Abstract: The present invention provides a resin composition based on crystalline polypropylene which includes: (a) 3-65% by weight of a component soluble in paraxylene of 23° C., (b) 35-97% by weight of a component soluble in paraxylene of 135° C. and insoluble in paraxylene of 23° C., and (c) 0-30% by weight of a compoent insoluble in paraxylene of 135° C. The component (a) soluble in paraxylene of 23° C. is composed substantially of an elastomeric constituent (a1) having a content of styrene or its derivative in the range of 0-35% by weight and an intrinsic viscosity (n) in the range of 0.1-5 dl/g, the component (b) soluble is paraxylene of 135° C. and insoluble in paraxylene of 23° C.

Abstract: Present invention provides a resin composition bases on crystalline polypropylene which does not suffer from occurrence of flow mark and rashes caused from polymer gel upon molding and, thus, can produce molded articles exhibiting superior appearance and having excellent mechanical strength, such as flexural modulus and so on, together with better flowability upon the molding and which can be obtained at a lower cost by choosing starting materials of high productivity.

Abstract: A polypropylene resin composition exibiting a high melt tension and superior moldability, which can be molded efficiently by a high-speed molding into scarcely deformable larger molded articles of better appearance with high stiffness and which comprises polypropylene as a main component and has the following characteristic features 1) to 4), namely, 1) that a melt flow rate (MFR, determined at 230° C. under a load of 2.16 kg) is in the range of 0.01 to 5 g/10 min., 2) that a content of a high molecular weight polypropylene exhibiting an intrinsic viscosity [&eegr;], determined at 135° C. in decalin, of 8-13 dl/g is in the range of 15 to 50% by weight, 3) that a gel areal density in number is 3,000/450 cm2 or less and 4) that a molecular weight distribution determined by gel permeation chromatography (GPC) is 6-20, as expressed by Mw/Mn, and is 3.5 or higher, as expressed by Mz/Mw.

Abstract: Polypropylene block-copolymer resin exhibiting high melt tension and improved moldability with balanced stiffness and impact resistance may be molded at high speed into large-sized articles, including, stretched films, with good appearance and resistance to deformation. The block copolymer includes a higher molecular weight polypropylene segment, a lower molecular weight polypropylene segment and an ethylene &agr;-olefin copolymer segment. When subjected to dissolution fractionation m paraxylene, a large proportion is insoluble at 23° C. but soluble at 135° C., and a smaller portion is soluble at 23° C. The block copolymer has a melt flow rate of 0.01 to 5 g/10 min at 230 C. (2.16 kg) and a molecular weight distribution Mw/Mn of 6-20 and Mz/Mw of at least 3.5. A continuous multistage polymerization may be used to form the block copolymer.