Rinse aid system

Abstract

The present invention relates to a rinse aid system, preferably in the form of a rinse aid block, which is suitable in particular for rinsing and descaling kitchen appliances or cooking appliances, such as for example commercial dishwashers, baking ovens, automated grills, convection ovens, large cooking containers and degreasing systems from the commercial kitchen sector, and coffee machines.

Description

[0001] Rinse aid system

[0002] The present invention relates to a rinse aid system, preferably in the form of a rinse aid block, which is particularly suitable for rinsing and descaling kitchen appliances or cooking appliances, such as commercial dishwashers, ovens, grills, convection ovens, large cooking containers and degreasing systems from the commercial kitchen sector, as well as coffee machines.

[0003] Various types of rinse aid for cooking appliances are available on the market, each based on different active ingredients. While the detergent, which performs the actual cleaning action, is added at the beginning of the cleaning cycle, special rinse aids are used in the final rinse cycle. These are designed to prevent water droplets from remaining on the surface being washed or the dishes being washed when rinsing with water. These droplets, once dried, leave behind stains from substances and salts dissolved or dispersed in the droplets. These rinse aids are usually available in liquid or powder form.

[0004] These rinse aids usually consist of rinse-aid ingredients combined with a so-called salt substitute. The rinse-aid ingredients are usually special non-ionic surfactants and polymers with a substantive effect on hard surfaces.

[0005] Commercial use also requires the rinse aid to be used in an automatic cleaning program that, once programmed, runs in the absence of operating personnel. In this regard, the rinse aid must withstand several hours of exposure to adverse conditions (high humidity, high temperatures) without loss of usability or effectiveness, even after unpacking.

[0006] One object of the invention is therefore to improve the consistency, rinsability, stability, and rinsing efficiency of a solid rinse aid, a manufacturing process for such a solid rinse aid, and its use for rinsing and descaling commercial dishwashers and commercial cooking appliances. The object described here is achieved, on the one hand, by a rinse aid system according to claim 1, a manufacturing process for such a rinse aid system according to claim 11, and, on the other hand, by a use of the rinse aid system according to claim 13.

[0007] Such a rinse aid system according to the invention, in particular in the form of a rinse aid block, comprises

[0008] - an acidic rinse aid for rinsing commercial dishwashers and commercial cooking appliances, comprising a rinse aid system for a rinse cycle of a machine,

[0009] - comprising at least two acids, wherein the at least two acids are selected from dicarboxylic acids and / or tricarboxylic acids,

[0010] - wherein the total proportion of acids is more than 88% by weight, preferably more than 95% by weight, particularly preferably more than 96% by weight, in particular more than 97% by weight, particularly preferably more than 98% by weight, and

[0011] - wherein the total proportion of acids is at most 99.5% by weight, preferably at most 99% by weight.

[0012] A rinse aid system within the meaning of the present invention is a single- or multi-phase rinse aid that has at least one solid phase and is capable of dissolving in an aqueous environment, particularly during the final rinse cycle. It is preferably a rinse aid block.

[0013] The rinse aid system in the sense of the present invention is a rinse aid which, when dissolved in water in an at least 1% aqueous solution, results in an acidic pH value, ie a pH value of less than ?.

[0014] Surprisingly, it has been shown that such a rinse aid system, in particular a rinse aid block, advantageously exhibits high dimensional stability even at elevated temperatures (up to 80°C) due to the inventive use of dicarboxylic acids. The cartridges containing the rinse aid block are thus only partially deformable even at these temperatures and, in addition, rinse more evenly.

[0015] The preferred rinse aid preferably comprises, in the form of a solid block, a proportion of more than 98% by weight of acids. Such a proportion of acids advantageously results in significantly increased rinse aid or descaling efficiency. The advantageous rinse aid block can be present in a readily water-soluble phase and advantageously dissolves essentially completely in water. "Essentially completely" means that the rinse aid dissolves sufficiently, i.e., not too quickly and not too slowly, in the rinse cycle under normally prevailing conditions, such as solvent volume, temperature, etc., and thus has suitable solubility properties or solubility rate for efficient rinse.

