Concentrated liquid rinse aid suitable for dilution and reuse

Abstract

The present application discloses a concentrated liquid rinse aid formulation for automated dishwashing applications, the formulation comprising a surfactant mixture of an ethoxylated propoxylated C12 to C18 linear alcohol, and an ethoxylated C12 to C15 branched alcohol, wherein the minimum amount of the surfactant mixture in the concentrated liquid rinse aid formulation is at least about 30% by weight.

Description

Technical Field

[0001] The present application discloses a concentrated liquid rinse aid formulation for automatic dishwashing applications, the formulation comprising a surfactant mixture of ethoxylated propoxylated C12 to C18 linear alcohols and ethoxylated C12 to C15 branched alcohols, wherein the minimum amount of the surfactant mixture in the concentrated liquid rinse aid formulation is at least about 30% by weight. Background Art

[0002] One of the main concerns from consumers is finding wet dishes when opening the dishwashing door at the end of the dishwashing process. Emptying the load and using a towel to dry each item is an undesirable, time-consuming activity.

[0003] US Patent No. 5,273,677 to Arif discloses rinse aid compositions and rinse aid concentrates comprising an aqueous solution of a low-foaming surfactant, a solubilizing system for the low-foaming surfactant, and an anionic dispersant, see abstract.

[0004] European Patent Application No. 2963100 to Kolb Distribution Ltd discloses a liquid rinse aid composition comprising a blend of two nonionic surfactants, which simultaneously has good rinsing, drying, non-streaking, anti-filming and anti-spotting properties on substrates and also exhibits superior water run-off behavior compared to the prior art, see abstract.

[0005] Another consumer concern is sustainability. Consumers are looking for products that use less plastic and water and produce less CO2.

[0006] There remains a need for rinse aids that address these problems. Summary of the invention

[0007] Disclosed is a concentrated liquid rinse aid formulation comprising a surfactant mixture comprising (a) an ethoxylated propoxylated C 12 -C 18 Straight chain alcohol and (b) ethoxylated C 12 -C 15 Branched chain alcohols, essentially composed of (a) ethoxylated propoxylated C 12 -C 18 Straight chain alcohol and (b) ethoxylated C 12 -C 15 Branched alcohols, or (a) ethoxylated propoxylated C 12 -C 18 Straight chain alcohol and (b) ethoxylated C 12 -C 15The concentrated liquid rinse aid formulation disclosed may include one or more of the following aspects:

[0008] The surfactant mixture consists essentially of (a) ethoxylated propoxylated C 12 To C 18 Straight chain alcohols and (b) ethoxylated C 12 To C 15 Branched alcohol composition;

[0009] The surfactant mixture is composed of (a) ethoxylated propoxylated C 12 To C 18 Straight chain alcohols and (b) ethoxylated C 12 To C 15 Branched alcohol composition;

[0010] The minimum amount of surfactant mixture in the concentrated liquid rinse aid formulation is at least about 40% by weight;

[0011] The minimum amount of surfactant mixture in the concentrated liquid rinse aid formulation is at least 40% by weight;

[0012] The minimum amount of surfactant mixture in the concentrated liquid rinse aid formulation is at least about 50% by weight;

[0013] The minimum amount of surfactant mixture in the concentrated liquid rinse aid formulation is at least 50% by weight;

[0014] The maximum amount of the surfactant mixture in the concentrated liquid rinse aid formulation is less than about 60% by weight;

[0015] The maximum amount of surfactant mixture in the concentrated liquid rinse aid formulation is less than 60% by weight;

[0016] The maximum amount of the surfactant mixture in the concentrated liquid rinse aid formulation is less than about 58% by weight;

[0017] The maximum amount of surfactant mixture in the concentrated liquid rinse aid formulation is less than 58% by weight;

[0018] The maximum amount of the surfactant mixture in the concentrated liquid rinse aid formulation is less than about 55% by weight;

[0019] The maximum amount of surfactant mixture in the concentrated liquid rinse aid formulation is less than 55% by weight;

[0020] The ratio of (b):(a) is from about 1:1 to about 1:2;

[0021] · The ratio of (b):(a) is 1:1 to about 1:2;

[0022] The concentration of (a) in the concentrated liquid rinse aid formulation is from about 25% to about 35% by weight;

[0023] The concentration of (a) in the concentrated liquid rinse aid formulation is 25 wt % to 35 wt %;

[0024] The ethoxylated propoxylated C 12 To C 18 The straight chain alcohol has a cloud point of about 20°C to about 43°C measured in 1% water at 25°C;

[0025] The ethoxylated propoxylated C 12 To C 18 Straight chain alcohols have a cloud point between 20°C and 43°C measured in 1% water at 25°C;

[0026] The ethoxylated propoxylated C 12 To C 18 Straight-chain alcohols are liquids at room temperature and pressure;

[0027] The ethoxylated propoxylated C 12 To C 18 The straight chain alcohol has a dynamic viscosity of less than about 100 cps at room temperature (23°C);

[0028] The ethoxylated propoxylated C 12 To C 18 The linear alcohol has a dynamic viscosity of less than 100 cps at room temperature (23°C);

[0029] The ethoxylated propoxylated C 12 To C 18 The straight chain alcohol is a polyoxyalkylene condensate surfactant; the ethoxylated propoxylated C 12 To C 18 Straight-chain alcohols are the main unbranched fatty alcohols that are alkoxylated;

[0030] The ethoxylated propoxylated C 12 To C 18 The linear alcohols are methyl-ethylene oxide polymers with alkyl ether ethylene oxide block surfactants;

[0031] The ethoxylated propoxylated C 12 To C 18 The straight chain alcohol has the formula (I): R 1 2-CO-[[EO] m –

[0032] [PO] n ] x , where each R 1 Independently C 12 -C 18 alkyl; m is 1-100, preferably 1-50, more preferably 1-29; n is 1-100, preferably 1-50, more preferably 1-29; and x is 1-100, preferably 1-50, more preferably 1-29, and the EO and PO units may be random, alternating, block or grafted;

[0033] The ethoxylated propoxylated C 12 To C 18 The straight chain alcohol has the formula (I): R 1 2-CO-[[EO] m –

[0034] [PO] n ] x , where each R 1 Independently C 12 -C 18 alkyl; m is 1-10; n is 1-10; and

[0035] x is 1-10, and the EO and PO units may be random, alternating, block or grafted; the ethoxylated propoxylated C 12 To C 18 The straight chain alcohol has the formula (II): Z-CH2-CHZ-CH2-

