WO2024177869A1

WO2024177869A1 - Dispersant hydrophilic block copolymer

Info

Publication number: WO2024177869A1
Application number: PCT/US2024/015889
Authority: WO
Inventors: Fanwen Zeng; Scott BACKER; Wei Gao; Inna Shulman; Wen-Shiue YOUNG; Meng JING
Original assignee: Rohm and Haas Co; Union Carbide Corp
Current assignee: Rohm and Haas Co; Union Carbide Corp
Priority date: 2023-02-23
Filing date: 2024-02-15
Publication date: 2024-08-29
Anticipated expiration: 2025-08-23

Abstract

A dispersant hydrophilic block copolymer is provided including carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer; and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly(alkylene oxide) diol; wherein 90 to 100 wt% of the poly(alkylene oxide) diol polymer segments are esterified with two structural units of monoethylenically unsaturated carboxylic acid monomer present in the carboxylic acid polymer segments per poly(alkylene oxide) diol polymer segment.

Description

DISPERSANT HYDROPHILIC BLOCK COPOLYMER

[0001] The present invention relates to a dispersant hydrophilic block copolymer. In particular, the present invention relates a dispersant hydrophilic block copolymer, comprising: carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer; and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly(alkylene oxide) diol; wherein 90 to 100 wt% of the poly(alkylene oxide) diol polymer segments are esterified with two structural units of monoethylenically unsaturated carboxylic acid monomer present in the carboxylic acid polymer segments per poly(alkylene oxide) diol polymer segment.

[0002] In detergent applications, large volumes of ingredients are used. Because these ingredients may eventually enter the environment and reside in subsurface waters, it is desirable for such ingredients to be degradable in order to avoid any environmental concerns. Traditionally, detergents and cleaning agents contained phosphates. The phosphates were added to formulations as detergent builders, acting to sequester alkaline earth metal hardness ions, as encrustation inhibitors and as antiredeposition agents. Despite the fact that the well- known inorganic phosphorus compounds were highly effective and relatively non-toxic, there use in many applications has been discontinued.

[0003] Efforts have been ongoing in the detergent industry to convert from polyphosphates to materials such as polycarboxylic acid polymers such as poly(acrylic acids). While polycarboxylic acid polymers and copolymers currently used in detergent and water treatment formulations do not suffer from the same perceived drawbacks as phosphorus containing inorganic builders, the past has taught that it might be desirable for ingredients used in large volume applications which may enter the environment be biodegradable.

Unfortunately, most polycarboxylic acid polymers and copolymers useful in detergent and/or water treatment applications are not highly biodegradable.

[0004] Some efforts have been made to provide biodegradable water-soluble poly(acrylic acid) copolymers. Notable in this regard is U.S. Patent No. 5,318,719, in which Hughes et al. teach graft polymers as biodegradable detergent additives. In particular, Hughes et al. teach a class of biodegradable water soluble graft copolymers having building, antifilming, dispersing and threshold crystal inhibiting properties comprising (a) an acid functional monomer and optionally (b) other water soluble, monoethylenically unsaturated monomers copolymerizable with (a) grafted to a biodegradable substrate comprising polyalkylene oxides and/or polyalkoxylated materials. Notwithstanding, the processing methodology taught in U.S. Patent No. 5,318,719 fails to produce high concentrations of poly(acrylic acid)/poly(alkylene oxide) copolymer.

[0005] Accordingly, it would be desirable to have high purity poly(acrylic acid)/poly(alkylene oxide) copolymers for use in various detergent and/or water treatment applications.

[0006] The present invention provides a dispersant hydrophilic block copolymer, comprising: carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer; and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly(alkylene oxide) diol; wherein 90 to 100 wt% of the poly( alkylene oxide) diol polymer segments are esterified with two structural units of monoethylenically unsaturated carboxylic acid monomer present in the carboxylic acid polymer segments per poly(alkylene oxide) diol polymer segment.