[0016] According to one aspect of the present invention, a manufacturing method for a rinse aid system, in particular in the form of a rinse aid block, is provided, which comprises the following steps:

[0017] (i) mixing at least two acids, wherein the at least two acids are selected from dicarboxylic acids and / or tricarboxylic acids,

[0018] (ii) optionally adding a surfactant,

[0019] (iii) if necessary, addition of water,

[0020] (iv) heating the mixture to a temperature of at least 80 °C, preferably at least 85 °C, in particular at least 90 °C,

[0021] (v) cooling the mixture to room temperature,

[0022] (vi) wherein the total proportion of acids in the cooled mixture is more than 88% by weight, preferably more than 95% by weight, particularly preferably more than 96% by weight, in particular more than 97% by weight, particularly preferably more than 98% by weight, and

[0023] (vii) wherein the total proportion of acids is at most 99.5 wt.%, preferably at most 99 wt.%.

[0024] By subsequent heating to a temperature of at least 80 °C, preferably at least 85 °C, in particular at least 90 °C and / or up to a maximum of 135 °C, the proportion of dissolved acids is advantageously increased by a factor of 1.5 to 2, and the insoluble components are enclosed in a stronger matrix or block upon cooling. Such heating of the mixture can be carried out, for example, in a heated mixing vessel with a stirrer (e.g., a conical mixer-dryer reactor) with stirring.

[0025] It is therefore possible to fill the still-liquid composition into a cartridge. The rinse aid system is preferably in block form and / or preferably in a container. The rinse aid system is preferably filled into a cartridge and has a solid, possibly waxy or gel-like, preferably cut-resistant, consistency. The term "cut-resistant" is understood here to mean a composition in which a cut with a knife remains visible as a cut.

[0026] Thanks to the manufacturing process according to the invention, in particular through processing at high temperatures, the rinse aid block can be stored at temperatures of up to 80°C without liquefying. Such high storage temperatures are necessary for sea transport near the equator, but also for truck transport in warm regions (such as Southern Europe, Africa, desert regions of the USA, Southeast Asia, Australia, etc.). Since the rinse aid system according to the invention is present in cartridges, it advantageously exhibits increased temperature resistance even during thermal food preparation. This is of particular interest because the rinse aid cartridges can thus be integrated into the appliance near a highly heated cooking chamber without the rinse aid liquefying.

[0027] Furthermore, the rinse aid system or rinse aid block, especially in the cartridge, remains dimensionally stable even at elevated temperatures (up to 80°C). The cartridges are therefore only partially deformable even at these temperatures and also rinse more evenly. The rinse aid block also has an improved consistency.

[0028] Processing at lower temperatures (from 60 °C) is also possible in principle, but results in a block that has a less uniform consistency and is less stable in storage.

[0029] Furthermore, the present invention relates to a rinse aid system, in particular a rinse aid block, which can preferably be produced or is producible by means of the above-mentioned method.

[0030] A further aspect relates to the inventive use of the rinse aid system, in particular the rinse aid block, for rinsing the interior of commercial kitchen appliances or cooking and cooking appliances, as well as for descaling appliances such as commercial dishwashers, ovens, grills, convection ovens, large cooking containers, degreasing systems, coffee machines, as well as particularly hot components of appliances in commercial kitchens or steam generators of coffee machines and the like. The use depends on the specific conditions within the appliance itself. Some appliances already offer a special dosing or dispensing device for the respective purpose, while in other appliances the rinse aid is introduced directly or dissolved in water into the space to be treated.

[0031] In commercial dishwashers, for example, the challenge also lies in introducing the rinse aid in such a way that it only dissolves at a certain temperature during the rinse cycle and is not dissolved during the cleaning cycle. Due to its high temperature stability, the rinse aid system according to the invention can advantageously be introduced into the commercial dishwasher in the form of a rinse aid block, which can preferably also be contained in a cartridge, before the start of the automatic cleaning cycle.

