GB2367565A - Toilet detergent dispenser - Google Patents

Abstract

A toilet detergent dispenser comprises a vessel (1) having one or more apertures (4) below the level of liquid detergent (3) contained within the vessel, wherein the liquid is displaced from the vessel by the evolution of gas from a substance also contained within the vessel. The liquid is suitably hydrogen peroxide or an alkali metal hypochlorite or a combination thereof and the substance is suitably a source of transition metal ions.

Description

Activated Lavatory cleaner system The present invention concerns a lavatory cleaning formulation wherein continuous dosing of the contents of a vessel containing such a formulation is achieved independent of external mechanical action.

Lavatory cleansing devices are numerous and can be conveniently divided in to those used in the cistern, those use in the toilet bowl and then subdivided in to solid or liquid compositions. The underlying task solved by all these devices is to contribute a limited amount of a cleansing or perfumery composition to the water used in flushing operations so as to clean, disinfect, deodorise, colour and give visible foam at each flush. In addition those devices which act on the water in the cistern give ongoing cleansing to the cistern.

A number of issues face these devices the most important being the inability to continuously disinfect/clean the toilet bowl in between flushing operations. As, for example, would be achievable by placing a device in the water of the toilet bowl. However, this is impractical as such devices are un-hygienic and simply flushed away unless they are firmly anchored.

Alternatively a device which mechanically doses disinfectant etc. over time may be used,

however, these are uneconomic for consumer use and theirrequirement for a power source e. g.

"/.' electricity incompatible with lavatory facilities.

As will be appreciated a single dose of disinfectant etc. at the flush will be active only so long.

Also the likelihood of intermediate toilet use (without associated flushing) between flushes logically increases with time between flushes and hence the amount of disinfectant delivered should optimally be proportional to time elapsed between flushes.

It is an object of the present invention to obviate or mitigate some or all of these disadvantages with prior art compositions.

The problem to be solved is therefore the need for automatic dosing, using non electrical, zn electronic or mechanically driven means of active substances in to the toilet bowl such that the amount delivered is independent of the flushing of a toilet and preferably so that the amount delivered is proportional to the time between flushes.

In addition such a device should preferably deliver additional product dosing at the flush to quickly disinfect the toilet.

According to the present invention there is provided a composition in conjunction with a device which achieves these ends.

The prior art teaches a vast number of devices, the basic concept of a liquid filled in a container with a small aperture, such that the when the container is inverted the contents of the container are delivered in a limited manner to the surrounding cistern or flushing water is well known in the art. Pertinent examples are GB 221,633 (Womer et al, 1924), DE 3419169 (Henkel), WO 92/20876 (Brookline Alpha), EP 538 597 (Sara Lee), EP 785 315 (Sara Lee), GB 2 338 494/5 (SC Johnson). Such devices are regarded as being in various degrees of a sort that are envisaged for use as one component of the current invention, i. e. an inverted vessel containing a liquid (however that liquid is derived) possessing a limited means of egress of the contents to the outside when surrounded by air and a less limited, but still limited, means of egress when the outlet of the vessel is contacted with water. Such devices are incapable of ongoing controlled dosing of active agents in to the toilet bowl, though they are capable of dosing in to the cistern or as activated by flushing.

The prior art on compositions on toilet disinfecting etc, compositions is large, however, the use of such compositions in dosing devices is rarely taught or practised due to the hygienic implications of refilling a device located in a toilet, particularly in the domestic environment.

However, such teaching is found in; GB 1,069, 213 (Calmic) disclosing a high level of a quaternary ammonium compound and EP 775 741 concerning a composition containing 1 to 25% by weight perfume, 10 to 50% by weight anionic or nonionic surfactant and evaporation regulator. Such compositions are incapable of participating as an active component of an automatic non-mechanical, non-electrical/electronic dosing system, or if they are, only as passive components.

It is an object of the present invention to obviate or mitigate the above mentioned disadvantages.

