EP0706558A1

EP0706558A1 - Dishwasher agents with biodegradable builders

Info

Publication number: EP0706558A1
Application number: EP94918884A
Authority: EP
Inventors: Willi Buchmeier; Hans Andree; Peter Krings; Birgit Burg; Jürgen Härer; Peter Jeschke
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1993-06-28
Filing date: 1994-06-20
Publication date: 1996-04-17
Also published as: HU9503694D0; WO1995000624A1; HUT73203A; CZ344395A3; CA2166277A1; PL312473A1; DE4321429A1

Abstract

The invention concerns low-alkaline agents for use in dishwashing machines, the agents containing builders which are readily biodegradable. These readily biodegradable builders are copolymers synthesized from the monomers of a monoethylenically unsaturated C3-C8 carboxylic acid, a 2-alkylallylsulphonic acid or 2-arylallylsulphonic acid and a carbohydrate, preferably saccharose.

Description

Dishwashing rinse with biodegradable builder component

The invention relates to alkaline dishwashing detergents for the mechanical cleaning of dishes with a biodegradable bath component.

The latest generation of low-alkaline agents for the automatic cleaning of dishes contain not only bleaching agents based on oxygen, surface-active substances and enzymes, but also a combination of water-soluble builders which are derived from complexing agents, e.g. Citrate, from alkali carriers, e.g. Soda, hydrogecarbonate or disilicate, and from dispersants such as e.g. Polycarboxylates exist. Other possible builder components are organophosphonic acids, aminocarboxylic acids or crystalline phyllosilicates; to the phosphates previously used, e.g. Pentanatriu tripolyphi-sphat is largely avoided today for ecological reasons.

The polycarboxylates used in today's dishwashing detergents, e.g. maleate / acrylate copolymers, prevent limescale deposits from accumulating when the residual water hardness is too high in cleaning and clearing agents. rinse cycle; if the rinsing liquor has a high salt load, they also improve the rinse aid effect.

A disadvantage of these polycarboxylates, however, must be considered that they are difficult to biodegrade. There is therefore a need for machine dishwashing detergents which contain biodegradable builder components, but at the same time show the usual performance spectrum of modern dishwashing detergents. Many biodegradable builder components such as Oxidized starch or polyaspartic acid are good dispersants for unusual calcium carbonate, but are poor complexing agents for water hardness.

Surprisingly, it has now been found that certain copolymers which are built up from at least three individual building blocks and are readily biodegradable are eminently suitable as builder components in machine dishwashing detergents.

The invention relates to a low-alkaline agent for mechanical cleaning of dishes, the 1% by weight aqueous solution of which has a pH of 8 to 11.5, preferably 9 to 10.5, containing water-soluble builder components and bleaching agents Oxygen base, characterized in that it contains, as a water-soluble builder component, a copolymer which is composed at least of the monomers of an onoethylenically unsaturated C3-C8 ~ carboxylic acid, a 2-A1-alkylallylsulfonic acid or 2-arylallylsulfonic acid and a carbohydrate .

The dishwashing detergents according to the invention also include those in which the copolymers are partially or wholly by the salts of the copolymers, that is to say those copolymers in which the carboxyl group were partially or completely converted to carboxylate groups, are replaced.

