Patent ID: 7723453

Claim:
A polymer having structure: (-A-) i (—B—) j (—C—) k wherein co-monomer A is a cationic repeating unit possessing one or more cationic charge(s) when measured at pH 4 to 10; wherein co-monomer B is a water insoluble repeating unit comprising at least one hydrophobic portion which is part of the co-monomer backbone or a pendant group attached to the backbone and which hydrophobic portion is defined as comprising 3 to 20 C 1 to C 3 alkylene groups and from 1 to 3 C 1 to C 3 , alkyl groups such that equivalent alkane carbon number (EACN) of pendant group is ≧4 and wherein B is selected from the group consisting of n-dodecyl methacrylamide (DMA), n-(n-octadecyl acrylamide) (ODA), n-tert-octylacrylamide (tOA) and mixtures thereof; wherein co-monomer C is a repeating unit selected to modify solubility of the overall polymer; wherein i, j, and k represent number of times each respective monomer is repeated in the polymer claim, with the proviso that ratio of j/i is from 0.1 to 0.4; and ratio of k/i is from 0.0 to 0.5; wherein cationic charge density of co-monomer A is ≧3 meq/g; and charge density of entire polymer ≧2; wherein molecular weight of said polymer is about 10,000.