WO2005026307A1

WO2005026307A1 - Cleaning method and cleaning composition

Info

Publication number: WO2005026307A1
Application number: PCT/GB2004/003480
Authority: WO
Inventors: Mark Coke; Andrew Thomson
Original assignee: Reckitt Benckiser (Uk) Limited
Priority date: 2003-09-12
Filing date: 2004-08-13
Publication date: 2005-03-24

Abstract

There is provided a cleaning method employing ultrasonic energy, a liquid cleaning composition for use in the method and a solid cleaning formulation from which the composition can be prepared. That formulation includes a peroxygen salt, for example a percarbonate and/or perborate. The co-delivery of a peroxygen salt and ultrasonic energy confers benefits.

Description

CLEANING METHOD AND CLEANING COMPOSITION

The present invention relates to ultrasonic cleaning, particularly to an ultrasonic cleaning method employing a cleaning composition, and to a cleaning composition for use in such an ultrasonic cleaning method.

There are various known methods and cleaning products which are employed for cleaning inanimate articles such as, for example, carpets, curtains and soft furnishings, as well as articles of clothing. Methods for removing soiling on a regular basis include laundering, vacuuming and wiping with a damp cloth. The suitability of known cleaning methods for cleaning a particular article depends of course on the nature of the article to be cleaned.

If a part of an article becomes heavily soiled or stained then a cleaning method may be employed wherein a special treatment is applied to the affected part. This may comprise a stand-alone treatment or a pre-treatment employed prior to employing a regular cleaning method. For example, if part of an article of clothing becomes stained a stain removal product may be applied to the stained part as a pre-treatment. The stain removal product may be applied by being rubbed into the clothing. An absorbent cloth may then be applied to the treated part to draw the stain out of the clothing. After the pre- treatment the clothing may then be washed in a conventional manner.

Known cleaning methods can be time-consuming and labour intensive and may not always be effective in removing soiling and in particular heavy soiling or stains from an article being cleaned.

Attempts have been made to address such problems associated with known cleaning methods by employing an ultrasonic device to apply ultrasonic energy to an article to be cleaned. Several methods of cleaning employing ultrasonic energy are known and various cleaning compositions and ultrasonic devices have been proposed and developed.

Several ultrasonic devices have been disclosed by Kao Corporation of Japan in various patent applications including: JP2002-186921 , JP2002-166238 , JP2001-310165, JP2001-113087, EP1149637 and EP1195460. However, many known cleaning compositions show little improvement in their effectiveness when employed together with ultrasonic energy. Indeed some even exhibit a decrease in performance. Accordingly, there exists the need for an improved cleaning composition which exhibits good removal of soiling when employed in a cleaning method together with ultrasonic energy.

According to a first aspect of the present invention, there is provided a method of cleaning an inanimate article, in which method a cleaning composition in liquid form is put in contact with the article, the cleaning composition comprising a peroxygen compound of solid form made part of the cleaning composition shortly prior to the commencement of the method; wherein while the cleaning composition in is contact with the article ultrasonic energy is applied to the article. The peroxygen compound of solid form is preferably soluble in the cleaning composition.

Suitable as a peroxygen compound is any compound which under the conditions used for the method of the invention breaks down to yield an active oxygen species. It is presumed that this occurs via hydrogen peroxide formation (although the mechanism of action is not of significance to this specification or in the utilisation of this invention) .

Suitable peroxygen compounds include salts, preferably metal salts, especially alkali metal salts, and most preferably sodium salts. Suitable salts are inorganic salts. Examples include persulphates and persulfonates . Preferred examples include percarbonates and perborates.

Thus a suitable percarbonate may preferably comprise an alkali metal percarbonate, for example sodium percarbonate .

Thus a suitable perborate may preferably comprise an alkali metal perborate, for example sodium perborate.

Preferably, the ultrasonic energy is supplied by an ultrasonic device. The ultrasonic device may be portable. In one embodiment a suitable ultrasonic device comprises a hand held ultrasonic transmitter. Preferably, the ultrasonic device comprises a transmitter and power source in a single unit which may be held by a user in one hand. In another embodiment the ultrasonic device may be part of or associated with an immersion chamber in which the article is immersed. An example of an immersion chamber could be a ware washing machine, preferably a washing machine for fabrics or a dishwashing machine.

Preferably, the ultrasonic device is of the type having a battery and ultrasonic generator in a main body part which is grasped by a user, and which has a tapering part leading to a contact head, of chisel -like shape, preferably 0.5-5 cm long, more preferably 1-3 cm long, by 0.2-4 mm wide, more preferably 1-3 mm wide. Such a device is available from Kao Corporation.

Suitably, ultrasonic energy is applied to an article to be cleaned from an ultrasonic device having a transmitting head which is arranged to make contact with the soiled area of the article.

Suitably, the ultrasonic device emits waves having a frequency of at least 10kHz, preferably at least 20kHz. Preferably, the ultrasonic energy has a frequency of up to 2MHz, more preferably up to 100kHz. Preferably, the ultrasonic device emits waves having a frequency of between 20 and 60kHz, for example 50kHz.

The ultrasonic waves are desirably of such a frequency that they provide a beneficial cleaning effect in combination with the cleaning composition.

