WO2005059082A1

WO2005059082A1 - Multi-phase tablet

Info

Publication number: WO2005059082A1
Application number: PCT/EP2003/051045
Authority: WO
Inventors: Werner Strothoff; Winfried Troll
Original assignee: Ecolab Inc.
Priority date: 2003-12-18
Filing date: 2003-12-18
Publication date: 2005-06-30
Also published as: ATE397057T1; DE60321404D1; AU2003298370A1; EP1723225B1; EP1723225A1

Abstract

The present invention refers to multi-phase tablet for use in a washing machine and/or dishwasher, the tablet comprises at least three phases, whereby a) the first phase comprises an alkalizing agent, whereby the amount of alkalizing agent is sufficient to obtain a washing liquid having a pH-value of 7,5 or more (20°C), b) the second phase comprises an acidifying agent, whereby the amount of acidifying agent is sufficient to obtain a washing liquid having a pH-value of 6,5 or less (20°C), and c) the third phase comprises an alkalizing agent, whereby the amount of alkalizing agent is sufficient to obtain a washing liquid having a pH-value of 7,5 or more (20°C) and to a process of cleaning articles.

Description

Multi-phase tablet

[0001] The present invention refers to a multi-phase tablet for use in a washing machine and/or a dishwasher having a single dose unit and to a process of cleaning articles.

[0002] There is an increasing demand in the art to develop suitable compositions and processes for cleaning articles in washing machines and dishwashers. The compositions and processes used therefore should guarantee a sufficient cleaning of articles such as crockery, dishes, plates, spoons, forks etc.. Furthermore the processes and compositions used should be used in commercially avail- able dishwashing and/or washing machines, whereby further modifications of the aforementioned machines should be avoided. Moreover, the processes and compositions used should not detrimentally effect the environment, i.e. the washing liquids used should not contain aggressive or toxic substances. In particular, the compositions used should not contribute to the corrosion of the washing machines or dishwashers.

[0003] The machine cleaning of kitchen- and tableware in domestic dishwashing machines normally involves a pre-wash cycle, a main wash cycle and a rinse cycle, interrupted by intermediate wash cycles. Normally the pre-wash cycle is selected by the user only for highly soiled ware so that in the majority of cases the wash cycle is carried out without the pre-wash step. Present domestic household washing processes have only alkaline wash cycles but no acid wash cycles.

[0004] For these alkaline washing processes multi-phase tablets are known containing for example different phases like detergent, rinse aid and additives against water hardness. Such tablets are for example described in CA 2,318,000 A1 , CA 2,317, 182 A1 , US2003/0166493 A1 , and US 2003/0166492 A1. [0005] WO 00/04117 A1 discloses such a multi-phase detergent tablet for use in an alkaline washing process, comprising two phases. The first phase comprises an alkalizing agent and the second phase comprises an acidifying agent. It was found that a more rapid solution of the tablets in the washing step can be achieved if certain alkalizing and acidifying agents are incorporated in the multiphase tablet. As acidifying agent sodium hydrogencarbonate is mentioned. These tablets have an improved pH control, and cleaning and enzyme performance. They are sufficiently robust to be able to withstand handling and transportation without sustained damage and they nevertheless dissolve sufficiently fast. When using said tablet, in a first step the first phase is dissolved in water, whereby an alkaline solution is formed. Subsequently, the second phase of the detergent tablet is dissolved in water, whereby the alkaline solution is partly neutralized. The multiphase detergent tablet according to WO 00/04117 comprises detergents as well as enzymes and the dissolution of the tablet is controlled in a way that the tablet has a pH rate change index (Delta pH) of no more than 0.15 units/min. Furthermore, the detergent tablet disclosed may comprise a further phase, whereby it is not mentioned that said phase comprises an alkalizing agent. One drawback of the tablet disclosed in WO 00/04117 is that a high amount of detergent and enzymes is necessary in order to achieve sufficient cleaning results of articles. Furthermore it can only be used in an alkaline washing cycle.

[0006] The invention is specifically directed towards a multi-phase tablet which can be used in a cleaning process having at least a first alkaline cleaning step, a second acid cleaning step and a third alkaline cleaning step.