[0036] [OCH2-CHZ-CH2] k -Z, wherein k = 2-29 and each Z is independently OH or R, provided that 4 to 25% of Z are R, wherein R is:

[0037] (a) -OCH2-CHOH-CH2-R', and each R' is independently

[0038] (i) a long chain alkyl group containing 6 to 20 carbon atoms, or

[0039] (ii) polyoxyalkylene glycol ether group -(CH2-CHR"-O) p -R"", wherein each R" is independently H, CH3 or CH2CH3, p=3-20, and R"' is a C1-C6 alkyl group, the average oxygen / carbon atom ratio of the group is not greater than 0.4:1, or

[0040] (b) -O-(CH2-CHR"-O) a-CH2-CHOH-CH2-O-, wherein a=6-40 and R" is as defined above in (a)(ii), wherein -(CH2-CHR"-O) a - The average oxygen:carbon ratio is not more than 0.4:1

[0041] wherein in the same or different units of formula (II), (a) constitutes one R and (b) constitutes two R;

[0042] The ethoxylated propoxylated C 12 To C 18 The straight chain alcohol is a combination of formula (I) and formula (II);

[0043] The ethoxylated propoxylated C 12 To C 18 The linear alcohol is a methyl-ethylene oxide block polymer with a monoisotridecyl ether ethylene oxide surfactant, which is sold by BASF under the trade name Plurafact™ LF-300;

[0044] The ethoxylated C 12 To C 15 Branched chain alcohols are not Guerbet alcohols;

[0045] The ethoxylated C 12 To C 15 The concentration of the branched chain alcohol in the concentrated liquid rinse aid is from about 20% to about 30% by weight;

[0046] The ethoxylated C 12 To C 15 The concentration of the branched alcohol in the concentrated liquid rinse aid is 20% to 30% by weight;

[0047] The ethoxylated C 12 To C 15 Branched chain alcohols have an HLB value of about 10 to about 12;

[0048] The ethoxylated C 12 To C 15 Branched chain alcohols have an HLB value of 10 to 12;

[0049] The ethoxylated C 12 To C 15 The branched chain alcohols have an HLB value of about 11 to about 11.5;

[0050] The ethoxylated C 12 To C 15 Branched chain alcohols have an HLB value of 11 to 11.5;

[0051] The ethoxylated C 12 To C15 Branched chain alcohols have an ethoxylation rating of 4 to 10;

[0052] The ethoxylated C 12 To C 15 Branched chain alcohols are liquids at room temperature and pressure;

[0053] The ethoxylated C 12 To C 15 The branched chain alcohol has a viscosity of less than about 100 cps at room temperature (23°C);

[0054] The ethoxylated C 12 To C 15 The branched alcohol has a viscosity of less than 100 cps at room temperature (23°C);

[0055] The ethoxylated C 12 To C 15 Branched chain alcohols are ethoxylated C 12 To C 15 Isoalcohols;

[0056] The ethoxylated C 12 To C 15 The branched alcohol was ethoxylated isotridecanol;

[0057] The preparation is a single-phase liquid;

[0058] further comprising a hydrotrope;

[0059] The hydrotrope is sodium cumene sulfonate;

[0060] further comprising from about 10% to about 20% by weight of a hydrotrope;

[0061] further comprising 10 to 20 wt % of a hydrotrope;

[0062] · further comprising a material care agent;

[0063] The material care agent is zinc acetate dihydrate, a polymer, BTA or a combination thereof;

[0064] The material care agent is a polymer;

[0065] The polymer is a pH-independent cationic polymer having at least one quaternary group;

[0066] The pH-independent cationic polymer has the formula (III): -(ROR-N+R2X-R-NH-C(=O)-NH-R-N+R2X-)n, wherein each R is independently C1-C4 alkyl, n=1-1000, and X=halogen, preferably Cl;

[0067] The pH-independent cationic polymer is an N,N'-bis[3-(dimethylamino)propyl]-urea polymer of 1,1'-oxybis[2-chloroethane] sold by BASF under the trade name Lugalvan P;

[0068] further comprising from about 0.01 wt % to about 0.1 wt % of a polymer;

[0069] further comprising 0.01 wt % to 0.1 wt % of a polymer;

[0070] further comprising from about 0.03 wt % to about 0.07 wt % of a polymer;

[0071] further comprising 0.03 wt % to 0.07 wt % of a polymer;

[0072] further comprising a pH adjusting agent;

[0073] wherein the pH adjusting agent is citric acid;

[0074] further comprising a preservative;

[0075] The preservative is potassium sorbate, 5-chloro-2-methyl-4-isothiazoline-3-one, 2-methyl-4-isothiazoline-3-one or any combination thereof;

[0076] The preservative is 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one or any combination thereof;

[0077] The concentrated liquid rinse aid is a single-phase liquid;

[0078] The concentrated liquid rinse aid is substantially free of disinfectant;

[0079] The concentrated liquid rinse aid is substantially free of anionic surfactants;

[0080] The concentrated liquid rinse aid is substantially free of percarboxylic acid;

[0081] The concentrated liquid rinse aid is substantially free of bleach;

[0082] The concentrated liquid rinse aid is substantially free of monocarboxylic acids;

[0083] The concentrated liquid rinse aid is substantially free of enzymes;

[0084] The concentrated liquid rinse aid is substantially free of carbonates or bicarbonates;

[0085] The concentrated liquid rinse aid is substantially free of humectants;

[0086] The concentrated liquid rinse aid is substantially free of zinc salts;

[0087] The concentrated liquid rinse aid is substantially free of zinc acetate dihydrate;

[0088] The concentrated liquid rinse aid is substantially free of zinc chloride;

[0089] The concentrated liquid rinse aid is substantially free of alkali metal or alkaline earth metal salts of alkyl diphenyl oxide sulfonic acids; and / or

[0090] - The concentrated liquid rinse aid shows no precipitation after two weeks at 25°C.

[0091] Also disclosed is a diluted liquid rinse aid product comprising one (1) part by volume of the concentrated liquid rinse aid formulation disclosed above and four (4) parts by volume of water. The disclosed diluted liquid rinse aid product may include one or more of the following aspects:

[0092] 50 mL of the concentrated liquid rinse aid formulation produces 62.5 individual 4 mL doses of dilute liquid rinse aid when combined with 200 mL of water; or

[0093] • 80 mL of concentrated liquid rinse aid produces 100 individual 4 mL doses of dilute liquid rinse aid when mixed with 320 mL of water.

