EP4688967A1

EP4688967A1 - Aqueous composition

Info

Publication number: EP4688967A1
Application number: EP24716680.4A
Authority: EP
Inventors: Klin Aloysius RODRIGUES; Matthew Michael VANDERHOOF; Sajal PANTHA
Original assignee: Nouryon Chemicals International BV
Current assignee: Nouryon Chemicals International BV
Priority date: 2023-03-30
Filing date: 2024-03-27
Publication date: 2026-02-11
Also published as: CN121002128A; WO2024200582A1

Abstract

An aqueous composition includes water, a binder, an optional pigment, and a particle. The particle itself includes at least one core polymer and at least one shell polymer. Each of the at least one core polymer and the at least one shell polymer is the polymerization reaction product of first and second monomer mixtures, respectively. Each of the first and second monomer mixtures includes a1)/a2) optionally one or more anionic ethylenically unsaturated monomers; b1)/b2) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain comprising a hydrophobe that has 7 or fewer carbon atoms; c1)/c2) optionally one or more associative monomers; d1)/d2) optionally one or more cross-linking monomers; e1)/e2) optionally one or more nonionic ethylenically unsaturated monomers; and f1)/f2) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain comprising a hydrophobe that has 8 or greater carbon atoms.

Description

AQUEOUS COMPOSITION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/493,084, filed March 30, 2023, and U.S. Provisional Application No. 63/359,323, filed February 29, 2024, wherein each of the disclosures are hereby expressly incorporated herein by reference in their entireties.

TECHNICAL FIELD

[0002] This disclosure generally relates to an aqueous composition including a particle that that is typically alkali swellable and can provide customizable viscosity properties to the composition. More specifically, the particle includes at least one core polymer and at least one shell polymer that is disposed about the at least one core polymer, wherein the at least one shell polymer is at least partially cross-linked.

BACKGROUND

[0003] Aqueous compositions are used in a variety of industries including, but not limited to, paints, coatings, adhesives, asphalts, etc. Depending on the application, adjustment of the rheology properties of such compositions can be challenging because the compositions typically must simultaneously exhibit additional physical properties such as leveling, sag resistance, stability, pH, solubility, compatibility, surface tension, etc.

[0004] As just one example, in paints, it may be difficult to build medium shear and high shear viscosity simultaneously especially if only one rheology modifier is used. Both KU and ICI viscosity are important measures of paint consistency because they can affect the paint's performance and application properties. For example, a paint with a high KU or ICI viscosity will be thicker and may be more difficult to apply evenly, while a paint with a low KU or ICI viscosity may be too thin and may not provide adequate coverage. It is important for paint manufacturers to carefully control these viscosity values to ensure that their products perform as intended.

[0005] Non-ionic synthetic associative thickeners (NSATs) are commonly used in various industries to control viscosity and rheological properties of aqueous compositions. While they offer many advantages such as improved performance and stability, there are some potential problems associated with their use. For example, NSATs may not be compatible with certain formulations or ingredients, leading to issues such as phase separation, reduced efficacy, or changes in appearance. In addition, the performance of NSATs can vary depending on factors such

1

SUBSTITUTE SHEET (RULE 26) as temperature, shear rate, and the presence of other additives. This variability can make it challenging to predict and control the rheological properties of the final product.

[0006] NSATs may also be sensitive to changes in formulation parameters, such as the type or concentration of other additives. Small changes in formulation can sometimes lead to significant changes in viscosity or rheological behavior. In some formulations, NSATs may contribute to syneresis, which is the expulsion of liquid from a gel or paste. Some NSATs may have environmental implications due to their chemical composition or manufacturing process.

[0007] Accordingly, there remains an opportunity to develop aqueous compositions that include new rheology modifiers that can be used both with and without NSATs.

BRIEF SUMMARY

[0008] This disclosure provides an aqueous composition that includes water, a binder, an optional pigment, and a particle. The particle itself includes at least one core polymer and at least one shell polymer that is disposed about the at least one core polymer. The at least one core polymer is the polymerization reaction product of a first monomer mixture. The first monomer mixture includes al) optionally one or more anionic ethylenically unsaturated monomers; bl) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 7 or fewer carbon atoms; cl) optionally one or more associative monomers; dl) optionally one or more cross -linking monomers; el) optionally one or more nonionic ethylenically unsaturated monomers; and fl) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 8 or greater carbon atoms. In this first monomer mixture, if al) is not present, then el) is present in the first monomer mixture. Moreover, if fl) is not present in the first monomer mixture then al) is present in an amount of from 0 to about 60 mol% based on a total number of moles of monomers in the first monomer mixture. Furthermore, if fl) is present in the first monomer mixture then al) is present in an amount of from 0 to about 80 mol% based on a total number of moles of monomers in the first monomer mixture. However, at least one of bl) and fl) is present in the first monomer mixture. Referring now to the at least one shell polymer, the at least one shell polymer is at least partially cross-linked and is the polymerization reaction product of a second monomer mixture. The second monomer mixture includes a2) optionally one or more anionic ethylenically unsaturated monomers; b2) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 7 or fewer carbon atoms; c2) optionally one or more associative monomers; d2) one or more cross-linking monomers; e2) optionally one or more nonionic ethylenically unsaturated monomers; and f2) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 8 or greater carbon atoms. In this second monomer mixture, if a2) is not present, then e2) is present in the second monomer mixture. Moreover, if f2) is not present in the second monomer mixture then a2) is present in an amount of from 0 to about 60 mol% based on a total number of moles of monomers in the second monomer mixture. Furthermore, if f2) is present in the second monomer mixture then a2) is present in an amount of from 0 to about 80 mol% based on a total number of moles of monomers in the second monomer mixture. In addition, at least one of b2) and f2) is present in the second monomer mixture while at least one of the first monomer mixture and the second monomer mixture includes al) or a2) in an amount greater than zero mol %, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and

[0010] FIG. 1 is a cross-sectional view of one embodiment of the particle of this disclosure wherein each of an at least one core polymer, a first shell polymer, and a second shell polymer has a cross-link density, the cross-link density of the first shell polymer is greater than the cross-link density of the at least one core polymer, and the cross-link density of the second shell polymer is greater than the cross-link density of the first shell polymer and greater than the cross-link density of the at least one core polymer;

[0011] FIG. 2 is a cross-sectional view of one embodiment of the particle of this disclosure wherein each of the at least one core polymer, the first shell polymer, and the second shell polymer has a cross-link density, the cross-link density of the first shell polymer is greater than the crosslink density of the at least one core polymer, and the cross-link density of the second shell polymer is less than the cross-link density of the first shell polymer and greater than the cross-link density of the at least one core polymer;

[0012] FIG. 3 is a cross-sectional view of one embodiment of the particle of this disclosure wherein each of the at least one core polymer, the first shell polymer, and the second shell polymer has a cross-link density, the cross-link density of the first shell polymer is less than the cross-link density of the at least one core polymer, and the cross-link density of the second shell polymer is greater than the cross-link density of the at least one core polymer and greater than the cross-link density of the first shell polymer;

[0013] FIG. 4 is a cross-sectional view of one embodiment of the particle of this disclosure wherein each of the at least one core polymer, the first shell polymer, and the second shell polymer has a cross-link density, the cross-link density of the first shell polymer is greater than the crosslink density of the at least one core polymer, and the cross-link density of the second shell polymer is less than the cross-link density of the at least one core polymer and less than the cross-link density of the first shell polymer;

[0014] FIG. 5 is a cross-sectional view of one embodiment of the particle of this disclosure wherein each of the at least one core polymer, the first shell polymer, and the second shell polymer has a cross-link density, the cross-link density of the first shell polymer is less than the cross-link density of the at least one core polymer, and the cross-link density of the second shell polymer is less than the cross-link density of the at least one core polymer and greater than the cross-link density of the first shell polymer;

[0015] FIG. 6 is a cross-sectional view of one embodiment of the particle of this disclosure wherein each of the at least one core polymer, the first shell polymer, and the second shell polymer has a cross-link density, the cross-link density of the first shell polymer is less than the cross-link density of the at least one core polymer, and the cross-link density of the second shell polymer is less than the cross-link density of the at least one core polymer and less than the cross-link density of the first shell polymer.

DETAILED DESCRIPTION

[0016] The following detailed description is merely exemplary in nature and is not intended to limit the current aqueous composition. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0017] Embodiments of the present disclosure are generally directed to polymers, compositions including the same, and methods for forming the same. For the sake of brevity, conventional techniques related to making polymers and such compositions may not be described in detail herein. Moreover, the various tasks and process steps described herein may be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. In particular, various steps in the manufacture of polymers and associated compositions are well-known and so, in the interest of brevity, many conventional steps will only be described briefly herein or will be omitted entirely without providing the well-known process details.

[0018] In this disclosure, the terminology “about” can describe values ± 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10%, in various embodiments. Moreover, it is contemplated that, in various non-limiting embodiments, it is to be appreciated that all numerical values as provided herein, save for the actual examples, are approximate values with endpoints or particular values intended to be read as “about” or “approximately” the value as recited. It is also contemplated that all isomers and chiral options for each compound described herein are hereby expressly contemplated for use herein in various non-limiting embodiments.

[0019] Throughout this disclosure, the terminology percent "actives" is well recognized in the art and means the percent amount of active or actual compound or molecule present as compared to, for example, a total weight of a diluted solution of a solvent and such a compound. Some compounds, such as a solvent, are not described relative to a percent actives because it is well known to be approximately 100% actives. Any one or more of the values described herein may be alternatively described as percent actives as would be understood by the skilled person.

[0020] In various embodiments, the terminology “free of’ describes embodiments that include less than about 5, 4, 3, 2, 1, 0.5, or 0.1, weight percent (or weight percent actives) of the compound or element at issue using an appropriate weight basis as would be understood by one of skill in the art. In other embodiments, the terminology “free of’ describes embodiments that have zero weight percent of the compound or element at issue.

[0021] The terminology “consists essentially of’ may describe various non-limiting embodiments that are free of one or more optional compounds described herein and/or free of one or more polymers, surfactants, additives, solvents, etc.

[0022] It is to be understood that the subscripts of polymers are typically described as average values because the synthesis of polymers typically produces a distribution of various individual molecules.

[0023] The polymers and compositions disclosed herein may suitably include, consist of, or consist essentially of the components, elements, described herein or may be formed by any process delineations described herein. The embodiments illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. Aqueous Composition

[0024] This disclosure provides an aqueous composition which may be alternatively described as the “composition” herein. The aqueous composition is not particularly limited in terms of use or application. For example, the aqueous composition may be alternatively described as an aqueous coating composition, aqueous paint composition, aqueous adhesive composition, aqueous asphalt composition, etc. Alternatively, the aqueous composition may be used as one component in a larger and otherwise aqueous or non-aqueous composition, e.g. a coating composition, paint composition, adhesive composition, asphalt composition, etc. The aqueous composition includes water and a particle as described below.

[0025] In various embodiments, the aqueous composition is further defined as an aqueous coating composition. The aqueous coating composition typically includes water (and/or a solvent), a binder, an optional pigment, and the particle. In various embodiments, the aqueous coating composition, is, consists essentially of, or consists of, the water (and/or a solvent), the binder, the optional pigment, and the particle. In any of these embodiments, a non-ionic synthetic associative thickener may be included or omitted, as described in detail below.

Water and/or Solvent

[0026] The term “aqueous” as applied herein typically describes that the composition includes water (and/or a polar solvent) in an amount sufficient to at least swell or dissolve the particle in the composition into which it is formulated. In various embodiments, a solvent may be used which may be water itself or may be a combination of water and water miscible solvents. The solvent may be described as any polar solvent known in the art. For example, the polar solvent may be or include an alcohol such as ethanol or methanol, butanol, isobutanol, acetone, methyl ethyl ketone, isopropanol, n-propanol, acetonitrile, DMSO (dimethyl sulfoxide), DMF (dimethyl formamide), ether alcohols, butyl cellosolve, dipropyleneglycol monomethylether, or combinations thereof. In one embodiment, the solvent is water without any additional polar solvent.

[0027] In other embodiments, the solvent may be or include an organic solvent which may be polar or non-polar. However, most typically, if utilized, the organic solvent will be present in a small amount as a co-solvent with the aforementioned water or polar solvent. Typically, no organic solvent is used. In various embodiments, glycols can be used as open time extenders in compositions such as aqueous coating compositions. Moreover, coalescents such as Texanol can also be used, e.g. Texanol 25265-77-477-68-93-Hydroxy-2,2,4-trimethylpentyl isobutyrate 2,2,4- Trimethyl- 1 ,3 -pentanediol monoisobutyrate.

[0028] However, if an organic solvent is used, the solvent may be a polar organic liquid such as an ether, especially lower alkyl ethers, esters, ketones, glycols, alcohols, amides, or combinations thereof. In one embodiment, polar organic liquids include dialkyl ketones, alkyl esters of alkane carboxylic acids and alkanols, especially such liquids including up to, and including, a total of 6 or 8 carbon atoms. Examples of the polar organic liquids include dialkyl and cycloalkyl ketones, such as acetone, methyl ethyl ketone, diethyl ketone, di-isopropyl ketone, methyl isobutyl ketone, di-isobutyl ketone, methyl ketone, methyl n-amyl ketone and cyclohexanone; alkyl esters such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, ethyl formate, methyl propionate, methoxypropyl acetate and ethyl butyrate; glycols and glycol esters and ethers, such as ethylene glycol, 2-ethoxy ethanol, 3 -methoxypropylpropanol, 3- ethoxypropylpropanol, 2 -butoxy ethyl acetate, 3 -methoxypropyl acetate, 3 -ethoxypropyl acetate and 2-ethoxyethyl acetate; alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol and dialkyl and cyclic ethers such as diethyl ether and tetrahydrofuran, and combinations thereof. In one embodiment, solvents such as alcohols, and esters of alkane carboxylic acids may be used. The polar organic liquid may include methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol, or mixtures thereof.

[0029] In various embodiments, the composition includes water (and/or the solvent) present in an amount of at least about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or even greater, weight percent based on a total weight of the composition. In other embodiments, water (and/or the solvent) is present in an amount of from about 5 to about 90, about 5 to about 85, about 10 to about 80, about 15 to about 75, about 20 to about 70, about 25 to about 65, about 30 to about 60, about 35 to about 55, about 40 to about 50, or about 45 to about 50, weight percent based on a total weight of the composition. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

Binder

[0030] Referring now to the binder, the term “binder” typically refers to a film forming component of the composition when the composition is, for example, a coating composition. Typically, a binder can include polymers, oligomers, or a combination thereof that are used to form a coating having desired properties, such as hardness, protection, adhesion, and others. Additional components, such as carriers, pigments, catalysts, rheology modifiers, antioxidants, UV stabilizers and absorbers, leveling agents, antifoaming agents, anti-cratering agents, or other conventional additives may not be included in the term “binder” unless one or more of these additional components are film forming constituents of the composition.

[0031] The film forming component can include any curable water-dispersible or latex polymer. A “latex” polymer means a dispersion of polymer particles in water. A latex polymer typically requires a secondary dispersing agent (e.g. a surfactant, polymeric colloid) for creating a dispersion or emulsion of polymer particles in water. A “water-dispersible” polymer means the polymer is itself capable of being dispersed into water (i.e., without requiring the use of a separate surfactant) or water can be added to the polymer to form a stable aqueous dispersion (i.e., the dispersion should have at least one month shelf stability at normal storage temperatures). Such water-dispersible polymers can include nonionic or anionic functionality on the polymer, which assist in rendering them water-dispersible. For such polymers, external acids or bases are typically used for anionic stabilization.

[0032] The binder may alternatively be chosen from a polyester-polyurethane polymer, a latex polymer, a melamine resin, and combinations thereof. It is to be appreciated that other polymers may be included in the composition or omitted therefrom.

[0033] Latex polymers, such as aqueous latex binders and their production, are well known to the skilled person. Aqueous (meth)acryl copolymer latex binders can typically be made by free- radical emulsion copolymerization of olefinically unsaturated free-radically copolymerizable comonomers. Typical latex binders used in paints are acrylics, vinyl -acrylic, styrene acrylics, ethylene-vinyl acetate, vinyl acetate, alkyd, vinyl chloride, styrene-butadiene, vinyl versatate, vinyl acetate-maleate or mixtures thereof and others that are known in the art.

[0034] Melamine resins may be partially or fully etherified with one or more alcohols like methanol or butanol. A non-limiting example is hexamethoxymethyl melamine. Non-limiting examples of suitable melamine resins include monomeric melamine, polymeric melamineformaldehyde resin, or a combination thereof. The monomeric melamines include low molecular weight melamines which contain, on an average, three or more methylol groups etherized with a Ci to Cs monohydric alcohol such as methanol, n-butanol, or isobutanol per triazine nucleus, and have an average degree of condensation up to about 2 and, in certain embodiments, of from about 1.1 to about 1.8, and have a proportion of mononuclear species not less than about 50 percent by weight. By contrast the polymeric melamines have an average degree of condensation of more than about 1.9. Some such suitable monomeric melamines include alkylated melamines, such as methylated, butylated, isobutylated melamines and mixtures thereof. Many of these suitable monomeric melamines are supplied commercially.

[0035] The polyester of the polyester-polyurethane polymer may be linear or branched. Useful polyesters can include esterification products of aliphatic or aromatic dicarboxylic acids, polyols, diols, aromatic or aliphatic cyclic anhydrides and cyclic alcohols. Non-limiting examples of suitable cycloaliphatic polycarboxylic acids are tetrahydrophthalic acid, hexahydrophthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4- cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, tricyclodecanedicarboxylic acid, endoethylenehexahydrophthalic acid, camphoric acid, cyclohexanetetracarboxylic, and cyclobutanetetracarboxylic acid. The cycloaliphatic polycarboxylic acids can be used not only in their cis but also in their trans form and as a mixture of both forms. Further non-limiting examples of suitable polycarboxylic acids can include aromatic and aliphatic polycarboxylic acids, such as, for example, phthalic acid, isophthalic acid, terephthalic acid, halogenophthalic acids, such as tetrachloro- or tetrabromophthalic acid, adipic acid, glutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, trimellitic acid, and pyromellitic acid. Combinations of polyacids, such as a combination of polycarboxylic acids and cycloaliphatic polycarboxylic acids, can be suitable. Combinations of polyols can also be suitable.

[0036] Non-limiting suitable polyhydric alcohols include ethylene glycol, propanediols, butanediols, hexanediols, neopentylglycol, diethylene glycol, cyclohexanediol, cyclohexanedimethanol, trimethylpentanediol, ethylbutylpropanediol, ditrimethylolpropane, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, polyethylene glycol and polypropylene glycol. If desired, monohydric alcohols, such as, for example, butanol, octanol, lauryl alcohol, ethoxylated or propoxylated phenols may also be included along with polyhydric alcohols to control molecular weight.

[0037] Non-limiting examples of suitable polyesters include branched copolyester polymers. Compounds with multifunctional groups such as AxBy (x,y=l to 3, independently) types including those having one carboxyl group and two hydroxyl groups, two carboxyl groups and one hydroxyl group, one carboxyl group and three hydroxyl groups, or three carboxyl groups and one hydroxyl group can be used to create branched structures. Non-limiting examples of such compounds include 2,3 dihydroxy propionic acid, 2,3 dihydroxy 2-methyl propionic acid, 2,2 dihydroxy propionic acid, 2,2-bis(hydroxymethyl) propionic acid, and the like.

[0038] The branched copolyester polymer can be conventionally polymerized from a monomer mixture including a chain extender selected from the group of a hydroxy carboxylic acid, a lactone of a hydroxy carboxylic acid, and a combination thereof; and one or more branching monomers. Some of the suitable hydroxy carboxylic acids include glycolic acid, lactic acid, 3- hydroxypropionic acid, 3 -hydroxybutyric acid, 3 -hydroxy valeric acid, and hydroxypyvalic acid. Some of the suitable lactones include caprolactone, valerolactone; and lactones of the corresponding hydroxy carboxylic acids, such as, e.g., 3-hydroxypropionic acid, 3-hydroxybutyric acid, 3 -hydroxy valeric acid, and hydroxypyvalic acid. In certain embodiments, caprolactone can is utilized. In various embodiments, the branched copolyester polymer can be produced by polymerizing, in one step, the monomer mixture including a chain extender and hyper branching monomers, or by first polymerizing the hyper branching monomers followed by polymerizing the chain extenders. It is to be appreciated that the branched copolyester polymer can be formed from acrylic core with extending monomers described above.

[0039] The polyester-polyurethane polymer can be produced from the polyester and polyisocyanates. The polyester can be polymeric or oligomeric organic species with at least two hydroxyl-functionalities or two-mercapto functionalities and their mixtures thereof. Polyesters and polycarbonates with terminal hydroxy groups can be effectively used as the diols.

