EP2221357A1 - Combined limescale remover and rinser for use in devices and assemblies with metallic, ceramic, glass or plastic surfaces - Google Patents

Abstract

Composition of decalcifier and rinse aid for devices and systems with metallic-, ceramic-, glass- or plastic-surfaces, comprises at least two fruit acids and a sequestering system that prevents the deposition of calcium on the device surface. An independent claim is included for producing the composition, comprising mixing all solid components of the composition, adding and equally distributing all liquid components of the composition, and optionally granulating or compacting the resulting mixture and preferably pressing the resulting mixture into a tab.

Description

The present invention relates to a combined decalcifier and rinse aid for use in devices and installations with metallic, ceramic, glass or plastic surfaces, a method for producing a combined decalcifier and rinse aid and the use of such a descaling and cleaning of equipment and systems with metallic, ceramic, glass or plastic surfaces.

In many domestic, commercial and industrial applications, devices and systems with metallic (i. E. Stainless steel surfaces), ceramic, glass or plastic surfaces are used. Here, the focus is primarily on equipment and systems from the food industry, food preparation or the cleaning of (crockery) parts in contact with food. In particular, on surfaces which are heated, persistent calcifications can settle, which must be removed for better heat transfer. In addition, the surfaces of the equipment tend to have clearly visible spots after cleaning, indicating that the water did not drain evenly in the cleaning step.

• mindestens zwei Fruchtsäuren sowie
• ein Sequestriersystem, das die Absetzung von Kalk auf der Geräteoberfläche verhindert.

Object of the present invention is to provide a combined decalcifier and rinse aid, which allows following a cleaning step to implement a decalcification with Klarspülfunktion so that the water runs smoothly on the equipment surfaces without residues and these no longer need to be aftertreated. Applications are varied, as in many processes of food treatment water is heated or evaporated, such as in the treatment of milk and other beverages, in fermentation processes, in commercial cooking appliances, in domestic or commercial Dampfgargeräten, in domestic or commercial dishwashers.
characterized in that it comprises the following components:

• at least two fruit acids as well
• a sequestering system that prevents the sedimentation of lime on the surface of the device.

In the work of the present invention, it has surprisingly been found that the combination of at least two fruit acids has a synergistic effect by improving the dissolving power of the combined acids over the individual acids, thereby making possible a combined decalcifier and rinse aid.

The combined descaling agent and rinse aid according to the invention may, in principle, be in a powdered, a solid extruded or cast form or a pressed tablet (i.e., as a tab). In a particularly preferred embodiment, the combined decalcifier and rinse aid is in the form of a tab or a tablet.

The fruit acids contained in the product according to the invention are preferably selected from citric acid, malic acid, tartaric acid, lactic acid, gluconic acid, fumaric acid and / or succinic acid, more preferably from hydroxycarboxylic acids, in particular from citric acid, malic acid and / or tartaric acid. Particular preference is given to the combinations of citric acid (for example as monohydrate or anhydrate) and malic acid and of citric acid and tartaric acid.

The combined descaler and rinse aid may further comprise a food approved acidulant.

Preferably, the acids are also selected so that the process is particularly supported. For example, other carboxylic acids, preferably those which are approved for food, are used as process auxiliaries. In a particularly preferred embodiment contains the combined decalcifier and rinse aid acidifying the dicarboxylic acid adipic acid, which is a particularly suitable Tablettierhilfsmittel and therefore is particularly preferred for tabs.

The sequestering system contained in the product according to the invention preferably comprises water-soluble polymers, in particular polycarboxylates (polymers of acrylic acid or copolymers of acrylic acid and maleic acid including sulfonated copolymers, eg Sokalan types from BASF or Alcosperse types from Akzo Nobel, particularly preferably Sokalan PA 25 CL, Sokalan PA 30 CL, Sokalan CP 5, Alcosperse 240 G, Alcosperse 726 G) and phosphonates (eg Cublen types from Zschimmer & Schwarz or Dequest types from Thermphos, particularly preferably Cublen K 60, Dequest 2010, Dequest 4266 D).

The acid content of the product according to the invention is preferably from 80 to 98 wt .-%, more preferably above 90 wt .-%.

The sequestering system is preferably contained in an amount of from 1 to 5% by weight, more preferably from 1.5 to 2.5% by weight.

The combined decalcifier and rinse aid may additionally contain one or more additives, for example selected from nonionic surfactants, disintegrants and / or flow aids and other conventional additives.