[0007] Such a process is described in WO 02/100993 A1 for the removal of soil and starch deposits. Said cleaning process can be used in commercial dishwashers as well as in domestic dishwashers for the mechanical cleaning of crockery. The process disclosed contains in a preferred embodiment three steps: First the crockery is treated with an alkaline washing liquid which is obtained by diluting an alkaline concentrate with water. In a subsequent step the crockery is contacted with an acid washing liquid which is obtained by diluting an acidic concentrate with water. In a preferred embodiment a third cleaning step is disclosed, whereby the crockery is treated with an alkaline washing liquid again. Said alkaline washing liquid is obtained by diluting an alkaline concentrate with water. Due to the different concentrates used in the alkaline and acid steps this process normally can 5 only be carried out in commercial multi-tank machines like hood machines or conveyor machines but not in domestic single tank machines.

[0008] Even if the process is carried out in multi-tank machines, the tanks for storing the alkaline concentrate and the acidic concentrate, respectively, must consist of a resistant material or have to be lined with a resistant material. Espe-o cially for the acidic concentrate, the tank must consist of an acid-resistant material or must be lined with an acid-resistant material, in particular when it is not foreseeable that these materials subsequently come into contact with alkaline agents.

[0009] WO 02/100993 A1 proposes to introduce the acid component through the clear rinsing arm if the process is carried out in a domestic dish wash-s ing machines. However this proposal has the disadvantage that the clear rinsing arm is not resistant to acids and tends to block with dried acid concentrates.

[0010] Since a domestic dishwasher generally has one tank dispensing the detergent and additionally a clear-rinsing arm, only a two-step process, i.e. the first alkaline step as well as the subsequent acidic step can be carried out. o [0011] Therefore the present invention aims to find a solution for carrying out the above described process having alkaline and acid washing steps in a standard domestic washing and /or dish washing machine without any change of construction of the machine.

[0012] The technical problem underlying the present invention is to provide5 a composition which can be used in domestic single dose unit washing and/or dishwashing machines for cleaning and in particular to remove starch deposits from articles. In particular, it is an object of the present invention to provide a com- position and a process for cleaning articles in which the tanks of a domestic and/or dishwashing machine are not blocked with concentrates or compositions.

[0013] The technical problem underlying the present invention is solved by a multi-phase tablet for the use in a washing machine and/or dishwasher, the tablet comprises at least three phases, whereby a) the first phase comprises an alkalizing agent, whereby the amount of alkalizing agent is sufficient to obtain a washing liquid having a pH-value of 7,5 or more (20°C), b) the second phase comprises an acidifying agent, whereby the amount of acidifying agent is sufficient to obtain a washing liquid having a pH-value of 6,5 or less (20°C), and c) the third phase comprises an alkalizing agent, whereby the amount of alkalizing agent is sufficient to obtain a washing liquid having a pH-value of 7,5 or more (20°C).

[0014] Preferably, when the entire first phase of the multi-phase tablet is dissolved in water, at a temperature of 20 °C the obtained washing liquid has an alkaline pH value of 8 or more. Preferably, the pH value is 8,5 or more, even more preferred 9 or more, preferably 10 or more, even more preferred 11 or more and in a most preferred embodiment 11 ,5 or more.

[0015] Preferably, when the entire second phase of the multi-phase tablet is dissolved in water, at a temperature of 20 °C the obtained washing liquid has an acidic pH value of 6 or less. Preferably, the pH-value is 5 or less, preferably 4 or less, even more preferred 3 or less, preferably 2.5 or less and most preferred 2 or less. [0016] Preferably, when the entire third phase of the multi-phase tablet is dissolved in water, at a temperature of 20 °C the obtained washing liquid has an alkaline pH value of 8 or more. Preferably, the pH value is 8,5 or more, even more preferred 9 or more, preferably 10 or more, even more preferred 11 or more and in 5 a most preferred embodiment 11 ,5 or more.

[0017] Household washing machines and/or dishwashers have specific washing programs. It is possible that the washing liquid is not discarded in the entire washing process and that there is a rinsing step only at the end of the washing process. Alternatively, in the washing process it is possible that there are differento washing liquids prepared. Such a washing liquid is discarded before the next washing liquid is prepared. Moreover, there may be one or more rinsing step in the washing program.

