GB2503409A

GB2503409A - Cleaning composition for treatment of lime scale

Info

Publication number: GB2503409A
Application number: GB1201813.1A
Authority: GB
Inventors: Matthew Stuart Clark; Tony Griffin; Matthew Stevenson; Amandine Sbardella; Dean HILL
Original assignee: Jeyes Group Ltd
Current assignee: Jeyes Group Ltd
Priority date: 2012-02-02
Filing date: 2012-02-02
Publication date: 2014-01-01
Also published as: GB201201813D0

Abstract

A composition for treatment of lime scale consists essentially of water, formic acid and sulfamic acid. A method of treating lime scale on an object, such as a shower head 14, is also claimed, wherein the object and a composition comprising water, formic acid and sulfamic acid are enclosed in a stand-up pouch 12. The composition is left to react with lime scale on the object and then the object is removed from the pouch and rinsed. In another aspect, a kit for the treatment of lime scale comprises the stand up pouch and the composition. Preferably, the pouch is made of a laminate having a layer of polyterephthalate and a layer of polyethylene. The stand up pouch can be translucent or transparent. A surfactant may be included in the composition, such as an alkoxylated alcohol, or a di or trialkyl amine ethoxylate salt. Suitably, the composition also comprises a surface modifying polymer formed from trimethyl-[2-(2-methyl-1-oxoprop-2-enoxy)ethyl]ammonium chloride, 2-propenoic acid and 2-propenamide. A C1-8 alcohol and thickener, such as propylene glycol and xanthan gum respectively, can also be included in the composition.

Description

Cleaning composition

INTRODUCTION

The present invention relates to a kit for treatment of lime scale comprising a stand-up pouch and a composition and to methods of treating lime scale using the kit.

The invention is also concerned with a composition that is particularly effective in treating lime scale using the kit.

BACKGROUND

Lime scaling is the deposition of inorganic salts on a surface or object. The most common inorganic salt present in lime scale is CaCO3. Soluble calcium bicarbonate (Ca(HCO3)2) in mains water is converted to insoluble CaCO3 when the water is heated. The CaCO3 precipitates out of the water forming limescale. Once formed, the inorganic salt, i.e. the scale, tends not to redissolve.

Visible lime scale deposits are aesthetically displeasing and moreover can impact on the performance of devices. Lime scale deposited on a shower head, for example, can impact on its spray pattern Furthermore, the formation of lime scale frequently occurs in combination with other types of soils, such as soap scum or grease, and can lead to the formation of limescale-soil mixture deposits (lime scale-containing soils). Such deposits are unsightly and may be considered unhygenic.

A number of lime scale removing compositions are of course already available on the market. These compositions are typically used by applying the lime scale removing liquid to the surface or object to be treated by pouring or squeezing it from a bottle or via a spray system. After leaving the liquid to react with the lime scale for a period of time, the surface or object is then rinsed. This method works best for surfaces and objects that are easy to access and generally planar since the liquid can be applied to such surfaces and it will generally remain in contact therewith.

When non-planar objects are treated with conventional lime scale removing methods, however, the liquid tends to run off of the surafce. Thus, for example, when a shower head is sprayed with lime scale removing liquid, the liquid tends to run around its surface and then drip or run off. This means that the contact time between the lime scale present on the shower head and the lime scale removing liquid is limited. This problem is exacerbated when the lime scale is present in a hard to reach locations, e.g. around the nozzles of the shower head. Lime scale removing liquid may be squeezed or sprayed onto such areas but it is difficult to additionally scrub or wipe them as they are generally positioned so closely together that access is difficult.

A need therefore exists for improved lime scale removing kits and methods that can be used to effectively remove lime scale, particularly from non-planar objects having difficult to reach areas, such as shower heads. The methods should dissolve lime scale quickly and preferably leave the object treated with an aesthetically pleasing appearance, e.g. with a shine. Obviously the kits and methods should not cause any damage to the objects treated.

SUMMARY OF INVENTION

Thus viewed from a first aspect, the present invention provides a kit for treatment of lime scale comprising: (a) a stand up pouch; and (b) a composition comprising: (i) water; (ii) formic acid; and (iii) sulfamic acid.

Viewed from a further aspect, the present invention provides the use of a kit as hereinbefore defined for treating lime scale on an object.

