EP1194515A1

EP1194515A1 - Hard surface cleaning composition comprising a uva-filter

Info

Publication number: EP1194515A1
Application number: EP00943940A
Authority: EP
Inventors: Scott Unilever Research Colworth Singleton; Patricia Unilever Research Port Sunlight REVELL
Original assignee: Unilever NV
Current assignee: Unilever NV
Priority date: 1999-07-12
Filing date: 2000-06-29
Publication date: 2002-04-10
Also published as: AU5822000A; AR024708A1; WO2001004251A1; HUP0202360A2

Abstract

The invention concerns hard surface cleaning compositions comprising a UVA filter and a surfactant. The compositions leave sufficient UV-absorber on the surface after cleaning to provide extended protection of the surface against the damaging effect of UV light. The compositions comprise: 0.1-50 wt% of a surfactant, 0.01-5 wt % of a UV absorbing agent with the proviso that the compositions do not contain fluoroaliphatic surfactants. Preferably the compositions also contain a polymer, particularly an anionic polymer, and/or a glycol ether or alkanol solvent.

Description

HARD SURFACE CLEANING COMPOSITION COMPRISING A UVA-FILTER

Field of the Invention

The present invention relates to hard surface cleaning compositions which contain a UV absorbing agent.

Background to the Invention

Many household fittings, fixtures and furnishings suffer from the harmful effects of the sun's rays, leading to physical changes of the surface. Such changes include colour change, gloss change and embrittlement of coatings. Thus, sun light can lead to discoloration of furniture (leather and wooden) and wooden floors and discoloration and degradation of painted surfaces. Discoloration can occur in various forms: it can occur as colour fading of coloured objects, it can occur as yellowing of white objects and it can occur as darkening of light coloured objects, particularly wood. It is believed that a significant part of this damage is caused by the UV components of the sunlight. The same problems are encountered in office and institutional environments.

It is known to protect textiles from UV radiation by treating them with a UV absorbing agent. For example, EP697481 (CIBA-GEIGY, 1995) concerns textile treatment with a composition comprising a UV absorbing compound (UV filter), emulsifying agent, water and polysiloxane (i.e. silicone) in an otherwise aqueous textile treatment composition which comprises: a) a non-reactive UV filter b) an emulsifying or dispersing agent for the UV filter c) water d) optionally, a polysiloxane based product.

A similar teaching is provided by WO 97/44422 (Unilever, 1997) and the literature cited therein. It is to be expected that a fabric will be easy to treat with UV filter compounds due to its tendency to adsorb liquids.

US 5,767,054 describes surface disinfection and cleaning compositions comprising as essential ingredients a biocidal agent, a solvent and a perfluoroalkanoic acid tenside. These compositions are intended for medical instruments and surfaces. They may also contain a UV filter, especially when the compositions are used to clean sensitive synthetic leather. The fluoroaliphatic tenside is said to leave a thin film on the cleaned surface. However, such tensides are expensive and not suitable for normal "household use" hard surface cleaning compositions.

Normal hard surface cleaning compositions, comprising the usual anionic and/or nonionic detergent surfactants, are not normally expected to leave a useful protective layer of any kind on a cleaned surface due to the tendency of these compositions to remove an agent from the surface rather than to deposit it.

It is generally believed that the most important component of UV radiation responsible for discoloration and degradation problems is the UVB range (280-320nm) , due to the high energy content of this UV range compared to the UVA range (320-400nm) . Many UV filter compounds known in the art absorb in the UVA as well as in the UVB range. Nevertheless, depending on the chemical structure, some filter compounds absorb more in the UVA than in the UVB range (UVA filters), whereas others do the reverse (UVB filters) . Based on this belief UVB filters would be expected to give better protection against sunlight than UVA filters.

Brief Description of the Invention

Contrary to popular belief it has been found that UV filter compounds which absorb more light in the UVA than in the UVB range (UVA filters) are better suited for protection of many hard surfaces against the deleterious effects of sunlight than UV filter compounds which have most of their absorbtion in the UVB range (UVB filters) . This holds particularly for indoor surfaces.

It has also been found that the deleterious effects of sun light on hard surfaces can be overcome, or at least greatly diminished, by treating these surfaces with a cleaning composition comprising a UVA filter. It has been found that the use of such a composition does leave sufficient UV- absorber on the surface being cleaned to reduce the damaging effect of UV light illuminating the said surface.

