EP0846155A2

EP0846155A2 - Use of lipases in low-alkaline mechanical dishwashing agents

Info

Publication number: EP0846155A2
Application number: EP96930089A
Authority: EP
Inventors: Christian Nitsch; Peter Jeschke; Jürgen Härer
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1995-08-25
Filing date: 1996-08-23
Publication date: 1998-06-10
Anticipated expiration: 2016-08-23
Also published as: ATE189696T1; ES2143777T3; WO1997008281A1; EP0846155B1

Abstract

The invention concerns low-alkaline mechanical dishwashing agents based on builder components, oxygen bleaches, anti-corrosion agents, hydrotropic substances, foam inhibitors and other components conventional in dishwashing agents. The object of the invention is to improve the cleaning of articles in which tea has been present. This object is achieved by the use of between 0.05 and 1.5 wt % of a lipase, optionally combined with between 1 and 15 wt % of a multipurpose organic acid, in particular citric acid.

Description

'Use of lipases in lower alkaline agents for automatic dishwashing'

The invention relates to a new use of the lipases known per se in the context of low-alkaline agents for the automatic washing of dishes and as a means for supporting the bending systems for removing tea stains.

Bleachable soiling is generally the case when washing dishes by machine at today's cleaning temperatures of approx. 55 ° to 65 ° C. easily removed. In the course of saving energy, dishwasher manufacturers are now starting to offer low-temperature cleaning programs with temperatures of around 40 ° C.

However, modern low-alkali automatic dishwashing detergents often do not meet the requirements at such low cleaning temperatures, especially with regard to the removal of bleachable soiling such as e.g. Tar residues.

There is therefore a need for automatic dishwashing detergents that reliably remove bleachable stains even at lower cleaning temperatures. Another aspect that has become particularly important in the course of the introduction of low-alkaline automatic dishwashing detergents is the problem of corrosion or tarnishing of silverware during the automatic washing process.

The problem of tarnishing silver became a topical issue when, as an alternative to the active chlorine compounds, active oxygen compounds, such as sodium perborate or sodium percarbonate, were used, which were used for

ORIGINAL DOCUMENTS Eliminate bleachable stains, such as tea stains / tea deposits, coffee residues, dyes from vegetables, lipstick residues and the like.

Increasing the content of active oxygen compounds (bleaching agents based on oxygen) leads to a better removal of bleachable soiling, but at the same time has the consequence that increased silver corrosion occurs. So-called silver corrosion inhibitors have proven to prevent silver corrosion.

The use of lipolytic enzymes in automatic dishwashing detergents is known per se. Those skilled in the art know that they are helpful in cleaving triglycerides and fatty ester contaminants. For example, EP-B-271 155 teaches the use of lipases in dishwashing detergents and in rinse aids. It is stated there that the formation of films and stains is significantly reduced. The reduction in film formation here means the reduction in greasy films, not the reduction in tea deposits.

Similarly, European patent application 346 136 describes the reduction of stains and film formation by a special, genetically modified lipase.

International application WO94 / 07985 claims the use of a combination of lipases and lime soap dispersants in dishwashing detergents. The patent application assumes that the mode of action of the lipase releases fatty acids which react with the existing water hardness to form lime soaps. These in turn are deposited on the items to be washed. The application claims the use of 0.001% by weight to 2% by weight of a lipolytically active enzyme. In the examples, however, the use of slightly more than 2% by weight of a lipase enzyme is described. For it is clear to the person skilled in the art in this field that under normal conditions of use, an effect of the lipase, as described in WO94 / 07985, is more likely to be expected in the higher dosage range.

A second effect of the lipase has now surprisingly been found. Thus, small amounts of lipase can drastically increase the effect of bleaching agents on tea stains under the conditions of machine dishwashing with lower alkaline dishwashing detergents. This was not to be expected since tea stains are not triglycerides. It seems important here that the effect, especially under practical conditions, i.e. H. also occurs in the presence of greasy dishes. It was also shown that these advantages occur particularly when the esterases, in particular lipases, are used in the main rinsing process before the remaining constituents.