[0032] Generally, the rinse aid according to the invention is used separately from a detergent and performs its rinse aid function essentially during the rinse cycle. For example, the rinse aid is contained in a cartridge and is installed in this form with the cartridge opening tilted slightly downward (for example, at an angle of approximately 15°) in a commercial dishwasher or a cooking or cooking appliance. The commercial dishwasher or cooking appliance may have one or more dedicated holders for this purpose.

[0033] Further preferred embodiments and refinements of the rinse aid system according to the invention and the manufacturing method according to the invention, as well as the use of such a rinse aid system, also emerge from the dependent claims and the following description of preferred embodiments and examples. The manufacturing method or the use can also be designed according to the dependent claims of the rinse aid system according to the invention or the manufacturing method.

[0034] According to a preferred embodiment, a rinse aid system comprises at least three organic acids, two of which are selected from dicarboxylic acids, and the third organic acid is preferably selected from a tricarboxylic acid, preferably a saturated tricarboxylic acid. The tricarboxylic acid is particularly preferably selected from citric acid. The addition of citric acid has the advantage that, as a complexing agent, it can bind multivalent metal ions and prevent their redeposition.

[0035] According to a further preferred embodiment, the dicarboxylic acids of the rinse aid system are selected from

[0036] - saturated dicarboxylic acids, such as adipic acid, and / or

[0037] - unsaturated dicarboxylic acids, such as maleic acid, preferably from at least one saturated dicarboxylic acid and at least one unsaturated dicarboxylic acid.

[0038] The saturated dicarboxylic acid is preferably selected from adipic acid; the unsaturated dicarboxylic acid is preferably selected from maleic acid. Optionally, the maleic acid can be formed from an anhydride. The term "formed from an anhydride" here means that the starting product of maleic acid is in the form of the anhydride and is hydrolyzed during production to form maleic acid.

[0039] It has been shown that the solubility of the rinse aid can be modified by the individual solubilities and proportions of the various acids in such a way that the rinse aid dissolves sufficiently quickly, but not too quickly, depending on the respective requirements and can thus develop the most efficient rinse aid effect possible.

[0040] Preferably, a rinse aid, or in the case of a combination of detergent and rinse aid, at least the rinse aid, is dosed using a conductivity probe. The conductivity can advantageously be modified, particularly by adjusting the maleic acid content.

[0041] According to a further preferred embodiment, a preferred rinse aid system or a preferred rinse aid block comprises at least one surfactant. Such a surfactant preferably has a proportion of at least 0.05 wt.% and / or at most 0.2 wt.% in the preferred rinse aid system. The preferred addition of the surfactant advantageously lowers the surface tension of the rinse aid liquid during the rinse cycle, allowing for better wetting with the rinse aid.

[0042] Non-ionic surfactants based on ethoxylated fatty alcohols are preferred for this purpose. Examples include Dehypon E 124 (a product from Cognis), Plurafac SLF 180 and Plurafac LF 431, 300, 303, 401, 220, and 802 from BASF, and Ethylan 1003 from Nouryon.

[0043] Furthermore, a preferred rinse aid system or a preferred rinse aid block contains a water content of preferably up to 12% by weight, preferably up to 11% by weight. A preferred rinse aid has a water content of at least 0.1% by weight. The amount of water is advantageous for processability.

[0044] During the final rinse cycle, the rinse aid system or rinse aid block exerts its effect via an acidic pH value. Advantageously, the rinse aid system in a 1% aqueous solution has a pH value of less than 4, preferably less than 3, particularly preferably less than 2, and at least 1.5, in particular between approximately 1.7 and 1.9.

