IE841296L - Cleaning composition. - Google Patents

Abstract

Aqueous hypochlorite bleach compositions are provided comprising from 0.1% to 5.0% of a C10-C18 alkyl C1-C4 alkyl diamine oxide or a C8-C18 alkyl substituted betaine together with from 0.001% to 0.25% of an organosilicon quaternary ammonium compound containing a C16-C20 alkyl group wherein the ionic strength ofthe compositions is less than 5.0 g moles/dm<3>.

Description

This invention relates to hypochlorite bleach compositions and in particular to aqueous hypochlorite bleaches containing a bactericidal material.

Aqueous bleach ccnpositions containing alkali metal hypohalites, particularly sodium hypochlorite, have been known for many years. Because of their powerful oxidising action they have also been acknowledged to be powerful germicides and have been used extensively where this property is beneficial, e.g. in the cleaning of baths, wash basins, flush toilets, drains and ceramic tile floors. However, it has long been recognised that the germicidal effectiveness of surface treatments using such materials is limited by the relatively short period of time during Which the aqueous composition containing the hypohalite is in contact with the surface concerned. Recent developments in the formulation of hypochlorite bleach products have shown a trend towards the use of higher viscosities, viz. -42-1 n s ' or greater, and this will increase the retention of such products on non horizontal surfaces.

Nevertheless, the increase in retention time introduced by such a thickened formulation will not be particularly significant, being measured in seconds or at most minutes, and a need exists for a bactericidal and germicidal material that is capable of retention cm a target surface for much longer periods. 3 Quaternary anmonium compounds, in general, are known to have bactericidal characteristics, and certain water soluble quaternary ammonium surfactants such as cetyl pyridinium bromide are very effective antibacterial agents. Polymeric 5 dialkyl siloocane and silane structures are well known as having a high affinity for siliceous surfaces and thus a combination of a quaternary ammonium function and a siloocane or si lane grouping might be expected to provide a long lasting antibacterial effect on siliceous surfaces of the 10 type mentioned abov®* Such is indeed the case and the antimicrobial effectiveness of a representative alkoxy si lane (3(trimethoocy silyl) propyl dine thy 1 octadecyl amnonium chloride) on a variety of surfaces, siliceous, metallic, synthetic, plastic and natural textile in nature, has been 15 reported by A J Isquith et al in J. Applied Microbiology, 24 (6), 1972, pp 859-863.

However, the incorporation of quaternised alkoxy si lanes into aqueous cleaning or bleaching conpositions poses considerable difficulty. All alkoxy si lanes of this type 20 will hydrolyse in contact with water, to produce the corresponding silanol derivatives which themselves are prone to polymerisation via condensation of the silanol groups. The polymerised materials are less surface substantive than the parent silanols.

In the case of the more water soluble alkoxy si lanes, containing a C^2~C14 group in the quaternary ammonium portion of the molecule; the materials display physical stability in aqueous alkalis and commercial aqueous hypochlorite and also display surface substantive 30 properties. However, in the presence of hypochlorite-stable surfactants, surface substantivity is markedly impaired due to solubilisation into surfactant micelles. Furthermore, these shorter chain alkyl quaternised alkoxy silanes do not display broad range antibacterial efficacy.

Quaternary alkoxy si lanes containing an alkyl chain longer than C14 are less water soluble and do not even display long teen stability in aqueous alkaline solutions but precipitate therefrom, probably in polymerised, and hence 5 antibacterially ineffective, form.

However, it has surprisingly been found that those quaternised alkoxy si lanes containing a C^g-C^Q alkyl group can be incorporated into certain aqueous hypochlorite bleach cenpositions to produce a physically stable product 10 capable of delivering hydrophobic properties and a long lasting antibacterial effect to siliceous surfaces treated therewith.

Aqueous hypochlorite bleach compositions forming suitable vehicles for the delivery of the quaternised alkoxy si lanes 15 should be free or substantially free of anionic surfactants and preferably should have a low ionic strength.