The present invention therefore relates to the use of esterases, preferably lipases, in or together with lower alkaline agents for automatic dishwashing, containing 15 to 70% by weight of a builder component, 0.5 to 20% by weight of an oxygen-based bleaching agent and, if desired Bleach activators, surfactants, corrosion inhibitors, hydrotropic substances, foam inhibitors and other components customary in machine dishwashing detergents, characterized in that 0.001 to 1.5% by weight of lipase, if desired in combination with 1 to 25% by weight of multifunctional, organic carboxylic acids, are used , whereby the lower alkaline agents are brought into effect simultaneously or after the esterases.

The active ingredient can be used in a variety of ways in a first cleaning step. The esterase can be washed in, spread on or sprayed on in dissolved form or as a suspension. It is also possible to immerse the hard surfaces to be cleaned for a certain time, which may depend on the effectiveness of the dosage form to leave and to increase the effectiveness of the esterases if necessary by acting and leaving standing. However, other common procedures for manual or machine pre-rinsing can also be used.

Other realizations of a two-phase solution process, i. H. the release of the substance mixtures in the pre-wash and main wash cycle are conceivable. This can be implemented either technically using a suitable dishwasher design (e.g. a two-chamber system) or using chemical modifications. In the case of solid mixtures, the encapsulation of the grains or tablets which are to be released in the main rinse cycle with the aid of suitable reagents, e.g. with the help of paraffin.

The esterases used according to the invention can be used in a wide variety of dosage forms, v. a. Powders, blocks, tablets, compacts, granules, pastes, viscous liquids, and aqueous and non-aqueous solutions can be used. Granules and tablets are particularly preferred. However, they can also be used as components together with other substances in the dosage forms mentioned above.

The lipases to be preferably used according to the invention are enzymes with lipolytic activity, such as are also used in detergents, for example. Preferred lipases are of bacterial origin and can be found, for example, in strains such as Humicola sp. or Thermomyces sp. or Pseudomonas pseudoalkaligenes or Pseudomonas fluorescens occur. Lipases which can be generated from basic enzymes by genetic modification can also be used. Lipase mixtures which also have enzymes which have both proteolytic and lipolytic activities are also suitable. Preferred are, for example, lipases which are commercially available under the brand name Lipomax® CXT 1000 from Gist Brocades, or Lipolase® from Novo Nordisk (see EP 258 068). Also preferred is a lipase from Pseudomonos fluorescens, which can be obtained from Amano under the brand name Lipase P Amano.

According to a particularly preferred embodiment of the invention, the agents according to the invention contain, apart from the lipase, a multifunctional, organic acid as an essential component. Suitable multifunctional, organic acids are primarily citric acid, but also tartaric acid and dicarboxylic acids with 3 to 8 carbon atoms. The multifunctional, organic acid is the agents according to the invention as such, i. H. not added in salt form. It is important to ensure that the organic acid as such, i.e. H. not in salt form. Since the dishwashing detergents to be used according to the invention are generally not spontaneously soluble, it is assumed that the kinetics of dissolution, i.e. H. due to the comparatively quicker solubility of the acid component, an effect of some kind on the soiling of tea is achieved, which then leads to improved removability.

The dishwashing detergents to be used according to the invention are adjusted so that they have a pH value between 8.5 and 10.5, in particular 8.5 and 9.5, in 1% by weight aqueous solution.

The preparations according to the invention contain a builder component as an essential component.