[0040] The polyurethane polymers may be produced by reacting polyisocyanate(s) with polyol(s) in excess. In certain embodiments, low molar mass polyols defined by an empirical and structural formula, such as poly hydric alcohols, are utilized to form the polyurethane polymer. Non-limiting examples of polyhydric alcohols include ethylene glycol, propanediols, butanediols, hexanediols, neopentylglycol, diethylene glycol, cyclohexanediol, cyclohexanedimethanol, trimethylpentanediol, ethylbutylpropanediol, ditrimethylolpropane, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, polyethylene glycol and polypropylene glycol. In other embodiments, oligomeric or polymeric polyols with numberaverage molar masses of, for example, up to 8000, alternatively up to 5000, alternative up to 2000, and/or, for example, corresponding hydroxyl-functional poly ethers, polyesters or polycarbonates are utilized to form the polyurethane polymer. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[0041] Non-limiting examples of suitable polyisocyanates include aromatic, aliphatic or cycloaliphatic di-, tri- or tetra-isocyanates, including polyisocyanates having isocyanurate structural units, such as, the isocyanurate of hexamethylene diisocyanate and isocyanurate of isophorone diisocyanate; the adduct of two molecules of a diisocyanate, such as, hexamethylene diisocyanate and a diol such as, ethylene glycol; uretidiones of hexamethylene diisocyanate; uretidiones of isophorone diisocyanate or isophorone diisocyanate; the adduct of trimethylol propane and meta-tetramethylxylene diisocyanate. Other polyisocyanates disclosed herein can also be suitable for producing polyurethanes.

[0042] Aqueous polyurethane binders and their production are well known to the skilled person. Typical and useful non-limiting examples of aqueous polyurethane binders include aqueous polyurethane binder dispersions which can typically be made by first forming an NCO- functional hydrophilic polyurethane prepolymer by addition reaction of polyol type compounds and polyisocyanates, conversion of the so-formed polyurethane prepolymer into the aqueous phase and then reacting the aqueously dispersed NCO-functional polyurethane prepolymer with an NCO- reactive chain extender like, for example, a polyamine, a hydrazine derivative or water.

[0043] One non-limiting example of a polyester-polyurethane polymer is a polyurethane dispersion resin formed from a diol resin and a diisocyanate. Another non-limiting example of a polyester-polyurethane polymer is a polyurethane dispersion resin formed from a polycarbonatepolyester and an diisocyanate.

[0044] In some embodiments, the binder is a polymer or oligomer that has a crosslinkable- functional group, such as an isocyanate-reactive group. The term “crosslinkable-functional group" refers to functional groups that are positioned in the oligomer, in the polymer, in the backbone of the polymer, in the pendant from the backbone of the polymer, terminally positioned on the backbone of the polymer, or combinations thereof, wherein these functional groups are capable of crosslinking with crosslinking-functional groups (during the curing step) to produce a coating in the form of crosslinked structures. Typical crosslinkable-functional groups can include hydroxyl, thiol, isocyanate, thioisocyanate, acetoacetoxy, carboxyl, primary amine, secondary amine, epoxy, anhydride, ketimine, aldimine, or a workable combination thereof. Some other functional groups such as orthoester, orthocarbonate, or cyclic amide that can generate hydroxyl or amine groups once the ring structure is opened can also be suitable as crosslinkable-functional groups.

[0045] In various embodiments, the composition may include the binder in an amount of from about 0.1 to about 50, alternatively from about 1 to about 20, or alternatively from about 1 to about 10, wt.%, based on an active percent of binder basis. In other embodiments, the composition may include the binder in an amount of from about 5 to about 70 wt.%, alternatively from about 10 to about 50 wt.%, or alternatively from about 15 to about 25 wt.%, based on an active percent of binder basis. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

Pigment

[0046] The composition optionally includes the pigment which may be any known in the art. For example, the composition may include the pigment or may be free of the pigment. In one embodiment, the composition is free of the pigment and can be described as a clear coat composition.

[0047] The pigment may be or include a primary pigment. Non-limiting examples of suitable primary pigments include pigments with coloristic including: blue pigments including indanthrone blue Pigment Blue 60, phthalocyanine blues, Pigment Blue 15:1, 15:, 15:3 and 15:4, and cobalt blue Pigment Blue 28; red pigments including quinacridone reds, Pigment Red 122 and Pigment Red 202, iron oxide red Pigment Red 101, perylene reds scarlet Pigment Red 149, Pigment Red 177, Pigment Red 178, and maroon Pigment Red 179, azoic red Pigment Red 188, and diketo- pyrrolopyrrol reds Pigment red 255 and Pigment Red 264; yellow pigments including diarylide yellows Pigment Yellow 14, iron oxide yellow Pigment Yellow 42, nickel titanate yellow Pigment Yellow 53, indolinone yellows Pigment Yellow 110 and Pigment Yellow 139, monoazo yellow Pigment yellow 150, bismuth vanadium yellow pigment Yellow 184, disazo yellows Pigment Yellow 128 and Pigment Yellow 155; orange pigments including quinacridone orange pigments Pigment Yellow 49 and Pigment Orange 49, benzimidazolone orange pigment Pigment Orange 36; green pigments including phthalocyanine greens Pigment Green 7 and Pigment Green 36, and cobalt green Pigment Green 50; violet pigments including quinacridone violets Pigment Violet 19 and Pigment Violet 42, dioxane violet Pigment Violet 23, and perylene violet Pigment Violet 29; brown pigments including monoazo brown Pigment Brown 25 and chrome-antimony titanate Pigment Brown 24, iron chromium oxide Pigment Brown 29; white pigments such as anatase and rutile titanium dioxide (TiO2) Pigment White 6; and black pigments including carbon blacks Pigment Black 6 and Pigment Black 7, perylene black Pigment Black 32, copper chromate black Pigment Black 28.

[0048] The pigment may alternatively be or include an effect pigment selected from the group of metallic flake pigments, mica-containing pigments, glass-containing pigments, and combinations thereof.

[0049] In other embodiments, suitable pigments are, for example, Pigment Yellow 213, PY 151, PY 93, PY 83, Pigment Red 122, PR 168, PR 254, PR 179, Pigment Red 166, Pigment Red 48:2, Pigment Violet 19, Pigment Blue 15:1, Pigment Blue 15:3, Pigment Blue 15:4, Pigment Green 7, Pigment Green 36, Pigment Black 7 or Pigment White 6.

[0050] Further non-limiting examples of suitable pigments include metallic oxides, metal hydroxide, effect pigments including metal flakes, chromates, such as lead chromate, sulfides, sulfates, carbonates, carbon black, silica, talc, china clay, phthalocyanine blues and greens, organo reds, organo maroons, pearlescent pigments, other organic pigments and dyes, and combinations thereof. If desired, chromate-free pigments, such as barium metaborate, zinc phosphate, aluminum triphosphate and combinations thereof, can also be utilized.

[0051] Further non-limiting examples of suitable effect pigments include bright aluminum flake, extremely fine aluminum flake, medium particle size aluminum flake, and bright medium coarse aluminum flake; mica flake coated with titanium dioxide pigment also known as pearl pigments; and combinations thereof. Non-limiting examples of suitable colored pigments include titanium dioxide, zinc oxide, iron oxide, carbon black, mono azo red toner, red iron oxide, quinacridone maroon, transparent red oxide, dioxazine carbazole violet, iron blue, indanthrone blue, chrome titanate, titanium yellow, mono azo permanent orange, ferrite yellow, mono azo benzimidazolone yellow, transparent yellow oxide, isoindoline yellow, tetrachloroisoindoline yellow, anthanthrone orange, lead chromate yellow, phthalocyanine green, quinacridone red, perylene maroon, quinacridone violet, pre-darkened chrome yellow, thio-indigo red, transparent red oxide chip, molybdate orange, molybdate orange red, and combinations thereof. Titanium dioxide is commercially available in various grades with various coatings as is well known in the art. Any of such may be used herein. [0052] Extender pigments may also be utilized. The extender pigment may have a variety of configurations including, but not limited to, nodular, platelet, acicular, and fibrous. Non-limiting examples of suitable extender pigments include whiting, barytes, amorphous silica, fumed silica, diatomaceous silica, china clay, calcium carbonate, phyllosilicate (mica), wollastonite, magnesium silicate (talc), barium sulfate, kaolin, and aluminum silicate.

[0053] The composition may include the pigment, if at all, in an amount of greater than zero, for example, from about 0.1 to about 50, alternatively from about 1 to about 20, or alternatively from about 1 to about 10, wt.%, based on a total weight of the composition. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

Particle

[0054] Referring now to the particle itself, the particle may be alternatively described as a coreshell polymer. This core-shell polymer may include any polymer or co-polymer described herein. In the context of the disclosure, the term “(co)polymer” indicates polymer or copolymer. The term “polymer” and the term “copolymer” can be used herein interchangeably, as understood by one of skill in the art.

[0055] As used herein and throughout the specification, the terms “core-shell morphology”, “core-shell structure”, “core polymer”, “staged core polymer” and “two-staged polymer” or “multi-staged polymer” may be used interchangeably and mean a polymer or polymer particle prepared by a sequential or staged polymerization process wherein each sequence or stage of monomer repeating units is added to the polymerization reactor, in a batch or continuous process, and begins to undergo polymerization which may be before, or concurrently with, the addition and polymerization of the subsequent sequence or stage of repeating units is commenced. In some embodiments, the polymerization of one stage will be substantially complete before the monomers of the next stage are added to the polymerization reactor. In other embodiments, the polymerization of one stage may be only partially complete before the monomers of the next stage are added to the polymerization reactor.

[0056] The particle itself includes at least one core polymer and at least one shell polymer that is disposed about the at least one core polymer. The at least one core polymer is the polymerization reaction product of a first monomer mixture. The first monomer mixture includes al) optionally one or more anionic ethylenically unsaturated monomers; bl) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 7 or fewer carbon atoms; cl) optionally one or more associative monomers; dl) optionally one or more cross-linking monomers; el) optionally one or more nonionic ethylenically unsaturated monomers; and fl) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 8 or greater carbon atoms. In this first monomer mixture, if al) is not present, then el) is present in the first monomer mixture. Moreover, if fl) is not present in the first monomer mixture then al) is present in an amount of from 0 to about 60 mol% based on a total number of moles of monomers in the first monomer mixture. Furthermore, if fl) is present in the first monomer mixture then al) is present in an amount of from 0 to about 80 mol% based on a total number of moles of monomers in the first monomer mixture. However, at least one of bl) and fl) is present in the first monomer mixture. Referring now to the at least one shell polymer, the at least one shell polymer is at least partially cross-linked and is the polymerization reaction product of a second monomer mixture. The second monomer mixture includes a2) optionally one or more anionic ethylenically unsaturated monomers; b2) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 7 or fewer carbon atoms; c2) optionally one or more associative monomers; d2) one or more cross-linking monomers; e2) optionally one or more nonionic ethylenically unsaturated monomers; and f2) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 8 or greater carbon atoms. In this second monomer mixture, if a2) is not present, then e2) is present in the second monomer mixture. Moreover, if f2) is not present in the second monomer mixture then a2) is present in an amount of from 0 to about 60 mol% based on a total number of moles of monomers in the second monomer mixture. Furthermore, if f2) is present in the second monomer mixture then a2) is present in an amount of from 0 to about 80 mol% based on a total number of moles of monomers in the second monomer mixture. In addition, at least one of b2) and f2) is present in the second monomer mixture while at least one of the first monomer mixture and the second monomer mixture includes al) or a2) in an amount greater than zero mol %, respectively.

At Least One Shell Polymer

[0057] The at least one shell polymer may be disposed about all of the at least one core polymer or only about a portion of the at least one core polymer, e.g. disposed about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95+% of an outer surface of the at least one core polymer. For example, the particle can be in a form in which a core portion (e.g. core polymer) is completely coated or encapsulated, or non-completely coated or encapsulated, within or by a shell portion (e.g. shell polymer). It is also to be understood that in describing the “core polymer” and the “shell polymer”, there can be a significant amount of interpenetration of these polymers. Thus, the “core polymer” can extend somewhat into the at least one shell polymer and vice versa. The terms “core polymer” and “shell polymer” and like terminology are employed herein to describe the polymeric material in a general way without attempting to identify any particular polymers as strictly “shell” or strictly “core” polymers. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[0058] In various embodiments, core-shell polymers have a structure in which a polymer(s) forming the core portion, sequence or stage (e.g. core polymer) and the polymer(s) forming the shell portion, sequence or stage (e.g. shell polymer) are physically and/or chemically bonded and/or attracted to each other. The structure and/or chemical composition (e.g. monomer mixture and/or amount) of the core-shell polymer can change from the inside to the outside (i.e., from the at least one core polymer to the at least one shell polymer) and, as a result, may form gradient zones that can have different physical and chemical properties from each other. These gradient zones can be somewhat gradual, yielding a morphology having a gradient of polymeric structure or composition along any radius thereof. Alternatively, the gradient zones can be relatively well defined when moving outward along a radius from the center of the core-shell polymer, yielding a morphology having a relatively distinct core portion including one polymeric composition, and a relatively distinct shell portion including a different polymeric composition. The terminology “gradient” typically describes a pattern with a progressive change (e.g. increase or decrease) in a characteristic at issue. For example, the core-shell polymer can change when considered from the inside to the outside, or when considered from the outside to the inside, relative to a progressive change in physical and/or chemical properties, e.g. an amount of cross-linking.

[0059] The core-shell morphology can include multiple layers or zones of differing polymeric composition. A rate of change in polymeric morphology is not particularly critical as long as the polymer exhibits the desired physical properties described herein. Accordingly, as used herein in various embodiments, the terms “core” and “shell” refer to the polymeric content of the inside and the outside of the core-shell polymer, respectively, and the use of such terms should not be construed as meaning that the core-shell polymer will necessarily exhibit a distinct interface between the polymers of the inside and the outside.

[0060] The core-shell polymers can include one or more core polymers and one or more shell polymers, which can be the same as or different from the at least one core polymer and from each other with respect to both the type and proportions of monomers used to form a polymer backbone. [0061] In various embodiments, one or both of the at least one core polymer and the at least one shell polymer includes an increasing gradient of cross-link density measured in an outward direction extending from a center of the at least one core polymer towards the at least one shell polymer wherein the cross-link density of the at least one core polymer is less than the cross-link density of the at least one shell polymer.

[0062] Alternatively, one or both of the at least one core polymer and the at least one shell polymer includes an increasing gradient of cross-link density measured in an inward direction extending from an outermost layer of the at least one shell polymer towards a center of the at least one core polymer towards wherein the cross-link density of the at least one core polymer is greater than the cross-link density of the at least one shell polymer.

[0063] The core-shell polymer may be present in the composition in any amount. Typically, the core-shell polymer is present in an amount of from about 0.01 to about 10 weight percent, about 0.05 to about 2 weight percent, or about 0.1 to about 2 weight percent, based on a total weight of the composition. In other embodiments, this amount is from about 0.1 to about 1.9, about 0.2 to about 1.8, about 0.3 to about 1.7, about 0.4 to about 1.6, about 0.5 to about 1.5, about 0.6 to about 1.4, about 0.7 to about 1.3, about 0.8 to about 1.2, about 0.9 to about 1.1, or about 1, weight percent, based on a total weigh of the composition. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

At Least One Core Polymer

[0064] Referring now to the at least one core polymer itself, the at least one core polymer is independent from the at least one shell polymer. The terminology “at least one” means that a single core polymer may be utilized. Alternatively, more than one core polymer may be utilized. For example, one or more seed polymers may be utilized and then encapsulated, either partially or entirely, by one or more other polymers, wherein the entire complex of seed polymers and encapsulating polymers may be described as a “core” polymer. Any one or more of these seeds polymers and/or encapsulating polymers may be any polymer described herein. Alternatively, the at least one core polymer may be a single core polymer.

[0065] The at least one core polymer can be, include, consist essentially of, or consist of, the polymerization reaction product of monomers present in the first monomer mixture, as first introduced above. For example, the monomers used to form the at least one core polymer may be chosen from a), b), c), d), e), f), and combinations thereof. In one embodiment, only a) and b) are utilized to form the at least one core polymer. In other embodiments, the following combinations are utilized: (a, b, c); (a, b, c, d); (a, b, d); (a, b, c, d, e); (a, b, e); (a, b, c, e); (a, b, d, e); (a, b, c, f); (a, b, c, d, f); (a, b, d, f); (a, b, c, d, e, f); (a, b, e, f); (a, b, c, e, f); (a, b, d, e, f); (a, b, f); (a, c, f); (a, d, f); (a, e, f); (a, b, c, f); (a, b, d, f); (a, b, e, f); and all combinations thereof. Any one or more of c, d, e, and f may be utilized or omitted from use.

[0066] As used herein, the monomers typically described for use in the first monomer mixture are labeled al), bl), cl), dl), el), and fl). The nomenclature “1” describes the potential inclusion in the first monomer mixture. Similarly, and as described in greater detail below, the monomers typically described for use in the second monomer mixture are labeled a2), b2), c2), d2), e2), and f2). The nomenclature “2” describes the potential inclusion in the second monomer mixture. However, the overarching nomenclature and options described herein related to choice of a, b, c, d, e, and f applies to both the “1” and “2” designations. For example, it is contemplated that any of al) and a2) may be any monomer described herein as “a”, any of bl) and b2) may be any monomer described herein as “b”, any of cl) and c2) may be any monomer described herein as “c”, any of dl) and d2) may be any monomer described herein as “d”, any of el) and e2) may be any monomer described herein as “e”, and any of fl) and f2) may be any monomer described herein as “f”. Moreover, it is contemplated that the descriptions below can also apply to the second monomer mixture, in various non-limiting embodiments.

[0067] Relative to the first monomer mixture, if al) is not present in the first monomer mixture then el) is present in the first monomer mixture. This is because there needs to be some hydrophilic monomer for the particle to swell.

[0068] Moreover, if fl) is not present in the first monomer mixture then al) is present in an amount of from 0 to about 60 mol% based on a total number of moles of monomers in the first monomer mixture. For example, this amount may be about 5 to about 55, about 10 to about 50, about 15 to about 45, about 20 to about 40, about 25 to about 35, or about 30 to about 35, mol %. In still other embodiments, the monomer mixture includes about 12 to about 60 mol % of al) based on a total number of moles of the monomers. In other embodiments, this amount is from greater than about 0 to about 10, about 1 to about 9, about 2 to about 8, about 3 to about 7, about 4 to about 6, or about 4 to about 5, mol % of al) based on a total number of moles of the monomers. In various embodiments, this amount is from about 15 to about 60, about 20 to about 55, about 25 to about 50, about 30 to about 45, or about 35 to about 40, mol % based on a total number of moles of monomer. In various non-limiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein. This is because if fl is not present a stable emulsion is not formed if al is substantially greater than 60 mole%. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[0069] Additionally, if fl) is present in the first monomer mixture then al) is present in an amount of from 0 to about 80 mol% based on a total number of moles of monomers in the first monomer mixture. For example, this amount may be about 5 to about 75, about 10 to about 70, about 15 to about 65, about 20 to about 60, about 25 to about 55, about 30 to about 50, about 35 to about 45, or about 35 to about 40, mol %. In other embodiments, this amount is from greater than about 0 to about 10, about 1 to about 9, about 2 to about 8, about 3 to about 7, about 4 to about 6, or about 4 to about 5, mol % of al) based on a total number of moles of the monomers in the first monomer mixture. This is because fl delivers a high level of hydrophobicity which allows for the formation of stable emulsion. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[0070] Moreover, at least one of bl) and fl) is present in the first monomer mixture. This is because a hydrophobic monomer is needed to form a emulsion. a) Anionic Ethylenically Unsaturated Monomers

[0071] As described above, the a) anionic ethylenically unsaturated monomer may describe al) and/or a2). As used herein, the term "anionic ethylenically unsaturated monomer" means an ethylenically unsaturated monomer which is capable of developing a negative charge when the polymer that it is used to form is in an aqueous solution, and which anionic monomer is not an associative monomer, as described below. One or more may be used as described above.

[0072] In various embodiments, the anionic ethylenically unsaturated monomer is an acid. The anionic ethylenically unsaturated monomers can include, but are not limited to, acrylic acid, methacrylic acid, 2-ethylacrylic acid, a-chloro-acrylic acid, a-cyano acrylic acid, P-methyl-acrylic acid (crotonic acid), a-phenyl acrylic acid, 0-acryloxy propionic acid, sorbic acid, a-chloro sorbic acid, angelic acid, 2-carboxyethyl (meth)acrylate, cinnamic acid, p-chloro cinnamic acid, 0-styryl acrylic acid (l-carboxy-4-phenyl butadiene- 1,3), itaconic acid, maleic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, fumaric acid, tricarboxy ethylene, muconic acid, 2- acryloxypropionic acid, 2-acrylamido-2-methyl propane sulfonic acid, vinyl sulfonic acid, sodium methallyl sulfonate, sulfonated styrene, allyloxybenzene sulfonic acid, and vinyl phosphonic acid. Combinations of anionic ethylenically unsaturated monomers can also be used. In one embodiment, the anionic ethylenically unsaturated monomer may be methacrylic acid, maleic acid, acrylic acid, itaconic acid, 2-acrylamido-2-methyl propane sulfonic acid or mixtures thereof. In one embodiment, most typically the anionic ethylenically unsaturated monomer is methacrylic acid or acrylic acid, or combinations thereof. As used herein, the term “(meth) acrylic” acid is meant to include both acrylic acid and methacrylic acid. Similarly, the term “alkyl (meth)acrylate” as used herein is meant to include alkyl acrylate and alkyl methacrylate. In various non-limiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein. b) Short Chain Hydrophobic Ethylenically Unsaturated Monomers

[0073] As described above, the b) short chain hydrophobic ethylenically unsaturated monomer may describe bl) and/or b2). As used herein, the term “short chain hydrophobic ethylenically unsaturated monomer” means a monomer that has a side chain including a hydrophobe that has 7 or fewer carbon atoms, e.g., 7, 6, 5, 4, 3, 2, or 1 carbon atom. This monomer is hydrophobic and tends to enable the formation of an emulsion system when reacted with am anionic ethylenically unsaturated monomer. One or more may be used as described above.

