EP0656937A1

EP0656937A1 - Dish-washing products with selected builder system.

Info

Publication number: EP0656937A1
Application number: EP93919136A
Authority: EP
Inventors: Konrad Engelskirchen; Willi Buchmeier; Herbert Fischer; Peter Jeschke
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1992-08-29
Filing date: 1993-08-21
Publication date: 1995-06-14
Anticipated expiration: 2013-08-21
Also published as: CA2143609A1; ES2102055T3; DE59306692D1; DE4228786A1; JPH08500626A; ATE154071T1; EP0656937B1; WO1994005762A1

Abstract

Solid, weakly alkaline, phosphate- and chlorine-free products for dish-washing machines contain organic water-soluble builders, alkali carbonate, oxygen-based bleaching agents, surfactants and if required further usual components. In order to avoid the inconvenient formation of lime deposits in the dish-washing machines used, and in particular on the washed dishes, washing products are disclosed which contain oxidation products of polyglucosanes and/or their soluble salts as builder components.

Description

Dishwashing detergent with selected builder system

The invention relates to a solid dishwashing detergent for the automatic cleaning of dishes.

Agents of the latest phosphate-free generation for the automatic cleaning of dishes contain, in addition to surface-active substances, oxygen-based oxidizing agents and a relatively complex builder combination of alkali carbonates and organic complexing agents. The organic complexing agents used hitherto include organophosphonic acids, hydroxycarboxylic acids, amino carboxylic acids and in particular polymeric polycarboxylic acids, which are often used in combination with low molecular weight polyhydroxy polycarboxylic acids, for example citric acid, or their water-soluble salts. In addition, alkali silicate is usually present as a further builder component. Agents composed in this way frequently, particularly in the case of relatively high water hardness, have the disadvantage of the formation of limescale deposits, both in the dishwasher used and in particular on the cleaned items.

Surprisingly, it has now been found that by using a builder combination which contains certain oxidation products of polyglucosans, it is possible to inhibit the formation of deposits caused by the dishwashing detergent in conjunction with the hardness constituents of the water.

The invention accordingly relates to a solid, lower alkali, phosphate and chlorine-free agent for machine cleaning of dishes, containing organic water-soluble builders, alkali carbonate, bleaching agents based on oxygen, surfactant and, if desired, other conventional constituents, which is characterized in that that it contains oxidation products of polyglucosans and / or their soluble salts as the builder component.

In the context of the present invention, oxidation products of polyglucosans are understood to mean polymers made from monosaccharides which at least partly consist of oxidized anhydroglucose units with one, two or there are three carboxyl groups per unit. These oxidized anhydroglucose units correspond to the constitutional formulas I, II or III:

Extensive knowledge exists for the production of such polysaccharide derivatives by oxidative treatment of, for example, cellulose, starch and dextrins. Reference is made, for example, to Houbeπ-Weyl "Methods of Organic Chemistry", Thieme-Verlag, Stuttgart (1987) Vol. E 20, Macromolecular Substances, here the subchapter "Polysaccharide Derivatives" edited by Dr. K. Engelskirchen, op. Cit. Pp. 2042 ff, in particular pp. 2124 ff (oxidation products of cellulose) and pp. 2166 ff (oxidized starches). Reference should also be made to the publication "Cellulose Chemistry and Its Applications" (1983), John Wiley & Sons, Chichester, GB, in particular TPNevell, "Oxidation of Cellulose" (Chapter 10), the extensive literature cited there, op. Cit Pp. 262 to 265, as well as on the European Pa-. tent applications EP 425 369, EP 455 522 and EP 472 042.