[0018] The specific amount of the alkalizing agents and the acidifying agent depends on the specific washing process of the household washing machine ors dishwasher. In the case that the washing liquid obtained by dissolution of the first phase is not discarded during washing, the amount of acidifying agent of the second phase must be sufficient to acidify said alkaline washing liquid, i.e. to obtain an acid washing liquid having a pH-value as given above. Moreover, in the case that said acid washing liquid is not discarded, too, the amount of alkalizing agent0 of the third phase must be sufficient to alkalize said acid washing liquid, i.e. to obtain an alkaline washing liquid having the pH-value as given above.

[0019] In the case that the first and/or second washing liquid is discarded, the amount of the specific alkalizing or acidifying agents in the multi-phase tablet can be lower, since the foregoing washing liquid has not to be neutralized. Any-5 way, the obtained specific washing liquid must have a pH-value as given above.

[0020] The feature multi-phase tablet encloses every shaped body in which the aforementioned three phases are present and separated from each other. It is possible that the tablet has the shape of a ball, whereby the third phase represents the core of the ball. In such an embodiment, the second phase surrounds the third phase and the first phase surrounds the second phase. Consequently, the first phase forms the surface of the ball. Alternatively, it is possible that the tablet has the form of a bar, whereby the bar comprises layers of the first, second and/or third phase. In another preferred embodiment it is possible that one or two of the three phases of the multi-phase tablet act as a substrate for the remaining phases. The remaining phases may have the shape of a ball or a similar shape and said balls are positioned on or in the phase or phases acting as a substrate.

[0021] Preferably, when the entire first phase of the multi-phase tablet is dissolved in water, at a temperature of 20 °C the obtained solution has an alkaline pH value of 7,5 or more and said solution is used as washing liquid. In a preferred embodiment, at a temperature of 20 °C the pH value of a 1 wt.-% aqueous solution of the first phase is 7.5 or more. Preferably, the pH value is 8 or more, even more preferred 9 or more, preferably 10 or more, even more preferred 11 or more and in a most preferred embodiment 11 ,5 or more.

[0022] The first phase can comprise any alkalizing agent which is customary to a person skilled in the art. Preferably, the alkalizing agent of the first phase is selected from the group consisting of metal hydroxides, sodium hydroxide, potassium hydroxide, alkali silicates, ethanolamines, triethanolamines, diethanolamine, monoethanolamine, alkali carbonate alkaline carriers, Na-tripolyphosphate, sodium salts of nitrilotriacetic acid, sodium nitrilotriacetate (Na₃-NTA), alkaline com- plexing agents and mixtures thereof.

[0023] Preferably, when the entire second phase of the multi-phase tablet is dissolved in water, at a temperature of 20 °C the solution obtained has an acidic pH value of 6.5 or less and said solution is used as washing liquid. Preferably, at a temperature of 20 °C, the pH value of a 1 wt.-% aqueous solution of the second phase is 6.5 or less. Even more preferred, the pH value is 6 or less, even more preferred 5 or less, preferably 4 or less, even more preferred 3 or less, preferably 2.5 or less and most preferred 2 or less. [0024] The acidifying agent of the second phase can be every acidifying agent customary to a person skilled in the art. Preferably, the acidifying agent of the second phase is selected from the group consisting of mineral acids, organic acids, sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, formic acid, ace- tic acid, hydroxy acetic acid, glycolic acid, citric acid, maleic acid, lactic acid, glu- conic acid, alkanesulfonic acid, amidosulfonic acid, sulfamic acid, succinic acid, glutaric acid, adipic acid, phosphonic acids, polyacrylic acids and mixtures thereof.

[0025] Preferably, when the entire third phase of the multi-phase tablet is dissolved in water, at a temperature of 20 °C the obtained solution has an alkaline pH value of 7,5 or more and is used as washing liquid. In a preferred embodiment, at a temperature of 20 °C the pH value of a 1 wt.-% aqueous solution of the third phase is 7.5 or more. Preferably, the pH value is 8 or more, even more preferred 9 or more, preferably 10 or more, even more preferred 11 or more and in a most preferred embodiment 11 ,5 or more.

