The present invention relates to a cleaning composition comprising an optical brightener and a bleach. Optical brighteners are common ingredients in fabric / laundry washing or cleaning agents. They are used to prevent /disguise discoloration of items being cleaned. This discoloration is commonly exhibited as a yellowing / greying of the item being cleaned and is particularly prevalent in light /white coloured items.

Optical brighteners operate by acting as a radiation absorber / emitter. Natural day light is adsorbed and then emitted with a blueish hue. This emitted light aids the overcoming of the discoloration issues.

It is an object of the present invention to provide an improved formulation comprising an optical brightener.

According to a first aspect of the present invention there is provided a composition comprising a bleach and an optical brightener.

According to a second aspect of the present invention there is provided the use of a composition comprising a bleach and an optical brightener as a pre-treatment composition in a laundry / fabric washing operation.

Preferably the optical brightener is present in an amount of 0.01 to 1 wt%, e.g. 0.25wt% (for synthetic fibres) or 0.35wt% optical brightener (for cotton fibres).

It is preferred that the optical brightener is selected from the substance class(es) of benzonitrile, benzoxazole, benzopyrazol as well as their derivatives and substituted compounds.

Preferred compounds are shown below:-

These compounds may be substituted.

The composition may additionally contain one or more supplementary optical brighteners. These may be present in an amount of from 0.01 to 10wt%.

Preferred examples of these include stilbene brighteners. Stilbene brighteners are aromatic compounds with two aryl groups separated by an alkene chain. They preferably have the following structural formula: wherein R1 is hydrogen, halogen, alkyl, alkoxy or phenyl; R2 is hydrogen or alkyl;

M is hydrogen, an alkali metal or ammonium ion; n-0-2, bul the formula musl contain al least one S03 M group; and m=1-2 and when m=1 , the substituent on Ihe linkage carbon is hydrogen.

Especially suitable stilbene brighleners for use herein are described in U.S. Pat. Nos. 4,309,316, 4,298,490 and 5.035,825.

Bleach-stable anionic brighteners with sulfonic acid group(s) which work on cotton (cellu!osics) are preferred.

The most preferred stilbene brighteners for use herein, because it is bleach-stable, is Tinooal@.R CBS- X, which is benzenesulfonic acid, 2,2'-((1 ,1'-biphenyl)-4,4'-diylddi2,1-ethenediyl)bis-, disodium salt (CA Index Name). The formula forTinopa@ R CBS-X is below.

Another preferred stilbene brightener for use herein has the formula below.

Preferred examples of these include coumarin brighteners. They preferably have the following structural formula

in which A represents an aromatic nucleus of which two vicinal carbon atoms form part of the unsaturated lactone ring, and which nucleus may contain substituents, R and R1 represent hydrogen or an alky I, aryl or aralkyl radical, which may contain substituents.

Preferred examples of these include benzoxazo!e brighteners. They preferably have the following structural formula

Preferred benzoxazoles have the formula below.

Other preferred compound include the following

1.4- Bis(4-cyanostyryl)benzene (CAS 13001-40-6);

2.5- Bis-2(5-Tert-ButykBenzoxalyl)thiophene (CAS 7128-64-5); 1 ,4-Bis(2-benzoxazolyl)naphthalene (CAS 5089-22-5);

Surprisingly, it has been found that the composition and use of the present invention have improved performance in stain treatment when used in a fabric / laundry cleaning operation. Furthermore this is achieved whilst avoiding the problem of "white halos/spotting" which typically occurs with local applications of optical brighteners on items being cleaned resulting in areas of the item having a different shade of white. Without wishing to be bound by theory it is postulated that this enhanced performance arises due to the ability of the optical brightener to camouflage any remnants of the stain in the stain treatment step.

Extremely surprising is the observation that the optical brightener works at low temperatures such as those experienced in a domestic laundry wash cycle (generally lower than 90°C, lower than 60°C, lower than 40°C, lower than 30°C and often lower than 20°C). This has been found to be surprising since some of the materials named above are used in textile finishing processes (especially for synthetic fabrics such as polyesters). In these finishes processed the fabrics are processed at a temperature of over 120°C and often at a temperature as high as 180°C. It is believed that in this conventional finishing process such a high temperature is needed to bring the material I to its glass transition temperature so that it can interact with the optical brightener. Thus it is unexpected that the optical brightener can interact with a fabric (such as polyester) at the low temperatures (see above) of a domestic laundry operation.

It is reasoned that this interaction is aided by the presence of a nonionc surfactant. It is thought that the nonionc surfactant aids the solubility of the optical brightener into the wash liquor. Further it is postulated that the nonionic surfactant aids the bonding of the optical brightener with the fabric surface; which in the case of many fibres (such as polyester) is hydrophobic.