Viewed from a further aspect, the present invention provides a method of treating lime scale on an object comprising: (i) enclosing said object and a composition as hereinbefore defined in a stand-up pouch; (ii) optionally shaking said pouch to distribute said composition over said object; (iii) leaving said composition to react with lime scale on said object; and (iv) removing said object from said pouch and rinsing it.

Viewed from a further aspect, the present invention provides a composition for treatment of lime scale consisting essentially of water, formic acid and sulfamic acid.

DETAILED DESCRIPTION OF INVENTION

As used herein the term lime scale is intended to encompass any precipitate which may be formed in a water system, especially a domestic water system. In domestic water systems, typical examples of lime scale include carbonate salts of group I and group II metals, e.g. CaCO3 and MgCO3. The composition of the present invention is particularly effective in treating lime scale comprising CaCO3.

Lime scale may be categorised as "thin lime scale". By "thin lime scale" is meant lime scale that has been formed over a period of less than 8 weeks.

Lime scale may also be categorised as "hard lime scale". By "hard lime scale" is meant lime scale that has been formed over a period of more than S weeks.

As used herein the term %wt refers to the percentage by weight of the entire composition unless otherwise specified.

As used herein the term stand-up pouch refers to a pouch that can stand upright unsupported when it is filled with a liquid.

Any type of conventional stand-up pouch may be used in the kits of the invention. Preferably, however, the stand-up pouch has a round bottomed gusset.

The stand-up pouch preferably comprises a front panel, a back panel and a gusset connected between the front and back panel to form the base of the pouch when the pouch is standing up. The gusset is preferably moveable relative to the front and back panels whereby the pouch is moveable between a folded or flat packed arrangement position in which the gusset is sandwiched between the front and back panels and a stand-up arrangement in which the pouch is opened up so that the gusset forms the bottom of the pouch.

The back and front panels each have a top edge, a bottom edge and side edges disposed between the top and bottom edges. The side edges of the front and back panels are permanently joined together to form a watertight seal (e.g by welding).

Similarly, the gusset is permanently joined to each of the front and the back panel to form a water tight gusset seal. In this way, the pouch will not leak when a composition is poured into the pouch.

The pouch also has a closing mechanism for temporarily closing the pouch, perhaps in the form of a zip seal, slider mechanism or similar seal which can be opened and closed repeatedly. Preferably the closing mechanism is located 1 to 5 cm, more preferably 2 to 4 cm from the top of the pouch, typically from the top edges of the front and back panels of the pouch. Spacing the closing mechanism from the upper ot top edge of the pouch reduces the risk of leakage if the pouch is knocked over, even if the closing mechanism is not 100% watertight.

The back and front panels are preferably rectangular in shape, still more preferably with 4 right angled corners. The gusset is generally an elongate oval shape with a pair of opposed edges joined at corner whereby the gusset forms a round or U-shaped bottom to the pouch. The skilled man will readily be able to determine a suitable size for the panels but preferably the front and back panels are 25 to 40 cm in length. Preferably the front and back panels are 15 to 25cm in width. Preferably the gusset is 15 to 25 cm in length. It will be appreciated that other suitable shapes may be used for the panels and gusset.

The gusset may be joined along one edge to the front panel and along its opposing edge to the back panel. The corners of the gusset may be sealed between the side edges of the front and back panels. The gusset seal may be located along a line which is spaced away from the bottom edge of the back and front panels. In preferred pouches the seal line is located between 2 and 5 cm, more preferably about 4 cm from the bottom edge of the front and back panels. The seal line may be parallel to or curved relative to the bottom edge. A curved seal line is preferred as it increases the strength of the pouch.

The stand-up pouches must of course be able to withstand the compositions described herein for the removal of lime scale. The compositions are highly corrosive, therefore the pouches must be made of chemically resistant material, preferably a polymer. The pouches must also be made of a material that is sufficiently rigid or self-supporting to enable the pouch to stand up.

Preferred stand-up pouches are made of polymer laminates having an inner layer and an outer layer. Preferably the inner layer comprises polyethylene terephthalate. Preferably the outer layer comprises polyethylene. Preferably the polymer laminate is impermeable to 002.

Preferably the stand-up pouch is transparent or at least translucent. This is advantageous as it enables the user to observe the progress of lime scale removal during the treatment of an object. The stand-up pouch of the kits of the present invention is preferably reusable. For instance, the stand-up pouch may be rinsed after use and then stored until it is required again.

Preferred kits of the invention further comprise instructions for the use of the kit.