Accordingly, a first aspect of the present invention relates to a hard-surface cleaning composition comprising:

a) 0.1-50% of a surfactant b) 0.01-5wt% of a UVA filter with the proviso that the composition does not contain fluoroaliphatic surfactants.

(All percentages mentioned herein are by weight of the total composition, unless indicated otherwise.) A second aspect of the present invention relates to a method of reducing UV damage to hard surfaces which comprises the step of treating the surface with a cleaning composition as described above.

Detailed Description of the Invention

For the purposes of this invention UVA filters are defined as set out below:

The absorbtion spectra of UV filter compounds were measured over the entire UVA and UVB ranges. By calculating the integrated area covered by the absorbtion spectrum over the UVA range (320-400nm) and the UVB range (280-320nm) respectively, the percentage of absorbance in the UVA range can be calculated using the formula:

Spectral area UVA x 100% = relative UVA absorbance Spectral area (UVA+UVB)

(Absorbtion spectra were determined as described herein below)

UVA filters are defined as UV filter compounds for which the relative UVA absorbance is at least 50%.

Suitable compounds are among the benzotriazol derivatives e.g. those marketed by Ciba-Geigy as "Tinuvin" such as: Tinuvin 328 (2- (2H-benzotriazol-2-yl) -4 , 6-ditert . pentyl- phenol, having a relative UVA absorbance of 59%), Tinuvin 234 (2- (2H-benzotriazol-2-yl) -4 , 6-bis ( 1-methyl-l- phenylethyl) phenol) and Tinuvin 327 (2, 4-ditert . utyl-6- (5- chlorobenzotriazol-2-yl) phenol) and those marketed by 3V as Uvasorb such as: Uvasorb SV (2- (2H-benzotriazol-2-yl) -4- methylphenol) and Uvasorb S26 (2- ( 3 ' -tert-butyl-2 ' -hydroxy- 5 ' -methylphenyl) -5-chlorobenzotriazole) . Another suitable compound is Uvinul D50 TM (bis (2 , 4-dιhydroxy-phenyl) methanone, having a relative UVA absorbance of 66%) marketed by BASF. The benzotriazol derivatives are particularly effective and Tinuvin 328 is especially preferred because of its stability.

Many laundry detergent compositions comprise so called optical whiteners or brighteners, i.e. fluorescent compounds which absorb UV light and re-emit part of this as visible, particularly blue light. Such compounds have no use in the hard surface cleaning compositions of the present invention and are therefore not comprised in the term ^λUV filter' .

Suitable levels of UV filters are from 0.01%wt upwards, preferably at least 0.05%, more preferably at least 0.08%. Higher amounts than 2%wt rarely serve a useful purpose and the amounts are preferably at most 1%, more preferably at most 0.5%.

Advantageously, the compositions of the invention are liquid, more preferably aqueous liquids and are preferably not macroscopic emulsions.

While the pH of the composition can fall in the range 1.0- 12, it is preferable that the pH of the composition is not below 2.0, more preferably not below 3.0. Above pH 8.5 the benefit of some UV filters falls off while other UV filters may succesfully be used up to pH 12. Below pH 3.0 damage to some hard surfaces may occur, especially to enamel surfaces. The preferred pH is from around 3.0 to 11 for compositions according to the present invention, more preferred 3.5-10. A base such as sodium hydroxide sodium carbonate, ammonia or an alkanolamine and/or an acid such as citric acid or other di/tricarboxylic acids are generally used to bring the pH to the desired level.

Surfactants :

It is essential that the compositions of the present invention comprise at least one detergent surfactant. Such surfactants may be chosen from a wide range of anionic, nonionic, cationic, amphoteric or zwitterionic surfactants well known in the art. Preferably the overall level of surfactant in the compositions of the invention is 0.1-

30%wt, more preferably 0.5-20%wt, most preferably 0.5-10%wt.

Preferably the compositions according to the invention comprise at least a nonionic surfactant in an amount of 20% by weight or more, more preferably 30% or more, of the total amount of surfactant in the composition.

Suitable anionic surfactants are e.g. water-soluble salts, particularly alkali metal, alkaline earth metal and ammonium salts, of organic sulphate esters and sulphonic acids having in the molecular structure a C8-C22 alkyl radical or a C10-

C24 alkaryl radical.

