EP1090098A1

EP1090098A1 - Method for producing alkaline aqueous cleaning agents in the form of creams

Info

Publication number: EP1090098A1
Application number: EP99929254A
Authority: EP
Inventors: Werner Strothoff
Original assignee: Henkel Ecolab GmbH and Co KG
Current assignee: Ecolab GmbH and Co OHG
Priority date: 1998-06-26
Filing date: 1999-06-17
Publication date: 2001-04-11
Also published as: CA2335840A1; DE19828578C2; WO2000000578A1; NO20006624D0; NO20006624L; AU4612499A; JP2002519476A; DE19828578A1; PL344833A1

Abstract

According to the inventive method, a premixed material is initially produced including one or several alcohols (a) and a powdery substance (b) of the group consisting of builder substances, antifoaming agents, surface active agents, salts and their mixtures. Said premixed material is then mixed with concentrated lye that may contain additional detergent active substances by stirring and by simultaneously or subsequently mixing with an inert gas. Normally, air is used as inert gas. The resulting cream products are particularly suitable for cleaning crockery and installations and devices in the food industry but also for washing textiles.

Description

“Process for the production of cream-like alkaline aqueous

Detergents "

The invention described below lies in the field of strongly alkaline cleaning agents, as are used in particular in the commercial sector for cleaning dishes and systems and equipment in the food industry, but also for washing textiles.

Highly alkaline cleaning agents for cleaning hard surfaces and textiles are known in various forms. For example, in the international patent applications WO 96/27653, WO 97/41203 and WO 98/13466 paste-like and block-shaped cleaning agents are described which contain certain alcohols and optionally further cleaning agents in addition to alkali metal hydroxide.

The present invention is based on the task of finding a new form of supply for highly alkaline, aqueous cleaning agents which has advantages over the previously known forms.

The present invention relates to a process for the production of cream-shaped alkaline-aqueous cleaning agents, in which a premix of a) one or more alcohols of the general formula I

R ¹ R ² R ³ COH (I) in which R ¹ and R ² independently of one another represent a hydrogen atom or a linear or branched, saturated or unsaturated, substituted or unsubstituted Ci to C ₃ alkyl group or a - (CH ₂ ) n - CH2-OH group with n = 0 to 5 and R ^{3 is} independently a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted Ci to Cιβ alkyl group or a group - (CH ₂ ) _m NR ⁴ R ⁵ , wherein R ⁴ and R ⁵ independently represent a hydrogen atom or a methyl group or the group - (CH ₂ ) _p -OH or the group - ((CH ₂ ) qO) _r H and m, p, q and r independently of one another have values between 2 and 5 may have, wherein the alcohol or alcohols make up between 0.1 and 30% by weight, preferably between 1 and 15% by weight and in particular between 3 and 8% by weight, based on the finished cleaning agent, and b) one Powdery substance from the group of builder substances, foam inhibitors, surfactants, salts and mixtures thereof in an amount of 2 to 70% by weight, preferably 10 to 60% by weight and in particular 30 to 50% by weight, based on the finished cleaning agent , with concentrated alkali metal hydroxide solution, which may optionally contain further cleaning agents, in an amount of 21 to 70% by weight, preferably 35 to 55% by weight and in particular 45 to 55% by weight, based on the finished cleaning agent, with stirring and simultaneous or subsequent mixing mixed with inert gas. Ordinary air is preferably used as the inert gas.

The new process makes it possible to produce cream-shaped products which, compared to products of the same composition but produced without gas, are distinguished by a lower density and, surprisingly, also by a lower viscosity. The production can therefore easily take place at room temperature. The new products do not harden. They are pumpable and therefore easier to dose and surprisingly dissolve faster in water.

In a particularly preferred embodiment of the new process, the gas is mixed in by stirring so quickly when the components are mixed or subsequently, that gas from the gas atmosphere above it is drawn into the viscous mixture and is evenly distributed there. Non-combustible gases are preferably used as inert gases, for example nitrogen, argon or particularly preferably ordinary air, the low content of carbon dioxide not interfering in the process according to the invention. The proportion of gas in the process is such that its proportion in the finished cleaning agent is between approximately 1 and approximately 35% by volume, preferably between approximately 2 and approximately 25% by volume and in particular between approximately 5 and approximately 15% by volume. The special composition of the other components of the cleaning agent ensures a stable dispersion of the finely divided gas in the cleaning agent.