In the simplest case, the copolymers used according to the invention contain two carboxylic acids and / or their salts and a carbohydrate as monomers. The first acidic monomer or its salt is derived from an onoethylenically unsaturated C3-Cg-monocarboxylic acid and preferably from a C3-C4-monocarboxylic acid, in particular from (meth) acrylic acid. The second acidic monomer or its salt is a derivative of an allylsulfonic acid which, in the 2-position, has an alkyl radical, preferably a C 1 -C 6 -alkyl radical, or an aromatic radical which is preferably derived from benzene or benzene derivatives. is substituted. Furthermore, the incorporation of further monomer units into the copoly is not excluded. Preferred copolymers contain 40 to 60% by weight, in particular 45 to 55% by weight of (meth) acrylic acid or (meth) acrylate with particular preference for acrylic acid or acrylate, 10 to 30% by weight. %, preferably 15 to 25% by weight of methallylsulfonic acid or methallylsulfonate, where methallylsulfonic acid or methallylsulfonate can also be partially replaced by a methacrylic acid-polyethylene glycol ester formed by addition of 1 to 10 ethylene oxide units on methacrylic acid, the weight ratio then being between Methacrylic acid polyethylene glycol ester and methallylsulfonic acid or sulfonate is 1:10 to 10: 1, and 15 to 40% by weight, preferably 20 to 40% by weight, of a carbohydrate. This carbohydrate can, for example, be a mono-, di-, oligo- or polysaccharide, mono-, di- or oligosaccharides being preferred. By incorporating this carbohydrate, predetermined breaking points are built into the polymer, which are responsible for the degradability of the polymer. In particular, sucrose is preferred as the carbohydrate. The copolymers used according to the invention can be prepared by any of the known and customary processes. In particular, the monomeric acids are reacted with the carbohydrate, whereupon the acids are then optionally neutralized to give preferably their alkali metal salts, such as the sodium or potassium salts, or ammonium salts or alkanolamine salts, such as the monoethanolamine salt or the triethanolamine salt.

Analogous to the known conventional (co) polymeric polycarboxylic acids or polycarboxylates such as the homo- or copolymeric acrylic acids or acrylates, those copolymers are also preferred which are either completely or at least partially, in particular more than 50%, based on the carboxyl groups present are neutralized. A completely neutralized copolymer is particularly preferred, ie it consists of the salts of the monomeric acids, in particular the sodium or potassium salts of the monomeric acids, and a carbohydrate. The copolymers generally have a relative molecular mass between 1000 and 200000, preferably between 2000 and 50,000 and in particular between 3000 and 10,000. They are preferably used in powdery, spray-dried form. Particularly preferred copolymers are produced by a process which is described in the earlier German patent application P 4221 381.9.

Preferred dishwashing detergents according to the invention contain the copolymer in amounts of 0.5 to 30% by weight, preferably 2 to 20% by weight, furthermore 0.5 to 20% by weight, preferably 5 to 15% by weight, a bleaching agent based on oxygen, in particular alkali perborate and / or percarbonate, and nonionic surfactants in an amount of a maximum of 5% by weight, preferably a maximum of 2% by weight, the agents being free from anionic, cationic or amphoteric surfactants.

In a preferred embodiment, alkali carbonates and / or bicarbonates, in particular the sodium salts, are used as alkali carriers. ze, in an amount of up to 60 wt .-%, preferably 5 to 50 wt .-%, contain.

The dishwashing detergents according to the invention can comprise further water-soluble builder components, such as synthetic polymers, which include the salts of polymerization products of unsaturated carboxylic acids and which include, for example, polyacrylates, polymethacrylates, poly alylates or copolymers of acrylic acid with maleic acid or maleic anhydride Contain amount of 0.5 to 30 wt .-%, preferably 2 to 20 wt .-%. Suitable polyacrylates are, for example, Alcosperse ( ^R ) 102, 104, 106, 404, 406 from Alco, Acrysole ( ^R ) A Nl, LMW 45 N, LMW 10 N from Norsohas, Degapas ( ^R ) from Degussa; Suitable copolymers of polyacrylic acid and maleic acid are, for example, Sokalan ( ^R ) CP 5, SP 7 from BASF, Acrysol ( ^R ) QR 1014 from Norsohaas, Alcosperse ( ^R ) 175 from Alco. In principle, phosphates can also be present, but the dishwashing detergents are preferably free of phosphate-containing builder components.

In the case of the surfactants which can be used in the agents according to the invention, their foaming behavior is decisive. Low-foam connections are preferred because of the mechanical mechanics. These are, a ^'ilem nicht¬ ionic surfactants; the dishwashing agents according to the invention) are therefore preferably free of anionic, cationic or amphoteric surfactants. The content of nonionic surfactants is at most 5% by weight, preferably at most 2% by weight. Addition products of 1 to 20 moles of ethylene oxide (E0) and / or 1 to 20 moles of propylene oxide (PO) with 1 mole of an aliphatic compound having 10 to 20 carbon atoms from the group of alcohols, carboxylic acids, fatty amines, are particularly suitable as nonionic surfactants. Carboxamides and alkanesulfona ide of interest. In addition to the water-soluble nonionic surfactants, it is also important that the water is not or not completely water-soluble glycol ethers with 2 to 7 ethylene glycol ether residues in the molecule, preferably these are used in combination with water-soluble nonionic surfactants. In addition, alkyl polyglycosides of the general formula R-0- (G) _x can also be used 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 represents a glycose unit with 5 or 6 carbon atoms and the degree of oligomerization x is between 1 and 10.

