Field of the Invention The invention generally relates to polymers having specifically designed hydrophobicity and hydrophilicity properties. The polymers themselves can be used in a number of areas such as aids in dispersion or suspension polymerization, low profile additives, sizing and coating applications, hot melt adhesives, powder coatings, and emulsifiers/dispersants for pigment dispersions and hydrophobic polymers (e. g., alkyds). The polymers can also be used in applications where low molecular weight surfactants have traditionally been used.

Background of the Invention Latices are typically made by an emulsion polymerization process involving the use of monomers, e. g., styrene, acrylates, etc., in an aqueous medium in the presence of free radical initiators, surfactants, and chain transfer agents. The surfactants are responsible to a great extent in providing stability to the emulsion, and they can be anionic, cationic, or nonionic in nature. While these surfactants have been known to be essential for stabilization of the latex, they can be detrimental to the application performance of the polymer. For example, upon film formation of the latex, these surfactants can migrate to the polymer/air interface

and can be leached out, thereby making the film water sensitive. Another possibility is that the surfactants can concentrate at the polymer/substrate interface and contribute adversely to properties such as adhesion and corrosion resistance.

Hence, it would be desirable to avoid using conventional surfactants in many applications.

Summary of the Invention It is an object of the invention to provide materials that address the problems noted above. In addition, it would be desirable if these materials were able to perform other functions upon film formation of the latex such as, for example, coalescing aids, adhesion promotion, and the like.

In one example, it has been attempted to design polymers by introducing functionality that would promote steric and/or electrostatic mechanisms of emulsion stabilization. This can be accomplished by introducing hydrophilic (e. g., ethylene oxide) and/or hydrophobic (e. g., alkyl) groups as pendant chains connected to a polymer main chain which may or may not have ionic functionality such as, for example sulfonate, phosphate esters, sulfates, and the like. Thus, in one aspect, the invention provides a polymer having specifically designed hydrophobic and hydrophilic properties. The polymer is comprised of (a) at least one monomer residue of an aromatic dicarboxylic acid, wherein a side chain is attached from the aromatic ring and is described by the formula: wherein Q is a substituent having a hydrophilic group, a hydrophobic group, or mixtures thereof ; (b) at least one monomer residue of an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, or mixtures thereof ; and (c) at least one monomer residue of an aliphatic alcohol, an aromatic alcohol, or mixtures thereof.

The monomer residues of (a), (b), and (c) are arranged to form the backbone of the polymer, and wherein the side chain of formula (I) is a pendant group extending

from the polymer backbone. Advantageously, when employed as a surfactant, the polymer is water dispersible.

In another aspect, the invention relates to a latex emulsion composition.

The composition comprises the polymer described hereinabove and a latex emulsion polymer. The polymer interacts with the latex emulsion polymer so as to stabilize the latex emulsion polymer.

The polymers of the invention are highly advantageous. These polymers can serve as a very valuable aid to polymer design and performance. These multifunctional polymers can be permanently incorporated into the latex particle by grafting reactions and hence cannot be leached out and give rise to foaming, lack of adhesion, and water sensitivity. Being tailor-made polymers instead of low molecular weight surfactants, they can thus be designed to modify the required end properties of the polymer made by emulsion polymerization, such that the polymer is more desirable in its specific end use.

Brief Description of the Drawings FIGS. 1 through 5 illustrate examples of structures of polymers encompassed by the scope of the invention; FIG. 6 illustrates a graph of surface tension versus concentration for the polymer of FIG. 1; FIG. 7 illustrates a graph of surface tension versus concentration for the polymer of FIG. 2; FIG. 8 illustrates a graph of surface tension versus concentration for the polymer of FIG. 3; FIG. 9 illustrates a graph of surface tension versus concentration for the polymer of FIG. 4; FIG. 10 illustrates a graph of surface tension versus concentration for the polymer of FIG. 5; and FIG. 11 illustrates hydrolysis stability of a polymer when employed as a surfactant of the invention versus time.

Detailed Description of the Preferred Embodiments The invention will now be described in greater detail with respect to the preferred embodiments with reference to the detailed description and drawings. It should be appreciated however that these embodiments are for illustrative purposes, and do not limit the scope of the invention which is defined by the claims.

In one aspect, the invention provides a polymer having specified hydrophobic and hydrophilic properties. In one example, the polymer may be used as a surfactant to stabilize latex emulsion polymers. The polymer is comprised of (a) at least one monomer residue of an aromatic dicarboxylic acid, wherein a side chain is attached from the aromatic ring and is described by the formula: wherein Q is a substituent having a hydrophilic group, a hydrophobic group, or mixtures thereof ; (b) at least one monomer residue of an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, or mixtures thereof ; and (c) at least one monomer residue of an aliphatic alcohol, an aromatic alcohol, or mixtures thereof.