In a nutshell, a large number of oxidation agents are used for the oxidation of polyglucosans. Examples include (air) oxygen, hydrogen peroxide, sodium hypochlorite or bron.it, periodic acid or periodates, lead (IV) acetate, nitrogen dioxide and cerium (IV) salts. These oxidation agents react very different from the anhydroglucose units, cf. for example the formula pictures in Houben-Weyl loc. cit. p. 2124. It is known that when nitrogen dioxide acts on cellulose, the oxidation of the primary alcohol group to the carboxy group is the predominant reaction. The oxidizing agent can be used in gaseous form or dissolved in an inert organic solvent, cf. here also Houben-Weyl op. cit. p. 2125 and the primary literature mentioned there in this context. Starting from the starch, too, largely selective oxidations of the primary alcohol group of the anhydroglucose unit to the carboxy group can be accomplished. The teaching according to the invention is based on this knowledge of the prior art.

For example, monocarboxyl starches with a freely selectable degree of conversion of the primary alcohol groups can be produced by their selective oxidation with nitrogen dioxide at low temperatures even without auxiliary agents, for example solvents or catalysts. The almost quantitative, largely selective implementation of the building blocks of the starch molecule is also possible.

However, such a quantitative implementation is not necessary for the purpose according to the invention of using such natural product derivatives as builders in the agents described. Rather, what is essential is the interaction of the following two parameters: adequate conversion of the primary alcohol groups to carboxy groups and, on the other hand, regulation of the average molecular weight of the natural polyglucosan molecule into adequately degraded sections. The first of these two parameters is likely to have functional significance for the interaction, for example, with the hardness constituents, while the sufficiently restricted average molecular weight of the modified polyglucosan building blocks can be important, among other things, for the sufficient solubility of the builder under conditions of use.

The following applies to these two parameters:

The preferred lower limit for the content of oxidized anhydroglucose units according to formulas I, II and / or III is in the polyglucosan derivatives at about 25 mole%, preferably at least about 35 mole% to 40 mole%. The almost quantitative conversion of one, two or three alcohol groups into carboxy groups is possible, so that the upper limit for the corresponding content of oxidized anhydroglucose units is 95 mol% to about 100 mol%. Corresponding oxidation products which are characterized by contents in the range from about 35 mol% to 80 mol% of oxidized anhydroglucose units can be particularly suitable for practical use, with their content in the range from about 40 mol in an important embodiment -% to 60 mol%.

In particular in the field of starch derivatization in the sense of the invention, it has been found that in the course of the oxidative treatment of the dry starch, which usually contains limited amounts of water, with NO 2 and, if appropriate, the oxidation products are converted into water-soluble salts in addition to the largely selective oxidation of the primary alcohol groups Degradation of the molar mass of the starch molecule takes place to such an extent that the resulting derivatized polyglucosans are particularly suitable as builders and give aqueous solutions with viscosities in the range mentioned above.

The oxidized polyglucosans to be used according to the invention preferably consist on average of at least 15 mol% of oxidized anhydroglucose units of the formula I and have average molecular weights below 15,000.

The builder component in the sense of the definition according to the invention is preferably used in the dishwashing detergents in amounts of 5% by weight to 60% by weight and in particular in the range from 10% by weight to 40% by weight, based in each case on the total weight of the detergents , used. Quantities in the range from 15% by weight to 30% by weight can often be expedient. Both the use in the form of the free carboxylic acid and the neutralized form, in particular the alkali metal salts, are possible. When the free carboxylic acid is used, the alkali metal salts generally form under the conditions of use. The composition of the cleaning agents can otherwise be chosen practically as desired within the scope of known formulations.

Cleaning agents for dishes according to the invention contain, as main constituents, surfactants, the builder component in the sense of the invention, peroxy bleach and the usual other dishwashing detergent constituents, such as enzymes, colorants and fragrances, alkalizing agents, such as soluble alkali silicates, and optionally neutral salts and water.

Among the compounds which serve as bleaching agents and supply H2O2 in water, sodium perborate tetrahydrate (NaBÜ2 ^■ H2O2 ^• 3H2O) and sodium perborate monohydrate (NaBθ2 * H2θ2) are of particular importance. Other bleaching agents that can be used are, for example, peroxycarbonate (Na2CO3 ^• 1.5 H2O2) or peracidic salts of organic acids, such as perbenzoates or salts of diperdodecanedioic acid. Suitable bleach activators for these oxidizing agents are, in particular, the N-acyl or O-acyl compounds which form organic peracids with H2O2, preferably N, N'-tetraacylated diamines such as N, N, N ', N'-tetraacetylethylenediamine. The oxygen content of the dishwashing detergent is preferably about 5% by weight to 15% by weight, in particular in combination with 1% by weight to 10% by weight, in particular 2% by weight to 5 Gew.- a bleach activator.

