WO2002092750A1

WO2002092750A1 - Antimicrobial cleaning wipe

Info

Publication number: WO2002092750A1
Application number: PCT/EP2002/004584
Authority: WO
Inventors: Andrew Stephen Hamieson; Carolyn Elizabeth Jones; Gianluca Lucchini; Lucia Pozzi; Venugopal Vijayakrishnan
Original assignee: Unilever Plc; Unilever Nv; Hindustan Lever Limited
Priority date: 2001-05-08
Filing date: 2002-04-25
Publication date: 2002-11-21
Also published as: GB0111176D0; WO2002092750A8; AR033715A1

Abstract

Pre-moistened wipe for cleaning hard surfaces such as floors, which comprises a substrate incorporating an aqueous composition comprising: (i) from 0.001 to 1% by weight, based on total weight of the composition, of an antimicrobially-active amphoteric surfactant; (ii) from 0 to 1% by weight of a nonionic co-surfactant; (iii) from 0.001 to 1% by weight, based on total weight of the composition, of a sequestering agent, and(iv) less than 0.5% by weight, based on total weight of the composition, of organic solvent having the general formula (I): R1-O-(EO)m-(PO)n-R2 (I) wherein R1 and R2 are independently C2-6 alkyl or hydrogen, but not both hydrogen, m and n are independently 0-5, EO represents an ethyleneoxy group and PO represents a propyleneoxy group.

Description

ANTIMICROBIAL CLEANING WIPE

TECHNICAL FIELD

The present invention relates to an antimicrobial cleaning wipe which is designed in particular for the hygienic cleaning of hard surfaces such as are found in the household, or in institutional or hospital environments. The wipe contains a hygienic cleaning formulation based on a particular type of amphoteric surfactant .

BACKGROUND TO THE INVENTION AND PRIOR ART

Hard surfaces in the household, or in institutional or hospital environments, are often contaminated with bacteria and other micro-organisms, which present a risk to human health, especially when they are present near food.

Antimicrobial compositions based on quaternary ammonium cationic surfactants such as benzalkonium chloride are widely used. However, a disadvantage of such compositions is that they tend to leave residues behind after use. This necessitates a rinsing step which is undesirable for the consumer .

EP 0 948 892 describes a liquid disinfectant for hard surfaces in which reduced filming or streaking is observed due, it is said, to the presence of a poly (alkylene glycol) alkyl ether. Organic solvents such as ethanol, butyl carbitol and n-butoxypropanol are also included to enhance cleaning. A problem with the above proposal is that the formulation contains a significant amount of volatile organic compounds as solvents. Environmental and flammability concerns have prompted research into reducing the level of volatile organic compounds in consumer products. The problem then arises that adding other ingredients to compensate for the reduced alcohol content is associated with a "streak" effect on the surface once the liquid dries due to residues left behind. Antimicrobial performance may also be compromised.

SUMMARY OF THE INVENTION

The present invention provides a pre-moistened wipe suitable for the hygienic cleaning of hard surfaces such as floors, and which comprises a substrate incorporating an aqueous composition comprising:

(i) from 0.001 to 1% by weight, based on total weight of the composition, of an antimicrobially-active amphoteric surfactant;

(ii) from 0 to 1% by weight of a nonionic co-surfactant;

(iii) from 0.001 to 1% by weight, based on total weight of the composition, of a sequestering agent, and

(iv) less than 0.5% by weight, based on total weight of the composition, of organic solvent having the general formula (I) :

_Rl_0- (EO)_m- (PO)_n-R₂ (I) wherein R]_ and R₂ are independently C₂-₆ alkyl or hydrogen, but not both hydrogen, m and n are independently 0-5, EO represents an ethyleneoxy group and PO represents a propyleneoxy group.

Wipes according to the invention show not only excellent cleaning, and antimicrobial properties, but also superior "end-results" (i.e. no significant residues, streaks or spotting left behind after use) . It has been found that these properties are apparent even at very low levels of active ingredient and with little or no organic solvent, which is surprising in view of the teachings of the prior art discussed above.

