Sulfopolyester polymer compositions with improved water dispersibility

Abstract

A sulfopolyester containing residues of 2,2,4,4-tetralkylcyclobutane-1,3-diol such as 2,2,4,4-tetramethylcyclobutane-1,3-diol is highly dispersible in water. This allows one to reduce the content of sulfonate groups or reduce the amount of ethylene glycol or other hydrophilic glycols to retain good water resistance in cured coatings. The sulfopolyester may also be a reaction product of a 2,2,4,4-tetralkylcyclobutane-1,3-diol along with 1,4-cyclohexanedimethanol, neopentyl glycol, or a mixture thereof with an acid component. Coating compositions may also contain these sulfopolyesters along with water and a polymer resin.

1 . A sulfopolyester comprising the reaction product of:
 (i) a polyhydroxyl component comprising:
 a. 2,2,4,4-tetraalkylcyclobutane-1,3-diol (TACD) in an amount ranging from 2 to 60 mole % based on the moles of the polyhydroxyl component, and 
 b. a polyhydroxyl compound other than TACD in an amount ranging from 40 mole % to 98 mole %, based on the moles of the polyhydroxyl component; and 
   (ii) an acid component comprising:
 a. dicarboxylic acid compounds, derivatives of dicarboxylic acid compounds, or combinations thereof, in a cumulative amount amount from 85 mole % to 95 mole %, based on the moles of the acid component; and 
 b. a sulfomonomer component in an amount ranging from 5 mole % to 15 mole %, based on the moles of the acid component, having at least one ionic sulfonate group covalently bonded directly or indirectly to an aromatic or cycloaliphatic ring, said ionic sulfonate group having the structure represented by the following formula:
   —SO 3   − .
 
 
   
     
     
         2 . (canceled) 
     
     
         3 . The sulfopolyester of  claim 1 , wherein the TACD compound is represented by the general structure: 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , R 3 , and R 4  each independently represent a branched or unbranched alkyl radical having 1 to 8 carbon atoms. 
     
     
         4 . The sulfopolyester of  claim 1 , wherein the TACD compound comprises 2,2,4,4-tetramethylcyclobutane-1,3-diol, 2,2,4,4-tetraethylcyclobutane-1,3-diol, 2,2,4,4-tetra-n-propylcyclobutane-1,3-diol, 2,2,4,4-tetra-n-butylcyclobutane-1,3-diol, 2,2,4,4-tetra-n-pentylcyclobutane-1,3-diol, 2,2,4,4-tetra-n-hexylcyclobutane-1,3-diol, 2,2,4,4-tetra-n-heptylcyclobutane-1,3-diol, 2,2,4,4-tetra-n-octylcyclobutane-1,3-diol, 2,2-dimethyl-4,4-diethylcyclobutane-1,3-diol, 2-ethyl-2,4,4-trimethylcyclobutane-1,3-diol, 2,4-dimethyl-2,4-diethyl-cyclobutane-1,3-diol, 2,4-dimethyl-2,4-di-n-propylcyclobutane-1,3-diol, 2,4-n-dibutyl-2,4-diethylcyclobutane-1,3-diol, 2,4-dimethyl-2,4-diisobutylcyclobutane-1,3-diol, or 2,4-diethyl-2,4-diisoamylcyclobutane-1,3-diol. 
     
     
         5 . The sulfopolyester of  claim 1 , wherein the TACD compound comprises 2,2,4,4-tetramethylcyclobutane-1,3-diol. 
     
     
         6 . The sulfopolyester of  claim 1 , wherein the TACD compound comprises a mixture of cis-2,2,4,4-tetraalkylcyclobutane-1,3-diol and trans-2,2,4,4-tetraalkylcyclobutane-1,3-diol. 
     
     
         7 . The sulfopolyester of  claim 6 , wherein the cis/trans molar ratio ranges from 1.7 to 0.2. 
     
     
         8 . The sulfopolyester of  claim 5 , wherein the amount of TACD compound present in the sulfopolyester is at least 7 mole %, based on the moles of the polyhydroxyl component. 
     
     
         9 . The sulfopolyester of  claim 8 , wherein the amount of TACD compound present in the sulfopolyester is at least 15 mole % and up to 57 mole %. 
     
