EP1791938B1 - Clear rinsing agent containing hydrophobically modified polycarboxylates - Google Patents

Abstract

Rinse agent formulations for machine dishwashing, comprising as components: a) 1% to 20% by weight of copolymers of a1) 20% to 80% by weight of at least one monomer from the group consisting of monoethylenically unsaturated C<SUB>3</SUB>-C<SUB>10 </SUB>monocarboxylic or dicarboxylic acids or their anhydrides, a2) 10% to 80% by weight of at least one monomer of the general formula (I) in which R<SUP>1</SUP>, R<SUP>2 </SUP>and R<SUP>3 </SUP>independently of one another are H, CH<SUB>3 </SUB>or C<SUB>2</SUB>H<SUB>5</SUB>, R<SUP>4 </SUP>is a linear, branched or cyclic radical having 1 to 6 carbon atoms or an aromatic radical having 6 to 12 carbon atoms, and a3) 0% to 80% by weight of at least one further monomer, selected from the group consisting of olefins having 10 or more carbon atoms or mixtures thereof and reactive polyisobutenes having on average 12 to 100 carbon atoms, b) 1% to 30% by weight of low-foaming nonionic surfactants, c) 0% to 50% by weight of nonaqueous solvents, d) 0% to 15% by weight of solubilizers, e) 0% to 15% by weight of acidifiers, f) 0% to 10% by weight of one or more further additives such as anionic, cationic, zwitterionic and amphoteric surfactants, dyes, fragrances and corrosion inhibitors; g) water to 100% by weight.

Description

The invention relates to rinse aid for machine dishwashing.

When cleaning dishes in the dishwasher this is freed during the cleaning cycle of dirt, which consists of a variety of food residues, which also contain greasy and oily ingredients. The detached dirt particles and components are pumped during further cleaning in the rinse water of the machine. Before the rinse cycle a large part of the water is exchanged. However, a smaller proportion of the water with the dirt dispersed therein remains in the rinse cycle, and with the additional water introduced, if no ion exchanger is used, new hardness ions are introduced into the machine.

The rinse aid is usually dosed automatically after the main rinse program. Another possibility is that so-called 2-in-1 or 3-in-1 systems are used. Here are the necessary components for the rinse cycle, which are integrated in the cleaner, z. B. in the form of a rinse aid of the detergent tablet, with the detergent formulation already at the beginning of the cleaning cycle in the machine and the necessary components for the rinse cycle are entrained in the rinse cycle.

In the rinse cycle, it is intended to ensure that the water runs off the ware during the drying process, as far as possible and without residues, and that the ware surfaces at the end of the washing program are residue-free and flawlessly shiny.

However, if the dirt residues also entrained in the rinse cycle are not sufficiently dispersed and emulsified, they can settle again on the dishes. This leads to unsightly coatings and film formations on the surfaces. Furthermore, the flow behavior in the final rinse cycle on these surfaces can be adversely affected by the thin deposits of dirt components, so that an increased "spotting" occurs. By this is meant that water does not run off as a film and quickly from the dishes, but leaves behind drops that lead to drying after staining and banding. These stains and stripes may consist of dirt residues. On the other hand, additional dry residues caused by water hardness can occur.

US 5,739,099 discloses rinse aid formulations containing nonionic surfactants, hydrotopes and copolymers of allyl alcohol alkoxylates and acrylic acid.

EP-A 0 851 021 discloses rinse aid formulations containing low foaming nonionic surfactants, hydrotopes, polycarboxylates and phosphate esters. As polycarboxylates, homopolymers or copolymers of acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid are mentioned.

DE-A 195 32 542 discloses rinse aids containing nonionic surfactants, organic carboxylic acids and certain cationic polymers.

DE-U 200 19 913 discloses rinse aids which contain nonionic surfactants, solvents, hydrotopes, acidifiers and copolymers of unsaturated carboxylic acids and sulfonic acid group-containing monomers.

WO-A-02/20708 discloses dishwashing detergent compositions containing a hydrophobically modified polycarboxylic acid.

There is therefore a need for polymers which are able to disperse insoluble salts of water hardness-causing metal ions (calcium ions, magnesium ions) on the one hand, just like a simple dishwashing-type polycarboxylate. In addition, however, the polymers should also be able to effectively disperse or emulsify the usual dirt during dishwashing.

The object of the invention is to provide rinse-aid formulations which give stain-free and coating-free dishes in machine dishwashing.

