IMPROVED PROPYLENE COPOLYMER HEAT SEAL RESIN AND ARTICLES THEREFROM

摘要

The temperature at which propylene-copolymers produced by metallocene catalyst form a full strength heat seal is found to be lower than correspondingly similar melting point copolymers produced by conventional Ziegler-Natta catalyzed copolymers. At similar melting points, films made from metallocene catalyzed copolymers were also found to exhibit higher tensile modulus values relative to films from Ziegler-Natta catalyzed polypropylene copolymers. Films and articles made in accordance with the present invention offer greater stiffness properties, yet are sealable at lower temperatures than currently available.