LIQUID CLEANING AGENT CONCENTRATE, READY-TO-USE SOLUTION, ITS USES AND CLEANING PROCEDURES

Description

[0001] The present invention relates to a liquid cleaning agent concentrate, ready-to-use application solutions, their uses for cleaning and / or disinfecting objects and cleaning methods.

[0002] In hospitals, medical and surgical instruments and equipment are typically mechanically cleaned using alkaline cleaning agents and then chemically or thermally disinfected. Strongly alkaline cleaning agents can be aggressive to sensitive surfaces. Therefore, mildly alkaline enzymatic cleaning agents are preferred, but these have the disadvantages of unsatisfactory cleaning performance and high application concentrations. Furthermore, the enzymatic cleaning agents known in the prior art often contain other aggressive components that are not well tolerated by all surfaces and can be corrosive, particularly on metal surfaces.

[0003] The invention is based on the object of providing a liquid cleaning concentrate and a ready-to-use application solution thereof, which enable very good cleaning performance with only a low application concentration and at the same time have a high material compatibility on various materials, in particular metal surfaces.

[0004] WO 02 / 02727 A1 relates to a liquid enzymatic cleaning composition in which the enzyme is stable at alkaline pH and in the presence of high water concentrations.

[0005] CN 106 635 488 A1 relates to enzyme-containing endoscope cleaning agents for the effective removal of biofilms and a process for its production.

[0006] The invention solves this problem by the features of claims 1, 9, 11 and 14. Claim 1 comprises a liquid cleaning agent concentrate comprising: a. at least one phosphonate, b. a first complexing agent selected from (hydroxyethyl)ethylenediaminetriacetic acid, methylglycinediacetic acid and salts thereof, c. a second complexing agent selected from (hydroxyethyl)ethylenediaminetriacetic acid, ethylenediaminetetraacetic acid, glutamic acid-N,N-diacetic acid, iminodisuccinic acid, methylglycinediacetic acid and salts thereof, wherein the first and second complexing agents are different from each other, and d. at least one enzyme, preferably a proteolytic enzyme, where the pH value of the liquid cleaning concentrate is 9 or >9.

[0007] Advantageous embodiments are found in the subclaims.

[0008] Within the scope of the invention, the liquid cleaning agent concentrate according to the invention can be diluted with water or a water-containing solvent mixture to form a ready-to-use solution. However, this does not preclude the liquid cleaning agent concentrate itself from containing water or a water-containing solvent mixture. The liquid cleaning agent concentrate preferably has a pH of 9-12, more preferably 10-12, and even more preferably 10-11. 1. Phosphonate

[0009] The liquid cleaning agent concentrate comprises at least one phosphonate. In the context of the invention, a phosphonate is a salt of a phosphonic acid. The phosphonate is preferably selected from the salts of phosphonobutanetricarboxylic acid (PBTC), aminotrismethylenephosphonic acid (ATMP), 1-hydroxyethane-1,1-diphosphonic acid (HEDP), diethylenetriamine penta(methylenephosphonic acid) (DTPMP), and mixtures thereof. The salts can be alkali metal salts, preferably sodium and potassium salts, more preferably sodium salts. More preferably, the phosphonate is the sodium salt of PBTC, the sodium salt of ATMP, or mixtures thereof.

[0010] Preferably, the phosphonate or the phosphonate mixture is present in the liquid cleaning agent concentrate in a weight proportion of 1 to 13 wt.%, more preferably 2 to 10 wt.%, even more preferably 3 to 8 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0011] Within the scope of the invention, the phosphonate demonstrates, on the one hand, the beneficial effect as a corrosion inhibitor. On the other hand, it has been observed that the phosphonate serves to stabilize the cleaning formulation. Without the phosphonate, significant fluctuations in the pH value of the liquid cleaning agent concentrate are observed when individual ingredients are varied. Thus, the phosphonate not only serves to inhibit corrosion but also functions as a pH buffer. 2. Complexing agents

[0012] The liquid cleaning agent concentrate comprises a first complexing agent selected from (hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), methylglycinediacetic acid (MGDA), and their salts. The salts can be alkali metal salts, preferably sodium and potassium salts, more preferably sodium salts.

[0013] Preferably, the first complexing agent is present in the liquid cleaning agent concentrate in a weight proportion of 0.5 to 10 wt.%, more preferably 1 to 8 wt.%, even more preferably 2 to 6 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0014] The liquid detergent concentrate further comprises a second complexing agent selected from HEDTA, EDTA, GLDA, IDS, MGDA, and their salts, wherein the first and second complexing agents are different from each other. Preferably, the second complexing agent is the sodium salt of HEDTA, EDTA, GLDA, IDS, or MGDA, more preferably the sodium salt of MGDA or HEDTA.

[0015] Preferably, the second complexing agent is present in the liquid cleaning agent concentrate in a weight proportion of 0.5 to 10 wt.%, more preferably 1 to 8 wt.%, even more preferably 2 to 6 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0016] In preferred embodiments, the liquid detergent concentrate comprises as phosphonate the sodium salt of PBTC, the sodium salt of ATMP or a mixture thereof, as first complexing agent the sodium salt of HEDTA and preferably as second complexing agent the sodium salt of MGDA.

[0017] Surprisingly, the preferred combination of the first and second complexing agents, in addition to the phosphonate, and their selection have a significant impact on the cleaning performance and corrosion resistance of the liquid cleaning agent. It has been observed that cleaning performance and corrosion inhibition are inversely related. Good corrosion inhibition results in poorer cleaning performance, and vice versa. However, by preferentially combining the first and second complexing agents, in addition to the phosphonate, both properties can be optimally adjusted. 3. Enzym

[0018] The liquid cleaning agent concentrate comprises at least one enzyme. The enzyme is preferably a proteolytic enzyme or enzyme mixture.

