Rinse-aid formulation

Technical area

The This invention relates to a rinse aid formulation for the dishwasher, which useful is to assist in the wetting performance of the rinse water as well as to deposits from hard water to prevent substrates whereby the spotting and filming of the dried substrate surface is reduced to becomes. More specifically, the present invention relates to inducing compatibility a low foaming, nonionic surfactant with a low molecular weight acid or neutralized poly (meth) acrylic acid to provide a stable, no Phase separating aqueous rinse aid dispersion under acidic conditions, without the aid of a high molecular weight, inducing compatibility Polymers and without the requirement of an additional nonionic surfactant with a high cloud point to build.

background the invention

rinsing aids are in commercial and institutional dishwashers and very often used in household dishwashers. During the rinse cycle is a final rinse with fresh water to the existing prior to the final rinse water and the accompanying detergent and dirt residues thereof to replace. Rinse aid formulations are aqueous solutions, what a low foaming, nonionic surfactant. During the rinse cycle the rinse aid in the fresh water of the last rinse in a concentration injected from about 100 to about 500 ppm. The surfactant in the rinse water reduces the surface tension the rinse water and improves the wetting action of the rinse water on the somewhat hydrophobic Substrate surfaces. Improved wetting reduces the tendency of the rinse water, on the substrate surface to form droplets containing dissolved solids, which at cause dry spots. Accordingly has the surfactant in the rinse aid, the Function, the surface tension while the duration of the draining and to reduce foaming little to Traces of foam on the rinsed To avoid substrate, which on evaporation a residue arise. Although low foaming Surfactants have improved on substrates the wetting performance of the rinse water, they have not completely solved the spotting and streaking problems. It is known that the Adding a low molecular weight neutralized polyelectrolyte, such as polyacrylate, to the rinse water reduce the stain or film or streaks continue can.

It It is known that poly (meth) acrylic acid polymers particularly useful are, since they do not contribute to foam formation and not the low Schmutzentschäumungsaktivität foaming Surfactants influence. It is also known that an important obstacle acrylic acid polymers the use of low molecular weight poly (meth) in rinse aids incompatibility these polymers in aqueous rinse aid formulations, containing low foaming Surfactants is. The combination of such polymers and surfactants in water has a phase separation result. forms on standing for a short period the water containing these polymers and surfactants, two or more layer with different compositions. These Phase separation is of course unsatisfactory because an uneven addition of the desired Components is carried out when the formulation in the dishwasher is injected. For example the formulation may contain too little surfactant contain to provide adequate wetting or too much Surfactant, which excessive foaming to Entails.

The Combination of low molecular weight polyelectrolyte with low foaming Surfactants in detergent formulations is known. discloses a reference the desirability the combination of polyelectrolytes with low foam Surfactants in rinse aid concentrates. However, this reference makes use of a Alkalineutralisierten, high molecular weight polymers required for compatibility of the low lathering nonionic surfactant with a low molecular weight neutralized Poly (meth) acrylic acid brought is to provide a stable, non-phase separating aqueous rinse aid dispersion to build.

The Formulation of a stable rinse aid composition by mixing a low-foaming nonionic surfactant, an acrylic acid polymer having a molecular weight of 1,000 to 250,000, and an additional nonionic surfactant having a cloud point of at least 70 ° C, which serves as a stabilizer, is also known.

It An object of the present invention, an aqueous rinse aid containing a low foaming nonionic Surfactant and a low molecular weight neutralized, partially neutralized or not <?page 3?>neutralized poly (meth) acrylic acid, without the use of a compatibilizing high molecular weight Polymers or a co-surfactant with a high cloud point to formulate. It is a further object of the invention, a stable, aqueous rinse aid dispersion provided that reduces the spotting and filming, while the Abfließwirkung and dripping can be improved.

background of the department

U.S. Patents Nos. 3,563,901 and 4,443,270 disclose hydrotropes such as sodium xylene sulfonate, Cumene and short chain alkyl sulfates, which of increasing cloud point of low foaming Surfactants are used in the formulation of stable aqueous concentrates to enable.

