WATER-SOFTENER IN POWDERED FORM WITH AN EFFERVESCENT SYSTEM

Abstract: Water-softener composition in powdered form containing at least one perfume, characterised in that the composition contains an effervescent system which is essentially free of surfactants and bleaching agents.

Description: Water-Softener In Powdered Form With An Effervescent System The invention relates to a perfumed water-softener composition in powdered form which contains an effervescent system. Cleaning agents and water-softener compositions often contain a perfume or perfume mixture, intended to impart a pleasant fragrance to items to be cleaned, such as laundry, and/or intended to release a fragrance that is pleasant to the user during the washing process, for example, when washing laundry by hand. The use of effervescent systems in detergent compositions - particularly these are in a tablet form - in order to accelerate dissolution in the washing water is known. Examples of this are described in W098/46714, W098/45283 or WO98/04667 which compositions contain surfactants and/or bleaching agents. The underlying objective of the invention is to improve water-softener compositions, preferably in powdered form (powder water softener compositions) , so that they produce a perfume effect sustained for a long period during its use. This objective is achieved by the invention, a water- softener composition, preferably in powdered form, containing at least one perfume, the composition also containing an effervescent system. The water-softening composition should be essentially free of any surfactant and bleaching agent . Preferably, the effervescent system contains at least one alkali metal carbonate and/or alkali hydrogen carbonate and at least one acidifying agent, the acidifying agent preferably containing at least one acid, most preferably an organic carboxylic acid. In a more preferred embodiment, the organic carboxylic acid is a fruit acid, preferably citric acid or malic acid. The invention also relates to the use of an effervescent system, preferably one as described above, used in water- softener compositions, preferably in the form of a powder, containing at least one perfume, to improve the durability of the fragrance given off by this perfume. The invention relates to the use of water-softener compositions, preferably in the form of a powder for applications involving manual laundering. Surprisingly, it has been found that adding an effervescent system to a water-softener composition produces a perfume effect which is sustained for a long period. This effect is particularly surprising since it has always been assumed that the perfuming substance will be dispelled significantly more rapidly due to the motion occurring in the washing liquid when using an effervescent system. In addition we have found that the addition of a water- softening composition, which contains a perfume and no effervescent system, to a liquid wash containing a detergent with an effervescent system does not lead to a sustained perfume effect. This effect can be regarded as positive with all conceivable water-softener compositions, it is of particular advantage for those in which the duration of the fragrancing effect of the perfume or the perfume mixture is particularly perceptible, i.e. in cases where the composition is deployed in such a way that the user is immediately aware of the perfume effect, such as when used for manual laundering, for example. One particularly preferred application, therefore, is the addition of an effervescent system to a water-softener composition in a powder form displaced with a fragrance for use in manual laundering, which is preferably added to the washing liquid prior to adding the actual washing agent, in order to enhance the cleansing effect. Tests to date have therefore mainly been conducted on compositions of this type. However, preliminary tests carried out on other water-softener compositions (e.g. for washing machines) have shown that the effect described above also occurs in a similar manner with these, i.e. essentially irrespective of what the rest of the composition of the water-softener might be. Although the system comprising sodium hydrogen carbonate and citric acid is used as the effervescent system in the example described below, it would, of course, also be possible to consider other effervescent systems, in particular those containing other acids, such as polymeric acids or glycolic acid, lactic acid, etc. Tests have shown that the effervescent system as such is not critical to the described effect. On the contrary, there is considerable flexibility, which means that a selection can be made to suit specific circumstances for the use of the water-softening composition. Preferred amounts of acidifying agent are present in the composition in the range of 0.51% w/w to 25% w/w, ideally 1% w/w to 20% w/w, preferably 2% w/w to 10% w/w and especially 2% w/w to 6% w/w. A preferred acidifying agent is citric acid. Preferred amounts of alkali metal carbonate and/or hydrogen carbonate are present in the composition in the range of 4% w/w to 70% w/w, ideally 15% w/w to 65% w/w, preferably 25% w/w to 60% w/w and especially 40% w/w to 58% w/w. The water softening component of the composition may contain any known water softening compound or mixture, such as water soluble water-softening agent or a water- insoluble water-softening agent, notably alkali-metal aluminosilicate. Water soluble water-softening agent may be organic or inorganic. Inorganic may be present include alkali metal (generally sodium) carbonate; while organic include polycarboxylate polymers, such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphonates, monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono- di- and trisuccinates, carboxymethyloxysuccinates , carboxymethyloxymalonates, dipicolinates and hydroxyethyliminodiacetates . If a composition contains only soluble water-softening agent, this may well be a salt of tripolyphosphate and/or ditric acid, such as the sodium salt, and/or a condensed phosphate . It is very well known that water-insoluble alkali metal aluminosilicates can function to soften water, removing calcium ions and to a lesser extent magnesium ions by ion exchange. Aluminosilicates have become strongly favoured as environmentally acceptable detergency builders. Suitable crystalline sodium aluminosilicate ion-exchange detergency builders are described, for example, in GB 1429143 (Procter & Gamble) . The preferred sodium aluminosilicates of this type are the well known commercially available zeolites A and X, and mixtures thereof. Also of interest is the novel zeolite P described and claimed in EP 384070 (Unilever) . Another category of water-insoluble material which can function as a water-softening agent is the layered sodium silicate builders disclosed in US-A-4464839 and US-A- 4820439 and also referred to in EP-A-551375. Quoted literature references describing the preparation of such materials include Glastechn. Ber. 37, 194-200 (1964), Zeitschrift fur Kristallogr. 129, 396-404 (1969), Bull. Soc. Franc. Min. Crist., 95, 371-382 (1972) and Amer. Mineral, 62, 763-771 (1977) . These materials also function to remove calcium and magnesium ions from water. It is customary to use a water-soluble water-softening agent, as described above, jointly with aluminosilicate, to enhance water-softening efficacy. Such water-soluble soluble water-softening agent are generally used in an 5 amount which is not greater than the amount of aluminosilicate, often less than half the amount of aluminosilicate . Preferred amounts of the water-softening component are 10 present in the composition in the range of 4% w/w to 65% w/w, ideally 15% w/w to 60% w/w, preferably 25% to 55% w/w and especially 35% w/w to 48% w/w. The amount of perfume added to the composition is 15 dependent upon the desired effect wanted to be achieved. Typical amounts may be from 0.05% w/w to 2% w/w. The composition is preferbly in the form of a powder, however other solid formulations are contemplated such as 20 tablets, either made by compaction or by extruding. Liquid formulations may also be used in which the ingredients may be suspended or dissolved in a non- aqueous liquid carrier medium, such liquid media include; 25 Preferred Compositions Example Various samples of a water-softener composition, mainly consisting of sodium hydrogen carbonate and sodium tripolyphosphate, with the same content of fragrance were displaced with differing contents of citric acid, which produced the intended effervescent effect in conjunction with the sodium hydrogen carbonate . The composition of samples I to IV is set out more specifically in Table I below. Table I The perfume effect was evaluated for strength of fragrance by a test panel on a scale of 1 to 5, where 1 represents no perceptible fragrance and 5 a very strong fragrance. The same test panel was also asked to evaluate the duration of the fragrance in terms of two categories "short" and "long" The results are set out in Table II below. Table I I The features of the invention as explained in the description above and defined in the claims may essentially be used individually or in any combination for the purposes of the invention and in their different embodiments.

