WO2002036725A1

WO2002036725A1 - Composition for cleaning hard surfaces

Info

Publication number: WO2002036725A1
Application number: PCT/EP2001/012352
Authority: WO
Inventors: Thomas Alexander Brunt; Geoffrey Newbold; Dawn Rigby; Martin Sharples; Thuy-Anh Pham
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Lever Ltd
Priority date: 2000-11-02
Filing date: 2001-10-18
Publication date: 2002-05-10
Also published as: AR031188A1; AU2002220660A1

Abstract

The invention provides aqueous liquid hard surface cleaning composition comprising a detergent surfactant and a water-soluble polymer having a high refractive index and which after application to the surface dries into a coherent, non-sticky film. The compositions preferably contain 0.2-15% polymer and 0.01-10% surfactant. The invention also provides a process for cleaning hard surfaces, particularly floors, comprising applying the composition above to the surface, distributing it over the surface with a suitable implement and letting the composition dry out on the surface leaving a polymer film thereon. Furthermore the invention provides the use in an aqueous liquid hard surface cleaning composition, of a polymer as above to provide a shiny, non-tacky film to a hard surface.

Description

Composition for cleaning hard surfaces

Field of the invention

The present invention is related to liquid compositions for cleaning and delivering shine to hard surfaces, particularly to floors.

Background to the invention

Many floor-cleaning compositions are known in the art. Apart from cleaning, many of them also claim to deliver shine at the same time, which in most cases is defined as the absence of streaks, spots or other residues of the cleaning product. Thus, they do give the floor an even appearance after cleaning, but dull parts of the floor remain dull. Such compositions are generally sold in the form of liquids, particularly aqueous liquids, which comprise one or more detergent surfactants to perform the cleaning, sometimes assisted by the presence of organic solvents such as alcohols or (poly) alkylene glycol ethers.

Such compositions are usually delivered to the floor as a dilute solution obtained by adding a small amount of a concentrate to a bucket of water, which thereafter is usually applied to the floor with a floor-cleaning mop or similar implement. Some compositions are intended to deliver positive shine in that they actually make worn and dull parts of a floor appear less dull. This is believed to be caused by the cleaning product leaving a thin layer or coat of material on the floor after the cleaning operation, which layer fills tiny cracks and scratches, thus making them less visible. These compositions intended for delivering shine generally comprise a dispersion of insoluble waxes and polymers and as such can build up on the floor.

W098/17761 (Henkel) describes liquid hard surface cleaning compositions comprising a detergent surfactant and specific grades of xanthan gum, particularly Kelzan T™ as a gloss retention aid.

W099/18182 (Procter & Gamble) describes floor-cleaning compositions comprising a detergent surfactant and a shear- thinning and hydrophilic polymer. Various natural gums are mentioned as suitable, as well as poly(styrene sulphonate) and poly-vinylpyrrolidone. Xanthan gum again appears to be preferred.

O00/12661 (Procter & Gamble) describes floor-cleaning compositions comprising a nonionic surfactant, a polyvinyl- pyrrolidone homo- or co-polymer and a polysaccharide which is preferably xanthan gum. The compositions are said to provide second time cleaning benefits and shine. The latter is defined as the absence of watermarks and dried-on salt and is evaluated after rinsing with water. Thus, the cleaning compositions are not intended to be left to dry out on the surface . WO98/36047 discloses hard surface cleaning compositions comprising a mixture of on the one hand non-, mono- or di- capped polyalkylene glycols and on the other hand homo- or co-polymers of vinylpyrrolidone. The compositions are said to give antiresoiling and second time cleaning benefits. Other cleaning compositions giving similar benefits and containing poly (acrylic acid) or acrylic acid/maleic anhydride copolymers and similar anionic polymers are discussed in W094/26858.

DE-A-25 22 091 discloses gloss and cleaning compositions particularly for floors comprising a water-soluble polycarboxy polymer and a complex of a polyvalent metal ion and a volatile ligand. Zn , Cu and Ni are specifically mentioned as suitable metal ions and ammonia as a suitable ligand. On drying out of the polymer solution on the metal ion is intended to cross-link the polymer molecules. Similar compositions, in which also Ca⁺ or Mg⁺ may be used, are disclosed in W097/24425, although they do not require a ligand.