The monomer residues of (a), (b), and (c) are arranged to form the backbone of the polymer, and wherein the side chain of formula (I) is a pendant group extending from the polymer backbone. The polymer is capable of displaying surface activity.

The polymer preferably has a number average molecular weight ranging from about 900 to about 10,000.

In the above formula, Q may represent various substituents that are capable of imparting hydrophobic and/or hydrophilic properties to the polymer. The selection of these groups are known to one skilled in the art. Preferably, Q is represented by the formula:

wherein: R is a substituent containing an alkyl group, an aromatic group, or mixtures thereof; Y is selected from the group consisting of -O-, and-NH- ; Z may be selected from the group consisting of-(CH2) n-;-(CH2CH2O) n-, and

wherein R5, is H or alkyl, preferably CH3; and n is an integer ranging from 1 to 50.

Q may also be described by the following formulas:

wherein m is an integer ranging from 1 to 50; p is an integer ranging from 1 to 50; n is an integer ranging from 1 to 30; and p'is an integer ranging from 1 to 50. In a preferred embodiment, the polymer may be described by the formula II:

In this structure of formula (II), R, l. Rl2, R2"and R, 3 are each independently selected from the group consisting of a saturated hydrocarbon group and an unsaturated hydrocarbon group. X may be selected from H or halogen. Q is a substituent having a hydrophilic group, a hydrophobic group, or mixtures thereof.

R", R, 2, R2,, and R13may be the same or different and can be selected from various saturated or unsaturated hydrocarbon groups such as, for example, aliphatic-containing groups, as well as aromatic-containing groups such as benzene and various derivatives thereof. These groups may be substituted with various substituents and functional groups if so desired. Examples of functional groups include, but are not limited to, hydroxyl, carboxyl, halogen, and amino. These groups may also be branched. Specific examples of these groups include, but are not limited to, polyols such as ethylene glycol; propylene glycol; 1.3-propanediol; 2,4-dimethyl-2ethyl-hexane-1,3-diol; 2,2-dimethyl-1,3-propanediol; 2-ethyl-2-

butyl-1,3-propanediol; 2-ethyl-2-isobutyl-1,3-propanediol; 1,3-butanediol; 1,4- butanediol; 1,5-pentanediol; 1,6-hexanediol; ; thiodiethanol; 1,2-cyclohexanedimethanol; 2,2,4,4,-tetramethyl-1,3- cyclobutanediol; and p-xylylenediol. Polyethylene glycols may also be used such as, but not limited to, diethylene glycol, triethylene glycol, tetraethylene glycol; pentaethylene, hexaethylene, heptaethylene, octaethylene, nonaethylene, and decaethylene glycol. Additionally, bis- (2-hydroxyethoxy)-phenol A; trimethylolpropane; trimethylolethane; glycerol, 2,2-bis (hydroxymethyl)-1,3- propanediol, 1,2,3,4,5,6-hexahydroxy hexane, and the like may be employed.

Mixtures of any of the above may be used.

Other components which may be used include, but are not limited to, ethoxylated amines; and polyalcohols derived from ethylene oxide and propylene oxide. Poly (ethylene/butylene) diol such as Kraton Liquidez L-2203 polymer, hydroxy functional polybutadienes, aromatic and cycloaliphatic epoxies, and the like can also be employed. Additionally, it should be emphasized that amines having structures similar to the polyols mentioned above can be used.

Other examples of groups that may represent R", R, 2, R2"and R, 3 include substituents that are derived from various acids and anhydrides. The use of these acids or anhydrides in making polymers is known to one skilled in the art. These acids or anhydrides include, but are not limited to, anhydrides and acids such as isophathalic, phthalic, terepthalic, acetylated hydroxy aromatic acids (e. g., acetoxy benzoic acid); diphenic, 4,4-oxydibenzoic, 4,4'-sulfonyldibenzoic, 4,4'-biphenyl- dicarboxylic and naphthalenedicarboxylic acids. Linear or branched-chain saturated aliphatic diacids including oxalic, malonic, dimethylmalonic, succinic, glutaric, adipic, trimethyladipic, pimelic, 2,2-dimethylglutaric, azelaic and sebacic acids may be used. Unsaturated aliphatic diacids including fumaric acid, maleic acid and itaconic acid can be employed. Unsaturated aromatic acids can also be used such as, but not limited to, phenylene diacrylic acid and bis-cinnamic acids.