The alcohols of the formula I used in the process according to the invention are monohydric or polyhydric aliphatic alcohols or amino alcohols. Methanol, ethanol, propanol, isopropanol, ethylene glycol, propylene glycol, butylene glycol, glycerin, ethanolamine, diethanolamine and triethanolamine are preferably used. Of these alcohols, ethylene glycol, propylene glycol and 1,3-butanediol are particularly preferred. Mixtures of several alcohols can of course also be used.

Potassium hydroxide solution, sodium hydroxide solution, mixtures of potassium hydroxide solution and sodium hydroxide solution and in particular sodium hydroxide solution alone are preferably used as the concentrated alkali hydroxide solution. According to the invention, a concentrated alkali hydroxide solution is understood to be one which has an alkali hydroxide content of at least 30% by weight. The alkali hydroxide content in the alkali should preferably be between approximately 30 and approximately 60% by weight, in particular between approximately 42 and approximately 55% by weight.

In the course of the process according to the invention, a premix is first prepared from a) one or more alcohols of the general formula I and b) a pulverulent substance from the group of builders, foam inhibitors, surfactants, salts and mixtures thereof and this then mixed with the concentrated alkali solution. The preparation of the premix from a) and b) is not critical and can be done in different ways. As a rule, the alcohols are sprayed onto the powder with agitation, but in special cases the alcohols of the formula I can also be introduced as a liquid and the powdery solids can be stirred into this liquid one after the other. If desired, liquid nonionic surfactants and / or paraffin oil can also be incorporated into the premix.

The premix of a) and b) can be mixed with the concentrated alkali metal hydroxide solution, for example, by stirring the premixture of a and b into the concentrated alkali metal hydroxide solution. However, it is also possible to stir the alkali solution into the premix. The latter variant has the advantage that it is possible to work in only one batch container. The inert gas can be mixed in with the premix of a) and b) during the mixing of the alkali metal hydroxide solution or subsequently. The entry of the gas during the mixing has the advantage that no excessive viscosities can be built up in the meantime, which make stirring more difficult. If the gas is only mixed in subsequently, this mixing preferably follows immediately after the premixing of a) and b) has been mixed with the alkali metal hydroxide solution in order to prevent the mixture from becoming thicker. The process according to the invention is preferably carried out at temperatures of about room temperature, but in principle it is also possible to work at higher temperatures up to about 65.degree. C., preferably up to about 42.degree. C. and then optionally to cool the cream-like product with stirring.

The entry of the gas into the alkaline cleaning agent can be effected in different ways. It is thus possible to blow the gas into the product through appropriately designed nozzles, with stirring being expediently carried out at the same time in such a way that larger gas bubbles are broken down and the gas is distributed evenly in the product. Another preferred option is the liquid to viscous Stir the detergent mixture so quickly that gas from the gas atmosphere above it is drawn into the viscous mixture and is evenly distributed there. For this variant, anchor stirrers with a scraper have proven particularly useful, possibly also as counter-rotating double agitators.

As a rule, the production process according to the invention is completed with the mixing of the premix from a and b and the concentrated sodium hydroxide solution, which optionally contains further detergent active ingredients, and the uniform mixing in of the inert gas. In special cases, additional components can also be mixed into the cleaning agent after these steps, if this appears expedient. In particular, finely divided solid alkali hydroxide, preferably sodium hydroxide, in amounts of about 1% by weight to about 25% by weight, in particular from about 5% by weight to about 15% by weight, can be subsequently mixed into the cleaning agent without that the creamy basic character of the product is destroyed. However, it is also possible at this point to mix further powdery constituents of the type already mentioned above or, for example, coated chlorine carriers, coated enzymes, coated phosphates and other complexing agents as well as liquid components such as paraffin oil and nonionic surfactants into the cleaning agent.