According to a first aspect of the present invention there is provided a detergent product comprising a vessel which when in use has the only aperture or apertures which freely communicate with the atmosphere below the level of a liquid or similar enclosed therein such that the liquid is predominantly released over an extended period of time by the evolution of gas from a substance also enclosed within the vessel.

Preferably the substance which evolves the gas is a bleach also capable of a disinfecting action.

Preferably the entire contents of the vessel will be liquid and also the apertures will be at substantially the lowest point of the vessel; when in normal use.

According to a second aspect of the present invention there is a chlorine bleach in liquid form contained in a vessel with a porous mass in the path, or if paths then any such path, of egress of the liquid from the vessel when used for the purposes of cleansing a toilet and capable of enhanced product release on flushing by virtue of a mechanism involving the porous mass.

Preferably the contents of the vessel should contain less than 1 part per million of transition metal ions (including titanium).

Preferably the chlorine bleach is sodium hypochlorite.

With products of the above mentioned description surprisingly improved cleansing of a toilet is obtained due to the progressive controlled'base line'release of active substance from the

device which may from time to time be enhanced by the action of flushing, should the device tn optionally be used in the path of flushing water.

ZD Any one aspect of the invention may be used in combination with any other aspect of the invention.

The invention consists of a vessel, and a method of evolving gas within that vessel such as to increase, typically temporarily, the pressure of the gas above the liquid such as to provide a force to displace liquid from the vessel.

The liquid formulation in accordance with the invention will include a potential source of gas that can be evolved over an extended period of time. The preferred gas is oxygen and the source of that gas is preferably that resulting from the decomposition of hydrogen peroxide or an alkali metal hypochlorite. Other suitable sources are alkali metal hypobromite, hypochlorous acid and hypobromous acid. Such materials may be developed in situ themselves from their own precursor. Peracids, such as peracetic acid and the like are less preferred embodiments of the invention.

An activator for the decomposition of the material used as the source of the gas may optionally be present. The preferred activators are the transition metal ions, particularly Iron, Titanium and Copper. Such ions if included (either directly or indirectly) are preferably present at less than 5 parts per million, more preferably at less than 1 part per million. Titanium is preferably substantially absent.

A further activator is light and as such the container for the liquid is therefore optionally but preferably substantially clear.

A stabiliser for the decomposition of the material used as the source of the gas may optionally be present. Suitable stabilisers are organic phosphonic acid derivatives such as sold under the name Request@ by Monsanto corporation or free radical scavengers such as Vitamin E, butyl hydroxy toluene and its more soluble analogues.

Not wishing to be bound by theory the use of such gas evolving compounds as regulated by the aforementioned activators and stabilisers in suitable balance will result in utilising the reactions below to controllably evolve oxygen.

Hydrogen peroxide decomposition

H202--H20 + 02

Sodium hypochlorite

NaOC ! NaCI + 02

The composition used with hydrogen peroxide is therefore preferably alkaline, more preferably with a pH of greater than 8, and most preferably between pH 9 and 11.

The composition used with hypochlorites is therefore preferably alkaline, more preferably with a pH of greater than 13, and most preferably between pH 13.5 and 14.

The ratio of activator to stabiliser will be chosen so as to give a half life of decomposition of the gas source (i. e. to predominantly evolve the gas or gasses) of 6 months, more preferably of 4 months, most preferably of some 3 to 4 months. The ratio of stabiliser to activator may optionally change over the lifetime of the product. In particular introduction of activator on assembling a product (e. g. disposable reservoir with re-usable base unit) is a highly preferred embodiment of the invention.

The detergent formulation in accordance with the invention will typically include at least one surface active agent that may, for example, be an anionic, cationic, non-anionic or amphoteric surface active agent. Any of the surface active agents widely used in detergent formulations may be employed in the present invention. Such agents are typically employed in amounts of from 1 to 15% by weight.