Cycloaliphatic diacids which may be used include 1,2-cyclohexane dicarboxylic acid and anhydride thereof; 1,3-cyclohexane dicarboxylic acid; 1,4-cyclohexane

diacarboxylic acid; and 1,3-cyclopentane dicarboxylic acid. Mixtures of the above may also be used.

In formula (II), Q may be represented by the formula:

wherein R is a substituent containing an alkyl group, an aromatic group, or mixtures thereof ; Y is selected from the group consisting of-O-, and-NH- ; and Z may be selected from the group consisting of -(CH2)n-, -(CH2CH2O)n-, and

wherein R5, is H or CH3. The alkyl substituent may be substituted or unsubstituted.

An example of a substituted alkyl that may be employed for R is CH, CL. The variable"n"is independently selected for each of the various substituents and encompasses integers ranging from 1 to 50.

Substituents which may be employed for R described above include, for example, alkyl groups such as CH3, and (CH2) n wherein n ranges from 0 to 18,

wherein R'can be, for example,-H, CH3,-CH2Cl, and the like, and n ranges from 1 to 50.

Various aromatic-containing substituents may be employed for R.

Examples of these substituents which may also be used are branched and include:

Examples of R'and R"include, but are not limited to, hydrogen and straight or branched alkyl chains having 6 to 12 carbon atoms.

The variables x, y, and z described in formula (II) preferably are integers ranging from 0 to 20, and more preferably 0 to 15. It is especially preferred that the x, y, and z be chosen such that the sum x+y+z ranges from 1 to 40. More preferably, the sum ranges from 5 to 25.

The above polymer described in formula (II) may be end-capped by use of a number of different components such as, for example, mono-functional alcohols, amines, or acids. Preferred alcohols include those in the Igepal CO and CA series, fatty alcohols, ethoxylated fatty alcohols, as well as others which are structurally similar. Components having isocyanate functionality may be employed if desired. Mixtures of the above may also be used. A preferred acid includes, for example, benzoic acid.

The variable X contained in the polymer of formula II may be selected from a number of substituents such as, but not limited to, hydrogen, chlorine, fluorine, bromine, and the like.

In addition to the more general description set forth hereinabove, the side chains which include Z and R on the polymers represented by the formula II may be either hydrophobic, hydrophilic, or a combination of the two. These side chains may contain various substituents and functional groups known in the art. An example of hydrophilic side chains may be represented by the formulae:

In this embodiment, R is CH3, Y is -O-, and Z is- (CH2CH2O) n,-wherein m is an integer ranging from 1 to 50.

An example of a hydrophobic side chain may be represented by the formula: wherein R is CH3, Z is- QCH2) p-, Y is -O-, and p is an integer ranging from 1 to 50.

Another example of a side chain which may be used is represented by the formula:

wherein R is CH3 (CH2) pC6H4, Z is -(CH2CH2O)n-, Y is -O-, n is an integer ranging from 1 to 30, and p'is an integer ranging from 1 to 50.

Specific side chain substituents for Z and R may be selected from: -O (CH2CH20) 14CH3, wherein r may be an integer ranging from 1 to 50. Groups which may also be used for Y include-O-,-NH-, and the like. Substituents which can be also used for Z include-(CH2CH2O) n-; wherein n and n'may be the same or different and range from 0 to 50; and R" may be, for example,-H,-CH3,-CH2Cl, and the like.

Examples of polymers that are preferably used as surfactants and encompassed by the invention are:

wherein s is an integer ranging from 1 to 50, t is an integer ranging from 1 to 50, and Z and R are defined herein; wherein u is an integer ranging from 1 to 50, v is an integer ranging from 1 to 50, and R is defined herein; and

wherein e is an integer ranging from 5 to 40; f is an integer ranging from 0 to 15, and Z is defined herein.

The polymers of the invention are made according to known and accepted techniques. Examples of techniques that may be followed in making these materials are provided in U. S. Patent Nos. 3,787,526; 4,588,668; 4,933,252; 4,393,059; 4,960,664; and 5,241,019, the disclosures of which are incorporated herein by reference in their entirety. Typically, the polymers are formed from the reaction between a polyfunctional organic acid or anhydride and a polyhydric alcohol under specified conditions. The polyfunctional organic acid or anhydride which may be employed are numerous. Suitable polyfunctional acids or anhydrides thereof include, but are not limited to, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexane dicarboxylic acid, succinic anhydride, adipic acid, sebacic acid, azealic acid, malonic acid, alkenyl succinic acids such as n-dodecenylsuccinic acid, docecylsuccinic acid, octadecenylsuccinic acid, and anhydrides thereof. Lower alkyl esters of any of the above may also be employed.