DETAILED DESCRIPTION OF THE INVENTION

Product Form and Ingredient Levels

Wipes of the invention are designed in particular for the hygienic cleaning of hard surfaces. By "hard surfaces" is meant those surfaces which are typically found in the household, or in institutional or hospital environments. Examples include lavatory fixtures, lavatory appliances (toilets, bidets, shower stalls, bathtubs and bathing appliances) , wall and flooring surfaces and those surfaces associated with kitchen environments and other environments associated with food preparation. Wipes of the invention are especially suitable for the hygienic cleaning of large surface areas such as floors. By "wipe" it is meant a disposable substrate such as a porous or absorbent sheet or cloth which has been pre- treated with the aqueous composition as defined above (hereinafter referred to as "the composition of the invention") so as to incorporate the composition of the invention into or onto the substrate prior to its use by the consumer.

This product form is particularly advantageous since it allows for safe and convenient one-step cleaning of surfaces by the user, without the need for dilution, spraying, or post-treatment rinsing.

Typically the wipe is formed by absorbing the composition of the invention onto the substrate to form a moist wipe. A batch of wipes can then be placed in a container which can be opened when needed and when closed, sufficiently seals to prevent evaporation of any components from the composition.

The composition of the invention is impregnated at the desired weight onto one or both sides of a substrate which may be formed from any woven or nonwoven fibre, fibre mixture or foam of sufficient wet strength and absorbency to hold an effective amount of the composition.

Preferable materials used to form the substrate include in general all nonwoven materials with sufficient liquid absorption capacity to contain the aqueous composition of the invention and to deliver it in use. Illustrative examples of suitable nonwoven materials include fibres from natural sources such as viscose, cellulose, or from synthetic origin such as polypropylene or polyester. Especially suitable are mixtures of these materials such as viscose/polyester, viscose/polypropylene, and cellulose/polyester.

Optionally one or more latex binders can be added. These latex binders can typically include one or more monomers selected from styrene-2-ethyl hexyl acrylate, butyl acrylate, methyl methacrylate, ethyl acrylate, methyl acrylate, acrylonitrile and vinyl acetate.

The materials can be formed into webs using technologies generally known in the art such as carding, drylaid, wetlaid, airlaid and extrusion.

Webs can be bonded using technologies known in the art such as needlepunch, stitchbond, hydroentangling, chemical bonding, thermal bonding, spunbinding and meltblowing.

Preferably the specific weight of the substrate ranges from 40 to 150 grams/sq.m, preferably from 60 to 100 grams/sq.m, most preferably from 75 to 90 grams/sq.m.

A commercially available example of a suitable material used to form the substrate is Akena VPE ex Orlandi, (a viscose/ polyester material available in different specific weights varying from 40 grams/sq.m to 150 grams/sq.m) . Compositions of the invention will typically have ingredient percentages (by weight based on total weight of the composition) as follows:

Antimicrobially-active amphoteric surfactant: from 0.002 to 0.5%, preferably from 0.005 to 0.3%, most preferably from 0.05% to 0.2%.

Nonionic co-surfactant : from 0.002 to 0.5%, preferably from 0.005 to 0.1%.

Sequestering agent: from 0.001 to 0.1%, preferably from 0.005 to 0.05%, most preferably from 0.01 to 0.02%.

Organic solvent of formula (I) : less than 0.1%, preferably less than 0.01%, preferably 0%.

Water: at least 80%, preferably at least 90%, most preferably at least 95%.

In the composition of the invention, the total content of surfactants present is preferably no greater than 0.2%, more preferably no greater than 0.1%, (by weight based on total weight of the composition) .

In a wipe according to the invention, the weight ratio of composition of the invention to substrate suitably ranges from 1:1 to 6:1, and is preferably from 1:1 to 4:1, more preferably from 2:1 to 3:1-. Compositions

The ingredients of the compositions of the invention will be further described as follows:

Water

Compositions of the invention are aqueous compositions which preferably contain relatively low levels of actives. Typically the principal ingredient is water, which is normally present at a level of at least 80%, preferably at least 90%, more preferably at least 95%, by weight based on total weight. The use of distilled or demineralised water is preferred, but not essential to the invention.