[0074] In various embodiments, the hydrophobic ethylenically unsaturated monomer can be sparingly soluble in water and have a water solubility of less than about 6, 5, 4, 3, 2, 1.6, 1, etc. grams per about 100 mis of water at about 25°C. These hydrophobic ethylenically unsaturated monomers may include linear or branched alk(en)yl, cycloalkyl, aryl, or alk(en)aryl moieties. [0075] Suitable hydrophobic ethylenically unsaturated monomers include C1-C7 alkyl esters of acrylic acid, maleic acid, itaconic acid and methacrylic acid; C1-C7 alkyl amides of acrylic acid, maleic acid, itaconic acid and methacrylic acid; benzyl (meth)acrylate, phenyl (meth)acrylate, benzyl ethoxylate (meth)acrylate, phenyl ethoxylate (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and styrene, alpha-methyl styrene, vinyl toluene, and p-chlorostyrene; vinyl acetate, vinyl butyrate, vinyl caprolate, vinyl valerate, vinyl hexanoate, vinyl caprolactam, (meth)acrylonitrile, isobutylene, diisobutylene, isoprene, vinyl chloride, vinylidene chloride, and combinations thereof.

[0076] In one embodiment, the bl) hydrophobic ethylenically unsaturated monomers are utilized in an amount such that an amount of al) and bl) sums to about 100 mol%. In various embodiments, the amount of bl) is from about 1 to about 99, about 5 to about 95, about 10 to about 90, about 10 to about 88, about 10 to about 85, about 15 to about 80, about 20 to about 75, about 25 to about 70, about 30 to about 65, about 35 to about 60, about 40 to about 55, or about 45 to about 50, mol% based on a total number of moles of monomer in the first monomer mixture described above typically not including an amount of any crosslinking monomer or agent used. In various nonlimiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein. c) Associative Monomers

[0077] As described above, the c) associative monomer may describe cl) and/or c2). As used herein, the term “associative monomer” describes an ethylenically unsaturated monomer including a hydrophobe and a spacer moiety which allows the hydrophobe to be sufficiently far away from the backbone of the core or shell polymer to form hydrophobic associations in aqueous solutions, and wherein the hydrophobe includes at least six carbon atoms. The spacer moieties are usually ethoxylate groups but any other group that extends the hydrophobe away from the backbone of the core and/or shell polymer may be used. One or more may be used as described above.

[0078] The hydrophobes with a spacer moiety may include, but are not limited to, alcohol ethoxylates, alkylphenoxy ethoxylates, propoxylated/butoxylated ethoxylates, ethoxylated silicones and the like. In an embodiment, the typical hydrophobes with spacer moieties include alcohol ethoxylates and/or alkylphenoxy ethoxylates. In another embodiment, alcohol ethoxylates have carbon chain lengths of from about 6 to about 40 and from about 6 to about 100 moles of ethoxylation. In yet another embodiment, alcohol ethoxylates have carbon chain lengths of from about 12 to about 22 and from about 15 to about 30 moles of ethoxylation. In various non-limiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein.

[0079] The hydrophobes may be linear or branched alk(en)yl, cycloalkyl, aryl, alk(en)aryl or an alkoxylated derivative. In an embodiment, the most typical hydrophobes are linear or branched alcohols and amines that include about 12 to about 32 carbons. The associative monomer may include an ethylenically unsaturated monomer covalently linked to the hydrophobe. In an embodiment, the ethylenically unsaturated monomer part of the associative monomer typically is a (meth)acrylate, itaconate and/or maleate which includes ester linking groups. However, the associative monomer may also include amide, urea, urethane, ether, alkyl, aryl and other suitable linking groups. The hydrophobe may be an alkylamine or dialkylamine ethoxylate. In an embodiment, the (meth)acrylate group is most typical. In another embodiment, typical associative monomers are Ci2-₃2(EO)io-₃o meth(acrylates) or Ci2-₃2(EO)io-₃o itaconates or Ci2-₃2(EO)io-₃o maleates.

[0080] In one embodiment, the associative monomer has the structure of formula (I) wherein:

Ri is chosen from -H, -CH₃, -COOH, or -CH2COOH;

A is chosen from -CH₂C(O)O-, -C(O)O-, -O-, -CH2O-, -CH₂C(O)N-, -C(O)N-, -CH₂-, -O-C(O)-, -NHC(O)O-, -NHC(O)NH-, -C₆H₄(R₅)-NH-C(O)-O-, -C₆H₄(R₅)-NH-C(O)-NH-, -C(O)O-CH₂- CH(CH₂OH)-O-, -C(O)O-CH₂-CH(CH₂OH)-NH-, -C(O)O-CH₂-CH-CH₂(OH)-O-, -C(O)O-CH₂- CH-CH₂(OH)-NH-, -CH2-O-CH₂-CH(CH₂OH)-O-, -CH2-O-CH₂-CH-CH₂(OH)-O-, -CH2-0- CH₂-CH(CH₂OH)-NH-, and -CH2-O-CH₂-CH-CH₂(OH)-NH-;

(R₃-O)n is a polyoxyalkylene, which is a homopolymer, a random copolymer, or a block copolymer of C2 to C₄ oxyalkylene units, wherein each R₃ is independently chosen from -C₂H₄-, -C₃He-, - C₄HS-, or a mixture thereof, and n is an integer of from about 5 to about 250, typically, n is about

5 to about 100, more typically about 10 to about 50 and most typically about 15 to about 30; R₄ is chosen from C6-C36 linear or branched, saturated or unsaturated alk(en)yl or alk(en)aryl, typically C8-C32 linear or branched alk(en)yl, more typically C10-C22 linear alk(en)yl or C10-C32 branched alk(en)yl; and R5 is -CH2- or -(C)(CH3)2--. In various non-limiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein.

[0081] Suitable associative monomers include methacrylate and itaconate esters of a hydrophilic ethoxylate chain and a hydrophobic alkyl chain.

[0082] In one embodiment, the associative monomer is an alkyl ethoxylate methacrylate ester having the structure of formula 1(A):

[0083] In one embodiment the associative monomer is an itaconate-based associative monomer such as cetyl ethoxylate itaconate, behenyl ethoxylate itaconate, or stearyl ethoxylate itaconate having the structure of formula I (B, C, D respectively)

B - Cethyl ethoxylate (20) itaconate Q > Behenyl ethoxylate (25) itaconate

D - Stearyl ethoxylate (20) itaconate [0084] In various embodiments, the associative monomers are utilized in an amount of from about 0.01 mol% to about 3 mol%, or from about 0.05 mol% to about 2 mol%, or from about 0.1 mol% to about 1 mol%, based on a total number of moles in the monomer mixture, In various nonlimiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein.

[0085] In various embodiments, the residue of the one or more optional associative monomers is not present in the at least one core polymer and/or the at least one shell polymer. In other words, in such embodiments, no associative monomers are used. For example, one or more cl) and c2) associative monomers may not be present in the first and/or second monomer mixtures. d) Cross-Linking Monomers (Cross-Linking Agents)

[0086] As described above, the d) cross-linking monomers may describe dl) and/or d2). Referring now to the cross-linking monomers, one or more may be used as described above. Alternatively, these monomers may be omitted from use. In various embodiments, the at least one core polymer is not cross-linked. However, some cross-linking can be used so long as the amount of cross-linking does not overly inhibit the ability of the core-shell polymer to swell as described herein.

[0087] In one embodiment, the at least one shell polymer is formed using the cross-linking monomer/agent while the at least one core polymer is not. Alternatively, both the at least one shell polymer and the at least one core polymer may be formed using the cross-linking monomer/agent. However, if an amount of cross-linker is the same in both polymers, typically the core-shell polymer of this disclosure is not formed and instead a traditional polymer is formed.

[0088] Typically, when the cross-linking monomer/agent is used, the polymer formed therefrom is or includes a partially or substantially-crosslinked network. In one embodiment, the at least one core polymer is formed using the cross-linking monomer/agent such that it is a partially or substantially-crosslinked network, as long as the mole percent of cross-linking monomer/agent used to form the at least one core polymer is less than the mole percent of the cross-linking monomer/agent used to form the at least one shell polymer.

[0089] For example, in various embodiments, the at least one core polymer includes a residue of the one or more crosslinking monomers in an amount that is less than an amount of the residue of the one or more crosslinking monomers in the shell by about 5 mol % of that amount or less. In other words, the at least one core polymer can be formed using a molar amount of the cross-linking monomer/agent that is about 5 mol % less than the amount of the cross-linking monomer/agent used to form the at least one shell polymer. In other embodiments, this amount is from about 5 to about 10 mol % less. In other embodiments, this amount is about 5, 4, 3, 2, 1, or even 0.5, mol % less. In various non-limiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein.

[0090] The cross-linking monomer/agent can be chosen from one or more of a crosslinking monomer having two or more carbon-carbon double bonds, a polyfunctional crosslinking compound that reacts with pendant functional groups on the relevant polymer, and combinations thereof.

[0091] Exemplary cross-linking monomer/agents include di(meth)acrylate compounds such as ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-butylene glycol di(meth)acrylate, 1,6- hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 2,2'-bis(4-(acryloxy-propyloxyphenyl)propane, 2,2'-bis(4-(acryloxydiethoxy-phenyl)propane, and zinc acrylate (i.e., 2(C3H3O2)Zn⁺⁺); tri(meth)acrylate compounds such as, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethyl(ethoxylate)propane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; tetra(meth)acrylate compounds such as ditrimethylolpropane tetra(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, and pentaerythritol tetra(meth)acrylate; hexa(meth) acrylate compounds such as dipentaerythritol hexa(meth) acrylate; allyl compounds such as allyl (meth)acrylate, diallyl phthalate, diallyl itaconate, diallyl fumarate, and diallyl maleate; polyallyl ethers of sucrose having from 2 to 8 alkyl groups per molecule, polyallyl ethers of pentaerythritol such as pentaerythritol diallyl ether, pentaerythritol triallyl ether, and pentaerythritol tetraallyl ether; polyallyl ethers of trimethylolpropane such as trimethylolpropane diallyl ether and trimethylolpropane triallyl ethers, and combinations thereof. Other suitable compounds include divinyl glycol, divinyl benzene, and N,N'-methylenebisacrylamide, and combinations thereof. In another embodiment, suitable monomers can be synthesized via an esterification reaction of a polyol made from ethylene oxide or propylene oxide or combinations thereof with unsaturated anhydride such as maleic anhydride, citraconic anhydride, itaconic anhydride, or an addition reaction with unsaturated isocyanate such as 3 -isopropenyl- a-a-dimethylbenzene isocyanate. [0092] Exemplary polyfunctional cross-linking monomer/agents include polyhaloalkanols such as 1,3 -dichloroisopropanol and 1,3-dibromoisopropanol; sulfonium zwitterions such as the tetrahydrothiophene adduct of novolac resins; haloepoxy alkanes such as epichlorohydrin, epibromohydrin, 2-methyl epichlorohydrin, and epiiodohydrin; polyglycidyl ethers such as 1,4- butanediol diglycidyl ether, glycerine- 1, 3 -diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, bisphenol A-epichlorohydrin epoxy resins and mixtures of the foregoing. e) Nonionic Ethylenically Unsaturated Monomers

[0093] As described above, the e) nonionic ethylenically unsaturated monomers may describe el) and/or e2). As used herein, the term "nonionic ethylenically unsaturated monomer" means an ethylenically unsaturated monomer which does not introduce a charge into the polymer that it is used to form, and which is neither a hydrophobic ethylenically unsaturated monomer nor an associative monomer nor a crosslinker, each as described herein. One or more may be used as described above or may be omitted.

[0094] In various embodiments, nonionic ethylenically unsaturated monomers include, but are not limited to, acrylamide, methacrylamide, N-Ci-C3alkyl(meth)acrylamides and N,N-Ci-Cs dialkyl(meth)acrylamides such as N-methylmethacrylamide, N-ethylacrylamide, N- propylacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, and N,N - dimethylmethacrylamide; vinyl morpholine, vinyl pyrrolidone, vinyl propionate, vinyl butanoate, ethoxylated alkyl, alkaryl or aryl monomers such as methoxypolyethylene glycol (meth)acrylate, allyl glycidyl ether, allyl alcohol, glycerol (meth)acrylate, Ci to C4 hydroxy alkyl esters of (meth)acrylic acid, and others. Nonionic ethylenically unsaturated monomers include (poly) Ci- C4alkoxylated (meth)acrylates such as poly(ethylene glycol)_n (meth)acrylate and polypropylene glycol)n (meth)acrylate where n = 1 to 100, typically 3 to 50, and most typically 5 to 20, ethoxylated C1-C4 alkyl, C1-C4 alkaryl or aryl monomers. In one embodiment, this monomer is methoxypolyethylene glycol (meth) acrylate. The optional Ci to C4 hydroxyalkyl esters of (meth)acrylic acid can include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and (butane diol mono(meth)acrylate). In one embodiment, the monomer is chosen from 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and 2- hydroxybutyl (meth)acrylate. In various non-limiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein.

[0095] In one embodiment, the optional nonionic ethylenically unsaturated monomer is utilized in an amount of from about 0 to about 85, from about 1 to about 85, from about 10 to about 85, about 15 to about 80, about 20 to about 75, about 25 to about 70, about 30 to about 65, about 35 to about 60, about 40 to about 55, or about 45 to about 50, mol% based on a total number of moles of monomer in the monomer mixture described above typically not including an amount of any crosslinking monomer/agent used. In various non-limiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein. f) Long Chain Hydrophobic Ethylenically Unsaturated Monomers

[0096] As described above, the f) long chain hydrophobic ethylenically unsaturated monomers may describe fl) and/or f2). The one or more long chain hydrophobic ethylenically unsaturated monomers have a side chain including a hydrophobe that has 8 or greater carbon atoms. Although there is no particular upper limit for carbon atoms, in various embodiments, the upper limit is about 50, 45, 40, 35, 30, 25, 20, 15, or 10. In other embodiments, the number of carbon atoms is from about 8 to about 32, 10 to about 30, 12 to about 28, 14 to about 26, 16 to about 24, 18 to about 22, or 20 to about 22. In various embodiments, at least one of fl) and f2) is independently chosen from C8-C32 alkyl esters of acrylic acid, maleic acid, itaconic acid and methacrylic acid; C8-C32 alkyl amides of acrylic acid, maleic acid, itaconic acid and methacrylic acid; 10-hydroxy decyl (meth)acrylate, t-butyl styrene, iso-propyl styrene, vinyl octanoate, vinyl nonanoate, vinyl decanoate, vinyl neodecanoate, vinyl laurate, vinyl caprolactam, (meth)acrylonitrile, isobutylene, diisobutylene, isoprene, vinyl chloride, vinylidene chloride, 1 -allyl naphthalene, 2-allyl naphthalene, 1 -vinyl naphthalene, 2-vinyl naphthalene, and combinations thereof. In various nonlimiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein.

[0097] In other embodiments, bl) and/or b2) and/or fl) and/or f2) may be chosen from the following, where appropriate, in view of the above definitions of such monomers: C1-C32 alkyl esters of acrylic and methacrylic acid including methyl (meth)acrylate, ethyl (meth)acrylate, n- propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, iso-butyl (meth)acrylate, n-amyl (meth)acrylate, iso-amyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, benzyl ethoxylate (meth)acrylate, phenyl ethoxylate (meth)acrylate, 6- hydroxyhexyl (meth)acrylate, 10-hydroxy decyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2- butyloctyl (meth)acrylate, 2-hexyldecyl (meth)acrylate, 2-octyldodecyl (meth)acrylate, 2- decyltetradecyl (meth)acrylate, 2-dodecylhexadecyl (meth)acrylate, behenyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth) acrylate; and C4-C32 alkyl amides of acrylic and methacrylic acid, including tertiary butyl (meth)acrylamide, t-octyl (meth)acrylamide, 2-ethylhexyl (meth)acrylamide, n-octyl (meth)acrylamide, lauryl (meth)acrylamide, stearyl (meth)acrylamide, and behenyl (meth)acrylamide, styrene, a-methyl styrene, vinyl toluene, t-butyl styrene, iso-propyl styrene, and p-chlorostyrene; vinyl acetate, vinyl butyrate, vinyl caprolate, vinyl valerate, vinyl hexanoate, vinyl octanoate, vinyl nonanoate, vinyl decanoate, vinyl neodecanoate, vinyl laurate, vinyl caprolactam, (meth)acrylonitrile, butadiene, isobutylene, isoprene, vinyl chloride, vinylidene chloride, 1 -allyl naphthalene, 2-allyl naphthalene, 1 -vinyl naphthalene, 2-vinyl naphthalene, ethyl (meth)acrylate, methyl (meth)acrylate, 2-ethylhexyl acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, t-butyl (meth)acrylate, vinyl acetate, tertiary butyl acrylamide and combinations thereof. In various embodiments, ethyl acrylate, methyl acrylate, methyl methacrylate, vinyl acetate, butyl acrylate and combinations thereof are typical. In other embodiments, exemplary alkyl (meth) acrylate monomers can be chosen from methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-amyl (meth)acrylate, iso-amyl (meth)acrylate, and mixtures thereof. In an embodiment, ethyl acrylate is typical.

[0098] In various embodiments, the amount of the fl) long chain hydrophobic ethylenically unsaturated monomers is from about 1 to about 99, about 5 to about 95, about 10 to about 90, about 10 to about 88, about 10 to about 85, about 15 to about 80, about 20 to about 75, about 25 to about 70, about 30 to about 65, about 35 to about 60, about 40 to about 55, or about 45 to about 50, mol% based on a total number of moles of monomer in the first monomer mixture described above typically not including an amount of any crosslinking monomer or agent used. In various nonlimiting embodiments, all values, both whole and fractional, between and including all of the above, are hereby expressly contemplated for use herein. Shell Polymer

[0099] Referring now to the at least one shell polymer, the at least one shell polymer is independently the polymerization reaction product of the second monomer mixture described above including the a2) optionally one or more anionic ethylenically unsaturated monomers; b2) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 7 or fewer carbon atoms; c2) optionally one or more associative monomers; d2) one or more cross-linking monomers; e2) optionally one or more nonionic ethylenically unsaturated monomers; and f2) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain including a hydrophobe that has 8 or greater carbon atoms. In other words, any of the above may be used to form the at least one shell polymer.

[00100] It is contemplated that any of the above description relative to the components or amounts thereof utilized in forming the at least one core polymer may also apply to the at least one shell polymer, in various non-limiting embodiments. Moreover, any one or more of the amounts of any one of al)-fl) above may also be independently utilized for any one or more of a2)-f2) in the second monomer mixture wherein the weight basis would be the second monomer mixture.

[00101] For example, the monomers used to form the at least one shell polymer may be chosen from a), b), c), d), e), f), and combinations thereof. In one embodiment, only a) and b) are utilized to form the at least one core polymer. In other embodiments, the following combinations are utilized: (a, b, c); (a, b, c, d); (a, b, d); (a, b, c, d, e); (a, b, e); (a, b, c, e); (a, b, d, e); (a, b, c, f); (a, b, c, d, f); (a, b, d, f); (a, b, c, d, e, f); (a, b, e, f); (a, b, c, e, f); (a, b, d, e, f); (a, b, f); (a, c, f); (a, d, f); (a, e, f); (a, b, c, f); (a, b, d, f); (a, b, e, f); and all combinations thereof. Any one or more of c, d, e, and f may be utilized or omitted from use in various non-limiting embodiments.

[00102] In various embodiments, the at least one shell polymer is at least partially cross-linked and includes from about 0.01 mol % to about 10 mol % of the residue of the one or more crosslinking monomers. In various embodiments, this amount is from about 0.05 to about 10, about 0.1 to about 10, about 1 to about 10, about 0.01 to about 0.1, about 0.05 to about 0.1, about 0.1 to about 1, mol%, etc. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein. [00103] In various embodiments, the one or more shell polymers can have any mole percent of residues of the crosslinking agent, as long as the at least one core polymer has a mole percent of residues of the crosslinking agent less than the at least one shell polymer.