The method of the invention may be of a nature as to be safely performed by an unskilled operator, for example a home occupier in their home. Alternatively, or additionally, the cleaning method according to the present invention may be performed by a professional cleaner. Suitably, the method comprises cleaning soft articles and/or soft surfaces of articles, where the whole article is not soft. Suitably, the method may comprise cleaning household textiles, for example carpets and/or soft furnishings and/or curtains and/or bedding. Alternatively, the method may comprise cleaning articles of clothing. Preferably, when the method comprises cleaning articles of clothing, said method comprises a pre-treatment process employed prior to a further cleaning process.

The cleaning method according to the present invention may be suitable for treating a small area of an article which has become heavily soiled, for example an article which has become stained. The cleaning method may be suitable for treating a variety of stains, for example a variety of food stains. The cleaning method according to the present invention may be suitable for cleaning the whole of an article which is lightly soiled. The cleaning method of the present invention may also be suitable for cleaning a whole article, the whole of which has become heavily soiled.

Suitably, the method comprises applying the cleaning composition to a surface of an article to be cleaned. Suitably, the article is dry. Suitably, once the cleaning composition has been applied to the article, ultrasonic energy is then applied to the treated area of the article without any appreciable time delay. For example, ultrasonic energy may be applied to the article within a minute of the cleaning composition being applied to the article. Alternatively, the article having the cleaning composition applied thereto may be left to stand before ultrasonic energy is applied thereto.

Preferably, in this type of method ultrasonic energy is applied to the article having the cleaning composition applied thereto for at least 5 seconds, more preferably for at least 10 seconds, still more preferably for at least 20 seconds, and most preferably for at least 30 seconds. Preferably, in this type of method ultrasonic energy is applied to the article for up to 5 minutes, more preferably up to 3 minutes, and still more preferably up to 2 minutes, and, especially, up to 70 seconds.

In an especially favoured method of this type the ultrasonic energy is applied for about 30 seconds.

Suitably, the cleaning composition soaks into the article to be cleaned before and/or during the application of ultrasonic energy.

Preferably, the treated article is left to stand following the application of ultrasonic energy. Preferably, the article is left to stand for at least 30 seconds, more preferably for at least 1 minute. Preferably, the article is left to stand for between 1 minute and 6 minutes, more preferably between 2 minutes and 5 minutes, more preferably between 4 minutes and 5 minutes, for example for around 4.5 minutes .

Suitably, after the application of ultrasonic energy and preferably after the article has been left to stand, the cleaning composition is removed. For example, the cleaning composition may be wiped off using an absorbent cloth which may be a damp cloth.

Alternatively, and as mentioned above, the article to be cleaned may be immersed in a volume of cleaning composition, for example in a bath, trough or ware washing machine. Preferably, once immersed in cleaning composition such that a soiled area of the article is in contact with said composition, ultrasonic energy is applied to the article. Suitably, in such methods the ultrasonic energy is applied for all or some of the period of immersion of the articles to be cleaned. Suitably the ultrasonic energy is applied for an extended period, for example the whole of a pre-wash or main wash, in a ware washing machine. Suitably, in such methods, ultrasonic energy is applied for at least 5 minutes, more preferably for at least 15 minutes, and most preferably for at least 30 minutes. Suitably, in such methods the ultrasonic energy is applied for up to 240 minutes, preferably for up to 150 minutes, and most preferably up to 80 minutes.

Preferably, following the application of ultrasonic energy, the treated article is removed from the volume of cleaning composition and any residual cleaning composition removed therefrom.

Suitably, when an article is treated according to either of the above described methods the cleaning composition is removed by washing with water. The article may be washed in cold water. The article may be washed by being placed under a flow of water. For example, the article may be placed under a running tap. Alternatively, the article may be washed in a washing machine . After the washing step the article may be dried in a tumble dryer. Alternatively, the article may be left to dry naturally.

Preferably, the cleaning composition employed in the method comprises:

a peroxygen compound supplied as a solid but dissolved in the cleaning composition when cleaning is to be effected;

a diluent;

and optionally one or more additional components selected from the group consisting of a base, a surfactant, a bleach activator and a binder.

Preferably, the cleaning composition employed in the method comprises a cleaning composition according to the second aspect which follows.

Thus, suitably the cleaning composition is produced shortly prior to use in the cleaning method, by a user forming a solution of the peroxygen compound in a diluent.

Preferably the solid peroxygen compound is comprised in a solid cleaning formulation. The solid cleaning formulation is preferably of particulate form, and is dissolved in the diluent when required.

Suitably, the cleaning formulation comprises all of the components of the cleaning composition other than the diluent . The cleaning formulation for use in the method may comprise a formulation according to the third aspect which follows .

According to a second aspect of the present invention there is provided a liquid cleaning composition for use in a method of cleaning an inanimate article employing ultrasonic energy, the cleaning composition being the composition which, in use, contacts the article, wherein the cleaning composition comprises:

0.1 to 50% by weight of the total weight of the cleaning composition of a cleaning agent which is a peroxygen compound;

one or more additional components selected from the group consisting of a base, a surfactant, a bleach activator and a binder; and

a diluent

Preferably, when the cleaning composition is for spot application to an article it comprises no more than 40% by weight of the peroxygen compound, more preferably no more than 30%, more preferably no more than 25%, still more preferably no more than 20%, for example, no more than 16%. Preferably, when the cleaning composition is for spot application of an article it comprises at least 0.1% by weight of the peroxygen compound, more preferably at least 0.5%, more preferably at least 1%, still more preferably at least 5%, more preferably at least 10%, and most preferably at least 12%; especially at least 14%.