US Patent No. 4,203,858 discloses a low foaming, phosphate-free dishwashing detergent composition, comprising an alkali metal or ammonium carbonate, such as sodium carbonate; a water soluble salt a polyelectrolyte having a molecular weight of about 500 to 4,000; and optionally up to 10 percent by weight of a suds suppressor nonionic surfactant. Typical of the polyelectrolytes are acrylic, methacrylic, Maleic and Itaconsäurepolymere. Homopolymers and copolymers of acrylic and methacrylic acid with a molecular weight range from 504 to 1291 are preferred. The '858 Patent discloses that the main Differences between this composition and previous polyelectrolyte composite Dishwashing compositions the low concentration of polyelectrolyte and the poor Metal ion Sequestrationsvermögen these polyelectrolytes.

Other References which poly acrylic acids, (meth) and their salts in detergent and cleaning applications disclose, include US Patent Nos 3,671,440. 3,853,981; 3,950,260; 3,933,673; 3,922,230 and 4,521,332 a. These References do not disclose the desirability of combining Polyelectrolytes with low foam Surfactants in rinse aid concentrates.

US Patent No. 4,678,596 discloses the use of an alkali-neutralized, high molecular weight polymer for causing the low compatibility lathering nonionic surfactant with a low molecular weight neutralized Poly (meth) acrylic acid, to provide a stable, non-phase separating aqueous rinse aid dispersion to build. Other related thereto references include the European Patent Nos. 245.987 and 308.221 a.

<patcit><text>EP 308.221 B1</text></patcit> disclosed a rinse aid composition, what a low foaming, nonionic surfactant; an acrylic acid polymer having a molecular weight 1000-250000; and an additional nonionic surfactant having a cloud point of at least 70 ° C, which serves as a stabilizer, containing.

All the above references to make (i) the use of a high molecular weight Polymers for effecting compatibility required, or require (ii) an additional nonionic surfactant having a cloud point of at least 70 ° C, to provide a stable, non-phase separating rinse aid provided.

US Patent No. 5,739,099 discloses a rinse aid composition, comprising a mixture of nonionic, cationic, anionic, zwitterionic and amphoteric surfactants, hydrotropes and copolymers of alkylene oxide adducts of allyl alcohol and acrylic acid, which in reducing spotting and filming on dishware is useful.

US Patent No. 5,516,452 discloses a rinse aid composition, which are not ionic, an anionic hydrotrope and a blend of two Surfactants, such as an alcohol alkoxylate and a block copolymer of ethylene oxide and propylene oxide, are used.

<patcit><text>DE 43 16 744</text></patcit> relates to rinse formulations containing low foaming Surfactants, easily biodegradable copolymers, and optionally organic Carboxylic acids, Solubilizers and / or hydrotropes and further additives. These formulations are distinguished by a good biodegradability.

The biodegradable copolymers are formed from monomers selected from the group of: a) monoethylenically unsaturated dicarboxylic acids and / or salts thereof; b) monoethylenically unsaturated monocarboxylic acids and / or salts thereof; Monomers which after polymerization hydroxy groups yield, which are bonded to a carbon chain; and d) optionally, other radically copolymerizable monomers. The only show graphs Copolymer comprises: 35% maleic anhydride, 45% acrylic acid and &lt;?page 4?&gt;20% vinyl acetate.

GB 2,311,537 A relates to a rinse aid composition, which a specific Aminotricarbonsäure or their salts or complexes contains.

<patcit><text>EP 659.971 A1</text></patcit> provides a rinse aid composition prepared containing a Chelatorkomponente selected from Ethylenediaminedisuccinic, ethylenediamine diglutaric acid, 2-Hydroxypropylethylendiamindibernsteinsäure or any salts or complexes thereof.

<patcit><text>EP 659.972 A1</text></patcit> looks a rinse aid composition before containing an organo aminophosphonic or their salts or complexes.

<patcit><text>EP 659.973 A1</text></patcit> provides a rinse aid composition ready containing an organo diphosphonic acid or its salts or complexes.