[0026] The third phase can comprise any alkalizing agent which is customary to a person skilled in the art. Preferably, the alkalizing agent of the third phase is selected from the group consisting of metal hydroxides, sodium hydroxide, potassium hydroxide, alkali silicates, ethanolamines, triethanolamines, diethanola- mine, monoethanolamine, alkali carbonate alkaline carriers, Na-tripolyphosphate, sodium salts of nitrilotriacetic acid, sodium nitrilotriacetate (Na3-NTA), alkaline complexing agents and mixtures thereof.

[0027] The multi-phase tablet can be manufactured according to methods known to a person skilled in the art. In particular, it is possible that the multi-phase tablet is manufactured by using a tablet press. Alternatively, it is possible that the three phases of the multi-phase tablet are prepared independently by extrusion, casting etc.. Subsequently, the multi-phase tablet is composed in a specific machine whereby the respective phases are combined. Such a machine can be a tablet press, too. [0028] The multi-phase tablet of the present invention preferably disintegrates when contacted with a liquid which is preferably water. In a preferred embodiment when the tablet is exposed to water, the first phase has substantially been dissolved in water, before the second and third phase commence to dissolve in water and, subsequently, when the second phase has substantially been dissolved in water, the third phase commences to dissolve in water. Due to the specific washing program of the washing machine and/or dishwasher, preferably the multi-phase tablet disintegrates in accordance with the washing program. The multi-phase tablet according to the invention disintegrates preferably dependent on the time intervals of the first alkaline, second acidic and third alkaline washing cycles and/or dependent on the temperature of the first alkaline, second acidic and third alkaline washing cycle.

[0029] Preferably, when the tablet is exposed to water, the first phase dissolves in water within 30 seconds to 30 minutes. In a further preferred embodiment the dissolution of the first phase in water takes 1 minute to 25 minutes, even more preferred 2 minutes to 20 minutes and most preferred 3 minutes to 15 minutes.

[0030] Preferably, when the tablet is exposed to water, the second phase dissolves in water within 30 seconds to 30 minutes. In a further preferred embodiment the dissolution of the second phase in water takes one minute to 25 minutes, even more preferred 2 minutes to 20 minutes and most preferred 2 minutes to 15 minutes.

[0031] Preferably, when the tablet is exposed to water, the third phase dissolves in water within 30 seconds to 30 minutes. In a further preferred embodi- ment the dissolution of the third phase in water takes one minute to 25 minutes, even more preferred 2 minutes to 20 minutes and most preferred 3 minutes to 15 minutes [0032] In a further preferred embodiment of the present invention a first barrier layer separates the first phase from the second phase and/or third phase. It is even more preferred that a second barrier layer separates the second phase from the first phase and/or third phase.

[0033] When a first barrier layer and/or second barrier layer is used, the aim of said barrier layer is to separate respective phases from each other. The first barrier layer and/or second barrier layer can comprise every substance which is suitable to separate the aforementioned phases from each other. Preferably, the first and/or second barrier layer comprises a polyethylene wax, paraffin wax, poly- ethylene and/or polypropylene glycols having an average molecular weight of from 1.000 to about 12.000, polyvinyl pyrolidone (PVP), especially PVP of a molecular weight of from 50000 to 150000, polyacrylates, sugars, sugar derivatives, starch, starch derivatives, such as hydroxypropyl methyl cellulose (HPMC), carboxymethyl cellulose (CMC), inorganic polymers, such as hexametaphosphate and mixtures thereof.

[0034] Preferably, the first barrier layer has a liquefying temperature of 20 to

99 °C. In an even more preferred embodiment the liquefying temperature of the first barrier layer is 40 to 70 °C, even more preferred 45 to 65 °C and most preferred 50 to 55 °C.

[0035] Preferably, the second barrier layer has a liquefying temperature of from 21 to 100 °C. In a further preferred embodiment the liquefying temperature of the second barrier layer is of from 45 to 90 °C, preferably 50 to 80 °C, more preferred 55 to 65 °C and most preferred 55 to 60 °C.

[0036] In a further preferred embodiment the first barrier layer has a lower liquefying temperature than the second barrier layer.

