EP3004304B1

EP3004304B1 - Composition for cleaning of hard surfaces

Info

Publication number: EP3004304B1
Application number: EP14803353.3A
Authority: EP
Inventors: Andrew Anthony Howard Barnes; Simon Anthony Johnson; Anthony Clifford KENT; Edward George Pelan; Simeon Dobrev Stoyanov; Weizheng Zhou; Huanjun ZHOU; Peng Zhang
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2013-05-31
Filing date: 2014-05-21
Publication date: 2017-10-25
Anticipated expiration: 2034-05-21
Also published as: BR112015029789B1; EP3004304A1; BR112015029789A2; WO2014190865A1; PL3004304T3; EP3004304A4; ZA201508128B

Description

The present invention relates to a cleaning composition for hard surfaces for household use, and to a method for cleaning hard surfaces using the composition.

BACKGROUND OF THE INVENTION

Cleaning liquids for household surfaces (e.g. tables, kitchen, bathroom) are well known. These liquids often contain ingredients that have the purpose to facilitate the easy removal of stains and soils from hard surfaces while abrasion and scratching of the surface should be as low as possible. Calcium carbonate is often used as an abrasive in such cleaning liquids, and tough soil on surfaces may be removed via these liquid abrasive cleaners. Calcium carbonate (CaCO₃) of known particle size, in the calcite crystal form, is used as the abrasive in current commercially available liquid abrasive cleaners. This abrasive is a highly effective tough soil remover, but with this presents the unavoidable potential for surface damage when cleaning. Increasing the level of calcite in the formulation improves cleaning, but also increases surface damage. The use of conventional CaCO₃ in cleaning compositions easily results in an undesired high viscosity, because relatively high levels of CaCO₃ are used to provide efficient cleaning.
EP 0 103 325 A1 discloses a liquid scouring cleaning composition comprising an abrasive powder, for example precipitated calcium carbonate (aragonite).
WO 2009/040597 discloses a cleaning composition for hard surfaces, containing solid inorganic microparticles having a particle size of from 0.5 to 5 micrometer, a surface area of from 10 to 50 m²/g and a crystallinity degree lower than 50 percent. The inorganic microparticles may be carbonates, and in one of the examples carbonate-substituted non-stoichiometric hydroxyapatite is used. These particles have the advantage that the abrasiveness has decreased.
US 2010/0263693 A1 discloses hard surface treatment compositions, wherein the particle size of an abrasive agent ranges from about 1 to 1000 micrometer, more preferably from about 10 to 100 micrometer. Abrasive agents that will not scratch glass or ceramic surfaces are preferred, and these include calcium carbonate, siliceous chalk, diatomaceous earth, colloidal silicon dioxide, sodium metasilicate, talc, and organic abrasive materials.
WO 2011/087733 A1 discloses a liquid cleaning composition comprising abrasive particles which have been defined based on roughness and hardness. The abrasive particles preferably comprise polymeric particles, e.g. polyurethane.

SUMMARY OF THE INVENTION

Current liquid abrasive cleaning compositions contain harsh abrasives, like chalk, to remove tough soil efficiently. The chalk, usually mainly comprising calcium carbonate, used nowadays has the disadvantage that it contributes to the scratching of hard surfaces. With each cleaning session, the surface to be cleaned looses gloss, and gets more damaged. Hence it is an objective of the present invention to provide a composition for cleaning and polishing of hard surfaces that facilitates the easy removal of soil, while minimising scratching and abrasion of the surface. It is a further objective of the present invention to provide a composition which even restores, at least to a certain extent, the original gloss of a damaged hard surface, which has lost gloss due to e.g. scratches, in this way polishing the hard surface.
Surprisingly, we have now found that this objective can be met by replacing at least part of the conventional ground calcium carbonate with particles in the form of platelets, like sheets or flakes. The particles are coated. The particles in the form of platelets, such as naturally observed for example in mica or clay particles, normally have two relatively large flat dimensions (length and breadth) and a relatively thin third dimension (depth). The coating, preferably a metal oxide coating, is visible on the sheets when using electron microscopy, as known in the art. When the coated particles in the form of platelets, preferably coated mica or coated clay particles or mixtures thereof, are introduced into a liquid cleaning and/or polishing composition, either totally or partially replacing the conventional ground calcium carbonate (or chalk), a greatly reduced damage profile is observed after use on the surface. Surprisingly, a damaged surface may even be repaired or polished when the composition of the invention is used. As set out above, a surface is considered repaired or polished if the scratches of a possible previously treatment are less visible, and the original gloss is restored at least to some extent. This is, at least partly, effected by treatment of a surface with a composition of the invention.
Hence in a first aspect the present invention provides a composition for cleaning and/or polishing of surfaces, comprising surfactant and coated particles in the form of platelets, wherein the composition is liquid at room temperature, the composition further comprising calcium carbonate. In a second aspect the present invention provides a method for cleaning and/or polishing a surface, wherein a composition according to the first aspect of the invention is used.