Examples of such anionic surfactants are water soluble salts of: - long chain (i.e. 8-22 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; alkyl benzene sulphonates, such as those in which the alkyl group contains from 6 to 18 carbon atoms; secondary alkanesulphonates . Also suitable are salts of: - alkyl glyceryl ether sulphates, especially those ethers of the fatty alcohols derived from tallow and coconut oil; fatty acid monoglyceride sulphates; sulphates of the reaction product of one mole of a fatty alcohol and from 1 to 6 moles of ethylene oxide; salts of 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.

As mentioned above, nonionic surfactants are very useful surfactants for use in the compositions according to the examples. They are preferably used in an amount of 0.1-

15%wt, more preferably 0.1-10%, most preferably 0.2-8.0%.

Many nonionic surfactants can be broadly described as compounds produced by the condensation of alkylene oxide groups which are hydrophilic in nature, with an organic hydrophobic compound which may be aliphatic or alkylaromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is attached to any particular hydrophobic group can be readily adjusted to yield a water-soluble or water dispersible compound having the desired balance between hydrophilic and hydrophobic elements.

Particular examples include: the condensation products of straight or branched chain aliphatic alcohols having 8-22 C-atoms with ethylene oxide, having 2-15 moles of ethylene oxide per mole of alcohol; condensates of alkylphenols, whose alkyl group have 6-16 C- atoms, with 2-25 moles of ethylene oxide per mole of alkylphenol; condensates of ethylene oxide with the reaction product of ethylenediamine and propylene oxide, the condensates containing 40-80% of ethylenoxy groups by weight and having a molecular weight of from 5,000 to 11,000.

Other examples of nonionic surfactants are: tertiary amine oxides of general structure RRRNO, where one R is a C8-C22 alkyl group (preferably C8-C18) and the other Rs are each C1-C5 (preferably C1-C3) alkyl or hydroxyalkyl groups, for instance dimethyldodecylamine oxide; tertiary phosphine oxides of structure RRRP0, where one R is a C8-C22 alkyl group (preferably C8-C18) and the other Rs are each C1-C5 (preferably C1-C3) alkyl or hydroxyalkyl groups, for instance dimethyl-dodecylphosphine oxide; dialkyl sulphoxides of structure RRS0 where one R is a C10-

C18 alkyl group and the other is methyl or ethyl, for instance methyltetradecyl sulphoxide; fatty acid alkylolamides; alkylene oxide condensates of fatty acid alkylolamides; alkyl mercaptans; alkyl polyglycosides .

Of these, alkoxylated alcohols, more particularly ethoxylated alcohols are most preferred as surfactants.

Cationic surfactants can be included in the compositions of the invention. Typically the cationic surfactants are quaternary ammonium salts of the general formula RιR₂R₃RN⁺X^", wherein all of the radicals are hydrocarbons with or without hydroxy substitution, at least one of the radicals R1-R4 is a C6-C22 alkyl, alkaryl or hydroxyalkyl, at least one of the radicals R1-R4 is a C1-C4 alkyl or hydroxy alkyl and X is a monovalent anion equivalent. Preferred are the quaternary nitrogen compounds wherein Rl and R2 are the same or different C1-C4 alkyl or hydroxy alkyl, R3 is a C6-C22 alkyl, alkaryl or hydroxyalkyl, R4 is a C1-C22 alkyl, alkaryl or hydroxyalkyl and X is a monovalent anion equivalent. Preferably X is a halogen, most preferably chloride or bromide. Preferably Rl and R2 are methyl. In embodiments of the invention R3 is preferably C8-C18 alkyl, more preferably C10-C16 alkyl, and R4 is preferably methyl, C8-C18 alkyl or benzyl. Thus, the cationic surfactants used can have three 'short chain' radicals such as methyl and one fatty-soluble 'long chain' radical or two 'short' chains and two fatty- soluble 'long chains', wherein the 'long chains' can be either linear or branched hydrocarbons or contain aromatic rings .

If present, typical levels of cationic surfactant are in the range of 0.05-5%wt on product. Preferred levels of cationic surfactant are around 0.2-3%wt.