[0007] The present invention provides a dispersant hydrophilic block copolymer, comprising: carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer; and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly(alkylene oxide) diol; wherein 40 to 100 wt% of the dispersant hydrophilic block copolymer is of formula (I)

wherein z1 is 1; wherein x1 2s 0 to 139; wherein r1 is 0 to 139; wherein x1 + z1 + r1 = 7 to 140; wherein z2 is 1; wherein xz is 0 to 139; wherein r2 is 0 to 139; wherein X2 + Z2 + r2 = 7 to 140; wherein each R¹ is individually selected from the group consisting of a hydrogen and a C1-3 alkyl group; and wherein y is an average of 4 to 84. DETAILED DESCRIPTION

[0008] Surprisingly, it has been found that, the dispersant hydrophilic block copolymer of the present invention, comprising: carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer; and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly(alkylene oxide) diol; wherein 90 to 100 wt% of the poly(alkylene oxide) diol polymer segments are esterified with two structural units of monoethylenically unsaturated carboxylic acid monomer present in the carboxylic acid polymer segments per poly(alkylene oxide) diol polymer segment when incorporated into automatic dishwashing compositions (particularly phosphate-free automatic dishwashing compositions), give surprisingly good spotting and filming performance on a range of surfaces versus conventional dispersant polymers while potentially having a more favorable biodegradability over said conventional dispersant polymers.

[0009] Unless otherwise indicated, ratios, percentages, parts, and the like are by weight. Weight percentages (or wt%) in the composition are percentages of dry weight, i.e., excluding any water that may be present in the composition. Percentages of monomer units in the polymer are percentages of solids weight, i.e., excluding any water present in a polymer emulsion.

[0010] As used herein, unless otherwise indicated, the terms "weight average molecular weight" and "Mw" are used interchangeably to refer to the weight average molecular weight as measured in a conventional manner with gel permeation chromatography (GPC)(also sometimes referred to as Size Exclusion Chromatography (SEC)) and conventional standards, such as polyethylene glycol standards. GPC techniques are discussed in detail in Striegel, A. M. et al., Modem Size Exclusion Liquid Chromatography, Practice of Gel Permeation and Gel Filtration (2 ed.) John Wiley & Sons, Inc. (2009), and in Podzimek, S., Light Scattering, Size Exclusion Chromatography and Asymmetric Flow Field Flow Fractionation: Powerful Tools for the Characterization of Polymers, Proteins and Nanoparticles, John Wiley & Sons, Inc. (2011). Weight average molecular weights are reported herein in units of Daltons.

[0011] Preferably, the dispersant hydrophilic block copolymer of the present invention, comprises: carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer (preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of (meth)acrylic acid, (meth) aery loxypropionic acid, itaconic acid, aconitic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, monomethyl maleate, monomethyl fumarate, monomethyl itaconate and mixtures thereof; more preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid and mixtures thereof; still more preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof; most preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is acrylic acid)(most preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is acrylic acid)(preferably, wherein the carboxylic acid polymer segments comprise 70 to 100 mol% (preferably, 80 to 100 mol%; more preferably, 90 to 100 mol%; still more preferably, 95 to 100 mol%; yet more preferably, 97 to 100 mol%; still yet more preferably, 98 to 100 mol%; yet still more preferably, 99 to 100 mol%; most preferably, 100 mol%) structural units of monoethylenically unsaturated carboxylic acid monomer (preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof; more preferably, wherein the monoethylenically unsaturated carboxylic acid monomer includes acrylic acid; most preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is acrylic acid)); and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly (alkylene oxide) diol (preferably, wherein the structural units of poly (alkylene oxide) diol are residues formed from esterification reactions of poly( alkylene oxide) diols according to formula A

wherein each R¹ is individually selected from the group consisting of a hydrogen and a C_1-3 alkyl group (preferably, a hydrogen and a C_1-2 alkyl group; more preferably, a hydrogen and a methyl group; most preferably, a hydrogen); and wherein y is an average of 4 to 84 (preferably, 5 to 75; more preferably, 10 to 70; most preferably, 12 to 67)); and wherein 90 to 100 wt% (preferably, 92 to 100 wt%; more preferably, 95 to 100 wt%; still more preferably, 97.5 to 100 wt%; yet more preferably, 98 to 100 wt%; most preferably, 99 to 100 wt%) of the poly( alkylene oxide) diol polymer segments are esterified with two structural units of monoethylenically unsaturated carboxylic acid monomer present in the carboxylic acid polymer segments per poly(alkylene oxide) diol polymer segment (preferably, wherein the poly( alkylene oxide) diol polymer segments form crosslinks within the dispersant hydrophilic block copolymer, wherein the crosslinks are selected from the group consisting of intra crosslinks and inter crosslinks)(intra crosslinks result when the esterifications form on the same carboxylic acid polymer segment; inter crosslinks result when the esterifications form on two separate carboxylic acid polymer segments).