[00104] In one embodiment, the residue of the one or more optional associative monomers is present in an amount of greater than zero and up to about 1.5 mol % in the at least one core polymer and/or the at least one shell polymer, e.g. about 0.05 to about 1.5, about 0.1 to about 1.5, about 0.5 to about 1.5, about 0.5 to about 1, or about 0.1 to about 0.15, mol %. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00105] In other embodiments, the at least one shell polymer is at least partially cross-linked and includes from about 0.01 mol % to about 10 mol % of the residue of the one or more crosslinking monomers. In various embodiments, this amount is from about 0.05 to about 10, about 0.1 to about 10, about 1 to about 10, about 0.01 to about 0.1, about 0.05 to about 0.1, about 0.1 to about 1, mol%, etc. In other embodiments, this amount is from about 0.1 to about 2.8, about 0.2 to about 2.7, about 0.3 to about 2.6, about 0.4 to about 2.5, about 0.5 to about 2.4, about 0.6 to about 2.3, about 0.7 to about 2.2, about 0.8 to about 2.1, about 0.9 to about 2, about 1 to about 1.9, about 1.1 to about 1.8, about 1.2 to about 1.7, about 1.3 to about 1.6, or about 1.4 to about 1.5, mol %. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00106] In other embodiments, the at least one core polymer includes from about zero mol % of the residue of the one or more crosslinking monomers up to an amount of less than about 25 mol % of the amount of the residue of the one or more crosslinking monomers present in the at least one shell polymer. In various embodiments, this amount is from about 0.05 to about 25, about 0.1 to about 25, about 1 to about 25, about 0.01 to about 0.1, about 0.05 to about 0.1, about 0.1 to about 1, mol%, etc. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00107] In other embodiments, the at least one core polymer includes about zero mol % of the residue of the one or more crosslinking monomers and further includes the residue of the one or more associative monomers in an amount of greater than zero mol %. This amount may be any amount greater than zero. For example, this amount may be from about 0.05 to about 100, about 0.1 to about 100, about 1 to about 100, about 0.01 to about 0.1, about 0.05 to about 0.1, about 0.1 to about 1, mol%, etc. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00108] In other embodiments, the at least one core polymer includes about zero mol % of the residue of the one or more crosslinking monomers and the at least one shell polymer includes the residue of the one or more associative monomers in an amount of greater than zero mol %. This amount may be any amount greater than zero. For example, this amount may be from about 0.05 to about 100, about 0.1 to about 100, about 1 to about 100, about 0.01 to about 0.1, about 0.05 to about 0.1, about 0.1 to about 1, mol%, etc. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00109] In other embodiments, the at least one core polymer includes about zero mole % of the residue of the one or more crosslinking monomers and the at least one shell polymer is at least partially cross-linked and includes greater than about 0.05 mol % of the residue of the one or more crosslinking monomers. This amount may be any amount greater than about 0.05 mol%. For example, this amount may be from about 0.05 to about 100, about 0.1 to about 100, about 1 to about 100, about 0.01 to about 0.1, about 0.05 to about 0.1, about 0.1 to about 1, mol%, etc. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00110] In one embodiment, the at least one core polymer includes from about 1% to about 95% by weight of one or more shell polymers, based on the total weight of the at least one core polymer. In another embodiment, the at least one core polymer includes about 5 wt% to about 60 wt% of the one or more shell polymers, based on the total weight of the at least one core polymer. In still other embodiments, the at least one shell polymer accounts for greater than about 5 wt% and less than about 90 wt% of a total weight of the monomer residues in the core- shell polymer. This value may be about 5 to about 85, about 10 to about 80, about 15 to about 75, about 20 to about 70, about 25 to about 65, about 30 to about 60, about 35 to about 55, about 40 to about 50, or about 45 to about 55, wt%. In other embodiments, this value is from about 15 to about 40, about 20 to about 35, or about 25 to about 30, wt%. Typically, if the amount is greater than about 90, the shell is too heavy and desired expansion/swelling is limited. This is not desirable. Similarly, if there is too high of a weight percent of shell and too high of a percentage of cross-linking in the shell, then expansion/swelling is hindered which again is undesirable. In various embodiments, the wt % of the shell is about 75 wt% and the amount of residue of the cross-linking monomer/agent is about 0.1 mol %. Similar ratios of shell weight and molar % of crosslinking monomer are also contemplated for use herein. If the weight percent is too low, e.g. less than about 15, 10, or 5 wt%, the core-shell polymer will not be complete and undesirable mixtures of side-products (polymers) will tend to form. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00111] In another embodiment, the at least one core polymer includes about 10 wt% to about 40 wt% or about 15 to about 35 wt % of the one or more shell polymers based on the total weight of the at least one core polymer. In still other embodiments, the at least one core polymer is present in an amount that is greater than about 60 wt% and up to about 95 wt% based on the total weight of the at least one core polymer. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00112] In still other embodiments, at least one shell polymer includes a mol % of residue of the d2) one or more crosslinking monomers that is greater than a mol % of residue of the dl) one of more cross-linking monomers in aid at least one core polymer. For example, this mol% may be 1, 2, 3, 4, 5, 10, 15, 20, 25... up to about 100 mol% greater. In other embodiments, the particle includes two or more shell polymers and at least one shell polymer includes a mol % of residue of the d2) one or more crosslinking monomers that is less than a mol % of residues of the dl) one of more cross-linking monomers in the at least one core polymer. In further embodiments, the at least core shell polymer accounts for greater than 5 wt % and less than about 90 wt % of a total weight of the particle, e.g. about 5 to about 90, about 10 to about 85, about 15 to about 80, about 20 to about 75, about 25 to about 70, about 30 to about 65, about 35 to about 60, about 40 to about 55, or about 50 to about 55, mol%. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein. [00113] In other embodiments, bl) and/or fl) is present in the first monomer mixture in at least about 1 mol% based on a total number of moles of monomers in the first monomer mixture and the al) anionic ethylenically unsaturated monomer is present in the first monomer mixture in 10 mol% or less based on a total number of moles of monomers in the first monomer mixture; and b2) and/or f2) is present in the second monomer mixture in at least about 1 mol% based on a total number of moles of monomers in the second monomer mixture and the a2) anionic ethylenically unsaturated monomer is present in the second monomer mixture in 10 mol% or less based on a total number of moles of monomers in the second monomer mixture. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00114] In still other embodiments, the at least one core polymer is the reaction product of al) and bl) and the at least one shell polymer is the reaction product of a2), b2), and d2); or the at least one core polymer is the reaction product of al), bl) and el) where al) is present in an amount of less than about 20 mol% of the first monomer mixture and el) is present in an amount of greater than about 5 mol% of the first monomer mixture and the at least one shell polymer is the reaction product of a2), b2), d2) and e2) wherein a2) is present in an amount of less than about 20 mol% of the second monomer mixture and e2) is present in an amount of greater than about 5 mol% of the second monomer mixture. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00115] It is contemplated that any of a2), b2), c2), d2), e2), and f2) may independently be present in any of the amounts or ranges of amounts that are described above relative to al), bl), cl), dl), el), and fl) even if one or more of al), bl), cl), dl), el), and fl) is not used or even if the amount of one or more of al), bl), cl), dl), el), and fl) is different from the amount of one or more of a2), b2), c2), d2), e2), and/or f2).

First and Second Shell Polymers

[00116] In other embodiments, the particle, e.g. core-shell polymer, includes a first shell polymer (12) and a second shell polymer (14) wherein the first shell polymer (12) is disposed on and in direct contact with the at least one core polymer (10) and the second shell polymer (14) is disposed on and in direct contact with the first shell polymer (12). Examples are shown in Figures 1-6. [00117] In one embodiment, e.g. as shown in FIG. 1, each of the at least one core polymer (10), the first shell polymer (12), and the second shell polymer (14) has a cross-link density, the crosslink density of the first shell polymer (12) is greater than the cross-link density of the at least one core polymer (10), and the cross-link density of the second shell polymer (14) is greater than the cross-link density of the first shell polymer (12) and greater than the cross-link density of the at least one core polymer (10).

[00118] In another embodiment, e.g. as shown in FIG. 2, each of the at least one core polymer (10), the first shell polymer (12), and the second shell polymer (14) has a cross-link density, the cross-link density of the first shell polymer (12) is greater than the cross-link density of the at least one core polymer (10), and the cross-link density of the second shell polymer (14) is less than the cross-link density of the first shell polymer (12) and greater than the cross-link density of the at least one core polymer (10).

[00119] In another embodiment, e.g. as shown in FIG. 3, each of the at least one core polymer (10), the first shell polymer (12), and the second shell polymer (14) has a cross-link density, the cross-link density of the first shell polymer (12) is less than the cross-link density of the at least one core polymer (10), and the cross-link density of the second shell polymer (14) is greater than the cross-link density of the at least one core polymer (10) and greater than the cross-link density of the first shell polymer (12).

[00120] In another embodiment, e.g. as shown in FIG. 4, each of the at least one core polymer (10), the first shell polymer (12), and the second shell polymer (14) has a cross-link density, the cross-link density of the first shell polymer (12) is greater than the cross-link density of the at least one core polymer (10), and the cross-link density of the second shell polymer (14) is less than the cross-link density of the at least one core polymer (10) and less than the cross-link density of the first shell polymer (12).

[00121] In another embodiment, e.g. as shown in FIG. 5, each of the at least one core polymer (10), the first shell polymer (12), and the second shell polymer (14) has a cross-link density, the cross-link density of the first shell polymer (12) is less than the cross-link density of the at least one core polymer (10), and the cross-link density of the second shell polymer (14) is less than the cross-link density of the at least one core polymer (10) and greater than the cross-link density of the first shell polymer (12). [00122] In another embodiment, e.g. as shown in FIG. 6, each of the at least one core polymer (10), the first shell polymer (12), and the second shell polymer (14) has a cross-link density, the cross-link density of the first shell polymer (12) is less than the cross-link density of the at least one core polymer (10), and the cross-link density of the second shell polymer (14) is less than the cross-link density of the at least one core polymer (10) and less than the cross-link density of the first shell polymer (12).

[00123] It is also contemplated that, e.g. in any one or more of FIGS. 1-6, any one of the described layers may be an outermost layer of the particle or may be an inner layer. The term “outermost” describes an embodiment wherein the layer is disposed such that it forms an exterior layer of the particle that is exposed to the environment and does not include another layer disposed on its exterior. The terminology “inner layer” describes that the layer has another layer disposed on at least one surface/side thereof. The inner layer is not exposed to the environment and is not an outer layer.

[00124] Alternatively, there may be one or more intervening polymers disposed between the at least one shell polymer and the at least one core polymer. Such intervening polymers may be any known in the art and any described herein.

Additives

[00125] The composition may include or be free of one or more additives, e.g. any described herein.

[00126] For example, the pH of the composition can be adjusted with any combination of acidic and/or basic pH adjusting agents known to the art. In various embodiments, an alkaline material is incorporated into the composition to neutralize the core-shell polymer and can be referred to as a neutralizing agent or pH adjusting agent. Many types of neutralizing agents can be used, including inorganic and organic bases, and combinations thereof. Examples of inorganic bases include but are not limited to the alkali metal hydroxides (especially sodium, potassium, and ammonium), and alkali metal salts of inorganic acids, such as sodium borate (borax), sodium phosphate, sodium pyrophosphate, and the like; and mixtures thereof. Examples of organic bases include but are not limited to triethanolamine (TEA), diisopropanolamine, triisopropanolamine, aminomethyl propanol, dodecylamine, cocamine, oleamine, morpholine, triamylamine, triethylamine, tetrakis(hydroxypropyl)ethylenediamine, L-arginine, aminomethyl propanol, 2-amino 2- hydroxymethyl-l,3-propanediol, and PEG-15 cocamine. Alternatively, other alkaline materials can be used alone or in combination with the above mentioned inorganic and organic bases. Such materials include surfactants, surfactant mixtures, pre-neutralized surfactants or materials that when combined in a composition including the polymer is capable of neutralizing or partially neutralizing the carboxyl groups on the polymer backbone. Any material capable of increasing the pH of the composition is suitable.

[00127] Various acidic materials can be utilized as a pH adjusting agent. Such acidic materials include organic acids and inorganic acids, for example, acetic acid, citric acid, tartaric acid, alphahydroxy acids, beta-hydroxy acids, salicylic acid, lactic acid, glycolic acid, and natural fruit acids, or inorganic acids, for example, hydrochloric acid, nitric acid, sulfuric acid, sulfamic acid, phosphoric acid, and combinations thereof. The addition of the acidic pH adjusting agent can be incorporated after the addition of the basic pH adjusting agent in the composition. As with the alkaline pH adjusting agents, other acidic materials can be used alone or in combination with the above mentioned inorganic and organic acids.

[00128] Buffering agents can also be used. Suitable buffering agents include, but are not limited to, alkali or alkali earth metal carbonates, phosphates, bicarbonates, citrates, borates, acetates, acid anhydrides, succinates, and the like, such as sodium phosphate, sodium citrate, sodium acetate, sodium bicarbonate, and sodium carbonate. The pH adjusting agent and/or buffering agent can be utilized in any amount necessary to obtain and/or maintain a desired pH value in the composition. [00129] In addition to the components above, the composition may include, or be free of, other ingredients, for example, fluidizing agents, anti- sedimentation agents, plasticizers, surfactants, anti-foam agents, rheology modifiers, levelling agents, gloss modifiers, preservatives, pH adjustors such as organic amines, biocides, and the like, and combinations thereof. Conventional additives may include, but are not limited to, dispersants, antioxidants, UV stabilizers and absorbers, surfactants, wetting agents, leveling agents, antifoaming agents, anti-cratering agents, or combinations thereof. In various embodiments, one or more organic liquids which may be used as film-forming resins can be used. Examples of such resins include polyamides and cellulose ethers, such as ethyl cellulose and ethyl hydroxyethyl cellulose, nitrocellulose and cellulose acetate butyrate resins, including mixtures thereof. Examples of paint resins include short oil alkyd/melamine-formaldehyde, polyester/melamine-formaldehyde, thermosetting acrylic/melamine-formaldehyde, long oil alkyd, poly ether polyols and multi-media resins such as acrylic and urea/aldehyde. [00130] The core-shell polymers of this disclosure can provide desirable rheological properties to compositions having a pH of from about 2 to about 12, about 3 to about 10, about 4 to about 9, about 5 to about 8, or about 6 to about 7. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00131] The core-shell polymers can be used in aqueous compositions that include one or more surfactants (e.g., anionic, cationic, amphoteric, non-ionic, and/or combinations of any two or more thereof). In some embodiments the core-shell polymers are useful thickeners in products including active acid components and are useful thickeners and emulsifiers for emulsions. The core-shell polymers can be used as film formers, spreading aids and deposition aids for products including surfactants, colorants, silicones, etc.

[00132] As used herein, polymers may be described as including a certain weight or mole percentage of a monomer, crosslinker, etc. It is to be appreciated that this terminology describes that the polymer includes the residue of such compounds because such compounds no longer exist after polymerization.

[00133] The composition may further include, or be free of, a non-ionic synthetic associative thickener (NSAT). Non-ionic synthetic associative thickeners can be used to provide viscosity and rheological control. These thickeners are typically non-ionic, meaning they do not carry any net charge in solution. These thickeners typically work by forming associations or interactions with other molecules, such as water or polymer chains, to increase viscosity.

[00134] Hydrophobically Modified Ethoxylated Urethanes (HEUR) thickeners typically include a polyethylene oxide (PEO) backbone with hydrophobic groups (such as alkyl chains) attached via urethane linkages. These hydrophobic groups interact with each other and with the hydrophobic domains of other molecules, leading to thickening. In various embodiments, the composition includes less than about 2, 1.5, 1, 0.5, or 0.1, weight % actives of a hydrophobically modified ethoxylated polyurethane (HEUR) based on a total weight of the composition. Alternatively, the composition may be free of such a polyurethane.

[00135] Hydrophobically Modified Cellulosics (HMHECs) thickeners are cellulose derivatives modified with hydrophobic groups, such as alkyl or alkylaryl moieties, attached to the cellulose backbone. These hydrophobic groups facilitate the association of cellulose chains, leading to increased viscosity. [00136] Hydrophobically Modified Polyacrylic Acid (HMPAA) thickeners are based on polyacrylic acid (PAA) or its derivatives modified with hydrophobic groups. These hydrophobic modifications allow the polymer chains to associate with each other and with other molecules in the system, resulting in thickening.

[00137] Hydrophobically Modified Polyurethanes (HMPU) thickeners are polyurethane-based polymers modified with hydrophobic groups. Similar to other associative thickeners, the hydrophobic groups facilitate the association of polymer chains, leading to viscosity enhancement. [00138] In some embodiments, inclusion of one or more non-ionic synthetic associative thickeners (NSAT) can build KU to unacceptable levels without a corresponding increase in ICI to desired levels. However, in other embodiments, it is preferred to include one or more non-ionic synthetic associative thickeners (NSAT). In various embodiments, the non-ionic synthetic associative thickener is present in an amount of from about 0.01 to about 5, about 0.05 to about 2%, or about 0.1 to about 1, weight percent, based on a total weight of the composition. In other embodiments, this amount is from about 0.01 to about 0.09, about 0.02 to about 0.08, about 0.03 to about 0.07, about 0.04 to about 0.06, about 0.04 to about 0.05, from about 0.1 to about 0.9, about 0.2 to about 0.8, about 0.3 to about 0.7, about 0.4 to about 0.6, about 0.4 to about 0.5, about 1 to about 5, about 2 to about 4, or about 2 to about 3, weight percent, based on a total weight of the composition. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

Alkali-Swellable

[00139] In various embodiments, the particle is further defined as an alkali swellable particle. The terminology “alkali swellable” means that, in these embodiments, the particle can swell when exposed to alkali conditions, e.g. in water, in a composition etc. In various embodiments, the swelling of the composition can be measured via laser diffraction, e.g. using a particle size analyzer such as a Malvern Mastersizer. Any method can be used, e.g. ASTM E3340-22, ASTM D1921- 18, International Standard ISO 13320-1, etc. Moreover, diameters may be reported as xio (D_v10), xso (D_v50), X90 (D_v90), and D[4,3] (volume moment mean), etc. Said a different way, any one or more of DvlO and/or DnlO, Dv50 and/or Dn50, Dv90 and/or Dn90, may be used to report and evaluate particle size Moreover, any type of instrument type, software version, light scattering model applied, real and imaginary part of complex refractory index if Mie theory is applied, etc. may be used as specified in such methods.

[00140] In various embodiments, particle size can be calculated as follows using a Malvern Zetasizer Nano S. For example, three measurements are performed in succession, with the number of runs per measurement automatically determined by the instrument. Measuring position and attenuation are set automatically by the instrument. The measurement sequence is performed at 25°C after a 120 second equilibration time. The preset values for water viscosity (0.8872 centipoise) and refractive index (1.330) are used for the dispersant parameters. A refractive index and absorption for the samples are set at 1.590 and 0.010, respectively. At the completion of the sample measurement sequence, cumulants and distribution analyses are performed by the instrument software (Malvern Zetasizer Software, version 7.10). The reported z-average (in nm) is used as the measure of particle size. In some instances, the particle size distribution can be such that a cumulants analysis is not successful (as indicated by instrument software quality reports) and therefore the z-average, while reported, may not be reliably calculated. In such cases where the cumulants analysis/z-average fails to be reliable, and if the distribution analysis passes quality checks as indicated by the instrument software, then the particle size of the highest volume fraction peak of the volume particle size distribution as reported by the instrument software can be used as the particle size.

[00141] In various embodiments, the particle has a first diameter measured at a pH of from about 3 to about 5, and has a second diameter measured at a pH of about 8, wherein the second diameter is larger than the first diameter. For example, the second diameter may be about 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50... up to about 100% or more, larger than the first diameter. Again, this diameter may be measured and reported using any method described above or known in the art so long as the first and second diameters are measured using the same method for accurate comparison. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

Viscosity Modification of the Composition

[00142] Without intending to be limited by theory, it is believed that the core-shell polymer swells when neutralized in the composition which increases the viscosity of the composition. The swelling of the core-shell polymer are also thought to affect both the low shear, medium shear (KU viscosity) and high shear (ICI viscosity) viscosity profile.

[00143] In various embodiments, the composition exhibits an ICI viscosity of greater than about 0.8 Poise and exhibits a KU viscosity of less than about 140 Krebs units. In other embodiments, the composition exhibits an ICI viscosity of greater than about 0.6 Poise and exhibits a KU viscosity of less than about 140 Krebs units. In various embodiments, the ICI viscosity is from about 0.6 to about 2, about 0.7 to about 2, about 0.8 to about 2, about 0.9 to about 1.9, about 1 to about 1.8, about 1.2 to about 1.7, about 1.3 to about 1.6, about 1.4 to about 1.5, Poise. In other embodiments, the ICI viscosity is greater than about 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9, Poise. In still other embodiments, the ICI viscosity is from about 1.2 to about 1.7, about 1.2 to about 1.6, about 1.2 to about 1.5, about 1.5 to about 2, about 1.6 to about 1.9, about 1.6 to about 1.8, about 1.5 to about 1.8, etc., Poise, typically measured at about 25°C. ICI viscosity can be determined using methods in accordance with ASTM D4287, ISO 2884 and BS 2900. More specifically, ICI viscosity is typically obtained using a Brookfield CAP 2000+ ICI cone and plate viscometer, high torque model, available from AMETEK Brookfield with USA headquarters in Middleboro, MA. The model is in compliance with ASTM D4287, ISO 2884 and BS 2900. Samples are typically analyzed for ICI viscosity at 25°C, 900 RPM, with a number 1 spindle. Sample temperature is first allowed to equilibrate between the cone and plate for 60 seconds, and then the measurement is run over 30 seconds.