[0094] A method of rinsing hard surfaces in an automatic dishwasher is also disclosed. One (1) volume of any of the concentrated liquid rinse aid formulations disclosed above is added to four (4) volumes of tap water to produce a diluted liquid rinse formulation. The rinse aid compartment of the automatic dishwasher is filled with the diluted liquid rinse formulation. The automatic dishwasher is started. The disclosed method may include one or more of the following aspects:

[0095] The hard surface is glass, ceramic, porcelain, plastic, stainless steel, or any combination thereof;

[0096] The hard surface is glass;

[0097] ·The hard surface is porcelain;

[0098] The hard surface is ceramic;

[0099] The hard surface is plastic;

[0100] The hard surface is stainless steel;

[0101] The method provides 0 to 9 drops of water on hard surfaces;

[0102] The method provides fewer water droplets remaining on hard surfaces at the end of the dishwashing cycle compared to the commercial formulations in the Examples;

[0103] The method provides a surface modification of 3.5 or more on a hard surface after 25 repeated dishwashing cycles;

[0104] The method provides less cloudy hard surfaces at the end of the dishwashing cycle compared to the commercial formulations in the Examples;

[0105] - The method provided less spotting at the end of the dishwashing cycle compared to the commercial formulations in the Examples.

[0106] The above-described embodiments are exemplary only. Other embodiments as described herein are within the scope of the disclosed subject matter.

[0107] definition

[0108] As used herein, the terms "a" or "an" mean one or more.

[0109] As used herein, the term "comprising" is inclusive or open-ended and does not exclude any additional elements; the term "consisting of" does not include any additional elements; and the term "consisting essentially of" is intermediate, allowing only additional elements that do not substantially affect the characteristics of the product or process. For example, a surfactant mixture consisting essentially of two nonionic surfactants does not include any additional surfactants, but may further include preservatives, impurities or solvents, such as water, lower C1-C4 alcohols, glycols or glycol ethers.

[0110] As used herein, the terms "about" or "approximately" mean plus or minus 10% of the stated value.

[0111] As used herein, the w / w percentage of an ingredient is based on the weight of the ingredient in grams out of the total weight of the formulation in grams. When an ingredient does not contain close to or equal to 100% active material, two percentages may be provided: one for the weight of the ingredient and the other for the weight of the active ingredient. For example, 37.73 g of sodium cumene sulfonate in water contains about 40% active material, which is equivalent to about 15.09 g of sodium cumene sulfonate in the formulation. This would be expressed as 37.73 g (15.09 g) of sodium cumene sulfonate.

[0112] As used herein, any and all ranges are inclusive of their endpoints. For example, a pH in the range of 10.5-11.2 would include formulations having a pH of 10.5, formulations having a pH of 11.2, and formulations having any pH between 10.5-11.2.

[0113] As used herein, the phrase "substantially free" means a concentration of less than 0.2 g / L, preferably less than 0.1 g / L, more preferably less than 0.05 g / L, and most preferably 0.001 g / L.

[0114] As used herein, the abbreviation EO refers to repeating ethoxy groups, also known as ethylene oxide or ethylene oxide groups, represented by the formula -(O-CH2-CH2)-.

[0115] As used herein, the abbreviation PO refers to repeating propoxy groups, also known as propylene oxide or methyl oxirane groups, represented by the formula -[O-CH(CH3)-CH2]-. DETAILED DESCRIPTION

[0116] The present invention discloses a concentrated liquid rinse aid formulation. The concentrated liquid rinse aid formulation comprises a surfactant mixture, wherein the surfactant mixture comprises (a) an ethoxylated propoxylated C 12 To C 18 Straight chain alcohol and (b) ethoxylated C 12 To C 15 Alternatively, the surfactant mixture consists essentially of (a) ethoxylated propoxylated C 12 To C 18 Straight chain alcohol and (b) ethoxylated C 12 To C 15 In another alternative, the surfactant mixture consists of (a) ethoxylated propoxylated C 12 To C 18 Straight chain alcohol and (b) ethoxylated C 12 To C 15 Branched chain alcohol composition.

[0117] The concentrated liquid rinse aid contains at least about 30% by weight of the surfactant mixture, preferably at least about 40% by weight, and more preferably at least about 50% by weight of the total weight of the concentrated liquid rinse aid formulation. The concentrated liquid rinse aid contains up to less than about 60% by weight, preferably less than about 58% by weight, and more preferably less than about 55% by weight of the surfactant mixture. In other words, the disclosed concentrated liquid rinse aid contains from about 30% by weight to about 60% by weight, preferably from about 40% by weight to about 58% by weight, and more preferably from about 50% by weight to about 55% by weight of the surfactant mixture.

[0118] The concentrated liquid rinse aid contains at least 30 wt %, preferably at least 40 wt %, and more preferably at least 50 wt % of the surfactant mixture, of the total weight of the concentrated liquid rinse aid formulation. The concentrated liquid rinse aid contains at most less than 60 wt %, preferably less than 58 wt %, and more preferably less than 5 wt % of the surfactant mixture. In other words, the disclosed concentrated liquid rinse aid contains from about 30 wt % to 60 wt %, preferably from 40 wt % to 58 wt %, and more preferably from 50 wt % to 55 wt % of the surfactant mixture.

[0119] As shown in the following examples, stability problems occur at this level of nonionic surfactant. Similarly, as shown in U.S. Patent No. 5,273,677, higher concentrations of nonionic surfactants require a solubilizing system to keep them in solution (column 4, lines 45-48 and examples). The applicant believes that the combination of the claimed straight-chain and branched nonionic surfactants provides the molecular geometry required to prevent precipitation in the concentrated liquid rinse aid formulation. The applicant similarly believes that the increased concentration (i.e., the reduction in water content) of the combination of straight-chain nonionic surfactants in the rinse aid disclosed in European published patent application No. 2,963,100 may exhibit similar stability problems as described in the examples and potential foaming problems. The carbon chain length and alkoxylation of each surfactant in the disclosed surfactant blend are selected to provide less foam than the shorter carbon chain nonionic surfactant disclosed in EP2963100. The carbon chain length and alkoxylation of each surfactant are also selected to provide a suitable cloud point, thereby obtaining a transparent concentrated liquid rinse aid.

