The present invention relates to a propylene-ethylene block copolymer composition.
Propylene-ethylene block copolymers are used as sheets, molded articles, and also as materials for production of car parts, home electric appliances, and so forth because they are superior in stiffness and low temperature impact strength. Because of poor transparency, however, they can find only limited applications. Thus, to increase the transparency of the copolymers, it has been proposed to add nucleating agents. In this case, a problem arises in that the low temperature impact strength drops. Furthermore, an attempt has been made to increase the low temperature impact strength of propylene-ethylene block copolymers in order to extend their applications by compounding inorganic filler such as talc. Addition of such inorganic filler, however, results in a decrease in transparency of the copolymers.
Thus it has been desired to improve the transparency of propylene-ethylene block copolymers without deteriorating their superior stiffness and low temperature impact strength or while at the same time more increasing the stiffness and low temperature impact strength.