[0019] The enzyme or enzyme mixture is preferably present in the liquid cleaning agent concentrate in a weight proportion of 0.05 to 4 wt.%, more preferably 0.1 to 2 wt.%, based on the total mass of the liquid cleaning agent concentrate. The enzyme activity is preferably 30×10 -2 to 100×10 -2 KNPU / g, more preferably 70×10 -2 to 85×10 -2 KNPU / g. 4. Other components

[0020] The liquid cleaning agent concentrate may further comprise other ingredients selected from surfactants, hydrotropes, alkanolamines, alkali metal hydroxides, solvents, corrosion inhibitors, fragrances and dyes.

[0021] The surfactants can be cationic surfactants, anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof. Cationic surfactants are selected, for example, from alkylamines and polyamines. Anionic surfactants are selected, for example, from alkyl carboxylates and amino acid-based surfactants. Non-ionic surfactants are selected, for example, from alkyl alkoxylates, alkylphenol ethoxylates, fatty alcohol alkoxylates, fatty acid amides, fatty acid alkoxylates, fatty acid alkyl esters, fatty amines, alkyl polyamines, fatty amide ethoxylates, and amine oxides. Amphoteric surfactants are selected, for example, from betaines, sultaines, and glycinates. The surfactants are preferably selected from fatty alcohol alkoxylates, amino acid-based surfactants, and mixtures thereof.

[0022] The fatty alcohol alkoxylate can be selected from fatty alcohol ethoxylates (FAEO) and fatty alcohol propoxylates (FAPO), butyl-etherified fatty alcohol ethoxylates (FAEOBV), butyl-etherified fatty alcohol propoxylates (FAPOBV), methyl-etherified fatty alcohol ethoxylates (FAEOMV), methyl-etherified fatty alcohol propoxylates (FAPOMV), butyl-etherified fatty alcohol-based EO / PO copolymers (FAEOPOBV), methyl-etherified fatty alcohol-based EO / PO copolymers (FAEOPOMV), and fatty alcohol-based EO / PO copolymers (FAEOPO). Preferably, the fatty alcohol alkoxylate is a fatty alcohol-based EO / PO copolymer.

[0023] The fatty alcohol alkoxylate may comprise 0-10 EO units, preferably 1-4 EO units, more preferably 1-2 EO units. Furthermore, the fatty alcohol alkoxylate may comprise 0-8 PO units, preferably 1-8 PO units, more preferably 4-8 PO units. Furthermore, the fatty alcohol alkoxylate may have at least one C6-C16 fatty alcohol residue, preferably C12-C15 fatty alcohol residue. The fatty alcohol alkoxylate can be selected from the group consisting of C12-C15 fatty alcohol residue with 2EO / 6PO units, C12-C15 fatty alcohol residue with 8EO / 4PO units, methyl- or butyl-etherified C12-C14 fatty alcohol residue with 10EO units, C10-C12 fatty alcohol residue with 6EO / 8PO units, C12-C14 fatty alcohol residue with 2EO / 4PO units, C12-C14 fatty alcohol residue with 4EO / 5PO units, methyl-etherified C13-C15 fatty alcohol residue with 5EO / 3PO units and C13-C15 fatty alcohol residue with 5EO / 3PO units.Preferably, the fatty alcohol alkoxylate is selected from C12-C15 fatty alcohol residue with 2EO / 6PO units, C12-C14 fatty alcohol residue with 2EO / 4PO units and C12-C14 fatty alcohol residue with 4EO / 5PO units.

[0024] The fatty alcohol alkoxylate may be present in the liquid cleaning agent concentrate in a weight proportion of 0.1 to 9 wt.%, preferably 0.4 to 2 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0025] The addition of the fatty alcohol alkoxylate can dampen the effect of foam-forming surfactants. The desired foaming behavior of the liquid cleaning agent concentrate can be achieved by selecting the fatty alcohol alkoxylate. Excessive foaming is disadvantageous, as low-foaming components are required for use in automated cleaning processes, for example, instrument washers or washer-disinfectors (WDs). Excessive foaming leads to a drop in dosing pump pressure during automated cleaning, ultimately resulting in the interruption of the cleaning process.

[0026] The amino acid-based surfactant may be selected from compounds having a saturated or monounsaturated C10-C18 carbon residue, preferably a saturated C12-C16 carbon residue.

[0027] The amino acid-based surfactant can further be selected from sarcosines, taurines, glutamic acids, and their salts. The salts can be alkali metal salts, preferably sodium and potassium salts, more preferably sodium salts. Preferred embodiments of the amino acid-based surfactant are selected from lauroylsarcosine, oleoylsarcosine, myristoylsarcosine, stearoylsarcosine, and lauroylglutamic acid and their sodium salts. Lauroylsarcosine and lauroylglutamic acid and their sodium salts are particularly preferred.

[0028] The amino acid-based surfactant may be present in the liquid detergent concentrate in a weight proportion of 0.05 to 5 wt.%, preferably 0.1 to 2 wt.%, based on the total mass of the liquid detergent concentrate.

[0029] The liquid cleaning concentrate may comprise hydrotropes. In the context of the invention, "hydrotropes" are compounds that act as solubilizers. According to the invention, these are, in particular, amphiphilic compounds with a relatively small polar moiety and a larger non-polar moiety, which are soluble in both non-polar and polar solvents. The compounds defined as hydrotropes according to the invention have less hydrophobic properties and higher solubility in water. The polar moiety ensures higher solubility in water, while the non-polar moiety acts as a functional group. Hydrotropes according to the invention enable, in particular, the formulation of a clear and stable liquid cleaning concentrate and a clear, ready-to-use application solution. According to the invention, the compounds defined as surfactants are not hydrotropes.