[0037] Preferably, the multi-phase tablet of the present invention comprises at least one further phase. In a preferred embodiment at least one of the first phase, second phase, third phase or further phases comprises an additive. As additives all additives customary to a person skilled in the art can be used. Preferably the additive is selected from the group consisting of carriers, detergents, surfactants, enzymes, builder, sequestering agents, defoamer, complexing agents, clear rinsing agents, disinfectants, anti-microbial compounds, corrosion inhibitors and mixtures thereof.

[0038] In a preferred embodiment, the first phase of the multi-phase tablet does not comprise a detergent and/or surfactant and/or enzyme. Moreover, preferably the second phase does not comprise a detergent and/or surfactant and/or enzyme. It is even more preferred that the third phase does not comprise a detergent and/or surfactant and/or enzyme.

[0039] The multi-phase tablet of the present invention can be used in a washing machine and/or dishwasher for removing soiling and deposits from articles. In particular, the multi-phase tablet of the present invention preferably can be used for removing starch deposits from articles. The term "articles" encompasses all articles which are customarily used in a household such a crockery, dishes, spoons, plates, knives, forks, pans etc..

[0040] Moreover, the present invention provides a process of cleaning articles in a washing machine or dishwasher, comprising the steps of a) exposing the multi-phase tablet to a liquid comprising water, thereby forming a first alkaline solution of the first phase of the tablet and contacting the articles with said first alkaline solution, b) exposing the remaining tablet to a liquid comprising water, thereby forming a second acidic solution of the second phase of the tablet and contact- ing the articles with said second acidic solution, and c) exposing the remaining tablet to a liquid comprising water, thereby forming a third alkaline solution of the third phase of the tablet and contacting the articles with said third alkaline solution, and d) optionally, rinsing of the articles with a liquid comprising water, whereby the rinsing step is carried out at least after one of steps a), b), c) and/or after step c).

[0041] Preferably, the process comprises at least one further cleaning and/or rinsing step.

[0042] Surprisingly, it has been found that by using the multi-phase tablet of the present invention articles can safely be cleaned in a washing machine and/or dishwasher. In particular, starch deposits can be removed in a safe way from said articles. Furthermore, the articles cleaned are more shiny compared with cleaning procedures known in the art. Especially, glasses, stainless steel, china and dishes are more shiny when cleaned with the multi-phase tablet of the present invention. When using the multi-phase tablet and the process of the present invention it is not necessary that the washing machine or the dishwashing machine comprises separate tanks for dosing, dispensing and storing the compositions and/or concentrates used for washing and cleaning the articles. Thus, it is not necessary that further tanks have to be present in the washing machine or dishwasher. Moreover, no tanks having acid-resistance properties are needed any more. The tanks which are generally present in a washing or dishwashing machine can now be used for storing clear rinsing agents or for salts which are used when the water has a high hardness. Furthermore, the washing liquids of the process of the present invention are not critical with respect to ecological risks. Thus, the process of the present invention is environmentally friendly.

[0043] The multi-phase tablet according to the invention allows to carry out a washing process with alkaline and acid washing cycles in a single dose unit do- mestic washing or dishwashing machine without any further change of the construction of the machine.

[0044] The following examples explain the invention in more detail without limiting it to specific embodiments. Examples

[0045] A glass tube which is closed on one end is filled with 5.3 gr. sodium hydroxide first as the third phase. Then, a paraffin layer 1 having a melting point of 57 to 60 °C is applied to the sodium hydroxide, whereby the paraffin layer 1 has a thickness of 1.5 mm and seals the third phase. 10.0 gr. of amidosulfonic acid is placed on the paraffin layer 1 as second phase. A paraffin layer 2 having a melting point of 51 to 53 °C is applied to the amidosulfonic acid, whereby the paraffin 2 layer has a thickness of 1.5 mm and seals the second phase. Subsequently, 1.0 gr. sodium hydroxide is placed on the paraffin layer 2 as the first phase and in order to close the tube, a paraffin wax having a melting point of 35 °C is placed on the sodium hydroxide. Alternatively, a polyethylene glycol having a molecular weight of 8.000 can be used for closing the tube in order to obtain a multi -phase tablet according to the present invention.