[0012] More preferably, the dispersant hydrophilic block copolymer of the present invention, comprises: carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer (preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of (meth)acrylic acid, (meth) aery loxypropionic acid, itaconic acid, aconitic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, monomethyl maleate, monomethyl fumarate, monomethyl itaconate and mixtures thereof; more preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid and mixtures thereof; still more preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof; most preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is acrylic acid)(most preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is acrylic acid)(preferably, wherein the carboxylic acid polymer segments comprise 70 to 100 mol% (preferably, 80 to 100 mol%; more preferably, 90 to 100 mol%; still more preferably, 95 to 100 mol%; yet more preferably, 97 to 100 mol%; still yet more preferably, 98 to 100 mol%; yet still more preferably, 99 to 100 mol%; most preferably, 100 mol%) structural units of monoethylenically unsaturated carboxylic acid monomer (preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof; more preferably, wherein the monoethylenically unsaturated carboxylic acid monomer includes acrylic acid; most preferably, wherein the monoethylenically unsaturated carboxylic acid monomer is acrylic acid)); and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly (alkylene oxide) diol (preferably, wherein the structural units of poly (alkylene oxide) diol are residues formed from esterification reactions of poly( alkylene oxide) diols according to formula A

wherein each R¹ is individually selected from the group consisting of a hydrogen and a C1-3 alkyl group (preferably, a hydrogen and a C_1-2 alkyl group; more preferably, a hydrogen and a methyl group; most preferably, a hydrogen); and wherein y is an average of 4 to 84 (preferably, 5 to 75; more preferably, 10 to 70; most preferably, 12 to 67)); and wherein 40 to 100 wt% (preferably, 50 to 100 wt%; more preferably, 55 to 100 wt%; still more preferably, 60 to 100 wt%; yet more preferably, 75 to 100 wt%; most preferably, 90 to 100 wt%) of the dispersant hydrophilic block copolymer is of formula (I)

wherein z1 is 1 to 2 (preferably, 1); wherein x1 is 0 to 139 (preferably, 0 to 140; more preferably, 0 to 104; most preferably, 0 to 83); wherein r2 is 0 to 139 (preferably, 0 to 140; more preferably, 0 to 104; most preferably, 0 to 83); wherein x1 + z1 + H = 7 to 140 (preferably, 21 to 140; more preferably, 28 to 104; most preferably, 48 to 83); wherein Z2 is 1 to 2 (preferably, l)(preferably, wherein z1 = z2); wherein xz is 0 to 139 (preferably, 0 to 140; more preferably, 0 to 104; most preferably, 0 to 83); wherein rz is 0 to 139 (preferably, 0 to 140; more preferably, 0 to 104; most preferably, 0 to 83); wherein xz + Z2 + rz - 7 to 140 (preferably, 21 to 140; more preferably, 28 to 104; most preferably, 48 to 83); wherein each R¹ is individually selected from the group consisting of a hydrogen and a C1-3 alkyl group (preferably, a hydrogen and a C_1-2 alkyl group; more preferably, a hydrogen and a methyl group; most preferably, a hydrogen); and wherein y is an average of 4 to 84 (preferably, 5 to 75; more preferably, 10 to 70; most preferably, 12 to 67)(preferably, the poly(alkylene oxide) diol copolymer segments are esterified at random positions along the carboxylic acid copolymer segments)(optionally, some of the carboxylic acid copolymer segments corresponding to x1, z1, r1 and x2, Z2, r2 form a single carboxylic acid copolymer segment, wherein the poly(alkylene oxide) diol copolymer segment esterified thereto forms an internal crosslink within the single carboxylic acid copolymer segment) (preferably, the carboxylic acid copolymer segments corresponding to each x1, z1, rj and X2, Z2, in the dispersant hydrophilic block copolymer are distinct carboxylic acid copolymer segments that are joined together only by the poly( alkylene oxide) diol copolymer segments)(preferably, the dispersant hydrophilic block copolymer comprises less than 5 wt% (preferably, 0 to 3 wt%; more preferably, 0 to 2 wt%; still more preferably, 0 to 1 wt%; yet more preferably, 0 to 0.5 wt%; most preferably, 0 to 0.1 wt%) dispersant hydrophilic block copolymer having a poly( alkylene oxide) diol copolymer segment internal crosslink).