Preferably, when the cleaning composition is for immersion of an article it comprises no more than 10% by weight of the peroxygen compound, more preferably no more than 6%, more preferably no more than 4%, most preferably no more than 2%, for example, no more than 1%.

Preferably, when the cleaning composition is for immersion of an article it comprises at least 0.1% by weight of the peroxygen compound, more preferably at least 0.2%, more preferably at least 0.3%, and most preferably at least 0.4%.

Preferably, said cleaning agent is a percarbonate or a perborate, or a combination of percarbonate and perborate.

Suitably, the cleaning composition may be produced by combining a cleaning formulation comprising a solid peroxygen compound with a diluent, for example water. The cleaning composition may be produced by an end user combining said cleaning formulation and diluent shortly before employing the cleaning composition in a cleaning method.

The cleaning formulation may comprise a formulation according to the third aspect which follows. The cleaning formulation (and hence, ultimately, the cleaning composition) may comprise a base. The cleaning formulation (and hence, ultimately, the cleaning composition) may comprise a surfactant.

The cleaning formulation (and hence, ultimately, the cleaning composition) may comprise a bleach activator.

The cleaning formulation (and hence, ultimately, the cleaning composition) may comprise a binder, for example polypropylene glycol .

The cleaning formulation (and hence, ultimately, the cleaning composition) may comprise a bleaching agent, additional to the peroxygen compound mentioned above.

This could be another bleaching agent of the active oxygen type, for example hydrogen peroxide.

The cleaning formulation (and hence, ultimately, the cleaning composition) may comprise a complexing agent.

Preferably, the diluent comprises water.

Preferably, the cleaning composition (i.e. the liquid used to contact the article in the method) has a viscosity of at least 1 centipoise, preferably at least 3 centipoises. Preferably, the composition has a viscosity of less than 25 centipoise, still more preferably less than 20 centipoise, more preferably less than 15 centipoise, and most preferably less than 10 centipoise. Suitably, for this definition the viscosity is measured with a commercially available Brookfield DV II and viscometer using spindle LV3 at a temperature of 22 °C. Suitably, the cleaning composition has a viscosity which may allow for ready application of the composition to an article to be cleaned. Suitably, the cleaning composition has a viscosity which may provide good soil removal in a cleaning method employing ultrasonic energy. Suitably, the cleaning composition has a viscosity which may allow the composition to be readily removed from the article following the application of ultrasonic energy. The cleaning composition may have a viscosity which allows it to soak into the article to be cleaned. Preferably, the cleaning composition soaks into the article to be cleaned before and/or during the application of ultrasound. Preferably, following the application of ultrasound the cleaning composition can then be removed, partially or, preferably substantially wholly from the article.

Suitably, the viscosity of the cleaning composition is selected to be of an above defined value such that it allows for effective transmission of ultrasonic energy to the article to be cleaned.

A surfactant, when present, may comprise an amine oxide surfactant. The cleaning composition may comprise a surfactant, additional to the amine oxide. Alternatively, the composition may comprise a surfactant alternative to an amine oxide surfactant. Suitably, the additional or alternative surfactant comprises an anionic surfactant. By surfactant we include herein a hydrotrope. For example, the composition may comprise sodium xylene sulfonate.

Preferably, the cleaning composition comprises no more than 11% by weight (active component) of a surfactant, more preferably no more than 9%, more preferably no more than 7%, more preferably no more than 5%, for example, no more than 4%. The cleaning composition may comprise no more than 1% by weight of a surfactant, more preferably no more than 0.5%, and most preferably no more than 0.1%.

The cleaning composition may comprise at least 0.001% by weight (active component) of a surfactant, more preferably at least 0.01%.

A suitable amine oxide surfactant has the formula

R¹R²R³N⁺- 0 ^'

wherein R¹ is suitably an alkyl group containing 5-25, preferably 8-20, preferably 10-18, more preferably 11-13, for example 12, carbon atoms and wherein R² and R³ are, each, independently, suitably a hydroxyalkyl or, preferably, an alkyl group, in each case containing 1 to 6 and preferably 1 to 2 carbon atoms, most preferably 1 carbon atom. Preferably, R¹ comprises a linear alkyl group .

Preferred amine oxide surfactants in particular include C₁₀-Ci₈ alkyl dimethyl amine oxides, most preferred are C_n- C₁₃ alkyl dimethyl amine oxide, for example a C₁₂ alkyl dimethyl amine oxides. Preferably, the amine oxide comprises INπSf-dimethyl-N-dodecylamine N-oxide.

The cleaning composition may comprise at least 2.3% by weight of an amine oxide surfactant, more preferably at least 2.5%, for example, at least 2.9%. The statements above about preferred upper limits of surfactants apply also to amine oxide surfactants.

