Patent ID: 6878799

Claim:
A carboxylic acid functional pigment dispersant having the structure: wherein: PE is a linear or branched polyester homo- or co-polymer with a molecular weight between 500-20,000, preferably 800-5,000, and wherein the degree of polymerization m is in the range of 1-100; PA is selected from the group consisting of: a. a polyalkylpolyamine wherein the alkyl is C 2 -C 10 alkyl selected from the group consisting of diethylene triamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine, pentaethylenehaxamine, bis(hexamethylene)triamine, pentapropylenehexamine, N,N′-bis(3-aminopropyl)-ethylenedimine, tris(aminoethyl)amine, hexaethyleneheptamine, hexapropyleneheptamine, spermidine and spermine; b. a linear or branched polyalkylene imine selected from the group consisting of polyethyleneimine with a molecular weight up to 50,000, linear and branched polypropyleneimine with a molecular weight of up to 50,000, c. polyallylamine; wherein x=10-1,000; d. a cycloaliphatic amine with more than two amine functional groups per molecule, selected from the group consisting of a hydrogenated polyformaldehyde—aniline adduct, piperazinylethyldiethylenetriamine, piperazinylethylethylenediamine, piperazinylethyltriethylenetetraamine, piperazinylethyltetraethylenepentamine and hydrogenated diaminopyrimidine; e. a mixture of polyalkylpolyamines defined above; and A is a moiety formed from the reaction of a 5 or 6 member ring anhydride with the free primary or secondary amines resulting from the condensation reaction of the polyester and the polyamine, an amic acid with the structure: wherein B, C═H, C 1 -C 20 alkyl or alkenyl or B and C together form a double bond, a cyclic aliphatic or aromatic group selected from the group consisting of benzyl, carboxyl substituted benzyl, cyclohexyl and cyclohexenyl, alkyl substituted cyclohexyl and cyclohexenyl, wherein alkyl is linear or branched C 1 -C 20 , and n=2-100 and the anhydride is elected from the group consisting of maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyl hexahydropthalic anhydride, trimellitic anhydride, alkenyl and alkyl succinic anhydride wherein the alkenyl or alkyl moiety is C 1 -C 20 alkenyl or alkyl.