Accordingly the present invention provides a chlorine bleach-containing composition comprising i) a surfactant, ii) a chlorine bleach, iii) non-bleach inorganic compounds, iv) an organosilicon mono-long chain alkyl quaternary ammonium compound of formula R„ (R3)y (R3°) 3-ySi(CH2> 3 ,+ " R1 R2 25wherein Rx is long chain alkyl, R2 is C^-C^ alkyl, R3 is C1-C4 alkyl, y is an integer from 0 to 2 and X~ is a water soluble anion; or the silanol derivative thereof wherein R3 is H; and v) compatible optional ingredients, wherein a) the composition is aqueous, the percentage weight of water present together with that of components i) to v) totalling 100% by weight, b) the chlorine bleach is an alkali metal hypochlorite comprised in the amount of from 1% to 12% by weight, c) the surfactant is selected from amine oxides of formula R4R5R6N-X> wherein R4 is a C10"C18 allcyl group and R5 and Rg are C1~C4 alkyl groups, substituted betaines of formula R7RgRgN+ - R4QC00" where R? is a Cg-C18 alkyl group, Rg and Rg are C1-C4 alkyl groups and R10 is a C1~C4 alkylene group and mixtures thereof, and is comprised in the amount of from 0.1% to 5% by weight, d) the ionic strength of the composition is less than 5.0 g moles/dm and the pH of the composition is in the range from 10 to 13, e) the alkyl group R^ of the organosilicon compound contains from 16 to 20 carbon atoms, this organosilicon compound being comprised in the amount of from 0.001% to 0.25% by weight, f) the composition is substantially free of anionic surfactant species and, g) the non-bleach inorganic compounds are comprised in the amount of from 1% to 15% by weight. 6 Preferably the composition contains from 0.005% to 0.05% and most preferably from 0.01% to 0.03% of the organosilicon quaternary ammonium conpound. Preferably is a C^g alkyl group.

In highly preferred conpositions in accordance with the invention, the viscosity of the composition is at least 2 x 10 1Pa.s at 20% and comprises alkali metal hypochlorite in an amount of from 8% to 10% by weight, a alkyl dimethyl amine oxide as the only surfactant in an amount of from 1.0 to 1.5% by weight together with at least 400ppn of a secondary or tertiary alcohol as hereinafter defined or the ester thereof with a Cj-Cg alkanoic acid, and the composition has an ionic strength of less than 4.0 g moles/dm3.

The above mentioned reference to viscosity is to the dynamic viscosity */j which is measured by a Brookfield RVT viscometer and for the purposes of this specification measurements are made with Spindle No. 3 at 100 rpm and a liquid temperature of 20°C. Fluid viscosity can also be expressed as the kinematic viscosity J in itm^/s (centistokes) as measured by an Ostwald viscometer and is characterised by the expression \J = \)/p where /Jia the dynamic viscosity in mPa.s (centipoises) and is the density in g/cm3. Conpositions in accordance with the present invention have a density in the 3 range from 1.10 to 1.25 g/cm , typically approximately 1.15 3 g/cm , so that the numerical value of the kinematic 2 viscosity in mm /s is slightly less than that of the dynamic viscosity in mPa.s.

Organosilicon quaternary ammonium compounds having the desired combination of broad spectrum antibacterial activity and physico chemical stability in compositions in accordance with the invention have the general structure: *2 I (R3)yCR30]3_ySi(aJ2)3- X- I *2 wherein is alkyl, Rj is C^-C^ alkyl, Rg is Cj-Cj alkyl, y is an integer from 0 to 2, and X~ is a water soluble anion. A preferred chain length for is C18 for antibacterial efficacy reasons, and for reasons of cost and ease of preparation and R^ are usually methyl. In aqueous alkaline solution the (R^O) groups will hydrolyse to give the silanol derivative or, depending on the pH, the corresponding zwitterion, so that references herein to the organic silicon quaternary ammonium compound include the silanol derivative thereof. X~ is normally halide, particularly chloride, but can also include methosulphate, acetate or phosphate.

The level of incorporation of the organosilicon compound is from 0.001% to 0.25% based on the total weight of the composition but is more usually in the rcmge of from 0.005% to 0.05% and most preferably from 0.01% to 0.03% fcy weight.