[0120] The foaming amount increases with the ethoxylated C 12 -C 15 Therefore, although the substitution weight ratio of the two surfactants as shown in Example 1 can be stable and suitable for formulations of different intended uses, the (b) ethoxylated C 12 To C 15 Branched alcohols and (a) ethoxylated propoxylated C 12 To C 18 The weight ratio of the linear alcohol is preferably in the range of about 1:1 to about 1:2, and more preferably in the range of about 1:1 to about 1:1.5. Alternatively, the surfactant mixture (b) ethoxylated C 12 To C 15 Branched alcohols and (a) ethoxylated propoxylated C 12 To C 18 The weight ratio of the linear alcohol is preferably 1:1-1:2, more preferably 1:1-1:1.5.

[0121] Applicants believe that ethoxylated propoxylated C 12 To C 18 Straight chain alcohols and ethoxylated C 12 To C 15 The combination of branched alcohols reduces the surface tension of water more than either surfactant alone. The different sizes and properties of these surfactants can produce a more compact layer of the surfactant mixture on the surface of the substrate, which helps to reduce the surface tension of the water and promote the sheeting effect of the disclosed rinse aid. This theory is confirmed in Example 2, which shows that compared with the individual ethoxylated propoxylated C 12 To C 18 The claimed surfactant mixtures have improved drying index on glass and polypropylene surfaces compared to linear alcohols. These results are surprising compared to the disclosure in paragraph 0036 of European Published Patent Application No. 3,015,540 stating that Plurafac LF 300 exhibits a longer drying time.

[0122] Ethoxylated Propoxylated C 12 To C 18 Straight chain alcohols are polyoxyalkylene condensates. Ethoxylated propoxylated C 12 To C 18 C of straight chain alcohol 12 To C 18 Straight chain fatty alcohols are mainly unbranched. Ethoxylated propoxylated C 12 To C 18 Straight chain alcohols are liquid at room temperature and pressure. 12 To C 18 The linear alcohol has a dynamic viscosity of less than 100 cps as measured by Brookfield LVT at room temperature (23°C). 12 To C 18 The straight chain alcohols have a cloud point of about 20°C to about 43°C, as measured in 1% water at 25°C. Exemplary ethoxylated propoxylated C 12 To C 18 The straight chain alcohol may have the formula (I): R 1 2-CO-[[EO] m –[PO] n ] x ,

[0123] Each R 1 It is C 12 -C 18alkyl; m is 1-100, preferably 1-50, more preferably 1-29; n is 1-100, preferably 1-50, more preferably 1-29; and x is 1-100, preferably 1-50, more preferably 1-29, and the EO and PO units may be random, alternating, block or grafted;

[0124] And / or formula (II): Z-CH2-CHZ-CH2-[OCH2-CHZ-CH2] k -Z,

[0125] wherein k=2-29, and each Z is independently OH or R, provided that 4% to 25% of Z are R, wherein R is:

[0126] (a) -OCH2-CHOH-CH2-R', and each R' is independently

[0127] (i) a long chain alkyl group containing 6 to 20 carbon atoms, or

[0128] (ii) polyoxyalkylene glycol ether group -(CH2-CHR"-O) p -R"", where each R"

[0129] are independently H, CH3 or CH2CH3, p=3-20, and R"' is C1-C6 alkyl,

[0130] The average oxygen / carbon atom ratio of the group is not greater than 0.4:1, or

[0131] (b).-O-(CH2-CHR”-O) a -CH2-CHOH-CH2-O-, wherein a=6-40 and R" is as defined above in (a)(ii), wherein -(CH2-CHR"-O) a -The average oxygen:carbon ratio is not greater than 0.4:1,

[0132] wherein in the same or different units of formula (II), (i) constitutes one R and (ii) constitutes two R. One of ordinary skill in the art will recognize that surfactants are blends of closely related molecules having carbon chain lengths, EO and PO within a defined number range.

[0133] Exemplary ethoxylated propoxylated C suitable for use in the disclosed concentrated liquid rinse aid formulations 12 To C 18Straight chain alcohols include, but are not limited to, methyl-ethylene oxide polymers with alkyl ether ethylene oxide block surfactants. Exemplary methyl-ethylene oxide polymers with alkyl ether ethylene oxide block surfactants include methyl-ethylene oxide polymers with monooctadecyl ether ethylene oxide blocks, methyl-ethylene oxide polymers with hexadecyl ether blocks, and / or methyl-ethylene oxide polymers with monoisotridecyl ether ethylene oxide blocks, available from BASF under the trade name Plurafact TM LF-300 is sold. Preferably, the ethoxylated propoxylated C 12 To C 18 The linear alcohol is a methyl ethylene oxide polymer with a monoisotridecyl ether ethylene oxide block. The viscosity of a batch of Plurafac™ LF-300 measured at 23°C using a Brookfield DV-II with spindle 27 is 0 mPas at 5 RPM, 0-25 mPas at 10 RPM, 25-37 mPas at 20 RPM, 50 mPas at 50 RPM, and 55 mPas at 100 RPM. Ethoxylated Propoxylated C 12 To C 18 The concentration of the straight chain alcohol in the liquid rinse aid formulation is from about 25% to about 35% by weight.

[0134] Ethoxylated C 12 To C 15 Branched chain alcohols are not Guerbet alcohols. Ethoxylated C 12 To C 15 Branched chain alcohols are liquids at room temperature and pressure. As measured by Brookfield LVT at room temperature (23°C), ethoxylated C 12 To C 15 Branched chain alcohols have a dynamic viscosity of less than 100 cps. 12 To C 15 The HLB value of branched alcohols ranges from 10 to 12, preferably from 11 to 11.5. 12 To C 15 The branched chain alcohols have an ethoxylation rating of 4 to 10. Exemplary ethoxylated alcohols suitable for use in the disclosed concentrated liquid rinse aid formulations are: 12 To C 15 Branched chain alcohols include, but are not limited to, ethoxylated C 12 To C 15Isoalcohol, preferably ethoxylated isotridecanol. Ethoxylated isotridecanol with 6 EOs is available from Sasol as Alfonic™ TDA-6 or from BASF as Lutensol™ TO 6. One of ordinary skill in the art will recognize that surfactants are blends of closely related molecules with carbon chain lengths and EOs within a defined number range. A batch of Alfonic was measured at 23°C using a Brookfield DV-II with spindle 27. TM The viscosity of TDA-6 is 0 mPas at 5 RPM and 25-37 mPas at 20 RPM. 12 To C 15 The concentration of the branched chain alcohol in the liquid rinse aid formulation is from about 20% to about 30% by weight.