[0030] Within the scope of the invention, hydrotropes can be selected from alkyl sulfates, preferably C6-C10 alkyl sulfates and their sodium salts, more preferably sodium octyl sulfate and sodium ethylhexyl sulfate; alkyl sulfonates, preferably C6-C10 alkyl sulfonates; aromatic sulfonates, preferably xylenesulfonate, p-toluenesulfonate and their sodium salts; propionates, preferably iso-octyl iminodipropionate, n-octyl iminodipropionate, caprylic and capric amphopropionate; C4-C10 ether carboxylic acids having 4-10 EO units, preferably alkyl(8)polyethercarboxylic acid having 8 EO units and alkyl(4-8)polyethercarboxylic acid having 5 EO units; Alkyl, alkyldi-, alkylpolyglycosides and mixtures thereof, wherein the alkyl radical is preferably a branched or unbranched C4-C16 alkyl radical and the glycoside radical is preferably selected from hexose unit and pentose unit, further preferably selected from glucopyranose unit and xylopyranose unit.Preferably, the hydrotrope is sodium octyl sulfate, sodium ethylhexyl sulfate or a mixture thereof.

[0031] In the context of the invention, the hydrotrope acts to clarify the formulation within a certain temperature range and, if necessary, as a solubilizer for the fatty alcohol alkoxylate.

[0032] The hydrotrope may be present in the liquid detergent concentrate in a weight proportion of 0.05 to 13 wt.%, preferably 0.1 to 7 wt.%, more preferably 0.15 to 3.5 wt.%, based on the total mass of the liquid detergent concentrate.

[0033] The alkanolamine is preferably selected from monoethanolamine, triethanolamine, monoisopropanolamine, and mixtures thereof. Within the scope of the invention, the alkanolamine or its mixture serves, in particular, to adjust the alkalinity of the liquid cleaning agent. Monoethanolamine has the advantage of being a good protein cleaner. The alkanolamine or its mixture is preferably present in the liquid cleaning agent concentrate in a weight proportion of 1 to 26 wt.%, more preferably 4 to 18 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0034] The alkali metal hydroxide is preferably sodium hydroxide and / or potassium hydroxide, more preferably potassium hydroxide. Within the scope of the invention, the alkali metal hydroxide serves, in particular, to adjust the alkalinity of the liquid cleaning agent. Potassium hydroxide is preferably present in the liquid cleaning agent concentrate in a weight proportion of 1 to 8 wt.%, more preferably 2 to 5 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0035] The solvent can be water or a water-containing solvent mixture. Preferred solvent mixtures are those that, in addition to water, comprise organic solvents selected from ethanol, 2-propanol, glycols, glycerin, and mixtures thereof. A preferred glycol is 1,2-propylene glycol. The organic solvent is preferably present in the liquid cleaning agent concentrate in a weight proportion of 0.5 to 10 wt.%, more preferably 3 to 7 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0036] Preferably, water is present in the liquid cleaning agent concentrate in a weight proportion of 30 to 90 wt.%, more preferably 35 to 70 wt.%, even more preferably 35 to 60 wt.%, even more preferably 35 to 50 wt.%, even more preferably 35 to 45 wt.%, based on the total mass of the liquid cleaning agent concentrate.

[0037] The invention is based on the surprising finding that the combination of at least one phosphonate and a first complexing agent in the liquid cleaning agent concentrate achieves very good cleaning performance at only a low application concentration and at the same time has a high material compatibility when used on various materials, in particular on metal surfaces.

[0038] It was observed that the active ingredients contained in the liquid cleaning concentrate can be used in significantly lower dosages than those of other cleaning agents known in the prior art. This is primarily due to a synergistic effect with regard to the achieved cleaning performance. The cleaning performance of the concentrate, comprising the combination of phosphonate and the first complexing agent, with regard to blood is better than that of the individual components. This particularly applies to complexing agents selected from the class of aminopolycarboxylic acids and their salts.

[0039] In the current state of the art, enzymatic, mildly alkaline, liquid cleaning agents, preferably containing surfactants, are typically added to machine cleaning at a water temperature of around 40°C. This is necessary because the cleaners tend to foam excessively at lower temperatures. The disadvantage, however, is that the cleaning programs take longer to run, as the warm-up time from the inlet temperature (usually around 18-22°C) to 40°C is required before the cleaner can take effect.However, the liquid cleaning agent concentrate according to the invention makes it possible to carry out cold dosing immediately after the water inlet, at a temperature preferably of 38°C or less, more preferably of 18 to 35°C, even more preferably of 20 to 30°C, even more preferably of 22 to 27°C, and even more preferably at approximately 25°C, without the program being aborted due to excessive foam development. Such cold water dosing is currently not possible with the liquid cleaning agents known from the prior art and commercially available. The cold dosing of the liquid cleaning agent concentrate has its own inventive content.

[0040] Another important requirement for the liquid cleaning agent concentrate is the highest possible material compatibility when applied to various materials. Corrosion protection of stainless steel and (color) anodized aluminum parts is particularly important with regard to medical and / or surgical instruments and / or devices. Surprisingly, the concentrate exhibits high material compatibility when applied to various materials. In particular, the presence of the combination of phosphonate and first complexing agent leads to significantly improved corrosion inhibition behavior on stainless steel and (color) anodized aluminum parts. Furthermore, surprisingly, with more frequent use of the liquid cleaning agent concentrate according to the invention, an improved shine and an improved feel, particularly on stainless steel parts, are observed.

[0041] It has been observed that the phosphonate in the invention not only functions as a complexing or dispersing agent, but also exhibits beneficial effects as a corrosion inhibitor. Furthermore, without phosphonate, significant fluctuations in the pH value of the liquid cleaning agent concentrate are observed when individual formulation ingredients are varied. Thus, the concentrate not only serves as a corrosion inhibitor, but also functions as a buffer.

