Patent ID: 11926731
Assignee: KRATON CORPORATION
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  A | IPC C

Claim 0:
1. A hydrogenated block copolymer comprising block copolymer components (a) and (b), wherein
block copolymer component (a) is a selectively hydrogenated block copolymer comprising one or more structures A-B-A, (A-B-A)nX, A-(B-A)n, and (A-B)nX;
block copolymer component (b) is a selectively hydrogenated block copolymer comprising one or more structures C-D, D-C-D, and (D-C-)nX; and
wherein “n” is 1-30, and “X” is a residue of a coupling agent;
wherein before hydrogenation,
A is a polymer block of a vinyl aromatic monomer, having a peak molecular weight (Mp) of 14-60 kg/mol,
B is a polymer block comprising 60-100 mol % of one or more conjugated dienes, and 0-40 mol % of a vinyl aromatic monomer;
C is a polymer block of a vinyl aromatic monomer, having a peak molecular weight of 1-8 kg/mol; and
D is a polymer block comprising 60-100 mol % of one or more conjugated dienes, and 0-40 mol % of a vinyl aromatic monomer;

wherein after hydrogenation,
80 to 100 mol % of the polymerized diene units in the polymer blocks B and D are reduced; and
0-20 mol % of the polymerized vinyl aromatic monomer units in the polymer blocks A, B, C and D are reduced;

wherein the vinyl aromatic monomers of the polymer blocks A, B, C and D are independently same or different and the conjugated diene monomers for the polymer blocks B and D are independently same or different;
wherein the block copolymer component (a) has a peak molecular weight of 100-1,000 kg/mol and the block copolymer component (b) has a peak molecular weight of 6-60 kg/mol; and
wherein the hydrogenated block copolymer has a compression set after 24 hrs. at 70° C. of less than 50%, measured according to ASTM D395, an apparent viscosity measured at 230° C., and a shear rate of 5000/s of <70 Pa·s.