1. a) 1 bis 20 Gew.-% Copolymere aus
   • a1) 30 bis 70 Gew.-% mindestens eines Monomeren aus der Gruppe bestehend aus Maleinsäure, Maleinsäureanhydrid, Acrylsäure, Methacrylsäure, Fumarsäure, Itaconsäure und citraconsäure.
   • a2) 10 bis 50 Gew.-% mindestens eines Monomeren, ausgewält aus der Grappe bestehend aus Isobuten, Diisobuten, Baten, Penten, Hexen and Styrol, und
   • a3) 5 bis 20 Gew.-% eines weiteren Monomeren, ausgewählt aus der Gruppe bestehend aus 1-Decen, 1-Dodecen, 1-Tetradecen, 1-Hexadecen, 1-Octadecen, 1-Eicosen, 1-Docosen, 1-Tetracosen, 1-Hexacosen und reaktiven Polyisobatenen Mit in Mittel 12 bis 100 Kohlenstoffatomen.
2. b) 1 bis 30 Gew.-%, bevorzugt 5 bis 15 Gew.-% schwach schäumende nichtionische Tenside,
3. c) 0 bis 50 Gew.-%, bevorzugt 5 bis 40 Gew.-% nicht wässrige Lösungsmittel,
4. d) 0 bis 15 Gew.-%, bevorzugt 1 bis 10 Gew.-% Lösungsvermittler,
5. e) 0 bis 15 Gew.-%, bevorzugt 1 bis 10 Gew.-% Acidifizierungsmittel,
6. f) 0 bis 10 Gew.-% ein oder mehrere weitere Zusatzstoffe wie anionische, kationische, zwitterionische und amphotere Tenside, Farbstoffe, Duftstoffe und Korrosionsinhibitoren;
7. g) Wasser zur Ergänzung auf 100 Gew.-%.

The object is achieved by rinse aid formulations for machine dishwashing containing as components:

1. a) 1 to 20 wt .-% copolymers of
   • a1) 30 to 70 wt .-% of at least one monomer from the group consisting of maleic acid, maleic anhydride, acrylic acid, methacrylic acid, fumaric acid, itaconic acid and citraconic acid.
   • a2) 10 to 50 wt .-% of at least one monomer selected from the Grappe consisting of isobutene, diisobutene, Baten, pentene, hexene and styrene, and
   • a3) 5 to 20 wt .-% of a further monomer selected from the group consisting of 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docoses, 1-tetracoses , 1-hexacoses and reactive polyisobatenes having in average 12 to 100 carbon atoms.
2. b) from 1 to 30% by weight, preferably from 5 to 15% by weight, of low-foaming nonionic surfactants,
3. c) 0 to 50% by weight, preferably 5 to 40% by weight, of nonaqueous solvents,
4. d) 0 to 15% by weight, preferably 1 to 10% by weight, of solubilizer,
5. e) 0 to 15% by weight, preferably 1 to 10% by weight, of acidifying agent,
6. f) 0 to 10 wt .-% of one or more other additives such as anionic, cationic, zwitterionic and amphoteric surfactants, dyes, fragrances and corrosion inhibitors;
7. g) water to supplement to 100 wt .-%.

The object is further achieved by the use of copolymers a), as defined above, in dishwashing rinse aids for reducing stain and deposit formation.

It has been found that the hydrophobically modified polycarboxylates used according to the invention significantly improve the rinsing result. This is lower film and Deposit formation as well as an improved execution behavior determined. These are polycarboxylates which additionally contain hydrophobic monomers. While the common polyacrylates, such as polyacrylate homopolymer or maleic-acrylic acid copolymers, also very effectively disperse water hardness, their interaction with the typical soil produced by machine dishwashing is low. The copolymers used according to the invention assist in the dispersion of dirt during machine dishwashing, so that film and deposit formation are reduced. Furthermore, the polymers mentioned support the dispersion of water-insoluble salts, which are contained either in the rinse water or in the food residues. These are, for example, calcium or magnesium carbonates or phosphates.

The rinse aid formulations according to the invention can be used both for household applications and for industrial applications. The composition of the cleaner is irrelevant. Both phosphate-based systems and phosphate-free cleaners can be used in combination with the rinse aid formulations. The rinse aid formulations themselves may also be part of a dishwashing detergent formulation.

Suitable monomers a1) are maleic acid, maleic anhydride, acrylic acid, methacrylic acid, fumaric acid, itaconic acid and citraconic acid. Preferred copolymers a) contain as monomers a1) monomers which are selected from the group consisting of maleic acid, maleic anhydride and acrylic acid.

