The surfactant can also be an anionic murfactant.

10 Such anionic surface active agents are frequently provided in a salt form, such as alkali metal salts, ammonium salts, amine salts, aminoalcohol salts or magnesium salts. Contemplated as useful are one or more sulfate or sulfonate compounds including: alkyl 15 sulfates, alkyl ether sulfates, alkylamidoether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkyleulfonates, alkylamide sulfonates, alkylaryleulfonates, olefinsulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether 20 sulfosuccinates, alkylamide sulfosuccinates, alkyl sulfosuccinamate, alkyl sulfoacetates, alkyl phosphates, alkyl ether phosphates, acyl sarconsinates, acyl isethionates, and N-acyl taurates. Generally, the alkyl or acyl radical in these various compounds comprise a 25 carbon chain containing 12 to 20 carbon atoms.

Particularly preferred are alkyl sulfate anionic surfactants. Most preferred are the non-ethoxylated C12-l5 primary and secondary alkyl sulfates, especially sodium 30 lauryl sulfate.

Polymer Suitable polymers are those that are water-soluble 3s and include polycarboxylate polymer (such as those that can be purchased by Rohm and Haas under the Acusol 445N

s name) and polycarboxylic acid copolymers (such as can be purchased under the Sokalan CP9 name by BASF) The invention will now be illustrated by the following Examples.

Ingredient1 Gl 1 G2 1 Gl & G2 %wt 1 %wt Genapol 26L-3 I 4.900 Genapol 26L60 3.lOO ater Soft r 84.586 Borax to H20 _O.514 Preservative 0.050 Acusol 2.000 Disperant O.lOO | Propyleneglycol 1 4.000 CaCl2 *2H20 r 0. 100 Savinase 0.440 Perfume O.2l0 | Hydrogen peroxide 5.800 l Nonionic 1 3. 000 _ _ I Phosphonate 0.120 WATER &M.C. 90.880

Dosage | 1 ml and Y reflectance Gl G2 Gl+G2 value _ Protein 65.0 70.5 70. 0 oxidi able soil Oxidinable soil 63.0 64.0 66.0 Conditions of tent l ml of product was placed on the 15 soil, scrubbed five times by hand and left to react for 5 minutes. The materials were then washed in a US top loading washing-machine (Whirlpool Imperial) on the cycle for medium load at 30C temp with water of 12 F hardness and a 1. 5/l Ca/Mg ratio. The materials were evaluated by

5 measuring the reflectance (Y value) using a Ultrascan XE Spectrofotometer.

Claims

1 1 5 Claims

1. A process for stain removal at a surface, comprising applying to that surface an aqueous composition of hydrogen peroxide or an organic peracid, which 10 composition has a pH of 10 or less and comprises a mixture of: c) an aqueous composition comprising hydrogen peroxide or an organic peracid having a pH of greater than O 15 but less than 7 [hereinafter component (a)] and d) an aqueous composition [hereinafter component (b)] comprising an enzyme, 20 wherein components (a) and/or (b) additionally comprise at least one murfactant or water-soluble polymer and are mixed not more than two hours before being applied to the surface requiring stain removal.

25

2. A process as claimed in claim 1 wherein at least one surfactant is in component (b)

3. A process as claimed in claim 1 or claim 2 wherein the surfactant is a non-ionic surfactant.

4. A process as claimed in claim 3 wherein (a) or (b) additionally contains a polycarboxylate.

5. A process as claimed in any claim from 1 to 4 wherein 35 the pH of component (b) is higher than the pH of component (a).

6. A process as claimed in claim 5 wherein component (a) does not contain a pH buffer.

5

7. A process as claimed in claim 5 wherein component (b) does contain a pH buffer.

8. A two-compartment dispenser comprising 10 a first compartment containing an aqueous composition comprising hydrogen peroxide or an organic peracid and having a pH of greater than O but less than 7: 5 a second compartment containing an aqueous composition comprising an enzyme and; dispensing means adapted to dispense the contents (or part thereof) of the compartments on to a surface 20 either sequentially or simultaneously to form a mixture thereof.