[0045] The matrix of the rinse aid system can also contain a retarding agent or a dissolving or solubility accelerator, which delays or accelerates dissolution so that the rinse aid system achieves its best possible effect during the rinse cycle. The time delay can be conveniently controlled via the solubility of the active ingredients or the matrix of the main detergent system, or it can also be temperature-dependent, so that a noticeable dissolution of the rinse aid components of the rinse aid system only occurs at elevated temperatures during the rinse cycle. According to a preferred embodiment, hydrophobic substances are used to delay the solubility of the rinse aid system. These can be mixed into the matrix or applied to the surface of the rinse aid as a coating. Examples of such hydrophobic substances are waxes or similarly acting retarding agents.Substances with a slow-release effect include stearates, such as glycerol monostearate, also known under the trade name Cutina (from Cognis), or magnesium stearate, as well as fatty acid alkanolamides, also known under the trade name Comperlan (from Cognis). However, a slow-release effect can also be achieved with substances that form a gel during the dissolution process. These include carboxymethylcelluloses, gelatin, starch, or fumed silica.

[0046] If a rinse aid system is combined with a detergent, such as a detergent tablet, an adhesive can be used to releasably bond the rinse aid system and the detergent tablet. Polyethylene glycol, for example, can be used for this purpose. This can be introduced into a recess of a detergent tablet during the manufacturing process, for example, in molten form, and distributed by pressing the rinse aid system or the rinse aid block into a recess of a detergent, such as a detergent tablet.

[0047] Particularly preferably, the advantageous rinse aid system is individually packaged in cartridges. The cartridges are inserted into the appliance in such a way that the rinse aid can be easily drained or rinsed out. For this purpose, the cartridge can be inserted into the commercial appliance, for example, with the opening facing downwards, slightly tilted horizontally or vertically, and the rinse aid can be rinsed out after a cleaning cycle depending on the automatic cleaning program. Individual packaging of each rinse aid system is particularly preferred, as this can prevent any risk to users from the ingredients. Cartridges of this type can preferably contain a rinse aid quantity sufficient for more than one rinse cycle.

[0048] The rinse aid can also be modified with other, possibly functional, compartments or substances. For example, the rinse aid system can additionally contain sulfonated polystyrenes and sulfonated polystyrene-maleic acid copolymers, preferably with a molecular weight of 15,000–1,000,000 g / mol, in an amount of 0.1–5.0 wt.%. This polymer system prevents the calcium salts formed by water hardness from settling by finely dispersing them and keeping them suspended during rinse water changes. Furthermore, a suitable rinse aid can contain (partially neutralized) polyacrylic acids, acrylic acid-maleic acid copolymers, and polycarboxylates.

[0049] In addition, for example, separate layers or areas can be provided as long as they are stable in the (acidic) environment of the rinse aid system or are appropriately shielded against the (acidic) environment.

[0050] A rinse aid system preferably comprises an unsaturated dicarboxylic acid in a proportion of at least 50 wt.%, preferably at least 52 wt. A rinse aid system preferably comprises an unsaturated dicarboxylic acid in a proportion of at most 70 wt.%, preferably at most 68 wt.%.

[0051] A rinse aid system preferably comprises a saturated dicarboxylic acid content of at least 5% by weight, preferably at least 7% by weight. A rinse aid system preferably comprises a saturated dicarboxylic acid content of at most 15% by weight, preferably at most 13% by weight.

[0052] The unsaturated dicarboxylic acid from maleic acid can optionally be formed from an anhydride.

[0053] In particular, a rinse aid system comprises a tricarboxylic acid in a proportion of at least 20 wt.%, preferably at least 22 wt.%. A tricarboxylic acid in a proportion of at most 30 wt.%, preferably at most 28 wt.%, is contained.

[0054] Further features of the invention will become apparent from the following description of exemplary embodiments in conjunction with the claims. It should be noted that the invention is not limited to the embodiments of the described exemplary embodiments, but is determined by the scope of the appended claims. In particular, the individual features in embodiments of the invention can be implemented in different combinations than in the examples listed below.