Antimicrobially-active Amphoteric Surfactant

Compositions of the invention contain an antimicrobially- active amphoteric surfactant.

Examples of suitable antimicrobially-active amphoteric surfactants are the alkyl (polyaminoalkyl) glycines sold by Goldschmidt under the tradename TEGO^® .

Materials of this type are described in US 5,160,666, and their structures correspond to the following general formulae (a) , (b) or (c) : R- (NH- (CH ) _n) m-NH-CH₂ -COOH (a)

[ (R- (NH- (CH₂ ) n) mJ 2 -N-CH2 -COOH (b)

(R) (R¹) -N- (CH₂) _n-NH) _m -CH₂ -COOH (c)

wherein R represents Cs to Cis alkyl,

R represents ((CH )_n - NH) _m -(CH₂)_n - NH2, n is an integer ranging from 2 to 4 and m is an integer ranging from 1 to 5.

Mixtures of compounds of any of the above general formulae can also be used, as can their respective salts with acids such as mineral acids.

Specific examples are dodecyl-di- (aminoethyl) glycine; dodecyl aminopropylglycine; N-(N'- [Cs-iβ alkyl] -3- aminopropyl) -glycine; N- (N¹ - (N¹ ' - [Cs-is alkyl] -2-aminoethyl)

-2-aminoethyl) -glycine; N,N-bis (N'-tCβ-iβ alkyl] -2- aminoethyl) -glycine, and salts and mixtures thereof.

The alkyl (polyaminoalkyl) glycines of the formulae (a), (b) and (c) and salts and mixtures thereof are commercially available from Goldschmidt under the tradename TEGO^®, in the form of aqueous solutions.

Especially preferred are those alkyl (polyaminoalkyl) glycines of formula (a) , where n = 3 and m = 1. A commercially available example of such a material is TEGO^® 2000, ex Goldschmidt .

Nonionic Co-surfactant

Preferably, compositions of the invention contain a nonionic co-surfactant. Such materials have been found to interact favourably with the antimicrobially-active amphoteric surfactant to boost antimicrobial performance.

Nonionic surfactants typically contain polyoxyalkylene chains within the molecule, with appropriate end groups altering the hydrophilic/hydrophobic balance of the compound. The oxyalkylene component is usually selected from oxypropylene or oxyethylene linkages, or a mixture of the two .

More specific suitable classes of nonionic surfactants suitable for use in compositions of the invention include nonionic alkoxylates, nonionic alkylphenol polyethers, alcohol alkoxylates (e.g. alcohol ethoxylates and alcohol propoxylates and mixed ethoxylates/propoxylates) , nonionic condensates of branched chain primary or secondary alcohols and alkylene (especially ethylene) oxides, alkoxylated amines, amine oxides, and nonionic condensates of fatty acids and alkylene oxides .

Mixtures of any of the above nonionic surfactants may also be used. Preferably the nonionic surfactant is or includes an alcohol alkoxylate, such as alkoxylated Cg-₂0/ especially Cιo-₁₅ natural or synthetic alcohols, which may be primary or secondary, straight or branched chain, saturated or unsaturated.

Particularly preferred is NONIDAC ^® 103A, ex Condea, which is a blend of alcohol ethoxylate, alcohol ethoxylate/propoxylate and amine et oxylate/propoxylate .

Sequestering Agent

Compositions of the invention contain a sequestering agent. Suitable sequestering agents include ethylenediamine tetraacetate, organophosphonic acids and their salts, phosphates and a wide variety of other polyfunctional organic acids and salts. Preferred sequestering agents are organophosphonic acids and their salts, such as those in the DEQUEST® range. Examples include hydroxyethylidene diphosphonic acid (DEQUEST® 2010) , ethylenediamine tetra (methylene-phosphonic acid) (DEQUEST® 2040), diethylene-triamine penta (methylene-phosphonic acid) (DEQUEST® 2060) and their salts.

pH

Compositions of the invention will generally have a pH of greater than 7, preferably between 8 and 12. The pH of the aqueous composition may fall when in contact with the wipe substrate, however for improved preservation it is preferred that it does not fall below 8. A water soluble base such as an alkali metal hydroxide, (typically sodium hydroxide) is generally used to regulate the pH to the required level .