It may be preferred to add any liquid component (in addition to the diluent) separately from the cleaning formulation, to form the cleaning composition. However a surfactant could be part of the cleaning formulation if it was of solid, dissolvable form, or if it was of a liquid but did not promote premature degradation of the peroxygen compound.

The cleaning composition may comprise a peroxygen compound, a base and a diluent. The cleaning composition may also comprise a peroxygen compound, a base, a surfactant and a diluent. The cleaning composition preferably does not comprise any additional cleaning agents comprising enzymes. The cleaning composition may not comprise any additional cleaning agents comprising bleach activators. Alternatively, the cleaning composition may comprise a bleach activator. The cleaning composition may suitably comprise a peroxygen compound, a base, a surfactant, a binder and a diluent. A suitable cleaning composition consists essentially of these components. The cleaning composition may alternatively comprise oa peroxygen compound, a base, a bleach activator, a surfactant and a diluent. A suitable cleaning composition consists essentially of these components .

A suitable cleaning composition may have a diluent which consists of at least 80% by weight of the total cleaning composition. When a bleach actuator is present it suitably constitutes up to 7% by weight (active component) of the total weight of the cleaning composition. Preferably, the cleaning composition comprises up to 6% by weight of a bleach activator, more preferably between 3 and 5%. Suitable bleach activators may include sodium nonanoyloxybenzene sulphonate (NOBS or SNOBS) and tetraacetylethylene-diamine (TAED) .

Suitably, the cleaning composition has a pH of between 6 and 12. Preferably, the cleaning composition has a pH of between 7 and 11, more preferably between 8 and 11, more preferably between 8.5 and 10.5, and more preferably of between 9 and 10.5. For example the cleaning composition may have a pH of 9.5, alternatively it may have a pH of 10.

Preferably, the base, when present, comprises one or more of an alkali metal (preferably sodium) bicarbonate, carbonate and hydroxide.

When a base is present it preferably constitutes up to 20% by weight (active component) , more preferably up to 10% by weight, of the total weight of the cleaning formulation. Preferably, the cleaning formulation comprises a base in an amount necessary to adjust the pH of the liquid composition to be within a preferred pH range. Preferably, the cleaning formulation comprises up to 8% by weight of a base, more preferably up to 5% by weight. Preferably, the cleaning formulation comprises between 0.01 and 8% by weight (active component) of a base, more preferably between 0.1 and 6%, more preferably between 0.5 and 6%, for example between 1 and 5%. /026307 16

When a complexing agent is present it is preferably present in an amount of up to 5% by weight (active component) of the total weight of the cleaning formulation, more preferably up to 1%.

Preferably, if present the complexing agent comprises a chelating agent. Preferably, the complexing agent comprises a phosphorous containing compound. The complexing agent may comprise a phosphonate compound such as that of formula (1) described in EP 0009839. Preferably the complexing agent comprises sodium salt of diethylenetriamine pentamethylene phosphonic acid. The complexing agent may further comprise sodium salt of diethylenetriamine trimethylene phosphonic acid and may further comprise sodium salt of diethylene triamine tetramethylenephosphonic acid and sodium salt of diethylenetriamine tetramethylenephosphonic acid. Preferably, at least 70% by weight, more preferably at least 80% by weight of the complexing agent comprises sodium salt of diethylenetriamine pentamethylene phosphonic acid.

When a bleaching agent is present it is, preferably provided in an amount of up to 10% by weight (active component) of the total weight of the cleaning formulation. Preferably, the formulation comprises between up to 7% by weight (active component) of bleaching agent. Preferably, the bleaching agent, if present, comprises a peroxide, preferably the bleaching agent comprises hydrogen peroxide. The cleaning formulation may comprise a binder, for example dipropylene glycol . The binder may be present in an amount of up to 1% by weight (active component) .

Preferably, the binder is present in an amount of between 0.001 and 0.5% by weight, more preferably between 0.02 and

0.1%, for example between 0.01 and 0.1%.

The cleaning composition, and preferably the cleaning formulation, may further comprise additional cleaning agents. Suitable additional cleaning agents may include agents selected from the group comprising; builders, surfactants, enzymes, colorants, perfume, lime soap dispersants, polymeric dye transfer inhibiting agents, antibacterial agent, crystal growth inhibitors, anti- tarnishing agents, anti-microbial agents, anti-oxidants, anti-redeposition agents, soil release polymers, electrolytes, buffering agents, thickeners, abrasives, divalent metal ions, metal ion salts, enzyme stablizers, corrosion inhibitors, diamines, suds stablizing polymers, process aids, fabric softening agents, optical brighteners, hydrotropes and mixtures thereof.

Suitably, the cleaning composition is arranged to be suitable for treating food stains, ink stains and personal soiling stains. For example the cleaning composition may be arranged to be effective in treating stains caused by one or more of food, red wine, fruit juice, turmeric, tea, coffee, grass, ink, sweat, urine, sebum, vegetable or mineral grease and vegetable or mineral oil.

Suitably, the cleaning composition is arranged to be employed with ultrasonic energy having a frequency as described in the first aspect. Suitably, the cleaning composition is arranged to be employed to clean soft articles and/or soft surfaces of articles, where the whole article is not soft; especially textile surfaces. Suitably, the cleaning composition may be employed to clean household textiles, for example carpets and/or soft furnishings and/or curtains and/or bedding. Alternatively, the cleaning composition may be employed to clean articles of clothing. Preferably, when employed to clean articles of clothing the cleaning composition is employed as a pre-treatment prior to a further cleaning process.