The composition of the present invention preferably has a viscosity of 2 to 100 cps, more preferably 5 to 50 cps and still more preferably 7 to 20 cps, especially about cps. At this viscosity, the composition is in liquid form. Preferred compositions are therefore in liquid form. This ensures that the composition can be readily poured into a stand-up pouch and distributed over the object present therein by shaking.

Preferred compositions of the present invention comprise 65-85 %wt, more preferably to 80 %wt and still more preferably 72 to 77 %wt water. The water may be tap water, distilled water or deionised water. Tap water is preferred, particularly soft tap water. Soft tap water is generally substantially free of any undesirable impurities such as organics or inorganics, especially mineral salts, which are present in hard water and which may undesirably interfere with the operation of the compositions of the invention.

An important feature of the compositions of the present invention is the acids present therein. Preferred compositions of the present invention have a pH of 0.3 to 3.0, still more preferably 0.5 to 2.0 and still more preferably 0.7 to 1.3. The acidic pH of the composition of the invention ensures that it treats lime scale. The acids present in the composition react with the lime scale. Generically the Ca003 reacts with the acid to produce a soluble calcium salt, carbon dioxide and water. The successful treatment of lime scale with the composition of the invention can often be determined by the observation of bubbles at the treatment site. This is due to the release of 002 in the reaction. The compositions of the invention preferably treat lime scale, e.g. as evidenced by the release of 002, within 10 minutes, more preferably within 5 minutes and yet more preferably within 2 minutes of its application to the lime scale.

The compositions of the present invention comprise formic acid, i.e. methanoic acid. Preferably the formic acid incorporated into the compositions of the invention has a concentration of 80 to 95 % wt and still more preferably about 90 % wt. Formic acid, e.g. 90 %wt formic acid for use in the compositions of the invention is commercially available from a range of suppliers, e.g. Univar.

Preferred compositions of the invention comprise 2 to 20 %wt formic acid, still more preferably 3 to 15 %wt formic acid and yet more preferably 3 to 5 %wt or 8 to 12 % formic acid. Thus when formic acid is used in the form of a 90 % wt aqueous solution, the amount of formic acid added to the composition is preferably in the range 3 to 20 %wt, more preferably 4 to 15 %wt and still more preferably 4 to 6 %wt or 9 to 13 %wt formic acid.

The compositions additionally comprise sulfamic acid. It has been surprisingly found that the combination formic acid and sulfamic acid is particularly effective in combination. Particularly preferably the compositions display a synergistic effect in the performance of its acids. Thus in preferred compositions, the effect of the combination of formic acid and sulfamic acid on lime scale exceeds the additive effect of the use of formic acid and sulfamic acid individually. This is highly advantageous since it means that the overall amount of acid, which is corrosive, present in the compositions of the invention can be reduced.

Preferred compositions of the invention comprise 7.5 to 12.5 %wt sulfamic acid, still more preferably 8 to 12 %wt sulfamic acid and yet more preferably 9 to 10 % wt sulfamic acid. Sulfamic acid is commercially available for a range of suppliers, e.g. Univar.

Preferably the total amount of acid present in the composition is 12 to 25 %wt and still more preferably 20 to 25 %wt or 12 to 15 %wt, especially 20 to 25 %wt.

The compositions optionally comprise a number of other ingredients, e.g. a surfactant, a surface modifying polymer, a C8 alcohol and/or a thickener.

Some preferred compositions further comprise at least one surfactant. When present the surfactant may be anionic, cationic or non-ionic. Preferred compositions comprise at least two surfactants, e.g. two surfactants. Particularly preferred compositions comprise a non-ionic surf actant and a cationic surfactant.

The presence of a non-ionic surfactant in the compositions has been found to enhance their cleaning performance, e.g. in soap scum removal. As a result, when compositions comprising a non-ionic surfactant are used to clean an object they tend to leave a shine that is aesthetically pleasing. Such compositions tend to be highly rated in consumer tests.

A particularly preferred class of non-ionic surfactant for use in the compositions are alkoxylated alcohols. Such surfactants can be readily made by condensation reactions that are well known in the art. Additionally a huge range of alkoxylated alcohol surfactants, and especially ethoxylated alcohol surfactants, are commercially available.