[00144] The viscosity value is obtained using a Cone/Plate Type Viscometer and gives information about the flow properties of the material under high-shear conditions similar to those encountered during application: brushing, spraying, electrostatic disk, or roll coating. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00145] Moreover, the composition can exhibit a KU viscosity of less than about 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, or 90, Krebs units. In various embodiments, the KU viscosity is from about 90 to about 140, about 95 to about 135, about 100 to about 130, about 105 to about 125, about 110 to about 120, about 115 to about 120, about 100 to about 110, about 100 to about 105, or about 105 to about 110, Krebs units typically measured at about 23°C. KU viscosity is determined using ASTM D562. KU viscosity is typically reported in Krebs units (KU), which tend to be unique to Stormer viscometers and the like. Vibrating viscometers, such as resonant or vibrational viscometers, can also be used. Most typically, approximately 300 grams of the composition is added to a 12 oz, wide mouth plastic jar and then analyzed for KU viscosity using a DS Byko-visc model Stormer viscometer manufactured by BYK-Gardner Gmbh headquartered in Geretsried, Germany, in compliance with ASTM D 562 and run at 200 rpm at about 23°C using paddle spindle 8340. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00146] The relative importance of ICI and KU viscosities depends on the formulation typically broken down in to Do-It-Yourself (DIY) and contractor formulations. Pigment volume concentration, or PVC, is used to describe the volume (not weight) of pigment in a paint film. PVC denotes how much of the volume of the paint film is made up of pigment versus the amount made up of binder. Critical pigment volume concentration or CPVC is the pigment concentration where the pigments are packed as close as possible and the binder is exactly the amount required to fill the space between the pigments. In many DIY premium paints, the PVC is typically lower than the CPVC. In contractor formulations, the PVC is typically higher than the CPVC.

[00147] In most premium DIY paint formulations, a KU viscosity of from about 95 to about 105 and an ICI viscosity of about 1.2 to about 1.5 is desirable. In contractor formulations, the KU viscosity typically is from about 95 to about 120 while the ICI viscosity is typically about 0.6 or greater. In certain geographies the contractor will dilute the formulation such that a lower drop in KU viscosity can be useful. Surprisingly, the polymers of this disclosure exhibit a lower drop in KU viscosity upon dilution, as exemplified in at least Examples HH and II described below, as compared to a control formulation.

Core-Shell Polymer Preparation

[00148] The core-shell polymer may be formed using any method in the art. More specifically, the core-shell polymer includes at least two polymers (i.e., the at least one core polymer and the at least one shell polymer) which may be synthesized using any methods known in the art. For example, the polymerization may occur sequentially via free radical emulsion polymerization techniques known to the art.

Core Polymer Synthesis [00149] In various embodiments, the at least one core polymer is synthesized in a first emulsion polymerization step from the first monomer mixture including one or more of al)-fl) described above. A chain transfer agent also can be used, as described in greater detail below.

[00150] In another embodiment, a first monomer pre-emulsion may be utilized wherein the first monomer mixture can be emulsified in a water and surfactant mixture in a first vessel before being added to a reactor where emulsion polymerization takes place. In another embodiment, the first monomer mixture has no added water or surfactant before being added to the reactor where emulsion polymerization takes place.

[00151] The monomers al)-fl)may be polymerized in the presence of a suitable free radical forming initiator, e.g. to provide an emulsion of the at least one core polymer. In one embodiment, the polymerization typically begins with a “seed” process in which seed polymer particles are formed that serve as loci for subsequent polymerization.

[00152] In a free radical emulsion polymerization, free radical initiators that generate a free radical during the polymerization process are utilized. As used herein, the initiating system may be any free radical initiating system. The free radical initiators are typically present in an amount of from about 0.01 wt% to about 3 wt% based on total monomer weight. In an embodiment, the initiating system is soluble in water to at least 0.1 weight percent at 25°C. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00153] Suitable initiators include, but are not limited to, peroxides, azo initiators as well as redox systems, such as hydrogen peroxide and erythorbic acid, and metal ion based initiating systems. Initiators may also include both inorganic and organic peroxides, such as hydrogen peroxide, benzoyl peroxide, acetyl peroxide, and lauryl peroxide; organic hydroperoxides, such as cumene hydroperoxide and t-butyl hydroperoxide. In an embodiment, the inorganic peroxides, such as sodium persulfate, potassium persulfate and ammonium persulfate, are typical. In another embodiment, the initiators include metal ion based initiating systems including Fe and hydrogen peroxide, as well as Fe in combination with other peroxides. Organic peracids such as peracetic acid can be used. Peroxides and peracids can optionally be activated with reducing agents, such as sodium bisulfite, sodium formaldehyde, or ascorbic acid, transition metals, hydrazine, and the like. Azo initiators, especially water soluble azo initiators, may also be used. Water soluble azo initiators include, but are not limited to, 2,2'-Azobis[2-(2-imidazolin-2- yl)propane]dihydrochloride, 2,2'-Azobis[2-(2-imidazolin-2-yl)propane]disulfate dihydrate, 2,2'- Azobis(2-methylpropionamidine)dihydrochloride, 2,2'-Azobis[N-(2-carboxyethyl)-2- methylpropionamidine]hydrate, 2,2'-Azobis{2-[l-(2-hydroxyethyl)-2-imidazolin-2- yl]propane} dihydrochloride, 2,2'-Azobis[2-(2-imidazolin-2-yl)propane], 2,2'-Azobis(l -imino- 1- pyrrolidino-2-ethylpropane)dihydrochloride, 2,2'-Azobis{2-methyl-N-[l,l-bis(hydroxymethyl)- 2-hydroxyethl]propionamide}, 2,2'-Azobis[2-methyl-N-(2-hydroxyethyl)propionamide] and others.

[00154] Optionally, other emulsion polymerization additives and processing aids which are well known in the emulsion polymerization art, such as auxiliary emulsifiers, solvents, buffering agents, chelating agents, inorganic electrolytes, polymeric stabilizers, biocides, antifoam agents, and pH adjusting agents can be included in the polymerization system. The primary emulsifier is typically an anionic surfactant and these such as sodium lauryl sulfate are well known in the art.

[00155] In one embodiment, an auxiliary emulsifying aid chosen from an ethoxylated Cioto C22 fatty alcohol (or their mixtures) can be added to the reactor. In one embodiment, the fatty alcohol includes from about 5 to about 250 moles of ethoxylation, from about 8 to 100 moles in another aspect, and from about 10 to 50 moles in a further aspect. Exemplary ethoxylated fatty alcohols include lauryl alcohol ethoxylate, myristyl alcohol ethoxylate, cetyl alcohol ethoxylate, stearyl alcohol ethoxylate, cetearyl alcohol ethoxylate, sterol ethoxylate, oleyl alcohol ethoxylate, and behenyl alcohol ethoxylate. In another aspect, suitable ethoxylated fatty alcohols include Ceteth- 20, Ceteareth-20, and Steareth-20, Behenth-25, and mixtures thereof. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00156] If employed, the amount of ethoxylated fatty alcohol can be from about 0.01% to 10% by weight in one embodiment, from about 0.1% to about 5% by weight in another aspect, and from about 0.3% to about 3% by weight in a further aspect, based on a total weight of emulsion basis. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

Two-Stage Polymerization

[00157] The following describes a typical two-stage polymerization which may be utilized or omitted. First, a first monomer mixture including one or more of al )-f 1 ) described above and an optional chain transfer agent are added to a first vessel with mixing and are combined with a solution of emulsifying surfactant (e.g., anionic surfactant) in water to prepare a monomer preemulsion. Optional processing aids can be added as desired (e.g., auxiliary emulsifier(s)).

[00158] The monomers may be introduced to an aqueous charge that optionally includes a surfactant in a reactor either as a monomer pre-emulsion or a separate monomer mixture and aqueous surfactant solution. When the first monomer mixture is used, an aqueous surfactant solution can be added to the reactor at the same time as or directly after the addition of the first monomer mixture. The reactor contents can be stirred and a small amount of free -radical initiator can be added to the reactor to initiate the formation of seed particles, which is known as a seed stage. Upon completion of the seed stage, the first monomer mixture can be added as a as a monomer mixture or monomer pre-emulsion concurrent with an initiator feed, or as a first monomer mixture added concurrently with an aqueous surfactant solution feed and an initiator feed, to the reactor. Alternatively, the initiator can be added prior to the addition of the monomer mixture to the reactor. Typically, core polymer or polymer emulsion has a total polymer solids content of from about 10 to about 45 weight percent. While the at least one core polymer is synthesized in an emulsion, it should be recognized that the at least one core polymer can be supplied in dried powder form if desired. This is particularly useful for adhesives that are redispersible powders.

[00159] Next, the at least one shell polymer is formed in a second polymerization step. The second monomer mixture of a2)-f2) may be added as a monomer mixture or as a monomer pre-emulsion concurrent with an initiator feed, or as a second monomer mixture added concurrently with an aqueous surfactant solution feed and an initiator feed. Alternatively, the initiator can be added prior to the addition of the second monomer mixture to the reactor. The end-product is a two stage polymer including the at least one core polymer surrounded or partially surrounded by the at least one shell polymer.

[00160] In an alternative embodiment, only a portion of the full amount of surfactant to be used is initially present in the reactor, and the remainder is added as a concurrent stream along with the stream of monomer mixture and the stream of initiator, during all steps of the polymerization.

[00161] Optionally, further successive free radical emulsion polymerization stages can be run to obtain multi-layer polymer morphologies such that successive polymer stages differ at least by the mole percent of crosslinking agent utilized in that stage. In a stage where it is desired to have a linear polymer, a monomer mixture can be used that is devoid of crosslinking agent. In a stage where it is desired to have a crosslinked polymer, the monomer mixture will include a crosslinking agent.

[00162] To obtain the desired properties for any particular end-use application, it is possible to adjust any of (i) the relative mole ratios of the individual monomers, (ii) the mass percent of each of the at least one core and the at least one shell polymers, (iii) the choice of monomers, crosslinking agent, or associative monomers in any of the polymers, (iv) the addition rate of first and second monomer mixtures, surfactant solutions, and initiator solutions, and (v) the mole percentage of crosslinking monomer/agent in any of the polymers, etc.

[00163] While the core-shell polymer can be synthesized by successive emulsion polymerization steps to yield an aqueous polymer emulsion, it should be recognized that the core-shell polymer can ultimately be supplied in dried powder form if desired.

[00164] The emulsion polymerization can be carried out in a staged batch process, in a staged semi-batch monomer addition process or multi-step continuous process, or the polymerization can be initiated as a batch process and then the bulk of the monomers can be continuously staged into the reactor (seeded semi-batch process), as described above.

[00165] Typically, the emulsion polymerization reactions are carried out at a reaction temperature of from about 20 to about 99°C. However, higher or lower temperatures can be used. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00166] The emulsion polymerization reactions can be performed in an aqueous or aqueous alcohol medium.

[00167] The surfactant can be added to the first and/or second monomer mixtures to form a preemulsion. Alternatively, the surfactant can be added directly to the reactor during the emulsion polymerization. Alternatively, both methods can be utilized. In one embodiment, the emulsion polymerization is carried out in the presence of surfactant of in the amount of from about 0.01% to about 10% by weight, about 0.1% to about 5%, or about 0.3% to about 3% by weight, each based on a total emulsion weight basis. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein. [00168] Suitable surfactants include anionic, nonionic, amphoteric, and cationic surfactants, as well as mixtures thereof. Most commonly, anionic and nonionic surfactants can be utilized as well as mixtures thereof.

[00169] Suitable anionic surfactants for facilitating emulsion polymerizations are well known in the art and include, but are not limited to, sodium lauryl sulfate, sodium dodecyl benzene sulfonate, sodium (C6-C16) alkyl phenoxy benzene sulfonate, disodium (C6-C16) alkyl phenoxy benzene sulfonate, disodium (C6-C16) di-alkyl phenoxy benzene sulfonate, disodium laureth-3 sulfosuccinate, sodium dioctyl sulfosuccinate, sodium di-sec-butyl naphthalene sulfonate, disodium dodecyl diphenyl ether sulfonate, disodium n-octadecyl sulfosuccinate, phosphate esters of branched alcohol ethoxylates, and the like.

[00170] Nonionic surfactants suitable for facilitating emulsion polymerizations are well known in the polymer art, and include, without limitation, linear or branched alcohol ethoxylates, Cs to C 12 alkylphenol alkoxylates, such as octylphenol ethoxylates, polyoxyethylene polyoxypropylene block copolymers, and the like. Other useful nonionic surfactants include Cs to C22 fatty acid esters of polyoxyethylene glycol, mono and diglycerides, sorbitan esters and ethoxylated sorbitan esters, Cs to C22 fatty acid glycol esters, block copolymers of ethylene oxide and propylene oxide having an HLB value of greater than about 12, ethoxylated octylphenols, and combinations thereof. In another embodiment, linear alcohol alkoxylates include polyethylene glycol ethers of cetearyl alcohol (a mixture of cetyl and stearyl alcohols) sold under the trade names PLURAFAC® C-17, PLURAFAC® A-38 and PLURAFAC® A-39 by BASF Corp. In still another embodiment, polyoxyethylene polyoxypropylene block copolymers include copolymers sold under the trade names PLURONIC® F127, and PLURONIC® L35 by BASF Corp.

[00171] Other suitable nonionic surfactants include, but are not limited to, Ethoxylated linear fatty alcohols such as DISPONIL® A 5060 (Cognis), Ethal LA-23 and Ethal LA-50 (Ethox Chemicals), branched alkyl ethoxylates such as GENAPOL® X 1005 (Clariant Corp.), secondary C12 to O14 alcohol ethoxylates such as TERGITOL® S 15-30 and S 15-40 (Dow Chemical Co.), ethoxylated octylphenol-based surfactants such as TRITON® X-305, X-405 and X-705 (Dow Chemical Co.), IGEPAL® CA 407, 887, and 897 (Rhodia, Inc.), ICONOL® OP 3070 and 4070 (BASF Corp.), SYNPERONIC® OP 30 and 40 (Uniqema), block copolymers of ethylene oxide and propylene oxide such as PLURONIC® L35 and F127 (BASF Corp.), and secondary C11, alcohol ethoxylates such as EMULSOGEN® EPN 407 (Clariant Corp.). Numerous other suppliers are found in the trade literature.

[00172] In addition, suitable surfactants are also described in The Handbook of Industrial Surfactants (Fifth Edition, by Michael and Irene Ash) which is hereby fully incorporated by reference.

[00173] The emulsion polymerization can be carried out in the presence of a suitable polymeric stabilizer. Suitable polymeric stabilizers (also known as protective colloids) for the emulsion polymerization process of this disclosure are water-soluble polymers, including, for example, synthetic polymers, such as polyvinyl alcohol, partially hydrolyzed polyvinyl acetate, polyvinylpyrrolidone, polyacrylamide, polymethacrylamide, carboxylate-functional addition polymers, polyalkyl vinyl ethers and the like; water-soluble natural polymers, such as gelatin, pectins, alginates, casein, starch, and the like; and modified natural polymers, such as methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, allyl modified hydroxyethylcellulose, and the like. In some cases, it can be of advantage to use mixtures of a synthetic and a natural protective colloid, for example, a mixture of polyvinyl alcohol and casein. Further suitable natural polymers are mixed ethers such as methylhydroxy ethylcellulose and carboxy methy Imethy Icellulo se .

[00174] Polymeric stabilizers can be utilized in amounts up to about 10 weight percent based on the total emulsion weight, or up to about 7.5 weight percent, or up to about 5 weight percent, or up to about 2.5 weight percent, or up to about 2 weight percent based on the total emulsion weight. In another embodiment, when utilized, a polymeric stabilizer is included in an amount of from about 0.001 weight percent to about 10 weight percent, or from about 0.01 weight percent to about 7.5 weight percent, or from about 0.1 weight percent to about 5 weight percent, or from about 0.5 weight percent to about 2.5 weight percent, or even from about 1 weight percent to about 2 weight percent, based on the total emulsion weight. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00175] In various embodiments, a polymerization reactor is charged with a desired amount of water, additional surfactant and optional processing aids. The polymerization reactor is equipped with attached inert gas inlet and feed pumps, and the reactor contents are maintained under inert atmosphere and heated with mixing agitation. The contents of the reactor are brought to a temperature of from about 55 to 98°C, and are maintained at those conditions for about one hour. [00176] A seed stage can then be performed in a manner consistent with the addition of monomer and surfactant via a pre-emulsion as described above. The desired amount of core stage monomer pre-emulsion is fed subsurface into the reactor, and a free radical initiator solution is fed separately and concurrently with the core stage monomer mixture into the reactor contents over a period of about one half to two hours. During this time, the reaction temperature is controlled at from about 45 to about 95 °C. After a desired amount of the core monomer mixture has been added to the reactor, the feed may be stopped and, if desired, an additional quantity of free radical initiator can optionally be added to the reactor. The resulting reaction mixture can be held at a temperature of about 45 to 95°C for a time period sufficient to complete or substantially complete the polymerization reaction and obtain a first stage core-shell polymer emulsion. In various nonlimiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00177] The second monomer mixture used for forming the at least one shell polymer can be mixed in a separate vessel following the same procedures as described above. Alternatively, to the first vessel including remaining material from forming the at least one core polymer, a crosslinking agent can be added and mixed with agitation to form the second monomer mixture. Additional monomers can be added if desired.

[00178] In other embodiments, monomers used to form the at least one shell polymer are metered into the reactor at a constant rate and mixed with aforementioned emulsion used to form the at least one core polymer. Simultaneously with a feed used to introduce monomers used to form the at least one shell polymer, a free radical initiator solution in an amount sufficient to reinitiate polymerization can be metered into the reaction mixture, such that the monomers are polymerized in the presence of the at least one core polymer. The temperature is then typically maintained at about 85°C for about one half to two and a half hours or until polymerization is complete. Unreacted monomer can be eliminated by completing a monomer chase step, such as addition of more initiator and/or by adjusting and maintaining temperature for a period of time to maintain radical flux from thermal initiator residues, as is well known in the emulsion polymerization art. [00179] While a typical two- stage polymer process is generally described immediately above, multi-staged or multi-layered polymers can be formed through the sequential emulsion polymerization of monomer charges in the presence of polymer particles of a previously formed emulsion polymer.

[00180] Chain transfer agents can be used in any stage of the polymerization process for any one or more monomers described above or can be omitted. The chain transfer agent can be any chain transfer agent known in the art. Suitable chain transfer agents include, but are not limited to, thio and disulfide containing compounds, such as Cl -Cl 8 alkyl mercaptans, Cl -Cl 8 alkyl mercaptoalcohols, mercaptocarboxylic acids, mercaptocarboxylic esters, thioesters, C1-C18 alkyl disulfides, aryldisulfides, polyfunctional thiols such as trimethylolpropane-tris-(3- mercaptopropionate), pentaerythritol-tetra-(3-mercaptopropionate), pentaerythritol-tetra- (thioglycolate), and pentaerythritol-tetra-(thiolactate), dipentaerythritol-hexa-(thioglycolate), and the like; phosphites and hypophosphites; haloalkyl compounds, such as carbon tetrachloride, bromotrichloromethane, and the like; and catalytic chain transfer agents such as, for example, cobalt complexes (e.g., cobalt (II) chelates).

[00181] In one embodiment, the chain transfer agent is chosen from n-dodecyl mercaptan, methyl mercaptopropionate, and 3-mercaptopropionic acid, 2-mercaptoethanol, combinations thereof and the like, octyl mercaptan, t-dodecyl mercaptan, hexadecyl mercaptan, octadecyl mercaptan, isooctyl 3 -mercaptopropionate, butyl 3 -mercaptopropionate, butyl thioglycolate, isooctyl thioglycolate, and dodecyl thioglycolate.

[00182] The chain transfer agent can be utilized an amount less than about 0.75, about 0.5, about 0.25, or about 0.1, mol% based on the monomers present typically not including the crosslinking agent. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

Additional Embodiments

[00183] In one embodiment, the weight proportion of the at least one shell polymer to the at least one core polymer and the amount of crosslinking agent in each of the at least one shell polymer and the at least one core polymer are selected to provide typical rheological properties for a particular end-use application. [00184] In another embodiment, the at least one core polymer is greater than 5, 10, 20, 30, 40, 50,60 70, 80, 90 wt% of the core-shell polymer. In another embodiment, the core-shell polymer includes at least one core polymer including zero mol% of a residue of a crosslinking agent.

[00185] In some embodiments, the core- shell polymer includes at least one core polymer including a residue of C1-C6 alkyl (meth) acrylate monomers. In some embodiments, the at least one core polymer includes both at least one residue of a C 1-C6 alkyl acrylate monomer and at least one residue of a C1-C6 alkyl methacrylate monomer.