[0055] Examples

[0056] Compositions and preparation of rinse aid systems according to the invention:

[0057] The formulations listed in Table 1 (see below) were prepared: the data for the examples according to the invention (in percent by weight) refer in each case to the total amount of the rinse aid system or rinse aid block produced.

[0058] As already described, the use of at least two dicarboxylic acids and / or tricarboxylic acids in various concentrations is conceivable. As explained above, additional organic acids can also be added. Table 1: Composition of exemplary rinse aid systems according to the invention.

[0059] To produce the rinse aid systems, the acids were initially introduced and heated with stirring in a heated mixing vessel equipped with a stirrer (in this case, an AMT conical mixer-dryer reactor from Amixon). During the heating process, the water was sprayed in while stirring. Once the target temperature was reached (between 90 and 120 °C, depending on the recipe), the surfactant was sprayed in, the mixture was homogenized, and filled into a cartridge at a temperature of > 80 °C, in this case > 95 °C.

[0060] The first step was to assess the consistency of the rinse aid blocks. The results showed that the rinse aid blocks and rinse aid cartridges could not be significantly dented or deformed by hand, even at elevated temperatures of 80°C.

[0061] The rinse process was carried out in a commercial cooking appliance with an automatic cleaning program. The rinse aid system consisted of a rinse aid block in a rinse aid cartridge, which was mounted in a designated holder at an angle of 15° (with the opening facing downwards) in the commercial dishwasher.

[0062] The following method, which is also commonly used to determine the dissolution time of tablets, was used to determine the dissolution rate: A cube with an edge length of 1 cm was placed on a perforated plate (hole diameter = 1.8 mm, hole spacing = 2.4 mm) and immersed in a beaker containing 1 liter of tap water at 20°C. Eventually, the cube disintegrates within a few seconds, and the material of the cube (i.e., the composition) falls through the perforated plate. The time at which the cube has essentially completely disintegrated and the composition falls from the perforated plate was determined. The time determined was standardized to the previously determined weight. Evaluation of the rinse aid efficiency (rinsing and descaling) of the rinse aid systems according to the invention, based on the above-mentioned composition, compared to conventional rinse aids (in this case, compared to a Miele GP DC CX 0061 T rinse aid tablet (column X, Table 2) from the prior art):

[0063] Table 2: Physicochemical parameters of exemplary rinse aid systems according to the invention from Table 1 in comparison to a conventional rinse aid.

[0064] The results clearly show that the efficiency of the rinse aid systems according to the invention is significantly improved compared to the conventional rinse aid Miele GP DC CX 0061 T.

[0065] Assessment of stability compared to state-of-the-art rinse aids:

[0066] The compositions according to the invention (in the form of rinse aid cartridges) were stored at 80°C with the opening slightly tilted downward (angle of inclination approximately 15°), and any possible leakage of liquid or liquefaction of the contents was observed. Lainox Solid Cal was used as a reference product. During storage for more than one week, only negligible amounts of liquid (< 20 ml of a total of 560 ml) were allowed to leak out.

[0067] It has been shown that the compositions according to the invention have a temperature stability of at least 80°C. The competitor product Lainox Solid Cal, on the other hand, was only stable up to approx. 50°C. Since the rinse aid systems described in detail above are exemplary embodiments, they can be modified to a wide extent by those skilled in the art in the usual way without departing from the scope of the invention. In particular, specific embodiments of the rinse aid systems can exist in forms other than those described here. Likewise, the recipes of the rinse aid systems can be modified by those skilled in the art in the sense of the specific exemplary embodiments described above. The skilled person also knows how to adapt the individual weight proportions to the corresponding requirements within the framework of the inventive solution to the problem. Furthermore, the use of the indefinite articles “a” and “an” includes the following:“one” does not exclude the possibility that the features in question may also be present more than once.