Preferred alkoxylated alcohols for use in the compositions are of formula (I): RO(CH2CH2O) O(CH2CH2CH2O) H (I) where P is a C224 alkyl or alkylene, preferably alkyl, chain; and e and p represent the average degree of ethoxylation and propoxylation respectively and are each, independently from 0 to 24, wherein the sum of e and p is at least 2.

In preferred compounds of formula (I) R is 0418, more preferably 0612.

Preferably R is straight chain alkyl.

In further preferred compounds of formula (I) p is 0.

In yet further preferred compounds of formula (I) e is 1 to 20, preferably 5 to 15, e.g. 6to 12.

A particularly preferred class of cationic surfactants for use in the compositions are quaternary ammonium surfactants, particularly di or trialkyl amine ethoxylate salts.

Preferably the alkyl groups present in these surfactants contain between 1 and 22 carbon atoms. The alkyl groups may be saturated or unsaturated but are preferably saturated. The average degree of ethoxylation is preferably 2 to 20. The degree of propoxylation is preferably 0 to 20. Such cationic surfactants are commercially available.

Preferred quaternary ammonium surfactants for use in the compositions of the invention are of formula (ID: R1R2R3N(CH2CH2O)H X II wherein each of P1 and P2 is independently a C124 alkyl or alkylene, preferably alkyl, chain; P3 is (CH2CH2O)1H or a C124 alkyl or alkylene, preferably alkyl, chain; n is between 2 and 24, preferably 3 to 16, still more preferably 3 to 12; m is between 2 and 24, preferably 3 to 16, still more preferably 3 to 12; and Xis a counter ion.

In preferred compounds of formula (II) R1 is 04-18 alkyl, more preferably 06-16 alkyl, still more preferably C1218 alkyl. Preferably P1 is straight chained alkyl.

In further preferred compounds of formula (II) P2 is C alkyl, more preferably Cl_s alkyl, e.g. methyl, ethyl or propyl. Particularly preferably P2 is methyl.

In further preferred compounds of formula (II) R3 is (CH2CH2O)mH. When P3 is C124 alkyl, however, it is preferably alkyl, more preferably C13 alkyl, e.g. methyl, ethyl or propyl, especially methyl.

In compounds of formula (II) X may be any counter ion, e.g. a halide such as cr or Br.

A preferred surfactant blend comprising a non-ionic surfactant and a cationic surfactant is commercially available from Chemlink under the name Link 706. It is indicated by its supplier to be an aqueous surfactant blend comprising 60-70 % wt of ethoxylated 0721 alcohol and 20-30 %wt of a chloride salt of a quaternary coco alkyl methyl amine ethoxylate. Compositions comprising Link 706 are observed to have excellent cleaning characteristics giving surfaces a shiny appearance.

When present, there is preferably 0.10 to 1.00 %y total surfactant in the compositions, more preferably 0.15 to 0.75 %wt total surfactant and still more preferably 0.20 to 0.50 %wt total surfactant. Particularly preferred compositions comprise 0.06 to 0.7 %wt of non-ionic surfactant, more preferably 0.09 %wt to 0.50 %wt and still more preferably 0.12 to 0.5 %wt. Further particularly preferred compositions comprise 0.02 to 0.3 %wt of cationic surfactant, more preferably 0.03 %wt to 0.2 %wt and still more preferably 0.04 to 0.15 %wt.

Some further preferred compositons comprise a surface modifying polymer.

Preferred surface-modifying polymers impart a shine on the object treated. Preferred polymers comprise charged side chains, still more preferably positively charged side chains. Particularly preferred surface-modifying polymers comprise side chains comprising an ammonium salt. Whilst not wishing to be bound by theory it is hypothesised that such polymers impart a hydrophilic and easy cleaning property to the surface to which they are applied.

When present, the surface-modifying polymer is preferably formed from a trimethyl-[2-(2-methyl-1 -oxoprop-2-enoxy)ethyl]ammonium salt, e.g. trimethyl-[2-(2-methyl-i -oxoprop-2-enoxy)ethyl]ammonium chloride. Although homopolymers formed from trimethyl-[2-(2-methyl-1 -oxoprop-2-enoxy)ethyl]ammonium salt could be used, copolymers of trimethyl-[2-(2-methyl-1 -oxoprop-2-enoxy)ethyl]ammonium salt are preferred.

Particularly preferred surface-modifying polymers for use in the compositions are also formed from a C36 alkenoic acid, e.g. of formula CH2=CH(CH2)aCOOH where a is an integer between 0 and 3. Especially preferred surface-modifying polymers are formed from 2-propenoic acid.