In compositions in accordance with the invention, the hypochlorite bleach, and the alkali metal chloride and chlorate salts which acccnpany it in conmiercially available material, provide the majority and preferably substantially all of the ionic strength requirement. This will normally result in an ionic strength of at least 3.0 g moles/dm .

O Ionic strength values in excess of 5.0 g moles/dm are not desirable beacuse of their adverse influence on the stability of both the hypochlorite and organosilicon quaternary 8 ammonium compound components. Preferably the ionic strength 3 is less than 4.0 g moles/dm and values in the region of 3 3.4-3.8 g moles/dm are considered to be optimum where a stable pcoduct of viscosity ^2x 10-1Pa.s is desired. 5 The alkali meted hypochlorite may be a lithium, potassium or sodium hypochlorite and the level of hypochlorite in the composition is normally arranged to lie in the range 1-12%, preferably 5-10% by weight. Customarily hypochlorite bleach compositions contain approximately 6% or 9% hypochlorite by 10 weight. However, the activity of chlorine bleaching conpositions is conventionally expressed in terms of the weight percentage of available chlorine in the composition, and the actual weight percentage of bleaching species is arranged to provide the desired level of 'available 15 chlorine'. The preferred hypochlorite species is sodium hypochlorite which contains 95.3% available chlorine.

Alkali metal hypochlorites are commercially available as aqueous solutions containing 10-15% by weight 'available chlorine1 and the bulk suppliers normally produce material 20 having available chlorine contents towards the upper end of this range viz. 12-14% by weight. These commercially available hypochlorite solutions contain other salts as byproducts or contaminants, more specifically free alkalinity in the form of alkali metal hydroxide and alkali metal 25 carbonate, and alkali metal chloride. Low levels of other species such as sodium chlorate are also believed to be formed during hypochlorite manufacture but their chemical stability is sufficiently low that they have largely decomposed by the time the hypochlorite is employed in 30 product formulations. Hie levels of the byproduct materials depend on the processing conditions employed in the 4 i 9 manufacture of the hypochlorite but in general they fall within the ranges 0.2 - 1.0% alkali metal hydroxide 0.01 - 0.1% alkali meted carbonate 10.0 - 18.0% alkali metal chloride expressed as a weight percentage of the hypochlorite solution as supplied.

Amine oxides useful in the present invention have the formula R^Rj-RgN—>0 wherein R4 is a c^o~C18 alkyl group and and Rg are C^-Cj alkyl groups.

The amine oxide is present in an amount of from 0.5% to 5%, more preferably from 0.5% to 2.5% and, in preferred embodiments of the invention in vdiich the R^ average chain length csl4 carbon atoms, from 1% to 1.5% by weight of the oanposition. The R^ group may be linear or branched and may be derived from natural or synthetic hydrocarbon sources. For the purposes of the present invention linear groups are defined as including moieties incorporating up to 25% methyl branching, predominantly in the 2-position relative to the nitrogen atom of the amine oxide.

Methyl branching on the alkyl chain also predominates in those amine oxides useful in the present invention in which the R^ group is branched, rather than linear in nature.

Commercially available sources of these amine oxides sure normally a mixture of r5 R 1 CH 'CHg N f 0 where R7 is methyl, and R7 r6 r5 R CHg CHj N > O R® which mixture arises as a result of the processing route used to form the precursor alcohol or aldehyde. This route involves carbonylating or hydrofonnylating an olefin, preferably a linear «C -olefin and leads to a mixture of the 5 desired branched chain aldehyde or alcohol of the same carbon number. For olefin starting materials having a range of carbon chain length, the resultant alcohol or aldehyde mixture contains compounds of different carbon number and isomers containing straight chain and 2-alkyl branched chain 10 alkyl groups. A typical commercially available mixture comprises 65 to 75% by weight and 35 to 25% by weight C15 amine oxides with approximately 50% by weight straight chain and 50% by weight 2-alkyl branched chain Where the 2-alkyl group is predominantly methyl. These are available 13 from Id under the trade name Synprolam 35 EM0*as a 30% aqueous solution. The branched chain amine oxides and mixtures thereof with linear chain amine oxides are used at levels towards the upper end of the range viz. JJ, 2% by weight of the composition and typically from 2.0% to 2.5% by weight. 20 Although the above-described mixture of straight chain and branched chain alkyl dimethyl amine oxides has been found suitable for the purposes of the invention, their use does not constitute the most preferred execution of the invention. This is because a bleaching composition 25 containing 8-10% hypochlorite and an amine oxide in which the long chain alkyl group has a carbon lumber of about 13.3 requires an ionic strength of at least 4.7 g moles/dm to achieve the preferred product viscosity of at least 2 x 10 1 Pa.s. This level of ionic strength is believed to make the storage 30 stability of the hypochlorite bleach less than that which is considered desirable for the expected shelf life of the product. The preferred amine oxide structure for 'thickened' products having a viscosity of ^ 2 x 10_1Pa.s is one in which R4 is a linear group which has an average chain length in the ♦Trade Mark 11 range C^-C^. Conpositions containing these preferred amine oxides require a lower amine oxide level viz. *.2.0%, more typically 1.0-1.5% and also a lower ionic strength viz. 3 3.'0 g moles/dm minimum in order to acfhieve target 5 viscosity. Both of these reductions in ingredient level lead to inproved storage stability and also lower the cost of the product.