DETAILED DESCRIPTION

The technical and scientific terms herein have their common meaning as understood by the skilled person, unless stated otherwise.
All percentages, unless otherwise stated, refer to the percentage by weight. The abbreviation 'wt%' or'% (w/w)' refers to percentage by weight.
In case a range is given, the given range includes the mentioned endpoints.
In the context of the present invention, the expressions 'soil' and 'stain' generally comprise all kinds of soils and stains generally encountered in the household, either of organic or inorganic origin, whether visible or invisible to the naked eye, including soiling solid debris and/or with bacteria or other pathogens.
In the context of the present invention, a liquid composition refers to a composition that will flow under the force of gravity. The viscous modulus G" preferably is higher than the elastic modulus G'. This is in contradiction of pastes or gels, which keep their shape under the force of gravity.

Particles in the form of platelets

According to the present invention, coated particles in the form of platelets are present in a liquid cleaning and/or polishing composition. The particles suitably comprise particles of for example Al₂O₃, SiO₂, glass, calcium aluminum borosilicate, mica, clay, or mixtures thereof, more preferably mica, clay or mixtures thereof. The coated particles in the form of platelets preferably comprise coated mica particles, coated SiO2 particles or coated clay particles, or mixtures thereof. Preferably coated particles in the form of platelets are coated mica particles, coated clay particles or mixtures thereof.
The composition of the invention comprises particles in the form of platelets. Platelets represent a shape which is easily recognised by the skilled person. Platelets normally have two relatively large flat dimensions (length and breadth) and a relatively thin third dimension (depth). "Sheets" or "flakes" are considered synonyms for "platelets". Preferred materials in the present invention, naturally show a platelet form when the particles are present at the microscopic size one would apply them in a cleaning or polishing composition. For example, mica or clay particles exhibit a platelet like morphology.
The coated particles in the form of platelets preferably have a length (longest dimension of the particle) ranging from 2 to 200 micrometer, more preferably from 5 to 100 micrometer, even more preferably from 10 to 60 micrometer. A range of from 3 to 50 micrometer may be preferred, or even from 4 to 40 micrometer. Especially in case the coated particle is mica, or SiO₂ the length is preferably in the range of 5 micrometer to 60 micrometer. A range of from 3 to 50 micrometer may be preferred, or even from 4 to 40 micrometer. Especially in case the coated particle is clay, the length is preferably in the range of 5 micrometer to 200 micrometer. These sizes result in optimal polishing effects.
The particles preferably have a depth (shortest dimension of the particle, perpendicular to the length and breadth) ranging from 0.1 to 3 micrometer, preferably from 0.5 to 2 micrometer, even more preferably of from 0.75 to 1.5 micrometer. Most preferably, of from 0.5 to 1 micrometer. Least damage and optimal polishing effects to the treated surface is obtained by coated platelets which have an average depth according to these preferred ranges.
Preferably, the lengths and depths as mentioned above can be combined, e.g. preferably the coated particles have a length of 2-200 micrometer and a depth of 0.1 to 3 micrometer.
For the purposes of the present invention, preferably the coated platelet particles, preferably the mica particles, are crystals. The term 'crystal' means an essentially fully dense solid composed of atoms arranged in an orderly repetitive array bounded by plane surfaces which are the external expression of internal structure.
Particle morphology and structure may be determined by standard techniques known to those skilled in the art such as scanning electron microscopy (SEM). SEM is an imaging and analysis technique based on the detection of electrons and X-rays that are emitted from a material when irradiated by a scanning electron beam. Imaging allows the user to distinguish between primary particle and agglomerate sizes.
Automated image analysis using computer software enables the user to determine particle size distributions. Scanning electron microscopy (SEM) is a particle counting technique and produces a number-weighted size distribution. Accordingly the dimensions quoted herein for particle length and depth will generally represent average values over a population of particles, more specifically the D[1,0] number-length mean of the particle length or the particle depth respectively.
The particles as used in the present invention preferably have a hardness of between 2 and 7 Moh, preferably between 2 and 6 Moh, more preferably of between 2 and 5 Moh, even more preferably of between 2.5 and 3.5 Moh. Moh values are based on the hardness of the coated particles. The Mohs scale of mineral hardness is known to the skilled person and characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. Particles with a Moh value that is too high, such as e.g. aluminium silicate, result in an abrasive effect, resulting in undesired scratching and loss of polishing. As known in the art, the Moh value is a result of the crystal material as well as the crystal structure.

Mica particles

The mica group of sheet silicate (phyllosilicate) minerals includes several closely related materials having close to perfect basal cleavage. All are monoclinic, with a tendency towards pseudohexagonal crystals, and are similar in chemical composition. The nearly perfect cleavage, which is the most prominent characteristic of mica, is explained by the hexagonal sheet-like arrangement of its atoms. The mica group of sheet silicate (phyllosilicate) minerals includes several closely related materials having close to perfect basal cleavage. All are monoclinic, with a tendency towards pseudohexagonal crystals, and are similar in chemical composition. The nearly perfect cleavage, which is the most prominent characteristic of mica, is explained by the hexagonal sheet-like arrangement of its atoms. The main mica groups are:

Biotite - K(Mg,Fe)₃(AlSi₃)O₁₀(OH)₂
Muscovite - KAl₂(AlSi₃)O₁₀(OH)₂
Phlogopite - KMg₃(AlSi₃)O₁₀(OH)₂
Lepidolite - K(Li,Al)_2-3(AlSi₃)O₁₀(OH)₂
Margarite - CaAl₂(Al₂Si₂)O₁₀(OH)₂
Glauconite - (K,Na)(Al,Mg,Fe)₂(Si,Al)₄O₁₀(OH)₂

For the purposes of cleaning and polishing the choice of mica is not important. Muscovite and phlogopite are commercially best available and therefore preferred.