[0135] The stability of the disclosed concentrated liquid rinse aid formulations can be improved by including a polymer, preferably a pH independent cationic polymer having at least one quaternary group. An exemplary pH independent cationic polymer has the formula (III): -(RORN + R2X-R-NH-C(=O)-NH-RN + R2X-) n ,

[0136] wherein each R is independently a C1-C4 alkyl group, n=1-1000, and X=halogen, preferably Cl. Exemplary pH-independent cationic polymers suitable for use in the disclosed concentrated liquid rinse aid formulations include polyquaternium-2, also known as N,N'-bis[3-(dimethylamino)propyl]-urea polymer with 1,1'-oxybis[2-chloroethane]. Polyquaternium-2 is available from BASF under the trade name Lugalvan P or from Solvay under the trade name Mirapol TM 15 is commercially available. Only a small amount of polymer is required in the formulation. The concentration of the polymer in the disclosed concentrated liquid rinse aid formulation ranges from about 0.03% to about 0.1% by weight, preferably from about 0.04% to about 0.08%. Alternatively, the concentration of the polymer in the disclosed concentrated liquid rinse aid formulation is from 0.03% to 0.1% by weight, preferably from 0.04% to 0.08%.

[0137] The polymer also acts as a material care ingredient, providing glass protection and minimizing corrosion. Alternative material care ingredients can be used in the disclosed concentrated liquid rinse aid formulations without departing from the teachings of this article. For example, the material care ingredient can be selected from a zinc salt, such as zinc chloride or zinc acetate; a cationic polymer; benzotriazole (BTA); or any combination thereof. As disclosed in the following examples, 1.2 wt % zinc acetate dihydrate appears to affect the stability of the disclosed concentrated liquid rinse aid formulation. Therefore, the disclosed concentrated liquid rinse aid formulation can be formulated with 0 wt % zinc salt, such as zinc chloride or zinc acetate dihydrate. Alternatively, further evaluation may reveal that lower concentrations of zinc salts or mixtures of zinc salts with other material care ingredients may not affect the stability of the disclosed concentrated liquid rinse aid formulation. For example, the disclosed concentrated liquid rinse aid formulation may contain about 0.1 wt % to about 0.75 wt % zinc salt, preferably about 0.1 wt % to about 0.5 wt %, more preferably about 0.1 wt % to about 0.25 wt %. In another example, the disclosed concentrated liquid rinse aid formulation may include 0.1 wt % to 0.75 wt % of a zinc salt, preferably 0.1 wt % to 0.5 wt %, more preferably 0.1 wt % to 0.25 wt %.

[0138] The disclosed concentrated liquid rinse aid formulation may further include a hydrotrope. Hydrotropes are similar to surfactants in that they have a hydrophilic portion and a hydrophobic portion. However, the hydrophobic portion of a hydrotrope is too small to cause spontaneous self-aggregation associated with a surfactant. As a result, hydrotropes do not exhibit a critical micelle concentration (cmc) or a critical vesicle concentration (csc) associated with surfactant activity. Exemplary hydrotropes include urea, toluenesulfonate, cumenesulfonate, and xylenesulfonate. Preferably, the hydrotrope is sodium cumenesulfonate or sodium xylenesulfonate. The disclosed concentrated liquid rinse aid formulation contains about 10% by weight to about 20% by weight of a hydrotrope, preferably about 12% by weight to about 18% by weight, more preferably about 14% by weight to about 16% by weight. Alternatively, the disclosed concentrated liquid rinse aid formulation contains 10% by weight to 20% by weight of a hydrotrope, preferably 12% by weight to 18% by weight, more preferably 14% by weight to 16% by weight.

[0139] The disclosed concentrated liquid rinse aid formulation may further include a pH adjuster to maintain the pH of the formulation between about 2 and about 4, preferably between 2 and 4, more preferably between about 2.5 and about 3.5, and most preferably between 2.5 and 3.5. Exemplary pH adjusters include acids such as HCl, H2SO4, citric acid, lactic acid, sorbic acid, acetic acid, boric acid, formic acid, maleic acid, adipic acid, malic acid, malonic acid, glycolic acid, and mixtures thereof. Preferably, the pH adjuster has a pKa of about 3, such as acetic acid, ascorbic acid, benzoic acid, citric acid or formic acid. Alternatively, the pH adjuster can be a buffer such as citric acid and Na2HPO4, citric acid and sodium citrate, sodium acetate and acetic acid, or a combination thereof. Preferably, a small amount (e.g., 5-6 wt%) of citric acid is used as a pH adjuster because higher amounts produce spots on glass. Because the pH of the formulation is low, the disclosed concentrated liquid rinse aid formulation is substantially free of any carbonate or bicarbonate that increases the pH of the formulation. Additionally, carbonates / bicarbonates may react with the pH adjuster to form gas bubbles, which is undesirable.

[0140] The disclosed concentrated liquid rinse aid formulation may further include a preservative. Exemplary preservatives include sodium benzoate, sodium formate, benzyl alcohol, formic acid, potassium sorbate, isothiazolinones such as 5-chloro-2-methyl-4-isothiazoline-3-one and / or 2-methyl-4-isothiazoline-3-one, or any combination thereof. The combination of 5-chloro-2-methyl-4-isothiazoline-3-one and / or 2-methyl-4-isothiazoline-3-one is more effective at the acidic pH of the disclosed concentrated liquid rinse aid formulation.

[0141] The disclosed concentrated liquid rinse aid formulation is a clear single-phase solution. The synthesis of a single-phase solution is faster and easier than the synthesis of an emulsion or suspension. The stability of a single-phase solution is also easier to maintain than alternative liquid formulations. Mixing of the liquid rinse aid formulation with water occurs faster than mixing of a concentrated powder or tablet formulation.

[0142] The disclosed concentrated liquid rinse aid formulations are substantially free of any disinfectants. One of ordinary skill in the art will recognize that the dishwashing detergents and the temperature of the dishwashing process eliminate the need for any further sanitization or whitening during the rinse cycle. Thus, the disclosed concentrated liquid rinse aid formulations are substantially free of bleaching agents such as hydrogen peroxide, percarboxylic acids, TAED or manganese salt catalysts.

[0143] Similarly, because the disclosed concentrated liquid rinse aid formulations are used during the rinse cycle, the disclosed concentrated liquid rinse aid formulations are substantially free of enzymes or monocarboxylic acids that are used to break down organic molecules and loosen particles from dishes.