If an amphoteric surface active agent is used it may be present in the formulation in an amount of 0.1 to 10% by weight, more preferably 0.5 to 5%, even more preferably 1 to 4% on the same basis.

The amphoteric surface active agent may be betaine surface active agent. Preferred betaines may be either of the formula (I) or (II).

R' I R'-N±CH2-COO- (I) I R2

R' I R'CONHCH2CH2CH2N±CH2COO (II) R2 . Kl

In the above formula, R1 and R2 may be the same or different Ci-4 alkyl groups whereas R3 is an alkyl group having 8-22 carbon atoms, more preferably 12 to 18 carbon atoms e. g. mixed CIO to C14.

The preferred betaine for use is cocoamidopropyl betaine.

An alternative amphoteric surface active agent for use in the formulation of the invention is a glycinate of the formula R'NHCH2C02H where R3 is as defined above.

Other suitable materials are as given in chapter 1 of"Amphoteric Surfactants", E. G. Lomax Ed, Marcel Decker, New York 1996.

It is preferred that a cationic surface active agent is employed in conjunction with the amphoteric surface active agent. The cationic surface active agent is preferably used in an amount of up to 6 % by weight of the formulation and is conveniently added in conjunction with a clay especially as herein described. Examples of suitable cationic surface active agents include quaternary ammonium salts having three lower (C, 4) alkyl groups (preferably methyl groups) and a long chain (C8-20) alkyl group, e. g. coco trimethyl ammonium chloride. Further examples include alkyl pyridinium salts and other compounds in which the nitrogen atom of the pyridine assumes a quaternary form, e. g. as in an alkyl pyridinium bromide. Cationics with C10 to C20, more preferably with, C12 to C18 alkyl chains are preferred.

Further examples of cationic surface active agents which may be used include amine and imidazoline salts.

If an anionic surface active agent is used then it is preferably present in the formulation in an amount of up to 20%, more preferably up to 10%, even more preferably up to 5% by weight of the formulation. Examples of anionic surface active agents that may be employed include alkylaryl sulphonates; alkyl sulphates, ether sulphates and ether carboxylates all as conventionally employed in laundry detergent formulations. Di-anionic surfactants are noted as being particularly useful. Anionics with C10 to C20, more preferably with, C12 to C18 alkyl chains are preferred.

If a non-ionic surface active agent is used then it is preferably present in an amount of up to 20% by weight of the formulation, more preferably 2 to 10% on the same basis.

Examples of predominantly liquid non-ionic surface active agents which may be used include alkoxylates, ethylene oxide/propylene oxide block copolymers, alkanolamides (e. g. monoethanolamides and diethanolamides), esters and amine oxides. Non-ionics with C10 to C20, more preferably with, C12 to C18 alkyl chains are preferred. If a liquid non-ionic surface active agent is to be included then it may for example an alcohol ethoxylate. The alcohol residue (which may be of a primary or secondary alcohol) may for example comprise 8 to 18 carbon atoms and be ethoxylated with an average of 3 to 20 moles of ethylene oxide per mole of alcohol.

Suitable liquid non-ionic surface active agents are available from ICI under the designations SYNPERONIC A3 and SYNPERONIC A7. Mixtures of the A7 and A3 active agents may also be used. Also suitable are LUTENSOL AO3 and LUTENSOL AO7 (ex BASF).

Examples of solid non-ionic surface active agents which may be used in the formulation in accordance with the first aspect of the formulation include alkyl (cl-22) polyglycosides. The preferred glycoside employed in the present invention is a glucoside (i. e. based on glucose), functionalised with a primary alcohol (e. g. C12-C). More preferably the glucoside is in the form of a polyglucoside, with a preferred degree of polymerisation of between 1-2, most preferably about 1.4. Non-ionic surface active agents may be used in the form of particles or granules containing at least 30% by weight, more preferably at least 40% by weight of solid non-ionic surface active agent.

