Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-07-16
2004-06-15
Webb, Gregory (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S220000, C510S224000, C510S504000, C510S506000, C510S514000, C134S026000
Reexamination Certificate
active
06750187
ABSTRACT:
TECHNICAL FIELD
The present invention is in the field of dishwashing, in particular it relates to dishwashing methods suitable for the removal of cooked-, baked- and burnt-on soils from cookware and tableware.
BACKGROUND OF THE INVENTION
Cooked-, baked- and burnt-on soils are amongst the most severe types of soils to remove from surfaces. Traditionally, the removal of cooked-, baked- and burnt-on soils from cookware and tableware requires soaking the soiled object prior to a mechanical action. Apparently, the automatic dishwashing process alone does not provide a satisfactory removal of cooked-, baked- and burnt-on soils. Manual dishwashing process requires a tremendous rubbing effort to remove cooked-, baked- and burnt-on soils and this can be detrimental to the safety and condition of the cookware/tableware.
The use of cleaning compositions containing solvent for helping in the removal of cooked-, baked- and burnt-on solids is known in the art. For example, U.S. Pat. No. 5,102,573 provides a method for treating hard surfaces soiled with cooked-on, baked-on or dried-on food residues comprising applying a pre-spotting composition to the soiled article. The composition applied comprises surfactant, builder, amine and solvent. U.S. Pat. No. 5,929,007 provides an aqueous hard surface cleaning composition for removing hardened dried or baked-on grease soil deposits. The composition comprises nonionic surfactant, chelating agent, caustic, a glycol ether solvent system, organic amine and anti-redeposition agents. WO-A-94/28108 discloses an aqueous cleaner concentrate composition, that can be diluted to form a more viscous use solution comprising an effective thickening amount of a rod micelle thickener composition, lower alkyl glycol ether solvent and hardness sequestering agent. The application also describes a method of cleaning a food preparation unit having at least one substantially vertical surface having a baked food soil coating. In practice, however, none of the art has been found to be very effective in removing baked-on, polymerized soil from metal and other substrates.
The use of solvents in the automatic dishwashing context is also known. JP-A-10,017,900 discloses an automatic dishwashing auxiliary composition comprising non-ionic low foaming surfactant, organic solvent and water. The composition delivers detergency and drying benefits. JP-A-11,117,000 discloses a cleaning assistant composition for automatic dishwashing machines comprising surfactant, organic high-molecular polyelectrolyte, water-soluble solvent and water. The claimed assistant composition helps in the cleaning of stubborn dirt such as that due to oil or lipstick.
There is still the need for a method and products having improved efficacy for the removal of cooked-, baked- and burnt-on soils from cookware and tableware using an automatic dishwashing machine and avoiding the use of a pre-treatment step.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a method of removing cooked-, baked-, or burnt-on food soil (such as grease, meat, dairy, fruit, pasta and any other food especially difficult to remove after the cooking process) from cookware and tableware (including stainless steel, glass, plastic, wood and ceramic objects). The method comprises washing the cookware/tableware in an automatic dishwashing machine in presence of a plurality of compositions, including at least one organic solvent composition. The purpose of using a plurality of compositions is to have different compositions for the cleaning of the different soils and substrates present in a dishwashing machine load. The plurality of compositions are formulated not only for the basic cleaning purpose but also for providing the dishwashing load with good aesthetic features such as shine, filming, spotting, etc. Organic solvent compositions (comprising a single solvent compound or a mixture of solvent compounds) for use herein preferably have a volatile organic content above 1 mm Hg of less than about 50%, preferably less than about 20% and more preferably less than about 10% by weight of the solvent system. Herein volatile organic content of the solvent system is defined as the content of organic components in the solvent system having a vapor pressure higher than the prescribed limit at 25° C. and atmospheric pressure.
In preferred embodiments the plurality of compositions includes at least one organic solvent composition and at least one automatic dishwashing detergent composition or the plurality of compositions includes two or more solvent compositions. The optimum concentration of solvent in the wash liquor is from about 100 ppm to about 10000 ppm, preferably from about 200 to about 8000 and more preferably from about 500 to about 5000 ppm. Preferably, the wash liquor has a liquid surface tension of less than about 35 mN/m, preferably less than about 32 mN/m more preferably less than about 30 mN/m and especially less than about 28 mN/m. The pH of the wash liquor will generally be in the alkaline range, preferably at least 10.5 or more preferably at least 11.0, this pH being provided by means of an alkalinity source or sources in one or more compositions used for delivery of the solvent, surfactant and builder.
The compositions of the invention can be delivered into the same or different cycles of the automatic dishwashing machine. The soiled cookware/tableware is washed in the resulting solvent-containing wash liquor.
Thus, according to another embodiment the removal of cooked-, baked-, or burnt-on food soil from cookware and tableware can be carried out by the use of a plurality of compositions, including one or more organic solvent compositions (wherein “solvent composition” is understood to comprise the organic solvent system and optional additional active ingredients and diluents) and one or more automatic dishwashing detergent compositions. The organic solvent composition can be built, unbuilt or generally unbuilt, but when used as an additive composition in conjunction with a dishwashing detergent composition, the solvent composition will normally be relatively unbuilt by comparison with the detergent composition. By “relatively unbuilt” is meant that under normal use conditions, the solvent composition will deliver a minor proportion (less than 50%, preferably less than 25%, more preferably less than 10% by weight) of the total builder delivered to the wash liquor by the one or more solvent compositions and the one or more detergent compositions. By “generally unbuilt” is meant that the composition contains less than about 5% by weight of detergency builder.
According to different embodiments of the present invention, the solvent compositions and automatic dishwashing detergent compositions can be delivered either at the same or at different points of the dishwashing cycle, for example: i) solvent composition and automatic dishwashing detergent composition are independently delivered in the pre-wash cycle and in the main-wash cycle, respectively; ii) a solvent composition and a first automatic dishwashing detergent composition are delivered in the pre-wash cycle and a second automatic dishwashing detergent composition in the main-wash cycle; iii) a first solvent composition and a first automatic dishwashing detergent composition are delivered in the pre-wash cycle and a second solvent composition and a second automatic dishwashing detergent composition in the main-wash cycle; iv) a solvent composition and an automatic dishwashing detergent composition are delivered simultaneously in the main-wash cycle; and v) a solvent composition and an automatic dishwashing detergent composition are delivered in the pre-wash and in the main-wash cycle.
Another embodiment provides a method of removing cooked-, baked-, or burnt-on food soil from cookware and tableware comprising washing the cookware/tableware in the pre-wash cycle of an automatic dishwashing machine in the presence of an organic solvent composition and thereafter rinsing the cookware/tableware in the rinse cycle of the automatic dish
Alam Elizabeth Ann
Bennie Brenda Frances
Campbell Mairi
DeNome Frank William
Kapur Neha
The Proter & Gamble Company
Waugh Kevin L.
Webb Gregory
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