     
         10 . The sulfopolyester of  claim 1 , wherein said polyhydroxyl compound (i)(b) comprises 2,2-dimethyl-1,3-propanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4-trimethyl-1,3-pentanediol, hydroxypivalyl hydroxypivalate, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2,4,4-tetramethyl-1,6-hexanediol, 1,10-decanediol, 1,4-benzenedimethanol, and hydrogenated bisphenol A, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, or combinations thereof. 
     
     
         11 . The sulfopolyester of  claim 10 , wherein said polyhydroxyl compound (i)(b) comprises 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, 2,2,4-trimethyl-1,3-pentanediol, hydroxypivalyl hydroxypivalate, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, or combinations thereof. 
     
     
         12 . The sulfopolyester of  claim 10 , wherein the amount of polyhydroxyl compound (i)(b) residues present in the sulfopolyester, based on the total moles of the polyhydroxyl component (i), is at least 40 mole % and up to 98 mole %. 
     
     
         13 . The sulfopolyester of  claim 12 , wherein the amount of polyhydroxyl compound (i)(b) residues present in the sulfopolyester, based on the total moles of the polyhydroxyl component (i), is at least 40 mole % and up to 85 mole %. 
     
     
         14 . The sulfopolyester of  claim 1 , wherein the TACD compound comprises 2,2,4,4,-tetramethylcyclobutane-1,3-diol, and the polyhydroxyl compound (i)(b) comprise: 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, ethylene glycol, or a combination thereof, provided that when ethylene glycol is present, it is in combination with an additional polyhydroxyl compound (i)(b) other than ethylene glycol. 
     
     
         15 . The sulfopolyester of  claim 14 , wherein the polyhydroxyl compound (i)(b) comprise 1,4-cyclohexanedimethanol. 
     
     
         16 . The sulfopolyester of  claim 1 , wherein polyhydroxyl compounds having one unit or repeating units represented by the structure:
   —(OCH 2 —CHR)— wherein R═H or C1-C4alkyl
   
       are present as residues in the sulfopolyester, if at all, in an amount of no more than 3 mole % based on the total moles of polyhydroxyl compounds (i). 
     
     
         17 . The sulfopolyester of  claim 1 , wherein the dicarboxylic acid compounds or derivatives of dicarboxylic acid compounds comprise isophthalic acid, dimethyl isophthalate, terephthalic acid, dimethyl terephthalate, phthalic acid, phthalic anhydride, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, dodecanedioic acid, sebacic acid, azelaic acid, maleic acid or anhydride, fumaric acid, succinic anhydride, succinic acid, adipic acid, 2,6-naphthalenedicarboxylic acid, glutaric acid, itatonic acid, diglycolic acid; 2,5-norbornanedicarboxylic acid; 1,4-naphthalenedicarboxylic acid; 2,5-naphthalenedicarboxylic acid; diphenic acid; 4,4′-oxydibenzoic acid; 4,4′-sulfonyldibenzoic acid, or their derivatives, or mixtures thereof. 
     
     
         18 . The sulfopolyester of  claim 1 , wherein the acid component comprises a derivative of a dicarboxylic acid. 
     
     
         19 . The sulfopolyester of  claim 18 , wherein the derivative of the dicarboxylic acid compound comprises dimethyl terephthalate, dimethyl isophthalate, or combinations thereof. 
     
     
         20 . The sulfopolyester of  claim 1 , wherein the dicarboxylic acid compound or derivatives of the dicarboxylic acid compound or combinations thereof are present in an amount of at least 80 mole % and up to 97 mole %, based on the total moles of the acid component. 
     
     
         21 . The sulfopolyester of  claim 1 , wherein the sulfonate group is in the form of a salt such that the sulfomonomer contains an —SO 3 M group attached to an aromatic or cycloaliphatic nucleus wherein M is an alkali metal ion, an alkaline earth metal ion, a transition metal ion, or a nitrogen containing cation. 
     
     
         22 . The sulfopolyester of  claim 21 , wherein M is Na + , Li + , K + , Ca ++ , Mg ++ , Ni ++ , Cu ++ , Fe ++ , or Fe +++ , or the cation of ammonia, dimethylethanolamine, diethanolamine, triethanolamine, pyridine, morpholine, or piperidine. 
     