Suitable monomers a2) are isobutene, diisobutene, butene, pentene, hexene and styrene. Further preferred copolymers a) comprise as monomers a2) monomers which are selected from the group consisting of isobutene, diisobutene (2-methyl-3,3-dimethyl-1-butene) and styrene.

Suitable monomers a3) are 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docoses, 1-tetracoses and 1-hexacoses. Further preferred copolymers a) contain as monomers a3) monomers selected from the group consisting of 1-dodecene, 1-octadecene, C ₂₂ -alpha-olefin, a mixture of C ₂₀ -C ₂₄ -alpha-olefins and polyisobutene with on average 12 to 100 carbon atoms.

Particularly preferred copolymers a) contain both monomers a1), which are selected from maleic acid, maleic anhydride and acrylic acid, as well as monomers a2) which are selected from isobutene, diisobutene and styrene as well as monomers a3), which are selected from the group consisting of 1-dodecene, 1-octadecene, C ₂₂ -alpha-olefin, a mixture of C ₂₀ -C ₂₄ -alpha-olefins and polyisobutene having an average of 12 to 100 carbon atoms. Particular preference is given to copolymers of 30 to 70% by weight of maleic acid and maleic anhydride as monomers a1), 20 to 40% by weight of isobutene as monomers a2) and 5 to 20% by weight of octadecene as monomers a3).

As component b), the rinse aid formulations according to the invention contain weakly foaming nonionic surfactants.

• worin R² ein linearer oder verzweigter Alkylrest mit 8 bis 22 C-Atomen ist,
• R¹ und R³ unabhängig voneinander Wasserstoff oder ein linerarer oder verzweigter Alkylrest mit 1-10 C-Atomen oder H sind, wobei R¹ bevorzugt Methyl ist, und
• p und m unabhängig voneinander 0 bis 300 sind. Bevorzugt ist p = 1-50 und
• m = 0-30.

Suitable nonionic surfactants include the surfactants of the general formula (II)

R ² -O- (CH ₂ CH ₂ O) _p - (CHR ¹ CH ₂ O) _m -R ³ (II)

• wherein R ^{2 is} a linear or branched alkyl radical having 8 to 22 C atoms,
• R ¹ and R ^{3 are} independently hydrogen or a linear or branched alkyl radical having 1-10 C atoms or H, wherein R ^{1 is} preferably methyl, and
• p and m are independently 0 to 300. Preferably, p = 1-50 and
• m = 0-30.

The surfactants of formula (II) may be both random copolymers and block copolymers, preferably block copolymers.

Further, di- and multiblock copolymers composed of ethylene oxide and propylene oxide, are used, for example, under the name Pluronic ^® (BASF Aktiengesellschaft) or Tetronic ^® (BASF Corporation) are commercially available. Furthermore, reaction products of sorbitan esters with ethylene oxide and / or propylene oxide can be used. Also suitable are amine oxides or alkyl glycosides. An overview of suitable nonionic surfactants are the EP-A 851 023 as well as the DE-A 198 19 187 ,

Other suitable nonionic surfactants which can be used beyond this are alkyl glycosides, amine oxides, fatty acid alkanolamides and polyhydroxy fatty acid amides, as described, for example, in US Pat DE-U 200 19 913 are described.

US 4,366,326 ; 4,624,803 ; 4,280,919 ; 4,340,766 ; 3,956,401 ; 5,200,236 ; 5,425,894 and 5,294,365 describe in detail suitable low foaming, nonionic surfactants, which in the rinse aid formulations according to the invention as a component (a) can be used, as well Surfactants Science Series, edited by Martin J. Schick, Nonlonic Surfactants, Vols. 19 and 23 ,

As component c), the rinse aid formulations according to the invention may contain nonaqueous solvents.

Suitable, non-aqueous solvents are mono- or polyhydric alcohols, alkanolamines or glycol ethers, preferably ethanol, n-propanol, i-propanol, 1-butanol, 2-butanol, ethylene glycol, propanediol, butanediol, glycerol, diglycol, propyldiglycol, butyldiglycol, hexylene glycol , Ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, propylene glycol methyl, ethyl or propyl ether, dipropylene glycol methyl ether or ethyl ether, methoxy, ethoxy or butoxy triglycol, 1-butoxyethoxy-2-propanol, 3 Methyl 3-methoxybutanol, propylene glycol t-butyl ether and mixtures of 2 or more of these solvents.