Another hypochlori te-stahle surfactant suitable for the purposes of the present invention is a substituted betaine of 10 formula wherein is a Cg-C^g alkyl group, preferably a C10~Cl4 all^rl 9rot?)» Kg and Rg are Cj-C^ alkyl groups, more preferably methyl groups, and R^ is a 15 alkylene group more preferably a alkylene group. Specific examples include octyl, decyl, dodecyl, tetradecyl and hexadecyl betaines in tfiich R^q is an ethylene or propylene group and Rg and Rg are methyl groups.

Mixtures of hypochlorite-stable surfactants are also known in the art particularly where it is desired to increase the viscosity of the system and examples of other hypochlorite-stable surfactants include saturated fatty acid soaps, alkyl sulphates, alkane sulphonates, sarcosinates and 25 taurides. These surfactants which are anionic in type should be enplcyed at levels which do not interfere with the efficacy of the quaternised alkoxy si lane. Because of the tendency of cationic and anionic surfactant species to react to form high molecular weight, relatively water-insoluble 30 complexes, anionic surfactants should be present at less than the amount necessary to complex the quaternised alkoxy si lane completely. It has been found that quaternised alkoxy silane deposited on a siliceous surface from compositions in accordance with the invention provides 80% to 90% reduction in 12 bacteria (E. Goli) count on exposed surfaoes When the treated surfaoes are subsequently exposed to an innoculun of fresh bacteria in a distilled water environment. However the presence in the composition of anionic surfactants in excess 5 of the amount necessary to complex the quaternised alkoxy si lane leads to a significant diminution of the bacteria count reduction under the same conditions.

Accordingly, the composition should be substantially free of anionic surfactants, substantially free being defined as 10 less than the amount of surfactant necessary to completely complex the quaternised alkoxy si lane, and preferably should be completely free of such surfactants.

A highly preferred optional component for hypochlorite bleach compositions suitable for incorporating the 15 quaternised alkoxy silanes, particularly those utilising from 1.0 to 2.0% of an amine oxide wherein has an average chain length of about 14 carbon atoms, is at least 400 ppm based on the weight of the composition, of at least one secondary or tertiary alcohol selected from cedrol, tetra 20 hydro linalool, tetra hydro muguol (a 50;50 mixture of tetra hydro linalool and a positional isomer, tetra hydroanyrcenol), verdol, dihydro terpineol, isoborneol, 4-tertiazy butyl cyclo hexanol and menthol and mixtures of any of these or of their lydrolysabLe carboxylic acid esters. These alcohols and their C^-Gj alkanoic acid esters are known and used as ingredients in fragrances, including those employed in detergent compositions. As such their level of incorporation conventionally lies between 10 ppm and 600 ppm of the composition depending on the perfume formulation and 30 the nature of the detergent composition.