The pulverulent fractions can be used completely as component b for the preparation of the premix, but it is also possible, as described above, to mix in a part subsequently. This subsequently admixed proportion is preferably not more than about 60% by weight, in particular not more than about 40% by weight, based on the powdery components as a whole.

There now follows a description of the other constituents of the cleaning agents produced according to the invention. Both anionic surfactants and cationic surfactants, amphoteric surfactants and nonionic surfactants can be used as surfactants. Depending on the application, z. B. when cleaning dishes and surfaces weakly foaming surfactants, especially nonionic surfactants, in an amount of up to 10 wt .-%, preferably 1 to 5 wt .-% and particularly preferably 2 to 4 wt .-%. Extremely low-foaming compounds are usually used for automatic dishwashing. These preferably include C ₂ -C ₈ -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 non-foaming non-foaming surfactants known, such as. B. Ci ₂ -Ci ₈ -Alkylpolyethylenglykolpolybutylenglykolether each with up to 8 moles of ethylene oxide and butylene oxide units in the molecule and end-capped alkyl polyalkylene glycol mixed ethers.

If the agents according to the invention are used for machine washing laundry, a higher surfactant content is recommended, which is generally up to 20% by weight, preferably 0.1 to 15, particularly preferably 1 to 10% by weight and extremely preferred 2 to 4 wt .-% can be based on the total agent. In addition to nonionic, cationic and amphoteric surfactants, anionic surfactants from the group of alkylbenzenesulfonates, fatty alcohol sulfates, fatty alcohol ether sulfates and the like are then used. a. known anionic surfactants.

Paraffin oil, which according to the invention can contain up to 10% by weight, means long-chain hydrocarbons which can be branched or not branched. In a preferred embodiment, they are added to the agents produced according to the invention in amounts between 0.1 and 8% by weight, particularly preferably between 0.5 and 3% by weight. The paraffin oil, like liquid nonionic surfactants, can be mixed in at different stages of the process, for example in the premix of a) and b) in the sodium hydroxide solution or in the cream-like product. The builder substance contained in the cleaning agents according to the invention can in principle be any substance which is known in the prior art as a builder suitable in the broadest sense for detergents and cleaning agents. Water-soluble builder substances are preferably used. The coated builder substances known in the prior art can also be used and are even preferred when working with chlorine-containing bleaching agents.

As builder substances come e.g. B. alkali phosphates in question, which may be in the form of their sodium or potassium salts. Examples of these are: tetrasodium 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.

Furthermore, complexing agents are to be mentioned, such as. B. nitrilotriacetate or ethylenediaminetetraacetate. Soda and borax are also among the builder substances in the context of the present invention.

Other possible water-soluble builder components are e.g. B. organic polymers of native or synthetic origin, especially polycarboxylates. For example, polyacrylic acids and copolymers of maleic anhydride and acrylic acid and the sodium salts of these polymer acids are suitable. Commercial products are e.g. B. Sokalan® CP 5 and PA 30 from BASF, Alcosperse® 175 and 177 from Alco, LMW® 45 N and SPO2 ND from Norsohaas. Suitable native polymers include, for example, oxidized starch and polyamino acids such as polyglutamic acid or polyaspartic acid, e.g. B. the companies Cygnus, Bayer, Rohm & Haas, Rhόne-Pouienc or SRCHEM.

Other possible builder components are naturally occurring hydroxy carboxylic acids such as. B. mono-, dihydroxy-succinic acid, α-hydroxypropion- acid, citric acid, gluconic acid, and their salts. Citrates are preferably used in the form of trisodium citrate dihydrate.

Amorphous metasilicates or layered silicates can also be mentioned as builder substances. Crystalline layered silicates are also suitable builders insofar as they are sufficiently stable to alkali; Crystalline layered silicates are sold by Hoechst AG (Germany) under the trade name Na-SKS, e.g. B.