Preferred dishwashing detergents according to the invention also contain complexing agents from the group of di- and honorally functional organic carboxylic acids or their salts, e.g. Nitrilotriacetic acid, but especially citric acid or its salts, in an amount of 0.5 to 60% by weight, preferably 20 to 50% by weight.

The usual alkalizing agents used in low-alkaline machine dishwashing agents include alkali carbonates, bicarbonates and alkali silicates with a molar ratio SiO 2 / M 2 O (M = alkali atom) of 1.5: 1 to 2.5: 1. The agents preferred according to the invention Alkali carbonates and hydrogen carbonates used are the sodium carbonates and hydrogen carbonates, which are contained in the amounts already mentioned above. The use of the highly alkaline metasilicates as alkali carriers is preferably avoided. Instead of the metasilicates, preference is given to alkali silicates, preferably sodium silicates with a SiO 2 Na 2 O molar ratio of 1.5: 1 to 2.5: 1, in amounts of up to 30% by weight, preferably 5 to 20% by weight, based on the entire dishwashing detergent used.

Among the compounds used as oxygen-based bleaches, sodium perborate tetrahydrate (NaBÜ2 ^• H2O2 • 3H2O) has sodium perborate monohydrate (NaBÜ2 ^• H2O2) and peroxycarbonate (a2CÜ3 ^• 1.5 H2O2) special meaning. Further bleaching agents which can be used are, for example, persic acid salts of organic acids, such as perbenzoates or salts of diperdodecanedioic acid. It preferably contains 0.5 to 20% by weight, particularly preferably 5 to 15% by weight, of an oxygen-based bleach, in particular alkali perborates and / or percarbonates. In addition, the addition of small amounts of known bleach stabilizers such as borates or metaborates and metasilicates and magnesium salts, for example magnesium sulfate, can be expedient.

Suitable bleach activators for these oxidizing agents are in particular N-acyl and O-acyl compounds, preferably tetraacylated diamines such as N, N, N ', N'-tetraacetylethylene diamine (TAED). The agents according to the invention contain such conventional bleach activators in an amount of 0.1 to 10% by weight, preferably 1 to 5% by weight. The agents according to the invention are preferably free of active chlorine-releasing agents such as e.g. Trichloroisocyanuric acid.

Enzymes such as proteases, amylases, lipases or cellulases can be used to better remove protein or starch-containing food residues, for example proteases such as BLAP ( ^R ) 140 from Henkel, 0ptimase ( ^R ) -M-440, 0ptimase ( ^R ) -M-330 , 0pticlean ( ^R ) -M-375, Opti- clean ( ^R ) -M-250 from Solvay Enzymes, Maxacal ( ^R ) CX 450,000, Maxapem ( ^R ) from Ibis, Savinase ( ^R ) 4.0 T, 6 , 0 T, 8.0 T from Novo or Experase ( ^R ) T from Ibis; Amylases such as Termamyl ( ^R ) 60 T, 90 T from Novo, Amylase-Lτ ( ^R ) from Solvay Enzymes or Maxamyl ( ^R ) P 5000, CXT 5000 or CXT 2900 from Ibis; Lipases such as Lipolase ( ^R ) 30 T from Novo; Cellulases such as Celluzym ( ^R ) 0.7 T from Novo Nordisk. Enzymes are contained in the agents according to the invention in an amount of 0.1 to 5% by weight, preferably 0.5 to 2% by weight, based on the total dishwashing detergent. To prevent tarnishing of silver cutlery, optional silver protection agents, as described in the older German patent application P 43 15 397.6, in particular water-soluble Mn (II) salts, can be used in an amount of up to 2% by weight, preferably 0.1 to 0.5% by weight.