The surfactant is, for example, an anionic or nonionic surfactant or mixture thereof. The nonionic surfactant is preferably a surfactant having a formula RO(CH ₂ CH ₂ O) _n H wherein R is a mixture of linear, even carbon-number hydrocarbon chains ranging from C12H25 to C16H33 and n represents the number of repeating units and is a number of from about 1 to about 12. Examples of other non-ionic surfactants include higher aliphatic primary alcohol containing about twelve to about 16 carbon atoms which are condensed with about three to thirteen moles of ethylene oxide.

Other examples of nonionic surfactants include primary alcohol ethoxylates (available under the Neodol trade name from Shell Co.), such as C _{1 1} alkanol condensed with 9 moles of ethylene oxide (Neodol 1- 9), C12-13 alkanol condensed with 6.5 moles ethylene oxide (Neodol 23-6.5), C12-13 alkanol with 9 moles of ethylene oxide (Neodol 23-9), C12-15 alkanol condensed with 7 or 3 moles ethylene oxide (Neodol 25- 7 or Neodol 25-3), C _19-15 alkanol condensed with 13 moles ethylene oxide (Neodol 45-13), C _19-11 linear ethoxylated alcohol, averaging 2.5 moles of ethylene oxide per mole of alcohol (Neodol 91-2.5), and the like.

Other examples of nonionic surfactants suitable for use in the present invention include ethylene oxide condensate products of secondary aliphatic alcohols containing 11 to 18 carbon atoms in a straight or branched chain configuration condensed with 5 to 30 moles of ethylene oxide. Examples of commercially available non-ionic detergents of the foregoing type are C _{1 1-15} secondary alkanol condensed with either 9 moles of ethylene oxide (Tergitol 15-S-9) or 12 moles of ethylene oxide (Tergitol 15-S-12) marketed by Union Carbide, a subsidiary of Dow Chemical.

Octylphenoxy polyethoxyethanol type nonionic surfactants, for example, Triton X-100, as well as amine oxides can also be used as a nonionic surfactant in the present invention. Other examples of linear primary alcohol ethoxylates are available under the Tomadol trade name such as, for example, Tomadol 1-7, a C11 linear primary alcohol ethoxylate with 7 moles EO; Tomadol 25-7, a C12-C15 linear primary alcohol ethoxylate with 7 moles EO; Tomadol 45-7, a C14-C15 linear primary alcohol ethoxylate with 7 moles EO; and Tomadol 91-6, a Cg-C _{1 1} linear alcohol ethoxylate with 6 moles EO.

Other examples of linear primary alcohol ethoxylates are available under the Lutensol trade name such as, for example, Lutensol A3N, a C13-15 linear primary alcohol ethoxylate with 3 moles EO; Lutensol LA60, a Ci3-15 linear primary alcohol ethoxylate with 7 moles EO. Also Genapol such as, for example, Genapol LA3, a C13-15 linear primary alcohol ethoxylate with 3 moles EO; Genapol LA070, a C13-15 linear primary alcohol ethoxylate with 7 moles EO Tomadol 45-7, a C _14-15 linear primary alcohol ethoxylate with 7 moles EO; and Tomadol 91-6, a C _19-11 linear alcohol ethoxylate with 6 moles EO.

Other nonionic surfactants are amine oxides, alkyl amide oxide surfactants.

Preferably the ratio of the nonionc surfactant to the optical brightener is around from 1-1000:1. This ratio may be around 10:1 for a powder formulation and 600:1 for a liquid formulation.

Preferred nonionic surfactants include alcohol ethoxylates with short (C1-C10) EO (and or PO/BO) chains.

Preferably the fabric treatment composition comprises a surfactant. Where present the composition comprises from 0.001% to 99.99%, preferably 0.05% to 15%, e.g. about 10%, by weight of surfactants. The composition may include other surfactants.

Preferred anionic surfactants are frequently provided as alkali metal salts, ammonium salts, amine salts, aminoalcohol salts or magnesium salts. Contemplated as useful are one or more sulfate or sulfonate compounds including: alkyl benzene sulfates, alkyl sulfates, alkyl ether sulfates, alkylamidoether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkylsulfonates, alkylamide sulfonates, alkylarylsulfonates, olefinsulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamide sulfosuccinates, alkyl sulfosuccinamate, alkyl sulfoacetates, alkyl phosphates, alkyl ether phosphates, acyl sarconsinates, acyl isethionates, and N-acyl taurates. Generally, the alkyl or acyl radical in these various compounds comprise a carbon chain containing 12 to 20 carlson atoms.

Other surfactants which may be used are alkyl naphthalene sulfonates and acyl / oleoyl sarcosinates and mixtures thereof.

Preferably the fabric treatment composition comprises a bleach. Where present the composition comprises from 0.001% to 99.99%, preferably 0.001% to 7%, preferably 2% to 6%, most preferably about 7%, by weight, of bleach. The bleach is preferably peroxide bleach, most preferably hydrogen peroxide. Peroxide sources other than H202 can be used.