Na-SKS-1 (Na ₂ Si ₂₂ O ₅ xH ₂ O, Kenyaite), Na-SKS-2 (Na ₂ Si ₁₄ O ₂₉ xH ₂ O, magadiite), Na-SKS-3 (Na ₂ Si ₈ O ₁₇ xH ₂ O), Na-SKS-4 (Na ₂ Si ₄ O ₉ xH ₂ O), makatite), Na-SKS-5 (- Na ₂ Si ₂ O ₅ ), Na-SKS-7 (ß-Na ₂ Si ₂ O ₅ , natrosilite), Na-SKS-11 (τ-Na ₂ Si ₂ O ₅ ) and Na-SKS-6 (δ-Na ₂ Si ₂ O ₅ ).

Particularly preferred builder substances are those selected from the group consisting of pentasodium triphosphate, trisodium citrate, nitrilotriacetate, ethylenediaminetetraacetate, soda, alkali silicate and mixtures thereof. The builder content in the agents produced according to the invention can be up to about 60% by weight and is preferably between about 15 and about 45% by weight.

Bleaches customary in washing and cleaning agents can also be present in the agents produced according to the invention, then preferably between 0.5 and 10% by weight and particularly preferably between 1.5 and 10% by weight. These can be selected from the group of oxygen-based bleaches, such as. B sodium perborate also in the form of its hydrates, or sodium percarbonate, or from the group of chlorine-based bleaches, such as N-chloro-p-toluenesulfonamide, trichloroisocyanuric acid, alkali metal dichloroisocyanurate, alkali metal hypochlorites, and alkali metal hypochlorite-releasing agents, with alkali-stable bleaching agent compositions being particularly preferred. These can be both alkali-stable substances or components stabilized by suitable processes, such as surface coating or passivation. Other possible ingredients in the cleaners produced according to the invention are defoamers. These can be used in concentrations between 0.1 and 5% by weight, preferably 0.5 and 3% by weight, if a selected surfactant foams too much under the given circumstances, or have a foam-suppressing effect on foaming food residues in the Dishwasher. Defoamers (foam inhibitors) are understood to mean all foam-suppressing substances known in the prior art, but preferably those based on silicone and paraffin, particularly preferably based on paraffin.

Optional ingredients are other common detergent ingredients, such as. B. neutral salts, such as sodium sulfate, dyes, enzymes in coated form or alkali-stable perfume substances. In principle, abrasive ingredients can be present, but the cleaning agents produced according to the invention are preferably free of them.

Although in addition thickeners such. B. swellable layered silicates of the montmorillonite type, bentonite, kaolin, talc or carboxymethyl cellulose can optionally be used to vary the strength, they are not required to achieve the desired consistency in the process according to the invention, d. H. such thickeners can be dispensed with.

The use of high-melting paraffins or high-melting polyethylene glycols to solidify mixtures is also not necessary here in order to achieve the success according to the invention. However, such agents may also be included. The use of long-chain fatty acids and long-chain fatty acid salts, such as those used in the soap industry (chain lengths between C12 and C18), is also not necessary to achieve the consistency according to the invention. As a rule, however, such substances are not detrimental to the success according to the invention. The production of liquid-crystalline structures for thickening is also not necessary. The cream-shaped products produced according to the invention preferably have viscosities of approximately 20,000 to approximately 150,000 mPas, measured at 20 ° C. using a Brookfield viscometer (5 revolutions per minute, spindle depending on viscosity). The viscosity can be varied within wide limits by the amount of gas introduced and depends only to an astonishing extent on the viscosity of the gas-free basic mixture, which is determined by its composition. A subsequent change in viscosity is possible, for example, by rolling the cream on a roller mill.

The cream-like nature of the products produced according to the invention facilitates their dosing and improves the dissolution rate in water considerably. Low-viscosity representatives of the cleaning agents produced according to the invention, which are able to flow under their own weight, can be offered, for example, in head-up bottles, from which they can be easily removed. Highly viscous products are also suitable for delivery by means of pressure pumps and thus allow easy dosing in appropriate cleaning machines. Dosing from appropriate cartridge dispensers is also possible without any problems.

