Abstract: The polyolefin-based resin composition (I) of the present invention comprises (A) 99.9 to 80% by mass of a propylene (co)polymer having (a) a melt flow rate (MFR) of 0.1 to 200 g/10 min, (b) a meso-pentad fraction [mmmm] of an ordinary temperature (25° C.) xylene-insoluble component of 97.0% or higher, and (c) a content of an ordinary temperature (25° C.) xylene-soluble component of 4 to 50% by mass; and (B) 0.1 to 20% by mass of a copolymer containing propylene chains of an isotactic structure, and copolymer chains constituted from at least two monomer units selected from the group consisting of ethylene, C3 to C20 ?-olefins, cyclic olefins and aromatic vinyl monomers which are graft-bonded and/or block-bonded to said copolymer, and exhibits not only a high rigidity but also a highly enhanced impact strength and is well-balanced between the physical properties thereof.

Abstract: The polyolefin-based resin composition (I) of the present invention comprises (A) 99.9 to 80% by mass of a propylene (co)polymer having (a) a melt flow rate (MFR) of 0.1 to 200 g/10 min, (b) a meso-pentad fraction [mmmm] of an ordinary temperature (25° C.) xylene-insoluble component of 97.0% or higher, and (c) a content of an ordinary temperature (25° C.) xylene-soluble component of 4 to 50% by mass; and (B) 0.1 to 20% by mass of a copolymer containing propylene chains of an isotactic structure, and copolymer chains constituted from at least two monomer units selected from the group consisting of ethylene, C3 to C20 &agr;-olefins, cyclic olefins and aromatic vinyl monomers which are graft-bonded and/or block-bonded to said copolymer, and exhibits not only a high rigidity but also a highly enhanced impact strength and is well-balanced between the physical properties thereof.

Abstract: Disclosed are a flexible polypropylene resin suitable as thermoplastic elastomer, a propylene based elastomer composition containing the flexible polypropylene resin, and a process for producing the above flexible polypropylene resin and the propylene based elastomer composition. The above flexible polypropylene resin is composed of specific boiling heptane-soluble polypropylene and specific boiling heptane-insoluble polypropylene. The above propylene based elastomer composition comprises the above flexible polypropylene resin and an ethylene/propylene copolymer or an ethylene/propylene/polyene copolymer. The above process for the production of olefin polymers may be carried out by non-solvent polymerization methods such as a gas phase one-step polymerization method, and a gas phase multi-step polymerization method, using a specific catalyst.

Abstract: Disclosed are a flexible polypropylene resin suitable as thermoplastic elastomer, a propylene based elastomer composition containing the flexible polypropylene resin, and a process for producing the above flexible polypropylene resin and the propylene based elastomer composition. The above flexible polypropylene resin is composed of specific boiling heptane-soluble polypropylene and specific boiling heptane-insoluble polypropylene. The above propylene based elastomer composition comprises the above flexible polypropylene resin and an ethylene/propylene copolymer or an ethylene/propylene/polyene copolymer. The above process for the production of olefin polymers may be carried out by non-solvent polymerization methods such as a gas phase one-step polymerization method, and a gas phase multi-step polymerization method, using a specific catalyst.

Abstract: Polypropylene based resins and compositions comprising the resin having extremely high stiffness, heat resistance and impact strength, with these properties being well-balanced, are provided. The polypropylene based resins are characterized by comprising:(1) a propylene polymer having a content of alpha-olefin other than propylene of not more than 4 mole percent, and the following properties (2), (3) and (4):(2) a pentad fraction (mmmm fraction) measured by .sup.13 C-NMR of not less than 96.0 percent,(3) a main elution fraction peak position of not less than 118.0.degree. C. and a peak half value width of less than 4.0, these values being measured by the temperature raising separation method, and(4) an intrinsic viscosity of not less than 0.5 dl/g, but not more than 5.0 dl/g; and,(5) a rubber content measured by pulse NMR of more than 25 percent.

Abstract: A process for producing a branched polycarbonate comprising reacting a dihydric phenol, such as 2,2-bis(4-hydroxyphenyl) propane, a polyfunctional organic compound, such as 1,1,1-tris-(4-hydroxyphenyl)ethane, and phosgene to produce a polycarbonate oligomer, and then polycondensing with stirring the polycarbonate oligomer with a dihydric phenol, such as 2,2-bis(4-hydroxyphenyl) propane, and a monohydric phenol, such as p-tert butylphenol, whereby the interfacial area of the resultant emulsion is not less than 40 m.sup.2 /L.

Abstract: A branched polycarbonate having (1) an intrinsic viscosity of 0.3 to 2 dl/g, (2) a branching parameter of 0.05 to 0.9, (3) a degree of branching of 0.2.times.10.sup.-4 and optionally (4) a taking-off parameter of 2.5 to 20. The branched polycarbonate is useful as a raw material for blow-moldings.