[0046] In a standard household dishwasher (Bosch SMS 2022, program 3) starch soiled dishes were cleaned with the multi -phase tablet according to the pre- sent invention and with a Topmat Tab (available from Ecolab), which comprises an alkalizing agent and enzymes, as a comparative example. The starch deposits were colored with a black dye. The washing program of the machine was not modified.

[0047] In the washing program 3 of the household dishwasher, water was sprayed to the aforementioned multi-phase tablet of the present invention at a temperature of from 20 - 53 °C for a duration of 7 minutes, whereby an alkaline washing liquid was formed. Subsequently, for a period of time of 2 minutes and at a temperature of from 53 to 60 °C water was sprayed to the multi -phase tablet of the present invention to form an acidic washing liquid. In the subsequent step, at a temperature of from 60 °C to 69 °C and for 13 minutes water was sprayed to the multi-phase tablet to form an alkaline washing liquid. As a last step tap water was 5 used for rinsing the dishes.

[0048] As comparative example, water having the same temperature as given above was sprayed to the Topmat Tab for the same period of time.

[0049] The multi-phase tablet of the present invention disintegrated during the washing program. First, the paraffin or polyethylene mixture which sealed theo tube liquefied. In the first step the sodium hydroxide diluted in water whereby a washing liquid having a pH of 11, measured at a temperature of 20 °C, was formed. During the second step of the washing program, the paraffin layer having the melting point of 51 to 53 °C liquefied and subsequently the amidosulfonic acid dissolved in water, whereby a washing liquid having a pH of 2 (20 °C) was formed.s Then, as the next step the paraffin layer having a melting point of 57 to 60 °C was liquefied. Subsequently, the sodium hydroxide was dissolved, thereby forming an alkaline washing liquid, having a pH of 11 measured at a temperature of 20 °C. The last step of the program 3 of the household dishwashing machine Bosch SMS 2022 was a rinsing step with tap water. o [0050] The cleaning performance of the substances used was determined visually, whereby 0 means no cleaning effect and 10 means a perfect cleaning effect. In order to achieve a better visual control of the cleaning performance, the starch deposits were colored with a black dye.

[0051] The multi-phase tablet of the present invention has a cleaning per-5 formance of from 9 to10. In contrast thereto, the Topmat Tab has a cleaning performance of from 3 to 5. Moreover, the dishes are more shiny when cleaned with the multi-phase tablet of the present invention. Thus, the multi-phase tablet of the present invention is capable of providing a superior cleaning result compared to the compositions known in the prior art.

Claims

1. A multi-phase tablet for use in a washing machine and/or dishwasher, the tablet comprising at least three phases, whereby a) the first phase comprises an alkalizing agent, whereby the amount of al- kalizing agent is sufficient to obtain a washing liquid having a pH -value of 7,5 or more (20°C), b) the second phase comprises an acidifying agent, whereby the amount of acidifying agent is sufficient to obtain a washing liquid having a pH-value of 6,5 or less (20°C), and c) the third phase comprises an alkalizing agent, whereby the amount of alkalizing agent is sufficient to obtain a washing liquid having a pH -value of 7,5 or more (20°C).

2. The multi-phase tablet of claim 1 , characterized in that at a temperature of 20 °C the pH-value of a 1 wt.-% aqueous solution of the first phase is 7,5 or more.

3. The multi-phase tablet of claims 1 or 2, characterized in that the alkalizing agent of the first phase is selected from the group consisting of metal hydroxides, sodium hydroxide, potassium hydroxide, alkali silicates, ethanolamines, triethanolamine, diethanolamine, monoethanolamine, alkali carbonate alkaline carriers, Na -tripolyphosphate, sodium salts of nitrilotriacetic acid, sodium ni- trilotriacetate (Na₃-NTA), alkaline complexing agents and mixtures thereof.

4. The multi-phase tablet of at least one of the claims 1 to 3, characterized in that at a temperature of 20 °C the pH-value of a 1 wt.-% aqueous solution of the second phase is 6,5 or less.