     
         23 . The sulfopolyester of  claim 1 , wherein the sulfomonomer comprises a sulfonate salt of sulfophthalic acid, sulfoterephthalic acid, sulfoisophthalic acid, or combinations thereof. 
     
     
         24 . The sulfopolyester of  claim 1 , wherein the sulfomonomer comprises sodium, lithium, or potassium salts of sulfoisophthalic acid, sulfoterephthalic acid, sulfophthalic acid, or derivatives thereof. 
     
     
         25 . The sulfopolyester of  claim 1 , wherein the sulfomonomer comprises 5-sodiosulfoisophthalic acid or dimethyl 5-sodiosulfoisophthalate. 
     
     
         26 . The sulfopolyester of  claim 1 , wherein the sulfomonomer comprises an adduct of a monofunctional sulfomonomer with a polyol. 
     
     
         27 . The sulfopolyester of  claim 1 , wherein the amount of sulfomonomer is at least 3 mole %, based on the total moles of the acid component. 
     
     
         28 . The sulfopolyester of  claim 1 , wherein the amount of sulfomonomer is at least 5 mole % and up to 20 mole %, based on the total moles of the acid component. 
     
     
         29 . The sulfopolyester of  claim 1 , wherein the sulfopolyester comprises the reaction product of:
 (i) a polyhydroxyl component comprising:
 a. TACD in an amount ranging from 10 mole % to 60 mole %, based on the moles of the polyhydroxyl component, and 
 b. a polyhydroxyl compound comprising neopentyl glycol, 1,4-cyclohexanedimethanol (CHDM), or a mixture thereof, in a cumulative amount ranging from 40 mole % to 90 mole %, based on the moles of the polyhydroxyl component; and 
   (ii) an acid component comprising:
 a. isophthalic acid, dimethyl isophthalate, terephthalic acid, dimethyl terephthalate, or a mixture thereof, in a cumulative amount from 85 mole % to 95 mole %, based on the moles of the acid component, and 
 b. a sulfomonomer in an amount ranging from 5 mole % to 15 mole %, based on the moles of the acid component. 
   
     
     
         30 . The sulfopolyester of  claim 1 , wherein the sulfopolyester has an acid number less than about 30 mg KOH/g and a number average molecular weight ranging from 800 to 15,000 g/mole. 
     
     
         31 . (canceled) 
     
     
         32 . (canceled) 
     
     
         33 . The sulfopolyester of  claim 5 , wherein the sulfopolyester is water dispersible, and wherein the sulfopolyester is not water dispersible if all the TACD residues are replaced with a polyhydroxyl compound other than those having one unit or repeating units represented by the structure:
   —(OCH 2 —CHR)— wherein R═H or C1-C4alkyl.
   
     
     
         34 . A coating composition comprising:
 A. a sulfopolyester present in an amount of 5 to about 95 weight %, based on the weight of the total resin solids of (A) and (C), said sulfopolyester containing residues of 2,2,4,4-tetraalkylcyclobutanediol; and   B. water present in an amount of 50 to about 85 weight %, based on the weight of the aqueous coating composition   C. a polymer resin present in an amount of 5 wt % to about 95 wt %, based on the weight of the total resin solids of (A) and (C).   
     
     
         35 . The coating of  claim 34 , wherein residues of TACD comprise residues of 2,2,4,4-tetramethylcyclobutane-1,3-diol. 
     
     
         36 . The coating of  claim 34 , wherein the sulfopolyester comprises the reaction product of:
 (i) a polyhydroxyl component comprising:
 a. TACD in an amount ranging from 10 mole % to 60 mole %, based on the moles of the polyhydroxyl component, and 
 b. a polyhydroxyl compound comprising neopentyl glycol, 1,4-cyclohexanedimethanol (CHDM), or a mixture thereof, in a cumulative amount ranging from 40 mole % to 90 mole %, based on the moles of the polyhydroxyl component; and 
   (ii) an acid component comprising:
 a. isophthalic acid, dimethyl isophthalate, terephthalic acid, dimethyl terephthalate, or a mixture thereof, in a cumulative amount from 85 mole % to 95 mole %, based on the moles of the acid component, and 
 b. a sulfomonomer in an amount ranging from 5 mole % to 15 mole %, based on the moles of the acid component.