Field of the invention

The present invention relates to a cleaning composition for use in cleaning surfaces, in particular for cleaning submerged surfaces such as toilet bowls.

Background of the invention

There is a need to provide consumers with cleaning compositions that are able to remove stains on for household surfaces, for example on kitchen and bathroom surfaces. Particularly, there is need for cleaning compositions that are effective at removing stains submerged in water, for example in toilet bowls.

Cleaning compositions known in the art for cleaning toilet bowls are effective at maintaining a hygienic surface (antimicrobial), but typically such cleaning compositions, tend to have low cleaning efficacy on submerged surfaces.

There remains a need for a cleaning composition that has stain removal efficacy even on surfaces submerged in water, and that ensures maintenance of a hygienic environment.

It is an object of the present invention to provide a composition that provides a cleaning benefit on submerged surfaces.

In a first aspect, there is provided a unit dose, preferably solid, cleaning composition comprising: a) a surfactant system comprising cationic surfactant, b) one or more substituted phenols selected from thymol, sec-butylphenol, carvacrol, eugenol, propylphenol or mixtures thereof, preferably thymol, c) one or more aliphatic terpene alcohol, preferably menthol; and d) one or more unsaturated terpenes selected from limonene, alpha-terpinene, terpinolene, cymene, phellandrene or mixtures thereof, preferably limonene, wherein the composition comprises an effervescent system having a basic component and an acidic component. It has been surprisingly found that a cleaning composition as per the present invention is able to provide a cleaning benefit on submerged surfaces e. g. toilet bowls.

For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of” or "composed of". Thus, the term "comprising" is meant not to be limiting to any subsequently stated elements, but rather to optionally also encompass non-specified elements of major or minor functional importance. In other words, the listed steps or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Unless specified otherwise, numerical ranges expressed in the format "x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and is abbreviated as “wt%”.

The unit dose may be solid or liquid. Preferably, the unit-dose is a concentrate, capsule, tablet, lozenge or block. Preferably the unit dose is a solid. Preferably the unit dose is a tablet, lozenge or block. The unit dose is preferably a liquid and the liquid unit dose is a concentrate or capsule.

The composition comprises a cationic surfactant. Preferably, the cationic surfactant is a quaternary ammonium surfactant, preferably the quaternary ammonium surfactant is selected from cetyl trimethyl ammonium chloride (CTAC), didecyl dimethyl ammonium chloride (DDAC), alkyl dimethyl benzyl ammonium chloride (ADBAC), cetyl pyridinium chloride and mixtures thereof. Other salts e. g. bromide salts and iodide salts, of cetyl trimethyl ammonium, dodecyl dimethyl ammonium, alkyl dimethyl benzyl ammonium and cetyl pyridinium may also be used. More preferably, the quaternary ammonium surfactant is alkyl dimethyl benzylammonium chloride e.g. benzalkonium chloride (BKC). Preferably, the composition comprises 0.1 to 20 wt%, cationic surfactant, more preferably 0.5 to 15 wt%, even more preferably 1 to 10 wt%, preferably 1 to 8 wt%, still more preferably 1.5 to 5 wt%.

Preferably, the sum of a), b), c) and d) is in the range of 0.1 to 10 wt%, more preferably 1 to 9 wt%, even more preferably 2 to 8 wt%, most preferably 3 to 7 wt%.

The composition preferably comprises: b) 0.01 to 5 wt%, of one or more substituted phenols selected from thymol, sec- butylphenol, carvacrol, eugenol, propylphenol or mixtures thereof, preferably thymol, c) 0.01 to 5 wt%, of one or more aliphatic terpene alcohol, preferably menthol; and d) 0.01 to 5 wt%, of one or more unsaturated terpenes selected from limonene, alpha-terpinene, terpinolene, cymene, phellandrene or mixtures thereof, preferably limonene,

The amount of the one or more substituted phenols selected from thymol, sec-butylphenol, carvacrol, eugenol, propylphenol or mixtures thereof is preferably in range of 0.01 to 5 wt%, preferably 0.02 to 2.5 wt%, more preferably 0.05 to 2 wt%, even more preferably 0.075 to 1.5 wt%, yet more preferably 0.1 to 1.0 wt% and most preferably 0.5 to 1.0 wt%.

Preferably the substituted phenol is thymol. The structural isomer of thymol (carvacrol) may also preferably be used.

Preferably, the composition comprises 0.01 to 5 wt%, more preferably 0.02 to 2.5 wt%, even more preferably 0.05 to 2 wt%, further more preferably 0.075 to 1.5 wt%, yet more preferably 0.1 to 1.0 wt%, most preferably 0.5 to 1.0 wt% of thymol. The composition comprises one or more aliphatic terpene alcohols. Preferably, the composition comprises 0.01 to 5 wt%, more preferably 0.02 to 2.5 wt%, even more preferably 0.025 to 1.0 wt%, yet more preferably 0.05 to 0.75 wt% and even more preferably 0.1 to 0.5 wt% of terpene alcohol.