The compositions can further comprise one or more amphoteric surfactants, preferably betaines, or other surfactants such as amine-oxide and alkyl-amino-glycinates . Betaines are preferred for reasons of cost, low toxicity and wide availability. Polymers :

Optionally, the compositions according to present invention comprise a water soluble polymer. Such polymers may be included for obtaining antiresoiling benefits on the surfaces treated with the compositions. Also, such polymers help in retaining the UV filter on the surface.

The polymers may be cationic, nonionic or anionic. Anionic polymers are particularly preferred, especially those having an average molecular weight of less than 1,000,000 since it is believed that as the molecular weight increases above this limit the cleaning benefit of the polymer is reduced Typically, these anionic polymers are polymers bearing carboxylate functional groups, although the use of other anionic polymers is possible. In the context of the present invention, anionic polymers are those which under proper pH conditions are capable of carrying a negative charge. Mixtures of polymers can be employed. Particularly useful are polymers of acrylic or methacrylic acid or maleic anhydride, or co-polymers of one or more of these, either together or with other monomers such as ethylene, styrene or methyl vinyl ether. Such polymers are readily available in the market place .

Preferably, the average molecular weight of the polymer is at least 5000, more preferably at least 50,000 and most preferably in excess of 100,000. VERSICOL E-ll ™ (ex. Allied Colloids) which is a polyacrylic acid, has been found to be a suitable polymer for use in compositions according to the invention.

If present, the cleaning compositions preferably comprise at least 0.01% polymer. The positive benefit of the presence of polymer as regards the improvement in cleaning properties can be identified even when very low levels of polymer and surfactant are present. This property of a low concentration threshold is particularly advantageous in applications of the invention where considerable dilution is expected, such as in floor cleaning. More preferably the level of polymer is at least 0.05% at which level the anti-resoiling benefits become particularly significant. Even more preferably at least 0.1% of polymer is present, most preferably at least 0.2%. Higher levels of polymer than 3% or even 2% do not give significant further cleaning advantages taking common dilution factors into account, while increasing the cost of compositions. However, for very concentrated products which are strongly diluted prior to use, the initial polymer level can be as high as 5%.

If the compositions according to the invention do contain an anionic polymer then anionic surfactants are preferably only present in relatively small amounts i.e. below 2% of the composition, preferably below 1%. Most preferably anionic surfactants are then absent from the composition. As described in further detail below some amount of fatty acid soap may still be present as an antifoam.

Solvents :

One or more organic solvents may be present in the compositions of the invention. The presence of solvents is often beneficial. Suitable solvents include aliphatic alcohols and glycol ethers as set out below. The compositions of the present invention may comprise glycol ether or alkanol solvents of the general formula:

Rl-0-(E0)_ra-(PO)_n-R2,

wherein Rl and R2 are independently C1-C6 alkyl or H, but not both hydrogen, m and n are independently 0-5, E stands for an ethylene group and P stands for a propylene group. Preferably one of Rl and R2 is H.

The alcohol solvents are selected from the C1-C6 branched or straight chain alkanols, more preferably one or more of methanol, ethanol, propanols or butanols. Ethanol and iso-propanol are particularly preferred.

Preferably, the solvent or solvent mixture comprises at least one glycol ether selected from the group comprising diethylene glycol mono-butyl ether (such as available in the marketplace as Butyl Digol™) , ethylene glycol mono-butyl ether and propylene glycol mono-butyl ether.

The total level of such solvents in the detergent compositions according to the invention is preferably at most 25%, more preferably 20% or less, most preferably 10% or less. On the other hand the compositions preferably contain at least 0.5%wt of these solvents, more preferably at least 1.0% and most preferably 2% or more.

Antimicrobials :

Optionally antimicrobial agents can be used in the compositions of the present invention. Useful antimicrobials are the quaternary ammonium compounds mentioned above and/or phenolic compounds.

Typical levels of antimicrobial agent in compositions according to the invention range from 0.01 to 8%wt, with levels of 0.05-4wt%, particularly around 2% being preferred for normal compositions and up to two or four times that concentration being present in so called, 'concentrated' products. Normal concentration products may often be used neat and concentrated products will normally be diluted by the user before use. For sprayable products, which are seldom diluted prior to use, the concentration of the antimicrobial agent preferably is in the range 0.05-0.5%wt.