Coating

The present invention describes the use of coated platelet particles. It was surprisingly found that using coated platelet particles, the particles provided highly increased polishing capabilities, compared with non-coated particles. In fact, the non-coated particles showed little polishing effect, compared to the coated particles. The coating comprises preferably particles which are spherical particles, like metal oxide particles. The hardness of the coating particles is preferably of between 5 and 7 Moh. Preferably the hardness of the coating particles is higher than the hardness of the platelet particles that are to be coated. Preferably the coated particles are particles coated with metal oxide. The coating particles can be from a metal oxide with a high refractive index, e.g. for coloring purposes. The skilled person is aware which metal oxides qualify as high refractive index metal oxides and hardness of coating particles, and they can be purchased for example from Merck or ECKART. Preferably the particles are coated with TiO₂, Fe₂O₃, ZrO₂, Cr₂O₃, or mixtures thereof. Also other metal oxides can be used. Preferably the particles are coated with TiO₂. The platelet particles are preferably coated with metal oxide, preferably in the form of metal oxide particles. Preferably the size of the coating particles, e.g. the metal oxide particles, is in the range of from 30 nanometer to 200 nanometer.
Coated platelet particles normally exist in the art and are commercially available. For example, coated mica is an ingredient which is known in the pearlescence paint art. It can for example be bought under the trade names Balance Blue™, Red Lustre™, Silver Lustre™ or Silver Fine™, as produced by Merck for food grade use. Non-food grades may also be used for cleaning and polishing applications, for example Timiron Supersheen™. Coated SiO₂ is offered by Merck under the trade names Xirona Nordic Sunset and Xirona Indian Summer.
The polishing effect (% recovery) can be measured by using the test as described in the Examples. The recovery, as calculated according to the formula in the Examples, is preferably higher than 50 %, more preferably higher than 60%, more preferably higher than 70%, even more preferably higher than 80%, more preferably higher than 90%.
It is preferred that the concentration of the coated particles in the form of platelets, preferably the concentration of coated mica particles, clay particles or mixtures thereof, ranges from 0.2 to 40 wt%, preferably of from 1 to 40 wt%, preferably from 1 to 30%, more preferably of from 2 wt% to 30 wt%, more preferably of from 5 wt% to 30 wt%, more preferably, it ranges from 2 to 20%, preferably from 5 to 15%, based on the total weight of the composition. The concentration of coated mica particles preferably ranges from 0.2 to 40 wt%, preferably of 1 to 40 wt%, preferably from 1 to 30%, more preferably, it ranges from 2 to 20%, preferably from 5 to 15%, based on the total weight of the composition. The concentration of coated SiO₂ particles preferably ranges from 0.2 to 40 wt%, preferably of 1 to 40 wt%, preferably from 1 to 30%, more preferably, it ranges from 2 to 20%, preferably from 5 to 15%, based on the total weight of the composition. The concentration of coated clay particles preferably ranges from 0.2 to 40 wt%, preferably of 1 to 40 wt%, preferably from 1 to 30%, more preferably, it ranges from 2 to 20%, preferably from 5 to 15%, based on the total weight of the composition.
Therefore, preferably the composition only contains coated particles in the form of platelets, preferably only coated mica particles, coated clay particles or mixtures thereof, as abrasive material. These abrasive particles are used in combination with calcium carbonate, e.g. CaCO₃ in the calcite crystal form. The advantage of this is that the viscosity of the composition is lower and the cleaning performance is maintained, while the damage, as resulting from calcium carbonate is drastically reduced or even absent.
For example, a 10%/10% mix of coated mica and chalk shows good results in terms of keeping the cleaning result comparable to that of a calcium carbonate based abrasive cleaner with very much reduced damage. If more polishing is desired, the level of calcium carbonate is preferably lower and preferably the level of coated particles in the form of platelets is increased. If only a slightly reduced damage is desired, a small amount of chalk could be replaced by coated platelets, e.g. coated mica. For example, a 1% coated mica/19% chalk mixture provided about 20% damage reduction compared to calcium carbonate based abrasive cleaner. The composition of the invention comprises calcium carbonate. It may therefore be preferred, for example in this mentioned case, that the total concentration of coated particles in the form of platelets, preferably the total concentration of coated mica particles, coated clay particles or mixtures thereof, ranges from 15 to 40 wt%, more preferably from 18 to 30 wt%, even more preferably from 20 to 25 wt% by weight of the composition. It may be preferred, that the composition of the invention comprises 15 to 40 wt%, more preferably from 18 to 30 wt%, even more preferably from 20 to 25 wt% by weight of the composition of a total amount of calcium carbonate and coated particles in the form of platelets. It can be preferred that CaCO3, e.g. ground CaCO3, is present in an amount of form 0.1 to 10 wt%, preferably of from 0.5 to 7 wt%, even more preferably of from 1 to 6 wt%, based on the weight of the composition. The level of CaCO3, e.g. ground CaCO3, is preferably not too high, as it might damage the surface to be cleaned or polished during use of the composition.
