The present invention relates to an agent for use in automatic dishwashers and to a device for its dosed introduction during the rinsing and drying cycles for the purpose of fragrancing the inside of the dishwasher during protracted operating intervals and for improving the pearl-off performance of the rinsing water on washed items during the drying cycle, said agent having a solid, e.g. granular, structure at normal temperatures.
Consumer research shows that one- or two-person households run their dishwasher only twice a week. The reason for this is that only during this period do enough dirty items accumulate for a full or almost full dishwasher load. Thus, over a period of two, three or more days, the dishwasher is filled with items contaminated with leftovers. After just a short time, unpleasant odours develop inside the dishwasher, to which the consumers are exposed when they open the dishwasher in order to put in other dirty items. It is estimated that the consumer is exposed to these odours 8 to 10 times during an operating interval lasting several days.
Odour-improving agents for fragrancing dishwashers are known from the prior art. For example, Reckitt Benkiser and Henkel manufacture such products under the brand names “Calgonite” and “Somat Deoperls”. Reckitt Benkiser's product is based on a liquid fragrance formulation with up to 60% fragrance. This is held in a plastic reservoir and has a membrane through which the fragrance diffuses into the interior of the dishwasher. The disadvantage of this product is that the reservoir must be filled with large volumes of fragrance in order to ensure that the effect lasts for an adequate length of time, for example 30 days. This large volume is needed because of the high loss of liquid fragrance every time the dishwasher is operated, a consequence of the hot-water and hot-air temperatures during the rinsing and drying cycles. High costs are caused by the excessive introduction of fragrance. In addition, fragrance release while the product is in use is non-uniform, i.e., at first, the more volatile fragrance components are released. In consequence, the original smell of the fragrance undergoes a significant change while the product is in use, which does not promote acceptance of the product among consumers.
The Henkel product is based on the release of fragrance from a solid, granulated carrier material of ethylene vinyl acetate (EVA), a material of limited water solubility, which is described in DE 10237066. The maximum proportion of fragrance that can be incorporated in this carrier material is 40%. A special container described in DE 10303352 is utilized for releasing the fragrance in the dishwasher; this ensures release of the fragrance on contact with hot water and hot air during the dishwasher's rinsing and drying cycles. This is effected by way of the high water and air temperatures occurring during the dishwasher's rinsing and drying cycles. However, with this product the fragrance release is limited. The most significant disadvantage of this product is that a maximum fragrance content of 40% necessitates the use of large volumes of carrier material in order to maintain a sufficient fragrance intensity inside the dishwasher during operating intervals.
Another problem occurring in connection with the use of dishwashers is that there remains a “film” or spotting on items after washing, which is especially noticeable on glassware. This problem is particularly acute in localities in which the water supply has a high mineral content. Until now, this problem has been solved by the additional use—besides the washing-up agent and maybe an air freshener—of a product known as a rinse aid, which improves the degree to which rinsing water adhering to the washed items pearls off. An example of a commercially available product of this kind is “Finish”, produced by Reckitt Benkiser.
An immense disadvantage of the known air fresheners and rinse aids is that these products have to be put into the dishwasher as separate products, in addition to the actual washing-up agent.
The object of this invention is therefore to develop a product that allows not only the fragrancing of the dishwasher during protracted operating intervals, but also improves the pearling off of the rinsing water from the washed items, thus creating a shiny effect.
Another object of this invention is to provide a device that allows the dosed release of this agent in order to produce a combined fragrancing and shine effect during the dishwasher's rinsing and drying cycles. At the same time, this device should prevent any agglomeration of the chip-like, pearl-like or granular solid agent should operating temperatures reach 60° C. or more.
The problem of developing an agent for producing a combined fragrancing and shine effect is solved by the features of claim 1.
The problem of providing a device for releasing the agent during the dishwasher's rinsing and drying cycles is solved by the features of claim 7.