[0013] Preferably, the carboxylic acid copolymer segments comprise 0 to 30 mol% (preferably, 0 to 20 mol%; more preferably, 0 to 10 mol%; still more preferably, 0 to 5 mol%; yet more preferably, 0 to 3 mol%; still yet more preferably, 0 to 2 mol%; yet still more preferably, 0 to 1 mol%; most preferably, 0 mol%) of structural units selected from the group consisting of structural units of monoethylenically unsaturated nonionic monomer, structural units of sulfonated monomer and mixtures thereof. More preferably, the carboxylic acid copolymer segments comprise 0 to 30 mol% (preferably, 0 to 20 mol%; more preferably, 0 to 10 mol%; still more preferably, 0 to 5 mol%; yet more preferably, 0 to 3 mol%; still yet more preferably, 0 to 2 mol%; yet still more preferably, 0 to 1 mol%; most preferably, 0 mol%) of structural units selected from the group consisting of structural units of monoethylenically unsaturated nonionic monomer, structural units of sulfonated monomer and mixtures thereof; wherein the monoethylenically unsaturated nonionic monomer is a CM alkyl (meth)acrylate (preferably, wherein the monoethylenically unsaturated nonionic monomer is selected from the group consisting of a methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth) acrylate and mixtures thereof; more preferably, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate and mixtures thereof; still more preferably, ethyl (meth)acrylate, n-butyl (meth) acrylate and mixtures thereof; most preferably, ethyl acrylate, butyl acrylate and mixture thereof); and wherein the sulfonated monomer is selected from the group consisting of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), 2-methacrylamido-2-methylpropane sulfonic acid, 4-styrenesulfonic acid, vinyl sulfonic acid, 3-allyloxy sulfonic acid, 2 -hydroxy-1 -propane sulfonic acid (HAPS), 2-sulfoethyl(meth)acrylic acid, 2-sulfopropyl(meth)acrylic acid, 3-sulfopropyl(meth)acrylic acid, 4-sulfobutyl(meth)acrylic acid and salts thereof (preferably, wherein the sulfonated monomer is 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomer (preferably, wherein the sulfonated monomer is selected from the group consisting of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), 2-methyacrylamido-2-methylpropane sulfonic acid, vinyl sulfonic acid and salts thereof; more preferably, wherein the sulfonated monomer is selected from the group consisting of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), 2-methyacrylamido-2-methylpropane sulfonic acid and salts thereof; most preferably, wherein the sulfonated monomer is selected from the group consisting of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and salts thereof).

[0014] Preferably, the dispersant hydrophilic block copolymer has a carboxylic acid copolymer segment weight average molecular weight of 500 to 10,000 Daltons per molecule of dispersant hydrophilic block copolymer (preferably, 1,500 to 10,000 Daltons; more preferably, 2,000 to 7,500 Daltons; most preferably, 2,500 to 6,000 Daltons); and the dispersant hydrophilic block copolymer has a poly (alkylene oxide) diol copolymer segment weight average molecular weight of 250 to 5,000 Daltons (preferably, 300 to 4,650 Daltons; more preferably, 600 to 4,200 Daltons; most preferably, 720 to 4,020 Daltons) per molecule of dispersant hydrophilic block copolymer.

[0015] Preferably, the dispersant hydrophilic block copolymer has a molar ratio of poly( alkylene oxide) diol polymer segments to carboxylic acid polymer segments of 0.01 to 0.03 (preferably, 0.01 to 0.03; more preferably, 0.01 to 0.029; most preferably, 0.0125 to 0.0285).