[00186] In other embodiments, the binder is chosen from acrylate, vinyl acrylate, styrene acrylate, and combinations thereof.

[00187] In other embodiments, the binder is chosen from acrylics, vinyl -acrylic, styrene acrylics, ethylene-vinyl acetate, vinyl acetate, alkyd, vinyl chloride, styrene-butadiene, vinyl versatate, vinyl acetate-maleate, and combinations thereof.

[00188] In other embodiments, the at least one core polymer includes a residue of the one or more crosslinking monomers in an amount that is less than an amount of the residue of the one or more crosslinking monomers in the shell by about 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.5, or 0.1, mol % of that amount or less. In various non-limiting embodiments, all whole and fractional values and ranges of whole and fractional values including and between each value set forth above, are hereby expressly contemplated for use herein.

[00189] In other embodiments, the at least one core polymer is the reaction product of a) and b) and the at least one shell polymer is independently the reaction product of a), b), and d).

[00190] In other embodiments, if al or a2 is present in an amount of less than about 10 mol%, then el or e2, respectively, is present in an amount of greater than about 10 mol% and up to any amount described above relative to el and/or e2.

[00191] In various non-limiting embodiments, one or more method steps, process steps, components, etc. may be used herein as is described in WO 2019/096976 and/or U.S. 8,673,277, each of which is expressly incorporated herein in its entirety by reference in non-limiting embodiments.

EXAMPLES

[00192] The following examples are intended to illustrate various embodiments of the disclosed rheology modifiers and formulations including these rheology modifiers, and are not intended to limit the scope of the claims appended hereto. In the following Examples, the terminology “core” monomer mixture/solution and “shell” monomer mixture/solution describe mixtures of monomers that are used to form the “core polymer” and “shell polymer”, respectively, as are described throughout the disclosure. These can be alternatively described as first and second monomer mixtures, respectively.

[00193] In the Examples and accompanying tables, the following materials and abbreviations are used.

BA - n-butyl acrylate available from Arkema, AL

EA - ethyl acrylate available from Sasol-Bayonne, NJ

MAA - methacrylic acid available from Evonik- Avondale, LA

MMA - methyl methacrylate available from Lucite-Nederland, TX

BEI - behenyl ethoxylate itaconate of formula 1(B) available from AkzoNobel Chemicals, NC CD559 - alkyl ethoxylate methacrylate ester of formula 1(A), illustrated above available from AkzoNobel Chemicals, NC

SLS - sodium lauryl sulfate 30% solution available from Royal Coatings and Specialty Polymers, IN

2-ME - 2-mercaptoethanol available from Millipore Sigma, MA

TMPTA - trimethylolpropane triacrylate available from Millipore Sigma, MA

EGDMA - ethylene glycol dimethacrylate available from Millipore Sigma, MA

DAP - diallyl phthalate available from Millipore Sigma, MA

Kathon LX - biocide available from Lanxess, PA

IPEL BP 507 - biocide available from Lanxess, PA

Foamblast 327 - defoamer available from DyStar, North Carolina

Bermocoll Prime 3500 - cellulosic thickener available from Nouryon, IL

Bermocoll Prime 2500 - cellulosic thickener available from Nouryon, IL

Bermocoll EHM Extra - cellulosic thickener available from Nouryon, IL

Bermocoll EHM 200 - cellulosic thickener available from Nouryon, IL

Bermocoll Flow - cellulosic thickener available from Nouryon, IL

Alcosperse 787 - dispersant available from Nouryon, IL

Viscodis 177 - dispersant available from Arkema, PA

Ethylan 1008SA - Alcohol alkoxylates surfactant available from Nouryon, IL

Masodol 900 - nonionic surfactant available from Pilot Chemical, OH AMP-95 - alkanolamine available from Fisher Scientific, MA

Tipure R-902+ - titanium dioxide available from Tipure, DE

Tiona 596 - titanium dioxide available from Tronox, MS

Minex 4 - Nepheline syenite available from Sibelco, NC

Omyacarb 5 - calcium carbonate available from Omya, OH

Karnin 2000C - calcined kaolin clay available from KaMin, GA

Jyck 95 - dehydroxylated aluminium silicate available from Avidco, Singapore

BYK 024 - defoamer available from BYK-Gardner Gmbh, Germany

Texanol - coalescent agent available from Eastman Chemical, TN

Optifilm 300 - coalescent agent available from Eastman Chemical, TN

Celocor AF - opaque polymer available from Arkema, PA

Encor 282 - vinyl acrylic binder available from Arkema, PA

Encor 481 - styrene acrylic binder available from Arkema, PA

Encor 657 - acrylic binder available from Arkema, PA

Hubercarb Q200 - calcium carbonate available from Huber Materials, GA

Suzorite 80-SF - mica available from Imerys, Paris

Expancel 920 WE 40 d24 - dry expanded thermoplastic microspheres available from Nouryon,

IL

P - Poise

Nipacide CFX 3 - biocide available from Clariant, Switzerland

Steatite 10 - micronized talc

Primal AC 261 - acrylic binder available from Dow, MI

Aquaflow NLS-200 - nonionic synthetic associative thickener available from Ashland Specialty Chemical Company, DE

Aquaflow NHS-300 - nonionic synthetic associative thickener available from Ashland Specialty

Chemical Company, DE

Example A

[00194] Example A demonstrates the synthesis of a core/shell particle.

[00195] 278.1 grams of water and 5.72 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00196] A “core” mixture was prepared by adding 75.3 grams methacrylic acid to a solution of 292.4 grams water and 5.72 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 75.2 grams methyl methacrylate, 87.50 grams ethyl acrylate, and 0.1352 grams n-dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 10.9 grams water.

[00197] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 27.4 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.31 grams ammonium persulfate dissolved in 21.8 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes.

[00198] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 75 minutes. Simultaneously, an initiator feed including 126 milligrams ammonium persulfate dissolved in 11.48 grams water was added to the reactor contents over the same 75 minutes.

[00199] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 15 minutes. The “shell” monomer solution was prepared by mixing 15.07 grams methacrylic acid, 15.04 grams methyl methacrylate, 17.5 grams ethyl acrylate, and 0.0991 grams EGDMA, and then mixing the contents thoroughly.

[00200] An initiator feed including 25.2 milligrams ammonium persulfate dissolved in 2.3 grams water was also added over the same 15 minutes as the shell monomer mixture.

[00201] At the completion of the shell monomer mixture addition, 209 milligrams of ammonium persulfate dissolved in 19.0 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature, and to the contents was added 2.1 grams of 50% sodium hydroxide mixed in 19.3 grams water over the course of one half hour. The contents were mixed for 15 minutes. Then to the contents was added 0.35 grams Nalco/Exxon EC9086A mixed in 0.74 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.6 and a solids content of 31.3%.

Example B

[00202] Example B demonstrates the synthesis of a core shell particle with 20 mole % al) and a2) for improved water sensitivity, and the use of el) and e2) (hydroxypropyl acrylate).

[00203] 278.1 grams of water and 5.72 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00204] A “core” mixture was prepared by adding 43 grams methacrylic acid to a solution of 292.4 grams water and 5.72 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 62.6 grams methyl methacrylate, 97.6 grams hydroxypropyl acrylate and then 62.6 grams ethyl acrylate to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 10.9 grams water.

[00205] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 28.7 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.31 grams ammonium persulfate dissolved in 21.8 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes.

[00206] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 75 minutes. Simultaneously, an initiator feed including 126 milligrams ammonium persulfate dissolved in 11.48 grams water was added to the reactor contents over the same 75 minutes.

[00207] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 15 minutes. The “shell” monomer solution was prepared by mixing 8.61 grams methacrylic acid, 12.52 grams methyl methacrylate, 12.52 grams ethyl acrylate, 19.52 grams hydroxypropyl acrylate and 0.0991 grams EGDMA, and then mixing the contents thoroughly. [00208] An initiator feed including 20.3 milligrams ammonium persulfate dissolved in 1.85 grams water was also added over the same 15 minutes as the shell monomer mixture.

[00209] At the completion of the shell monomer mixture addition, 209 milligrams of ammonium persulfate dissolved in 19.02 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature, and to the contents was added 1.2 grams 50% sodium hydroxide mixed in 19.3 grams water over the course of one half hour. The contents were mixed 15 minutes, then to the contents was added 0.44 grams Nalco/Exxon EC9086A mixed in 0.93 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.6 and a solids content of 29.6%.

Example C

[00210] Example C demonstrates the synthesis of a core/shell particle without a2) in the shell.

[00211] 222.48 grams of water and 4.58 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00212] A “core” mixture was prepared by adding 60.24 grams methacrylic acid to a solution of 233.92 grams water and 4.58 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 60.16 grams methyl methacrylate and then 70 grams ethyl acrylate and 0.1082 grams dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 8.72 grams water.

[00213] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 21.9 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.25 grams ammonium persulfate dissolved in 17.44 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes.

[00214] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 75 minutes. Simultaneously, an initiator feed including 100.8 milligrams ammonium persulfate dissolved in 9.18 grams water was added to the reactor contents over the same 75 minutes.

[00215] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 15 minutes. The “shell” monomer solution was prepared by mixing 20.8 grams hydroxypropyl acrylate, 12.03 grams methyl methacrylate, 12 grams ethyl acrylate and 0.0793 grams EGDMA, and then mixing the contents thoroughly.

[00216] An initiator feed including 20.2 milligrams ammonium persulfate dissolved in 1.84 grams water was also added over the same 15 minutes as the shell monomer mixture.

[00217] At the completion of the shell monomer mixture addition, 167 milligrams of ammonium persulfate dissolved in 15.22 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature, and to the contents was added 1.4 grams 50% sodium hydroxide mixed in 15.44 grams water over the course of one half hour. The contents were mixed for 15 minutes. Then to the contents were added 0.35 grams Nalco/Exxon EC9086A mixed in 0.75 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.35 and a solids content of 28.91%.

Example D

[00218] Example D demonstrates the synthesis of a core/shell particle without al) in the core.

[00219] 222.48 grams of water and 4.58 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00220] A surfactant feed solution was prepared by dispensing 242.5 grams of water and 4.58 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) into a 1 liter glass graduated cylinder. The surfactant feed was fed to completion into the reactor contents over a period of 90 minutes, started simultaneously with the 9 minute core feed described below.

[00221] A “core” mixture was prepared by adding 12 grams ethyl acrylate, 10.85 grams methacrylic acid, and 0.1165 grams dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation. [00222] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, 22.96 grams of the core monomer solution was added to the reactor contents, subsurface, over the course of 1 minute. After the contents had been stirring for 15 minutes, an initiator feed including 25 milligrams ammonium persulfate dissolved in 17.44 grams water was also added as a shot to the reactor contents, after which the reactor contents were stirred for 15 minutes.

[00223] After the 15 minutes of stirring, 22.96 grams of the core monomer solution was slowly added to the reactor contents, subsurface, for 9 minutes. Simultaneously, an initiator feed including 12 milligrams ammonium persulfate dissolved in 1.1 grams water was added to the reactor contents over the same 9 minutes.

[00224] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 81 minutes. The “shell” monomer solution was prepared by mixing 64.96 grams methacrylic acid, 75.52 grams ethyl acrylate, 64.73 grams methyl methacrylate, and 0.4272 grams ethylene glycol dimethacrylate, and then mixing the contents thoroughly.

[00225] An initiator feed including 109 milligrams ammonium persulfate dissolved in 9.91 grams water was also added over the same 81 minutes as the shell monomer mixture.

[00226] At the completion of the shell monomer mixture addition, 167 milligrams of ammonium persulfate dissolved in 15.23 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00227] The next day, to the reactor contents was added a mixture of 1.66 grams of 50% sodium hydroxide solution diluted with 15.44 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 1.76 grams Nalco/Exxon EC9086A mixed in 3.52 grams water and the milky white emulsion product was dispensed from the reactor after brief mixing, with a solids content of 29.9%.

Example E

[00228] Example E demonstrates the synthesis of a particle with gradient crosslinking, the crosslinker concentration increasing out from the direction of the interior of the particle to the surface.

[00229] 222.48 grams of water and 4.58 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00230] A “core” mixture was prepared by adding 20.64 grams methacrylic acid to a solution of 233.92 grams water and 4.58 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 60.1 grams methyl methacrylate and then 44.1 grams ethyl acrylate and 0.1082 grams dodecyl mercaptan to a glass beaker and 124.98 grams hydroxypropyl acrylate. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 8.72 grams water.

[00231] A crosslinker mixture was prepared in a separate vessel by adding 4.7592 grams ethylene glycol dimethacrylate to 16 grams ethyl acrylate.

[00232] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 24.8 grams of the monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.25 grams ammonium persulfate dissolved in 17.44 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes.

[00233] Then, the remaining monomer solution was slowly added to the reactor contents, subsurface, for 90 minutes. Simultaneously, the crosslinker mixture was slowly added to the monomer mixture over the same 90 minutes. Simultaneously, an initiator feed including 121 milligrams ammonium persulfate dissolved in 11 grams water was added to the reactor contents over the same 90 minutes.

[00234] At the completion of the monomer and crosslinker mixture additions, 167 milligrams of ammonium persulfate dissolved in 15.22 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00235] The next day, the reactor contents was added a mixture of 0.29 grams of 50% sodium hydroxide solution diluted with 26.24 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 0.35 grams Nalco/Exxon EC9086A mixed in 0.74 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.1 and a solids content of 32.1%.

Example F

[00236] Example F demonstrates the synthesis of a core/shell particle incorporating cl) and c2).. [00237] 278.1 grams of water and 5.72 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00238] A “core” mixture was prepared by adding 97.04 grams methacrylic acid and 2.38 grams 50% solution of CD-559 associative monomer in water to a solution of 292.4 grams water and 5.72 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 63.17 grams methyl methacrylate and then 75.57 grams ethyl acrylate and 0.1363 grams dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 10.9 grams water.

[00239] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 27.36 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.31 grams ammonium persulfate dissolved in 21.8 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes. [00240] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 75 minutes. Simultaneously, an initiator feed including 126 milligrams ammonium persulfate dissolved in 11.48 grams water was added to the reactor contents over the same 75 minutes.

[00241] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 15 minutes. The “shell” monomer solution was prepared by mixing 18.45 grams methacrylic acid, 0.45 grams 50% solution of CD- 559 associative monomer in water, 12.01 grams methyl methacrylate, 14.36 grams ethyl acrylate, and 0.0949 grams EGDMA, and then mixing the contents thoroughly. [00242] An initiator feed including 25.2 milligrams ammonium persulfate dissolved in 2.3 grams water was also added over the same 15 minutes as the shell monomer mixture.

[00243] At the completion of the shell monomer mixture addition, 209 milligrams of ammonium persulfate dissolved in 19.02 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00244] The next day, the reactor contents was added a mixture of 2.97 grams of 50% sodium hydroxide solution diluted with 19.3 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. Then, 2 grams of Nalco/Exxon EC 9086 mixed in 3 grams of water was added to the contents. The milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.2 and a solids content of 28.9%.

Example G

[00245] Example G demonstrates the synthesis of a core/shell particle with the incorporation of fl) and f2).

[00246] 247 grams of water and 7.58 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00247] A “core” mixture was prepared by adding 111.71 grams methacrylic acid to a solution of 275.1 grams water and 7.58 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 62.12 grams methyl methacrylate, 63.54 grams ethyl acrylate, 2.37 grams 2-ethylhexyl acrylate and 0.0888 grams 2-mercaptoethanol to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation.

[00248] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 26.12 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.31 grams ammonium persulfate dissolved in 17.53 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes. [00249] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 100 minutes. Simultaneously, an initiator feed including 101.5 milligrams ammonium persulfate dissolved in 21.98 grams water was added to the reactor contents over the same 120 minutes.

[00250] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 20 minutes. The “shell” monomer solution was prepared by mixing 20.37 grams methacrylic acid, 11.33 grams methyl methacrylate, 11.59 grams ethyl acrylate and 0.0162 grams 2-mercaptoethanol, and 1.94 grams trimethylolpropane triacrylate, then mixing the contents thoroughly.

[00251] An initiator feed including 20.3 milligrams ammonium persulfate dissolved in 4.396 grams water was also added over the same 20 minutes as the shell monomer mixture.

[00252] At the completion of the shell monomer mixture addition, 168 milligrams of ammonium persulfate dissolved in 36.42 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature. The milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 2.47 and a solids content of 29.96%.

Example H

[00253] Example H demonstrates the synthesis of a core/shell particle with 83 mole % a2) with the use of f2 (2-ethylhexyl acrylate). The successful synthesis of an emulsion with such a high amount of a2) is quite surprising in light of the fact that 65 mole% or more of anionic ethylenically unsaturated monomer content with bl or b2 alone leads to coagulation and destabilization of emulsion polymers.

[00254] 278.1 grams of water and 5.72 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00255] A “core” mixture was prepared by adding 76.33 grams methacrylic acid to a solution of 292.4 grams water and 5.72 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 76.06 grams methyl methacrylate, 88.74 grams ethyl acrylate and 0.1370 grams n-dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 10.9 grams water.

[00256] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 21.89 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.31 grams ammonium persulfate dissolved in 21.8 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes. [00257] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 75 minutes. Simultaneously, an initiator feed including 126 milligrams ammonium persulfate dissolved in 11.48 grams water was added to the reactor contents over the same 75 minutes.

[00258] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 15 minutes. The “shell” monomer solution was prepared by mixing 32.18 grams methacrylic acid, 13.66 grams 2-ethylhexyl acrylate, and 0.0926 grams EGDMA, and then mixing the contents thoroughly.

[00259] An initiator feed including 25.2 milligrams ammonium persulfate dissolved in 2.3 grams water was also added over the same 15 minutes as the shell monomer mixture.

[00260] At the completion of the shell monomer mixture addition, 209 milligrams of ammonium persulfate dissolved in 19 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature. Over the course of 30 minutes, to the contents were added 2.77 grams 50% sodium hydroxide in 29.3 grams water. To the contents were added 2 grams Nalco/Exxon EC9086A mixed in 3 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 4.7 and a solids content of 28.6%.

[00261] Examples I-M demonstrate the synthesis of polymer particles with three layers (a core and two shells), each with various levels of crosslinker. The examples also demonstrate such multilayered particles with varying anionic ethylenically unsaturated monomer content, as well as the use of a hydroxyl containing monomer (a nonionic ethylenically unsaturated monomer), hydroxyethyl acrylate.

Example I [00262] 266.1 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00263] A surfactant feed solution was prepared by dispensing 280.7 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) into a 1 liter glass graduated cylinder. The surfactant feed was fed to completion into the reactor contents over a period of 90 minutes, started simultaneously with Layer 1.

[00264] A “Layer 1” mixture was prepared by adding 43.41 grams methacrylic acid to a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 93.74 grams ethyl acrylate and 0.1423 grams dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation.

[00265] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, the Layer 1 monomer solution was slowly added to the reactor contents, subsurface, for 45 minutes. Simultaneously, an initiator feed including 72 milligrams ammonium persulfate dissolved in 6.54 grams water was added to the reactor contents over the same 45 minutes.

[00266] At the completion of the “Layer 1” monomer mixture feed, a "Layer 2" monomer mixture was added subsurface into the reactor from a graduated cylinder over 23 minutes. The “Layer 2” monomer solution was prepared by mixing 5.16 grams methacrylic acid, 38.97 grams ethyl acrylate, 19.48 grams hydroxypropyl acrylate, 0.0592 grams dodecyl mercaptan and 4.9689 grams trimethylolpropane triacrylate, and then mixing the contents thoroughly.

[00267] An initiator feed including 37 milligrams ammonium persulfate dissolved in 3.34 grams water was also added over the same 23 minutes as the Layer 2 monomer mixture.

[00268] At the completion of the “Layer 2” monomer mixture feed, a "Layer 3" monomer mixture was added subsurface into the reactor from a graduated cylinder over 23 minutes. The “Layer 3” monomer solution was prepared by mixing 20.8 grams methacrylic acid, 44.91 grams ethyl acrylate, 0.0682 grams dodecyl mercaptan and 2.8630 grams trimethylolpropane triacrylate, and then mixing the contents thoroughly. [00269] An initiator feed including 37 milligrams ammonium persulfate dissolved in 3.34 grams water was also added over the same 23 minutes as the Layer 3 monomer mixture.

[00270] At the completion of the Layer 3 monomer mixture addition, 200 milligrams of ammonium persulfate dissolved in 18.23 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00271] The next day, the reactor contents was added a mixture of 1.61 grams of 50% sodium hydroxide solution diluted with 18.53 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 2.11 grams Nalco/Exxon EC9086A mixed in 4.22 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.5 and a solids content of 29.1%.

Example J

[00272] 266.98 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00273] A surfactant feed solution was prepared by dispensing 280.7 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) into a 1 liter glass graduated cylinder. The surfactant feed was fed to completion into the reactor contents over a period of 90 minutes, started simultaneously with Layer 1.

[00274] A “Layer 1” mixture was prepared by adding 12.95 grams ethyl acrylate and 0.0128 grams dodecyl mercaptan to a glass graduated cylinder.