Suitably, the cleaning composition is arranged to be applied onto a surface of an article to be cleaned. Alternatively, or in addition, the cleaning composition may be such that an article to be cleaned can be immersed in a volume of the cleaning composition.

Suitably, the cleaning composition is arranged such that it can be removed from an article after ultrasonic energy has been applied to an article in a cleaning operation. Suitably, the composition is arranged such that it can be washed and/or wiped off the article.

According to a third aspect of the present invention there is provided a cleaning formulation for use in a method of cleaning an inanimate article employing ultrasonic energy, wherein the cleaning formulation comprises a cleaning agent which is a solid peroxygen compound; one or more additional components selected from the group consisting of a base, a surfactant, a hydrotrope, a bleach activator and a binder; and

wherein said cleaning formulation is substantially devoid of free water.

Preferred features of the cleaning formulation are as stated above in relation to the first and second aspects; except that the diluent is not present.

According to a fourth aspect of the present invention there is provided a packaged product comprising a container comprising a cleaning formulation according to the third aspect, and an applicator, said applicator being adapted to enable a cleaning composition produced by combining a quantity of said cleaning formulation and a diluent to be applied to an article to be cleaned.

According to a fifth aspect of the present invention there is provided a kit of parts comprising a packaged product according to the fourth aspect and a device arranged to emit ultrasonic energy.

Specific embodiments of the present invention will now be described by way of example.

Experimental Method

Fabric Preparation

Stained fabrics were prepared to test cleaning compositions of the invention comprising an amine oxide surfactant with the method of the invention. Such fabrics were also used to test comparative examples. The same procedures, outlined below, were employed for each.

Fabric Stripping

A fabric was stripped by three consecutive washes, as follows .

Wash Number 1 - the fabric to be stripped (max weight 6 pounds (2.7 kg)) was added to a washer and the machine set to hot water (90°C) wash/cold water rinse, large load, normal cycle. When the water level was full one scoop (approx 90g) of washing powder (TIDE - trade mark) and 1 cup (240 ml) of household chlorine bleach (1% sodium hypochlorite) was added. The fabric was washed for 12 minutes .

Wash Number 2 - the machine was set to hot water wash/cold water rinse, large load, normal cycle. When the water level was full one scoop of washing powder (TIDE) was added. The fabric was washed for 12 minutes.

Wash Number 3 - The machine was set to hot water wash/cold water rinse, large load, normal cycle and the fabric washed for 12 minutes with no detergent .

The fabric was dried on a dried normal drying cycle until dry. Stained Fabric preparation:

A variety of stains were produced on the stripped fabric according to the following procedures.

Coffee

Prestained test swatches supplied by Westlairds Ltd.

Food Grease 500g of corn oil was fried with 150g of potatoes for 5 mins . The grease was allowed to cool and 0.1% sudan red dye added. 10 drops of food grease were pipetted onto a stripped fabric and allowed to dry overnight before use.

Bolognese 2.5g of Ragu (TM) Bolognese sauce was smeared onto a stripped fabric in an even circle approximately 6cm in diameter. This was allowed to dry with the skin which formed being carefully scraped off whilst damp and the stain then being allowed to dry overnight before use.

Stain Removal Tests

Stained fabrics were treated either with a cleaning composition of the invention comprising an amine oxide surfactant together with ultrasonic energy or alternatively with a comparative cleaning composition and/or without using ultrasonic energy according to one of the following test methods. "Dry" ultrasonic test method

2g of cleaning composition was pipetted onto the stain and ultrasonic energy applied using an ultrasonic device for 30 seconds by direct contact of the device head with the stain in a gentle stroking motion. The fabric was left for another 4.5 min before washing in cold tap water and drying in a tumble drier.

"Dry" non-ultrasonic test method:

2g of cleaning composition was applied to the fabric and the stain was rubbed for 30 seconds. The fabric was left for 43^ min before washing in cold tap water. The fabric was then dried in a tumble drier.

Stain removal assessment

Stain removal was assessed according to the following method.

Change in reflectance calculation.

The reflectance of a stained area was measured before and after treatment using a Minolta CM-3700D reflectometer and the difference in reflectance calculated.

Examples

Cleaning compositions were prepared by combining a percarbonate cleaning agent with additional components and these were tested with ultrasound according to the above described procedures as detailed below. Comparative tests were performed using compositions containing a percarbonate cleaning agent within the range of the invention without ultrasound.

Example 1

A liquid cleaning composition having a percarbonate cleaning agent present in an amount of 15% by weight was prepared according to the following formulation:

15% by weight sodium percarbonate;

10% by weight AMMONYX LO-E (Trade Mark) available from Stepan UK, being a surfactant solution comprising 30% by weight of the amine oxide N,N-dimethyl-N-dodecylamine N- oxide;

5% by weight Na₂C0₃ to give a pH of around 10;

<1% by weight NaHC0₃ as required to adjust pH to pH 10;

5% by weight sodium nanonoyloxybenzene sulphonate (NOBS) (bleach activator) ; and

balance - deionised water.