[0144] The disclosed concentrated liquid rinse aid formulation can be prepared by adding the solid materials to the liquid hydrotrope under mixing until dissolved. The liquid preservative and polymer are then added sequentially to the mixed formulation and blended until uniform. The nonionic surfactant is then added sequentially to the mixed formulation and mixed until uniform, preferably with the larger amount of material added before the smaller amount of material. Applicants have also noted that when the ethoxylated C 12 -C 15 Branched alcohols are preceded by the addition of ethoxylated propoxylated C 12 -C 18 The formulation remains clear when a straight chain alcohol is added. However, the reverse order may also be used without departing from the teachings herein, as the formulation eventually regains clarity after mixing. Finally, the dye is added and mixed until uniform. Throughout the mixing process, the speed of mixing should be controlled to produce a uniform solution while preventing foaming. One of ordinary skill in the art will recognize that the size of the mixing tank and paddles will determine the desired mixing speed. Similarly, heating may be used to help reduce mixing times, preferably between about 25°C and about 40°C.

[0145] The disclosed concentrated liquid rinse aid formulation can be used for rinsing hard surfaces in an automatic dishwasher. One (1) volume of the concentrated liquid rinse aid formulation is added to four (4) volumes of tap water to produce a diluted liquid rinse formulation. Since the concentrated liquid rinse aid formulation is substantially free of any charged surfactants, such as cationic or anionic surfactants, the hardness of the water has little effect on the performance of the resulting diluted liquid rinse formulation. The rinse aid compartment of the automatic dishwasher is filled with the diluted liquid rinse formulation and started. The rinsing method can be used on hard surfaces such as glass, porcelain, ceramic, plastic, stainless steel, any other cutlery or tableware material and combinations thereof.

[0146] The disclosed concentrated liquid rinse aid formulation uses a smaller package than a standard rinse aid, resulting in less plastic use and cheaper shipping costs. Preferably, the disclosed concentrated liquid rinse aid formulation is transported in a container suitable for cooperating with the threaded neck of a bottle. The bottle may include a fill line indicating the amount of water required to dilute the disclosed concentrated liquid rinse aid formulation. Water is added to the fill line, and then the container is screwed onto the threaded neck of the bottle. In a preferred embodiment, the container includes a sealing mechanism that releases the contents of the bottle after the container and the bottle cooperate, thereby allowing the disclosed concentrated liquid rinse aid formulation to be easily transferred. Exemplary containers include those described in U.S. Patent No. 11,198,546 or U.S. Patent Application No. 2022 / 0002045 of BNOVASA, the contents of which are incorporated herein by reference in their entirety. Alternatively, the container may include a dispensing nozzle that allows the disclosed concentrated liquid rinse aid to be transferred from its packaging container to a bottle suitable for dilution. In another alternative, the container may include a standard cap.

[0147] The disclosed concentrated liquid rinse aid formulation also provides more doses of rinse aid than conventional liquid rinse aid packaging. Consumers can use a compact starting material to obtain the same or better builder performance, which is highly efficient, can be diluted in a ratio of 1:4, and has better stain removal and drying performance than existing formulations. For example, when mixed with 200mL of water, 50mL of concentrated liquid rinse aid formulation produces 62.5 separate 4mL doses of diluted liquid rinse aid, and when mixed with 320mL of water, 80mL of concentrated liquid rinse aid produces 100 separate 4mL doses of diluted liquid rinse aid. When the diluted liquid rinse aid product is used in the rinse cycle of the dishwasher, the hard surface has 00 to 9 drops of water. Compared with the commercially available formulations in the examples, this is less water droplets retained on the hard surface at the end of the dishwashing cycle. When the diluted liquid rinse aid product is used in the rinse cycle of the dishwasher, the hard surface has a surface modification of 3.5 or more after 25 repeated dishwashing cycles. When the diluted liquid rinse aid product was used in the rinse cycle of a dishwasher, hard surfaces had less spotting and less cloudiness at the end of the dishwashing cycle compared to the commercial formulations in the Examples.

[0148] The following examples illustrate exemplary embodiments of the present invention. It should be understood that these examples are provided by way of illustration only and that additional embodiments may be generated based on the teachings of the present invention.

[0149] Example

[0150] The formulations in the following examples were prepared using the ingredients identified in Table A:

[0151] Table A:

[0152]

[0153] Comparative Example 1:

[0154] Initial testing was performed using the applicant's current commercial formulation as a starting point. The applicant hopes that removing water from the commercial formulation will provide a concentrated and eco-friendly solution. Unfortunately, the formulation A shown in the following table 1a precipitates after three (3) days at 40°C and 50°C. In the formulations B to L in the following tables 1a and 1b, additional and alternative solvents were included in an attempt to keep the precipitate in solution without success. Formulations B to L also show precipitation over time. Alternative nonionic surfactants were also tested separately in formulation O or in formulations M and N in combination with existing nonionic surfactants, but concentrated formulations do not remain stable. Those of ordinary skill in the art will recognize that liquid crystal formation can occur under such high nonionic surfactant concentration levels.

[0155] Table 1a:

[0156]

[0157] *0.08% CIT / MIT raw material = 0.0024% CIT and 0.0008% MIT active level

[0158] Table 1b:

[0159]

[0160] *0.08% CIT / MIT raw material = 0.0024% CIT and 0.0008% MIT active level

[0161] Comparative Example 2:

[0162] Instead of a concentrated liquid rinse aid, applicants have also considered formulating a tablet rinse aid. However, the concentrations required to achieve the desired results are not commercially viable because the tablet size required is too large. Current liquid rinse aid dispensing bottles have a 1.5 cm neck opening. A 250 mL rinse aid bottle with this 1.5 cm neck opening would require two (2) 14.1 cm long x 1.5 cm wide x 1.5 cm deep tablets. The same 250 mL rinse aid bottle would require eight (8) 3.55 cm long x 1.5 cm wide x 1.5 cm deep tablets. The same 250 mL rinse aid bottle would require 29 balls with a 1.5 cm diameter. Increasing the size of the neck opening in order to make larger tablets would result in the use of more plastic in the bottle, which would defeat the eco-friendly goal of the present invention. These tablets would also take time to dissolve. Therefore, the disclosed concentrated rinse aid formulations must be provided in liquid form.

[0163] Example 1: (1) Stability

[0164] The following exemplary formulations were prepared and stability tested at 5°C and 50% relative humidity (RH), uncontrolled room temperature, 40°C and 75% RH, and / or 50°C and uncontrolled humidity for six (6) weeks or less if a problem was detected. None of the formulations showed any precipitation.

[0165] An exemplary formulation was prepared by sequentially adding KS and CA to SCS under mixing until dissolved. CIT / MIT and LP were then sequentially added to the mixed formulation and blended until uniform. LF300 and TDA6 were then sequentially added to the mixed formulation and blended until uniform. Finally, D was added and mixed until uniform. Throughout the mixing process, the speed of mixing was controlled to produce a uniform solution while preventing foaming.