The total content of surfactants in the compositions is generally between 0.5% by weight and 5% by weight and can preferably be 0.8 to 3% by weight. Usual surfactants for cleaning agents belong to the groups of anionic, nonionic and / or zwitterionic surfactants, preference being given to the use of anionic and / or nonionic surfactants. Suitable anionic surfactants are, in particular, sulfonates and sulfates as well as soaps composed of preferably natural fatty acids or fatty acid mixtures. Cg-13-alkylbenzenesulfonates, olefin sulfonates, esters of alpha-sulfofatty acids or alpha-sulfofatty acid disalts are used, for example, as surfactants of the sulfonate type. Suitable surfactants of the sulfate type are the sulfuric acid monoesters from primary alcohols of natural or synthetic origin, ie from C ^ -IS "^ ⁶ ^^ ³ ^ ⁰ " ⁰ ^ ⁶ "° ^er from Cιo-20" 0 ^χoa ^ ^on ° l ^en ^and those secondary alcohols of these chain length. The sulfuric acid monoesters of the alcohols reacted with 1 to 6 mol of ethylene oxide (EO) are also suitable.

Addition products of preferably 2 to 20 moles of EO to 1 mole of an aliphatic compound having essentially 10 to 20 carbon atoms from the group of alcohols, carboxylic acids, fatty amines, carboxamides and alkanesulfonones are of particular interest as nonionic surfactants. In addition to the water-soluble nonionic surfactants, polyglycol ethers with 2 to 7 ethylene glycol ether residues in the molecule that are not or not completely water-soluble are also important, especially when they are used together with water-soluble nonionic or anionic surfactants. In addition, it is also possible to use alkyl polyglycosides of the general formula R-0- (G) _x as nonionic surfactants, in which R denotes a primary, straight-chain or branched aliphatic radical having 8 to 22, preferably 12 to 18, carbon atoms, G for is a glycose unit with 5 or 6 carbon atoms and the degree of oligomerization x is between 1 and 10.

In a preferred embodiment, the dishwashing detergents of the invention contain no more than 10% by weight of water-soluble organic complexing agents or co-builders from the group of synthetic polymeric polycarboxylates, which are taken to mean the salts of polymerization products of unsaturated carboxylic acids and which include, for example, polyacrylates, polymethacrylates, polymaleinates or copolymers of acrylic acid with maleic acid or maleic anhydride. Such substances are preferably completely absent from the agents according to the invention. In a further preferred embodiment of the agents according to the invention, further complexing agents such as citric acid or alkali citrates and / or the salts of nitrilotriacetic acid are not present, or at most in quantities not exceeding 30% by weight, in particular not exceeding 10% by weight.

The usual alkalizing agents used in solid dishwashing detergents include, in addition to the alkali carbonates, the alkali silicates. Preferred alkali silicates are the sodium silicates, in particular the amorphous sodium silicates, with a Na2O: SiO2 molar ratio of 1: 1.5 to 1: 2.5. Such amorphous alkali silicates are, for example, under the commercial na en Porti] W commercially available. The alkali silicates in the agents according to the invention can be up to 30% by weight, based on the water-free substance. Amorphous sodium silicate contents in the range below 20% by weight, in particular from 5% by weight to 15% by weight, are preferred. Alkali carbonate is preferably present in the inventive agents in amounts of 10% by weight to 60% by weight, in particular 20% by weight to 40% by weight, at least some of the carbonate being hydrogen carbonate, the content of which is then preferably 30% by weight to 50% by weight, based on the total mean, can be replaced.