The nonionic surfactant can be selected, for example, from surfactants available for commercial or automatic dishwashing, low-foaming or foam-controlling surfactants (for example Plurafac grades from BASF or Dehypon grades from Cognis, particularly preferably Plurafac LF 303) , Plurafac LF 431, Plurafac LF 901), and this may be in an amount of 0.05 to 2% by weight, preferably 0.1 to 0.5% by weight. be included.

The surfactant group is diverse and includes, inter alia, fatty alcohol ethoxylates, fatty alcohols with EO / PO groups, alkyl hydroxy ether and guerbet alcohol ethoxylates. The ethoxylates can be end-capped. For another Characterization of these surfactant groups is reported in the German edition of the SOFW Journal, vol. 134, 10-2008 "The Characterization of Foam Control Surfactants" referenced to which reference is incorporated by reference.

As the decomposition agent, polyvinyl alcohol is preferable, more preferably in ground form, and it is generally contained in an amount of 0.1 to 5% by weight, preferably 1.5 to 3.5% by weight. Polyvinyl alcohol has the particular advantage that this also acts as a brightener for metallic surfaces to be treated.

As a flow aid, for example, silica can be used, and this is preferably contained in an amount of 0.1 to 2 wt .-%.

The combined decalcifier and rinse aid according to the invention is preferably used in devices and systems with metallic, ceramic, glass or plastic surfaces, which have a temperature of at least 90 ° C at least on a part of their surface. The temperature is preferably in a range between 90 ° C and 350 ° C, in particular between 100 ° C and 300 ° C, between 150 ° C and 300 ° C or between 200 ° C and 300 ° C.

1. (a) Mischen aller festen Bestandteile des kombinierten Entkalkers und Klarspülers;
2. (b) Zugeben und gleichmäßiges Verteilen aller flüssigen Bestandteile des kombinierten Entkalkers und Klarspülers und
3. (c) gegebenenfalls Granulieren oder Kompaktieren der erhaltenen Mischung und insbesondere Verpressen der erhaltenen Mischung zu einem Tab.

Moreover, the invention relates to a method for producing a combined decalcifier and rinse aid, which comprises the following steps:

1. (a) mixing all solid components of the combined decalcifier and rinse aid;
2. (b) adding and evenly distributing all the liquid components of the combined decalcifier and rinse aid and
3. (c) optionally granulating or compacting the resulting mixture and in particular compressing the resulting mixture into a tab.

In the process according to the invention, particular preference is given to liquid constituents, in particular surfactants, completely or predominantly in advance granulated with a portion of the solids to a premix, and this premix is then added to the remaining ingredients of the combined decalcifier and rinse aid. In order to achieve a uniform distribution, the liquid constituents are preferably added via an atomization system during the mixing.

The combined decalcifier and rinse aid according to the invention is particularly preferably used for the descaling and cleaning of appliances and systems for steam generation or heat treatment of food.

• Entkalkung einer Wärmetauscherschlange in einem Edelstahlbehälter mit Klarspülfunktion für die Behälteroberfläche
• Entkalkung einer Heizspirale in einem Edelstahlgerät (z.B. Wasserkocher) mit Klarspülfunktion für die Geräteoberflächen
• Anwendung in gewerblichen Dampfgargeräten bzw. Multifunktions-Kochgeräten mit einem Garraum, in dem von einem Dampfgenerator (Verdampfer) erzeugter Dampf zum Garen eingesetzt wird, insbesondere zur Entkalkung eines Heizbereiches (z.B. im Verdampfer) mit anschließender Klarspülfunktion im Garraum des Geräts,
• Entkalkung der Ablagerungen in einem häuslichen oder gewerblichen Geschirrspüler mit anschließender Klarspülfunktion für die inneren Oberflächen

In the following, basic application possibilities of the combined decalcifier and rinse aid are described without any claim to completeness:

• Descaling of a heat exchanger coil in a stainless steel container with rinsing function for the container surface
• Descaling of a heating coil in a stainless steel appliance (eg kettle) with rinsing function for the device surfaces
• Application in commercial Dampfgargeräten or multifunction cooking appliances with a cooking chamber in which steam generated by a steam generator (evaporator) is used for cooking, in particular for descaling a heating area (eg in the evaporator) followed by rinse in the oven,
• Decalcification of the deposits in a domestic or commercial dishwasher with subsequent rinsing function for the inner surfaces

The use depends on the conditions in the device itself Some devices already offer a special dosing or flushing device for the respective purpose, while in other devices the combined decalcifier and rinse aid is introduced directly or dissolved in water into the room to be treated. In the case of a domestic dishwasher, for example, the challenge is also to introduce the agent in such a way that the agent dissolves only at a certain temperature in the main wash program and is not already dissolved in the pre-wash program.

