Hard surface cleaning wipe

HARD SURFACE CLEANING WIPE

Technical Field

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

Background to the Invention and Prior Art

Various liquid compositions have been described which were designed in particular for the cleaning of hard surfaces without residues, streaking or spotting left behind after use.

EP 0 240 009 describes a pre-moistened wipe for cleaning a hard surface to a substantially streak-free finish comprising a flexible substrate carrying a liquid cleaning composition based on surface active agent, aliphatic alcohol and water. The cleaning composition typically contains from 15 to 25% by weight ethanol .

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. O98/50518 describes aqueous alkaline hard surface cleaners demonstrating superior film/streak performance. The compositions are designed for spray dispensation and are based on a low level of anionic surfactant (preferably alkyl sulphate) in combination with ethanol, at a typical level of 5.0% by weight, and an alkalising agent in order to raise the pH above 12.5.

EP 0 823 937 relates to glass cleaning compositions which impart good cleaning without objectionable levels of filming or streaking which comprise less than 1% by weight of a linear alkyl sulphate detergent surfactant, in combination with water, hydrophobic solvent and non-aqueous polar solvent. The compositions typically contain at least 2% by weight of non-aqueous polar solvent such as ethanol, and at least 2% by weight of hydrophobic solvent such as butoxypropanol .

A problem with the above proposals is that the formulations all contain a significant amount of volatile organic compounds as solvents. As is described in EP 0 604 996, a high alcohol content is traditionally seen as desirable in formulations for cleaning hard surfaces without streaking or spotting. However, 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. The solution proposed by EP 0 604 996 uses a pre- moistened wiping article comprising a flexible substrate carrying a liquid composition comprising an aqueous solution of from 5 to 15% by weight of a onohydric aliphatic alcohol, preservative and from 0.01 to 1% by weight of an alkylpolyglycoside. This is stated to be a low alcohol content formulation which still achieves the favourable results associated with higher alcohol content formulations.

It can be seen that the formulation of EP 0 604 996 still contains a significant amount of alcohol (typically 6-8% by weight) .

WOOO/23553 provides a surface cleaner for misting showers and bathtubs which does not spot or streak when dry and which is aqueous based and alcohol free. The composition contains chelating agent in combination with from 0.1 to 1% by weight of a surfactant which is preferably a combination of amine oxide and alkylpolyglycoside. According to WOOO/23553, the composition is not an aggressive cleaner and is not designed for scrubbing or wiping. The cleaner of WOOO/23553 is described as a rinsing solution which maintains a shower clean after repeated cycles of spray application by keeping deposits in suspension and rinsable from the surfaces during subsequent showers .

Summary of the Invention

The present invention provides a pre-moistened wipe suitable for the 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 alkyl alkoxylated sulphate surfactant having the general formula (I) :

RO (A) mS0₃M

wherein R is an unsubstituted C₆-C₂₀ alkyl or hydroxyalkyl group having a C₅-C₂₀ alkyl component, A is an ethoxy or propoxy unit, m is an integer greater than one, and M is a suitable counterion;

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

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

R₁-0-(EO)_m-(PO)_n-R₂

wherein Rη_ 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 both excellent cleaning and 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 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 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:

Alkyl alkoxylated sulphate surfactant of formula (I) : from 0.002 to 0.5%, preferably from 0.005 to 0.1%, most preferably about 0.05%.

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

Organic solvent of formula (II) : 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%, most preferably no greater than 0.05% (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. Alkyl Alkoxylated Sulphate Surfactant

Compositions of the invention contain an alkyl alkoxylated sulphate surfactant having the general formula (I) :

RO (A) mS0₃M

wherein R is an unsubstituted C₆-C₂₀ alkyl or hydroxyalkyl group having a C₆-C₂₀ alkyl component, A is an ethoxy or propoxy unit, m is an integer greater than one, and M is a suitable counterion.

Suitable counterions M include hydrogen or a cation such as an alkali metal cation (e.g., sodium, potassium, lithium, calcium, and magnesium) or ammonium or substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl ammonium cations and quaternary ammonium cations, such as tetramethyl- ammonium and dimethyl piperidinium cations and quaternary ammonium cations derived from alkylamines such as ethylamine, diethylamine, triethylamine, and mixtures thereof) . M is preferably sodium.

R is preferably a Cs-Cis alkyl or hydroxyalkyl group, more preferably C₁₀-C₁₆ alkyl or hydroxyalkyl, most preferably C₁₂-C₁₄ alkyl. R can be linear, branched or mixed linear/branched, and is preferably linear.

m is preferably between 2 and 6, more preferably 2 or 3 , especially 3. An example of a suitable commercially available alkyl alkoxylated sulphate surfactant is COSMACOL® AES 70-3-24, ex Condea. This material can be described as

RO- (CH₂CH₂0) ₃S0₃Na where R is linear C₁₂-₁₄ alkyl.

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

A liquid formulation was prepared having ingredients as shown in the following Table :

<img file="WO02090484A2_D0001.tif" />A floor cleaning wipe was formed by impregnating a spunlace substrate with the above liquid formulation.

The wipe was used to treat a test surface and gave excellent cleaning performance with substantially no streaks left behind after use. The presence of streaks was significantly reduced in comparison with wipes impregnated with control formulations in which the following alternative surfactants were substituted in place of the COSMACOL® AES 70-3-24:

* NONIDAC® 103A (fatty alcohol ethoxylate based nonionic surfactant, ex Condea)

* LIAL® 111 (10EO) (fatty alcohol ethoxylate based nonionic surfactant, ex Condea) * Alkyl ether sulphate (1EO)

Streaking was also significantly reduced in comparison to a wipe impregnated with a control formulation consisting purely of demineralised water.

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.