[0016] Preferably, the dispersant hydrophilic block copolymer of the present invention, comprises 0 to 60 wt% (preferably, 0 to 50 wt%; more preferably, 0 to 45 wt%; still more preferably, 0 to 40 wt%; yet more preferably, 0 to 25 wt%; most preferably, 0 to 10 wt%) of residual carboxylic acid polymer segments that remain unesterified with a poly(alkylene oxide) diol polymer segment.

[0017] Preferably, the dispersant hydrophilic block copolymer of the present invention, comprises 0 to 1 wt% (preferably, 0 to 0.5 wt%; more preferably, 0 to 0.25 wt%; still more preferably, 0 to 0.1 wt%; yet more preferably, 0 to 0.01 wt%; most preferably, 0 to 0.001 wt%) of residual poly(alkylene oxide) diol polymer segments that remain unesterified with a carboxylic acid polymer segment.

[0018] The dispersant hydrophilic block copolymers of the present invention can be made using the synthesis described in Syntheses S2-S5 below. [0019] The dispersant hydrophilic block copolymers of the present invention can be used as dispersant polymers in detergent (e.g., laundry/dish) and/or water treatment formulations for inhibiting scale formation.

[0020] Some embodiments of the present invention will now be described in detail in the following Examples.

Synthesis SI: Preparation of poly (acrylic acid)

[0021] To a 2 liter, 4 neck round bottom reactor equipped with overhead stirrer, thermocouple, heating mantle, adapter inlet, Claisen head fitter with a water condenser and nitrogen inlet was added deionized water (312.50 g). The reactor contents were heated to 95 °C under nitrogen. A monomer mixture was prepared by mixing deionized water (158.00 g) and acrylic acid (1,090.91 g). A cofeed catalyst solution was prepared by mixing sodium persulfate (21.6 g) and deionized water (133.06 g). A chain regulator mixture was prepared by mixing sodium hydrogen sulfite monohydrate (105.98 g) with deionized water (347 g). Chain regulator mixture (168 g) was charged to the reactor using an addition funnel over 10 minutes. The temperature set point was adjusted to 85 °C. Once the reactor contents reached 85 °C, the cofeed catalyst solution feed to the reactor was initiated and continued for 93 minutes. One minute after initiation of the cofeed catalyst solution feed, the monomer mixture and chain regulator feeds were started simultaneously and continued for 90 minutes. The initial exotherm was noticed to reach up to 95 °C, but the temperature stabilized and was maintained at 93 °C for the duration of the reactant feeds. The reactor contents were maintained at 93 °C for another 15 minutes to finish the reaction. The reactor was then vented and cooled to 70 °C. Then deionized water (19.98 g) was added to the reactor contents. The reactor contents were allowed to continue cooling to ambient temperature. Once the temperature of the reactor contents fell below 40 °C, the product was recovered. The product had a solids level of 57.13 wt%, a pH of 2.47 and a Tg of 77.05 °C. Based on aqueous gel permeation chromatography (GPC) analysis, the product had a weight average molecular weight of 1,899 Daltons and a number average molecular weight of 660 Daltons.

Syntheses S2-S5: Polyfacrylic acid)/polv(ethylene oxide) diol copolymer

[0022] The poly( acrylic acid)/poly(ethylene oxide) diol copolymers of Syntheses S2-S5 were prepared according to the following procedure. To a 25 mL scintillation vial equipped with a small magnetic stirrer was added (A) a polyacrylic acid homopolymer having a weight average molecular weight of 1,800 Daltons (57.13 wt% in water, 18.42 g) prepared according to Synthesis SI; followed by the addition of polyethylene oxide) diol (7.02 g) having the weight average molecular weight as noted in TABLE 1. The vial contents were then heated to 70 °C while stirring at 500 rpm for at least 1 hour. Once they were clear and well mixed, the vial contents were poured into small aluminum pan. The aluminum pan was then covered with a piece of aluminum foil and secured by folding the edges of the aluminum foil over the pan. The aluminum foil was then punctured with a syringe to create small holes. The aluminum pan was then placed into a vacuum oven at 30 mm Hg vacuum with a set point temperature of 120 °C overnight. The aluminum pan was then removed from the oven and allowed to cool. Upon cooling, the product was removed from the aluminum pan and collected.