Claims: Claims 1. Water-softener composition containing at least one perfume, characterised in that the composition contains an effervescent system. 2. Water-softener composition as claimed in claim 1, characterised in that the effervescent system contains at least one alkali metal carbonate and/or hydrogen carbonate and at least one acidifying agent . 3. Water-softener composition as claimed in claim 2, characterised in that the acidifying agent contains at least one acid. 4. Water-softener composition as claimed in claim 3, characterised in that the acid is a carboxylic acid. 5. Water-softener composition as claimed in claim 4, characterised in that the fruit acid is citric acid or malic acid. 6. Water-softener composition as claimed in any preceeding claim in the form of a powder. 7. Use of an effervescent system in water-softener compositions containing at least one perfume in order to improve the durability of the fragrancing effect of this perfume. 8. Use as claimed in claim 7 with a water-softener composition in powdered form for applications involving manual laundering. 9. Use as claimed in claim 7 or 8, characterised in that the effervescent system is of the type as claimed in one of claims 2 to 6. 10. Water-softener composition in powdered form comprising 1) 0.51% w/w of a water-softening compound or mixture thereof; 2) 4% w/w to 70% w/w of an alkali metal carbonate and/or hydrogen carbonate; 3) 0.51% to 25% w/w of an acidifying agent; 4) and a perfume .

Inventors: AMICONI FABIO, BOSCO MANUELA, ROBINSON PAUL WILLIAM, AMICONI, FABIO, BOSCO, MANUELA, ROBINSON, PAUL
Applicants: AMICONI FABIO, BOSCO MANUELA, RECKITT BENCKISER NV, ROBINSON PAUL WILLIAM, AMICONI, FABIO, BOSCO, MANUELA, RECKITT BENCKISER N.V., ROBINSON, PAUL
Application year: 2001
Main classification: C11D3
IPC codes: C11D3