It has now surprisingly been found that in aqueous hypochlorite bleach solutions containing from 1.0% to 2.0% of a C14~C16 amine oxide as the only surfactant, the incorporation of at least one of the above mentioned 13 secondary or tertiary alcohols or an ester thereof with Cj-Cj alkanoic acid provides an enhancement of the viscosity of the bleach solution and facilitates the generation of viscosities of 200 centipoises and greater at 5 20°C. Preferably the secondary or tertiary alcohol ox ester is present in em amount of more than 600 ppm and, where the amine oxide level is $1.5% by weight is more preferably present in an amount of at least 800 ppm. Advantageously a mixture of the alcohols or their Cj-C^ alkanoic acid 10 esters is used in a total amount of from 600 to 1600 ppm although it is preferred that one of the canponents of the mixture should be present in an amount of at least 500 ppm by weight of the composition.

The most preferred materials are cedrol, tetrahydro 15 linalool, tetrahydro rayrcenol and dihydro terpineol and their acetate esters. These materials have tertiary alcohol functionality and are relatively immune to breakdown in lypochlori te-containing solutions, resulting in viscosity-enhancement effects which are stable with time. 20 The mode of operation of these materials in this system is not fully understood but it is hypothesised that in the absence of anionic surfactants, hydrogen bonding occurs between adjacent alcohol functions of the relatively water insoluble alcohols held in the amine oxide micelles. This is 25 believed to lead to the formation of an extended micellar structure in the solution which provides an increased viscosity. The maximum viscosity of the system is not reached immediately upon mixing, but develops over a period of time and accordingly viscosity is measured 24 hours after 30 the product has been made.

Thickened aqueous hypochlorite bleach conpositions including the above mentioned alcohol derivatives are particularly preferred for the incorporation of the quaternised alkoxy si lame antibacterial component as such compositions utilise the minimum 14 amounts of amine oxide surfactant and ionic salts necessary to generate the desired product viscosity and hence enhance the stability of the quaternised alkoxy si lanes.

As stated hereinbefore, the salts acocnpanying the hypochlorite k 5 bleach provide most if not all of the ionisable species necessary for the ionic strength requirement. However, other non surface ( active organic or inorganic coupounds can be added where necessary to provide an ionic strength in the desired range.

The ioni sable coupound(s) can be inorganic in nature eg. 10 hydroxide, sulphate, halide, (particularly chloride), carbonate, nitrate, or orthcphosphate, pyrophosphate, or polyphosphate, or organic such as formate, acetate or succinate.

In the preferred embodiments of the invention inorganic compounds such as silicates and organic ccnpounds incorporating 15 oxidisable groups are avoided because of their tendency to have adverse effects on physical and/or chemical stability of the conpositions on storage. Certain organic sequestrants such as the amino poly (alkylene phosphorates) salts can, however, be incorporated in an oxidised form in which they are not susceptible 20 to attack by the hypochlorite bleach. Such sequestrants are normally present in amounts of from 0.1% to 0.5% by weight of the conposition.

The ionic strength of the composition is calculated by means of the expression Total Ionic Strength I = J^C.Z. ^ 2 where C. is the molar concentration of the ionic 3 v species in g moles/dm Zj is the valency of the species.

The function CjZ? is calculated for each of the ionic 30 species in solution, these functions are sunned and divided by two to give the conposition ionic strength.

The ionisahle alkali metal ccnpound normally comprises a caustic alkali such as sodium or potassium 'hydroxide either alone or in admixture with alkali metal salts. This gives a conposition pH (as is) of 10 to 13, although in-use the pH of the bleaching 5 solution normally has a value in the range from 11 to 12.

For product safety reasons the amount of caustic alkali is normally limited to a value in the range of from 0.5% to 2%, more usually frcm 0.75% to 1.5% by weight of the conposition.

A desirable optional component of conpositions in accordance 10 with the invention is a perfume which is present at a level of from 0.01% to 0.5% preferably from 0.05% to 0.25% by weight of the conposition. In the preferred thickened bleach conpositions incorporating one or more of the above described secondary or tertiary alcohol components the alcohol conponent(s) can 15 conveniently be incorporated in the perfume mixture.

A further desirable optional component in conpositions in : accordance with the invention is an agent for siliceous glaze protection such as zinc oxide, or aluminium oxide and water soluble bismuth salts. This can be added in an amount of from 0.01% to 20 o.l% by weight of the conposition more preferably from 0.02% to 0.06% by weight.