In principle, all builders commonly used in machine dishwashing detergents are possible as builder components, especially water-soluble builder components, e.g. B. polymeric alkali phosphates in the form of their alkaline neutral or acidic sodium or potassium salts can be present. Examples include: tetrasodium diphosphate, disodium dihydrogen diphosphate, pentasodium triphosphate, so-called sodium hexametaphosphate and the corresponding potassium salts or mixtures of sodium hexametaphosphate and the corresponding potassium salts or mixtures of sodium and potassium salts. The amounts of phosphate are in the range of up to about 30% by weight, based on the total agent; for ecological reasons, however, the agents according to the invention are preferably free of such phosphates. Other possible builder components are e.g. B. organic polymers of native or synthetic origin, especially polycarboxylates, which act in particular in hard water systems as a co-builder. For example, polyacrylic acids and copolymers of maleic anhydride and acrylic acid and the sodium salts of these polymer acids are suitable. Commercial products include Sokalan® CP 5 and PA 30 from BASF, Alcosperse® 175 or 177 from Alco, LMW® 45 N and SPO2 N from Norsohaas. The native polymers include, for example, oxidized starch and polyamino acids such as polyglutamic acid or polyaspartic acid, e.g. B. from the companies Cygnus and SRCHEM.

Crystalline layered silicates such as the product sold by Hoechst AG under the trade name Na-SKS-6 are suitable. Other possible builder components are naturally occurring hydroxycarboxylic acids such as. B. mono-, dihydroxysuccinic acid, α-hydroxypropionic acid and gluconic acid.

Preferred builder components are the salts of citric acid, in particular trisodium citrate, which can be used either as the sole builder substance or in a mixture with other builder substances. The salts of citric acid are preferably present in an amount of 15 to 70% by weight, in particular 20 to 60, very particularly preferably 25 to 45% by weight, based on the total agent. Come as trisodium citrate anhydrous trisodium citrate or preferably trisodium citrate dihydrate. Trisodium citrate dihydrate can be used as a fine or coarse crystalline powder.

According to a particularly preferred embodiment, trisodium citrate in a mixture with sodium or potassium hydrogen carbonate is used as the builder component. Trisodium citrate, in particular in the form of the dihydrate, in amounts of 20 to 60% by weight with sodium bicarbonate in amounts of 5 to 50% by weight, preferably 20 to 40% by weight, can be used, with up to 40 % By weight, preferably from 5 to 10% by weight, of sodium carbonate may be present.

The agents to be used according to the invention contain an oxygen-based bleaching agent as a further mandatory component. Customary oxygen-based bleaching agents are, for example, sodium perborate mono- and tetrahydrate or sodium percarbonate in an amount of up to 10% by weight, based on the total agent. The use of bleach activators such as PAG (pentaacetylglucose), DADHT (1,5-diacetyl-2,4-dioxo-hexahydro-1,3,5-triazine), ISA (isatoic anhydride) or N, N, N ', N'-tetraacetylethylenediamine (TAED) in principle possible, but not necessary. Since these bleach activators often favor silver corrosion, they are preferably avoided.

The agents to be used according to the invention can optionally also be added surfactants, in particular low-foaming nonionic surfactants, which serve to better detach fatty food residues, as wetting agents, as granulating aids or as dispersing aids for better, homogeneous distribution of the aforementioned silver corrosion inhibitors in the washing liquor and on the silver surfaces. Their amount is then preferably up to 10% by weight, in particular 0.5 to 5% by weight. Extremely low-foam connections are usually used. These preferably include C ₁₂ -C ₁₈ - Alkyl polyethylene glycol polypropylene glycol ether, each with up to 8 moles of ethylene oxide and propylene oxide units in the molecule. But you can also use other, known as low-foam nonionic surfactants, such as. B. C ₁₂ -C ₁₈ alkyl polyethylene glycol polybutylene glycol ether, each with up to 8 moles of ethylene oxide and butylene oxide units in the molecule, end-capped alkyl polyalkylene glycol mixed ethers and the foaming but ecologically attractive C ₈ -C ₁₄ alkyl polyglucosides with a degree of polymerization of about 1 - 4 ( e.g. APG® 225 and APG® 600 from Henkel) and / or C ₁₂ - C ₁₄ alkyl polyethylene glycols with 3 - 8 ethylene oxide units in the molecule. Bleached quality should be used, otherwise brown granules will result. Also suitable are surfactants from the family of glucamides such as, for example, alkyl-N-methyl-glucamides (alkyl = fatty alcohol with the C chain length C ₆ -C ₁₄ ). It is partially advantageous if the surfactants described are used as mixtures, for. B. the combination of alkyl polyglycoside with fatty alcohol ethoxylates or glucamides with alkyl polyglycosides etc.