[0166] As shown in the examples below, the formulations provide improved results compared to commercial formulations and test formulations containing a single nonionic surfactant.

[0167] Table 2:

[0168]

[0169] *0.08% CIT / MIT raw material = 0.0024% CIT and 0.0008% MIT active level

[0170] Example 2: Drying performance test of dishwasher

[0171] The drying performance test was performed using formulations Q and T from Table 2 above, compared to the formulations provided in Table 3 below. U is a commercially available rinse aid. 80 mL of V was diluted with 320 mL of tap water to produce 400 mL of diluted liquid rinse aid product. 4 mL of the diluted liquid rinse aid product was added to the rinse aid chamber of the dishwasher for the drying performance test.

[0172] Table 3:

[0173]

[0174] For this purpose, a machine load consisting of glass, stainless steel, porcelain and plastic was washed in a Bosch SMS46CW03E / 41 dishwasher in the Eco 50°C program without varying the speed with water of 9 German hardness. The plastics included polypropylene, polyethylene, melamine and styrene-acrylonitrile copolymer (SAN). No ballast soil was added. Commercially available automatic dishwashing tablets without any rinse aid formulation were used for the wash cycle. At the beginning of the last drying step, the dishwasher was opened and 4 mL of rinse aid formulation was added manually using a pipette.

[0175] The drying index was determined 30 minutes after the dishwashing program was completed. The door of the dishwasher remained closed during these 30 minutes. The maximum score for perfect drying was 1 and the worst score was 0. The reported values ​​represent the average of three tests. The results are provided in Table 4:

[0176] Table 4:

[0177] Glass Stainless steel porcelain plastic Q 0.94 0.99 0.77 0.26 T 0.86 0.99 0.74 0.26 U 0.72 0.98 0.75 0.16 V 0.69 0.99 0.68 0.15

[0178] As shown in Table 4, Exemplary Formulations Q and T provided superior drying efficacy on glass and plastic compared to commercial Formulation U and Formulation V containing only one nonionic surfactant. Exemplary Formulations Q and T also provided superior drying efficacy on porcelain compared to one nonionic surfactant of Formulation V. Formulations Q, T, U, and V all exhibited similar drying performance on stainless steel.

[0179] Formulation V was subjected to stability testing. Precipitation was observed after 3 weeks at 5°C. This suggests that the replacement of ZA with LP is not solely responsible for the stability of the disclosed concentrated liquid rinse aid formulations, especially when only one nonionic surfactant is included in the concentrated liquid rinse aid formulation.

[0180] Example 3: Dry Performance Test-Water Droplet Count

[0181] A new drying method based on water droplet counting was developed to allow for better discrimination of samples. Formulation T was tested against commercial multi-benefit detergent formulation W, the ingredients of which are provided in Table 5 below, while commercial multi-benefit detergent formulation X was used in Example 4 below. Lists of ingredients in these commercial formulations are available from the manufacturers' websites.

[0182] Table 5:

[0183]

[0184]

[0185]

[0186] Drying performance was evaluated by running a dishwashing cycle in a Bosch SMS 6ECW 57E / 10 dishwasher in the Eco 50°C program with Speed ​​Perfect Plus and 21 German hardness water. The dishwasher was loaded with standard dishware. Ballast soil was added to the dish items to simulate consumer relevant conditions. The ballast soil composition was based on the publication by Hubbuch et al., Amount and composition of soils in German dishwashers. Composition to standard test method. Journal–Seifen Fette Wachse, 125, 14-20, 1999. At the beginning of the last drying step, the dishwasher was opened and 4 mL of the rinse aid formulation was manually added using a pipette. The drying score was determined 15 minutes after the dishwashing program was completed. The evaluation was based on counting the droplets on the tableware items, where 0 = no droplets, to 9 = 9 droplets, and 10 = 10 or more droplets. The evaluation scheme is based on a public drying performance method (the so-called Cognis method), with a scale expanded to 10. The results are provided in Table 6:

[0187] Table 6:

[0188] Glass Stainless steel porcelain plastic total T 2.1 0 0.5 2.2 1.2 W 4.6 1.5 1.6 8.9 4.2

[0189] As shown in Table 6, Exemplary Formulation T provided superior drying efficacy on all surfaces tested compared to the commercial multi-benefit detergent formulation W. This example demonstrates that the disclosed rinse aids exhibit better drying than formulations containing ingredients such as bleach, carbonates, enzymes, or humectants.

[0190] Example 4: Gloss Performance Test - Spots

[0191] A gloss test was conducted to compare Multi-Benefit Formulation X alone or in combination with a commercially available rinse aid U or an exemplary concentrated rinse aid T. Gloss performance was evaluated by running several consecutive dishwashing cycles in a commercial dishwasher containing standard dishware items. A ballast load of soil was added to the dishware items to simulate consumer relevant conditions. Evaluation of the dishware items was based on a five (5) point scale with 1 being the best and 5 being the worst. Two parameters were evaluated: 1) spotting (clear discrete spots) and 2) filming (no clear contrast, no borders / boundaries, mostly covering the entire dishware). The results are provided in Table 7:

[0192] Table 7:

[0193] Glass Stainless steel porcelain plastic X+T 2.0 2.0 2.0 5.0 X+U 3.4 2.0 3.5 5.0 X 3.8 2.0 3.5 5.0

[0194] As shown in Table 7, Exemplary Formulation T provided superior gloss on glass and porcelain compared to Commercial Multi-Benefit Detergent Formulation X alone or in combination with Commercial Rinse Aid U.

[0195] Example 5: Glass opacity

[0196] To verify the material care performance of the disclosed concentrated rinse aid formulations, glass haze was evaluated using commercial multi-benefit detergent formulation W with or without formulation T. The results are provided in Table 8:

[0197] Table 8:

[0198] 25 loops 50 cycles 100 cycles W+T 3.6 3.1 2.5 W 3.0 2.5 2.0

[0199] As shown in Table 8, and considering that higher scores indicate better performance, Exemplary Formulation T provided less glass haze than the commercial multi-benefit detergent Y alone.

[0200] For the purpose of illustration and description, the above description of various aspects of the present invention has been given. The embodiments and / or features therein can be freely combined with each other. It is not intended to be exhaustive or limit the present invention to the disclosed precise form, and it is obvious that many modifications and variations are possible. These modifications and variations that are obvious to those skilled in the art are intended to be included in the scope of the present invention defined by the appended claims.