Suitable polyglycosides are available under the name Glucopon (Henkel).

The surfactant can be present at up to 25 %, more preferably between 1 % and 20 %. For textile washing compositions the most preferable range is between 10 and 20% and for hard surface cleaning between 1 and 5 % and for fabric refresher and air freshener products less than 1 %. The preferred surfactant is one carrying an electrical charge, most preferably an amphoteric or anionic surfactant.

Additional detergent components Builder The formulation may include at least one builder salt in a total amount of 0. 1 % to 50 % by weight of the formulation. Mixtures of builder salts are typically employed. The builder may be for example be an alkali metal phosphate or alkali metal carbonate. The person skilled in the art will select a suitable combination of phosphates from ortho, pyro and triphosphates. In particular alkali metal triphosphates with a Phase 1 content of greater than 40% are preferable for applications requiring rapid dissolution, whereas for applications requiring slow release a

Phase 2 content of greater than 40 % is desirable. Similarly the degree of hydration of the salts will be chosen, salts with less than 5% water of hydration are preferred. Other suitable builders are zeolites, citric acid, nitrilo tri-acetic acid, Alkali metal carbonates or sodium citrate. Zeolites X, Y and MAP are all considered suitable.

Polymeric components A number of polymeric components will typically be considered for use as part of compositions within the scope of the invention.

A variety of polymers may be added to perform variety of functions. For example as thickeners and anti scaling agents, anti-redeposition agents, colourants, conductive layers, reflective layers, oxygen permeability barriers, moisture permeability barriers, water softeners, heavy metal sequestrants, antioxidants.

Suitable polymers include, Addition polymers-e. g. Poly Vinyl; ethers, esters, amides, carboxylates, maleates, methacrylates, acrylates, alcohols, acetates, sulphonated polymers and amphoteric polymers and copolymers thereof. In particular block copolymers, homo polymer and copolymer prepared using vinyl carboxylates in combination with monomer selected from the group consisting of (meth) acrylonitrile, 2-trimethylsiloxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-trimethyl-siloxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, sorbyl (meth) acrylate, butyl (meth) acrylate, ethyl (meth) acrylate, glycidyl (meth) acrylate, hexyl (meth) acrylate, hexyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, (meth) acrylonitril, lauryl (meth) acrylate, methyl (meth) acrylate, octyl (meth) acrylate, p-tolyl (meth) acrylate, phenyl (meth) acrylate, propyl (meth) acrylate, sorbyl (meth) acrylate, and stearyl (meth) acrylate, may be used. Homo and block polymers of the above monomers are particularly suitable for use in the inks of the invention.

Other suitable polymers include condensation polymers-e. g. Poly; esters, and urethanes, gelatine, Carrageen, Gum Arabic (e. g. grade NF FCC ex Sarcom Inc), Agar (e. g. Agar-Agar NF FCC Gel 10 ex Sarcom Inc), Guar Gum (e. g. Powder HV-101 NF FCC ex Sarcom Inc), Locust Bean Gum (e. g. SG-14 FCC ex Sarcom Inc), Ghatti Gum (e. g. #1 FCC ex Sarcom Inc), Karaya Gum (e. g. #1 FCC ex Sarcom Inc), Karaya Gum (e. g. #1 FCC ex Sarcom Inc), Xanthan Gums (e. g. XAN-90 NF FCC ex Sarcom Inc. ) and alginates.

Particularly preferred polymers are the Chitins, Chitosan and derivatives for their synergistic potentiation of antibacterial efficacy in combination with the selected organic bactericides of table 1.

Preferred molecular weights are from 5,000 to 100,000. More preferably from 10,000 to 30,000.

Suitable polymeric materials known in the art are Hydrogenated caster oils (e. g. Croduret 50 ex Croda), acrylic acid polymers (e. g. ex National Starch) Acrylate maleate polymers (e. g. Sokolan CP-5 and CP-10 ex BASF) and poly ethylene glycols (e. g. ex Hoechst), poly vinyl pyrrolidone (e. g. K50 ex ISP), Carbopol (ex 3V). Suitable levels of polymer inclusion are between 0.1 to 10% more preferably between 0.2 and 2% most preferably between 0.3 and 1.2%.