Preferably the fabric treatment composition comprises a solvent. Where present the composition comprises from 0% to 99.99% preferably from 0% to 10% by weight, of solvent. The solvent constituent may comprise one or more alcohol, glycol, acetate, ether acetate or glycol ether. Exemplary alcohols useful in the compositions of the invention include C2-8 primary and secondary alcohols which may be straight chained or branched, preferably pentanol and hexanol. More preferably the solvent is a glycol ether. Preferred examples of glycol ethers include glycol ethers having the general structure Ra-O-Rb- OH, wherein Ra is an alkoxy of 1 to 20 carbon atoms, or aryloxy of at least 6 carbon atoms, and Rb is an ether condensate of propylene glycol and/or ethylene glycol having from 1 to 10 glycol monomer units. Preferred are glycol ethers having 1 to 5 glycol monomer units. Specific and preferred solvents are selected from propylene glycol methyl ether, dipropylene glycol methyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, ethylene glycol n-butyl ether, diethylene glycol n-butyl ether, diethylene glycol methyl ether, propylene glycol, ethylene glycol, isopropanol, ethanol, methanol, diethylene glycol monoethyl ether acetate, and particularly useful are, propylene glycol phenyl ether, ethylene glycol hexyl ether and diethylene glycol hexyl ether.

Most preferably the solvent or mixture of solvent is from the propanol series (Dowanol P-series) and among these Dipropylene Glycol n-Propyl Ether, Dipropylene Glycol n- Butyl Ether and Propylene Glycol Phenyl Ether. These are commercially available from Dow Chemicals as Dowanol DPnP, Dowanol DPnB and Dowanol PPH respectively.

Other useful solvents are hydrotropes such as sodium toluene sulfonate and sodium cumene sulfonate, short-chain alcohols such as ethanol and isopropanol, and the like. They can be present in the compositions as only solvents or in combination with other solvents.

Preferably the fabric treatment composition comprises a builder. Where present the composition comprises from 0% to 99.99% preferably from 0% to 10% by weight, of builder. The fabric treatment composition may comprise minor amounts of various optional ingredients, including enzymes (such as proteases, amylases, lipases and / or cellulases) in an amount of 0.001 to 1 wt%, dye transfer inhibition agents, dye catchers, preservatives, antistatic agents, fragrances, odour absorbing components. The pH range of the fabric treatment composition is typically from about 3 to about 8, preferably about 3.5.

The composition is most preferably suitable for discharge / application onto an item being cleaned using a spray device. Indeed in a preferred embodiment of the second aspect of the invention a spray device is employed.

Such application typically occurs before the item is washed in an automatic washing machine, i.e. the composition is used as pre-treater. In this application it is most noticeable that the problem of white halos/spotting is avoided.

The spray device may comprise a propellant and thus be in the form of an aerosol type device, wherein the pressure of the propellant is used to aid the discharge of the contents of the spray device when the spray device is activated. Alternatively the spray device may be manually operated and thus be in the form of a trigger spray device. In these device application of pressure to an operating lever causes the operation of a pump which brings about dispense of the contents of the spray device.

The invention is now described with reference to the following non-limiting (Examples.

Preferred Examples of forumlua are as follows:

Liquid

Powder

Products tested:

• Test Conditions

Fabrics tested

Standard textiles:

• WFK 20A: 65% pes/35% cotton

• WFK30A: 100% pes

New Textiles provided by tessport

3 polyesters & 1 polyamide, different textures

Evaluations:

Instrumental via spectrophotometer 650: Ganz Value (means of 4 readings)

Both Uvitex exibrth improved whitening performance vs Wing powder on polyamide and polyester fabrics, based on instrumental evaluation

Good improvement in whitening performance of polyester and polyamide from all new OBA tested, after 5 washes

Screening for OBA in Liquid

Testing Protocol

Test Conditions:

Screening Test Results Standard Fabrics - Instrumental Evaluation (60°C - 0,2% OBA)

Good improvement in whitening performance of polyester and polyamide from all new OBA tested, already after 1 wash

Screening Test Results Standard Fabrics - Instrumental Evaluation (60°C - 0,2% OBA)

Good improvement in whitening performance of polyester and polyamide from all new OBA tested

Washing Test

PRODUCTS AND THEIR DOSAGE:

Treatment was in wash. Ref # 1 was washed at 40°C and Ref#2 at 20°C.

CONDITION OF TEST

FABRICS TYPE USED IN TEST

Results

The higher the Ganz Index value the better the Whitening performance

CONCLUSIONS

Vanish White gel with Optiblanc RGF 250% delivers best and higher whitening performance at 20°C washing in cold water vs the use of Laundry Detergent Powder at 40°C.