As component d), the rinse aid formulations according to the invention may contain solubilizers (hydrotopes).

Suitable solubilizers are 1 to 5-fold with C ₁ -C ₅ alkyl-substituted benzenesulfonates such as toluene, cumene or xylenesulfonate, dihexylsulfosuccinate and short-chain alkyl sulfates. Suitable solubilizers are in US 3,563,901 and US 4,443,270 described.

As component e), the rinse aid formulations according to the invention may contain acidifying agents.

Suitable acidifying agents are inorganic or organic acids, preferably solid mono-, oligo- or polycarboxylic acids or sulfonic acids, for example citric acid, tartaric acid, succinic acid, malonic acid, adipic acid, maleic acid, fumaric acid, oxalic acid, polyacrylic acid and amidosulfonic acid and mixtures thereof, for example a mixture of succinic acid, glutaric and adipic acid, which is available under the trade name Sokalan ^® DCS from BASF AG.

As component f), the rinse aid formulations according to the invention may comprise further additives such as anionic, cationic, zwitterionic or amphoteric surfactants, dyes, fragrances and corrosion inhibitors.

Suitable anionic surfactants are, for example, sodium or potassium alkyl sulfates, in particular those obtained by sulfation of C ₈ -C ₁₈ -alcohols, such as those obtained from glycerides of tallow or coconut oil. Further examples are sodium and potassium alkylbenzenesulfonates having 9 to 15 C atoms in the alkyl chain, the linear alkylbenzenesulfonates having 11 to 13 C atoms in the alkyl group being particularly preferred.

Further suitable anionic surfactants are alkyl glyceryl ether sulfonates, in particular ethers of higher alcohols, as can be obtained from tallow or coconut oil, sulfonates and sulfates of coconut oil fatty acid monoglycerides, alkylphenol ether sulfates having 1 to 10 ethylene oxide units and 8 to 12 carbon atoms in the Alkyl group, alkyl ether sulfates having 1 to 25 ethylene oxide units and 10 to 20 C atoms in the alkyl group, and α-sulfonated fatty acid esters having 6 to 20 C atoms in the fatty acid alkyl group and 1 to 10 C atoms in the ester group, and 2 Acyloxyalkanesulfonic acids containing 9 to 23 C atoms in the alkyl group and 8 to 20 C atoms in the acyl group.

Particularly preferred anionic surfactants are the alkali metal salts of C ₁₁ -C ₁₃ -alkylbenzenesulfonates, C ₁₂ -C ₁₈ -alkyl sulfates and C ₁₂ -C ₁₈ -alkyl ether sulfates containing 1 to 10 mol of ethylene oxide.

Further suitable anionic surfactants are also the sulfosuccinates, which are monoesters and / or diesters of sulfosuccinic acid with fatty alcohols or ethoxylated fatty alcohols. Preferred sulfosuccinates contain C ₈ -C ₁₈ fatty alcohol radicals. Also suitable as anionic surfactants are soaps, for example the salts of lauric acid, myristic acid, palmitic acid, steararic acid, hydrogenated erucic acid and behenic acid and soap mixtures derived from natural fatty acid mixtures, for example coconut, palm kernel or tallow fatty acid.

The anionic surfactants, including the soaps, may be in the form of their sodium, potassium or ammonium salts and as soluble salts of organic bases, such as mono-, di-triethanolamine, preferably in the form of their sodium or potassium salts, especially in the form of the sodium salts ,

The invention is further illustrated by the following examples.

Examples

To test the rinse effect, the copolymers to be tested were mixed into a rinse aid formulation. The test was carried out under the specified conditions at 3 ° dH and with addition of IKW ballast dirt, according to SÖFW- Journal, 124th year, 14/98, p. 1029 , performed in main and rinse cycle.

The cleaner used was the following formulation: 50% by weight Sodium tripolyphosphate (Na ₃ P ₃ O ₁₀ .6H ₂ O) 27% by weight sodium 3% by weight Sodium disilicate (x Na ₂ O y SiO ₂ ; x / y = 2.65; 80% pure) 6% by weight Sodium percarbonate (Na ₂ CO ₃ 1.5 H ₂ O) 2% by weight Tetraacetylenediamine (TAED) 2% by weight Low-foaming nonionic surfactant based on fatty alcohol alkoxylates 3% by weight Low-foaming nonionic surfactant based on fatty alcohol alkoxylates 5% by weight sodium sulphate 2% by weight Polyacrylic acid sodium salt (M _w 8 000)