A variety of substantially water insoluble polymers may be added to perform a variety of functions for example soil release agents and tablet excipients. E. g. polyoxyethylene terephthalate, polyethylene terephthalate and cellulose and its hydroxy alkyl and carboxy alkyl derivatives.

Supplementary Bleaches A supplementary bleaching composition may also be included. The preferred supplemamtary bleaching system for use in the invention comprises a hydrogen peroxide precursor compound and the bleach activator as known in the art which is capable of reacting with the hydrogen peroxide to generate a peracid.

The hydrogen peroxide precursor compound may, for example, be an inorganic persalt e. g. a perborate (in the monohydrate and/or tetra hydrate form), a percarbonate or a persulphate.

The alkali metal salts of these compounds are preferred, particularly sodium and potassium salts. The bleaching agent may be a urea-hydrogen peroxide complex. Pre-formed per acids known in the art are also considered suitable. Specific examples of pre-formed per acids bleaches which may be used in the detergent formulations of the invention include phthalimidc peroxihexanoic acid e. g. Eureco (TM) ex Ausimont) and diphthaloyl peroxide.

Specific examples of bleach activators which may be used in the detergent formulations of the invention include l, 5-diacetyl-2, 4-dioxo-hexahydro-1, 2,5-triazin (DAHT) tetra alkyl alkylene

diamines, particularly N, N, N', N'- tetra acetyl ethylene diamine (TAED), The precursors of Perimidic acid (e. g. Sokolanw BM G), glycerol tri alkylates, particularly glycerol triacetate (HAS), hexa acetyl sorbitol, hexa acetyl mannitol, penta acetyl glucose, octa acetyl sucrose and combinations thereof. For example Sorman'ex Cerestar. Particularly preferred are hexa acetyl sorbitol and hexa acetyl mannitol which may be used in admixture, e. g. as disclosed in EP-A-0 525 239. Further examples are compounds having nitrogen atoms in the basic carbohydrate skeleton, e. g. the peracetylated forms of N-methyl gluconamide, N-methyl glucamine and glucopyronosyl amine.

It is considered particularly preferable to combine such bleach activators and such pre-formed per acids with one another to promote antibacterial and bleachable stain and soils cleaning. Particularly preferred combinations are of per acetic acid precursors with precursors of higher alkyl peracids such as fall in the range propyl to behenate. Particularly preferred are the branched alkyl analogues of such materials.

Various supplementary chlorine bleaches may also be employed either as a hypochlorite, for example, an alkali metal hypochlorite or as a precursor compound such as Trichloro iso cyanuric acid, sodium dichloro isocyanurate and its di hydrate (e. g. Oxidan (TM) DCN/WSG ex Sigma). Such systems may be used in conjunction with a suitable catalyst for example as described in EP 937 772 (Procter).

Effervescent systems An effervescent system may be employed. Suitable agents include a mixture of an acid and an alkali metal carbonate or bicarbonate, for example citric acid and sodium carbonate. Sodium percarbonate peroxohydrate (e. g. ex Eka chemicals) is also considered.

Clays A clay may be used in the composition, either per se or as a carrier for perfume. The clay which is used in the formulation of the invention may be any one of the fabric softening clays having fabric softening properties used in laundry detergent formulations. Such clays are generally of the"lamellar type"and are such that the layers"separate"to become deposited on the garments being washed. The clay may for example be a Smectite such as a Laponite, Bentonite, Montmorrillonite, Hectorite or Saponite. For example, the clay may be a Sodium Montmorrillonite, a Sodium Hectorite, a Sodium Saponite, a Calcium Montmorrillonite or a Lithium Hectorite.