Further preferred surface-modifying polymers for use in the compositions are also formed from a C33 alkenamide, e.g. of formula CH2=CH(0H2)bCONH2 where b is an integer between 0 and 3. Especially preferred surface-modifying polymers are formed from 2-propenamide.

A preferred surface-modifying polymer for use in the compositions is commercially available under the tradename Flexipel SR-SO from Chemlink. It is supplied in the form of a 10-30% wt dispersion in water. Its suppliers indicate that it is a polymer formed from trimethyl-[2-(2-methyl-1 -oxoprop-2-enoxy)ethyl]ammonium chloride, 2-propenoic acid and 2-propenamide.

The compositions preferably comprise 0.001 to 0.15 %wt of surface-modifying polymer, more preferably 0.005 to 0.10 %wt and still more preferably 0.01 to 0.03 %wt.

Some preferred compositions comprise a C15 alcohol, especially a diol.

Representative examples of suitable C18 alcohols that may be present in the compositions of the invention include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol. Propylene glycol is particularly preferred.

The compositions preferably comprise 0.05 to 5 %wt Cl_s alcohol, more preferably 0.1 to 3 %wt C1-8 alcohol and still more preferably 0.25 to 1 % wt 018 alcohol.

Some preferred compositions comprise a thickener. When present the thickener is preferably a polysaccharide. Suitable polysaccharides for use in the compositions include substituted cellulose materials such as carboxymethylcellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxymethyl cellulose, succinoglycan gum, xanthan gum, gellan gum, guar gum, locust bean gum, tragacanth gum. Derivatives of any of the afore-going and/or mixtures of the afore-going may also be used.

Preferred compositions comprise a polysaccharide selected from the group consisting of succinoglycan gum, xanthan gum, gellan gum, guar gum, locust bean gum, tragacanth gum and derivatives thereof. More preferably the compositions comprise a polysaccharide selected from the group consisting of xanthan gum, gellan gum, guar gum and derivatives thereof. Most preferably, the compositions comprise xanthan gum or derivatives thereof.

Polysaccharides for use in the present invention are commercially available.

Suitable xanthan gum and derivatives thereof are, for example, commercially available from Rhodia under the trade name Rhodopol extra2 clear.

Typically, the compositions comprise 0.05 % wt to 2 % wt by weight of the total composition of a thickener (e.g. polysaccharide), more preferably 0.1 % wt to 1 % wt and most preferably 0.2 % wt to 0.5 %wt. At these levels the composition is still in the form of a liquid.

One particularly preferred composition comprises: (i) 65 to 85 % wt water; (ii) 2 to 20 %wt formic acid; (iii) 7.5 to 12.5 %wt sulfamic acid; (iv) 0 to 2.0 %wt thickener, preferably xanthan gum or a derivative thereof; (v) 0 to 1.00 %wt surfactant, preferably a blend of non-ionic and cationic surfactant; (vi) 0 to 0.15 %wt surface-modifying polymer, preferably surface-modifying polymer which comprises side chains comprising an ammonium salt; and (vii) 0 to 5.0 %wt alcohol, preferably propylene glycol.

Another particularly preferred composition comprises: (i) 65 to 85 % wt water; (ii) 3 to 5 %wt formic acid; (iii) 7.5 to 12.5 °Awt sulfamic acid; (iv) 0.2 to 0.5 %wt thickener, preferably xanthan gum or a derivative thereof; (v) 0.20 to 0.50 %wt surfactant, preferably a blend of non-ionic and cationic surfactant; (vi) 0.01 to 0.03 %wt surface-modifying polymer, preferably surface-modifying polymer which comprises side chains comprising an ammonium salt; and (vii) 0.25 to 1.0 %wt 01-8 alcohol, preferably propylene glycol.

Another particularly preferred composition comprises: (i) 72 to 77 % wt water; (ii) 8 to 13 %wt formic acid; and (iii) 8 to 12 %wt sulfamic acid.

Notwithstanding the afore-going a particularly preferred composition consists essentially of water, formic acid and sulfamic acid. An especially preferred composition consists of water, formic acid and sulfamic acid.

Thus an especially preferred composition consists essentially of (e.g. consists of): (i) 72 to 77 % wt water; (ii) 8 to 14 %wt formic acid; and (üi) 8 to 12 %wt sulfamic acid.

