Patent ID: 7241845

Claim:
An organic solvent-soluble linear random block copolymer hydrogel containing discrete polymeric first and second segments, the first segments comprising hydrophilic mainly polyethylene oxide segments —(CH 2 CH 2 O) n —, the second segments being of relatively more hydrophobic character than the first segments, wherein the second polymer segments are disposed randomly in the polymer chain as discrete blocks, successive segments being connected through urethane —NHCOO— linkages to hydrophobic connecting segments, a minor proportion of which also containing urea —NHCONH— groups, which urea groups are present as units of formula —NHCONH—R—NHCONH— wherein R represents a hydrocarbyl group, all of said first, second, and connecting segments being randomly distributed throughout the copolymer, the proportion of urea groups comprising from 0.1 to 5.0% by weight of the copolymer.