Enzymes An enzyme may be included in the composition. The enzyme may, for example, be a protease, amylase, lipase, an endo and exo cellulases, cholesterol oxidases (particularly as described in WO 99/45106 (Meiji Seika) ) or mixtures thereof such as commonly used in detergent formulations. Examples of suitable enzymes are available under the names Opticlean (TM), Savinase (TM), Esperase (TM); Termamyl (TM), Maxamayl (TM), Lipomax (TM), Lipolase (TM); Celluzyme (TM) and Carezyme (TM). The amount of enzyme incorporated in the formulation will depend on activity but will typically be 0.1 to 3 %. This level is particularly suitable for Savinase 6. 0T, Termamyl 60T, Celluzyme 0.7T and Lipomax.

It is a preferred that the bactericides listed be combined with one or more enzymatic components. The person skilled in the art will readily identify those materials which do not significantly inhibit enzymatic activity and thereby identify those were synergistic bactericidal effects are obtained.

It will be appreciated that the formulation may incorporate additional components as conventionally included in a hard surface cleaner, laundry detergent, fabric refresher, fabric conditioner or similar product.

The incorporation of amine oxides for foam enhancement is a particularly preferred additional component.

For a laundry detergent formulation it will be appreciated that the formulation may incorporate additional components as conventionally included. One example of such an additional component is a soap or fatty acid which may be used in an amount of up to 5 % by weight as an antifoam or processing aid. Particularly preferred are those with C8 to C22 alkyl chains, more preferably C12 to C12 alkyl and with an iodine value less than 5 more preferably less than 1. Mono, di and trifunctional acids are not without the scope of the invention.

Particularly suitable are the Prifac (TM) and Pristerine (TM) materials supplied by Uniquema.

Further examples include anti-foam agents, whiteness maintenance agents (e. g. CMC, polyoxyethylene terephthalate, polyethylene terephthalate), colorants (e. g. dyestuffs), perfume, flow control agents (e. g. a sulphate) flow enhancer (e. g. a zeolite), pH regulators (e. g. a carbonate or bicarbonate), anti-corrosion agents, dye transfer inhibitors (e. g. PVP) and optical brighteners (e. g. Tinopal CBS-X and Tinopal DMS-X). These components may, for example, each be present in amounts up to 1 % by weight of the formulation.

Cyclodextrins and cyclodextrinoids, optionally as alcohol, amide, ether, ester, hydrophobised, conjugated, granulated, encapsulated and solubilised, derivatised and embodied as such are all envisaged as being potentially incorporated ways of changing their use provided that they retain some ability to complex smaller molecules.

Cyclodextrin incorporation of between 0 and 5%, more preferably between 0.05 and 2%, most preferably between 0. 075 and 1. 25 % is within the scope of the invention.

Perfumes A perfume will typically be formulated in a product using the invention. The perfume ingredients and compositions of this invention are the conventional ones known in the art. Selection of any perfume component, or amount of perfume, is based on aesthetic considerations.

Bactericide A (supplementary) bactericide may be optionally included in the detergent product or the external carton packaging. Compositions containing bactericide will contain from 5 to 0. 0001% bactericide, virucide or anti-microbial agent, preferably from 2 to 0. 001%, more preferably from 1 to 0.005% most preferably from 0.1 to 0. 01%. Biocides as listed in annex 1 of the Biocidal Products Directive of the EC. are considered particularly suitable. Such materials may be used in combination, when used in combination such bactericidal, virucidal or anti-microbial agents will each be present at a level of from 5 to 0.00003% bactericide, virucide or anti-microbial agent, preferably from 3 to 0. 0001%, more preferably from 1 to 0. 0001% most preferably from 0.1 to 0. 001%.

Most preferred are the bactericidal agents in table 1 which are single organic molecules with a molecular weight above 250. Not wishing to be bound by theory such molecules possess lower potential for human toxicity by virtue of their higher molecular weigh and absence of inorganic materials.