In duplicate tests, performed within 30 minutes of adding the NOBS and percarbonate, a fabric having a food grease stain was treated with the composition according to the dry ultrasonic test method and the change in reflectance measured. The result is shown in Table 1 below. Comparative Example A

As a comparative example the composition of Example 1 was employed without ultrasound. In duplicate tests a fabric having a food grease stain was treated according to the dry non-ultrasonic test method and the change in reflectance measured. The result is shown in Table 1 below.

As can be seen the composition was more effective when used in combination with ultrasonic energy.

Example 2

A liquid cleaning composition containing a percarbonate cleaning agent was prepared by mixing a dry powder cleaning formulation having the following formulation: 55% by weight sodium percarbonate;

44.5% by weight sodium carbonate;

0.2% by weight dipropylene glycol; and 0.3% by weight sodium xylene sulfonate with water to form a solution, in the relative amount 500ml water to 4g cleaning formulation.

In triplicate tests performed within 30 minutes of forming the cleaning composition a fabric having a Bolognese stain was treated with the composition according to the dry ultrasonic test method and the change in reflectance measured. The result is shown in Table 2 below.

Comparative Example [B]

As a comparative example the composition of Example 2 was employed without ultrasound. In triplicate tests performed within 30 minutes of prepared the cleaning composition a fabric having a Bolognese stain was treated according to the dry non-ultrasonic test method and the change in reflectance measured. The result is shown in Table 2 below.

Table 2

It can clearly be seen that the combination of ultrasonic energy and the percarbonate cleaning composition was beneficial .

Example 3

A cleaning composition was prepared by mixing a dry powder cleaning formulation having the following formulation:

55% by weight sodium percarbonate;

44.5% by weight sodium carbonate;

0.2% by weight dipropylene glycol; and

0.3% by weight sodium xylene sulfonate

with water to form a solution, in the relative amount of 500ml water and 4g cleaning formulation.

In triplicate tests performed within 30 minutes of forming the cleaning composition, a fabric having a coffee stain was treated with the composition according to the dry ultrasonic test method and the change in reflectance measured. The result is shown in Table 3 below.

Comparative Example [C]

As a comparative example the composition of Example 3 was employed without ultrasound. In triplicate tests performed within 30 minutes of preparing the cleaning composition a fabric having a coffee stain was treated according to the dry non-ultrasonic test method and the change in reflectance measured. The result is shown in Table 3 below.

Table 3

It can clearly be seen that the use of ultrasonic energy with the percarbonate containing cleaning composition exhibits an improved effect.

It will be readily understood that the cleaning compositions of the present invention and the cleaning method of the present invention may give improvements in the removal of many types of soiling. The present invention may thus allow for more efficient and effective cleaning of soiled articles than has previously been practical .

Effect of Amine Oxide

Cleaning compositions were prepared by combining an amine oxide surfactant solution with additional components and these were tested with ultrasound according to the above described procedures as detailed below. Comparative tests were performed using compositions containing an amine oxide surfactant within the range of the invention without ultrasound and also using other cleaning compositions both with and without ultrasound.

Example 1

A cleaning composition having an amine oxide surfactant present in an amount of 5% by weight was prepared according to the following formulation:

16.7% by weight of AMMONYX LO-E (Trade Mark) available from STEPAN UK, being a surfactant solution comprising 30% by weight of the amine oxide N,N-dimethyl-N-dodecylamine N-oxide; and

83.3% by weight of deionised water to make up the balance.

In duplicate tests a fabric having a food grease stain was treated with the composition according to the trough ultrasonic test method and the SRI was measured. The result is shown in Table 1 below.

Example 2

A cleaning composition having an amine oxide surfactant present in an amount of 10% by weight was prepared according to the following formulation:

33% by weight of AMMONYX LO-E; and

77% by weight of deionised water.

In duplicate tests a fabric having a food grease stain was treated with the composition according to the trough ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 1 below.

Comparative Example A

As a comparative example a cleaning composition having an amine oxide surfactant present in am amount of 1% by weight was prepared according to the following formulation:

3.3% by weight of AMMONYX LO-E; and

96.7% by weight of deionised water. In duplicate tests a fabric having a food grease stain was treated with the composition according to the trough ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 1 below. Comparative Example B

As a comparative example, AMMONYX LO-E was used as a cleaning composition as supplied. The amine oxide surfactant level was thus 30%.

TABLE 1 Amine oxide% Stain Test SRI

As shown in Table 1 the use of a composition comprising an amine oxide surfactant within the range of the invention (2.2 to 12% by weight) gives a beneficial increase in the SRI in comparison to compositions comprising lower and in particular higher levels of amine oxide surfactant. Without wishing to be bound by theory it is believed this benefit may be due to the viscosity of the cleaning compositions being within a range which allows the composition to respond well when employed with ultrasonic energy.

Example 3 A cleaning composition having an amine oxide surfactant present in an amount of 5% by weight was prepared according to the formulation of Example 1 :

16.7% by weight of AMMONYX LO-E; and

83.3% by weight of deionised water,

In duplicate tests a fabric having a food grease stain was treated with the composition according to the trough ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 2 below.

Comparative Example C

As a comparative example the composition of Example 3 was employed without ultrasound. In duplicate tests a fabric having a food grease stain was treated with the composition according to the trough non-ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 2 below.