[0042] Additionally, it was found that the preferential combination of two complexing agents, in addition to the phosphonate, and their selection has a significant impact on both cleaning performance and corrosion inhibition capacity. Complexing agents with higher complexation constants for Ca 2+< and Mg 2+< ions, when combined, demonstrate better cleaning performance with respect to blood. It was observed that cleaning performance and corrosion resistance are inversely related. Good corrosion inhibition results in poorer cleaning performance, and vice versa. However, these properties can be optimally optimized by preferably combining a first and a second complexing agent, in addition to the phosphonate.

[0043] The invention further relates to a ready-to-use application solution comprising 0.05 to 99.9% of the liquid cleaning agent concentrate according to the invention, wherein a pH value of the ready-to-use application solution is 9 or >9, preferably 9-12, more preferably 10-12, even more preferably 10-11.

[0044] The ready-to-use application solution preferably comprises 0.05 to 10%, more preferably 0.1 to 1% of the liquid cleaning agent concentrate according to the invention.

[0045] The previously listed components, properties, and beneficial effects of the ready-to-use solution correspond to those previously defined for the liquid cleaning agent concentrate. However, the components in the ready-to-use solution are present in the following weight proportions: The phosphonate or phosphonate mixture is preferably present in the ready-to-use solution in a weight proportion of 0.0005 to 1.3 wt.%, more preferably 0.002 to 0.1 wt.%, and even more preferably 0.003 to 0.08 wt.%, based on the total mass of the ready-to-use solution.

[0046] Preferably, the first complexing agent is present in the ready-to-use application solution in a weight proportion of 0.00025 to 1.0 wt.%, more preferably 0.001 to 0.08 wt.%, even more preferably 0.002 to 0.06 wt.%, based on the total mass of the ready-to-use application solution.

[0047] Preferably, the second complexing agent is present in the ready-to-use application solution in a weight proportion of 0.00025 to 1.0 wt.%, more preferably 0.001 to 0.08 wt.%, even more preferably 0.002 to 0.06 wt.%, based on the total mass of the ready-to-use application solution.

[0048] Preferably, the enzyme or enzyme mixture is present in the ready-to-use application solution in a weight proportion of 0.000025 to 0.04 wt.%, more preferably 0.0001 to 0.02 wt.%, based on the total mass of the ready-to-use application solution.

[0049] The fatty alcohol alkoxylate may be present in the ready-to-use application solution in a weight proportion of 0.00005 to 0.9 wt.%, more preferably 0.0004 to 0.02 wt.%, based on the total mass of the ready-to-use application solution.

[0050] The amino acid-based surfactant may be present in the ready-to-use application solution in a weight proportion of 0.000025 to 0.5 wt.%, preferably 0.0001 to 0.02 wt.%, based on the total mass of the ready-to-use application solution.

[0051] The hydrotrope may be present in the ready-to-use application solution in a weight proportion of 0.000025 to 1.3 wt.%, preferably 0.0001 to 0.07 wt.%, even more preferably 0.00015 to 0.035 wt.%, based on the total mass of the ready-to-use application solution.

[0052] The alkanolamine or its mixture may be present in the ready-to-use application solution in a weight proportion of 0.0005 to 2.6 wt.%, preferably 0.004 to 0.18 wt.%, based on the total mass of the ready-to-use application solution.

[0053] The alkali metal hydroxide may be present in the ready-to-use application solution in a weight proportion of 0.0005 to 0.8 wt.%, preferably 0.002 to 0.05 wt.%, based on the total mass of the ready-to-use application solution.

[0054] The organic solvent may be present in the ready-to-use application solution in a weight proportion of 0.00025 to 1.0 wt.%, preferably 0.003 to 0.07 wt.%, based on the total mass of the ready-to-use application solution.

[0055] Water may be present in the ready-to-use application solution in a weight proportion of 90.0 to 99.985 wt.%, preferably 95.0 to 99.98 wt.%, more preferably 99.6 to 99.96 wt.%, based on the total mass of the ready-to-use application solution.

[0056] The invention further relates to the use of the liquid cleaning agent concentrate according to the invention or the ready-to-use application solution according to the invention for cleaning and / or disinfecting objects, preferably for mechanical cleaning and / or disinfection of objects. In an advantageous embodiment, the liquid cleaning agent concentrate or the ready-to-use application solution is preferably dosed cold, more preferably at a temperature of 38°C or less, even more preferably from 18 to 35°C, even more preferably from 20 to 30°C, even more preferably from 22 to 27°C, even more preferably at about 25°C.

[0057] Within the scope of the invention, mechanical cleaning takes place without human intervention during an automatic program sequence, preferably in an instrument washer or a washer-disinfector. The term "cleaning and / or disinfection" expresses that the liquid cleaning agent concentrate and the ready-to-use application solution can be used both in a combination of cleaning and disinfection in a single process step and in program sequences in which a cleaning step is followed by a separate disinfection step.

[0058] The objects are preferably medical and / or surgical instruments and / or devices. The invention further relates to a method for cleaning medical and / or surgical instruments and / or devices, characterized by the following steps: a) preparing a ready-to-use application solution according to one of claims 9 or 10, b) cleaning the medical and / or surgical instruments and / or apparatus with the ready-to-use application solution.

[0059] In an advantageous embodiment, the ready-to-use application solution is preferably prepared cold, more preferably at a temperature of 38°C or less, even more preferably from 18 to 35°C, even more preferably from 20 to 30°C, even more preferably from 22 to 27°C, and even more preferably at about 25°C. The ready-to-use application solution can be prepared by dosing the liquid cleaning concentrate according to the invention. Optionally, the ready-to-use application solution can also be prepared manually starting from the liquid cleaning concentrate according to the invention.