5. The multi-phase tablet of at least one of the claims 1 to 4, characterized in that the acidifying agent of the second phase is selected from the group consisting of mineral acids, organic acids, sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, formic acid, acetic acid, hydroxy acetic acid, glycolic acid, cit- ric acid, maleic acid, lactic acid, gluconic acid, alkylsulfonic acid, amidosulfonic acid, sulfamic acid, succinic acid, glutaric acid, adipic acid, phosphonic acids, polyacrylic acids and mixtures thereof.

6. The multi-phase tablet of at least one of the claims 1 to 5, characterized in that at a temperature of 20 °C the pH-value of a 1 wt.-% aqueous solution of the third phase is 7,5 or more.

7. The multi-phase tablet of at least one of the claims 1 to 6, characterized in that the alkalizing agent of the third phase is selected from the group consisting of metal hydroxides, sodium hydroxide, potassium hydroxide, alkali silicates, ethanolamines, triethanolamine, diethanolamine, monoethanolamine, alkali carbonate alkaline carriers, Na-tripolyphosphate, sodium salts of nitrilotriacetic acid, sodium nitrilotriacetate (Na₃-NTA), alkaline complexing agents and mixtures thereof.

8. The multi-phase tablet of at least one of the claims 1 to 7, characterized in that when the tablet is exposed to water, the first phase has substantially been dis- solved in water before the second and third phase commence to dissolve in water and, subsequently, when the second phase has substantially been dissolved in water the third phase commences to dissolve in water, wherein the disintegration is dependent on the time and/or temperature of the washing program.

9. The multi-phase tablet of claim 8, characterized in that when the tablet is exposed to water the first phase dissolves in water within 30 seconds to 30 minutes.

10. The multi-phase tablet of claim 8, characterized in that when the tablet is exposed to water the second phase dissolves in water within 30 seconds to 30 minutes.

11. The multi-phase tablet of claim 8, characterized in that when the tablet is ex- 5 posed to water the third phase dissolves in water within 30 seconds to 30 minutes.

12. The multi-phase tablet of at least one of the claims 1 to 11, characterized in that a first barrier layer separates the first phase from the second phase and/or third phase.

ιo 13. The multi-phase tablet of at least one of the claims 1 to 11, characterized in that a second barrier layer separates the second phase from the first phase and/or third phase.

14. The multi-phase tablet according to claim 12, characterized in that the first barrier layer has a liquefying temperature of from 20 to 99 °C.

is 15. The multi-phase tablet according to claim 13, characterized in that the second barrier layer has a liquefying temperature of from 21 to 100 °C.

16. The multi-phase tablet according to claims 12 and 13, characterized in that the first barrier layer has a lower liquefying temperature than the second barrier layer.

20 17. The multi-phase tablet according to any of the claims 1 to 16, characterized in that the multi-phase tablet comprises at least one further phase.

18. The multi-phase tablet according to any of the claims 1 to 17, characterized in that at least one of the first phase, second phase, third phase or further phase comprises an additive.

19. The multi-phase tablet according to claim 18, characterized in that the additive is selected from the group consisting of caπiers,+ detergents, surfactants, builder, sequestering agents, defoamer, complexing agents, clear rinsing agents, disinfectants, antimicrobial compounds, corrosion inhibitors and mixtures thereof.

20. Use of the multi-phase tablet according to any of the claims 1 to 19 in a wash- ing machine and/or dishwasher.

21. The use according to claim 20 for removing starch deposits from articles.

22. Process of cleaning articles in a washing machine or dishwasher, comprising the steps of: a) Exposing the multi-phase tablet according to any of the claim 1 to 19 to a liquid comprising water, thereby forming a first alkaline solution of the first phase of the tablet and contacting the articles with said first alkaline solution, b) Exposing the remaining tablet to a liquid comprising water, thereby forming a second acidic solution of the second phase of the tablet and contact- ing the articles with said second acidic solution, c) Exposing the remaining tablet to a liquid comprising water, thereby forming a third alkaline solution of the third phase of the tablet and contacting the articles with said third alkaline solution, and d) Optionally, rinsing of the articles with a liquid comprising water, whereby the rinsing step is carried out at least after one of steps a), b), c) and/or after step c).

23. The process according to claim 22 comprising at least one further cleaning and/or rinsing step.