Additional optional components The detergent used in the invention may also contain an optical brighteners or fluorescer. For

example Tinopal CBS-X (disodium 2, 2'-bis- (phenyl-styryl) disulphonate and Tinopal DMS-X (4, 4'bis- (2-morpholino-4-anilino-s-triazin-6-ylamino) stilbene disulphonate) and the various possible alkali metal salts thereof particularly the potassium salts.

An integral part of the invention is a container/vessel for the liquid which utilises the evolution of the gas to dispense the liquid. Such a container of the invention has as its essential components a substantially airtight area or region when in use, a region for the retention of a liquid, these two regions being in communication one with another such as to transmit changes in pressure from one to another. Such regions typically effectively make use of the same enclosed area. Airtight means an area not subject to the substantial movement of gasses in the absence of a pressure gradient, i. e. capable of gas transmission by gas-gas diffusion only.

A further essential component of the container of the invention is an aperture or apertures which freely communicate with the outside of the container. Such apertures are small enough that the liquid, with reference to the surface tension and liquid viscosity is used for a particular device, will not substantially loose i. e. drip'glug'etc. the liquid when there is effectively no net pressure difference between the liquid surface and the atmosphere and the container is inverted so that the plane of the liquid interface is horizontal and above the surrounding atmosphere in which it is in communication.

Hence, there is provided a vessel which when in use has the only aperture or apertures which freely communicate with the atmosphere below the level of a liquid or similar enclosed therein such that the liquid can be released over an extended period of time due to changes the pressure differential across the aforementioned air/liquid interface.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the attached drawing. In which: Figure 1 is a diagrammatic representation of a suitable dispensing device, in the orientation required for operation and which is depicted as containing the liquid essential for the operation of the device.

1 is a container which posses a one or more apertures, those apertures above the level of the liquid in normal use (6) are sealed and at least one aperture below the level of the liquid (4) is open to the outside. The liquid in the container (3) remains inside the container when placed in the orientation shown as, either on filling or after partial loss of the liquid an area of reduced pressure (2) develops above the liquid such that an equilibrium is reached wherein no further liquid is lost. The container (1) may optionally be flexible enough that, for example, the force of flushing water will marginally alter its dimensions, disrupting the pressure differential between

inside (2) the container and ambient pressure such that liquid is lost from the container through ins] t : l an orifice or orifices (4). Any such loss is optionally caught by a plate, porous mass, sponge or similar placed in its path so as to prolong the dissipation of the liquid in to the toilet bowl and surrounds.

Figure 2 is also a diagrammatic representation of the same device illustrating the mode of action

resulting from the inventive combination of a liquid capable of evolving a gas and a device as t, z : l described above which is the subject of this application.

Over time the liquid (3) evolves gas (8) either as bubbles or not, such that the pressure in the space above the liquid (2) is increased (7) thereby causing liquid to egress (9) from the orifice (s) provided below the level of the liquid. The liquid, when the device is operated in a toilet bowl or cistern then serves to give disinfecting, odiferous, cleaning, colouring or other action.

The orifice (4) is preferably a small number of holes or channels of cross sectional area of less

than 5 mm2 preferably less than 3 mm and greater than 1 mm2 and most preferably a single hole.

In another embodiment of the invention the orifice may be composed of a plurality of small orifices as present in a porous mass, e. g. a sponge, fibre bundle or similar.

In a further aspect of the invention a porous mass is present at all orifices which communicate the contents of the reservoir to the atmosphere and the average pore size of the porous mass is less than lmm, more preferably less than 0. 4mm and preferably from 0.25 to O. 01mm.

In the aforementioned aspect of the invention the porous mass will preferably have a cross sectional surface area of between 0.2 and 6cm2 preferably between 0.5 and 3cm2, most

2 preferably between 1 and 2 cm.

To give greater safety, convenience and storage life the device is preferably sold with a partial vacuum above the liquid (2) such that pressure takes longer to build up.