The (co) polymer was used in the following rinse aid formulation: 20% by weight Low-foaming nonionic surfactant based on fatty alcohol alkoxylates 10% by weight Hydrotop (cumene sulphonate) 5% by weight isopropanol 4% by weight copolymer 61% by weight water

• Polymer 1: Copolymer aus Maleinsäure und Diisobuten (Gewichtsverhältnis 51:49) mit einem Molekulargewicht von 12 000 g/ mol; (nicht erfindangsgemäss)
• Polymer 2: Copolymer aus Maleinsäureanhydrid, Isobuten und C18-Olefin (Gewichtsverhältnis 65:26:9), Molekulargewicht 3 000 g/mol; (erfindungsgemäss)
• Polymer 3: Copolymer aus Maleinsäure und Isobuten (Gewichtsverhältnis 68:32) mit einem Molekulargewicht von 4000 g/mol; (nicht erfindungsgemäss)

The following copolymers 1-3 were tested.

• Polymer 1: copolymer of maleic acid and diisobutene (weight ratio 51:49) having a molecular weight of 12,000 g / mol; (not according to the invention)
• Polymer 2: copolymer of maleic anhydride, isobutene and C18 olefin (weight ratio 65: 26: 9), molecular weight 3,000 g / mol; (Invention)
• Polymer 3: Copolymer of maleic acid and isobutene (weight ratio 68:32) having a molecular weight of 4000 g / mol; (not according to the invention)

The rinsing tests were carried out under the following conditions: Dishwasher: Miele G 686 SC rinses: 1 rinse 55 ° C normal (without pre-rinse) ware: Knife (WMF table knife Berlin, monobloc); Glasses (Willy cup, 0.3 l); black KS plates, black dessert plates; EMSA Superline - Box (cover PE blue, PP box transparent) Dishwashing liquid: 21 g ballast soil 50 g in the main rinse cycle; 2 g in the rinse cycle Rinse temperature: 65 ° C Rinse-aid: 1 g Water hardness: 3 ° dH (German hardness, corresponding to 53 mg CaCO ₃ / kg water)

At the end of the wash cycle, the door was opened and the dishes were left to dry for 60 minutes with the machine door open. The washware was then evaluated by visual matching in a black painted light box with halogen spot and pinhole using a score scale of 0 (very poor, very strong filming, very spotting, more than 50% of the surface covered with spots) to 4 (very good, no filming, no spots).

The results are summarized in the table below. Table: Washing results Tableware (mean) Plastic (mean) Without polymer 2.4 0.8 Polymer 1 3.3 1.5 Polymer 2 3.4 1.2 Polymer 3 2.7 1.3

Claims (4)

1. The use of mixtures consisting of

   a) 1% to 20% by weight of copolymers of

   a1) 30% to 70% by weight of at least one monomer from the group consisting of maleic acid, maleic anhydride, acrylic acid, methacrylic acid, fumaric acid, itaconic acid and citraconic acid,

   a2) 10% to 50% by weight of at least one monomer, selected from the group consisting of isobutene, diisobutene, butene, pentene, hexene and styrene,

   a3) 5% to 20% by weight of at least one further monomer, selected from the group consisting of 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docosene, 1-tetracosene, 1-hexacosene and reactive polyisobutenes having on average 12 to 100 carbon atoms,

   b) 1% to 30% by weight of low-foaming nonionic surfactants,

   c) 0% to 50% by weight of nonaqueous solvents,

   d) 0% to 15% by weight of solubilizers,

   e) 0% to 15% by weight of acidifiers,

   f) 0% to 10% by weight of one or more further additives such as anionic, cationic, zwitterionic and amphoteric surfactants, dyes, fragrances and corrosion inhibitors,

   g) water to 100% by weight,

   as rinse agent formulations for machine dishwashing.
2. The use according to claim 1, wherein in the copolymer a) the monomers a1) are selected from the group consisting of maleic acid, maleic anhydride and acrylic acid, the monomers a2) are selected from the group consisting of isobutene, diisobutene and styrene, and the monomers a3) are selected from the group consisting of 1-dodecene, 1-octadecene, C₂₂ alpha-olefin, a mixture of C₂₀-C₂₄ alpha-olefins and polyisobutene having on average 12 to 100 carbon atoms.
3. The use of copolymers a) as defined in claim 1 in rinse agents for machine dishwashing for the purpose of reducing spotting and deposition.
4. The use of mixtures as defined in claim 1 as a constituent of detergent formulations for machine dishwashing.