In general, whatever the strength of the product the ratio of surfactant to the antimicrobial agent will preferably be in the range 50:1 to >1:1, more preferably 30:1 to >1:1 i.e. an excess of surfactant will be present relative to the antimicrobial .

Where antimicrobial agents are not present at a significant level it is advantageous that the compositions comprise a preservative. A suitable preservative is PROXEL LV™ or FORMOL™.

The compositions of the invention may comprise further components which are desirably deposited upon a surface. One class of such additional components is insect repellent materials. Suitable insect repellents include 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. The level of insect repellent required will vary with the nature of the material used. For essential oils and terpenoids, preferred levels are 0.1-5% on product .

The compositions according to the invention can contain other minor ingredients which are not essential, but aid in their cleaning performance and in maintaining the stability of the product .

Hydrotropes, are useful optional components. The use of hydrotropes enables the cloud point of the compositions to be raised without requiring the addition of anionic surfactants. Suitable hydrotropes include, alkali metal toluene sulphonates, alkali metal xylene and cumene sulphonates, alkalimetal short chain aliphatic sulphonates, urea, polyglycols, >20EO ethoxylated alcohols, short chain, preferably C2-C5 alcohols and glycols. Preferred amongst these hydrotropes are the sulphonates, particularly the cumene, xylene and toluene sulphonates. For the purposes of this invention the aromatic sulphonate hydrotropes are not considered anionics surfactants.

Typical levels of hydrotrope range from 0-5% for the sulphonates. Correspondingly higher levels of urea and alcohols are required. Hydrotropes are not always required for normal concentration, such as sprayable products, but may be useful if lower EO or longer alkyl ethoxylates are used or the cloud point needs to be raised considerably. Typically, the cloud point of the final composition should preferably be 15

in the range 45-50°C. The sodium cumene sulphonate (SCS) is the most preferred hydrotrope.

A further optional ingredient for compositions according to the invention may be a suds regulating material, which can be employed in compositions according to the invention which have a tendency to produce excessive suds in use. One example of a suds regulating material is soap. Soaps are salts of fatty acids and include alkali metal soaps such as the sodium, potassium, ammonium and alkanol-ammonium salts of C8- C24 fatty acids, and preferably C10-C20. Particularly useful are the sodium and potassium and mono-, di- and tri- ethanolamine salts of the mixtures of fatty acids derived from well known vegetable oils. When employed, the amount of soap generally is at least 0.005%, preferably 0.5% - 2% by weight of the composition.

Further examples of suds regulating materials are organic solvents, hydrophobic silicas, silicone oils, hydrocarbons, and mixed EO/PO nonionic surfactants.

Bleaching compounds generally serve no useful purpose in cleaning compositions of the present invention and will therefore normally be absent.

Although solid hard surface cleaning compositions, such as dry powders or tablets, are known in the art, the compositions according to the invention are preferably liquid, more specifically aqueous solutions of the active ingredients. They may be concentrated, such as to be diluted by the consumer before use. They may also be more diluted ("normal" concentration) which are also suitable for direct application on the surface. In the latter case the total amount of surfactant in the composition is preferably at most 8%, more preferably at most 7%. Such compositions are very suitable for delivery to the surface as a spray or foam using a suitable dispensing system such as a trigger spray head or other devices known in the art.

The compositions according to the invention are intended for cleaning hard surfaces and therefore the invention also provides a process for cleaning hard surfaces and at simultaneously protecting it against UVA induced damage comprising applying to the surface a cleaning composition as described above, either as a dilute aqueous solution or neat. The compositions are especially suitable for treating wooden or painted surfaces.

Preferred Composition:

Preferred compositions according to the present invention have a pH of 3-10 and comprise:

A a) 1.0-10%wt (preferably 1.0-8%) of 2-15EO ethoxylated C8 C18 alcohol nonionic surfactant, b) 0.1-4%wt of a water soluble, anionic polymer having an average molecular weight less than 1,000,000, said polymer being a (co) polymer of at least one of acrylic acid, methacrylic acid or maleic anhydride, with at least one of acrylic acid, methacrylic acid, maleic anhydride, ethylene, styrene and methyl vinyl ether, c) 0.01-l%wt of a UVA filter d) 0-l%wt of anionic surfactants. B a) 1.0-7.0%wt of 2-15EO ethoxylated C8-C18 alcohol nonionic surfactant, b) 1.0-7.0%wt of alkali metal or ammonium salts of organic sulphate esters and sulphonic acids having in the molecular structure a C8-C22 alkyl radical or a C10-C24 alkaryl radical. c) 0.01-l%wt of a UVA filter d) 1.0-10% of diethylene glycol mono-butyl ether, ethylene glycol mono -butyl ether and propylene glycol mono-butyl ether or mixtures thereof.