Mixtures of any of the above are suitable.

Suitable polyhydric alcohols which may be used in forming the polymers include, but are not limited to, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,3 hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 1,3-butylene glycol, 1,6-hexanediol, hydrogeneated bisphenol"A", cyclohexane dimethanol, 1,4-cyclohexanol, ethylene oxide adducts of bisphenols, propylene oxide adducts of bisphenols, sorbitol, 1,4- sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4- butanetriol, 1,2,5-pentanetriol, glycerol, 2-methyl-propanetriol, 2-methyl-1,2,4- butanetriol, trimethylol ethane, trimethylol propane, and 1,3,5-trihydroxyethyl benzene. Mixtures of the above alcohols may be used. These ingredients may be added in amounts known to the skilled artisan.

In another aspect, the invention relates to a latex emulsion composition.

The composition comprises a polymer typically in the form of a surfactant described hereinabove and a latex emulsion polymer. Advantageously, the

polymer acts as a surfactant and interacts with the latex emulsion polymer so as to stabilize the latex emulsion polymer. The polymers can be used to stabilize various latex emulsion polymers without employing conventional surfactants. For the purposes of the invention the term,"latex emulsion polymers"is to be construed broadly to include all of those which are typically stabilized by conventional cationic, anionic, and nonionic surfactants. Examples of emulsion polymers include those made from a number of monomers including, but not limited to, aliphatic conjugated diene monomers, non-aromatic unsaturated ester monomers, aromatic unsaturated monomers, monomers based on the half ester of an unsaturated dicarboxylic acid monomer, unsaturated mono-or dicarboxylic acid monomers, unsaturated nitrogen containing monomers, monoethylenically unsaturated aliphatic hydrocarbons, and vinyl ester monomers. Emulsion polymers which are formed from the above monomers are made in accordance with known and suitable techniques.

The polymers of the invention may also be used in conjunction with conventional surfactants if so desired. Examples of these surfactants are typically those of the anionic, cationic, or nonionic type. Examples of surfactants are set forth in U. S. Patent Application Serial No. 08/856,789 filed 15 May 1997 and U. S.

Patent No. 5,296,627 to Tang et al., the disclosures of which are incorporated herein by reference in their entirety. The selection of these surfactants is known to one skilled in the art.

Although Applicants do not wish to be bound by any one theory, it is believed that the polymer interacts with the latex emulsion polymer by either being grafted or adsorbed onto the latex emulsion polymer to stabilize the latex emulsion polymer. The process for making these latices can be either batch or semicontinuous.

Typically, the levels of polymers that may be employed in the latex emulsion composition may range from about 0.1 to about 10 percent based on 100 parts of monomer, and more preferably between about 1 and 7 percent based on 100 parts of monomer. The polymers can also be used to make hybrid emulsions where the level of usage of the polymers may range from 10 to 80 percent based on

100 parts of monomer. A typical procedure for making these polymers and the emulsions are set forth herein.

The following examples are intended to illustrate the invention, and are not meant as a limitation thereon.

Example 1 Polymer Synthesis 150 g (0.2 mol) of poly (ethylene glycol) mono-methyl ether with an average molecular weight of 750 (MPEG 750) was charged with 39.62 g (0.2 mol) of trimellitic anhydride in a 1000 mL four-neck round bottomed flash. The flask was purged with nitrogen and maintained at 80°C for 30 min. Thereafter, 49.92 g of neopentyl glycol, 17.94 g of phthallic anhydride, 7.92 g of maleic anhydride, and 0.5 g of Fascat 2001 were added. The esterification reaction proceeded at 232°C and was monitored by acid value titration. The polymer thus synthesized possessed an acid value of 2.5 (PS-3412-67), Example 2 Polymer Synthesis 245.45 g of poly (ethylene glycol) mono-methyl ether with an average molecular weight of 2000 (MPEG 2000) was charged with 146.05 g of Brij 98, and 48.89 g of trimellitic anhydride in a 1000 mL four-neck round bottomed flash.

The flask was purged with nitrogen and maintained at 80°C for 30 min.