Other optional ingredients that may be present in the compositions include perfume, dye, pigments, organic solvents, chelating agents, ferrous ion (and/or ferrous ion compounds), radical scavengers, buffers, bactericides, hydrotropes, colorants, stabilizers, bleaches, bleach activators, enzymes, soil suspenders, brighteners, anti dusting agents and dispersants. The skilled man will readily be able to determine the necessary amount of each of these ingredients. Generally compositions will comprise 0-5 wt% of such ingredients, preferably less than 3 %wt of such ingredients and still more preferably less than 2 %wt.

The compositions may be prepared using methods conventional in the art.

Typically the composition is prepared by mixing (i) water; (ii) formic acid; (iii) sulfamic acid; and optionally (iv) thickener; (v) surfactant; (vi) surface-modifying polymer and (vii) C18 alcohol using a stirrer. The composition may be prepared by mixing the ingredients in any order and the skilled man will be able to determine suitable procedures. One preferred method, however, comprises (e.g. consists of): mixing (i) water; (ii) formic acid, and (iii) sulfamic acid, still more preferably without adding any thickeners or surfactants.

The compositions are preferably provided as a ready to use composition. It can then be directly poured into the stand up pouch. The compositions may be packaged in any suitable container particularly bottles or pots. Preferred bottles and pots are formed from HDPE. HDPE is preferred as it is chemically resistant. Particularly preferred bottles and pots comprise a lined cap, especially an expanded polyethylene lined cap. Such caps provide excellent sealing.

The present invention further encompasses a method of treating lime scale on an object comprising: (i) enclosing said object and said composition in a stand-up pouch; (ii) optionally shaking or agitating said pouch to distribute said composition over said object; (iii) leaving said composition to react with lime scale on said object; and (iv) removing said object from said pouch and rinsing it. Preferred methods comprise the step of shaking or agitating the pouch.

In the step of enclosing the object and the composition in the stand-up pouch the pouch may not be completely sealed. This allows 002 released during lime scale treatment to escape from the pouch. Alternatively the pouch may be sealed but be of sufficient volume to contain the 002 released.

The object treated using the kit and compositions of the invention encompass any object prone to lime scale formation and which can be enclosed in a stand-up pouch. These include water-valves, shower heads and shower fittings and parts thereof. The method of the invention is, however, particularly suited to the treatment of shower heads. These can usually be easily detached from a shower unit and are suitably sized for enclosure in a stand-up pouch as hereinbefore described.

Preferred objects treated with the kits and compositions of the present invention have non-planar surfaces that are difficult to clean by conventional methods wherein the lime scale treatment composition is simply poured onto the object and left to react.

The kit and composition of the invention are advantageous as it enables entire objects to be exposed, and preferably soaked, in a composition. This enables the composition to contact spaces and cavities on the object that are prone to lime scale build up but which are difficult to access by conventional techniques. The fact the pouch stands up makes the kit and composition convenient to use and easy to handle.

In a preferred method of the invention the composition is left to react with lime scale for 2 to 20 minutes, more preferably for 5 to 15 minutes, still more preferably for about 10 minutes.

Preferably rinsing is with water. Preferably the resulting surface has a shiny appearance.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in the following non-limiting examples and Figures wherein: Figures la and lb shows front views of a kit according to present invention; Figures 2a and 2b are front and side views of the stand up pouch of Figure 1; and Figures 3a to 3j shows the performance of testing of a composition of the invention in treatment of lime scale.

DETAILED DESCRIPTION OF THE DRAWINGS

Figures la and lb shows a kit for treatment of lime scale on an object 14, the kit comprising a pouch 12 and a container 10 holding a composition 16. In use, said object is placed within said pouch as shown in Figure la and said composition is poured into said pouch until the level of composition within said pouch is sufficient to cover said object as shown in Figure lb. The pouch is then closed and may be agitated or shaken to distribute said composition over said object. The closed bag is then left for sufficient time, e.g. 5 minutes, to allow said composition to react with lime scale on said object. The bag may not be completely sealed to allow CO2 released during the dissolution of lime scale to be released. The object is then removed from said pouch and rinsed.

As shown in Figures 1 a and 1 b, the object treated using the kit is a shower head. It will be appreciated that other similar objects, e.g. water-valves, other shower fittings and parts thereof could also be treated. Furthermore, as shown in Figures la and 1 b, the stand-up pouch is preferably transparent or at least translucent so that a user can observe the progress of lime scale removal during the treatment of an object.