It may be preferred that the concentration of the coated particles in the form of platelets, preferably the concentration of coated mica particles, SiO₂ particles, coated clay particles or mixtures thereof, ranges from 0.2 to 40 wt%, preferably of 1 to 40 wt%, preferably from 1 to 30%, more preferably of from 2 wt% to 30 wt%, more preferably of from 5 wt% to 30 wt%, more preferably, from 2 to 20%, preferably from 5 to 15%, based on the total weight of the composition. The composition of the invention is a liquid cleaning composition, preferably a liquid cleaning and polishing composition. Liquid means liquid at RT. The composition is preferably for cleaning and/or polishing hard surfaces, preferably with a hardness of 0.2 to 2 GPa. The composition is preferably a composition to clean household surfaces such as formica surfaces as seen on a kitchen desk, acrylic baths, table surfaces, desks, kitchen furniture, kitchen apparatus. But it might be a composition to clean and polish dentures, such as tooth paste.
The composition preferably is water based, for optimal cleaning purposes. The composition preferably comprises water. Water is preferably present in an amount of from 10 to 90 wt%, more preferably of from 20 to 80 wt%, even more preferably of from 30 to 70 wt%. The composition preferably does not comprise oil, as this might well require a second cleaning step to remove the oil from the surface. The content of oil or fat is preferably less than 5 %, preferably less than 2 wt%, most preferably the composition is free from oil or fat.
It may be preferred that the composition does not comprise humectants. The concentration of polyols, such as glycerol or sorbitol, is preferably less than 20 wt%, preferably less than 10 wt%, even more preferably less than 5 wt%, even more preferably less than 2 wt%, even more preferably less than 1 wt%, most preferably polyol is not present in the composition.
It can be preferred, that the composition of the invention is a cleaning and or polishing composition comprising surfactant and coated particles in the form of platelets, wherein the particles have a length (longest dimension of the particle) ranging from 2 to 200 micrometer, preferably 5 to 100 micrometer, preferably from 10 to 60 micrometer, and wherein the particles have a depth (shortest dimension of the particle, perpendicular to the length and breadth) ranging from 0.5 to 3 micrometer, preferably from 0.75 to 1.5 micrometer, and wherein
the particles have a hardness of between 2 and 7 Moh, preferably 2 to 6 Moh, preferably 2 to 5 Moh and wherein the coated particles are particles coated with metal oxide, and wherein
the concentration of the particulates ranges from 0.2 to 40 wt%, preferably from 1 to 30 wt%, preferably from 5 to 30 wt%, based on the total weight of the composition, and optionally comprising CaCO₃.
It can be preferred, that the composition of the invention is a cleaning and or polishing composition, preferably a cleaning and polishing composition, comprising surfactant and coated particles in the form of platelets, wherein
the particles have a length (longest dimension of the particle) ranging from 2 to 200 micrometer, preferably from 3 to 60 micrometer, more preferably from 10 to 60 micrometer, and wherein
the particles have a depth (shortest dimension of the particle, perpendicular to the length and breadth) ranging from 0.5 to 3 micrometer, preferably from 0.75 to 1.5 micrometer, and wherein
the particles have a hardness of between 2 and 7 Moh, preferably 2 to 6 Moh, and wherein
the particles comprise coated mica particles, coated clay particlesor mixtures thereof, preferably the particles comprise coated mica particles, coated SiO2 particles, coated clay particles or mixtures thereof and wherein
the coated particles are particles coated with metal oxide, and wherein the concentration of the particulates ranges from 0.2 to 40 wt%, preferably from 1 to 30 wt%, preferably from 5 to 30 wt%, based on the total weight of the composition, and optionally comprising CaCO₃.
It can be preferred, that the composition of the invention is a cleaning and polishing composition comprising surfactant, water and coated particles in the form of platelets, wherein
the particles have a length (longest dimension of the particle) ranging from 2 to 200 micrometer if they are clay particles and from 5 to 60 micrometer if they are not clay particles, and wherein
the particles have a depth (shortest dimension of the particle, perpendicular to the length and breadth) ranging from 0.5 to 3 micrometer, preferably from 0.75 to 1.5 micrometer, and wherein
the particles have a hardness of between 2 and 6 Moh, and wherein
the particles comprise coated mica particles, coated clay particles, coated SiO₂ particles or mixtures thereof and wherein
the coated particles are particles coated with metal oxide, and wherein
the concentration of the particulates ranges from 0.2 to 40 wt%, preferably of 1 to 40 wt%, preferably from 1 to 30 wt%, preferably from 5 to 20 wt%, based on the total weight of the composition.