DE-A-43 35 046 discloses floor cleaning compositions which contain a high molecular weight water-insoluble polymer and a lower molecular weight water-soluble polymer. Both polymers are of the acrylate/acrylate ester copolymer or acrylate/styrene copolymer type. The compositions also contain a surfactant and a plasticizer such as a mono- or di-ethylene or -propylene glycol ether.

For compositions intended to deliver positive shine it has been problematic to leave an even coat or film of material, i.e. to prevent it from leaving spots and streaks on drying out. Shine is also much influenced by the smoothness of the film and by its optical properties. Films which are easily scratched or dented themselves will only provide a very temporary solution to the dulling problem. Furthermore, many polymer films, which do give a smooth and shiny appearance, appear to be tacky. On such films footprints are easily visible and dust and dirt sticks to the surface. Finally, film residues tend to build up on floors and similar surfaces after repeated cleaning and thereby lead to an unsightly appearance, unless the film material is such that the old film is easily removed and replaced by a new film in the next cleaning operation.

Brief description of the invention

The present invention provides liquid hard surface cleaning compositions comprising an aqueous solution of a detergent surfactant and a water-soluble polymer or polymers having a high refractive index and which after application to the surface dries into a coherent, non-sticky film.

The present invention further provides a process for cleaning and providing shine to hard surfaces involving applying a cleaning composition according to the invention to the surface, distributing it evenly over the surface using a cloth, mop, wipe or similar implement and letting the composition dry out on the surface. During the distribution step the combined action of the cleaning composition and the implement cleans the surface and applies a thin polymer film.

Furthermore, the invention provides the use of a water- soluble polymer in a cleaning composition to leave a shiny film on the surface after cleaning.

Detailed description of the invention

All percentages mentioned herein are by weight calculated on the total composition unless specifically indicated otherwise.

Polymers:

Ready to use compositions according to the invention comprise one or more polymers, preferably in an amount of 0.2-15%, more preferably 1.0-10%, most preferably up to 5%. Contrary to many polymers which can be dispersed in water leading to a turbid or opaque system, the polymers used for the purpose of the present invention are completely soluble in water at 20°C in the concentration in which they are used, and at a suitable pH which may need to be adapted to the polymer in question. Preferably they give a completely clear solution.

Concentrated compositions, which are intended to be diluted prior to use, may contain proportionally higher concentrations of the polymers than the concentrations mentioned above. In order to provide a uniformly shiny surface the polymers in solid film form, have a high refractive index, preferably at least 1.50, more preferably at least 1.53, even more preferably at least 1.55, or even 1,56 or above (measured as fresh film) .

The polymers have a weight average molecular weight of between 1000 and 10,000,000, preferably at least 5000, most preferably at least 10,000. For easy solubility the polymers preferably have a molecular weight below 4,000,000, more preferably below 1,500,000, most preferably at most 1000,000 or even 500, 000.

The polymers may be nonionic, cationic or anionic and may be linear or branched. Cross-linked polymers are not preferred unless the cross-linking is limited such that it does not interfere with complete solubility in water, preferably to allow the preparation of a clear aqueous solution. Nonionic and anionic polymers are preferred.

The polymer films left on the surface have sufficient toughness not to be easily marked by foot traffic in use.

Examples of suitable polymers, which meet the refractive index and hardness criteria, may be found among e.g. :

1 - polyvinyl alcohols and vinylalcohol/vinylacetate copolymers ;

2 - acrylic acid and methacrylic acid polymers and copolymers and their salts; 3 - copolymers of (meth) acrylic acid with other vinyl monomers (such as styrene or maleic anhydride) and their salts;

4 - polyacrylamides; 5 - polymaleic acid and salts

6 - copolymers of maleic anhydride with styrene or alkyl vinylethers . Specific examples of class 1 are polyvinyl alcohols marketed by Clariant as Mowiol™ 40-88, 26-88, 4-88, 3-83 and 30-92. A specific example of class 2 is the acrylic polymer marketed by Ciba as Rheovis CR2.

Specific examples of class 3 are the acrylic copolymers marketed by Goodrich as Avalure™ AC115, 118, 125 and 315, the styrene/acrylic copolymers marketed by Ciba as Glascol™ LS16 and LS26 and the maleic/acrylic copolymer marketed by BASF as Sokalan™ CP9.

Specific examples of class 6 are styrene/maleic copolymers marketed by Hercules as Scripset™ 520, 550 and 720

Detergent surfactants:

The compositions contain at least one surfactant which may be chosen from anionic, nonionic, zwitterionic and amphoteric surfactants. Preferably the compositions contain at least an anionic and/or nonionic surfactant, most preferable at least a nonionic surfactant.