TABLE 1

Synthesis S6: AA/mPEG Copolymer

[0023] A poly(acrylic acid)/poly(ethylene glycol) methyl ether (mPEG) monol copolymer was prepared according to Synthesis S2 with the substitution of a polyethylene glycol) methyl ether (mPEG) monol having a weight average molecular weight of 2,000 Daltons for the polyethylene oxide) diol.

Synthesis S7: AA/MPEGMA Copolymer

[0024] To a 2 liter, 4 neck round bottom reactor equipped with overhead stirrer, thermocouple, heating mantle, adapter inlet, Claisen head fitted with a water condenser and nitrogen inlet was charged deionized water (499.80 g) and phosphorus acid (2.2 g). The reactor contents were heated to 100 °C under nitrogen. A monomer mixture containing acrylic acid (174.12 g) and a 50% aqueous solution of mehoxypolyethylene glycol methacrylate having a weight average molecular weight of 2,000 (MPEGMA) (335.24 g) was then metered into the reactor over 5 hours followed by a deionized water rinse. A catalyst cofeed solution of ammonium persulfate (18.37 g) and deionized water (96.90 g) was prepared. A 40% aqueous sodium hydrogen sulfite chain regulator solution (46.24 g) was prepared. The catalyst cofeed solution and the chain regulator solution were concurrently added to the reactor over 5 hours with addition of the monomer mixture as the reactor temperature was maintained at 100 °C. After completion of the reactant feeds, the reactor contents were stirred for 2 hours while maintaining a temperature of 100 °C. The reactor contents were then cooled to room temperature and adjusted to pH of 7.2 by adding a 50% aqueous solution of sodium hydroxide (190.40 g) over 1 hour. The contents of the reactor were transferred to a storage bottle along with a reactor rinse of deionized water (190.40 g). The product polymer had a solids content of 25.91 wt% and a pH of 7.78.

[0025] Based on gel permeation chromatography (GPC) analysis, the product polymer had a weight average molecular weight of 4,336 Daltons and a number average molecular weight of 1,195 Daltons. The product polymer was determined by two dimensional liquid chromatography analysis to primarily consist of a copolymer of acrylic acid and MPEGMA.

Synthesis S8: Poly (acrylic acid) polymerized in presence of polyethylene glycol) (following process exemplified in U.S. Patent No. 5,318,719)

[0026] To a two liter, 4 neck flask equipped with a mechanical stirrer, reflux condenser, and inlets for the gradual addition of the monomers, caustic solution and initiator solution were added deionized water (380.0 g), a 0.15 wt% copper (II) sulfate pentahydrate aqueous solution (25.3 g) and polyethylene glycol having a weight average molecular weight of 3,350 Daltons (152.0 g). The flask contents were heated to reflux. Then glacial acrylic acid (383.84 g), an initiator solution of 30% hydrogen peroxide (126.67 g) and a 50% aqueous solution of sodium hydroxide (316.92 g) were added linearly and separately to the flask contents over two hours. Once the additions were complete, the system was maintained at reflux for an additional twenty minutes. The system was then cooled to 60 °C. Then a 50% aqueous solution of sodium hydroxide (76.0 g) was added to the flask contents as a post neutralization.

[0027] Based on gel permeation chromatography (GPC) analysis, the product has a weight average molecular weight of 18,067 Daltons and a number average molecular weight of 3,370 Daltons. The product was determined by two dimensional liquid chromatography analysis to primarily consist of two separate homopolymer with a small amount of poly( acrylic acid)/poly(ethylene glycol) copolymer.

Comparative Examples CF1-CF2 and Example Fl: Dishwashing formulations [0028] Dishwashing compositions were prepared in each of Comparative Examples CF1- CF2 and Example Fl having the component formulations identified in TABLE 2. ABLE 2

Comparative Examples CF3-CF4 and Examples F2-F5; Dishwashing formulations [0029] Dishwashing compositions were prepared in each of Comparative Examples CF3- CF4 and Examples F2-F5 having the component formulations identified in TABLE 3.

Comparative Examples CF5-CF8 and Examples F6-F7: Dishwashing formulations

[0030] Dishwashing compositions were prepared in each of Comparative Examples CF5-

CF8 and Examples F6-F7 having the component formulations identified in TABLE 4.