<patcit><text>EP 851.021 A2</text></patcit> concerns Rinse aid compositions, comprising low-foaming, nonionic surfactants, polycarboxylate and optional hydrotropes and certain phosphate esters or certain Alkyliminodialkanoate.

Summary the invention

The met invention the above requirements by providing a stable, aqueous rinse aid dispersion. According to a Aspect of the present invention, the rinse aid dispersion: (I) a low foaming, nonionic surfactant in a range of 2 to 80 wt .-% the rinse aid dispersion is present; (Ii) a hydrotrope present in a range of 0.5 to 20 Wt .-% of the rinse aid dispersion is present; and (iii) a polyacrylate copolymer formed from at least 50 wt .-% acrylic acid and 50 wt .-% or less of a copolymerizable co-monomers, chosen from lower alkyl (C₂-C₄) Acrylates, methacrylic and lower alkyl (C₂-C₄) methacrylates and amides, in the range of 0.1 to 15 wt .-% of the rinse aid dispersion present. The copolymer has a weight average molecular weight in the range of 1,000 to 50,000 and is not at least 75% neutralized. The rinse aid dispersion has a pH in the range 2 to 6

According to a another aspect of the present invention, the rinse aid: (I) a low foaming, nonionic surfactant in a range of 2 to 80 wt .-% the rinse aid dispersion is present; (Ii) a hydrotrope in a range of 0.5 to 20 wt .-% of the Rinse aid dispersion is present; and (iii) a polyacrylate copolymer formed from at least 50 wt .-% acrylic acid and 50 wt .-% or less of a copolymerizable co-monomers, chosen from lower alkyl (C₂-C₄) Acrylates, methacrylic and lower alkyl (C₂-C₄) methacrylates and amides, in the range of 0.1 to 15 wt .-% of the rinse aid dispersion is present, the copolymer does not neutralize at least 75% is. The rinse aid dispersion has a pH in the range 3 to 5 The hydrotrope is selected from the group consisting of sodium cumene, sodium xylene sulfonate, Sodium toluene, dioctyl, alkylnaphthalene and dihexyl.

Detailed Description of the Invention

In the preferred embodiment the present invention includes the rinse aid dispersion: a (i) low foaming, nonionic surfactant in a range of 2 to 80 wt .-% the rinse aid dispersion is present; (Ii) a hydrotrope present in a range of 0.5 to 20 Wt .-% of the rinse aid dispersion is present; and (iii) a polyacrylate copolymer formed from at least 50 wt .-% acrylic acid and 50 wt .-% or less of a copolymerizable co-monomers, chosen from lower alkyl (C₂-C₄) Acrylates, methacrylic acid and Lower alkyl (C₂-C₄) methacrylates and amides, in the range of 0.1 to 15 wt .-% of the rinse aid dispersion is present, the copolymer does not neutralize at least 75% is. The rest is water. The copolymer has a weight average Molecular weight in the range of 1,000 to 50,000. The rinse aid dispersion has a pH in the range 2 to 6

Nonionic surfactant

The in the rinse aid dispersion useful nonionic surfactant, any known low foaming be non-ionic surfactant which in applications of the machine dishwashing is used. Typical suitable nonionic surfactants include the available following commercially Materials: &lt;?page 5?&gt;Triton R^TM CF-10 (an alkylaryl polyether) and Triton DF-16 (a modified polyalkoxylated alcohol) manufactured by the Rohm and Haas Company; Plurafac LF404^TMWhich is a mixed linear alcohol alkoxylate; and Pluronic L-62 RTM (a polyoxyethylene-polyoxypropylene block copolymer), both manufactured by the BASF Wyandotte Corporation. The inventive rinse aid formulation may be one or a mixture of such low foaming nonionic surfactants contain.

in the essentially can any nonionic surfactants useful for cleaning purposes, be included in the compositions. Exemplary non-limiting Classes of useful nonionic Surfactants are listed below:

(I) Nonionic polyhydroxy fatty acid amide

polyhydroxy, which are suitable for use herein, have the structural formula R₂CONR₁Z wherein: R₁ H, C₁-C₄Hydrocarbyl, 2-hydroxyethyl, 2-hydroxypropyl or a mixture thereof, preferably C₁-C₄Alkyl, more preferably C₁- or C₂Alkyl, most preferably C₁Alkyl (ie, methyl); and R₂ on C₅-C₃₁hydrocarbyl, preferably straight chain C₅-C₁₉Alkyl or alkenyl, more preferably a chain C₉-C₁₇alkyl or alkenyl, most preferably straight chain C₁₁-C₁₇Alkyl or alkenyl, or a mixture thereof; and Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least three hydroxyl groups directly connected to the chain, or an alkoxylated derivative (preferably ethoxylated or propoxylated) . thereof Z preferably will be derived from a reducing sugar in a reductive amination reaction derived; more preferably Z a glycityl.

(Ii) Nonionic condensates of alkylphenols

The Polyethylene, polypropylene, and polybutylene oxide condensates of alkyl phenols are suitable for use herein. In general, the polyethylene oxide condensates are prefers. These compounds include the condensation products of alkyl phenols having an alkyl group containing from about 6 to about 18 carbon atoms, in either a straight chain or branched chain Configuration with the alkylene oxide.

(Iii) Nonionic ethoxylated alcohol surfactant

The Alkyl ethoxylate condensation products of aliphatic alcohols having about 1 to about 25 moles of ethylene oxide are suitable for use herein suitable. The alkyl chain of the aliphatic alcohol can either straight or branched, or primary or secondary contains his and generally 6 to 22 carbon atoms. Particular preference the condensation products of alcohols having an alkyl group containing 8 to 20 carbon atoms with from about 2 moles to about 10 ethylene oxide per mole of alcohol.

(Iv) Nonionic ethoxylated / propoxylated fatty alcohol

The ethoxylated C₆-C₁₈fatty alcohols and the mixed ethoxylated / propoxylated C₆-C₁₈Fatty alcohols are particularly preferred Surfactants for use herein, particularly where water soluble. Preferably the ethoxylated fatty alcohols are the ethoxylated C₁₀-C₁₈fatty alcohols with a degree of ethoxylation from 3 to 50; most preferably they are the ethoxylated C₁₂-C₁₈Fatty alcohols with a degree of ethoxylation from 3 to 40. Preferably the mixed ethoxylated / propoxylated Fatty alcohols have an alkyl chain length from 10 to 18 carbon atoms, a degree of ethoxylation of 3 to 30 and a degree of propoxylation of 1 to 10

(V) Nonionic EO / PO condensates with propylene glycol

The Condensation products of ethylene oxide with a hydrophobic base, formed by the condensation of propylene oxide with propylene glycol, are suitable for use herein. The hydrophobic portion of these Compounds preferably has a molecular weight of about 1500 to about 1800 and exhibits water insolubility. Examples of compounds Close this type certain of the commercially available Pluronic^TMSurfactants one that marketed by BASF will.

(Vi) Nonionic EO condensation products with propylene oxide / ethylene diamine adducts

The Condensation products of ethylene oxide with the product obtained from the reaction of propylene oxide and ethylenediamine are suitable for use useful herein. The hydrophobic moiety of these products&lt;?page 6?&gt;consists has from the reaction product of ethylenediamine and excess propylene oxide, and generally have a molecular weight of from 2,500 to 3,000. Examples For this certain type of nonionic surfactant include the commercially available Tetronic^TMCompounds a, through which BASF sold.