[00275] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, the Layer 1 monomer solution was slowly added to the reactor contents, subsurface, for 1 minute. Simultaneously, an initiator feed including 1 milligram ammonium persulfate dissolved in 0.1 grams water was added to the reactor contents over the same 1 minute.

[00276] At the completion of the “Layer 1” monomer mixture feed, a "Layer 2" monomer mixture was added subsurface into the reactor from a graduated cylinder over 71 minutes. The “Layer 2” monomer solution was prepared by mixing 66.52 grams methacrylic acid, 143.63 grams ethyl acrylate, 0.2180 grams dodecyl mercaptan and 6.5409 grams trimethylolpropane triacrylate in a glass graduated cylinder, and then mixing the contents thoroughly.

[00277] An initiator feed including 103 milligrams ammonium persulfate dissolved in 7.26 grams water was also added over the same 71 minutes as the Layer 2 monomer mixture.

[00278] At the completion of the “Layer 2” monomer mixture feed, a "Layer 3" monomer mixture was added subsurface into the reactor from a graduated cylinder over 14 minutes. The “Layer 3” monomer solution was prepared by mixing 12.63 grams methacrylic acid, 27.28 grams ethyl acrylate, 0.0414 grams dodecyl mercaptan and 3.9752 grams trimethylolpropane triacrylate, and then mixing the contents thoroughly.

[00279] An initiator feed including 20 milligrams ammonium persulfate dissolved in 1.43 grams water was also added over the same 14 minutes as the Layer 3 monomer mixture.

[00280] At the completion of the Layer 3 monomer mixture addition, 173 milligrams of ammonium persulfate dissolved in 12.14 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00281] The next day, the reactor contents was added a mixture of 1.84 grams of 50% sodium hydroxide solution diluted with 18.53 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 2.5 grams Nalco/Exxon EC9086A mixed in 5 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.6 and a solids content of 29.4%.

Example K

[00282] 266.98 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00283] A surfactant feed solution was prepared by dispensing 280.7 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) into a 1 liter glass graduated cylinder. The surfactant feed was fed to completion into the reactor contents over a period of 90 minutes, started simultaneously with Layer 1.

[00284] A “Layer 1” mixture was prepared by adding 4.17 grams methacrylic acid, 9 grams ethyl acrylate and 0.0137 grams dodecyl mercaptan and 0.5482 grams ethylene glycol dimethacrylate to a glass graduated cylinder.

[00285] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, the Layer 1 monomer solution was slowly added to the reactor contents, subsurface, for 4.5 minutes. Simultaneously, an initiator feed including 300 milligram ammonium persulfate dissolved in 20.93 grams water was added to the reactor contents over the same 4.5 minutes.

[00286] At the completion of the “Layer 1” monomer mixture feed, a "Layer 2" monomer mixture was added subsurface into the reactor from a graduated cylinder over 14.4 minutes. The “Layer 2” monomer solution was prepared by mixing 23.13 grams methacrylic acid, 17.92 grams ethyl acrylate, 0.0442 grams dodecyl mercaptan and 2.8391 grams ethylene glycol dimethacrylate in a glass graduated cylinder, and then mixing the contents thoroughly.

[00287] An initiator feed including 24 milligrams ammonium persulfate dissolved in 2.23 grams water was also added over the same 14.4 minutes as the Layer 2 monomer mixture.

[00288] At the completion of the “Layer 2” monomer mixture feed, a "Layer 3" monomer mixture was added subsurface into the reactor from a graduated cylinder over 71.1 minutes. The “Layer 3” monomer solution was prepared by mixing 68.45 grams methacrylic acid, 147.8 grams ethyl acrylate, 0.2244 grams dodecyl mercaptan and 0.4502 grams ethylene glycol dimethacrylate, and then mixing the contents thoroughly.

[00289] An initiator feed including 121 milligrams ammonium persulfate dissolved in 11 grams water was also added over the same 71.1 minutes as the Layer 3 monomer mixture.

[00290] At the completion of the Layer 3 monomer mixture addition, 200 milligrams of ammonium persulfate dissolved in 18.26 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00291] The next day, the reactor contents was added a mixture of 2.23 grams of 50% sodium hydroxide solution diluted with 18.53 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 2.5 grams Nalco/Exxon EC9086A mixed in 5 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.6 and a solids content of 28.9%.

Example L

[00292] 266.98 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00293] A surfactant feed solution was prepared by dispensing 280.7 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) into a 1 liter glass graduated cylinder. The surfactant feed was fed to completion into the reactor contents over a period of 90 minutes, started simultaneously with Layer 1.

[00294] A “Layer 1” mixture was prepared by adding 3.99 grams methacrylic acid, 8.62 grams ethyl acrylate, 0.0131 grams dodecyl mercaptan and 1.1028 grams ethylene glycol dimethacrylate to a glass graduated cylinder.

[00295] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, the Layer 1 monomer solution was slowly added to the reactor contents, subsurface, for 1 minute. Simultaneously, an initiator feed including 300 milligrams ammonium persulfate dissolved in 20.93 grams water was added to the reactor contents over the same 1 minute.

[00296] At the completion of the “Layer 1” monomer mixture feed, a "Layer 2" monomer mixture was added subsurface into the reactor from a graduated cylinder over 67 minutes. The “Layer 2” monomer solution was prepared by mixing 65.12 grams methacrylic acid, 140.6 grams ethyl acrylate, and 0.2134 grams dodecyl mercaptan in a glass graduated cylinder, and then mixing the contents thoroughly.

[00297] An initiator feed including 115 milligrams ammonium persulfate dissolved in 10.44 grams water was also added over the same 67 minutes as the Layer 2 monomer mixture.

[00298] At the completion of the “Layer 2” monomer mixture feed, a "Layer 3" monomer mixture was added subsurface into the reactor from a graduated cylinder over 18 minutes. The “Layer 3” monomer solution was prepared by mixing 12.63 grams methacrylic acid, 27.28 grams ethyl acrylate, 0.0414 grams dodecyl mercaptan and 3.9752 grams trimethylolpropane triacrylate, and then mixing the contents thoroughly. [00299] An initiator feed including 31 milligrams ammonium persulfate dissolved in 2.78 grams water was also added over the same 18 minutes as the Layer 3 monomer mixture.

[00300] At the completion of the Layer 3 monomer mixture addition, 200 milligrams of ammonium persulfate dissolved in 18.23 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00301] The next day, the reactor contents was added a mixture of 2.17 grams of 50% sodium hydroxide solution diluted with 18.53 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 2.5 grams Nalco/Exxon EC9086A mixed in 5 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.5 and solids content of 29.8%.

Example M

[00302] 266.98 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00303] A surfactant feed solution was prepared by dispensing 280.7 grams of water and 5.49 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) into a 1 liter glass graduated cylinder. The surfactant feed was fed to completion into the reactor contents over a period of 90 minutes, started simultaneously with Layer 1.

[00304] A “Layer 1” mixture was prepared by adding 3.99 grams methacrylic acid, 3.99 grams methacrylic acid, 8.62 grams ethyl acrylate, 0.0131 grams dodecyl mercaptan and 1.1028 grams ethylene glycol dimethacrylate to a glass graduated cylinder.

[00305] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, the Layer 1 monomer solution was slowly added to the reactor contents, subsurface, for 1 minute. Simultaneously, an initiator feed including 300 milligrams ammonium persulfate dissolved in 20.93 grams water was added to the reactor contents over the same 1 minute.

[00306] At the completion of the “Layer 1” monomer mixture feed, a "Layer 2" monomer mixture was added subsurface into the reactor from a graduated cylinder over 40 minutes. The “Layer 2” monomer solution was prepared by mixing 36.92 grams methacrylic acid, 79.72 grams ethyl acrylate, and 0.1210 grams dodecyl mercaptan and 6.7992 grams ethylene glycol dimethacrylate in a glass graduated cylinder, and then mixing the contents thoroughly.

[00307] An initiator feed including 68 milligrams ammonium persulfate dissolved in 6.22 grams water was also added over the same 40 minutes as the Layer 2 monomer mixture.

[00308] At the completion of the “Layer 2” monomer mixture feed, a "Layer 3" monomer mixture was added subsurface into the reactor from a graduated cylinder over 45 minutes. The “Layer 3” monomer solution was prepared by mixing 23.89 grams methacrylic acid, 89.51 grams ethyl acrylate, 23.96 grams hydroxyethyl acrylate, and 0.1359 grams dodecyl mercaptan, and then mixing the contents thoroughly.

[00309] An initiator feed including 77 milligrams ammonium persulfate dissolved in 7 grams water was also added over the same 45 minutes as the Layer 3 monomer mixture.

[00310] At the completion of the Layer 3 monomer mixture addition, 200 milligrams of ammonium persulfate dissolved in 18.23 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00311] The next day, the reactor contents was added a mixture of 1.50 grams of 50% sodium hydroxide solution diluted with 18.53 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 2.5 grams Nalco/Exxon EC9086A mixed in 5 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.5 and a solids content of 29.8%.

[00312] Examples N and O demonstrate the synthesis of core/shell materials with an ethoxylated crosslinker.

Example N

[00313] 278.1 grams of water and 5.72 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00314] A “core” mixture was prepared by adding 75.3 grams methacrylic acid to a solution of 292.4 grams water and 5.72 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 75.2 grams methyl methacrylate and then 87.5 grams ethyl acrylate and 0.1352 grams dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 10.9 grams water.

[00315] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 27.4 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.31 grams ammonium persulfate dissolved in 21.8 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes.

[00316] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 75 minutes. Simultaneously, an initiator feed including 126 milligrams ammonium persulfate dissolved in 11.48 grams water was added to the reactor contents over the same 75 minutes.

[00317] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 15 minutes. The “shell” monomer solution was prepared by mixing 15.07 grams methacrylic acid, 15.04 grams methyl methacrylate, 17.5 grams ethyl acrylate and 0.346 grams Komerate T063, and then mixing the contents thoroughly.

[00318] An initiator feed including 25.2 milligrams ammonium persulfate dissolved in 2.3 grams water was also added over the same 15 minutes as the shell monomer mixture.

[00319] At the completion of the shell monomer mixture addition, 209 milligrams of ammonium persulfate dissolved in 19.02 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00320] The next day, the reactor contents was added a mixture of 1.2 grams of 50% sodium hydroxide solution diluted with 19.3 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 0.44 grams Nalco/Exxon EC9086A mixed in 0.93 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.6 and a solids content of 29%. Example O

[00321] 222.48 grams of water and 4.58 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions. The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least 1 hour.

[00322] A “core” mixture was prepared by adding 60.24 grams methacrylic acid to a solution of 233.92 grams water and 4.58 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 60.16 grams methyl methacrylate and then 70 grams ethyl acrylate and 0.1082 grams dodecyl mercaptan to a glass beaker. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 8.72 grams water.

[00323] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 21.9 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution including 0.25 grams ammonium persulfate dissolved in 17.44 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes.

[00324] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 75 minutes. Simultaneously, an initiator feed including 100.8 milligrams ammonium persulfate dissolved in 9.18 grams water was added to the reactor contents over the same 75 minutes.

[00325] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 15 minutes. The “shell” monomer solution was prepared by mixing 20.8 grams hydroxypropyl acrylate, 12.03 grams methyl methacrylate, 12 grams ethyl acrylate and 0.2768 grams Komerate T063 and then mixing the contents thoroughly.

[00326] An initiator feed including 20.2 milligrams ammonium persulfate dissolved in 1.84 grams water was also added over the same 15 minutes as the shell monomer mixture.

[00327] At the completion of the shell monomer mixture addition, 167 milligrams of ammonium persulfate dissolved in 15.22 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature and allowed to sit overnight.

[00328] The next day, the reactor contents was added a mixture of 1.4 grams of 50% sodium hydroxide solution diluted with 15.44 grams of water over a period of 30 minutes. The contents were mixed for 15 minutes. To the contents were added 0.35 grams Nalco/Exxon EC9086A mixed in 0.75 grams water, and the milky white emulsion product was dispensed from the reactor after brief mixing, with a pH of 5.5 and a solids content of 29.1%.

[00329] Examples P-R demonstrate the formulation of the paints used for testing core/shell particles.

Example P: Flat paint formulation

[00330] The paint formulation process includes two steps: the grind, and the letdown. In the grind step, water, biocide, grind defoamer, cellulosic thickener, dispersant, surfactant, and amine are charged into the reactor. Titanium dioxide, nepheline syenite, calcined clay and/or calcium carbonate, and/or dehydroxylated aluminum silicate are then dispersed into the mixture under high agitation. In the letdown process, binder, biocide, and coalescent agent are added one by one with mixing, and then the rheology modifier, neutralizing agent, and additional water are added to the mixture, dropwise, to make the final paint.

Grind Step

[00331] 1008.8 grams of water was added to a 2-gallon wide open mouth grind container and agitated at the lowest setting of the INDCO HSL-2 mixer using an 18-inch shaft with 3-inch disperser blade. 6 grams of AMA-415 LX and 12 grams of BYK-22 were added sequentially into the container with one minute of mixing after each addition. 4 grams of Bermocoll Prime 2500 was then added to the container and allowed to mix for 5 minutes. Once all of the Bermocoll Prime 2500 was dispersed, 28.8 grams of Alcosperse 787, 8 grams of Ethylan 1008SA and 1.33 grams of AMP-95 were added sequentially to the container and mixed for 1 minute after each addition. At the end of the last mix, the three pigments and fillers were added slowly as shots, allowing time in between for the added material to disperse into the grind mixture. 700 grams of Tipure R-902+ was added as shots over 15 minutes. At the end of the addition, the grind mix was mixed for further 5 minutes. 460 grams of Minex 4 was then added to the grind mix as shot addition over 10 minutes. The grind mixture was allowed to mix for 5 minutes following the Minex 4 addition. 460 grams of Karnin 2000C was then added into the grind mixture as shot addition over 15 minutes. The final grind mixture was mixed for 20 minutes. After 20 minutes, a sample of the grind mixture was collected using a 5 ml syringe and emptied to the deep end of the Hegman gauge. The paint was drawn with the flat edge along the grooves while applying uniform motion. The Hegman gauge was then observed for noticeable streaks.

[00332] For the letdown stage, 2684.9 grams of the grind composition was added to the gallon wide mouth jar. The grind mix was then mixed using the IKA RW20 mixer with a propeller blade at 400. 1376 grams of Encor 636 was added slowly to the grind mix and the mixture was mixed for 5 minutes. 8.0 grams of BYK 024 was added to the mixture and mixed for 2 minutes. It was followed by a slow addition of 68.0 grams of Texanol. The mixture was the mixed for 10 minutes. This letdown mixture was then used to make paint formulation with additional 6.8 wt. % total of rheology modifiers, AMP-95 and water. Example Q: Semi Gloss formulation

[00333] The grind and letdown materials were produced by the procedure described in Example

P:

Example R: Semi Gloss formulation

[00334] The grind and letdown materials were produced by the procedure described in Example

P:

[00335] Examples S-U demonstrate the use of two layered, core/shell particles in paints. KU and ICI viscosities for these Examples were obtained as described in Example S.

Example S

[00336] Example S exhibits the good performance (> 0.8 ICI, < 140 KU) of a two layered, core/shell particle in paint.

[00337] The polymer of Example 1 was added dropwise to the paint formulation of Example Q, with overhead stirring. During the addition, 50% solution of AMP-95 in water, additional water, and RM 2020 rheology modifier were added to the paint formulation as specified in the table below.

[00338] Paint formulated with Example 1 :

To obtain KU viscosity:

[00339] Approximately 300 grams of the prepared paint in a 12 oz, wide mouth plastic jar was analyzed for KU viscosity using a DS Byko-visc model Stormer viscometer manufactured by BYK-Gardner Gmbh headquartered in Geretsried, Germany, in compliance with ASTM D 562 and run at 200 rpm at about 23 C using paddle spindle 8340.

To obtain ICI viscosity:

[00340] ICI viscosity was obtained on a Brookfield CAP 2000+ ICI cone and plate viscometer, high torque model, available from AMETEK Brookfield with USA headquarters in Middleboro, MA. The model is in compliance with ASTM D4287, ISO 2884 and BS 2900. Samples were analyzed for ICI viscosity at 25 C, 900 RPM, with a number 1 spindle. Sample temperature was first allowed to equilibrate between the cone and plate for 60 seconds, and then the measurement was run over 30 seconds.

Example T

[00341] Example T exhibits the good performance (> 0.8 ICI, < 140 KU) of a two layered, 20 mole %al) and a2) containing core/shell particle with el) and e2), in paint.

[00342] The polymer of Example B was added dropwise to the paint formulation of Example R, with overhead stirring. During the addition, 50% solution of AMP-95 in water, additional water, and RM 2020 rheology modifier were added to the paint formulation as specified in the table below.

Paint formulated with Example :

Example U

[00343] Example U exhibits the good performance (> 0.8 ICI, < 140 KU) of a two layered core/shell particle with e2(hydroxypropyl acrylate) and without a2) in the shell, in paint.

[00344] The polymer of Example C was added dropwise to the paint formulation of Example P, with overhead stirring. During the addition, 50% solution of AMP-95 in water, and additional water were added to the paint formulation as specified in the table below.

Paint formulated with Example C:

Example V

[00345] Example V exhibits the good performance (> 0.8 ICI, < 140 KU) of a two layered core/shell particle with no al) in the core and a 90% shell, in a paint.

[00346] The polymer of Example D was added dropwise to the paint formulation of Example P, with overhead stirring. During the addition, 50% solution of AMP-95 in water, and additional water were added to the paint formulation as specified in the table below.

Paint formulated with Example D:

[00347] Examples W-AA demonstrate the use of multilayered core/shell particles in paints.

Example W

[00348] Example W exhibits the good performance (> 0.8 ICI, < 140 KU) of a three layered core/shell particle with a 10 mole % a2) in the second layer and the presence of e2)in the second layer, in paint.

[00349] The polymer of Example I was added dropwise to the paint formulation of Example P, with overhead stirring. During the addition, 50% solution of AMP-95 in water, and additional water were added to the paint formulation as specified in the table below.

Paint formulated with Example 9:

Surprisingly, the particle imparts KU and ICI viscosity to the paint formulation, in spite of the low amount (10 mole %) of a2) in the second layer.

Example X

[00350] Example X exhibits the good performance (> 0.8 ICI, < 140 KU) of a three layered core/shell particle with no al) in the first layer, in paint.

[00351] The polymer of Example J was added dropwise to the paint formulation of Example P, with overhead stirring. During the addition, 50% solution of AMP-95 in water, and additional water were added to the paint formulation as specified in the table below.

Paint formulated with Example J:

To obtain KU viscosity:

[00352] Approximately 300 grams of the prepared paint in a 12 oz, wide mouth plastic jar was analyzed for KU viscosity using a DS Byko-visc model Stormer viscometer manufactured by BYK-Gardner Gmbh headquartered in Geretsried, Germany, in compliance with ASTM D 562 and run at 200 rpm at about 23 C using paddle spindle 8340.

To obtain ICI viscosity:

[00353] ICI viscosity was obtained on a Brookfield CAP 2000+ ICI cone and plate viscometer, high torque model, available from AMETEK Brookfield with USA headquarters in Middleboro, MA. The model is in compliance with ASTM D4287, ISO 2884 and BS 2900. Samples were analyzed for ICI viscosity at 25 C, 900 RPM, with a number 1 spindle. Sample temperature was first allowed to equilibrate between the cone and plate for 60 seconds, and then the measurement was run over 30 seconds. Example Y

[00354] Example Y exhibits the good performance (> 0.8 ICI, < 140 KU) of a three layered core/shell particle with a difunctional crosslinker throughout the particle and 60 mole % a2) in the second layer, in paint.

[00355] The polymer of Example K was added dropwise to the paint formulation of Example P, with overhead stirring. During the addition, 50% solution of AMP-95 in water, and additional water were added to the paint formulation as specified in the table below.

Paint formulated with Example K:

Example Z

[00356] Example Z exhibits the good performance (> 0.8 ICI, < 140 KU) of a three layered core/shell particle with a difunctional crosslinker throughout the particle and with a 50 mole % a2) in the third layer, in paint.

[00357] The polymer of Example L was added dropwise to the paint formulation of Example P, with overhead stirring. During the addition, 50% solution of AMP-95 in water, and additional water were added to the paint formulation as specified in the table below.

Paint formulated with Example L Example AA

[00358] Example AA exhibits the good performance (> 0.8 ICI, < 140 KU) of a three layered core/shell particle with a difunctional crosslinker throughout the particle and e2) (hydroxyethyl acrylate) in the third layer.

[00359] The polymer of Example M was added dropwise to the paint formulation of Example P, with overhead stirring. During the addition, 50% solution of AMP-95 in water, and additional water were added to the paint formulation as specified in the table below.

Paint formulated with Example M:

[00360] Examples BB and CC exhibit the successful use of a core/shell particle in joint compounds.