[0060] The disclosure will now be described by way of example with reference to some embodiments and the accompanying drawings. In the drawings: Figure 1: Corrosion tests with grey cast iron chips GG25 based on DIN 51360 Part 2 at different concentrations of the application solutions (i.e. 1a) 10% and 1b) 5%) Figure 2: Current density-potential curves of the anodic partial reactions on test specimens of stainless steel quality 1.4034, whereby the measurements with the inventive approach (I), the approach (II) without phosphonate and salt solutions of different pH values ​​are shown as comparisons Figure 3: Current density-potential curves of the anodic partial reactions on test specimens of stainless steel quality 1.4031, whereby the measurements with the inventive approach (I), the approach (II) without phosphonate and salt solutions of different pH values ​​are shown as comparisons Figure 4: Position of the corrosion potentials, i.e. the current density minima,(top) and graphical results of the panel analysis with test specimens of stainless steel quality 1.4034 (bottom) Figure 5: Results of the immersion cleaning tests with the inventive approach (I) and the approach (II) without phosphonate as a comparison with heparinized sheep blood as soiling Figure 6: Cleaning performance of ready-to-use application solutions comprising phosphonate and MGDA with respect to sheep blood with variation of a second complexing agent, plotted in comparison with log(K) literature values ​​for Ca 2+< and Mg 2+< Figure 7: Cleaning performance and corrosion behavior of ready-to-use application solutions comprising phosphonate and MGDA with respect to sheep blood with variation of a second complexing agent,plotted in comparison with log (K) literature values ​​for Ca 2+< and Mg 2+< Figure 8: Pressure and temperature curves for the cold water dosing of a liquid cleaning agent concentrate according to the invention in a concentration of 3 ml / l at 25°C Figure 9: Pressure and temperature curves for the cold water dosing of the cleaners known from the state of the art and commercially available with the respective standard recommended concentration at 25°C, 1. Phosphonate 1. Corrosion tests with grey cast iron chips GG25 based on DIN 51360 Part (not according to the invention)

[0061] Four different phosphonates (i.e., the sodium salts of ATMP, HEDP, PBTC, DTPMP) and two other complexing agents (i.e., sodium glucoheptonate, HEDTA) were tested for their corrosion inhibition effect in an otherwise constant liquid cleaning formulation in equimolar ratios, with the pH adjusted where necessary. For the evaluation, corrosion tests were conducted with gray cast iron chips GG25 in accordance with DIN 51360 Part 2 at various concentrations of the application solutions (i.e., 10% and 5%). a. Equipment and materials Petri dishes Ø 100 mm (glass or plastic) Filter paper Ø 70 mm 589 from Whatman ash-free, medium-fast filtering Gray cast iron GG 25 chips according to DIN 51360 T2 (Riegger Industriehandel, article 03-39) Deionized water b. Procedure 2.0 g ± 0.1 g of the chips were weighed onto the filter paper placed in the Petri dish using a spoon spatula. The chips were distributed as centrally as possible over an area of ​​Ø 40-50 mm. The chips and the filter paper were evenly moistened with 2 ml of the 10% or 5% ready-to-use solution and the Petri dish was closed with the lid. The samples prepared in this way were stored for 2 hours ± 10 minutes at room temperature (20-25°C) without direct sunlight or drafts. The chips were removed and discarded. The filter paper was rinsed under running deionized water and swirled in acetone for 5-10 seconds. The filter paper was dried at room temperature (20-25°C).The degree of corrosion was determined immediately after drying. Each test was performed in duplicate. c. Evaluation: For the evaluation, instead of a visual assessment, the area of ​​corrosion was related to the total area of ​​the filter paper used. The area integrals were determined using the ImageJ software. d. Result. Figure 1 shows the results of the corrosion tests with grey cast iron chips GG25 in accordance with DIN 51360 Part 2 at different concentrations of the application solutions (sample 1: Na-ATMP, sample 2: Na-HEDP, sample 3: Na-PBTC, sample 4: Na-glucoheptonate, sample 5: Na-DTPMP, sample 6: Na-HEDTA; sample ref: comparison without additive), where Figure 1a ) the tests with 10% ready-to-use solutions and Figure 1b) show the tests with 5% ready-to-use solutions. In both cases, the best results were obtained with the ready-to-use solutions containing Na-ATMP (sample 1) and Na-PBTC (sample 3). 2. pH tests (not according to the invention)

[0062] It has been shown that the phosphonate acts as a corrosion inhibitor. A further effect of the phosphonate can be observed by systematically varying other components, such as the complexing agent, while maintaining an otherwise constant composition of the cleaning agent concentrate. Table 1: pH values ​​when varying complexing agents in the presence or absence of phosphonate (PBTC) Complexing agents pH value without phosphonate pH value with phosphonate HEDTA 12,6 10,9 EDDS 11,0 10,6 1< IDS 11,7 10,9 GLDA 12,4 10,9 Polyaspartate 11,6 10,8 EDTA 12,6 10,9 MGDA 12,3 10,9 - 10,8 1< raw material used only ¾ deprotonated

[0063] It turns out that the pH value is stable when phosphonate is present. In its absence, significant pH fluctuations are observed when varying the ingredients, i.e., when adding different complexing agents (see Table 1). Thus, the phosphonate not only serves as a corrosion inhibitor in the liquid cleaning concentrate and the ready-to-use solution, but also acts as a buffer. 2. Combination of phosphonate and complexing agent

[0064] Electrochemical corrosion measurements and immersion cleaning tests with heparinized sheep blood were conducted. Two batches were prepared for this purpose. Batch (I) is a liquid cleaning concentrate according to the invention, prepared from the following ingredients: 3.5 wt.% Endoprotease 10 wt.% 50% PBTC 8.5 wt.% 45% KOH 6.0 wt.% 40% MGDA, 3Na 6.0 wt.- 40% HEDTA 0.5 wt.% Fatty alcohol alkoxylate C12-C15 with 2EO / 4PO 3.2 wt.% 42% sodium octyl sulfate 16 wt.% 99% triethanolamine to 100 wt.% Water