Optional Ingredients

Compositions of the invention can contain other optional ingredients which aid in their cleaning performance and maintain the physical and chemical stability of the product.

Examples include: preservatives, perfumes, colours and dyes, hygiene agents, foam-control agents, viscosity modifying agents and mixtures thereof.

The invention will now be illustrated by the following non- limiting Examples, in which all percentages are by weight based on total weight, unless otherwise indicated.

EXAMPLE

Two liquid formulations A and B were prepared having ingredients as shown in the following Table:

Antimicrobial floor cleaning wipes were formed by impregnating a spunlace substrate with either formulation A or formulation B.

The wipes were used to treat a test surface. Each gave excellent cleaning and hygienic performance (measured by standard European suspension test) with substantially no streaks left behind after use. The presence of streaks was significantly reduced in comparison with a commercially available wipe impregnated with a formulation containing cationic surfactant (benzalkonium chloride) as the antimicrobial agent.

These results are particularly surprising given that the formulation of the Example has such low levels of active ingredient and is free of organic solvent.

Claims

1. A pre-moistened wipe suitable for the cleaning of hard surfaces such as floors, and which comprises a substrate incorporating an aqueous composition comprising:

(ii) from 0 to 1% by weight of a nonionic co- surfactant;

Ri-O- (EO)_m- (P0)_n-R₂ (I)

wherein R]_ and R₂ are independently C₂_6 alkyl or hydrogen, but not both hydrogen, m and n are independently 0-5, EO represents an ethyleneoxy group and PO represents a propyleneoxy group.

2. A wipe according to claim 1, in which the antimicrobially-active amphoteric surfactant is an alkyl (polyaminoalkyl) glycine corresponding to the following general formulae (a) , (b) or (c) :

R- (NH- (CH₂ ) _n) _m-NH-CH₂-C00H (a)

[ (R- (NH- (CH₂ ) _n) m] ₂ -N-CH₂-C00H (b)

(R) (R¹) -N- (CH₂ ) _n-NH) _m -CH₂-C00H (c)

wherein R represents Cs to C ₈ alkyl, R represents

((CH₂)_n - NH) _m -(CH₂)_n - NH₂, n is an integer ranging from 2 to 4 and m is an integer ranging from 1 to 5. R in formula (I) is a linear C₁₂-C₁₄ alkyl group and m in formula (I) is 3,

or salts and mixtures thereof

3. A wipe according to claim 1 or 2 , in which the sequestering agent is an organophosphonic acid or salt thereof.

. A wipe according to any of claims 1 to 3 , in which the aqueous composition has a pH of from 8 to 12.

5. A wipe according to any of claims 1 to 4 , in which the aqueous composition has ingredient percentages (by weight based on total weight of the aqueous composition) as follows: Antimicrobially-active amphoteric surfactant: from 0.002 to 0.5%, preferably from 0.005 to 0.3%, most preferably from 0.05% to 0.2%.

Nonionic co-surfactant : from 0.002 to 0.5%, preferably from 0.005 to 0.1%.

Sequestering agent: from 0.001 to 0.1%, preferably from 0.005 to 0.05%, most preferably about 0.01 to 0.02%.

Water: at least 80%, preferably at least 90%, most preferably at least 95%.

6. A wipe according to any one of claims 1 to 5, in which the non-ionic co-surfactant is a blend of alcohol ethoxylate, alcohol ethoxylate/propoxylate and amine ethoxylate/propoxylate.

7. A method of cleaning hard surfaces such as floors comprising wiping the hard surface with a wipe according to any one of claims 1 to 6.

8. Use of a wipe according to any one of claims 1 to 6 for cleaning hard surfaces such as floors .