Preferred embodiments of the agent constitute the features of claims 2 to 6; preferred embodiments of the device for releasing the agent during the dishwasher's rinsing and drying cycles constitute the features of claims 7 to 9.
In the following, the invention will be explained on the basis of an embodiment, with reference to the drawings of
The incorporation of liquid fragrances in a solid carrier material of fatty alcohol or a mixture of fatty alcohol and other components is described in the PCT application WO 2004/035721 and in the German patent application DE 10 2004 052 929.9, and this reference is intended to create a connection to the present invention. Surprisingly, it became apparent that the carrier material—in the form of fatty alcohol or a mixture of fatty alcohol and other components—selected for the incorporation of the liquid fragrance additionally has a positive influence on the water's pearl-off performance during the drying cycle. This is due to fatty alcohol dissolving in the rinse water.
A solution of fragrance in C22 fatty alcohol proved to be a particularly suitable agent.
It also became apparent that replacing up to 20 wt. % of fatty alcohol by surfactants derived from fatty alcohol ethylene/propylene oxide can further improve the effectiveness with which the rinsing water pearls off the washed items, without reducing the carrier material's capacity to incorporate fragrance. An example of a commercially available product which has the aforementioned composition and which can replace up to 20% of the carrier material is DEHYPON 3697 from Cognis-Care Chemicals. Although the choice of fatty alcohol or of substances containing a proportion of fatty alcohol, especially C22 fatty alcohol, as carrier material for the fragrance surprisingly ensures good pearl-off performance of the water, thus reducing film formation and spotting and consequently producing a shine effect, this effect is reinforced by the aforementioned addition of surfactants derived from fatty alcohol ethylene/propylene oxide.
For efficient release of both the fragrance and the substances that improve the rinse water's pearl-off performance, the invention provides for an innovative dispensing device suitable for attachment inside the dishwasher. This ensures good contact between the agent according to the invention and the water during the rinsing cycles, and prevents the solid carrier material within the dispensing device from agglomerating under its own weight at temperatures higher than 50° C., which are reached during the rinsing and drying cycles. If the carrier material were not prevented from agglomerating, the adequate release—during the dishwasher's running time—of fragrance and of the substances that improve the rinsing water's pearl-off performance could be increasingly impaired.
The device according to
During the rinsing cycles, rinsing water flows through the sieve-like openings of the door 4 and the rear wall of the body 2 and dissolves the substance that improves the rinse water's pearl-off performance, i.e. the fatty alcohol and any surfactants that may be mixed therewith, which serves as carrier material for the liquid fragrance. Simultaneously, under the influence of heat, i.e. of hot water and, in particular, of the hot drying air flowing in after the rinsing cycles, the fragrance is released from the solid, granular structure of the agent according to the invention.
The fatty alcohol, and possibly further surfactants, dissolved in the dishwater permits a largely film-free and spotless pearling off of the rinsing water during the drying cycle, while the fragrance released from the granular agent by the drying heat provides a pleasant smell that lasts for several days inside the dishwasher, largely masking the unpleasant smell of items that are contaminated with leftovers and accumulate in the dishwasher over a few days.
If fragrances are used which simultaneously develop an antibacterial effect, for instance cineole or methyl phenyl butanol, the product according to the invention is imbued additionally with a deodorizing effect, meaning that unpleasant smells are not only masked but also combated. The invention thus makes it possible, without having to add special rinse aids or deodorizing agents, to confer a triple effect on the agent, which, in prior art products, only played a fragrancing role.
This device is a pouch made of a semi-soft thermoplastic with sieve-like perforations. It is divided into a number of chambers 9 by spaced, seamlike, transverse heat seals 8. Since only small amounts of the granular agent are contained in each chamber, as in the case of the device of
The embodiment of a dispensing device as illustrated in
Number | Date | Country | Kind |
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10 2005 025 041.6 | May 2005 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2006/002259 | 3/11/2006 | WO | 00 | 11/16/2007 |