Comparative Example D As a comparative example deionised water was employed as a cleaning composition with ultrasound. In duplicate tests a fabric having a food grease stain was treated with the composition according to the trough ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 2 below.

Comparative Example E

As a comparative example deionised water was employed as a cleaning composition without ultrasound. In duplicate tests a fabric having a food grease stain was treated with the composition according to the trough non-ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 2 below.

As can readily be seen, the use of a composition comprising an amine oxide without ultrasound was less effective than water alone without ultrasonic energy. However the composition comprising the amine oxide surfactant was much more effective at removing staining than water alone when used in combination with ultrasonic energy. A beneficial effect was clearly obtained from the combination of ultrasound and a cleaning composition comprising an amine oxide surfactant. Without wishing to be bound by theory it is believed that at the concentrations of amine oxide surfactant employed in the present invention the cleaning composition and the ultrasonic energy each enhance the effectiveness of the other.

Example 4

A cleaning composition having an amine oxide surfactant present in an amount of 3% by weight was prepared according to the following formulation:

10% by weight of AMMONYX LO-E; and 90% by weight of deionised water.

In duplicate- tests a fabric having a food grease stain was treated with the composition according to the dry ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 3 below.

Comparative Example F

As a comparative example the composition of Example 4 was employed without ultrasound. In duplicate tests a fabric having a food grease stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 3 below) .

Example 5

10% by weight of AMMONYX LO-E;

4% by weight of LUTENSOL (Trade Mark) , available from BASF - a non- ionic surfactant comprising an ethoxylated fatty alcohol .

86% by weight of deionised water.

In duplicate tests a fabric having a food grease stain was treated with the composition according to the dry ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 3 below.

Comparative Example G

As a comparative example the composition of Example 5 was employed without ultrasound. In duplicate tests a fabric having a food grease stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 3 below.

Example 6

10% by weight of AMMONYX LO-E;

1% by weight of LUTENSOL; and

89% by weight of deionised water.

Comparative Example H

As a comparative example the composition of Example 6 was employed without ultrasound. In duplicate tests a fabric having a food grease stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 3 below.

Comparative Example I

As a comparative example (Example J below) a commercially available cleaning composition "SPRAY N' WASH Extra Strength" (Trade Mark) available from Reckitt Benkiser was employed without ultrasound. This cleaning composition comprises non-ionic surfactants and enzymes. In duplicate tests a fabric having a food grease stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the SRI measured. The result is shown in Table 3.

As can be seen, the cleaning compositions containing the amine oxide surfactant either with or without the additional non-ionic surfactant gave a far better SRI when used together with ultrasonic energy than that given by one of the most effective commercial products without ultrasonic energy. It can also be seen that the combination of the non-ionic surfactant with the amine oxide surfactant gives an enhanced cleaning effect with ultrasonic energy in comparison to the amine oxide surfactant alone. However, the improvement is less marked with ultrasonic energy than without and without wishing to be bound by theory it is believed it is the interaction between ultrasonic energy, the amine oxide surfactant and the stain which provides the major contribution to the SRI values observed for Examples 4 and 5.

Example 7

10% by weight of AMMONYX LO-E;

6% by weight of hydrogen peroxide; 0.2% by weight of DEQUEST 2066 (Trade Mark) available from Solutia, a solution comprising sodium salt or diethylenetramine pentamethylenephosphonic acid as the major active component;

2.0 - 4.0% by weight of 1M NaOH as required to adjust the pH to 9; and

81.8 - 79.8% by weight of deionised water to make up the balance.

In triplicate tests a fabric having a coffee stain was treated with the composition according to the dry ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 4 below.

Comparative Example J

As a comparative example the composition of Example 7 was employed without ultrasound. In triplicate tests a fabric having a coffee stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 4 below.

Example 8

10% by weight of AMMONYX LO-E; 6% by weight of hydrogen peroxide;

0.2% by weight of DEQUEST 2066;

2.0 - 4.0% by weight of 1M NaOH as required to adjust the pH to 9.5; and

81.8 - 79.8% by weight of deionised water to make up the balance.

Comparative Example K

As a comparative example the composition of Example 8 was employed without ultrasound. In triplicate tests a fabric having a coffee stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 4 below.

Comparative Example L

As a comparative example a commercially available cleaning composition KALIA OXY ACTION GEL (Trade Mark) , Examples L and M below, available from Reckitt Benkiser was employed with and without ultrasound, examples L and M below. This cleaning composition is a fabric pre-treater and comprises around 6% by weight hydrogen peroxide at around pH4 and between 5 and 15% by weight non- ionic surfactants and between 5 and 15% by weight anionic surfactants. In triplicate tests a fabric having a coffee stain was treated with the composition according to the dry ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 4 below. Comparative Example M

As a comparative example the composition of Comparative Example L was employed without ultrasound. In triplicate tests a fabric having a coffee stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 4 below.