[0065] Approach (II) is a comparison not according to the invention without phosphonate, with an otherwise identical formulation, whereby the pH was set identically to approach (I). The experiments conducted clearly demonstrate the synergistic effect of the phosphonate in combination with aminopolycarboxylates as complexing agents. 1. Electrochemical corrosion measurements a. Measurement method

[0066] First, the open-circuit potential (OCP) of the system was determined. To ensure sufficient equilibrium, this was done over a period of 600 s. Subsequently, the current density-potential curve was recorded over a potential range of -0.1 to +1.5 V relative to the measured OCP. For this purpose, a step size of 0.001 V was set at a scan speed of 0.01 V / s. b. Implementation

[0067] To conduct the electrochemical corrosion experiments, a measurement setup consisting of an Autolab PGSTAT204 potentiostat and a corrosion cell for flat samples (Metrohm AG) with a three-electrode arrangement and a silver / silver chloride reference electrode was used. Ground stainless steel sheets of grades 1.4034 and 1.4301 were used as test specimens.

[0068] Electrochemical corrosion tests were carried out on test specimens of the two stainless steel qualities 1.4034 (chrome steel; less corrosion-resistant; cf. Figure 2 ) and 1 .4301 (chrome-nickel steel; corrosion-resistant; cf. Figure 3). For this purpose, a 10% working solution of each of the batches (I) and (II) was prepared in a 0.9% solution of sodium chloride (equivalent to physical saline solution) to obtain the required corrosive conditions, and current density-potential curves were recorded. The pH values ​​were 10.5 for batch (I) with phosphonate and 11.5 for batch (II) without phosphonate. Despite the lower pH of the working solution of batch (I), the measurements showed lower corrosion currents than for the phosphonate-free variant with a higher pH value (see Figure 2 ). In principle, it would have been expected that the corrosion resistance of steels would also increase with increasing pH, so that improved resistance at a comparatively lower pH indicates a significant inhibition effect.

[0069] To rule out the possibility that the pH value was responsible for the observed behavior, further tests were conducted with salt solutions in which the pH was adjusted to 10.5 or 11.5 with potassium hydroxide solution. This corresponds to the measured pH values ​​of the two application solutions, but without any components of the cleaning solutions being able to influence the corrosion behavior. As a reference, a test was also conducted with sodium chloride solution without pH adjustment (pH = 7.9). The corresponding current density-potential curves (see Figure 2 ) clearly show that the corrosion current decreases with increasing pH. As expected, a lower current is observed at pH = 11.5 compared to pH = 10.5 and pH = 7.9.

[0070] Especially in the test series with the less corrosion-resistant steel 1.4034 (cf. Figure 2), the effects of the pH value alone and the additional effect of the two formulations can be clearly differentiated. The corrosion potentials and corrosion rates of the individual measurements determined by Tafel analysis clearly illustrate the described effects. These can be found in Table 2 below and in Figure 4 .

[0071] The increasing pH led to a reduction in the corrosion rate in the NaCl solutions, as well as a shift in the corrosion potential toward more positive potentials. The addition of the application solutions enhanced both effects within the same pH range, with the variant according to the invention containing phosphonate exhibiting the most strongly shifted corrosion potentials toward more positive values, even though the pH value here, as previously described, is lower than in the comparison variant without phosphonate. Table 2: Corrosion potentials and corrosion rates from the table analysis of the corrosion experiments carried out, whereby the tests of approaches (I) and (II) were each carried out as duplicate determinations (A) and (B) Steel 1.4034 Corrosion potential [V] Corrosion rate [mm / year] 0.9% NaCl pH=7.9 -0.332 0.046 0.9% NaCl pH=10.5 -0.289 0.006 0.9% NaCl pH=11.5 -0.287 0.004 Approach II (A) -0.269 0.001 Approach II (B) -0.238 0.001 Approach I (A) -0.227 0.001 Approach I (B) -0.221 0.001 2. Cleaning tests in the immersion bath a. Equipment and materials

[0072] Stainless steel plate (slightly roughened, area 1 cm × 9 cm) sheep blood heparinized with 10 IU / ml

[0073] Protamine sulfate or protamine chloride: ACILA GmbH Marking points Ø 8mm green demineralized water b. Implementation

[0074] Preparation of the test plates from heparinized, reactivated sheep blood: The heparinized sheep blood and the protamine sulfate / protamine chloride were stored in a climate-controlled cabinet at 6°C until the test. For the preparation of the test soil, the sheep blood and the protamine sulfate / protamine chloride should have reached a temperature of 20°C. The grease-free stainless steel plates were mounted on a rack and aligned horizontally as straight as possible.

[0075] 75 µl of protamine sulfate or protamine chloride were briefly mixed with 5 ml of heparinized sheep blood in a 50 ml beaker on a magnetic stirrer. 100 µl of this solution was pipetted onto each plate and distributed evenly using an inoculation loop, avoiding contaminating the mounting holes and the side surfaces. Each batch was then incubated for 1 hour at room temperature in water vapor-saturated air (100% relative humidity). The plate rack can be immersed in the deionized water, but the platelets must be stored above the water level. To achieve 100% relative humidity, the bottom of an 8.5 l plastic container was filled with at least 1 l of deionized water. The deionized water must completely cover the bottom of the horizontally positioned dish. The dish was covered with a lid at least 2 hours before starting the experiment (atmosphere conditioning).After 1 hour, the wet test specimens with the coagulated blood stain were removed from the plastic tray and dried at room temperature.