The terpene alcohol is preferably selected from menthol, isomenthol, neomenthol, neoisomenthol and mixtures thereof. The terpene alcohol may be the (+) or (-) stereoisomers, for example (+)-menthol, (+)-isomenthol, (+)-neomenthol, (+)-neoisomenthol, (-)-menthol, (-)-isomenthol, (-)-neomenthol, (-)-neoisomenthol.

The structure of menthol is given below:

Within the meaning of the present application “aliphatic terpene” preferably means that the terpene does not contain unsaturated (carbon-carbon) bonds.

The composition of the present invention also comprises one or more unsaturated terpenes. Preferably, the composition comprises 0.01 to 5 wt%, more preferably 0.02 to 2.5 wt%, even more preferably 0.025 to 1.0 wt%, yet more preferably 0.05 to 0.75 wt% and even more preferably 0.1 to 0.5 wt% one or more unsaturated terpenes.

Preferably, the one or more unsaturated terpenes comprises limonene, alpha-terpinene, terpinolene, cymene, phellandrene or mixtures thereof, more preferably limonene. Within the meaning of the present application “unsaturated terpene” preferably means that the terpene does contains unsaturated (carbon-carbon) bonds and does not contain a hydroxy group.

Preferably, the unsaturated terpene is limonene. The structure of a limonene is given below:

Preferably, the composition comprises thymol, menthol, and limonene. Preferably, the composition comprises 0.05 to 2 wt% thymol, 0.025 to 1 wt% menthol, 0.025 to 2 wt% limonene.

The composition preferably comprises 0.1 to 10 wt%, preferably 1 to 9 wt%, more preferably 2 to 8 wt%, most preferably 3 to 7 wt% of the substituted phenols, aliphatic terpene alcohols, unsaturated terpenes or mixtures thereof.

Preferably, the substituted phenol, the aliphatic terpene alcohol and the unsaturated terpene are present in the ratio 1:0.5:0.5.

It will be understood that if the substituted phenol is present in 1 part, then the aliphatic terpene alcohol is present in 0.5 part and the unsaturated terpene is present in 0.5 part.

For example, if a substituted phenol e. g. thymol or eugenol or butyl phenol, is present in 1 part, then an aliphatic terpene alcohol e. g. menthol, is present in 0.5 part; and an unsaturated terpene e. g. limonene, alpha terpinene or terpinolene is present in 0.5 part. The composition comprises an effervescent system having a basic component and an acidic component.

The basic component is preferably selected from carbonates, bicarbonates, sequicarbonates and mixtures thereof. More preferably, the carbonate component is preferably an alkali metal carbonate, preferably sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium glycine carbonate and mixtures thereof.

The acidic component is preferably selected from an organic acid, for example a carboxylic acid, organic acid salts, organic acid anhydrides, inorganic acids, inorganic acid salts, and mixtures thereof. Preferably, the organic acid, and related salts and anhydrides are selected from carboxylic acids having up to 8 carbon atoms.

The acidic component is present in the effervescent system in an amount preferably ranging from 20 to 80 wt%, more preferably from 20 to 60 wt% and even more preferably ranging from 20 to 40 wt%.

Preferably, the acid component is an organic acid, an acid anhydride, sodium dihydrogen phosphate, disodium dihydrogen pyrophosphate, acid citrate salts, sodium acid sulphite and mixtures thereof, preferably wherein the acid source is an organic acid selected from citric acid, malic acid, tartaric acid, fumaric acid, sulfamic acid, oxalic acid, maleic acid, gluconic acid, succinic acid, salicylic acid, adipic acid and mixtures thereof, more preferably wherein the acid is citric acid.

The acidic and basic components are included in amounts to achieve rapid, complete solubility of the unit dose. Consequently, the molar ratio of acid component to basic component should be approximately within a range of from about 1.0:2.0 to about 1.0:4.0.

Preferably, the combination of acidic and basic components should comprise 50 wt% of the unit dose. More preferably, the acidic and basic components comprise at least 75 wt% of the unit dose and most preferably, at least 80 wt% of the unit dose.

Preferably, the composition comprises 0.1 to 20 wt%, more preferably 0.5 to 20 wt%, even more preferably 1 to 15 wt% of a surfactant system comprising a cationic surfactant. The composition preferably comprises less than 5 wt%, more preferably less than 2.5 wt%, most preferably less than 1 wt% of one or more anionic surfactants.

Preferably, the anionic surfactant is selected from alkylbenzene sulfonates, alkyl sulfonates, alkyl sulfates, salts of fluorinated fatty acids, silicones, fatty alcohol sulfates, polyoxyethylene fatty alcohol ether sulfates, a-olefin sulfonate, polyoxyethylene fatty alcohol phosphates ether, alkyl alcohol and mixtures thereof.

Preferably, the surfactant system comprises less than 2%, preferably less than 1% of non ionic surfactants, most preferably the composition is free of non-ionic surfactants.