The dishwashing detergents according to the invention are preferably in the form of pulverulent, granular or tablet-shaped preparations which can be prepared in a conventional manner, for example by mixing, granulating, roller compacting and / or by spray drying. It is also possible for the copolymers used according to the invention to be used in the form of a compound as an additive component to other granular constituents of the dishwashing detergent.

For the preparation of cleaning agents according to the invention in tablet form, the procedure is preferably such that all the constituents are mixed with one another in a mixer and the mixture is produced by means of conventional tablet presses, for example eccentric presses or rotary presses, with pressing pressures in the range from 200 • 10 ^ Pa to 1 500 ^• 10 ^ Pa pressed. In this way, break-resistant tablets are obtained, which nevertheless dissolve sufficiently quickly under application conditions, with bending strengths of normally more than 150 N. A tablet produced in this way preferably has a weight of 15 g to 40 g, in particular 20 g to 30 g, with one pass ¬ knife from 35 mm to 40 mm.

The manufacture of machine dishwashing detergents in the form of non-dusting, storage-stable, free-flowing powders and / or granules with high bulk densities in the range from 800 to 900 g / 1 is characterized in that in a first stage of the process, the builder components are used with at least one portion liquid mixing com- components are mixed while increasing the bulk density of this premix and subsequently - if desired after an intermediate drying - the further components of the dishwasher detergent are combined with the premix obtained in this way.

Since the alkali carbonate content strongly influences the alkalinity of the product, the intermediate drying must be carried out in such a way that the decomposition of the sodium bicarbonate into sodium carbonate is as low as possible (or at least as constant as possible). An additional sodium carbonate portion resulting from the drying would have to be taken into account when formulating the granule formulation. Low drying temperatures not only counteract the sodium bicarbonate disintegration, but also increase the solubility of the granulated cleaning agent during use. It is therefore advantageous for drying to have a supply air temperature which, on the one hand, should be as low as possible to avoid bicarbonate decomposition and, on the other hand, must be as high as necessary in order to obtain a product with good storage properties. A supply air temperature of approximately 80 ° C. is preferred during drying. The granules themselves should not be heated to temperatures above about 60 ° C.

In the first sub-stage of the mixing process, the builder is generally mixed with at least one further component of the dishwashing 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 by the liquid nonionic surfactants and / or the solution of the fragrances and intimately mixed. 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 generally not necessary here. The accumulated material The mixture is then in the form of a free-flowing, dust-free powder of the desired high bulk densities, in the range from 800 to 900 g / l.

The pre-granules are then mixed with the 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 from 1 to 5 minutes.

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

With the automatic dishwashing agents according to the invention, products are available which, in addition to their better biodegradability, are superior to conventional modern dishwashing agents above all with regard to the deposit inhibition and the rinse aid effect on glasses and knife blades.

The following examples are intended to explain the subject of the invention in more detail, but without restricting it thereto. Examples

Granular dishwashing detergents of the following composition (agent A according to the invention and comparative agent B and agent C according to the invention) were produced.

Agent A contained 10% by weight of the copolymer which, according to the disclosure of the older German patent application P 42 21 381.9, consists of 50% by weight of acrylic acid, 33% by weight of sucrose and 17% by weight of 2-methallylsulfonic acid was produced and then completely neutralized.

Comparative Example B contained 10% by weight of an acrylate maleate sold by BASF under the trade name Sokalan ( ^R ) CP5.

Reiniqunqsleistunq

The cleaning performance of agents A and B was tested in a Miele G 531 dishwasher (Universal 65 ° C program) at doses of 30 g each in 7.0 l water at 16 ° dH in the cleaning cycle (soiling as described in "Th . Altenschöpfer, SÖFW, 98 (1972) 763 - 765 ": tea, milk, minced meat, pudding, fat stick, starch, oatmeal).

The agent A according to the invention had a superior cleaning performance compared to the agent B not according to the invention, especially when removing the starch, grease stick and oatmeal stains, and showed one with the other stains - apart from the tea stain comparable cleaning performance.