To give increased storage life the device is preferably sold with an (optionally removable) cover

over one of the orifices such that gas may freely pass through but liquid not. Such materials are 0 well known in the trade and Gortex TM is a well known type thereof. For the purposes of the invention such a cover, though gas permeable, is not considered an orifice as to be an orifice is required that liquid may reasonably pass through.

The invention is illustrated by the following non-limiting examples : Z=l Liquid compositions

Component 1 2 3 Comparative Sodium Hypochlorite Nil 30% Nil Hydrogen Peroxide 30% Nil Nil 40% Dequest 2046 Nil Nil 0. 2% ex Monsanto/Solutia Sodium hydroxide 1% 1% 0. 1% Na alkyl ether (3EO) sulphate 1. 5% 1. 5% 1. 5% Alkyl Amine Oxide Cl2 1. 5% 1. 5% 1. 5% Perfume TB 16620% 20% 20% ex Carvansons UK Ltd Water To 100% To 100% To 100% In all cases the total heavy metal ion content (primarily Iron) was 0. 5ppm.

Device used.

The device described in international design application DM 051/876 in the name of Yplon SA, as moulded using thin polyethylene and currently available as part of the product'Spring Fresh, liquid rim block'ex Wilkinsons Hardware stores UK was used with the orifice covered with a 2mm thick Teflon TM plate with a hole of 2mm diameter drilled in its centre.

The vessel was filled with the liquid (approximately 275ml) and inverted. The liquid ran out initially until a partial vacuum was established in the space above the liquid. The Teflon plate was then wiped to remove excess droplets of liquid and the whole assembly was suspended from below a weighing balance and the weight of the device monitored over time. The results are an average of three repeat tests per composition all sequentially using the same device. Weight is weight decrease compared to initial weight

Time Composition3 0 0 0 0 1 0.5 0.5 0.4 2 0.6g 0.6g 1.0g 3 0.6g 1.1g 1.2g 4 1.3g 1.4g 5 0.7g 1.4g 1.9g 6 0.7g 2.0g 2.1g

This data shows the continuous dispensing of liquid achieved by the gas evolution. The low loss of composition 1 can be accounted for by evaporation of the perfume and no loss of liquid to the vessel below (c. f. toilet bowl) was observed. The initial loss of all devices was due to the delay in fully establishing the vacuum above the liquid, i. e. a kinetic effect.

Claims (1)

1. Claims 1) A detergent product for toilet cleaning and the like comprising a vessel which when in use has the only aperture or apertures which freely communicate with the atmosphere below the level of a liquid or similar enclosed therein such that the liquid is released over an extended period of time by the evolution of gas from a substance also enclosed within the vessel.

   2) A detergent dispensing combination as described in claim 1 wherein the liquid contains hydrogen peroxide or an alkali metal hypochlorite or a combination thereof.

   3) A detergent dispensing combination as described in claim 1 wherein the liquid contains less than 5 parts per million of transition metal ions.

   4) A detergent dispensing combination as described in claims 2 or 3 wherein the liquid is alkaline.

   5) A detergent dispensing combination as described in claim 2 wherein the half life of decomposition of the 6) A detergent dispensing combination as described in claim 2 wherein the hydrogen peroxide or an alkali metal hypochlorite or a combination thereof win the presence of activators or stabilisers as described has a half life of decomposition of more than 3 months.

   7) A detergent dispensing combination as described in any proceeding claim in which the vessel

   is capable of changing its shape, orientation or is mechanically activated during a flushing Z > operation when contacted with a flushing action of a conventional flush toilet such as to deliver additional liquid.

   8) A detergent dispensing combination as described in any proceeding claim in which the vessel is at least partially transparent.

   9) A detergent dispensing combination as described in claim 6 wherein the transparent part or parts of the vessel are in direct communication with the liquid and in which they are capable of substantially transmitting light of less than 400nm.