[0076] The quality of the dry test plates was checked. Plates with air bubbles on the soil or irregularities were discarded. A green marker dot was applied to all other plates. The test plates were stored in screw-capped test tubes at room temperature until use in the immersion test.

[0077] Carrying out the diving test: Concentration: 2,5 ml / l Water qualities: demineralized water Temperature: 45°C ± 1°C Holding time: 4 minutes Stirring speed: 350 rpm (stirrer IKA RCT classic) Test plates: Heparinized, reactive sheep blood

[0078] Immersion cleaning tests were conducted with both test batches at a dosage of 2.5 ml / l in deionized water and a temperature of 45°C with a contact time of 4 minutes. Four individual experiments were conducted with each formulation variant; the residue was stained with a 0.1% amido black solution, and the area was determined. The mean values ​​of the quadruplicate determinations are shown in Figure 3 applied. c. Evaluation

[0079] The evaluation was performed visually using the dried slides. In addition, the analysis was performed using the integrals of the remaining blood residues relative to the total area of ​​the test specimen using the ImageJ software. d. Results

[0080] Figure 5 shows the results of the immersion cleaning tests with the inventive approach (I) and approach (II) without phosphonate, using heparinized sheep blood as soil.

[0081] How Figure 5 As shown, the inventive approach (I) achieved a slightly better cleaning result in the removal of heparinized sheep blood than the comparative approach (II), which contains no phosphonate and only aminopolycarboxylates as complexing agents. Furthermore, the pH of the inventive application solution of approach (I), at 10.5, was even slightly lower than that of the application solution of approach (II), for which a pH of 10.7 was determined.

[0082] Compared to the cleaning concentrate and its ready-to-use solution of approach (I) without phosphonate, the liquid cleaning concentrate according to the invention and its ready-to-use solution of approach (II) demonstrate improved corrosion protection with respect to stainless steel, better material compatibility, e.g., with aluminum, and improved cleaning performance with respect to blood, despite a lower pH value, which usually has the opposite effect. Furthermore, a buffering effect of the desired pH value was observed over a wide concentration range due to the presence of the phosphonate. 3. Combination of complexing agents

[0083] The complexing agent MGDA was combined with a second complexing agent (i.e., HEDTA, EDDS, IDS, GLDA, polyaspartate, EDTA) in a liquid cleaning concentrate according to the invention, in addition to the phosphonate PBTC contained therein. The corrosion inhibition properties and cleaning performance of all test batches in this series were investigated with respect to sheep blood. The combinations with EDDA and polyaspartate are not according to the invention. 1. Corrosion tests

[0084] The corrosion tests were conducted with gray cast iron chips GG25 in accordance with DIN 51360 Part 2 at a concentration of 2.5%. The tests were conducted and evaluated analogously to the corrosion tests with phosphonates described above. The tests with polyaspartate and DTPMP are not in accordance with the invention. 2. Cleaning tests in the immersion bath a. Equipment and materials

[0085] Stainless steel plate (slightly roughened, area 1 cm x 9 cm) Sheep blood heparinized with 10 IU / ml protamine sulfate or protamine chloride: ACILA GmbH Marking points Ø 8mm green Deionized water b. Implementation

[0086] The test specimens were prepared using heparinized, reactivated sheep blood as described above. Immersion test procedure: Concentration: 2,0 ml / l Water qualities: demineralized water Temperature: 45°C ± 1°C Holding time: 4 minutes Stirring speed: 350 rpm (stirrer IKA RCT classic) Test plates: Heparinized, reactive sheep blood

[0087] Immersion cleaning tests were conducted with both formulations at a dosage of 2.0 ml / l in deionized water and a temperature of 45°C with a contact time of 4 minutes. Four individual experiments were conducted with each formulation variant. The residue was stained with a 0.1% amido black solution, and the area was determined. c. Evaluation

[0088] The cleaning results were evaluated visually using the dried plates. In addition, the evaluation was carried out by integrating the area relative to other individual tests. 3. Results of corrosion and cleaning tests

[0089] On the one hand, it was observed that the selection of the second complexing agent has an influence on both the cleaning performance and the corrosion behavior of the liquid cleaning agent (cf. Figures 6 and 7 ). On the other hand, a reciprocal relationship between corrosion behavior and cleaning performance was found (cf. Figure 7 ). Thus, improved corrosion protection leads to a deterioration in cleaning performance, and vice versa. A further correlation can be observed between cleaning performance and the complex stabilities (log(K)) of the complexing agents with Ca 2+< and Mg 2+< ions (cf. Figure 6The use of complexing agents with higher log(K) values ​​leads to improved cleaning performance in the ready-to-use solution; this performance deteriorates accordingly when complexing agents with lower stability constants are used. This relationship is particularly evident when all three parameters are plotted against the mean of the log(K) values ​​for Ca 2+< and Mg 2+< ions in ascending order (cf. Figure 7 ). 4. Cold water dosing

[0090] In the current state of the art, enzymatic, mildly alkaline, liquid cleaning agents, preferably containing surfactants, are typically added for machine cleaning at a water temperature of around 40°C. This is necessary because the cleaning agents tend to foam excessively at lower temperatures. However, the disadvantage of dosing at a temperature of around 40°C is that the cleaning program runs longer, as a certain amount of time must first be allowed for the system to heat up from the inlet temperature (usually around 18-22°C) to a temperature of 40°C before the cleaning agent can take effect.

[0091] The liquid cleaning agent concentrate according to the invention and the ready-to-use application solution, however, enable cold dosing immediately after the water inlet, preferably at a temperature of 38°C or less, even more preferably between 18 and 35°C, even more preferably between 20 and 30°C, even more preferably between 22 and 27°C, and even more preferably at approximately 25°C, without causing the program to abort due to excessive foam development. This is currently not possible with the cleaning agents known from the prior art.