Claims

1. A concentrated liquid rinse aid, comprising a surfactant mixture, wherein the surfactant mixture comprises (a) an ethoxylated propoxylated C 12 To C 18 Straight chain alcohol and (b) ethoxylated C 12 To C 15 Branched chain alcohols, or substantially composed of (a) ethoxylated propoxylated C 12 To C 18 Straight chain alcohol and (b) ethoxylated C 12 To C 15 Branched alcohols, or (a) ethoxylated propoxylated C 12 To C 18 Straight chain alcohol and (b) ethoxylated C 12 To C 15 Branched alcohol compositions wherein the minimum amount of surfactant in the composition is at least 30 wt%, preferably at least 40 wt%, more preferably at least 50 wt%.

2. A concentrated liquid rinse aid as claimed in claim 1, wherein the maximum amount of surfactant in the composition is less than 60 wt%, preferably less than 58 wt%, more preferably less than 55 wt%.

3. A concentrated liquid rinse aid as claimed in claim 1 or 2, wherein the ratio of (b):(a) is from 1:1 to 1:

2.

4. A concentrated liquid rinse aid according to any one of claims 1 to 3, wherein the concentration of (a) in the concentrated liquid rinse aid is from 25% to 35% by weight.

5. A concentrated liquid rinse aid as claimed in any one of claims 1 to 4 wherein (a) has a cloud point of from 20°C to 43°C measured in 1% water at 25°C.

6. A concentrated liquid rinse aid as claimed in any one of claims 1 to 5 wherein (a) is a liquid at room temperature and pressure.

7. A concentrated liquid rinse aid as claimed in any one of claims 1 to 6 wherein (a) is a polyoxyalkylene condensate surfactant having a formula selected from: a) Formula (I): R 1 2-C-O-[[EO] m –[PO] n x ,​ Where R 1 It is C 12 -C 18 alkyl; m is 1-100, preferably 1-50, more preferably 1-29; n is 1-100, preferably 1-50, more preferably 1-29; and x is 1-100, preferably 1-50, more preferably 1-29, and the EO and PO units may be random, alternating, block or grafted; b) Formula (II): Z-CH2-CHZ-CH2-[OCH2-CHZ-CH2] k -Z, wherein k=2-29, and each Z is independently OH or R, provided that 4% to 25% of Z are R, wherein R is: (i) -OCH2-CHOH-CH2-R', and each R' is independently a. a long chain alkyl group containing 6 to 20 carbon atoms, or b. Polyoxyalkylene glycol ether group -(CH2-CHR"-O) p -R"", wherein each R" is independently H, CH3 or CH2CH3, p=3-20, and R"' is a C1-C6 alkyl group, the average oxygen / carbon atom ratio of the group is not greater than 0.4:1, or (ii) -O-(CH2-CHR"-O) a -CH2-CHOH-CH2-O-, wherein a=6-40 and R" is as defined above in (a)(ii), wherein -(CH2-CHR"-O) a - the average oxygen:carbon ratio is not greater than 0.4:1, wherein in the same or different units of formula (II), (i) constitutes one R, and (ii) constitutes two R; c) or a combination thereof.

8. A concentrated liquid rinse aid according to any one of claims 1 to 7, wherein the polyoxyalkylene condensate surfactant is a methyl-ethylene oxide polymer surfactant with alkyl ether ethylene oxide blocks, preferably a methyl-ethylene oxide block polymer surfactant with monoisotridecyl ether ethylene oxide, which is commercially available from BASF under the trade name Plurafact TM LF-300 for sale.

9. A concentrated liquid rinse aid as claimed in any one of claims 1 to 8 wherein (b) is not a Guerbet alcohol.

10. A concentrated liquid rinse aid according to any one of claims 1 to 9, wherein the concentration of (b) in the concentrated liquid rinse aid is from 20% to 30% by weight.

11. A concentrated liquid rinse aid as claimed in any one of claims 1 to 10 wherein (b) has an HLB value of from 10 to 12, preferably from 11 to 11.

5.

12. A concentrated liquid rinse aid as claimed in any one of claims 1 to 11 wherein (b) has an ethoxylation level of from 4 to 10.

13. A concentrated liquid rinse aid as claimed in any one of claims 1 to 12 wherein (b) is a liquid at room temperature and pressure.

14. A concentrated liquid rinse aid as claimed in any one of claims 1 to 12 wherein (b) is an ethoxylated C 12 -C 15 Isoalcohol, preferably ethoxylated isotridecanol.

15. A concentrated liquid rinse aid according to any one of claims 1 to 14 further comprising a hydrotrope, preferably sodium cumene sulfonate.

16. The concentrated liquid rinse aid composition of claim 15, wherein the concentrated liquid rinse aid comprises from about 10% to about 20% by weight of the hydrotrope.

17. A concentrated liquid rinse aid according to any one of claims 1 to 16, further comprising a polymer, preferably a pH independent cationic polymer having at least one quaternary group.

18. A concentrated liquid rinse aid according to claim 17, wherein the pH independent cationic polymer has the formula (III): -(RORN + R2X-R-NH-C(=O)-NH-RN + R2X-) n , wherein each R is independently C1-C4 alkyl, n=1-1000, and X=halogen, preferably Cl.

19. A concentrated liquid rinse aid according to claim 17 or 18, wherein the pH independent cationic polymer is sold under the trade name Lugalvan P by BASF or under the trade name Mirapol by Solvay TM 15 Sold as a polymer of N,N'-bis[3-(dimethylamino)propyl]-urea with 1,1'-oxybis[2-chloroethane].

20. A concentrated liquid rinse aid as claimed in any one of claims 17 to 19, wherein the concentrated liquid rinse aid comprises from about 0.03 wt% to about 0.1 wt% polymer.

21. A concentrated liquid rinse aid according to any one of claims 1 to 20, wherein the concentrated liquid rinse aid is a single phase liquid.

22. A concentrated liquid rinse aid as claimed in any one of claims 1 to 21, wherein the concentrated liquid rinse aid does not exhibit precipitation after two weeks at 25°C.

23. A method of rinsing hard surfaces in an automatic dishwasher, the method comprising: a. adding 1 part by volume of the concentrated liquid rinse aid of any one of claims 1 to 22 to 4 parts by volume of tap water to produce a diluted liquid rinse formulation, b. filling the rinse aid compartment of the automatic dishwasher with the diluted liquid rinse formulation, c. Start the automatic dishwasher.

24. The method of claim 23, wherein: The hard surface is glass, ceramic, plastic, stainless steel or any combination thereof.

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