Surfactants

The cleaning and/or polishing composition of the invention comprises a surfactant, preferably at a concentration of maximally 50% by weight of the composition. The surfactant helps building the structure of the composition. It appeared to prevent, or reduce, the agglomeration of platelets into larger more damaging entities. It further reduces the soil and debris from interfering with polishing activity. The surfactant (detergent active) is generally chosen from anionic and nonionic detergent actives. The cleaning and/or polishing composition may further comprise cationic, amphoteric and zwitterionic surfactants. Preferably, the total amount of surfactant the cleaning composition is at least 0.1%, more preferably at least 0.5%. The maximum amount is usually less than 30%, more preferably not more than 20%, or even at or below 10% by weight.
Suitable synthetic (non-soap) anionic surfactants are water-soluble salts of organic sulphuric acid mono-esters and sulphonic acids which have in the molecular structure a branched or straight chain alkyl group containing from 6 to 22 carbon atoms in the alkyl part. Examples of such anionic surfactants are water soluble salts of:

(primary) long chain (e.g. 6-22 C-atoms) 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;
alkyl benzene 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 aliphatic alcohols containing 1-12 ethyleneoxy groups;
alkylphenol ethylenoxy-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,

The preferred water-soluble synthetic anionic surfactants are the alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of alkyl-benzenesulphonates and mixtures with olefinsulphonates and alkyl sulphates, and the fatty acid mono-glyceride sulphates.
The most preferred anionic surfactants are alkyl-aromatic sulphonates such as alkylbenzenesulphonates containing from 6 to 20 carbon atoms in the alkyl group in a straight or branched chain, particular examples of which are sodium salts of alkylbenzenesulphonates or of alkyl-toluene-, -xylene- or -phenolsulphonates, alkylnaphthalene-sulphonates, ammonium diamylnaphthalene-sulphonate, and sodium dinonyl-naphthalene-sulphonate.
If synthetic anionic surfactant is to be employed the amount present in the cleaning compositions of the invention will generally be at least 0.1 %, preferably at least 0.5%, more preferably at least 1.0%, but not more than 20%, preferably at most 15%, more preferably at most 10%.
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 aliphatic or alkyl-aromatic hydrophobic compound having a reactive hydrogen atom. 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 classes of nonionic surfactants are:

tertiary amine oxides of structure R¹R²R³N-O, where R¹ is an alkyl group of 8 to 20 carbon atoms and R² and R³ are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, e.g. dimethyldodecylamine oxide;
tertiary phosphine oxides of structure R¹R²R³P-O, where R¹ is an alkyl group of 8 to 20 carbon atoms and R² and R³ are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, for instance dimethyl-dodecylphosphine oxide;
dialkyl sulphoxides of structure R¹R²S=O, where R¹ is an alkyl group of from 10 to 18 carbon atoms and R² is methyl or ethyl, for instance methyl-tetradecyl sulphoxide;
fatty acid alkylolamides, such as the ethanol amides;
alkylene oxide condensates of fatty acid alkylolamides;
alkyl mercaptans.

The concentration of the nonionic surfactant preferably employed in the cleaning and/or polishing composition of the invention will preferably be at least 0.1%, more preferably at least 0.5%, most preferably at least 1%. The amount is suitably at most 20%, preferably not more than 15% and most preferably not more than 10%.
It is also possible optionally to include amphoteric, cationic or zwitterionic surfactants in said compositions. 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.
Examples of suitable cationic surfactants can be found among quaternary ammonium salts having one or two alkyl or aralkyl groups of from 8 to 20 carbon atoms and two or three small aliphatic (e.g. methyl) groups, for instance cetyltrimethylammonium chloride.
A specific group of surfactants are the tertiary amines obtained by condensation of ethylene and/or propylene oxide with long chain aliphatic amines. The compounds behave like nonionic surfactants in alkaline medium and like cationic surfactants in acid medium.
Examples of suitable zwitterionic surfactants can be found among derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic group of from 8 to 18 carbon atoms and an aliphatic group substituted by an anionic water-solubilising group, for instance betaine and betaine derivatives such as alkyl betaine, in particular C₁₂-C₁₆ alkyl betaine, 3-(N,N-dimethyl-N-hexadecylammonium)-propane-1-sulphonate betaine, 3-(dodecylmethyl-sulphonium)-propane-1-sulphonate betaine, 3-(cetylmethyl-phosphonium)-propane-1-sulphonate betaine and N,N-dimethyl-N-dodecyl-glycine. Other well known betaines are the alkylamidopropyl betaines e.g. those wherein the alkylamido group is derived from coconut oil fatty acids.
Further examples of suitable surfactants are compounds commonly used as surface-active agents given in the well-known textbooks: 'Surface Active Agents' Vol.1, by Schwartz & Perry, Interscience 1949; 'Surface Active Agents' Vol.2 by Schwartz, Perry & Berch, Interscience 1958; the current edition of 'McCutcheon's Emulsifiers and Detergents' published by Manufacturing Confectioners Company; 'Tenside-Taschenbuch', H. Stache, 2nd Edn., Carl Hauser Verlag, 1981.
The pH of the composition according to the invention preferably ranges from 7 to 12, more preferably from 8 to 11, most preferred from 9 to 11.
The pH of the cleaning and/or polishing composition of the invention may be adjusted with organic or inorganic acids or bases. Preferred inorganic bases are preferably alkali or alkaline earth hydroxides, ammonia, or bicarbonates, the alkali metal preferably being sodium or potassium or the alkaline earth metal preferably being calcium or magnesium. The organic bases are preferably amines, alkanolamines and other suitable amino compounds. Inorganic acids may include hydrochloric acid, sulphuric acid or phosphoric acid, and organic acids may include acetic acid, citric acid or formic acid as well as dicarboxylic acid mixtures such as Radimix (trade mark, Radici Group) and Sokalan DCS (trade mark, BASF).