If the cleaning agents foam too much during use, they can still contain up to 6% by weight, preferably about 0.5 to 4% by weight, of a foam-suppressing compound, preferably from the group of silicone oils, mixtures of silicone oil and hydrophobized silica, Paraffin oil / Guerbet alcohols, paraffins, hydrophobized silica, the bisstearic acid amides and other other known commercially available defoamers can be added. Other optional additives are e.g. B. Perfume oils.

Depending on the builder substances used, the agents to be used according to the invention additionally contain the alkali carriers present in conventional machine dishwashing agents, such as. B. alkali silicates, alkali carbonates and / or alkali hydrogen carbonates. The alkali carriers commonly used include carbonates, hydrogen carbonates and alkali silicates with a SiO ₂ / M ₂ O (M = alkali atom) molar ratio of 1.5: 1 to 2.5: 1. Alkali silicates can be used in amounts of up to 30% by weight, based on the total agent, may be included. The use of the highly alkaline metasilicates as alkali carriers is preferably avoided. The alkali carrier system preferably used in the agents to be used according to the invention is a mixture of essentially carbonate and hydrogen carbonate, preferably sodium carbonate and hydrogen carbonate, in an amount of up to 60% by weight, preferably 10 to 40% by weight, based on the total Means, is included. Depending on which pH value is ultimately desired or set, the ratio of carbonate and bicarbonate used varies; Usually, however, an excess of sodium hydrogen carbonate is used, so that the weight ratio between hydrogen carbonate and carbonate is generally 1: 1 to 15: 1.

The dishwashing detergents according to the invention, preferably enzymes such as proteases, amylases, lipases, cutinases and cellulases in an amount of up to 5% by weight, preferably 1 to 3% by weight, can be used to better remove protein, fat or starch-containing food residues. , contain, for example proteases such as BLAP® 140 from Henkel; Optimase® -M-440, Optimase® - M-330, Opticlean® -M-375, Opticlean® -M-250 from Solvay Enzymes; Maxacal® CX 450,000, Maxapem® from Ibis; Savinase® 4.0 T, 6.0 T, 8.0 T from Novo; Esperase® T from Ibis and amylases such as Termamyl® 60 T, 90 T and Duramyl® from Novo; Amylase-LT® from Solvay Enzymes, Purafect OxAm® from Genencor or Maxamyl® P 5000, CXT 5000 or CXT 2900 from Ibis; Lipases such as Lipolase® 30 T from Firm Novo; Cellulases such as Celluzym® 0.7 T from Novo Nordisk. The dishwashing agents preferably contain proteases and / or amylases.

The dishwashing detergents to be used according to the invention are preferably in the form of powdery, granular or tablet-like preparations which can be prepared in a conventional manner, for example by mixing, granulating, roller compacting and / or by spray drying. The preparation of the present invention applicable preparations in tablet form, the procedure is preferably such that mixing all ingredients together in a mixer and the mixture using conventional tablet presses, for example eccentric presses or rotary presses with press pressures in the range of 200 ^• 10 ⁵ Pa to 1,500 ^■ 10 ⁵ Pa pressed. In this way, unbreakable tablets are obtained with a flexural strength of normally more than 150 N that are sufficiently quickly soluble under conditions of use. A tablet produced in this way preferably has a weight of 15 g to 40 g, in particular 20 g to 30 g, with a diameter of 35 mm to 40 mm.