In this regard, the combined decalcifier and rinse aid may be provided in a temperature controlled water soluble film. As a concrete example, a preferred inventive combined decalcifier and rinse aid in the form of a tab or a tablet is described in more detail.

For use in devices with Einspüfeinrichtung a tablet is preferably chosen because it is given for the user a simple dosage in the form of number of tablets. However, the tablets should be adjusted so that they can disintegrate during the flushing process via the dispenser flap / drawer and can thus be introduced with the water flow during the limited flushing time (a few seconds to a few minutes).

Similar conditions are known, for example, for Waschmitteltabs, which are dosed via the Einspülschublade of modern washing machines. In Waschmitteltabs the rapid disintegration is usually achieved by insoluble cellulose-containing swelling agent. However, such insoluble disintegrants are not suitable for the application considered here, since they can leave residues on the surfaces during the rinse-off function and thus give the user the impression that they have not been sufficiently cleaned. The biggest challenge for the tablet targeted here is therefore to set a defined disintegration behavior without the use of the usual tablet disintegrating agents.

The desired decomposition behavior starts from disintegration times in the range of 1 min to 30 min, preferably between 5 min and 25 min, particularly preferably between 10 min and 20 min. The disintegration time is determined on a grid (1 × 1 cm mesh size) in non-stirred water at 18 ° C.

• Das Produkt kann je nach Anwendung zum Entkalken mit heißen Oberflächen (200 bis über 300°C) in Berührung kommen, so dass inhaltsstoffe, welche sich bei diesen hohen Temperaturen zersetzen, nicht zum Einsatz kommen können. Bei einem Entkalkerprodukt beispielsweise kann die üblicherweise eingesetzte Amidosulfonsäure nicht verwendet werden.
• Die Anwendung im gewerblichen Bereich sieht vor, dass die Entkalker- und Klarspülfunktion bei einem Reinigungsprogramm eingesetzt werden, welches nach Programmierung in Abwesenheit vom Bedienpersonal abläuft. Diesbezüglich muss das Tabs-Produkt auch nach dem Auspacken aus der schützenden Flowpackfolie mehrere Stunden in widriger Umgebung (hohe Luftfeuchtigkeit, hohe Temperaturen) ohne Mangel an Einsetzbarkeit und Wirksamkeit überstehen.
• Die für Entkalkertabs üblicherweise eingesetzten Rohstoffe (Säuren in kristalliner Form) können in der Regel nicht zu einer Tablette verpresst werden, da die kristalline Form der Partikel keine Deformation innerhalb der Tablette zulässt. Folglich ist ein System von Hilfsstoffen zu definieren, welches diese Eigenschaften überwindet. Üblicherweise wird in einem solchen System von Hilfsstoffen Polyethylenglykol in signifikanter Menge eingesetzt, was jedoch bei dem hier betrachteten Produkt in der Anwendung zu starker Schaumbildung führt und sich zu schlecht ausspülen lässt.
• Das Auflöse- und Zerfallsverhalten der Tabs bestimmt in besonders hohem Maße deren Anwendbarkeit in Geräten mit Einspülvorrichtung. Bei zu schnellem Zerfall können mechanische Teile der Geräte durch die Zerfallsbrocken blockieren. Bei zu langsamem Zerfall können Reste von den Tabs in der Einspülkammer verbleiben und stehen somit für die effiziente Wirkung des Produktes nicht mehr zur Verfügung. Hier müssen Systeme definiert werden, welche über Anpassungen an der Zusammensetzung und/oder dem Herstellverfahren die gewünschten Tabs-Eigenschaften auch in engen Grenzen gewährleisten.