Other optional ingredients

The compositions may contain other ingredients which aid in their cleaning and/or polishing performance. For example, they may contain detergent builders and mixtures of builders in an amount of up to 25%, in particular when the composition contains one or more anionic surfactants. If present, the builder preferably will form at least 0.1 % of the cleaning composition. Suitable inorganic and organic builders are well known to those skilled in the art.
A further optional ingredient for compositions used according to the invention is a suds regulating material, which can be employed in compositions which have a tendency to produce excessive suds in use. Examples thereof are fatty acids or their salts (soap), isoparaffins, silicone oils and combinations thereof. Soaps are salts of fatty acids and include alkali metal soaps such as the sodium, potassium and ammonium salts of fatty acids containing from about 8 to about 24 carbon atoms, and preferably from about 10 to about 20 carbon atoms. Particularly useful are the sodium and potassium and mono-, di- and triethanolamine salts of the mixtures of fatty acids derived from palm oil, coconut oil and ground nut oil. When employed, the amount of fatty acid or soap can form at least 0.005%, preferably 0.1 % to 2% by weight of the composition.
Where a hydrocarbon solvent is present at a sufficiently high level this may itself provide some or all of the required antifoaming activity.
Compositions may also contain, in addition to the ingredients already mentioned, various other optional ingredients such as colourants, whiteners, optical brighteners, soil suspending agents, detersive enzymes, compatible bleaching agents (particularly peroxide compounds and active chlorine releasing compounds), solvents, co-solvents, gel-control agents, further freeze-thaw stabilisers, bactericides, preservatives (for example 1,2-benzisothiazolin-3-one), hydrotropes and perfumes.

Liquid Dispensers

The composition of the invention may be stored in and dispensed by any suitable means, but spray applicators are particularly preferred. Pump dispensers (whether spray or non-spray pumps) and pouring applicators (bottles etc.) are also possible. Thus, preferably the composition of the invention is comprised in a container, wherein the container comprises a spray dispenser for dispensing the composition in the form of a spray. The spray dispenser is preferably a trigger spray but may be any mechanical means for ejecting the liquid in spray or aerosol form.

Method for cleaning and/or polishing

In a second aspect the present invention provides a method for cleaning and/or polishing of a surface, wherein a composition according to the invention is used. Therefore, the present invention relates to a method for cleaning of a surface, wherein a composition according to the present invention used, the method comprising the steps of:

Applying the composition on the surface,
Rubbing the composition over the surface,
Removing the composition from the surface.

The present invention further relates to a method for polishing of a surface, wherein a composition according to the invention is used, the method comprising the steps of:

Applying the composition onto the surface,
Rubbing the composition over the surface,
Removing the composition from the surface.

The surface to be cleaned and/or polished can be surfaces as present in household cleaning, like baths, tables, kitchen desks, windows. The composition can be a household cleaning and/or polishing composition. These materials can comprise for example Perspex, formica, plastic, steel, glass or ceramics. It can be tooth enamel, e.g. in case the composition is a tooth paste. The surface is normaly a hard surface. The surface preferably has a nanoindentation hardness of from 0.2 GPa to 2 GPa.
The composition can be applied onto the surface using a spray dispenser, but can alternatively be poured on the surface direct from the container.
The invention further relates to the use of coated particles in the form of platelets for polishing a surface. The use is preferably in a liquid, preferably an aqueous composition, preferably comprising surfactant. Scratches become less visible and the gloss of a damaged hard surface is at least to some extend restored.
The methods of the invention can be employed by the person skilled in the art. The result of the method is that a hard surface is easily cleaned without damage to the surface. It was surprisingly found that in addition to cleaning, the surface is also polished, as facilitated by the composition of the invention. Preferably, the composition is sprayed onto the surface using a spray dispenser. The surface is preferably polished by the composition of the invention.

DESCRIPTION OF FIGURES

Figure 1 : Scanning electron microscopy image (scale bar width is 100 micrometer) of TiO₂-coated Mica platelet particles.

EXAMPLES

The following non-limiting examples illustrate the present invention.

Methods

Cleaning test

23 g of liquid abrasive cleaner and polishing mix (as described in Table 2) is placed on a pre-soiled stainless steel tile of known weight.
The soil is prepared from castor oil, applied to a stainless steel tile and baked in an oven at 180°C for 35 minutes.
A 'WIRA' (is the Wool Institute Research Association scrubbing machine that moves a cloth in a motion that describes lissajous figures, in a regular, but nonlinear motion) is used to clean in a regular pattern for a set number of lissajous (1, 3 or 5 lissajous in this analysis, with 1 lissajous = 16 cycles), with a 992 g head weight.
The liquid abrasive cleaner and polishing mix is then washed off the tile, which is then allowed to dry.
The tile is re-weighed and the percentage soil removal calculated.
3 replicates for each product.