(Vii) Nonionic Alkylpolysaccharide

Suitable Alkylpolysaccharides for use herein are described in US Patent no. 4,565,647, Llenado, issued January 21, 1986. and have a hydrophobic group containing from about 6 to about 30 carbon atoms, preferably about 10 to about 16 carbon atoms, and a hydrophilic Polysaccharide, z. B. a polyglycoside containing about 1.3 to about 10, preferably about 1.3 to about 3, most preferably about 1.3 to about 2.7, saccharide units on. It can be any reducing saccharide containing 5 or 6 carbon atoms are used will; z. B. can the glucosyl, glucose, galactose and galactosyl moieties be substituted. (Optionally the hydrophobic group to the 2-, 3-, 4-positions, etc. bound with a glucose or galactose is obtained as opposed to a glucoside or galactoside.) The intersaccharide can z., between the one position of the additional saccharide units and the 2-, 3-, 4- and / or 6-positions on the preceding saccharide units present.

The Preferred alkylpolyglycosides have the formula: <st32:che xmlns:st32="http://lighthouseip.com/">R²O (C_nH_2nO) t (glycosyl)_x</st32:che>where R² chosen is selected from the group consisting of alkyl, alkylphenyl, hydroxyalkyl, Hydroxyalkylphenyl, and mixtures thereof, wherein the alkyl groups 10 to 18, preferably 12 to 14, carbon atoms; n 2 or 3, preferably about 1.3 to about 3, most preferably about 1.3 to about 2.7. The glycosyl is preferably from glucose derived.

(Viii) Nonionic Fettsäureamidtensid

fatty acid amide, which are suitable for use herein have the formula: <img img-content="cf" img-format="tif" he="12" wi="24" file="00080001.tif" />where R⁶ a Alkyl group having 7-21, preferably 9-17, carbon atoms , and each R⁷ is selected from the group consisting from hydrogen, C₁-C₄alkyl, C₁-C₄hydroxyalkyl and - (C₂H₄O)_xH, wherein x is in the range of 1 to 3rd

The in the present rinse aid dispersion useful Hydrotrope is selected from the group consisting of sodium cumene, sodium xylene sulfonate, Sodium toluene, dioctyl, alkylnaphthalene and dihexyl. Preferably, the hydrotrope Sodium cumene.

polyacrylate

The Polyacrylate copolymer is neutralized to at least 75%. Alternatively, the polyacrylate copolymer is non-neutralized.

Typically the polyacrylate is a copolymer formed from at least 50 wt .-% acrylic acid and 50 wt .-% or less of a copolymerizable co-monomers, chosen from lower alkyl (C₂-C₄) Acrylates, methacrylic and lower alkyl (C₂-C₄) methacrylates and amides, such as acrylamidosulfonic acids including 2-acrylamido-2-methylpropanesulfonic acid (AMPS). The copolymer is a low molecular weight copolymer or an alkali metal or ammonium salt thereof having a weight average Molecular weight range from 2,000 to 40,000.

The low molecular weight acrylic acid containing polymer is a copolymer comprising the essential acrylic acid or acrylic acid salt monomer units includes. copolymers can essentially any suitable other monomer units lock in, including modified acrylic, fumaric, maleic, itaconic, aconitic, mesaconic, Citraconic and methylenemalonic or their salts, maleic anhydride, Acrylamide, alkylene, vinylmethyl ether, styrene and any mixtures . thereof

&lt;?page 7?&gt;

acid

If 0.1-20 Wt .-% of an acid to the rinse aid dispersion are added, any acid can be used, although organic acids more preferred; and the preferred organic acid is Citric acid.

It It has been discovered that even in the absence of a compatibilizing high molecular weight Polymers, but with the addition of a hydrotrope and in acidic conditions, the stable rinse aid dispersion during storage for a reasonable period or under actual use conditions no phase separation through and each component allows effective to reduce spotting and filming and the discharge effect to improve, without the Foam and defoaming affects of the surfactant becomes.

The inventive rinse aid formulation is an aqueous dispersion with a pH 2 to 6 Preferably, the pH ranges 3 to 5

The inventive rinse aid dispersion preferably by stirring the desired amount the surfactant in an aqueous solution of low molecular weight, non-neutralized or only partially neutralized (no more than 25% neutralized) polyacrylate copolymers, followed by the slow addition of the hydrotrope and if necessary of citric acid, to adjust the pH of the dispersion within the desired range set, produced.