Determination of absorbtion spectra

The absorbtion spectra of the UV filter compounds were measured dissolved in 5% aqueous solutions of Imbentin 91-

3.5 TM (C9-11 ethoxylated alcohol nonionic surfactant ethoxylated with 5EO (average) units) against the same solution as reference. Tinuvin 328 and Uvinul M40 were predissolved (2.5%) in diethylene glycol n-butyl ether, which solutions were thereafter dispersed in 5% Imbentin 91- 3.5 solution. The UV filter solutions were diluted with 5% Imbentin 91-3.5 solution to give spectra with maximum absorbances below 2.

The solution spectra were measured on a Perkin Elmer Lambda 40 Bio UV/visible spectrophotometer . 1cm pathlength UV compatible cuvettes were used. The wavelength range scanned was 500nm-250nm. Measurements were made at 20°C.

In order that the present invention may be further understood it will be described hereinafter by way of examples . Examples

EXAMPLE 1

The following hard surface cleaning compositions were prepared:

Formula 1

1) Trademark of Shell

2) Trademark of Condea Dae Formula 2

The UV filters used in the above cleaning compositions were Uvinul D50, Uvinul M40 and Tinuvin 328. Uvinul D50 was dispersed as such in the cleaning compositions. Uvinul M40 was first dissolved in diethylene glycol n-butyl ether (10% wt solution) which solution was thereafter incorporated at 1% in the cleaning composition. Likewise Tinuvin 328 was first dissolved (10% wt) in Isopar L, which solution was used in 1% in the cleaning composition.

Solution Spectra

1:50 dilutions of the cleaning compositions, and the cleaning compositions plus sunscreens were made up in distilled water. The solution spectra were measured as outlined above. The background was corrected for the appropriate dilute cleaning composition, and the reference cuvette contained diluted cleaning composition. The measurements are summarized in the tables 1-3 below:

Table 1

Table 2

EXAMPLE 2

Irradiation of test surfaces

To measure the influence of sun light and discriminate between the influence of the full UV spectrum and only the UVA range of the sun's spectrum test pieces of standard white painted metal, varnished pine and varnished beech were irradiated using using an Atlas Suntest CPS+ with a UV filter, which gives an output spectrum closely resembling that of sunlight, but of higher irradiance. The Suntest was operated at 765Wrrf², with a black standard temperature set at 35°C. Two coats of Ronseal Quick Drying Clear Gloss Varnish were applied to the wooden test pieces

To filter out light below 320 nm (i.e. UVB) test pieces were

TM covered with MYLAR 1000D film (Du Pont de Nemours) .

The colour of the samples before and after exposure was measured using a Dr Lange Colour Meter, using the CIELab colour space, L*a*b*. L* measures light-dark. The larger L*, the lighter, so a negative dL* signifies darkening. a* measures red-green, positive a* are red, negative are green. For all the woods tested, a* was positive, so a positive da* indicates increased redness. b* measures blue-yellow, positive b* are yellow, negative are blue. For all woods tested, b* was positive, so a positive db* indicates an increase in yellowness.

Templates were used to ensure that the same area was measured before and after exposure. Comparative tests were always done on the same pieces of wood as the UV filter tests to exclude as much as possible the natural variation in wood properties.

The results are given in table 3 below. Values quoted are colour differences between the initial and the final measurement.

Table 3

It appeared that pine and beech woods give rapid responses, in terms of colour change, in simulated sunlight, and therefore can act as a rapid test of sunscreen efficacy.

To measure the influence of the UVA versus UVB filters in cleaning compositions on the discoloration of wood, test pieces were treated with cleaning composition 1 containing either Tinuvin 328, Uvinul D50 or Uvinul M40. According to the definition given herein the former two are UVA filters and the latter is a UVB filter.