example

6.75 kg of sodium nitrilotriacetate (powder 92%), 5.7 kg of calcined soda and 0.3 kg of powdered paraffin foam inhibitor were placed in a Lödige ploughshare mixer with a volume of 100 liters and, with the mixer being circulated, 1. Sprayed 5 kg of ethylene glycol. The premix was homogenized by subsequent circulation for a further 3 minutes. The premix was then stirred in portions into sodium hydroxide solution, which was in a 50 liter stirred kettle and was stirred with an anchor stirrer in an air atmosphere (100 revolutions per minute). During the addition, the temperature rose to a little above 30 ° C. After the addition was complete, the mixture was stirred for a further 20 minutes under these conditions and cooled to below 30 ° C. The cream-shaped product was then homogenized on a roller mill with a contact pressure of 29 bar and a gap width of 0.2 mm. The density of the finished product was 1.4. It contained 6.5 percent by volume of air. The viscosity, determined with a Brookfield viscometer at 20 ° C., 5 revolutions per minute with spindle 7, was 120,000 mPas.

Claims

claims

1. A process for the preparation of cream-shaped alkaline-aqueous cleaning agents, in which a premix of a) one or more alcohols of the general formula I

R ¹ R ² R ³ COH (I) in which R ¹ and R ² independently of one another represent a hydrogen atom or a linear or branched, saturated or unsaturated, substituted or unsubstituted Ci to C ₃ alkyl group or a - (CH ₂ ) _n - CH ₂ -OH- group with n = 0 to 5 and R ³ independently of it a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted Ci to C-ι ₈ alkyl group or a group - (CH ₂ ) _m NR ⁴ R ⁵ means in which R ⁴ and R ⁵ independently of one another represent a hydrogen atom or a methyl group or the group - (CH ₂ ) _p -OH or the group - ((CH ₂ ) _q -O) _r H and m , p, q and r can independently have values between 2 and 5, the alcohol (s) accounting for between 0.1 and 30% by weight, based on the finished cleaning agent, and b) a powdery substance from the group of builder substances, foam inhibitors , Surfactants, salts and their mixtures, in a quantity of n 2 to 70% by weight, based on the finished cleaning agent, with concentrated alkali metal hydroxide solution, which may optionally contain further cleaning agents, in an amount of 21 to 70% by weight, based on the finished cleaning agent, with stirring and simultaneous or subsequent Mixing of inert gas mixed.

2. The method according to claim 1, wherein the mixing in of the gas is effected by stirring the remaining components sufficiently quickly under a corresponding gas atmosphere, in particular in air.

3. The method according to any one of claims 1 or 2, wherein the amount of alcohol of formula I is between 1 and 15 wt .-% and preferably between 3 and 8 wt .-%, based on the finished detergent.

4. The method according to any one of claims 1 to 3, wherein the proportion of the powdery constituents (b) is 10 to 60 wt .-% and preferably 30 to 50 wt .-%, based on the finished detergent.

5. The method according to any one of claims 1 to 4, is used in the concentrated alkali solution in an amount of 35 to 55 wt .-% and preferably from 45 to 55 wt .-%, based on the finished detergent, this alkali solution Alkali hydroxide content of preferably 30 to 60 wt .-%, in particular 42 to 55 wt .-%.

6. The method according to any one of claims 1 to 5, in which the amount of inert gas is dimensioned such that its proportion in the finished cleaning agent 1 to 35 vol .-%, preferably 2 to 25 vol .-% and in particular 5 to 15 vol .-%.

7. The method according to any one of claims 1 to 6, in which after mixing the premix from a) and b) with the concentrated alkali solution while introducing gas with further stirring, finely divided solid alkali hydroxide, preferably in amounts of 1 to 25 wt .-% , in particular from 5 to 15% by weight, based on the finished cleaning agent, is mixed in.

8. The method according to any one of claims 1 to 7, in which sodium hydroxide is used as the alkali metal hydroxide solution and optionally as the solid alkali metal hydroxide.

9. The method according to any one of claims 1 to 8, wherein the powdery component b) is selected from the group Na ₂ CO ₃ , sodium nitrilotriacetate, Sodium ethylenediaminetetraacetate, sodium polyphosphates, powdered foam inhibitors and mixtures thereof.

10. Use of a cleaning agent, which is obtainable according to one of claims 1 to 9, for cleaning hard surfaces or textiles.