Example BB

[00361] 299.00 g of Hubercarb Q200, 20.00 g of Suzorite 80-SF and 7.50 g of Attagel 40 were added to a KitchenAid 6-quart bowl. Using the dough hook, dry components were mixed slowly with the speed set to 1. The powder was mixed for 5 minutes and then transferred to a secondary container. In the same KitchenAid bowl, 153.35 g of water and 14.0 g of Avicor 325 were added. The solution was then mixed at speed 2. While mixing, 0.50 g of Mergal 17411, 0.15 g of BYK 035 and 1.50 g of propylene glycol were added slowly. 4.0 g of Example C was added to the bowl slowly and then mixed for 2-3 minutes. After 5 minutes, the powder mixture was slowly dispensed into the KitchenAid bowl including the liquid mixture with the mixing speed set to 2. Occasionally the mixing was paused, and the powder stuck to the side of the mixture was mixed into the bowl using a rubber spatula. Once all the joint compound was added, the speed was increased to 3 and the joint compound formulation was allowed to mix for additional 10 minutes. Final formulation was glossy with creamy consistency. Example CC

[00362] 156.20 g of Hubercarb Q200, 31.24 g of Suzorite 80-SF, 11.72 g of Attagel 40 and 27.34 g of Expancel 920 WET 40 D24 were added to a KitchenAid 6-quart bowl. Using the dough hook, dry components were mixed slowly with the speed set to 1. The powder was mixed for 5 minutes and then transferred to a secondary container. In the same 6-quart bowl, 243.28 g of water and 21.87 g of Avicor 325 were added. The solution was then mixed at speed 2. While mixing, 0.78 g of Mergal 17411, 0.23 g of BYK 035 and 2.34 g of propylene glycol were added slowly. 5.0 g of Example C was added to the bowl slowly and then mixed for 2-3 minutes. After 5 minutes, the powder mixture was slowly dispensed into the KitchenAid bowl including the liquid mixture with the mixing speed set to 2. Occasionally the mixing was paused, and the powder stuck to the side of the mixture was mixed into the bowl using a rubber spatula. Once all the joint compound was added, the speed was increased to 3 and the joint compound formulation was allowed to mix for 10 additional minutes. Final formulation was glossy with creamy consistency.

Example DD

[00363] Example DD illustrates the use of a core/shell particle in an asphalt formulation.

[00364] To prepare the anionic, slow-setting asphalt emulsion, the polymer of Example A is dispersed in water with the Redicote E-7000. The pH of the mixture is adjusted to pH 10 - 12 with 50% sodium hydroxide, and is then heated to 50 C. The mixture is combined with hot (130 C) 40- 90 penetration Bitumen by means of a laboratory colloid mill at high speed. The final slow-setting emulsion produced is cooled to room temperature.

Examples EE and FF

[00365] Examples EE and FF demonstrate the swollen nature and swelling capability of core/shell particles upon neutralization. Example FF is particularly surprising in view of the lack of a2) in the shell. [00366] 100 grams of 1% active mixtures of each of the rheology modifying emulsion or binder were prepared by diluting the emulsions in individual plastic cups, with deionized water.

[00367] With stirring, a solution of 50% aminomethyl propanol in water was dispensed into each emulsion mixture to give 90% neutralization of the total acid groups in the polymer. The amount of 50% aminomethyl propanol needed to neutralize 90% of the acid groups in 1 wet gram of emulsion polymer was determined by the following equation:

[00368] [Grams methacrylic acid used in synthesis / (86.1 * total grams of material in synthesis batch) ]* 0.875 * 89.1 * 2

[00369] The mixtures were stirred for an additional 15 minutes and then immediately prepared for particle sizing.

[00370] One drop of the emulsion or binder mixture from above was dispensed into a Fisherbrand disposable cuvette from Fisher Scientific, catalog number 14955129, and repeatedly diluted with deionized water until white haze is barely visible or just below visibility. The neat (nonneutralized), starting emulsions or binder were also diluted with DI water in individual cuvettes to the same condition.

[00371] The diluted sample particle sizes were measured with a Malvern Zetasizer Nano S. Three measurements were performed in succession, with the number of runs per measurement automatically determined by the instrument. Measuring position and attenuation were set automatically by the instrument. The measurement sequence was performed at 25 C after a 120 second equilibration time. The preset values for water viscosity (0.8872 centipoise) and refractive index (1.330) were used for the dispersant parameters. A refractive index and absorption for the samples were set at 1.590 and 0.010, respectively. At the completion of the sample measurement sequence, cumulants and distribution analyses were performed by the instrument software (Malvern Zetasizer Software, version 7.10).

[00372] The reported z-average (in nm) was used as the measure of particle size. In some instances, the particle size distribution was such that a cumulants analysis was not successful (as indicated by instrument software quality reports) and therefore the z-average, while reported, was not reliably calculated. In such cases where the cumulants analysis/z-average failed to be reliable, and if the distribution analysis did pass quality checks as indicated by the instrument software, then the particle size of the highest volume fraction peak of the volume particle size distribution as reported by the instrument software was used as the particle size for the purpose of determining the amount of swelling of the emulsion or binder particles.

[00373] The swelling that occurred for each sample was reported as the percentage of the difference between the neutralized and the initial un-neutralized particle sizes, divided by the initial un-neutralized particle size.

The above data indicate the swelling of the core/shell particles of the current disclosure. In particular, Example FF surprisingly demonstrates 1631% increase in particle size, in spite of there being no a2) in the shell.

EXAMPLE GG

[00374] The grind and letdown materials were produced by the procedure described in Example

EXAMPLE HH

[00375] The grind and letdown materials were produced by the procedure described in Example

P:

[00376] The grind and letdown materials were produced by the procedure described in Example

EXAMPLE JJ

[00377] Example JJ exhibits the higher opacity upon dilution of paints formulated with the materials of the disclosure, compared to a paint formulated with traditional rheology modifiers. Quite surprisingly, paints formulated with the materials of the current disclosure uniquely maintain their opacity upon drying into films, even after dilution up to 35%.

[00378] The paints were prepared as described in Examples GG - II. The paint dilutions were prepared by adding water to the paints and mixing the water/paint mixtures. The amount of water added was determined by calculating the amount of water needed to decrease the solids content of the paints by the intended amount. Calculating the amount of water needed per 100 grams of paint formulation was determined by the formula:

[00379] 100 g / (1 - Dilution percent desired x 100) - 100 g = grams of water needed per 100 grams starting paint formulation to obtain desired dilution percent

[00380] From each paint and paint dilution, a film was drawn with a 6 mL bar (3 mL wet) at 100 rpm on a Leneta opacity chart. After drying for at least 24 hours, the contrast ratio was measured for each film.

Example KK

[00381] Example KK demonstrates the synthesis of an associative monomer containing particle with 16 weight percent shell and 1.4 mole % crosslinker (trimethylolpropane triacrylate).

[00382] 247 grams of water and 7.58 grams of 30% sodium lauryl sulfate solution in water (Stanfax 234) were added to a 1 liter glass reactor with inlet ports for an agitator, water cooled condenser, thermocouple, nitrogen sparging and adapters for the addition of monomer and initiator solutions The contents were heated to 85 °C with overhead stirring and nitrogen sparge for at least I hr.

[00383] A “core” mixture was prepared by adding 19.5 grams of 50% CD-559 associative monomer and 105.5 grams methacrylic acid to a solution of 275.1 grams water and 7.58 grams 30% sodium lauryl sulfate solution in water (Stanfax 234) in a beaker. The contents were dispensed into a graduated cylinder with overhead agitation. A monomer solution was prepared by adding 61.6 grams methyl methacrylate and then 63 grams ethyl acrylate and 0.0874 grams 2- mercaptoethanol. The monomer solution was added to the contents of the graduated cylinder with agitation, and the remnants in the beaker were rinsed out into the graduated cylinder with 14.1 grams water.

[00384] After the reactor contents had been sparged with nitrogen at 85 °C for at least an hour, a seed stage was then performed as follows: 27.32 grams of the core monomer mixture was added to the reactor contents over a 2 minute period. This was agitated for 15 minutes, and then a seed stage initiator solution comprising 0.31 grams ammonium persulfate dissolved in 17.53 grams water was added as a shot to the reactor contents. This was allowed to stir for an additional 15 minutes.

[00385] Then, the remaining core monomer solution was slowly added to the reactor contents, subsurface, for 100 minutes. Simultaneously, an initiator feed comprising 121 milligrams ammonium persulfate dissolved in 26.17 grams water was added to the reactor contents over the same 100 minutes.

[00386] At the completion of the “core” monomer mixture feed, a "shell" monomer mixture was added subsurface into the reactor from a graduated cylinder over 20 minutes. The “shell” monomer solution was prepared by mixing 3.9 grams CD-559 associative monomer, 21.1 grams methacrylic acid, 12.3 grams methyl methacrylate, 12.6 grams ethyl acrylate, 0.0175 grams 2-mercaptoethanol and 2.1 grams trimethylolpropane triacrylate, and then mixing the contents thoroughly.

[00387] An initiator feed comprising 24 milligrams ammonium persulfate dissolved in 5.23 grams water was also added over the same 20 minutes as the shell monomer mixture.

[00388] At the completion of the shell monomer mixture addition, 145 milligrams of ammonium persulfate dissolved in 31.4 grams water was fed into the reactor over a period of 50 minutes. Then the temperature was increased to 90 °C, and the reactor contents cooked for 1 hour. The sample was cooled to ambient temperature. The milky white emulsion product was dispensed from the reactor after brief mixing, with a solids content of 29.77% and a pH of 2.6.

Example LL

[00389] The grind and letdown materials were produced by the procedure described in Example 6 to produce a paint with a pigment volume concentration of 70%, without a cellulosic thickener:

Contractor paint Letdown for Example LL [00390] The polymer of Example KK was added dropwise to this paint formulation, with overhead stirring. During the addition, Acrysol RM 2020 and additional water was added to the paint formulation as specified in the table below.

Paint formulated with Example KK:

Example MM

[00391] The grind and letdown materials were produced by the procedure described in Example 6 to produce a paint with a pigment volume concentration of 70%, with the cellulosic Natrosol Plus 330:

Contractor paint Letdown for Example MM

[00392] Acrysol RM 2020 was added to the paint formulation as specified in the table below.

[00393] The performance of Examples LL and MM demonstrate the surprisingly superior ICI development of polymers of the current invention over that of a cellulosic thickener in contractor paint formulations at similar KU as well as more efficiency as evidenced by much lower dosage rate to give these KU and ICI:

[00394] The formulation data of Examples S - AA exhibit the KU and ICI building properties of the core/shell particles of the current disclosure. The data in Example JJ demonstrate paints formulated with the core/shell particles of the current disclosure provide better opacity upon dilution compared to the currently available materials, an unexpected benefit of the present invention.

[00395] As shown in Examples W - AA, the technology of the current disclosure allows for the use of multiple layers of monomer composition and crosslink density. This means that performance in terms of viscosity development across a large shear range (e.g., Brookfield viscosity, KU viscosity, and ICI viscosity), paint opacity, spreadability, sag and levelling, and stability can be finely controlled. Moreover, this differs from what is known in the art because the art tends to require that an outer layer has the most cross linker wherein, in this disclosure and the Examples, more or less crosslinker is allowed.

[00396] Surprisingly, even in the case of 0 - 10% anionic ethylenically unsaturated monomer content, swelling of the particles occurs. This is demonstrated in Example FF, in which the shell has 0 mole % anionic ethylenically unsaturated monomer, and this is unexpected because anionic ethylenically unsaturated monomer content is a key driver of polymer chain solubility and expansion. Without being bound by theory, it is believed that, in spite of the 0% anionic ethylenically unsaturated monomer content in the shell, the polymer swells due to the presence of a nonionic ethylenically unsaturated monomer in the shell.

[00397] Surprisingly, it was found that while the use of up to 60 mol% anionic ethylenically unsaturated monomer forms a stable emulsion with minimal coagulation (as in Example K), if the layer contains more than 10 mole % of a long chain hydrophobic ethylenically unsaturated monomer, a viable emulsion is still obtained (as in Example H with 83 mole % anionic ethylenically unsaturated monomer in the shell). This is surprising because 65 mole % or more anionic ethylenically unsaturated monomer content with bl or b2 alone leads to coagulation and destabilization of emulsion polymers. [00398] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims.

Claims

CLAIMS What is claimed is:

1. An aqueous coating composition comprising:

I. water;

II. a binder;

III. an optional pigment; and

IV. a particle comprising:

A. At least one core polymer that is the polymerization reaction product of a first monomer mixture comprising: al) optionally one or more anionic ethylenically unsaturated monomers; bl) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain comprising a hydrophobe that has 7 or fewer carbon atoms; cl) optionally one or more associative monomers; dl) optionally one or more cross -linking monomers; el) optionally one or more nonionic ethylenically unsaturated monomers; and fl) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain comprising a hydrophobe that has 8 or greater carbon atoms; wherein if al) is not present in said first monomer mixture then el) is present in said first monomer mixture; wherein if fl) is not present in said first monomer mixture then al) is present in an amount of from 0 to about 60 mol% based on a total number of moles of monomers in said first monomer mixture; wherein if fl) is present in said first monomer mixture then al) is present in an amount of from 0 to about 80 mol% based on a total number of moles of monomers in said first monomer mixture; wherein at least one of bl) and fl) is present in said first monomer mixture; and B. at least one shell polymer disposed about said at least one core polymer wherein said at least one shell polymer is at least partially cross-linked and is the polymerization reaction product of a second monomer mixture comprising: a2) optionally one or more anionic ethylenically unsaturated monomers; b2) optionally one or more short chain hydrophobic ethylenically unsaturated monomers having a side chain comprising a hydrophobe that has 7 or fewer carbon atoms; c2) optionally one or more associative monomers; d2) one or more cross-linking monomers; e2) optionally one or more nonionic ethylenically unsaturated monomers; and f2) optionally one or more long chain hydrophobic ethylenically unsaturated monomers having a side chain comprising a hydrophobe that has 8 or greater carbon atoms; wherein if a2) is not present in said second monomer mixture then e2) is present in said second monomer mixture; wherein if f2) is not present in said second monomer mixture then a2) is present in an amount of from 0 to about 60 mol% based on a total number of moles of monomers in said second monomer mixture; wherein if f2) is present in said second monomer mixture then a2) is present in an amount of from 0 to about 80 mol% based on a total number of moles of monomers in said second monomer mixture; wherein at least one of b2) and f2) is present in said second monomer mixture; and wherein at least one of said first monomer mixture and said second monomer mixture comprises al) or a2) in an amount greater than zero mol %, respectively.

2. The aqueous coating composition of claim 1 having an ICI viscosity of greater than about 0.6 Poise and a KU viscosity of less than about 140 Krebs units, wherein said particle is further defined as an alkali swellable particle.

3. The aqueous coating composition of claim 1 or 2 wherein the particle is further defined as an alkali swellable particle, has a first diameter measured at a pH of from about 3 to about 5, and has a second diameter measured at a pH of about 8, wherein the second diameter is at least about 10% larger than the first diameter.

4. The aqueous coating composition of any preceding claim wherein said at least one shell polymer comprises a mol % of residue of said d2) one or more crosslinking monomers that is greater than a mol % of residue of said dl) one of more cross-linking monomers in said at least one core polymer.

5. The aqueous coating composition of any one of claims 1 to 3 wherein said particle comprises two or more shell polymers and at least one shell polymer comprises a mol % of residue of said d2) one or more crosslinking monomers that is less than a mol % of residues of said dl) one of more cross-linking monomers in said at least one core polymer.

6. The aqueous coating composition of any preceding claim wherein said at least core shell polymer accounts for greater than 5 wt % and less than about 90 wt % of a total weight of said particle.

7. The aqueous coating composition of any preceding claim wherein: bl) and/or fl) is present in said first monomer mixture in at least about 1 mol% based on a total number of moles of monomers in said first monomer mixture and said al) anionic ethylenically unsaturated monomer is present in said first monomer mixture in 10 mol% or less based on a total number of moles of monomers in said first monomer mixture; and b2) and/or f2) is present in said second monomer mixture in at least about 1 mol% based on a total number of moles of monomers in said second monomer mixture and said a2) anionic ethylenically unsaturated monomer is present in said second monomer mixture in 10 mol% or less based on a total number of moles of monomers in said second monomer mixture.

8. The aqueous coating composition of any preceding claim wherein one or both of said at least one core polymer and said shell polymer comprises an increasing gradient of cross- link density measured in an outward direction extending from a center of said at least one core polymer towards said shell polymer wherein said cross-link density of said at least one core polymer is optionally less than said cross-link density of said shell polymer.

9. The aqueous coating composition of any preceding claim wherein said first monomer mixture is free of said dl) one or more cross-linking monomers.

10. The aqueous coating composition of any preceding claim wherein said particle comprises a first shell polymer and a second shell polymer wherein said first shell polymer is disposed on and in direct contact with said at least one core polymer and said second shell polymer is disposed on and in direct contact with said first shell polymer.

11. The aqueous coating composition of claim 10 wherein each of said at least one core polymer, said first shell polymer, and said second shell polymer has a cross-link density, said cross-link density of said first shell polymer is greater than said cross-link density of said at least one core polymer; and said cross-link density of said second shell polymer is greater than said cross-link density of said first shell polymer and greater than said cross-link density of said at least one core polymer.

12. The aqueous coating composition of claim 10 wherein each of said at least one core polymer, said first shell polymer, and said second shell polymer has a cross-link density, said cross-link density of said first shell polymer is greater than said cross-link density of said at least one core polymer; and said cross-link density of said second shell polymer is less than said cross-link density of said first shell polymer and greater than said cross-link density of said at least one core polymer.

13. The aqueous coating composition of claim 10 wherein each of said at least one core polymer, said first shell polymer, and said second shell polymer has a cross-link density, said cross-link density of said first shell polymer is less than said cross-link density of said at least one core polymer; and said cross-link density of said second shell polymer is greater than said cross-link density of said at least one core polymer and greater than said cross-link density of said first shell polymer.

14. The aqueous coating composition of claim 10 wherein each of said at least one core polymer, said first shell polymer, and said second shell polymer has a cross-link density, said cross-link density of said first shell polymer is greater than said cross-link density of said at least one core polymer; and said cross-link density of said second shell polymer is less than said cross-link density of said at least one core polymer and less than said cross-link density of said first shell polymer.

15. The aqueous coating composition of claim 10 wherein each of said at least one core polymer, said first shell polymer, and said second shell polymer has a cross-link density, said cross-link density of said first shell polymer is less than said cross-link density of said at least one core polymer; and said cross-link density of said second shell polymer is less than said cross-link density of said at least one core polymer and greater than said cross-link density of said first shell polymer.

16. The aqueous coating composition of claim 10 wherein each of said at least one core polymer, said first shell polymer, and said second shell polymer has a cross-link density, said cross-link density of said first shell polymer is less than said cross-link density of said core; and said cross-link density of said second shell polymer is less than said cross-link density of said at least one core polymer and less than said cross-link density of said first shell polymer.

17. The aqueous coating composition of any preceding claim wherein said one or more cl) and c2) associative monomers are not present in said first and second monomer mixtures.

18. The aqueous coating composition of any preceding claim further comprising a nonionic synthetic associative thickener (NSAT).

19. The aqueous coating composition of any preceding claim wherein: at least one of bl) and b2) is independently chosen from C1-C7 alkyl esters of acrylic acid, maleic acid, itaconic acid and methacrylic acid; C1-C7 alkyl amides of acrylic acid, maleic acid, itaconic acid and methacrylic acid; benzyl (meth)acrylate, phenyl (meth)acrylate, benzyl ethoxylate (meth)acrylate, phenyl ethoxylate (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and styrene, alpha-methyl styrene, vinyl toluene, and p-chlorostyrene; vinyl acetate, vinyl butyrate, vinyl caprolate, vinyl valerate, vinyl hexanoate, vinyl caprolactam, (meth)acrylonitrile, isobutylene, diisobutylene, isoprene, vinyl chloride, vinylidene chloride, and combinations thereof; and at least one of fl) and f2) is independently chosen from C8-C32 alkyl esters of acrylic acid, maleic acid, itaconic acid and methacrylic acid; C8-C32 alkyl amides of acrylic maleic acid, itaconic acid and methacrylic acid; 10-hydroxy decyl (meth)acrylate, t-butyl styrene, iso-propyl styrene, vinyl octanoate, vinyl nonanoate, vinyl decanoate, vinyl neodecanoate, vinyl laurate, vinyl caprolactam, (meth)acrylonitrile, isobutylene, diisobutylene, isoprene, vinyl chloride, vinylidene chloride, 1 -allyl naphthalene, 2-allyl naphthalene, 1 -vinyl naphthalene, 2-vinyl naphthalene, and combinations thereof.

20. The aqueous coating composition of any preceding claim wherein said at least one core polymer is the reaction product of al) and bl) and said at least one shell polymer is the reaction product of a2), b2), and d2); or said at least one core polymer is the reaction product of al), bl) and el) where al) is present in an amount of less than about 20 mol% of said first monomer mixture and el) is present in an amount of greater than about 5 mol% of said first monomer mixture and said at least one shell polymer is the reaction product of a2), b2), d2) and e2) wherein a2) is present in an amount of less than about 20 mol% of said second monomer mixture and e2) is present in an amount of greater than about 5 mol% of said second monomer mixture.