The previously mentioned other cleaning agent components, which are usually only present in small amounts, can make up in particular up to 20% by weight, preferably 5 to 10% by weight. These small components include, for example, further organic bullder components, foam inhibitors and enzymes of the type of proteases, aylases, lipases and / or cellulases, and water which is not bound as water of crystallization or is associated with the constituents in a similarly solid form. The enzymes can be adsorbed onto carrier substances in a conventional manner and / or embedded in coating substances and are preferably used in amounts of not more than 5% by weight, in particular 2 to 4% by weight. Suitable non-surfactant-like and preferably used foam inhibitors are organopolysiloxanes and their mixtures with microfine, optionally signed silica. The foam-inhibiting use of long-chain soaps is also possible. Mixtures of different foam inhibitors can also be suitable, e.g. those made of silicones and paraffins or waxes. These foam inhibitors are preferably bound to a granular, water-soluble or dispersible carrier substance.

The solid, pourable dishwashing detergents 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.

For the preparation of cleaning agents according to the invention in tablet form, the procedure is preferably such that all the components are in one Mixers are mixed together and the mixture is pressed using conventional tablet presses, for example eccentric presses or rotary presses, with pressures in the range from 200 ^· 10 ⁵ Pa to 1 500 ^• 10 ⁵ Pa. In this way, unbreakable tablets are obtained which, under application conditions, dissolve sufficiently quickly and have flexural strengths of normally more than 150 N. Preferably, a tablet produced in this way 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 manufacture of machine dishwashing agents within the scope of the invention in the form of non-dusting, storage-stable, free-flowing powders and / or granules with high bulk densities in the range of preferably 750 to 1,000 g / l is characterized in that in a first process stage the builder component is mixed with at least a portion of liquid mixture components while increasing the bulk density of this premix and subsequently - if desired after an intermediate drying - the further components of the machine dishwashing detergent are combined with the premix obtained in this way.

In the first stage of the process, the liquid phase used is in particular the surfactant compounds which are liquid under normal conditions - in particular the corresponding nonionic surfactants - and, if desired, further liquid parts of the overall formulation. The fragrances dissolved in carrier liquids and / or limited amounts of water or aqueous solutions of mixture components of the desired dishwashing detergent come into consideration here.

In the first part of the mixing process according to the invention, the builder is generally mixed with at least one further component of the dishwasher detergent with the liquid components. Here, for example, a precursor comes into consideration, in which the builder component in admixture with perborate is acted upon and intimately mixed with the liquid nonionic surfactants and the solution of the fragrances. The remaining components are then added and the entire mixture is worked through and homogenized in the mixing device. The use of additional amounts of liquid, in particular the use of additional water, is usually not necessary here. The mixture of substances obtained is then in the form of a free-flowing, dust-free powder of the desired high bulk densities, approximately in the range from 800 to 900 g / l.

In another embodiment, greater agglomeration with the formation of heavy agglomerate particles is important. In this case, the use of larger amounts of liquid may be expedient or necessary, in which case even larger amounts of the components to be combined can be subjected to the premixing together with the builder component. Here, for example, the builder component can be mixed with alkali carbonate and at least a portion of the finely divided solid alkali silicate and agglomerated in a densifying manner by adding limited amounts of water and / or aqueous alkali silicate solutions. For example, when working in a Lödige ploughshare mixer with a knife ring, heavy granules with bulk densities in the range of up to 950 g / l are obtained in the procedure described in the examples below.

If water is used as auxiliary liquid in such amounts in the course of this granulation process that residual moisture in the finished product exceeds the range of about 4 to 7% by weight, it may be expedient to subject the pre-granules formed to intermediate drying. For this purpose, drying in the fluidized bed is suitable, for example. As a rule, such a drying treatment with product temperatures in the range of about 80 ° C. for a limited period of time - for example 10 to 15 minutes - is sufficient to set the desired residual moisture in the product within the range of about 4 to 7% by weight .