The agents to be used according to the invention can be used both in household dishwashers and in commercial dishwashers. They are added by hand or using suitable dosing devices. The application concentrations in the cleaning liquor are about 2 to 8 g / l, preferably 2 to 5 g / l.

The rinse program is generally supplemented and ended with a few intermediate rinse cycles with clear water and a rinse cycle with a common rinse aid following the cleaning cycle. After drying, not only a completely clean and hygienically perfect tableware is obtained, but above all also bright silver parts.

The agents to be used according to the invention can contain, as further substances, anti-corrosion agents, in particular anti-corrosion agents against silver corrosion. Reference is made here to the relevant prior art, for example to the international application WO94 / 26859 and to WO95 / 10588. Substances containing nitrogen are particularly preferred. In a particular embodiment, substances from the group of benzotriazoles and their derivatives are contained. But also Inorganic salts and complexes of manganese and cobalt and their related elements can be used in a preferred embodiment.

The agents used according to the invention can furthermore contain hydrotropic substances, if desired. Lime soap dispersants can also be used in principle; however, this is only recommended if the water hardness and lipase levels are high.

Lime soap dispersants should be used in amounts of 1 to 10% by weight, preferably 2 to 4% by weight. For example, fatty alcohol ether sulfates, such as C ₁₆ -4EO sulfate, are suitable, but nonionic surfactants with a dispersing action. Further lime soap dispersants are described in the aforementioned WO94 / 07985.

The agents according to the invention contain bleaching agents based on oxygen, bleaching agents based on chlorine or hypochlorite, can, if then, only be used in extremely small amounts.

Examples

(1) Production of tea soiling

16 l of cold city water (16 ° d) are briefly heated to boiling in a water treatment boiler. 96 g of black tea are drawn in the nylon net with the lid closed for 5 minutes and the tea is transferred to a diving apparatus with heating and agitator.

60 teacups are immersed 25 times in one-minute intervals at 70 ° C in the prepared tea infusion. The cups are then removed and placed on a tray with the opening facing down to dry.

(1) Addition of the agents according to the invention in a one-step process

(2) detergent composition

The following low-alkaline base product was first prepared, whose 1% by weight solution in distilled water gave a pH of 9.5:

55.0% trisodium citrate dihydrate 36.0% sodium hydrogen carbonate

6.1% sodium carbonate, anhydrous

1.2% mixture of nonionic surfactants such as APG 225 (C ₈ -C ₁₀ alkyl oligoglucoside), Dehydol® LS2 (C ₁₂ -C ₁₄ fatty alcohol 2EO ethoxylate) and Dehypon LT 104 (butyl-locked C ₁₂ -

C ₁₈ fatty alcohol 10 EO ethoxylate).

Lipase (Lipomax® CXT 1000 from Gist Brocades, Delft, the Netherlands) and citric acid, on the other hand, were added to this basic product in the amounts mentioned under (3) below. (3) Test results

The cleaning performance of the detergents for the soiling of tea according to the instructions under (1) was carried out visually by experts and graded, the rating "0" meaning no cleaning on a scale of 0-10 and "10" meaning complete removal of the stains.

The teen notes were measured for washing conditions 55 ° C / 16 ° d water hardness / 20 g cleaner (according to recipe (2)) in the main rinse cycle (ie "hard conditions").

0% lipase 0.1% lipase 0.5% lipase 1% lipase

0% lemon 2.8 2.8 acid

3% Citron 7.0 7.0 acid

15% lemon 9.0 9.8 acid

With an additional 50 g of standard grease contamination (pumpable!) Before opening the dosage box, the following values were obtained.

0% lipase 0.1% lipase 0.5% lipase 1% lipase

0% Citron 2.5 2.5 9.1 acid

3% citric acid

15% lemon 7.8 8.0 8.5 9.8 acid

-> pH "in the flotl e" was always> _ 9

The improved cleaning of tea stains by adding lipase has been proven. (II) Addition of the agents according to the invention in a multi-step process

(2ι detergent composition in pre-rinse

First, lipase (Lipomax® CXT 1000 from Gist Brocades, Delft, The Netherlands was used) and citric acid in the amounts mentioned below were added in the pre-rinse cycle.

