Patent ID: 8044111

Claim:
An actinically crosslinkable prepolymer, comprises: poly(oxyalkylene) blocks; polysiloxane blocks; and actinically-crosslinkable groups, wherein the block copolymer is obtained by copolymerizing a mixture comprising (1) at least one linear poly(oxyalkylene) with two first reactive groups, (2) at least one linear polysiloxane with two second reactive groups, (3) a branched poly(oxyalkylene) with multiple first reactive groups, a branched polysiloxane with multiple second reactive groups, or combination thereof, and (4) optionally a hetero difunctional compound having one ene-containing group and one first or second reactive group, wherein the first and second reactive groups, different from each other, are either thiol groups or acryl groups and undergo Michael addition reaction to form carbon-sulfur bonds.