Figures 1 a and lb also shows that the pouch 12 stands upright whether or not there is any liquid therein. The pouch is particularly stable when it is filled with a liquid.

Any type of conventional stand-up pouch may be used in the kits of the invention and the details of one such pouch are shown in Figures 2a and 2b.

As shown, the stand-up pouch comprises a front panel 22, a back panel 24 and a gusset 26 which is connected between the front and back panel. The gusset is moveable relative to the front and back panels. The pouch is thus moveable between a folded or flat packed arrangement position in which the gusset is sandwiched between the front and back panels and a stand-up arrangement in which the pouch is opened up so that the gusset forms the bottom of the pouch. The use of a gusset enables the pouch to be opened more than if the back and front panels were joined together along their bottom edges.

The back and front panels each have a top edge 32, 42, a bottom edge 34, 44 and side edges disposed between the top and bottom edges. As shown, the back and front panels are rectangular in shape with four right angled corners. The gusset is generally an elongate oval shape with a pair of opposed edges joined at corners 38 whereby the gusset forms a round or U-shaped bottom to the pouch. It will be appreciated that other suitable shapes may be used.

The side edges of the front and back panels are permanently joined together to form a water tight seal 28. Similarly, the gusset is permanently joined to each of the front and the back panel to form a water tight gusset seal 30. In this way, the pouch will not leak when composition is poured into the pouch. The pouch also has a closing mechanism 36 for temporarily closing the pouch, perhaps in the form of a zip seal, slider mechanism or similar seal which can be opened and closed repeatedly. Once the composition and object have been placed in the pouch, the closing mechanism 36 is closed so that no composition leaks out if the pouch is accidentally knocked over. The closing mechanism is located 1 to 5 cm from the top edges of front and back panels of the pouch so that if the closing mechanism is not completely water tight, the spillage is minim ised.

As shown in Figures 2a and 2b, the water tight gusset seal 30 is formed along one opposing edge of the gusset and the front panel and along the other opposing edge of the gusset and the back panel. The corners 38 of the gusset are sealed between the side edges of the front and back panels. The gusset seal is located along a line which is spaced away from the bottom edge of the back and front panels. By spacing the gusset seal line from the bottom edge, the bottom portions of the front and back panels below the seal line act like feet when the pouch is in the stand-up position.

This helps to stabilise the pouch. In preferred pouches the gusset seal line is located between 2 and 5 cm from the bottom edge of the front and back panels. The gusset seal line may be parallel to or curved relative to the bottom edge. A curved seal line may allow the bottom of the pouch to be U-shaped in the stand-up arrangement.

Again, this may increase the stabilisation and strength of the pouch.

EXAMPLES

Determination methods The viscosities of the compositions described herein were measured using a Brookfield viscometer, with spindle 2 at 20 rpm.

pH was determined using a Mettler Toledo pH probe which was inserted into the sample composition. The composition was stirred until the pH reading was constant.

The composition tested is described below. All % are by weight of the composition.

Ingredients % w/w % w/w Time Viscosity (cps) pH Composition water 75.92% 76.0633 initial (RT) 10 (sp2; 20rpm) 0.73 Sulfamic acid 9.75% 9.75 90% Formic acid 14.33% 12.897 The compostion was prepared by the following method: Sulfamic acid was added to soft water in beaker and mixed. Formic acid was added and mixing continued until a solution was formed.

Test method 1. A picture was taken of the showerhead before the experiment. 5 different types of shower head were tested. These pictures are shown in Figures 3a to 3e.

2. Each shower head was then immersed in 500 ml of the composition in a beaker and left for 5 minutes 3. After 5 minutes the showerhead was removed and rinsed with hot water.

Another photo was then taken. The results are shown in Figures 3f to 3j.

Figures 3a-e show the shower heads before cleaning and Figures 3f-3j show the same shower heads after cleaning respectively. As shown in Figures 3f to 3j, the composition is visibly able to clean limescale from the range of showerheads within 5 minutes. This includes the areas around the nozzles of the shower heads that are difficult to clean by conventional techniques.

A further preferred composition is described in the Table below.

Ingredient %w/w %w/w composition Viscosity (cps) pH water 84.37% 84.868 initial (RT) 236 (spi; 20rpm) 1.17 Rhodopol extra 2 0.25% 0.25 Propylene Glycol 0.50% 0.50 Sulfamic acid 9.75% 9.75 90% Formic acid 4.78% 4.302 Link 706 0.25% 0.25 Flexipel SR-80 0.10% 0.02 * Rhodopol extra2 clear is a polysaccharide, specifically a modified xanthan gum.