The conpositions are made by conventional mixing techniques. Because of the relatively low aqueous solubility of the organo silicon compound which is normally supplied as a solution in 25 methanol, a premix of the amine oxide, perfune, added caustic alkali and water is normally prepared and the organo silicon compound is thai added with vigorous agitation.

This mixture is then added to the hypochlorite solution to sake the final product. Other orders of addition can be used but unless 30 the amine oxide is present in the solution to which the organo silicon compound solution is added, problems of incomplete solution or precipitation can arise.

The invention is illustrated in the following exanples in which percentages cure expressed by weight of the composition unless 35 otherwise stated. 1 6 In the Examples, reference to ingredients have been abbreviated as follows: CigEMftO C14PMAD NaCl NaCH NaOCl EXAMPLE 1 C15 alkyl dimethyl amine oxide in Which the alkyl group is 95% C15 and approximately 50% of the alkyl groups contain methyl branching on the 2-carbon atom.

Cj4 alkyl dimethyl amine oxide in Which the alkyl gzoqp is a predominantly linear C14 ( 94%) moiety. Available from Albright & Wilson Ltd as Bnpigen OH* Sodium chloride Sodium hydroxide Sodium hypochlorite 420g of a 30% solution of C^4 alkyl dimethyl amine oxide was added to 3555.6 g of demineralised Mater and 12.5 g of a perfume material oontaining 6.4g of isdbornyl acetate was dispersed therein. To this solution was slowly added, with vigorous agitation, 11.9 g of a 42% solution in methanol of 3(trimethaxy silyl) propyl dimethyl octadecyl ammonium chloride (available from Dow Corning Ltd as DC 5700) to farm a premix solution. 125 g of solid sodium hydroxide was dissolved in 5875 g of sodium hypochlorite solution (15.3% AVCI2 solution supplied by ICI Ltd) and 4000 g of the premix was then blended with high shear agitation into this solution.

* Trade Mark It 17 This conposition had the following analysis, in percent , / ,3 2 by weight and had a density of 1.15 g/cm . a NfiOCl 9.43 (= 9.0% available chlorine) 1.46 g NaCl 9.40 1.84 M IfaCH 1.25 0.36 " Amine Oxide 1.26 DC5700 0.05 Perfume 0.125 Water & Misc 78.485 100.000 This product was a single phase solution having a dynamic viscosity of~2.7 x 10_1 Pa.s as measured at 20#C with a 15 Brookfield viscometer using the No. 3 spindle at 100 rpm on product that was 24 hours old.

The ionic strength of this composition was calculated to be 3.66.

EXAMPLE 2 The following conpositions are prepared according to the technique of Exanple 1: (a) (b) (c) (d) c14dm\o 1.2 1.5 1.75 c15dmao 1.2 dc5700 0.02 0.02 0.02 0.02 NaCH 1.0 1.0 1.0 1.0 NaOCl 9.0 9.0 9.0 9.0 NaCl 9.0 9.0 9.0 9.0 Isoborneol 0.05 0.06 0.04 Dihydroterpinyl 0.06 acetate Vfeter & Misc. to 100 Viscosity x 10-1Ra.s 3.5 1.9 2.45 3.24 18 The density of each of these compositions is 1.15 g/ml and the ionic strength far each conposition is calculated to be 3.5 3 g moles/dm . The product viscosity was measured at 20"C using the technique of Exanple 1.

EXAMPLE 3 The following conpositions were prepared according to the technique of Example 1. The alcohol and ester levels are given in ppm. (a) (b) (c) (d) 1.26 0.02 1.0 9.0 9.0 733 NaOH NaOCl NaCl Cedrol C1A DMRO 14 DC5700 1.26 0.02 1.0 9.0 9.0 733 1.26 1.26 0.02 0.02 1.0 1.0 9.0 9.0 9.0 9.0 Tetrahydroli nalool Verdol Dihydro teipinyl acetate Isobornyl Acetate 641 4 Tertiary butyl cyclohexyl acetate Isobornyl propionate Menthyl acetate Water — 687 290 517 to 100 450 641 511 647 19 Brookfield viscosity measurements were made after 24 and 72 hours and were as follows; values are in Pa.s x 10 (a) (b) (c) (d) 24 hours 2.95 1.90 0.70* 2.40 72 hours 2.95 2.15 3.55 2.55 ♦The solution was cloudy and appeared to display nan homogeneity. This disappeared after further storage.