For the application of a descaling and rinsing absabs in plants and equipment for the treatment of food, however, a number of other requirements must be complied with, which represent a strong limitation compared to the commonly used raw materials for the composition of such a product:

• Depending on the application, the product may come into contact with hot surfaces (200 to over 300 ° C) for descaling, so that ingredients which decompose at these high temperatures can not be used. For example, in a descaling product, the commonly used sulfamic acid can not be used.
• The application in the commercial sector provides that the descaling and rinsing function are used in a cleaning program, which runs after programming in the absence of the operating personnel. In this regard, even after unpacking from the protective flowpack film, the Tabs product must survive several hours in adverse environments (high humidity, high temperatures) without lack of applicability and effectiveness.
• The raw materials (acids in crystalline form) usually used for descaler tabs can not usually be compressed into a tablet, since the crystalline form of the particles does not allow any deformation within the tablet. Consequently, a system of adjuvants is to be defined which overcomes these properties. Usually, polyethylene glycol is used in significant amounts in such a system of excipients, but this results in the product considered here in the application to excessive foaming and can be rinsed too bad.
• The dissolution and decay behavior of the tabs particularly determines their applicability in devices with a dispenser. If the decay is too rapid, mechanical parts of the equipment may be blocked by the decay chips. If the decay is too slow, residues from the tabs can remain in the dispenser and are thus no longer available for the efficient action of the product. Here, systems must be defined which ensure the desired tab properties even within narrow limits through adjustments to the composition and / or the manufacturing process.

The combined decalcifier and rinse aid according to the invention preferably has an active ingredient content of 85 to 99 wt .-% (more preferably above 90 wt .-%). The active ingredient content is the acids, the sequestering system and the surfactants.

The decalcification effect is achieved by a synergistic acid system consisting of at least two fruit acids (hydroxycarboxylic acids, such as citric acid, malic acid, tartaric acid, and the like). The synergetic effect consists in a solubility improvement of the system compared to the individual acids. The acids can be used both as hydrates and in anhydrous form. The anhydrous form is preferred whenever there is a risk during transport, storage or use at higher temperatures (> 40 ° C.) that the hydrates would give off water and thus swell and agglutinate the tabs.

The acid system for decalcification is complemented by a sequestering system, which prevents the limescale from the solution or dispersion settling on the surfaces of the device again. The sequestering system preferably consists of a combination of water-soluble polymers and phosphonates. This ensures that the effect is as broad as possible and, depending on the region and drinking water composition, the desired descaling function is ensured for different types of limescale deposits. For optimal wetting of the surfaces with the decalcifying solution, the tabs may contain nonionic surfactants in a concentration of 0.05 to 2% by weight (preferably 0.1 to 0.5% by weight), which is characterized by very low foaming distinguished.

The system of auxiliaries is preferably tailored specifically to the processability and the desired properties of the tabs. In this case, a dicarboxylic acid (preferably adipic acid, which is also approved as an acidulant in foods) can be used as tabletting aid. As a disintegrating agent, which has the task to direct water into the inside of the tabs, the use of polyvinyl alcohol has proven itself. This also has the advantage that it acts as a brightener for the metallic surfaces to be treated. Since polyvinyl alcohol has a rather negative effect on the stickiness of the powder and thus on the Tablets tability, an uneven distribution in the powder mixture should be avoided. Therefore, the polyvinyl alcohol is preferably used in ground form.

The production of preferred tabs according to the invention is described below.

The powder for the tabs is preferably mixed in a compulsory mixer, wherein the mixing times are to be optimized so that the powder is not already mechanically comminuted with good mixing quality. For example, mixing times of from 1 to 6 minutes (preferably from 2 to 4 minutes) have proven successful in so-called plowshare mixing. The distribution of liquid surfactants plays a special role here. To achieve a uniform distribution, these are preferably added via an atomization system during the mixing. A uniform distribution of the surfactants ensures a longer disintegration time and thus a delayed release of active ingredient. Some device cleanup applications will require such behavior from the tab. For fast cleaning processes, however, it is necessary to significantly reduce the disintegration time of the tab. This can be achieved by the surfactants not evenly distributed as a film, but are fixed locally in granular particles. The latter is achieved by granulating a portion of the solids together with all or at least the majority of the surfactants separately beforehand and then adding them as a so-called premix. For the production of such a premix, all known mixers, granulators or compactors can be used. Examples include plowshare mixer, Tellerpelletizer, fluidized bed, fluidized bed and twin-shaft mixer.