The pre-granules are then mixed with the still missing components of the dishwashing detergent to form the finished product. In all the cases shown here, the mixing time is both in the preliminary stage of the compacting mixture under the influence of liquid components and in the subsequent final mixture with the other components in the range of a few minutes, for example in the range of 1 to 5 minutes.

In a particular embodiment, it can be expedient in the production of fine granules by powdering the surface of the formed to further stabilize and level out the granules. Small amounts of water glass powder or powdered alkali carbonate are particularly suitable for this purpose.

B e i s p i e l e

Example 1: Preparation of the oxidized polyglucosans

275.2 g of potato starch (1.6 ol based on anhydroglucose unit) with a moisture content of approx. 6% by weight were suspended in 825 g of carbon tetrachloride and transferred to a 2 l stirred autoclave. After evacuating the autoclave and flushing with nitrogen, 73.6 g of condensed dinitrogen tetroxide (0.8 mol) were added. The reaction mixture was heated to 50 ° C. within 30 minutes. The internal pressure in the autoclave was 0.5 bar (adjusted with nitrogen). By pressing in oxygen, an internal pressure of 2 bar was maintained within the first hour of the reaction, which was raised to 6 bar within the next hour. After a reaction time of 4.5 hours, no more oxygen was consumed, noticeably from the drop in pressure. The autoclave was cooled to room temperature, decompressed, and 1 l of demineralized water was added to the reaction mixture. The suspension of the oxidation product was filtered through a glass suction filter. The product was first washed with acetone, then with water until the washing liquid had a neutral reaction, dewatered with acetone and dried (70 ° C., vacuum drying cabinet). 256 g of white, powdery polycarboxylate B1 with an acid number of 324 were obtained, corresponding to an average content of about 1 carboxyl group per anhydroglucose unit. The product had a reduced viscosity (* t _re d) ^of 3 ml / g measured on the 2% by weight solution of the sodium salt in 1N aqueous sodium nitrate solution at 20 ° C.

Example 2

The raw materials listed in Table 1 below were mixed in the amounts listed there (% by weight, based in each case on the finished product) in a Lödige mixer with a knife ring. The agents M1 to M6 according to the invention were obtained using the polycarboxylate B1 prepared according to Example 1 and, for comparison, the agents VI and V2 not according to the invention. Table 1: Composition of cleaning agents (% by weight)

a) Trinatriu citrate dihydrate b) Na-Poly (acrylate / maleinate) (Sokalan ( ^R ) CP 5, manufacturer BASF) c) Monohydrate d) Plurafac ( ^R ) LF 403 (manufacturer BASF) e) l: l mixture of protease - (BLAP ( ^R ) 140, manufacturer Biozym) and Ayase granules (Termamyl ( ^R ) 60 T, manufacturer Novo)

Example 3

The cleaning performance of the agents according to Example 2 was tested in a dishwasher (Miele G531; Universal 55 program) at doses of 20 g each in 7 l of water at 16 ° dH in the cleaning cycle (soiling, as in the case of Th. Altenschöpfer, SÖFW 98 (1972) 763-765, described, tea, milk, minced meat, pudding, fat stick, starch, oatmeal). The agents Ml to M6 reported particularly in Entfer¬ voltage of starch and oatmeal stains superior rhyme ^'- performance and showed a cleaning performance comparable to the comparable products VI or V2 with the other soiling.

In a Bosch S 712 dishwasher (doses of 20 g each in 6.2 l water at 16 ° dH, operating temperature 50 ° C), 50 g pumpable soiling (mixture of ketchup, gravy, mustard, potato starch, egg yolk, Milk, margarine) the deposit formation over 10 rinse cycles of the agents according to Example 2 tested. On a scale from 1 (= no deposit) to 10 (= very heavy deposit), the agents M1 to M3 according to the invention achieved the values given in Table 2 below for the formation of deposits in the machine (value A) or the formation of deposits on the wash ware (Porcelain / glass / cutlery; value B). In all cases, these values were significantly better than the values for the comparative product VI. Likewise, the values of the means M4 to M6 were significantly better than the values of the similarly structured comparative product V2.