Ready to use compositions contain a total amount of surfactant of 0.01-10%, preferably at least 0.05% and at most 5%. Concentrated compositions, which are intended to be diluted prior to use, may contain proportionally higher concentrations of surfactant than the concentrations mentioned above. The ratio between polymer and surfactant is 1:1 or more, preferably at least 1.5:1, more preferably at least 2:1 or even 3:1.

A suitable class of anionic surfactants are water-soluble salts of organic sulphuric acid esters and sulphonic acids having in the molecular structure an alkyl group containing 6-22 C atoms or an alkylaryl group containing 6-20 C atoms in the alkyl part. Alkali metal, ammonium or alkanol- ammonium salts are preferred.

Examples of such anionic surfactants are water-soluble salts of: long chain (i.e. 6-22 C-atom) alcohol sulphates

(hereinafter referred to as PAS) , especially those obtained by sulphating the fatty alcohols produced by reducing the glycerides of tallow or coconut oil; - alkylbenzene-sulphonates, such as those in which the alkyl group contains from 6 to 20 carbon atoms; secondary alkanesulphonates. Also suitable are the salts of: alkylglyceryl ether sulphates, especially of the ethers of fatty alcohols derived from tallow and coconut oil; fatty acid monoglyceride sulphates; sulphates of ethoxylated C₈-C₂ aliphatic alcohols containing 1-8 ethyleneoxy groups; alkylphenol ethyleneoxy-ether sulphates with from 1 to 8 ethyleneoxy units per molecule and in which the alkyl groups contain from 4 to 14 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralised with alkali .

A suitable class of nonionic surfactants can be broadly described as compounds produced by the condensation of simple alkylene oxides, which are hydrophilic in nature, with an organic hydrophobic compound which may be aliphatic or alkyl- aromatic in nature. The length of the hydrophilic or polyoxyalkylene chain, which is attached to any particular hydrophobic group, can be readily adjusted to yield a compound having the desired balance between hydrophilic and hydrophobic elements. This enables the choice of nonionic surfactants with the right HLB. Particular examples include: the condensation products of aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration with ethylene oxide, such as a coconut alcohol ethylene oxide condensates having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol; - condensates of alkylphenols having C6-C15 alkyl groups with 5 to 25 moles of ethylene oxide per mole of alkylphenol ; condensates of the reaction product of ethylene-diamine and propylene oxide with ethylene oxide, the condensates containing from 40 to 80% of ethyleneoxy groups by weight and having a molecular weight of from 5,000 to 11,000.

Other suitable classes of nonionic surfactants are : - alkylglycosides, which are condensation products of long chain aliphatic alcohols and saccharides; tertiary amine oxides of structure RRRNO, where one R is an alkyl group of 8 to 20 carbon atoms and the other R's are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, e.g. dimethyldodecylamine oxide; - tertiary phosphine oxides of structure RRRPO, where one R is an alkyl group of 8 to 20 carbon atoms and the other R's are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, for instance dimethyl-dodecylphosphine oxide; - dialkyl sulphoxides of structure RRS0 where one R is an alkyl group of from 10 to 18 carbon atoms and the other is methyl or ethyl, for instance methyl-tetradecyl sulphoxide; fatty acid alkylolamides; - alkylene oxide condensates of fatty acid alkylolamides;

Suitable amphoteric surfactants are derivatives of aliphatic secondary and tertiary amines containing an alkyl group of 8 to 20 carbon atoms and an aliphatic group substituted by an anionic water-solubilising group, for instance sodium 3- dodecylamino-propionate, sodium 3 -dodecylaminopropane- sulphonate and sodium N-2-hydroxy-dodecyl-N-methyltaurate.

Further examples of suitable surfactants are compounds commonly used as surface-active agents given in the well- known textbooks: "Surface Active Agents" Vol.l, by Schwartz & Perry, Interscience 1949, Vol .2 by Schwartz, Perry & Berch, Interscience 1958; in the current edition of "McCutcheon¹ s Emulsifiers and Detergents" published by Manufacturing Confectioners Company; or in "Tenside-

Taschenbuch" , H. Stache, 2nd Edn., Carl Hauser Verlag, 1981. Ready to use compositions according to the invention preferably have a viscosity of at most 300mPa.s at 21 s^~ (Brookfield viscometer) , more preferably lOOmPA.s or less, even more preferably 1.0-30 mPa.s, or even 10-mPa.s or less. Thus, polymers which give an appreciable thickening effect leading to a viscosity above 30mPa.s at the required concentration are generally less suitable.

