Patent ID: 7915347

Claim:
A block polymer comprising at least one first block and at least one second block that are incompatible with each other and that have different glass transition temperatures (Tg), wherein the block polymer is not an elastomer; wherein the at least one first and second blocks are linked together via an intermediate segment comprising at least one constituent monomer of the at least one first block and at least one constituent monomer of the at least one second block; wherein said intermediate block is a random copolymer block; wherein the block polymer has a polydispersity index I ranging from 2.8 to 6; wherein the at least one first block has a Tg of greater than or equal to 40° C. and is present in an amount ranging from 30% to 85% by weight relative to the total weight of the block polymer; and wherein the at least one second block has a Tg of between 20 and 40° C. and is present in an amount ranging from 10% to 50% by weight relative to the total weight of the block polymer; wherein each of the at least one first and second blocks comprises at least one monomer chosen from acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters; wherein the at least one first block is totally or partially derived from at least one monomer wherein a homopolymer prepared from the at least one monomer has a Tg of greater than or equal to 40° C. and the at least one monomer is chosen from the following monomers: methacrylates of formula CH 2 ═C(CH 3 )—COOR 1 wherein R 1 is chosen from linear and branched unsubstituted alkyl groups comprising from 1 to 4 carbon atoms, or R 1 is chosen from a C 4 to C 12 cycloalkyl group, acrylates of formula CH 2 ═CH—COOR 2 wherein R 2 is chosen from C 4 to C 12 cycloalkyl groups, and a tert-butyl group; and (meth)acrylamides of formula: wherein R 7 and R 8 , which may be identical or different, each are chosen from a hydrogen atom and linear and branched alkyl groups comprising 1 to 12 carbon atoms; or R 7 is H and R 8 is a 1,1-dimethyl-3-oxobutyl group, and R′ is chosen from H and methyl.