Table 2: Deposit formation using the cleaning agents

nb: not determined

Claims

P a t e n t a n s r u c h e

1. Solid, lower alkaline, phosphate and chlorine-free agent for the mechanical cleaning of dishes, containing organic water-soluble builders, alkali carbonate, bleaching agents based on oxygen, Ten¬ sid and, if desired, other conventional ingredients, characterized in that it contains oxidation products of polyglucosans and / or their soluble salts as builder components.

2. Composition according to claim 1, characterized in that the oxidation product is a polymer of anhydroglucose units, which at least partially from oxidized anhydroglucose units of the formulas I, II and / or III,

with one, two or three carboxy groups and / or their soluble salts per unit.

3. Composition according to claim 1 or 2, characterized in that the content of oxidized anhydroglucose units according to formulas I, II and / or III in the polyglucosan derivatives at least 25 mol%, in particular at least 35 mol--; and preferably at least 40 moles, the upper limit of the content being about 100 mol%, in particular 95 mol%.

4. Composition according to claim 2 or 3, characterized in that it as a builder oxidation products of polyglucosans, which in statistical

I Agents at least 15 mol% consist of oxidized anhydroglucose units of the formula I and have average molecular weights below 15,000, and / or contains their soluble salts.

Agent according to one of claims 1 to 4, characterized in that it builders based on the selectively oxidized polyglucosans in amounts of 5 wt .-% to 60 wt .-%, in particular 10 wt .-% to 40 wt .-%, be ¬ each based on the total weight of the agent contains.

Agent according to Claim 5, characterized in that it contains no more than 10% by weight of water-soluble organic complexing agents from the group of synthetic polymeric carboxylates and is preferably at least largely free of these.

Agent according to one of claims 1 to 6, characterized in that there are no further complexing agents such as citric acid or alkali citrates and / or the salts of nitrilotriacetic acid or at most in amounts not exceeding 30% by weight, in particular not exceeding 10% by weight, contains.

Agent according to one of claims 1 to 7, characterized in that it

15% by weight to 30% by weight of oxidation products of polyglucosans, 10% by weight to 60% by weight, in particular 20% by weight to 40% by weight of alkali carbonate and / or hydrogen carbonate,

5% by weight to 15% by weight of alkali perborate and / or percarbonate, 2% by weight to 10% by weight, in particular 1% by weight to 5% by weight of bleach activator,

0.5% by weight to 5% by weight, in particular 0.8 to 3% by weight of surfactant, in particular nonionic surfactant, up to 30% by weight, in particular 5% by weight to 20% by weight. % Alkali silicate, not more than 5% by weight, in particular 2% by weight to 4% by weight of enzyme, does not contain more than 5% by weight, in particular 0.5% by weight to 2% by weight, of fragrance.

9. Powder or granular composition according to one of claims 1 to 8, characterized in that it has a bulk density of 750 g / 1 to 1000 g / 1.

10. Tablet-like composition according to one of claims 1 to 8, characterized in that it is obtained by mixing all of its components in a mixer and pressing the mixture by means of a tablet press at compression pressures in the range from 200 ^• 10 ⁵ Pa to 1 500 ^• 10 ⁵ Pa is available.

11. A process for the preparation of agents according to claim 9 in powder and / or granule form with bulk densities in the range from 750 to 1,000 g / 1, characterized in that in a first process sub-stage the builder component with at least a portion of liquid Mi¬ Mixing components mixed with increasing the bulk density, if necessary drives off an excess of moisture and then combined with the other components of the dishwashing detergent.

12. The method according to claim 11, characterized in that as the liquid phase in the first stage of the process, liquid surfactant compounds, in particular corresponding nonionic surfactants, solutions of fragrances in carrier liquids and / or water or aqueous solutions of mixture components, in particular aqueous alkali silicate solutions , inserts.

13. The method according to claim 11 or 12, characterized in that a final powdering and rounding of the granules with powdered alkali silicate and / or alkali carbonate takes place in the course of granulation of the active ingredient mixture.