Small volumes (50uL) of cleaning formulation 1 with and without UV filters were pipetted onto the wooden surfaces, and then spread using the edge of a glass microscope slide, that had been coated with non-porous Scotch Pressure Sensitive Tape. The treated wood was then left to dry before testing. After testing any product residues are removed by rinsing in water, and then drying. Irradiations were carried out as described above except that the irradiated surface (the whole test piece) area was 1.25x10-3 m2. The exposure time was 3 hours. In comparing the data those of UV protected samples should only be compared with the corresponding blank. For these tests Tinuvin 328 was added to the cleaning composition as a 10% solution in dipropylene glycol n-butyl ether.

The results for 0.5% and 0.1% UV filter in the cleaning composition (cleaner) are given in the tables 4-7 below

Table 4

Table 5

Table 6

Table 7

Comparing differences between untreated and treated wood, the differences are bigger for Tinuvin 328 than for Uvinul M40 in the majority of cases, both with and without Mylar film. Uvinul D50 also shows benefits over Uvinul M40, because of its greater absorbance in UVA. The MYLAR film largely filters out UVB, like window glass and therefore the results on the pieces covered with MYLAR film are representative of in-house use.

EXAMPLE 3

A cleaning composition was prepared according to the formula of table 8 below. The influence of a UVA filter (Tinuvin

328) in this composition on the colour change of varnished beech wood was measured using a simulated "spray and wipe" regime .

Table 8

1) Trademark of Condea Dae

2) Trademark of BASF Cleaning compositions with 0.1% Tinuvin 328 and without UV filter were tested on test pieces in comparison with

2 untreated test pieces. To this end a 432cm test surface containing removable test pieces was cleaned by pipetting 0.44ml cleaning product on the test surface, which was thereafter wiped with a dishcloth dampened with 25 ml hot tap water.

The samples were exposed in an Heraeus Suntest CPS+ at

— 0

250Wm with a black standard temperature of 35°C to minimise effects due to heating. This is equivalent to a 4 times acceleration factor compared to outdoor exposure in Central Europe. A Mylar D1000 film filter was used to exclude the UV-B portion of light from the substrates, thus simulating indoors, behind glass exposure. The Suntest was operated on a 24-hour cycle, with 16 hours of radiation, followed by 8 hours of darkness. Table 9 shows the matrix of samples and treatments examined in this experiment.

Table 9: Systems Investigated

Results

Tables 10 and 11 list the changes in yellowness and redness of the samples after 22 days exposure. Table 10: Change in yellowness

Daily application of 0.1% Tinuvin 328 via a "spray and wipe" regime gave a 34% reduction in yellowing of varnished beech compared to an untreated control sample after 22 days of exposure to simulated sunlight.

Table 11: Change in Redness

Daily application of 0.1% Tinuvin 328 via a "spray and wipe" regime gave a 19% reduction in reddening of varnished beech compared to an untreated control sample after 22 days of exposure to simulated sunlight.

Conclusions

0.1% Tinuvin 328, when incorporated into a cleaning formulation, can give a detectable reduction in photo induced colour change of varnished beech wood when used under realistic application conditions.

Claims

1. A hard surface cleaning composition comprising: a) 0.1-50%wt surfactant, b) 0.01-5%wt of a UVA-filter compound with the proviso that the composition does not contain fluoroaliphatic surfactants.

2. Compositions according to claim 1 which are aqueous liquids

3. Composition according to claim 1 wherein the amount of surfactant is 0.5-20%.

4. Composition according to claims 1-3 wherein the surfactant comprises a nonionic surfactant in an amount of at least 20% of the total amount of surfactant in the composition.

5. Composition according to claim 1 which further comprise a water soluble polymer.

6. Composition according to claim 5 wherein the polymer is an anionic polymer having a molecular weight of less than 1,000,000.

7. Composition according to claim 5 or 6 wherein the amount of polymer is 0.01-5%.

8. Composition according to claim 1 which further comprises a glycol ether or alkanol solvent of the general formula:

Rl-0-(E0)_m-(PO)_n-R2,

wherein Rl and R2 are independently C1-C6 alkyl or H, but not both hydrogen, m and n are independently 0-5, E stands for an ethylene group and P stands for a propylene group, in an amount of 25% or less.

9. A process for cleaning hard surfaces and simultaneously protecting them against UVA induced damage comprising applying to the surface either neat or as an aqueous solution a cleaning composition according to any one of claims 1-8.