OLEFIN BLOCK COPOLYMER

摘要

PURPOSE: An olefin block copolymer is provided to display excellent heat resistance, elasticity, and processability. CONSTITUTION: An olefin block copolymer comprises a plurality of blocks or segments which include ethylene based or propylene based recurring unit andα-olefin based recurring unit at different weight fraction. The olefin block copolymer satisfies the following chemical formula 1 at 60 deg. Celsius or greater when 5-10 kg load is given for 12 hours or greater to the sheet type molded product of the block copolymer and removed. The chemical formula 1 is same as the follow: 60% >= ((T_0 - T)/T_0)×100. In the chemical formula 1, T_0 indicates an initial thickness of the sheet-form molded body of the block copolymer. T indicates the thickness of the sheet-form molded body after the load being added and eliminated. A first differentiating value in which 1000 carbons of each chain which is included in the block copolymer per number of short chain branch(Y) differentiate for a molecular weight of the copolymer chains(X) is either negative number or positive number of -1.5×10^(-4) or greater.