As can be seen the cleaning compositions comprising the amine oxide surfactant are more effective under conditions of higher pH. Although the amine oxide surfactant containing compositions exhibit only a small improvement when employed with ultra sonic energy rather than without it will be observed that this is largely due to the fact they are very effective at treating coffee stains even without the use of ultrasonic energy. Most significantly, the compositions of the invention do not show a decrease in performance when used with ultrasound as was the case with the commercially available composition KALIA. Example 9

A cleaning composition having an amine oxide surfactant present in an amount of 3% by weight was prepared according to the formulation of Example 7 :

10% by weight of AMMONYX LO-E;

6% by weight of hydrogen peroxide; 0.2% by weight of DEQUEST 2066

2.0 - 4.0% by weight of 1M NaOH as required to adjust the pH to 9; and 81.8 - 79.8% by weight of deionised water to make up the balance .

In triplicate tests a fabric having a grass stain was treated with the composition according to the dry ultrasonic test method and the change in reflectance measured. The result is shown in Table 5 below.

Comparative Example N

As a comparative example the composition of Example 9 was employed without ultrasound. In triplicate tests a fabric having a grass stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 5 below.

Example 10

A cleaning composition having an amine oxide surfactant present in an amount of 3% by weight was prepared according to the formulation of Example 8:

10% by weight of AMMONYX LO-E;

6% by weight of hydrogen peroxide;

0.2% by weight of DEQUEST 2066;

2.0 - 4.0% by weight of 1M NaOH as required to adjust the pH to 9.5; and 81.8 - 79.8% by weight of deionised water to make up the balance .

In triplicate tests a fabric having a grass stain was treated with the composition according to the dry ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 5 below.

Comparative Example O

As a comparative example the composition of Example 10 was employed without ultrasound. In triplicate tests a fabric having a grass stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 5 below.

Comparative Example P

As a comparative example a commercially available cleaning composition KALIA OXY ACTION GEL was employed with ultrasound. In triplicate tests a fabric having a grass stain was treated with the composition according to the dry ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 5 below.

Comparative Example Q

As a comparative example the composition of Comparative Example P was employed without ultrasound. In triplicate tests a fabric having a grass stain was treated with the composition according to the dry non-ultrasonic test method described in Example 1, and the change in reflectance measured. The result is shown in Table 5 below.

As can be seen cleaning compositions comprising the amine oxide surfactant were more effective on grass stains at a lower pH. It will also be noted that there was a marked improvement at their effectiveness when employed with rather than without ultrasonic energy. In contrast KALIA showed little improvement when used together with ultrasonic energy. It will be readily understood that the cleaning compositions and method of the present invention may give benefits in the removal of many types of soiling. The present invention may thus give efficient and effective cleaning of soiled articles.

Claims

1. A method of cleaning an inanimate article, in which method a cleaning composition in liquid form is put in contact with the article, the cleaning composition comprising a peroxygen compound of solid form made part of the cleaning composition shortly prior to the commencement of the method; wherein while the cleaning composition in is contact with the article ultrasonic energy is applied to the article.

2. A method as claimed in claim 1 wherein the peroxygen compound is an inorganic salt of an alkali metal.

3. A method as claimed in claim 2, wherein the peroxygen compound is selected from sodium percarbonate and sodium perborate .

4. A method as claimed in any preceding claim wherein the cleaning composition is applied to the article where soiled and an ultrasonic energy is subsequently applied to the same location.

5. A method as claimed in any of claims 1 to 3 wherein the article is immersed in the cleaning composition while the ultrasonic energy is applied.

6. A method as claimed in claim 6 wherein the method is carried out in a ware-washing machine.

7. A liquid cleaning composition for use in a method of cleaning an inanimate article employing ultrasonic energy, the cleaning composition being the composition which, in use, contacts the article, wherein the cleaning composition comprises:

1 to 50% by weight of the total weight of the cleaning composition of a cleaning agent which prior to the formation of the composition is a solid peroxygen compound;

one or more additional components selected from the group consisting of a base, a surfactant, a bleach activator and a binder;

a diluent.

8. A cleaning composition as claimed in claim 7 and which consists of a percarbonate and/or perborate, a base, a surfactant, a binder and a diluent.

9. A cleaning composition as claimed in claim 7 and which consists of a percarbonate and/or perborate, a base, a bleach activator, a surfactant and a diluent.

10. A cleaning method as claimed in any of claims 1 to 6 and employing a cleaning composition as claimed in any of claims 7 to 9.

11. A cleaning formulation for use in a method of cleaning an inanimate article employing ultrasonic energy, wherein the cleaning formulation comprises a cleaning agent which is a solid peroxide compound; one or more additional components selected from the group consisting of a base, a surfactant, a bleach activator, a hydrotrope and a binder; and

wherein said cleaning formulation is substantially devoid of free water.

12. A packaged product comprising a container of a cleaning formulation according as claimed in claim 11, and an applicator, said applicator being adapted to enable a cleaning composition, produced by combining a quantity of said cleaning formulation and a diluent, to be applied to an article to be cleaned.

13. A kit of parts comprising a cleaning formulation as claimed in claim 11 or a packaged product as claimed in claim 12, together with a device arranged to emit ultrasonic energy.

14. An ultrasonic cleaning method, or a cleaning composition for use in an ultrasonic cleaning method, or a cleaning formulation able to form such a cleaning composition; or a package, product or kit of parts to facilitate the method; in any such aspect being substantially as hereinbefore described with particular reference to the examples of the invention herein.