The preferred pH of the compositions according to the invention is chosen so as to maximise solubility as well as the film forming properties of polymer in the composition. The pH is generally chosen at 7 or above, more preferably 8 or above. A pH-regulating component, as well known in the art, is added to the composition to the extent necessary to obtain the desired pH.

The tackiness of the film left on the surface after it has been treated with the compositions according to the invention is primarily determined by the properties of the polymer, although the properties and the amount of surfactant have an influence as well, with higher polymer/surfactant ratios leading to less tackiness. The compositions according to the invention provide films with a tackiness (work of adhesion) of 15Jm or less when measured according to the test procedure described below. Preferably the tackiness is 10Jm^"2 or less, more preferably 5Jπf² or less.

Tackiness (work of adhesion) was measured using the Texture Analyser model TA XT2i, made by Stable Microsystems (www.stablemicrosytems.com). A rubber bung (Fisher Scientific "red rubber") was used as the probe material, which was brought into contact with the coated sample and then compressed to give a pre-determined contact pressure. The probe was then removed from the sample at a predetermined unloading rate and the force was recorded throughout the loading and unloading cycle. The work of adhesion is calculated by integrating the area under the adhesive region of the force-distance curve. A maximum contact pressure of 120, OOONrrf², a loading speed of 0. Imms^"1 and an unloading speed of lOmms^"1 were used. The composition to be tested was applied to a clean glass surface by dragging a cloth saturated in the composition across the glass surface to simulate a wiping process. The resultant liquid film was then allowed to dry in ambient conditions for at least 1 hour before tack measurements were made. This wiping procedure generally leads to a thin and substantially uniform dry polymer-based film of a thickness of around lOOnm. The measurements were carried out at 20°C and a typical humidity of 60% RH.

Optional components:

The compositions according to the invention may comprise various optional components to improve ease of use or cleaning properties, or otherwise increase consumer appeal of the compositions. Such components include: perfumes; - insect repellents including essential oils such as those of genus Mentha, particularly Mentha arvensis, mentha piperita, Mentha spicata and Mentha cardica;

Lemongrass East Indian oil, Lemon oil, Citronella,

Cedarwood and Pine oil; terpenoids, particularly limonene, carvone, cineole, linalool, Gum Camphor, citronellal, alpha- and beta-terpenol, fencholic acid, borneol, iso-borneol, bornyl acetate and iso-bornyl acetate; colorants; antifoams, such as hydrophobic silica's, silicone oils, hydrocarbons and other hydrophobic organic solvents, mixed EO/PO nonionic surfactants; antimicrobials or preservatives; thickeners, if necessary to give the composition a desired viscosity within the limits specified above; - UV absorbers, to provide protection of the hard surface against deterioration by ON light.

Organic solvents such as C1-C6 aliphatic alcohols and (poly) alkylene glycol ethers (e.g. C1-C6 alkyl mono- or di- ethylene glycol ethers and mono- or dipropylene glycol ethers) may be present in the compositions according to the invention, however, preferably they are absent because they do not normally contribute much to the cleaning or shine- giving properties .

Since the present invention does not involve the cross- linking of polymer chains by polyvalent metal ions, complexes of metal ions with volatile ligand do not perform a useful function in the compositions of the present invention such complexes or the metal ions as such are therefore generally absent . Small amounts of Mg or Ca , may be present as counterions of an anionic surfactant, although monovalent counterions are preferred.

The compositions according to the invention are intended for being applied to the surface as is, without further dilution. However, as outlined above, they may be provided in concentrated form to be prediluted to the required strength before application to the surface.

The compositions may be used on any hard surface to which a shine is desirably applied. They are particularly useful for application on large surfaces such as floors.

The compositions may be simply poured on the surface from a bottle or similar container before being evenly distributed with a mop, cloth or similar implement. In a preferred embodiment, to simplify even distribution over the surface, they are sprayed on the surface, e.g. from a pressurised container, or from a container provided with a pump spray or trigger spray dispensing device. Thereafter, the composition is evenly distributed over the surface, while at the same time cleaning the surface, with a mop, cloth, wipe or similar implement. For large surfaces, such as floors, a mop attached to a handle via a swivel mechanism is a useful and well-known tool. They are often provided with an interchangeable cloth, such as described in EP774229 and WO01/12052. Particularly useful cloths for this purpose are made of a material, which does not itself absorb much liquid, because it would otherwise take up and absorb the liquid composition rather than distribute it over the floor. Such cloths may be made of polypropylene fibre or similar relatively hydrophobic fibre material .