Thereafter, 76.34 g of poly (ethylene glycol) (average molecular weight 200), 37.69 g of 5-sulfoisophthalic acid sodium salt, and 0.5 g of Fascat 2001 were added. The esterification reaction proceeded at 232°C and was monitored by acid value titration. The polymer thus synthesized possessed an acid value of 10.49 (PS- 3414-24),

Example 3 Preparation of Emulsions A 1000 ml reactor was charged with a pre-charge composition having the following recipe: Ingredient parts PS-3412-67 (50%) 8 PS-3414-24 (50%) 7.5 Water 150 NH40H 3.1 The mixture was agitated and then exposed to a inert nitrogen atmosphere.

The mixture was heated to 70°C, and then 5 ml of initiator solution including lpart of APS and 50 parts of water was added. The resulting mixture was held for 10 minutes. A seeding composition was subsequently added to the above mixture.

The seeding composition was as follows: Ingredient parts Pre-Emulsion 27 MAA 4 The pre-emulsion had the following composition: Ingredient parts Styrene 20 MMA 60 BA 120 PS-3412-67 (50%) 16 S-120 0.4 Water 130 The seeding took place for 45 minutes. After seeding, the temperature was raised to 75°C and a remaining amount of pre-emulsion was fed to the mixture at a rate of 0.5 g/min. Initiator solution was fed to this mixture at a rate of 4 ml/hr.

Subsequently, the polymerization continued for about 1 hour. The solids content of the resulting latex was 37.7 percent. The latex particle size was 143 mn.

Examples 4-23 Molecular Weight Determination Examples 4-23 listed in Tables 2-6 represent molecular weight data of polymers described herein. The polymers in each of the tables correspond in structure to the figure referred to by each table. As can be seen, a wide variety of polymers can be made.

Table 2-Figure 1 Structure POLYMER SIDE CHAIN MAIN CHAIN Mn MV/Mn AN Example 4 MPEG 750 Jeffamine J-230 940 1. 9 10.54 Example 5 MPEG 750 PEG 200 2220 2. 3 17. 68 Example 6 MPEG 750 PEG 600 1830 2. 5 20. 53 Table 3-Figure 2 Structure

POLYME SIDE CHAIN SIDE MAIN Mn M,/M, AN R CHAIN CHAIN Example 7 Lgepal CO-MPEG 750 Neopentyl 2370 2.1 17.5 210 glycol Example 8 Lgepal CO-MPEG 750 PEG 200 2720 2.3 14.2 210 Example 9 Lgepal CO-MPEG 750 PEG 400 2280 2.8 14.8 210 Example 10 Lgepal CO-MPEG 750 PEG 600 2330 2.1 17.7 210 Table 4-Figure 3 Structure POLYMER SIDE CHAIN MAIN CHAIN Mn M"/Mn AN Example 11 Lgepal CO-210 PEG 200 1500 3. 5 22 Example 12 Lgepal CO-210 PEG 600 1240 2. 6 18.99 Example 13 Lgepal CO-210 PEG 1000 1270 2. 6 16.7 Example 14 Lgepal CO-210 PEG 1450 1900 2. 8 16 Table 5-Figure 4 Structure POLYMER SIDE CHAIN MAIN CHAIN Mn M"/Mn AN Example 15 Lgepal CO-210 PEG 200 900 2. 4 19.62 Example 16 Lgepal CO-210 PEG 600 670 2. 2 25.04 Example 17 Lgepal CO-210 PEG 1000 1560 2. 6 16.78 Example 18 Lgepal CO-210 PEG 1450 1560 2. 5 14

Table 6-Figure 5 Structure POLYMER SIDE CHAIN Mn MW/Mn AN Example19 MPEG 750 1 2800 1. 9 0.6 Example20 MPEG 750 2 2640 2 2.5 Example 21 MPEG 750 3 2650 2. 5 1.2 Example22 MPEG 750 5 3490 2. 1 0.68 Example23 MPEG 750 7 2150 2. 9 3.8 The latex emulsion polymers which contain the polymers of the invention are useful in a number of applications. For example, the latex emulsion polymers may be used in printing inks, slasher dyeing, toner applications, sizing applications for use with glass or other fibers to improve strength, pigment encapsulation for imaging applications, coatings, and the like.

The applications for which the polymers can be used are many in number.

The polymers themselves can be used as aids in dispersion or suspension polymerization, low profile additives, sizing and coating applications, hot melt adhesives, powder coatings, emulsifiers/dispersants for pigment dispersions and hydrophobic polymers (e. g., alkyds), and in general applications where low molecular weight surfactants have traditionally been used. It should be noted that the polymers can be used in non-aqueous (i. e., organic) solutions if so desired by the end user.

Disclosed herein are typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation of the scope of the invention.