Preferably, the non-ionic surfactant is selected from aminopolyglucoside (APG), fatty alcohol ethoxylate, alkyl phenol ethoxylate and fatty acid alkoxylate and tergitol (ethoxylated alcohol).

In a second aspect, there is provided a method of preparing a unit dose cleaning composition, comprising the steps: i. combining a basic component, an acidic component and a cationic surfactant, with a) one or more substituted phenols selected from thymol, sec-butylphenol, carvacrol, eugenol, propylphenol or mixtures thereof, preferably thymol, b) one or more aliphatic terpene alcohols, preferably menthol; and c) one or more unsaturated terpenes selected from limonene, alpha-terpinene, terpinolene, cymene, phellandrene or mixtures thereof, preferably limonene to provide a cleaning composition, preferably a solid cleaning composition.

The components and amounts described for the cleaning composition apply mutatis mutandis to the method of preparing a cleaning composition.

Preferably, the method comprises a step of forming a solid cleaning composition, more preferably forming a unit-dose. Preferably, the unit-dose is a concentrate capsule, tablet, lozenge or block.

In a third aspect, there is provided a method of cleaning a submerged surface, preferably a toilet bowl, comprising the step of contacting the composition as defined herein with water, preferably in a toilet bowl. In a fourth aspect, there is provided a use of the composition as defined herein for cleaning a submerged surface, preferably a toilet bowl.

The invention shall now be exemplified by the following non-limiting examples.

EXAMPLES

The materials used in the experiments were commercially available and were purchased from its supplier indicated below:

Thymol (Ronak Fine Industries), 4-Secondary butyl phenol (catalogue number B7033; TCI Chemicals India private limited), Eugenol (Nishant Aromas),

Menthol (catalogue number M2772; Sigma Aldrich),

D-Limonene (Cutrale),

Terpinolene (catalogue number 86485; Sigma Aldrich); and Alpha terpinene (catalogue number 223182; Sigma Aldrich).

Compositions (in tablet form) according to Table 1 were prepared.

Table 1

Ratio: Thymol:menthol:limonene = 1:0.5:0.5 Limescale removal test

A limescale removal test was carried out in a plastic device having similar shape and dimension of a typical siphon of a toilet. 12 tablets (per composition according to Table 1) were mounted on a silicon plate (P) on the inclined side (60° angle) of the apparatus (corresponding at 24 cm ² area). A second silicon plate (L) had 8 limescale tablets (corresponding at 16 cm ² area) mounted on it placed horizontally on the bottom of the apparatus. The device was filled with 2 litres of tap water, afterwards 80 g of neat products (mentioned in Table 1) are added. After 30 minutes contact time, the mounted tablets are removed, rinsed for 30 seconds under gently running tap water and then dried at 70 ^° C overnight before re-weighing to calculate the tablets weight loss. A minimum of 3 replicates are used to assess each system.

LIMESCALE REMOVAL = (P i - P f) / 24 + (L i - L f) / 16 = mg of limescale removed / 1 cm ²

P i = Initial weight (mg) of 12 tablets before starting with the test P f = Final weight (mg) of 12 tablets after they have been dried overnight

L i = Initial weight (mg) of 8 tablets before starting with the test L f = Final weight (mg) of 8 tablets after they have been dried overnight

Table 2

Additionally, limescale removal ability of compositions according to the invention (in table 3 below) was also evaluated using Carrara marble tiles (8 cm ^c 3 cm ^c 1 cm) as a representative surface. The method measures the level of dissolution of calcium carbonate which is the main component of the marble as well as limescale. Calcium carbonate dissolution obtained due to these test compositions is then evaluated by gravimetric method. Briefly, the tiles were cleaned with dried with compressed air to remove marble residues followed by placing them in an oven (105°C for 2h). After 2h, the tiles were removed and were cooled at room temperature in a glass dryer; and were weighed to record the ‘initial weight’ in grams. Such tiles were then used further. The tiles were soaked into a plastic cylinder with 80 g of test compositions (10 g of a composition dissolved in 70 mL water) shown in table 3 for 1h (along with a solution at 2% HCI as reference that provided 4.01 ± 0.03 % soil removal). After this, the tiles were rinsed under tap water to remove all product residues. The tiles were then placed in an oven (105°C for 2 h), cooled at room temperature in a glass dryer thereafter; and weighed to record the ‘final weight’ in grams.

Soil removal is determined in terms of the weight of Carrara marble removed using the following equation:

% Soil removed = (initial weight - final weight) / initial weight ^c 100 Table 3

¹ Ratio: 1 :0.5:0.5 Table 4

Stain removal test Compositions according to the invention (1, Table 1) were compared to commercially available toilet cleaner (Harpic). 23 consumers tested the compositions and comparative product for 3 days. Stain removal was assessed on a 10 point scale - from 1 no stain removal to 10 complete stain removal. Table 5