Propylene block copolymer, process for preparing same, and modified copolymer using propylene block copolymer

Abstract

There are here disclosed a propylene block copolymer comprising (A) 50 to 95 wt % of a specific propylene polymer block which contains a propylene unit or the propylene unit and 4 wt % or less of an olefin unit having 2 to 8 carbon atoms and (B) 50 to 5 wt % of an ethylene-propylene copolymer block containing 20 to 90 wt % of an ethylene unit, 0.001 to 15.0 wt % of a unit derived from a diolefin being contained in at least one of the components (A) and (B), a reduced viscosity at a concentration of 0.05 g/dl measured in decalin at 135.degree. C. being in the range of 0.01 to 30 dl/g; its preparation process; a hydrogenated copolymer obtained from the propylene block copolymer; and a modified copolymer obtained by introducing a functional group into at least 5% of unsaturated bonds of the copolymer. The above-mentioned copolymer can inhibit the formation of a gel, is excellent in balance between stiffness and impact resistance, has a good moldability, and possesses an unsaturated group useful for a modification reaction. In addition, the copolymer is excellent in adhesive properties, printability, hydrophilic nature, polymer modifying properties, antistatic properties and flame resistance.

Dependencies are inferred from the claim text.