Claims

Patent claims 1. Rinse aid system, in particular in the form of a rinse aid block, comprising an acidic rinse aid for rinsing commercial dishwashers and commercial cooking appliances, comprising a rinse aid system for a final rinse cycle of a machine, comprising at least two acids, wherein the at least two acids are selected from dicarboxylic acids and / or tricarboxylic acids, wherein the total proportion of the acids is more than 88% by weight, preferably more than 95% by weight, particularly preferably more than 96% by weight, in particular more than 97% by weight, particularly preferably more than 98% by weight, and wherein the total proportion of the acids is at most 99.5% by weight, preferably at most 99% by weight.

2. Rinse aid system according to one of the preceding claims, comprising at least three organic acids, wherein two organic acids are selected from dicarboxylic acids and the third organic acid is preferably selected from a tricarboxylic acid, preferably from a saturated tricarboxylic acid.

3. Rinse aid system according to claim 1 or 2, wherein the dicarboxylic acids are selected from - saturated dicarboxylic acids, such as adipic acid, and / or - unsaturated dicarboxylic acids, such as maleic acid, preferably from at least one saturated dicarboxylic acid and at least one unsaturated dicarboxylic acid.

4. Rinse aid system according to one of the preceding claims, comprising at least one surfactant.

5. Rinse aid system according to one of the preceding claims, comprising a proportion of water of up to 12% by weight, preferably up to 11% by weight, and / or at least 0.1% by weight.

6. Rinse aid system according to one of the preceding claims, wherein the rinse aid system tern in an at least 1% aqueous solution has a pH of less than 4, preferably less than 3, particularly preferably less than 2 and at least 1.5, in particular from about 1.7 to 1.

9.

7. Rinse aid system according to one of the preceding claims, wherein the saturated dicarboxylic acid has a proportion of at least 5 wt.%, preferably of at least 7 wt.%, and / or wherein the saturated dicarboxylic acid has a proportion of at most 15 wt.%, preferably of at most 13 wt.%, in the rinse aid system.

8. Rinse aid system according to one of the preceding claims, wherein the unsaturated dicarboxylic acid has a proportion of at least 50% by weight, preferably of at least 52% by weight, and / or wherein the unsaturated dicarboxylic acid has a proportion of at most 70% by weight, preferably of at most 68% by weight, in the rinse aid system.

9. Rinse aid system according to one of the preceding claims, wherein the tricarboxylic acid has a proportion of at least 20 wt.%, preferably of at least 22 wt.%, and / or wherein tricarboxylic acid has a proportion of at most 30 wt.%, preferably of at most 28 wt.%, in the rinse aid system.

10. Rinse aid system according to one of the preceding claims, - wherein the saturated dicarboxylic acid is selected from adipic acid, - wherein the unsaturated dicarboxylic acid is selected from maleic acid, and - wherein the optional tricarboxylic acid is selected from citric acid.

11. Manufacturing process for a rinse aid system, in particular in the form of a rinse aid block, comprising the steps (i) mixing at least two acids, wherein the at least two acids are selected from dicarboxylic acids and / or tricarboxylic acids, (ii) optionally adding a surfactant, (iii) if necessary, addition of water, (iv) heating the mixture to a temperature of at least 80 °C, preferably at least 85 °C, in particular at least 90 °C, (v) cooling the mixture to room temperature, (vi) wherein the total proportion of acids in the cooled mixture is more than 88 wt.%, preferably more than 95 wt.%, particularly preferably more than 96 % by weight, in particular more than 97 % by weight, particularly preferably more than 98 % by weight, and (vii) wherein the total proportion of acids is at most 99.5 wt.%, preferably at most 99 wt.%.

12. Rinse aid system, in particular in the form of a rinse aid block, according to one of claims 1 to 10, wherein the rinse aid block is preferably obtainable by a process according to claim 11.

13. Use of a rinse aid system according to one of claims 1 to 10 and 12, in particular in the form of a rinse aid block, for rinsing and descaling commercial dishwashers and commercial cooking appliances.

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