2.8 g citric acid

0.2 g lipase

2 g surfactants (see above

(3) Detergent composition in the main wash cycle

The following low-alkaline standard product on the market was then produced, whose 1% by weight solution in distilled water gave a pH of 9.5:

Trisodium citrate dihydrate (42.0%)

Sodium bicarbonate (25.0%)

Sodium carbonate, anhydrous (6.1%)

Mixture of non-ionic surfactants (1.2%) such as APG 225 (C ₈ -C ₁₀ alkyl oligoglucoside), Dehydol® LS2 (C ₁₂ -C ₁₄ - fatty alcohol 2EO ethoxylate) and Dehypon LT 104 (butyl-locked C ₁₂ -C ₁₈ - Fatty alcohol-10 EO ethoxylate).

Bleach (12% by weight percarbonate, 2% by weight TAED)

Protease (0.7% by weight BLAP® 200 S) amylase (1% by weight Termamyl® 60 T Without lipase / citric acid or other additives in the pre-rinse cycle, the tea note is 2 with the additives according to the invention [eg according to recipe (11.2)] in the pre-rinse cycle at 7.

When using a 25 g tablet [composition as in example (11.3)] in which 5 g of model cleaner detach in the pre-wash cycle and 20 g in the main wash cycle, i.e. H. a mean without citric acid / lipase the teen grade is 3.

This demonstrates the improved cleaning performance of the citric acid / lipase system when used in the pre-rinse cycle. It is also evident when using additional grease contamination in the cleaning water in the pre-rinse cycle.

Claims

claims

1. Use of esterases, preferably lipases, in or together with lower alkaline agents for automatic dishwashing

15 to 70% by weight of a builder component,

0.5 to 20% by weight of an oxygen-based bleaching agent and, if desired, bleach activators, surfactants, corrosion inhibitors, hydrotropic substances, foam inhibitors and other components customary in machine dishwashing detergents, characterized in that

- 0.001 to 1.5 wt .-% lipase, if desired in combination with

- 1 to 15 wt .-% polyfunctional, organic carboxylic acids are used, the lower alkaline agents being brought into effect at the same time or after the esterases.

2. Embodiment according to claim 1, characterized in that the automatic dishwashing detergents in 1% by weight, aqueous solution have a pH of 8.5 to 10.5, in particular 8.5 to 9.5.

3. Embodiment according to one of claims 1 or 2, characterized in that salts of citric acid, if desired in a mixture with sodium bicarbonate, are used as the builder component.

4. Embodiment according to one of claims 1 to 3, characterized in that 20 to 60 wt .-% trisodium citrate (in particular in Form of the dihydrate) together with 5 to 50% by weight, preferably 20 to 40% by weight, sodium hydrogen carbonate and up to 40% by weight, preferably 5 to 10% by weight, sodium carbonate.

5. Embodiment according to one of claims 1 to 4, characterized in that additional surfactants, in particular nonionic surfactants in amounts up to 10 wt .-%, preferably from 0.5 to 5 wt .-%, are used.

6. Embodiment according to claim 5, characterized in that low-foaming, nonionic surfactants are used.

7. Embodiment according to one of claims 1 to 6, characterized in that amylases and / or proteases and / or cellulases are used as further enzymes.

8. Embodiment according to one of claims 1 to 7, characterized in that in a pre-rinse biologically active substances, preferably esterases, in particular lipases, in combination with higher functional carboxylic acids, preferably citric acid and / or tartaric acid, and / or surfactants, preferably nonionic surfactants, be used.

9. Embodiment according to claim 8, characterized in that cellulases and / or proteases and / or amylases are used as further enzymes in the pre-rinse cycle.