Claims (11)

1. 1. A chlorine bleach-containing composition comprising i) a surfactant^ ii) a chlorine bleach, iii) non-bleach inorganic compounds, iv) an organosilicon mono-long chain alkyl quaternary ammonium compound of formula R2 l (R3)y(R30)3.ySi(CH2)3N+ - ^ x" , wherein is long chain alkyl, R2 is C1~C4 alkyl, is C1-C4 alkyl, y is an integer from 0 to 2 and X*" is a water soluble anion; or the silanol derivative thereof wherein R3 is H; and v) compatible optional ingredients,;wherein a) the composition is aqpieous, the percentage weight of water present together with that of components i) to v) totalling 100% by weight,;b) the chlorine bleach is an alkali metal hypochlorite comprised in the amount of from 1% to 12% by weight,;c) the surfactant is selected from amine oxides;of formula R^RgRgN^O wherein R4 is a C10~C18 alIcY1 9rouP and R5 and Rg are C1~C4 alkyl groups, substituted betaines of formula R7RgRgN+ - R4QCOO~ where R? is a C8-C18 alkyl group, Rg and Rg are C1~C4 alkyl groups and R1Q is a C1~C4 alkylene group and mixtures thereof* and is comprised in the amount of from 0.1% to 5% by weight, d) the ionic strength of the composition is less than 5.0 g moles/dm and the pH of the composition is in the range from 10 to 13, e) the alkyl group R1 of the organosilicon compound contains from 16 to 20 carbon atoms, this organosilicon compound being comprised in the amount of from 0.001% to 0.25% by weight, f) the composition is substantially free of anionic surfactant species and, g) the non-bleach inorganic compounds are comprised in the amount of from 1% to 15% by weight.

2. A bleaching composition according to Claim 1 wherein is and X~ is a halide anion.

3. A bleaching ocroposition according to either one of Claims 1 and 2 wherein the ionic strength of the ccnposition is less 3 than 4.0 g moles/dm . 22

4. A bleaching composition according to any one'of Claims 1-3 wherein an alkyl dimethyl amine oxide, in which the alkyl group is linear and has an average carbon chain length of from 14 to 15 carbon atoms, is the only surfactant species 5 present. '

5. A bleaching composition according to claim 4 wherein the amine oxide comprises from 1.0% to 2.0% by weight of the composition.

6. A bleaching conposition according to claim 5 further 10 incorporating from 0.01% to 0.1% by weight of a glaze protection agent selected from zinc oxide aluminium oxide and water soluble bismuth salts.

7. A thickened bleaching ccnposition according to either one of claims 5 and 6 wherein the conposition incorporates at least 400ppm, by weight, of a compound selected frcm cedrol, tetrahydro linaool, tetra hydro myrcenol, verdol, dihydro terpineol, isoborneol, 4- tertiary butyl cyclo hexanol and menthol, the hydrolysable C2-Cj carboxylic acid esters of any of the foregoing, and mixtures of any thereof, whereby the conposition has a viscosity of Zx 10'^Pa.s at 20°C.

8. A thickened bleaching conposition according to claim 7 Wherein the amine oxide level is from 1.0% to 1.5% and said selected compound is present in any amount of at least 600 ppm.

9. A thickened bleach conposition according to claim 7 or 8 25 Wherein a mixture of alcohols and/or C2~C3 aiteroic acid esters thereof is present in a total amount of from 600 ppm to 1600 ppm. 15 20

10. A thickened composition according to any one of claims 7-9 wherein the compound is selected from cedrol, tetrahydro linacol, tetra hydro myrcenol or dihydro terpineol, the C2~C3 alkanoic acid esters of any of the foregoing and mixtures, thereof.

11. A chlorine bleach-containing composition according to claim 1, substantially as hereinbefore described and exemplified. F. R. KELLY & CO., AGENTS FOR THE APPLICANTS.