In another useful embodiment of the invention a wipe of a woven or non-woven fabric, such as are well known in the art, is impregnated with the liquid composition according to the invention so as to form a moist wipe which is ready for use.

In still another embodiment, the liquid composition may be absorbed in to a specially designed wipe containing a material that is able to hold a large amount of liquid which is gradually released. In that case the wipe acts as a liquid reservoir and the composition is distributed over the floor from the wipe. If the wipe is fitted to a mop, the mop handle may be additionally fitted with a reservoir from which the liquid composition is fed to the mop. Such systems are described e.g. in 099/18182

After the compositions have been applied to the hard surface, they are left to dry without any further rinsing or wiping. The polymer film thus left on the surface after drying generally has a thickness of at least 50nm, more preferably a thickness of 100-lOOOnm, most preferably 200-500nm.

Examples

The floor cleaning compositions in table 1 were prepared. All compositions contained perfume, dye and preservative and water to make up to 100% and were set at pH 8.5 using ammonia solution as required. Table 1

Neodol™ is market by Shell C9-C11 8EO alkoxylated alcohol nonionic surfactant C9-C11 5EO alkoxylated alcohol nonionic surfactant Na dodecyl sulphate.

* Films 2 months old. The refractive index of the polymer films tends to increase with time, probably due to further loss of water that was still retained in fresh dry films . ** These compositions are not according to the invention because the polymer films had too lo refractive index or too high tackiness .

The compositions were sprayed on ceramic tiles . The tiles were thereafter wiped with a non-woven cloth (Ballerina™) and left to dry. The tiles were evenly covered with a polymer film. The compositions according to the invention showed excellent shine. The refractive index was measured with a laser ellipsometer (DRE-RISS EL X-02C) , using an excitation wavelength of 632.8 nm and an incident angle of 70°.

The cleaning properties of the compositions were tested in comparison with a commercial product (Echo) on a 1:4 fat/particulate model soil on Formica™ sheets. Product was applied on Ballerina cloth and cleaning measured after 5 cycles at a head pressure of 80g/cm . The amount of soil remaining was assessed colorimetrically (DR LANGE MICRO COLOUR colorimeter) .

Soil removal was :

Market cleaning/shine product (Echo) : 32% Example 2 : 58%

Claims

1. Aqueous liquid hard surface cleaning compositions comprising a detergent surfactant and a water-soluble polymer characterized in that the detergent surfactant is present in an amount of 0.01-10%, the water soluble polymer has a refractive index of at least 1.50 and is present in an amount of 0.2-15%, the polymer/surfactant ratio is at least 1:1 and the composition after application to the surface dries into a coherent, non- tacky film.

2. Cleaning compositions according to claim 1 wherein the polymer is present in an amount of 1.0-10% and has a refractive index of at least 1.55.

3. Cleaning compositions wherein the polymer is nonionic or anionic.

4. Cleaning compositions according claims 1 or 2 wherein the polymer/surfactant ratio is at least 1.5:1

5. Cleaning compositions according to claims 1-3 wherein the tackiness of the film is 15Jm^"2 or less.

6. Cleaning compositions according to claims 1-5 wherein the compositions has pH of 7 or higher

7. Cleaning compositions according to claims 1-6 which contain at least an anionic and/or nonionic surfactant .

8. Cleaning compositions according to claims 1-7 having a viscosity of 300mPa.s or less.

9. Process for cleaning and providing shine to a hard surface comprising the steps of : i) applying to the surface an aqueous liquid cleaning composition according to any one of claims 1-8; ii) distributing the composition evenly over the surface using a cloth, mop, wipe or similar implement; iii) thereafter letting the composition dry out on the surface to leave a polymer film thereon.

10. Process according to claim 9 wherein the hard surface is a floor.

11. Use, in an aqueous liquid hard surface cleaning composition comprising a surfactant, of a water soluble polymer having a refractive index of at least 1.50 and which after application to a hard surface dries into a coherent film having a tackiness of 15Jm or less, to provide a shiny, non-tacky hard surface.

12. Use according to claim 11 wherein polymer/surfactant ratio is at least 1:1.

13. Use according to claims 11-12 wherein the hard surface is a floor.