The Formulation may also contain other additives, including sequestrants as NTA, EDTA or sodium citrate, and water-miscible solvents such as ethanol, isopropanol and propylene glycol. Ethanol is the preferred Solvent, which desirably in a range from about 0.1 to about 10 wt .-% of the rinse aid dispersion and preferably in a range of about 2 to about 8 wt .-% exists.

In an even more preferred embodiment, the present invention includes the stable rinse aid dispersion: (I) a low foaming, nonionic surfactant in a range of 2 to 60 wt .-% the rinse aid dispersion is present; (Ii) a hydrotrope present in a range of 0.5 to 20 Wt .-% of the rinse aid dispersion is present; and (iii) a at least 75% non-neutralized Polyacrylate copolymer formed from at least 50 wt .-% acrylic acid and 50 wt .-% or less of a copolymerizable co-monomers selected from Lower alkyl (C₂-C₄) Acrylates, methacrylic and lower alkyl (C₂-C₄) methacrylates and amides, in the range of 0.1 to 15 wt .-% of the rinse aid dispersion present. The rinse aid dispersion preferably has a pH within a range 3 to 4 The Hydrotrope is selected from the group consisting of sodium cumene, sodium xylene sulfonate, Sodium toluene, dioctyl, alkylnaphthalene and dihexyl. Preferably, the hydrotrope is sodium cumene. The partially neutralized poly (meth) acrylic acid polymer is a polyacrylate copolymer which is neutralized to about 20%. In the preferred embodiment is the stable aqueous rinse aid dispersion substantially free of a compatibilizing high molecular weight Polymer and also free of an additional nonionic surfactant having a cloud point of at least 70 ° C.

The following examples are intended to illustrate the invention.

example 1

A inventive rinse aid dispersion was prepared as follows from the following composition, wt .-%, were prepared: <tables><table><tgroup cols="2"><colspec colname="1" colwidth="1.01*" /><colspec colname="2" colwidth="1.00*" /><tbody><row><entry colname="1">Low lathering nonionic surfactant</entry><entry colname="2">20.0%</entry></row><row><entry colname="1">Sodium cumene-hydrotrope</entry><entry colname="2">7.0%</entry></row><row><entry colname="1">polyacrylate (20% neutralized)</entry><entry colname="2">4.5%</entry></row><row><entry colname="1">ethanol</entry><entry colname="2">6.0%</entry></row><row><entry colname="1">water</entry><entry colname="2">62.5%</entry></row></tbody></tgroup></table></tables>

example 2

A other inventive rinse aid dispersion was prepared as follows from the following composition&lt;?page 8?&gt;tion, wt .-%, manufactured: <tables><table><tgroup cols="2"><colspec colname="1" colwidth="1*" /><colspec colname="2" colwidth="1*" /><tbody><row><entry colname="1">Low lathering nonionic surfactant</entry><entry colname="2">15.0%</entry></row><row><entry colname="1">Sodium cumene-hydrotrope</entry><entry colname="2">7.0%</entry></row><row><entry colname="1">polyacrylate (20% neutralized)</entry><entry colname="2">5.0%</entry></row><row><entry colname="1">citric acid</entry><entry colname="2">2.5%</entry></row><row><entry colname="1">ethanol</entry><entry colname="2">6.0%</entry></row><row><entry colname="1">water</entry><entry colname="2">64.5%</entry></row></tbody></tgroup></table></tables>

example 3

In another example, a rinse aid dispersion according to the invention by the following process: 15.0 g of a low-foaming, nonionic surfactant (Plurafac LF404^TM) 15.0 g of a 45% active sodium cumene-hydrotrope (45% active SCS), 10.0 g of a 50% active polyacrylate (Acusol 480^TMManufactured by Rohm &amp; Haas), 5.0 g a 50% active citric acid, 6.0 g of ethanol and 49.0 g of deionized water were placed in a beaker added and stirred in succession. The resulting mixture was a clear single-phase dispersion and proved to be stable, with no phase separation occurred, when the obtained mixture in a closed container for a mounted 2-week period undisturbed at a temperature of 50 ° C has been.