Belaqsinhibierunq

The formation of deposits on agents A and B was carried out in a Miele G 590 dishwasher (Universal 65 ° C. program) at doses of 20 g each in 7.0 l of water at 16 ° dH with the addition of 50 g of pumpable soiling (Mixture of ketchup, gravy, mustard, potato starch, egg yolk, milk, margarine) tested in the presence of 3.0 ml of a commercial rinse aid over 10 rinse cycles. The rinsing effect ("spotting") was rated on a scale from 1 (= very bad rinsing effect) to 8 (= very good rinsing effect, no water stains). The results of the rinsing effects achieved with agent A according to the invention and comparative agent B on glasses, knife blades and porcelain plates can be found in Table 1. Table 1

Glasses 6

Knife blades 5.5

Porcelain plate 5

It can be seen that agent A according to the invention is superior to comparative agent B above all with regard to the rinse aid effect on glasses and knife blades.

Agent C according to the invention showed cleaning and deposit inhibition performances comparable to agent A according to the invention; due to the presence of MnSÜ4, it showed superior properties, especially with regard to the prevention of tarnishing of silverware.

Claims

claims

1. A low-alkaline agent for machine cleaning of dishes, the 1% by weight aqueous solution of which has a pH of 8 to 11.5, preferably 9 to 10.5, containing water-soluble builder components and oxygen-based bleaching agents characterized in that it contains, as a water-soluble builder component, a copolymer which is composed at least of the monomers of a monoethylenically unsaturated C3-C8 carboxylic acid, a 2-alkylallylsulfonic acid or 2-arylallylsulfonic acid and a carbohydrate.

2. Composition according to claim 1, characterized in that the copolymer is 40 to 60 wt .-%, preferably 45 to 55 wt .-%, of (meth) acrylic acid, preferably acrylic acid, 10 to 30 wt .-% , preferably 15 to 25% by weight, of methallylsulfonic acid, where methallylsulfonic acid can also be partially replaced by a methacrylic acid polyethylene glycol ester formed by the addition of 1 to 10 ethylene oxide units to methacrylic acid, the weight ratio between methacrylic acid polyethylene glycol ester and methallylsulfonic acid then being 1:10 to 10: 1, and 15 to 40 wt .-%, preferably 20 to 40 wt .-%, consists of a carbohydrate, preferably sucrose.

3. Composition according to claim 1 and 2, characterized in that it is 0.5 to 30 wt .-%, preferably 2 to 20 wt .-% copolymer and 0.5 to 20 wt .-%, preferably 5 to 15 wt .-% %, of an oxygen-based bleach, in particular alkali perborate and / or percarbonate, and that it is free of anionic, cationic or amphoteric surfactants and the content of nonionic surfactants is max. 5% by weight, preferably max. 2% by weight, based in each case on the total agent.

4. Composition according to claim 1 to 3, characterized in that it contains up to 60 wt .-%, preferably 5 to 50 wt .-%, alkali carbonate and / or bicarbonate.

5. Composition according to claim 1 to 4, characterized in that there are complexing agents from the group of di- and polyfunctional organic carboxylic acids or their salts, in particular citric acid or their salts, in an amount of 0.5 to 60 % By weight, preferably 20 to 50% by weight, based on the total agent.

6. Composition according to claim 1 to 5, characterized in that it is up to 30 wt .-%, preferably 5 to 20 wt .-%, based on the total agent, alkali silicate with a molar ratio Siθ2 / 2θ (M = alkali atom) of 1.5: 1 to 2.5: 1 contains.

7. Composition according to claim 1 to 6, characterized in that it is free of active chlorine-releasing agents.

8. Composition according to claim 1 to 7, characterized in that it contains enzymes in an amount of 0.1 to 5 wt .-%, preferably 0.5 to 2 wt .-%, based on the total agent.

9. tablet-like composition according to claim 1 to 8, characterized gekenn¬ characterized in that it by mixing all of its constituents in a mixer and pressing the mixture by means of a tablet press at press pressures of 2 • 10? Pa up to 1.5 ^• 10 ^ Pa is available.

10. Powder or granular composition according to claim 1 to 8, da¬ characterized in that it has a bulk density of 750 g / 1 to 1000 g / 1.

11. Use of the agent according to one of claims 1 to 10 for machine cleaning of dishes.