Damage test

5 g of liquid abrasive cleaner and polishing mix (as described in Table 2) is placed on a damp cloth ('Ballerina', ex Unilever) (80 cm²) and mounted on a linear scrubbing device (Erichsen).
The cloth is moved in a linear motion 40 times over a clean Perspex surface (Perspex = polymethyl methacrylate - PMMA).
Three different head weights ('low', 'medium', 'high') are used in this analysis, respectively, to assess the different levels of damage cause by increased pressure. 'Low': no addition weight is added to the scrubbing head. 'Medium' 836 g weight added to scrubbing head. 'Heavy': a second weight is added to the scrubbing head giving a total additional weight of 1,327 g. The maximum pressure to be used is 80 g.cm^-2, The following pressure ranges are employed, respectively for the heads: 5-20 g.cm^-2, 15-50 g.cm^-2, and 25-80 g.cm^-2.
The Perspex is measured over 7 points with a gloss meter before and after scrubbing to assess the loss of gloss to the surface. These measurements are carried out at 20° and 60° (reflectance angles at which the gloss is measured) and presented as a percentage loss of gloss. An angle of 20° is most relevant for a shiny surface.
Loss of gloss is calculated from: $% Loss of Gloss = (\frac{G_{(Undamaged)} - G_{(Damaged)}}{G_{(Undamaged)}}) \times 100$

Abrasive test

The pre-screening of raw materials for abrasion is done with an abrasion testing machine (Abrasion Tester AT2010, Leaderpower, China), and the number of revolutions is set at 87,000.
Pre-treatment of screen: Prepare 250 ml 0.5 wt% Alconox solution (Concentrated, anionic detergent, ex Alconox (White Plains, NY, USA), in sonic bath for 1 minute. Then put copper screen in the solution and sonicate for 5 minutes. Rinse the screen under hot running tap water for 3 minutes, holding with tweezer. Put the screen in distilled water and sonicate for 5 minutes, and 3 minutes more in distilled water. Heat
the screen at 105°C for 20 minutes and cool down in a desiccator. Weigh the screen on
a balance with at least 4 significant figures and record the data as W _before.
The copper screen is put at the bottom of fully dispersed raw material slurry (10.0 g of material in 90.0 g of water) and rubbed with PVC tube. After the testing, rinse the screen under hot running water until visible debris is removed. Then wash it with distilled water in sonic bath for 2 minutes, and 2 more minutes with running distilled water. At last, heat it at 105°C for 20 minutes and cool down in a desiccator. Re-weigh the screen and record the data as W _after .
The abrasion value is calculated by. $abrasion [mg loss / 100, 000 revolutions] = \frac{100, 000}{87, 000} \times (W_{before} - W_{after})$

Materials

Table 1 Properties and suppliers of coated mica and calcium carbonate materials

Candurin Silver Lustre particle size (platelet) 10 - 60 micron length and breadth, 0.5 - 3 micron thick, Food Grade, Merck

RonaFlair Mica M particle size (platelet) <15 micron (uncoated mica, comparative example), Merck

RonaFlair SynMicaM particle size (platelet) 1 - 40 micron, (Uncoated Mica, comparative example) Merck

RonaFlair Silk Mica particle size (platelet) < 50 micron (Uncoated Mica, comparative example), Merck

CaCO₃Omyacarb 30 AV particle size (blocky) 1 - 30 micron (chalk, comparative example), Omya

Table 2 Standard composition of liquid abrasive cleaner

Ingredient	Tradename	Supplier	concentration [wt%]
PREMIX
Demineralised water 50°C		In house	12.775
LAS Acid (linear alkylbenzene sulfonic acid)			4.91
Caustic soda			0.70
Tallow-based oleic acid	Priolene 6907	Croda	0.348
Hydrophobically modified Alkali Soluble acrylic polymer Emulsion	Acusol 820	Rohm Haas	0.030

MAIN MIX
Demineralised water 50°C			to 100%
Silicone antifoam	Silicone DB-310	Dow Corning	0.006
Preservative (1,2-benzisothiazolin-3-one)	Proxel GXL	Zeneca	0.016
Sodium carbonate			3.0
Calcium carbonate abrasive (various combinations tested, see Table 3)			Variable, see table 3
Coated Mica (various combinations tested, see Table 3)			Variable, see table 3
Titanium dioxide		Kemira	0.007
Surfactant	Lialet 125-5	Sasol	1.875
Perfume		Firmenich	0.330
Butyl digol		Dow	1.0
Premix		made in house	19.675

First the premix is made, involving reacting LAS Acid with caustic soda to produce anionic surfactant. The premix is mixed with the other ingredients of the main mix.