TABLE 4

Procedure for preparing food soil

[0031] The STIWA food soil described in TABLE 5 was prepared by the following procedure. a) Bringing the water to a boil. b) Mixing in a paper cup the instant gravy, the benzoic acid and the potato starch; and then adding the mixture to the boiling water. c) Adding the milk and margarine to the product of (b). d) Letting the product of (c) cool down to approximately 40 °C e) Adding cooled mixture from (d) to a kitchen mixer (Polytron). f) Combining in another paper cup, the egg yolk, the ketchup and the mustard and mixing with a spoon. g) Adding the product of (f) to the mixture of (e) in the blender with continuous stirring. h) Letting the product of (g) stir in the blender for 5 minutes. i) While stirring the product of (h) remove 50 g aliquots of the product food soil mixture and place in wide mouth vials j) The 50 g aliquots are then placed in a freezer. k) A 50 g aliquots of frozen food soil of (j) is placed into the dishwasher at beginning of the main wash.

TABLE 5

Dishwashing Test Conditions

[0032] Machine: Miele SS-ADW, Model G1223SC Labor. Wash at 65 °C - 30 min wash cycle, followed by two rinse cycles with a rinse water temperature of 65 °C and a final 30 minute drying step. After the drying cycle was complete, the dishwasher door was opened for 30 minutes to allow the steam to evaporate. Water: initial water supplied to the dishwasher had a total water hardness of 40 °fH hardness, Ca²⁺:Mg²⁺= 3: 1 and a temporary water hardness of 27 °fH. Food soil: 50 g of the composition noted in TABLE 3 was introduced to the wash liquor frozen in a cup. Each dishwashing composition from Comparative Examples CF1-CF8 and Examples F1-F7 were tested. The food soil was added at the beginning of the wash cycle. The test detergents were also charged to the dishwasher at the beginning of the wash cycle. The test detergents were each dosed at 17 g per wash (based on solids). The number of wash cycles used in this experiment to generate filming and spotting was 14.

Schott® Glass Evaluation

[0033] After 14 wash cycles under the above dishwashing test conditions, the Schott® Glasses were dried in open air for at least 18 hours. After drying in open air following the 14^th wash, filming and spotting ratings were determined in a light box with controlled illumination from below. Schott® tumblers were rated for filming and spotting according to ASTM method ranging from 1 (no film/spots) to 5 (heavily filmed/spotted). An average value of 1 to 5 for filming and spotting was determined as reported in TABLES 6-8. TABLE 6

TABLE 7

TABLE 8

304 Polished Stainless Steel Coupons Evaluation

[0034] After 14 wash cycles under the above dishwashing test conditions, polished 304 stainless steel coupons were dried in open air for at least 18 hours. After drying in open air filming and spotting ratings were determined in a light box with controlled illumination. Polished 304 stainless steel coupons were rated for filming and spotting ranging from 1 (no film/spots) to 5 (heavily filmed/spotted). An average value of 1 to 5 for filming and spotting was determined as reported in TABLES 9-11.

TABLE 9

TABLE 10

Acrylic Poly(styrent-acrylic) Clear Plastic Drinkware Evaluation

[0035] After 14 wash cycles under the above dishwashing test conditions, plastic drinkware was dried in open air for at least 18 hours. After drying in open air filming and spotting ratings were determined in a light box with controlled illumination. Plastic drinkware was rated for filming and spotting ranging from 1 (no film/spots) to 5 (heavily filmed/spotted). An average value of 1 to 5 for filming and spotting was determined as reported in TABLES 12-14.

TABLE 12

TABLE 13

TABLE 14

Additional Plastic Test Substrates Evaluation

[0036] After 14 wash cycles under the above dishwashing test conditions, additional plastic substrates — an opaque plastic poly(high density polyethylene) lid from a food storage container (OPL), a blue translucent plastic polypropylene) lid from a ZIPLOC® food storage container (Ziploc) and a white translucent plastic polypropylene) lid from a Ny-Hi® food storage container (Ny-Hi) — were dried in open air for at least 18 hours. After drying in open air filming and spotting ratings were determined in a light box with controlled illumination. Additional plastic substrates were rated for filming and spotting ranging from 1 (no film/spots) to 5 (heavily filmed/spotted). An average value of 1 to 5 for filming and spotting was determined as reported in TABLES 15-17.