* Link 706 is an aqueous surf actant blend comprising 60-70 % wt of ethoxylated 0721 alcohol and 20-30 %wt of a chloride salt of a quaternary coco alkyl methyl amine ethoxylate * Flexipel SR-SO is a 10-30% wt dispersion in water of a polymer formed from triniethyl-[2-(2-methyl-1 -oxoprop-2-enoxy)ethyl]ammonium chloride, 2-propenoic acid and 2-propenamide.

Claims

CLAIMS: 1. A kit for treatment of lime scale comprising: (a) a stand up pouch; and (b) a composition comprising: (i) water; (ii) formic acid; and (iii) sulfamic acid.
2. A kit as claimed in claim 1, further comprising instructions for use thereof.
3. A kit as claimed in claim 1 or 2, wherein said stand-up pouch has a closing mechanism for temporarily closing the pouch.
4. A kit as claimed in any preceding claim, wherein said stand-up pouch is made of a laminate having a layer of polyterephthalate and a layer of polyethylene.
5. A kit as claimed in any preceding claim, wherein said stand-up pouch is transparent or translucent.
6. A kit as claimed in any preceding claim, wherein said composition has a viscosity of 5 to 100 cps.
7. A kit as claimed in any preceding claim, wherein said composition has a pH of 0.3 to 3.0.
8. A kit as claimed in any preceding claim, wherein said composition comprises 2 to 20% wt formic acid.
9. A kit as claimed in any preceding claim, wherein said composition comprises 3 to 5% wt formic acid.
10. A kit as claimed in any one of claims 1-8, wherein said composition comprises 8 to 13% wt formic acid.
11. A kit as claimed in any preceding claim, wherein said composition comprises 7.5 to 12.5 %wt sulfamic acid.
12. A kit as claimed in any preceding claim, wherein said composition further comprises a surfactant.
13. A kit as claimed in any preceding claim, wherein said surfactant is a non-ionic surfactant and a cationic surfactant.
14. A kit as claimed in claim 13, wherein said non-ionic surfactant is an alkoxylated alcohol.
15. A kit as claimed in claim 13 or 14, wherein said cationic surfactant is a di or trialkyl amine ethoxylate salt.
16. A kit as claimed in any preceding claim, wherein said composition further comprises a surface modifying polymer.
17. A kit as claimed in claim 16, wherein said surface-modifying polymer is formed from a trimethyl-[2-(2-methyl-1 -oxoprop-2-enoxy)ethyl]ammonium salt.
16. A kit as claimed in claim 16 or 17, wherein said surface-modifying polymer is formed from trimethyl-[2-(2-methyl-1 -oxoprop-2-enoxy)ethyl]ammonium chloride, 2-propenoic acid and 2-propenamide.
19. A kit as claimed in any preceding claim, wherein said composition further comprises a C13 alcohol.
20. A kit as claimed in any preceding claim, wherein said alcohol is a diol.
21. A kit as claimed in claim 20, wherein said C alcohol is propylene glycol.
22. A kit as claimed in any preceding claim, wherein said composition further comprises a thickener.
23. A kit as claimed in claim 22, wherein said thickener is a polysaccharide.
24. A kit as claimed in claim 23, wherein said thickener is xanthan gum or a derivative thereof.
25. A kit as claimed in any one of claims 1 to 11, wherein said composition consists essentially of water, formic acid and sulfamic acid.
26. Use of a kit as claimed in any one of claims 1 to 25 for treating lime scale on an object.
27. A method of treating lime scale on an object comprising: (i) enclosing said object and a composition as defined in any one of claims 1 to 25 in a stand-up pouch; (ii) optionally shaking said pouch to distribute said composition over said object; (iii) leaving said composition to react with lime scale on said object; and (iv) removing said object from said pouch and rinsing it.
28. A method as claimed in claim 27, wherein said composition is left to react with lime scale for 2 to 20 minutes.
29. A method as claimed in claim 27 or 28, wherein said object is a shower head.
30. A composition for treatment of lime scale consisting essentially of water, formic acid and sulfamic acid.
31. A composition as claimed in claim 30, wherein said composition is as defined in any one of claims 6 to 11.