Table 1 below shows some example compositions for the decalcifier and rinse aid of the present invention prepared as described above. The numbers in the table refer to the wt .-% contained. <b> Table 1 </ b> Example A Example B Example C Example D Citric acid anhydrate
(eg from Jungbunzlauer) 43 30 50 Citric acid monohydrate
(eg from Jungbunzlauer) 60 Äpfefsäure
(eg from Polynt) 47.5 62 tartaric acid
(Reference eg via Stockmeier) 25 33.5 adipic acid
(eg from BASF) 8th 5 5 10 polyacrylates 1
Alcosperse
240 G by Akzo Nobel 1.5
1% Alcosperse 240 G from Akzo Nobel and 0.5% Sokalan PA 25 CL from BASF 1.5
1% Alcosperse 240 G from Akzo Nobel and 0.5% Sokalan PA 25 CL from BASF 1.5
1% Sokalan PA 30 CL from BASF and 0.5% Alcosperse 726 from Akzo Nobel phosphonates 0.5
Cublen K60 from Z & S 0.4
Dequest 4266 D from Thermphos 1
Dequest 2010 from Thermphos 1
Dequest 4266 D from Thermphos polyvinyl alcohol 5
Mowiol 4-88
G by Kuraray 2.5
Mowiol 4-88
G by Kuraray 0 3
Mowiol 4-88
G by Kuraray Nonionic surfactant 0.5
Plurafac LF
303 from BASF 0.1
Plurafac LF
303 from BASF 0.5
Plurafac LF
901 from BASF 1
Plurafac LF
431 from BASF flow aids optional (0,5)
Cab-O-Sil from Cabot optional (0,5)
Aerosil 200 from Evonics optional (0,5)
Aerosil 200 from Evonics optional (0,5)
Cab-O-Sil from Cabot

Claims (14)

Combined decalcifier and rinse aid for use in devices and installations with metallic, ceramic, glass or plastic surfaces, characterized in that it comprises the following components: - at least two fruit acids as well - A sequestering system that prevents the settling of lime on the surface of the device. Combined decalcifier and rinse aid according to claim 1, characterized in that it is in the form of a tab or a tablet. Combined descaling agent and rinse aid according to claim 1 or 2, characterized in that the fruit acids are selected from: citric acid, malic acid, tartaric acid, lactic acid, gluconic acid, fumaric acid and / or succinic acid. Combined descaler and rinse aid according to one of claims 1 to 3, characterized in that it further comprises a food approved acidulant, preferably adipic acid. Combined descaling agent and rinse aid according to one of claims 1 to 4, characterized in that the sequestering system comprises water-soluble polymers, in particular polycarboxylates, and phosphonates. Combined descaler and rinse aid according to one of claims 1 to 5, characterized in that the acid content of this 80 to 98 wt .-%, preferably about 90 wt .-%, makes up. Combined descaling agent and rinse aid according to one of Claims 1 to 6, characterized in that the sequestering system constitutes from 1 to 5% by weight, preferably from 1.5 to 2.5% by weight. Combined descaler and rinse aid according to one of claims 1 to 7, characterized in that it contains one or more additives which are selected from nonionic surfactants, disintegrating agents and / or flow aids. Combined descaler and rinse aid according to claim 8, characterized in that
that the nonionic surfactant is selected from a weakly-foaming surfactants and / or that this in the amount of 0.05 to 2 wt .-%. preferably 0.1 to 0.5 wt.%,
and or
that the disintegration aid is polyvinyl alcohol, preferably in ground form, and this is present in an amount of from 0.1 to 5% by weight, preferably from 1.5 to 3.5% by weight,
and or
that the flow aid is silicon oxide and this is contained in an amount of 0.1 to 2 wt .-%. Combined decalcifier and rinse aid according to one of claims 9 to 12, characterized in that the devices and installations have at least a part of their surface at a temperature of at least 90 ° C. Combined descaler and rinse aid according to claim 13, characterized in that the temperature in a range between 90 ° C and 350 ° C, in particular in a range between 100 ° C and 300 ° C, between 150 ° C and 300 ° C or between 200 ° C and 300 ° C. Process for the preparation of a combined decalcifier and rinse aid according to one of Claims 1 to 11, characterized in that it comprises the following steps: (a) Mixing all solid components of the combined decalcifier and rinse aid: (b) adding and evenly distributing all the liquid components of the combined decalcifier and rinse aid and (c) optionally granulating or compacting the resulting mixture and in particular compressing the resulting mixture into a tab. A method according to claim 12, characterized in that the liquid constituents, in particular surfactants, are completely or predominantly granulated in advance with a portion of the solids to a premix and then this premix is added to the remaining constituents of the combined decalcifier and rinse aid. Use of a combined decalcifier and rinse aid according to any one of claims 1 to 13 for the decalcification and purification of equipment and installations with metallic, ceramic, glass or plastic surfaces, in particular for steam generation or heat treatment of food.