TABLE 15

TABLE 16

TABLE 17

Claims

We claim:

1. A dispersant hydrophilic block copolymer, comprising: carboxylic acid polymer segments comprising structural units of a monoethylenically unsaturated carboxylic acid monomer; and poly(alkylene oxide) diol polymer segments, consisting of structural units of a poly( alkylene oxide) diol; wherein 90 to 100 wt% of the poly(alkylene oxide) diol polymer segments are esterified with two structural units of monoethylenically unsaturated carboxylic acid monomer present in the carboxylic acid polymer segments per poly(alkylene oxide) diol polymer segment.

2. The dispersant hydrophilic block copolymer of claim 1, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of (meth)acrylic acid, (meth) aery loxypropionic acid, itaconic acid, aconitic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, monomethyl maleate, monomethyl fumarate, monomethyl itaconate and mixtures thereof.

3. The dispersant hydrophilic block copolymer of claim 1, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid and mixtures thereof.

4. The dispersant hydrophilic block copolymer of claim 1, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof.

5. The dispersant hydrophilic block copolymer of claim 1, wherein the carboxylic acid polymer segments further comprise structural units of monoethylenically unsaturated nonionic monomer; wherein the monoethylenically unsaturated nonionic monomer is a CM alkyl (meth)acrylate.

6. The dispersant hydrophilic block copolymer of claim 1, wherein the carboxylic acid polymer segments further comprise structural units of sulfonated monomer; wherein the sulfonated monomer is selected from the group consisting of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), 2-methacrylamido-2-methylpropane sulfonic acid, 4-styrenesulfonic acid, vinylsulfonic acid, 3-allyloxy sulfonic acid, 2-hydroxy-l -propane sulfonic acid (HAPS), 2-sulfoethyl(meth)acrylic acid, 2-sulfopropyl(meth)acrylic acid, 3-sulfopropyl(meth)acrylic acid, 4-sulfobutyl(meth)acrylic acid and salts thereof (preferably, wherein the sulfonated monomer is 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomer.

7. The dispersant hydrophilic block copolymer of claim 1, wherein the molar ratio of poly(alkylene oxide) diol polymer segments to carboxylic acid polymer segments in the dispersant hydrophilic block copolymer is 0.005 to 0.03.

8. The dispersant hydrophilic block copolymer of claim 1, wherein 40 to 100 wt% of the dispersant hydrophilic block copolymer is of formula (I)

wherein x1 is 0 to 139; wherein r1 is 0 to 139; wherein x1 + z1 + r1 = 7 to 140; wherein z2 is 1; wherein X2 is 0 to 139; wherein r2 is 0 to 139; wherein

140; wherein each R¹ is individually selected from the group consisting of a hydrogen and a C_1-3 alkyl group; and wherein y is an average of 4 to 84. wherein the dispersant hydrophilic block copolymer has a carboxylic acid copolymer segment weight average molecular weight of 500 to 10,000 Daltons per molecule of dispersant hydrophilic block copolymer; wherein the dispersant hydrophilic block copolymer has a poly(alkylene oxide) diol copolymer segment weight average molecular weight of 250 to 5,000 Daltons per molecule of dispersant hydrophilic block copolymer.

9. The dispersant hydrophilic block copolymer of claim 8, wherein the monoethylenically unsaturated carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof; wherein the dispersant hydrophilic block copolymer comprises 0 to 60 wt% of residual carboxylic acid polymer segments that remain unesterified with a poly(alkylene oxide) diol polymer segment; and wherein the dispersant hydrophilic block copolymer comprises 0 to 1 wt% of residual poly( alkylene oxide) diol polymer segments that remain unesterified with a carboxylic acid polymer segment.

10. The dispersant hydrophilic block copolymer of claim 9, wherein the carboxylic acid polymer segments further comprise structural units selected from the group consisting of structural units of monoethylenically unsaturated nonionic monomer, structural units of sulfonated monomer and mixtures thereof.