Example 1: Testing Coated Mica

The following compositions of liquid abrasive cleaners containing coated mica abrasive were tested in the formulations as disclosed in Table 2. The cleaning and damage results are given in the following table. Some samples on 1, 3, or 5 lissajous tested

Table 3 Combinations of mica and calcium carbonate abrasives used in the composition of Table 2, results on cleaning (1, 3, or 5 Polishing Cycles, and Loss of Gloss (Damage after polishing 5 lissajous)

Formulation		%wt (comp. Example)	%wt	%wt	%wt
Silver Lustre %wt		0	10	15	20
Omycarb 30 AV (CaCO3), %wt		20	10	5	0
Cleaning test	1	12	7	7	6
Soil removal after X polishing lissajous cycles (%)	1	12	7	7	6
	3	22	19	14	9
	5	38	38	30	24
Damage test		25	2	∼0	∼0
Loss of Gloss at 20° angle. After 5 polishing lissajous cycles

These results show that using the coated mica according to the invention shows much less damage than the standard calcium carbonate of the prior art with acceptable cleaning, up to a level which is comparable to that observed for conventional chalk formulations. Table 4. Recovery Capability of coated mica compared to pristine (uncoated) mica

Formulation %wt (comparative example) %wt

Silver Lustre %wt 0 20

Pristine Mica (Uncoated) 20 0

Recovery % 30 93
The coated mica demonstrates superior recovery data over non-coated mica, indicating a polishing effect, i.e. a surface restoration by removal of the damage. The applicants are not aware that such an effect has ever been described in the art for a surface cleaning product.

Example 2

Coated SiO₂ was tested for its polishing behaviour on a Perspex surface.
In order to assess the polishing power of test slurry, optically-flat black Perspex (PMMA) sheet was employed. First a scratched Perspex surface was created by rubbing with a standard fine ground natural chalk formulation for 1 min in one direction ('damaged'). This FGNC formulation comprises 20% calcium carbonate on water as scratching ingredient. This was rinsed with tap water.
A test slurry (20 wt % test ingredient in water) was then applied onto the surface. A cloth was then used to scrub in a perpendicular direction to damaged procedure (as 'polished'). The surface was further cleaned with demineralised water. The gloss value was measured at 20° using a Gloss meter (Multi Gloss 268plus, Konica Minolta, Germany) before scratching, after scratching and after polishing.
The recovery was calculated using: $% Recovery = (\frac{G_{(polished)} - G_{(damaged)}}{G_{(undamaged)} - G_{(damaged)}}) \times 100$
Coated SiO₂ platelets, Xirona Nordic Sunset and Xirona Indian Summer, from Merck, where used, coated with TiO₂ and Fe₂O₃ respectively and a hardness of the SiO₂ of about 5.5 Moh and a size of 5-60 micrometer.
The resulting Recovery was for both compounds 59%. Silver Fine (coated mica) was used as a comparison and resulted in 70% recovery. Both coated SiO2 compounds qualified as excellent polishing materials. The platelet-like shapes cause less damage to Perspex and make the particles slide well on Perspex surface without slippery movement. Furthermore, the coating layers (TiO2 or Fe2O3) increase the Mohs hardness of the mica platelets which also contribute to the improvement of polishing effect, without damaging effects. Also good results are obtained if the polishing composition comprises surfactant. Without willing to be bound to theory, polishing is less chemically based but rather mechanically based.

Claims

A composition for cleaning and polishing surfaces, comprising surfactant, and coated particles in the form of platelets, wherein the composition is liquid at room temperature, the composition further comprising calcium carbonate.
A composition according to claim 1, wherein the composition further comprises water.
A composition according to any of the preceding claims, wherein the concentration of the particulates ranges from 0.2 to 40 wt%, preferably of 1 to 40 wt%, preferably from 2 to 30 wt%, preferably of from 5 to 30 wt%, based on the total weight of the composition.
A composition according to claim 1, wherein the particles have a length ranging from 2 to 200 micrometer, preferably from 10 to 60 micrometer.
A composition according to any of the preceding claims, wherein particles have a depth ranging from 0.5 to 3 micrometer, preferably from 0.75 to 1.5 micrometer.
A composition according to any of the preceding claims, wherein the particles have a hardness of between 2 and 7 Moh.
A composition according to any of the preceding claims, wherein the particles comprise coated mica particles, coated SiO2 particles, coated clay particles or mixtures thereof.
A composition according to any of the preceding claims, wherein the coated particles are particles coated with metal oxide.
Composition according to claim 1, further comprising water, wherein
the particles have a length (longest dimension of the particle) ranging from 2 to 200 micrometer if they are clay particles and from 5 to 60 micrometer if they are not clay particles, and
wherein the particles have a depth (shortest dimension of the particle, perpendicular to the length and breadth) ranging from 0.5 to 3 micrometer, preferably from 0.75 to 1.5 micrometer, and
wherein the particles have a hardness of between 2 and 7 Moh, preferably between 2 and 5 Moh, and
wherein the particles comprise coated mica particles, coated clay particles, coated SiO2 particles or mixtures thereof and
wherein the coated particles are particles coated with metal oxide, and wherein
the concentration of the particulates ranges from 0.2 to 40 wt%, based on the total weight of the composition.
A method for cleaning of a surface, wherein a composition according to any one of claims 1 to 9 is used, the method comprising the steps of:
• Applying the composition on the surface,

• Rubbing the composition over the surface,

• Removing the composition from the surface.
A method for polishing of a surface, wherein a composition according to any one of claims 1 to 9 is used, the method comprising the steps of:
• Applying the composition onto the surface,

• Rubbing the composition over the surface,

• Removing the composition from the surface.
A method according to claim 10 or 11, wherein the surface has a nano indentation hardness of between 0.2 and 2 GPa.
A method according to any of claims 10 to 12, wherein the composition is applied onto the surface using a spray dispenser.