[0092] In Figure 8 The correct and complete program sequence (pressure and temperature curves) from a cleaning and disinfection system (UniClean PL II from MMM) is shown. The liquid cleaning agent concentrate according to the invention was dosed at a concentration of 3 ml / l at 25°C.

[0093] This was carried out analogously for some of the state-of-the-art and commercially available cleaners with the standard recommended concentration at 25°C (including Dr. Weigert, neodisher MediClean forte, 6 ml / l, #681964; Ruhof, Endozyme AW plus, 3.5 ml / l; Dr. Schumacher, thermoshield Xtreme, 3 ml / l, #460764; Borer, deconex Twin pH10 + Twin Zyme, 3 ml / l + 1.5 ml / l, #0370073 + #0,397577; Prolystica, Prolystica 2x concentrate alkaline cleaner, 3 ml / l, #290186). For these cleaners, a program termination as described in Figure 9 is shown, observed.

Claims

1. Liquid cleaning agent concentrate comprising: a. at least one phosphonate, b. a first chelating agent selected from (hydroxyethyl)ethylenediaminetriacetic acid, methylglycine diacetic acid and salts thereof, c. a second chelating agent selected from (hydroxyethyl)ethylenediaminetriacetic acid, ethylenediaminetetraacetic acid, glutamic acid-N,N-diacetic acid, iminodisuccinic acid, methylglycine diacetic acid and salts thereof, wherein the first and second chelating agents are different from one another, and d. at least one enzyme, preferably proteolytic enzyme, wherein a pH of the liquid cleaning agent concentrate is 9 or >9.

2. Liquid cleaning agent concentrate according to Claim 1, characterized in that the liquid cleaning agent concentrate has a pH of 9-12, preferably 10-12, more preferably 10-11.

3. Liquid cleaning agent concentrate according to Claim 1 or 2, characterized in that the at least one phosphonate is selected from salts of phosphonobutanetricarboxylic acid (PBTC), of aminotrismethylenephosphonic acid (ATMP), of 1-hydroxyethane-1,1-diphosphonic acid (HEDP), of diethylenetriamine penta(methylenephosphonic acid) (DTPMP) and mixtures thereof.

4. Liquid cleaning agent concentrate according to any of Claims 1 to 3, characterized in that the phosphonate is the sodium salt of phosphonobutane tricarboxylic acid, of aminotrismethylenephosphonic acid, or a mixture thereof.

5. Liquid cleaning agent concentrate according to any of Claims 1 to 3, characterized in that the first chelating agent is the sodium salt of (hydroxyethyl)ethylenediaminetriacetic acid or the sodium salt of methylglycine diacetic acid.

6. Liquid cleaning agent concentrate according to any of Claims 1 to 5, characterized in that the liquid cleaning agent concentrate comprises the sodium salt of phosphonobutanetricarboxylic acid, the sodium salt of aminotrimethylenephosphonic acid or a mixture thereof as the phosphonate, the sodium salt of (hydroxyethyl)ethylenediaminetriacetic acid as the first chelating agent, and preferably the sodium salt of methylglycine diacetic acid as the second chelating agent.

7. Liquid cleaning agent concentrate according to any of Claims 1 to 6, characterized in that the liquid cleaning agent also comprises further constituents selected from surfactants, hydrotropes, alkanolamines, alkali metal hydroxides, solvents, corrosion inhibitors, fragrances and dyes.

8. Liquid cleaning agent concentrate according to any of Claims 1 to 7, characterized in that at least one of the following constituents is present in the liquid cleaning agent concentrate in the following proportions by weight in each case: - the phosphonate or phosphonate mixture in a proportion by weight of 1 to 13% by weight, preferably of 2 to 10% by weight, based on the total mass of the liquid cleaning agent concentrate; - the first chelating agent in a proportion by weight of 0.5 to 10% by weight, preferably of 1 to 8% by weight, based on the total mass of the liquid cleaning agent concentrate; - the second chelating agent in a proportion by weight of 0.5 to 10% by weight, preferably of 1 to 8% by weight, based on the total mass of the liquid cleaning agent concentrate; - the enzyme or enzyme mixture in a proportion by weight of 0.05 to 4% by weight, preferably 0.1 to 2% by weight, based on the total mass of the liquid cleaning agent concentrate.

9. Ready-to-use application solution comprising 0.05 to 99.9% of the liquid cleaning agent concentrate according to any of Claims 1 to 8, wherein a pH of the ready-to-use application solution is 9 or >9.

10. Ready-to-use application solution according to Claim 9, characterized in that the liquid cleaning agent concentrate has a pH of 9-12, preferably 10-12, more preferably 10-11.

11. Use of the liquid cleaning agent concentrate according to any of Claims 1 to 8 or of the ready-to-use application solution according to either of Claims 9 or 10 for cleaning and / or disinfecting objects, preferably for machine cleaning and / or disinfecting objects.

12. Use according to Claim 11, characterized in that the objects are medical and / or surgical instruments and / or apparatuses.

13. Use according to Claim 11 or 12, characterized in that the liquid cleaning agent concentrate or the ready-to-use application solution is dispensed cold, preferably at a temperature of 38°C or less, more preferably of 18 to 35°C, further preferably of 20 to 30°C, still more preferably of 22 to 27°C, even more preferably at about 25°C.

14. Method for cleaning medical and / or surgical instruments and / or apparatuses, characterized by the following steps: a) preparing a ready-to-use application solution according to either of Claims 9 or 10, b) cleaning of the medical and / or surgical instruments and / or apparatuses with the ready-to-use application solution.

15. Method according to Claim 14, characterized in that the ready-to-use application solution is prepared cold, preferably at a temperature of 38°C or less, more preferably of 18 to 35°C, further preferably of 20 to 30°C, still more preferably of 22 to 27°C, even more preferably at about 25°C.